WO2019167498A1 - Impact tool - Google Patents

Impact tool Download PDF

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Publication number
WO2019167498A1
WO2019167498A1 PCT/JP2019/002481 JP2019002481W WO2019167498A1 WO 2019167498 A1 WO2019167498 A1 WO 2019167498A1 JP 2019002481 W JP2019002481 W JP 2019002481W WO 2019167498 A1 WO2019167498 A1 WO 2019167498A1
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WO
WIPO (PCT)
Prior art keywords
hammer
spindle
cam groove
cam
impact tool
Prior art date
Application number
PCT/JP2019/002481
Other languages
French (fr)
Japanese (ja)
Inventor
大 平野
村上　卓宏
Original Assignee
工機ホールディングス株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 工機ホールディングス株式会社 filed Critical 工機ホールディングス株式会社
Priority to JP2020502869A priority Critical patent/JP6801817B2/en
Publication of WO2019167498A1 publication Critical patent/WO2019167498A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
    • B25B21/00—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose
    • B25B21/02—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose with means for imparting impact to screwdriver blade or nut socket

Definitions

  • the present invention relates to an impact tool for rotating an anvil to a predetermined rotation while hitting the anvil using a hammer.
  • An impact tool is known that transmits the rotational force of a motor to a hammer and applies a striking force in the rotational direction to the anvil using the hammer.
  • the technique of Patent Document 1 is known as an example.
  • Impact tools are widely used for tightening screw members to wood, fixing bolts to concrete, loosening screw members and bolts, and the like.
  • the motor is driven to rotate the spindle via the speed reduction mechanism.
  • the hammer connected to the spindle by the hammer spring and the cam ball rotates.
  • the rotational force is transmitted through the hammer hitting claw and the blade portion of the anvil, and the anvil rotates.
  • a tip tool mounting hole is formed at the tip of the anvil in the axial direction, and a screw or a bolt can be tightened via a tip tool such as a hexagonal bit mounted in the mounting hole.
  • the housing of the impact tool 201 includes a main body housing 202 and a hammer case 203 provided thereon.
  • the impact tool 201 uses the rechargeable battery pack 10 as a power source and drives the rotary impact mechanism using the motor 4 as a drive source.
  • the anvil 260 which is the output shaft, is given a rotational force and a striking force from the striking mechanism, and a rotating striking force is applied to a tip tool (not shown) such as a driver bit held in the mounting hole 261a formed in the bit holding portion 70. It is transmitted continuously or intermittently, and operations such as screw tightening and bolt tightening are performed.
  • the motor 4 is accommodated in a cylindrical body 202a of the main body housing 202 having a substantially T-shape when viewed from the side.
  • the rotation shaft 4a of the motor 4 is disposed such that its axis A1 extends in the longitudinal direction of the body portion 202a.
  • a cooling fan 13 is provided on the rotating shaft 4 a on the front side of the motor 4 and rotates in synchronization with the motor 4. As the cooling fan 13 rotates, outside air is sucked from the intake ports 217a, 217b and the like at the rear of the main body housing 202, and the outside air cools the motor 4 and then flows to the outside from the exhaust port 217c formed around the cooling fan 13. Discharged.
  • a trigger switch 6 is disposed in an upper portion of a handle portion 202b that integrally extends substantially perpendicularly from the body portion 202a, and a trigger 6a that is an operation lever is exposed from the trigger switch 6 to the front side of the main body housing 202.
  • a forward / reverse switching lever 7 for switching the rotation direction of the motor 4 is provided above the trigger switch 6.
  • a diameter-expanded portion 202c is formed at the lower portion in the handle portion 202b in order to attach the battery pack 10.
  • the enlarged diameter portion 202c is a portion formed so as to expand in the radial direction (orthogonal direction) from the longitudinal central axis of the handle portion 202b, and the battery pack 10 is mounted on the lower side of the enlarged diameter portion 202c.
  • the battery pack 10 is a pack of a plurality of secondary batteries such as lithium ion batteries. When charging the battery pack 10, the battery pack 10 is removed from the impact tool 201 while pushing the latch button 11, and is illustrated. Do not attach to
  • the rotary striking mechanism includes a planetary gear reduction mechanism 220, a spindle 230, a hammer 240, and an anvil 260, and a rear end is held by a bearing 219b and a front end is held by a needle bearing 219a.
  • the motor 4 starts to rotate in the direction set by the forward / reverse switching lever 7, and the rotational force is decelerated by the planetary gear reduction mechanism 220 and transmitted to the spindle 230.
  • the spindle 230 is rotated at a predetermined speed.
  • the spindle 230 and the hammer 240 are connected by a cam mechanism, and the cam mechanism includes two V-shaped spindle cam grooves 233 and 234 formed on the outer peripheral surface of the spindle 230, and the inner peripheral surface of the hammer 240. Are formed by two hammer cam grooves and cam balls 251 and 252 engaged with these cam grooves.
  • FIG. 23 is a cross-sectional view of a hitting portion of a conventional impact tool 201, and (1) shows a state where the hammer 240 is in a normal position.
  • the hammer 240 is always urged forward by the hammer spring 254, and when stationary, the hammer 240 is at the front side position by the engagement between the cam balls 251 and 252 and the hammer cam grooves 244 and 245.
  • This position is such that the hitting claws 246a and 246b of the hammer 240 overlap with the hitting claws (not shown) of the anvil 260 in the direction of the axis A1.
  • the spindle 230 When the spindle 230 is driven to rotate, the rotation is transmitted to the hammer 240 via the cam mechanism, and the hammering claws 246a and 246b of the hammer 240 are moved by the hammering claws 263a and 263b ( (See FIG. 22).
  • the hammer 240 and the anvil 260 rotate synchronously (continuous rotation) for the time being from the start of tightening the impact tool 201. Thereafter, as the tightening progresses, the counter torque transmitted from the tip tool gradually increases, and when the counter torque exceeds the spring pressure of the hammer spring 254, the hammer 240 has the spindle cam grooves 233 and 234 and the hammer cam grooves 244 and 245.
  • the hammer spring 254 is compressed in accordance with the shape of the motor and gradually retracts backward (motor side).
  • the contact length in the front-rear direction of the hammering claw of the hammer 240 and the hitting claw of the anvil 260 decreases, and finally FIG.
  • the contact length as shown in FIG. When the contact length in the front-rear direction of the hammering claws 246a, 246b of the hammer 240 and the hitting claws 263b (see FIG. 22) of the anvil 260 becomes 0 mm, the engagement of the hammer 240 with the anvil 260 in the rotational direction is disengaged. Will do.
  • the size of the torque acting immediately prior to the disengagement between the hammer 240 and the anvil 260, the hammer 240 and the anvil 260 are "leaving torque T B" when leaving.
  • the striking pawl 246a of the hammer 240 by the retraction of the hammer 240, 246b is rotated over the struck pawls (not shown) of the anvil 260, the hammer 240 With the compressive force of the hammer spring 254, it is engaged with (or collides with) the next hitting claw of the anvil 260 as seen in the rotational direction while being pushed forward.
  • the hammer 240 is rapidly accelerated in the rotational direction and forward by the action of the elastic energy accumulated in the hammer spring 254 and the cam mechanism, and forward by the urging force of the hammer spring 254.
  • the striking claws 246a, 246b re-engage with the striking claws 263a, 263b (see FIG. 22) of the anvil 260 and rotate together.
  • the rotational striking force is transmitted to the screw via a tip tool (not shown) mounted in the mounting hole 261a (see FIG. 22) of the anvil 260.
  • the impact tool has been increased in torque, and products having a tightening torque of 150 N ⁇ m or more are commercially available.
  • the spring constant of the hammer spring 254 that normally biases the hammer 240 toward the anvil 260 is set high.
  • the detachable torque T B achieve higher output by increasing the spring constant of the hammer spring 254, it slows the timing of transition from the continuous rotary motion into striking movement, counter torque acting on the impact tool 201 becomes larger, and it becomes difficult for the operator to perform the screwing operation while holding the impact tool with one hand.
  • the impact tool with a high spring constant may not reach the separation torque during the screw tightening operation, and the striking operation will be performed easily.
  • the length of the spindle cam grooves 233 and 234 is increased in order to increase the retraction amount of the hammer 240, that is, the hammer back amount, in order to increase the hitting torque. If both ends of the two spindle cam grooves 233 and 234 are in contact with each other, the amount of hammerback cannot be sufficiently obtained. Although it is also possible to make the erosion of the hammer 240 by increased receding angle of the spindle cam grooves 233 and 234 (the Kamurido angle), in which case, further increases disengaged torque T B.
  • the hammer and the spindle may be worn out early and the life may be shortened.
  • the present invention has been made in view of the above background, an object of the present invention, while suppressing an increase in withdrawal torque T B of the hammer and the anvil, to provide an impact tool capable of increasing the striking force in the rotational direction There is.
  • Another object of the present invention is to provide an impact tool that achieves high output and improves the operational feeling at the time of transition from continuous rotation to start of striking and is easy to work while holding with one hand.
  • Still another object of the present invention is to make the hammer hitting nail fly the next hitting nail of the anvil so that the next next hitting nail or the next next hitting nail can be hit.
  • An object of the present invention is to provide an impact tool that can realize a sufficiently large tightening torque without increasing the spring constant of the spring.
  • a motor a spindle driven in the rotational direction by the motor, the spindle having a spindle shaft portion and a spindle cam groove provided in the spindle shaft portion;
  • a hammer configured to be relatively movable in the axial direction and the rotational direction of the spindle shaft portion within a predetermined range with respect to the spindle, wherein the hammer is relatively movable in the axial direction and the rotational direction with respect to the spindle shaft portion.
  • a first cylindrical portion configured to be movable, a hammer cam groove configured to be relatively movable in the axial direction with respect to the spindle cam groove via a cam ball, and a diameter of the first cylindrical portion.
  • a hammer that is biased forward by a spring, and is rotatably provided in front of the hammer, the hammer being forward
  • An impact tool comprising: an anvil that is struck in a rotational direction by the hammer when rotated while moving; and a housing that houses the motor, spindle, hammer, and anvil, wherein the spindle shaft portion and the first cylinder
  • a first restricting portion that restricts the movement of the hammer relative to the spindle in the radial direction is configured by the shaped portion, and the spindle cam groove, the cam ball, and the hammer cam groove restrict the axial movement of the hammer relative to the spindle.
  • a second restricting portion is configured, and a third restricting portion for restricting the inclination of the hammer relative to the spindle is provided separately from the first and second restricting portions.
  • the third restricting portion is provided between the spindle and the hammer, or is provided between the housing and the hammer.
  • the third restricting portion is a sliding member having a sliding resistance smaller than that of the rolling member or the hammer.
  • the third restricting portion contacts the outer peripheral surface of the hammer so as to support the outer peripheral surface of the hammer.
  • the third restricting portion is disposed between the outer periphery of the hammer and the inner wall of the housing. An abutting surface is formed on the housing, and the third restricting portion is abutted against the abutting surface.
  • the third restricting portion is a member different from the hammer, and is a rolling member or a sliding member provided on the inner peripheral surface of the hammer and in contact with the spindle. is there.
  • One or two spindle cam grooves and two hammer cam grooves are provided, and the same number of cam balls as the number of spindle cam grooves are arranged in the spindle cam groove. Only one spindle cam groove and one cam ball are provided.
  • the spindle cam groove so that the distance from the center point of the circle forming one arc forming the rear end of the spindle cam groove to the center point of the circle forming the other arc exceeds 180 degrees in the circumferential direction. Is extended.
  • a wall portion is formed in a sliding portion between the spindle and the hammer and sandwiched between the one rear end and the other rear end of the spindle cam groove.
  • the range of the spindle cam groove in the longitudinal direction overlaps with the axial movement range of the support member or the support member arrangement range.
  • the support member is located on the inner peripheral side of the hammer and behind the hammer cam groove, or on the outer peripheral side of the hammer, and the axial center position of the support member is the axial center of the movable range of the hammer. It provided so that it might become the back side rather than a position.
  • a motor a spindle driven in the rotational direction by the motor, and a cam movable relative to the spindle in an axial direction and a rotational direction within a predetermined range.
  • An impact tool comprising: a hammer that is biased forward by a mechanism and a spring; and an anvil that is rotatably provided in front of the hammer and is struck by the hammer when the hammer rotates while moving forward.
  • the cam mechanism is provided on the spindle, and extends in a continuous manner from one rear end through the front end to the other rear end, and a hammer cam groove formed on the inner peripheral side of the hammer, A cam ball disposed in the spindle cam groove and the hammer cam groove, wherein the spindle cam groove is formed on the spindle cam groove. Between from one center of the center of the circles forming the arcs constituting the edges to the other of the center extends beyond 180 degrees in the circumferential direction, or are provided only one. Apart from the cam mechanism, a support member for supporting the radial direction of the hammer is provided separately from the hammer.
  • the cam mechanism is provided on the spindle, and extends in a continuous manner from one rear end through the front end to the other rear end, and the inner circumference of the hammer.
  • a hammer cam groove formed on the side Including a cam ball disposed in the spindle cam groove and the hammer cam groove, and the spindle is provided with only one spindle cam groove.
  • a rolling member such as a bearing or a sliding member such as a metal or an O-ring is provided between the outer peripheral surface of the spindle and the inner peripheral surface of the hammer.
  • a low-speed operation mode in which hammers and anvil claws are successively hit a medium-speed operation mode in which hits are made while skipping one by one
  • a high-speed operation mode in which hits are made while skipping two by two it was possible to realize a wide range from a low output state to a high output state while maintaining a good operation feeling when hitting.
  • the tightening torque is increased, the separation torque remains the same as the conventional one, so that a high output screw tightening operation can be performed with one hand as in the conventional product.
  • a regulation part for regulating the inclination of the hammer with respect to the spindle between the hammer and the spindle accommodating part or between the hammer and the housing is provided. Since the gap between them can be reduced, the inclination of the hammer with respect to the spindle can be prevented, and the play of the spindle can be sufficiently suppressed, and the sliding characteristics and durability of the hammer can be greatly improved.
  • the hammer is supported by the two spindles on the spindle by two cam balls to prevent the hammer from rattling against the spindle. Since a rolling member such as a needle bearing is provided between the housing part of the spindle or the hammer and the hammer case, the spindle is supported at multiple points by the steel ball and the rolling member, which can greatly improve the sliding characteristics of the hammer. It became possible. As a result, the tilt of the hammer with respect to the spindle can be prevented and the play of the spindle can be sufficiently suppressed, and the durability has been greatly improved.
  • the overall length of the body of the impact tool (the total length of the hammer and spindle) can be shortened. Grease leakage from the inside of the hammer case can be greatly suppressed.
  • FIG. 2 is a developed perspective view of a hitting part and a hit part of FIG. 1. It is sectional drawing of the striking part of the impact tool 1 of FIG.
  • FIG. 3 is a front view of an assembly of the spindle 30 and the hammer 40 of FIG. 2. It is sectional drawing of the striking part of the impact tool 1 of FIG. 1, Comprising: (1) shows the state in which the hammer 40 exists in a normal position, (2) shows the state at the time of the hammer 40 retreating. It is a partial expanded sectional view of the needle bearing 56 vicinity provided in the hammer 40 of FIG.
  • FIGS. 15A and 15B are longitudinal sectional views in the vicinity of an impact portion of the impact tool 101 in FIG. 15, where FIG. 15A shows a state in which the hammer 140 is in a normal position, and FIG. It is a fragmentary longitudinal cross-sectional view of impact tool 101A which concerns on the 1st modification of 2nd Example of this invention, Comprising: (1) shows the state in which the hammer 140 exists in a normal position, (2) shows the hammer 140 retracting
  • FIG. 20 is a developed perspective view of the hitting part and the hit part of FIG. 19. It is a fragmentary longitudinal cross-sectional view of impact tool 101C concerning the 3rd modification of the 2nd example of the present invention. It is a longitudinal cross-sectional view which shows the internal structure of the conventional impact tool 201.
  • FIG. 1 is a longitudinal sectional view showing an internal structure of an impact tool 1 according to an embodiment of the present invention.
  • the basic configuration is the same as that of the conventional impact tool 201 shown in FIG. 22.
  • the configurations and shapes of the spindle 30 and the hammer 40 are different, and the dimensions of the hammer case 3 and the like are adjusted in accordance with the shape change. Is slightly modified to change the characteristics of the hammer spring 54 and the like.
  • the housing of the impact tool 1 is constituted by a main body housing 2 (2a to 2c) and a hammer case 3 provided thereon.
  • An elastic cover 5 made of an elastic material is provided at the tip of the hammer case 3.
  • the motor 4 is a universal motor, and its rotating shaft 4a is arranged coaxially with the axis A1 of the speed reduction mechanism 20 and the spindle 30.
  • the type of the motor 4 is not limited, and it may be driven by an inverter circuit that drives a brushless DC motor, other electric motors, or an arbitrary drive source.
  • the rotating shaft 4a of the motor 4 is supported by bearings 18a and 18b of two ball bearings on the front end side and the rear end side.
  • the hammer case 3 is a tapered cylindrical metal case for housing the speed reduction mechanism 20, the striking mechanism (spindle 30, hammer 40, etc.) and the striking mechanism (anvil 60), and the rotation center thereof. Are arranged along the axis A1.
  • the rotation shaft 4a of the motor 4 is arranged such that its axis A1 extends in the longitudinal direction of the body portion 2a.
  • a mounting hole 61 a having a hexagonal cross section is formed at the tip of the anvil 60, and the tip tool is held by the one-touch mounting type bit holder 70.
  • the anvil 60 is integrally formed with a blade portion 63 as an impacted portion and an output shaft portion 61, and the output shaft portion 61 is provided with two steel balls 69 for holding a tip tool to be mounted.
  • the rotational driving force of the motor 4 is transmitted from the rotating shaft 4a to the striking mechanism via the speed reduction mechanism 20.
  • the speed reduction mechanism 20 transmits the output of the motor 4 to the spindle 30.
  • the speed reduction mechanism 20 using a planetary gear is used.
  • the speed reduction mechanism 20 is disposed between a sun gear 21 fixed to the tip of the rotating shaft 4 a of the motor 4, a ring gear 23 provided to surround the outer periphery of the sun gear 21 at a distance, and the sun gear 21 and the ring gear 23.
  • a plurality (three in this case) of planetary gears 22 meshed with both of these gears are configured.
  • the three planetary gears 22 revolve around the sun gear 21 while rotating around the shaft.
  • the ring gear 23 is fixed to the main body housing 2 side and is a non-rotating member.
  • the shafts of the three planetary gears 22 are fixed to planetary carrier portions (flange portions 37 and 38, which will be described later with reference to FIG. 2) formed at the rear end portion of the spindle 30, and the revolving motion of the planetary gears 22 is caused by the planetary carrier.
  • the spindle 30 rotates because it is converted into the rotational motion of the part.
  • the cylindrical portion 39 at the rear end of the spindle 30 is supported by a bearing 19b such as a ball bearing.
  • the spindle 30 is disposed on the front side of the planetary carrier portion of the speed reduction mechanism 20.
  • a substantially V-shaped groove is formed as the spindle cam groove 33 in a side view, but in contrast to the two conventional spindle cam grooves 233 and 234 shown in FIG.
  • a set of spindle cam grooves 33 is provided in the spindle 30. Since the cam ball 51 rolls in the spindle cam groove 33, the recess has a semicircular cross section.
  • the spindle cam groove 33 is set as one set, the number of cam balls 51 used is also one. For this reason, it is possible to make the retraction amount of the hammer 40 significantly larger than the conventional one while the spindle shaft portion 31 (refer to FIG. 2 described later) is the same as the conventional one.
  • a control circuit board 9 having a function of controlling the speed of the motor 4 by the pulling operation of the trigger 6a is accommodated in the enlarged diameter portion 2c of the main body housing 2.
  • the control circuit board 9 is arranged so as to be substantially horizontal, and is provided with an output changeover switch 12 for switching the striking torque.
  • FIG. 2 is a developed perspective view of the hitting part and the hit part of FIG. 1.
  • the basic configuration in which the anvil 60, the hammer 40, and the spindle 30 are arranged in this order from the front side is the same configuration as the conventional impact tool 201 shown in FIG.
  • the number of cam balls 51 used is reduced from two to one.
  • a needle bearing 56 is mounted at a position on the inner peripheral side of the hammer 40 and in contact with the outer peripheral surface of the spindle shaft portion 31.
  • the anvil 60 forms an output shaft of the impact tool 1 and forms a hit portion of the hammer 40, and the output shaft and the hit portion are integrally formed.
  • the anvil 60 is an integral part of a metal manufactured by cutting after casting or forging, and a hitting claw by three blade portions 63a to 63c is formed behind the cylindrical output shaft portion 61. It is a thing.
  • a mounting hole 61a for mounting the tip tool is formed in the inner portion from the front end portion of the output shaft portion 61 in cross section.
  • the small diameter portion 61b in which the mounting hole 61a is formed is formed to provide the bit holding portion 70, and two through holes 61c penetrating in the radial direction are formed behind the small diameter portion 61b.
  • a steel ball 69 (see FIG.
  • the blade portions 63a to 63c are hitting claws that are evenly arranged so as to be separated by 120 degrees when viewed in the rotation direction, and are arranged so as to extend radially outward.
  • the side surfaces in the rotational direction of the blade portions 63a to 63c are hitting surfaces 64a to 64c which are hit by the hammering pawls of the hammer 40 when rotating in the tightening direction, and hits which are formed on the opposite side and hit when rotating in the loosening direction.
  • Surfaces 65a to 65c are formed.
  • a cylindrical shaft portion 66 (see FIG. 1) is formed on the rear side of the hit portion, and the anvil 60 and the spindle 30 can be rotated relative to each other by engaging the shaft portion 66 with the fitting hole 32 of the spindle 30. Connected in a normal state.
  • the hammer 40 is a member that is held by the spindle 30 and is attached to the spindle 30 from the front side.
  • the hammer 40 is ideally held so as to be in a floating state or a non-contact state with respect to the spindle 30, and in order to maintain a floating state and a non-contact state in the conventional spindle 230, two cam balls 251, 252 (see FIG. 22) was used.
  • the number of cam balls is reduced by one, while needle bearings 56 are arranged on the outer peripheral surface of the spindle shaft portion 31 and the inner peripheral surface of the hammer 40.
  • the needle bearing 56 can be fixed to either the hammer 40 side or the spindle 30 side, but is fixed to the hammer 40 side in this embodiment.
  • FIG. 2 the shape of the inner peripheral side of the needle bearing 56, in particular, the illustration of needle rollers and the like is omitted.
  • Three hitting claws 46a to 46c are formed at three locations on the outer peripheral side of the front surface 42a of the hammer 40 so as to protrude forward in the axial direction (anvil 60 side).
  • the hitting claws 46a to 46c are equally arranged so that their center positions are separated by 120 degrees in rotation angle when viewed in the rotation direction.
  • the two side surfaces of the hitting claws 46a to 46c in the rotational direction are given a predetermined angle in the rotational direction so as to make good surface contact with the three blade parts 63a to 63c of the anvil 60 at the time of collision.
  • the outer periphery of the hammer 40 is a cylindrical portion 43 and has a through hole 41a at the center.
  • a hammer cam groove 44 is formed on the inner peripheral side forming the through hole 41a and on the front side.
  • the hammer cam groove 44 is a recess having a substantially trapezoidal outline when the inner peripheral surface of the hammer 40 is developed into a plane, and forms a space that restricts the movement of the cam ball 51 together with the spindle cam groove 33.
  • a wall portion 45 that separates the side portions of the adjacent hammer cam grooves 44 is formed at one place in the circumferential direction of the inner peripheral surface of the hammer 40.
  • the wall 45 is a portion adjacent to or in contact with the outer peripheral surface of the spindle 30 on the front end side, and the hammer 40 contributes to maintaining the posture of relative rotation with respect to the spindle 30.
  • An insertion groove 44a for inserting the cam ball 51 into the cam groove at the time of assembly is formed at a location facing the wall portion 45 of the hammer 40 in the circumferential direction.
  • a location where the first cylindrical portion and the spindle shaft portion 31 face each other corresponds to the first restricting portion in the present invention, and the first restricting portion restricts the movement of the hammer 40 relative to the spindle 30 in the radial direction.
  • Only one spindle cam groove 33 is formed on the cylindrical portion of the spindle 30, that is, on the outer peripheral surface of the spindle shaft portion 31.
  • the spindle cam groove 33 is provided at a position facing the hammer cam groove 44 formed on the inner peripheral surface of the hammer 40.
  • the spindle 30 and the hammer 40 are combined so that a predetermined space is formed by the spindle cam groove 33 and the hammer cam groove 44.
  • the hammer 40 is rotated by the cam mechanism so as to be substantially interlocked with the spindle 30.
  • the cam ball 51 is one, the relative position in the rotation direction and the axial direction of the hammer 40 with respect to the spindle 30 is not stable as it is. Then, the needle bearing 56 is used together.
  • the needle bearing 56 supports the axial movement of the hammer 40 relative to the spindle 30 and the rotation in the circumferential direction.
  • the cam mechanism including the spindle cam groove 33, the cam ball 51, and the hammer cam groove 44 corresponds to a second restricting portion that restricts the movement of the hammer 40 relative to the spindle 30 in the axial direction.
  • a fitting hole 32 for fitting the shaft portion 66 of the anvil 60 is formed in the front end portion of the spindle shaft portion 31, and the planetary carrier portion of the speed reduction mechanism 20 is formed on the rear side of the spindle shaft portion 31.
  • Flange portions 37 and 38 are formed.
  • the flange portion 37 has a disk shape orthogonal to the axis A1, and three fitting holes 37a to 37c are formed at equal intervals in the rotation direction.
  • a disc-shaped flange portion 38 is provided on the rear side with a predetermined distance from the flange portion 37 so as to be parallel to the flange portion 37.
  • the flange portion 38 is also formed with three fitting holes 38a to 38c (only 38a can be seen in the figure) at equal intervals in the rotation direction, and together with the fitting holes 37a to 37c of the flange portion 37, the planetary gear 22 is pivoted. Fix the supporting shaft.
  • FIG. 3 is a cross-sectional view of the impact portion of the impact tool 1.
  • the hammer 40 can be relatively rotated with respect to the spindle 30 about the axis A1 by a predetermined angle, and can also be relatively rotated in the axial direction.
  • the state shown in FIG. 3 is a state where the hammer 40 is located at the most front side with respect to the spindle 30.
  • the hammer 40 has a shape in which the front sides of the two cylindrical portions 41 and 43 having different inner diameters are connected in the radial direction by the connection portion 42.
  • the hammer 40 is made of metal, and its diameter (outer diameter) is preferably about 35 to 44 mm, and the inertia is preferably 0.39 kg ⁇ cm 2 [0.000003 N ⁇ m 2 ] or less.
  • a fitting hole 34 that is recessed forward in the direction along the axis A ⁇ b> 1 is formed at the end of the spindle 30 on the motor 4 side, and serves as a housing space for the sun gear 21.
  • a cylindrical fitting hole 32 is formed at the end of the spindle 30 on the anvil 60 side so as to be recessed rearward along the axis A1.
  • the tubular portion 41 and the wall portion 45 correspond to the first tubular portion of the present invention
  • the tubular portion 43 corresponds to the second tubular portion of the present invention.
  • the hammer spring 54 is a compression spring, and a plurality of steel balls 52 are disposed on the front side of the hammer spring 54 while being pressed by the washer 53, and the rear side thereof is held by the flange portion 37 of the spindle 30 by a stepped washer 55. Is done. On the inner peripheral side of the washer 55, a hollow hole 55 a is formed so that the rear end portion 41 c of the cylindrical portion 41 inside the hammer 40 can penetrate the center.
  • a damper made of an elastic body such as rubber is arranged on the inner peripheral side of the stepped washer 55 so that the hammer 40 and the flange portion 37 are collided when the hammer 40 is fully retracted. You may suppress an impact. If the collision between the hammer 40 and the flange portion 37 is avoided, it is possible to avoid the cam ball 51 from colliding with the end portion in the spindle cam groove 33.
  • the hammer 40 is held so as not to rattle by the connection to the spindle 30 via the cam ball 51 and the contact between the wall 45 and the spindle 30.
  • the hammer 40 is movable in the axial direction with respect to the spindle 30, and can be largely moved particularly on the rear side. Since the hammer 40 is always urged forward by the hammer spring 54 (see FIG. 1) with respect to the spindle 30, the movement of the hammer 40 toward the rear side is a movement while compressing the hammer spring 54.
  • the wall portion 45 at the front end portion of the hammer 40 is only one in the circumferential direction.
  • the needle bearing 56 is attached in the vicinity of the rear end portion 41c on the inner peripheral side of the hammer 40.
  • the outer ring is fixed to the hammer 40 side, and a plurality of needle rollers provided inside contact with the outer peripheral surface of the spindle 30.
  • FIG. 4 is a front view of the assembly of the spindle 30 and the hammer 40. Note that the cross-sectional view of FIG. 3 corresponds to a cross section taken along the line BB of FIG.
  • the front surface 42a of the hammer 40 has a planar shape, and three striking claws 46a to 46c are provided so as to protrude forward in the axial direction from the front surface 42a at equal intervals in the circumferential direction.
  • the side surfaces on one side of the hitting claws 46a to 46c become the hitting surfaces 47a to 47c when tightening, and the other side surfaces, ie the hitting surfaces 48a to 48c, become the hitting surfaces when loosened.
  • the striking surfaces 47a to 47c and the striking surfaces 48a to 48c are formed substantially parallel to the virtual surface including the axis A1 in order to facilitate the retraction of the hammer 40.
  • the hammer cam groove 44 formed in the hammer 40 is arranged so as to show substantially one round except for the wall portion 45.
  • An insertion groove 44a for inserting the cam ball 51 at the time of assembly is formed in a part of the hammer cam groove 44 and in the vicinity of a position axially symmetric with respect to the wall 45.
  • the cam ball 51 shown in the figure can move from the position shown in the drawing to one side (clockwise) or the other direction (counterclockwise) by nearly a half turn.
  • FIG. 5 is a cross-sectional view of the impacting portion of the impact tool 1, wherein (1) shows a state in which the hammer 40 is in a normal position, and (2) shows a state in which the hammer 40 is retracted.
  • FIG. 5A is the same as FIG. 3, but here, the range from the front end position to the rear end position of the spindle cam groove 33 is indicated by R g .
  • the movement range of the needle bearing 56 is indicated by Rb .
  • the groove formation range Rg and the movement range Rb of the needle bearing 56 they are in a positional relationship such that a part thereof overlaps in the direction of the axis A1.
  • the spindle cam groove 33 can be made sufficiently long because almost one round of the outer peripheral surface of the spindle shaft portion 31 can be used for forming the spindle cam groove 33.
  • the amount of retraction of the hammer 40 increases.
  • moving range R b of formation of the groove ranges R g and needle bearing 56 so as to overlap in the axial direction a large spindle 30 in spite of a longer formation range R g groove in the axial direction A1
  • a compact striking mechanism that is not much different from the conventional spindle 230 can be realized.
  • the front surface 42 a of the hammer 40 and the blade portion 63 a of the anvil 60 are determined by the balance between the engagement position of the cam ball 51, the spindle cam groove 33 and the hammer cam groove 44 and the biasing force of the hammer spring 54.
  • the rear end face is located at a position slightly spaced in the axial direction.
  • the blade portion 63a of the anvil 60 and the striking claw 46a of the hammer 40 are in a positional relationship such that they overlap when viewed in the direction of the axis A1.
  • the engagement amount refers to the axial length of the contact area between the striking claws 46a to 46c of the hammer 40 and the blade portions 63a to 63c of the anvil 60 as viewed in the direction of the axis A1.
  • the engagement amount becomes maximum at the initial position before hitting.
  • the amount of engagement changes due to the backward movement of the hammer 40.
  • the counter torque transmitted to the hammer 40 by the force received by the anvil 60 from the tip tool side increases, the position of the cam ball 51 moves and the hammer 40 moves.
  • the relative positional relationship of the anvil 60 changes.
  • FIG. 6 is a partially enlarged cross-sectional view of the vicinity of the needle bearing 56 provided on the hammer 40.
  • a stepped portion 41b is formed in the vicinity of the rear end of the cylindrical portion 41 inside the hammer 40, and a needle bearing 56 is attached to the stepped portion 41b.
  • the needle bearing 56 becomes a shell 57 whose outer ring is fixed to the hammer 40 side, and a plurality of needle rollers 58 are provided in a portion surrounded by the shell 57, and the outer peripheral surface of the needle rollers 58 contacts the spindle shaft portion 31. .
  • the rotation shafts 59 of the plurality of needle rollers 58 are pivotally supported by the shell 57 so as to be parallel to the axis A1.
  • the order of S 1 is the gap between the inner peripheral surface and the spindle 30 of the hammer 40 on average here, the inner needle roller 58 portion of the needle bearing 56 becomes substantially zero.
  • the needle bearing 56 may be used in an environment filled with grease.
  • the rolling member such as the needle bearing 56 corresponds to the third restricting portion of the present invention, and the third restricting portion restricts the inclination of the hammer 40 with respect to the spindle 30.
  • FIG. 7A is a top view of the spindle 30.
  • the spindle 30 is made of metal, and its diameter D is preferably about 10 to 18 mm, and here it is 13.8 mm.
  • the outer peripheral surface of the spindle 30 is shaped to recede from the front end portion 33d in a substantially V shape when viewed from the direction orthogonal to the axis A1.
  • the spindle cam groove 33 has a predetermined cam lead angle ⁇ from the front end portion 33d.
  • the cam lead angle ⁇ of the forward rotation groove 33b used when tightening the screw and the reverse rotation groove 33a used when tightening the screw is set to the same angle, for example, within a range of 20 to 36 degrees.
  • FIG. 7 (2) is a bottom view of the spindle 30.
  • the rear end portion 33c of the reverse rotation groove portion 33a and the rear end portion 33e of the forward rotation groove portion 33b are extended close to each other, almost the entire circumference of the spindle shaft portion 31 can be used for the spindle cam groove 33.
  • a length close to double the cam grooves 233 and 234 can be secured.
  • the movement range R b of the needle bearing 56 overlap in the axial direction as shown. Therefore, the needle bearing 56 moves to a part where the spindle cam groove 33 exists.
  • the moving range R b in the range R g and needle bearing 56 occupied by the spindle cam groove 33 so as to arranged so as not to overlap in the axial direction, in which case the axial direction of the spindle 30 length Becomes bigger.
  • the length of the spindle shaft portion 31 is suppressed by partially overlapping the range Rg and the movement range Rb .
  • FIG. 8 is a development view showing the shape of the cam groove of the spindle.
  • (1) shows the conventional spindle cam grooves 233 and 234, and (2) shows the spindle cam groove 33 of this embodiment.
  • the two spindle cam grooves 233 and 234 of the conventional spindle shaft portion 231 are formed with reverse rotation groove portions 233a and 234a and normal rotation groove portions 233b and 234b, respectively.
  • the two sets of spindle cam grooves 233 and 234 are arranged in the circumferential direction, it is difficult to increase the length L 0 occupied in the axial direction. Accordingly, the rotation angle C 0 between from one center of the center of the circle (dotted lines) to form an arc which forms the rear end of the groove to the other center, less than 180 degrees.
  • the spindle shaft portion 31 has only one spindle cam groove 33.
  • the spindle cam groove 33 has a forward rotation groove 33b, and the reverse rotation groove 33a has a lead angle ⁇ of the same angle.
  • the rotation angle in the circumferential direction exceeds 180 degrees and extends to nearly 360 degrees. Therefore, the axial distance L 1 from the central front end portion 33 d of the spindle cam groove 33 to the two rear end portions 33 c and 33 e can be made sufficiently longer than the axial distance L 0 of the conventional spindle 230.
  • the rotation angle C 1 between the one center of the center of the circle (dotted lines) to form an arc which forms the rear end of the groove to the other center it becomes 180 degrees or more, more than for example 270 ° Can be set.
  • FIG. 9 is a diagram showing the relationship between the impact energy and the separation torque in the impact tool 1 of the present embodiment.
  • the hammer 40 does not rotate 1/3 after the rotation starts, but the hammering claws 46a to 46c of the hammer 40 abut against the blade portions 63a to 63c of the anvil 60 to rotate the anvil 60.
  • the hammer 40 compresses the hammer spring 54 along the spindle cam groove 33 of the cam mechanism, and the motor 4 side. Start retreating.
  • the hammer 40 is moved backward by the hammer 40 over the blades 63a to 63c of the anvil 60 and the engagement state between the hammers is released, the hammer 40 is added to the rotational force of the spindle 30.
  • the elastic energy accumulated in the hammer spring 54 and the action of the cam mechanism it is rapidly accelerated forward while rotating in the rotational direction.
  • the hammering claws 46a to 46c of the hammer 40 are re-engaged with the blade portions 63a to 63c of the next anvil 60 after the rotation so that strong hammering is performed.
  • the hammer 40 and the anvil 60 begin to rotate together. Since a strong rotational force is applied to the anvil 60 by this impact, the rotational impact force is transmitted to the screw through a tip tool (not shown) mounted in the mounting hole 61a of the anvil 60. Thereafter, the same operation is repeated, and the rotational impact force is intermittently repeatedly transmitted from the tip tool to the screw.
  • the screw is screwed into a material to be fastened such as wood.
  • the above shows the state when the anvil 60 is normally struck by the hammer 40.
  • the hammer 40 has three striking claws and three blade portions of the anvil 60. To do.
  • the hitting can be done by either “single skipping blow” or “two skipping hitting” with the rotational speed of the motor 4 as a high speed region above a predetermined rotational speed, or continuous hitting as a low speed region below a predetermined rotational speed.
  • the hammering torque applied to the anvil 60 by the hammer 40 can be switched by performing a striking operation on either of them.
  • the striking energy E is energy that the hammer 40 has immediately before the hammer 40 strikes the anvil 60.
  • the operation amount (pull amount) of the trigger 6a is maximum
  • the material to be tightened is a bolt
  • the restitution rate is 0.41.
  • the separation torque T B [kg ⁇ cm] and the impact energy E [N ⁇ m 2 ⁇ (rad / s) 2 ] are values calculated by the following formulas 1 and 2.
  • withdrawal torque T B [kg ⁇ cm] spring constant [kg / cm] ⁇ (spring pressing height) [cm] ⁇ tan (cam angle [deg] ⁇ cam contact radius [cm]), however, the pressing spring
  • the height [cm] is the free length of the spring [cm] ⁇ the spring height [cm] when detached (1.1 cm in this embodiment).
  • the cam contact radius [cm] is the distance from the center axis of the spindle 30 to the center point of the cam R shape formed on the spindle (0.7 cm in this embodiment).
  • withdrawal torque T B shown here shows the withdrawal torque in a static state, it is possible to easily calculated from the dimensions of the parts described above.
  • Each plot point illustrated in FIG. 9 is a plot of the hitting specifications according to the present invention and the prior art, and the hitting claw 46 a arranged on the hammer 40 is detached from the blade part 63 a arranged on the anvil 60. Later, in the middle speed operation mode in which the rotation angle until the next blade portion 63b is blown and engaged with the next next blade portion 63c is 240 degrees, until the next next blade portion 63a is engaged. In the high-speed operation mode in which the rotation angle is 360 degrees, the range of the impact energy E, the separation torque T B , and the coefficient K is displayed as the upper limit coefficients K 2 and K 4 and the lower limit coefficients K 1 and K 3. did.
  • Plot group 91 is the relationship withdrawal torque T B and impact energy E when hit jumping one current product on the market.
  • the conventional product becomes larger striking breakaway torque T and the spring pressure to increase the hammer spring 54 in order to further increase the energy E B (now impact tool which is commercially available).
  • the hitting claw 46a disposed on the hammer 40 detaches from the blade portion 63a disposed on the anvil 60 and then hits the next blade portion 63c, so-called “one-flying blow mode ( In addition to “medium speed operation mode”, after separating from the blade portion 63a, the next blade portion 63b and the next blade portion 63c are blown, and the original blade portion 63a is hit again. "Blow mode (high-speed operation mode)" was also added. In the case of this high-speed operation mode, the hammer 40 is struck only once during one rotation with respect to the anvil 60, and the plot group 92 is a plot of these struck specifications.
  • the switching control of the rotation speed of the motor 4 is important. is there.
  • the operation mode of high impact energy in the range of the coefficients K 3 to K 4 the operation mode of medium impact energy of the coefficients K 1 to K 2 , and the coefficient K 1 or less.
  • Impact tools that can handle a wide range of tightening operations from light-load screw tightening operations to high-load bolt tightening operations, by selecting three low impact energies that perform “continuous striking” as with conventional impact tools Can be realized.
  • This factor K 3 high impact energy modes of operation than the striking relationship between energy E and the disengagement torque T B is, 10.0 ⁇ as shown in the plot group 92 T B ⁇ E ⁇ of 16.7 ⁇ T B It will be a blow in the area.
  • FIG. 10 is a comparison table showing numerical values of the striking mechanism in the conventional impact tool and the impact tool 1 of the present embodiment.
  • the numerical value of the conventional example is an impact tool that performs “one skipping impact mode” at the time of high output, and the numerical value of this embodiment can also be restated as an impact tool that performs “two skipping impact mode” at the time of high output.
  • the diameters of the shaft portions of the spindles 30 and 230 are 13.8 mm and are the same.
  • the rebound rate from the material to be fastened is 0.31 assuming a thick screw with a large load, and in this embodiment, the rebound rate is 0.41 assuming a hard bolt due to an improvement in tightening torque.
  • the distance between the hammerbacks is 10.5 mm in the conventional example and 19.3 mm in the present embodiment, which is 1.8 times or more due to the difference between two cam balls.
  • the distance of the hammerback is 17 with a margin. .3 mm so that the cam ball 51 does not reach the rear end portions 33c and 33e of the spindle cam groove 33 to prevent the end of the groove from being damaged.
  • the conventional impact tool has a separation torque of 13.5 [N ⁇ m] and 13.5. While being further reduced to [N ⁇ m], the maximum impact energy E obtained was significantly improved from 9.7 to 18.1 [N ⁇ m 2 ⁇ (rad / s) 2 ].
  • FIG. 11 is a diagram showing a hit state by the hammer 40 and the anvil 60.
  • the vertical axis indicates the position of the hammer 40 in the front-rear direction, where + is the front side (tip tool side) and-is the rear side (motor side), indicating how many mm from the reference position.
  • 0 is the position of the front end of the hammering claw 46a of the hammer 40 when it is stationary or rotating in a low load state, and the front side position of the blade portion 63a at this time is also 0.
  • the horizontal axis is the rotation angle, which is one turn at 360 degrees ([deg]).
  • the blade portions 63a to 63c are arranged at intervals of 120 degrees.
  • the solid line 71 indicates the movement trajectory of the corner portion on the front side in the axial direction and the front side in the rotational direction of the hitting claw 46a
  • the dotted line 72 indicates the front side in the axial direction and the rear side in the rotational direction of the hitting claw 46a. It is the movement locus
  • the control circuit controls the rotation of the motor 4 so as to rotate the spindle 30 at a rotation speed at which the continuous hitting is favorably performed. This is the impact hitting that has been performed conventionally. In FIG. 11, only the striking claw 46a is shown, but the striking claws 46b and 46c similarly perform the retreat and striking operations.
  • FIG. 11 (2) shows a state of “one skipping blow”.
  • the next blade The rear side of the part 63b can also pass through and hit the next blade part 63c (the next blade part as viewed from the blade part 63a).
  • a solid line 73 indicates the movement trajectory of the corner portion on the front side in the axial direction and the front side in the rotational direction of the hitting claw 46a
  • a dotted line 74 indicates the front side in the axial direction and the rear side in the rotational direction of the hitting claw 46a.
  • FIG. 11 (3) shows a state of “two skipping hits”.
  • the rotation speed of the motor 4 is further increased and the impact claw 46a rotates through the rear side of the blade portion 63a, not only the next blade portion 63b but also the next next blade portion 63c passes through.
  • the blade portion 63a ("next next blade portion" as viewed from the blade portion 63a) can be hit again.
  • a solid line 75 indicates the movement trajectory of the corner portion on the front side in the axial direction and the front side in the rotational direction of the hitting claw 46a
  • a dotted line 76 indicates the front side in the axial direction and the rear side in the rotational direction of the hitting claw 46a. It is the movement locus
  • the hammer 40 that has compressed the hammer spring 54 and moved to the rear side has to be moved before the hammer 40 returns to the front side in the axial direction. It is necessary to rotate the spindle 30 at a sufficiently high speed so as to pass behind the part 63b and the blade part 63c.
  • the present embodiment can be realized the impact tool maintaining good blow feel by suppressing the increase in the withdrawal torque T B. Further, at that time, the striking energy E can be greatly improved as compared with the prior art by significantly increasing the spindle speed and performing one or two hits. Furthermore, if the continuous rotation is performed by significantly reducing the spindle rotation speed when shifting to the striking operation, it is possible to achieve a good feeling from the continuous rotation to the start of striking.
  • the present embodiment is not limited to the above example, and various modifications can be made.
  • FIG. 12 is a development view showing the shape of the cam groove of the spindle, (1) shows the shape of the spindle cam groove 33 of this embodiment, and (2) shows the spindle according to the first modification of this embodiment.
  • the shape of the cam groove 82 of the shaft portion 81 is shown, and (3) shows the shape of the cam groove 84 of the spindle shaft portion 83 according to the second modification of this embodiment.
  • the forward rotation groove 33b and the reverse rotation groove 33a have the same lead angle ⁇ .
  • the lead angle theta in FIG. 12 (2), the reverse rotation groove 82a has a small lead angle theta 1 of forward rotation groove 82b.
  • FIG. 13 is a view showing third and fourth modifications of the present invention, in which (1) is an example using a sintered metal 85 instead of the needle bearing 56, and (2) is an O-ring 86. It is a figure which shows the used example.
  • a stepped portion 41B is formed on the inner peripheral surface of the rear end side of the hammer 40B so as to be recessed radially outward, and a cylindrical sintered metal 85 is press-fitted therein.
  • the sintered metal 85 is a sliding bearing used in a self-lubricated state by impregnating a porous metal body manufactured by a powder metallurgy method with a lubricating oil, and the spindle shaft portion 31 is located near the rear end of the hammer 40B.
  • a lubricating oil film is formed on the sliding surface by the lubricating oil present between the sintered metal 85 and the spindle shaft portion 31.
  • the inner diameter of the sintered metal 85 is in good contact with the spindle shaft portion 31 of the spindle 30 so that they can slide well in the axial direction and the rotational direction.
  • FIG. 13 (2) shows a continuous groove 41C that is recessed in a radially outward shape in a trapezoidal shape in cross section in the vicinity of the rear end of the hammer 40C, and an O-ring 86 is attached thereto.
  • the groove portion 41C is obtained by moving a lubricating groove 241c (see FIG. 23) for storing lubricating oil, which has been conventionally provided, rearward in the axial direction and then increasing the size of the groove.
  • the O-ring 86 reduces the sliding resistance of two members (hammer 40C and spindle shaft portion 31) facing each other in an environment filled with lubricating oil, so that the rotation direction and axial direction of the hammer 40C and spindle shaft portion 31 are reduced.
  • a felt wiper that is sufficiently dipped in lubricating oil can be used, and is supported so that the inner peripheral surface of the O-ring 86 slides relative to the spindle shaft portion 31. .
  • sliding members such as the sintered metal 85 and the O-ring 86 correspond to the third restricting portion, and the third restricting portion restricts the inclination of the hammer 40 relative to the spindle 30.
  • FIG. 14 is a view showing an example of a hammer according to a fifth modification of the present invention.
  • hemispherical projections 88a to 88c for reducing the sliding resistance between the hammer 40D and the spindle 30 are provided.
  • the protrusions 88a to 88c are formed inside the rear end portion of the hammer 40, and are arranged at three locations in the circumferential direction.
  • the protrusions 88a to 88c may be formed integrally with the hammer 40D, or another metal or resin member formed with the three protrusions 88a to 88c may be mounted instead of the needle bearing 56.
  • the radial positions of the protrusions 88a to 88c protrude inward from the position of the fitting hole 32D, and are in a point contact state or a minute region contact state in contact with the outer peripheral surface of the spindle shaft portion 31 in a small region.
  • the protrusions 88a to 88c are formed on the hammer 40D side.
  • a plurality of hemispherical protrusions are formed on the spindle side in the circumferential direction, and the cylindrical inner peripheral surface of the hammer 40D is formed. What is necessary is just to make it a contact state in a point contact state or a micro area
  • the shape of the projection provided is not limited to a hemispherical shape, and may be any other shape as long as the sliding characteristics between the hammer 40D and the spindle shaft portion 31 are good.
  • the needle bearing 56 is provided on the inner peripheral side of the hammer 40, that is, between the hammer 40 and the spindle 30. Further, the number of cam balls 51 is one and the spindle cam groove 33 is formed long.
  • the needle bearing 180 is provided not on the inner peripheral side of the hammer 140 but on the outer peripheral side. The needle bearing 180 serves as a support member that supports the outer peripheral surface of the hammer 140, and is held between the hammer 140 and the hammer case 103 and on the inner wall side of the hammer case 103.
  • the number of cam balls 51 is only one as in the first embodiment, and the spindle cam groove 133 can be secured long. Furthermore, the type of the motor 104 as a drive source was changed to change from a brushed DC motor to a brushless DC motor. However, the type of the motor is arbitrary and does not directly affect the configuration of the characteristic striking mechanism of the present invention.
  • the main body housing 102 has a compact shape with a short length in the front-rear direction of the body portion 102 a due to a difference in the motor 104. Therefore, the shape of the hammer case 103 that houses the speed reduction mechanism 20 and the striking mechanism (130, 140, 160, etc.) is also changed.
  • the hammer case 103 was changed to a cup-like shape having a bottom surface perpendicular to the axis and not a tip-drawing shape in which the diameter is gradually reduced toward the front side.
  • These changes in shape are mainly due to the difference in design that the upper part of the trigger lever 6a is designed to be compact, and the internal mechanical configuration is not changed. Therefore, it is good also as a pre-drawing shape similarly to the first embodiment.
  • the speed reduction mechanism 20 transmits the output of the motor 104 to the spindle 130.
  • a planetary gear speed reduction mechanism similar to that shown in FIG. 1 is used.
  • the spindle 130 can be the same as or substantially the same as the spindle 30 of the first embodiment. Since the hammer 140 is rotated while the outer peripheral surface 140a is in contact with the needle bearing 180, the diameter of the outer peripheral surface excluding the striking claw portion is configured to be a constant size from the front end to the rear end. Further, since the shape of the hammer case 103 is determined in accordance with the shape of the hammer 140, the diameter of the inner wall surface of the hammer case 103 is formed to be a cylindrical surface.
  • the anvil 160 can be a common component as shown in FIG.
  • a bit holding portion 70 is formed at the tip thereof.
  • the shaft portion of the anvil 160 is supported by a needle bearing 19a.
  • a narrow cylindrical portion 103a extending forward from the vertical wall 103b is formed on the front side of the hammer case 103. That is, needle bearings (19a, 180) are disposed in the hammer case 103 on the inside of the small diameter cylindrical portion 103a and on the inside of the large diameter cylindrical portion 103c, respectively.
  • a vertical wall 103b extending in a radial direction substantially perpendicular to the axis A1.
  • the second embodiment is characterized in that two bearing devices (19a, 180) are provided in a metal integrally formed hammer case 103 made of an aluminum alloy or the like.
  • One bearing device (needle bearing 19 a) rotatably supports the anvil 160 on the hammer case 103.
  • the other bearing device (needle bearing 180) supports the hammer 140 on the hammer case 103. That is, the two bearing devices pivotally support (hold) different components (anvil 160, hammer 140). In other words, different components are pivotally supported (held) on the same component (hammer case 103) by two bearing devices.
  • An abutting portion 103e is formed inside the thick cylindrical portion 103c of the hammer case 103, and the inner diameter of the hammer case 103 on the rear side of the abutting portion 103e is formed slightly larger.
  • a needle bearing 180 is fixed to the rear side of the abutting portion 103e by a clearance fit.
  • a needle roller bearing with a cage can be adopted, for example. Since the needle roller bearing with a cage does not have a shell in the radially outer portion of the plurality of needle rollers, the outer diameter is reduced, which is convenient for suppressing the increase in the size of the hammer case 103.
  • the elongated cylindrical needle roller 181 included in the needleless bearing 180 without a shell has an axial center arranged in a direction parallel to the axis A1 (that is, the front-rear direction in FIG. 15).
  • Cages 182a and 182b are provided and held by one connecting member (not visible in the figure) that prevents the front and rear cages 182a and 182b from rotating.
  • the inside of the hammer case 103 including the arrangement area of the needle bearing 180 is filled with grease for preventing wear of machine parts.
  • the needle shape with a cage without a shell is provided. Since grease easily collects around the needle roller 181 of the roller bearing, it is advantageous in terms of lubrication.
  • the rear side of the needle bearing 180 is held in the axial direction by the ring gear 23 of the speed reduction mechanism 20.
  • An inner cover 17 for holding the two bearings 18a and 19b is provided on the rear side of the ring gear 23.
  • the inner cover 17 suppresses the axial movement of the ring gear 23 and positions the rotation center.
  • This is a cylindrical integral part made of synthetic resin, and is constituted by a member different from the main body housing 102.
  • a needle bearing 180 having a length LN in the front-rear direction along the axis A1 is disposed, and almost all of the outer peripheral surface 140a except the striking claw of the hammer 140 contacts the needle bearing 180 when retracted.
  • a needle roller bearing with a cage is used as the needle bearing 180. That is, the needle bearing 180 is provided with a plurality of cages 182a and 182b and needle rollers 181 held by the cages.
  • the hammer case 103 has a stepped abutting portion (stepped portion) 103e formed so as to be continuous in the circumferential direction, and a needle bearing 180 is provided behind the abutting portion 103e by clearance fitting. Be placed.
  • the ring gear 23 Since the ring gear 23 is inserted into the rear end side of the needle bearing 180, the ring gear 23 becomes a suitable pressing member when viewed in the direction of the axis A1, and the needle bearing 180 is sandwiched between the abutting portion 103e and the ring gear 23.
  • the retractable amount of the hammer 140 In order to improve the performance of the impact tool 101, it is sufficient to ensure a sufficient retractable amount of the hammer 140. However, if the outer diameter of the spindle 130 is the same as that of the prior art, the retractable amount is determined, so it is difficult to increase the retractable amount. On the other hand, there is also a desire to lay down the cam lead angle in order to reduce the separation torque. In order to satisfy the demand, the retractable amount of the hammer 140 within a limited space is further reduced.
  • a normal cam mechanism has two cam balls, and only one cam ball 51 is provided to form one V-shaped cam groove (FIG. 8 (2)). As a result, the retractable amount of the hammer 140 can be secured up to about twice the conventional amount.
  • the cam lead angle ⁇ (see FIG. 12 (1)) is reduced, and the separation torque of the hammer 140 for moving to the striking operation is made lower than before. Furthermore, in this embodiment, the rotation balance of the hammer 140 due to the single cam ball 51 is prevented from being lost by providing the needle bearing 180 that holds the outer peripheral surface of the hammer 140. As in the first embodiment, it is efficient to arrange the hammer 140 on the inner peripheral side behind the hammer 140, but this is a trade-off that the length of the spindle 130 becomes longer.
  • the second embodiment since it is held on the outer peripheral side of the hammer 140, it is possible to achieve a sufficient rotational balance without providing the needle bearing 56 (see FIG. 2) on the inner peripheral side. . Furthermore, since the needle bearing 180 is held on the hammer case 103 side, even if the impact tool uses a small hammer 140, it is not necessary to easily process the inner peripheral surface of the hammer.
  • the spindle shaft portion 131 is located on the front side of the planetary carrier portion of the speed reduction mechanism 20, and a set of V-shaped spindle cam grooves 133 are provided on the outer peripheral surface thereof.
  • the length L H of the hammer 140, the length L N of the needle bearing 180 is formed long enough. That is, the size of the needle bearing 180 is set so that it always comes into contact with the needle bearing 180 within the movable range of the hammer 140.
  • the rotation axis of the hammer 140 can be well matched with the axis A1. As is apparent from FIG. 16, the axial arrangement range of the needle bearing 180 overlaps the axial range from the front end position to the rear end position of the spindle cam groove 133.
  • the longitudinal center position 185 of the needle bearing 180 (black triangle mark in the figure) is occupied by the length L H of the hammer 140. Located behind the area. Further, the center position 149 in the front-rear direction of the hammer 140 (the black triangular mark in the figure) is located on the rear side of the front end position of the needle bearing 180.
  • the position in which the hammer 140 is the most retreated (retracted position) a length L H occupied portion of the hammer 140 as shown in FIG. 17 (2), the length of L N fully occupied by needle bearings 180 The positional relationship is such that it enters the interior.
  • the needle bearing 180 may be arranged on the front side (anvil 160 side) from the position of the needle bearing in FIGS. good. That is, the needle bearing 180 may be disposed so that at least a part of the hammer 140 is in contact with the needle bearing 180 in a state where the hammer 140 is in the forward movement position and the backward movement position.
  • the needle bearing 180 is provided on the outer peripheral side of the hammer 140 in the second embodiment, the hammer 140 can be stably held with respect to the spindle 130 by only one cam ball 51. Moreover, since the needle bearing 180 is provided on the hammer case 103 side, it is not necessary to substantially change the configuration of the spindle 230 and the hammer 240 shown in FIG. Therefore, the realization of the second embodiment is relatively easy. Further, in terms of assemblability, the number of steps for incorporating the needle bearing 180 into the hammer case 103 is increased, and the other assembly steps may be the same as the conventional one, so that an increase in cost can be suppressed.
  • the grease applied to the spindle surface is scattered by the centrifugal force toward the hammer case disposed on the outer peripheral side.
  • the grease on the sliding part of the spindle and the hammer is depleted, which causes galling, heat generation, wear, and the like, which impairs durability.
  • the needle bearing 180 is provided between the hammer 140 and the hammer case 103 (on the outer peripheral side of the hammer 140)
  • the grease applied to the spindle surface is on the needle bearing 180 side by centrifugal force. As a result, there is no grease depletion and the durability can be greatly improved.
  • bearings are not provided on the inner peripheral side of the hammer 140, but the outer peripheral side and inner peripheral side of the hammer 140 are used in combination with the first and second embodiments. It is also possible to provide bearings on both sides.
  • the needle bearing 180 is provided in the configuration in which the cam ball 51 (spindle cam groove 133) is one, but the needle bearing 180 has two cam balls (spindle) as shown in FIG. You may apply to the conventional structure of 2 cam grooves. Further, the needle bearing 56 of the first embodiment may be applied to a conventional configuration.
  • FIG. 18 illustrates a first modification of the second embodiment.
  • the impact tool 101A shown in FIG. 18 uses a needle bearing 180A having a short length LN in the axial direction, and the shape of the hammer case 103A (particularly the position of the abutting portion) is changed accordingly. Further, the rear side of the needle bearing 180A is pressed by the front cylindrical portion of the ring gear 23A. Other components are the same as those of the impact tool 101 shown in FIGS. Here, compared to the length L H of the outer peripheral surface of the hammer 140, the length L N of the needle bearing 180A is short.
  • the hammer 140 is in a state where at least a part of the length L H and the length L N overlap at any position from the front end position to the rear end position.
  • the hammer 140 comes into contact with the needle bearing 180A substantially in the vicinity of the center in the axial direction of the outer peripheral surface 140a of the hammer 140, so that the posture of the hammer 140 is not disturbed smoothly. Rotate.
  • the length of the needle bearings 180 and 180A in the front-rear direction may be arbitrarily set as long as the hammer 140 can be disposed in contact with the needle rollers at any front-rear position.
  • the shape of the needle bearing 180B is changed from a needle roller bearing with a cage to a shell needle roller bearing. That is, the needle bearing 180B is a bearing in which an outer ring is formed of a thin steel plate and the needle rollers 181 and the shell 183 are assembled on the raceway surface. Retainers 182a and 182b are provided on both sides in the axial direction of the needle roller 181 and inside the shell. The axial length of the needle bearing 180B is the same as that of the needle bearing 180 shown in FIG.
  • the shape of the hammer case 103B is a shape corresponding to the size of the needle bearing 180B becoming slightly larger radially outward, but the basic configuration is the same as the hammer case 103 shown in FIG.
  • a shell 183 as an outer ring is formed on the outer peripheral side, and a needle roller 181 is disposed on the inner peripheral side, so that the rolling shaft (the needle roller 181) is directly attached to the hammer 140 without using the inner ring.
  • the outer peripheral surface can be a track.
  • the outer ring has a structure that cannot be separated from the needle rollers 181 and the cages 182a and 182b, the rigidity is high, and a retaining ring or the like is used for fixing in the direction of the axis A1 simply by press-fitting into the hammer case 103B with an appropriate fit. Is no longer necessary.
  • the hammer case 103B is cup-shaped, and a through hole is formed at the center of the tip, and a thin cylindrical portion 103a is formed from the edge of the through hole.
  • a needle bearing 19a for pivotally supporting the anvil 160 is attached to the inside of the small-diameter cylindrical portion 103a.
  • a needle bearing 180B is inserted inside the cylindrical portion 103c of the hammer case 103, and is fixed by, for example, an intermediate fit.
  • a large number of needle rollers 181 are provided on the inner peripheral side of the needle bearing 180 ⁇ / b> B, and the rotation axis direction thereof is parallel to the rotation center of the spindle 130.
  • the anvil 160 forms the output shaft of the impact tool 101 ⁇ / b> B and the hit part of the hammer 140. Its shape is almost the same as the anvil 60 shown in FIG.
  • the anvil 160 has a hitting claw formed by three blade portions 163a to 163c behind the cylindrical output shaft portion 161.
  • a mounting hole 161 a is formed in the front end portion of the output shaft portion 161.
  • the blade portions 163a to 163c are hitting claws that are evenly arranged so as to be separated by 120 degrees when viewed in the rotation direction, and are arranged so as to extend radially outward.
  • a cylindrical shaft portion 166 behind the hit portion engages with the fitting hole 132 of the spindle 130.
  • the hammer 140 is a member that is held by the spindle 130.
  • the hammer 140 is held so as to be in a floating state or a non-contact state with respect to the spindle 130.
  • the needle bearing 180B is positioned on the outer peripheral side of the hammer 140, and the needle bearing is not mounted on the inner peripheral side.
  • Three striking claws 146a to 146c projecting forward in the axial direction (anvil 160 side) are arranged at three positions on the outer periphery on the front side of the hammer 140 so as to be separated by 120 degrees in rotation angle. The two side surfaces of the striking claws 146a to 146c make good surface contact with the three blade portions 163a to 163c of the anvil 160 at the time of collision.
  • the outer peripheral surface 140a of the hammer 140 has a cylindrical shape parallel to the axis, and has a through hole 141a at the center.
  • a hammer cam groove 144 is formed on the inner peripheral side forming the through hole 141a and on the front side.
  • a wall portion 145 is formed at one place in the circumferential direction of the inner peripheral surface of the hammer 140.
  • the wall portion 145 becomes a portion adjacent to or in contact with the outer peripheral surface of the spindle 130 on the front end side, and the hammer 140 contributes to maintaining the posture of relative rotation with respect to the spindle 130.
  • An insertion groove 144a for inserting the cam ball 51 into the cam groove at the time of assembly is formed at a location facing the wall portion 145 of the hammer 140 in the circumferential direction.
  • a metal 186 made of a sintered material is used instead of the needle bearing 180.
  • the metal 186 is fixed inside the hammer case 103C by an interference fit.
  • the frictional force between the metal 186 located on the outer peripheral side and the hammer 140 is sufficiently reduced.
  • the A gap 187 is open between the rear side of the metal 186 and the front end portion of the ring gear 23.
  • the shape of the ring gear 23 is changed and extended to the front side so that no gap is generated. You may comprise like this.
  • the shaft center of the hammer 140 is stable without being shaken. Rotation operation and batting operation are possible.
  • an example of a needle bearing and a metal is shown as a bearing member.
  • other bearings other than the needle type may be used as long as they have good sliding characteristics with the hammer 140. It may be a material.
  • SYMBOLS 1 Impact tool, 2 ... Main body housing, 2a ... Body part, 3 ... Hammer case, 4 ... Motor, 4a ... Rotary shaft, 5 ... Elastic cover, 6 ... Trigger switch, 6a ... Trigger, 7 ... Forward / reverse switching lever, DESCRIPTION OF SYMBOLS 9 ... Control circuit board, 10, 10A ... Battery pack, 11, 11A ... Latch button, 12 ... Output changeover switch, 13 ... Cooling fan, 17 ... Inner cover, 18a, 18b ... Bearing, 19a ... Needle bearing, 19b ... Bearing , 20 ... Deceleration mechanism, 21 ... Sun gear, 22 ... Planetary gear, 23 ... Ring gear, 30 ...
  • shaft part 69 ... steel ball, 70 ... bit holding part, 71, 73, 75 ... solid line (movement trajectory at the front corner of the hitting nail), 72, 74, 76 ... dotted line (after hitting nail) 78a to 78c ... projection, 81,83 ... spindle shaft, 82,84 ... spindle cam groove, 82a, 84a ... reverse rotation groove, 82b, 84b ... forward rotation groove, 85 ... sintering Metal, 86 ... Rings 88a to 88c ... Projection, 91, 92 ... Plot group, 101, 101A to 101C ... Impact tool, 102 ... Body housing, 102a ... Body part, 102b ...
  • spindle 231 ... spindle shaft, 233, 234 ... spindle cam groove, 233a, 234a ... reverse rotation groove 233b, 234b ... forward rotation groove portion, 237 ... flange portion, 238 ... flange portion, 239 ... cylindrical portion, 240 ... hammer, 241c ... lubrication groove, 244, 245 ... hammer cam groove, 246a, 246b ... striking claw, 251, 252 ... cam ball, 254 ... hammer spring, 260 ... anvil, 261a ... mounting hole, 263a, 263b ... hit claw, A1 ... (motor) axis, TB1 ... release torque, TB2 ... release torque

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Drilling And Boring (AREA)
  • Percussive Tools And Related Accessories (AREA)

Abstract

This impact tool is added with a support member for preventing loosening and tilting of a hammer. The impact tool is provided with: a spindle (130); a hammer (140) which is biased by a spring toward the front side of the spindle (130); a cam mechanism for supporting the hammer (140) in the axial direction; and an anvil (160) which is struck by the hammer (140), wherein a needle bearing (180) is provided for supporting the outer peripheral surface of the hammer (140). The cam mechanism comprises: a spindle cam groove (133) and a hammer cam groove (144); and a cam ball (51) which is disposed in the two grooves. The needle bearing (180) is fixed inside a hammer case (103), has on the inner peripheral surface thereof a plurality of needle rollers (181), and pivotally supports the rotational and axial movements of the hammer (140) by coming into contact with the outer peripheral surface (140a) of the hammer (140).

Description

インパクト工具Impact tools
本発明は、ハンマを用いてアンビルを打撃しながらアンビルを所定回転に回転させるインパクト工具に関する。  The present invention relates to an impact tool for rotating an anvil to a predetermined rotation while hitting the anvil using a hammer.
モータの回転力をハンマに伝達して、ハンマを用いてアンビルに回転方向の打撃力を加えるインパクト工具が知られており、その一例として特許文献１の技術が知られている。インパクト工具は、木材へのねじ部材の締め付けや、コンクリートにボルトを固定する作業、及び、ねじ部材やボルトを緩める作業等に広く用いられている。インパクト工具のトリガスイッチのレバーを引くと、モータが駆動されて、減速機構を介してスピンドルを回転させる。スピンドルが回転すると、ハンマスプリングとカムボールによりスピンドルに連結されているハンマが回転する。ハンマが回転すると、ハンマの打撃爪とアンビルの羽根部を介して回転力が伝達されてアンビルが回転する。アンビルの軸方向の先端には先端工具の装着孔が形成されており、装着孔に装着された六角ビット等の先端工具を介して、ねじやボルトの締め付けを行うことができる。  An impact tool is known that transmits the rotational force of a motor to a hammer and applies a striking force in the rotational direction to the anvil using the hammer. The technique of Patent Document 1 is known as an example. Impact tools are widely used for tightening screw members to wood, fixing bolts to concrete, loosening screw members and bolts, and the like. When the lever of the trigger switch of the impact tool is pulled, the motor is driven to rotate the spindle via the speed reduction mechanism. When the spindle rotates, the hammer connected to the spindle by the hammer spring and the cam ball rotates. When the hammer rotates, the rotational force is transmitted through the hammer hitting claw and the blade portion of the anvil, and the anvil rotates. A tip tool mounting hole is formed at the tip of the anvil in the axial direction, and a screw or a bolt can be tightened via a tip tool such as a hexagonal bit mounted in the mounting hole.
ここで従来のインパクト工具の構成を図２２を用いて説明する。インパクト工具２０１のハウジングは、本体ハウジング２０２とそれに設けられるハンマケース２０３によって構成される。インパクト工具２０１は、充電可能な電池パック１０を電源とし、モータ４を駆動源として回転打撃機構を駆動する。出力軸であるアンビル２６０には、打撃機構から回転力と打撃力が与えられ、ビット保持部７０に形成された装着孔２６１ａに保持されるドライバビット等の図示しない先端工具に、回転打撃力が連続的に又は間欠的に伝達され、ねじ締めやボルト締め等の作業が行なわれる。  Here, the configuration of a conventional impact tool will be described with reference to FIG. The housing of the impact tool 201 includes a main body housing 202 and a hammer case 203 provided thereon. The impact tool 201 uses the rechargeable battery pack 10 as a power source and drives the rotary impact mechanism using the motor 4 as a drive source. The anvil 260, which is the output shaft, is given a rotational force and a striking force from the striking mechanism, and a rotating striking force is applied to a tip tool (not shown) such as a driver bit held in the mounting hole 261a formed in the bit holding portion 70. It is transmitted continuously or intermittently, and operations such as screw tightening and bolt tightening are performed.
モータ４は、側面視で略Ｔ字状の形状を成す本体ハウジング２０２の筒状の胴体部２０２ａ内に収容される。モータ４の回転軸４ａは、その軸線Ａ１が胴体部２０２ａの長手方向に伸びるように配置される。モータ４の前方側の回転軸４ａには冷却ファン１３が設けられ、モータ４と同期して回転する。冷却ファン１３の回転によって本体ハウジング２０２の後方の吸気口２１７ａ、２１７ｂ等から外気が吸引されて、外気はモータ４を冷却した後に、冷却ファン１３の周囲に形成された排気口２１７ｃ等から外部に排出される。  The motor 4 is accommodated in a cylindrical body 202a of the main body housing 202 having a substantially T-shape when viewed from the side. The rotation shaft 4a of the motor 4 is disposed such that its axis A1 extends in the longitudinal direction of the body portion 202a. A cooling fan 13 is provided on the rotating shaft 4 a on the front side of the motor 4 and rotates in synchronization with the motor 4. As the cooling fan 13 rotates, outside air is sucked from the intake ports 217a, 217b and the like at the rear of the main body housing 202, and the outside air cools the motor 4 and then flows to the outside from the exhaust port 217c formed around the cooling fan 13. Discharged.
胴体部２０２ａから略直角に一体に延びるハンドル部２０２ｂ内の上部にはトリガスイッチ６が配設され、トリガスイッチ６から本体ハウジング２０２の前方側には操作レバーたるトリガ６ａが露出する。またトリガスイッチ６の上方には、モータ４の回転方向を切り替えるための正逆切替レバー７が設けられる。ハンドル部２０２ｂ内の下部は、電池パック１０を取り付けるために拡径部２０２ｃが形成される。拡径部２０２ｃはハンドル部２０２ｂの長手方向中心軸から径方向（直交方向）に広がるように形成された部分で、拡径部２０２ｃの下側に電池パック１０が装着される。電池パック１０は例えばリチウムイオン電池等の複数本の二次電池をパック化したもので、電池パック１０を充電するときは、ラッチボタン１１を押し込みながら電池パック１０をインパクト工具２０１から取り外して、図示しない専用の充電器に装着する。  A trigger switch 6 is disposed in an upper portion of a handle portion 202b that integrally extends substantially perpendicularly from the body portion 202a, and a trigger 6a that is an operation lever is exposed from the trigger switch 6 to the front side of the main body housing 202. A forward / reverse switching lever 7 for switching the rotation direction of the motor 4 is provided above the trigger switch 6. A diameter-expanded portion 202c is formed at the lower portion in the handle portion 202b in order to attach the battery pack 10. The enlarged diameter portion 202c is a portion formed so as to expand in the radial direction (orthogonal direction) from the longitudinal central axis of the handle portion 202b, and the battery pack 10 is mounted on the lower side of the enlarged diameter portion 202c. The battery pack 10 is a pack of a plurality of secondary batteries such as lithium ion batteries. When charging the battery pack 10, the battery pack 10 is removed from the impact tool 201 while pushing the latch button 11, and is illustrated. Do not attach to a dedicated charger.
回転打撃機構は、遊星歯車減速機構２２０とスピンドル２３０とハンマ２４０とアンビル２６０を備え、後端が軸受２１９ｂ、前端がニードルベアリング２１９ａにより保持される。トリガ６ａが引かれてモータ４が起動されると、正逆切替レバー７で設定された方向にモータ４が回転を始め、その回転力は遊星歯車減速機構２２０によって減速されてスピンドル２３０に伝達され、スピンドル２３０が所定の速度で回転駆動される。ここで、スピンドル２３０とハンマ２４０とはカム機構によって連結され、このカム機構は、スピンドル２３０の外周面に形成されたＶ字状の２つのスピンドルカム溝２３３、２３４と、ハンマ２４０の内周面に形成された２つのハンマカム溝と、これらのカム溝に係合するカムボール２５１、２５２によって構成される。  The rotary striking mechanism includes a planetary gear reduction mechanism 220, a spindle 230, a hammer 240, and an anvil 260, and a rear end is held by a bearing 219b and a front end is held by a needle bearing 219a. When the trigger 6a is pulled and the motor 4 is started, the motor 4 starts to rotate in the direction set by the forward / reverse switching lever 7, and the rotational force is decelerated by the planetary gear reduction mechanism 220 and transmitted to the spindle 230. The spindle 230 is rotated at a predetermined speed. Here, the spindle 230 and the hammer 240 are connected by a cam mechanism, and the cam mechanism includes two V-shaped spindle cam grooves 233 and 234 formed on the outer peripheral surface of the spindle 230, and the inner peripheral surface of the hammer 240. Are formed by two hammer cam grooves and cam balls 251 and 252 engaged with these cam grooves.
図２３は従来のインパクト工具２０１の打撃部の断面図であって、（１）はハンマ２４０が通常位置にある状態を示す。 ハンマ２４０は、ハンマスプリング２５４によって常に前方に付勢されており、静止時にはカムボール２５１、２５２とハンマカム溝２４４、２４５との係合によってハンマ２４０は前方側位置にある。この位置はハンマ２４０の打撃爪２４６ａ、２４６ｂがアンビル２６０の被打撃爪（図示せず）と軸線Ａ１方向に重なる位置にある。スピンドル２３０が回転駆動されると、その回転はカム機構を介してハンマ２４０に伝達され、ハンマ２４０が半回転しないうちにハンマ２４０の打撃爪２４６ａ、２４６ｂがアンビル２６０の被打撃爪２６３ａ、２６３ｂ（図２２参照）に係合する。インパクト工具２０１の締め付け開始から当分の間はハンマ２４０とアンビル２６０が同期して回転する（連続回転）。その後、締め付けの進行に応じて徐々に先端工具から伝わる反トルクが高くなって、この反トルクがハンマスプリング２５４のバネ圧を上回ると、ハンマ２４０はスピンドルカム溝２３３、２３４とハンマカム溝２４４、２４５の形状に沿ってハンマスプリング２５４を圧縮しながら後方側（モータ側）に徐々に後退する。図２３（１）の状態からハンマ２４０が矢印２４９のように後退すると、ハンマ２４０の打撃爪とアンビル２６０の被打撃爪の前後方向の接触長さが小さくなって、最後には図２３（２）に示すような接触長さが０の位置まで来る。ハンマ２４０の打撃爪２４６ａ、２４６ｂとアンビル２６０の被打撃爪２６３ｂ（図２２参照）、２６３ａの前後方向の接触長さが０ｍｍとなった時、回転方向に対するハンマ２４０のアンビル２６０に対する係合が離脱することになる。この離脱する直前にハンマ２４０とアンビル２６０間に作用するトルクの大きさが、ハンマ２４０とアンビル２６０とが離脱する際の“離脱トルクＴＢ”である。  FIG. 23 is a cross-sectional view of a hitting portion of a conventional impact tool 201, and (1) shows a state where the hammer 240 is in a normal position. The hammer 240 is always urged forward by the hammer spring 254, and when stationary, the hammer 240 is at the front side position by the engagement between the cam balls 251 and 252 and the hammer cam grooves 244 and 245. This position is such that the hitting claws 246a and 246b of the hammer 240 overlap with the hitting claws (not shown) of the anvil 260 in the direction of the axis A1. When the spindle 230 is driven to rotate, the rotation is transmitted to the hammer 240 via the cam mechanism, and the hammering claws 246a and 246b of the hammer 240 are moved by the hammering claws 263a and 263b ( (See FIG. 22). The hammer 240 and the anvil 260 rotate synchronously (continuous rotation) for the time being from the start of tightening the impact tool 201. Thereafter, as the tightening progresses, the counter torque transmitted from the tip tool gradually increases, and when the counter torque exceeds the spring pressure of the hammer spring 254, the hammer 240 has the spindle cam grooves 233 and 234 and the hammer cam grooves 244 and 245. The hammer spring 254 is compressed in accordance with the shape of the motor and gradually retracts backward (motor side). When the hammer 240 moves backward as indicated by an arrow 249 from the state shown in FIG. 23 (1), the contact length in the front-rear direction of the hammering claw of the hammer 240 and the hitting claw of the anvil 260 decreases, and finally FIG. The contact length as shown in FIG. When the contact length in the front-rear direction of the hammering claws 246a, 246b of the hammer 240 and the hitting claws 263b (see FIG. 22) of the anvil 260 becomes 0 mm, the engagement of the hammer 240 with the anvil 260 in the rotational direction is disengaged. Will do. The size of the torque acting immediately prior to the disengagement between the hammer 240 and the anvil 260, the hammer 240 and the anvil 260 are "leaving torque T B" when leaving.
先端工具から伝わる反力が離脱トルクＴＢを越えると、ハンマ２４０の後退動によってハンマ２４０の打撃爪２４６ａ、２４６ｂがアンビル２６０の被打撃爪（図示せず）を乗り越えて回転し、ハンマ２４０はハンマスプリング２５４の圧縮力で、前方側に押し出されながら回転方向に見てアンビル２６０の次の被打撃爪と係合（又は衝突）することになる。この際、ハンマ２４０は、スピンドル２３０の回転力に加え、ハンマスプリング２５４に蓄積されていた弾性エネルギーとカム機構の作用によって回転方向及び前方に急速に加速されつつ、ハンマスプリング２５４の付勢力によって前方へ移動し、打撃爪２４６ａ、２４６ｂがアンビル２６０の被打撃爪２６３ａ、２６３ｂ（図２２参照）に再び係合して一体に回転し始める。このとき、強力な回転打撃力がアンビル２６０に加えられるため、アンビル２６０の装着孔２６１ａ（図２２参照）に装着される図示しない先端工具を介してネジに回転打撃力が伝達される。以後、同様の動作が繰り返され、締付け対象の締め付けが完了するまで、離脱、係合の動作を繰り返す（打撃動作）。締付け対象が締め付けられるにつれて、締付け対象から受ける反トルクが徐々に高くなるため、ハンマ２４０の後退量も増加する。これは、締付け対象に生じる反トルクの増加に伴い、ハンマ２４０とアンビル２６０間に発生する反発率が高くなるためである。  When the reaction force transmitted from the tool bit exceeds the disengagement torque T B, the striking pawl 246a of the hammer 240 by the retraction of the hammer 240, 246b is rotated over the struck pawls (not shown) of the anvil 260, the hammer 240 With the compressive force of the hammer spring 254, it is engaged with (or collides with) the next hitting claw of the anvil 260 as seen in the rotational direction while being pushed forward. At this time, in addition to the rotational force of the spindle 230, the hammer 240 is rapidly accelerated in the rotational direction and forward by the action of the elastic energy accumulated in the hammer spring 254 and the cam mechanism, and forward by the urging force of the hammer spring 254. The striking claws 246a, 246b re-engage with the striking claws 263a, 263b (see FIG. 22) of the anvil 260 and rotate together. At this time, since a strong rotational striking force is applied to the anvil 260, the rotational striking force is transmitted to the screw via a tip tool (not shown) mounted in the mounting hole 261a (see FIG. 22) of the anvil 260. Thereafter, the same operation is repeated, and the disengagement and engagement operations are repeated until the tightening of the tightening target is completed (blow operation). As the tightening target is tightened, the counter torque received from the tightening target is gradually increased, so that the retraction amount of the hammer 240 also increases. This is because the repulsion rate generated between the hammer 240 and the anvil 260 increases as the counter torque generated in the tightening target increases.
特開２０１７－０３５７７２号公報JP 2017-035772 A
近年、インパクト工具の高トルク化が図られており、締め付けトルク１５０Ｎ・ｍ以上の製品が市販されている。インパクト工具において締め付けトルクを高めるためには、通常ではハンマ２４０をアンビル２６０側に付勢するハンマスプリング２５４のばね定数を高く設定する。しかしながら、ハンマスプリング２５４のばね定数を高めて高出力化を図ると離脱トルクＴＢが高くなってしまうため、連続回転動作から打撃動作に移行するタイミングが遅くなり、インパクト工具２０１に作用する反トルクが大きくなって作業者が片手でインパクト工具を把持したままねじ締め作業を行うことが困難となる。また、高い締め付けトルクを必要とされない柔らかい木材等へのねじ締め等の場合、スプリングのばね定数を高めたインパクト工具ではねじ締め作業中に離脱トルクに到達しないことがあり、なかなか打撃動作が行われないという問題が生ずる。打撃動作が行われないと、ネジの十字溝から先端工具のネジ山が浮きやすく、六角ビットが外れて弾かれたり、その場で空転してネジ頭が痛んでしまう虞が高くなる。このように、離脱トルクＴＢが高すぎるとインパクト工具の“打撃”という特徴を生かせないことになり、特にカムアウトを防ぐ効果が得られない。一方、従来のスピンドル２３０で左右対称の２つのカム溝を設けた構成では、打撃トルクを大きくするためにハンマ２４０の後退量、即ちハンマバック量を稼ぐためにスピンドルカム溝２３３、２３４の溝長を伸ばそうとすると、２つのスピンドルカム溝２３３、２３４の両端部が接触してしまうため、ハンマバック量を充分に稼ぐことができなかった。また、スピンドルカム溝２３３、２３４の後退角（カムリード角）を大きくことによってハンマ２４０の後退量を稼ぐことも可能であるが、その場合は、離脱トルクＴＢがさらに大きくなる。また、インパクト工具においては、ハンマとスピンドルの間の隙間が大きい場合に、ハンマのガタツキが大きくなり、ハンマが打撃中に傾いて、安定した打撃が行われなくなる虞がある。安定した打撃が行われない場合は、ハンマとスピンドルが早期に摩耗し、寿命が短くなる虞がある。  In recent years, the impact tool has been increased in torque, and products having a tightening torque of 150 N · m or more are commercially available. In order to increase the tightening torque in the impact tool, the spring constant of the hammer spring 254 that normally biases the hammer 240 toward the anvil 260 is set high. However, since becomes high and the detachable torque T B achieve higher output by increasing the spring constant of the hammer spring 254, it slows the timing of transition from the continuous rotary motion into striking movement, counter torque acting on the impact tool 201 Becomes larger, and it becomes difficult for the operator to perform the screwing operation while holding the impact tool with one hand. Also, in the case of screw tightening to soft wood that does not require high tightening torque, the impact tool with a high spring constant may not reach the separation torque during the screw tightening operation, and the striking operation will be performed easily. The problem arises. If the striking operation is not performed, the thread of the tip tool tends to float from the cross groove of the screw, and there is a high possibility that the hexagonal bit will be released and bounced, or the head of the screw may be damaged by slipping on the spot. Thus, it can not Ikase a feature that "striking" of the impact tool when disengaged torque T B is too high, not particularly effective to prevent the coming-out is obtained. On the other hand, in the conventional configuration in which two symmetrical cam grooves are provided in the spindle 230, the length of the spindle cam grooves 233 and 234 is increased in order to increase the retraction amount of the hammer 240, that is, the hammer back amount, in order to increase the hitting torque. If both ends of the two spindle cam grooves 233 and 234 are in contact with each other, the amount of hammerback cannot be sufficiently obtained. Although it is also possible to make the erosion of the hammer 240 by increased receding angle of the spindle cam grooves 233 and 234 (the Kamurido angle), in which case, further increases disengaged torque T B. Further, in the impact tool, when the gap between the hammer and the spindle is large, the hammer becomes loose, and the hammer is inclined during the hitting, and there is a possibility that the stable hitting may not be performed. If stable striking is not performed, the hammer and the spindle may be worn out early and the life may be shortened.
本発明は上記背景に鑑みてなされたもので、本発明の目的は、ハンマとアンビルの離脱トルクＴＢの上昇を抑えつつ、回転方向への打撃力を高くすることができるインパクト工具を提供することにある。本発明の他の目的は、高出力を達成すると共に、連続回転時から打撃開始への移行時の操作フィーリングを良くした、片手で把持しながら作業のしやすいインパクト工具を提供することにある。本発明の更に他の目的は、ハンマ打撃爪がアンビルの次の被打撃爪を飛ばして、次の次の被打撃爪、又は、次の次の次の被打撃爪を打撃可能にして、ハンマスプリングのバネ定数を上昇させることなく、十分大きな締め付けトルクを実現可能としたインパクト工具を提供することにある。本発明の更に他の目的は、スピンドルに対するハンマの傾きを規制するようにしたインパクト工具を提供することにある。本発明の更に他の目的は、ハンマの外側に支持部材を設けることで、ハンマやスピンドルの全長が長くなることを防止して、ハウジングの大型化を防止すると共に、グリス漏れの虞を大幅に低下させたインパクト工具を提供することにある。  The present invention has been made in view of the above background, an object of the present invention, while suppressing an increase in withdrawal torque T B of the hammer and the anvil, to provide an impact tool capable of increasing the striking force in the rotational direction There is. Another object of the present invention is to provide an impact tool that achieves high output and improves the operational feeling at the time of transition from continuous rotation to start of striking and is easy to work while holding with one hand. . Still another object of the present invention is to make the hammer hitting nail fly the next hitting nail of the anvil so that the next next hitting nail or the next next hitting nail can be hit. An object of the present invention is to provide an impact tool that can realize a sufficiently large tightening torque without increasing the spring constant of the spring. It is still another object of the present invention to provide an impact tool that regulates the inclination of the hammer with respect to the spindle. Still another object of the present invention is to provide a support member on the outside of the hammer, thereby preventing the total length of the hammer and spindle from being increased, preventing an increase in the size of the housing, and greatly increasing the risk of grease leakage. It is to provide a reduced impact tool.
本願において開示される発明のうち代表的なものの特徴を説明すれば次の通りである。本発明の一つの特徴によれば、モータと、前記モータによって回転方向に駆動されるスピンドルであって、スピンドル軸部と、前記スピンドル軸部に設けられたスピンドルカム溝とを有するスピンドルと、前記スピンドルに対して所定の範囲内で前記スピンドル軸部の軸方向及び回転方向に相対的に移動可能に構成されたハンマであって、前記スピンドル軸部に対して軸方向及び回転方向に相対的に移動可能に構成された第１の筒状部分と、前記スピンドルカム溝に対してカムボールを介して軸方向に相対的に移動可能に構成されたハンマカム溝と、前記第１の筒状部分の径方向外側に設けられた第２の筒状部分とを有し、スプリングによって前方に付勢されるハンマと、前記ハンマの前方において回転可能に設けられ、前記ハンマが前方に移動しながら回転したときに前記ハンマによって回転方向に打撃されるアンビルと、前記モータ、スピンドル、ハンマ及びアンビルを収容するハウジングと、を備えたインパクト工具において、前記スピンドル軸部と前記第１の筒状部分によって前記ハンマの前記スピンドルに対する径方向の移動を規制する第１の規制部が構成され、前記スピンドルカム溝、前記カムボール及び前記ハンマカム溝によって前記ハンマの前記スピンドルに対する軸方向の移動を規制する第２の規制部が構成され、前記第１及び第２の規制部とは別に前記ハンマの前記スピンドルに対する傾きを規制する第３の規制部を設けた。前記第３の規制部は、前記スピンドルと前記ハンマとの間に設けられるか、又は前記ハウジングと前記ハンマの間に設けられる。前記第３の規制部は転動部材又は前記ハンマよりも摺動抵抗の小さい摺動部材である。前記第３の規制部は、前記ハンマの外周面を支持するよう前記ハンマの外周面に接触する。前記第３の規制部を前記ハンマの外周と前記ハウジングの内壁の間に配置した。前記ハウジングには突き当て面を形成し、前記突き当て面に前記第３の規制部を突き当てるようにした。  The characteristics of representative ones of the inventions disclosed in the present application will be described as follows. According to one aspect of the present invention, a motor, a spindle driven in the rotational direction by the motor, the spindle having a spindle shaft portion and a spindle cam groove provided in the spindle shaft portion; A hammer configured to be relatively movable in the axial direction and the rotational direction of the spindle shaft portion within a predetermined range with respect to the spindle, wherein the hammer is relatively movable in the axial direction and the rotational direction with respect to the spindle shaft portion. A first cylindrical portion configured to be movable, a hammer cam groove configured to be relatively movable in the axial direction with respect to the spindle cam groove via a cam ball, and a diameter of the first cylindrical portion. A hammer that is biased forward by a spring, and is rotatably provided in front of the hammer, the hammer being forward An impact tool comprising: an anvil that is struck in a rotational direction by the hammer when rotated while moving; and a housing that houses the motor, spindle, hammer, and anvil, wherein the spindle shaft portion and the first cylinder A first restricting portion that restricts the movement of the hammer relative to the spindle in the radial direction is configured by the shaped portion, and the spindle cam groove, the cam ball, and the hammer cam groove restrict the axial movement of the hammer relative to the spindle. A second restricting portion is configured, and a third restricting portion for restricting the inclination of the hammer relative to the spindle is provided separately from the first and second restricting portions. The third restricting portion is provided between the spindle and the hammer, or is provided between the housing and the hammer. The third restricting portion is a sliding member having a sliding resistance smaller than that of the rolling member or the hammer. The third restricting portion contacts the outer peripheral surface of the hammer so as to support the outer peripheral surface of the hammer. The third restricting portion is disposed between the outer periphery of the hammer and the inner wall of the housing. An abutting surface is formed on the housing, and the third restricting portion is abutted against the abutting surface.
本発明の他の特徴によれば、前記第３の規制部は、前記ハンマとは別の部材であり、前記ハンマの内周面に設けられ前記スピンドルと接触する転動部材又は摺動部材である。前記スピンドルカム溝と、前記ハンマカム溝は、それぞれ１つずつ、又は、２つずつ設けられ、前記スピンドルカム溝に、前記スピンドルカム溝の数と同じ数のカムボールが配置される。前記スピンドルカム溝及び前記カムボールはそれぞれ１つのみ設けられている。前記スピンドルカム溝の後端を構成する一方の円弧を形成する円の中心点から他方の円弧を形成する円の中心点までの間が、円周方向で１８０度を超えるように前記スピンドルカム溝が延びる。前記スピンドルと前記ハンマの摺動部であって前記スピンドルカム溝の前記一方の後端と前記他方の後端に挟まれる部分に壁部を形成した。  According to another feature of the invention, the third restricting portion is a member different from the hammer, and is a rolling member or a sliding member provided on the inner peripheral surface of the hammer and in contact with the spindle. is there. One or two spindle cam grooves and two hammer cam grooves are provided, and the same number of cam balls as the number of spindle cam grooves are arranged in the spindle cam groove. Only one spindle cam groove and one cam ball are provided. The spindle cam groove so that the distance from the center point of the circle forming one arc forming the rear end of the spindle cam groove to the center point of the circle forming the other arc exceeds 180 degrees in the circumferential direction. Is extended. A wall portion is formed in a sliding portion between the spindle and the hammer and sandwiched between the one rear end and the other rear end of the spindle cam groove.
本発明の他の特徴によれば、前記スピンドルカム溝の軸方向の前後方向に占める範囲は、前記支持部材の軸方向の移動範囲又は前記支持部材の配置範囲とオーバーラップする。前記支持部材を、前記ハンマの内周側であって前記ハンマカム溝よりも後方側、又は、前記ハンマの外周側であって前記支持部材の軸方向中心位置が前記ハンマの可動範囲の軸方向中心位置よりも後方側になるように設けた。  According to another aspect of the invention, the range of the spindle cam groove in the longitudinal direction overlaps with the axial movement range of the support member or the support member arrangement range. The support member is located on the inner peripheral side of the hammer and behind the hammer cam groove, or on the outer peripheral side of the hammer, and the axial center position of the support member is the axial center of the movable range of the hammer. It provided so that it might become the back side rather than a position.
本発明の他の特徴によれば、モータと、前記モータによって回転方向に駆動されるスピンドルと、前記スピンドルに対して所定の範囲内で軸方向及び回転方向に相対的に移動可能であってカム機構とスプリングによって前方に付勢されるハンマと、前記ハンマの前方において回転可能に設けられ、前記ハンマが前方に移動しながら回転したときに前記ハンマによって打撃されるアンビルと、を備えたインパクト工具において、前記カム機構は、前記スピンドルに設けられ、一方の後端から前端を経て他方の後端へと１つながりに延びるスピンドルカム溝と、前記ハンマの内周側に形成されたハンマカム溝と、前記スピンドルカム溝及び前記ハンマカム溝に配置されたカムボールと、を含み、前記スピンドルカム溝は、前記スピンドルカム溝の後端を構成する円弧を形成する円の中心の一方の中心から他方の中心までの間が円周方向で１８０度を超えて延びる、又は、１つのみ設けられている。前記カム機構とは別に前記ハンマの径方向を支持する支持部材を、前記ハンマとは別に設けた。  According to another aspect of the present invention, a motor, a spindle driven in the rotational direction by the motor, and a cam movable relative to the spindle in an axial direction and a rotational direction within a predetermined range. An impact tool comprising: a hammer that is biased forward by a mechanism and a spring; and an anvil that is rotatably provided in front of the hammer and is struck by the hammer when the hammer rotates while moving forward. The cam mechanism is provided on the spindle, and extends in a continuous manner from one rear end through the front end to the other rear end, and a hammer cam groove formed on the inner peripheral side of the hammer, A cam ball disposed in the spindle cam groove and the hammer cam groove, wherein the spindle cam groove is formed on the spindle cam groove. Between from one center of the center of the circles forming the arcs constituting the edges to the other of the center extends beyond 180 degrees in the circumferential direction, or are provided only one. Apart from the cam mechanism, a support member for supporting the radial direction of the hammer is provided separately from the hammer.
本発明の他の特徴によれば、インパクト工具において、カム機構は、スピンドルに設けられ、一方の後端から前端を経て他方の後端へと１つながりに延びるスピンドルカム溝と、ハンマの内周側に形成されたハンマカム溝と、スピンドルカム溝及びハンマカム溝に配置されたカムボールを含み、スピンドルにはスピンドルカム溝が１つのみ設けるようにした。スピンドルの外周面とハンマの内周面の間には、ベアリング等の転動部材、又は、メタルやＯリング等の摺動部材を設けるようにした。  According to another feature of the present invention, in the impact tool, the cam mechanism is provided on the spindle, and extends in a continuous manner from one rear end through the front end to the other rear end, and the inner circumference of the hammer. Including a hammer cam groove formed on the side, a cam ball disposed in the spindle cam groove and the hammer cam groove, and the spindle is provided with only one spindle cam groove. A rolling member such as a bearing or a sliding member such as a metal or an O-ring is provided between the outer peripheral surface of the spindle and the inner peripheral surface of the hammer.
本発明の他の特徴によれば、ハンマとアンビルの爪同士を順次打撃する低速動作モードと、１つずつ飛ばしながら打撃を行う中速動作モードと、２つずつ飛ばしながら打撃を行う高速動作モードを設けたので、打撃時の良好な操作フィーリングを維持しながら低出力状態から高出力状態までを広範に実現できた。特に、締め付けトルクが上昇しているのに対して離脱トルクは従来と同等のままなので、従来の製品と同様に片手で高出力のねじ締め作業が可能となる。  According to another aspect of the present invention, a low-speed operation mode in which hammers and anvil claws are successively hit, a medium-speed operation mode in which hits are made while skipping one by one, and a high-speed operation mode in which hits are made while skipping two by two. As a result, it was possible to realize a wide range from a low output state to a high output state while maintaining a good operation feeling when hitting. In particular, while the tightening torque is increased, the separation torque remains the same as the conventional one, so that a high output screw tightening operation can be performed with one hand as in the conventional product.
本発明によれば、スピンドルのカム溝を１つとすることで、スピンドルの径を太くすることなくカム溝の距離を十分稼ぐことが可能となり、ハンマの後退量（ハンマバック量）を稼ぐことが可能となる。また、別の本発明によれば、ハンマとスピンドルの収容部又はハンマとハウジングの間にハンマのスピンドルに対する傾きを規制する規制部を設けたことで、ハンマとスピンドルの収容部又はハンマとハウジングの間の隙間を減らすことができるため、スピンドルに対するハンマの傾きを防止してスピンドルのガタツキを十分に抑制することが可能となり、ハンマの摺動特性及び耐久性を大きく向上させることができる。より具体的には、従来のインパクト工具では２つのカムボールにより、ハンマをスピンドルに２点支持することでハンマのスピンドルに対するガタツキを防止していたが、本発明ではカムボールを一つとすると共に、ハンマとスピンドルの収容部又はハンマとハンマケースの間にニードルベアリング等の転動部材を設けたので、スピンドルがスチールボールと転動部材による多点支持となり、ハンマの摺動特性を大幅に向上させることが可能になった。この結果、スピンドルに対するハンマの傾きを防止してスピンドルのガタツキの十分な抑制が可能となり、耐久性も大きく向上した。特に、ハンマのガタツキを抑制する支持部材（摺動部材又は転動部材）をハンマの外側に設けるようにすれば、インパクト工具の胴体部の全長（ハンマやスピンドルの全長）の短縮が図れ、しかもハンマケース内からのグリス漏れを大幅に抑制することができる。  According to the present invention, by using one spindle cam groove, it is possible to earn a sufficient cam groove distance without increasing the diameter of the spindle, and it is possible to earn a hammer retraction amount (hammer back amount). It becomes possible. Further, according to another aspect of the present invention, a regulation part for regulating the inclination of the hammer with respect to the spindle between the hammer and the spindle accommodating part or between the hammer and the housing is provided. Since the gap between them can be reduced, the inclination of the hammer with respect to the spindle can be prevented, and the play of the spindle can be sufficiently suppressed, and the sliding characteristics and durability of the hammer can be greatly improved. More specifically, in the conventional impact tool, the hammer is supported by the two spindles on the spindle by two cam balls to prevent the hammer from rattling against the spindle. Since a rolling member such as a needle bearing is provided between the housing part of the spindle or the hammer and the hammer case, the spindle is supported at multiple points by the steel ball and the rolling member, which can greatly improve the sliding characteristics of the hammer. It became possible. As a result, the tilt of the hammer with respect to the spindle can be prevented and the play of the spindle can be sufficiently suppressed, and the durability has been greatly improved. In particular, if a support member (sliding member or rolling member) that suppresses rattling of the hammer is provided outside the hammer, the overall length of the body of the impact tool (the total length of the hammer and spindle) can be shortened. Grease leakage from the inside of the hammer case can be greatly suppressed.
本発明の実施例に係るインパクト工具１の内部構造を示す縦断面図である。It is a longitudinal cross-sectional view which shows the internal structure of the impact tool 1 which concerns on the Example of this invention. 図１の打撃部及び被打撃部の展開斜視図である。FIG. 2 is a developed perspective view of a hitting part and a hit part of FIG. 1. 図１のインパクト工具１の打撃部の断面図である。It is sectional drawing of the striking part of the impact tool 1 of FIG. 図２のスピンドル３０とハンマ４０の組立体の正面図であるFIG. 3 is a front view of an assembly of the spindle 30 and the hammer 40 of FIG. 2. 図１のインパクト工具１の打撃部の断面図であって、（１）はハンマ４０が通常位置にある状態を示し、（２）はハンマ４０が後退時の状態を示す。It is sectional drawing of the striking part of the impact tool 1 of FIG. 1, Comprising: (1) shows the state in which the hammer 40 exists in a normal position, (2) shows the state at the time of the hammer 40 retreating. 図１のハンマ４０に設けられるニードルベアリング５６付近の部分拡大断面図である。It is a partial expanded sectional view of the needle bearing 56 vicinity provided in the hammer 40 of FIG. 図１のスピンドル３０単体を示す図であり、（１）上面図であり、（２）は底面図である。It is a figure which shows the spindle 30 single-piece | unit of FIG. 1, (1) It is a top view, (2) is a bottom view. スピンドルのカム溝の形状を示す展開図であり、（１）は従来のスピンドルカム溝２３３、２３４を示し、（２）は本実施例のスピンドルカム溝３３を示す。It is an expanded view which shows the shape of the cam groove of a spindle, (1) shows the conventional spindle cam groove 233,234, (2) shows the spindle cam groove 33 of a present Example. 本発明の実施例に係るインパクト工具１における打撃エネルギーＥと離脱トルクＴＢの関係を示す図である。It is a diagram showing the relationship between impact energy E and the detachable torque T B in the impact tool 1 according to an embodiment of the present invention. 従来のインパクト工具２０１と本実施例に係るインパクト工具１における打撃機構の数値を示す比較表である。It is a comparison table | surface which shows the numerical value of the impact mechanism in the conventional impact tool 201 and the impact tool 1 which concerns on a present Example. 本発明の実施例に係るインパクト工具１におけるハンマ４０、アンビル６０による打撃状態を示す図であって、（１）は連続打撃時であり、（２）は一つ飛ばし打撃時の状態であり、（３）は二つ飛ばし打撃時の状態である。It is a figure which shows the hammering state by the hammer 40 and the anvil 60 in the impact tool 1 which concerns on the Example of this invention, Comprising: (1) is at the time of continuous hitting, (2) is the state at the time of one blow hitting, (3) is the state when two shots are hit. 本発明の実施例の変形例に係るスピンドルのカム溝形状を示す図である。It is a figure which shows the cam groove shape of the spindle which concerns on the modification of the Example of this invention. 本発明の実施例の変形例を示す図であり、ニードルベアリング５６に代えて、（１）は焼結メタル８５を用いた例であり、（２）はＯリング８６を用いた例を示す図である。It is a figure which shows the modification of the Example of this invention, it replaces with the needle bearing 56, (1) is an example using the sintered metal 85, (2) is a figure which shows the example using the O-ring 86. It is. 本発明の実施例の変形例に係るハンマ４０Ｄの正面図である。It is a front view of hammer 40D concerning the modification of the example of the present invention. 本発明の第二の実施例に係るインパクト工具１０１の内部構造を示す縦断面図である。It is a longitudinal cross-sectional view which shows the internal structure of the impact tool 101 which concerns on the 2nd Example of this invention. 図１５のハンマ１４０の後退時の状態を示す部分縦断面図である。It is a fragmentary longitudinal cross-section which shows the state at the time of backward movement of the hammer 140 of FIG. 図１５のインパクト工具１０１の打撃部付近の縦断面図であって、（１）はハンマ１４０が通常位置にある状態を示し、（２）はハンマ１４０が後退時の状態を示す。FIGS. 15A and 15B are longitudinal sectional views in the vicinity of an impact portion of the impact tool 101 in FIG. 15, where FIG. 15A shows a state in which the hammer 140 is in a normal position, and FIG. 本発明の第二の実施例の第一変形例に係るインパクト工具１０１Ａの部分縦断面図であって、（１）はハンマ１４０が通常位置にある状態を示し、（２）はハンマ１４０が後退時の状態を示す。It is a fragmentary longitudinal cross-sectional view of impact tool 101A which concerns on the 1st modification of 2nd Example of this invention, Comprising: (1) shows the state in which the hammer 140 exists in a normal position, (2) shows the hammer 140 retracting | retreating Indicates the state of the hour. 本発明の第二の実施例の第二変形例に係るインパクト工具１０１Ｂの部分縦断面図であり、ハンマ１４０が通常位置にある状態を示す。It is a fragmentary longitudinal cross-sectional view of the impact tool 101B which concerns on the 2nd modification of the 2nd Example of this invention, and shows the state which has the hammer 140 in a normal position. 図１９の打撃部及び被打撃部の展開斜視図である。FIG. 20 is a developed perspective view of the hitting part and the hit part of FIG. 19. 本発明の第二の実施例の第三変形例に係るインパクト工具１０１Ｃの部分縦断面図である。It is a fragmentary longitudinal cross-sectional view of impact tool 101C concerning the 3rd modification of the 2nd example of the present invention. 従来のインパクト工具２０１の内部構造を示す縦断面図である。It is a longitudinal cross-sectional view which shows the internal structure of the conventional impact tool 201. FIG. 従来のインパクト工具２０１の打撃部の断面図であって、（１）はハンマ２４０が通常位置にある状態を示し、（２）はハンマ２４０が後退時の状態を示す。It is sectional drawing of the hit | damage part of the conventional impact tool 201, (1) shows the state in which the hammer 240 exists in a normal position, (2) shows the state at the time of the hammer 240 retreating.
以下、本発明の実施例を図面に基づいて説明する。尚、以下の図において、同一の部分には同一の符号を付し、繰り返しの説明は省略する。また、本明細書においては、前後、上下の方向は図中に示す方向であるとして説明する。  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same portions are denoted by the same reference numerals, and repeated description is omitted. Further, in the present specification, description will be made assuming that the front and rear directions and the up and down directions are directions shown in the drawing.
図１は本発明の実施例に係るインパクト工具１の内部構造を示す縦断面図である。基本的な構成は、図２２で示した従来のインパクト工具２０１と同じであり、ここではスピンドル３０とハンマ４０の構成や形状が異なり、それらの形状変更に合わせるために、ハンマケース３等の寸法をやや修正し、ハンマスプリング５４等の特性を変更したものである。インパクト工具１のハウジングは、本体ハウジング２（２ａ～２ｃ）とそれに設けられるハンマケース３によって構成される。ハンマケース３の先端には、弾力性のある素材でできた弾性カバー５が設けられる。モータ４はユニバーサルモータであって、その回転軸４ａは、減速機構２０及びスピンドル３０の軸線Ａ１と同軸上に配置される。尚、本発明ではモータ４の種類は問われずに、インバータ回路を用いてブラシレスＤＣモータを駆動するもの、その他の電気モータや任意の駆動源によって駆動するようにしても良い。モータ４の回転軸４ａは前端側と後端側にて２つのボールベアリングによる軸受１８ａ、１８ｂによって軸支される。ハンマケース３は、減速機構２０と打撃機構（スピンドル３０、ハンマ４０等）と被打撃機構（アンビル６０）を収容するための先細り形状の円筒状の金属製のケースであって、それらの回転中心が軸線Ａ１に並ぶように配置する。モータ４の回転軸４ａは、その軸線Ａ１が胴体部２ａの長手方向に伸びるように配置される。アンビル６０の先端には断面形状が六角形の装着孔６１ａが形成され、ワンタッチ装着式のビット保持部７０により先端工具が保持される。アンビル６０は被打撃部たる羽根部６３と出力軸部６１を一体に形成したもので、出力軸部６１には装着される先端工具を保持するための２つのスチールボール６９が設けられる。  FIG. 1 is a longitudinal sectional view showing an internal structure of an impact tool 1 according to an embodiment of the present invention. The basic configuration is the same as that of the conventional impact tool 201 shown in FIG. 22. Here, the configurations and shapes of the spindle 30 and the hammer 40 are different, and the dimensions of the hammer case 3 and the like are adjusted in accordance with the shape change. Is slightly modified to change the characteristics of the hammer spring 54 and the like. The housing of the impact tool 1 is constituted by a main body housing 2 (2a to 2c) and a hammer case 3 provided thereon. An elastic cover 5 made of an elastic material is provided at the tip of the hammer case 3. The motor 4 is a universal motor, and its rotating shaft 4a is arranged coaxially with the axis A1 of the speed reduction mechanism 20 and the spindle 30. In the present invention, the type of the motor 4 is not limited, and it may be driven by an inverter circuit that drives a brushless DC motor, other electric motors, or an arbitrary drive source. The rotating shaft 4a of the motor 4 is supported by bearings 18a and 18b of two ball bearings on the front end side and the rear end side. The hammer case 3 is a tapered cylindrical metal case for housing the speed reduction mechanism 20, the striking mechanism (spindle 30, hammer 40, etc.) and the striking mechanism (anvil 60), and the rotation center thereof. Are arranged along the axis A1. The rotation shaft 4a of the motor 4 is arranged such that its axis A1 extends in the longitudinal direction of the body portion 2a. A mounting hole 61 a having a hexagonal cross section is formed at the tip of the anvil 60, and the tip tool is held by the one-touch mounting type bit holder 70. The anvil 60 is integrally formed with a blade portion 63 as an impacted portion and an output shaft portion 61, and the output shaft portion 61 is provided with two steel balls 69 for holding a tip tool to be mounted.
モータ４の回転駆動力は、回転軸４ａから減速機構２０を介して打撃機構に伝達される。減速機構２０はモータ４の出力をスピンドル３０に伝達するものであり、ここでは、遊星歯車を用いた減速機構２０が用いられる。減速機構２０は、モータ４の回転軸４ａの先端に固定されるサンギヤ２１と、サンギヤ２１の外周側に距離を隔てて取り囲むように設けたリングギヤ２３と、サンギヤ２１及びリングギヤ２３の間に配置され、これら双方のギヤに噛み合わされる複数（ここでは３つ）のプラネタリーギヤ２２を含んで構成される。３つのプラネタリーギヤ２２はシャフトの回りを自転しつつサンギヤ２１の回りを公転する。リングギヤ２３は本体ハウジング２側に固定されるもので非回転部材である。３つのプラネタリーギヤ２２の各シャフトは、スピンドル３０の後端部分に形成された遊星キャリア部（図２で後述するフランジ部３７、３８）に固定され、プラネタリーギヤ２２の公転運動が遊星キャリア部の回転運動に変換されるためスピンドル３０が回転する。スピンドル３０の後端の円筒部３９は、ボールベアリング等の軸受１９ｂによって軸支される。  The rotational driving force of the motor 4 is transmitted from the rotating shaft 4a to the striking mechanism via the speed reduction mechanism 20. The speed reduction mechanism 20 transmits the output of the motor 4 to the spindle 30. Here, the speed reduction mechanism 20 using a planetary gear is used. The speed reduction mechanism 20 is disposed between a sun gear 21 fixed to the tip of the rotating shaft 4 a of the motor 4, a ring gear 23 provided to surround the outer periphery of the sun gear 21 at a distance, and the sun gear 21 and the ring gear 23. A plurality (three in this case) of planetary gears 22 meshed with both of these gears are configured. The three planetary gears 22 revolve around the sun gear 21 while rotating around the shaft. The ring gear 23 is fixed to the main body housing 2 side and is a non-rotating member. The shafts of the three planetary gears 22 are fixed to planetary carrier portions ( flange portions 37 and 38, which will be described later with reference to FIG. 2) formed at the rear end portion of the spindle 30, and the revolving motion of the planetary gears 22 is caused by the planetary carrier. The spindle 30 rotates because it is converted into the rotational motion of the part. The cylindrical portion 39 at the rear end of the spindle 30 is supported by a bearing 19b such as a ball bearing.
スピンドル３０は、減速機構２０の遊星キャリア部の前方側に配置される。本実施例では、スピンドルカム溝３３として側面視で略Ｖ字状の溝が形成されるが、図２２で示した従来のスピンドルカム溝２３３、２３４が２組設けられるのに対して、本実施例のインパクト工具１では、１組のスピンドルカム溝３３がスピンドル３０に設けられる。スピンドルカム溝３３にはカムボール５１が転動するため、その窪みの断面形状は半円状とされる。本実施例では、スピンドルカム溝３３を１組としたため、用いられるカムボール５１の数も１つである。このためスピンドル軸部３１（符号は後述の図２参照）を従来と同じにしながら、ハンマ４０の後退量を従来よりも大幅に大きくすることが可能となった。  The spindle 30 is disposed on the front side of the planetary carrier portion of the speed reduction mechanism 20. In the present embodiment, a substantially V-shaped groove is formed as the spindle cam groove 33 in a side view, but in contrast to the two conventional spindle cam grooves 233 and 234 shown in FIG. In the example impact tool 1, a set of spindle cam grooves 33 is provided in the spindle 30. Since the cam ball 51 rolls in the spindle cam groove 33, the recess has a semicircular cross section. In this embodiment, since the spindle cam groove 33 is set as one set, the number of cam balls 51 used is also one. For this reason, it is possible to make the retraction amount of the hammer 40 significantly larger than the conventional one while the spindle shaft portion 31 (refer to FIG. 2 described later) is the same as the conventional one.
本体ハウジング２の拡径部２ｃの内部には、トリガ６ａの引き動作によってモータ４の速度を制御する機能を備えた制御回路基板９が収容される。制御回路基板９は略水平になるように配置され、打撃トルクを切り換えるための出力切替スイッチ１２が設けられる。  A control circuit board 9 having a function of controlling the speed of the motor 4 by the pulling operation of the trigger 6a is accommodated in the enlarged diameter portion 2c of the main body housing 2. The control circuit board 9 is arranged so as to be substantially horizontal, and is provided with an output changeover switch 12 for switching the striking torque.
図２は、図１の打撃部及び被打撃部の展開斜視図である。前方側からアンビル６０、ハンマ４０、スピンドル３０の順に配置されるという基本構成は、図２２にて示した従来のインパクト工具２０１と同じ構成である。しかしながら用いられるカムボール５１は２つから１つに削減されている。カムボール５１を１つにしたことによりスピンドル３０に形成されるスピンドルカム溝３３の形状も変更される。さらに、ハンマ４０の内周側であって、スピンドル軸部３１の外周面と当接する位置にはニードルベアリング５６が装着される。  FIG. 2 is a developed perspective view of the hitting part and the hit part of FIG. 1. The basic configuration in which the anvil 60, the hammer 40, and the spindle 30 are arranged in this order from the front side is the same configuration as the conventional impact tool 201 shown in FIG. However, the number of cam balls 51 used is reduced from two to one. By forming one cam ball 51, the shape of the spindle cam groove 33 formed in the spindle 30 is also changed. Further, a needle bearing 56 is mounted at a position on the inner peripheral side of the hammer 40 and in contact with the outer peripheral surface of the spindle shaft portion 31.
アンビル６０はインパクト工具１の出力軸を形成すると共に、ハンマ４０の被打撃部を形成するものであって、出力軸と被打撃部が一体に形成される。アンビル６０は鋳造又は鍛造後に切削加工をすることにより製造される金属の一体品であって、その円筒形の出力軸部６１の後方に、３つの羽根部６３ａ～６３ｃによる被打撃爪が形成されたものである。出力軸部６１の前側端部から内側部分には、断面形状が六角形であって先端工具を装着するための装着孔６１ａが形成される。装着孔６１ａが形成される細径部６１ｂは、ビット保持部７０を設けるために形成されるもので、細径部６１ｂの後方には径方向に貫通する２つの貫通穴６１ｃが形成され、ビット保持部７０の構成要素となるスチールボール６９（図１参照）が配置される。軸方向に見て貫通穴６１ｃと羽根部６３ａ～６３ｃとの間は研磨された円柱面とされ、この領域の外周側にニードルベアリング１９ａ（図１参照）が配置されることによりアンビル６０はハンマケース３（図１参照）に回転可能に軸支される。羽根部６３ａ～６３ｃは、回転方向に見て１２０度ずつ隔てるように均等に配置された被打撃爪であり、径方向外側に伸びるように配置される。羽根部６３ａ～６３ｃの回転方向の側面は、ハンマ４０の打撃爪によって締め付け方向の回転時に打撃される被打撃面６４ａ～６４ｃと、その反対側に形成され緩め方向の回転時に打撃される被打撃面６５ａ～６５ｃが形成される。被打撃部の後方側には、円筒状の軸部６６（図１参照）が形成され、軸部６６がスピンドル３０の嵌合孔３２に係合することよってアンビル６０とスピンドル３０が相対回転可能な状態で接続される。  The anvil 60 forms an output shaft of the impact tool 1 and forms a hit portion of the hammer 40, and the output shaft and the hit portion are integrally formed. The anvil 60 is an integral part of a metal manufactured by cutting after casting or forging, and a hitting claw by three blade portions 63a to 63c is formed behind the cylindrical output shaft portion 61. It is a thing. A mounting hole 61a for mounting the tip tool is formed in the inner portion from the front end portion of the output shaft portion 61 in cross section. The small diameter portion 61b in which the mounting hole 61a is formed is formed to provide the bit holding portion 70, and two through holes 61c penetrating in the radial direction are formed behind the small diameter portion 61b. A steel ball 69 (see FIG. 1), which is a component of the holding unit 70, is disposed. A portion between the through hole 61c and the blades 63a to 63c as viewed in the axial direction is a polished cylindrical surface, and a needle bearing 19a (see FIG. 1) is disposed on the outer peripheral side of this region, whereby the anvil 60 is hammered. The case 3 (see FIG. 1) is rotatably supported. The blade portions 63a to 63c are hitting claws that are evenly arranged so as to be separated by 120 degrees when viewed in the rotation direction, and are arranged so as to extend radially outward. The side surfaces in the rotational direction of the blade portions 63a to 63c are hitting surfaces 64a to 64c which are hit by the hammering pawls of the hammer 40 when rotating in the tightening direction, and hits which are formed on the opposite side and hit when rotating in the loosening direction. Surfaces 65a to 65c are formed. A cylindrical shaft portion 66 (see FIG. 1) is formed on the rear side of the hit portion, and the anvil 60 and the spindle 30 can be rotated relative to each other by engaging the shaft portion 66 with the fitting hole 32 of the spindle 30. Connected in a normal state.
ハンマ４０は、スピンドル３０にて保持される部材であり、前方側からスピンドル３０に装着される。ハンマ４０は理想的にはスピンドル３０に対して浮いた状態、又は、非接触状態の姿勢を保つように保持され、従来のスピンドル２３０では浮かす状態、非接触状態を保つために２つのカムボール２５１、２５２（図２２参照）が用いられていた。本実施例ではカムボールの数を一つ減らした一方で、スピンドル軸部３１の外周面とハンマ４０の内周面にニードルベアリング５６を配置した。ニードルベアリング５６はハンマ４０側又はスピンドル３０のいずれか側に固定できるが、本実施例ではハンマ４０側に固定する。尚、図２ではニードルベアリング５６の内周側の形状、特に針状ころ等の図示を省略しているので注意されたい。ハンマ４０の前面４２ａの外周側の３カ所には、軸方向の前方側（アンビル６０側）に突出する３つの打撃爪４６ａ～４６ｃが形成される。打撃爪４６ａ～４６ｃは、回転方向に見てその中心位置が回転角で１２０度ずつ隔てるように均等に配置される。打撃爪４６ａ～４６ｃの回転方向にみて２つの側面は、アンビル６０の３つの羽根部６３ａ～６３ｃと衝突時に良好に面接触するように回転方向に所定の角度が付けられたもので、一方側（４７ａ～４７ｃ）が締め付け方向時の打撃面となり、他方側（４８ａ～４８ｃ）が緩め方向時の打撃面となる。ハンマ４０の外周部は筒状部分４３とされ、中央部には貫通孔４１ａを有する。貫通孔４１ａを形成する内周側であって前方側にはハンマカム溝４４が形成される。ハンマカム溝４４は、ハンマ４０の内周面を平面に展開した際に略台形状の輪郭を有する窪みであって、スピンドルカム溝３３と共にカムボール５１の動きを制限する空間を形成する。ハンマ４０の内周面の周方向の一箇所において、隣接するハンマカム溝４４の辺部を分離する壁部４５が形成される。壁部４５は前端側のスピンドル３０の外周面と隣接又は当接する箇所となり、ハンマ４０がスピンドル３０に対する相対回転の姿勢維持に貢献する。ハンマ４０の壁部４５と周方向に対向する箇所には、組立時にカム溝内にカムボール５１を挿入するための挿入溝４４ａが形成される。第１の筒状部分とスピンドル軸部３１とが対向する箇所が本発明における第１の規制部に該当し、第１の規制部はハンマ４０のスピンドル３０に対する径方向の移動を規制する。  The hammer 40 is a member that is held by the spindle 30 and is attached to the spindle 30 from the front side. The hammer 40 is ideally held so as to be in a floating state or a non-contact state with respect to the spindle 30, and in order to maintain a floating state and a non-contact state in the conventional spindle 230, two cam balls 251, 252 (see FIG. 22) was used. In this embodiment, the number of cam balls is reduced by one, while needle bearings 56 are arranged on the outer peripheral surface of the spindle shaft portion 31 and the inner peripheral surface of the hammer 40. The needle bearing 56 can be fixed to either the hammer 40 side or the spindle 30 side, but is fixed to the hammer 40 side in this embodiment. Note that in FIG. 2, the shape of the inner peripheral side of the needle bearing 56, in particular, the illustration of needle rollers and the like is omitted. Three hitting claws 46a to 46c are formed at three locations on the outer peripheral side of the front surface 42a of the hammer 40 so as to protrude forward in the axial direction (anvil 60 side). The hitting claws 46a to 46c are equally arranged so that their center positions are separated by 120 degrees in rotation angle when viewed in the rotation direction. The two side surfaces of the hitting claws 46a to 46c in the rotational direction are given a predetermined angle in the rotational direction so as to make good surface contact with the three blade parts 63a to 63c of the anvil 60 at the time of collision. (47a to 47c) is a striking surface in the tightening direction, and the other side (48a to 48c) is a striking surface in the loosening direction. The outer periphery of the hammer 40 is a cylindrical portion 43 and has a through hole 41a at the center. A hammer cam groove 44 is formed on the inner peripheral side forming the through hole 41a and on the front side. The hammer cam groove 44 is a recess having a substantially trapezoidal outline when the inner peripheral surface of the hammer 40 is developed into a plane, and forms a space that restricts the movement of the cam ball 51 together with the spindle cam groove 33. A wall portion 45 that separates the side portions of the adjacent hammer cam grooves 44 is formed at one place in the circumferential direction of the inner peripheral surface of the hammer 40. The wall 45 is a portion adjacent to or in contact with the outer peripheral surface of the spindle 30 on the front end side, and the hammer 40 contributes to maintaining the posture of relative rotation with respect to the spindle 30. An insertion groove 44a for inserting the cam ball 51 into the cam groove at the time of assembly is formed at a location facing the wall portion 45 of the hammer 40 in the circumferential direction. A location where the first cylindrical portion and the spindle shaft portion 31 face each other corresponds to the first restricting portion in the present invention, and the first restricting portion restricts the movement of the hammer 40 relative to the spindle 30 in the radial direction.
スピンドル３０の円柱部分、即ちスピンドル軸部３１の外周面には、スピンドルカム溝３３が１つだけ形成される。スピンドルカム溝３３は、ハンマ４０の内周面に形成されたハンマカム溝４４に対向する位置に設けられる。スピンドル３０とハンマ４０は、スピンドルカム溝３３とハンマカム溝４４によって所定の空間が形成されるように組み合わされる。カム機構によってハンマ４０はスピンドル３０とほぼ連動するように回転するが、カムボール５１が１つであるためそのままではハンマ４０のスピンドル３０に対する回転方向及び軸方向の相対位置が安定しないため、本実施例ではニードルベアリング５６が併用される。ニードルベアリング５６は、スピンドル３０に対するハンマ４０の軸方向移動、及び、周方向の回転を支持するものである。本実施例において、スピンドルカム溝３３、カムボール５１及びハンマカム溝４４からなるカム機構は、ハンマ４０のスピンドル３０に対する軸方向の移動を規制する第２の規制部に該当する。  Only one spindle cam groove 33 is formed on the cylindrical portion of the spindle 30, that is, on the outer peripheral surface of the spindle shaft portion 31. The spindle cam groove 33 is provided at a position facing the hammer cam groove 44 formed on the inner peripheral surface of the hammer 40. The spindle 30 and the hammer 40 are combined so that a predetermined space is formed by the spindle cam groove 33 and the hammer cam groove 44. The hammer 40 is rotated by the cam mechanism so as to be substantially interlocked with the spindle 30. However, since the cam ball 51 is one, the relative position in the rotation direction and the axial direction of the hammer 40 with respect to the spindle 30 is not stable as it is. Then, the needle bearing 56 is used together. The needle bearing 56 supports the axial movement of the hammer 40 relative to the spindle 30 and the rotation in the circumferential direction. In this embodiment, the cam mechanism including the spindle cam groove 33, the cam ball 51, and the hammer cam groove 44 corresponds to a second restricting portion that restricts the movement of the hammer 40 relative to the spindle 30 in the axial direction.
スピンドル軸部３１の前方端部には、アンビル６０の軸部６６が嵌挿されるための嵌合孔３２が形成され、スピンドル軸部３１の後方側には、減速機構２０の遊星キャリア部となるフランジ部３７、３８が形成される。フランジ部３７は軸線Ａ１とは直交する円盤状であって、回転方向には均等間隔で３つの嵌合穴３７ａ～３７ｃが形成される。フランジ部３７と所定の距離を隔てて後方側には、フランジ部３７と平行となるように円盤状のフランジ部３８が設けられる。フランジ部３８にも回転方向には均等間隔で３つの嵌合穴３８ａ～３８ｃ（図では３８ａしか見えない）が形成され、フランジ部３７の嵌合穴３７ａ～３７ｃと共に、プラネタリーギヤ２２を軸支するシャフトを固定する。  A fitting hole 32 for fitting the shaft portion 66 of the anvil 60 is formed in the front end portion of the spindle shaft portion 31, and the planetary carrier portion of the speed reduction mechanism 20 is formed on the rear side of the spindle shaft portion 31. Flange portions 37 and 38 are formed. The flange portion 37 has a disk shape orthogonal to the axis A1, and three fitting holes 37a to 37c are formed at equal intervals in the rotation direction. A disc-shaped flange portion 38 is provided on the rear side with a predetermined distance from the flange portion 37 so as to be parallel to the flange portion 37. The flange portion 38 is also formed with three fitting holes 38a to 38c (only 38a can be seen in the figure) at equal intervals in the rotation direction, and together with the fitting holes 37a to 37c of the flange portion 37, the planetary gear 22 is pivoted. Fix the supporting shaft.
図３はインパクト工具１の打撃部の断面図である。ハンマ４０はスピンドル３０に対して軸線Ａ１を中心として所定の角度だけ相対回転が可能であり、かつ、軸方向にも相対回転が可能である。図３の状態はスピンドル３０に対してハンマ４０が最も前側に位置している状態である。ハンマ４０は、内径の異なる２つの筒状部分４１、４３の前方側を接続部４２にて径方向につなげたような形状とされる。ここではハンマ４０は金属製であり、その直径（外径）は３５～４４ｍｍ程度、イナーシャは０．３９ｋｇ・ｃｍ２[０.０００３８Ｎ・ｍ２]以下となるように構成すると良い。スピンドル３０におけるモータ４側の端部には、軸線Ａ１に沿った方向で前方側に窪む嵌合孔３４が形成され、サンギヤ２１の収容空間とされる。一方、スピンドル３０のアンビル６０側の端部には、軸線Ａ１に沿って後方に窪むように形成された円柱状の嵌合孔３２が形成される。本実施例においては、筒状部分４１及び壁部４５が本発明の第１の筒状部分に、筒所部分４３が本発明の第２の筒状部分に該当する。  FIG. 3 is a cross-sectional view of the impact portion of the impact tool 1. The hammer 40 can be relatively rotated with respect to the spindle 30 about the axis A1 by a predetermined angle, and can also be relatively rotated in the axial direction. The state shown in FIG. 3 is a state where the hammer 40 is located at the most front side with respect to the spindle 30. The hammer 40 has a shape in which the front sides of the two cylindrical portions 41 and 43 having different inner diameters are connected in the radial direction by the connection portion 42. Here, the hammer 40 is made of metal, and its diameter (outer diameter) is preferably about 35 to 44 mm, and the inertia is preferably 0.39 kg · cm 2 [0.000003 N · m 2 ] or less. A fitting hole 34 that is recessed forward in the direction along the axis A <b> 1 is formed at the end of the spindle 30 on the motor 4 side, and serves as a housing space for the sun gear 21. On the other hand, a cylindrical fitting hole 32 is formed at the end of the spindle 30 on the anvil 60 side so as to be recessed rearward along the axis A1. In the present embodiment, the tubular portion 41 and the wall portion 45 correspond to the first tubular portion of the present invention, and the tubular portion 43 corresponds to the second tubular portion of the present invention.
ハンマスプリング５４は圧縮スプリングであり、その前方側には複数のスチールボール５２がワッシャ５３に押さえられた状態で配置され、その後方側は段差付きのワッシャ５５によってスピンドル３０のフランジ部３７にて保持される。ワッシャ５５の内周側においては、中央をハンマ４０の内側の筒状部分４１の後端部４１ｃが貫通できるようにくり抜き孔５５ａが形成される。ここでは図示していないが、段差付きのワッシャ５５の内周側にゴム等の弾性体で構成されるダンパを配置して、ハンマ４０の最大後退時におけるハンマ４０とフランジ部３７との衝突による衝撃を抑制しても良い。ハンマ４０とフランジ部３７との衝突を回避するようにすれば、スピンドルカム溝３３内においてカムボール５１が端部に衝突することも回避できる。 The hammer spring 54 is a compression spring, and a plurality of steel balls 52 are disposed on the front side of the hammer spring 54 while being pressed by the washer 53, and the rear side thereof is held by the flange portion 37 of the spindle 30 by a stepped washer 55. Is done. On the inner peripheral side of the washer 55, a hollow hole 55 a is formed so that the rear end portion 41 c of the cylindrical portion 41 inside the hammer 40 can penetrate the center. Although not shown here, a damper made of an elastic body such as rubber is arranged on the inner peripheral side of the stepped washer 55 so that the hammer 40 and the flange portion 37 are collided when the hammer 40 is fully retracted. You may suppress an impact. If the collision between the hammer 40 and the flange portion 37 is avoided, it is possible to avoid the cam ball 51 from colliding with the end portion in the spindle cam groove 33.
ハンマ４０は、カムボール５１を介したスピンドル３０への接続と、壁部４５とスピンドル３０の当接によって、がたつきかないように保持される。ハンマ４０は、スピンドル３０に対して軸方向に移動可能であり、特に後方側には大きく移動可能とされる。ハンマ４０は、ハンマスプリング５４（図１参照）によってスピンドル３０に対して常に前方側に付勢されるので、ハンマ４０の後方側への移動はハンマスプリング５４を圧縮しながらの移動となる。しかしながら、本実施例の構成ではカムボール５１は１つであるので、ハンマ４０の前端部の壁部４５も周方向に１箇所だけとなる。そこで、本実施例では、ハンマ４０とスピンドル３０の相対位置関係を安定させるために、ハンマ４０の内周側の後端部４１ｃ付近にニードルベアリング５６を取りつけた。ニードルベアリング５６は、外輪がハンマ４０側に固定され、内側に設けられる複数の針状ころがスピンドル３０の外周面と接触する。このようにニードルベアリング５６を設けたことによって、スピンドル３０の外周面とニードルベアリング５６が常に良好な当接状態を保つので、それ以外の接触箇所、即ちカムボール５１を介した保持と、壁部４５による保持によってハンマ４０の姿勢が良好に保持され、ハンマ４０のスムーズな動きが実現できる。  The hammer 40 is held so as not to rattle by the connection to the spindle 30 via the cam ball 51 and the contact between the wall 45 and the spindle 30. The hammer 40 is movable in the axial direction with respect to the spindle 30, and can be largely moved particularly on the rear side. Since the hammer 40 is always urged forward by the hammer spring 54 (see FIG. 1) with respect to the spindle 30, the movement of the hammer 40 toward the rear side is a movement while compressing the hammer spring 54. However, since there is only one cam ball 51 in the configuration of the present embodiment, the wall portion 45 at the front end portion of the hammer 40 is only one in the circumferential direction. Therefore, in this embodiment, in order to stabilize the relative positional relationship between the hammer 40 and the spindle 30, the needle bearing 56 is attached in the vicinity of the rear end portion 41c on the inner peripheral side of the hammer 40. In the needle bearing 56, the outer ring is fixed to the hammer 40 side, and a plurality of needle rollers provided inside contact with the outer peripheral surface of the spindle 30. By providing the needle bearing 56 in this way, the outer peripheral surface of the spindle 30 and the needle bearing 56 are always kept in a good contact state, so that the other contact portions, that is, holding via the cam ball 51, and the wall portion 45 are maintained. The position of the hammer 40 can be satisfactorily held by the holding, and a smooth movement of the hammer 40 can be realized.
図４はスピンドル３０とハンマ４０の組立体の正面図である。尚、図３の断面図は図４のＢ－Ｂ部の断面に相当するものである。ハンマ４０の前面４２ａは平面状になっており、周方向に等間隔で前面４２ａよりも軸方向前方に突出するように３つの打撃爪４６ａ～４６ｃが設けられる。打撃爪４６ａ～４６ｃの一方側の側面は、締め付け時の打撃面４７ａ～４７ｃとなり、他方側の側面、即ち、打撃面４８ａ～４８ｃは緩め時の打撃面となる。打撃面４７ａ～４７ｃと打撃面４８ａ～４８ｃは、ハンマ４０の後退を容易にするために軸線Ａ１を含む仮想面に対して略平行に形成される。ハンマ４０に形成されるハンマカム溝４４は、壁部４５を除いてほぼ一周分を示すように配置される。ハンマカム溝４４の一部であって壁部４５とは軸対称の位置付近には、組立時にカムボール５１を挿入するための挿入溝４４ａが形成される。図示しているカムボール５１は図示の位置から、一方向側（時計回り）又は他方向側（反時計回り）に半周分近く移動可能である。  FIG. 4 is a front view of the assembly of the spindle 30 and the hammer 40. Note that the cross-sectional view of FIG. 3 corresponds to a cross section taken along the line BB of FIG. The front surface 42a of the hammer 40 has a planar shape, and three striking claws 46a to 46c are provided so as to protrude forward in the axial direction from the front surface 42a at equal intervals in the circumferential direction. The side surfaces on one side of the hitting claws 46a to 46c become the hitting surfaces 47a to 47c when tightening, and the other side surfaces, ie the hitting surfaces 48a to 48c, become the hitting surfaces when loosened. The striking surfaces 47a to 47c and the striking surfaces 48a to 48c are formed substantially parallel to the virtual surface including the axis A1 in order to facilitate the retraction of the hammer 40. The hammer cam groove 44 formed in the hammer 40 is arranged so as to show substantially one round except for the wall portion 45. An insertion groove 44a for inserting the cam ball 51 at the time of assembly is formed in a part of the hammer cam groove 44 and in the vicinity of a position axially symmetric with respect to the wall 45. The cam ball 51 shown in the figure can move from the position shown in the drawing to one side (clockwise) or the other direction (counterclockwise) by nearly a half turn.
図５はインパクト工具１の打撃部の断面図であって、（１）はハンマ４０が通常位置にある状態を示し、（２）はハンマ４０が後退時の状態を示す。図５（１）は図３と同じ図であるが、ここにはスピンドルカム溝３３の前端位置から後端位置までの範囲をＲｇで示している。一方、ニードルベアリング５６の移動範囲をＲｂにて示している。ここで、溝の形成範囲Ｒｇとニードルベアリング５６の移動範囲Ｒｂを比較するとわかるように、それらは軸線Ａ１方向に一部が重複するような位置関係となる。本実施例のインパクト工具１では、カムボール５１を一つだけとしたため、スピンドルカム溝３３の形成のためにスピンドル軸部３１の外周面のほぼ一周分を利用できるため、スピンドルカム溝３３を十分長くすることができ、ハンマ４０の後退量が増大する。しかしながら、溝の形成範囲Ｒｇとニードルベアリング５６の移動範囲Ｒｂが軸方向に重なるようにしたことにより、溝の形成範囲Ｒｇを軸線Ａ１方向に長くしたにもかかわらずにスピンドル３０の大型化を抑制でき、従来のスピンドル２３０とさほど変わらないようなコンパクトな打撃機構が実現できた。  FIG. 5 is a cross-sectional view of the impacting portion of the impact tool 1, wherein (1) shows a state in which the hammer 40 is in a normal position, and (2) shows a state in which the hammer 40 is retracted. FIG. 5A is the same as FIG. 3, but here, the range from the front end position to the rear end position of the spindle cam groove 33 is indicated by R g . On the other hand, the movement range of the needle bearing 56 is indicated by Rb . Here, as can be seen by comparing the groove formation range Rg and the movement range Rb of the needle bearing 56, they are in a positional relationship such that a part thereof overlaps in the direction of the axis A1. In the impact tool 1 of the present embodiment, since only one cam ball 51 is provided, the spindle cam groove 33 can be made sufficiently long because almost one round of the outer peripheral surface of the spindle shaft portion 31 can be used for forming the spindle cam groove 33. The amount of retraction of the hammer 40 increases. However, by moving range R b of formation of the groove ranges R g and needle bearing 56 so as to overlap in the axial direction, a large spindle 30 in spite of a longer formation range R g groove in the axial direction A1 Thus, a compact striking mechanism that is not much different from the conventional spindle 230 can be realized.
スピンドル３０の静止時には、カムボール５１、スピンドルカム溝３３と、ハンマカム溝４４との係合位置と、ハンマスプリング５４との付勢力とのバランス関係によって、ハンマ４０の前面４２ａとアンビル６０の羽根部６３ａの後端面とは軸方向に僅かに隙間を隔てた位置にある。一方、アンビル６０の羽根部６３ａとハンマ４０の打撃爪４６ａは、軸線Ａ１方向にみて重なるような位置関係となる。ここで、係合量とは、軸線Ａ１の方向に見てハンマ４０の打撃爪４６ａ～４６ｃと、アンビル６０の羽根部６３ａ～６３ｃの当接領域の軸方向長さであって、静止時又は打撃前の初期位置においてその係合量が最大となる。係合量は、ハンマ４０の後方向の移動によって変化するもので、アンビル６０が先端工具側から受ける力によりハンマ４０に伝わる反トルクが大きくなると、カムボール５１の位置が移動することによりハンマ４０とアンビル６０の相対的位置関係が変化する。  When the spindle 30 is stationary, the front surface 42 a of the hammer 40 and the blade portion 63 a of the anvil 60 are determined by the balance between the engagement position of the cam ball 51, the spindle cam groove 33 and the hammer cam groove 44 and the biasing force of the hammer spring 54. The rear end face is located at a position slightly spaced in the axial direction. On the other hand, the blade portion 63a of the anvil 60 and the striking claw 46a of the hammer 40 are in a positional relationship such that they overlap when viewed in the direction of the axis A1. Here, the engagement amount refers to the axial length of the contact area between the striking claws 46a to 46c of the hammer 40 and the blade portions 63a to 63c of the anvil 60 as viewed in the direction of the axis A1. The engagement amount becomes maximum at the initial position before hitting. The amount of engagement changes due to the backward movement of the hammer 40. When the counter torque transmitted to the hammer 40 by the force received by the anvil 60 from the tip tool side increases, the position of the cam ball 51 moves and the hammer 40 moves. The relative positional relationship of the anvil 60 changes.
ハンマ４０がスピンドル３０に対して相対回転しながら、矢印４９の方向に後退しても、図５（２）に示すようにハンマ４０の筒状部分４１の後端部４１ｃが断面がＬ型のワッシャ５５の内側にまで後退することを許容する。従って、ニードルベアリング５６の移動空間を効率良く確保でき、スピンドル３０の全長が長くなることを抑制できる。また、スピンドル３０の主軸部の直径、ハンマ４０の内径及び外径は、従来のハンマ２４０と略同じであるので、容易に本発明を実施できる。  Even if the hammer 40 rotates relative to the spindle 30 and retreats in the direction of the arrow 49, the rear end portion 41c of the cylindrical portion 41 of the hammer 40 has an L-shaped cross section as shown in FIG. Retreating to the inside of the washer 55 is allowed. Therefore, the movement space of the needle bearing 56 can be secured efficiently, and the increase in the overall length of the spindle 30 can be suppressed. Moreover, since the diameter of the main shaft portion of the spindle 30 and the inner diameter and outer diameter of the hammer 40 are substantially the same as those of the conventional hammer 240, the present invention can be easily implemented.
図６はハンマ４０に設けられるニードルベアリング５６付近の部分拡大断面図である。ハンマ４０の内側の筒状部分４１の後端付近には段差部４１ｂが形成され、その段差部４１ｂにニードルベアリング５６が装着される。ニードルベアリング５６は、外輪がハンマ４０側に固定されるシェル５７となり、シェル５７によって囲まれる部分に複数の針状ころ５８が設けられ、針状ころ５８の外周面がスピンドル軸部３１と当接する。複数の針状ころ５８の回転軸５９は、軸線Ａ１と平行になるようにシェル５７にて軸支される。ここではハンマ４０の内周面とスピンドル３０との隙間は平均でＳ１程度となるが、ニードルベアリング５６の内側の針状ころ５８部分は、ほぼ０になる。尚、ハンマとスピンドルの周囲は、十分なグリスが塗布されているので、ニードルベアリング５６もグリスが満たされた環境下で使用できるものとすると良い。以上のように、ニードルベアリング等の転動部材を設けることにより、ハンマ４０のスピンドル軸部３１に対するガタツキを抑制することができ、１つのカムボール構成であってもスムーズな打撃動作が可能となる。本実施例においてはニードルベアリング５６等の転動部材が本発明の第３の規制部に該当し、第３の規制部はハンマ４０のスピンドル３０に対する傾きを規制する。  FIG. 6 is a partially enlarged cross-sectional view of the vicinity of the needle bearing 56 provided on the hammer 40. A stepped portion 41b is formed in the vicinity of the rear end of the cylindrical portion 41 inside the hammer 40, and a needle bearing 56 is attached to the stepped portion 41b. The needle bearing 56 becomes a shell 57 whose outer ring is fixed to the hammer 40 side, and a plurality of needle rollers 58 are provided in a portion surrounded by the shell 57, and the outer peripheral surface of the needle rollers 58 contacts the spindle shaft portion 31. . The rotation shafts 59 of the plurality of needle rollers 58 are pivotally supported by the shell 57 so as to be parallel to the axis A1. Although the order of S 1 is the gap between the inner peripheral surface and the spindle 30 of the hammer 40 on average here, the inner needle roller 58 portion of the needle bearing 56 becomes substantially zero. In addition, since sufficient grease is applied to the periphery of the hammer and the spindle, the needle bearing 56 may be used in an environment filled with grease. As described above, by providing a rolling member such as a needle bearing, rattling of the hammer 40 with respect to the spindle shaft portion 31 can be suppressed, and a smooth hitting operation is possible even with a single cam ball configuration. In this embodiment, the rolling member such as the needle bearing 56 corresponds to the third restricting portion of the present invention, and the third restricting portion restricts the inclination of the hammer 40 with respect to the spindle 30.
次に図７を用いてスピンドル３０の形状を説明する。図７（１）はスピンドル３０の上面図である。スピンドル３０は金属製であって、その直径Ｄは１０～１８ｍｍ程度とすると良く、ここでは１３．８ｍｍである。スピンドル３０の外周面には軸線Ａ１と直交する方向から見た際に前端部３３ｄから略Ｖ字状に後退するような形状とされる。スピンドルカム溝３３は前端部３３ｄから所定のカムリード角θを有する。本実施例では、ねじを締める時に用いられる正転用溝部３３ｂと、ねじを締める時に用いられる逆転用溝部３３ａのカムリード角θは同一角度とし、例えば２０～３６度の範囲内になるように設定される。カムリード角θが大きくなると、離脱トルクが多くなる上に打撃エネルギーが高くなる。一方、カムリード角θを小さくすると、離脱トルクが小さくなるが、打撃エネルギーも小さくなる。従って、離脱トルクを小さく抑えながら、できるだけ大きい打撃エネルギーが得られるようにすることが重要である。  Next, the shape of the spindle 30 will be described with reference to FIG. FIG. 7A is a top view of the spindle 30. The spindle 30 is made of metal, and its diameter D is preferably about 10 to 18 mm, and here it is 13.8 mm. The outer peripheral surface of the spindle 30 is shaped to recede from the front end portion 33d in a substantially V shape when viewed from the direction orthogonal to the axis A1. The spindle cam groove 33 has a predetermined cam lead angle θ from the front end portion 33d. In the present embodiment, the cam lead angle θ of the forward rotation groove 33b used when tightening the screw and the reverse rotation groove 33a used when tightening the screw is set to the same angle, for example, within a range of 20 to 36 degrees. The As the cam lead angle θ increases, the separation torque increases and the impact energy increases. On the other hand, when the cam lead angle θ is reduced, the separation torque is reduced, but the impact energy is also reduced. Therefore, it is important to obtain as much striking energy as possible while keeping the separation torque small.
図７（２）はスピンドル３０の底面図である。ここでは逆転用溝部３３ａの後端部３３ｃと正転用溝部３３ｂの後端部３３ｅは近接するまで延ばされるので、スピンドル軸部３１のほぼ一周分をスピンドルカム溝３３に使用できるので、従来のスピンドルカム溝２３３、２３４（図２２参照）の倍近い長さを確保できる。スピンドルカム溝３３の前端位置から後端位置までの軸方向の範囲Ｒｇに対して、ニードルベアリング５６の移動範囲Ｒｂは図示のように軸方向にオーバーラップする。そのため、ニードルベアリング５６はスピンドルカム溝３３のある部分まで移動することになる。スピンドルカム溝３３の占める範囲Ｒｇとニードルベアリング５６の移動範囲Ｒｂを軸方向に重ならないように並べて配置するように構成することも可能であるが、その場合はスピンドル３０の軸方向の長さが大きくなる。本発明では、範囲Ｒｇと移動範囲Ｒｂを部分的に重ねることによってスピンドル軸部３１の長さを抑制した。  FIG. 7 (2) is a bottom view of the spindle 30. Here, since the rear end portion 33c of the reverse rotation groove portion 33a and the rear end portion 33e of the forward rotation groove portion 33b are extended close to each other, almost the entire circumference of the spindle shaft portion 31 can be used for the spindle cam groove 33. A length close to double the cam grooves 233 and 234 (see FIG. 22) can be secured. With respect to the axial direction ranging R g from the front end position of the spindle cam groove 33 to the rear end position, the movement range R b of the needle bearing 56 overlap in the axial direction as shown. Therefore, the needle bearing 56 moves to a part where the spindle cam groove 33 exists. It is also possible to configure the moving range R b in the range R g and needle bearing 56 occupied by the spindle cam groove 33 so as to arranged so as not to overlap in the axial direction, in which case the axial direction of the spindle 30 length Becomes bigger. In the present invention, the length of the spindle shaft portion 31 is suppressed by partially overlapping the range Rg and the movement range Rb .
図８はスピンドルのカム溝の形状を示す展開図であり、（１）は従来のスピンドルカム溝２３３、２３４を示し、（２）は本実施例のスピンドルカム溝３３を示す。従来のスピンドル軸部２３１の２つのスピンドルカム溝２３３、２３４は、それぞれ、逆転用溝部２３３ａ、２３４ａと正転用溝部２３３ｂ、２３４ｂが形成される。しかしながら、周方向に２組のスピンドルカム溝２３３、２３４を並べるために、軸方向に占める長さＬ０を大きくすることは難しい。従って、溝の後端を構成する円弧を形成する円（点線）の中心の一方の中心から他方の中心までの間の回転角Ｃ０が、１８０度未満となる。  FIG. 8 is a development view showing the shape of the cam groove of the spindle. (1) shows the conventional spindle cam grooves 233 and 234, and (2) shows the spindle cam groove 33 of this embodiment. The two spindle cam grooves 233 and 234 of the conventional spindle shaft portion 231 are formed with reverse rotation groove portions 233a and 234a and normal rotation groove portions 233b and 234b, respectively. However, since the two sets of spindle cam grooves 233 and 234 are arranged in the circumferential direction, it is difficult to increase the length L 0 occupied in the axial direction. Accordingly, the rotation angle C 0 between from one center of the center of the circle (dotted lines) to form an arc which forms the rear end of the groove to the other center, less than 180 degrees.
本実施例ではスピンドル軸部３１は、１つのスピンドルカム溝３３だけとした。図８（２）においてスピンドルカム溝３３は、正転用溝部３３ｂ、逆転用溝部３３ａは同じ角度のリード角θで構成される。スピンドルカム溝３３の２つの後端部３３ｃ、３３ｅの間は円周方向の回転角で１８０度を超えて３６０度近くまで延びる。従って、スピンドルカム溝３３の中央の前端部３３ｄから２つの後端部３３ｃ、３３ｅまでの軸方向距離Ｌ１は、従来のスピンドル２３０の軸方向距離Ｌ０に比べて十分長くすることができる。また、溝の後端を構成する円弧を形成する円（点線）の中心の一方の中心から他方の中心までの間の回転角Ｃ１が、１８０度以上となり、例えば２７０度を超える程度にまで設定できる。  In this embodiment, the spindle shaft portion 31 has only one spindle cam groove 33. In FIG. 8B, the spindle cam groove 33 has a forward rotation groove 33b, and the reverse rotation groove 33a has a lead angle θ of the same angle. Between the two rear end portions 33c and 33e of the spindle cam groove 33, the rotation angle in the circumferential direction exceeds 180 degrees and extends to nearly 360 degrees. Therefore, the axial distance L 1 from the central front end portion 33 d of the spindle cam groove 33 to the two rear end portions 33 c and 33 e can be made sufficiently longer than the axial distance L 0 of the conventional spindle 230. Furthermore, to the extent the rotation angle C 1 between the one center of the center of the circle (dotted lines) to form an arc which forms the rear end of the groove to the other center, it becomes 180 degrees or more, more than for example 270 ° Can be set.
図９は本実施例のインパクト工具１における打撃エネルギーと離脱トルクの関係を示す図である。トリガ６ａが引かれてモータ４が起動されると、正逆切替レバー７で設定された方向にモータ４が回転を開始し、その回転力は減速機構２０によって所定の減速比で減速されてスピンドル３０に伝達され、スピンドル３０が所定の速度で回転駆動される。ここで、スピンドル３０とハンマ４０とはカム機構によって連結され、スピンドル３０が回転駆動されると、その回転はカム機構を介してハンマ４０に伝達される。ハンマ４０は回転開始後に１／３回転もしないうちにハンマ４０の打撃爪４６ａ～４６ｃがアンビル６０の羽根部６３ａ～６３ｃに当接してアンビル６０を回転させる。その際、アンビル６０からの係合反力によってスピンドル３０とハンマ４０との間に相対回転が生ずると、ハンマ４０はカム機構のスピンドルカム溝３３に沿ってハンマスプリング５４を圧縮しながらモータ４側へと後退を始める。そして、ハンマ４０の後退動によってハンマ４０の打撃爪４６ａ～４６ｃがアンビル６０の羽根部６３ａ～６３ｃを乗り越えて両者の係合状態が解除されると、ハンマ４０は、スピンドル３０の回転力に加え、ハンマスプリング５４に蓄積されていた弾性エネルギーとカム機構の作用によって回転方向に回転しながら前方に急速に加速される。  FIG. 9 is a diagram showing the relationship between the impact energy and the separation torque in the impact tool 1 of the present embodiment. When the trigger 6a is pulled and the motor 4 is started, the motor 4 starts to rotate in the direction set by the forward / reverse switching lever 7, and the rotational force is decelerated by the reduction mechanism 20 at a predetermined reduction ratio, and the spindle The spindle 30 is rotationally driven at a predetermined speed. Here, the spindle 30 and the hammer 40 are connected by a cam mechanism, and when the spindle 30 is driven to rotate, the rotation is transmitted to the hammer 40 via the cam mechanism. The hammer 40 does not rotate 1/3 after the rotation starts, but the hammering claws 46a to 46c of the hammer 40 abut against the blade portions 63a to 63c of the anvil 60 to rotate the anvil 60. At this time, when relative rotation occurs between the spindle 30 and the hammer 40 due to the reaction force of engagement from the anvil 60, the hammer 40 compresses the hammer spring 54 along the spindle cam groove 33 of the cam mechanism, and the motor 4 side. Start retreating. When the hammer 40 is moved backward by the hammer 40 over the blades 63a to 63c of the anvil 60 and the engagement state between the hammers is released, the hammer 40 is added to the rotational force of the spindle 30. By the elastic energy accumulated in the hammer spring 54 and the action of the cam mechanism, it is rapidly accelerated forward while rotating in the rotational direction.
ハンマ４０がハンマスプリング５４の付勢力によって前方へ移動すると、ハンマ４０の打撃爪４６ａ～４６ｃが、回転後の次のアンビル６０の羽根部６３ａ～６３ｃに再び係合することにより強い打撃が行われ、ハンマ４０とアンビル６０は一体に回転し始める。この打撃により強力な回転力がアンビル６０に加えられるため、アンビル６０の装着孔６１ａに装着される図示しない先端工具を介してねじに回転打撃力が伝達される。以後、同様の動作が繰り返されて先端工具からねじに回転打撃力が間欠的に繰り返し伝達され、例えば、ねじが木材等の図示しない被締結材にねじ込まれる。以上がハンマ４０によるアンビル６０の通常打撃時の状態を示すものであるが、本実施例では、ハンマ４０の打撃爪とアンビル６０の羽根部がそれぞれ３本形成されたことにより、特徴的な打撃を行うようにした。その打撃は、モータ４の回転速度を所定の回転数以上の高速領域として“一つ飛ばしの打撃”、“二つ飛ばしの打撃”をするか、所定の回転数以下の低速領域として連続打撃をするか、のいずれかを打撃動作を行うことによってハンマ４０によるアンビル６０への打撃トルクを切り替え可能とした。  When the hammer 40 is moved forward by the urging force of the hammer spring 54, the hammering claws 46a to 46c of the hammer 40 are re-engaged with the blade portions 63a to 63c of the next anvil 60 after the rotation so that strong hammering is performed. The hammer 40 and the anvil 60 begin to rotate together. Since a strong rotational force is applied to the anvil 60 by this impact, the rotational impact force is transmitted to the screw through a tip tool (not shown) mounted in the mounting hole 61a of the anvil 60. Thereafter, the same operation is repeated, and the rotational impact force is intermittently repeatedly transmitted from the tip tool to the screw. For example, the screw is screwed into a material to be fastened such as wood. The above shows the state when the anvil 60 is normally struck by the hammer 40. In this embodiment, the hammer 40 has three striking claws and three blade portions of the anvil 60. To do. The hitting can be done by either “single skipping blow” or “two skipping hitting” with the rotational speed of the motor 4 as a high speed region above a predetermined rotational speed, or continuous hitting as a low speed region below a predetermined rotational speed. The hammering torque applied to the anvil 60 by the hammer 40 can be switched by performing a striking operation on either of them.
打撃エネルギーＥは、ハンマ４０がアンビル６０を打撃する直前に、ハンマ４０が有するエネルギーである。ここでは、トリガ６ａの操作量（引き量）は最大、被締め付け材はボルトで、その反発率は０．４１という条件下で算出した。離脱トルクＴＢ［ｋｇ・ｃｍ］、及び打撃エネルギーＥ［Ｎ・ｍ２×（ｒａｄ／ｓ）２］は次の式１、式２で算出した値である。式１：　離脱トルクＴＢ［ｋｇ・ｃｍ］＝ばね定数［ｋｇ／ｃｍ］×（ばね押付け高さ）［ｃｍ］×ｔａｎ（カム角度［ｄｅｇ］×カム接点半径［ｃｍ］）　但し、ばね押付け高さ［ｃｍ］は、ばねの自由長［ｃｍ］－離脱時のばね高さ［ｃｍ］である（本実施例では１．１ｃｍ）。カム接点半径［ｃｍ］は、スピンドル３０の中心軸からスピンドルに形成されたカムＲ形状の中心点までの距離である（本実施例では０．７ｃｍ）。尚、ここに示す離脱トルクＴＢは静的な状態における離脱トルクを示しており、上記した部品の各寸法から容易に算出することが可能である。式２：　打撃エネルギーＥ＝０．５×ハンマイナーシャ［Ｎ・ｍ２］×（ハンマ打撃直前速度［ｒａｄ／ｓ］）２　（単位：Ｎ・ｍ２×（ｒａｄ／ｓ）２）　但し、ハンマ打撃直前速度［ｒａｄ／ｓ］　＝　スピンドル角速度［ｒａｄ／ｓ］＋（スピンドル角速度［ｒａｄ／ｓ］×反発率を考慮した係数）　スピンドル角速度［ｒａｄ／ｓ］＝２×π×スピンドル回転数［ｒｐｓ］　反発率を考慮した係数は、本実施例では２．４である。ここに示すスピンドル回転数は、ねじ締め作業時におけるスピンドル回転数を示しており、ねじ締め作業時におけるロータの実用回転数を検証すれば、遊星歯車の減速比から容易に算出することが可能である。また、反発率を考慮した係数については木材の硬さにより変動することになる。  The striking energy E is energy that the hammer 40 has immediately before the hammer 40 strikes the anvil 60. Here, the operation amount (pull amount) of the trigger 6a is maximum, the material to be tightened is a bolt, and the restitution rate is 0.41. The separation torque T B [kg · cm] and the impact energy E [N · m 2 × (rad / s) 2 ] are values calculated by the following formulas 1 and 2. Formula 1: withdrawal torque T B [kg · cm] = spring constant [kg / cm] × (spring pressing height) [cm] × tan (cam angle [deg] × cam contact radius [cm]), however, the pressing spring The height [cm] is the free length of the spring [cm] −the spring height [cm] when detached (1.1 cm in this embodiment). The cam contact radius [cm] is the distance from the center axis of the spindle 30 to the center point of the cam R shape formed on the spindle (0.7 cm in this embodiment). Incidentally, withdrawal torque T B shown here shows the withdrawal torque in a static state, it is possible to easily calculated from the dimensions of the parts described above. Formula 2: Impact energy E = 0.5 × Hammer minor [N · m 2 ] × (Speed immediately before hammering [rad / s]) 2 (Unit: N · m 2 × (rad / s) 2 ) However, hammer Speed immediately before impact [rad / s] = spindle angular velocity [rad / s] + (spindle angular velocity [rad / s] × coefficient considering repulsion rate) spindle angular velocity [rad / s] = 2 × π × spindle speed [rps] The coefficient considering the repulsion rate is 2.4 in this embodiment. The spindle speed shown here indicates the spindle speed at the time of screw tightening work. If the practical speed of the rotor at the time of screw tightening work is verified, it can be easily calculated from the reduction gear ratio of the planetary gear. is there. In addition, the coefficient considering the restitution rate varies depending on the hardness of the wood.
図９にて図示した各プロット点は、本発明、従来における打撃諸元をそれぞれプロットしたものであり、かつ、ハンマ４０に配した打撃爪４６ａが、アンビル６０に配した羽根部６３ａから離脱した後に、次の羽根部６３ｂを飛ばして次の次の羽根部６３ｃに係合するまでの回動角度を２４０度とした中速動作モード、次の次の次の羽根部６３ａに係合するまでの回動角度を３６０度とした高速動作モードにおける、打撃エネルギーＥと離脱トルクＴＢ、及び、係数Ｋの範囲を、上限の係数Ｋ２、Ｋ４と下限の係数Ｋ１、Ｋ３として表示した。プロット群９１は市販されている現行品の一つ飛び打撃時の打撃エネルギーＥと離脱トルクＴＢの関係である。この従来品（現在市販されているインパクト工具）の打撃エネルギーＥをさらに大きくするためにハンマスプリング５４のバネ圧を大きくすると離脱トルクＴＢも大きくなってしまう。しかしながら、本実施例では、ハンマ４０に配した打撃爪４６ａが、アンビル６０に配した羽根部６３ａから離脱した後に、次の次の羽根部６３ｃに打撃するという、いわゆる“１つ飛ばし打撃モード（中速動作モード）”に加えて、羽根部６３ａから離脱した後に、次の羽根部６３ｂと、その次の羽根部６３ｃを飛ばして、再びもとの羽根部６３ａを打撃するという“２つ飛ばし打撃モード（高速動作モード）”も追加した。この高速動作モードの場合は、ハンマ４０がアンビル６０に対して１回転する間に１回だけ打撃することになり、それらの打撃諸元をそれぞれプロットしたのがプロット群９２である。  Each plot point illustrated in FIG. 9 is a plot of the hitting specifications according to the present invention and the prior art, and the hitting claw 46 a arranged on the hammer 40 is detached from the blade part 63 a arranged on the anvil 60. Later, in the middle speed operation mode in which the rotation angle until the next blade portion 63b is blown and engaged with the next next blade portion 63c is 240 degrees, until the next next blade portion 63a is engaged. In the high-speed operation mode in which the rotation angle is 360 degrees, the range of the impact energy E, the separation torque T B , and the coefficient K is displayed as the upper limit coefficients K 2 and K 4 and the lower limit coefficients K 1 and K 3. did. Plot group 91 is the relationship withdrawal torque T B and impact energy E when hit jumping one current product on the market. The conventional product becomes larger striking breakaway torque T and the spring pressure to increase the hammer spring 54 in order to further increase the energy E B (now impact tool which is commercially available). However, in the present embodiment, the hitting claw 46a disposed on the hammer 40 detaches from the blade portion 63a disposed on the anvil 60 and then hits the next blade portion 63c, so-called “one-flying blow mode ( In addition to “medium speed operation mode”, after separating from the blade portion 63a, the next blade portion 63b and the next blade portion 63c are blown, and the original blade portion 63a is hit again. "Blow mode (high-speed operation mode)" was also added. In the case of this high-speed operation mode, the hammer 40 is struck only once during one rotation with respect to the anvil 60, and the plot group 92 is a plot of these struck specifications.
アンビル６０に配した羽根部６３ａから離脱した後に、次の次の次の羽根部に係合するまでの前記回動角度を３４０～３８０度となるインパクト工具の打撃エネルギーＥと離脱トルクＴＢ、及び、係数ＫＰの関係性をＥ＝ＫＰ×ＴＢ［Ｋ１＜ＫＰ］とした場合では、プロット群９２で示すように離脱トルクを１２～１８ｋｇ・ｃｍを保ったまま打撃エネルギーＥをプロット群９１よりも段違いに向上させることができ、実線Ｋ３の領域よりも上側領域の高い打撃エネルギーＥを得ることが可能となった。  The impact tool impact energy E and the release torque T B , with which the rotation angle is 340 to 380 degrees after the release from the blade 63a disposed on the anvil 60 until the next blade is engaged. When the relationship of the coefficient K P is E = K P × T B [K 1 <K P ], as shown by the plot group 92, the impact energy E is maintained while the separation torque is maintained at 12 to 18 kg · cm. also can be staggered improved than plot group 91, it becomes possible to obtain a high upper region impact energy E than the area of the solid line K 3.
プロット群９１に示すような、いわゆる“１つ飛ばし打撃モード”から、プロット群９２に示すような、いわゆる“２つ飛ばし打撃モード”に切り替えるには、モータ４の回転速度の切替制御が重要である。このようにモータ４の速度をうまく制御することによって、係数Ｋ３～Ｋ４の範囲の高い打撃エネルギーの動作モード、係数Ｋ１～Ｋ２の中打撃エネルギーの動作モード、係数Ｋ１以下であって従来のインパクト工具と同様に“連続打撃”を行う低打撃エネルギーの３つを選択できるようにして、軽負荷のねじ締め作業から高負荷のボルト締め作業まで、幅広い締め付け作業に対応できるインパクト工具を実現できる。この係数Ｋ３よりも高い打撃エネルギーの動作モードでは、打撃エネルギーＥと離脱トルクＴＢとの関係が、プロット群９２に示すような１０．０×ＴＢ＜Ｅ＜１６．７×ＴＢの領域での打撃となる。  In order to switch from the so-called “single skipping mode” as shown in the plot group 91 to the so-called “double skipping mode” as shown in the plot group 92, the switching control of the rotation speed of the motor 4 is important. is there. By controlling the speed of the motor 4 in this way, the operation mode of high impact energy in the range of the coefficients K 3 to K 4 , the operation mode of medium impact energy of the coefficients K 1 to K 2 , and the coefficient K 1 or less. Impact tools that can handle a wide range of tightening operations, from light-load screw tightening operations to high-load bolt tightening operations, by selecting three low impact energies that perform “continuous striking” as with conventional impact tools Can be realized. This factor K 3 high impact energy modes of operation than the striking relationship between energy E and the disengagement torque T B is, 10.0 × as shown in the plot group 92 T B <E <of 16.7 × T B It will be a blow in the area.
図１０は、従来のインパクト工具と本実施例のインパクト工具１における打撃機構の数値を示す比較表である。従来例の数値は、高出力時に“１つ飛ばし打撃モード”を行うインパクト工具であり、本実施例の数値は、高出力時に“２つ飛ばし打撃モード”を行うインパクト工具とも言い換えることができる。スピンドル３０、２３０の軸部の直径は１３．８ｍｍで同一とする。被締結材からの反発率は、従来は負荷の大きい太いビスを想定して０．３１とし、本実施例では締め付けトルクの向上から硬いボルトを想定して反発率を０．４１としている。ハンマバック量は、カムボールが２つと一つの違いから従来例では１０．５ｍｍ、本実施例では１９．３ｍｍと１．８倍以上の距離を確保できるが、本実施例では余裕を持たせて１７．３ｍｍとして、カムボール５１がスピンドルカム溝３３の後端部３３ｃ、３３ｅに到達しないようにして、溝の端部の破損を防止するように構成した。このように製品として必要とされる出力を得るために、ハンマスプリング５４、２５４を選択することにより、従来例のインパクト工具では離脱トルクが１５．９［Ｎ・ｍ］に対して、１３．５［Ｎ・ｍ］と更に低くしながら、得られる最大打撃エネルギーＥは、９．７から１８．１［Ｎ・ｍ２×（ｒａｄ／ｓ）２］と大幅に向上させることができた。  FIG. 10 is a comparison table showing numerical values of the striking mechanism in the conventional impact tool and the impact tool 1 of the present embodiment. The numerical value of the conventional example is an impact tool that performs “one skipping impact mode” at the time of high output, and the numerical value of this embodiment can also be restated as an impact tool that performs “two skipping impact mode” at the time of high output. The diameters of the shaft portions of the spindles 30 and 230 are 13.8 mm and are the same. Conventionally, the rebound rate from the material to be fastened is 0.31 assuming a thick screw with a large load, and in this embodiment, the rebound rate is 0.41 assuming a hard bolt due to an improvement in tightening torque. The distance between the hammerbacks is 10.5 mm in the conventional example and 19.3 mm in the present embodiment, which is 1.8 times or more due to the difference between two cam balls. In this embodiment, the distance of the hammerback is 17 with a margin. .3 mm so that the cam ball 51 does not reach the rear end portions 33c and 33e of the spindle cam groove 33 to prevent the end of the groove from being damaged. In order to obtain the output required as a product in this way, by selecting the hammer springs 54 and 254, the conventional impact tool has a separation torque of 13.5 [N · m] and 13.5. While being further reduced to [N · m], the maximum impact energy E obtained was significantly improved from 9.7 to 18.1 [N · m 2 × (rad / s) 2 ].
図１１はハンマ４０、アンビル６０による打撃状態を示す図である。縦軸はハンマ４０の前後方向の位置を示し、＋が前方側（先端工具側）で、－が後方側（モータ側）であって、基準位置から何ｍｍの位置にあるかを示す。０が静止時又は低負荷状態で回転時のハンマ４０の打撃爪４６ａの前方端の位置であり、この際の羽根部６３ａの前方側位置も０である。横軸は回転角度であり、３６０度（［ｄｅｇ］）にて１周である。ここでは羽根部６３ａ～６３ｃは１２０度の間隔で配置される。図１１（１）において、トリガ６ａを一杯に引いてスピンドル３０が回転中に、ハンマ４０の打撃爪４６ａに所定の反力が加わり、離脱トルクを越えると、ハンマ４０が後退する。ハンマ４０の後退量が羽根部６３ａとの最大係合量Ａよりも大きくなると、打撃爪４６ａと羽根部６３ａとの係合状態が解除され、打撃爪４６ａが羽根部６３ａの後方側をすり抜けて回転し、次の羽根部６３ｂを打撃する。この際のスピンドル３０の回転は後述する図１１（２）（３）に比べると低速である。図中、実線７１で示すのが打撃爪４６ａの軸方向前方側且つ回転方向前方側の角部の移動軌跡であり、点線７２で示すのが打撃爪４６ａの軸方向前方側且つ回転方向後方側の角部の移動軌跡である。この連続打撃を行う際には、制御回路は連続打撃が良好に行われるような回転速度にてスピンドル３０を回転させるべく、モータ４の回転制御を行う。これが従来から行われてきたインパクト打撃である。図１１においては、打撃爪４６ａしか図示していないが、同様に打撃爪４６ｂ、４６ｃも後退及び打撃動作を行う。  FIG. 11 is a diagram showing a hit state by the hammer 40 and the anvil 60. The vertical axis indicates the position of the hammer 40 in the front-rear direction, where + is the front side (tip tool side) and-is the rear side (motor side), indicating how many mm from the reference position. 0 is the position of the front end of the hammering claw 46a of the hammer 40 when it is stationary or rotating in a low load state, and the front side position of the blade portion 63a at this time is also 0. The horizontal axis is the rotation angle, which is one turn at 360 degrees ([deg]). Here, the blade portions 63a to 63c are arranged at intervals of 120 degrees. In FIG. 11 (1), when the trigger 6a is fully pulled and the spindle 30 is rotating, a predetermined reaction force is applied to the striking claw 46a of the hammer 40, and the hammer 40 moves backward when the separation torque is exceeded. When the retraction amount of the hammer 40 becomes larger than the maximum engagement amount A with the blade portion 63a, the engagement state between the striking claw 46a and the blade portion 63a is released, and the striking claw 46a passes through the rear side of the blade portion 63a. It rotates and strikes the next blade part 63b. The rotation of the spindle 30 at this time is lower than that of FIGS. 11 (2) and 11 (3) described later. In the figure, the solid line 71 indicates the movement trajectory of the corner portion on the front side in the axial direction and the front side in the rotational direction of the hitting claw 46a, and the dotted line 72 indicates the front side in the axial direction and the rear side in the rotational direction of the hitting claw 46a. It is the movement locus | trajectory of this corner | angular part. When performing this continuous hitting, the control circuit controls the rotation of the motor 4 so as to rotate the spindle 30 at a rotation speed at which the continuous hitting is favorably performed. This is the impact hitting that has been performed conventionally. In FIG. 11, only the striking claw 46a is shown, but the striking claws 46b and 46c similarly perform the retreat and striking operations.
図１１（２）は“一つ飛ばし打撃”の状態を示すものである。ハンマ４０の後退量が羽根部６３ａとの最大係合量Ａよりも大きくなって、打撃爪４６ａが羽根部６３ａの後方側をすり抜けて回転する際の回転速度が中速にすると、次の羽根部６３ｂの後方側も通過して、その次の羽根部６３ｃ（羽根部６３ａから見て次の次の羽根部）を打撃することができる。図中、実線７３で示すのが打撃爪４６ａの軸方向前方側且つ回転方向前方側の角部の移動軌跡であり、点線７４で示すのが打撃爪４６ａの軸方向前方側且つ回転方向後方側の角部の移動軌跡である。このように、打撃を行う際に打撃爪４６ａが、次の羽根部６３ｂでなくて次の次の羽根部６３ｃを打撃するためには、ハンマスプリング５４を圧縮して後方側に移動したハンマ４０が軸方向前方側に戻る前に、羽根部６３ｂの後方を通過するような中速でスピンドル３０を回転させる。  FIG. 11 (2) shows a state of “one skipping blow”. When the retraction amount of the hammer 40 is larger than the maximum engagement amount A with the blade portion 63a, and the rotation speed when the striking claw 46a rotates through the rear side of the blade portion 63a is set to the medium speed, the next blade The rear side of the part 63b can also pass through and hit the next blade part 63c (the next blade part as viewed from the blade part 63a). In the figure, a solid line 73 indicates the movement trajectory of the corner portion on the front side in the axial direction and the front side in the rotational direction of the hitting claw 46a, and a dotted line 74 indicates the front side in the axial direction and the rear side in the rotational direction of the hitting claw 46a. It is the movement locus | trajectory of this corner | angular part. Thus, in order to hit the next next blade portion 63c, not the next blade portion 63b, when the hitting claw 46a hits the hammer 40 that has compressed the hammer spring 54 and moved rearward. Before the shaft returns to the front side in the axial direction, the spindle 30 is rotated at a medium speed so as to pass behind the blade portion 63b.
図１１（３）は“二つ飛ばし打撃”の状態を示すものである。ここではモータ４の回転速度をさらに高速にして、打撃爪４６ａが羽根部６３ａの後方側をすり抜けて回転した際に、次の羽根部６３ｂだけでなく次の次の羽根部６３ｃも通過して、再び羽根部６３ａ（羽根部６３ａから見て「次の次の次の羽根部」）を打撃することができるようにした。図中、実線７５で示すのが打撃爪４６ａの軸方向前方側且つ回転方向前方側の角部の移動軌跡であり、点線７６で示すのが打撃爪４６ａの軸方向前方側且つ回転方向後方側の角部の移動軌跡である。このように、打撃爪４６ａが、次の次の次の羽根部６３ａを打撃するためには、ハンマスプリング５４を圧縮して後方側に移動したハンマ４０が軸方向前方側に戻る前に、羽根部６３ｂと羽根部６３ｃの後方を通過するように十分な高速でスピンドル３０を回転させることが必要である。  FIG. 11 (3) shows a state of “two skipping hits”. Here, when the rotation speed of the motor 4 is further increased and the impact claw 46a rotates through the rear side of the blade portion 63a, not only the next blade portion 63b but also the next next blade portion 63c passes through. The blade portion 63a ("next next blade portion" as viewed from the blade portion 63a) can be hit again. In the drawing, a solid line 75 indicates the movement trajectory of the corner portion on the front side in the axial direction and the front side in the rotational direction of the hitting claw 46a, and a dotted line 76 indicates the front side in the axial direction and the rear side in the rotational direction of the hitting claw 46a. It is the movement locus | trajectory of this corner | angular part. Thus, in order for the striking claw 46a to strike the next next blade portion 63a, the hammer 40 that has compressed the hammer spring 54 and moved to the rear side has to be moved before the hammer 40 returns to the front side in the axial direction. It is necessary to rotate the spindle 30 at a sufficiently high speed so as to pass behind the part 63b and the blade part 63c.
図１１（１）～（３）の打撃爪４６ａの軸方向前方側角部の移動軌跡７１～７６をみて理解できるように、カムボールを２つ用いるスピンドルにおいては、図１０にて示したようにハンマバック量が１０．５ｍｍ程度しかないため、ハンマスプリング５４のバネ圧を調整しても図１１（３）のような“二つ飛ばし打撃”を実現することができなかった。しかしながら、本実施例では、図１０にて示したようにハンマバック量を１７．３ｍｍと十分大きくすることができたので、ハンマスプリング５４のバネ圧を調整するとともに、従来よりもモータの回転速度を高めることによって“二つ飛ばし打撃”を実現することができた。また、モータ４の回転制御によって“飛ばしを行わない打撃（従来と同様の打撃）”と“一つ飛ばし打撃”と“二つ飛ばし打撃”を自在に切り替え可能なので、締め付け対象に合わせた最適な出力を得ることが可能となる。  As shown in FIG. 10, in the spindle using two cam balls, as can be understood from the movement trajectories 71 to 76 of the front corners in the axial direction of the hitting claw 46a in FIGS. Since the hammer back amount is only about 10.5 mm, even if the spring pressure of the hammer spring 54 is adjusted, it is not possible to realize the “double hitting” as shown in FIG. However, in this embodiment, as shown in FIG. 10, the hammer back amount can be sufficiently increased to 17.3 mm. Therefore, the spring pressure of the hammer spring 54 is adjusted, and the rotational speed of the motor is higher than that of the prior art. It was possible to realize “two skipping blows” by increasing In addition, it is possible to switch freely between “blow without hitting (same hitting as before)”, “one hitting hitting” and “two hitting hits” by controlling the rotation of the motor 4, which is optimal for the tightening target. An output can be obtained.
以上説明したように、本実施例によれば、離脱トルクＴＢの上昇を抑えて良好な打撃フィーリングを維持したインパクト工具を実現できる。また、その際にスピンドル回転数を大幅に高くして一つ飛ばし打撃又は二つ飛ばし打撃を行うことにより、打撃エネルギーＥを従来よりも大幅に向上させることができる。さらに、打撃動作に移行した際にスピンドル回転数を大幅に低くして連続打撃を行うようにすれば、連続回転から打撃開始に至るまでの好フィーリング化を図ることができる。尚、本実施例は上述の例だけに限られずに様々な変更が可能である。  As described above, according to this embodiment can be realized the impact tool maintaining good blow feel by suppressing the increase in the withdrawal torque T B. Further, at that time, the striking energy E can be greatly improved as compared with the prior art by significantly increasing the spindle speed and performing one or two hits. Furthermore, if the continuous rotation is performed by significantly reducing the spindle rotation speed when shifting to the striking operation, it is possible to achieve a good feeling from the continuous rotation to the start of striking. The present embodiment is not limited to the above example, and various modifications can be made.
図１２は、スピンドルのカム溝の形状を示す展開図であり、（１）は本実施例のスピンドルカム溝３３の形状を示し、（２）は本実施例の第１の変形例にかかるスピンドル軸部８１のカム溝８２の形状を示し、（３）は本実施例の第２の変形例にかかるスピンドル軸部８３のカム溝８４の形状を示す。図１２（１）に示すように本実施例のスピンドルカム溝３３は、正転用溝部３３ｂ、逆転用溝部３３ａが同じリード角θとされる。一方、図１２（２）では逆転用溝部８２ａのリード角θに対して、正転用溝部８２ｂのリード角θ１を小さくした。このように構成することにより正転時の離脱トルクＴＢ１と、逆転時の離脱トルクＴＢ２の大きさを変えることが可能となり、正転時の離脱トルクＴＢを小さくできるので、正逆時の離脱トルクを下げ、カムアウト低減を可能にできる。また、逆転時はネジやボルト等を緩める作業であって、カムアウトがおきない場合はほとんどなので、カムリード角を小さくする必要性が少ない。  FIG. 12 is a development view showing the shape of the cam groove of the spindle, (1) shows the shape of the spindle cam groove 33 of this embodiment, and (2) shows the spindle according to the first modification of this embodiment. The shape of the cam groove 82 of the shaft portion 81 is shown, and (3) shows the shape of the cam groove 84 of the spindle shaft portion 83 according to the second modification of this embodiment. As shown in FIG. 12A, in the spindle cam groove 33 of this embodiment, the forward rotation groove 33b and the reverse rotation groove 33a have the same lead angle θ. On the other hand, the lead angle theta in FIG. 12 (2), the reverse rotation groove 82a, has a small lead angle theta 1 of forward rotation groove 82b. And the detachable torque T B1 during forward rotation With this arrangement, it is possible to vary the withdrawal magnitude of the torque T B2 of the reverse rotation, since the disengagement torque T B during forward rotation can be reduced, Seigyakuji The release torque can be reduced and the cam-out can be reduced. Also, during reverse rotation, it is an operation to loosen screws, bolts, etc., and in most cases where no cam-out occurs, there is little need to reduce the cam lead angle.
図１２（３）では逆転用溝部８４ａと正転用溝部８４ｂのリード角をともにθ１で小さくした。このように双方のリード角θ１を小さくすれば、正転時と逆転時の双方で離脱トルクＴＢを小さくすることができるので、子ネジ等を締め付け対象とするような小出力用のインパクト工具にも本発明を適用することができる。通常ではリード角θ１を小さくすると打撃トルクが小さくなるが,本実施例では１つ飛ばし打撃、又は／及び、２つ飛ばし打撃を併用することによって、リード角θ１の減少によるトルク低下分を補うことができる。  In FIG. 12 (3), the lead angles of the reverse rotation groove 84 a and the normal rotation groove 84 b are both reduced by θ 1 . Thus small both lead angle theta 1, it is possible to reduce the withdrawal torque T B in both reverse rotation and forward rotation, the impact for the small output as the target tightening children screws The present invention can also be applied to tools. Usually becomes smaller impact torque A smaller lead angle theta 1 is at one skip blow in this embodiment, or / and, by combining the two skipping blow, the torque decrease caused by a decrease of the lead angle theta 1 Can be supplemented.
図１３は、本発明の第３及び第４の変形例を示す図であり、ニードルベアリング５６に代えて（１）は焼結メタル８５を用いた例であり、（２）はＯリング８６を用いた例を示す図である。図１３（１）はハンマ４０Ｂの後端側内周面に径方向外側に窪むような段差部４１Ｂを形成し、そこに円筒状の焼結メタル８５を圧入したものである。焼結メタル８５は、粉末冶金法により製造した多孔質の金属体に潤滑油を含浸させて、自己給油の状態で使用される滑り軸受であって、ハンマ４０Ｂの後端付近をスピンドル軸部３１に対して支持する部材である。焼結メタル８５とスピンドル軸部３１との間に存在する潤滑油により、摺動面に潤滑油膜が形成される。焼結メタル８５の内径は、スピンドル３０のスピンドル軸部３１と良好に当接して、それらが軸方向及び回転方向に良好に摺動可能な状態とする。ハンマ４０Ｂの段差部４１Ｂよりも前方であって、スピンドルカム溝３３の形成されていない部分との隙間Ｓ１を所定量だけ設けるようにして、ハンマ４０Ｂのスピンドル軸部３１に対する摺動抵抗をなくしている。  FIG. 13 is a view showing third and fourth modifications of the present invention, in which (1) is an example using a sintered metal 85 instead of the needle bearing 56, and (2) is an O-ring 86. It is a figure which shows the used example. In FIG. 13A, a stepped portion 41B is formed on the inner peripheral surface of the rear end side of the hammer 40B so as to be recessed radially outward, and a cylindrical sintered metal 85 is press-fitted therein. The sintered metal 85 is a sliding bearing used in a self-lubricated state by impregnating a porous metal body manufactured by a powder metallurgy method with a lubricating oil, and the spindle shaft portion 31 is located near the rear end of the hammer 40B. It is the member which supports with respect to. A lubricating oil film is formed on the sliding surface by the lubricating oil present between the sintered metal 85 and the spindle shaft portion 31. The inner diameter of the sintered metal 85 is in good contact with the spindle shaft portion 31 of the spindle 30 so that they can slide well in the axial direction and the rotational direction. A forward a than the step portion 41B of the hammer 40B, the gap S 1 between the portion which is not formed in the spindle cam groove 33 be provided by a predetermined amount, eliminating the sliding resistance with respect to the spindle shaft portion 31 of the hammer 40B ing.
図１３（２）はハンマ４０Ｃの後端付近内周面に断面視で台形状に径方向外側に窪むような連続した溝部４１Ｃを形成し、そこにＯリング８６を装着したものである。溝部４１Ｃは従来から設けられていた潤滑油を溜めるための潤滑溝２４１ｃ（図２３参照）を軸方向後方に移動させたうえで、溝の大きさを大きくしたものである。Ｏリング８６は、潤滑油が充填された環境下で対向する２つの部材（ハンマ４０Ｃとスピンドル軸部３１）の摺動抵抗を小さくして、ハンマ４０Ｃとスピンドル軸部３１の回転方向及び軸方向の動きをスムーズにする摺動部材であり、潤滑油を充分に浸したフェルトワイパを用いることができ、Ｏリング８６の内周面がスピンドル軸部３１に対して摺動するように支持される。ハンマ４０Ｃの溝部４１Ｃ以外の部分であって、スピンドルカム溝３３の形成されていない部分との隙間Ｓ２は所定量だけ設けるようにして、ハンマ４０Ｃのスピンドル軸部３１に対する摺動抵抗を小さくできるように構成することが重要である。以上のように、ニードルベアリング等の転動部材に代えて、焼結メタル８５やＯリング８６等の摺動部材を設けることにより、ハンマのスピンドルに対するガタツキを抑制することができ、１つのカムボール構成であってもスムーズな打撃動作が可能となる。本実施例においては、焼結メタル８５やＯリング８６等の摺動部材が第３の規制部に該当し、第３の規制部はハンマ４０のスピンドル３０に対する傾きを規制する。  FIG. 13 (2) shows a continuous groove 41C that is recessed in a radially outward shape in a trapezoidal shape in cross section in the vicinity of the rear end of the hammer 40C, and an O-ring 86 is attached thereto. The groove portion 41C is obtained by moving a lubricating groove 241c (see FIG. 23) for storing lubricating oil, which has been conventionally provided, rearward in the axial direction and then increasing the size of the groove. The O-ring 86 reduces the sliding resistance of two members (hammer 40C and spindle shaft portion 31) facing each other in an environment filled with lubricating oil, so that the rotation direction and axial direction of the hammer 40C and spindle shaft portion 31 are reduced. A felt wiper that is sufficiently dipped in lubricating oil can be used, and is supported so that the inner peripheral surface of the O-ring 86 slides relative to the spindle shaft portion 31. . A portion other than the groove 41C of the hammer 40C, the clearance S 2 between the portion which is not formed in the spindle cam groove 33 be provided by a predetermined amount, it is possible to reduce the sliding resistance with respect to the spindle shaft portion 31 of the hammer 40C It is important to configure as follows. As described above, by providing a sliding member such as a sintered metal 85 or an O-ring 86 instead of a rolling member such as a needle bearing, it is possible to suppress backlash of the hammer with respect to the spindle. Even so, a smooth hitting operation is possible. In the present embodiment, sliding members such as the sintered metal 85 and the O-ring 86 correspond to the third restricting portion, and the third restricting portion restricts the inclination of the hammer 40 relative to the spindle 30.
図１４は、本発明の第５の変形例に係るハンマの例を示す図である。ここではニードルベアリング５６を設ける代わりに、ハンマ４０Ｄとスピンドル３０の摺動抵抗を減らすための半球状の突起８８ａ～８８ｃを設けたものである。突起８８ａ～８８ｃはハンマ４０の後端部内側に形成するものであって、周方向の３箇所に配置される。突起８８ａ～８８ｃはハンマ４０Ｄと一体に形成しても良いし、または３つの突起８８ａ～８８ｃを形成した金属製又は樹脂製の別部材をニードルベアリング５６に替えて装着するようにしても良い。突起８８ａ～８８ｃの径方向位置は、嵌合孔３２Ｄの位置よりも内側に突出し、スピンドル軸部３１の外周面と点接触状態又は小さい領域にて接触する微小領域接触状態となる。このようにハンマ４０Ｄ側とスピンドル軸部３１との接触面積を小さくすることにより、良好な摺動特性を達成しながらハンマ４０Ｄの姿勢を安定して保持することができる。尚、ここでは突起８８ａ～８８ｃをハンマ４０Ｄ側に形成したが、この関係を逆にして、スピンドル側に半球状の突起を周方向に複数形成して、ハンマ４０Ｄの円筒状の内周面と点接触状態又は微小領域にて接触状態となるようにすれば良い。尚、設けられる突起の形状は半球状だけに限られず、ハンマ４０Ｄとスピンドル軸部３１との摺動特性が良好であればその他の形状であっても良い。  FIG. 14 is a view showing an example of a hammer according to a fifth modification of the present invention. Here, instead of providing the needle bearing 56, hemispherical projections 88a to 88c for reducing the sliding resistance between the hammer 40D and the spindle 30 are provided. The protrusions 88a to 88c are formed inside the rear end portion of the hammer 40, and are arranged at three locations in the circumferential direction. The protrusions 88a to 88c may be formed integrally with the hammer 40D, or another metal or resin member formed with the three protrusions 88a to 88c may be mounted instead of the needle bearing 56. The radial positions of the protrusions 88a to 88c protrude inward from the position of the fitting hole 32D, and are in a point contact state or a minute region contact state in contact with the outer peripheral surface of the spindle shaft portion 31 in a small region. As described above, by reducing the contact area between the hammer 40D side and the spindle shaft portion 31, the posture of the hammer 40D can be stably held while achieving good sliding characteristics. Here, the protrusions 88a to 88c are formed on the hammer 40D side. However, by reversing this relationship, a plurality of hemispherical protrusions are formed on the spindle side in the circumferential direction, and the cylindrical inner peripheral surface of the hammer 40D is formed. What is necessary is just to make it a contact state in a point contact state or a micro area | region. Note that the shape of the projection provided is not limited to a hemispherical shape, and may be any other shape as long as the sliding characteristics between the hammer 40D and the spindle shaft portion 31 are good.
次に図１５を用いて本願発明の第二の実施例について説明する。第一の実施例ではハンマ４０の内周側、即ち、ハンマ４０とスピンドル３０の間にニードルベアリング５６を設けるようにした。また、カムボール５１の数を一つとしてスピンドルカム溝３３を長く形成した。これに対して第二の実施例では、ハンマ１４０の内周側でなくて外周側にニードルベアリング１８０を設けた。ニードルベアリング１８０は、ハンマ１４０の外周面を支持する支持部材となるもので、ハンマ１４０とハンマケース１０３の間であってハンマケース１０３の内壁側に保持される。カムボール５１の数は、第一の実施例と同様に１つだけであり、スピンドルカム溝１３３が長く確保できるように構成した。さらに、駆動源たるモータ１０４の形式を変更し、ブラシ付き直流モータからブラシレスＤＣモータに変更した。但し、モータの形式は任意で有り、本願発明の特徴的な打撃機構の構成には直接影響しない。  Next, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment, the needle bearing 56 is provided on the inner peripheral side of the hammer 40, that is, between the hammer 40 and the spindle 30. Further, the number of cam balls 51 is one and the spindle cam groove 33 is formed long. On the other hand, in the second embodiment, the needle bearing 180 is provided not on the inner peripheral side of the hammer 140 but on the outer peripheral side. The needle bearing 180 serves as a support member that supports the outer peripheral surface of the hammer 140, and is held between the hammer 140 and the hammer case 103 and on the inner wall side of the hammer case 103. The number of cam balls 51 is only one as in the first embodiment, and the spindle cam groove 133 can be secured long. Furthermore, the type of the motor 104 as a drive source was changed to change from a brushed DC motor to a brushless DC motor. However, the type of the motor is arbitrary and does not directly affect the configuration of the characteristic striking mechanism of the present invention.
本体ハウジング１０２の形状は、モータ１０４の違いに起因して胴体部１０２ａの前後方向の長さが短くてコンパクトな形状とされている。そのため、減速機構２０と打撃機構（１３０、１４０、１６０等）を収容するハンマケース１０３の形状も変更される。ハンマケース１０３は、前側に行くにつれて径を徐々に絞る様な先絞り形状ではなくて、軸線と鉛直な底面を有するカップ状のような形状に変更した。これらの形状の変更は、トリガレバー６ａよりも上側部分をコンパクトに設計したことにデザイン上の違いよるものが主な理由であり、内部の機械的な構成を変更した訳ではない。よって、第一の実施例と同様に先絞り形状としても良い。  The main body housing 102 has a compact shape with a short length in the front-rear direction of the body portion 102 a due to a difference in the motor 104. Therefore, the shape of the hammer case 103 that houses the speed reduction mechanism 20 and the striking mechanism (130, 140, 160, etc.) is also changed. The hammer case 103 was changed to a cup-like shape having a bottom surface perpendicular to the axis and not a tip-drawing shape in which the diameter is gradually reduced toward the front side. These changes in shape are mainly due to the difference in design that the upper part of the trigger lever 6a is designed to be compact, and the internal mechanical configuration is not changed. Therefore, it is good also as a pre-drawing shape similarly to the first embodiment.
減速機構２０はモータ１０４の出力をスピンドル１３０に伝達するものであり、ここでは、図１で示したものと同様の遊星歯車減速機構を用いる。スピンドル１３０は第一の実施例のスピンドル３０と同じ又はほぼ同じものを用いることができる。ハンマ１４０は、外周面１４０ａをニードルベアリング１８０に当接させながら回転させるため、打撃爪部分を除く外周面の直径が、前端から後端まで一定の大きさとなるように構成される。またハンマ１４０の形状に合わせてハンマケース１０３の形状も決定されるため、ハンマケース１０３の内壁面の径状は円筒面となるように形成される。アンビル１６０は、図１で示したものと共通部品とすることができ、その先端にはビット保持部７０が形成される。アンビル１６０の軸部分はニードルベアリング１９ａによって軸支される。ニードルベアリング１９ａを保持するために、ハンマケース１０３の前方側には、垂直壁１０３ｂから前方側に延在する細径円筒部１０３ａが形成される。つまり、ハンマケース１０３には、細径円筒部１０３ａの内側と、太径の円筒部１０３ｃの内側に、それぞれニードルベアリング（１９ａ、１８０）が配置されることになる。細径円筒部１０３ａと円筒部１０３ｃの間は、軸線Ａ１とほぼ垂直な径方向に延在する垂直壁１０３ｂとなっている。このように第二の実施例では、アルミニウム合金等による金属製の一体成形のハンマケース１０３に、２つの軸受装置（１９ａ、１８０）を設けたことが一つの特徴となっている。一方の軸受装置（ニードルベアリング１９ａ）はアンビル１６０をハンマケース１０３に回転可能に軸支している。他方の軸受装置（ニードルベアリング１８０）はハンマ１４０をハンマケース１０３に軸支している。すなわち、２つの軸受装置は異なる構成部品（アンビル１６０、ハンマ１４０）を軸支（保持）している。言い換えると、異なる構成部品は２つの軸受装置によって同じ構成部品（ハンマケース１０３）に軸支（保持）されている。  The speed reduction mechanism 20 transmits the output of the motor 104 to the spindle 130. Here, a planetary gear speed reduction mechanism similar to that shown in FIG. 1 is used. The spindle 130 can be the same as or substantially the same as the spindle 30 of the first embodiment. Since the hammer 140 is rotated while the outer peripheral surface 140a is in contact with the needle bearing 180, the diameter of the outer peripheral surface excluding the striking claw portion is configured to be a constant size from the front end to the rear end. Further, since the shape of the hammer case 103 is determined in accordance with the shape of the hammer 140, the diameter of the inner wall surface of the hammer case 103 is formed to be a cylindrical surface. The anvil 160 can be a common component as shown in FIG. 1, and a bit holding portion 70 is formed at the tip thereof. The shaft portion of the anvil 160 is supported by a needle bearing 19a. In order to hold the needle bearing 19a, a narrow cylindrical portion 103a extending forward from the vertical wall 103b is formed on the front side of the hammer case 103. That is, needle bearings (19a, 180) are disposed in the hammer case 103 on the inside of the small diameter cylindrical portion 103a and on the inside of the large diameter cylindrical portion 103c, respectively. Between the small-diameter cylindrical portion 103a and the cylindrical portion 103c is a vertical wall 103b extending in a radial direction substantially perpendicular to the axis A1. As described above, the second embodiment is characterized in that two bearing devices (19a, 180) are provided in a metal integrally formed hammer case 103 made of an aluminum alloy or the like. One bearing device (needle bearing 19 a) rotatably supports the anvil 160 on the hammer case 103. The other bearing device (needle bearing 180) supports the hammer 140 on the hammer case 103. That is, the two bearing devices pivotally support (hold) different components (anvil 160, hammer 140). In other words, different components are pivotally supported (held) on the same component (hammer case 103) by two bearing devices.
ハンマケース１０３の太径の円筒部１０３ｃの内側には、突き当て部１０３ｅが形成され、突き当て部１０３ｅよりも後方側のハンマケース１０３の内径がやや大きく形成される。突き当て部１０３ｅよりも後方側にはニードルベアリング１８０がすきまばめによって固定される。ニードルベアリング１８０の種類としては、例えば、保持器付針状ころ軸受を採用できる。保持器付針状ころ軸受は、複数の針状ころの径方向外側部分にシェルを有しないため、外径が小さくなりハンマケース１０３の大型化抑制には好都合である。シェル無しのニードルベアリング１８０に含まれる細長い円筒状の針状ころ１８１は、その軸心が軸線Ａ１と平行方向（つまり図１５の前後方向）に配置され、針状ころ１８１の前後にはリング状の保持器１８２ａ、１８２ｂ（符号は図１６参照）が設けられて、前後の保持器１８２ａ、１８２ｂを回り止めをする１本の連結部材（図では見えない）にて保持されている。ニードルベアリング１８０の配置領域を含むハンマケース１０３の内側には、機械部品の摩耗を防ぐためのグリスが充填されているが、内側にてハンマ１４０が高速回転すると、シェル無しの保持器付針状ころ軸受の針状ころ１８１の周囲にグリスが溜まりやすくなるので、潤滑上有利である。  An abutting portion 103e is formed inside the thick cylindrical portion 103c of the hammer case 103, and the inner diameter of the hammer case 103 on the rear side of the abutting portion 103e is formed slightly larger. A needle bearing 180 is fixed to the rear side of the abutting portion 103e by a clearance fit. As a kind of needle bearing 180, a needle roller bearing with a cage can be adopted, for example. Since the needle roller bearing with a cage does not have a shell in the radially outer portion of the plurality of needle rollers, the outer diameter is reduced, which is convenient for suppressing the increase in the size of the hammer case 103. The elongated cylindrical needle roller 181 included in the needleless bearing 180 without a shell has an axial center arranged in a direction parallel to the axis A1 (that is, the front-rear direction in FIG. 15). Cages 182a and 182b (see FIG. 16 for reference numerals) are provided and held by one connecting member (not visible in the figure) that prevents the front and rear cages 182a and 182b from rotating. The inside of the hammer case 103 including the arrangement area of the needle bearing 180 is filled with grease for preventing wear of machine parts. However, when the hammer 140 rotates at a high speed on the inside, the needle shape with a cage without a shell is provided. Since grease easily collects around the needle roller 181 of the roller bearing, it is advantageous in terms of lubrication.
ニードルベアリング１８０の後方側は、減速機構２０のリングギヤ２３によって軸方向に保持される。リングギヤ２３の後方側には、２つの軸受１８ａ、１９ｂを保持するインナカバー１７が設けられ、インナカバー１７がリングギヤ２３の軸方向の動きを抑制すると共に回転中心の位置決めを行うもので、プラスチック等の合成樹脂製の筒状の一体部品であって、本体ハウジング１０２とは別部材にて構成される。  The rear side of the needle bearing 180 is held in the axial direction by the ring gear 23 of the speed reduction mechanism 20. An inner cover 17 for holding the two bearings 18a and 19b is provided on the rear side of the ring gear 23. The inner cover 17 suppresses the axial movement of the ring gear 23 and positions the rotation center. This is a cylindrical integral part made of synthetic resin, and is constituted by a member different from the main body housing 102.
次に図１６を用いてハンマ１４０とニードルベアリング１８０の関係を更に説明する。ハンマ１４０が図１５の状態からハンマスプリング５４を圧縮しながら後退して最も後側に位置すると、図１６の位置になる。この状態はカムボール５１がＶ字状のスピンドルカム溝１３３のうち、一方側の後端部（図８（２）のスピンドルカム溝３３の後端部３３ｅ）付近に到達した状態である。ハンマケース１０３の内側には、軸線Ａ１に沿った前後方向の長さＬＮのニードルベアリング１８０が配置され、後退時にはハンマ１４０の打撃爪を除く外周面１４０ａのほぼ全部がニードルベアリング１８０に接触する。ここでは、ニードルベアリング１８０として、保持器付針状ころ軸受を用いた。つまり、ニードルベアリング１８０には、保持器１８２ａ、１８２ｂとそれに保持される針状ころ１８１が複数設けられる。ハンマケース１０３の内側には円周方向に連続するように形成された段差状の突き当て部（段差部）１０３ｅを有し、すきまばめによって突き当て部１０３ｅよりも後方側にニードルベアリング１８０が配置される。ニードルベアリング１８０の後端側は、リングギヤ２３が挿入されるので、軸線Ａ１方向にみてリングギヤ２３が好適な押さえ部材となって、突き当て部１０３ｅとリングギヤ２３の間にニードルベアリング１８０を挟持する。  Next, the relationship between the hammer 140 and the needle bearing 180 will be further described with reference to FIG. When the hammer 140 moves backward from the state shown in FIG. 15 while compressing the hammer spring 54 and is located at the rearmost position, the position becomes the position shown in FIG. This state is a state in which the cam ball 51 reaches the vicinity of the rear end portion on one side (the rear end portion 33e of the spindle cam groove 33 in FIG. 8B) of the V-shaped spindle cam groove 133. Inside the hammer case 103, a needle bearing 180 having a length LN in the front-rear direction along the axis A1 is disposed, and almost all of the outer peripheral surface 140a except the striking claw of the hammer 140 contacts the needle bearing 180 when retracted. . Here, a needle roller bearing with a cage is used as the needle bearing 180. That is, the needle bearing 180 is provided with a plurality of cages 182a and 182b and needle rollers 181 held by the cages. The hammer case 103 has a stepped abutting portion (stepped portion) 103e formed so as to be continuous in the circumferential direction, and a needle bearing 180 is provided behind the abutting portion 103e by clearance fitting. Be placed. Since the ring gear 23 is inserted into the rear end side of the needle bearing 180, the ring gear 23 becomes a suitable pressing member when viewed in the direction of the axis A1, and the needle bearing 180 is sandwiched between the abutting portion 103e and the ring gear 23.
インパクト工具１０１の高性能化を図るためには、ハンマ１４０の後退可能量を十分確保すれば良い。しかしながら、スピンドル１３０の外径が従来と同じならば後退可能量が決まってしまうので、後退可能量を伸ばすことは難しい。一方で、離脱トルクを下げるためにはカムリード角を寝かせたいという要望もある。その要望を満たすには、限られたスペース内でのハンマ１４０の後退可能量がさらに減ってしまう。本実施例では、その対策として通常のカム機構にはカムボールが２つあるところを、カムボール５１を１つだけにして側面視で１つのＶ字状のカム溝（図８（２））とすることで、ハンマ１４０の後退可能量を従来の約２倍近くまで確保できるようにした。一方、ハンマ後退量が大幅に増えたことでカムリード角θ（図１２（１）参照）を小さくして打撃動作に移るためのハンマ１４０の離脱トルクを従来よりも下げるようにした。さらに本実施例では、カムボール５１を一つにしたことによるハンマ１４０の回転バランスの崩れを、ハンマ１４０の外周面を保持するニードルベアリング１８０を設けたことにより回避するように構成した。第一の実施例のようにハンマ１４０の後方の内周側に配置するのも効率的であるが、スピンドル１３０の長さが長くなってしまうことのトレードオフになる。そこで第二の実施例では、ハンマ１４０の外周側で保持するようにしたので、内周側にニードルベアリング５６（図２参照）を設けなくても十分な回転バランスをとることが可能となった。さらに、ハンマケース１０３側でニードルベアリング１８０を保持するので、小形のハンマ１４０を使用するインパクト工具の場合であっても、ハンマ内周面の難易な加工をしなくても済む。  In order to improve the performance of the impact tool 101, it is sufficient to ensure a sufficient retractable amount of the hammer 140. However, if the outer diameter of the spindle 130 is the same as that of the prior art, the retractable amount is determined, so it is difficult to increase the retractable amount. On the other hand, there is also a desire to lay down the cam lead angle in order to reduce the separation torque. In order to satisfy the demand, the retractable amount of the hammer 140 within a limited space is further reduced. In this embodiment, as a countermeasure, a normal cam mechanism has two cam balls, and only one cam ball 51 is provided to form one V-shaped cam groove (FIG. 8 (2)). As a result, the retractable amount of the hammer 140 can be secured up to about twice the conventional amount. On the other hand, since the amount of retraction of the hammer is greatly increased, the cam lead angle θ (see FIG. 12 (1)) is reduced, and the separation torque of the hammer 140 for moving to the striking operation is made lower than before. Furthermore, in this embodiment, the rotation balance of the hammer 140 due to the single cam ball 51 is prevented from being lost by providing the needle bearing 180 that holds the outer peripheral surface of the hammer 140. As in the first embodiment, it is efficient to arrange the hammer 140 on the inner peripheral side behind the hammer 140, but this is a trade-off that the length of the spindle 130 becomes longer. Therefore, in the second embodiment, since it is held on the outer peripheral side of the hammer 140, it is possible to achieve a sufficient rotational balance without providing the needle bearing 56 (see FIG. 2) on the inner peripheral side. . Furthermore, since the needle bearing 180 is held on the hammer case 103 side, even if the impact tool uses a small hammer 140, it is not necessary to easily process the inner peripheral surface of the hammer.
次に図１７を用いてハンマ１４０とアンビル１６０の位置関係をさらに説明する。スピンドル軸部１３１は、減速機構２０の遊星キャリア部の前方側に位置し、その外周面にＶ字状の１組のスピンドルカム溝１３３が設けられる。ここではハンマ１４０の長さＬＨに対して、ニードルベアリング１８０の長さＬＮが十分長く形成される。つまり、ハンマ１４０の可動範囲では必ずニードルベアリング１８０と接触するようにニードルベアリング１８０の大きさを設定した。（１）に示すハンマ１４０が通常位置（後退していない状態）では、ハンマ１４０とニードルベアリング１８０は部分的にはオーバーラップしているが、完全にはオーバーラップしていない。これは、（１）の状態ではハンマ１４０の打撃爪１４６ａ～１４６ｃ（図では１４６ｃは見えない）とアンビル１６０の羽根部１６３ａ～１６３ｃ（図では１６３ｃは見えない）が当接している状態で、ハンマ１４０の軸ぶれの度合いが少ないため、ハンマ１４０の外周面の後端付近だけを保持すれば十分だからである。一方、（２）に示すようにハンマスプリング５４を圧縮して、ハンマ１４０が後退しているような状態は、ハンマ１４０の打撃爪１４６ａ～１４６ｃ（図では１４６ｃは見えない）とアンビル１６０の羽根部１６３ａ～１６３ｃ（図では１６３ｃは見えない）が非接触状態であるので、ハンマ１４０は内周側で１つのカムボール５１で保持されている不安定な状態である。しかしながら、ハンマ１４０がアンビル１６０との係合状態が離脱する際には、打撃爪を除くハンマ１４０の外周面全体がニードルベアリング１８０の針状ころ１８１に接触するので、ハンマ１４０の姿勢を精度良く保持し、ハンマ１４０の回転軸を軸線Ａ１と良好に一致させることが可能となった。なお、図１６から明らかなように、ニードルベアリング１８０の軸方向の配置範囲は、スピンドルカム溝１３３の前端位置から後端位置までの軸方向の範囲に対してオーバーラップしている。  Next, the positional relationship between the hammer 140 and the anvil 160 will be further described with reference to FIG. The spindle shaft portion 131 is located on the front side of the planetary carrier portion of the speed reduction mechanism 20, and a set of V-shaped spindle cam grooves 133 are provided on the outer peripheral surface thereof. Here the length L H of the hammer 140, the length L N of the needle bearing 180 is formed long enough. That is, the size of the needle bearing 180 is set so that it always comes into contact with the needle bearing 180 within the movable range of the hammer 140. When the hammer 140 shown in (1) is in a normal position (in a state where the hammer 140 is not retracted), the hammer 140 and the needle bearing 180 partially overlap, but do not completely overlap. This is because the hammering claws 146a to 146c (146c is not visible in the figure) and the blades 163a to 163c (163c are not visible in the figure) of the anvil 160 are in contact with each other in the state (1). This is because it is sufficient to hold only the vicinity of the rear end of the outer peripheral surface of the hammer 140 because the degree of shaft shake of the hammer 140 is small. On the other hand, as shown in (2), when the hammer spring 54 is compressed and the hammer 140 is retracted, the hammering claws 146a to 146c of the hammer 140 (146c is not visible in the figure) and the blades of the anvil 160 Since the parts 163a to 163c (163c is not visible in the drawing) are in a non-contact state, the hammer 140 is in an unstable state being held by one cam ball 51 on the inner peripheral side. However, when the hammer 140 is disengaged from the anvil 160, the entire outer peripheral surface of the hammer 140 excluding the striking claw comes into contact with the needle rollers 181 of the needle bearing 180. The rotation axis of the hammer 140 can be well matched with the axis A1. As is apparent from FIG. 16, the axial arrangement range of the needle bearing 180 overlaps the axial range from the front end position to the rear end position of the spindle cam groove 133.
図１７（１）に示すようにハンマ１４０が通常位置（前進位置）にあるとき、ニードルベアリング１８０の前後方向中心位置１８５（図中の黒三角マーク）が、ハンマ１４０の長さＬＨが占める領域よりも後方側に位置する。また、ハンマ１４０の前後方向中心位置１４９（図中の黒三角マーク）がニードルベアリング１８０の前端位置よりも後方側に位置する。一方、ハンマ１４０が最も後退した位置（後退位置）にあるときには、図１７（２）に示すようにハンマ１４０の長さＬＨが占める部分が、完全にニードルベアリング１８０の占める長さＬＮの内部に入る様な位置関係となる。このようにニードルベアリング１８０の軸方向の長さが長いほどハンマ１４０のがたつきを効果的に防止できる。また、ニードルベアリング１８０の長さＬＮが長いほど、ハンマケース１０３内に挿入するときの組み立て性が向上する。従って図１７のニードルベアリング１８０は、ハンマケース１０３に対して強固な回り止めをしなくても済む。また、ハンマケース１０３側にはキー溝を設けるなどの特別な仕組みをすることは不要であるが、確実に回り止めを行うためにキー溝を設けても良い。また、本実施例ではニードルベアリング１８０及びハンマ１４０の中心位置１８５及び１４９を上述の通りとしたが、図１７や図１８のニードルベアリングの位置よりも前方側（アンビル１６０側）に配置しても良い。すなわち、ハンマ１４０が前進位置及び後退位置にある状態において、少なくともハンマ１４０の一部がニードルベアリング１８０に接するようニードルベアリング１８０を配置すれば良い。  As shown in FIG. 17A, when the hammer 140 is in the normal position (advanced position), the longitudinal center position 185 of the needle bearing 180 (black triangle mark in the figure) is occupied by the length L H of the hammer 140. Located behind the area. Further, the center position 149 in the front-rear direction of the hammer 140 (the black triangular mark in the figure) is located on the rear side of the front end position of the needle bearing 180. On the other hand, when in the position in which the hammer 140 is the most retreated (retracted position), a length L H occupied portion of the hammer 140 as shown in FIG. 17 (2), the length of L N fully occupied by needle bearings 180 The positional relationship is such that it enters the interior. Thus, the longer the axial length of the needle bearing 180, the more effectively the hammer 140 can be prevented from rattling. Further, as the length LN of the needle bearing 180 is longer, the assemblability when inserted into the hammer case 103 is improved. Therefore, the needle bearing 180 shown in FIG. Further, it is not necessary to provide a special mechanism such as providing a key groove on the hammer case 103 side, but a key groove may be provided in order to reliably prevent rotation. In the present embodiment, the center positions 185 and 149 of the needle bearing 180 and the hammer 140 are as described above. However, the needle bearing 180 and the hammer 140 may be arranged on the front side (anvil 160 side) from the position of the needle bearing in FIGS. good. That is, the needle bearing 180 may be disposed so that at least a part of the hammer 140 is in contact with the needle bearing 180 in a state where the hammer 140 is in the forward movement position and the backward movement position.
以上説明したように、第二の実施例においてはハンマ１４０の外周側にニードルベアリング１８０を設けたので、ハンマ１４０を１つのカムボール５１だけでスピンドル１３０に対して安定して保持することができる。しかも、ニードルベアリング１８０をハンマケース１０３側に設けたので図２３で示したスピンドル２３０及びハンマ２４０側の構成を実質的に変更する必要が無い。従って、第二の実施例の実現は比較的容易である。また、組立性においても、ハンマケース１０３内にニードルベアリング１８０を組み込む工程が増えるだけで、それ以外の組み立て工程は従来と同じで良いので、コストアップも抑制できる。また、従来構造では、スピンドル表面に塗布されたグリスは遠心力により外周側に配されたハンマケース側に飛散することになる。これより、スピンドルとハンマの摺動部のグリスが枯渇することでカジリ、発熱、磨耗などが生じて耐久性を損ねる問題があった。しかしながら、第二の実施例によれば、ニードルベアリング１８０をハンマ１４０とハンマケース１０３との間（ハンマ１４０の外周側）に設けたため、スピンドル表面に塗布されたグリスは遠心力によってニードルベアリング１８０側に飛散することになり、グリスの枯渇がなく耐久性も大幅に向上させることができる。尚、第二の実施例では、ハンマ１４０の内周側にはベアリングが設けられないが、第一の実施例と第二の実施例を併用して、ハンマ１４０の外周側と内周側の双方にベアリングを設けることも可能である。また、第二の実施例では、カムボール５１（スピンドルカム溝１３３）を１つとした構成においてニードルベアリング１８０を設けたが、ニードルベアリング１８０を図８（１）に示すようなカムボールが２つ（スピンドルカム溝が２つ）の従来の構成に適用しても良い。また、第一の実施例のニードルベアリング５６を従来の構成に適用しても良い。  As described above, since the needle bearing 180 is provided on the outer peripheral side of the hammer 140 in the second embodiment, the hammer 140 can be stably held with respect to the spindle 130 by only one cam ball 51. Moreover, since the needle bearing 180 is provided on the hammer case 103 side, it is not necessary to substantially change the configuration of the spindle 230 and the hammer 240 shown in FIG. Therefore, the realization of the second embodiment is relatively easy. Further, in terms of assemblability, the number of steps for incorporating the needle bearing 180 into the hammer case 103 is increased, and the other assembly steps may be the same as the conventional one, so that an increase in cost can be suppressed. In the conventional structure, the grease applied to the spindle surface is scattered by the centrifugal force toward the hammer case disposed on the outer peripheral side. As a result, the grease on the sliding part of the spindle and the hammer is depleted, which causes galling, heat generation, wear, and the like, which impairs durability. However, according to the second embodiment, since the needle bearing 180 is provided between the hammer 140 and the hammer case 103 (on the outer peripheral side of the hammer 140), the grease applied to the spindle surface is on the needle bearing 180 side by centrifugal force. As a result, there is no grease depletion and the durability can be greatly improved. In the second embodiment, bearings are not provided on the inner peripheral side of the hammer 140, but the outer peripheral side and inner peripheral side of the hammer 140 are used in combination with the first and second embodiments. It is also possible to provide bearings on both sides. Further, in the second embodiment, the needle bearing 180 is provided in the configuration in which the cam ball 51 (spindle cam groove 133) is one, but the needle bearing 180 has two cam balls (spindle) as shown in FIG. You may apply to the conventional structure of 2 cam grooves. Further, the needle bearing 56 of the first embodiment may be applied to a conventional configuration.
図１８は第二の実施例の第一変形例を説明する。図１８に示すインパクト工具１０１Ａは軸方向に短い長さＬＮのニードルベアリング１８０Ａを用いたもので、それに合わせてハンマケース１０３Ａの形状（特に突き当て部の位置）を変更している。また、リングギヤ２３Ａの前側円筒部でニードルベアリング１８０Ａの後方を押さえるようにしている。それ以外の構成部品は、図１５～図１７で示したインパクト工具１０１と同じである。ここでは、ハンマ１４０の外周面の長さＬＨに比べて、ニードルベアリング１８０Ａの長さＬＮが短い。しかしながら、ハンマ１４０が前端位置から後端位置のいずれにおいても、長さＬＨと長さＬＮの少なくとも一部がオーバーラップする状態にある。また、図１８（２）に示すようにハンマ１４０が後退した際には、ハンマ１４０の外周面１４０ａの軸方向ほぼ中央付近でニードルベアリング１８０Ａと接するので、ハンマ１４０の姿勢が乱れること無くスムーズに回転する。このように、ハンマ１４０がどの前後位置にあっても針状ころと接する配置にできるならば、ニードルベアリング１８０、１８０Ａの前後方向の長さは任意に設定しても良い。  FIG. 18 illustrates a first modification of the second embodiment. The impact tool 101A shown in FIG. 18 uses a needle bearing 180A having a short length LN in the axial direction, and the shape of the hammer case 103A (particularly the position of the abutting portion) is changed accordingly. Further, the rear side of the needle bearing 180A is pressed by the front cylindrical portion of the ring gear 23A. Other components are the same as those of the impact tool 101 shown in FIGS. Here, compared to the length L H of the outer peripheral surface of the hammer 140, the length L N of the needle bearing 180A is short. However, the hammer 140 is in a state where at least a part of the length L H and the length L N overlap at any position from the front end position to the rear end position. As shown in FIG. 18 (2), when the hammer 140 is retracted, the hammer 140 comes into contact with the needle bearing 180A substantially in the vicinity of the center in the axial direction of the outer peripheral surface 140a of the hammer 140, so that the posture of the hammer 140 is not disturbed smoothly. Rotate. As described above, the length of the needle bearings 180 and 180A in the front-rear direction may be arbitrarily set as long as the hammer 140 can be disposed in contact with the needle rollers at any front-rear position.
次に図１９を用いて第二の実施例の第二変形例に係るインパクト工具１０１Ｂを説明する。図１９に示すインパクト工具１０１Ｂでは、ニードルベアリング１８０Ｂの形状を保持器付針状ころ軸受からシェル形針状ころ軸受に変更したものである。つまり、ニードルベアリング１８０Ｂは、薄い鋼板にて外輪を形成して、その軌道面に針状ころ１８１とシェル１８３を組付けた軸受である。針状ころ１８１の軸方向両側であってシェルの内側には保持器１８２ａ、１８２ｂが設けられる。ニードルベアリング１８０Ｂの軸方向の長さは、図１５で示したニードルベアリング１８０と同じである。また、ハンマケース１０３Ｂの形状は、ニードルベアリング１８０Ｂのサイズが径方向外側にやや大きくなったことに対応させた形状であるものの、基本構成は図１５で示したハンマケース１０３と同じである。ニードルベアリング１８０Ｂは、外輪たるシェル１８３が外周側に形成され、内周側には針状ころ１８１が配置されるので、内輪を用いずに転動軸（針状ころ１８１）を直接ハンマ１４０の外周面を軌道とすることが可能である。また、外輪が針状ころ１８１及び保持器１８２ａ、１８２ｂから分離できない構造であるので、剛性が高く、ハンマケース１０３Ｂに適切な嵌め合いで圧入するだけで軸線Ａ１方向の固定のために止め輪などが不要となる。  Next, an impact tool 101B according to a second modification of the second embodiment will be described with reference to FIG. In the impact tool 101B shown in FIG. 19, the shape of the needle bearing 180B is changed from a needle roller bearing with a cage to a shell needle roller bearing. That is, the needle bearing 180B is a bearing in which an outer ring is formed of a thin steel plate and the needle rollers 181 and the shell 183 are assembled on the raceway surface. Retainers 182a and 182b are provided on both sides in the axial direction of the needle roller 181 and inside the shell. The axial length of the needle bearing 180B is the same as that of the needle bearing 180 shown in FIG. Further, the shape of the hammer case 103B is a shape corresponding to the size of the needle bearing 180B becoming slightly larger radially outward, but the basic configuration is the same as the hammer case 103 shown in FIG. In the needle bearing 180B, a shell 183 as an outer ring is formed on the outer peripheral side, and a needle roller 181 is disposed on the inner peripheral side, so that the rolling shaft (the needle roller 181) is directly attached to the hammer 140 without using the inner ring. The outer peripheral surface can be a track. Further, since the outer ring has a structure that cannot be separated from the needle rollers 181 and the cages 182a and 182b, the rigidity is high, and a retaining ring or the like is used for fixing in the direction of the axis A1 simply by press-fitting into the hammer case 103B with an appropriate fit. Is no longer necessary.
図２０は図１９に示す打撃部及び被打撃部の展開斜視図である。前方側からハンマケース１０３Ｂ、アンビル１６０、ハンマ１４０、スピンドル１３０の順に配置されるという基本構成は、図１にて示した第一の実施例のインパクト工具１と同じである。カムボール５１の数は１つである。ハンマケース１０３はカップ状であって、先端中央部に貫通穴が形成され、貫通穴の縁部から細径円筒部１０３ａが形成される。細径円筒部１０３ａの内側にはアンビル１６０を軸支するためのニードルベアリング１９ａが取りつけられる。ハンマケース１０３の円筒部１０３ｃの内側には、ニードルベアリング１８０Ｂが挿入され、例えば中間ばめによって固定される。ニードルベアリング１８０Ｂの内周側には、多数の針状ころ１８１が設けられ、その回転軸心方向は、スピンドル１３０の回転中心と平行方向になる。  20 is a developed perspective view of the hitting part and the hit part shown in FIG. The basic configuration in which the hammer case 103B, the anvil 160, the hammer 140, and the spindle 130 are arranged in this order from the front side is the same as the impact tool 1 of the first embodiment shown in FIG. The number of cam balls 51 is one. The hammer case 103 is cup-shaped, and a through hole is formed at the center of the tip, and a thin cylindrical portion 103a is formed from the edge of the through hole. A needle bearing 19a for pivotally supporting the anvil 160 is attached to the inside of the small-diameter cylindrical portion 103a. A needle bearing 180B is inserted inside the cylindrical portion 103c of the hammer case 103, and is fixed by, for example, an intermediate fit. A large number of needle rollers 181 are provided on the inner peripheral side of the needle bearing 180 </ b> B, and the rotation axis direction thereof is parallel to the rotation center of the spindle 130.
アンビル１６０はインパクト工具１０１Ｂの出力軸を形成すると共に、ハンマ１４０の被打撃部を形成する。その形状は図２で示したアンビル６０とほぼ同じである。アンビル１６０は、その円筒形の出力軸部１６１の後方に、３つの羽根部１６３ａ～１６３ｃによる被打撃爪が形成されたものである。出力軸部１６１の前側端部には装着孔１６１ａが形成される。羽根部１６３ａ～１６３ｃは、回転方向に見て１２０度ずつ隔てるように均等に配置された被打撃爪であり、径方向外側に伸びるように配置される。被打撃部の後方の、円筒状の軸部１６６は、スピンドル１３０の嵌合孔１３２に係合する。  The anvil 160 forms the output shaft of the impact tool 101 </ b> B and the hit part of the hammer 140. Its shape is almost the same as the anvil 60 shown in FIG. The anvil 160 has a hitting claw formed by three blade portions 163a to 163c behind the cylindrical output shaft portion 161. A mounting hole 161 a is formed in the front end portion of the output shaft portion 161. The blade portions 163a to 163c are hitting claws that are evenly arranged so as to be separated by 120 degrees when viewed in the rotation direction, and are arranged so as to extend radially outward. A cylindrical shaft portion 166 behind the hit portion engages with the fitting hole 132 of the spindle 130.
ハンマ１４０は、スピンドル１３０にて保持される部材である。ハンマ１４０はスピンドル１３０に対して浮いた状態、又は、非接触状態の姿勢を保つように保持される。本実施例ではハンマ１４０の外周側にニードルベアリング１８０Ｂが位置するようにし、内周側にはニードルベアリングを装着していない。ハンマ１４０の前面側の外周３カ所には、軸方向の前方側（アンビル１６０側）に突出する３つの打撃爪１４６ａ～１４６ｃが、回転角で１２０度ずつ隔てるように配置される。打撃爪１４６ａ～１４６ｃの回転方向にみて２つの側面は、アンビル１６０の３つの羽根部１６３ａ～１６３ｃと衝突時に良好に面接触する。ハンマ１４０の外周面１４０ａは軸線と平行な筒状され、中央部には貫通孔１４１ａを有する。貫通孔１４１ａを形成する内周側であって前方側にはハンマカム溝１４４が形成される。ハンマ１４０の内周面の周方向の一箇所には壁部１４５が形成される。壁部１４５は前端側のスピンドル１３０の外周面と隣接又は当接する箇所となり、ハンマ１４０がスピンドル１３０に対する相対回転の姿勢維持に貢献する。ハンマ１４０の壁部１４５と周方向に対向する箇所には、組立時にカム溝内にカムボール５１を挿入するための挿入溝１４４ａが形成される。  The hammer 140 is a member that is held by the spindle 130. The hammer 140 is held so as to be in a floating state or a non-contact state with respect to the spindle 130. In this embodiment, the needle bearing 180B is positioned on the outer peripheral side of the hammer 140, and the needle bearing is not mounted on the inner peripheral side. Three striking claws 146a to 146c projecting forward in the axial direction (anvil 160 side) are arranged at three positions on the outer periphery on the front side of the hammer 140 so as to be separated by 120 degrees in rotation angle. The two side surfaces of the striking claws 146a to 146c make good surface contact with the three blade portions 163a to 163c of the anvil 160 at the time of collision. The outer peripheral surface 140a of the hammer 140 has a cylindrical shape parallel to the axis, and has a through hole 141a at the center. A hammer cam groove 144 is formed on the inner peripheral side forming the through hole 141a and on the front side. A wall portion 145 is formed at one place in the circumferential direction of the inner peripheral surface of the hammer 140. The wall portion 145 becomes a portion adjacent to or in contact with the outer peripheral surface of the spindle 130 on the front end side, and the hammer 140 contributes to maintaining the posture of relative rotation with respect to the spindle 130. An insertion groove 144a for inserting the cam ball 51 into the cam groove at the time of assembly is formed at a location facing the wall portion 145 of the hammer 140 in the circumferential direction.
スピンドル１３０のスピンドルカム溝１３３は１つだけ形成される。スピンドルカム溝１３３とハンマカム溝１４４及びカムボール５１によるカム機構によって、ハンマ１４０はスピンドル１３０とほぼ連動するように回転する。ハンマ１４０のスピンドル１３０に対する回転及び軸方向移動は、ニードルベアリング１８０Ｂによって効果的に保持される。スピンドル軸部１３１の後方側には、減速機構２０の遊星キャリア部となるフランジ部１３７、１３８が形成される。フランジ部１３７、１３８は、３つのプラネタリーギヤ２２のシャフトを軸支する。  Only one spindle cam groove 133 of the spindle 130 is formed. The hammer 140 rotates so as to be substantially interlocked with the spindle 130 by the cam mechanism by the spindle cam groove 133, the hammer cam groove 144 and the cam ball 51. The rotation and axial movement of the hammer 140 relative to the spindle 130 is effectively retained by the needle bearing 180B. On the rear side of the spindle shaft portion 131, flange portions 137 and 138 that are planetary carrier portions of the speed reduction mechanism 20 are formed. The flange portions 137 and 138 support the shafts of the three planetary gears 22.
次に図２１を用いて第二の実施例の第三変形例を説明する。図２１に示すインパクト工具１０１Ｃでは、ニードルベアリング１８０の代わりに焼結材からなるメタル１８６を用いたものである。メタル１８６はしまりばめによってハンマケース１０３Ｃの内側に固定する。このようにハンマ１４０の外周面をメタル１８６の接触面にて滑らすようにしても、ハンマ１４０の回転及び軸方向移動時の姿勢を効果的に保持できるので、ハンマ１４０の軸心が振れないように安定して保持できる。尚、ハンマケース１０３Ｃとインナカバー１７に囲まれる空間内にはグリス等の潤滑油が潤沢に塗布されているので、外周側に位置するメタル１８６とハンマ１４０の間の摩擦力は十分に低減される。メタル１８６の後方側とリングギヤ２３の前端部の間は、隙間１８７が開いているが、この空間を設けることは必須ではなく、リングギヤ２３の形状を変更して前方側に延ばして隙間が生じない様に構成しても良い。  Next, a third modification of the second embodiment will be described with reference to FIG. In the impact tool 101 </ b> C shown in FIG. 21, a metal 186 made of a sintered material is used instead of the needle bearing 180. The metal 186 is fixed inside the hammer case 103C by an interference fit. Thus, even if the outer peripheral surface of the hammer 140 is slid on the contact surface of the metal 186, the posture of the hammer 140 during rotation and axial movement can be effectively maintained, so that the axis of the hammer 140 does not shake. Can be held stably. In addition, since lubricating oil such as grease is sufficiently applied in the space surrounded by the hammer case 103C and the inner cover 17, the frictional force between the metal 186 located on the outer peripheral side and the hammer 140 is sufficiently reduced. The A gap 187 is open between the rear side of the metal 186 and the front end portion of the ring gear 23. However, it is not essential to provide this space. The shape of the ring gear 23 is changed and extended to the front side so that no gap is generated. You may comprise like this.
第二の実施例のいずれの例においても、ハンマケース１０３の内周部にベアリングを配置し、ハンマ１４０の外周面を保持するように構成したので、ハンマ１４０の軸心がぶれずに安定した回転動作、打撃動作が可能となる。尚、第二の実施例では軸受部材としてニードルベアリングとメタルの例を示したが、ハンマ１４０と良好な摺動特性を有するならば、ニードル式でない他のベアリングであっても、その他の摺動材であっても良い。  In any example of the second embodiment, since the bearing is disposed on the inner peripheral portion of the hammer case 103 and the outer peripheral surface of the hammer 140 is held, the shaft center of the hammer 140 is stable without being shaken. Rotation operation and batting operation are possible. In the second embodiment, an example of a needle bearing and a metal is shown as a bearing member. However, other bearings other than the needle type may be used as long as they have good sliding characteristics with the hammer 140. It may be a material.
以上、本発明を２つの実施例に基づいて説明したが、本発明は上述の実施例や種々の変形例に限定されるものではなく、その趣旨を逸脱しない範囲内で更なる変更が可能である。例えば、上述のハンマ４０は３本の打撃爪を配した構成にて説明したが、１８０度隔てた位置に打撃爪と羽根部を有する２本羽根のアンビルと、２つの打撃爪を有するハンマを用いるインパクト工具においても同様に適用できる。また、ハンマとスピンドルとの間、又は、ハンマとハンマケースの間に設けられる転動部材、軸受部材は、ニードルベアリングや上述の例だけに限られずにその他の部材を用いても良い。  As mentioned above, although this invention was demonstrated based on two Example, this invention is not limited to the above-mentioned Example and various modifications, Further change is possible within the range which does not deviate from the meaning. is there. For example, the above-described hammer 40 has been described with a configuration in which three hitting claws are arranged. However, a hammer having two hitting claws and a two-blade anvil having hitting claws and a vane portion at a position 180 degrees apart. The same applies to the impact tool used. Further, the rolling member and the bearing member provided between the hammer and the spindle or between the hammer and the hammer case are not limited to the needle bearing or the above example, and other members may be used.
１…インパクト工具、２…本体ハウジング、２ａ…胴体部、３…ハンマケース、４…モータ、４ａ…回転軸、５…弾性カバー、６…トリガスイッチ、６ａ…トリガ、７…正逆切替レバー、９…制御回路基板、１０，１０Ａ…電池パック、１１，１１Ａ…ラッチボタン、１２…出力切替スイッチ、１３…冷却ファン、１７…インナカバー、１８ａ，１８ｂ…軸受、１９ａ…ニードルベアリング、１９ｂ…軸受、２０…減速機構、２１…サンギヤ、２２…プラネタリーギヤ、２３…リングギヤ、３０…スピンドル、３１…スピンドル軸部、３２，３２Ｄ…嵌合孔、３３…スピンドルカム溝、３３ａ…逆転用溝部、３３ｂ…正転用溝部、３３ｃ，３３ｅ…後端部、３３ｄ…前端部、３４…嵌合孔、３７…フランジ部、３７ａ～３７ｃ…嵌合穴、３８…フランジ部、３８ａ…嵌合穴、３９…円筒部、４０，４０Ｂ，４０Ｃ，４０Ｄ…ハンマ、４１…筒状部分、４１ａ…貫通孔、４１ｂ，４１Ｂ…段差部、４１ｃ…後端部、４１Ｃ…溝部、４２…接続部、４２ａ…前面、４３…筒状部分、４４…ハンマカム溝、４４ａ…挿入溝、４５…壁部、４６ａ～４６ｃ…打撃爪、４７ａ～４７ｃ…打撃面、４８ａ～４８ｃ…打撃面、５１…カムボール、５２…スチールボール、５３…ワッシャ、５４…ハンマスプリング、５５…ワッシャ、５５ａ…くり抜き孔、５６…ニードルベアリング、５７…シェル、５８…針状ころ、５９…回転軸、６０…アンビル、６１…出力軸部、６１ａ…装着孔、６１ｂ…細径部、６１ｃ…貫通穴、６３，６３ａ～６３ｃ…羽根部、６４ａ～６４ｃ…被打撃面、６５ａ～６５ｃ…被打撃面、６６…軸部、６９…スチールボール、７０…ビット保持部、７１，７３，７５…実線（打撃爪前方角部の移動軌跡）、７２，７４，７６…点線（打撃爪後方角部の移動軌跡）、７８ａ～７８ｃ…突起部、８１，８３…スピンドル軸部、８２，８４…スピンドルカム溝、８２ａ，８４ａ…逆転用溝部、８２ｂ，８４ｂ…正転用溝部、８５…焼結メタル、８６…リング８８ａ～８８ｃ…突起、９１，９２…プロット群、１０１，１０１Ａ～１０１Ｃ…インパクト工具、１０２…本体ハウジング、１０２ａ…胴体部、１０２ｂ…ハンドル部、１０２ｃ…拡径部、１０３，１０３Ａ～１０３Ｃ…ハンマケース、…１０３ａ…細径円筒部、１０３ｂ…垂直壁、１０３ｃ…円筒部、１０３ｅ…突き当て部、１０４…モータ、１３０…スピンドル、１３１…スピンドル軸部、１３２…嵌合孔、１３３…スピンドルカム溝、１３７…フランジ部、１４０…ハンマ、１４０ａ…外周面、１４１ａ…貫通孔、１４４…ハンマカム溝、１４４ａ…挿入溝、１４５…壁部、１４６ａ～１４６ｃ…打撃爪、１４９…（ハンマ外周面の）前後方向中心位置、１６０…アンビル、１６１ａ…装着孔、１６３ａ～１６３ｃ…被打撃爪、１８０，１８０Ａ，１８０Ｂ…ニードルベアリング、１８１…針状ころ、１８２ａ，１８２ｂ…保持器、１８３…シェル、１８５…（ニードルベアリングの）前後方向中心位置、１８６…メタル１８７…隙間、２０１…インパクト工具、２０２…本体ハウジング、２０２ａ…胴体部、２０２ｂ…ハンドル部、２０２ｃ…拡径部、２０３…ハンマケース、２１７ａ，２１７ｂ…吸気口、２１７ｃ…排気口、２１９ａ…ニードルベアリング、２１９ｂ…軸受、２２０…遊星歯車減速機構、２３０…スピンドル、２３１…スピンドル軸部、２３３，２３４…スピンドルカム溝、２３３ａ，２３４ａ…逆転用溝部、２３３ｂ，２３４ｂ…正転用溝部、２３７…フランジ部、２３８…フランジ部、２３９…円筒部、２４０…ハンマ、２４１ｃ…潤滑溝、２４４，２４５…ハンマカム溝、２４６ａ，２４６ｂ…打撃爪、２５１，２５２…カムボール、２５４…ハンマスプリング、２６０…アンビル、２６１ａ…装着孔、２６３ａ，２６３ｂ…被打撃爪、Ａ１…（モータの）軸線、ＴＢ１…離脱トルク、ＴＢ２…離脱トルク   DESCRIPTION OF SYMBOLS 1 ... Impact tool, 2 ... Main body housing, 2a ... Body part, 3 ... Hammer case, 4 ... Motor, 4a ... Rotary shaft, 5 ... Elastic cover, 6 ... Trigger switch, 6a ... Trigger, 7 ... Forward / reverse switching lever, DESCRIPTION OF SYMBOLS 9 ... Control circuit board, 10, 10A ... Battery pack, 11, 11A ... Latch button, 12 ... Output changeover switch, 13 ... Cooling fan, 17 ... Inner cover, 18a, 18b ... Bearing, 19a ... Needle bearing, 19b ... Bearing , 20 ... Deceleration mechanism, 21 ... Sun gear, 22 ... Planetary gear, 23 ... Ring gear, 30 ... Spindle, 31 ... Spindle shaft, 32, 32D ... Fitting hole, 33 ... Spindle cam groove, 33a ... Reverse rotation groove, 33b: Forward rotation groove portion, 33c, 33e: Rear end portion, 33d: Front end portion, 34: Fitting hole, 37 ... Flange portion, 37a to 37c ... Fitting hole, 38 Flange part, 38a ... fitting hole, 39 ... cylindrical part, 40, 40B, 40C, 40D ... hammer, 41 ... cylindrical part, 41a ... through-hole, 41b, 41B ... step part, 41c ... rear end part, 41C ... Groove, 42 ... Connecting portion, 42a ... Front surface, 43 ... Cylindrical portion, 44 ... Hammer cam groove, 44a ... Insertion groove, 45 ... Wall, 46a-46c ... Hitting claw, 47a-47c ... Hitting surface, 48a-48c ... Striking surface, 51 ... cam ball, 52 ... steel ball, 53 ... washer, 54 ... hammer spring, 55 ... washer, 55a ... hollow hole, 56 ... needle bearing, 57 ... shell, 58 ... needle roller, 59 ... rotary shaft, 60 ... anvil, 61 ... output shaft portion, 61a ... mounting hole, 61b ... small diameter portion, 61c ... through hole, 63, 63a-63c ... blade portion, 64a-64c ... impact surface, 65a-65 ... strike surface, 66 ... shaft part, 69 ... steel ball, 70 ... bit holding part, 71, 73, 75 ... solid line (movement trajectory at the front corner of the hitting nail), 72, 74, 76 ... dotted line (after hitting nail) 78a to 78c ... projection, 81,83 ... spindle shaft, 82,84 ... spindle cam groove, 82a, 84a ... reverse rotation groove, 82b, 84b ... forward rotation groove, 85 ... sintering Metal, 86 ... Rings 88a to 88c ... Projection, 91, 92 ... Plot group, 101, 101A to 101C ... Impact tool, 102 ... Body housing, 102a ... Body part, 102b ... Handle part, 102c ... Expanded part, 103, 103A to 103C ... Hammer case ... 103a ... Thin cylindrical part 103b ... Vertical wall 103c ... Cylindrical part 103e ... Butting part 104 ... Motor 130 ... Spind 131, spindle shaft portion, 132, fitting hole, 133, spindle cam groove, 137, flange portion, 140, hammer, 140a, outer peripheral surface, 141a, through hole, 144, hammer cam groove, 144a, insertion groove, 145 ... Wall portion, 146a to 146c ... Hitting claw, 149 ... Center position in the front-rear direction (on the outer peripheral surface of the hammer), 160 ... Anvil, 161a ... Mounting hole, 163a to 163c ... Hail to be hit, 180, 180A, 180B ... 181 ... Needle rollers, 182a, 182b ... Retainer, 183 ... Shell, 185 ... Center position in the longitudinal direction (of the needle bearing), 186 ... Metal 187 ... Gap, 201 ... Impact tool, 202 ... Main body housing, 202a ... Body 202b ... handle portion, 202c ... enlarged diameter portion, 203 ... hammer case, 217a, 217 ... intake port, 217c ... exhaust port, 219a ... needle bearing, 219b ... bearing, 220 ... planetary gear reduction mechanism, 230 ... spindle, 231 ... spindle shaft, 233, 234 ... spindle cam groove, 233a, 234a ... reverse rotation groove 233b, 234b ... forward rotation groove portion, 237 ... flange portion, 238 ... flange portion, 239 ... cylindrical portion, 240 ... hammer, 241c ... lubrication groove, 244, 245 ... hammer cam groove, 246a, 246b ... striking claw, 251, 252 ... cam ball, 254 ... hammer spring, 260 ... anvil, 261a ... mounting hole, 263a, 263b ... hit claw, A1 ... (motor) axis, TB1 ... release torque, TB2 ... release torque

Claims (15)

  1. モータと、
    前記モータによって回転方向に駆動されるスピンドルであって、スピンドル軸部と、前記スピンドル軸部に設けられたスピンドルカム溝とを有するスピンドルと、
    前記スピンドルに対して所定の範囲内で前記スピンドル軸部の軸方向及び回転方向に相対的に移動可能に構成されたハンマであって、前記スピンドル軸部に対して軸方向及び回転方向に相対的に移動可能に構成された第１の筒状部分と、
    前記スピンドルカム溝に対してカムボールを介して軸方向に相対的に移動可能に構成されたハンマカム溝と、
    前記第１の筒状部分の径方向外側に設けられた第２の筒状部分とを有し、スプリングによって前方に付勢されるハンマと、
    前記ハンマの前方において回転可能に設けられ、前記ハンマが前方に移動しながら回転したときに前記ハンマによって回転方向に打撃されるアンビルと、
    前記モータ、スピンドル、ハンマ及びアンビルを収容するハウジングと、
    を備えたインパクト工具において、
    前記スピンドル軸部と前記第１の筒状部分によって前記ハンマの前記スピンドルに対する径方向の移動を規制する第１の規制部が構成され、前記スピンドルカム溝、前記カムボール及び前記ハンマカム溝によって前記ハンマの前記スピンドルに対する軸方向の移動を規制する第２の規制部が構成され、前記第１及び第２の規制部とは別に前記ハンマの前記スピンドルに対する傾きを規制する第３の規制部を設けたを設けたことを特徴とするインパクト工具。      A motor,
    A spindle driven in the rotational direction by the motor, the spindle having a spindle shaft portion and a spindle cam groove provided in the spindle shaft portion;
    A hammer configured to be relatively movable in an axial direction and a rotational direction of the spindle shaft portion within a predetermined range with respect to the spindle, and relative to the spindle shaft portion in the axial direction and the rotational direction. A first cylindrical portion configured to be movable to
    A hammer cam groove configured to be movable relative to the spindle cam groove in the axial direction via a cam ball;
    A second cylindrical portion provided on the radially outer side of the first cylindrical portion, and a hammer biased forward by a spring;
    An anvil which is rotatably provided in front of the hammer and is struck in the rotation direction by the hammer when the hammer rotates while moving forward;
    A housing for housing the motor, spindle, hammer and anvil;
    In impact tools with
    The spindle shaft portion and the first cylindrical portion constitute a first restricting portion for restricting the movement of the hammer in the radial direction relative to the spindle, and the spindle cam groove, the cam ball, and the hammer cam groove constitute the hammer. A second restricting portion for restricting movement in the axial direction with respect to the spindle is configured, and a third restricting portion for restricting the inclination of the hammer with respect to the spindle is provided separately from the first and second restricting portions. An impact tool characterized by the provision.
  2. 前記第３の規制部は、前記スピンドルと前記ハンマとの間に設けられるか、又は前記ハウジングと前記ハンマの間に設けられることを特徴とする請求項１に記載のインパクト工具。  The impact tool according to claim 1, wherein the third restricting portion is provided between the spindle and the hammer, or is provided between the housing and the hammer.
  3. 前記第３の規制部は転動部材又は前記ハンマよりも摺動抵抗の小さい摺動部材であることを特徴とする請求項１又は２に記載のインパクト工具。  The impact tool according to claim 1 or 2, wherein the third restricting portion is a rolling member or a sliding member having a sliding resistance smaller than that of the hammer.
  4. 前記第３の規制部は、前記ハンマの外周面を支持するよう前記ハンマの外周面に接触することを特徴とする請求項１から３のいずれか一項に記載のインパクト工具。 4. The impact tool according to claim 1, wherein the third restricting portion contacts the outer peripheral surface of the hammer so as to support the outer peripheral surface of the hammer. 5.
  5. 前記第３の規制部を前記ハンマの外周と前記ハウジングの内壁の間に配置したことを特徴とする請求項１又は２に記載のインパクト工具。 The impact tool according to claim 1 or 2, wherein the third restricting portion is disposed between an outer periphery of the hammer and an inner wall of the housing.
  6. 前記ハウジングには突き当て面を形成し、前記突き当て面に前記第３の規制部を突き当てるようにしたことを特徴とする請求項５に記載のインパクト工具。  The impact tool according to claim 5, wherein an abutting surface is formed on the housing, and the third restricting portion is abutted against the abutting surface.
  7. 前記第３の規制部は、前記ハンマとは別の部材であり、前記ハンマの内周面に設けられ前記スピンドルと接触する転動部材又は摺動部材であることを特徴とする請求項１から６のいずれか一項に記載のインパクト工具。  The third restriction portion is a member different from the hammer, and is a rolling member or a sliding member provided on an inner peripheral surface of the hammer and in contact with the spindle. The impact tool according to any one of 6.
  8. 前記スピンドルカム溝と、前記ハンマカム溝は、それぞれ１つずつ、又は、２つずつ設けられ、前記スピンドルカム溝に、前記スピンドルカム溝の数と同じ数のカムボールが配置されることを特徴とする請求項４から７のいずれか一項に記載のインパクト工具。  The spindle cam groove and the hammer cam groove are provided one by one or two, respectively, and the same number of cam balls as the number of the spindle cam grooves are arranged in the spindle cam groove. The impact tool according to any one of claims 4 to 7.
  9. 前記スピンドルカム溝及び前記カムボールはそれぞれ１つのみ設けられていることを特徴とする請求項８に記載のインパクト工具。  9. The impact tool according to claim 8, wherein only one spindle cam groove and one cam ball are provided.
  10. 前記スピンドルカム溝の後端を構成する一方の円弧を形成する円の中心点から他方の円弧を形成する円の中心点までの間が、円周方向で１８０度を超えるように前記スピンドルカム溝が延びることを特徴とする請求項８又は９に記載のインパクト工具。  The spindle cam groove so that the distance from the center point of the circle forming one arc forming the rear end of the spindle cam groove to the center point of the circle forming the other arc exceeds 180 degrees in the circumferential direction. The impact tool according to claim 8, wherein the impact tool extends.
  11. 前記スピンドルと前記ハンマの摺動部であって前記スピンドルカム溝の前記一方の後端と前記他方の後端に挟まれる部分に壁部を形成したことを特徴とする請求項１０に記載のインパクト工具。  11. The impact according to claim 10, wherein a wall portion is formed in a sliding portion between the spindle and the hammer and sandwiched between the one rear end and the other rear end of the spindle cam groove. tool.
  12. 前記スピンドルカム溝の軸方向の前後方向に占める範囲は、前記支持部材の軸方向の移動範囲又は前記支持部材の配置範囲とオーバーラップすることを特徴とする請求項４から１１のいずれか一項に記載のインパクト工具。  The range occupied in the front-rear direction of the spindle cam groove in the axial direction overlaps the range of movement of the support member in the axial direction or the range of arrangement of the support member. Impact tool as described in
  13. 前記支持部材を、前記ハンマの内周側であって前記ハンマカム溝よりも後方側、又は、前記ハンマの外周側であって前記支持部材の軸方向中心位置が前記ハンマの可動範囲の軸方向中心位置よりも後方側になるように設けたことを特徴とする請求項１２に記載のインパクト工具。  The support member is located on the inner peripheral side of the hammer and behind the hammer cam groove, or on the outer peripheral side of the hammer, and the axial center position of the support member is the axial center of the movable range of the hammer. The impact tool according to claim 12, wherein the impact tool is provided so as to be rearward of the position.
  14. モータと、
    前記モータによって回転方向に駆動されるスピンドルと、前記スピンドルに対して所定の範囲内で軸方向及び回転方向に相対的に移動可能であってカム機構とスプリングによって前方に付勢されるハンマと、前記ハンマの前方において回転可能に設けられ、前記ハンマが前方に移動しながら回転したときに前記ハンマによって打撃されるアンビルと、を備えたインパクト工具において、前記カム機構は、前記スピンドルに設けられ、一方の後端から前端を経て他方の後端へと１つながりに延びるスピンドルカム溝と、前記ハンマの内周側に形成されたハンマカム溝と、前記スピンドルカム溝及び前記ハンマカム溝に配置されたカムボールと、を含み、前記スピンドルカム溝は、前記スピンドルカム溝の後端を構成する円弧を形成する円の中心の一方の中心から他方の中心までの間が円周方向で１８０度を超えて延びる、又は、１つのみ設けられていることを特徴とするインパクト工具。      A motor,
    A spindle driven in the rotational direction by the motor, a hammer that is movable relative to the spindle in the axial direction and the rotational direction within a predetermined range, and is biased forward by a cam mechanism and a spring; An impact tool comprising: an anvil that is rotatably provided in front of the hammer and is hit by the hammer when the hammer rotates while moving forward; the cam mechanism is provided on the spindle; A spindle cam groove extending in a continuous manner from one rear end through the front end to the other rear end, a hammer cam groove formed on the inner peripheral side of the hammer, and a cam ball disposed in the spindle cam groove and the hammer cam groove And the spindle cam groove has a center of a circle forming an arc constituting a rear end of the spindle cam groove. Impact tool between from one center to the other center extends beyond 180 degrees in the circumferential direction, or, characterized in that it is provided only one.
  15. 前記カム機構とは別に前記ハンマの径方向を支持する支持部材を、前記ハンマとは別に設けたことを特徴とする請求項１４に記載のインパクト工具。  The impact tool according to claim 14, wherein a support member that supports the radial direction of the hammer is provided separately from the hammer apart from the cam mechanism.
PCT/JP2019/002481 2018-02-28 2019-01-25 Impact tool WO2019167498A1 (en)

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US3030839A (en) * 1959-12-11 1962-04-24 Bosch Gmbh Robert Torque transmitting and impacting apparatus
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US20140338946A1 (en) * 2013-05-14 2014-11-20 Robert Bosch Gmbh Handheld tool apparatus
JP2016159383A (en) * 2015-02-27 2016-09-05 日立工機株式会社 Impact tool
JP2017035772A (en) * 2015-08-07 2017-02-16 日立工機株式会社 Power tool

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US2907240A (en) * 1957-01-31 1959-10-06 Bosch Gmbh Robert Power-operated, rotary impact-type hand tool
US3030839A (en) * 1959-12-11 1962-04-24 Bosch Gmbh Robert Torque transmitting and impacting apparatus
US3053360A (en) * 1960-12-30 1962-09-11 Albertson & Co Inc Rotary impact wrench mechanism
US20140338946A1 (en) * 2013-05-14 2014-11-20 Robert Bosch Gmbh Handheld tool apparatus
JP2016159383A (en) * 2015-02-27 2016-09-05 日立工機株式会社 Impact tool
JP2017035772A (en) * 2015-08-07 2017-02-16 日立工機株式会社 Power tool

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112823081A (en) * 2018-10-11 2021-05-18 株式会社村技术 Installation formula aligning device and electric tool

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