CN112706044A

CN112706044A - Electric tool

Info

Publication number: CN112706044A
Application number: CN202010613095.XA
Authority: CN
Inventors: 倪沐阳; 赵祥
Original assignee: Nanjing Deshuo Industrial Co Ltd
Current assignee: Nanjing Chervon Industry Co Ltd; Nanjing Deshuo Industrial Co Ltd
Priority date: 2019-10-25
Filing date: 2020-06-30
Publication date: 2021-04-27
Also published as: WO2021078251A1; CN212635318U; CN112706043A

Abstract

The present invention provides an electric tool, including: an electric machine including at least a rotor shaft extending along a first axis; a housing supporting the motor; the bearing is used for positioning the rotor shaft and comprises a front bearing and a rear bearing which are arranged at two ends of the motor; the switch is used for controlling the opening and closing of the motor; a control assembly that controls operation of the power tool; a power supply device for supplying power to the motor; the electric tool also comprises a detection device for detecting the rotation position of the motor, the detection device comprises a first detection element and a second detection element, the tail end of the rotor shaft is provided with a mounting hole for placing the first detection element, the projections of the first detection element and the second detection element are at least partially overlapped in the axial direction of the first axis, and the projection of the mounting hole and the projection of the rear bearing in the radial direction of the first axis are at least partially overlapped. The detection device of the electric tool can optimize the dustproof effect and enable the internal structure of the electric tool to be compact and stable.

Description

Electric tool

Technical Field

The present invention relates to an electric power tool.

Background

The electric tool provides power output operation through the motor, and in order to guarantee the normal operation of motor, generally need set up the heat dissipation air current and dispel the heat to the motor, but this will lead to the easy entering of piece that produces in the electric tool working process inside the electric tool. The wood dust can cause abrasion to affect the service life of internal elements of the electric tool, metal debris is influenced by the power-on state of an electronic device and current change, is very easy to be adsorbed on pins of the electronic device, an electric path is formed between the pins of the electronic device in an accumulated mode, and a stator and a rotor of the motor are also easy to be blocked by the sucked debris to cause rotation blockage or abrasion. Therefore, it is necessary to provide the power tool with a dust-proof structure to optimize the performance of the power tool, but providing an additional dust-proof structure undoubtedly increases the cost and is disadvantageous to the size reduction of the power tool.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention mainly aims to provide an electric tool which has a good dustproof effect and is compact in size.

In order to solve the above main object of the invention, there is provided an electric power tool including: a housing; a motor supported by the housing, the motor including at least a rotor shaft extending along a first axis; the bearing is used for positioning the rotor shaft and comprises a rear bearing and a front bearing which are arranged at two ends of the motor; the switch is used for controlling the opening and closing of the motor; the operating piece is used for being operated by a user; the control assembly is connected with the switch, wherein the rear bearing is arranged between the motor and the control assembly; the electric power tool further includes: the pull rod is connected with the switch and the operating piece; the housing includes a main housing and a rear bearing chamber formed inside the main housing for supporting a rear bearing, the rear bearing chamber including: an accommodation chamber in which the rear bearing is disposed; the through hole is used for the pull rod to pass through; the partition part is arranged between the accommodating cavity and the through hole.

Optionally, the electric tool further includes a detection device for detecting a rotation position of the motor, the detection device includes a first detection element and a second detection element, and the end of the rotor shaft is provided with a mounting hole for placing the first detection element.

Optionally, the projection of the mounting hole and the rear bearing in the radial direction of the first axis at least partially overlap.

Optionally, the housing further comprises a bracket for fixing the second detection element, and a projection of the bracket arranged in the axial direction of the first axis at least partially overlaps with a projection of the accommodation chamber.

Optionally, the support frame and the main housing are integrally formed, and a shortest projection distance between the support frame and the rear bearing chamber in the direction of the first axis is less than or equal to 3cm and greater than or equal to 0 cm.

Optionally, the first detecting element is a magnet, and the second detecting element includes a printed circuit board and a magnetic encoder.

Optionally, a through hole is provided between the main housing and the received cavity such that the tie rod is trapped between the main housing and the motor.

Optionally, the heat dissipation fan is connected to the rotor shaft; and a dust-proof fan disposed between the rear bearing chamber and the motor.

Optionally, the housing includes a motor accommodating portion, and the motor is disposed in the motor accommodating portion; the angle grinder further comprises an operating piece, and the operating piece is arranged on one side of the motor accommodating portion.

Optionally, the electric tool further comprises a battery pack and a display interface, the battery pack is detachably connected to the housing, and the display interface is used for controlling the rotating speed of the motor.

Drawings

FIG. 1 is a perspective view of an angle grinder in accordance with one embodiment of the present invention;

FIG. 2 is an internal block diagram of the angle grinder of FIG. 1;

FIG. 3 is a cross-sectional view of the angle grinder of FIG. 1;

FIG. 4 is a plan view of the angle grinder of FIG. 1;

FIG. 5 is a bottom view of the angle grinder of FIG. 1;

FIG. 6 is a perspective view of a first housing of the angle grinder of FIG. 1;

FIG. 7 is a view of the interior of the angle grinder of FIG. 1;

FIG. 8 is an enlarged schematic view of portion A of the angle grinder of FIG. 7;

FIG. 9 is a schematic interior plan view of the angle grinder of FIG. 1;

FIG. 10 is a perspective view of a control assembly of the angle grinder of FIG. 1;

FIG. 11 is a schematic plan view of a control assembly of the angle grinder of FIG. 1;

FIG. 12 is a top view of the internal structure of the angle grinder of FIG. 1;

FIG. 13 is a top cross-sectional view of the angle grinder of FIG. 1;

FIG. 14 is a top plan view of the angle grinder of FIG. 1 without a shroud;

FIG. 15 is a plan view of a display interface of the angle grinder of FIG. 14;

FIG. 16 is a cross-sectional view of an electric circular saw according to one embodiment;

FIG. 17 is a side view of the electric circular saw of FIG. 16 with the rear bearing housing assembled with the support;

fig. 18 is a rear view schematically showing the structure in which the rear bearing housing of the electric circular saw of fig. 16 is assembled with the holder.

Detailed Description

The present invention provides an electric tool, taking an angle grinder 100 as an example, and referring to fig. 1 to 3, comprising: the motor 400 comprises at least a rotor shaft 410 extending along a first axis 101, the motor 400 driving the rotor shaft 410 to rotate about the first axis 101 when the motor 400 is operated, a drive circuit 300, a switch 500 and an operating member 600. The operation element 600 is disposed on the housing 200, the operation element 600 is operated by a user, the operation element 600 is connected to the switch 500, and the user drives the switch 500 to displace by operating the operation element 600. The driving circuit 300 comprises a power line 310, the power line 310 is connected with a switch 500 and the motor 400, the switch 500 is driven by an operating element 600 to generate displacement to control the on and off of the motor 400, the angle grinder 100 further comprises a control assembly 700, the control assembly 700 is connected with the driving circuit 300, and the control assembly 700 controls the operation of the angle grinder 100.

Referring to fig. 3, the angle grinder 100 further includes an output shaft 110, the output shaft 110 being disposed to extend along the second axis 102. The output shaft 110 is used for supporting a working accessory to drive the working accessory to rotate around the second axis 102, the working accessory can be one or a combination of a grinding disc, a drill bit, a saw blade, a grinding wheel, a polishing wheel, a brush head and polishing cloth, and the working accessory is driven by the output shaft 110 to rotate so as to perform operations such as grinding and polishing on a workpiece. The angle grinder further includes a transmission 120, and the transmission 120 connects the rotor shaft 410 and the output shaft 110, and transmits the output torque of the rotor shaft 410 to the output shaft 110, so that the motor 400 rotates the output shaft 110 around the second axis 102. The transmission 120 includes bevel gears engaged with each other to connect the rotor shaft 410 and the output shaft 110, respectively, such that the rotation axis of the output shaft 110 can be disposed perpendicularly to the rotation axis of the rotor shaft 410.

Referring to fig. 4, the main housing 220 has a front end 201 and a rear end 202 in the direction of the first axis 101, and the housing 200 further includes a grip portion 210 and a power interface 260, the power interface 260 being provided at the rear end 202 of the housing 200 for connecting with a power supply device 221. The power supply 221 may be a pluggable battery pack or a power connector matching with commercial power. The grip portion 210 is held by a user, and the motor 400, the control assembly 700, and the switch 500 are disposed in the grip portion 210. Referring to fig. 3, the grip portion 210 and the power interface 260 are connected, and both the grip portion 210 and the power interface 260 extend in the direction of the first axis 101. A gear box 140 is coupled to the front end 201 of the main housing 220, the gear box 140 is used to accommodate the support transmission 120 and the output shaft 110, and a motor 400 is disposed at the front end 201 of the main housing 220 such that a rotor shaft 410 is coupled to the transmission 120.

Referring to fig. 5, the gear case 140 includes an exhaust hole 141 and a filter device (not shown) disposed in the exhaust hole 141, the exhaust hole 141 being used to adjust air pressure inside the gear case 140, and the filter device may be felt to prevent lubricating oil on the transmission 120 from flowing out of the exhaust hole 141.

Referring to fig. 5 and 6, the housing 200 includes a main housing 220, the main housing 220 is in a left-right half type and includes a first housing 230 and a second housing 240, the first housing 230 and the second housing 240 together form a complete main housing 220, and an accommodating space 250 is formed inside the main housing 220, and the accommodating space 250 includes a motor accommodating portion 251 for accommodating the motor 400. The motor 400 is supported by the housing 200 and placed into the motor receiving part 251. Referring to fig. 3, the angle grinder 100 is further provided with a heat radiating fan 150, the heat radiating fan 150 is connected to the rotor shaft 410, and the heat radiating fan 150 is disposed near the gear box 140. When the motor 400 operates, the heat dissipation fan 150 is driven to rotate, and the heat dissipation fan 150 generates heat dissipation airflow to dissipate heat of the motor 400 and the gear box 140. The main housing 220 has an air outlet 222 at the front end 201 thereof, and an air inlet 223 at the rear end 202 thereof, so that when the angle grinder 100 operates, the heat dissipation fan 150 operates to generate an air flow, and the air flow enters the accommodating space 250 from the air inlet 223, flows through the control assembly 700 and the motor 400, and then flows out from the air outlet 222.

Referring to fig. 3 and 6, a bearing 420 is further provided in the housing 200, the bearing 420 being used to position the rotor shaft 410, the bearing 420 including a front bearing 421 and a rear bearing 422 provided at both ends of the motor 400. A rear bearing 422 is provided between the motor 400 and the control assembly 700, and a front bearing 421 is provided at the other end of the motor 400. The housing 200 includes a rear bearing chamber 270 created inside the main housing 220, the rear bearing chamber 270 for supporting the rear bearing 422.

Referring to fig. 7 and 8, the angle grinder 100 further includes a pull rod 170 connecting the switch 500 and the operating member 600, wherein the pull rod 170 extends in the accommodating space 250 and is movable to at least a first position and a second position. The user can push the operating element 600 to switch the first position and the second position of the pull rod 170, so as to drive the switch 500 to displace, thereby controlling the motor 400 to be turned on. The housing 200 is provided with an opening at a side thereof, the operating element 600 is disposed outside the housing, and the lever 170 is disposed in the accommodating space, through which the lever 170 can be coupled to the operating element 600 outside the housing. The switch 500 is disposed between the motor 400 and the control unit 700, the operation member 600 is disposed to be connected to the main housing 220, the operation member 600 is disposed in front of the grip portion 210 to overlap the motor 400 in a radial direction of the first axis 101, and the link relationship between the operation member 600 and the switch 500 is realized by the lever 170. The draw bar 170 extends at one side inside the receiving space 250 and partially overlaps the switch 500 and the motor 400 in a radial direction of the first axis 101. The operation element 600 is arranged in front of the holding part 210, and when a user holds the holding part 210, the user can conveniently touch the operation element 600 to control the operation of the angle grinder 100, so that the operation of the angle grinder 100 can be realized by one hand when the user uses the angle grinder 100, and the use is convenient for the user.

Alternatively, the rear bearing chamber 270 is integrally formed with the main housing 220, the rear bearing chamber 270 is configured to support the rear bearing 422, and the rear bearing chamber 270 includes a support seat 274, a receiving cavity 271, a through hole 272, and a partition 273. The supporting seat 274 extends from the inner surface of the main housing 220 to the accommodating space 250, and forms a cylindrical accommodating cavity 271. Optionally, the supporting seats 274 are respectively formed on the first casing 230 and the second casing 240, and extend from the inner surfaces of the first casing 230 and the second casing 240 to the accommodating space 250, and after the first casing 230 and the second casing 240 are spliced, the supporting seats 274 on both sides are connected to form the accommodating cavity 271. A through hole 272 and a partition 273 are formed on the support seat 274 at one side, and the through hole 272 is penetrated by the pull rod 170, so that the rear bearing chamber 270 limits the pull rod 170, the pull rod 170 can move between a first position and a second position, and the position of the pull rod 170 is prevented from being shifted to influence the function of the switch 500.

The partition 273 is formed by a pitched-roof molding process, and when the rear bearing chamber 270 is molded, the through hole 272 is formed by using a pitched-roof mold, and the mold is withdrawn after molding, so that the rear bearing chamber 270 and the main housing 220 are integrally formed, and the through hole 272 and the partition 273 can be formed by the support seat 274 at one side. The through hole 272 is provided between the main housing 220 and the receiving cavity 271 so that the tie bar 170 is confined between the main housing 220 and the motor 400. The through hole 272 is sized in a radial direction of the first axis 101 to prevent the lever 170 from being displaced without interfering with the user's operation of the operating member 600.

The partition 273 is provided between the housing chamber 271 and the through hole 272 such that the through hole 272 penetrates the support seat 274 in the axial direction of the first axis 101, and the through hole 272 is partitioned by the partition 273 in the radial direction of the first axis 101 without penetrating the support seat 274 in the radial direction of the first axis 101. In the operation of angle grinder 100, the work piece of work annex is polished and can be produced pollutants such as saw-dust, metal piece and dust, and the air current drives some pollutants and gets into inside casing 200 from air intake 223, because air intake 223 sets up the end at main casing 220, can effectual reduction pollutant get into the inside quantity of casing 200.

The chips entering the angle grinder 100, such as wood chips, will cause abrasion and affect the service life of internal components, while the metal chips are easily adsorbed on the pins of the electronic device due to the influence of the on-state and current change of the electronic device switch 500, and form an electric path between the pins of the electronic device; or attracted by a magnetic field generated by the stator or rotor of the motor 400, and attached to the stator or rotor, or attached to a gap between the stator and the rotor. Thus, the electronics are highly susceptible to electrical paths formed by metal debris and short circuits, and the stator and rotor of the motor 400 are also susceptible to clogging from ingested debris and to stalling or wear. Especially the angle grinder 100 using the brushless motor 400, it is desirable to structurally enclose the motor 400 to avoid the influence of metal debris in the space on the motor 400 and the circuit. The partition 273 provided in the support seat 274 can effectively prevent contaminants from entering the bearing 420 and the motor 400, and prevent dust from entering the accommodating cavity 271 through the support seat 274 and then entering the motor 400.

Optionally, the motor 400 is configured as a sensorless brushless motor, and the angle grinder 100 further includes a detection device 180 for detecting a rotational position of the motor 400. The sensing device 180 includes a first sensing element 181 and a second sensing element 182, and the second sensing element 182 is mounted on the printed circuit board. The end of the rotor of the motor 400 is provided with a mounting hole 411, the first detecting element 181 is disposed in the mounting hole 411, the second detecting element 182 is disposed in the housing 200, and the second detecting element 182 is disposed opposite to the first detecting element 181, and the second detecting element 182 can sense the position where the first detecting element 181 rotates, so as to detect the rotation speed of the rotor of the motor 400, that is, the rotation speed of the motor 400.

The first detection element 181 is disposed in the mounting hole 411, and projections of the first detection element and the second detection element at least partially overlap in the axial direction of the first axis 101, and projections of the mounting hole and the rear bearing in the radial direction of the first axis at least partially overlap. The first detection element 181 can be installed by utilizing the axial length of the rotor, the space for installing the first detection element 181 does not need to be additionally increased, the axial size of the whole machine is reduced, the installation space is saved, the optimization of the structure of the whole machine is facilitated, the first detection element 181 can be protected by the hole wall in the installation hole 411, the first detection element 181 is prevented from being damaged, and the probability of the electric tool in failure is reduced. After the first detecting element 181 is installed in the installation hole 411 on the rotor of the motor 400, the first detecting element 181 can be partially or even completely accommodated in the installation hole 411, which is beneficial to reducing the size of the electric tool along the axial direction of the rotor shaft 410. The projections of the blind hole and the rear bearing 422 in the radial direction of the first axis 101 at least partially overlap, and optionally, the projections of the blind hole and the rear bearing 422 in the radial direction of the first axis 101 completely overlap, so that the size of the motor 400 can be reduced in the axial direction of the first axis 101.

The housing further includes a bracket for fixing the second detection element, the bracket being disposed such that a projection in the axial direction of the first axis at least partially overlaps a projection of the rear bearing. Optionally, the projection of the bracket on the first axis is overlapped with the projection of the accommodating cavity 271 in the direction, so that the inside of the rear bearing 270 is protected from dust by the bracket and the second detecting element mounted on the bracket, and the first detecting element and the second detecting element are arranged oppositely, so that the position of the rotor can be effectively detected.

The first detecting element 181 is a magnet, and the second detecting element 182 is a magnetic encoder, which is disposed on the printed circuit board, and the printed circuit board is disposed close to the end surface of the rotor of the motor 400 and opposite to the end surface of the rotor, so that the second detecting element 182 on the printed circuit board is opposite to the first detecting element 181. The magnet is made by sintering, the connection mode of the magnet and the mounting hole 411 on the motor 400 is gluing, and the magnet is firstly magnetized and then is placed in the mounting hole 411.

In other embodiments, the sensing device 180 may alternatively be an encoder with a code wheel and a readhead, where the first sensing element 181 is a code wheel and the second sensing element 182 is a readhead. The code wheel rotates along with the rotor of the motor 400, and the reading head reads the numbers on the code wheel to detect the rotating speed of the motor 400.

Optionally, the mounting hole 411 is a blind hole and is disposed at the rear end 202 of the rotor, and the front end of the rotor is an output end and is in transmission connection with the grinding head, so that the torque of the motor 400 is transmitted to the grinding head. The mounting hole 411 extends from the rear end 202 face of the rotor in the axial direction of the motor 400. In one embodiment, the magnet within the mounting hole 411 is substantially circular in cross-section, and the corresponding mounting hole 411 is also a circular hole.

As mentioned above, the second sensing element 182 may be a magnetic encoder disposed on the printed circuit board. A bracket 280 for supporting the rear end 202 of the rotor may be provided in the housing 200, the bracket 280 may be provided between the motor 400 and the switch 500 in the axial direction of the first axis 101, the rear end 202 of the rotor may be supported on the bracket 280 through a bearing 420, the bracket 280 may be a mounting rib integrally formed inside the housing 200, and the printed circuit board may be provided on the bracket 280. Since the pcb is disposed opposite to the rear end 202 of the rotor, the pcb is directly mounted using the rear bearing chamber 270 supporting the rear bearing 422, and the rear bearing chamber 270 is integrally formed with the bracket 280, thereby facilitating assembly.

The bracket 280 is integrally formed with the main housing 220, and by injection molding, since the housing 200 is formed in two halves, and the two halves of the housing 200 are respectively integrally formed with one half of the bracket 280, when the two halves of the housing 200 are combined, the complete bracket 280 is formed. The bracket 280 is provided with a clamping groove 281, the printed circuit board is clamped in the clamping groove 281, and the bracket 280 is provided with the clamping groove 281 for clamping the printed circuit board, so that the assembly is more convenient, and the assembly efficiency can be improved. Alternatively, the bracket 280 may be a separate mounting bracket, and is not limited thereto.

After the pcb is engaged in the engaging slot 281, the holder 280 has a protection function for the pcb, which can prevent the contaminants from attaching to the pcb and causing bad effects. Optionally, the shortest projection distance between the bracket 280 and the rear bearing chamber 270 in the direction of the first axis 101 is less than or equal to 4cm and greater than or equal to 0cm, and the projection of the bracket 280 disposed in the direction of the axis of the first axis 101 at least partially overlaps the projection of the accommodating chamber 271. Optionally, the shortest projection distance between the bracket and the rear bearing chamber in the direction of the first axis is less than or equal to 3mm and greater than or equal to 1 mm. The printed circuit board is supported by the bracket 280, because the bracket 280 and the rear bearing chamber 270 are oppositely disposed and closely spaced, so that the bracket 280 forms an isolation region between the motor receiving part 251 and the switch 500 to prevent foreign materials from falling into the motor receiving part 251 to affect or damage the motor 400. Therefore, the bracket 280 has a function of enclosing the rear bearing chamber 270, so that an additional package assembly is not required, the cost is reduced, and the assembly steps are reduced.

The angle grinder 100 further comprises a dustproof fan 160, the dustproof fan 160 is arranged between the rear bearing chamber 270 and the motor 400, the dustproof fan 160 is connected to the rotor shaft 410 and is driven to rotate by the rotor shaft 410 when the motor 400 operates, and the size of the dustproof fan 160 in the radial direction of the first axis 101 is close to that of the rear bearing 422, so that pollutants are further prevented from entering the motor 400, and the dustproof effect of the motor accommodating part 251 of the angle grinder 100 is improved.

Referring to fig. 9 and 10, the control assembly 700 includes a power unit 710 and a control unit 720, the power unit 710 is connected to the motor 400, the control unit 720 is connected to the switch 500, and the power unit 710 and the control unit 720 are at least partially overlapped in a radial direction of the first axis 101, so that the overall size of the control assembly 700 can be reduced. The control assembly 700 is disposed within the grip portion 210, and the control assembly 700 is disposed to extend along a first plane 104 parallel to the first axis 101 and the second axis 102, and a length L1 of the control assembly 700 in the direction of the first axis 101 is 75mm or less and 105mm or more, so that a ratio of a length L1 of the control assembly 700 in the direction of the first axis 101 to a length of a stator stack length of the motor 400 in the first direction is 2.5 or more and 4.2 or less. The size of the control assembly 700 is shortened, the overall arrangement of the angle grinder 100 is optimized, and the output performance of the angle grinder is guaranteed.

The control assembly 700 further includes a first connector 740 and a second connector 750, the first connector 740 and the second connector 750 being disposed between the power unit 710 and the control unit 720 and electrically connecting the power unit 710 and the control unit 720. Optionally, the first connector 740 is configured as a copper pillar, the second connector 750 is configured as a pin header, the first connector 740 can transmit current greater than or equal to 1A, and the pin header is used for transmitting current and signals, so that the power unit 710 and the control unit 720 are electrically connected and signal transmission are realized through the matching of the first connector 740 and the second connector 750. The cross-sectional area of the copper pillar in the first plane is set to be greater than or equal to 0.4 square centimeter and less than or equal to 2 square centimeter, so that the copper pillar can provide a stable supporting function. The copper pillar serves as a connecting support for the power unit 710 and the control unit 720, so that the connection between the power unit 710 and the control unit 720 is stable and the electric transmission is stable, the service life of the control assembly 700 is prolonged, and the cost can be reduced.

Referring to fig. 10 to 12, the stacked arrangement of the power unit 710 and the control unit 720 may increase the temperature rise generated during use, thereby affecting the performance of the power unit 710 and the control unit 720. In this regard, the control assembly 700 further includes a heat dissipation member 730, the heat dissipation member 730 and the power unit 710 are at least partially overlapped in a radial direction of the first axis 101, the heat dissipation member 730 includes a plurality of substrates 734, heat dissipation ribs 731, a clamping section 732 formed between the heat dissipation ribs 731, and a connection hole 733, the heat dissipation ribs 731 and the connection hole 733 are formed on the substrates 734, the power line 310 passes through the heat dissipation member 730 from the connection hole 733, and a portion of the power line 310 is defined on the clamping section 732 by the heat dissipation ribs 731. The heat dissipating ribs 731 are protrusions formed on the surface of the heat dissipating member 730, a clamping region 732 is formed between a plurality of heat dissipating ribs 731, and the heat dissipating ribs 731 are used for clamping the power line 310. The power line 310 extends from the power unit 710 and passes through the heat dissipating member 730 through the connection hole 733, and a portion of the power line 310 is fixed by the clamping section 732. The power line 310 is fixed by the heat dissipation member 730, so that the flat cable can be optimized, the power line 310 does not need to be fixed by an additional flat cable assembly, and the heat dissipation of the power line 310 can be realized.

In the operation of the angle grinder 100, part of the heat generated by the control element and the power element is transferred to the heat dissipation element 730 through heat conduction, the heat dissipation airflow flows from the end of the main housing 220 to the front end 201 of the main housing 220, and the heat is taken away through convection through the surface of the heat dissipation element 730, and the heat dissipation ribs 731 can increase the effective heat dissipation surface area and improve the heat dissipation effect.

Optionally, the projected height of the power line 310 in the direction parallel to the first axis 101 is lower than the projected height of the heat dissipation rib 731, that is, the power line 310 does not exceed the height of the heat dissipation rib 731 in the direction parallel to the first plane 104. The control assembly 700 comprises a first side 701 and a second side 702 parallel to the first axis 101, and the projection of the power line 310 onto the first plane 104 is within the area defined by the straight line of the first side 701 and the second side 702, so that the whole machine is compact and the wiring is reasonable.

Referring to fig. 13, the power tool further includes a signal line 320, the signal line 320 connecting the control assembly 700 and the switch 500; the first plane 104 divides the grip portion 210 into a first cavity 211 and a second cavity 212, the first cavity 211 and the second cavity 212 are disposed at two sides of the control assembly 700, at least a portion of the power line 310 is disposed in the first cavity 211, and at least a portion of the signal line 320 is disposed in the second cavity 212, so as to prevent the signal line 320 and the power line 310 from being entangled or interfering with each other, and to fully utilize the accommodating space 250.

Optionally, the holding portion 210 is provided with a first air inlet 2231 and a second air inlet 2232, the first air inlet 2231 is disposed in the first casing 230, the second air inlet 2232 is disposed in the second casing 240, the first air inlet 2231 is communicated with the first cavity 211, and the second air inlet 2232 is communicated with the second cavity 212. When the angle grinder 100 is used, the air flow enters the first cavity 211 from the first air inlet 2231 and enters the second cavity 212 from the second air inlet 2232, so that the air flow flows into the two sides of the control assembly 700, and the heat dissipation effect is improved. The housing 200 includes a flow guide part 290 disposed in a circumferential direction of the fan, a side surface of the flow guide part 290 includes an air outlet 222, and the flow guide part 290 is integrally formed with the main housing 220.

The housing of the electric tool of the present invention is integrally formed with the multi-functional member, and the guide 290, the rear bearing housing 270, and the bracket 280 are integrally molded with the main housing, thereby simplifying the manufacturing process, reducing the number of connecting parts, reducing the size of the entire machine, reducing the weight, and making the performance of the electric tool more stable.

Referring to fig. 9, the switch 500 is provided to extend in the direction of the third axis 103, and in a projection onto the first plane 104, the angle between the third axis 103 and the second axis 102 is 10 degrees or more and 20 degrees or less. The switch 500 is disposed obliquely with respect to the second axis 102 as a whole, so that the length of the angle grinder in the axial direction of the first axis can be shortened, and the partial grip portion 210 can be disposed obliquely, so that the user can grip the angle grinder 100 more stably, improving the grip feeling of the user.

Optionally, the housing of the angle grinder can also be a cylindrical housing, and a rear bearing chamber is arranged in the cylindrical housing and used for supporting the rear bearing and the limiting pull rod. The rotor shaft is internally provided with a mounting hole for placing a detection device, so that the limitation is not caused.

Alternatively, the motor may be a non-inductive motor, and the rear bearing chamber is sealed in the axial direction of the first axis at this time, and dust is prevented from entering the motor accommodating chamber.

Referring to fig. 14, the angle grinder further includes a display interface 800, the display interface 800 includes four display units 810 and a speed adjusting mechanism 820, the four display units 810 can be sequentially lighted to indicate a current gear of the angle grinder, the four display units 810 can also be simultaneously flashed or extinguished to indicate a fault state of the angle grinder, the speed adjusting mechanism 820 is configured to be operated to wake up the display interface 800 when the display interface 800 is in a screen-off state, and to be operated to adjust the gear of the angle grinder when the display interface 800 is in a wake-up state, so that a rotation speed of an output shaft changes, and the battery pack is electrically connected to the display interface 800 and the speed adjusting mechanism 820, respectively.

In the angle grinder provided by the embodiment, the speed regulating mechanism 820 is arranged at the rear end of the holding part, so that more holding positions can be provided for a user, the angle grinder is convenient to use, once the angle grinder breaks down, the display unit 810 of the angle grinder can also prompt the user, the use satisfaction of the user is improved, the speed regulating mechanism 820 provided by the invention can be operated, the display interface 800 can be awakened when the display interface 800 is in a screen-off state, and the gear position of the angle grinder can also be adjusted when the display interface 800 is in the awakening state. The display interface 800 is arranged at the rear end of the holding part, so that a user can more directly acquire information prompted by the display interface 800, the user can conveniently adjust the speed of the gears of the angular mill through the speed adjusting mechanism 820 on the display interface 800, the current gear information and fault information are displayed through the display unit 810 of the display interface 800, the information collection is realized, the information acquisition efficiency is improved, and the use is facilitated. The display interface 800 with the speed regulation structure is arranged at the rear end of the holding part, so that the speed regulation can be carried out at the tail part of the angle grinder by a user, and the use safety is improved.

The gears of the angle grinder are different, the rotating speed of the motor is different, and the rotating speed of the motor is gradually increased along with the lifting of the gears. Since the angle grinder of this embodiment has four gears, the number of the display units 810 of this embodiment is four, the four display units 810 are arranged in parallel in a row and are electrically connected to the speed adjusting mechanism 820, the gears of the angle grinder are different, and the number of the display units 810 to be lit is different. Specifically, when the angle grinder is in the first gear, the first display unit 810 is turned on; when the angle grinder is in the second gear, the first two display units 810 are lighted; when the angle grinder is in the third gear, the first three display units 810 are lighted; when the angle grinder is in the fourth gear, all four display units 810 are lit. Of course, in other embodiments of the present invention, the angle grinder has different gears, and may be lighted by the display unit 810 at different positions.

The detection device further includes a current sensor or a voltage sensor for detecting a current value or a voltage value of the motor, and the detection device is electrically connected to the battery pack and control assembly 700. The detection device detects the state parameters of the angle grinder operation and transmits the state parameters to the control assembly 700, the control assembly 700 analyzes the detected state parameter information to obtain the current angle grinder operation state, specifically including the angle grinder fault state, the control assembly 700 analyzes the prompt mode of the display interface 800 and controls the display unit 810 to flicker or extinguish correspondingly, and therefore the user is reminded of the angle grinder fault state information in time.

Of course, in other embodiments of the present invention, the angle grinder may also be a multi-function tool, a gun drill, or other angle grinders. The lighting modes of the gear and the display unit 810 of the present invention can be in other forms, for example, the gears of the angle grinder are different, the positions of the lighted display units 810 are different, and the lighting modes of the display units 810 correspond to the gear information of the angle grinder one by one, that is, when the angle grinder is in the first gear, only the first display unit 810 is lighted; when the angle grinder is in the second gear, only the second display unit 810 is lighted; when the angle grinder is in the third gear, only the third display unit 810 is lighted; when the angle grinder is in the fourth gear, only the fourth display unit 810 is turned on, in other embodiments, the gear of the angle grinder and the display unit 810 may be turned on in other one-to-one correspondence manners, and the gear of the angle grinder and the display unit 810 may be specifically set according to actual needs. The working voltage of the angle grinder can be V, and can also be V or other voltage values, and is set according to actual conditions.

Of course, in other embodiments of the present invention, the number of the gears of the angle grinder is not limited to four in this embodiment, and the number of the corresponding display units 810 is also not limited to four in this embodiment, and may be other numbers, and the number of the display units 810 is set corresponding to the gears of the angle grinder.

The display interface 800 is arranged at the rear end of the holding part, and the display interface 800 can display the gear of the angle grinder, the rotating speed of the motor and fault information. The battery pack is located in the installation cavity and electrically connected to the motor, the speed adjusting mechanism 820, the display unit 810 and the display interface 800, and the battery pack of this embodiment is a rechargeable battery pack. When charging the battery package, in order to show the charged state of battery package, still be equipped with charge indicator on the angle grinder of this embodiment, when charging the battery package, can look over the charged state of current battery package through charge indicator, the user of being convenient for charges to the battery package.

Referring to fig. 15, the speed adjusting mechanism 820 of the present embodiment is a button and includes a first speed adjusting mechanism 821 and a second speed adjusting mechanism 822, and the control assembly 700 includes a micro control unit (MCU, not shown in the drawings). The first speed regulating mechanism 821 and the second speed regulating mechanism 822 are respectively arranged on two sides of the display interface 800, the first speed regulating mechanism 821 is used for increasing the gear of the angle grinder to increase the rotating speed of the output shaft, and the second speed regulating mechanism 822 is used for decreasing the gear of the angle grinder to decrease the rotating speed of the output shaft. Specifically, the first speed adjusting mechanism 821 and the second speed adjusting mechanism 822 can trigger different D values (that is, values obtained by converting analog signals into digital signals), and then the micro control unit determines the increase or decrease of the gear of the angle grinder through the detected different D values, and simultaneously the number of the lighted display units 810 increases or decreases accordingly, so that the gears of the angle grinder correspond to the number of the lighted display units 810 one by one.

Further, the angle grinder of the present embodiment further includes a field effect transistor (not shown in the figure) located in the mounting cavity, and the detection device further includes a temperature sensor (not shown in the figure) configured to detect a temperature of the field effect transistor, wherein the temperature sensor and the field effect transistor are electrically connected to the battery pack, respectively.

It should be noted that the display interface 800, the MCU, and the speed adjusting mechanism 820 of the angle grinder of this embodiment are always connected to the battery pack, that is, the battery pack always supplies power to the display interface 800, the MCU, and the speed adjusting mechanism 820, and no matter whether the switch is turned on or off, the display interface 800 is in the wake-up state, and the speed adjusting mechanism 820 is pressed and released, so that the gear of the angle grinder changes.

The control module 700 of the present embodiment can be implemented as a processing and computing device such as a circuit board, an integrated circuit, a single chip, etc. As shown in the figure, the control assembly 700 is located in the installation cavity, the control assembly 700 is connected to the battery pack, and the speed adjusting mechanism 820, the display unit 810, the display interface 800, the MCU, the temperature sensor and the field effect transistor are electrically connected to the control assembly 700 respectively. The control assembly 700 is used for analyzing the operation condition of the angle grinder, such as a fault state, analyzing the flashing mode or extinguishing mode of the display interface 800 corresponding to the fault state, and the control assembly 700 is used for controlling the display unit 810 of the display interface 800 to flash or extinguish so as to remind a user of the current fault state of the angle grinder, so that the angle grinder can be conveniently and timely processed by the user, the angle grinder is prevented from being further damaged, and the user or the environment is prevented from being injured.

The electric tool provided by the application is not limited to the angle grinder, only the angle grinder is taken as an example for introduction, and the electric tool can also be products such as an electric drill, a multifunctional tool, an electric saw and the like. Referring to fig. 16 to 18, the motor 400a of the circular saw 100a has a motor outer case 200a corresponding to the aforementioned housing and an inner case corresponding to the aforementioned rear bearing chamber 270a, and the rear bearing chamber 270a is screwed into the housing.

The second sensing element 182a is disposed on a bracket 280a, and the bracket 280a is mounted on the rear bearing chamber 270a by screws. As described above, in the present embodiment, the rear bearing chamber 270a is an inner casing of the motor 400a, the rear bearing chamber 270a has a substantially cylindrical shape, and the bracket 280a is fixed to a cylindrical bottom of the cylindrical shape by screws. The bottom of the cylinder is provided with a through hole for the second detecting element 182a on the bracket 280a to be opposite to the first detecting element 181a, so as to detect the rotating speed of the motor 400 a. The rear end of the rotor of the motor 400a extends into the bottom of the drum so that the first detecting element 181a at the rear end of the rotor is close to the second detecting element 182 a. The bracket 280a is a plastic member, and the second detecting element 182a is sealed on the bracket 280a by glue.

Claims

1. A power tool, comprising:

an electric machine including at least a rotor shaft extending along a first axis;

a housing supporting the motor;

the bearing is used for positioning the rotor shaft and comprises a front bearing and a rear bearing which are arranged at two ends of the motor;

the switch is used for controlling the on and off of the motor;

a control assembly that controls operation of the power tool;

a power supply device for supplying power to the motor;

the electric tool is characterized by further comprising a detection device for detecting the rotation position of the motor, wherein the detection device comprises a first detection element and a second detection element, a mounting hole for placing the first detection element is formed in the tail end of the rotor shaft, the projections of the first detection element and the second detection element are at least partially overlapped in the axial direction of the first axis, and the projection of the mounting hole and the projection of the rear bearing in the radial direction of the first axis are at least partially overlapped.

2. The power tool of claim 1, wherein:

the housing includes a main housing and a rear bearing chamber generated inside the main housing, the rear bearing chamber being configured to support the rear bearing, the housing further includes a bracket configured to fix the second detection element, and a projection of the bracket disposed in an axial direction of the first axis at least partially overlaps a projection of the rear bearing.

3. The power tool of claim 2, wherein: the support with main casing integrated into one piece, the support with the shortest projection distance of rear bearing room in the direction of first axis is less than or equal to 4mm and is more than or equal to 0 mm.

4. The power tool of claim 2, wherein: the support with main casing integrated into one piece, the support with the shortest projection distance of rear bearing room in the direction of first axis is less than or equal to 3mm and is more than or equal to 1 mm.

5. The power tool of claim 2, wherein the first sensing element is a magnet and the second sensing element includes a printed circuit board and a magnetic encoder.

6. The power tool of claim 1, comprising:

a heat radiation fan connected to the rotor shaft;

a dust-proof fan disposed between the rear bearing compartment and the motor.

7. The power tool of claim 6, wherein:

the casing is including setting up the ascending water conservancy diversion portion of circumference of fan, the side of water conservancy diversion portion includes the air outlet.

8. The power tool of claim 1, wherein:

the electric tool includes:

a drive circuit including a power line connecting the motor and the control assembly,

the control assembly includes:

a power unit connected to the power line;

a heat-dissipating component comprising:

a substrate;

the plurality of radiating ribs are connected to the substrate;

the clamping area is formed between the heat dissipation ribs;

the power line penetrates through the connecting hole, and part of the power line is fixed in the clamping area by the heat dissipation ribs.

9. The power tool of claim 8, wherein:

an output shaft for driving a working attachment, the output shaft extending along a second axis;

the power unit is disposed to extend along a first plane parallel to the first axis and the second axis;

the control assembly further comprises a control unit, and orthographic projections of the control unit and the power unit arranged on the first plane at least partially overlap.

10. The power tool of claim 9, wherein:

at least part of an orthographic projection of the heat dissipation element and the power unit on the first plane overlaps;

and a copper column is arranged between the power unit and the control unit, so that the power unit is electrically connected with the control unit.

11. The power tool of claim 1, comprising:

the display interface, the display interface with the control assembly electricity is connected, the display interface includes a plurality of display element and the speed adjusting mechanism of in bank distribution, and is a plurality of the display element can be lighted in proper order, in order to instruct electric tool's current fender position, the control assembly control is a plurality of the display element is through scintillation or the instruction of going out electric tool's fault condition, speed adjusting mechanism is manipulated in order to adjust electric tool's fender position.