CN111750056A

CN111750056A - Opening and closing member drive device

Info

Publication number: CN111750056A
Application number: CN202010217635.2A
Authority: CN
Inventors: 石水昭夫
Original assignee: Nidec Sankyo Corp
Current assignee: Nidec Instruments Corp
Priority date: 2019-03-28
Filing date: 2020-03-25
Publication date: 2020-10-09
Anticipated expiration: 2040-03-25
Also published as: WO2020195648A1; CN111750056B; JP2020162695A; JP7320367B2

Abstract

An opening/closing member drive device in which an auxiliary spring for urging an output shaft is disposed in a double layer, and interference between an inner spring and an outer spring is avoided. The opening/closing member drive device (1) is provided with: an output shaft (2) protruding from a housing (10), a motor (3) as a drive source, a transmission mechanism (4) that transmits the rotation of the motor (3) to the output shaft (2), and an assist spring (5) that biases the output shaft (2). The auxiliary spring (5) is provided with a first spring (51) and a second spring (52) arranged on the inner peripheral side of the first spring (51). The case (10) is provided with an intermediate plate (161) that partitions the internal space, and a support portion (6) and ribs (7) that protrude from the intermediate plate (161) toward the output shaft (2). The support section (6) rotatably supports the output shaft (2) and is disposed on the inner peripheral side of the second spring (52). The rib (7) is disposed between the first spring (51) and the second spring (52).

Description

Opening and closing member drive device

Technical Field

The present invention relates to an opening/closing member drive device including an output shaft connected to an opening/closing member, a drive source for driving the output shaft, and a housing for accommodating the drive source.

Background

As an opening/closing member drive device for opening/closing an opening/closing member such as a toilet seat and a toilet lid of a western-style toilet, a device is used in which rotation of a drive source such as a motor is transmitted to an output shaft via a transmission mechanism such as a gear train. Patent document 1 discloses such an opening/closing member driving device (lid opening/closing device). In the lid body opening/closing device of patent document 1, an auxiliary spring that urges an output shaft to assist opening/closing of an opening/closing member is incorporated. In addition, a torque limiter is incorporated to prevent damage to the motor and the transmission mechanism due to an excessive load applied thereto when the opening/closing member is suddenly opened and closed.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2014-200458

Disclosure of Invention

Technical problem to be solved by the invention

In the lid opening and closing device of patent document 1, the motor and the reduction gear set are housed in the case. The output shaft includes a gear portion that meshes with a final gear of the reduction gear set, and a shaft portion that extends in the axial direction from the center of the gear portion, and the tip of the shaft portion protrudes outside the housing. The auxiliary spring is disposed on the outer peripheral side of the shaft portion. One end of the assist spring is locked to a fixing hole provided in an end face of the gear portion. The other end of the auxiliary spring is locked to a locking portion provided on an inner wall of the housing.

In the opening/closing member driving device including the assist spring, a configuration has been proposed in which a plurality of assist springs are combined to increase the assist force and to freely set the assist force. For example, a structure in which a plurality of auxiliary springs are arranged in two layers is proposed. However, when the assist spring is configured in two layers, the assist spring may be deformed in an intended outward direction to interfere with each other when the output shaft rotates and the assist spring is deflected. When the auxiliary springs interfere with each other, a normal spring operation may not be performed, and a designed elastic force may not be obtained. In addition, abnormal stress may occur, and durability may be impaired.

In view of the above problems, the present invention has been made to solve the above problems, and an object of the present invention is to avoid interference between an inner spring and an outer spring in an opening/closing member driving device in which an auxiliary spring for biasing an output shaft is arranged in two stages.

Technical scheme for solving technical problem

In order to solve the above-described problems, the present invention provides an opening/closing member driving device including: a housing; an output shaft protruding from the housing; a motor housed in the case; a transmission mechanism that is housed in the case and transmits rotation of the motor to the output shaft; and an assist spring that generates an assist force that urges the output shaft in a second rotational direction opposite to the first rotational direction in accordance with rotation of the output shaft in the first rotational direction, the assist spring including a first spring and a second spring disposed on an inner peripheral side of the first spring, the first spring and the second spring being torsion coil springs, the housing including an intermediate plate that partitions an internal space, and a support portion and a rib that protrude from the intermediate plate toward the output shaft, the support portion rotatably supporting the output shaft, the support portion being disposed on an inner peripheral side of the second spring, the rib being disposed between the first spring and the second spring.

According to the present invention, the auxiliary spring for biasing the output shaft includes the first spring and the second spring disposed on the inner peripheral side of the first spring, and includes two torsion coil springs disposed in a double-layer arrangement. The case includes an intermediate plate that partitions the inside, a support portion that is disposed on an inner peripheral side of the auxiliary spring and protrudes from the intermediate plate, and a rib that is disposed between the first spring and the second spring. In this way, by disposing the rib of the housing between the first spring and the second spring, interference between the first spring and the second spring can be suppressed. This reduces the risk that the first spring and the second spring interfere with each other, and the normal spring operation cannot be performed, and the designed elastic force cannot be obtained. In addition, the risk of damage to durability due to abnormal stress caused by interference of the first spring and the second spring can be reduced.

In the present invention, it is preferable that at least a part of an outer peripheral edge of the rib has a shape along an inner periphery of the first coil of the first spring. In this way, the rib can guide the first spring from the inner peripheral side. Therefore, the positional accuracy of the first spring can be improved. In addition, since the deformation of the first spring can be suppressed, the interference between the first spring and the second spring can be suppressed.

In the present invention, it is desirable that a radial gap is provided between the rib and the first coil of the first spring. By providing a certain degree of clearance between the rib and the first spring in this way, contact between the first spring and the rib can be suppressed when the first spring is deformed by rotation of the output shaft. Therefore, a decrease in durability due to contact between the first spring and the rib can be suppressed.

In the present invention, it is preferable that the rib has a protruding portion protruding outward in the radial direction of the first spring. By providing the protruding portion, the rotation of the first spring can be restricted by the protruding portion. Therefore, the first spring can be prevented from rotating.

In the present invention, it is preferable that the intermediate plate includes an opening portion in which an end portion of the first spring is disposed, and the protruding portion protrudes toward the opening portion. In this way, the protruding portion functions as a guide portion for extending the end portion of the spring toward the opening portion. Therefore, the positional accuracy of the first spring can be improved. In addition, the assembly work of the first spring becomes easy.

In the present invention, the projection is a receiving portion that supports a part of the first spring. Thus, for example, the winding start portion of the first winding is supported by the intermediate plate, and the winding end portion of the first winding is supported by the receiving portion. Therefore, the inclination of the first spring can be suppressed, and therefore, the first spring and the second spring can be suppressed from interfering with each other.

In the present invention, it is desirable that the height of the rib is lower than the wire diameter of the first spring. In this way, the first spring can be prevented from floating from the intermediate plate. Therefore, the first spring can be supported by the intermediate plate in a stable state, and therefore, the inclination of the first spring can be suppressed.

In the present invention, it is desirable that the rib is tapered such that a width in a radial direction becomes narrower as it goes away from the protruding portion in a circumferential direction. In this way, the radial gaps between the ribs and the first and second springs can be increased as they are spaced apart from the protruding portion in the circumferential direction. Therefore, it is possible to provide a certain degree of clearance between the rib and the portion other than the end portion of the first spring while improving the positional accuracy of the end portion of the first spring disposed in the opening portion. Therefore, contact between the first spring and the rib when the first spring is deformed by rotation of the output shaft can be suppressed, and reduction in durability due to contact between the first spring and the rib can be suppressed.

In the present invention, it is preferable that an inner peripheral edge of the rib has a shape along an outer periphery of the second spring. In this way, the rib can guide the second spring from the outer peripheral side. Therefore, the positional accuracy of the second spring can be improved. In addition, since the deformation of the second spring can be suppressed, the interference between the first spring and the second spring can be suppressed.

In the present invention, it is preferable that the support portion includes a groove portion extending in a radial direction, an end portion of the second spring is disposed in the groove portion, and a groove width of the groove portion increases as going from a center of the support portion in the radial direction to a radially outer side. In this way, the end portion of the second spring can be inclined in the circumferential direction in the groove portion. Therefore, when the output shaft rotates, the elastic force of the second spring is not generated from the reference position to the predetermined angle.

In the present invention, it is preferable that the rib has a symmetrical shape with respect to a straight line connecting the opening and the center of the support portion in the radial direction. Thus, the first spring can be mounted even if the winding direction of the first spring is reversed. Therefore, since the first spring in the winding direction corresponding to the rotation direction of the output shaft can be attached, it is not necessary to change the shape of the rib in accordance with the rotation direction of the output shaft, and it is not necessary to change the shape of the housing. Therefore, the parts can be made common.

(effect of the invention)

According to the present invention, the auxiliary spring for biasing the output shaft includes the first spring and the second spring disposed on the inner peripheral side of the first spring, and includes two torsion coil springs disposed in a double-layer arrangement. The case includes an intermediate plate that partitions the inside, a support portion that is disposed on an inner peripheral side of the auxiliary spring and from which a rib disposed between the first spring and the second spring protrudes. In this way, by disposing the rib of the housing between the first spring and the second spring, interference between the first spring and the second spring can be suppressed. This reduces the risk that the first spring and the second spring interfere with each other, and the normal spring operation cannot be performed, and the designed elastic force cannot be obtained. In addition, the risk of damage to durability due to abnormal stress caused by interference of the first spring and the second spring can be reduced.

Drawings

Fig. 1 is an external perspective view of an opening/closing member drive device to which the present invention is applied.

Fig. 2 is an explanatory diagram of a western-style toilet including the opening/closing member drive device 1 of fig. 1.

Fig. 3 is a sectional view of the opening and closing member driving device of fig. 1.

Fig. 4 is an exploded perspective view of the opening and closing member driving device of fig. 1.

Fig. 5 is a perspective view of the motor, the driving force transmission mechanism, and the output shaft when viewed from the other side in the first direction.

Fig. 6 is an exploded perspective view of the output gear and the output shaft.

Fig. 7 is an exploded perspective view of the output gear, the output shaft, and the assist spring.

Fig. 8 is a perspective view of the first housing and the intermediate housing as viewed from the other side in the first direction.

Fig. 9 is an explanatory diagram showing planar shapes of the support portion, the rib, and the auxiliary spring.

Fig. 10 is an explanatory diagram showing a state of the assist spring when the output shaft is at the reference position.

Fig. 11 is an explanatory diagram showing a state of the assist spring when the output shaft is at the action start position of the second spring.

Fig. 12 is an explanatory diagram showing a state of the assist spring when the output shaft is at the action start position of the first spring.

Description of the symbols

1 … opening and closing member driving device; 2 … output shaft; 3 … electric motor; 4 … transfer mechanism; 5 … auxiliary spring; 6 … a support portion; 7 … ribs; 8 … potentiometer; 9 … opening part; 10 … a housing; 11 … a first side wall; 12 … second side wall; 13 … a third side wall; 14 … fourth side wall; 15 … a first housing; 16 … a middle shell; 17 … a second housing; 18 … a reinforcing member; 19 … O-ring; 21 … a base; 22 … connecting shaft; 23 … protrusions; 24 … circular recesses; 25 … spring catch holes; 30 … motor body; 31 … rotating shaft; a 32 … bearing member; 33 … a bay; 34 … spring receivers; a 40 … worm; 41 … a first gear; 42 … second gear; 43 … third gear; 44 … fourth gear; 45 … output gear; 46 … torque limiter; 50A … wire; 50B … wire; 61 … groove parts; 71 … inner periphery; 72A, 72B … arc portions; 73 … projection; 74A, 74B … straight portions; 81 … potentiometer gear; 82 … detection part; 100 … western style toilet; 110 … toilet body; 120 … toilet seat; 130 … toilet lid; 140 … water tank; 151 … bottom panel; 152 … frame portion; 153 … spring holding parts; 154 … spring retention holes; 155 … inclined plane; 161 … intermediate plate; 162 … middle frame portion; 163 … opening; 164 … opening; 165 … box section; 181 … reinforcing the member-side opening; 182 … shaft holding part; 183 … output gear receiving part; 411 … first large diameter gear; 412 … a first small diameter gear; 413 … first fulcrum; 421 … second large diameter gear; 422 … second small diameter gear; 423 … second fulcrum; 431 … third large diameter gear; 432 … third small diameter gear; 433 … third fulcrum; 450 … annular portion; 451 … center hole; 452 … recesses; 453, 453 … notch portion; 454 … a first face; 455 … second side; 510a … first turn; 510 … spring portion; 511 … a first end; 512 … second end; 513 … straight line portion; 520 … spring portion; 521 … a first end; 522 … second end; CCW … second direction of rotation; CW … first direction of rotation; the axis of the L … output shaft; the rotational centerline of the L1 … motor; l0 … is a straight line connecting the radial centers of the opening and the support; the radial center of the P … bearing portion; r1 … first effect start position; r2 … second effect start position; s … radial clearance; a third direction of X …; a second direction of Y …; z … first direction.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. Fig. 1 is an external perspective view of an opening/closing member drive device 1 to which the present invention is applied. Fig. 2 is an explanatory diagram of a western-style toilet 100 including the opening/closing member drive device 1 of fig. 1. Fig. 3 is a sectional view of the opening/closing member driving device 1 of fig. 1. Fig. 4 is an exploded perspective view of the opening/closing member driving device 1 of fig. 1. Fig. 5 is a perspective view of the motor 3, the transmission mechanism 4, and the output shaft 2 when viewed from the other side Z2 in the first direction Z.

In the present specification, three directions orthogonal to each other are referred to as a first direction Z, a second direction Y, and a third direction X. The first direction Z is a direction of the axis L of the output shaft 2, the second direction Y is a longitudinal direction of the housing 10, and the third direction X is a short-side direction (width direction) of the housing 10. Further, one side in the first direction Z is Z1, the other side is Z2, one side in the second direction Y is Y1, the other side is Y2, one side in the third direction X is X1, and the other side is X2. The side of the output shaft 2 protruding from the housing 10 is the other side Z2 in the first direction Z, and the side of the housing 10 on which the output shaft 2 is disposed is the one side Y1 in the second direction Y.

(Overall Structure)

The opening/closing member driving device 1 shown in fig. 1 is a device for opening/closing an opening/closing member such as a lid or a door by rotating the opening/closing member. The western-style toilet 100 shown in fig. 2 has a toilet body 110, a toilet seat 120, a toilet lid 130, and a water tank 140. The toilet seat 120 and the toilet lid 130 are connected to an output shaft 2 (see fig. 3) of the opening/closing member drive device 1. The toilet seat 120 and the toilet lid 130 are displaced by the rotation of the output shaft 2 to a closed position where they are covered on the toilet body 110 and an open position where they stand from the toilet body 110. Furthermore, the western-style toilet 100 may be configured such that only one of the toilet seat 120 and the toilet lid 130 is rotated by the opening/closing member driving device 1.

As shown in fig. 3, the opening/closing member drive device 1 includes a motor 3, an output shaft 2, a transmission mechanism 4 for transmitting a drive force of the motor 3 to the output shaft 2, an assist spring 5 for biasing the output shaft 2, and a housing 10 for housing the motor 3 and the transmission mechanism 4. The output shaft 2 includes a base 21 housed in the housing 10 and a connecting shaft 22 protruding from the opening 9 of the housing 10. An opening/closing member such as a toilet seat 120 and a toilet lid 130 shown in fig. 2 is connected to the connecting shaft 22. As shown in fig. 1, the housing 10 has a shape elongated in the second direction Y when viewed from the first direction Z which is the axial direction of the output shaft 2. The opening 9 of the housing 10 in which the output shaft 2 is disposed is located at one end of the housing 10 in the second direction Y, which is the longitudinal direction.

The case 10 is made of resin. As shown in fig. 1, the housing 10 includes a first side wall 11 and a second side wall 12 extending parallel to the second direction Y. The housing 10 includes a third side wall 13 connecting one end of the other side Y2 of the first side wall 11 and the second side wall 12 in the second direction Y, and a fourth side wall 14 connecting one end of the one side Y1 of the first side wall 11 and the second side wall 12 in the second direction Y. The third side wall 13 extends linearly in the third direction X. The fourth side wall 14 has a convex shape protruding toward one side Y1 in the second direction Y. In the present embodiment, the fourth side wall 14 is a semicircular curved surface when viewed from the other side Z2 in the first direction Z.

As shown in fig. 1 and 3, the casing 10 includes a first casing 15, an intermediate casing 16, and a second casing 17 arranged along the first direction Z. The first casing 15 is located on one side Z1 of the intermediate casing 16 in the first direction Z, and the second casing 17 is located on the other side Z2 of the intermediate casing 16 in the first direction Z. The case 10 is assembled by fixing the intermediate case 16 to the first case 15 and fixing the second case 17 to the intermediate case 16.

The first casing 15 includes a bottom plate 151 and a frame portion 152 extending from an outer peripheral edge of the bottom plate 151 to the other side Z2 in the first direction Z. The frame portion 152 constitutes an end portion of one side Z1 in the first direction Z of the first side wall 11, the second side wall 12, the third side wall 13, and the fourth side wall 14 of the casing 10. The motor 3 is fixed to the first housing 15. The motor 3 includes a motor main body 30 and a rotating shaft 31 protruding from the motor main body 30. The rotary shaft 31 faces a direction intersecting the axis L of the output shaft 2. In the present embodiment, the rotation center line L1 (see fig. 4) of the rotary shaft 31 is orthogonal to the axis L of the output shaft 2. In addition, the rotation shaft 31 is inclined with respect to the second direction Y (the longitudinal direction of the housing 10) when viewed from the first direction Z. The front end of the rotary shaft 31 is rotatably supported by a bearing member 32 held by the first housing 15.

The intermediate case 16 includes an intermediate plate 161 and an intermediate frame portion 162 extending from an outer peripheral edge of the intermediate plate 161 to the other side Z2 in the first direction Z. The middle frame portion 162 constitutes a middle portion in the first direction Z of the first side wall 11, the second side wall 12, the third side wall 13, and the fourth side wall 14 of the casing 10. Some of the gears constituting the transmission mechanism 4 are housed in an intermediate case 16. Further, the base portion 21 of the output shaft 2 is housed in the intermediate case 16.

A plate-like reinforcing member 18 is fixed to an end of the intermediate case 16 on the second case 17 side. The rigidity of the reinforcing member 18 is higher than that of the case 10. In the present embodiment, the reinforcing member 18 is made of metal. The reinforcing member 18 is provided with a reinforcing member side opening 181, and the output shaft 2 protrudes from the reinforcing member side opening 181 to the other side Z2 in the first direction Z. Further, a potentiometer 8 is attached to the reinforcing member 18. The potentiometer 8 is disposed at an end portion on the opposite side (the other side Y2 in the second direction Y) from the output shaft 2 in the second direction Y.

The potentiometer 8 includes a potentiometer gear 81 (see fig. 5) that meshes with any one of a plurality of gears constituting the transmission mechanism 4, and a detection unit 82 (see fig. 3 and 4) that detects a rotational angle position of the potentiometer gear 81. The detection unit 82 includes a circuit board. The potentiometer gear 81 is positioned on one side Z1 in the first direction Z of the reinforcing member 18, and meshes with a third small-diameter gear of the third gear. The detection portion 82 is located on the other side Z2 of the reinforcing member 18, and the circuit board is fixed to the reinforcing member 18.

The second housing 17 is plate-shaped, and covers the intermediate housing 16 from the other side Z2 in the first direction Z. The second case 17 is connected to an end of the other side Z2 of the first direction Z of the first side wall 11, the second side wall 12, the third side wall 13, and the fourth side wall 14 of the case 10, and covers the reinforcing member 18 from the other side Z2 of the first direction Z. The second case 17 includes an opening 9 that penetrates through a portion overlapping with the reinforcing member side opening 181 when viewed in the first direction Z. As shown in fig. 3, a gap between the output shaft 2 disposed in the opening 9 and the inner peripheral surface of the opening 9 is sealed by an O-ring 19.

As shown in fig. 5, the transmission mechanism 4 includes a worm 40, a first gear 41, a second gear 42, a third gear 43, a fourth gear 44, and an output gear 45 from the upstream side to the downstream side of the drive force transmission path. The worm 40 is fixed to the outer peripheral side of the rotary shaft 31 of the motor 3. As shown in fig. 4, the worm 40 and the first gear 41 are disposed in the first housing 15. As shown in fig. 3, the second gear 42, the third gear 43, the fourth gear 44, and the output gear 45 are disposed in the intermediate housing 16.

The first gear 41 includes a first large-diameter gear 411 that meshes with the worm 40, and a first small-diameter gear 412 that is coaxial with the first large-diameter gear 411 and has a smaller outer diameter than the first large-diameter gear 411. The first large-diameter gear 411 is located on one side Z1 in the first direction Z of the first small-diameter gear 412. The first gear 41 is rotatably supported by a first support shaft 413 (see fig. 4) extending in the first direction Z. One end of the first support shaft 413 is held by the bottom plate 151 of the first housing 15, and the other end is held by the intermediate plate 161 of the intermediate housing 16. The first gear 41 includes a torque limiter 46 that maintains and blocks transmission of the driving force between the first large-diameter gear 411 and the first small-diameter gear 412.

The second gear 42 is a composite gear including a second large-diameter gear 421 meshing with the first small-diameter gear 412 and a second small-diameter gear 422 coaxial with the second large-diameter gear 421 and having a smaller outer diameter than the second large-diameter gear 421. The second large-diameter gear 421 is located on one side Z1 of the second small-diameter gear 422 in the first direction Z. The second large-diameter gear 421 meshes with the first small-diameter gear 412 via an opening 163 (see fig. 8) provided in the intermediate plate 161 of the intermediate housing 16. The second gear 42 is rotatably supported by a second support shaft 423 (see fig. 5) extending in the first direction Z.

The third gear 43 is a composite gear including a third large-diameter gear 431 meshing with the second small-diameter gear 422 and a third small-diameter gear 432 coaxial with the third large-diameter gear 431 and having an outer diameter smaller than that of the third large-diameter gear 431. The third large-diameter gear 431 is located on one side Z1 in the first direction Z of the third small-diameter gear 432. The third gear 43 is rotatably supported by a third fulcrum 433 extending in the first direction Z. One end of the third support shaft 433 is held by the intermediate plate 161 of the intermediate case 16, and the other end thereof is held by the second case 17 through the reinforcing member 18.

The fourth gear 44 is a spur gear that meshes with the third small-diameter gear 432 and the output gear 45. The fourth gear 44 and the output gear 45 are aligned in the second direction Y. The fourth gear 44 is disposed coaxially with the second gear 42 and is rotatably supported by the second fulcrum 423. One end of the second support shaft 423 is held by the intermediate case 16, and the other end is held by the reinforcing member 18. That is, the reinforcing member 18 includes a shaft holding portion 182 (see fig. 3) that holds the second support shaft 423 that supports the second gear 42 and the fourth gear 44.

Fig. 6 is an exploded perspective view of the output gear 45 and the output shaft 2. The output gear 45 is made of metal. The output shaft 2 made of resin is coaxially fixed to the output gear 45. The output gear 45 is an annular member having a center hole 451 that opens in the first direction Z. A plurality of recesses 452 are circumferentially provided on the inner peripheral surface of the center hole 451, and a plurality of protrusions 23 that fit into the recesses 452 on the inner peripheral surface of the output gear 45 are provided on the outer peripheral surface of the base portion 21 of the output shaft 2. Therefore, the output gear 45 and the output shaft 2 are connected in a state of being relatively non-rotatable about the axis L. The base portion 21 of the output shaft 2 is a resin portion and is fixed to the output gear 45 by heat caulking.

The output gear 45 is rotatably supported by the reinforcing member 18. The output gear 45 includes an annular portion 450 having no teeth on the outer peripheral surface at the end portion on the other side Z2 in the first direction Z. On the other hand, the reinforcing member 18 includes an output gear receiving portion 183 (see fig. 3) at an outer peripheral portion of the reinforcing member side opening portion 181, and rotatably supports the annular portion 450 of the output gear from the outer peripheral side. The output gear receiving portion 183 is an annular tube portion that extends while being bent toward the other side in the first direction of the reinforcing member side opening portion 181 of the reinforcing member 18, and is formed by, for example, burring.

Fig. 7 is an exploded perspective view of the output gear 45, the output shaft 2, and the assist spring 5. As shown in fig. 3 and 7, the assist spring 5 includes a first spring 51 and a second spring 52. The first spring 51 and the second spring 52 are torsion coil springs. As shown in fig. 3, the second spring 52 is disposed on the inner peripheral side of the first spring 51. The first spring 51 is located on one side Z1 of the first direction Z of the output gear 45. The second spring 52 is located on one side Z1 in the first direction Z of the output shaft 2 and on the inner peripheral side of the first spring 51.

As shown in fig. 7, the first spring 51 includes a spring portion 510 formed by winding a wire 50A having a rectangular cross section in a spiral shape, a first end portion 511 extending from the spring portion 510 to one side Z1 in the first direction Z, and a second end portion 512 extending from the spring portion 510 to the other side Z2 in the first direction Z. As shown in fig. 5, the second end portion 512 of the first spring 51 is disposed in the cutout portion 453, and the cutout portion 453 is formed by cutting the outer peripheral surface of the output gear 45 to the inner peripheral side. The output gear 45 has a tooth portion formed on the outer peripheral surface of the range excluding the notched portion 453. The cutout 453 includes a first surface 454 provided at one end in the circumferential direction and a second surface 455 provided at the other end in the circumferential direction. As described later, when the output shaft 2 rotates to a predetermined angular position, the second end 512 contacts the second surface 455. When the output shaft 2 further rotates, the output shaft 2 is urged by the first spring 51 via the output gear 45.

Fig. 8 is a perspective view of the first casing 15 and the intermediate casing 16 when viewed from the other side Z2 in the first direction Z. As shown in fig. 3 and 8, the intermediate case 16 includes the support portion 6 protruding from the intermediate plate 161 to the other side Z2 in the first direction Z. As shown in fig. 3, the support portion 6 is located on the inner peripheral side of the first spring 51 and the second spring 52 and protrudes further than the first spring 51 and the second spring 52 toward the other side Z2 in the first direction Z. That is, the first spring 51 and the second spring 52 are held by the support portion 6 and are supported by the intermediate plate 161 from the first direction Z1 side.

In the present embodiment, the motor 3 is disposed on one side Z1 of the intermediate plate 161 in the first direction Z. The intermediate plate 161 divides an inner space of the housing 10 into a lower space in which the motor 3 is disposed and an upper space in which the output shaft 2, the assist spring 5, and the like are disposed. The motor 3 includes a receiving portion 33 that supports the intermediate plate 161 from one side Z1 in the first direction Z. The receiving portion 33 is a side surface of the other side Z2 of the motor main body 30 in the first direction Z, and is formed of, for example, a metal motor case. In the present embodiment, since the motor main body 30 has a square cross section, the receiving portion 33 is a flat surface perpendicular to the axis L. The receiving portion 33 supports the intermediate plate 161 and supports the support portion 6 from the side opposite to the output shaft 2 in the direction of the axis L (i.e., the side Z1 in the first direction Z).

The output shaft 2 and the output gear 45 are rotatably supported by the tip end portions of the support portions 6. The output shaft 2 is provided with a circular recess 24 recessed toward the other side Z2 on the end surface of one side Z1 in the first direction Z of the base 21, and the tip end portion of the support portion 6 is disposed in the circular recess 24 and contacts the bottom surface of the circular recess 24. Here, the other side Z2 in the first direction Z of the support portion 6 has a distal end extending to a position on the inner peripheral side of the output gear receiving portion 183 of the reinforcing member 18 that rotatably supports the annular portion 450 of the output gear 45.

As shown in fig. 8, the intermediate case 16 is provided with an opening 164 penetrating the intermediate plate 161 in the first direction Z. The opening 164 is provided in the middle frame 162 of the middle case 16 between the frame 165 on the side X1 in the third direction X and the support portion 6, of the pair of frames extending parallel to the second direction Y. Opening 164 is provided at a position where first end 511 of first spring 51 can be arranged when first spring 51 and second spring 52 are attached to the outer peripheral side of support portion 6. Further, the first housing 15 is provided with a spring holding portion 153 at a position overlapping the opening 164 of the intermediate housing 16 when viewed in the first direction Z. The spring holding portion 153 includes a spring locking hole 154 recessed toward one side Z1 in the first direction Z. The first end portion 511 of the first spring 51 protrudes from the opening portion 164 of the intermediate case 16 to one side Z1 in the first direction Z, and is inserted into the spring latching hole 154 of the spring holding portion 153 provided in the first case 15.

In the first housing 15, the spring holding portion 153 is supported by the motor 3 from a direction intersecting the first direction Z, which is a direction in which the spring locking hole 154 opens. That is, the motor 3 includes the spring receiving portion 34 that receives the spring holding portion 153 from a direction intersecting the opening direction (first direction Z) of the spring locking hole 154. As shown in fig. 8, the spring holding portion 153 protrudes from the inner surface of the frame portion 152 of the first case 15 toward the side where the motor body 30 is located (the other side X2 in the third direction X). The spring holding portion 153 includes an inclined surface 155 cut at the end portion of the other side X2 in the third direction X so as to be parallel to the side surface of the motor main body 30. When the motor 3 is housed in the first housing 15, the inclined surface 155 of the spring holding portion 153 is supported by the side surface of the motor main body 30 from the other side X2 in the third direction X. That is, the spring receiving portion 34 is a side surface of the motor main body 30, and is formed of, for example, a metal motor case.

As shown in fig. 7, the second spring 52 includes a spring portion 520 formed by winding a wire 50B having a circular cross section in a spiral shape, a first end portion 521 bent radially inward from one end portion of the spring portion 520 at one side Z1 in the first direction Z and extending linearly, and a second end portion 522 extending from the spring portion 520 at the other side Z2 in the first direction Z. The first end 521 of the second spring 52 is disposed in the groove 61 provided in the support portion 6 (see fig. 8, 9 b, and 10 b), whereby the first end 521 of the second spring 52 is locked to the intermediate case 16, as shown in fig. 7, the output shaft 2 includes a spring locking hole 25 provided in an end surface of the one side Z1 of the base portion 21, and the second end 522 of the second spring 52 is disposed in the spring locking hole 25 of the output shaft 2.

(Rib shape)

As shown in fig. 8, the intermediate case 16 includes a rib 7 extending in the circumferential direction on the outer circumferential side of the support portion 6. The rib 7 protrudes from the intermediate plate 161 to the other side Z2 in the first direction Z. When first spring 51 and second spring 52 are attached to the outer peripheral side of support portion 6, one end of rib 7 in the circumferential direction is disposed between first spring 51 and second spring 52 (see fig. 3). The inner circumferential edge 71 of the rib 7 is circular-arc shaped. That is, the inner peripheral edge 71 of the rib 7 is shaped to follow the outer periphery of the spring portion 520 of the second spring 52, which is a spring disposed on the inner peripheral side. The outer peripheral edge of the rib 7 is provided with

circular arc portions

72A and 72B along the inner periphery of the spring portion 510 of the first spring 51 at both ends in the circumferential direction, and is provided with a protruding portion 73 protruding outward in the radial direction at the center in the circumferential direction. The protruding portion 73 is shaped to protrude toward the inside of the opening 164. The outer peripheral edge of the rib 7 is provided with

linear portions

74A, 74B extending in the tangential direction of the

circular arc portions

72A, 72B on both sides of the tip end of the protruding portion 73 in the circumferential direction.

As shown in fig. 7, the first spring 51 includes a linear portion 513 extending from a winding start position of the first turn 510A of the spring portion 510 in a tangential direction of the first turn 510A, and the first end 511 extends from a tip of the linear portion 513 to a side Z1 in the first direction Z.

Fig. 9 is an explanatory diagram showing the planar shapes of the support portion 6, the rib 7, and the auxiliary spring 5. The planar shape of the first spring 51 shown in fig. 9 is the planar shape of the first coil 510A, the linear portion 513, and the first end 511. In the rib 7 provided in the intermediate case 16, the circular arc portion 72A provided at one circumferential end portion of the outer peripheral edge extends along the inner circumference of the winding start portion of the first turn 510A of the spring portion 510. Further, a straight portion 74A extending from the circular arc portion 72A to the tip of the protruding portion 73 extends along the straight portion 513. The first spring 51 is arranged in a state where the winding start portion and the linear portion 513 of the first turn 510A of the spring portion 510 extend along the outer peripheral edge of the rib 7. Thereby, the rotation stop of the first spring 51 is achieved by the protruding portion 73 of the rib 7, and the linear portion 513 of the first spring 51 is positioned at an angular position extending toward the opening portion 164.

The rib 7 is symmetrical with respect to a straight line L0 connecting the opening 164 at the first end 511 and the center P in the radial direction of the support portion 6. As shown in fig. 9, the tip of the protruding portion 73 is located on a straight line L0, and the rib 7 includes a straight portion 74A extending from the tip of the protruding portion 73 to one circumferential side and a straight portion 74B extending to the other circumferential side. The rib 7 includes an arc portion 72A extending to one side in the circumferential direction of the linear portion 74A and an arc portion 72B extending to the other side in the circumferential direction of the linear portion 74B. That is, the straight portions 74A and the arc portions 72A and the straight portions 74B and the arc portions 72B are symmetrical with respect to the straight line L0. The rib 7 is provided within an angular range of 180 ° with the straight line L0 as the center in the circumferential direction.

That is, as shown in fig. 9, the first spring 51 of the present embodiment has a shape in which the linear portion 513 is guided by the linear portion 74A located on one side in the circumferential direction with respect to the tip end of the protruding portion 73, but when the winding direction of the first spring 51 is reversed, the linear portion 513 can be guided by the linear portion 74B located on the other side in the circumferential direction with respect to the tip end of the protruding portion 73, and the first spring 51 can be attached. That is, even when the winding direction of the first spring 51 is reversed, the shape of the rib 7 does not need to be changed.

The protruding height of the rib 7 in the first direction Z is smaller than the wire diameter of the wire 50A constituting the first spring 51. In the first spring 51, the winding end portion of the first turn 510A of the spring portion 510 extends in the circumferential direction on one side Z1 in the first direction Z of the protruding portion 73 of the rib 7. Therefore, the protruding portion 73 functions as a receiving portion that supports a part of the first spring 51 from the one side Z1 in the first direction Z.

The radial width of both ends in the circumferential direction of the rib 7 (portions where the

circular arc portions

72A, 72B are provided) is not fixed, and both ends in the circumferential direction of the rib 7 are tapered such that the radial width becomes narrower as being away from the protruding portion 73 in the circumferential direction. Therefore, a radial gap S is formed between the first ring 510A of the first spring 52 and the arc portion 72A of the rib 7.

The inner circumferential edge 71 of the rib 7 is an inclined surface whose distance from the center P in the radial direction of the support portion 6 increases in a direction toward the other side Z2 in the first direction Z. Therefore, the second spring 52 is supported by the inner peripheral edge 71 from the one side Z1 in the first direction Z.

(action)

In the opening/closing member drive device 1, when the motor 3 is driven in the forward direction or the reverse direction, the drive force of the motor 3 is transmitted to the output shaft 2 via the transmission mechanism 4, and the output shaft 2 rotates in the first rotation direction CW or the second rotation direction CCW. Thereby, the opening/closing member such as a toilet seat and a toilet lid fixed to the output shaft 2 is rotated in the opening direction or the closing direction. When the opening and closing member rotates, the potentiometer 8 outputs a signal corresponding to the position of the opening and closing member. When the opening/closing member connected to the output shaft 2 rotates in the first rotation direction CW, the assist spring 5 applies an elastic force to the output shaft 2 to rotate the output shaft 2 about the axis L in a second rotation direction CCW opposite to the first rotation direction CW. That is, when the opening/closing member is driven, an assisting force that urges the output shaft 2 is applied to the output shaft 2. Further, since the transmission mechanism 4 includes the torque limiter 46 in the first gear 41, when an excessive load is applied to the transmission mechanism 4 from the opening/closing member via the output shaft 2, the torque limiter 46 acts to block the transmission of the driving force by the transmission mechanism 4. This can prevent the transmission mechanism 4 from being damaged by an excessive load from the outside.

(range of angle of operation of auxiliary spring)

The first spring 51 and the second spring 52 of the assist spring 5 have different operating angle ranges (angle ranges in which the elastic force is generated). In the case where the opening/closing member is a toilet seat or a toilet lid, a load curve showing a relationship between a rotational load when the opening/closing member is rotated by a predetermined angle from a reference position and a rotational angle from the reference position is not a shape showing a simple proportional relationship. Therefore, by combining a plurality of springs having different operating angle ranges, a graph showing the relationship between the driving force of the motor 3 and the sum of the elastic forces of the first spring 51 and the second spring 52 and the rotation angle is made to approach the load curve.

Fig. 10 is an explanatory diagram showing a state of the assist spring 5 when the output shaft 2 is at the reference position R0. Fig. 11 is an explanatory diagram showing a state of the assist spring 5 when the output shaft 2 is at the action start position R2 of the second spring 52. Fig. 10 (a) and 11 (a) show the rotational position of the output shaft 2, and fig. 10 (b) and 11(b) show the state of the assist spring 5. Fig. 12 is an explanatory diagram showing a state of the assist spring 5 when the output shaft 2 is at the action start position R1 of the first spring 51.

As shown in fig. 10 (a), when the output shaft 2 is at the reference position R0, the second end portion 512 of the first spring 51 is located closer to the one side of the notch 453 of the output gear 453 in the circumferential direction and is away from the second surface 455. Therefore, the first spring 51 does not apply an elastic force to the output gear 45. As shown in fig. 10 (b), the first end 521 of the second spring 52 is located at the circumferential center of the groove 61 provided in the support portion 6. The groove 61 has the following shape: the width in the circumferential direction (groove width) increases from the center of the support portion 6 in the radial direction toward the outer side in the radial direction, and the first end portion 521 can move in the circumferential direction within a range not contacting the inner surface of the groove portion 61. Therefore, no elastic force is applied from the second spring 52 to the output shaft 2.

As shown in fig. 11 (a), when the output shaft 2 rotates in the first rotational direction CW to the action start position R2 of the second spring 52, the second end 512 of the first spring 51 approaches the second surface 455 but is still separated from the second surface 455. Therefore, the first spring 51 does not apply an elastic force to the output gear 45. On the other hand, as shown in fig. 11(b), as the output shaft 2 rotates, the first end 521 of the second spring 52 is inclined in the first rotation direction CW in the groove 61 and contacts the inner surface of the groove 61. Therefore, when the output shaft 2 further rotates in the first rotation direction CW from this, the second spring 52 deforms and generates an elastic force.

Next, as shown in fig. 12, when the output shaft 2 further rotates in the first rotational direction CW and reaches the action start position R1 of the first spring 51, the second end 512 of the first spring 512 comes into contact with the second surface 455. Therefore, when the output shaft 2 further rotates in the first rotation direction CW from this, the first spring 51 deforms and generates an elastic force. Thus, the assist spring 5 generates no assist force from the reference position R0 to the action start position R2 of the second spring 52, and generates only the second spring 52 from the action start position R2 to the action start position R1, so that the assist force is generated by only one spring. Since both the second spring 52 and the first spring 51 generate elastic force from the action start position R1, the resultant force thereof becomes the assist force.

In the present embodiment, when the rotation angle of the output shaft 2 at the reference position R0 is set to 0 ° and the rotation angle of the output shaft 2 at the maximum rotation position is set to Rmax °, the operation angle range (first operation angle range) of the first spring 51 is a range from the operation start position R1 of the first spring 51 to the maximum rotation position. The operation angle range (second operation angle range) of the second spring 52 is a range from the operation start position R2 of the second spring 52 to the maximum rotation position. For example, when Rmax ° is 120 ° and the rotation angle at the action start position R1 of the first spring 51 is 50 °, the first action angle range is 50 ° to 120 °. When the rotation angle at the operation start position R2 of the second spring 52 is 20 °, the second operation angle range is 20 ° to 120 °. Therefore, the assisting force is not generated until the output shaft 2 rotates 20 ° from the reference position R0, but the elastic force of the second spring 52 is the assisting force in the range of the rotation angle from the reference position R0 of 20 ° to 50 °, and the sum of the elastic force of the second spring 52 and the elastic force of the first spring 51 is the assisting force in the range of the rotation angle from the reference position R0 of 50 ° to 120 °.

The spring constant of the first spring 51 of the auxiliary spring 5 is larger than that of the second spring 52. The first spring 51 is formed of a wire 50A having a square cross section, the second spring 52 is formed of a wire 50B having a circular cross section, and the wire diameters of the

wires

50A and 50B are the same. When the wire diameter is the same, the coil spring formed of a wire rod having a square cross section has a larger spring constant than the coil spring formed of a wire rod having a circular cross section.

In addition, the auxiliary spring 5 has a smaller operating angle range (first operating angle range) for the first spring 51 having a large spring constant than for the second spring 52 having a small spring constant. As described above, when the operation start position R1 of the first spring 51 is 50 ° and the operation start position R2 of the second spring 52 is 20 °, the second spring 52 having a small spring constant first starts to generate an elastic force when the opening/closing member is rotated from the closed position to the open position.

(main effect of the present embodiment)

As described above, the opening/closing member driving device 1 of the present embodiment includes: the electric power tool includes a housing 10, an output shaft 2 protruding from the housing 10, a motor 3 housed in the housing 10, a transmission mechanism housed in the housing 10 and transmitting rotation of the motor 3 to the output shaft 2, and an assist spring 5 that generates an assist force that urges the output shaft 2 in a second rotation direction CCW opposite to the first rotation direction CW in accordance with rotation of the output shaft 2 in the first rotation direction CW. The assist spring 5 includes a first spring 51 and a second spring 52 disposed on an inner peripheral side of the first spring 51, and the first spring 51 and the second spring 52 are torsion coil springs. The housing 10 includes an intermediate plate 161 that partitions an internal space, and a support portion 6 and a rib 7 that protrude from the intermediate plate 161 toward the output shaft 2 side. The support portion 6 rotatably supports the output shaft 2 and is disposed on the inner peripheral side of the second spring 52. Further, the rib 7 is disposed between the first spring 51 and the second spring 52.

According to the present embodiment, the auxiliary spring 5 for biasing the output shaft 2 includes the first spring 51 and the second spring 52 disposed on the inner peripheral side of the first spring 51, and includes two torsion coil springs disposed in a double-layer arrangement. The case 10 includes an intermediate plate 161 that partitions an internal space in the first direction Z, a support portion 6 that is disposed on an inner peripheral side of the auxiliary spring 5 and a rib 7 that is disposed between the first spring 51 and the second spring 52 that protrude from the intermediate plate 161. By disposing the rib 7 provided in the housing 10 between the first spring 51 and the second spring 52 in this way, it is possible to suppress interference between the first spring 51 and the second spring 52. Therefore, the first spring 51 and the second spring 52 interfere with each other, and a normal spring operation is not performed, and there is little risk that a designed elastic force cannot be obtained. Further, there is little risk of abnormal stress being generated and durability being impaired by interference between the first spring 51 and the second spring 52.

In the present embodiment, at least the circular arc portion 72A of the outer peripheral edge of the rib 7 is shaped along the inner periphery of the first coil 510A of the first spring 51, and therefore, the rib 7 can guide the first spring 51 from the inner periphery side, and the positional accuracy of the first spring 51 can be improved. In addition, since the deformation of the first spring 51 can be suppressed, the interference between the first spring 51 and the second spring 52 can be suppressed.

Further, a radial gap S is provided between the arc portion 72A of the rib 7 and the first turn 510A of the first spring 51. By providing a certain degree of clearance S between the rib 7 and the first spring 51 in this way, contact between the first spring 51 and the rib 7 can be suppressed even when the first spring 51 is deformed by rotation of the output shaft 2. Therefore, a decrease in durability due to contact between the first spring 51 and the rib 7 can be suppressed.

In the present embodiment, since the rib 7 includes the protruding portion 73 protruding outward in the radial direction of the first spring 51, the linear portion 513 of the first spring 51 can be locked by the protruding portion 73. Therefore, the first spring 51 can be prevented from rotating by the projection 73.

In the present embodiment, the intermediate plate 161 is provided with the opening 164 in which the end portion of the first spring 51 is disposed, and the protruding portion 73 of the rib 7 protrudes toward the opening 164, so the protruding portion 73 functions as a guide portion for extending the spring end portion of the first spring 51 toward the opening 164. Therefore, the positional accuracy of the first spring 51 can be improved. In addition, since positioning is easy when the first spring 51 is assembled, the assembly work is easy.

The protruding portion 73 of the rib 7 of the present embodiment functions as a receiving portion that supports a part of the first spring 51. Therefore, for example, the winding start portion of the first winding 510A may be supported by the intermediate plate 161, and the winding end portion of the first winding 510A may be supported by the receiving portion (the projecting portion 73). This can suppress the inclination of the first spring 51. Therefore, the first spring 51 and the second spring 52 can be suppressed from interfering with each other.

In the present embodiment, since the height of the rib 7 is lower than the wire diameter of the first spring 51, the first spring 51 can be prevented from floating from the intermediate plate 161. Therefore, since the first spring 51 can be supported by the intermediate plate 161 in a stable state, the inclination of the first spring 51 can be suppressed.

In the present embodiment, the rib 7 is tapered such that the radial width thereof becomes narrower as it goes away from the protruding portion 73 in the circumferential direction. This makes it possible to increase the radial gap between the ribs 7 and the first and

second springs

51 and 52 as they are separated from the protruding portion 73 in the circumferential direction. Therefore, while the positional accuracy of the first end 511 disposed in the opening 164 is improved, a certain degree of clearance can be provided between each part of the first ring 510A and the rib 7. Therefore, contact of the first spring 51 and the rib 7 when the first spring 51 is deformed by rotation of the output shaft 2 can be suppressed. Therefore, a decrease in durability due to contact between the first spring 51 and the rib 7 can be suppressed.

In the present embodiment, since the inner peripheral edge 71 of the rib 7 has a shape along the outer periphery of the second spring 52, the second spring 52 can be guided from the outer peripheral side. Therefore, the positional accuracy of the second spring 52 can be improved. In addition, since the deformation of the second spring 52 can be suppressed, the interference between the first spring 51 and the second spring 52 can be suppressed.

In the present embodiment, the support portion 6 disposed on the inner peripheral side of the second spring includes the groove portion 61 extending in the radial direction, and the first end portion 521 of the second spring 52 is disposed in the groove portion. The groove portion 61 has a shape in which the groove width increases from the center P in the radial direction of the support portion 6 toward the radial outer side. This allows the first end 521 of the second spring 52 to be inclined freely to some extent in the circumferential direction in the groove 61. Therefore, when the output shaft 2 rotates, the second spring 52 does not generate the spring force until the predetermined angle from the reference position.

In the present embodiment, the rib 7 disposed between the first spring 51 and the second spring 52 is symmetrical with respect to the straight line L0 connecting the opening 164 at the spring end of the first spring 51 and the center P in the radial direction of the support portion 6, and therefore, the winding direction of the first spring 51 can be reversed. Therefore, it is not necessary to change the shape of the rib 7 in accordance with the rotation direction of the output shaft 2 and to change the shape of the housing 10, and therefore, the components can be used in common.

Claims

1. An opening/closing member driving device comprising:

a housing;

an output shaft protruding from the housing;

a motor housed in the case;

a transmission mechanism that is housed in the case and transmits rotation of the motor to the output shaft; and

an assist spring that generates an assist force that urges the output shaft in a second rotational direction opposite to the first rotational direction in accordance with rotation of the output shaft in the first rotational direction,

the auxiliary spring includes a first spring and a second spring disposed on an inner peripheral side of the first spring, the first spring and the second spring are torsion coil springs,

the housing includes an intermediate plate that partitions an internal space, and a support portion and a rib that protrude from the intermediate plate toward the output shaft side, the support portion rotatably supporting the output shaft,

the support portion is disposed on an inner peripheral side of the second spring,

the rib is disposed between the first spring and the second spring.

2. The shutter drive device according to claim 1,

at least a portion of an outer periphery of the rib is shaped to follow an inner periphery of the first turn of the first spring.

3. The opening-closing member driving device according to claim 1 or 2,

a radial gap is provided between the rib and the first coil of the first spring.

4. The opening/closing member driving device according to any one of claims 1 to 3,

the rib has a projection projecting radially outward of the first spring.

5. The shutter drive device according to claim 4,

the intermediate plate has an opening portion in which an end portion of the first spring is disposed,

the protruding portion protrudes toward the opening portion side.

6. The shutter drive device according to claim 5,

the projection is a receiving portion that supports a part of the first spring.

7. The shutter drive device according to claim 6,

the height of the rib is lower than the wire diameter of the first spring.

8. The opening-closing member driving device according to any one of claims 4 to 7,

the rib is tapered such that a radial width thereof tapers away from the projection in the circumferential direction.

9. The opening-closing member driving device according to any one of claims 1 to 8,

the inner periphery of the rib is shaped along the outer periphery of the second spring.

10. The opening-closing member driving device according to any one of claims 1 to 9,

the support portion includes a groove portion extending in a radial direction, an end portion of the second spring is disposed in the groove portion,

the groove width of the groove portion increases from the center of the support portion in the radial direction toward the outer side in the radial direction.

11. The opening-closing member driving device according to any one of claims 5 to 7,

the rib has a symmetrical shape with respect to a straight line connecting the opening and the center of the support portion in the radial direction.