CN111749572B

CN111749572B - Opening/closing member drive device and opening/closing device

Info

Publication number: CN111749572B
Application number: CN202010224159.7A
Authority: CN
Inventors: 钱一君; 石水昭夫
Original assignee: Nidec Sankyo Zhejiang Corp; Nidec Sankyo Corp
Current assignee: Nidec Sankyo Zhejiang Corp; Nidec Instruments Corp
Priority date: 2019-03-28
Filing date: 2020-03-26
Publication date: 2022-02-22
Anticipated expiration: 2040-03-26
Also published as: JP2020162697A; CN111749572A; JP7339756B2; WO2020195649A1

Abstract

A shutter drive device and a shutter device are provided, which can change the rotation direction of the output shaft of the shutter drive device and can realize the easy assembly operation. 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 (44) for transmitting the rotation of the motor to the output shaft, and an assist spring (5) for urging the output shaft. The transmission mechanism (4) is provided with an output gear (45) which rotates integrally with the output shaft and a fourth gear (44) which is a front gear and meshes with the output gear, and the first tooth portion (T1) and the second tooth portion (T2) of the output gear are symmetrical with respect to a straight line (L2) which connects the center of the output gear and the center of the fourth gear which is the front gear. Therefore, the rotation direction of the output shaft can be changed by changing only the winding direction of the assist spring without changing the shape and the origin position (RA) of the output shaft.

Description

Opening/closing member drive device and opening/closing device

Technical Field

The present invention relates to an opening/closing member drive device and an opening/closing 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 an excessive load from being applied to the motor and the transmission mechanism to damage the motor and the transmission mechanism when the opening and 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

The lid opening/closing device of patent document 1 accommodates a motor and a reduction gear set in a 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. 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.

Here, when the rotation direction of the output shaft of the lid opening/closing device is only one direction, it is not possible to cope with the change of the installation posture and the change of the opening/closing direction of the opening/closing member. Therefore, in patent document 1, two types of assist springs having different winding directions can be selectively attached so that the rotation direction of the output shaft when the opening/closing member is driven can be selected. Specifically, the output shaft is provided with two fixing holes for arranging the end portions of the assist spring.

However, in a configuration in which rotation of the output shaft in both directions is possible, it is necessary to assemble the output shaft so as to align the origin position of the output shaft in accordance with the rotation direction. Further, in the case where fixing holes are provided at two places to correspond to the change of the winding direction of the assist spring as in patent document 1, there is a possibility that the end portion of the assist spring is inserted into the wrong fixing hole at the time of assembly. Therefore, there is a problem that the assembling work is difficult.

In view of the above problems, the present invention has been made to change the rotational direction of an output shaft in an opening/closing member drive device and to facilitate assembly work.

Technical scheme for solving technical problem

In order to solve the above-described problems, an opening/closing member drive device according to the present invention includes: a housing; an output shaft protruding from the housing; a motor housed in the case; and a transmission mechanism that is housed in the case and transmits rotation of the motor to the output shaft, the transmission mechanism including an output gear that rotates integrally with the output shaft and a preceding gear that meshes with the output gear, the output gear including a first tooth portion and a second tooth portion, the first tooth portion meshing with the preceding gear during rotation of the output shaft from an origin position in a first rotational direction, the second tooth portion meshing with the preceding gear during rotation of the output shaft from the origin position in a second rotational direction opposite to the first rotational direction, the first tooth portion and the second tooth portion having a shape that is symmetrical with respect to a straight line connecting a center of the output gear and a center of the preceding gear.

According to the present invention, the transmission mechanism for transmitting the rotation of the electric motor to the output shaft includes the output gear that rotates integrally with the output shaft and the preceding gear that meshes with the output gear, and the first tooth portion and the second tooth portion of the output gear are symmetrical with respect to a straight line connecting the center of the output gear and the center of the preceding gear. Thus, the output shaft can be operated in the same rotational angle with different rotational directions without changing the shape and the origin position of the output shaft. Further, since it is not necessary to perform assembly by aligning the origin position in accordance with the rotation direction of the output shaft, the assembly work is facilitated.

In the present invention, it is preferable that the output gear includes a notch portion that cuts a gap between an end portion of the first tooth portion in the second rotational direction and an end portion of the second tooth portion in the first rotational direction, and each of the end portion of the first tooth portion in the second rotational direction and the end portion of the second tooth portion in the first rotational direction includes a stopper that interferes with a tooth top of the preceding gear. In this way, by providing the stoppers in the first tooth portion and the second tooth portion, respectively, it is possible to provide the rotation stopper that restricts the rotation range on one side and the rotation range on the other side in the output shaft direction.

In the present invention, it is preferable that an assist spring generating an assist force for urging the output shaft in a rotational direction is provided, and the assist spring includes a spring end portion disposed in the cutout portion. In this way, the end portion of the assist spring is disposed in the cutout portion of the output gear, and the assist spring can be increased in size in the radial direction. Therefore, the assist force can be increased, and the output torque can be increased. When the output shaft rotates to one side, one end of the notch portion engages with the spring end to generate an assist force, and when the output shaft rotates to the other side, the other end of the notch portion engages with the spring end to generate an assist force. Therefore, since it is not necessary to change the shape of the output gear in accordance with the change in the winding direction of the assist spring, it is possible to change the winding direction of the assist spring, that is, to correspond to the change in the rotation direction of the output shaft, without changing the shape of the output gear.

In the present invention, it is preferable that the output gear includes a first surface provided at one circumferential end of the cutout portion and a second surface provided at the other circumferential end, the first surface includes a first relief portion that cuts a corner portion of the auxiliary spring on the side in the circumferential direction, and the second surface includes a second relief portion that cuts a corner portion of the auxiliary spring on the side in the circumferential direction. In this way, when the winding end portion of the spirally wound wire material is bent in the axial direction and arranged in the notch portion of the output gear, the auxiliary spring can be prevented from being inclined by interference between the bent portion of the wire material and the corner portion of the output gear.

In the present invention, it is preferable that the output gear is made of metal. In this way, the risk of the output gear being deformed or damaged by the load applied from the spring end of the assist spring is reduced.

In the present invention, it is preferable that the output shaft includes a resin portion disposed in a center hole provided in the output gear, and the output gear is fixed to the resin portion by thermal caulking. In this way, by making the portion to which the load is applied from the spring end portion of the assist spring made of metal and making the other portion made of resin, the component cost can be reduced as compared with the case where the output shaft and the output gear are made of metal components as a whole. Further, since the output gear is fixed by the heat caulking, the output gear does not shake with respect to the output shaft, and therefore, the positional accuracy of the output shaft can be improved.

The present invention is a switchgear including the above-described shutter drive device, wherein the output shaft is connected to a shutter that is displaced to a closed position and an open position in accordance with rotation of the output shaft. For example, the opening/closing member is a toilet seat or a toilet lid.

(effect of the invention)

According to the present invention, the transmission mechanism for transmitting the rotation of the electric motor to the output shaft includes the output gear that rotates integrally with the output shaft and the preceding gear that meshes with the output gear, and the first tooth portion and the second tooth portion of the output gear are symmetrical with respect to a straight line connecting the center of the output gear and the center of the preceding gear. Thus, the output shaft can be operated in the same rotational angle with different rotational directions without changing the shape and the origin position of the output shaft. Further, since it is not necessary to perform assembly by aligning the origin position according to the rotation direction of the output shaft, the assembly work becomes easy.

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.

Fig. 13 is a plan view of the transmission mechanism and the output shaft when the output shaft is at the origin position.

Fig. 14 is a plan view of the transmission mechanism, the output shaft, and the assist spring when the output shaft is rotated by the maximum angle from the origin position.

Fig. 15 is a side view of the output shaft, the output gear, and the first spring.

Description of the reference numerals

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; a 47 … stop; 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; 101 … opening and closing device; 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; 231 … front end portion; 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; 456 … a first escape; 457 … second escape portion; 471 … engagement surfaces; 510a … first turn; 510 … spring portion; 511 … a first end; 512. 512a … second end; 513. 513a … straight line portion; 520 … spring portion; 521 … a first end; 522 … second end; CCW … second direction of rotation; CW … first direction of rotation; center of the C1 … output gear; center of C2 … fourth gear; the axis of the L … output shaft; l0 … is a straight line connecting the opening and the center of the support in the radial direction; the rotational centerline of the L1 … motor; l2 … straight line connecting the center of the output gear and the center of the fourth gear; r0 … reference position; r1 … first effect start position; r2 … second effect start position; RA … origin position; t1 … first tooth; t2 … second tooth; 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 and 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 opening and closing members that are displaced by the rotation of the output shaft 2 to a closed position covering the toilet body 110 and an open position standing from the toilet body 110. Therefore, the western-style toilet 100 includes an opening/closing device 101 for opening and closing the toilet seat 120 and the toilet lid 130 with respect to the toilet body 110 by the opening/closing member driving device 1. The opening/closing device 101 may be configured to rotate only one of the toilet seat 120 and the toilet lid 130 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 in 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 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. The base portion 21 of the output shaft 2 is a resin portion, and is fixed to the output gear 45 by heat caulking. Fig. 7 shows a state before the output gear 45 and the output shaft 2 are assembled so as not to be relatively rotatable and subjected to heat caulking. In a state before the heat caulking, the convex portion 23 of the output shaft 2 protrudes from the concave portion 452 of the output gear 45 to the one side Z1 in the first direction Z. The tip 231 of the convex portion 23 on the first direction Z side Z1 is tapered such that the dimension of projection on the first direction Z side Z1 increases radially outward. Therefore, the radially outer portion of the distal end 231 is largely crushed by the heat caulking, and is crushed into a shape expanding radially outward of the concave portion 452. Thus, the squashed resin locks the inner peripheral edge of the end face of the output gear 45, and the output gear 45 is fixed to the output shaft 2.

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.

A spring locking hole 25 is formed in the projection 23 provided on the outer peripheral surface of the base portion 21 of the output shaft 2. As shown in fig. 7, since the convex portion 23 is fitted into the concave portion 452 provided in the output gear 45, the resin portion surrounding the spring latching hole 25 is reinforced by the output gear 45 made of metal. Therefore, even if the wall thickness of the resin portion surrounding the spring retaining hole 25 is thin, the base portion 21 of the output shaft 2 is less likely to be deformed or damaged by the load applied from the second end portion 522 inserted into the spring retaining hole 25.

(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. On the other hand, 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 inward 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

arcuate 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 front end of the projection 73 is located on a straight line L0. The rib 7 includes a linear portion 74A extending from the tip of the protruding portion 73 to one circumferential side and a linear portion 74B extending to the other circumferential side. The arc portion 72 includes an arc portion 72A extending to one side in the circumferential direction of the straight portion 74A and an arc portion 72B extending to the other side in the circumferential direction of the straight 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.

As shown in fig. 9, the first spring 51 has a shape in which a linear portion 513 is guided by a linear portion 74A located on one side in the circumferential direction with respect to the tip of the protruding portion 73. As will be described later, in the present embodiment, the rotation direction of the output shaft 2 can be changed by using the first spring 51A (see fig. 14 (b)) having the winding direction opposite to that of the first spring 51. That is, when the first spring 51A having the winding direction opposite to that of the first spring 51 is attached, the rib 7 of the present embodiment can guide the linear portion 513A of the first spring 51A 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 (see fig. 14B), and can also prevent the rotation of the first spring 51A by the protruding portion 73. That is, even when the first spring 51A having the winding direction of the first spring 51 reversed is attached, 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. With 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 of the rib 7 in the circumferential direction (portions where the

circular arc portions

72A, 72B are provided) is not constant, but is tapered such that the radial width becomes narrower as it goes away from the protruding portion 73 in the circumferential direction. Therefore, a radial gap S is formed between the first turn 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 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 operation angle 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 from the open position to the closed position and a rotational angle of the output shaft 2 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 brought close to 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 51 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 portion 521 of the second spring 52 is inclined in the first rotation direction CW in the groove portion 61 and contacts the inner surface of the groove portion 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 opening/closing member moves from the open position to the closed position, the output shaft 2 rotates within a range from the reference position R0 to the maximum rotation position Rmax. In this case, the action angle range (first action angle range) of the first spring 51 is a range from the action start position R1 of the first spring 51 to the maximum rotation position Rmax. The action angle range (second action angle range) of the second spring 52 is a range from the action start position R2 of the second spring 52 to the maximum rotation position Rmax. For example, when the rotation angle of the output shaft 2 at the reference position R0 is 0 °, the rotation angle of the output shaft 2 at the maximum rotation position Rmax is 120 °, and the rotation angle of the output shaft 2 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 of the output shaft 2 at the action start position R1 of the second spring 52 is 20 °, the second action angle range is 20 ° to 120 °. Therefore, the output shaft 2 rotates from the reference position R0 to 20 °, no assist force is generated, the biasing force of the second spring 52 is an assist force in a range of 20 ° to 50 ° in rotation from the reference position R0, and the sum of the spring force of the second spring 52 and the spring force of the first spring 51 is an assist force in a range of 50 ° to 120 ° in rotation from the reference position R0.

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.

(response to change of rotation direction of output shaft)

As described with reference to fig. 10 to 12, the output shaft 2 deforms the assist spring 5 and accumulates the elastic force when rotating from the reference position R0 toward the maximum rotation position Rmax. Therefore, the opening/closing member driving device 1 is provided so that when the opening/closing member such as a toilet seat or a toilet lid is driven by the opening/closing member driving device 1, the maximum rotation position Rmax is set to the origin position RA of the output shaft 2, the opening/closing member is located at the closed position at the origin position RA, and the opening/closing member is located at the open position at the reference position R0. Thus, in a state where the load of the opening/closing member is applied as a load, the assisting force acts in a direction to reduce the load.

Fig. 13 is a plan view of the transmission mechanism 4 and the output shaft 2 when the output shaft 2 is at the origin position RA. As described above, the origin position RA is a position at which the output shaft 2 is rotated from the reference position R0 shown in fig. 10 to a side at which the assist spring 5 is deformed. For example, in the present embodiment, a position rotated by 120 ° from the reference position R0 is the origin position RA. The rotational direction from the reference position R0 toward the origin position RA is the same rotational direction as the winding direction of the

wire materials

50A, 50B constituting the assist spring. The rotation angle of the origin position RA with respect to the reference position R0 is not limited to 120 °, and may be changed as appropriate.

Fig. 14 is a plan view of the transmission mechanism 4, the output shaft 2, and the assist spring 5 when the output shaft 2 is rotated by the maximum angle from the origin position RA. Fig. 14 (a) shows a case where the rotation direction from the origin position RA is the second rotation direction CCW. Fig. 14 (b) shows a case where the rotation direction from the origin position RA is the first rotation direction CW. The opening/closing member driving device 1 of the present embodiment can reverse the direction of the assisting force by selectively attaching one of the two types of assisting

springs

5 and 5A having different winding directions. Thus, as shown in fig. 14 (a), the first mode in which the assist force acts when rotating from the origin position RA in the second rotation direction CCW may be adopted, or as shown in fig. 14 (b), the second mode in which the assist force acts when rotating from the origin position RA in the first rotation direction CW may be adopted.

In the present specification, the form of the first spring 51 shown in fig. 3, 5 to 7, and 10 to 12 is the form of the first spring 51 used in the first embodiment shown in fig. 14 (a). In the first embodiment, the assist force acts when rotating from the origin position RA in the second rotation direction CCW. In the first embodiment, the first spring 51 and the second spring 52 in which the

wire materials

50A and 50B are wound in the first rotational direction CW from the one side Z1 toward the other side Z2 in the first direction Z are used as the assist spring 5. On the other hand, in the second embodiment shown in fig. 14 (b), a first spring 51A whose winding direction is opposite to that of the first spring 51 and a second spring (not shown) whose winding direction is opposite to that of the second spring 52 are used as the assist spring 5A. As described with reference to fig. 9, the rib 7 provided in the intermediate case 16 is provided with the

linear portions

74A and 74B on both sides in the circumferential direction of the protruding portion 73. In the first embodiment, the linear portion 513 of the first spring 51 is guided by the linear portion 74A, and the first spring 51 is locked. In the second embodiment, the linear portion 513A (see fig. 14 (B)) of the first spring 51A is guided by the linear portion 74B, and the first spring 51A is prevented from rotating. That is, the intermediate case 16 is configured to hold the first spring 51A having the winding direction opposite to that of the first spring 51 without changing the shape.

In the first embodiment shown in fig. 14 (a), the second end 512 of the first spring 51 engages with the second surface 455 when accumulating the elastic force, and the second surface 455 is located at the end of the notch 453 provided in the output gear 455 on the second rotation direction CCW side. On the other hand, in the second embodiment shown in fig. 14 (b), the second end 512A of the first spring 51A engages with the first surface 454 when accumulating the elastic force, and the first surface 454 is located at the end of the cutout 453 provided in the output gear 455 on the first rotation direction CW side. In fig. 13, the engagement state between the second end 512 and the second surface 455 in the first embodiment and the engagement state between the second end 512A and the first surface 454 in the second embodiment are shown by broken lines.

As shown in fig. 13 and 14, the output gear 45 includes a first tooth portion T1 and a second tooth portion T2, and the first tooth portion T1 meshes with the fourth gear 44 as a front stage gear during rotation of the output shaft 2 from the origin position RA in the first rotation direction CW, and the second tooth portion T2 meshes with the fourth gear 44 as a front stage gear during rotation of the output shaft 2 from the origin position RA in the second rotation direction CW on the opposite side of the first rotation direction CW. The first tooth portion T1 and the second tooth portion T2 are symmetrical with respect to a straight line L2 connecting the center C1 of the output gear 45 and the center C2 of the fourth gear 44, which is a front stage gear.

In this way, when the first tooth T1 and the second tooth T2 are symmetrical with respect to the straight line L2, the origin position RA of the output shaft 2 is the same regardless of whether the first embodiment shown in fig. 14 (a) or the second embodiment shown in fig. 14 (b) is employed. Therefore, in the present embodiment, it is not necessary to change the origin position of the output shaft 2 in accordance with the rotation direction of the output shaft 2.

In the output gear 45, the notch 453 is a portion that cuts between the end portion of the first tooth portion T1 on the second rotation direction CCW side and the end portion of the second tooth portion T2 on the first rotation direction CW side, and is symmetrical with respect to a straight line L2 that connects the center C1 of the output gear 45 and the center C2 of the fourth gear 44 that is the front stage gear. Further, the end portion of the first tooth portion T1 on the second rotation direction CCW side and the end portion of the second tooth portion T2 on the first rotation direction CW side are provided with stoppers 47 that interfere with the tooth tips of the fourth gear 44 as the front stage gear, respectively. The stopper 47 includes an engagement surface 471 that comes into contact with the tooth tip of the fourth gear 44 from the radially outer side. The rotation of the output gear 45 and the fourth gear 44 is restricted by the contact of the fourth gear 44 and the engagement surface 471 in the radial direction.

Fig. 15 is a side view of the output shaft 2, the output gear 45, and the first spring 51. As described above, the output gear 45 includes the first surface 454 provided at one circumferential end of the cutout 453 and the second surface 455 provided at the other circumferential end. The first surface 454 includes a first escape portion 456 that cuts out a corner of the side (the first direction Z side Z1) where the assist spring 5 is located in the circumferential direction. The second surface 455 includes a second escape portion 457 that cuts a corner of the side (the first direction Z side Z1) where the assist spring is located in the circumferential direction.

The first spring 51 shown in fig. 15 is a spring in the winding direction used in the first embodiment shown in fig. 14 (a). In the first mode, the second end portion 512 of the first spring 51 is bent and extended from the winding end portion 514 of the spring portion 510 to the other side Z2 of the first direction Z. When the output shaft 2 rotates in the first rotation direction CW and the second end 512 is in a state of abutting on the second surface 455, the second escape 457 is disposed inside the curved portion formed by the winding end portion 514 and the second end 512. That is, since the output gear 45 includes the second escape portion 457 formed by cutting the portion disposed inside the bent portion of the wire 50A when the first spring 51 is engaged with the second escape portion 457, the auxiliary spring 5 is prevented from being inclined due to interference between the bent portion of the wire 50A and the corner portion of the output gear 45 when the first spring 51 is engaged with the output gear 45. Similarly, the first escape 456 provided in the first surface 454 has a shape in which a portion disposed inside the bent portion of the wire 50A is notched when the first spring 51A having the winding direction opposite to that of the first spring 51 is attached. Therefore, the case where the auxiliary spring 5 is inclined by the interference of the corner portion of the output gear 45 and the curved portion of the wire 50A in the case where the first spring 51A whose winding direction is opposite to that of the first spring 51 is used is suppressed.

(main effect of the embodiment)

As described above, the opening/closing member drive device 1 of the present embodiment includes: the transmission mechanism 4 includes a housing 10, an output shaft 2 protruding from the housing 10, a motor 3 housed in the housing 10, and a transmission mechanism 4 housed in the housing 10 and transmitting rotation of the motor 3 to the output shaft 2, and the transmission mechanism 4 includes an output gear 45 rotating integrally with the output shaft 2 and a fourth gear 44 as a front stage gear meshing with the output gear 45. The output gear 45 includes a first tooth portion T1 and a second tooth portion T2, and the first tooth portion T1 meshes with the fourth gear 44 as a front stage gear during rotation of the output shaft 2 from the origin position RA in the first rotation direction CW, and the second tooth portion T2 meshes with the fourth gear 44 as a front stage gear during rotation of the output shaft 2 from the origin position RA in the second rotation direction CW on the opposite side of the first rotation direction CW. The first tooth portion T1 and the second tooth portion T2 are symmetrical with respect to a straight line L2 connecting the center of the output gear 45 and the center of the fourth gear 44 as the front stage gear.

In the present embodiment, the transmission mechanism 4 that transmits the rotation of the motor 3 to the output shaft 2 includes the output gear 45 that rotates integrally with the output shaft 2 and the fourth gear 44 that is a preceding gear that meshes with the output gear 45, and the first tooth portion T1 and the second tooth portion T2 of the output gear 45 are symmetrical with respect to the straight line L2 that connects the center C1 of the output gear 45 and the center C2 of the fourth gear 44 that is a preceding gear. Therefore, the output shaft 2 can be operated in the same rotational angle with the rotation direction only changed without changing the shape of the output shaft 2 and the origin position RA and by changing the winding direction of the assist spring 5. This makes it possible to change the rotation direction of the output shaft 2 and eliminate the need to assemble the output shaft 2 while aligning the origin position RA with the rotation direction of the output shaft 2. Therefore, the assembling work of the opening/closing member drive device 1 is easy.

In the present embodiment, the output gear 45 includes the notch 453 that cuts between the end of the first tooth T1 in the second rotational direction CCW and the end of the second tooth T2 in the first rotational direction CW. The end of the first tooth T1 in the second rotational direction CCW and the end of the second tooth T2 in the first rotational direction CW each include a stopper 47 that interferes with the tooth tip of the fourth gear 44, which is the front gear. By providing the stoppers 47 at the ends of the first teeth T1 and the second teeth T2, respectively, it is possible to provide rotation stoppers that limit the range of rotation of the output shaft 2 in the first rotational direction CW and the range of rotation in the second rotational direction CCW.

In the present embodiment, the auxiliary spring 5 that generates the auxiliary force for biasing the output shaft 2 in the rotational direction is provided, the auxiliary spring 5 includes the second spring 52 and the first spring 51 disposed on the outer peripheral side of the second spring 52, and the first spring 51 includes the second end portion 512 disposed as the spring end portion of the cutout 453. In this way, by disposing the end portion of the assist spring 5 in the notch 453 formed by partially cutting out the circumferential direction of the tooth portion of the output gear 45, the assist spring 5 can be increased in size in the radial direction. This can increase the assist force and improve the output torque. When the output shaft 2 rotates in the first rotation direction CW, the second surface 455 provided at the end of the cutout 453 in the second rotation direction CCW is engaged with the second end 512 of the first spring 51, which is the spring end, to generate the assist force, and when the output shaft 2 rotates in the second rotation direction CCW, the first surface 454 provided at the end of the cutout 453 in the first rotation direction CW is engaged with the second end 512A of the first spring 51A to generate the assist force. Therefore, it is not necessary to change the shape of the engagement portion of the spring end portion on the output shaft 45 side in accordance with the change of the winding direction of the assist spring 5, and therefore, it is possible to cope with the change of the rotation direction of the output shaft 2 only by changing the winding direction of the assist spring 5.

In the present embodiment, the output gear 45 includes a first surface 454 provided at an end of the cutaway portion 453 in the first rotation direction CW and a second surface 455 provided at an end of the cutaway portion CCW, the first surface 454 includes a first escape portion 456 formed by cutting a corner portion of the side where the auxiliary spring 5 is located (the side Z1 in the first direction Z) in the circumferential direction, and the second surface 455 includes a second escape portion 457 formed by cutting a corner portion of the side where the auxiliary spring 5 is located (the side Z1 in the first direction Z) in the circumferential direction. Therefore, when the winding end portion of the wire 50A wound in a spiral shape is bent in the first direction Z and disposed in the notch 453 of the output gear 45, it is possible to suppress the auxiliary spring 5 from being inclined by interference between the bent portion of the wire 50A and the corner of the output gear 45.

In the present embodiment, since the output gear 45 is made of metal, there is less risk of deformation and damage of the output gear 45 due to the load applied from the

second end portions

512 and 512A.

In the present embodiment, the output shaft 2 includes the resin base 21 disposed in the center hole 451 provided in the output gear 45, and the output gear 45 is fixed to the base 21 by heat caulking. By making the portion (the notched portion 453) to which the load is applied from the first spring 51 having a large spring constant be made of metal and making the other portion be made of resin in this way, the component cost can be reduced as compared with the case where the output shaft 2 and the output gear 45 are made of metal as a whole. Further, by fixing the output shaft 2 and the output gear 45 by heat caulking, rattling of the output gear 45 with respect to the output shaft 2 can be eliminated. Therefore, the positional accuracy of the output shaft 2 can be improved.

Claims

1. An opening/closing member drive device, comprising:

a housing;

an output shaft protruding from the housing;

a motor housed in the case; and

a transmission mechanism housed in the case and transmitting rotation of the motor to the output shaft,

the transmission mechanism includes: an output gear that rotates integrally with the output shaft; and a backing gear meshed with the output gear,

the output gear includes: a first tooth portion that meshes with the front stage gear during rotation of the output shaft from an origin position in a first rotational direction; and a second tooth portion that meshes with the front stage gear while the output shaft rotates in a second rotational direction opposite to the first rotational direction from the origin position,

the first tooth portion and the second tooth portion are symmetrical with respect to a straight line connecting a center of the output gear and a center of the front stage gear,

the output gear includes a notch portion formed by cutting a gap between an end portion of the first tooth portion in the second rotational direction and an end portion of the second tooth portion in the first rotational direction,

having an assist spring that generates an assist force that urges the output shaft in a rotational direction,

the auxiliary spring includes a spring end portion disposed at the cutout portion so as to be movable in a circumferential direction.

2. The shutter drive device according to claim 1,

the end portion of the first tooth portion on the second rotational direction side and the end portion of the second tooth portion on the first rotational direction side are provided with stoppers that interfere with the tooth tops of the front stage gears, respectively.

3. The shutter drive device according to claim 2,

the output gear includes: a first surface provided at one circumferential end of the notch portion; and a second surface provided at the other end in the circumferential direction,

the first surface is provided with a first escape part formed by cutting a corner part of the auxiliary spring on one side in the circumferential direction,

the second surface includes a second escape portion formed by cutting a corner portion of the auxiliary spring on the side in the circumferential direction.

4. The shutter drive device according to claim 3,

the output gear is constructed of metal.

5. The opening/closing member driving device according to any one of claims 2 to 4,

the output shaft includes a resin portion disposed in a center hole provided in the output gear,

the output gear is fixed to the resin portion by heat caulking.

6. An opening/closing device comprising the opening/closing member drive device according to any one of claims 1 to 5,

an opening/closing member that is displaced to a closed posture and an open posture in accordance with rotation of the output shaft is connected to the output shaft.

7. The opening-closing device according to claim 6,

the opening and closing part is a toilet seat or a toilet cover.