JP6849120B2 - Motor case and motor - Google Patents

Description

The present invention relates to a motor case and a motor.

Conventionally, a motor with a deceleration mechanism is known in which a motor unit as a drive source and a deceleration unit having a deceleration mechanism for decelerating the rotation of the rotation shaft of the motor unit are integrally assembled (for example, Patent Document 1 and the like). .. The speed reduction portion of this motor includes a gear housing in which a speed reduction mechanism is housed and a cover that closes an opening of the gear housing. As a structure for fixing the cover to the gear housing, a so-called snap-fit structure is used in which a locking portion provided on the outer surface of the gear housing and a locking portion provided on the peripheral edge of the cover are locked to each other. The cover is fixed to the housing.

Japanese Unexamined Patent Publication No. 2009-171686

In the fixed structure of the gear housing and the cover in the motor, if the locking state of the locking portions of the gear housing and the cover is set to be strong, the locking portions of the gear housing and the cover are locked to each other in the process of locking the locking portions. It becomes easy to interfere and the assembling property is impaired. On the other hand, if a large gap is set in the process of locking the locking portions to improve the assembling property, the locking state of the locking portions becomes weak and the gear housing and the cover are fixed. The strength is low. This can happen not only for motor cases such as gear housings and covers, but also for other motor cases that use similar snap-fit structures.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a motor case capable of achieving both improvement in assembling property and improvement in fixing strength, and a motor provided with the motor case. To do.

The motor case for solving the above problems includes a first case member having a storage recess for accommodating motor components, and a second case member for closing the opening of the storage recess of the first case member. A locking projection is provided on the outer surface of the case member, and a locking piece having a locking hole is provided on the second case member, so that the locking projection and the locking piece having the locking hole are in a locked state. This is a motor case having a configuration in which the first and second case members are fixed to each other, and the locking projection is on the outer surface of the first case member in the mounting direction of the first and second case members. The locking piece projects outward in a direction orthogonal to the first case member, extends along the mounting direction of the first and second case members, and is the first on the outer surface of the first case member. When the front side of the locking projections in the mounting direction of the first and second case members is the first surface and the back side of the locking projections in the same mounting direction is the second surface, the second surface is more than the first surface. The surface is located on the outside, and the locking piece provided on the second case member is a tip inner corner portion in the mounting direction of the locking piece in a direction orthogonal to the mounting direction of the first and second case members. Is configured by setting the dimensions located between the first surface and the second surface, and the locking piece of the second case member is the locking of the locking projection and the locking piece. In the state, there is a gap between the first surface and the second surface, and the dimensions are set so as to come into contact with the second surface.

According to this configuration, on the outer surface of the first case member, the second surface on the back side of the locking projection in the mounting direction of the first and second case members is more than the first surface on the front side of the locking projection. Located on the outside, the locking piece of the second case member has a gap with its first surface and abuts with the second surface. That is, in the process of mounting the first and second case members, the chance that the locking piece of the second case member collides with the first surface of the first case member, that is, the opening of the accommodating recess is reduced, and the assembling property is improved. Can be planned. Further, since the locking piece comes into contact with the second surface of the first case member and is locked at the root portion of the locking projection, the mutual locking state is strengthened, and the first and second case members Fixing strength can be improved.

In the above motor case, on the outer surface of the first case member, the locking projection and the second surface are continuously provided in the mounting direction of the first and second case members without any gap.

In the above motor case, a plurality of fixing points of the first and second case members are provided by locking the locking projection and the locking piece.
According to this configuration, the locking pieces are provided on the first case member (first surface) by providing a plurality of fixing points of the first and second case members by locking the locking projections and the locking pieces. It is very significant to apply the above dimensional settings because it is easy to collide.

In the above motor case, the second surface on the back side of the locking projection is provided independently at least for each of the adjacent fixing points.
According to this configuration, the second surface on the back side of the locking projection is provided independently at least for each adjacent fixed portion. That is, high dimensional accuracy is required for the second surface of the first case member with which the locking piece abuts, but since each fixed portion is independent, the requirement for high dimensional accuracy is outside the first case member. Be partial on the side. Therefore, the production of the first case member is relatively simple.

The above motor case is used for a motor with a deceleration mechanism in which a motor unit as a drive source and a deceleration unit having a deceleration mechanism for decelerating the rotational drive of the motor unit are integrally assembled. The case member is a gear housing that accommodates the speed reduction mechanism, and the second case member is a cover that closes an opening of the gear housing.

According to this configuration, it is possible to improve the assembling property of the gear housing and the cover of the speed reducing portion of the motor with the speed reducing mechanism and to improve the mutual fixing strength at the same time.
A motor that solves the above problems is configured by including motor components in the above motor case.

According to this configuration, it is possible to provide a motor having a motor case capable of achieving both improvement in assembling property and mutual improvement in fixing strength.

According to the motor case of the present invention, it is possible to achieve both improvement in assembling property and improvement in fixing strength. Further, according to the motor of the present invention, it is possible to achieve both improvement of assembling property and improvement of fixing strength in the motor case.

It is a front view of the motor of an embodiment. (A) is a perspective view of the speed reduction mechanism of the embodiment, and (b) is an enlarged sectional view thereof. (A) is a perspective view of the speed reduction unit of the embodiment before assembly, and (b) is a cross-sectional view thereof. (A) is a perspective view after assembling the speed reducing portion of the embodiment, and (b) is a cross-sectional view thereof.

Hereinafter, an embodiment of the motor case will be described.
As shown in FIG. 1, the motor 10 is composed of a motor with a speed reduction mechanism that uses a motor unit 20 and a speed reduction unit 30 connected to the motor unit 20.

The motor unit 20 includes a substantially bottomed tubular yoke housing (hereinafter referred to as a yoke) 21, a magnet (not shown) fixed to the inner circumference of the yoke 21, and an armature 22 housed in the yoke 21. , The armature 22 is driven to rotate. The tip side of the rotating shaft 23 of the armature 22 projects from the opening 21a of the yoke 21 into the deceleration section 30, and drives and transmits the drive to the deceleration section 30 side.

As shown in FIGS. 1, 2 (a) and 3 (a), the speed reduction unit 30 includes a speed reduction mechanism 31 that reduces the rotational drive of the motor unit 20, a gear housing 32 that houses the speed reduction mechanism 31 and the like. It is provided with a cover 33 that closes the opening 37b of the gear housing 32 (the gear accommodating portion 37 described later). The gear housing 32 and the cover 33 are made of synthetic resin.

The gear housing 32 includes a motor fixing portion 35, a worm accommodating portion 36, and a gear accommodating portion 37. The opening 21a of the yoke 21 of the motor portion 20 is fixed to the motor fixing portion 35. The worm accommodating portion 36 is configured to extend coaxially from the motor fixing portion 35 to the rotating shaft 23 of the motor portion 20. The worm shaft 41 constituting the speed reduction mechanism 31 is rotatably supported and accommodated in the worm accommodating portion 36. The worm shaft 41 is connected to the rotating shaft 23 so as to rotate integrally.

The gear accommodating portion 37 is configured on one side of the worm accommodating portion 36. The gear accommodating portion 37 has a substantially elliptical accommodating recess 37a surrounded by a bottom wall and a side wall and having one surface open, and the first reduction gear 42 and the second reduction gear 43 are engaged in the accommodating recess 37a. Each is rotatably supported and housed. The first reduction gear 42 is arranged closer to the motor unit 20, the second reduction gear 43 is arranged farther from the motor unit 20, and the first and second reduction gears 42 and 43 are arranged in the axial direction of the motor unit 20. They are arranged side by side. The large-diameter gear portion 42a of the first reduction gear 42 meshes with the worm shaft 41, and the small-diameter gear portion 42b of the first reduction gear 42 meshes with the large-diameter gear portion 43a of the second reduction gear 43. An output unit 43b is provided at the center of the second reduction gear 43, and the output unit 43b is provided with a connection hole 43c for drive connection with a device (not shown) on the load side. Both the first and second reduction gears 42 and 43 are made of synthetic resin.

Incidentally, regarding the detailed structure of the second reduction gear 43, as shown in FIG. 2A, the large-diameter gear portion 43a, which is the remaining portion of the substantially cylindrical output portion 43b provided in the central portion, is provided. It has an outer peripheral tooth portion 45 forming an annular shape on the outer peripheral edge, and a connecting portion 46 connecting the outer peripheral tooth portion 45 and the output portion 43b in the central portion. Further, the connecting portion 46 is composed of an inner peripheral connecting portion 47 and an outer peripheral connecting portion 48. The inner peripheral connecting portion 47, which is a portion of the connecting portion 46 on the output portion 43b side, has a thin plate shape and is appropriately lightened. On the other hand, in the outer peripheral connecting portion 48, which is a portion of the connecting portion 46 on the outer peripheral tooth portion 45 side, a plurality of reinforcing ribs 49 are provided at equal intervals in the circumferential direction. As shown in FIG. 2B, the reinforcing rib 49 has an inclined shape that gradually becomes taller toward the outer peripheral tooth portion 45 side. As a result, when the outer peripheral tooth portion 45 (second reduction gear 43) and the small diameter gear portion 42b of the first reduction gear 42 mesh with each other during drive transmission, the outer peripheral tooth portion 45 receives a reaction force from the small diameter gear portion 42b to move inward. The reinforcing rib 49 suppresses deformation and the like that are about to fall.

The opening 37b of the gear accommodating portion 37 (including a part of the worm accommodating portion 36) accommodating the first and second reduction gears 42 and 43 is closed by the cover 33. As for the mounting mode of the cover 33 with respect to the gear accommodating portion 37 in the gear housing 32, the portion on the first reduction gear 42 side is fixed by three screws 50, and the portion on the second reduction gear 43 side is on the gear accommodating portion 37 side. The locking projection 53 and the locking piece 33a on the cover 33 side are locked, that is, fixed at four points by a so-called snap fit.

Regarding the detailed configuration of the snap fit, the outer surface 51 of the gear accommodating portion 37 in the gear housing 32 has four convex surface portions 52 that are slightly convex outward in the radial direction of the gear accommodating portion 37 at equal intervals within a range of approximately half a circumference. It is provided. The convex surface portion 52 has a width equal to the width of the locking piece 33a and is provided independently of the adjacent convex surface portion 52, and the surface of the convex surface portion 52 has an arc shape along the outer peripheral shape of the gear accommodating portion 37. I'm doing it. A substantially triangular locking projection 53 is erected on the convex surface portion 52, that is, the locking projection 53 is formed so as to project outward in the radial direction of the gear accommodating portion 37.

Further, the convex surface portion 52 has a step 54 between the opening 37b side and the anti-opening side of the gear accommodating portion 37 with the lower end position of the locking projection 53 (the end portion on the anti-opening 37b side of the gear accommodating portion 37) as a boundary. have. The surface of the convex surface 52 on the opening 37b side of the gear accommodating portion 37, that is, the surface on the front side in the mounting direction of the cover 33 is the introduction surface 52a from the step 54 (the lower end position of the locking projection 53), and the gear accommodating the gear accommodating portion 54 Assuming that the anti-opening side of the portion 37, that is, the surface on the back side of the cover 33 in the mounting direction is the contact surface 52b, the contact surface 52b is located radially outside the gear accommodating portion 37 with respect to the introduction surface 52a.

On the other hand, the cover 33 is provided with a locking piece 33a at each position corresponding to the convex surface portion 52 of the gear accommodating portion 37. Each of the rectangular locking pieces 33a is arranged in the axial direction of the first and second reduction gears 42 and 43 so that the tip portion 33b of each locking piece 33a is arranged slightly inside the gear accommodating portion 37 in the radial direction. That is, it extends substantially along the mounting direction of the cover 33. Each locking piece 33a is formed with a locking hole 33c for locking with the locking projection 53 of the convex surface portion 52 of the gear accommodating portion 37. In other words, by integrally connecting the tips of the pair of side sides of the locking piece 33a with the tip 33b to form a rectangular frame, a rectangular locking hole 33c is formed inside the frame. It is formed.

Further, as shown in FIG. 3B, regarding the positional relationship between the locking piece 33a and the convex surface portion 52 on the gear accommodating portion 37 side, the reference assembling position in which the cover 33 is coaxially assembled with respect to the gear accommodating portion 37. The radial position P3 of the inner corner portion 33d of the tip portion 33b of the locking piece 33a is the diameter of the radial position P1 of the introduction surface 52a and the contact surface 52b on the convex surface portion 52 on the gear accommodating portion 37 side. It is set to be between the direction position P2.

Here, when the introduction surface 52a of the convex surface portion 52 is set to a virtual radial position P0 that overlaps the contact surface 52b (radial position P2) of the convex surface portion 52 in the radial direction of the gear accommodating portion 37, the cover is covered. In the process of mounting the 33 on the gear accommodating portion 37, there is a concern that the tip end 33b of the locking piece 33a may collide with the opening 37b of the gear accommodating portion 37 before reaching the introduction surface 52a of the convex surface portion 52. .. In particular, if the tip portion 33b of the locking piece 33a comes into contact with the contact surface 52b of the convex surface portion 52 after getting over the locking projection 53, a collision is more likely to occur.

However, in the present embodiment, the introduction surface 52a (position P1) of the convex surface portion 52 is located radially inside the gear accommodating portion 37 with respect to the contact surface 52b (position P2) of the convex surface portion 52, and the tip of the locking piece 33a. Since the portion 33b (position P3) is arranged between them, the collision between the tip portion 33b of the locking piece 33a and the opening portion 37b of the gear accommodating portion 37 can be reduced. Further, even before the tip 33b of the locking piece 33a comes into contact with the locking projection 53, there is a radial gap (clearance) of the gear accommodating portion 37 between the introduction surface 52a and the tip 33b of the locking piece 33a. Is formed, and the chance that the tip end portion 33b of the locking piece 33a comes into contact with the gear accommodating portion 37 is also reduced. As a result, the assembling property of the cover 33 to the gear housing 32 is improved.

In addition, when the tip end portion 33b of the locking piece 33a gets over the locking projection 53, the locking piece 33a spreads radially outward of the gear accommodating portion 37 against the elastic force and gets over the locking projection 53. .. Then, when the locking projection 53 moves to a position within the locking hole 33c of the locking piece 33a, the locking piece 33a elastically returns, and as shown in FIG. 4A, the tip of the locking piece 33a When the inner edge portion of the portion 33b and the end surface portion of the locking projection 53 are locked in the direction opposite to the mounting of the cover 33, the locking piece 33a is locked with respect to the locking projection 53. Further, as shown in FIG. 4B, after the locking piece 33a gets over the locking projection 53, the convex surface portion 52 is radially outside the gear accommodating portion 37 with respect to the tip end portion 33b of the locking piece 33a. Since it is composed of the abutting surface 52b located, the tip end 33b of the locking piece 33a comes into contact with the abutting surface 52b of the convex surface 52. In the present embodiment, the tip end portion 33b of the locking piece 33a is elastically contacted with the contact surface 52b of the convex surface portion 52 and urged inward in the radial direction. As a result, since the locking piece 33a is maintained so as to be reliably positioned at the root portion of the locking projection 53, the locked state between the locking piece 33a and the locking projection 53 is strengthened, and the gear housing of the cover 33 The fixing strength with respect to 32 can be improved.

Next, the characteristic effects of this embodiment will be described.
(1) On the outer surface 51 of the gear accommodating portion 37 of the gear housing 32 (first case member), the contact surface 52b (second surface) on the back side of the locking projection 53 in the mounting direction of the cover 33 is engaged. It is located radially outside the gear accommodating portion 37 with respect to the introduction surface 52a (first surface) on the front side of the stop projection 53. Then, a gap (clearance) is formed between the locking piece 33a and the introduction surface 52a, and the dimensions are set so that the locking piece 33a and the contact surface 52b come into contact with each other. That is, in the process of mounting the cover 33 on the gear housing 32, the locking piece 33a of the cover 33 collides with the introduction surface 52a of the gear accommodating portion 37 of the gear housing 32, that is, the locking piece 33a of the cover 33 is the gear accommodating portion 37. Collision with the opening 37b can be reduced, and the assembling property of the cover 33 can be improved. Further, in the locked state with the locking projection 53, the locking piece 33a is in contact with the contact surface 52b and is locked at the root portion of the locking projection 53, so that the mutual locking state can be strengthened. , It is possible to improve the fixing strength of the cover 33 with respect to the gear housing 32.

(2) In fixing by snap fit, the contact surface 52b of the gear housing 32 (gear accommodating portion 37) with which the locking piece 33a abuts is required to have high dimensional accuracy, but is behind the locking projection 53. Since the structure is such that the contact surface 52b is in contact with only the contact surface 52b, it is possible to reduce the area of the outer surface of the gear housing 32 that requires high dimensional accuracy. Therefore, the gear housing 32 can be manufactured relatively easily.

(3) The locking pieces 33a collide with the gear housing 32 (gear accommodating portion 37) because a plurality of fixing points (4 points) are provided by locking the locking projection 53 and the locking piece 33a. Since it is easy to make a situation, it is significant to apply the above dimensional setting.

(4) Since the contact surface 52b on the back side of the locking projection 53 is independently provided for each adjacent fixed portion, high dimensional accuracy is also required on the outer surface of the gear housing 32. The area can be reduced and the gear housing 32 can be easily manufactured.

The above embodiment may be changed as follows.
-In the above embodiment, in fixing the gear housing 32 and the cover 33, the snap fit using the locking projection 53 and the locking piece 33a is fixed at four places, but it may be fixed at one place. There may be a plurality of locations other than the locations.

In the above embodiment, the convex surface portion 52 is provided at each of the four fixed locations, and the introduction surface 52a and the contact surface 52b are provided at each of the convex surface portions 52, but the convex surface portions 52 are continuously provided at at least two adjacent locations. May be formed as a target. Further, it may be formed continuously over all the fixed portions. Further, the introduction surface 52a may be omitted in the convex surface portion 52, that is, the introduction surface 52a may not be convex in the radial direction and may be flush with the outer surface of the gear housing 32 (gear accommodating portion 37). Further, the contact surface 52b of the convex surface portion 52 may be flush with the outer surface of the gear housing 32, and the introduction surface 52a may be recessed inward in the radial direction. That is, the contact surface 52b may be relatively located radially outside the introduction surface 52a.

In the above embodiment, the step 54 at the boundary between the introduction surface 52a and the contact surface 52b is set at the lower end position of the locking projection 53 on the convex surface portion 52, but it is slightly shifted upward within the range where the locking projection 53 is provided. It may be set.

In the above embodiment, the gear housing 32 accommodating the reduction mechanism 31 and the cover 33 are fixed, but other motor cases may be fixed.
-In addition, the structure of the motor 10 of the above embodiment may be changed as appropriate.

Next, the technical idea that can be grasped from the above embodiment and another example will be added below.
(A) A first case member having an accommodating recess for accommodating motor components and a second case member for closing the opening of the accommodating recess of the first case member are provided on the outer surface of the first case member. A locking protrusion is provided and a locking piece having a locking hole is provided in the second case member, and the locking protrusion and the locking piece having the locking hole are in a locked state, so that the first and the first and the first A motor case having a structure in which the second case members are fixed to each other.
The locking projections project outward on the outer surface of the first case member in a direction orthogonal to the mounting direction of the first and second case members, and the locking pieces are the first and second case members. It extends along the mounting direction of the case member.
On the outer surface of the first case member, the front side of the first and second case members in the mounting direction is the first surface, and the back side of the locking projection in the same mounting direction is the second surface. When it is a surface, the second surface is located outside the first surface, and the inner corner of the tip of the locking piece of the second case member is located between the first surface and the second surface. A motor case characterized by being configured by dimensional setting.

10 ... motor, 20 ... motor unit, 30 ... reduction unit, 31 ... reduction mechanism, 42 ... first reduction gear (motor component), 43 ... second reduction gear (motor component), 37a ... accommodation recess, 37b ... Opening, 32 ... Gear housing (first case member), 33 ... Cover (second case member), 51 ... Outer surface, 53 ... Locking protrusion, 33c ... Locking hole, 33a ... Locking piece, 52a ... Introduction Surface (first surface), 52b ... Contact surface (second surface).

Claims (6)

A first case member having an accommodating recess for accommodating motor components and a second case member for closing the opening of the accommodating recess of the first case member are provided, and a locking protrusion is provided on the outer surface of the first case member. The first and second cases are provided by providing a locking piece having a locking hole in the second case member and bringing the locking projection and the locking piece having the locking hole into a locked state. It is a motor case with a structure that allows the members to be fixed to each other.
The locking projections project outward on the outer surface of the first case member in a direction orthogonal to the mounting direction of the first and second case members, and the locking pieces are the first and second case members. It extends along the mounting direction of the case member.
On the outer surface of the first case member, the front side of the first and second case members in the mounting direction is the first surface, and the back side of the locking projection in the same mounting direction is the second surface. When it is a surface, the second surface is located outside the first surface, and the locking piece provided on the second case member engages in the direction orthogonal to the mounting direction of the first and second case members. The inner corner of the tip of the stop piece in the mounting direction is configured to be located between the first surface and the second surface, and the locking piece of the second case member is the locking piece. A motor case characterized in that a gap is provided between the first surface and the second surface in a locked state between the locking projection and the locking piece, and the dimensions are set so as to abut the second surface. In the motor case according to claim 1,
On the outer surface of the first case member, the locking projection and the second surface are continuously provided in the mounting directions of the first and second case members without any gap. .. In the motor case according to claim 1 or 2.
A motor case characterized in that a plurality of fixing points of the first and second case members are provided by locking the locking projection and the locking piece. In the motor case according to claim 3,
A motor case characterized in that the second surface on the back side of the locking projection is provided independently at least for each of the adjacent fixing points. The motor case according to any one of claims 1 to 4 has a deceleration mechanism in which a motor unit as a drive source and a deceleration unit including a deceleration mechanism for decelerating the rotational drive of the motor unit are integrally assembled. It is used for motors and
The motor case is characterized in that the first case member is a gear housing accommodating the speed reduction mechanism, and the second case member is a cover that closes an opening of the gear housing. A motor according to any one of claims 1 to 5, wherein the motor case is provided with motor components.

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