Motor with reduction mechanism

Abstract

To provide a motor with a speed reduction mechanism that can improve water exposure resistance reliability without using a large-sized component, and can enhance versatility.SOLUTION: A gear cover 80 is provided with a breathing function so that even if the gear cover 80 is exposed to water, a differential pressure is less likely to occur between the inside and outside of the gear cover 80. A breather cap 95 covering a pair of slits 93a and 93b is provided to restrain rainwater and the like from reaching a communicating hole 91 through the slits 93a and 93b and a tubular member 93. Therefore, it is possible to effectively prevent rainwater and the like from entering the inside of the gear cover 80 without relying on a large waterproof cover, thereby improving the water exposure resistance reliability. Further, since the breather cap 95 is attached to a gear cover 80 and a gear case, it is not affected by a length and thickness of a frame member to which a wiper motor 40 is fixed, and versatility can be enhanced.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a motor with a reduction mechanism, which includes a motor section having a rotating shaft, and a reduction mechanism section having a reduction mechanism for reducing the rotation speed of the rotating shaft. [Background technology]

[0002] A motor with a reduction mechanism is used as a drive source for a wiper device, a power window device, etc. In particular, a motor with a reduction mechanism (wiper motor) used as a drive source for a wiper device is installed in an engine room with a high-temperature atmosphere and is operated continuously for a relatively long time. Therefore, the motor with a reduction mechanism becomes hot, and if it is exposed to water in this state, it will be cooled rapidly. Then, the inside of the housing becomes negative pressure, and there is a risk that rainwater or the like will enter the inside of the housing. Therefore, in order to prevent the wiper motor from being exposed to water, a waterproof cover is installed so as to cover the upper part of the wiper motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-141310 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology described in the above-mentioned Patent Document 1, two fixing rings and one engaging claw are provided on the waterproof cover, the fixing ring is fixed to a frame member forming the wiper device, and the engaging claw is fixed to a housing of the wiper motor. This makes it unavoidable to increase the size of the waterproof cover, and also requires individual design (exclusive design) for wiper devices with different specifications (frame members with different lengths and thicknesses).

[0005] An object of the present invention is to provide a motor with a reduction mechanism that can improve water resistance without using large parts and can increase versatility. [Means for solving the problem]

[0006] In one aspect of the present invention, a motor with a reduction mechanism includes a motor section having a rotating shaft, and a reduction mechanism section having a reduction mechanism for reducing the rotation speed of the rotating shaft, the reduction mechanism including a housing for accommodating the reduction mechanism, a communication hole provided in the housing for communicating the inside and the outside of the housing, and a communication hole provided on the outside of the housing. and the housing. the housing includes a cylindrical member extending in the axial direction of the communicating hole and communicating with the communicating hole, a slit provided in the cylindrical member and extending in the axial direction of the cylindrical member, and a slit covering member attached to the housing and covering the slit from the radial outside of the cylindrical member, wherein the slit covering member has a cap portion that closes an opening provided on the tip side of the cylindrical member, and a hook portion that is hooked onto an engaging portion provided on the housing. Effect of the Invention

[0007] According to the present invention, the housing is provided with a breathing function, so that even if the housing is submerged in water, a pressure difference is unlikely to occur between the inside and outside of the housing. In addition, since a slit covering member is provided to cover the slit, rainwater, etc. can be prevented from reaching the communication hole through the slit and the cylindrical member. Therefore, it is possible to effectively prevent rainwater, etc. from entering the inside of the housing without relying on a large waterproof cover, and thus to improve water resistance. Furthermore, since the slit covering member is attached to the housing, it is not affected by the length or thickness of the frame member to which the reduction gear motor is fixed, and versatility can be improved. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a vehicle equipped with a wiper motor. [Diagram 2] FIG. 2 is a perspective view showing the wiper motor shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] 3 is a diagram showing an internal structure of the wiper motor shown in FIG. 2. [Diagram 5] FIG. 3 is an enlarged view of a portion B circled by a dashed line in FIG. [Figure 6] FIG. 5 is an enlarged view of a portion C circled by a dashed line in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line DD in FIG. [Figure 8] FIG. [Figure 9] 13A and 13B are perspective views of the breather cap alone. [Figure 10] 3 is an exploded perspective view of a speed reduction mechanism of the wiper motor of FIG. 2. [Figure 11] 11A and 11B are diagrams illustrating the flow of rainwater and the like through a cylindrical member. [Figure 12] 3 is an explanatory diagram of another mounting posture of the wiper motor in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] FIG. 1 is a schematic diagram of a vehicle equipped with a wiper motor, FIG. 2 is an oblique view of the wiper motor of FIG. 1, FIG. 3 is a cross-sectional view along line AA of FIG. 2, FIG. 4 is a diagram showing the internal structure of the wiper motor of FIG. 2, FIG. 5 is an enlarged view of dashed circle B of FIG. 2, FIG. 6 is an enlarged view of dashed circle C of FIG. 4, FIG. 7 is a cross-sectional view along line DD of FIG. 6, FIG. 8 is an oblique view of the gear cover alone, FIGS. 9(a) and (b) are oblique views of the breather cap alone, FIG. 10 is an exploded oblique view of the reduction mechanism of the wiper motor of FIG. 2, FIG. 11 is a diagram explaining the flow of rainwater, etc. relative to the tubular member, and FIG. 12 is an explanatory diagram of another mounting position of the wiper motor of FIG. 2.

[0011] As shown in Fig. 1, a wiper device 20 is mounted in an engine room (not shown) at the front side of a vehicle 10 such as an automobile. The wiper device 20 swings a pair of wiper members 30 provided corresponding to a driver's seat side (Driver) and a passenger seat side (Assist). The wiper member 30 includes a wiper arm 31 formed in a substantially rod shape, and a base end side in the longitudinal direction of the wiper arm 31 is fixed to a pivot shaft 11 provided rotatably on the vehicle 10. A wiper blade 32 is attached to a tip side in the longitudinal direction of the wiper arm 31. Thus, by driving the wiper device 20, the wiper arm 31 swings on the windshield 12.

[0012] The wiper device 20 includes a wiper motor (motor with a speed reducer) 40. The wiper motor 40 includes an output shaft 41, and a link mechanism 42 is provided between the output shaft 41 and the pair of pivot shafts 11 to convert the rotational motion of the output shaft 41 into the swinging motion of the pair of pivot shafts 11. As a result, when the wiper motor 40 is operated, the rotational motion of the output shaft 41 becomes the swinging motion of the pivot shafts 11 via the link mechanism 42, and the wiper blades 32 perform a reciprocating wiping motion in each wiping range 13.

[0013] Here, when the wiper motor 40 is mounted on the vehicle 10, the mounting posture of the wiper motor 40 with respect to the vehicle 10 is the posture shown in Fig. 2. That is, the gear case 70 side from which the output shaft 41 protrudes faces downward of the vehicle 10, and the gear cover 80 side attached to the gear case 70 faces upward of the vehicle 10. In addition, the speed reduction mechanism 60 side in the longitudinal direction of the wiper motor 40 is inclined toward the downward side of the vehicle 10, and the breathing mechanism 90 side in the lateral direction of the wiper motor 40 is inclined toward the downward side of the vehicle 10. Therefore, the rainwater WA running down the surface of the wiper motor 40 flows as indicated by the dashed arrow.

[0014] As shown in Fig. 2, the wiper motor 40 forming the wiper device 20 includes a motor section 50 and a reduction mechanism section 60. The motor section 50 includes a yoke (motor case) 51 formed into a substantially cylindrical shape with a bottom by deep drawing a steel plate or the like, and a total of four magnets 52 (only two are shown in the figure) are fixed to the radially inner side of the yoke 51 as shown in Fig. 3. In addition, an armature core 53 is rotatably provided on the radially inner side of each magnet 52 via a predetermined gap (air gap).

[0015] An armature shaft (rotating shaft) 54 made of a round steel bar is fixed to the center of rotation of the armature core 53. The armature shaft 54 ​​rotates together with the rotation of the armature core 53. A pair of worms 55 are integrally provided on the tip side (left side in FIG. 3) of the armature shaft 54, and the twisting directions of the respective worms 55 are opposite to each other.

[0016] Furthermore, a commutator 56 is fixed between the worm 55 and the armature core 53 in the longitudinal direction of the armature shaft 54. A total of three brushes 57 (only two are shown in the figure) are in sliding contact with the outer periphery of the commutator 56. In this manner, the wiper motor 40 is an electric motor with brushes, and is driven to rotate in the forward or reverse direction by the supply of driving current from a battery (not shown) or the like installed in the engine room or the like.

[0017] As shown in Fig. 2, the reduction mechanism section 60 includes a gear case 70 and a gear cover 80. The gear case 70 and the gear cover 80 correspond to the housing in the present invention. As shown in Fig. 3 and Fig. 10, the reduction mechanism SD is housed inside the gear case 70 and the gear cover 80. The reduction mechanism SD is formed of a pair of worms 55 provided on the armature shaft 54, a pair of counter gears 61 meshed with the worms 55, and a single spur gear 62 meshed with the counter gears 61.

[0018] A pair of worms 55 are meshed with the large diameter tooth portions 61a of the pair of counter gears 61, respectively. As a result, the pair of counter gears 61 are rotated in the same direction (counterclockwise direction) as indicated by arrow R2 in conjunction with the rotation of the armature core 53 (see arrow R1). Furthermore, teeth 62a of the spur gear 62 are meshed with the small diameter tooth portions 61b of the pair of counter gears 61. As a result, the spur gear 62 is rotated in the clockwise direction as indicated by arrow R3.

[0019] As a result, the high-speed rotation of the armature core 53 (armature shaft 54) is decelerated by the pair of worms 55 and the pair of counter gears 61, causing the spur gear 62 to rotate at a low speed. As a result, a high-torque rotational force is output from the output shaft 41 fixed to the rotation center of the spur gear 62 toward the link mechanism 42 (see FIG. 1).

[0020] 2, the gear case 70 forming the reduction mechanism 60 is formed into a roughly bowl-like shape with a case bottom wall 71 (see FIG. 4) by pouring molten aluminum material into a mold. The gear cover 80 forming the reduction mechanism 60 is formed into a roughly bowl-like shape with a cover bottom wall 81 by pouring molten plastic material into a mold (not shown).

[0021] When the gear case 70 and the gear cover 80 are butted against each other, a hollow portion 63 (see FIGS. 4, 6 and 7) is formed therein, and the reduction gear mechanism SD is housed inside the hollow portion 63. The reduction gear mechanism SD is rotatably supported on a case bottom wall 71 of the gear case 70. When the motor section 50 and the reduction gear mechanism section 60 are assembled, the inside of the hollow portion 63 and the inside of the yoke 51 (not shown) are in communication with each other.

[0022] In addition, the connection (butting portion) between the gear case 70 and the gear cover 80, and the connection (butting portion) between the gear case 70 and the yoke 51 are sealed with each other via a sealing member (not shown) such as an O-ring, thereby preventing rainwater and the like from entering the inside of the wiper motor 40 through these connection portions.

[0023] Here, a total of three mounting legs 72 (only two are shown in the figure) are integrally provided on the case bottom wall 71 of the gear case 70, and the wiper motor 40 is fixed to the vehicle 10 via these mounting legs 72. In addition, the output shaft 41 fixed to the spur gear 62 is rotatably supported at approximately the center of the case bottom wall 71 via a seal member (not shown) such as an O-ring. This prevents rainwater and the like from entering the inside of the wiper motor 40 from between the output shaft 41 (see FIG. 3) and the case bottom wall 71. Furthermore, the central shaft 61c (see FIG. 3) of the pair of counter gears 61 is also rotatably supported on the case bottom wall 71 of the gear case 70.

[0024] 2 and 10, the gear cover 80 attached to the gear case 70 is fixed to the gear case 70 by a total of four fixing screws SC1. A connector connection portion 82 is integrally provided on the gear cover 80. An external connector (not shown) provided on the vehicle 10 is connected to a tip portion (left side in the figure) of the connector connection portion 82. This allows a drive current to be supplied to the wiper motor 40 from a battery or the like of the vehicle 10. Here, the external connector is connected to the connector connection portion 82 from the opposite side to the motor unit 50 side of the gear cover 80. In other words, the connector connection portion 82 is disposed substantially coaxially with the motor unit 50 as shown in FIG. 2.

[0025] 2 and 4 to 7, a breathing mechanism 90 is provided near the connector connection portion 82 in the gear cover 80. The breathing mechanism 90 includes a communication hole 91, a small diameter cylindrical portion 92, a cylindrical member 93, a filter 94, and a breather cap 95. The communication hole 91, the small diameter cylindrical portion 92, and the cylindrical member 93 are integrally provided in the gear cover 80 and are formed together when the gear cover 80 is molded. The breathing mechanism 90 has a function of providing the wiper motor 40 with a breathing function in order to suppress pressure fluctuations inside and outside the wiper motor 40.

[0026] Specifically, the breathing mechanism 90 has a function of allowing air to smoothly flow in and out (breathe) in response to pressure fluctuations inside and outside the wiper motor 40, while preventing rainwater, etc. from entering the inside of the wiper motor 40. Here, to obtain an ideal breathing mechanism 90, it is necessary to achieve both of the above-mentioned contradictory phenomena, that is, facilitating "breathing" and preventing rainwater, etc. from entering.

[0027] The breathing mechanism 90 is disposed in a portion of the gear cover 80 away from the motor unit 50 (see FIG. 2). As a result, even if rainwater or the like enters the inside of the wiper motor 40 via the breathing mechanism 90, the entered rainwater or the like is less likely to reach the commutator 56 or the brushes 57 (see FIG. 3). This effectively prevents the wiper motor 40 and a controller (not shown) that controls the wiper motor 40 from being damaged by an overcurrent.

[0028] 6 and 7, the communication hole 91 is provided in a cover flat portion 84 that is offset in the axial direction of the output shaft 41 (see FIG. 3) from the cover bottom wall 81 of the gear cover 80. Specifically, the communication hole 91 is provided in a portion of the gear cover 80 closer to the gear case 70 (lower portion in FIG. 6) in the axial direction of the output shaft 41. The inner diameter of the communication hole 91 is about 2 mm. The communication hole 91 communicates between the inside and outside of the gear cover 80 (wiper motor 40) and functions as a so-called "breathing hole."

[0029] The small diameter cylindrical portion 92 is provided outside the gear cover 80 and extends in the axial direction of the communication hole 91. An air passage 92a is provided radially inside the small diameter cylindrical portion 92, and the longitudinal base end side (lower side in FIG. 6) of the air passage 92a communicates with the communication hole 91. That is, the longitudinal base end side of the small diameter cylindrical portion 92 is integrally provided with the cover flat portion 84. The inner diameter dimension of the air passage 92a is about 2 mm, which is the same as the inner diameter dimension of the communication hole 91. The outer diameter dimension of the small diameter cylindrical portion 92 is about 5 mm. Furthermore, the height dimension of the small diameter cylindrical portion 92 from the cover flat portion 84 is about 2 / 3 of the distance from the cover flat portion 84 to the cover bottom wall 81.

[0030] Moreover, the cylindrical member 93 is provided integrally with the cover flat surface portion 84 of the gear cover 80, and is disposed so as to surround the periphery of the small diameter cylindrical portion 92. That is, the cylindrical member 93 extends in the axial direction of the small diameter cylindrical portion 92 and the communication hole 91 (the axial direction of the output shaft 41). Specifically, the cylindrical member 93 is provided outside the gear cover 80, and the axial base end side of the cylindrical member 93 is fixed to the cover flat surface portion 84.

[0031] Here, the inner diameter dimension of the cylindrical member 93 is about 10 mm, and the radially inner side of the cylindrical member 93 is communicated with the communication hole 91 via the air passage 92a of the small diameter cylindrical portion 92. As a result, the inside and outside of the wiper motor 40 are communicated with each other via the cylindrical member 93, the small diameter cylindrical portion 92, and the communication hole 91, and air flows through these cylindrical member 93, the small diameter cylindrical portion 92, and the communication hole 91. In other words, a small diameter cylindrical portion 92 having a smaller diameter than the cylindrical member 93 is provided on the radially inner side of the cylindrical member 93, and an air passage 92a on the radially inner side of the small diameter cylindrical portion 92 is communicated with both the radially inner side of the cylindrical member 93 and the communication hole 91.

[0032] The height dimension of the cylindrical member 93 from the cover flat portion 84 is approximately equal to the distance from the cover flat portion 84 to the cover bottom wall 81. This prevents the cylindrical member 93 (breathing mechanism 90) from significantly protruding in the axial direction of the communication hole 91, thereby preventing the wiper motor 40 from becoming large. In other words, the breathing mechanism 90 is disposed in a relatively large dead space DS (see FIGS. 2, 5 and 7) formed in the gear cover 80.

[0033] In this way, by providing a small diameter cylindrical portion 92 and a cylindrical member 93 that communicate with the communication hole 91, when the wiper motor 40 becomes wet, rainwater, etc. that runs down the surface of the wiper motor 40 is less likely to reach the hollow portion 63 inside the wiper motor 40.

[0034] As shown in Figs. 7 and 8, the cylindrical member 93 is provided with a pair of slits 93a, 93b. These slits 93a, 93b extend in the axial direction of the cylindrical member 93 and are provided over the entire longitudinal area of ​​the cylindrical member 93. The pair of slits 93a, 93b penetrate the cylindrical member 93 in the radial direction to communicate the inside and outside of the cylindrical member 93. The pair of slits 93a, 93b are arranged at approximately 90 degree intervals from each other in the circumferential direction of the cylindrical member 93. As a result, even if a breather cap 95 is attached to the axial tip side of the cylindrical member 93, air can circulate between the inside and outside of the cylindrical member 93 via the pair of slits 93a, 93b.

[0035] 7, one slit 93a is disposed on the side farther from the hollow portion 63, and the other slit 93b is disposed on the side closer to the hollow portion 63. In addition, in the mounting posture of the wiper motor 40 on the vehicle 10, one slit 93a is disposed toward the lower side of the vehicle 10, and the other slit 93b is disposed toward the upper side of the vehicle 10 (see FIG. 11).

[0036] The opening width of one slit 93a on the inner side of the cylindrical member 93 is wider than the opening width on the outer side. In other words, the opening width of one slit 93a in the circumferential direction of the cylindrical member 93 is narrower on the outer side than on the inner side of the cylindrical member 93. Here, the wider opening width of the slit 93a is about 2.5 mm, and the narrower opening width is about 1.5 mm.

[0037] This makes it difficult for rainwater, etc. to enter the inside of the cylindrical member 93 through one of the slits 93a. Even if rainwater, etc. does enter the inside of the cylindrical member 93, the amount is very small, and the rainwater, etc. tends to collect inside the one of the slits 93a (the part with the wider opening width). Therefore, rainwater, etc. that has entered the inside of the cylindrical member 93 through one of the slits 93a can be quickly discharged to the outside of the cylindrical member 93.

[0038] In addition, the opening width of the other slit 93b is also wider on the inner side of the cylindrical member 93 than on the outer side. In other words, the opening width of the other slit 93b in the circumferential direction of the cylindrical member 93 is narrower on the outer side than on the inner side of the cylindrical member 93. Here, the wider opening width of the slit 93b is about 2.5 mm, and the narrower opening width is about 1.5 mm.

[0039] 7 and 8, a pair of rib members 93c are provided on the radially outer side of the cylindrical member 93 at approximately 90 degree intervals in the circumferential direction of the cylindrical member 93. These rib members 93c have approximately the same thickness as the cylindrical member 93, protrude radially outward from the cylindrical member 93, and extend in the axial direction of the cylindrical member 93.

[0040] Here, the base end side of the rib member 93c in the axial direction of the cylindrical member 93 is fixed to the cover flat portion 84. A tapered portion TP is provided on the tip side of the rib member 93c in the axial direction of the cylindrical member 93, and the tapered portion TP is formed so that the height dimension of the rib member 93c in the radial direction of the cylindrical member 93 gradually decreases toward the tip side of the rib member 93c. This makes it possible to easily release the mold used when injection molding the gear cover 80.

[0041] The pair of slits 93a, 93b and the pair of rib members 93c are arranged at positions alternately shifted by approximately 45 degrees in the circumferential direction of the cylindrical member 93. More specifically, as shown in Fig. 7, when the cylindrical member 93 is viewed from the axial direction, the other slit 93b, the rib member 93c, the one slit 93a, and the rib member 93c are arranged in this order from the left in the drawing in the circumferential direction of the cylindrical member 93.

[0042] Here, the pair of rib members 93c are disposed on both sides of one slit 93a in the circumferential direction of the cylindrical member 93. This makes it possible to direct rainwater, etc., running down the surface of the wiper motor 40 away from one slit 93a when the wiper motor 40 is in an attached position to the vehicle 10 (see FIG. 11). In other words, the pair of rib members 93c have a function of preventing rainwater, etc., from entering the inside of the cylindrical member 93 through one slit 93a.

[0043] As shown in Figs. 4, 6 and 10, the filter 94 is formed in a thin disk shape and is fixed to the longitudinal tip side (upper side in Fig. 6) of the small diameter cylindrical portion 92 by adhesive, welding or the like. Specifically, the filter 94 is provided so as to block the air passage 92a of the small diameter cylindrical portion 92. The filter 94 is made of a porous film made of, for example, polytetrafluoroethylene (PTFE) and has the property of allowing air to pass through while blocking water, dust and the like. This improves the water-resistant reliability of the wiper motor 40. However, the filter 94 can be omitted depending on the water-resistant performance required for the wiper motor 40.

[0044] 5 to 7 and 9, the breather cap 95 is made of a resin material such as plastic and has a predetermined shape, and corresponds to the slit covering member of the present invention. The breather cap 95 includes a slit covering wall 96, a cap portion 97, and a hook portion 98.

[0045] 7, in a state in which the breather cap 95 is attached to the wiper motor 40 (the gear case 70 and the gear cover 80), the slit covering wall 96 is disposed on the radially outer side of the cylindrical member 93. The slit covering wall 96 has a cross-sectional shape in a direction intersecting with the axial direction of the cylindrical member 93 that is substantially V-shaped, and covers the pair of slits 93a, 93b from the radially outer side of the cylindrical member 93.

[0046] Here, a predetermined first gap S1 is formed between the slit covering wall 96 and the pair of slits 93a, 93b. As a result, the pair of slits 93a, 93b are not blocked by the slit covering wall 96, and air can flow in and out between the inside and outside of the cylindrical member 93.

[0047] Further, a predetermined second gap S2 (see FIG. 5) is formed between the slit covering wall 96 and the cover flat portion 84 in the axial direction of the cylindrical member 93. This also allows air to flow in and out between the inside and outside of the cylindrical member 93 without the pair of slits 93a, 93b being blocked by the slit covering wall 96.

[0048] Furthermore, in the axial direction of the cylindrical member 93, a cap portion 97 is provided integrally on one side of the slit covering wall 96. As shown in Fig. 9(b), a fitting cylinder portion 97a is provided integrally on the inside of the cap portion 97. The fitting cylinder portion 97a extends toward the base end side of the cylindrical member 93 and fits into an opening 93d (see Fig. 6) provided on the tip side of the cylindrical member 93 to close the opening 93d. Here, the fitting cylinder portion 97a corresponds to the fitting portion in the present invention.

[0049] In addition, when the fitting cylinder portion 97a is fitted into the opening 93d, the pair of slits 93a, 93b are not entirely blocked by the fitting cylinder portion 97a. In other words, when the breather cap 95 is attached to the cylindrical member 93, air can flow in and out between the inside and outside of the cylindrical member 93 via the pair of slits 93a, 93b.

[0050] Furthermore, a leg portion 99 extending in the axial direction of the cylindrical member 93 is provided integrally on the other side of the slit covering wall 96 in the axial direction of the cylindrical member 93. One longitudinal side of the leg portion 99 is provided integrally with the cap portion 97, and a hook portion 98 is provided integrally on the other longitudinal side of the leg portion 99.

[0051] 6, the hook portion 98 protrudes in a direction intersecting the axial direction of the cylindrical member 93 toward the fitting cylindrical portion 97a by a predetermined height. This allows the hook portion 98 to be hooked onto the engagement portion 73 integrally provided with the gear case 70. The hook portion 98 is also integrally provided with a protrusion 98a formed in a substantially cylindrical shape. The protrusion 98a extends toward the tip side of the cylindrical member 93 and protrudes from the cap portion 97 by a predetermined height.

[0052] The protruding portion 98a of the hook portion 98 is hooked into the recessed portion 73a of the engaging portion 73 provided on the gear case 70. Here, the engaging portion 73 of the gear case 70 is provided in the vicinity of the breathing mechanism 90 in the gear case 70, and protrudes at a predetermined height radially outward from the cylindrical member 93. Specifically, the engaging portion 73 is formed in a substantially triangular shape as shown in Fig. 7, and includes a recessed portion 73a (see Fig. 6) recessed in the axial direction of the cylindrical member 93. The recessed portion 73a is recessed toward the gear cover 80 in the axial direction of the cylindrical member 93, and the protruding portion 98a fits into and engages with the recessed portion 73a.

[0053] In this manner, the fitting tubular portion 97a of the breather cap 95 is fitted into the opening 93d of the tubular member 93 from one axial side (tip side) of the tubular member 93. Also, the convex portion 98a of the breather cap 95 is engaged with the concave portion 73a of the engagement portion 73 from the other axial side of the tubular member 93. This prevents the breather cap 95 from rattling in the axial direction of the tubular member 93 and firmly fixes it to both the gear case 70 and the gear cover 80. In other words, the convex portion 98a of the hook portion 98 has a function of preventing the fitting tubular portion 97a of the cap portion 97 from falling off from the opening 93d.

[0054] Here, to attach the breather cap 95 to the gear case 70 and the gear cover 80, first, the fitting cylinder portion 97a is fitted into the opening 93d. Next, the protrusion 98a is inserted and hooked into the recess 73a. At this time, since the breather cap 95 is made of resin such as plastic, it has some flexibility. Therefore, when the protrusion 98a is hooked into the recess 73a, the leg portion 99 bends, making it possible to easily hook the protrusion 98a into the recess 73a.

[0055] In this manner, in the present embodiment, the hook portion 98 provided on the leg portion 99 is hooked to the engagement portion 73 of the gear case 70. This allows the leg portion 99 to be relatively long, making the hooking operation easy. If the hook portion 98 were to be hooked to the gear cover 80, the leg portion 99 would be short. This would make the hooking operation difficult and would require the protrusion 98a to be small. This would result in a decrease in the fixing strength and would make the cap more likely to come off due to thermal contraction or the like. However, if the material of the breather cap 95 is devised to ensure sufficient fixing strength, the hook portion 98 can also be hooked to the gear cover 80. In this case, the breather cap 95 can be further miniaturized.

[0056] 6 and 9(a), the cap portion 97 is provided with a through hole portion 97b penetrating in the axial direction of the cylindrical member 93. The through hole portion 97b faces a protrusion 98a of the hook portion 98 in the axial direction of the cylindrical member 93. Specifically, the through hole portion 97b is provided at an intersection between the cap portion 97 and a line CL that extends in the axial direction of the cylindrical member 93 and passes through the hook portion 98. As a result, the through hole portion 97b is disposed radially outward of the cylindrical member 93 with respect to the opening 93d.

[0057] In this way, the line CL extending in the axial direction of the tubular member 93 and passing through the hook portion 98 is positioned so as to be shifted (offset) in the radial direction of the tubular member 93, and a through hole portion 97b is provided at a position opposite the convex portion 98a of the hook portion 98 in the axial direction of the tubular member 93, thereby making it possible to easily manufacture the breather cap 95 using simple upper and lower molds without creating undercuts.

[0058] Furthermore, a partition wall 97c is provided inside the breather cap 95 between the fitting cylinder portion 97a and the through-hole portion 97b to separate them. As shown in Fig. 7, the partition wall 97c has a substantially V-shaped cross section in a direction intersecting the axial direction of the cylindrical member 93. Thus, the partition wall 97c has a function of reinforcing the slit covering wall 96.

[0059] 6 and 9(b), a base end side of the partition wall 97c is provided integrally with the cap portion 97. Meanwhile, a tip side of the partition wall 97c protrudes at a predetermined height toward the convex portion 98a of the hook portion 98. Specifically, the protruding height of the partition wall 97c from the cap portion 97 is approximately twice the protruding height of the fitting cylindrical portion 97a from the cap portion 97.

[0060] As a result, even if rainwater or the like enters from the outside to the inside of the breather cap 95 through the through hole 97b, the rainwater or the like running along the inside of the through hole 97b is less likely to reach the pair of slits 93a, 93b. In other words, the partition wall 97c also has a function of preventing rainwater or the like from entering the inside of the cylindrical member 93.

[0061] Next, the breathing function and the function when the wiper motor 40 is wetted will be described in detail with reference to Fig. 11. In Fig. 11, the filter 94 and the breather cap 95 are omitted in order to make it easier to understand the path of the rainwater WA.

[0062] First, the respiratory function of the wiper motor 40 will be described.

[0063] When the wiper motor 40 installed in the engine room is operated, the internal temperature of the wiper motor 40 rises due to the heat generated by the wiper motor 40 and the high temperature atmosphere in the engine room. If the wiper motor 40 is splashed with rainwater WA in this state and the wiper motor 40 is wetted, the wiper motor 40 is rapidly cooled. Thus, a temperature difference occurs between the inside and outside of the wiper motor 40. Then, the hollow portion 63 (see Figs. 4, 6, and 7) of the wiper motor 40 becomes relatively colder than the outside of the wiper motor 40. As a result, the hollow portion 63 becomes negative pressure, and the air outside the gear case 70 flows into the hollow portion 63 through the gap between the breather cap 95 and the cylindrical member 93, the pair of slits 93a and 93b, the air passage 92a, and the communication hole 91. This suppresses the generation of a pressure difference between the inside and outside of the wiper motor 40.

[0064] On the other hand, when the internal temperature of the wiper motor 40 rises significantly by operating the wiper motor 40 at high speed for a long period of time, and the internal temperature of the wiper motor 40 exceeds the external temperature, the hollow portion 63 becomes hotter than the outside of the wiper motor 40. Then, contrary to the above, the hollow portion 63 becomes positive pressure, and the air inside the hollow portion 63 is discharged to the outside through the communication hole 91, the air passage 92a, the pair of slits 93a, 93b, and between the breather cap 95 and the cylindrical member 93. This suppresses the generation of a pressure difference between the inside and outside of the wiper motor 40.

[0065] However, the inside and outside of the wiper motor 40 are always in communication with each other through the gap between the breather cap 95 and the cylindrical member 93, the pair of slits 93a, 93b, the air passage 92a, and the communication hole 91. Therefore, air does not suddenly move between the inside and outside of the wiper motor 40. Therefore, even if the filter 94 is provided, the wiper motor 40 can fully exhibit its breathing function.

[0066] Next, the function of the wiper motor 40 when it is wet will be described.

[0067] For example, when the vehicle 10 runs in heavy rain, rainwater WA enters the engine compartment and wets the wiper motor 40. Then, as shown by arrow M1, the rainwater WA flows along the surface of the gear cover 80 toward the breathing mechanism 90. After that, the rainwater WA that reaches the breathing mechanism 90 flows between the breather cap 95 and the cylindrical member 93, and flows in two directions with the cylindrical member 93 as a boundary, as shown by arrows M2 and M3. In particular, the rainwater WA flowing along arrow M2 reaches the other slit 93b.

[0068] In contrast, rainwater WA flowing along arrow M3 reaches one rib member 93c (on the right side in the figure) and then flows down from one rib member 93c to the bottom of the vehicle 10 as shown by arrow M4. Therefore, the rainwater WA flowing along arrows M3 and M4 flows down to the bottom of the vehicle 10 at a position away from one slit 93a. At this time, one slit 93a is covered by the slit covering wall 96 (see FIG. 7), so that the rainwater WA has difficulty reaching one slit 93a.

[0069] Most of the rainwater WA that reaches the other slit 93b as shown by arrow M2 passes over the other slit 93b and flows along arrow M5. Then, it reaches the other rib member 93c (left side in the figure). After that, the rainwater WA that reaches the other rib member 93c flows from the other rib member 93c as shown by arrow M6, and flows down from between the breather cap 95 and the cylindrical member 93 to the bottom of the vehicle 10. As a result, the rainwater WA flowing along arrows M2, M5, and M6 flows down to the bottom of the vehicle 10 at a position away from one of the slits 93a.

[0070] Note that, as shown by arrow M7 (dashed line), a portion of the rainwater WA that reaches the other slit 93b may enter the inside of the cylindrical member 93 from the other slit 93b. The rainwater WA that has entered the inside of the cylindrical member 93 flows along the inside of the cylindrical member 93 and is smoothly collected in one slit 93a. Thereafter, as shown by arrow M8 (dashed line), the rainwater WA that has flowed along the inside of the cylindrical member 93 flows down from one slit 93a to the bottom of the vehicle 10, passing between the breather cap 95 and the cylindrical member 93.

[0071] This makes it difficult for rainwater WA to reach the small diameter cylindrical portion 92 and the air passage 92a, and thus the intrusion of rainwater and the like into the inside of the wiper motor 40 (hollow portion 63) is suppressed.

[0072] Here, the wiper motor 40 can also be mounted on the vehicle 10 in an installation position as shown in Fig. 12. In other words, the wiper motor 40 according to the present embodiment can be adapted to various installation positions on the vehicle 10, and the reliability against water exposure is further improved.

[0073] Specifically, in the mounting posture of the wiper motor 40 on the vehicle 10 shown in Fig. 12, first, similarly to the mounting posture shown in Fig. 2, the gear case 70 side from which the output shaft 41 (see Fig. 2) protrudes faces downward of the vehicle 10, and the gear cover 80 side attached to the gear case 70 faces upward of the vehicle 10. Also, the speed reduction mechanism 60 side in the longitudinal direction of the wiper motor 40 is inclined downward of the vehicle 10. Meanwhile, unlike the mounting posture shown in Fig. 2, the breathing mechanism 90 side in the lateral direction of the wiper motor 40 is inclined upward of the vehicle 10. Therefore, the rainwater WA running down the surface of the wiper motor 40 flows as indicated by the dashed arrow.

[0074] Even when the wiper motor 40 is mounted on the vehicle 10 in this manner, the slit covering walls 96 of the breather cap 95 cover a pair of slits 93a, 93b from the radial outside of the tubular member 93, as shown in Figure 7, thereby preventing rainwater WA from entering the inside of the tubular member 93 while maintaining the breathing function.

[0075] As described above in detail, according to the wiper motor 40 of this embodiment, the gear cover 80 is provided with a breathing function, so that even if the gear cover 80 is wetted, a pressure difference between the inside and outside of the gear cover 80 is unlikely to occur. In addition, since the breather cap 95 covering the pair of slits 93a, 93b is provided, rainwater, etc. can be prevented from reaching the communication hole 91 through the slits 93a, 93b and the cylindrical member 93. Therefore, it is possible to effectively prevent rainwater, etc. from entering the inside of the gear cover 80 without relying on a large waterproof cover, and thus to improve the reliability against water exposure. Furthermore, since the breather cap 95 is attached to the gear cover 80 and the gear case 70, it is not affected by the length or thickness of the frame member to which the wiper motor 40 is fixed, and versatility can be improved.

[0076] In addition, the wiper motor 40 according to this embodiment has a gear case 70 which rotatably supports the reduction mechanism SD, and a gear cover 80 which is attached to the gear case 70, an engagement portion 73 is provided on the gear case 70, and a cylindrical member 93 is provided on the gear cover 80.

[0077] This allows the breather cap 95 to be attached so as to straddle both the gear case 70 and the gear cover 80. This allows the legs 99 of the breather cap 95 to be made relatively long, which in turn makes it easier to hook the breather cap 95 onto the gear case 70 and the gear cover 80.

[0078] Furthermore, according to the wiper motor 40 of this embodiment, a through hole portion 97b that penetrates the axial direction of the tubular member 93 is provided at the intersection of a line CL that extends in the axial direction of the tubular member 93 and passes through the hook portion 98 (convex portion 98a) and the cap portion 97, and the through hole portion 97b is positioned radially outward of the tubular member 93 than the opening 93d.

[0079] This allows the breather cap 95 to be easily manufactured using simple upper and lower molds without causing undercuts.

[0080] In addition, according to the wiper motor 40 of this embodiment, the cap portion 97 is provided with an engaging cylindrical portion 97a extending toward the base end side of the tubular member 93 and engaging with the opening 93d, and the hook portion 98 is provided with a convex portion 98a extending toward the tip side of the tubular member 93 and engaging with the concave portion 73a provided in the engagement portion 73.

[0081] This allows the breather cap 95 to be firmly fixed to both the gear case 70 and the gear cover 80 without rattling in the axial direction of the cylindrical member 93.

[0082] Furthermore, the wiper motor 40 according to the present embodiment can improve the water-wet reliability to extend the product's lifespan and ultimately reduce the energy required for production. This contributes to the Sustainable Development Goals (SDGs) led by the United Nations, particularly to Goal 7 (Ensure access to affordable, reliable, sustainable and modern energy) and Goal 13 (Take urgent action to combat climate change and its impacts).

[0083] The present invention is not limited to the above embodiment, and it goes without saying that various modifications are possible without departing from the gist of the present invention. For example, in the above embodiment, the breathing mechanism 90 is provided in the gear cover 80, but the present invention is not limited to this. For example, in the case of an installation position in which the output shaft 41 faces upward of the vehicle 10, the breathing mechanism can be provided in the gear case 70.

[0084] In addition, in the above embodiment, the wiper motor 40 is applied to a front wiper device that wipes the wiping area 13 on the windshield 12, but the present invention is not limited to this and can also be applied to a rear wiper device that wipes a wiping area on the rear windshield.

[0085] Furthermore, in the above embodiment, the motor section 50 of the wiper motor 40 is a brushed electric motor equipped with brushes 57, but the present invention is not limited to this, and a brushless electric motor not equipped with brushes in the motor section can also be adopted.

[0086] In addition, in the above embodiment, the wiper motor 40 has been described as an example, but the present invention is not limited to this, and can also be applied to motors with reduction mechanisms for other applications that have a similar mounting position and may be exposed to water.

[0087] Additionally, the material, shape, size, number, installation location, etc. of each component in the above-described embodiment may be arbitrary as long as it achieves the present invention, and is not limited to the above-described embodiment. [Explanation of symbols]

[0088] 10: vehicle, 11: pivot shaft, 12: windshield, 13: wiping range, 20: wiper device, 30: wiper member, 31: wiper arm, 32: wiper blade, 40: wiper motor (motor with reduction mechanism), 41: output shaft, 42: link mechanism, 50: motor section, 51: yoke, 52: magnet, 53: armature core, 54: armature shaft (rotating shaft), 55: worm, 56: commutator, 57: brush, 60: reduction mechanism section, 61: counter gear, 61a: large diameter tooth section, 61b: small diameter tooth section, 61c: central shaft, 62: spur gear, 62a: tooth section, 63: hollow section, 70: gear case (housing), 71: case bottom wall, 72: mounting leg, 73: engagement section, 73a: Recess, 80: gear cover (housing), 81: cover bottom wall, 82: connector connection part, 84: cover flat part, 90: breathing mechanism, 91: communication hole, 92: small diameter cylinder part, 92a: air passage, 93: cylinder-shaped member, 93a, 93b: slit, 93c: rib member, 93d: opening, 94: filter, 95: breather cap (slit covering member), 96: slit covering wall, 97: cap part, 97a: fitting cylinder part (fitting part), 97b: through hole part, 97c: partition wall, 98: hook part, 98a: protrusion part, 99: leg part, CL: line extending in the axial direction of the cylinder-shaped member and passing through the hook part, DS: dead space, S1: first gap, S2: second gap, SD: reduction mechanism, TP: tapered part, WA: rainwater

Claims

1. A motor unit having a rotating shaft; a speed reduction mechanism unit having a speed reduction mechanism for reducing the rotation speed of the rotating shaft; A motor with a reduction mechanism comprising: a housing that accommodates the reduction mechanism; a communication hole provided in the housing for communicating between the inside and the outside of the housing; a cylindrical member that is formed from a member provided outside the housing and the housing, extends in the axial direction of the communication hole, and communicates with the communication hole; A slit is provided in the cylindrical member and extends in an axial direction of the cylindrical member; a slit covering member attached to the housing and covering the slit from a radially outer side of the cylindrical member; having The slit covering member is a cap portion that closes an opening provided at a tip side of the cylindrical member; a hook portion that is hooked onto an engagement portion provided on the housing; The present invention is characterized in that it comprises Motor with reduction mechanism.

2. 2. The motor with a reduction mechanism according to claim 1, The housing includes: a gear case that rotatably supports the reduction mechanism; A gear cover attached to the gear case; having The gear case is provided with the engagement portion, and the gear cover is provided with the cylindrical member. Motor with reduction mechanism.

3. 3. The motor with a reduction mechanism according to claim 1, a through-hole portion penetrating the tubular member in the axial direction is provided at an intersection between a line extending in the axial direction of the tubular member and passing through the hook portion and the cap portion, The through hole portion is disposed radially outward of the cylindrical member relative to the opening portion. Motor with reduction mechanism.

4. The motor with a reduction mechanism according to any one of claims 1 to 3, The cap portion is provided with a fitting portion that extends toward a base end side of the tubular member and fits into the opening, The hook portion is provided with a protrusion extending toward the tip side of the tubular member and engaging with a recess provided in the engaging portion. Motor with reduction mechanism.

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