JP2011255769A - Wiper motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the wobbling of a wiper motor, and to improve productivity.SOLUTION: A motion conversion mechanism 27 housed in a gear frame 21 has: a pinion gear 35 fixed to the base end of an output shaft 26; a motion conversion member 36 including a sector gear 36a engaged with the pinion gear 35; and a holding plate 37 for connecting a gear shaft 39 disposed in the axial center of the sector gear 36a and the output shaft 26 to swing. The motion conversion member 36 is rotatably connected to a worm wheel 32 by a connection shaft 38 set in a position shifted from the axial center of the worm wheel 32 in a diameter direction. A cap-shaped sliding member 42 formed of an elastic material such as rubber is fixed to the base end of each of the connection shaft 38, the gear shaft 39, and the output shaft 26. The sliding member 42 is struck to the inner surface of the gear cover 24 in a compressed state.

Description

  The present invention relates to a wiper motor including a motion conversion mechanism that converts a rotational motion of an electric motor into a swing motion and transmits the swing motion.

  For example, in a rear wiper device for wiping a rear window glass of a vehicle such as an automobile, a wiper motor including a motion conversion mechanism that converts a rotational motion of an electric motor into a swing motion and transmits the swing motion to an output shaft is used. The wiper motor has a bottomed gear frame that accommodates the motion conversion mechanism and a gear cover that closes an opening of the gear frame, and the gear frame is attached to the electric motor. The gear frame also houses a speed reduction mechanism comprising a worm rotated by an electric motor and a worm wheel meshing with the worm. The rotation of the electric motor is decelerated by the speed reduction mechanism and transmitted to the motion conversion mechanism. It has come to be.

  The motion conversion mechanism includes a pinion gear fixed to the base end portion of the output shaft, and a motion conversion member that converts the rotational motion of the worm wheel into a swing motion and transmits the swing motion to the pinion gear. The motion conversion member includes a sector gear portion that is rotatably connected to the worm wheel by a connecting shaft that is provided at a predetermined distance in the radial direction from the shaft center of the worm wheel and meshes with the pinion gear. Further, the motion conversion mechanism is provided with a holding plate that slidably connects a gear shaft provided at the axis of the sector gear portion and the output shaft, and the meshing state between the pinion gear and the sector gear portion is maintained. With this motion conversion mechanism, the rotational motion of the worm wheel is converted into a swing motion and transmitted to the output shaft so that the wiper member attached to the tip of the output shaft is driven to swing within a predetermined swing range. It has become.

  In such a wiper motor, a backlash suppressing structure is provided to suppress backlash in the axial direction of each member housed in the gear frame. For example, in the wiper motor described in Patent Document 1, resin sliding contact members mounted on the base end portions of the coupling shaft, the gear shaft, and the output shaft are brought into sliding contact with the inner surface of the gear cover. As a result, the axial movement of each member housed in the gear frame is restricted, and the backlash in the axial direction is suppressed, so that it is possible to prevent rattling of each member inside the gear frame. It has become.

JP 2007-38949 A

  By the way, in order to reliably prevent rattling of each member inside the gear frame, there is a technique of providing a spring washer between each member accommodated in the gear frame or between each member and the gear frame. Are known. The spring washer is provided in a compressed state, for example, between the worm wheel and the bottom wall of the gear frame, or between the pinion gear and the bottom wall of the gear frame. The elastic force of the spring washer acts on each member in the axial direction. The The elastic force strongly restricts the movement of each member accommodated in the gear frame in the axial direction, and rattling of each member inside the gear frame is surely prevented.

  However, when the spring washer is used to suppress the backlash in the axial direction of the wiper motor, the spring washer has a shape that is easy to overlap with each other and difficult to peel off, so that the assembly work of the spring washer becomes complicated. That is, when the spring washer is assembled to the wiper motor, the spring washer overlaps each other, so that the spring washer is easily clogged in the spring washer feeding device provided in the production line, which causes a decrease in the productivity of the wiper motor.

  An object of the present invention is to suppress the play of the wiper motor and improve productivity.

  The wiper motor of the present invention is a wiper motor comprising an electric motor and a motion conversion mechanism that converts the rotational motion of the electric motor into a swing motion and transmits the swing motion to an output shaft, the worm being rotated by the electric motor, and the A worm wheel that meshes with a worm, a reduction mechanism that decelerates the rotation of the electric motor and transmits it to the motion conversion mechanism, a gear case that is attached to the electric motor and houses the reduction mechanism and the motion conversion mechanism, A first connection shaft provided with a pinion gear fixed to a base end portion of the output shaft and rotating integrally with the output shaft, and a sector gear portion meshing with the pinion gear, and provided at a position radially displaced from the shaft center of the worm wheel And a motion conversion member rotatably connected to the worm wheel and a shaft center of the sector gear portion. A holding plate for swingably connecting the second connecting shaft and the output shaft, and an elastic member made of an elastic material that is elastically deformable in the axial direction of each of the shafts, the first connecting shaft and the second It has a backlash suppressing structure that is attached to one end of the connecting shaft and that slidably abuts against the inner surface of the gear case in a state where the elastic member is compressed in the axial direction.

  The wiper motor of the present invention is a wiper motor comprising an electric motor and a motion conversion mechanism that converts the rotational motion of the electric motor into a swing motion and transmits the swing motion to an output shaft, the worm being rotated by the electric motor, and the A worm wheel that meshes with a worm, a reduction mechanism that decelerates the rotation of the electric motor and transmits it to the motion conversion mechanism, a gear case that is attached to the electric motor and houses the reduction mechanism and the motion conversion mechanism, A motion converting member whose one end is rotatably connected to the worm wheel by a first connecting shaft provided at a position radially displaced from the axial center of the worm wheel, and provided at the other end of the motion converting member. A second connecting shaft and the output shaft are slidably connected, fixed to a base end portion of the output shaft, and rotated integrally with the output shaft. A connecting plate and an elastic member made of an elastic material that is elastically deformable in the axial direction of each of the shafts. The elastic member is attached to one end of each of the first connecting shaft and the second connecting shaft. And a backlash suppressing structure that is slidably abutted against the inner surface of the gear case in a state compressed in a direction.

  The wiper motor according to the present invention is characterized in that the backlash suppressing structure includes a sliding contact member as the elastic member that is slidably abutted against an inner surface of the gear case in a state of being compressed in the axial direction.

  In the wiper motor of the present invention, the backlash suppressing structure is a state in which the backlash-compressing structure is axially compressed between the sliding contact member that is slidably abutted against the inner surface of the gear case, and the sliding contact member and the motion conversion member A wiper motor comprising: the elastic member mounted on the wiper motor.

  The wiper motor according to the present invention is characterized in that a groove portion for holding a lubricant applied to an inner surface of the gear case is formed in the sliding contact member.

  According to the present invention, the elastic member made of an elastic material, which is attached to one end of each of the first connecting shaft and the second connecting shaft, is slidably projected on the inner surface of the gear case in a state where the elastic member is compressed in the axial direction. Since the backlash preventing structure to be applied is provided, rattling of each member inside the gear case can be reliably prevented without using a spring washer. Thus, by not using the spring washer, it is possible to prevent a decrease in productivity due to the use of the spring washer, and it is possible to improve the productivity of the wiper motor.

  According to the present invention, since the groove portion for holding the lubricant applied to the inner surface of the gear case is formed in the sliding contact member, the lubricant may be scattered around as the sliding contact member slides. Even if there is, the lubricant is held in the groove, so it is difficult for the sliding contact member to wear and the sliding resistance to increase due to running out of the lubricant, and to prevent the generation of abnormal noise (sliding noise) due to reduced slidability The durability of the sliding contact member can be improved.

It is a top view which shows the wiper motor which is one embodiment of this invention. It is sectional drawing which follows the AA line in FIG. It is sectional drawing which expands and shows the broken-line circle | round | yen B in FIG. It is sectional drawing which expands and shows the broken-line circle | round | yen C in FIG. It is sectional drawing which expands and shows the broken-line circle | round | yen D in FIG. It is a top view of a sliding contact member. It is a schematic sectional drawing which shows the wiper motor as a comparative example. It is sectional drawing of the wiper motor which shows the modification of a backlash suppression structure. It is a top view which shows the wiper motor which is other embodiment of this invention. It is sectional drawing which follows the EE line in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. A wiper motor 10 shown in FIG. 1 is used as a drive source of a rear wiper device for wiping a rear window glass of a vehicle such as an automobile. The wiper motor 10 includes a motor main body (electric motor) 11 and a gear unit portion 12 provided with a motion conversion mechanism that converts the rotational motion of the motor main body 11 into a swing motion and transmits it.

  The motor body 11 is a DC motor with a brush, and includes a motor case 13 formed into a bottomed cylindrical shape by pressing a thin steel plate or the like. On the inner peripheral surface of the motor case 13, a pair of arc-shaped permanent magnets 14 magnetized in the N-pole and the S-pole toward the radially inner side are fixed to face each other. An armature 15 that faces each permanent magnet 14 via a minute gap is rotatably accommodated in the motor case 13, and a plurality of coils 16 are wound around the armature 15. A motor shaft 17 passes through and is fixed to the rotation center of the armature 15.

  A cylindrical commutator 18 is fixed to the motor shaft 17 adjacent to the armature 15, and the end of each coil 16 is electrically connected to the commutator 18. A pair of brushes 19 are slidably contacted with the outer peripheral surface of the commutator 18, and a drive current is supplied to the coil 16 via each brush 19 and the commutator 18, whereby electromagnetic force torque in the rotational direction is generated in the armature 15. The motor shaft 17 is rotationally driven at a predetermined rotational speed.

  A gear frame 21 of the gear unit portion 12 is attached to the motor body 11 on the opening side of the motor case 13. The gear frame 21 is open to the motor case 13 side, and the gear frame 21 is fixed to the motor case 13 by a plurality of fastening screws 22 in a state where the respective opening end faces are abutted against each other. The distal end side of the motor shaft 17 is inserted into the gear frame 21, and a worm 23 having a helical tooth portion is integrally formed on the outer peripheral surface of the distal end side of the motor shaft 17.

  As shown in FIG. 2, the gear frame 21 is formed in a bottomed shape that opens to the side perpendicular to the axial direction of the motor shaft 17 by aluminum die casting, and a gear case 30 is formed by a gear cover 24 that closes the opening. is doing. In other words, the gear cover 24 is disposed at a predetermined distance from the bottom wall portion 21 a of the gear frame 21, and an accommodation space is formed between the bottom wall portion 21 a of the gear frame 21 and the gear cover 24. The gear frame 21 includes a speed reduction mechanism 25 that reduces and transmits the rotation of the motor shaft 17, and a motion conversion mechanism 27 that converts the rotational motion of the speed reduction mechanism 25 into a swing motion and transmits it to the output shaft 26. Is housed.

  The wiper motor 10 shown in FIG. 1 is a plan view with the gear cover 24 removed, and shows the internal structure of the gear frame 21. The gear cover 24 is formed in a predetermined shape from a steel plate or the like, and the wiper motor 10 is fixed to the vehicle body at a bracket portion (not shown) provided integrally with the gear cover 24.

  The output shaft 26 is made of a round bar made of metal such as steel, and the axial direction thereof is arranged in a direction orthogonal to the axial direction of the motor shaft 17, that is, in a direction orthogonal to the bottom wall portion 21 a of the gear frame 21. . The output shaft 26 is housed in the gear frame 21 at the base end side, and the distal end side protrudes outward from the gear frame 21 and extends through the bottom wall portion 21 a of the gear frame 21. . The bottom wall portion 21a of the gear frame 21 is integrally formed with a substantially cylindrical shaft holding portion 21b that protrudes outward from the gear frame 21 along the outer peripheral surface of the motor shaft 17, and the output shaft 26 is a shaft. It is inserted through the holding portion 21b and is rotatably supported by the shaft holding portion 21b. The tip of the output shaft 26 protrudes from the rear window glass to the outside of the vehicle body, and a wiper member (not shown) for wiping the outer surface of the rear window glass is fixed to the tip of the output shaft 26. It has become.

  A resin-made bearing member 28 is provided between the inner peripheral surface of the shaft holding portion 21b and the outer peripheral surface of the output shaft 26, and the output shaft 26 can freely rotate to the shaft holding portion 21b via the bearing member 28. It is supported. Further, the tip end portion of the shaft holding portion 21b is abutted against the rear window glass or the inner side surface of the vehicle body via the seal material 29, and rainwater, dust, or the like is prevented from entering the vehicle body or the gear frame 21. It is like that.

  The speed reduction mechanism 25 has a worm 23 that is rotated by the motor body 11 and a worm wheel 32 that meshes with the worm 23. The worm wheel 32 is formed into a substantially disk shape by injection molding of a resin material, and has a tooth portion that meshes with the worm 23 on the outer peripheral surface thereof. A rotation shaft 33 that is fixed to the bottom wall portion 21 a and extends in parallel with the output shaft 26 is inserted into the shaft center of the worm wheel 32, and the worm wheel 32 is rotatable inside the gear frame 21 by the rotation shaft 33. It is supported. Further, a cylindrical boss portion 32 a protruding toward the bottom wall portion 21 a along the outer peripheral surface of the rotating shaft 33 is provided on the axial end surface of the worm wheel 32 on the bottom wall portion 21 a side. Is slidably butted against the inner surface of the bottom wall portion 21a at the boss portion 32a. The rotation of the motor shaft 17 is decelerated and transmitted to the worm wheel 32 by the speed reduction mechanism 25 including the worm 23 and the worm wheel 32.

  As shown in FIG. 1, the worm wheel 32 is formed with a plurality of connection holes 34 that open to the gear cover 24 side at a position that is a predetermined distance away from the shaft center radially outward. A pair (two places) of connection holes 34 are provided along the rotation direction of the worm wheel 32, and each connection hole 34 is formed at a position where the radial distance from the axis of the worm wheel 32 is equal. The pair of coupling holes 34 are arranged at positions spaced apart by about 180 degrees along the rotational direction of the worm wheel 32 so as to face each other across the axis of the worm wheel 32.

  The motion conversion mechanism 27 includes a pinion gear 35 fixed to the base end portion of the output shaft 26, a motion conversion member 36 that converts the rotational motion of the worm wheel 32 into a swing motion and transmits it to the pinion gear 35, and motion conversion with the pinion gear 35. A holding plate 37 is provided to connect the member 36 to each other so as to be swingable. The motion conversion member 36 includes a sector gear portion 36a that meshes with the pinion gear 35, and an arm portion 36b that extends from the sector gear portion 36a toward the worm wheel 32. The sector gear portion 36a and the arm portion 36b are made of a metal material such as a steel plate. It is molded integrally.

  As shown in FIG. 2, the motion conversion member 36 is disposed closer to the gear cover 24 than the worm wheel 32, and the motion conversion member 36 and the worm wheel 32 are mutually connected on the abutting surface parallel to the bottom wall portion 21 a of the gear frame 21. It is slidably abutted on. A connecting shaft 38 as a first connecting shaft that is rotatably inserted into one of the pair of connecting holes 34 of the worm wheel 32 is fixed to the end of the arm portion 36b of the motion converting member 36. . In other words, the motion conversion member 36 and the worm wheel 32 are rotatably connected to each other by the connecting shaft 38 provided at a position shifted in the radial direction from the axial center of the worm wheel 32. The sector gear portion 36 a is a substantially fan-shaped spur gear, and is arranged on the same plane as the motion conversion member 36 and meshes with a pinion gear 35 that rotates integrally with the output shaft 26. The axial end surface of the pinion gear 35 on the bottom wall 21a side is slidably butted against the inner surface of the bottom wall 21a.

  The holding plate 37 is formed in a flat plate shape that extends between the pinion gear 35 and the sector gear portion 36a using a metal material such as a steel plate. The holding plate 37 is disposed closer to the gear cover 24 than the pinion gear 35 and the motion converting member 36, and the holding plate 37, the pinion gear 35, and the motion converting member 36 are arranged on the abutting surface parallel to the bottom wall portion 21 a of the gear frame 21. They are slidable against each other. A gear shaft 39 as a second connecting shaft extending in parallel with the output shaft 26 and the connecting shaft 38 is rotatably inserted into one end portion of the holding plate 37, and the gear shaft 39 is centered on the sector gear portion 36a. It is fixed. On the other hand, the output shaft 26 is rotatably inserted into the other end portion of the holding plate 37. By this holding plate 37, the gear shaft 39 is slidably connected to the output shaft 26, and the pinion gear 35 and the sector gear portion 36a are held in mesh with each other.

  When the worm wheel 32 is rotated by such a motion conversion mechanism 27, the motion conversion member 36 is reciprocally swung around the output shaft 26, and the output shaft 26 is engaged with the sector gear portion 36 a of the motion conversion member 36 and the pinion gear 35. Is reciprocally swung within a predetermined angle range. In other words, the rotational motion of the worm wheel 32 is converted into a swing motion by the motion conversion mechanism 27 and transmitted to the output shaft 26, and the wiper member is moved to a predetermined swing range, that is, a preset lower inversion position (stop position) and upper position. It is driven to swing between the reversing position.

  The wiper motor 10 is provided with a backlash suppressing structure for suppressing the backlash in the axial direction of each member housed in the gear frame 21. The backlash suppressing structure includes a sliding contact member 42 that is attached to the base end portion of each of the connecting shaft 38, the gear shaft 39, and the output shaft 26 and is slidably contacted with the inner surface of the gear cover 24. 3 is an enlarged cross-sectional view of broken line circle B in FIG. 2, FIG. 4 is an enlarged cross-sectional view of broken line circle C in FIG. 2, and FIG. 5 is an enlarged view of broken line circle D in FIG. FIG. FIG. 6 is a plan view of the sliding contact member, and shows the sliding contact member 42 viewed from the gear cover 24 side.

  As shown in FIG. 3, the connecting shaft 38 is fixed by being press-fitted into a fixing hole 43 formed in the arm portion 36 b of the motion conversion member 36 at the center in the axial direction, and the arm portion 36 b of the motion conversion member 36. In a state where the worm wheel 32 and the worm wheel 32 are slidably abutted with each other, the distal end portion of the connecting shaft 38 is rotatably inserted into the connecting hole 34 of the worm wheel 32. The base end portion of the connecting shaft 38 extends to the gear cover 24 side, and the base end surface thereof faces the inner side surface of the gear cover 24 via a predetermined gap. A sliding contact member 42 made of an elastic material such as rubber is attached to the base end portion of the connecting shaft 38.

  Further, as shown in FIG. 4, the gear shaft 39 is fixed by being press-fitted into the fixing hole 44 formed in the sector gear portion 36a of the motion converting member 36 at the tip end thereof, that is, the state shown in FIG. Under the reverse position, the gear shaft 39 and the sector gear portion 36 a of the motion conversion member 36 are slidably abutted against the bottom wall portion 21 a of the gear frame 21. A base end portion of the gear shaft 38 is rotatably inserted in an insertion hole 45 formed in one end portion of the holding plate 37 and extends to the gear cover 24 side. Are opposed to each other. A sliding contact member 42 formed of an elastic material such as rubber is attached to the base end portion of the gear shaft 39, and the holding plate 37 is interposed between the sector gear portion 36 a of the motion conversion member 36 and the sliding contact member 42. One end of the slidably supported. Note that, when the wiper member is in the upper inverted position, the gear shaft 39 is positioned between the worm wheel 32 and the gear cover 24, and the gear shaft 39 and the sector gear portion 36 a of the motion conversion member 36 are slidable on the worm wheel 32. It comes to be hit by.

  Further, as shown in FIG. 5, the base end portion of the output shaft 26 is press-fitted and fixed in a fixing hole 46 formed in the pinion gear 35, and the pinion gear 35 slides on the bottom wall portion 21 a of the gear frame 21. It is freely faced. Located on the gear cover 24 side of the pinion gear 35, the base end portion of the output shaft 26 is rotatably inserted into an insertion hole 47 formed in the other end portion of the holding plate 37 and extends to the gear cover 24 side. The base end face is opposed to the inner surface of the gear cover 24 via a predetermined gap. A sliding contact member 42 formed of an elastic material such as rubber is attached to the base end portion of the output shaft 26, and the other end portion of the holding plate 37 is slid between the pinion gear 35 and the sliding contact member 42. It is supported freely.

  The slidable contact members 42 attached to the base end portions of the coupling shaft 38, the gear shaft 39, and the output shaft 26 are substantially disc-shaped abutting portions 42a that abut against the inner surface of the gear cover 24, respectively. The cap portion has a cylindrical portion 42b extending from the outer peripheral portion of the abutting portion 42a toward the bottom wall portion 21a, and a mounting hole 42c is formed to open to the bottom wall portion 21a side. The base end portions of the shafts 26, 38, 39 are fitted in the mounting holes 42c of the respective sliding contact members 42, and the outer peripheral surfaces of the base end portions of the shafts 26, 38, 39 are covered by the cylindrical portion 42b. In addition, the abutting portion 42 a is sandwiched between the base end surfaces of the shafts 26, 38, and 39 and the inner surface of the gear cover 24. That is, each shaft 26, 38, 39 is slidably abutted against the inner surface of the gear cover 24 via the abutting portion 42 a of the sliding contact member 42. In addition, the sliding contact member 42 attached to each of the gear shaft 39 and the output shaft 26 has a cylindrical portion 42 b sandwiched between the end surface of the holding plate 37 on the gear cover 24 side and the inner surface of the gear cover 24.

  The sliding contact member 42 is formed of an elastic material that is elastically deformable in the axial direction of each of the shafts 26, 38, and 39. The sliding contact member 42 as an elastic member is compressed in the axial direction of the gear cover 24. It is slidably abutted against the inner surface. That is, in the sliding contact member 42 attached to the base end portion of each shaft 26, 38, 39, the abutting portion 42 a is a shaft between the base end surface of each shaft 26, 38, 39 and the inner surface of the gear cover 24. As shown by the arrows in the figure, the elastic force of the sliding contact member 42 is applied to the shafts 26, 38, 39 in the axial direction toward the bottom wall portion 21a. ing. Further, in the sliding contact member 42 attached to the gear shaft 39 and the output shaft 26, the cylindrical portion 42 b is compressed in the axial direction between the end surface of the holding plate 37 on the gear cover 24 side and the inner surface of the gear cover 24. The holding plate 37 is subjected to an elastic force by the sliding contact member 42 in the axial direction toward the bottom wall portion 21a. Due to the elastic force of the sliding contact member 42, each member housed in the gear frame 21, that is, each member constituting the speed reduction mechanism 25 and the motion conversion mechanism 27 is urged toward the bottom wall portion 21 a side of the gear frame 21. It is pressed in the axial direction between the portion 21 a and the gear cover 24. As a result, the axial movement of each member housed in the gear frame 21 is strongly restricted and the backlash in the axial direction is suppressed, so that rattling of each member inside the gear frame 21 is reliably prevented. It has become so.

  As shown in FIG. 6, a plurality of grease grooves (groove portions) 48 are formed on the abutting portion 42 a of each sliding contact member 42 on the abutting surface with the inner surface of the gear cover 24. Four grease grooves 48 are provided along the outer peripheral portion of the abutting portion 42a at equal intervals (approximately 90 ° intervals), and have a substantially semicircular shape that opens to the gear cover 24 side and radially outward. Grease (not shown) is applied to the abutting surface of each sliding contact member 42 and the gear cover 24, that is, the inner surface of the gear cover 24 so that the sliding contact member 42 slides smoothly with respect to the gear cover 24. The grease is held by a grease groove 48 as a grease collecting groove formed in each sliding contact member 42. As a result, even if the grease is scattered around as the sliding contact member 42 slides, the grease is held in the grease groove 48. The increase is less likely to occur, and the generation of abnormal noise (sliding noise) due to the decrease in slidability is prevented and the durability of the sliding contact member 42 is improved. Of course, the lubricant applied to the inner surface of the gear cover 24 is not limited to grease, and other lubricants may be used. Further, the shape and number of the grease grooves 48 formed in the sliding contact member 42 can be variously changed.

  FIG. 7 is a schematic cross-sectional view showing a wiper motor as a comparative example. In FIG. 7, the same members as those shown in FIG. In the wiper motor shown in FIG. 7, a sliding contact member 50 formed in a cap shape with a resin material is mounted on the base end portion of each of the connecting shaft 38, the gear shaft 39, and the output shaft 26. The spring washer 51 is assembled in a compressed state between the boss portion 32a of the worm wheel 32 and the bottom wall portion 21a of the gear frame 21 and between the pinion gear 35 and the bottom wall portion 21a of the gear frame 21. It has been. Due to the elastic force of the spring washer 51, each member accommodated in the gear frame 21 is urged in the axial direction toward the gear cover 24, and rattling of each member inside the gear frame 21 is prevented. It has become so. Thus, in the wiper motor that uses the spring washer 51 to suppress axial backlash, the spring washer 51 has a shape that is easy to overlap with each other and difficult to peel off. Therefore, the work of assembling the spring washer 51 to the wiper motor is complicated. It is. That is, when the spring washer 51 is assembled to the wiper motor, the spring washer 51 overlaps with each other, so that the spring washer 51 is likely to be clogged in the feeding device of the spring washer 51 provided in the production line, and the factor of reducing the productivity of the wiper motor. It becomes.

  On the other hand, in the wiper motor 10 shown in FIG. 2, the sliding contact member 42 is connected to each of the connecting shaft 38, the gear shaft 39, and the output shaft 26 with the sliding contact member 42 made of an elastic material such as rubber compressed in the axial direction. By attaching each to the base end portion, axial backlash of each member accommodated in the gear frame 21 is suppressed. Accordingly, rattling of each member inside the gear frame 21 can be reliably prevented without using the spring washer 51, and the productivity of the wiper motor 10 can be reduced by not using the spring washer 51. Can be improved. That is, it is possible to prevent a decrease in productivity due to the use of the spring washer 51 as described above.

  Further, in this wiper motor 10, since the backlash in the axial direction of the wiper motor 10 can be suppressed by mounting the sliding contact members 42 on the respective shafts 26, 38, 39, the sliding contact is made as in the wiper motor shown in FIG. There is no need to separately provide the spring washer 51 in addition to the member 50. Therefore, the number of parts can be reduced as compared with the wiper motor shown in FIG. 7, and the cost of the wiper motor 10 can be reduced and the assembly workability can be improved.

  In the wiper motor 10, the shafts 26, 38, and 39 are slidably abutted against the inner surface of the gear cover 24 through the sliding contact member 42 formed of an elastic material such as rubber. As compared with the case where the sliding contact member 50 made of the material is used, it is possible to suppress wear of the sliding contact member 42 and a decrease in slidability. Further, since the grease groove 48 for holding the grease applied to the inner surface of the gear cover 24 is formed in each sliding contact member 42, the wear of the sliding contact member 42 and the increase in sliding resistance due to the grease being cut off are formed. Therefore, it is possible to prevent the generation of abnormal noise (sliding noise) due to a decrease in slidability and to improve the durability of the sliding contact member 42.

  In the above-described embodiment, the sliding contact member 42 is attached to the base end of each of the connecting shaft 38, the gear shaft 39, and the output shaft 26. The sliding contact member 42 may not be provided. That is, it is possible to prevent rattling of each member inside the gear frame 21 by attaching the sliding contact members 42 to at least the base end portions of the connecting shaft 38 and the gear shaft 39, respectively. However, it goes without saying that the backlash suppressing effect of the wiper motor 10 is improved by mounting the sliding contact member 42 on the base end portion of the output shaft 26 in addition to the connecting shaft 38 and the gear shaft 39.

  FIG. 8 is a cross-sectional view of a wiper motor showing a modification of the play suppressing structure. In addition, the same code | symbol is attached | subjected to the member similar to the member mentioned above in FIG. 8, and the description is abbreviate | omitted. The looseness control structure provided in the wiper motor includes a sliding contact member 61 that is mounted on the base end portion of each of the connecting shaft 38, the gear shaft 39, and the output shaft 26 and that is in sliding contact with the inner surface of the gear cover 24; 61 and an O-ring 62 disposed so as to abut on the end of the bottom wall 21a side of 61.

  A cylindrical spacer 63 made of resin is mounted on the connecting shaft 38 so as to be closer to the gear cover 24 than the motion converting member 36, and the spacer 63 is abutted against the arm portion 36 b of the motion converting member 36. . The base end portion of the connecting shaft 38 extends through the spacer 63 to the gear cover 24 side, and the base end surface thereof is opposed to the inner surface of the gear cover 24 with a predetermined gap. A sliding contact member 61 made of a resin material is attached to the base end portion of the connecting shaft 38, and an O-ring 62 made of an elastic material such as rubber is sandwiched between the sliding contact member 61 and the spacer 63. It is. Similarly, a resin-made sliding contact member 61 is mounted between the holding plate 37 and the gear cover 24 at the base end portions of the gear shaft 39 and the output shaft 26, and the sliding contact member 61 and the holding plate are mounted. An O-ring 62 made of an elastic material such as rubber is sandwiched between them.

  The sliding contact members 61 mounted on the base end portions of the connecting shaft 38, the gear shaft 39, and the output shaft 26 are between the base end surfaces of the shafts 26, 38, 39 and the inner surface of the gear cover 24. It has a cap shape that includes an abutting portion 61a to be sandwiched and a cylindrical portion 61b that covers the outer peripheral surface of the base end portion of each shaft 26, 38, 39. That is, the shafts 26, 38, 39 are fitted into the mounting holes 61 c of the sliding contact member 61 and are slidably abutted against the inner surface of the gear cover 24 via the abutting portion 61 a. The O-ring 62 is in contact with the end surface of the cylindrical portion 61 b of the sliding contact member 61 on the bottom wall portion 21 a side, and is sandwiched between the spacer 63 and the holding plate 37.

  The O-ring 62 is formed of an elastic material that can be elastically deformed in the axial direction of each of the shafts 26, 38, and 39. It is mounted in a state compressed between the contact member 61 and the holding plate 37 in the axial direction. That is, the O-rings 62 attached to the base end portions of the connecting shaft 38 and the gear shaft 39 are compressed in the axial direction between the motion converting member 36 and the sliding contact member 61 via the spacer 63 and the holding plate 37. In this state, the spacer 63 and the holding plate 37 are subjected to an elastic force by the O-ring 62 in the axial direction toward the bottom wall 21 side. The O-ring 62 attached to the base end portion of the output shaft 26 is assembled in a state compressed in the axial direction between the holding plate 37 and the sliding contact member 61, and the O-ring is attached to the holding plate 37. The elastic force of 62 is applied in the axial direction toward the bottom wall 21 side. Due to the elastic force of the O-ring 62, each member housed in the gear frame 21 is urged toward the bottom wall 21a side of the gear frame 21, and is pressed in the axial direction between the bottom wall 21a and the gear cover 24. Yes. As a result, the axial movement of each member housed in the gear frame 21 is strongly restricted and the backlash in the axial direction is suppressed, so that rattling of each member inside the gear frame 21 is reliably prevented. It has become so.

  As described above, the sliding contact member 61 is mounted on the base end portion of each of the shafts 38, 39, and 26 with the O-ring 62 made of an elastic material such as rubber compressed in the axial direction. Since the backlash of each housed member is suppressed, rattling of each member inside the gear frame 21 can be reliably prevented without using the spring washer 51. Therefore, by not using the spring washer 51, the productivity of the wiper motor 60 can be improved. Further, in this wiper motor, the sliding contact member 61 is elastically abutted against the inner surface of the gear cover 24 by the elastic force of the O-ring 62, so that the wear of the sliding contact member 61 and a decrease in slidability are suppressed. be able to. Of course, grease grooves 48 for holding the grease applied to the inner surface of the gear cover 24 may be formed in each sliding contact member 61.

  The structure of the speed reduction mechanism 25 and the motion conversion mechanism 27 accommodated in the gear case 21 can be arbitrarily changed. For example, a link type motion conversion mechanism may be used. 9 is a plan view showing a wiper motor according to another embodiment of the present invention, and FIG. 10 is a cross-sectional view taken along line EE in FIG. Note that members similar to those described above in FIGS. 9 and 10 are denoted by the same reference numerals, and description thereof is omitted.

  The link type motion conversion mechanism 71 provided in the wiper motor 70 converts the rotational movement of the connecting plate 72 fixed to the base end portion of the output shaft 26 and the worm wheel 32 into a swinging motion and transmits it to the connecting plate 72. And a motion converting member 73 to be operated. The motion conversion member 73 is formed in a flat plate shape that extends between the worm wheel 32 and the connection plate 72 using a metal material such as a steel plate.

  As shown in FIG. 10, the motion conversion member 73 is disposed closer to the gear cover 24 than the worm wheel 32, and the motion conversion member 73 and the worm wheel 32 are mutually connected on the abutting surface parallel to the bottom wall portion 21 a of the gear frame 21. It is slidably abutted on. A first connection shaft 74 that is rotatably inserted into any one of the plurality of connection holes 34 of the worm wheel 21 is fixed to one end of the motion conversion member 36. That is, the motion conversion member 73 and the worm wheel 32 are connected to each other by the first connecting shaft 74 provided at a position shifted in the radial direction from the axis of the worm wheel 32.

  One end of the connection plate 72 is fixed to the base end of the output shaft 26 and rotates integrally with the output shaft 26. The connection plate 72 is disposed closer to the bottom wall 21 a than the motion conversion member 73, and the other end of the motion conversion member 73 and the other end of the connection plate 72 are parallel to the bottom wall 21 a of the gear frame 21. The abutting surfaces are slidable against each other. A second connection shaft 75 extending in parallel with the output shaft 26 and the first connection shaft 74 is rotatably inserted into the other end portion of the connection plate 72, and the second connection shaft 75 is connected to the other end of the motion conversion member 73. It is fixed to the part.

  When the worm wheel 32 is rotated by such a motion converting mechanism 71, the motion converting member 73 is reciprocally swung around the output shaft 26, and the output shaft 26 is moved to a predetermined position by the connection between the motion converting portion 73 and the connecting plate 72. Swing back and forth within an angular range. In other words, the rotational motion of the worm wheel 32 is converted into a swing motion by the motion conversion mechanism 71 and transmitted to the output shaft 26, and the wiper member has a predetermined swing range, that is, a preset lower reverse position and upper reverse position. It is designed to swing between them.

  Also in the wiper motor 70 provided with the link type motion converting mechanism 71, it is needless to say that the backlash of each member accommodated in the gear frame 21 can be suppressed by providing the backlash suppression structure as shown in FIG. Yes. That is, as shown in FIG. 10, the sliding contact member 42 as an elastic member that is slidably abutted against the inner surface of the gear cover 24 in the axially compressed state at the proximal end portions of the connecting shafts 74 and 75. Are attached, and the connecting shafts 74 and 75 and the motion converting portion 73 are subjected to elastic force by the sliding contact member 42 toward the bottom wall portion 21a. Due to the elastic force of the sliding contact member 42, the movement in the axial direction of each member accommodated in the gear frame 21 is strongly restricted and the backlash in the axial direction is suppressed. Shaking is reliably prevented. Therefore, by not using the spring washer 51, the productivity of the wiper motor 60 can be improved, and the same effect as the wiper motor 10 shown in FIG. 2 can be obtained.

  In addition, in the wiper motor 70 provided with the link type motion conversion mechanism 71, a backlash suppressing structure as shown in FIG. 8 may be provided. That is, a resin-made sliding contact member 61 slidably abutted against the inner surface of the gear cover 24, and an elastic member attached in an axially compressed state between the sliding contact member 61 and the motion conversion member 73 The O-ring 62 may be attached to the base end portions of the connecting shafts 74 and 75, respectively.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the electric motor 11 is not limited to a motor with a brush, and for example, a brushless motor or the like may be used. Further, the wiper motor 10 of the present invention is not limited to that used in a rear window device of a vehicle such as an automobile, and may be used in a wiper device mounted on an aircraft or a ship.

10 Wiper motor 11 Motor body (electric motor)
DESCRIPTION OF SYMBOLS 12 Gear unit part 13 Motor case 14 Permanent magnet 15 Armature 16 Coil 17 Motor shaft 18 Commutator 19 Brush 21 Gear frame 21a Bottom wall part 21b Shaft holding part 22 Fastening screw 23 Worm 24 Gear cover 25 Deceleration mechanism 26 Output shaft 27 Motion conversion mechanism 28 Bearing member 29 Sealing material 30 Gear case 32 Worm wheel 32a Boss portion 33 Rotating shaft 34 Connection hole 35 Pinion gear 36 Motion conversion member 36a Sector gear portion 36b Arm portion 37 Holding plate 38 Connection shaft (first connection shaft)
39 Gear shaft (second connecting shaft)
42 Sliding member (elastic member)
42a Abutting portion 42b Cylindrical portion 42c Mounting holes 43, 44 Fixed hole 45 Insertion hole 46 Fixed hole 47 Insertion hole 48 Grease groove (groove)
50 Sliding member 51 Spring washer 61 Sliding member 61a Abutting portion 61b Cylindrical portion 61c Mounting hole 62 O-ring (elastic member)
63 Spacer 70 Wiper motor 71 Motion conversion mechanism 72 Connection plate 73 Motion conversion member 74 First connection shaft 75 Second connection shaft

Claims (5)

A wiper motor comprising an electric motor and a motion conversion mechanism that converts the rotational motion of the electric motor into a swing motion and transmits it to an output shaft,
A worm that is rotated by the electric motor, and a worm wheel that meshes with the worm, a deceleration mechanism that decelerates the rotation of the electric motor and transmits it to the motion conversion mechanism;
A gear case attached to the electric motor and housing the speed reduction mechanism and the motion conversion mechanism;
A pinion gear fixed to the base end of the output shaft and rotating integrally with the output shaft;
A motion conversion member that includes a sector gear portion that meshes with the pinion gear, and that is rotatably connected to the worm wheel by a first connection shaft that is provided at a position radially displaced from the axial center of the worm wheel;
A holding plate for swingably connecting the second connecting shaft provided at the axis of the sector gear portion and the output shaft;
An elastic member made of an elastic material that is elastically deformable in the axial direction of each of the axes is provided, and is attached to one end of each of the first connecting shaft and the second connecting shaft, and the elastic member is compressed in the axial direction. A wiper motor having a backlash suppressing structure that is slidably abutted against an inner surface of the gear case in a state in which the wiper motor is in contact. A wiper motor comprising an electric motor and a motion conversion mechanism that converts the rotational motion of the electric motor into a swing motion and transmits it to an output shaft,
A worm that is rotated by the electric motor, and a worm wheel that meshes with the worm, a deceleration mechanism that decelerates the rotation of the electric motor and transmits it to the motion conversion mechanism;
A gear case attached to the electric motor and housing the speed reduction mechanism and the motion conversion mechanism;
A motion conversion member whose one end is rotatably connected to the worm wheel by a first connecting shaft provided at a position radially displaced from the axis of the worm wheel;
A second connecting shaft provided at the other end portion of the motion converting member and the output shaft so as to be swingable; a connecting plate fixed to a base end portion of the output shaft and rotating integrally with the output shaft; ,
An elastic member made of an elastic material that is elastically deformable in the axial direction of each of the axes is provided, and is attached to one end of each of the first connecting shaft and the second connecting shaft, and the elastic member is compressed in the axial direction. A wiper motor having a backlash suppressing structure that is slidably abutted against an inner surface of the gear case in a state in which the wiper motor is in contact.   3. The wiper motor according to claim 1, wherein the backlash suppressing structure includes a sliding contact member as the elastic member that is slidably abutted against an inner surface of the gear case in a state of being compressed in an axial direction. And wiper motor.   3. The wiper motor according to claim 1, wherein the backlash suppression structure includes a sliding contact member that is slidably abutted against an inner surface of the gear case, and an axial direction between the sliding contact member and the motion conversion member. A wiper motor comprising: the elastic member mounted in a compressed state.   5. The wiper motor according to claim 3, wherein a groove for holding a lubricant applied to an inner surface of the gear case is formed in the sliding contact member. 6.

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