JP2011084251A - Wiper motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress occurrence of disadvantages such as early gear wear and gear chipping, while achieving commonality of a warm wheel and improvement of forming accuracy. <P>SOLUTION: A joint plate 46 for swingably joining a gear shaft 51 and an output shaft 44 installed at the shaft center of a sector gear 45b is disposed on the bottom side of a gear housing 31 of a motion conversion member 45. A bend section 45c for disposing a joint portion 45a on the bottom side of the gear housing 31, and disposing the sector gear 45b on the opening side of the gear housing 31 is installed between the joint portion 45a of the motion conversion member 45 and the sector gear 45b. Thereby, the motion conversion member 45 is formed into a stepped shape, so that the joint portion 45a can be disposed close to the warm wheel 43, and the sector gear 45b can be disposed close to a gear cover 32. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wiper motor that swings and drives a wiper member, and particularly relates to a wiper motor that includes a motion conversion mechanism that converts a rotary motion of an electric motor into a swing motion and transmits the swing motion to an output shaft.

  2. Description of the Related Art Conventionally, a rear wiper device for wiping a rear glass of a vehicle such as an automobile has a wiper motor provided with a motion conversion mechanism that converts a rotational motion of an electric motor into a swing motion and transmits it to an output shaft. Then, by attaching the wiper member to the output shaft of the wiper motor and driving the wiper motor, the wiper member can be driven to swing between the predetermined reverse positions of the rear glass.

  Such a wiper motor includes a gear housing formed in a bottomed shape and a gear cover that closes an opening of the gear housing, and further includes an electric motor fixed to the gear housing. The gear housing accommodates a speed reduction mechanism and a motion conversion mechanism, and the speed reduction mechanism is formed of a worm rotated by an electric motor and a worm wheel meshing with the worm. As a result, the rotation of the worm is reduced to a predetermined speed to increase the torque, and the increased torque is output from the worm wheel.

  On the other hand, the motion converting mechanism is formed of a motion converting member having a sector gear and a connecting portion, and a pinion gear provided on the output shaft so as to be integrally rotatable and a connecting plate for holding the meshing of the sector gear. The connecting portion of the motion converting member is rotatably connected to a connecting shaft located away from the rotation center axis of the worm wheel, and the connecting plate is a gear shaft at the center of the sector gear and an output shaft that rotates together with the pinion gear. Both are rotatably connected. As a result, when the electric motor is driven, the worm wheel rotates and the motion converting member swings, and accordingly, the pinion gear that meshes with the sector gear, that is, the output shaft swings.

  As a wiper motor provided with such a motion conversion mechanism, for example, techniques described in Patent Document 1 and Patent Document 2 are known.

  The wiper motor described in Patent Literature 1 includes a flat plate power conversion member (motion conversion member), and a sector gear portion that meshes with a swing plate (connection plate) and an output gear (pinion gear) from the bottom side of the gear case (gear housing). They are arranged in the order of power conversion members (motion conversion members) having (sector gears). That is, the structure which rocks | couples a connection board between the bottom part of a gear case and a power conversion member is taken. The worm wheel forming the speed reduction mechanism is rotatably provided at the deepest part of the gear case, and the distance between the worm wheel and the power conversion member along the axial direction of the output shaft is long. Therefore, in order to secure the rocking space of the rocking plate, a protruding portion that partially protrudes in the axial direction is formed integrally with the worm wheel, and the power conversion member can be freely rotated through the connecting shaft to this protruding portion. It is connected.

  In contrast to the wiper motor described in Patent Document 2, the wiper motor described in Patent Document 2 is arranged from the bottom side of the gear case in the order of a power conversion member having a sector gear meshing with the output gear and a connecting plate. That is, a structure is adopted in which the connecting plate is swung between the power conversion member and the case cover that closes the gear case. Thereby, compared with patent document 1, the rocking | fluctuation space of the connection plate between a worm wheel and a power conversion member is abbreviate | omitted, and the worm wheel and the power conversion member are arrange | positioned closely. Therefore, it is not necessary to form a protruding portion that partially protrudes in the axial direction of the worm wheel, and the worm wheel can be shared. In other words, the connecting shaft for connecting the power conversion member can be arranged on the worm wheel in a plurality of installation patterns, so that the swing position of the wiper member can be changed according to the vehicle type, that is, a plurality of vehicle types with one worm wheel. Can be adapted to.

Japanese Patent Laying-Open No. 2006-088776 (FIGS. 1 and 2) JP 2007-189759 A (FIGS. 1 and 2)

  However, according to the wiper motor described in Patent Document 1, since a protruding portion that partially protrudes from the worm wheel is formed, the connecting shaft cannot be arranged in a plurality of installation patterns on the worm wheel, and the worm wheel can be shared. There wasn't. Also, the worm wheel is often formed by injection molding of a resin material such as plastic, and in particular, there is a sink phenomenon (shrinkage that occurs when the molten resin is cooled and hardened) in the protruding portion that is thick. easy. When this sink phenomenon occurs, the molding accuracy of the worm wheel is lowered, which may cause problems such as the generation of abnormal noise from the wiper motor.

  According to the wiper motor described in Patent Document 2, since the worm wheel does not include a protruding portion that partially protrudes, occurrence of a sink phenomenon as in the wiper motor described in Patent Document 1 can be suppressed. On the other hand, since the connecting plate is disposed on the gear cover side, the connecting plate swings at a position away from the output shaft guide portion (boss portion) of the gear case. That is, since the driving force of the electric motor is applied to the tip of the output shaft on the gear cover side, the output shaft may be bent when a large external force acts on the output shaft from the wiper member due to snow accumulation or the like. In this case, the meshing between the sector gear and the output gear becomes shallow, and as a result, problems such as premature wear of gears and gear chipping may occur.

  An object of the present invention is to provide a wiper motor capable of suppressing the occurrence of problems such as early gear wear and gear chipping while achieving common use of worm wheels and improvement of molding accuracy.

  The wiper motor according to the present invention includes a motion conversion mechanism that converts the rotational motion of the electric motor into a swing motion and transmits the swing motion to the output shaft, and swings the wiper member attached to the output shaft between predetermined inversion positions. A wiper motor that is driven, and is provided with a bottomed gear housing that houses the motion conversion mechanism, a gear cover that closes an opening of the gear housing, and an output shaft that is integrally rotatable. A pinion gear to be accommodated, a worm extending into the gear housing and rotated by the electric motor, a worm wheel rotatably accommodated in the gear housing and meshing with the worm, and a rotation center axis of the worm wheel A connecting shaft provided at a distant position, a connecting portion rotatably connected to the connecting shaft, and the pinion gear A motion conversion member having a sector gear that meshes with a coupling plate, and a connecting plate that is provided on the bottom side of the gear housing of the motion conversion member and that swingably connects a gear shaft provided at an axis of the sector gear and the output shaft. A bent portion provided between the connecting portion of the motion conversion member and the sector gear, the connecting portion being disposed on the bottom side of the gear housing, and the sector gear being disposed on the opening side of the gear housing. It is characterized by providing.

  The wiper motor of the present invention is characterized in that a sliding guide member that smoothly slides between the motion converting member and the gear cover is mounted between the motion converting member and the gear cover.

  According to the wiper motor of the present invention, on the bottom side of the gear housing of the motion converting member, the connecting plate for swingably connecting the gear shaft provided on the axis of the sector gear and the output shaft is provided, and the connecting portion of the motion converting member The connecting portion is disposed on the bottom side of the gear housing, and the bent portion is disposed on the opening side of the gear housing. Accordingly, the motion converting member can be formed in a step shape, and the connecting portion can be disposed close to the worm wheel and the sector gear can be disposed close to the gear cover.

  Therefore, the worm wheel does not need to be formed with a protrusion as in the prior art (Patent Document 1), and the worm wheel can be formed in a flush shape without the protrusion. Therefore, it becomes possible to arrange the connecting shafts in a plurality of installation patterns, so that the worm wheel can be shared. Moreover, since it is not necessary to form a protrusion part in a worm wheel, generation | occurrence | production of a sink phenomenon can be suppressed and the shaping | molding precision of a worm wheel can be improved. In addition, a space for swaying the connecting plate can be secured between the sector gear and the worm wheel along the axial direction of the output shaft, and the connecting plate is swayed between the motion conversion member and the case cover as in the past (Patent Document 2). You don't have to move it. Therefore, it is possible to suppress the occurrence of problems such as early gear wear and gear chipping due to shallow engagement between the sector gear and the pinion gear.

  According to the wiper motor of the present invention, since the sliding guide member that smoothly slides between the motion conversion member and the gear cover is mounted between the motion conversion member and the gear cover, the relative movement of the motion conversion member with respect to the gear cover is smoothly performed. Thus, the load on the electric motor can be reduced.

It is a front view which shows the wiper motor which concerns on 1st Embodiment. It is sectional drawing which follows the AA line of FIG. It is an expanded sectional view which expands and shows the broken-line circle | round | yen B part of FIG. It is explanatory drawing explaining the assembly | attachment procedure of the motion conversion mechanism in the wiper motor of FIG. (A), (b), (c) is explanatory drawing explaining the operation state of the motion conversion mechanism in the wiper motor of FIG. It is explanatory drawing explaining the assembly | attachment procedure of the motion conversion mechanism in the wiper motor which concerns on 2nd Embodiment.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

  1 is a front view showing the wiper motor according to the first embodiment, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is an enlarged cross-sectional view showing a broken-line circle B portion in FIG. Each figure is shown.

  A wiper motor 10 shown in FIG. 1 is used as a drive source of a rear wiper device (not shown) for wiping a rear window glass of a vehicle such as an automobile. The wiper motor 10 includes a motor unit 20 and a gear as an electric motor. And a unit unit 30.

  The motor unit 20 includes a motor case 21 formed into a bottomed cylindrical shape by pressing (deep drawing) a magnetic material such as a steel plate, and the cross section is formed in a substantially arc shape inside. The paired permanent magnets 22 are fixed to face each other. Inside each permanent magnet 22, an armature 24 around which a coil 23 is wound in a predetermined winding manner is rotatably provided, and an armature shaft 25 as a rotating shaft is fixed through the rotation center of the armature 24. ing.

  A cylindrical commutator (commutator) 26 is fixed to a substantially intermediate portion along the axial direction of the armature shaft 25, and the end of the coil 23 is electrically connected to the commutator 26. A pair of brushes 27 are in sliding contact with the outer peripheral portion of the commutator 26, whereby a drive current is supplied to each brush 27 from an in-vehicle controller (not shown), whereby the coil 23 is passed through the commutator 26. A drive current flows through the armature 24, and a rotational force (electromagnetic force) is generated in the armature 24. As a result, the armature shaft 25 rotates at a predetermined rotation direction / rotation speed.

  The armature shaft 25 protrudes from the motor case 21 and extends into the gear housing 31 of the gear unit portion 30. On the outer peripheral surface of the armature shaft 25 on the protruding end side (left end side in the figure), a helical tooth portion 28a is provided. The worm 28 having the above is integrally formed. Here, the worm 28 is formed by, for example, rolling. The worm 28 rotates integrally with the armature shaft 25 by supplying a drive current to the motor unit 20.

  As shown in FIGS. 1 to 3, the gear unit 30 includes a gear housing 31 formed in a bottomed shape, a gear mechanism 40 rotatably accommodated in the gear housing 31, and an opening of the gear housing 31. And a gear cover 32 that closes the door. Here, the gear mechanism 40 is formed of a speed reduction mechanism 41 and a motion conversion mechanism 42.

  The speed reduction mechanism 41 is formed by a worm 28 formed on the armature shaft 25 and a worm wheel 43 rotatably accommodated in the gear housing 31. The worm wheel 43 is formed by injection molding a resin material such as molten plastic, and is a large-diameter gear (helical gear) that occupies approximately half of the bottom area of the gear housing 31. A tooth portion 43 a is formed on the radially outer side of the worm wheel 43, and the tooth portion 43 a is engaged with the tooth portion 28 a of the worm 28. As a result, the rotation of the armature shaft 25 is decelerated to a predetermined speed, and the torque that has been increased in torque is output from the worm wheel 43.

  The worm wheel 43 is accommodated in a deep bottom accommodating portion 31 a that is deeper than the bottom surface P <b> 1 of the gear housing 31. The rotation center shaft 43 b of the worm wheel 43 passes through the bottom of the deep bottom housing portion 31 a of the gear housing 31 and is rotatably supported by the gear housing 31.

  A bottomed connecting hole 43c as a connecting shaft is formed at a position away from the rotation center shaft 43b of the worm wheel 43 by a predetermined amount radially outward. The connection holes 43c are provided at four locations along the circumferential direction of the worm wheel 43, and each connection hole 43c has the same distance from the rotation center shaft 43b.

  The thickness dimension along the axial direction of the worm wheel 43 is set to be approximately the same as the depth dimension of the deep bottom accommodating portion 31a of the gear housing 31, and the side surface P2 of the worm wheel 43, that is, the upper surface of each connection hole 43c ( 2 and 3, the bottom surface P1 of the gear housing 31 and the axial position thereof substantially coincide with each other. Further, the side surface P2 of the worm wheel 43 is formed in a flush shape, and there is no protrusion that protrudes outward from the side surface P2 with the side surface P2 as a reference position. Therefore, when the worm wheel 43 is injection-molded, the occurrence of a sink phenomenon due to the conventional molding of the protruding portion is suppressed, and the molding accuracy of the worm wheel 43 is improved.

  The motion conversion mechanism 42 includes a pinion gear 44 c of the output shaft 44, a motion conversion member 45, a connecting plate 46, and a sliding guide member 47. The motion conversion mechanism 42 converts the rotational motion of the motor unit 20 (armature shaft 25) into a swing motion via the speed reduction mechanism 41 and transmits it to the output shaft 44 (wiper member).

  As shown in FIG. 2, the output shaft 44 is made of a steel round bar, the proximal end side is disposed in the gear housing 31, and the distal end side extends out of the gear housing 31. The output shaft 44 is rotatably supported by a boss portion 31 b provided integrally with the gear housing 31. A rubber seal member 48 is mounted between the output shaft 44 and the boss portion 31 b, and the seal member 48 prevents rainwater, dust, and the like from entering the gear housing 31.

  On the distal end side (upper side in the figure) of the output shaft 44, a serration portion 44a to which a proximal end side of a wiper arm (not shown) forming a wiper member is fixed so as not to be relatively rotatable, and a proximal end side of the wiper arm are disposed on the output shaft 44. A male screw portion 44b to which a fixing screw (not shown) for fixing to the screw is screwed is integrally provided.

  A pinion gear 44c formed of a sintered material or the like is provided on the base end side (lower side in the drawing) of the output shaft 44 so as to be integrally rotatable. The pinion gear 44c is formed of a small-diameter spur gear. A resin cap 49 formed in a bowl shape is attached to the center portion of the pinion gear 44c, and the resin cap 49 is in sliding contact with the inner surface of the gear cover 32. The resin cap 49 plays a role of facilitating relative rotation of the pinion gear 44c with respect to the gear cover 32.

  The motion conversion member 45 is formed in a step shape (step shape) from a metal material such as an iron plate, and includes a connecting portion 45a, a sector gear 45b, and a bent portion 45c.

  The connecting portion 45a is disposed on the worm wheel 43 side, and a connecting pin 50 that is rotatably inserted into the connecting hole 43c of the worm wheel 43 is fixed to the connecting portion 45a. That is, the connecting portion 45a is rotatably connected to the connecting hole 43c via the connecting pin 50. Here, the insertion position of the connection pin 50 can be set in a plurality of installation patterns, that is, the connection pin 50 can be inserted into any connection hole 43c in each connection hole 43c. The moving position, stop position, etc. can be changed.

  The sector gear 45b is a substantially sector spur gear, meshed with the pinion gear 44c, and a gear shaft 51 is fixed to the axis of the sector gear 45b. The bent portion 45c is provided between the connecting portion 45a and the sector gear 45b. The bent portion 45c has the connecting portion 45a disposed on the bottom side (bottom surface P1 side) of the gear housing 31, and the sector gear 45b is opened in the gear housing 31. It is arranged on the part side (gear cover 32 side).

  On the bottom surface P1 side of the gear housing 31 in the sector gear 45b of the motion converting member 45, a connecting plate 46 formed in a predetermined shape by press forming a steel plate or the like is provided. A first pin hole 46a and a second pin hole 46b are formed on both sides in the longitudinal direction of the connecting plate 46. An output shaft 44 is swingably mounted in the first pin hole 46a, and the second pin hole 46b. A gear shaft 51 of the motion converting member 45 is swingably mounted on the motor. As described above, the connecting plate 46 connects the output shaft 44 and the gear shaft 51 so as to be swingable.

  Here, the distance between the first pin hole 46a and the second pin hole 46b is set to the sum of the pitch circle radius dimension of the sector gear 45b and the pitch circle radius dimension of the pinion gear 44c. The meshing state of the meshing portion G of each gear 44c, 45b is held without rattling.

  The distance between the side surface P2 of the worm wheel 43 and the side surface P3 of the sector gear 45b is longer than the thickness of the connecting plate 46 by the bent portion 45c, and the distance between the side surface P2 of the worm wheel 43 and the sector gear 45b. A swing space S having a height dimension h is formed between the side surface P3 and the side surface P3 as shown in FIG. The swing space S is a space that allows the connecting plate 46 to swing when the wiper motor 10 is driven, so that the connecting plate 46 can swing between the bottom side of the gear housing 31 and the motion converting member 45. It has become.

  The sliding guide member 47 is formed in a predetermined shape from a resin material such as plastic and is mounted on the gear cover 32 side of the motion conversion member 45, that is, provided between the motion conversion member 45 and the gear cover 32. The sliding guide member 47 is in sliding contact with the inner side surface of the gear cover 32, thereby facilitating sliding (relative movement) of the motion conversion member 45 with respect to the gear cover 32.

  The sliding guide member 47 is formed in a step shape following the step shape of the motion converting member 45 and covers substantially the entire surface of the motion converting member 45 on the gear cover 32 side. The sliding guide member 47 is attached to the first cap portion 47a attached to the connecting pin 50 fixed to the connecting portion 45a of the motion converting member 45 and the gear shaft 51 fixed to the sector gear 45b of the motion converting member 45. Second cap portion 47b. As a result, the sliding guide member 47 can be mounted with high accuracy without shifting along the shape of the motion converting member 45. The second cap portion 47b side of the sliding guide member 47 is in sliding contact with the gear cover 32.

  Next, a procedure for assembling the motion conversion mechanism 42 forming the wiper motor 10 will be described in detail with reference to the drawings.

  FIG. 4 is an explanatory diagram for explaining an assembly procedure of the motion conversion mechanism in the wiper motor of FIG. In FIG. 4, the motor case 21, the gear housing 31, the gear cover 32, and the like are omitted for easy understanding.

  As shown in FIG. 4, first, a wiper motor subassembly SA1 is prepared in which the armature shaft 25, the worm wheel 43, and the like are assembled to the motor case 21 and the gear housing 31 (see FIG. 1). In addition, an output shaft assembly SA2 in which the pinion gear 44c and the connecting plate 46 are mounted on the output shaft 44 is prepared. Furthermore, a motion converting member 45 and a sliding guide member 47 to which the connecting pin 50 and the gear shaft 51 are fixed are prepared.

  Next, the output shaft 44 is inserted into the boss portion 31 b of the gear housing 31 with the male screw portion 44 b side of the output shaft 44 facing from the opening side of the gear housing 31 as indicated by an arrow (1) in the drawing. After that, as shown by the arrow (2) in the figure, the motion conversion member 45 is faced, the connection hole 43c that meets the specifications of each connection hole 43c of the worm wheel 43 is selected, and the connection pin 50 is mounted. Further, the gear shaft 51 is mounted in the second pin hole 46 b of the connecting plate 46. At this time, the positions of the worm wheel 43 and the connecting plate 46 are appropriately adjusted so that the connecting pin 50 and the gear shaft 51 can be easily mounted. As a result, the pinion gear 44 c and the sector gear 45 b are engaged in the gear housing 31.

  Next, as shown by the arrow (3) in the figure, the sliding guide member 47 is faced and attached to the motion converting member 45. At this time, the first cap portion 47a of the sliding guide member 47 is made to correspond to the connecting pin 50, and the second cap portion 47b is made to correspond to the gear shaft 51, respectively. The sliding guide member 47 is integrally provided with a hooking claw 47c. By hooking the hooking claw 47c on the motion converting member 45, the sliding guide member 47 is prevented from falling off the motion converting member 45. Thereby, the assembly | attachment to the gear housing 31 of the motion conversion mechanism 42 is completed.

  Next, the operation of the wiper motor 10 formed as described above will be described in detail with reference to the drawings.

  FIGS. 5A, 5B, and 5C are explanatory views for explaining the operation state of the motion conversion mechanism in the wiper motor of FIG. In FIG. 5, component parts other than main parts are omitted for easy understanding of the description.

  When a driver or the like operates a wiper switch (not shown), a drive current is supplied to the motor unit 20 shown in FIG. 1 and the rotation of the worm 28 is transmitted to the worm wheel 43. Then, from the state shown in FIG. 5A, that is, the state where the wiper member is in the lower reverse position (storage position), the worm wheel 43 is increased in torque in the direction indicated by the arrow I (clockwise direction) in the figure. Rotate in the state. Along with this, the connecting portion 45a of the motion converting member 45 also rotates in the clockwise direction.

  Thereafter, the sector gear 45b swings and the pinion gear 44c meshing with the sector gear 45b swings clockwise about the rotation center C. As a result, the wiper member attached to the output shaft 44 swings in the direction of the arrow M1, and starts swinging from the lower inversion position (storage position) toward the upper inversion position.

  Thereafter, as shown by an arrow II in FIG. 5B, when the worm wheel 43 further rotates in the clockwise direction, the connecting plate 46 swings in the swing space S (see FIG. 3). The connecting plate 46 enters between the worm wheel 43 and the sector gear 45b. The pinion gear 44c also continues to swing around the rotation center C. As a result, the wiper member attached to the output shaft 44 continues to swing in the direction of the arrow M2 and approaches the upper inversion position.

  At this time, since the sufficient swinging space S is secured between the worm wheel 43 and the sector gear 45b by the bent portion 45c, the connecting plate 46 and the worm wheel 43 do not interfere with each other. Even if a large load is applied to the wiper member due to snow or the like, the connecting plate 46 is disposed on the bottom side of the gear housing 31 so that the output shaft 44 does not bend and the gears 44c and 45b are not bent. There is no such thing as a shallow mesh.

  Next, as indicated by an arrow III in FIG. 5C, when the worm wheel 43 further rotates in the clockwise direction, the pinion gear 44c starts to rotate in the counterclockwise direction as the sector gear 45b swings. . Here, the switching point at which the rotation direction of the pinion gear 44c is switched is a point at which the wiper member is in the upper reverse position. Thereafter, the wiper member attached to the output shaft 44 swings in the direction of the arrow M3 and starts swinging from the upper reverse position toward the lower reverse position (storage position). In this way, the rotational motion of the worm wheel 43 (motor unit 20) is converted into a swing motion by the motion conversion mechanism 42 and transmitted to the output shaft 44, that is, the wiper member. Thus, the wiper member is driven to swing between predetermined inversion positions (wiping range) on the rear window glass, and can wipe away rainwater, dust, and the like attached to the rear window glass.

  According to the wiper motor 10 according to the first embodiment formed as described above, the gear shaft 51 and the output shaft 44 provided at the shaft center of the sector gear 45b are swung on the bottom side of the gear housing 31 of the motion conversion member 45. A connecting plate 46 that is movably connected is provided, the connecting portion 45 a is disposed on the bottom side of the gear housing 31 between the connecting portion 45 a of the motion converting member 45 and the sector gear 45 b, and the sector gear 45 b is opened in the gear housing 31. A bent portion 45c is provided on the side. Thereby, the motion converting member 45 can be formed in a stepped shape, and the connecting portion 45a can be disposed close to the worm wheel 43 and the sector gear 45b can be disposed close to the gear cover 32.

  Therefore, it is not necessary to form a protrusion on the worm wheel 43 as in the prior art (Patent Document 1), and the worm wheel 43 can be formed in a flush shape with no protrusion. Therefore, the connection holes 43c can be arranged in a plurality of installation patterns, and as a result, the worm wheel 43 can be shared. Moreover, since it is not necessary to form a protrusion in the worm wheel 43, the occurrence of sink marks can be suppressed and the molding accuracy of the worm wheel 43 can be improved. Furthermore, the rocking space S of the connecting plate 46 can be ensured between the sector gear 45b along the axial direction of the output shaft 44 and the worm wheel 43, and between the motion conversion member and the case cover as in the past (Patent Document 2). Therefore, it is not necessary to swing the connecting plate. Therefore, it is possible to suppress the occurrence of problems such as early gear wear and gear chipping due to shallow engagement between the sector gear 45b and the pinion gear 44c.

  Further, according to the wiper motor 10 according to the first embodiment, the sliding guide member 47 that smoothly slides between the motion conversion member 45 and the gear cover 32 is mounted between the motion conversion member 45 and the gear cover 32. Therefore, the relative movement of the motion conversion member 45 with respect to the gear cover 32 can be smoothed, and the load on the motor unit 20 can be reduced.

  Next, a second embodiment of the present invention will be described in detail with reference to the drawings. Note that portions having the same functions as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 6 is an explanatory diagram for explaining a procedure for assembling the motion conversion mechanism in the wiper motor according to the second embodiment.

  The wiper motor according to the second embodiment differs from the first embodiment described above only in the shape of the worm wheel. As shown in FIG. 6, the worm wheel 60 has a thickness dimension at a portion having each connection hole 43 c along the axial direction of the worm wheel 60 as compared with the worm wheel 43 (see FIG. 4) according to the first embodiment. Only the thickness is increased, and the thickness dimension of the tooth portion 43a is relatively thin. That is, the worm wheel 60 employs a two-stage structure with the tooth portions 43a and the portions having the connection holes 43c. In this case, the reference position of the worm wheel 60 is the side surface P4 as shown in the drawing.

  Also in the second embodiment formed as described above, the same operational effects as those of the above-described first embodiment can be obtained. In the second embodiment, in addition to this, the length dimension of the connecting pin 50 can be increased. Therefore, the shake between the worm wheel 60 and the motion conversion member 45 can be effectively suppressed. Therefore, the gears can be engaged with each other more accurately, and the life of the wiper motor 10 (see FIG. 1) can be extended.

  It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, in each of the above embodiments, the worm wheels 43, 60 are provided with four connection holes 43c along the circumferential direction. However, the present invention is not limited to this, and the worm wheel can be allowed to be rigid. If it is within the range, the number can be freely set.

  In each of the above embodiments, the pinion gear 44c formed of a sintered material or the like and the motion converting member 45 formed of a metal material such as an iron plate are shown. However, the present invention is not limited to this, and the pinion gear 44c is not limited thereto. The motion converting member 45 may be formed of a resin material such as plastic.

  Further, in the present invention, the armature shaft 25 can be divided between the motor unit 20 and the gear unit unit 30, or four or more permanent magnets can be fixed to the motor case 21.

  In each of the above embodiments, the wiper motor 10 is applied to the drive source of the rear wiper device of a vehicle such as an automobile. However, the present invention is not limited to this, and the windshield glass of a vehicle such as an automobile is used. It can also be applied to a drive source of a front wiper device for wiping.

  Further, in each of the above embodiments, the wiper motor 10 is used as a drive source of a wiper device mounted on a vehicle such as an automobile. However, the present invention is not limited to this, and railroad vehicles, aircraft, ships, and the like. It can also be used as a drive source for the wiper device mounted on the.

10 Wiper motor 20 Motor part (electric motor)
DESCRIPTION OF SYMBOLS 21 Motor case 22 Permanent magnet 23 Coil 24 Armature 25 Armature shaft 26 Commutator 27 Brush 28 Worm 28a Tooth part 30 Gear unit part 31 Gear housing 31a Deep bottom accommodating part 31b Boss part 32 Gear cover 40 Gear mechanism 41 Deceleration mechanism 42 Motion conversion mechanism 43 Worm wheel 43a Teeth 43b Rotation center shaft 43c Connection hole (connection shaft)
44 Output shaft 44a Serration portion 44b Male thread portion 44c Pinion gear 45 Motion conversion member 45a Connection portion 45b Sector gear 45c Bending portion 46 Connection plate 46a First pin hole 46b Second pin hole 47 Slide guide member 47a First cap portion 47b Second cap part 47c hooked claw 48 sealing member 49 resin cap 50 the coupling pin 51 the gear shaft 60 worm wheel G meshing portion S swinging space P1 bottom P2~P4 side SA1 wiper motor subassembly SA2 output shaft assembly

Claims (2)

The rotational motion of the electric motor is converted into oscillating motion comprises a motion converting mechanism for transmitting the output shaft, a wiper motor that swings driven between predetermined reversing position wiper member mounted on said output shaft ,
A bottomed gear housing that houses the motion conversion mechanism;
A gear cover for closing the opening of the gear housing;
A pinion gear provided on the output shaft so as to be integrally rotatable, and housed in the gear housing;
A worm extending into the gear housing and rotated by the electric motor;
A worm wheel that is rotatably accommodated in the gear housing and meshes with the worm;
A connecting shaft provided at a position away from the rotation center axis of the worm wheel;
A motion conversion member having a connecting portion rotatably connected to the connecting shaft and a sector gear meshing with the pinion gear;
A connecting plate that is provided on the bottom side of the gear housing of the motion conversion member and that connects the gear shaft provided on the axis of the sector gear and the output shaft in a swingable manner;
Provided between the said and the connecting portion of the motion converting member sector gear, the connecting portion disposed on the bottom side of the gear housing, and a bent portion positioning the sector gear on the opening side of the gear housing A wiper motor characterized by that.   2. The wiper motor according to claim 1, wherein a sliding guide member that smoothly slides between the motion converting member and the gear cover is mounted between the motion converting member and the gear cover.

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