JP4369324B2 - Wiper motor - Google Patents

Description

  The present invention relates to a wiper motor that reciprocates a wiper that wipes a surface to be wiped.

  Among wiper motors for driving a wiper, in particular, a wiper motor for a rear wiper of a vehicle includes a swing mechanism that converts a one-way continuous rotational motion of the motor into a reciprocating rotational motion of an output shaft (for example, Patent Documents). 1).

  Such a wiper motor is provided with a wheel gear that is rotatably supported by a hollow container (housing) and continuously rotates in one direction by the driving force of the motor. The wheel gear includes a power conversion member (swing member). ) Is connected to the sector gear. The sector gear is rotatably connected at one end by a crank pin provided at a position different from the gear shaft of the wheel gear (position displaced in the radial direction), and a meshing portion (tooth portion) is formed at the other end. ing. The meshing portion meshes with a gear member that is integrally fixed to an output shaft that is rotatably supported by the housing. The sector gear is sandwiched between two holding members provided on both sides in the thickness direction (output shaft direction), and one end of each of the two holding members is provided on the sector gear. While being rotatably connected to the fixed shaft, each other end is rotatably connected to the output shaft.

  In the wiper motor configured as described above, the one-way continuous rotational motion of the wheel gear is converted into the reciprocating swing motion of the sector gear, and the gear member meshed with the meshing portion of the sector gear is reciprocally rotated, whereby the output shaft is reciprocally rotated. To do. At this time, the two holding members that connect the fixed shaft and the output shaft of the sector gear are reciprocally swung together with the sector gear so as to maintain the pitch between the fixed shaft and the output shaft of the sector gear. . In addition, since the sector gear is sandwiched between the two holding members, the engagement margin between the meshing portion and the gear member along the thickness direction of the sector gear is maintained (in the thickness direction of the sector gear). As a result, a stable meshing state between the sector gear and the gear member is ensured.

However, in the wiper motor having the above-described configuration, as described above, the two holding members provided on both sides in the thickness direction of the sector gear are configured to reciprocally swing together with the sector gear, so one holding provided on the wheel gear side is provided. It is necessary to secure a space for the member to swing back and forth between the sector gear and the wheel gear. For this reason, it is necessary to design a large space inside the housing, leading to an increase in the size of the apparatus.
JP-A-9-224350

  In view of the above-described facts, an object of the present invention is to provide a wiper motor that can maintain a good meshing state between a swing member and a gear member and can reduce the size of the apparatus.

  In order to solve the above-described problem, a wiper motor according to a first aspect of the present invention provides a housing that rotatably supports an output shaft to which a wiper is directly or indirectly coupled, and a unidirectional continuous rotational motion of a rotating member. A wiper motor that houses a swing mechanism that converts the output shaft into reciprocating rotational motion, the gear member being integrally provided on the output shaft and having gear teeth formed on the outer periphery, and one end connected to the rotating member A rocking member that has a meshing portion that meshes with the gear member on the other end side, and that converts a continuous rotational motion of the rotating member into a reciprocating rocking motion of the meshing portion, and a thickness direction of the rocking member A holding member that is disposed on one side and that connects a rocking central axis and the output shaft at the meshing portion of the rocking member to maintain a distance between both shafts, and the gear member includes the holding member The end of the gear tooth opposite to the A connecting wall for connecting adjacent each other, the engagement portion of the swing member by said holding member and said connecting wall is sandwiched in the thickness direction on both sides said, is characterized by.

  In the wiper motor according to claim 1, the one-way continuous rotational motion of the rotating member is converted into the reciprocating swinging motion of the meshing portion of the swinging member, and the gear member engaged with the meshing portion of the swinging member is reciprocally rotated. . Since this gear member is provided integrally with the output shaft, the output shaft is reciprocated together with the gear member, and the wiper directly or indirectly connected to the output shaft is reciprocated along with the reciprocal rotation of the output shaft. Driven.

  Here, in this wiper motor, the rocking center shaft and the output shaft in the meshing portion of the rocking member are connected by a single holding member provided on one side in the thickness direction of the rocking member. Therefore, the inter-axis distance (inter-axis pitch) between the oscillation center axis of the oscillation member and the output axis is maintained. Moreover, since the meshing portion of the swing member is sandwiched on both sides in the thickness direction by the holding member on one side in the thickness direction and the connecting wall of the gear member on the other side, the thickness direction of the swing member Even if there are no holding members on both sides, the meshing margin between the gear teeth and the meshing portion along the thickness direction of the rocking member is maintained (disengagement of the rocking member in the thickness direction is prevented). . Thereby, the favorable meshing state of the rocking member and the gear member can be maintained.

  Further, in this wiper motor, a single holding member is arranged on one side in the thickness direction of the oscillating member, rather than a configuration in which the holding members are arranged on both sides in the thickness direction of the oscillating member unlike the conventional wiper motor. With this configuration, the space for arranging the holding member can be reduced, and the overall configuration of the apparatus can be reduced in size.

  According to a second aspect of the present invention, a wiper motor according to a second aspect of the present invention provides a housing that rotatably supports an output shaft to which a wiper is directly or indirectly connected, and a unidirectional continuous rotational motion of a rotating member is a reciprocating rotational motion of the output shaft. A wiper motor that houses a swing mechanism for conversion, and is provided between the output shaft and the swing mechanism, and when a load greater than a predetermined value is applied around the axis of the output shaft, A clutch device that relatively idles the swinging mechanism and the output shaft, and the clutch device is supported in a state of being secured to the one side in the axial direction and rotatable relative to the output shaft; And a gear member that is reciprocally rotated around the output shaft by a driving force from the swing mechanism, and is positioned on the other side in the axial direction of the output shaft with respect to the gear member and the output shaft In The shaft is supported so as to be unrotatable around the axis and movable along the axial direction, and rotates together with the output shaft and engages with the gear member, and in the engaged state with the gear member, the gear An engagement plate that rotates integrally with a member; and the engagement plate that is located on the other side in the axial direction of the output shaft with respect to the engagement plate and that is directed from the engagement state toward the other side in the axial direction of the output shaft. An elastic member that provides resistance against axial movement, and the swing mechanism has a meshing portion that is connected to the rotating member at one end and meshes with the gear member at the other end. A swing member that converts the continuous rotational motion of the rotating member into a reciprocating swing motion of the meshing portion; and a position opposite to the engagement plate in the thickness direction of the swing member. A swing center axis in the meshing portion; A holding member that connects the output shaft and maintains a distance between the two shafts, and the gear member is a connection that connects the ends of the gear teeth opposite to the holding member adjacent to each other. It has a wall, The said meshing part of the said rocking | swiveling member is pinched | interposed by the said thickness direction both sides by this connection wall and the said holding member.

  In the wiper motor according to claim 2, in a normal use state, the gear member of the clutch device and the engagement plate are engaged with each other, and the engagement plate is changed from the engagement state of the gear member and the engagement plate. Even if it tries to move in the direction of the output shaft axis, since the predetermined drag is applied by the elastic member, the engagement state is maintained.

  In this state, when the rotating member is continuously rotated in one direction, the one-way continuous rotating motion is converted into the reciprocating swinging motion of the meshing portion of the swinging member, and the gear member meshed with the meshing portion of the swinging member. Is reciprocated around the output shaft. When the gear member is reciprocally rotated, a driving force is transmitted from the gear member to the engagement plate. Since the engagement plate is supported so as not to rotate around the axis with respect to the output shaft, the output shaft is rotated integrally with the engagement plate. As a result, the wiper connected directly or indirectly to the output shaft is driven to reciprocate as the output shaft reciprocates.

  On the other hand, for example, when a load (excessive external force) is applied around the axis of the output shaft via the wiper, the output shaft is reversed or restrained. Then, a rotational force in the direction of relative rotation with the gear member acts on the engagement plate that rotates integrally with the output shaft. When this rotational force exceeds a predetermined value (that is, when the load around the axis acting on the output shaft exceeds a predetermined value), the counter force applied by the elastic member is overcome and the engagement plate moves in the output axis direction. The engagement state is released by forcibly moving, and the engagement plate, that is, the output shaft, idles with respect to the gear member. Thereby, it is possible to prevent an excessive external force from acting on each component after the gear member (configuration from the output shaft such as the swinging mechanism and the motor main body toward the armature side).

  Here, in this wiper motor, the rocking center shaft and the output shaft in the meshing portion of the rocking member are connected by a holding member provided on one side in the thickness direction of the rocking member. Therefore, the inter-axis distance (inter-axis pitch) between the oscillation center axis of the oscillation member and the output axis is maintained. In addition, the meshing portion of the swing member is sandwiched on both sides in the thickness direction by the holding member on one side in the thickness direction and the connecting wall of the gear member on the other side (engagement plate side). Even if there is no holding member on both sides in the thickness direction of the moving member, the meshing margin between the gear teeth and the meshing portion along the thickness direction of the swinging member is maintained (engagement in the thickness direction of the swinging member) Detachment is prevented). Thereby, the favorable meshing state of the rocking member and the gear member can be maintained.

  Further, in this wiper motor, for example, if the holding member is arranged on the side opposite to the rotating member in the thickness direction of the swinging member, the interference between the holding member and the rotating member is prevented. The degree of freedom in setting the connection position between the moving member and the rotating member is improved.

  Further, in this wiper motor, a single holding member is arranged on one side in the thickness direction of the oscillating member, rather than a configuration in which the holding members are arranged on both sides in the thickness direction of the oscillating member unlike the conventional wiper motor. With this configuration, the space for arranging the holding member can be reduced, and the overall configuration of the apparatus can be reduced in size.

  Further, when holding members are arranged on both sides in the thickness direction of the rocking member (on both sides in the thickness direction of the gear member) as in the case of a conventional wiper motor, one holding member becomes an obstacle, and the engagement plate is Although it cannot be engaged with the gear member, in this wiper motor, the holding member is disposed only on the side opposite to the engagement plate in the thickness direction of the swing member (thickness direction of the gear member). The holding member does not obstruct the engagement between the gear member and the engagement plate, and it is possible to prevent the arrangement of the clutch device from being restricted.

  The wiper motor according to a third aspect of the present invention is the wiper motor according to the second aspect, wherein the elastic member is a coil spring wound around the axis of the output shaft and compressible in the axial direction of the output shaft, The coil spring is characterized in that it is arranged between the engagement plate and a large-diameter portion that is large in the radial direction of the output shaft and cannot move in the axial direction.

  In the wiper motor according to claim 3, since the elastic member is a coil spring wound around the output shaft and compressible in the axial direction of the output shaft, the spring characteristic is stable. That is, for example, when the elastic member is a rubber member, grease applied to the clutch device may adhere to the rubber member and deteriorate, but in the case of a coil spring, there is a risk of deterioration due to adhesion of grease or the like. The spring characteristics are stable because there is no. In addition, since the coil spring is disposed between the engagement plate and the large-diameter portion that has a large diameter in the radial direction of the output shaft and cannot be moved in the axial direction, the engagement plate is attached to the gear member. It can be stably pressed and can provide a stable drag.

  A wiper motor according to a fourth aspect of the present invention is the wiper motor according to any one of the first to third aspects, wherein the gear member has an outer periphery opposite to the gear teeth via the connecting wall. The circumferential surface is concentric with the output shaft, and the circumferential surface of the gear member is rotatably held with respect to the housing.

  In the wiper motor according to claim 4, the gear member supported by the output shaft has a circumferential surface on the side opposite to the gear teeth via a connecting wall, and the circumferential surface can be rotated by the housing. Is retained. That is, in this wiper motor, a gear member to which a load is input from the swing member is supported by the housing, and the output shaft is supported by the housing via the gear member. Therefore, the support strength of the gear member and the output shaft with respect to the housing can be improved.

Wiper motor according to the invention of claim 5, wherein, in the wiper motor according to any one of claims 1 to 4, wherein the gear member is made of a sintered metal molding the powder alloy, sintered in a metal It is characterized in that lubricating oil is impregnated.

The wiper motor according to claim 5, the gear member is, since a sintered metal molding the powder alloy can be manufactured with high precision by a so-called "powder metallurgy", yet good yield of material. Further, the gear member which is a sintered metal, because themselves are oil-containing lubricating oil, it is possible to have self-lubricating properties to gear meshing teeth portions meshed rocking member, wear and abnormal noise Can be prevented. Further, as in the wiper motor according to claim 2, when the gear member is engaged with the engagement plate, the engagement portion of the gear member with the engagement plate can be provided with self-lubricating properties and wear. In addition, abnormal noise can be prevented.
A wiper motor according to a sixth aspect of the present invention is the wiper motor according to any one of the second to fourth aspects, wherein the engagement plate is made of a sintered metal obtained by molding a powder alloy, It is characterized in that lubricating oil is impregnated.
In the wiper motor according to the sixth aspect, since the engagement plate is a sintered metal obtained by molding a powder alloy, the engagement plate can be manufactured with high accuracy by a so-called “powder metallurgy method” and the material yield is good. Further, since the engagement plate made of sintered metal itself contains lubricating oil, the portion engaged with the gear member can be provided with self-lubricating properties, and wear and abnormal noise can be prevented. .

  1 and 2 are perspective views showing the overall configuration of the wiper motor 90 according to the embodiment of the present invention, and FIG. 3 is an exploded perspective view showing the configuration of the wiper motor 90. Yes. Further, in FIG. 4 to FIG. 8, the configuration of the wiper motor 90 is shown in cross-sectional views.

  The wiper motor 90 is a wiper driving motor for driving a wiper device of the vehicle, and includes a motor main body 92, a swing mechanism 94, and a clutch device 10.

  As shown in FIGS. 4 and 6, the motor main body 92 includes a yoke housing 98. The yoke housing 98 has a bottomed shape whose one end in the axial direction is drawn, and a cross section in the orthogonal direction of the rotating shaft 110 is formed in a flat cylindrical shape with the axial direction of the output shaft 12 as a short direction. The side is integrally attached to the housing 96. A bearing 102 is disposed on the bottom wall 100 of the yoke housing 98. On the other hand, an end housing 104 made of an insulating resin is fixed to the other end of the yoke housing 98.

  A bearing 106 is disposed at the center portion of the end housing 104. The rotating shaft 110 of the armature 108 is supported by the bearing 106 and the bearing 102 of the yoke housing 98, and the armature 108 is accommodated in the yoke housing 98. A magnet 112 is fixed to the inner peripheral wall of the yoke housing 98 facing the armature 108.

  The end housing 104 holds a brush 114 via a brush case. The brush 114 is formed in a prismatic shape and is pressed against the commutator 116 of the armature 108. Further, a coupling pigtail 118 is drawn out from the brush 114, and the tip of the pigtail 118 is connected to a connection line for power feeding.

  The rotating shaft 110 of the motor main body 92 (armature 108) is coupled to the worm gear 122 of the swing mechanism 94 by a coupling 120.

  One end of the worm gear 122 is rotatably supported by the housing 96 via the bearing 124, and the other end is rotatably supported by the housing 96 via the bearing 126. The worm gear 122 meshes with a worm wheel 128 as a rotating member.

  The worm wheel 128 is disposed on one side with respect to the axis of the worm gear 122 and is housed in the housing 96 in a state of meshing with the worm gear 122, and rotates around the rotation axis 130 perpendicular to the axis of the worm gear 122 (rotation axis 110). Rotate to.

  The worm wheel 128 is connected to a sector gear 132 as a swing member. The sector gear 132 is rotatably connected at one end by a support shaft (crank pin) 134 provided at a position different from the rotating shaft 130 of the worm wheel 128 (position displaced in the radial direction), and at the other end is an engaging portion. The tooth part 136 is formed. The teeth 136 are engaged (engaged) with a gear member 28 of the clutch device 10 described later.

  Furthermore, a holding lever 138 as a holding member is disposed on one side in the thickness direction of the sector gear 132 (the side opposite to the worm wheel 128). One end of the holding lever 138 is connected to the swing center shaft 140 (support shaft provided at the center of the pitch circle of the tooth portion 136) in the tooth portion 136 of the sector gear 132, and the other end rotates to the housing 96. It is rotatably connected to an output shaft 12 that is freely supported. Thereby, the center distance (inter-axis pitch) between the oscillation center shaft 140 and the output shaft 12 is maintained, and the meshing state of the sector gear 132 and the gear member 28 along the radial direction of the output shaft 12 is maintained. Thus, the sector gear 132 is reciprocally swung by the rotation of the worm wheel 128, and the gear member 28 described later is reciprocally rotated by the reciprocating swing operation of the sector gear 132.

  A sliding member 147 made of a resin material or the like is attached to the holding lever 138 on the side opposite to the sector gear 132, and the sliding member 147 slides on a back cover 148 that closes the back side of the housing 96. Abutting as possible. Thereby, the movement along the thickness direction of the holding member 138 (the axial direction of the output shaft 12) is restricted. Further, since the output shaft 12 is disposed on the opposite side of the worm wheel 128 with respect to the axis of the worm gear 122, the sector gear 132 having one end connected to the worm wheel 128 intersects the axis of the worm gear 122 (a state of a twisted position). ) And the tooth portion 136 at the other end meshes with the gear member 28.

  On the other hand, as shown in FIGS. 9 and 10, the output shaft 12 has a distal end side (upper side in FIGS. 9 and 10) formed in a circular cross section to form a cylindrical portion 13, and a proximal end side (in FIGS. 9 and 10). The lower side has a substantially rectangular cross section (a so-called “cross-sectional double D-cut shape”) including a pair of planes formed on opposite sides 180 degrees in the circumferential direction and a pair of circumferential surfaces continuous with these planes. The relative rotation restricting portion 14 is formed.

  As shown in FIGS. 5 and 7, the cylindrical portion 13 of the output shaft 12 is rotatably supported by a bearing member 50 fixed to the housing 96. On the other hand, on the distal end side (the cylindrical portion 13 side) of the relative rotation restricting portion 14, a plurality of protrusions along the axial direction are formed on the circumferential surface portion, and a rotation stop portion 16 is provided. A retaining portion 18 is provided at the base end protruding end.

  An engagement base 20 as a large-diameter portion having a large diameter in the radial direction of the output shaft 12 is fixed to the rotation stop portion 16 of the relative rotation restricting portion 14 coaxially with the output shaft 12. The engagement base 20 is formed in a disk shape in which a support hole 22 having a substantially rectangular cross section (cross section double D-cut shape) corresponding to the relative rotation restricting portion 14 of the output shaft 12 is formed in the center portion. Is fixed to the rotation stop 16 so that it always rotates integrally with the output shaft 12 (it is impossible to move in the axial direction with respect to the output shaft 12). In addition, a stopper portion 26 that protrudes along the radial direction (the radial direction of the output shaft 12) is provided on the periphery of the engagement base 20. This stopper portion 26 corresponds to a stopper protrusion 142 described later formed on the housing 96.

  As described above, the output shaft 12 and the engagement base 20 are not limited to be formed separately and fixed. For example, the output shaft 12 and the engagement base 20 are integrally formed by cold forging or the like. (A configuration in which a flange-shaped large-diameter portion is integrally formed on the output shaft) may be employed.

  On the other hand, the aforementioned gear member 28 is coaxially attached to the output shaft 12 in the retaining portion 18 of the relative rotation restricting portion 14. The gear member 28 is formed in a cylindrical shape in which a shaft hole 30 having a circular cross section is formed in the center portion, and the retaining portion 18 of the output shaft 12 is inserted into the shaft hole 30 and attached to the protruding end of the retaining portion 18. By being prevented from being removed by the retaining clip 32, it is supported in a state of being secured to the one side in the axial direction (opposite side of the engagement base 20) with respect to the output shaft 12 so as to be rotatable. In the present embodiment, the gear member 28 is a sintered metal manufactured by a so-called “powder metallurgy method” in which a powder alloy is put into a molding die, compression-molded, and heated and sintered. Contains lubricating oil.

  Gear teeth 34 are formed on the outer periphery of the gear member 28 on one end side in the axial direction (the side opposite to the engagement base 20). The gear teeth 34 mesh with the teeth 136 of the sector gear 132 of the swing mechanism 94 described above. When a driving force is input from the sector gear 132, the gear member 28 rotates around the output shaft 12. ing.

  Also, as shown in FIG. 10, the gear member 28 is connected to the end of the gear tooth 34 on the other end side in the axial direction of the gear tooth 34 (on the engagement base 20 side, opposite to the holding lever 138 described above). A connecting wall 35 is formed. As shown in FIG. 11, the connecting wall 35 sandwiches the tooth portion 136 of the sector gear 132 together with the holding lever 138 on both sides in the thickness direction (the connecting wall 35 faces the end surface on one side in the thickness direction of the tooth portion 136. In addition, the movement of the sector gear 132 in the thickness direction is restricted by the holding lever 138 facing the end surface on the other side in the thickness direction of the tooth portion 136).

  Further, the gear member 28 has an outer periphery opposite to the gear teeth 34 via a connecting wall 35 and a circumferential surface 36 concentric with the output shaft 12, and this circumferential surface 36 is shown in FIGS. 7, the bearing member 52 fixed to the housing 96 is rotatably held (supported). That is, the gear member 28 includes a disc-shaped flange portion coaxial with the output shaft 12 on the other axial end side of the gear teeth 34, and the outer peripheral surface (circumferential surface 36) of the flange portion is a bearing member. 52 is supported.

  Furthermore, on the end surface of the gear member 32 on the other end side in the axial direction (on the side of the engagement base 20 and on the other side in the axial direction of the output shaft 12), there are four protrusions projecting toward the engagement base 20 at the peripheral edge thereof. An engagement protrusion 37 is provided. These four engagement protrusions 37 are provided concentrically with respect to the gear member 28, and are not equally spaced from each other along the circumferential direction of the gear member 28 (adjacent intervals along the circumferential direction are different from each other). As provided). These engagement protrusions 37 correspond to engagement plates 38 to be described later.

  On the other hand, the relative rotation restricting portion 14 of the output shaft 12 supports an engagement plate 38 coaxially with the output shaft 12 between the engagement base 20 and the gear member 28 described above. The engagement plate 38 is formed in a disk shape in which a shaft hole 40 having a substantially rectangular cross section (cross section double D-cut shape) corresponding to the relative rotation restricting portion 14 is formed in the center portion. When the (relative rotation restricting portion 18) is inserted, the gear member 28 is positioned on the other side in the axial direction of the output shaft 12 (the side of the engagement base 20) with respect to the gear member 28, and cannot rotate about the axis with respect to the output shaft 12. And supported so as to be movable along the axial direction. As a result, the engagement plate 38 always rotates integrally with the output shaft 12 and can move relative to the gear member 28 along the axial direction of the output shaft 12. In the present embodiment, the engagement plate 38 is a sintered metal manufactured by the so-called “powder metallurgy method” described above, and lubricating oil is contained in the sintered metal.

  On the back surface side of the engagement plate 38 (the gear member 28 side, one side in the axial direction of the output shaft 12), four engagement recesses 42 are provided in the peripheral edge portion (indented). These engagement recesses 42 correspond to the above-described four engagement protrusions 37 of the gear member 28, are provided concentrically with the engagement plate 38, and extend along the circumferential direction of the engagement plate 38. They are provided so as not to be equidistant from each other (so that adjacent intervals are different along the circumferential direction).

  Four engagement protrusions 37 of the gear member 28 can be fitted into these four engagement recesses 42 (that is, the engagement plate 38 can be engaged with the gear member 28). . Thereby, in a normal use state (rotation state), when the gear member 28 rotates, the rotational force of the gear member 28 is transmitted to the engagement plate 38 and the engagement plate 38 is rotated together. .

  However, as described above, the engagement protrusions 37 and the engagement recesses 42 are not equally spaced along the circumferential direction of the gear member 28 and the engagement plate 38 (the adjacent intervals are different from each other). Therefore, the engagement plate 38 (the output shaft 12 and the wiper) and the gear member 28 are engaged with each other only when the relative position along the circumferential direction is at a predetermined position. ing. That is, at a position other than the predetermined one position, even if one engagement protrusion 37 corresponds to the engagement recess 42, the other three engagement protrusions 37 do not correspond to the engagement recess 42. ing. Therefore, in a state in which the engagement protrusion 37 has come out of the engagement recess 42, the engagement plate 38 comes into contact with the gear member 28 via at least three engagement protrusions 37 (three-point support state). It is the composition which becomes).

  Further, here, the engaging protrusion 37 of the gear member 28 and the engaging recess 42 of the engaging plate 38 have inclined side walls (in other words, the cross-sectional shape is a so-called “trapezoid”). Have been). As a result, the gear member 28 rotates, and due to the rotational transmission force from the gear member 28 to the engagement plate 38, the component force along the axial direction of the output shaft 12 (toward the engagement base 20) is applied to the engagement plate 38. The resulting configuration.

  As described above, the output shaft 12 is not limited to the configuration in which the side walls of the engagement protrusion 37 of the gear member 28 and the engagement recess 42 of the engagement plate 38 are both “inclined surfaces”. It is good also as a structure which forms the inclined surface which inclines with respect to the circumferential direction. Even in this case, a component force along the axial direction of the output shaft 12 can be generated in the engagement plate 38 by the rotational transmission force from the gear member 28 to the engagement plate 38. Further, the degree of inclination of the “inclined surface” may be made different between one and the other, and the magnitude of the component force in the axial direction of the output shaft 12 may be made different. As a result, the clutch releasing force (engagement protrusion 37) between the case where the wiper arm fixed to the output shaft 12 is in the so-called open wiping operation from the lower inversion position to the upper inversion position and the so-called closed wiping operation in the opposite direction. And the force required to release the engagement between the engagement recess 42 and the engagement recess 42 can be set separately.

  Furthermore, a coil spring 44 that is wound around the output shaft 12 and can be compressed in the axial direction of the output shaft 12 is disposed between the engagement plate 38 and the engagement base 20. The coil spring 44 is disposed on the other side in the axial direction of the output shaft 12 of the engagement plate 38 from the engagement state of the engagement protrusion 37 of the gear member 28 and the engagement recess 42 of the engagement plate 38 (of the engagement base 20). A predetermined drag force (restoring force when the engaging plate 38 is elastically deformed by the axial movement of the engagement plate 38) is applied to the axial movement toward the side.

  In other words, normally, the engagement protrusion 37 of the gear member 28 enters the engagement recess 42 of the engagement plate 38 and the coil spring 44 maintains this fitted state. When the engagement plate 38 tries to move out in the axial direction toward the engagement base 20 in an attempt to escape from the engagement recess 42 of the engagement plate 38, an urging force (restoring force) against this is exerted. It is configured as follows.

  Further, as described above, the engaging projections 37 of the gear member 28 enter the engaging recesses 42 of the engaging plate 38, respectively, so that rotational force is transmitted from the gear member 28 to the engaging plate 38. The coil spring 44 exerts even when the engagement protrusions 37 of 28 are pulled out of the engagement recesses 42 of the engagement plate 38 (even when the engagement plate 38 is moved toward the engagement base 20). Due to the urging force (restoring force), a predetermined frictional force is generated between the engagement protrusion 37 of the gear member 28 and the back surface of the engagement plate 38, whereby the gear member 28 and the engagement plate 38 are rotated. Thus, the biasing force of the coil spring 44 is set.

  In the normal state (the state where the engagement plate 38 does not move toward the engagement base 20), the coil spring 44 has already been applied with a pressing force between the engagement base 20 and the engagement plate 38. Alternatively, only when the engagement plate 38 moves from the engaged state toward the engagement base 20 (the engagement protrusion 37 is about to come out of the engagement recess 42). In this case, the coil spring 44 may be configured to exert a biasing force (restoring force) against the coil spring 44.

  On the other hand, as shown in FIGS. 4 and 6, a stopper projection 142 is formed on the housing 96 corresponding to the stopper portion 26 of the engagement base 20 described above.

  The stopper protrusion 142 is formed in an arc shape and is located in the rotation locus of the stopper portion 26. One end portion in the circumferential direction and the other end portion in the circumferential direction of the stopper protrusion 142 are a rotation limiting portion 144 and a rotation limiting portion 146, respectively. In other words, the rotation restricting portion 144 and the rotation restricting portion 146 of the stopper protrusion 142 can be brought into contact with the stopper portion 26, respectively, and the stopper portion 26 comes into contact with the rotation restricting portion 144 or the rotation restricting portion 146 of the stopper protrusion 142. In this state, the engagement base 20 (output shaft 12) is prevented from rotating further. Therefore, the engagement base 20 (the output shaft 12) rotates together with the engagement plate 38 by the rotational driving force of the gear member 28, and the stopper portion 26 comes into contact with the rotation limiting portion 144 or the rotation limiting portion 146 of the stopper projection 142. After that, since the subsequent rotation of the engagement base 20 (output shaft 12) is forcibly blocked, the gear member 28 is configured to rotate relative to each other (idle) (see FIGS. 12 and 13).

  Further, a wiper (not shown) is directly connected to the output shaft 12 that is reciprocally driven by the gear member 28, or indirectly connected via a link, a rod, or the like. In this configuration, the output shaft 12 is driven to reciprocate as the output shaft 12 reciprocates.

  Next, the operation of the present embodiment will be described.

  In the wiper motor 90 configured as described above, when the motor main body 92 (armature 108) rotates, the rotational force is transmitted to the worm wheel 128 via the worm gear 122, and the worm wheel 128 rotates. When the worm wheel 128 rotates, the sector gear 132 connected to the worm wheel 128 is reciprocally swung, and the gear member 28 is reciprocally rotated by the reciprocating swing operation of the sector gear 132 (see FIGS. 4 to 7). .

  Here, in a normal use state, for example, as shown in FIGS. 5 and 12, the engagement protrusion 37 of the gear member 28 is engaged with the engagement recess 42 of the engagement plate 38 (they are fitted to each other). In addition, even if the engagement plate 38 tries to move in the axial direction of the output shaft 12 from the engagement state of the engagement protrusion 37 and the engagement recess 42, a predetermined drag force is applied by the coil spring 44. State is maintained. The engagement plate 38 is not rotatable about the axis with respect to the output shaft 12. For this reason, when the gear member 28 is driven to reciprocately rotate, a rotational driving force is transmitted from the gear member 28 to the engagement plate 38 via the engagement protrusion 37 and the engagement recess 42, and is integrated with the engagement plate 38. As a result, the output shaft 12 is rotated.

  As a result, the wiper connected to the output shaft 12 reciprocates as the output shaft 12 reciprocates.

  On the other hand, for example, when an excessive external force (load) is applied to the output shaft 12 via the wiper, the output shaft 12 is reversed or restrained. Then, a rotational force acts on the engagement plate 38 that rotates integrally with the output shaft 12 in the direction of relative rotation with the gear member 28. Here, the engaging protrusions 37 of the gear member 28 and the engaging recesses 42 of the engaging plate 38 have inclined side walls (because the cross-sectional shape is so-called “trapezoid”). Due to the relative rotational force between the gear member 28 and the engagement plate 38, a component force along the axial direction of the output shaft 12 (toward the engagement base 20) is generated in the engagement plate 38. That is, a part of the relative rotational force between the gear member 28 and the engagement plate 38 moves the engagement plate 38 in the axial direction of the output shaft 12, and the engagement projection 37 of the gear member 28 and the engagement plate 38 are This acts as a component force for releasing the engagement with the engagement recess 42. When this relative rotational force (component force) exceeds a predetermined value, the drag force applied by the coil spring 44 is overcome, and the engagement plate 38 is forced in the axial direction of the output shaft 12 as shown in FIGS. The engagement state is released by being moved (the engagement protrusion 37 of the gear member 28 comes out of the engagement recess 42 of the engagement plate 38 and the engagement is released). As a result, the engagement plate 38, that is, the output shaft 12 rotates idly with respect to the gear member 28.

  Therefore, in the wiper motor 90, for example, the wiper freezes at the regular stop position within the rotation range and sticks to the surface to be wiped, or snow accumulates on the wiper located at the regular stop position. When the motor main body 92 is operated in a restrained state and an excessive load or a sudden load is applied to the output shaft 12, it is in the middle of operation within the wiper rotation range (within the normal wiping range). When an excessive external force is applied to the output shaft 12 via the wiper (for example, when the wiper is wiped, snow accumulated on the roof falls on the wiper at a position other than the reverse position on the lower side along the glass surface. In the case where the driving force transmission components (sector gear 132, worm wheel 128, worm gear, etc.) after the gear member 28 are caused by idling by the clutch device 10. 122, excessive external force to the structure) toward the output shaft 12 such as a motor main body 92 in the armature 108 side can be prevented from acting. Thereby, each said part after the gear member 28 can be protected, and the damage of each said part, the burning of the motor main body 92, etc. can be prevented.

  Further, since the strength design of each component after the gear member 28 may be set based on the rotation transmission force (clutch release force) between the gear member 28 and the engagement plate 38, the excessive external force (load) described above. Therefore, it is not necessary to set the excessive strength of each part assuming the above action, and the structure can be made inexpensive.

  Moreover, the driven member (such as a wiper) connected to the output shaft 12 can also be protected from breakage because the shock is absorbed by the idling by the clutch device 10.

  Further, in this wiper motor 90, the swinging central shaft 140 of the sector gear 132 and the output shaft 12 are connected by a holding lever 138 provided on one side in the thickness direction of the sector gear 132. The inter-axis distance (inter-axis pitch) between the dynamic center shaft 140 and the output shaft 12 is kept constant. In addition, the tooth portion 136 of the sector gear 132 is sandwiched on both sides in the thickness direction by the holding lever 138 on one side in the thickness direction and the connecting wall 35 of the gear member 28 on the other side (engagement plate 38 side). Therefore, even if there are no holding members (holding levers) on both sides in the thickness direction of the sector gear 132, the meshing margin between the gear teeth 136 and the tooth portions 34 along the thickness direction of the sector gear 132 is maintained (the sector gear 132 The disengagement in the thickness direction is prevented). Thereby, the favorable meshing state of the sector gear 132 and the gear member 28 can be maintained.

  In the wiper motor 90, the holding lever 138 is disposed on the side opposite to the worm wheel 128 in the thickness direction of the sector gear 132. Therefore, the holding lever 138 does not interfere with the worm wheel 128, thereby improving the degree of freedom in setting the coupling position between the sector gear 132 and the worm wheel 128 (setting the mounting position of the support shaft 134 to the worm wheel 128). Freedom is improved).

  Further, the wiper motor 90 does not have a configuration in which holding members (holding levers) are arranged on both sides in the thickness direction of the sector gear 132 as in the conventional wiper motor, but a single holding on the one side in the thickness direction of the sector gear 132. Since the lever 138 is arranged, the space for arranging the holding member 138 can be reduced, and thereby the overall structure of the apparatus can be reduced in size and weight.

  Thus, in the wiper motor 90 according to the present embodiment, it is possible to maintain a good meshing state between the sector gear 132 and the gear member 28 and to reduce the size of the apparatus.

  In addition, when holding members are arranged on both sides of the sector gear in the thickness direction (both sides of the gear member in the thickness direction) as in the case of a conventional wiper motor, one of the holding members becomes an obstacle, and the engagement plate of the clutch device However, in this wiper motor 90, the holding lever 138 is disposed only on the opposite side of the engagement plate 38 in the thickness direction of the sector gear 132 (thickness direction of the gear member 28). It is a configuration. Therefore, the holding lever 138 does not interfere with the engagement between the gear member 28 and the engagement plate 38, thereby preventing the arrangement of the clutch device 10 from being restricted.

  Further, in the present wiper motor 90, the engagement base 20 (large diameter portion) is fixed and integrated with the rotation stop portion 16 of the output shaft 12 formed with a plurality of protrusions, particularly in the rotation direction around the axis. On the other hand, it is firmly fixed. On the other hand, the gear member 28 is prevented from being removed by the retaining portion 18 of the output shaft 12, and further, the relative rotation restricting portion 14 of the output shaft 12 (that is, between the engagement base 20 and the gear member 28) The engagement plate 38 is supported so as to be movable in the axial direction. That is, all the components are configured with reference to the output shaft 12, and the engagement plate 38 and the coil spring 44 are provided in a constant space (fixed dimension) between the engagement base 20 and the gear member 28. It is a configuration. Therefore, it is possible to easily set the force (clutch release force) required for the axial movement of the engagement plate 38 as described above.

  Further, in the wiper motor 90, since the elastic member is the coil spring 44, the spring characteristics are stable. That is, for example, when the elastic member is a rubber member, the grease applied to the clutch device 10 may adhere to the rubber member and deteriorate, but in the case of the coil spring 44, the grease or the like is attached. There is no fear of deterioration and the spring characteristics are stable.

  In addition, the coil spring 44 is wound between the engagement plate 38 and the engagement base 38 wound around the output shaft 12 and made large in the radial direction of the output shaft 12 and cannot move in the axial direction. It is an arranged configuration. For this reason, the engagement plate 38 can be stably pressed against the gear member 28 and a stable drag can be applied. That is, the elastic force of the coil spring 44 is uniformly distributed by the engagement plate 38 to the engagement portion between the gear member 28 and the engagement plate 38. Therefore, the engagement state between the gear member 28 and the engagement plate 38 is stabilized, and the rotational transmission force (clutch) between the gear member 28 and the engagement plate 38 (between the engagement protrusion 37 and the engagement recess 42). The value of the release force is also stable. Thereby, since the value of the clutch releasing force can be set more suitably, each component of the wiper motor 90 can be protected more reliably.

  In the wiper motor 90, the gear member 28 supported by the output shaft 12 has an outer periphery opposite to the gear teeth 34 via the connection wall 25 as a circumferential surface 36. The bearing member 52 fixed to the housing 96 is rotatably held (supported). That is, the wiper motor 90 has a configuration in which the gear member 28 to which a load is input from the sector gear 132 is directly supported by the bearing member 52 of the housing 96. Therefore, the support rigidity of the gear member 28 is improved, and this also stabilizes the meshing state of the gear member 28 and the sector gear 132. Moreover, the output shaft 12 has a configuration in which a base end portion thereof is supported by the housing 96 (bearing member 52) via the gear member 28. For this reason, a special space for supporting the base end portion of the output shaft 12 to the housing 96 is unnecessary (the installation space for the gear member 28 and the support space for the base end portion of the output shaft 12 are common), and the output shaft 12 The distance dimension along the axial direction of the output shaft 12 between the bearing member 52 that supports the base end portion of the output shaft 12 and the bearing member 50 that supports the distal end side of the output shaft 12 can be secured long. Thereby, the support rigidity with respect to the housing 96 of the output shaft 12 is also improved.

  Further, in the wiper motor 90, since both the gear member 28 and the engagement plate 38 are sintered metal obtained by molding a powder alloy, these members can be manufactured with high accuracy by powder metallurgy, and the material yield can be increased. Good. Further, since the gear member 28 and the engagement plate 38 made of sintered metal contain lubricating oil in the sintered metal, they are engaged with each other (such as the engagement protrusion 37 and the engagement recess 42). The gear teeth 34 of the gear member 28 engaged with the teeth 136 of the sector gear 132 can be provided with self-lubricating properties.

  Furthermore, in the wiper motor 90, the engagement protrusions 37 of the gear member 28 and the engagement recesses 42 of the engagement plate 38 are not equally spaced along the circumferential direction of the gear member 28 and the engagement plate 38, respectively. The engagement plate 38 is provided with at least three engagement protrusions 37 even in the clutch release state in which the engagement protrusions 37 have come out of the engagement recesses 42. Is engaged with the gear member 28 (because of the three-point support state), the engagement state between the engagement plate 38 and the gear member 28 in the clutch released state is stabilized.

  Moreover, the gear member 28 and the engagement plate 38 (the output shaft 12 and the wiper) can be engaged only when the relative positional relationship along the circumferential direction is at a predetermined position. For this reason, in the clutch release state in which each engagement protrusion 37 has come out of each engagement recess 42 (when the gear member 28 and the engagement plate 38 are in a relative positional relationship other than a predetermined position), for example, an occupant or the like When the wiper is manually rotated, the gear member 28 and the engagement plate 38 are always engaged at a predetermined position. Therefore, the engagement plate 38 (the output shaft 12 and the wiper) can be easily and quickly returned to the original set state (initial setting state) with respect to the gear member 28, and again without damaging the wiper device. Can be operated.

  In the clutch device 10 of the wiper motor 90, the gear member 28 is driven to decelerate and reciprocate by the swing mechanism 94 (worm gear 122, worm wheel 128, and sector gear 132), so that the output shaft 12 is driven with a large torque. Therefore, the wiper connected to the output shaft 12 can be suitably reciprocated.

  Accordingly, in the wiper motor 90, an excessive external force (load) acts on the output shaft 12 via the wiper (for example, snow accumulated on the roof of the vehicle falls substantially vertically along the glass surface and hits the wiper arm, and a large external force is applied. It is also suitable as a motor for driving a wiper for a vehicle having high probability, such as a truck having a cab over type cockpit or a construction machine.

  Further, in the clutch device 10 of the wiper motor 90, the engaging projection 37 of the gear member 28 enters the engaging recess 42 of the engaging plate 38, so that the rotational force is transmitted from the gear member 28 to the engaging plate 38. Since it was set as the structure, transmission of the driving force between the gear member 28 and the engagement plate 38 can be performed more reliably. Moreover, since the side wall portions of the engagement protrusion 37 of the gear member 28 and the engagement recess 42 of the engagement plate 38 are inclined surfaces, the inclination angle of the inclined surface and the drag force (elasticity of the coil spring 44). The clutch release force can be easily set based on the deformation force.

  Further, in the wiper motor 90, in the normal use state (rotation state), as described above, when the rotational driving force is transmitted from the gear member 28 of the clutch device 10 to the output shaft 12, the engagement protrusion 37 of the gear member 28 and In order to maintain the engagement state of the engagement plate 38 with the engagement recess 42, the drag force applied by the coil spring 44 to the axial movement of the engagement plate 38 from the engagement state is a sliding frictional force. It is not wasted. Therefore, it is possible to prevent a decrease in rotation transmission efficiency. In addition, since the rotational driving force can be transmitted without causing the sliding of the member, the generation of noise due to the sliding of the member is also prevented.

  In addition, as described above, the drag force applied by the coil spring 44 to the axial movement of the engagement plate 38 from the engagement state in order to maintain the engagement state of the engagement protrusion 37 and the engagement recess 42. Is received by an engagement base 20 fixed to the output shaft 12 and a gear member 28 supported in a state of being secured to one side in the axial direction with respect to the output shaft 12. That is, the force for maintaining the engaged state is received by the two components (the engagement base 20 and the gear member 28) attached to the output shaft 12. In other words, the clutch device 10 of the wiper motor 90 is configured to be completed as “a subassembly of the output shaft 12”, and is not configured to be completed depending on other components such as the housing 96. Therefore, the clutch device 10 can be handled as one component which is an “output shaft 12 subassembly”.

  As described above, the wiper motor 90 according to the present embodiment can maintain a good meshing state between the sector gear 132 and the gear member 28 and can reduce the size of the apparatus.

  In the above embodiment, both the gear member 28 and the engagement plate 38 constituting the clutch device 10 are “sintered metal containing lubricating oil”. Any one of the joint plates 38 may be “sintered metal containing lubricating oil”.

  In the above embodiment, the wiper motor 90 includes both the swing mechanism 94 and the clutch device 10. However, the present invention is not limited to this, and the wiper motor may have a configuration in which the clutch device is omitted. . In this case, the gear member is provided integrally with the output shaft (impossible relative movement).

It is a perspective view which shows the structure of the wiper motor which concerns on embodiment of this invention. It is the perspective view which saw through a part which shows the structure of the wiper motor which concerns on embodiment of this invention. It is a disassembled perspective view which shows the structure of the wiper motor which concerns on embodiment of this invention. It is a plane sectional view showing the composition of the wiper motor concerning an embodiment of the invention. FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 4 illustrating the configuration of the wiper motor according to the embodiment of the present invention. It is a plane sectional view showing the composition of the wiper motor concerning an embodiment of the invention. FIG. 7 is a cross-sectional view taken along the line 7-7 in FIG. 6 illustrating the configuration of the wiper motor according to the embodiment of the present invention. FIG. 8 is a view corresponding to FIG. 7 in a clutch released state, showing a configuration of a wiper motor according to an embodiment of the present invention. It is a disassembled perspective view which shows the structure of the clutch apparatus which is a structural member of the wiper motor which concerns on embodiment of this invention. It is a disassembled perspective view which shows the structure of the clutch apparatus which is a structural member of the wiper motor which concerns on embodiment of this invention. It is sectional drawing which shows the partial structure of the rocking | fluctuation mechanism and clutch apparatus which are the structural members of the wiper motor which concerns on embodiment of this invention. It is a perspective view which shows the structure of peripheral components containing the rocking | fluctuation mechanism which is a structural member of the wiper motor which concerns on embodiment of this invention, and a clutch apparatus, and shows a clutch connection state. It is a perspective view which shows the structure of peripheral components containing the rocking | fluctuation mechanism and clutch apparatus which are the structural members of the wiper motor which concerns on embodiment of this invention, and shows a clutch release state.

Explanation of symbols

10 .... Clutch device, 12 .... Output shaft, 20 .... Engage base (large diameter part), 28 ... Gear member, 34 ... Gear teeth, 35 ... Connection wall, 36 ... Circumferential surface, 38 .. Engaging plate, 44 .. Coil spring (elastic member), 52 .. Bearing member, 90 .. Wiper motor, 94 .. Oscillating mechanism, 96 .. Housing, 128 .. Worm wheel (rotating member), 132 ..Sector gear (swinging member) 136 ..Tooth part (meshing part) 138 ..holding lever (holding member) 140 ..fixed shaft

Claims (6)

A wiper motor that houses a swing mechanism for converting a one-way continuous rotational motion of a rotating member into a reciprocating rotational motion of the output shaft in a housing that rotatably supports an output shaft to which the wiper is directly or indirectly connected. And
A gear member provided integrally with the output shaft and having gear teeth formed on the outer periphery;
An oscillating member whose one end side is connected to the rotating member and has a meshing portion meshing with the gear member on the other end side, and converting the continuous rotational motion of the rotating member into the reciprocating rocking motion of the meshing portion;
A holding member that is disposed on one side in the thickness direction of the rocking member and that connects the rocking central axis and the output shaft in the meshing portion of the rocking member to maintain a distance between both axes;
With
The gear member has a connecting wall that connects the ends of the gear teeth opposite to the holding member adjacent to each other, and the meshing portion of the swinging member is made thick by the connecting wall and the holding member. Sandwiched on both sides
A wiper motor characterized by that. A wiper motor that houses a swing mechanism for converting a one-way continuous rotational motion of a rotating member into a reciprocating rotational motion of the output shaft in a housing that rotatably supports an output shaft to which the wiper is directly or indirectly connected. And
Provided between the output shaft and the swing mechanism, and when a load of a predetermined value or more is applied around the axis of the output shaft, the swing mechanism and the output shaft are relatively moved by the load. It has a clutch device that enables idling,
The clutch device is
A gear member that is supported in a rotatable state in one axial direction with respect to the output shaft and is rotatably supported, has gear teeth formed on the outer periphery thereof, and reciprocally rotates around the output shaft by a driving force from the swing mechanism When,
The gear member is positioned on the other side in the axial direction of the output shaft, is supported so as to be non-rotatable around the axis and movable along the axial direction with respect to the output shaft, and rotates integrally with the output shaft. An engagement plate that can be meshed with the gear member and that rotates integrally with the gear member in an engaged state with the gear member;
Positioned on the other side in the axial direction of the output shaft with respect to the engagement plate, a resistance is applied to the axial movement of the engagement plate from the engaged state toward the other side in the output shaft axial direction. An elastic member,
The swing mechanism is
An oscillating member whose one end side is connected to the rotating member and has a meshing portion meshing with the gear member on the other end side, and converting the continuous rotational motion of the rotating member into the reciprocating rocking motion of the meshing portion;
A holding member that is disposed on the opposite side of the engagement plate in the thickness direction of the swing member and connects the swing center shaft and the output shaft at the meshing portion of the swing member to maintain the distance between both shafts. A member, and
The gear member has a connecting wall that connects the ends of the gear teeth opposite to the holding member adjacent to each other, and the meshing portion of the swinging member is made thick by the connecting wall and the holding member. Sandwiched on both sides
A wiper motor characterized by that. The elastic member is a coil spring that is wound around the axis of the output shaft and can be compressed in the axial direction of the output shaft, and the coil spring has a large diameter in the radial direction of the output shaft and cannot move in the axial direction. Disposed between the large-diameter portion and the engagement plate,
The wiper motor according to claim 2. The gear member has an outer periphery opposite to the gear teeth via the connecting wall and a circumferential surface concentric with the output shaft, and the circumferential surface of the gear member is rotatable with respect to the housing. Retained,
The wiper motor according to any one of claims 1 to 3, wherein the wiper motor is provided. The gear member is made of a sintered metal molding the powder alloy, lubricating oil is oil-impregnated into the sintered within a metal,
The wiper motor according to any one of claims 1 to 4, wherein the wiper motor is provided. The engagement plate is made of a sintered metal obtained by molding a powder alloy, and lubricating oil is contained in the sintered metal.
The wiper motor according to any one of claims 2 to 4, wherein the wiper motor is provided.

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