JP2000289574A - Motor device for driving wiper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size and weight of a wiper-driving motor device in which a mechanism for converting the rotational movement of a rotating member into the swinging movement of a wiper-swinging output shaft is contained within a hollow container. SOLUTION: This device includes a wheel gear 22 serving as a rotating member, a crankpin 28a formed on the wheel gear 22, a gear 60 fixed to a wiper-swinging output shaft 62, a power conversion member 30 having at one end a meshing part 32 which meshes with the gear 60 and pivotably attached at the other end to the crankpin 28a to convert the rotational movement of the crankpin 28a into the reciprocating swinging movement of the output shaft 62, and sliding contact reducing parts 47, 48. The gear 60 and an upper holding member 40 made of a resin which is arranged between the power conversion member 30 and a cover covering the top to maintain engagement between the gear 60 and the power conversion member 30 are contained within a hollow container 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiper driving motor device used for a wiper device for wiping a glass surface of a vehicle.

[0002]

2. Description of the Related Art Conventionally, a motor device of this kind has a power conversion mechanism for reducing the rotation of a motor armature, converting the rotation into reciprocating motion, and swinging an output shaft, in a motor hollow container. is there. For example, as shown in FIG. 5, there is a motor device disclosed in Japanese Patent Application Laid-Open No. 9-224350 of the present applicant. This motor device includes a wheel gear 22 that engages the rotation of the motor with a worm (not shown).
And one end of the power conversion member 30 is pivotally connected to a crank pin 28a integrally formed on the wheel gear 22 to convert the rotational motion into a reciprocating rocking motion. A gear 60 fixed to an output shaft 62 connecting the meshing portion 32 provided at the other end to a wiper arm (not shown)
And the output shaft 62 is swung, and the gear 6
0 and a resin upper holding member 40 for holding the meshing of the power conversion member 30 between the gear 60 and the power conversion member 30 and the cover 12 to prevent disengagement of the mesh, The upper holding member 40 is slidably contacted with the gear 60, the power conversion member 30 and the respective surfaces of the cover 12 to thereby prevent the output shaft 62 of the respective members in the hollow container 10 from rattling in the output shaft 62.

[Problems to be solved by the invention]

However, in the above-described motor device,
As a result of the upper holding member 30 sliding on each surface of the power conversion member 30 and the gear 60 on one entire surface thereof, the sliding resistance becomes excessive and the motor efficiency is greatly reduced. For this reason, it is not possible to cope with the reduction in size and weight of the motor device, which is particularly required in recent years. Further, when the output shaft 62 is configured to have a small diameter in response to a demand for reducing the size and weight of the motor device, when an excessive pulling force is externally applied to the output shaft 62 by pulling a wiper arm or the like, the output shaft 62 is May fall off the gear 60.

Therefore, the present invention is to solve the above-mentioned problem, and the sliding resistance of the upper holding member 40 is small, and the output shaft 62 does not fall off from the gear 60. An object of the present invention is to provide a wiper drive motor device that can be reduced in size and weight.

[0005]

According to a first aspect of the present invention, there is provided a wiper driving mechanism in which a mechanism for converting a continuous rotational movement of a rotary member into a reciprocating swinging movement of an output shaft to which a wiper arm is fixed is housed in a hollow container. A motor device, comprising: a gear that swings integrally with the output shaft; and a meshing portion that meshes with the gear, the power for converting a continuous rotational motion of the rotating member into a reciprocating swinging motion of the meshing portion. A conversion member, a fixed shaft fixed to an engagement rotation center of a meshing portion of the power conversion member, a meshing state of the gear and the power conversion member, and a sliding contact with the gear and the power conversion member. A wiper drive motor device comprising: an upper holding member that swings integrally with the output shaft, which slides on an inner wall of the hollow container on the side opposite to the wiper arm, wherein the press-fitting fits with the gear of the output shaft. Joint part is other The press-fit fitting is provided so as to protrude beyond the outer diameter of the force shaft or beyond the thickness of the gear toward the wiper arm, and the upper holding member projects toward the sliding contact surface of the gear and the power conversion member. The gist of the invention is to provide a sliding contact reducing portion for reducing sliding contact between the gear and the power conversion member, including a sliding contact avoiding recess for avoiding sliding contact with the joining portion.

According to a second aspect of the present invention, in the motor device for driving a wiper according to the first aspect, the press-fitting portion includes:
The gist is that the diameter is gradually increased toward the inner wall side of the hollow container.

According to a third aspect of the present invention, in the motor device for driving a wiper according to the first and second aspects, the sliding contact reducing portion includes a fixed shaft around the sliding contact avoiding recess and the fixed shaft. The gist is that it is a round recess.

[0008]

According to the first aspect of the present invention, the press-fitting portion of the output shaft fitted with the gear is larger than the outer diameter of the other output shaft or exceeds the thickness of the gear. Since the gear is provided so as to protrude toward the wiper arm, the coupling force between the gear and the output shaft is increased, or the resistance of the output shaft in the falling direction is increased, so that the output shaft is prevented from falling from the gear. Is suppressed. Further, the upper holding member includes a sliding contact avoiding concave portion for avoiding sliding contact between the gear and the press-fitting portion protruding toward the sliding contact surface side of the power conversion member. Since the sliding contact reducing portion for reducing the sliding contact is provided, the sliding contact area is reduced and the sliding resistance loss is reduced, so that the motor efficiency can be increased. Based on the above, the size and weight of the wiper driving motor device can be reduced.

According to the second aspect of the present invention, since the diameter of the press-fitting portion gradually increases toward the inner wall of the hollow container, the resistance of the output shaft in the falling direction increases. Dropping of the output shaft from the gear is further suppressed.

According to the third aspect of the present invention, the sliding contact reducing portion is the sliding contact avoiding concave portion and the concave portion around the fixed shaft around the fixed shaft. Therefore, the sliding resistance of the part where the preload is maximum and the sliding speed is maximum is reduced, and the motor efficiency can be further increased.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, the same components as those of the related art are denoted by the same reference numerals, and a detailed description thereof will be partially omitted.

As shown in FIGS. 1 and 2, the motor device for driving a wiper according to the present embodiment includes a worm 20 which is rotated by rotation of a rotation shaft provided in a motor portion, and a gear shaft meshed with the worm 20. A wheel gear 22 serving as a rotating member that is decelerated and rotated around a center 24; and a crank arm portion 2 serving as a rotating member integrally formed on the wheel gear 22.
8 and a crank pin 28a, a gear 60 fixed to an output shaft 62 for connecting a wiper arm (not shown), and a meshing portion 32 at one end for meshing with the gear 60, and the other end pivotally connected to the crankpin 28a. And the crank pin 28a
Power conversion member 30 for converting the continuous rotary motion of the gears into a reciprocating swing motion of the output shaft 62, the gear 60 and the power conversion member 3
0 and the cover 60 which covers the upper part and becomes a part of the inner wall of the hollow container 10 and the gear 60 and the power conversion member 30
And an upper holding member 40 made of resin for holding the meshing of the power conversion member 30, and a lower holding member 50 made of resin similarly arranged for holding the meshing of the gear 60 and the power conversion member 30. These are housed in the hollow containers 10 and 12.

As shown in FIG. 1, a knurl is provided at the press-fitting portion 62a for fixing the gear 60 of the output shaft 62, so as to protrude beyond the thickness of the gear 60 toward the wiper arm. The gear 60 is press-fitted from the fixed side 62b of the wiper arm and fixed to the output shaft 62. Accordingly, the knurls remaining on the side opposite to the wiper arm do not have their knurls crushed.

The upper holding member 40 is shown in FIGS.
The fixed shaft 34a fixed to the center of the engagement portion 32 of the power conversion member 30 is inserted into the hole 34 provided at one end, and the output shaft 60 is rotatably inserted into the hole 46 provided at the other end. , The distance between both shafts is kept constant, and the meshing between the gear 60 and the power conversion member 30 is maintained. Also, a convex portion 4 is provided on the cover 12 side of the upper holding member 40 so as to slidably contact each member to be accommodated with the cover 12 in a state of slightly pressing so as to prevent play.
2, 44 are formed. Further, the upper holding member 40
A sliding contact reducing portion is provided on the sliding contact surface side of the gear 60 and the power conversion member 30 to avoid contact with a knurl, which is a press-fitting fitting portion 62a protruding toward the upper holding member 40, to reduce sliding resistance. And a circular groove-shaped recessed portion 48 around the fixed shaft as a sliding contact reducing portion that similarly reduces the sliding resistance around the fixed shaft 34a.

The lower holding member 50 is substantially the same as the upper holding member 50 as shown in FIG. 2. The fixed shaft 34a is inserted into a hole provided at one end, and the output shaft 60 is inserted into a hole provided at the other end.
Are rotatably inserted to keep the distance between both shafts constant, and to maintain the meshing between the gear 60 and the power conversion member 30.

In the wiper driving motor device configured as described above, when the wheel gear 22 is rotated by the rotation of the rotating shaft provided in the motor portion, the crank pin 28a shown in FIG. Draw the trajectory of The power conversion member 30, which is pulled by the crank pin 28a and one end of which is connected to the crank pin 28a, moves in the left-right direction along the swing locus of Y in FIG. At the same time, the crank pin 28a swings up and down about the fixed shaft 34a.
As a result, the upper holding member 40 is
Swings right and left about the cover 12 and the output shaft 62. The upper holding member 40 holds the gear 6 while holding the gear 60 and the power conversion member 30 in mesh with each other.
0 and the power conversion member 30 are slid on the surface.

Based on the above operation, the portion where the sliding speed of the upper holding member 40 with respect to the gear 60 and the power conversion member 30 is increased is around the output shaft 62 which is the pivot point and around the fixed shaft 34a. Becomes Further, the periphery of the output shaft 62 and the periphery of the fixed shaft 34a, which are the pivot points, are covered by the cover 1.
2 are the parts where the preload applied is the maximum, and the periphery thereof is the part where the sliding resistance is the largest. In the present example, since a circular groove-shaped sliding contact avoiding concave portion 47 and a circular groove-shaped concave portion around the fixed shaft 48 are provided in these peripheral portions, the sliding resistance is significantly reduced.

When an excessive pulling force is applied to the output shaft 62 from the outside by pulling the wiper arm or the like, the knurls of the knurls remaining on the side opposite to the wiper arm, where the knurls are not crushed, serve as pulling resistance and the output shaft falls off. Is blocked.

Next, the characteristic effects of the wiper driving motor device configured as described above will be described below. (1) A circular groove-shaped sliding contact avoiding concave portion 47 and a circular groove-shaped fixed shaft which do not slide with the upper holding member 40 around the output shaft 62 and the fixed shaft 34a, which are the maximum portions of the sliding speed and the preload. Since the surrounding recess 48 is provided, the sliding resistance is greatly reduced, and the efficiency of the motor device is increased. As a result, the size and weight of the motor device can be reduced, and the cost of the motor can be reduced.

(2) When an excessive pulling force is externally applied to the output shaft by pulling the wiper arm or the like,
The knurl in which the mountain of the knurl remaining on the side opposite to the wiper arm is not crushed acts as a pull-out resistance, thereby preventing the output shaft 62 from falling off. As a result, the outer diameter of the output shaft can be reduced as long as the allowable idle moment of the gear 60 is maintained, and the size and weight of the motor device can be reduced, and the cost of the motor device can be reduced.

The above embodiment may be modified and implemented as follows. As shown in FIG. 3, in the above embodiment, only the press-fitting portion 62a of the output shaft 62 may be formed by a knurl having a larger diameter than the other outer diameters. In this way, even when a large permissible slipping moment of the gear and a large pull-out resistance of the output shaft are required, it is possible to reduce the size and weight of other unnecessary parts. The projecting press-fitting portion is easily formed by cold forging.

As shown in FIG. 4, only the press fitting portion 62a of the output shaft 62 in the above embodiment is
A knurl that gradually increases in diameter toward the inner wall side of the cover 12 may be used. In this way, the resistance of the output shaft 62 in the falling direction is increased, and the falling of the output shaft 62 from the gear 60 is further suppressed.

[0023]

As described in detail above, according to the present invention,
The sliding resistance of the upper holding member 40 is greatly reduced, and the efficiency of the motor can be increased. Further, when an excessive pulling force is applied to the output shaft 62 from the outside by pulling the wiper arm or the like, the pullout resistance of the gear 60 fixed to the output shaft 62 increases, and the output shaft 62 is prevented from falling off. From the above, the motor size and output shaft 6
(2) The outer diameter can be reduced, and the size and weight of the wiper drive motor device can be reduced, and the cost of the motor can be reduced.

[Brief description of the drawings]

FIG. 1 is a partially broken plan view of a motor device according to the present embodiment.

FIG. 2 is a partially cutaway front view of the motor device of FIG. 1;

FIG. 3 is a partially broken front view of an output shaft of another example.

FIG. 4 is a partially broken front view of an output shaft of another example.

FIG. 5 is a partially cutaway front view of a conventional motor device.

[Explanation of symbols]

10 ... hollow container, 12 ... cover, 20 ... warm,
26 ... hole, 28 ... crank arm part, 28a ... crank pin, 30 ... power conversion member, 34 ... hole, 34a ...
Fixed shaft, 40 ... Upper holding member, 42, 44 ... Convex part,
46 ... hole, 47 ... sliding contact avoiding concave part, 48 ... concave part around fixed shaft, 50 ... lower holding member, 60 ... gear, 62 ... output shaft, 62a ... press fitting part, 62b ... wiper arm fixed side, 71 ... bearing

Claims (3)

[Claims] 1. A mechanism for converting a continuous rotary motion of a rotary member into a reciprocating swing motion of an output shaft to which a wiper arm is fixed,
A wiper driving motor device housed in a hollow container,
A power conversion member that includes a gear that swings integrally with the output shaft and a meshing portion that meshes with the gear, and that converts continuous rotation of the rotating member into reciprocating swinging motion of the meshing portion; A fixed shaft fixed to the meshing rotation center of the meshing portion of the member, holding the meshed state between the gear and the power conversion member, slidably contacting the gear and the power conversion member, and opposite the wiper arm side of the hollow container; And an upper holding member that swings integrally with the output shaft, which is in sliding contact with the inner wall of the wiper drive. The press-fit fitting is provided so as to protrude toward the opposite side of the wiper arm beyond the outer diameter of the shaft or beyond the thickness of the gear, and the upper holding member projects toward the sliding contact surface of the gear and the power conversion member. Avoid sliding contact with parts That sliding avoid includes a recess, said gear and said motive power conversion member and the wiper drive motor device characterized by comprising a sliding reduction unit for reducing the sliding contact. 2. The wiper driving motor device according to claim 1, wherein the press-fitting portion gradually increases in diameter toward the inner wall of the hollow container. 3. The wiper driving motor device according to claim 1, wherein the sliding contact reducing portion is a concave portion around the fixed shaft around the sliding contact avoiding concave portion and the fixed shaft.