JPH0751954Y2 - Wiper drive device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a wiper device used in a vehicle, particularly an automobile.

2. Description of the Related Art Various types of automobile wiper devices are known. Regarding the movement of the wiper shaft to which the wiper arm is connected when the curvature of the glass surface to be wiped is remarkably changed, there are JP 58-132757 A and JP 62-68159 A. In either case, a first bearing portion that rotatably supports the wiper shaft about the first axis and a first bearing portion that rotatably supports the first bearing portion about a second axis different from the first axis. A second bearing portion and a drive means for rotating the second bearing portion around a second axis are linked to the wiper motor for rotating the wiper shaft about the first axis. I am busy. Of these, Japanese Patent Laid-Open No. 62-68159 discloses that by doing so, the error angle is kept substantially constant over the entire rotation angle range of the wiper arm.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The structure described in the above-mentioned publicly known publications is complicated and bulky, and the drive for the wiper shaft drive unit and the second bearing unit is complicated. It is not specifically disclosed how to connect the means to keep the error angle substantially constant.

The present invention aims to solve such problems.

According to the present invention, a housing attached to a vehicle body, an eccentric shaft rotatably supported in a cylindrical hole of the housing around an axis of the hole, and the eccentric shaft are provided. An eccentric hole penetrating the shaft and having an axis inclined with respect to the axis, a wiper shaft rotatably supported by the eccentric hole, and a wiper shaft connected to a wiper motor to reciprocally rotate the wiper shaft by a predetermined angle. A wiper shaft drive unit, an eccentric shaft drive unit that rotationally drives the eccentric shaft, and a double speed increasing mechanism that connects the wiper shaft drive unit and the eccentric shaft drive unit to each other for one cycle operation of the wiper shaft. A wiper drive is provided in which the eccentric shaft is adapted to operate for two cycles.

First wiper shaft drive unit is connected to a wiper motor
Second gear and a link that connects the second gear and the eccentric shaft, and an eccentric shaft drive unit that meshes with the first gear, and a link that connects the first gear and the wiper shaft. It is desirable that the first gear and the second gear form a double speed increasing mechanism.

In the preferred embodiment, the angle of inclination of the two axes is preferably about 10 degrees.

The eccentric shaft is rotatably supported by the housing, and the wiper shaft is rotatably supported by the inclined hole penetrating the eccentric shaft. Therefore, the structure is remarkably compact and the size of the wiper shaft mounting portion is large. The size can be substantially the same as the conventional one.

By operating the eccentric shaft for 2 cycles with respect to the wiper shaft for 1 cycle, the error angle is reduced to 10
It can be less than or equal to degrees.

Embodiments FIGS. 1 and 2 show an embodiment of the present invention, in which 1 is a mounting plate, 2 is a housing, and 3 is a cylindrical hole provided in the housing 2 and the axis I-I of the hole is shown. An eccentric shaft 4 rotatably supported around the eccentric shaft 4 has an axis II-II which extends through the eccentric shaft 3 and is inclined about 10 degrees with respect to the axis I-I. A wiper shaft (not shown) is attached to the upper end of FIG. The eccentric shaft 3 and the wiper shaft 5 are connected to a second pinion gear 10 and a first gear wheel 11 which mesh with each other by links 6, 7 and 8, 9, respectively.
The first large gear 11 is rotationally driven by the wiper motor M. The links 6, 7, 8 and 9 are determined so as to appropriately determine the reciprocating rotation angles of the eccentric shaft 3 and the wiper shaft 5, and the gear ratios of the gears 10 and 11 with respect to one cycle operation of the wiper shaft 5. It is determined that the eccentric shaft 3 operates for two cycles, that is, the gear 10 rotates two times for one rotation of the gear 11, that is, the gear 11 and the gear 10 have two rotations.
Configure a speed-up mechanism. Fig. 3 shows a concrete example,
FIG. 3-1 assumes that a wiper having a wiping angle of 80 degrees wipes the glass surface 20. Third-
The broken line a in Fig. 2 shows the wiping angle as the horizontal axis.
It is a curve showing the error angle when the eccentric shaft 3 is fixed, and thus the bending of the glass surface 20. A thin solid line b indicates an error angle with respect to the virtual plane glass caused by the rotation of the eccentric shaft 3. In this case, since the inclination angle between the axis I-I and the axis II-II is 10 degrees, the maximum value of the curve b is +10 degrees and the minimum value is -10 degrees. The thick solid line c as the sum of the curve a and the curve b shows the error angle according to the present invention, and the maximum deviation is 7.6 degrees.

FIG. 4 is a diagram showing an example of calculation for obtaining the curve b in FIG. 3-2.

The triple structure of the housing 2, the eccentric shaft 3 and the wiper shaft 5 shown in FIG. 1 is fixed at a position where the eccentric shaft 3 is rotated by a desired angle in addition to the structure in which the eccentric shaft 3 is rotated. It is possible to appropriately adjust the inclination with respect to the surface. This makes it much easier to absorb dimensional errors in the part of the vehicle body in which the housing 2 is mounted, so that the error angle can be minimized.

Effect of the Invention According to the present invention, the eccentric shaft is rotatably supported by the housing, and the wiper shaft is rotatably supported by the inclined hole passing through the eccentric shaft. The size of the mounting portion of the wiper shaft can be made substantially the same as the conventional size.

By operating the eccentric shaft for 2 cycles with respect to the wiper shaft for 1 cycle, the error angle is reduced to 10
It can be less than or equal to degrees.

[Brief description of drawings]

1 is a cross-sectional view of a wiper driving device shown as an embodiment of the present invention, FIG. 2 is a bottom view of the device of FIG. 1, FIG. 3-1 is a plan view showing the relationship between a wiping angle and a glass surface, FIG. 3-2 is a graph showing the effect of reducing the error angle according to the present invention, and FIG. 4 is a table showing a calculation example for obtaining the graph of FIG. 3-2. 1: Mounting plate, 2: Housing, 3: Eccentric shaft, 4: Eccentric hole 5: Wiper shaft 6, 7, 8, 9: Link 10, 11: Gear

Claims (2)

[Scope of utility model registration request] 1. A housing attached to a vehicle body, an eccentric shaft rotatably supported in a cylindrical hole of the housing about an axis of the hole, and the axis provided through the eccentric shaft. An eccentric hole having an axis inclined with respect to the eccentric axis, a wiper shaft rotatably supported by the eccentric hole, a wiper shaft drive unit connected to the wiper motor to reciprocally rotate the wiper shaft by a predetermined angle, and an eccentric shaft. An eccentric shaft drive unit for rotating the wiper shaft, and a double speed increasing mechanism for connecting the wiper shaft drive unit and the eccentric shaft drive unit, so that the eccentric shaft operates for two cycles with respect to one cycle operation of the wiper shaft. Wiper drive device 2. The wiper shaft drive unit includes a first gear connected to the wiper motor and a link connecting the first gear and the wiper shaft, and the eccentric shaft drive unit includes the first gear.
2. The wiper drive device according to claim 1, further comprising a second gear meshing with the gear of FIG. 1 and a link connecting the second gear and the eccentric shaft.