JPS6364336B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wiper device used to ensure visibility through a windshield of a vehicle, and particularly to a wiper device designed to reduce operating noise of a swinging wiper device.

The configuration of a conventional wiper device, as shown in FIG.
and a ball bearing 15 assembled to the tip of the pivot lever 14 which is locked to the lower end of the wiper shaft 13 as shown in FIG. 17, and the uniform rotation of the wiper motor, that is, the circular orbit of the crank arm 11, is converted into the swinging motion of the wiper shaft 13 by a link mechanism of the connecting rod 17 and the pivot lever 14. Therefore,
The wiper blade fixed to the other end of the wiper shaft 13 wipes the windshield surface with a sinusoidal velocity characteristic as shown in FIG. For this reason, when reversing (points a and b in Figure 2), the rate of change in speed is large, and the moment of inertia of moving parts such as wiper blades has a large effect on the inertial force, resulting in an impact that acts on the backlash of each part. This has the disadvantage that it generates a sound, that is, a reversal sound, impairs comfort, and at the same time reduces the durability of various parts.

This invention was made to eliminate these drawbacks of the conventional technology.The purpose of this invention is to reduce reversal noise without adding any other complicated mechanism, improve comfort, and increase durability. An object of the present invention is to provide a wiper device with improved performance.

In order to achieve the above object, the present invention supports an eccentric plate 23 at the tip of a crank arm 21 that is engaged with a wiper motor rotation output shaft 26, and supports a link mechanism to a wiper shaft on one surface of the eccentric plate. A ball bearing 22 is mounted on the other surface, and an external gear 2 is mounted on the other surface.
5, the external gear 25 is meshed with the stationary large external gear 27 so as to be able to rotate automatically and revolve according to the rotation of the crank arm 21, and its length is twice per rotation of the crank arm 21. It has a configuration characterized in that swinging motion is transmitted to the wiper shaft by taking the maximum and minimum lengths.

Hereinafter, one embodiment of the present invention shown in the drawings will be described. 3 and 4, an eccentric plate 23 on which a ball bearing 22 is integrally or firmly assembled is attached to the tip of a well-known crank arm 21, and its rotating shaft 24 is eccentric by r from the ball bearing 22. It is rotatably supported in this position. A small external gear 25 is integrally or firmly connected coaxially to the other end of the rotating shaft 24, and in response to the rotation of the small external gear 25, the ball bearing 22 revolves with a radius r. It's summery. Further, the ball bearing 2
2 connects and supports a link mechanism consisting of a pivot lever 30 and connecting rod 29 fixed to the wiper shaft 31. On the other hand, the other end of the crank arm 21 is locked to the wiper motor rotation output shaft 26 through a known serration fitting or the like, and at the same time, a large external gear 27 located coaxially with the wiper motor rotation output shaft 26 is connected to the wiper motor rotation output shaft 26, for example. The wiper motor housing 28 is connected and fixed to the wiper motor housing 28, and the number of teeth thereof meshes with the small external gear 25 at a ratio of 2:1, and as the small external gear 25 rotates, the large external gear It is configured to revolve around 27.

Next, the operation of the apparatus of this embodiment will be explained.
With respect to the uniform rotation of the wiper motor output shaft 26, the center of the rotating shaft 24 pivotally supported by the crank arm 21 moves in a circular orbit A shown in FIG. At this time, since the small external gear 25 that meshes with the stationary large external gear 27 starts to rotate with the revolution of the circular orbit A, the ball bearing 22 on the eccentric plate 23 has a radius r around the rotating shaft 24. Starting to revolve, crank arm 2
1, that is, the distance between the ball bearing 22 and the wiper motor rotation output shaft 26 gradually becomes shorter, and an elliptical trajectory is drawn. Then, when the crank arm 21 rotates 90 degrees, the small external gear 25 rotates.
Since the ball bearing 22 rotates by 180 degrees, the ball bearing 22 and its eccentric plate 23 revolve to the position where the crank arm length is the minimum, and draw a 1/4 elliptical locus.
Then, as the rotation of the crank arm 21 further progresses, in the next 90 degrees, the ball bearing 22 revolves while drawing an elliptical locus so that the crank arm length changes from the minimum to the maximum, contrary to the above operation. and,
The ball bearing 22 returns to its state one cycle ago. This is further repeated as the crank arm 21 rotates. That is, for one rotation of the crank arm 21, the ball bearing 22 moves in an elliptical orbit B shown in the fourth figure. That is, since the crank arm length changes in accordance with the rotation of the crank arm 21, for example, point D shown in FIG. 4 is at the lower inverted position, and similarly point U is at the upper inverted position. As shown in FIG. 5, the swing rotational speed of the wiper shaft 31 by the pivot lever 30 connected to the connecting rod 29 can be made very slow near the time of reversal and fast in the middle of wiping.

In this way, since the speed before and after the reversal is extremely slow, the inertial force is also very small, so there is little impact during the reversal, and the reversal can be performed smoothly and quietly, while at the same time, no unreasonable force is applied. Therefore, durability can be improved.

As described above, in the present invention, a ball bearing is held at the tip of the crank arm that is locked to the wiper motor rotating output shaft via an eccentric mechanism, and the length of the crank arm is set to an ellipse for one rotation of the crank arm. The swing motion speed of the wiper shaft is changed to
Since the speed is extremely slow before and after the upper and lower reversal positions, the impact noise when the wiper is reversed can be significantly reduced, making it quieter and at the same time improving the durability of the wiper.

[Brief explanation of drawings]

FIG. 1 is a schematic system diagram of the main parts of a conventional wiper device, in which FIG. 1A is a side sectional view of the crank arm, FIG. Fig. 1C is a side sectional view of the wiper shaft portion, Fig. 2 is a diagram of the wiper shaft operation characteristics of the wiper device shown in Fig. 1, and Fig. 3 is a schematic sectional view of the main part of the crank arm of the wiper device according to an embodiment of the present invention. , FIG. 4 is a schematic system diagram of the main parts of the wiper device of the present invention, and FIG. 5 is a wiper shaft operating characteristic diagram of the wiper device of the present invention. 21... Crank arm, 22... Ball bearing, 2
3...Eccentric plate, 25...Small external gear, 27
...Large external gear, 26...Wiper motor rotation output shaft.

Claims (1)

[Claims] 1. An eccentric plate 23 is pivotally supported at the tip of a crank arm 21 that is locked to a wiper motor rotation output shaft 26, and a ball bearing 22 that supports a link mechanism to the wiper shaft is mounted on one surface of the eccentric plate 23, and a ball bearing 22 is mounted on the other surface of the eccentric plate 23 to support a link mechanism to the wiper shaft. An external gear 25 is provided, and the external gear 25 is meshed with a stationary large external gear 27 so as to be able to rotate and revolve according to the rotation of the crank arm 21, and the output shaft rotates for one rotation of the crank arm 21. The length from the center of 26 to the center of the ball bearing 22 is 2 degrees, which is the maximum and minimum length,
A wiper device characterized by transmitting rocking motion to a wiper shaft.