JPS6241148B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved structure of a windshield wiper (hereinafter referred to as a wiper) for wiping the front window glass of an automobile or the like.

The wipers that wipe the front windshield of a car are exposed to wind pressure when the car is running at high speed, and during the back-and-forth wiping operation, especially during the backward movement, the wiper may be lifted off the glass surface. There is a problem in that the glass surface is not wiped properly and the operation of the vehicle is significantly hindered. Particularly, the reason why the wiper floats up during the backward movement is thought to be because the wind speed hitting the wiper during the backward movement is equal to the vehicle speed plus the movement speed of the wiper.

Conventionally, various studies and ideas have been made to prevent the wiper lifting phenomenon.

For example, there is a method of strengthening the elastic force of a spring in a wiper device to make the pressing pressure of the blade against the glass surface stronger than usual. However, in this case, the contact friction resistance between the blade and the glass surface increases, so not only does the motor that drives the wiper device need to be powerful (large and consumes a lot of power), but also when the vehicle is running at low speed. When the vehicle is stopped or when it is drizzling, the wiper vibrates while wiping, resulting in a problem that the wiper cannot wipe properly.

Furthermore, for example, by attaching a wing-like object to the blade's support fitting or support arm, the force of the wind force that presses the blade against the glass surface (reverse lift force)
This causes the floating force to be offset.
In this case, it can be expected in principle that as the wind speed hitting the wing-shaped object increases, a commensurate blade pressing force will be generated, but the wind direction and speed in front of the window glass are not uniform and simple; Since the blade itself rotates and oscillates due to many factors, wipers equipped with the above-mentioned wing-like elements are effective when the angle of attack is appropriate, but depending on the vehicle speed and Depending on the direction of the wind, it may be blown up by the wind and lifted off the glass surface, or vibrations may occur, resulting in poor wiping. Furthermore, the installation of a large wing-like object may obstruct the driver's field of vision, and the increased weight of the wiper may cause structural and operational problems. There were many problems with the conventional ones.

In view of the above, an object of the present invention is to provide a windshield wiper device that can effectively and reliably prevent the wiper from lifting up while solving the conventional problems with a simple configuration. That is.

The present invention will be explained below with reference to the drawings. 1 to 4 show a first embodiment of the device of the present invention, in which 1 is an arm that rotates back and forth by a drive source such as a motor, 2 is a lever pivoted at the tip of arm 1, and 3 is a A pair of yokes are pivotally attached to both ends of the lever 2, 4 is a bucking supported by claws 3a provided at both ends of each yoke 3, and 5 is a blade rubber held by a rubber holding groove 41 provided in the bucking 4. It is made of an elastic material such as rubber. The difference between this embodiment and the conventionally known one is that, as shown in FIG. 4, one side of the backing 4 (portion 4a) is cut away as shown by the broken line. Note that it is not preferable to cut out both sides of the backing 4 or to make the width narrow over the entire length, as this will result in a decrease in the rigidity of the backing 4. The configuration of the backing 4 will be explained in more detail with reference to FIGS. 5 to 8. 4c is the front and back joint of the buckling 4. As is clear here, Batsuking 4 is part 4.
The portion a is asymmetrically cut out. Note that the engagement portion 4b with the yoke 3 is not cut out because the claw portion 3a of the yoke 3 is necessary for gripping the backing 4.

Further, FIG. 9 shows which side the notch portion 4a is on. FIG. 9 is a schematic sectional view of the front window portion of an automobile, where 6 is the front window, 7 is the roof, and 8 is the bonnet. The blade rubber 5 is pressed against the glass surface of the front window 6 by a spring force from a spring (not shown) acting on the arm 1. Here, the notch 4a of the backing 4 is provided on the A side, that is, on the side closer to the bonnet 8.
In other words, since the airflow blows as shown by the arrow in FIG. 9 when the vehicle is running, the notch 4a is provided in the backing 4 so as to be on the upstream side of the airflow.

FIG. 10 shows an enlarged cross-sectional view of the blade rubber 5 and buckling 4 of a conventional wiper. The state of the blade rubber 5 when the wiper is stationary on the glass surface is almost the same as that shown in Fig. 4, but when the wiper is actually in operation, the friction between the blade rubber 5 and the glass surface Therefore, when the wiping direction of the wiper is set to the direction of arrow A shown in FIG. 10, the blade rubber 5 deforms as shown in FIG.
On the other hand, since the backing 4 is supported by the yoke 3, it is held almost parallel to the glass surface 6 as shown in FIG. 10, although there is some play in the claw portion 3a. At this time, the wiping direction is set during the backward stroke where the lifting phenomenon is most problematic. In other words, it is assumed that the wipe is being performed in a direction opposite to the airflow shown by arrow B in FIG. 10 (in the direction of arrow A). When the blade rubber 5 deforms in this way, the blade rubber 5 on the upstream side (4c side)
A large space is created between the upstream side edge 5a and the upstream backing 4c. On the other hand, on the far upstream side, the airflow that was flowing along the surface of the windshield 6 becomes a flow over the blade rubber 5, so an upward airflow occurs in this part as shown by arrow B in FIG. Then, this rising airflow is caused by the upstream side edge 5 of the blade rubber 5.
Since there is a space between a and the upstream backing 4c, a force is generated that pushes up the backing 4 (particularly the 4c portion).

The force mentioned above (hereinafter referred to as "buckling push-up force")
), the bucking 4 and the blade rubber 5 lift up from the glass surface 6. In reality, buoyancy forces occur in addition to the bucking upward force described above. For example, the airflow passing over the mountain at the backing 5 is accelerated at the mountain crossing section. When the airflow is accelerated, static pressure decreases and buoyancy is generated according to Bernoulli's theorem (hereinafter referred to as ``Bernoulli buoyancy''). The bucking push-up force and the Bernoulli buoyancy force are estimated to be approximately the same based on experiments conducted by the present inventors.

FIG. 11 shows the state of the first embodiment of the present invention. Since the upstream side of the bucking 4 is cut out, the rising air flows without pushing up the bucking 4. In other words, the bucking push-up force is hardly generated in this embodiment. Therefore, the lifting characteristics of the wiper are significantly improved.

FIG. 12 shows a second embodiment of the present invention. This is a cutout of the upstream side edge 5a of the blade rubber 5, and is used to reduce the upward force generated by the upward airflow, similar to the bucking upward force. However, this push-up force is not as large as the bucking push-up force, and a significant improvement cannot be expected by using it alone, so it must be done at the same time as cutting out the bucking 4.

A third embodiment of the present invention is shown in FIGS. 13 to 15. By arranging the rubber holding groove 40b of the backing 4 to be shifted upstream from the center line of the backing 4, the upstream backing portion 40a has a narrow width. Since the operating state is shown in FIG. 16, the operation is exactly the same as that in FIG. 11, and almost no bucking and pushing force is generated.

As shown by the two-dot chain line in FIGS. 11, 12, and 16, if a small wing 42 is integrally provided on the downstream side of the bucking 4 to apply a downward force to the bucking 4, the wiper can more reliably prevent floating.

As described above, in the present invention, in order to reduce the protrusion of the backing that holds the blade rubber toward the upstream side of the airflow, the width of the backing on the upstream side of the airflow is formed narrower than the width of the upstream side of the airflow. Even if an upward air current passes over this blade rubber from the upstream side of the rubber, the protrusion of the bucking toward the upstream side of the airflow is extremely small, so the force pushing up the bucking can be greatly reduced by this upward airflow, which results in a large It is possible to reliably prevent the wiper from floating without providing a wing-like object, and since the width of the backing is narrow only on the upstream side of the airflow, the stiffness of the backing does not decrease significantly, which is an excellent effect. There is.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the first embodiment of the device of the present invention, FIG. 2 is a cross-sectional view taken along line A-A' shown in FIG. 1, and FIG. 3 is a cross-sectional view taken along line AA' shown in FIG. 1. FIG. 4 is a cross-sectional view taken along the line C-C' shown in FIG. 1, FIGS. 7
The figure is a cross-sectional view taken along line A-' shown in Figure 6.
The figure is a cross-sectional view taken along the line B-B' shown in Figure 6.
The figure is a schematic sectional view of the front window of a car showing the state in which the device shown in Figure 1 is installed, Figure 10 is a cross-sectional view showing the operating state of the conventional device, and Figure 11 is the operating state of the device shown in Figure 1. FIG. 12 is a cross-sectional view showing the operating state of the second embodiment of the device of the present invention, FIG. 13 is a plan view showing bucking in the third embodiment of the device of the present invention, and FIG. Cross-sectional view along line A-A' shown in Figure 13, No. 15
The figure is a cross-sectional view taken along the line BB' shown in FIG. 13, and FIG. 16 is a cross-sectional view showing the operating state of the third embodiment. DESCRIPTION OF SYMBOLS 1...Arm, 2, 3...Lever and yoke which constitute a bucking holding member, 4...Buckling, 4a...
Notch part, 4b...engaging part, 4c...front and rear joint part,
5...Blade rubber, 6...Front window, 4
0b, 41...Rubber holding groove.

Claims (1)

[Claims] 1. A blade rubber made of an elastic body such as rubber;
A buckling that holds this blade rubber, a buckling holding member that holds this buckling,
In a windshield wiper device comprising an arm that holds the bucking holding member, presses the blade rubber against the glass surface by a spring force, and rotates back and forth by a drive source such as a motor, A windshield wiper device characterized in that the width of this backing on the upstream side of the airflow is narrower than the width on the downstream side of the airflow in order to reduce protrusion toward the upstream side. 2. The width of the upstream side of the airflow of the bucking is narrower than the width of the downstream side of the airflow by providing a notch in a portion other than the front and rear joints of the buckling and the engagement portion with the bucking holding member. A windshield wiper device according to claim 1, characterized in that: 3. Claims characterized in that the width of the bucking on the upstream side of the airflow is narrower than the width on the downstream side of the airflow by providing the rubber holding groove of the buckling upstream of the airflow from the center line. The windshield wiper device according to item 1.