JPH0124656B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wiper device for ensuring visibility through a windshield of a vehicle, and more particularly to a wiper driving method and device for reducing operating noise of a swinging wiper device.

As shown in FIG. 1, the conventional configuration is such that a wiper blade 3 is rotatably fixed to the tip of a wiper arm 1 with a pin 4, and a coil spring 5 installed in a retainer 2 of the wiper arm moves the wiper blade 3 to a wind surface 6. The motor crank arm 7 and the link 8 swing the pivot lever 10, which is locked to the wiper shaft 9 as shown by the arrow A-A, to perform a wiping operation on the window surface 6.

In a wiper device having such a configuration, the wiping operation speed characteristics of the pivot lever 10 and, by extension, the wiper blade 3 with respect to the uniform rotation of the motor crank arm 7 are sinusoidal with respect to the passage of time on the horizontal axis, as shown in Fig. 2a. Draw a wave profile. The distance between A ₁ and A ₂ is the upstroke, and the distance between A ₂ and A ₃ is the downstroke. And A ₁ , A ₂ ,
Point A ₃ , ... is the point of reversal of the wiper blade.

On the other hand, since the coil spring 5 for pressurization is attached to the retainer 2 of the wiper arm 1,
As shown in FIG. 2b, the pressing force F against the window surface 6 is finite and constant in each stroke, and its finite value is determined by various conditions such as wiping performance and high-speed floating performance.

Therefore, at the reversal point A ₁ and the stroke A ₁ A ₂ , the wiper blade ₃ moves with the blade rubber largely tilted to the left in the figure, as shown in FIG. Since the moving direction is reversed, the wiper blade 3 is tilted significantly to the right in FIG. 2c. This is an inversion.

For this reason, the wiper blade 3 is impactfully struck against the window surface 6 by the pressing force F shown in FIG. The radiation, some of which is transmitted through the link mechanism, causes the car body to vibrate and generate harsh noise.

This is a reversal sound, which has the drawback of greatly impairing comfort and at the same time significantly reducing the durability of the wiper blade.

This invention was made to eliminate these conventional drawbacks, and its purpose is to reduce the reversal noise, improve the comfortable sound, and improve the durability.

An apparatus using the first embodiment of the method of the present invention will be described below.

The wiper arm 1 is integrally made of sheet metal, die casting, resin, etc. and has a free shape, and is integrally assembled with a nut 12 to a wiper shaft 9 that is pivotally supported by a holder 11 attached to the vehicle body. A wiper blade 3 is rotatably fixed to the tip of the wiper arm 1 with a pin 4, similar to conventional devices.

On the other hand, the pivot lever 10 of the wiper shaft 9
On the side, a pendulum arm 14 with a weight 13 attached to its tip is held between the holder 11 and the pivot lever 10. The pendulum arm 14 engages with the rotation of the wiper shaft 9 so that the pendulum arm 14 swings integrally with the swing movement of the pivot lever 10.

Specifically, this engagement relationship is such that the portion of the wiper shaft 9 that passes through the pendulum arm 14 has a non-circular cross section such as an oval shape, and the through hole of the pendulum arm 14 that the shaft 9 passes through also has a non-circular cross section such as an oval shape. This can be achieved by making the cross section circular.

Further, the pivot lever 10 is connected to the link 8 and the motor crank arm 7.

The operation of the device of this first embodiment will be explained.

In response to uniform rotation of the motor crank arm 7, the pivot lever 10 performs a swinging motion according to the link motion of the link 8 as indicated by arrows A'-A' in the third figure. At the same time, the pendulum arm 14, which is supported in conjunction with the pivot lever 10, also performs a swinging motion like the pivot lever 10, and the other end 14a of the pendulum arm 14 slides on the lower end of the holder 11. At this time, since the weight 13 is attached to the tip of the pendulum arm 14, Fc=mrω ² (m: mass of the weight, r: length of the pendulum arm, ω: Swinging angular velocity).

Therefore, a force always acts between the holder 11 and the pivot lever 10 in response to the swinging motion to push them open by a component of the centrifugal force Fc. This force is transmitted to the wiper shaft 9, passes through the wiper arm 1, acts on the wiper blade 3, and becomes a pressing force F against the window surface 6.

On the other hand, since the pivot lever 10 is fixed to the wiper shaft 9, the swinging motion of the pivot lever 10 becomes a swinging wiping motion on the wind surface 6 of the wiper blade 3 via the wiper shaft 9 and the wiper arm 1. In other words, an oscillating wiping movement is performed in which a pressing force corresponding to the oscillating movement acts.

The movement of the motor crank arm and link shown in FIG. 3 is a conventionally well-known movement, and its characteristics are sinusoidal as shown in FIG. 4a, similar to those in FIG. 2a. That is, the angular velocity of the pivot lever 10 is zero at the reversal points A ₁ ′, A ₂ ′, A ₃ ′, etc., and the angular velocity of the pivot lever 10 is zero during the wiping period of A ₁ ′A ₂ ′, A ₂ ′A ₃ ′, etc. from reversal to reversal. It has a finite, gently changing angular velocity characteristic.

Therefore, the centrifugal force F acting on the weight 13 reaches a reversal point as shown in FIG. 4b, depending on the velocity characteristics shown in FIG. 4a.
In A ₁ ′, A ₂ ′, A ₃ ′..., it becomes zero, and in other eradication periods, it becomes a certain finite and gently changing characteristic, and in the end,
The wiping behavior of the wiper blade 3 on the window surface 6 is as shown in FIG. 4c, when the wiper blade 3 is reversed, the blade rubber receives almost no pressing force and changes direction in a free and straight state.

During the upstroke of wiping, _the rubber tilts to the left ( _Fig .
At A ₂ ′ A ₃ ′, the rubber tilts to the left and performs a good wiping operation. In this way, when the wiper blade is reversed, the pushing force on the wiper blade is zero, so the reversal is effortless and no impact is applied to the blade, so the reversal can be performed smoothly and quietly, and at the same time, the blade rubber itself has a large impact. Because no force is applied,
Durability can be improved.

Next, other embodiments will be described.

First, as another embodiment, a certain finite pressing force F is applied even during reversal, but it is characterized in that it is lower than the pressing force during other wiping strokes. A second embodiment of the figure will be described.

This structure is almost the same as that of the first embodiment, but the difference is that the spring 15 is connected to the pendulum arm 14 and the holder 11.
The pressing force F when the wiper blade 3 is reversed is made to be a low value other than zero.

An example of the pressing force characteristic of the blade at this time is as shown in FIG. 6b, which is a positive finite value during reversal, but it is significantly smaller than in other wiping strokes, and it is possible to significantly reduce the reversal impact sound during reversal.

Next, the configuration and operation of FIGS. 7 and 8 will be explained as a third embodiment.

As in the second embodiment, the spring 15 is interposed between the holder 11 and the pivot lever 10 so as to always generate a constant pressing force F'. Further, the slider 16 having an inclined surface is connected to the pivot lever 1.
The end portions of the pivot lever 10 are arranged so as to come into contact and slide at both inversion positions of 0 to produce an appropriate lift, and are configured so that the pressing force becomes zero (or small) at the time of inversion. At this time, the pressing force characteristic of the blade is zero at the time of reversal as shown in FIG. 8b, and the other wiping strokes have a finite constant characteristic, so that the reversal impact sound at the time of reversal can be significantly reduced.

As described above, in the method of the present invention, during the period when the wiper blade is wiping the window surface, the wiper blade is pressed against the window surface while the wiper blade is in the inverted position of both the upper and lower limits of the window surface. Since the force is zero or reduced, the impact noise when the wiper blade is reversed can be significantly reduced, making it quieter. or,
Similarly, there is an effect that the durability of the blade rubber of the wiper blade can be improved.

In addition, a weight is provided that swings together with the wiper blade to reduce the pressing force of the wiper blade and converts its own centrifugal force into a pressing force in the positive or negative direction of the wiper blade, resulting in a simple structure and easy sliding. This has the effect of reducing dynamic contact noise and providing a wiper device that can be used directly in the wiper control method.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a conventional wiper device, FIG. 2 a, FIG. 2 b, and FIG. 2 c are operational characteristic diagrams of the wiper device shown in FIG. 1, respectively, and FIG. 3 is a first implementation of the method of the present invention. A schematic diagram of a wiper device using an example, FIG. 4a, FIG. 4b and FIG. 4c are operational characteristic diagrams of the device shown in FIG. 6a and 6b are characteristic diagrams according to FIG. 5, FIG. 7 is a schematic diagram according to the third embodiment of the present invention,
8a and 8b are characteristic diagrams according to FIG. 7. 6... Window surface, 3... Wiper blade, 1
3... Weight, 9... Wiper shaft, 10... Pivot lever.

Claims (1)

[Scope of Claims] 1. The wiper blade 3 is driven by a wiper shaft 9 that is pivotally supported by a holder attached to the vehicle body, and is equipped with a blade rubber that reciprocates and wipes the wind surface 6. The rotation force is converted into vertical movement of the wiper shaft according to the rotation speed of the wiper shaft, and the pressing force of the wiper blade 3 against the window surface 6 is changed by the vertical movement of the wiper shaft 9, and the rotation of the wiper shaft 9 is A method for driving a wiper, characterized in that the pressing force is reduced to zero or reduced when the upper and lower limits of the wiper blade 3 are reversed when the speed is zero. 2. The wiper blade 3 is driven by a wiper shaft 9 that is pivotally supported by a holder attached to the vehicle body, and is equipped with a blade rubber that reciprocates and wipes the windshield surface 6. The wiper blade 3 engages with the wiper shaft 9 and rotates the wiper shaft. Weight 1 that swings with movement
3, converts the centrifugal force acting on the weight according to the rotating speed of the wiper shaft into vertical movement of the wiper shaft, and presses the wiper blade 3 against the window surface 6 by the vertical movement of the wiper shaft 9. A wiper drive device comprising pressing force changing means 14 and 16 for changing the force and reducing the pressing force when the upper and lower limits of the wiper blade 3 are reversed.