JPH0336450Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a wiper arm for a vehicle, and particularly to a wiper arm for a vehicle whose structure is improved.

[Prior Art] A vehicle wiper mechanism for wiping the windshield surface of a vehicle during rain or other driving is well known, and FIG. 4 schematically shows such a vehicle wiper mechanism. In the figure, a wiper shaft 12 is provided on a cowl top 10 on the vehicle body side so as to be rotatable in a reciprocating manner, and a wiper head 14 is fixed to the wiper shaft 12 and rotates in a reciprocating manner together with the wiper shaft. is wiper arm 1
6, and this wiper arm 16 has a wiper blade 20 at its tip for wiping the glass surface of the window glass 18.

The wiper blade 20 is biased in the direction of arrow A by the arm spring 22 as shown in FIG.
8 is pressed against the glass surface.

As a result, as the wiper shaft 12 reciprocates, the wiper blade 20 performs a desired reciprocating wiping action.

In the above, the wiper arm 16 has a sixth
As shown in the figure, the cross section is usually bent into a substantially U-shape, and weight reduction is achieved while maintaining the necessary strength.

[Problems to be Solved by the Invention] Conventional Problems However, according to the structure of the conventional wiper arm 16, when the vehicle is running, a high-frequency whistling sound is generated from the wiper arm 16 at a constant speed, which may be harmful to the occupants. was causing discomfort.

This occurs when the vibration frequency caused by the velocity of wind flowing through the gap between the front body panel and the wiper arm 16 matches the natural resonance frequency of the wiper arm 16 when the vehicle is running, causing resonance and a loud whistling sound. However, in order to eliminate this whistling noise, it was necessary to change the speed of the vehicle or change the design of the wiper arm 16 to change its structure.

Purpose of the invention This invention was made in order to solve the above problem, and its purpose is to provide a wiper arm for a vehicle that can easily prevent whistling noise from the wiper arm at normal vehicle speeds.

[Means and effects for solving the problem] The wiper arm for a vehicle according to this invention improves resonance characteristics when the vehicle is running by providing a resonance prevention material on the inner wall that is bent to have a hollow space inside. It is characterized by being able to change.

As described above, the volume of the hollow space formed by the inner wall of the wiper arm changes, and the resonance frequency of the wiper arm can be easily changed.

Therefore, it is possible to effectively and easily prevent the whistling sound that has conventionally occurred at regular vehicle speeds.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows an external view of a wiper arm according to the present invention.

In the same figure, this wiper arm 24 is formed by bending a metal plate so as to have a hollow space inside, and has a U-shaped cross section as shown in FIG. 2, for example, and maintains a certain strength and Efforts are being made to reduce its weight.

The characteristic feature of the present invention is that the wiper arm 2
In this embodiment, a rubber or iron plate or the like is attached to the side wall 24a on the opening side, which has a U-shaped cross section, by appropriate means such as adhesion or welding. There is.

In this case, the anti-resonance material 26 is
It is effective to attach it over 1/3 or more of the length of 4a in the longitudinal direction.

In general, the resonant frequency n of a box body is expressed as n=v√/2π when the volume of the resonant box 28 is V and the flow velocity is v when looking at a resonator as shown in FIG. In this case, if S is the cross-sectional area of the mouth and l is the effective length of the neck, then A=l/S. Based on this principle, in this example,
Although v changes depending on the vehicle speed and the wind velocity, assuming that this is constant, the resonance frequency n is inversely proportional to the square root of the volume v formed by the side wall of the wiper arm 24.

Therefore, in this embodiment, the above n is changed by changing the cross-sectional area of the U-shape.

The resonance prevention material 26 is attached to the inner walls 24a, 24b, 24c of the wiper arm 24.
It may be in any aspect.

[Effects of the invention] As explained above, this invention eliminates the unpleasant whistling sound that previously occurred at normal vehicle speeds by providing a resonance prevention material on the inner wall that is bent to have a hollow space inside. can be effectively and easily eliminated.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view of a wiper arm for a vehicle according to the present invention, Fig. 2 is a sectional view taken along line BB, Fig. 3 is a diagram explaining the principle of a resonator, and Fig. 4 is a schematic cross-sectional side view of a wiper mechanism for a vehicle. FIG. 5 is an explanatory diagram showing the state in which the wiper arm is attached, and FIG. 6 is a cross-sectional view of the wiper arm. 24...Wiper arm, 26...Resonance prevention material.

Claims (1)

[Scope of utility model registration request] A wiper arm for a vehicle is provided with a wiper blade attached to the front surface of a car body windshield for wiping the glass surface, and which is bent to have a hollow space inside, and an anti-resonance material is provided on the bent inner wall. A wiper arm for a vehicle is characterized in that resonance characteristics when the vehicle is running are changed by providing the wiper arm.