JP2000233693A - Sound absorbing wheel cover for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound absorbing performance effective for reduction in noise by providing a body part formed of a rigid material fixed to partially cover a wheel, and a plurality of sound absorbing chambers fixed to the opposite surface to the wheel of the body part or one end of the body part, opened to the opposite surface to the wheel and closed in the other end. SOLUTION: A sound absorbing chamber 24 is formed so as to extend in the circumference direction of a wheel on the inner wall surface of a wheel house liner 23. The opening part of the sound absorbing chamber 24 is not formed linearly in the thickness direction of the wheel but randomly formed, and opened to the end part closest to the ground of the sound absorbing chamber 24. The sound absorbing chamber 24 is partitioned on the inner wall surface, which is the opposite surface to the wheel, of the body part 25 of the wheel house liner 23, in the thickness direction of the wheel. A plurality of sound absorbing chambers 24 is integrally formed with the body part 25 of the wheel house liner 23. The sound absorbing chambers 24 partitioned on the inner wall are opened to both ends of the body part 25 and partitioned toward the center.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle sound absorbing wheel cover for absorbing tire / road noise in vehicles such as automobiles and trucks.

[0002]

2. Description of the Related Art In recent years, external noise generated by vehicles such as automobiles and trucks has become a serious problem in everyday life for residents in large cities and around highways along with air pollution caused by exhaust gas. As a noise source of such external noise, an engine (50
%), Exhaust system (20%), tires (15-20%), and the like.

[0003] Further, when the vehicle is running at high speed and steady, the engine speed is kept low, so that the relative proportion of the noise from the engine, which is outside the vehicle, is reduced, and the noise from the tire as a sound source has become remarkable. . Here, in general, the noise generated from around the tires when the vehicle is running at a high speed has a loud sound having a frequency around 800 to 2 kHz.

[0004] Regarding the reduction of the noise of the engine system, the noise is reduced mainly by employing a shielding structure such as an engine block cover, an engine cover, and a body side cover. In addition, measures to reduce the noise generated from the exhaust system are taken by mufflers. In vehicles such as trucks, the attachment of a body side cover was also effective in reducing noise.

In order to reduce the noise generated from the tire, the noise is reduced by changing the rigidity and the pattern shape of the tire. However, with regard to the reduction of noise generated from tires, from the viewpoint of safety such as running stability, wet performance, braking distance stability, etc., the rigidity and pattern shape were changed to significantly reduce noise. Could not be obtained.

[0006] In addition, since the tires are rotating when the vehicle is running, there is also a problem that it is not possible to cover the sound generated by attaching a cover like an engine or the like.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a sound absorbing wheel cover for a vehicle having high sound absorbing performance which is effective for reducing noise generated from tires. .

[0008]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventor has repeatedly studied a vehicle wheel cover, and as a result, the vehicle wheel cover has a surface facing the wheel.
It has been found that the above problem can be solved by providing a plurality of sound absorbing chambers with open sound absorbing portions. That is, the vehicle sound-absorbing wheel cover of the present invention is fixed to the vehicle body and formed of a rigid material that covers a part of the wheel, and is fixed to a surface of the main body portion facing the wheel or one end of the main body portion. And a sound-absorbing section having a plurality of sound-absorbing chambers that are open on the surface opposite to the sound-absorbing member and have the other end closed.

The sound absorbing wheel cover for a vehicle according to the present invention has a sound absorbing chamber opened on a surface facing the wheel, so that the sound absorbing chamber functions as a branch pipe type resonance chamber, and absorbs noise generated around the wheel. , Noise can be reduced.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A sound absorbing wheel cover for a vehicle according to the present invention has a main body and a sound absorbing part. Here, the wheel cover includes not only a wheel house cover of the vehicle but also a mudguard arranged behind the wheel in the vehicle. The main body is formed of a rigid material fixed to the vehicle body and covering a part of the wheel. That is, it is a member that maintains the rigidity of the wheel cover having the sound absorbing portion and attaches the wheel cover to the vehicle body. The material of the main body may be any material such as resin and metal as long as it is a member having rigidity.

The sound absorbing portion is a member having a plurality of sound absorbing chambers fixed to the surface of the main body facing the wheel or one end of the main body, opened on the surface facing the wheel and closed at the other end. The sound absorbing portion is fixed to a surface of the main body facing the wheel or to one end of the main body. That is, being fixed to the surface of the main body facing the wheel means that the sound absorbing part is fixed in the wheel house, and being fixed to one end of the main body is outside the wheel house like mudguard. To be fixed to

The sound absorbing section has a plurality of sound absorbing chambers which are open on the surface facing the wheel and whose other end is closed. The sound absorbing room
It functions as a branch pipe type resonance chamber, and the sound generated from around the wheel is designed to bend at the opening at the resonance frequency depending on its length, thereby reducing the sound pressure.
For this reason, the sound absorbing chamber is opened on the surface facing the wheel.

The sound absorbing chamber is preferably partitioned into a tubular shape. Dividing the sound absorbing chamber into a tubular shape can be easily formed because the internal shape of the sound absorbing chamber is not complicated. In addition, the tubular shape of the sound-absorbing chamber is a state in which it is opened on the surface facing the wheel and the other end is closed, and its cross-sectional shape is not particularly limited. And a polygonal shape such as a square.

The sound absorbing section may be any member as long as it can define the sound absorbing chamber. The sound absorbing section may be formed of the same member as the main body section as long as the sound absorbing chamber is partitioned. Further, any material may be used as a material constituting the sound absorbing portion. That is, it can be formed of a material such as a metal and a resin. Also, the sound absorbing portion and the main body portion may be joined by any joining method that can be used for joining the respective materials. For example, bonding with an adhesive, welding, caulking, screwing, and the like can be given.

[0015] The length of the sound absorbing chamber from the opening to the other end of the surface facing the wheel is one of the wavelength of the sound to be absorbed.
/ 4 is preferred. In general, a branch pipe type resonance chamber has an effect of effectively absorbing a sound of a specific frequency. In this resonance chamber, the frequency of sound that can be absorbed changes depending on the length from the opening of the resonance chamber to the other end.

Specifically, when the resonance chamber has a tubular shape with one end open and the other end closed, the length is four times the length from the opening with one end open to the other end. The sound having the wavelength having the wavelength can be efficiently absorbed. That is, the incident wave that has entered the inside of the resonance chamber through the opening passes through the resonance chamber, is reflected at the other end, and is radiated from the opening outside the resonance chamber as a reflected wave after passing through the resonance chamber again. here,
At the opening of the resonance chamber, the phase of the incident wave and the reflected wave is 18
When there is a phase difference of 0 degrees, the incident wave and the reflected wave cancel each other, and the amplitude becomes zero.

The 180-degree phase difference is 1 in terms of wavelength.
/ 2 wavelengths. In order for a phase difference of １ ／ wavelength to occur when an incident wave reciprocates from the opening to the other end, the distance between the opening and the other end needs to be ４ wavelength. Therefore, by using a tubular sound-absorbing chamber having a length of 1/4 of the wavelength of the sound of the frequency to be absorbed, the sound of that frequency can be absorbed.

The sound absorbing chamber preferably absorbs sound having a frequency of 200 to 5 kHz. For sound having a frequency of less than 200 Hz, the length of the sound absorbing chamber that absorbs sound having a frequency in this range becomes long, and it becomes difficult to attach the vehicle wheel cover to the vehicle. On the other hand, for a sound having a frequency exceeding 5 kHz, the length of the sound absorbing chamber is shortened, and the sound absorbing chamber does not function as a branch pipe type resonance chamber. In addition, this 200-5
The length of the sound absorbing chamber corresponding to the frequency range of kHz is 425.
１７17 mm. A more preferred frequency range is 800
２2 kHz. That is, in general, the noise generated from around the tires when the vehicle is running at a high speed is 800 to 2 kHz.
Sound at frequencies near z is loud, and it is preferable to absorb sounds at frequencies in this range. The length of the sound absorbing chamber corresponding to the frequency range of 800 to 2 kHz is 106 to 42.5.
mm.

It is preferable that the sound absorbing chamber is partitioned into a bent tube. That is, when the sound absorbing chamber is bent, the length of the sound absorbing chamber can be increased, and low-frequency sound can be absorbed. It is preferable that the sound absorbing chamber extends upward from an opening that opens on a surface facing the wheel. Here, the upper position indicates a relative upper position, not an upper position in the vertical direction. Specifically, it extends vertically upward and diagonally upward. This is to prevent muddy water and the like that has jumped up from remaining in the sound-absorbing chamber when the vehicle passes through a puddle or the like when extending downward.

That is, it is preferable that the opening is directed downward from the horizontal direction so that muddy water or the like that has entered the sound absorbing chamber can be removed by gravity. It is preferable that the sound absorbing section is divided into a plurality of sound absorbing chambers that absorb sounds of different wavelengths. That is, by dividing a plurality of sound absorbing chambers having different lengths, sounds having different wavelengths can be absorbed.

The vehicle equipped with the vehicle sound absorbing wheel cover of the present invention can be applied not only to ordinary passenger cars but also to vehicles such as trucks.

[0022]

The present invention will be described below with reference to examples. As an example, a wheel house liner, a wheel house and a mudguard used in an actual vehicle were produced. (Example 1) Example 1 is a wheel house liner used for a passenger car. FIG. 2 shows the wheel house liner of the first embodiment. The wheel house liner according to the first embodiment is a member mounted on a surface of a wheel house of a vehicle facing a wheel. Here, an example of mounting the wheel house liner 20 of the first embodiment is shown in the vehicle diagram of FIG.

The wheel house liner 20 of the first embodiment
A plurality of sound-absorbing chambers 21 that are opened on the surface of the body portion 22 of the wheel house liner facing the wheel are integrally defined. That is, the sound absorbing chamber 21 is defined on the inner wall surface of the main body 22 that is the surface facing the wheel so as to extend in the circumferential direction of the wheel. A plurality of partitioned sound absorbing chambers 21
Are arranged in a straight line in the thickness direction of the wheel. Further, a sound absorbing chamber 21 is defined so as to protrude from the inner wall surface of the wheel house liner 20 toward the wheel. Further, the opening of the sound absorbing chamber 21 is open to the end of the sound absorbing chamber 21 closest to the ground. That is, the sound absorbing room 2
By forming an opening at the end near the ground, even if the water passes through a puddle and jumps up when the vehicle runs, the water does not stay in the sound absorbing room.

The sound-absorbing chambers have a length of about 50 to 100 mm and are arranged at 5 to 10 places. Here, the wheel house liner of Example 1 was manufactured by molding a resin material such as PP-EPDM. As another form of the wheel house liner of the first embodiment, there is a form in which the opening of the sound absorbing chamber 21 is randomly arranged on the inner wall surface facing the wheel. That is, the sound absorbing chamber is defined on the inner wall surface of the wheel house liner 23 so as to extend in the circumferential direction of the wheel, and the opening of the sound absorbing chamber is not formed linearly in the thickness direction of the wheel but randomly opened. A part is formed.
At this time, the sound absorbing chamber is open at the end closest to the ground. Fig. 3 shows a part of the inner wall of this wheel house liner.
It was shown to.

(Embodiment 2) In the wheel house liner 23 of Embodiment 2, the sound absorbing chamber 24 is
3 is a wheel house liner similar to that of the first embodiment except that the sound absorbing chamber 24 is partitioned in parallel to the axis of the wheel on the inner wall surface facing the wheel of the main body 25, that is, in the thickness direction of the wheel. is there.

The wheel house liner 23 of the second embodiment
In the main body 25 of the wheel house liner 23, a plurality of sound absorbing chambers 24 are integrally defined. FIG. 4 shows the inner wall surface of the wheel house liner 23 of the second embodiment. FIG.
Thus, the sound absorbing chamber 24 partitioned on the inner wall surface is partitioned so as to open toward both ends of the inner wall surface of the main body 25, that is, open in the axial direction of the wheel and extend toward the center.

The sound absorbing chamber 24 has a length of about 40 to 120 mm and is arranged at 5 to 10 places. (Embodiment 3) Embodiment 3 is a wheel house used for a rear wheel of a truck. An installation example of the wheel house of the third embodiment is shown in a vehicle diagram of FIG. FIG. 6 shows the wheel house 30 of the third embodiment.

The wheel house 30 of the third embodiment is formed in a substantially rectangular shape so as to cover a part of the wheel. The peripheral edge of the front and rear ends of the wheel house 30 is formed to have a large bulk thickness, and a sound absorbing chamber 31 is opened on the opposite surface side. The wheel house 30 according to the third embodiment includes the sound absorbing chamber 3
1 are integrally formed. The sound absorbing chamber 31 is formed into a tubular shape having one end opened on the surface facing the wheel and the other end closed. Here, the cross-sectional shape of the tubular sound absorbing chamber 31 is formed in a rectangular shape.

The sound absorbing room 3 partitioned by the wheel house 30
1 is about 40 to 120 mm in length and 2
About 0 places were located. Here, the wheel house liner of Example 3 was manufactured by molding a metal or resin material. (Embodiment 4) Embodiment 4 is a mudguard used for the front wheels of a truck. An installation example of the mudguard of Example 4 is shown together with the vehicle diagram of FIG. Further, the mudguard of Example 4 was replaced with the one shown in FIG.
It was shown to. The mudguard 40 of the fourth embodiment is mounted on the bottom surface side of the vehicle at the joint end between the bottom surface of the vehicle and the lower end of the wheel house.

As shown in FIG. 7, the mudguard 40 of the fourth embodiment is formed in a substantially triangular shape whose cross-sectional shape is convex downward from a contact surface fixed to the bottom surface of the vehicle. . In this substantially triangular shape, the surface facing the wheel is formed in a shape obtained by extending the curved shape of the wheel house. Further, the mudguard 40 of the fourth embodiment has a sound absorbing chamber 41 which is open at one end on a surface facing the wheel, extends obliquely from this opening, and is partitioned into a tubular shape with the other end closed.

The sound absorbing chamber 41 divided into mudguards 40
They were arranged at about 20 locations with a length of about 0 to 120 mm. (Embodiment 5) Embodiment 5 is a mudguard used for a front wheel of a truck, and is attached to a joint end portion between a wheel house of the front wheel and a bottom surface of a vehicle. The mudguard of Example 5 is shown in FIG.

Referring to FIG. 8, the mudguard 45 of the fifth embodiment has a contact surface with the vehicle such that it can contact the lower end of the wheel house and the end of the bottom surface of the vehicle joined to the lower end. . In the mudguard 45 according to the fifth embodiment, the facing surface facing the wheel is formed in a shape obtained by extending the curved shape of the wheel house. In addition, a sound absorbing chamber 46 that is open to the facing surface is defined. The sound absorbing chamber 46 is partitioned into a tubular shape that extends vertically upward after proceeding to the inside of the mudguard 45 from the opening.

The sound absorbing chamber 46 partitioned by the mudguard 45 has 4
They were arranged at about 20 locations with a length of about 0 to 120 mm. The mudguards of Examples 4 and 5 are mudguards mounted on trucks, but may be used in ordinary passenger cars as is apparent from the shape. The wheel covers of Examples 1 to 5 have a sound-absorbing chamber opened on a surface facing the wheel, and the sound-absorbing chamber functions as a branch pipe type resonance chamber. Can reduce the noise generated.

The wheel house liners of the first and second embodiments can be easily mounted even when it is relatively difficult to secure a space for mounting such as a wheel house of a passenger car. In addition, the usual wheel house cover is made of thin resin, so rigidity is insufficient and it is difficult to install it.However, the structure of the sound absorbing room can be replaced with ribs, so it can be easily installed on the vehicle. Has become.

[0035]

The sound absorbing wheel cover for a vehicle according to the present invention is
By having a sound-absorbing chamber opened on the surface facing the wheel,
This has the effect that sound can be absorbed in the vicinity of the wheel.
Further, by adjusting the length of the sound absorbing chamber, a sound of a predetermined frequency can be absorbed. In addition, the sound absorbing wheel cover for a vehicle of the present invention does not require a complicated process for attachment to the vehicle, and therefore is a sound absorbing wheel cover for a vehicle with low cost and high sound absorbing effect.

[Brief description of the drawings]

FIG. 1 is a diagram of a passenger car having a wheel house liner.

FIG. 2 is a diagram of a wheel house liner according to the first embodiment.

FIG. 3 is a view showing another embodiment of the wheel house liner of the first embodiment.

FIG. 4 is a diagram of a wheel house liner according to a second embodiment.

FIG. 5 is a diagram of a truck having mudguards.

FIG. 6 is a sectional view of a wheel house according to a third embodiment.

FIG. 7 is a cross-sectional view of a mudguard according to a fourth embodiment.

FIG. 8 is a cross-sectional view of a mudguard according to a fifth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Passenger car 15 ... Truck 20 and 23 ... Wheel house liner 21, 24 ... Sound absorption room 22, 25 ... Body part 30 ... Wheel house 31 ... Sound absorption room 40, 45 ... Mudguard 41, 46 ... Sound absorption room

Claims (4)

[Claims] 1. A main body fixed to a vehicle body and formed of a rigid material covering a part of a wheel, and fixed to a surface of the main body facing the wheel or one end of the main body and facing the wheel. A sound-absorbing wheel cover for a vehicle, comprising: a sound-absorbing portion having a plurality of sound-absorbing chambers that are open on the surface and have the other end closed. 2. The sound-absorbing chamber is characterized in that the length from the opening that opens to the surface facing the wheel to the other end is １ ／ of the wavelength of the sound to be absorbed. The vehicle sound absorbing wheel cover according to claim 1. 3. The sound absorbing wheel cover for a vehicle according to claim 1, wherein the sound absorbing chamber is partitioned into a bent tube. 4. The sound absorbing wheel cover for a vehicle according to claim 1, wherein the sound absorbing section includes a plurality of sound absorbing chambers for absorbing sounds of different wavelengths.