JP2002187405A - Rim for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce road noises without utilizing parts other than a rim and improve durability while reducing cost. SOLUTION: Two or more salients 6 formed by partially extruding a ledge part 5 of a rim 1 toward radially outer side are provided in the ledge part 5 while properly spaced apart from each other in the circumferential direction of the ledge part 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rim for an automobile, and more particularly, to a rim for a disc wheel for an automobile which can reduce road noise.

[0002]

2. Description of the Related Art Conventionally, in a vehicle tire, road noise is deteriorated due to air column resonance of a cavity (closed space) formed between an inner peripheral surface of the tire and an outer peripheral surface of a rim of a disk wheel. Are known. This is because the cavity formed by the tire and the rim has the same cross-sectional area in the circumferential direction of the tire, so that the resonance of the cavity is constant regardless of the rotation of the tire, and is always the same at a constant frequency. This is because they are vibrated in the direction.

As a method of suppressing the deterioration of the road noise, a plurality of movable shield plates are attached to a rim well portion,
When running, this shield plate is erected by centrifugal force to partition the above-mentioned lumen, and shifts the resonance frequency of air column resonance to a vibration frequency region that does not cause a problem of road noise so as to reduce road noise. Japanese Patent Laid-Open No. 11-2
No. 45605. This is referred to as a first conventional technique.

[0004] A flexible ring having a plurality of partitions for partitioning the lumen is inserted into the tire,
Patent No. 3 that reduces road noise as described above
No. 003478 discloses it. This is referred to as a second conventional technique.

[0005]

In the first and second prior arts, a shield plate and a flexible ring formed separately from the disk wheel are attached.
In addition to the increase in cost, in the first conventional technique, the tire may hit the shield plate when the tire is assembled, and the shield plate may be damaged.

Accordingly, the present invention aims to reduce the road noise by changing the change in the circumferential cross-sectional area of the lumen by the deformation of the rim itself, and to reduce the road noise. It is an object of the present invention to provide a rim for an automobile which specifies the position of a deformed portion so as not to hinder the mounting of a tire or a disk.

[0007]

In order to solve the above-mentioned problems, a first aspect of the present invention is directed to a convex portion formed by partially bending a ledge portion of a rim outward in a radial direction. Are provided at appropriate intervals in the circumferential direction of the ledge portion.

In the present invention, the cross-sectional area of the cavity formed by the tire and the rim is reduced in the circumferential direction of the tire by forming the protrusion at the ledge portion of the rim at appropriate intervals in the circumferential direction. (Rotational direction). for that reason,
The cross-sectional area of the cavity at the ground contact surface of the tire changes with the rotation of the tire, and the resonance frequency changes and the vibration direction changes with the rotation of the tire. Therefore, road noise can be reduced.

According to a second aspect of the present invention, in the first aspect of the present invention, the convex portion is formed such that a sectional area of a cavity surrounded by a rim and a tire is approximately 2.50 in a circumferential direction. It is formed so as to reduce by 5%.

The change in the cross-sectional area of the cavity in the circumferential direction may be 2.5% or more, but even if it is approximately 2.5%, it is possible to sufficiently reduce road noise practically. it can.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described based on an embodiment shown in FIGS.

FIG. 1 is a longitudinal sectional view showing a state where a tire is mounted on a rim of a disk wheel according to the present invention. The tire 3 is mounted on the vehicle. A sealed cavity 4 is formed between the outer peripheral surface of the rim 1 and the inner peripheral surface of the tire 3.

The shape of the rim 1 will be described with reference to FIGS.

The ledge portion 5 of the rim 1 is formed with convex portions 6 at appropriate intervals in the circumferential direction, and the convex portions 6 partially displace the rim itself outward by a molding die or the like. (Outside of the direction). Here, the ledge portion 5 is a portion excluding a beat portion 7, 8 in which the tire 3 is fitted and a drop portion 9 in which the disc 2 is fitted and fixed, as shown in FIG. The part shown in the range of D is referred to.

The top of the projection 6 is formed in a substantially perfect circle centered on the axis of the rim, and the recess 10 is formed in a substantially perfect circle centered on the axis of the rim.

As described above, by forming the convex portion 6 partially in the circumferential direction, the convex portion 6 and the portion other than the convex portion 6 are formed in the ledge portion 5 in the circumferential direction, that is, in the tire rotation direction. The formed recesses 10 are formed alternately.

The convex portion 6 and the concave portion 10 have a cross-sectional area in the circumferential direction of the cavity 4 surrounded by the tire 3 and the rim 1 that is relatively 2% or more between the convex portion 6 and the concave portion 10. Desirably, it is formed so as to change by about 2.5%. That is, the convex portion 6 is formed such that the cross-sectional area of the cavity portion 4 in the circumferential direction in the convex portion 6 is reduced by 2% or more, preferably 2.5% from the concave portion 10.

Although a desired number of the protrusions 6 are provided in the circumferential direction of the rim 1, the ledge 5 of the rim 1 is divided into four equal parts in the circumferential direction as shown in the embodiment of FIG. The convex portions 6 and the concave portions 10 are alternately arranged for each of the ranges of 4 and the two convex portions 6 are 18
It is desirable that the two concave portions 10 are arranged so as to face each other at a distance of 0 degrees and face each other at a distance of 180 degrees.

As described above, the unevenness is formed in the ledge portion 5 of the rim 1 to change the cross-sectional area of the cavity portion 4 in the circumferential direction, that is, in the tire rotation direction. The grounding of the tire 3 at the portion where the convex portion 6 is located and the grounding of the tire 3 at the portion where the concave portion 10 is located are performed alternately. As a result, the resonance frequency of the air column resonance can be changed so that road noise does not become a problem, and the vibration direction can be changed.

The experiment was performed using a wheel in which the convex portion 6 and the concave portion 10 were arranged at the positions of the embodiment shown in the figure, and the sectional area of the cavity 4 was changed by 2.5% in the circumferential direction. As a result, the frequency 200 at which road noise occurs
At ~ 300 Hz, the road noise was reduced by 3-6 dB.

The present invention is not limited to a two-piece plate wheel as in the above embodiment, but can be applied to a one-piece wheel such as casting and forging. Similar effects can be obtained.

[0022]

As described above, according to the present invention, road noise can be reduced by forming a convex portion on the ledge portion of the rim. Therefore, the number of components can be reduced and cost can be reduced as compared with the conventional case where a shielding plate or a flexible ring made of a component separate from the rim is provided.

Further, since the convex portion is formed on the ledge portion other than the flange portion and the drop portion which are restricted in order to assemble the tire and mount the disc, the convex portion is formed in the tire assembling and disc fitting. The portion does not hinder, and can be handled in the same manner as a general wheel having no conventional shielding plate or flexible ring.

Furthermore, since the protruding portion is formed by bending the ledge portion of the rim itself, it does not change with time as compared with the conventional shielding plate or flexible ring, and maintains durability equal to the useful life of the wheel. This effect can be maintained over the useful life of the wheel.

[Brief description of the drawings]

FIG. 1, showing an embodiment of the present invention, is a side sectional view in which a tire is mounted on a rim of a disk wheel of the present invention.

FIG. 2 is a perspective view showing an embodiment of a rim according to the present invention.

FIG. 3 is a side sectional view of the rim shown in FIG. 2;

FIG. 4 is a front view of the rim shown in FIG. 2;

FIG. 5 is a sectional view taken along line AA in FIG. 1;

FIG. 6 is a side sectional view illustrating a ledge portion of a rim.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rim 2 Disk 3 Tire 4 Cavity part 5 Ledge part 6 Convex part 10 Concave part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshihiro Moriya 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Yuji 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Inside the Automotive Industry Co., Ltd. (72) Inventor Kiichi Shimizu 2-2, Daito-cho, Anjo-shi, Aichi Chuo Seiki Co., Ltd. (72) Inventor Yasufumi Sugiura 2-2, Daito-cho, Anjo-shi, Aichi Chuo Seiki Co., Ltd. Inside

Claims (2)

[Claims] 1. An automobile, wherein a plurality of convex portions formed by partially bending a ledge portion of a rim radially outwardly are provided at appropriate intervals in a circumferential direction of the ledge portion. rim. 2. The rim for an automobile according to claim 1, wherein the convex portion is formed such that a sectional area of a cavity surrounded by the rim and the tire is reduced by approximately 2.5% at the convex portion in the circumferential direction. .