JP2007223425A - Disk wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk wheel capable of preventing the vibration of a tire to be transmitted to a vehicle body via a rim or an axle to form the vibration of air in a cabin, and the air vibration from reaching the ears of an occupant as the road noise. <P>SOLUTION: The disk wheel 20 comprises a rim 24 for fitting and holding a tire 22, and a disk 23 mounted on an axle to hold the rim 24. An iron plate member 52 curved at the radius of curvature smaller than that in the circumferential direction of a drop part 50 is arranged on an outer circumferential surface of the drop part 50 of the rim 24 so that a surface curved in a recess of the iron plate member 52 faces the outer circumferential surface of the drop part 52, and spot-welded at least at one point, and the entire surface curved in the recess of the iron plate member 52 is brought into contact with the outer circumferential surface of the drop part 50. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a disc wheel, and more particularly to a disc wheel that reduces road noise caused by tire vibration.

When the tires vibrate due to road surface irregularities or the like while the vehicle is running, the vibrations are transmitted to the rim and further to the vehicle body via the axle and suspension. The vibration transmitted to the vehicle body becomes air vibration in the passenger compartment and reaches the passenger's ear as unpleasant road noise. For example, in Patent Document 1, a metal band is tightened on the outer periphery of the rim with a fastener, and the resonance point of the rim is shifted away from the frequency band of the air column resonance, so that the vibration from the air column to the rim is reduced. A technique for suppressing transmission and reducing road noise is disclosed.
JP 2005-145172 A

  As described above, the technique disclosed in Patent Document 1 is based on the idea that the transmission of vibration is suppressed by shifting the resonance point, but is not intended to reduce the level of vibration. If the vibration transmitted from the tire itself can be attenuated, road noise can be effectively reduced.

  This invention is made | formed in view of such a condition, The objective is to provide the technique which suppresses transmission of the vibration of a tire and reduces road noise.

  In order to solve the above-described problems, a disc wheel according to an aspect of the present invention includes a rim that mounts and holds a tire, and a disc that is attached to an axle and holds the rim. On the outer peripheral surface of the drop portion of the rim, an iron plate member curved with a curvature radius smaller than the curvature radius in the circumferential direction of the drop portion is arranged so that the concave curved surface of the iron plate member and the outer peripheral surface of the drop portion face each other. Then, at least one spot is spot welded, and the entire concave surface of the iron plate member is in contact with the outer peripheral surface of the drop portion.

  According to this aspect, when the vibration of the tire is transmitted to the rim, friction is generated between the outer peripheral surface of the drop portion and the concavely curved surface of the iron plate member in contact with the surface due to the vibration of the rim. As a result, vibration energy is converted into frictional heat, so that the vibration of the rim is attenuated. As a result, the vibration of the tire is less likely to be transmitted from the rim to other members, so road noise is reduced.

  The width of the iron plate member may be substantially equal to the width of the outer peripheral surface of the drop portion. According to this aspect, the concavely curved surface of the iron plate member is in contact with the outer peripheral surface of the drop portion over a wide range in the width direction. Accordingly, friction can be generated by bringing the drop portion and the iron plate member into contact with each other over a wide range, so that the vibration of the rim can be damped better. As a result, road noise is reduced more favorably.

  The outer peripheral edge of the disc may be welded to the inner peripheral surface of the rim, and the iron plate member may be disposed so as to straddle the welded portion in the axle direction. In this aspect, in the rim, the rigidity of the portion where the outer peripheral edge of the disk is welded is higher than the rigidity of the other portions. The part with low rigidity tends to vibrate compared with the part with high rigidity. Then, if an iron plate member is arrange | positioned so that the welding part with the high rigidity may straddle an axle direction, an iron plate member can be made to contact a part with low rigidity. Accordingly, friction can be generated between the iron plate member and the drop portion even in a portion having low rigidity, so that the vibration of the rim can be damped better. As a result, road noise is reduced more favorably.

  A plurality of iron plate members may be arranged at equal intervals in the circumferential direction of the rim. As a result, the occurrence of eccentricity in the rim can be avoided, so that a good balance can be maintained during wheel rotation.

  According to the disc wheel of the present invention, road noise caused by tire vibration can be reduced.

FIG. 1 is a front view of a wheel according to the present embodiment. The wheel 10 includes a disc wheel 20 and a tire 22. Further, the disc wheel 20 includes a rim 24 for attaching and holding the tire 22 and a disc 23 attached to the axle for holding the rim. Here, the disc wheel 20 is configured by welding the outer edge of a disc-like disc 23 arranged coaxially with the cylindrical rim 24 to the inner peripheral surface of the rim 24. The disk 23 is attached to the axle at the center O via a hub (not shown). The disk 23 is attached to the hub by a plurality of bolts 36 around the center O of the disk 23. A plurality of openings 54 are formed in the disk 23 in the circumferential direction.
The iron plate members 52a, 52b, 52c, 52d and 52e having the same shape are fixed to the drop portion 50 of the rim 24 by spot welding. Hereinafter, these iron plate members are collectively referred to as “iron plate member 52”. In FIG. 1, the drop part 50 and the iron plate member 52 are indicated by broken lines. The entire surface of the iron plate member 52 is in contact with the outer peripheral surface of the drop portion 50.

  In the present embodiment, five steel plate members 52 having the same shape are arranged on the disc wheel 20 at equal intervals in the circumferential direction of the rim 24. That is, the angles formed by the straight lines connecting the centers of the adjacent iron plate members 52 and the center O of the rim 24 are all equal to 72 degrees. Here, a straight line connecting the center of the iron plate member 52 and the center O of the rim 24 is indicated by a one-dot chain line. For example, in FIG. 1, an angle α formed by a straight line 56 connecting the center of the iron plate member 52b and the center O of the rim 24 and a straight line 58 connecting the center of the iron plate member 52c and the center O of the rim 24 is 72 degrees. In this way, by arranging the iron plate members 52 at equal intervals in the circumferential direction of the rim 24, it is possible to avoid the eccentricity of the rim 24, so that it is possible to maintain a good balance during wheel rotation.

  FIG. 2 is a view for explaining attachment of the iron plate member 52 to the drop portion 50 of the rim 24. The same components as those in FIG. As shown in FIG. 2, a drop portion 50 is formed on the outer peripheral surface of the rim 24, and the outer peripheral surface of the drop portion 50 is not curved in the axle direction. The iron plate member 52 is a member curved with a radius of curvature smaller than the radius of curvature of the drop portion 50 in the circumferential direction. Further, the width of the iron plate member 52 is substantially equal to the width of the outer peripheral surface of the drop portion 50.

  The attachment of the iron plate member 52 to the drop part 50 will be described. First, as shown in FIG. 2, the iron plate member 52 is placed in the drop portion 50 so that the concavely curved surface of the iron plate member 52 (hereinafter also referred to as “concave curved surface”) and the outer peripheral surface of the drop portion 50 face each other. To place. At this time, the iron plate member 52 is arranged so that the direction of the central axis of the radius of curvature of the iron plate member 52 coincides with the rotational axis direction of the rim 24. Next, the convexly curved surface of the iron plate member 52 (hereinafter also referred to as “convex curved surface”) is pushed from above (arrow a), and the concave curved surface of the iron plate member 52 and the outer peripheral surface of the drop portion 50 are brought together. In a state of contact, spot welding is performed at at least one point of the iron plate member 52.

FIG. 3 is a view of the state in which the iron plate member 52 shown in FIG. 2 is welded to the drop portion 50 as viewed from above the rim 24. In the present embodiment, the iron plate member 52 is spot-welded at three points and attached to the drop portion 50. At this time, as indicated by broken lines in FIG. 3, all of the points 60 (hereinafter also referred to as “welding points”) on which spot welding is performed are located on a line along the circumferential direction of the rim 24. Further, the welding point 60 is located at the center of the iron plate member 52 in the width direction of the iron plate member 52, that is, in the rotation axis direction of the rim 24.
As described above, when the steel plate member 52 curved with a curvature radius smaller than the curvature radius in the circumferential direction of the drop portion 50 is elastically deformed and pressed from above to be spot welded to the drop portion 50, the entire concave curved surface of the iron plate member 52 is obtained. Strongly contacts the outer peripheral surface of the drop portion 50.

  FIG. 4 is a diagram illustrating a part of the AA cross section of FIG. 1. The same components as those in FIG. As described above, the rim 24 is mounted and held with the tire 22, and the iron plate member 52 is attached to the outer peripheral surface of the drop portion 50 of the rim 24. The outer peripheral edge of the disk 23 is fixed to the inner peripheral surface of the rim 24. Specifically, as shown in FIG. 4, the tip 23 of the outer peripheral edge of the disk 23 is attached to the rim 24 by, for example, arc welding. The iron plate member 52 is disposed and attached so as to straddle the portion where the disk 23 is welded to the rim 24, that is, the front end portion p at the outer peripheral edge of the disk 23.

  The central portion of the disk 23 is fixed to the hub 32 by a plurality of bolts 36. The hub 32 is assembled to the axle shaft 26 via a bearing 34, and the hub 32 and the disc wheel 20 are rotatable about the axle shaft 26 as a rotation axis. A disc rotor 38 of a disc brake is interposed between the disc 23 of the disc wheel 20 and the hub 32. The disc rotor 38 is disposed and accommodated in a space defined by the disc 23 and the rim 24 along a plane perpendicular to the axle. The disk rotor 38 is also fixed to the disk 23 and the hub 32 with bolts 36. For this reason, the disc rotor 38 can rotate together with the disc wheel 20.

  When the tire 22 vibrates during traveling of the vehicle, the vibration is transmitted to the rim 24. The vibration of the rim 24 includes vibration of a component in the circumferential direction of the drop part 50, and this vibration causes friction between the outer peripheral surface of the drop part 50 and the concave curved surface of the iron plate member 52 that contacts this surface. Occurs. As a result, the vibration energy is converted into frictional heat, so that the vibration of the rim 24 is attenuated. As a result, the vibration of the tire 22 becomes difficult to be transmitted from the rim 24 to the disk 23, the axle, or the like, so that road noise is reduced.

  In the present embodiment, the width of the iron plate member 52 is formed substantially equal to the width of the outer peripheral surface of the drop part 50. As a result, the concave curved surface of the iron plate member 52 contacts the outer peripheral surface of the drop portion over a wide range in the width direction. As a result, friction between the drop portion 50 and the iron plate member 52 can be generated in a wide range, so that the vibration of the rim 24 can be damped better. As a result, road noise is reduced more favorably.

  In the present embodiment, the disk 23 is attached by welding the vicinity of the outer peripheral edge to the rim 24. Accordingly, in the drop portion 50, the rigidity in the vicinity of the portion where the disk 23 is welded to the rim 24 is higher than that in the other portions. That is, when the vibration of the tire is transmitted to the rim 24 to the drop portion 50, the portion other than the vicinity of the welded portion is likely to vibrate compared to the vicinity of the welded portion. In the present embodiment, the iron plate member 52 is disposed and attached so as to straddle the portion where the disk 23 is welded to the rim 24 in the axle direction. Thereby, in the drop part 50, the iron plate member 52 can be made to contact a part with low rigidity compared with the part to which the disk 23 was welded. As a result, since the vibration of the rim 24 can be attenuated even in a portion other than the vicinity of the welded portion having low rigidity, road noise can be reduced more favorably.

In the present embodiment, as described above with reference to FIG. 3, the plurality of welding points 60 are located on the same line along the circumferential direction of the rim 24. As a result, it is possible to secure a wider area in which friction is generated by the vibration of the rim 24, so that the vibration of the rim 24 can be damped better. As a result, road noise can be reduced well. As a modification, for example, a plurality of welding points 60 may be positioned on the same straight line in the rotation axis direction of the rim 24. This also makes it possible to secure a wider area where friction occurs.
In the present embodiment, since the welding point is provided at the center in the width direction of the iron plate member 52, the balance of the iron plate member 52 during vibration of the rim 24 can be maintained well.

In the present embodiment, as described above, the five iron plate members 52 are attached to the rim 24. In this way, the effect of attenuating the vibration of the rim 24 is improved by attaching a larger number of iron plate members 52, so that road noise can be reduced more favorably.
Moreover, in this Embodiment, a certain amount of space | interval is provided between the iron plate members 52 arrange | positioned adjacently. Thereby, compared with the case where an iron plate member is attached so that the perimeter of the rim | limb 24 may be covered, the increase in the mass of the disc wheel 20 can be suppressed.

  The present invention has been described based on the embodiments. The embodiments are exemplifications, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are within the scope of the present invention. .

It is a front view of the wheel concerning an embodiment. It is a figure for demonstrating attachment of the iron plate member to the drop part of a rim | limb. It is the figure which looked at the state by which the iron plate member shown in FIG. 2 was welded to the drop part from the upper direction of the rim. It is a figure which shows a part of AA cross section of FIG.

Explanation of symbols

  10 wheels, 20 disc wheels, 22 tires, 23 discs, 24 rims, 26 axle shafts, 32 hubs, 34 bearings, 36 bolts, 38 disc rotors, 50 drop parts, 52 iron plate members, 54 openings.

Claims (4)

A rim for attaching and holding a tire;
A disc attached to the axle for holding the rim;
With
On the outer peripheral surface of the drop portion of the rim, an iron plate member curved with a radius of curvature smaller than the radius of curvature of the drop portion in the circumferential direction is opposed to the concave curved surface of the iron plate member and the outer peripheral surface of the drop portion. A disc wheel characterized by being arranged and spot-welded at least at one point, wherein the entire concavely curved surface of the iron plate member is in contact with the outer peripheral surface of the drop portion.   The disk wheel according to claim 1, wherein a width of the iron plate member is substantially equal to a width of an outer peripheral surface of the drop portion. The outer peripheral edge of the disc is welded to the inner peripheral surface of the rim,
The disc wheel according to claim 1, wherein the iron plate member is disposed so as to straddle a welded portion thereof in an axle direction.   The disc wheel according to any one of claims 1 to 3, wherein the plurality of iron plate members are arranged at equal intervals in a circumferential direction of the rim.

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