JP4672167B2 - Vehicle wheel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle wheel in which a wheel center portion and a rim portion are connected by a plurality of radial spoke portions, and relates to a vehicle wheel that achieves low noise and the lightest weight.
[0002]
[Prior art]
In-vehicle noise generated while a vehicle such as an automobile is traveling is called road noise, and vibration from a road surface picked up by a tire is transmitted to a vehicle body via an axle, a suspension, etc. via a wheel. In general, various measures are taken for the vehicle body to reduce road noise. For example, countermeasures for coping with the generated vibration and noise, such as construction of a vibration-damping sheet on the floor panel and attachment of a sound absorption / sound insulation mat, are adopted. However, since these measures are for the generated vibration and noise, the vibration and noise may not be reduced in a predetermined frequency region. Normally, as shown in the resonance frequency characteristics (example) of the wheel in FIG. 7, in the frequency band of 200 to 300 Hz, response transmission, that is, vibration transmission generated by resonance with the natural frequency of the wheel itself is large, and the in-vehicle noise deteriorates. I know you will.
[0003]
In the resonance mode of the wheel generated in a frequency band of 200 to 300 Hz, as shown in FIG. 8, a plurality of radial spoke parts 23 connecting the wheel center part 24 and the rim part 22 in the wheel 21 are twisted or bent. It has been analyzed that the phenomenon of surface tilt occurs and the “surface tilt mode” causes deterioration of in-vehicle noise. In particular, when the “face-down mode” occurs at 300 Hz or less, transmission due to tire cavity resonance (generated at about 250 Hz in the case of a 16-inch tire) increases, and there is a possibility that vehicle interior noise is doubled. On the other hand, by setting the “face tilt mode” to a high frequency of 400 Hz or higher, it is possible to reduce the vibration transmission from the tire by preventing the occurrence of resonance, but the mass also increases to ensure high rigidity of the wheel. However, the effect of reducing vibration and noise was small for the increase in weight.
[0004]
Therefore, by forming the curvature imparting portions 150, 152, 154, 156 on the surface of the wheel as disclosed in JP 2000-158902 A in FIG. 9, the rigidity of the wheel is increased, As a result, the primary natural frequency of the wheel is increased from the primary natural frequency of a tire or the like that transmits vibration to the wheel, thereby suppressing the wheel vibration and reducing the in-vehicle noise caused by road surface unevenness. A tire wheel constructed as described above was proposed.
[0005]
[Problems to be solved by the invention]
However, in this conventional tire wheel, although the vibration characteristics of the wheel are improved in cooperation with the tire in a state where the tire is mounted, the curvature imparting portion 150 is formed on the surface of the wheel rim portion or the disk portion. , 152, 154, and 156 must be formed, resulting in a complicated design and high cost. Moreover, the main point is to deviate the natural frequency of the mounted tire and the natural frequency of the wheel, and the wheel "tilt mode" still occurs depending on the compatibility with the mounted tire. There was a fear.
[0006]
Therefore, the present invention solves the problems in such a conventional vehicle wheel and can prevent the occurrence of in-vehicle vibration and noise due to the “face-down mode” of the wheel only by slight modification and arrangement of the spoke portion. The object is to provide the lightest vehicle wheel.
[0007]
[Means for Solving the Problems]
Therefore, the present invention provides a vehicle wheel in which a wheel center portion and a rim portion are connected by a plurality of radial spoke portions, and a pair of spoke portions are disposed on both sides of each hub bolt hole drilled in the wheel center portion. At the same time, these spoke parts are thicker toward the wheel center part side , and the natural frequency of the spoke parts is 400 HZ or more . Further, the present invention is characterized in that the spoke part is formed in a substantially square cross section. Further, the present invention is characterized in that the spoke portion is formed in a substantially trapezoidal cross section to constitute a casting draft gradient. The present invention, the cross-sectional second wheel center portion side of the spoke portion moment ^{I = bh 3/12 (b} : Spoke width, h: Spoke thickness) which is characterized in that is configured to maximize With the slight modification of the structure of the spokes and the identification of the arrangement only, the wheel center part, which is the support base, maintains higher rigidity than the rim part, which is the vibration part, adjacent to the tire in contact with the road surface, and the surface collapses. In addition, the pair of spokes can reinforce each other and efficiently transmit strain energy to the hub bolts that form the support base to prevent the surface of each spoke from falling down. Therefore, it is possible to prevent the occurrence of in-vehicle vibration and noise at low cost.
[0008]
Embodiment
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a vehicle wheel of the present invention will be described in detail with reference to the drawings. 1 and 2 show a first embodiment of a vehicle wheel according to the present invention. FIG. 1A is an overall perspective view of the wheel, FIG. 1B is an AA cross-sectional perspective view thereof, and FIG. C) is an AA cross-sectional view. As shown in FIG. 1, the vehicle wheel of the present invention is formed in the wheel center portion 4 in the vehicle wheel 1 in which the wheel center portion 4 and the rim portion 2 are connected by a plurality of radial spoke portions 3. In addition, a pair of spoke portions 3A, 3B are arranged on both sides of each hub bolt hole 5, and the spoke portions 3A, 3B are thicker toward the wheel center portion 4 side , and the natural frequency of the spoke portion is 400HZ or more. It is configured as described above .
[0009]
More specifically, as shown in FIG. 1 (A), the present embodiment is a wheel used in a relatively high-power vehicle provided with five hub bolt holes. For each of the five hub bolt holes 5 drilled in the wheel center portion 4, a pair of spoke portions 3 </ b> A, 3 </ b> B extend radially from both sides of each hub bolt hole 5 toward the radially outer rim portion 2. Is done. Each of these spoke portions 3A, 3B is usually shown by a solid line in FIG. 1 (B), which is an AA sectional perspective view of FIG. 1 (A), and in FIG. 1 (C), which is an AA sectional view. In contrast to the spoke part outline of the wheel, the reinforcing part 6 is fleshed out like a dotted outline.
[0010]
FIG. 10 schematically shows the vibration mode of the wheel. A mass m corresponding to the rim and the tire vibrates at the free end of the cantilever C corresponding to the spoke portion 3 supported with the wheel center portion 4 side as a base. Given as a load. The cantilever C has a base B which is the minimum necessary for securing the strength of the spoke portion and a base R on the wheel center portion 4 side so that the rigidity is increased, and a reinforcement R for increasing the resonance frequency is added to the base B. Yes. It is effective to strengthen the base of the cantilever C, that is, the wheel center part 4 side, in order to improve the rigidity by effectively using the mass m, and to increase the eigenvalue, particularly from the viewpoint of preventing the surface collapse. Although it is more effective to increase the thickness than to the width, in practice, the thickness cannot be increased without limitation because it is restricted by the design surface of the spoke part and interference with the brake parts.
[0011]
The model of the vibration mode of the wheel shown in FIG. 10 is composed of a base portion B necessary for the strength of the wheel and a reinforcement R for setting the surface tilt mode to 400 Hz or more. An ideal spoke portion is obtained by dividing C according to the wheel standard to be applied. That is, in the case of a type of wheel having five hub bolt holes 5, preferably, a pair of spoke portions 3A and 3B are combined with one hub bolt hole 5, so that 10 spoke portions of 5 × 2 = 10 are provided. It is formed. Accordingly, the number of hub bolt holes of a normal vehicle is 4 to 6, and the number of spoke portions is 8 to 12 because of conditions such as rigidity, strength, and manufacturing method. Further, the width of the spoke part is limited to casting or the like, and usually a minimum of about 7 mm is required.
[0012]
FIG. 2 is a schematic view of the spoke portion 3 of the present embodiment, which is formed in a substantially square cross section. The wheel center portion side on the right side of the drawing is thicker and has a substantially rectangular cross section extending from a substantially square cross section to the rim side on the left side of the drawing. An actual vehicle running test was carried out on the cobblestone road surface of the wheel constituted by adopting the spoke part having such a cross-sectional shape. FIG. 5 is a comparison of the sound in the front seat vehicle. At 200 to 300 Hz, the light weight wheel (thick line) with improved rigidity of the present invention is smaller by 1 to 2 dB than the normal light wheel (thin line), and the standard wheel (dotted line) It can be seen that there is no inferiority compared to the case of 1 kg per wheel. FIG. 6 is a comparison of the rear seat interior sound. At 200 to 300 Hz, the light weight wheel (thick line) with improved rigidity of the present invention is 3 to 4 dB smaller than the normal light wheel (thin line), and the standard wheel (dotted line). It can be seen that there is no inferiority or low noise.
[0013]
FIG. 3 is a schematic view of the spoke portion 3 showing a second embodiment of the vehicle wheel of the present invention. The present embodiment is characterized in that a casting draft gradient is formed by forming the spoke portion 3 in a substantially trapezoidal cross section. As can be understood from FIG. 3, when the cross section of the spoke portion 3 is basically formed in a trapezoidal shape so as to form a casting draft, the rim portion side is hardly increased without increasing the thickness of the spoke portion 3. In order to increase the rigidity of the wheel center side (ie to make it thicker), the rim side is thin and steep trapezoidal, whereas the wheel center side is formed in a large and gentle trapezoid in the width direction It is. If the inclination angle of the hypotenuse of the trapezoid is appropriately selected, the rigidity ratio between the rim portion side and the wheel center portion side can be appropriately designed.
[0014]
FIG. 4 is a schematic view of the spoke portion 3 showing a third embodiment of the vehicle wheel of the present invention. In this embodiment, the wheel moment of inertia of area center portion side I = bh ^3/12 in the spoke unit (b: Spoke width, h: spokes thickness) is characterized by being configured such that the maximum. That is, as the square shape on the wheel center side in the first embodiment of FIG. 2, the secondary moment of section I = bh ³ under limited conditions (constraints due to interference with the design surface and brake parts) The width b and the thickness (height) h are selected so that / 12 is the maximum value. As a result, the spoke part on the wheel center part side exhibits the highest rigidity in the thickness direction within a limited size range, and surface tilt is effectively prevented.
[0015]
As described above, the embodiment of the present invention has been described. However, within the scope of the present invention, the shape and type of the wheel (which can be applied to a tube-mounted type or a solid tire-mounted type wheel as well as a tubeless type), a material, The shape of the wheel center, the number of hub bolt holes, the number of spokes and their cross-sectional shape, and the reinforcing form of the reinforcing part for improving rigidity (in addition to the gradual increase in width and thickness to the wheel center part side, (Attachment, a groove or a notch portion in which the thickness and width to the rim portion side gradually decrease) may be selected as appropriate.
[0016]
【The invention's effect】
As described above in detail, according to the present invention, in a vehicle wheel in which a wheel center portion and a rim portion are connected by a plurality of radial spoke portions, each hub bolt hole drilled in the wheel center portion is provided. Adjacent to the tire in contact with the road surface by arranging a pair of spoke parts on both sides and making these spoke parts thicker toward the wheel center part and having a natural frequency of 400 HZ or more. As a result, the wheel center portion serving as the support base from the rim portion serving as the excitation portion retains higher rigidity to effectively prevent surface collapse, and the pair of spoke portions reinforce each other to serve as a support base. The strain energy can be transmitted efficiently to each spoke to prevent the spokes from falling down. The occurrence of fine noise can be prevented. In addition, the occurrence of resonance in the vicinity of 300 Hz, in which the “surface tilt mode”, which is the main cause of in-vehicle noise, and the cavity resonance of the tire occur, is prevented, and vibration transmission from the wheel to the vehicle body can be reduced.
[0017]
In addition, when the spoke part is formed in a substantially square cross section, it is possible to effectively prevent the surface part of the spoke part from collapsing in accordance with the restriction due to interference with the design surface and the brake parts.
Furthermore, when the spoke part is formed in a substantially trapezoidal cross section to form a casting slope, it is easy to remove the die after casting, and the wheel from the rim part side hardly increases the thickness of the spoke part. In addition to increasing the rigidity on the center side, the rigidity ratio between the rim part side and the wheel center part side can be appropriately designed if the inclination angle of the hypotenuse of the trapezoid is appropriately selected.
Furthermore, the second moment of the wheel center portion side of the spoke part ^{I = bh 3/12 (b} : Spoke width, h: spokes thickness) When is configured such that the maximum of the wheel center portion The spoke portion can exhibit the highest rigidity in the thickness direction within a limited size range, and can effectively prevent surface collapse.
[0018]
As this, according to the present invention, the only modification and arrangement of a small structure of the spoke portion, a vehicle wheel lightest is provided which can prevent vehicle vibration and generation of noise due to "tilt mode" of the wheel The
[Brief description of the drawings]
FIG. 1 shows a first embodiment of a vehicle wheel according to the present invention, FIG. 1 (A) is an overall perspective view of the wheel, FIG. 1 (B) is an AA sectional perspective view, and FIG. FIG.
FIG. 2 is a schematic diagram of the spoke portion 3;
FIG. 3 is a schematic view of a spoke portion showing a second embodiment of the vehicle wheel of the present invention.
FIG. 4 is a schematic view of a spoke portion showing a third embodiment of the vehicle wheel of the present invention.
FIG. 5 is a comparison diagram of sound in the front seat of the wheel road test.
FIG. 6 is a comparison diagram of the rear seat interior sound.
FIG. 7 is a diagram illustrating an example of resonance frequency characteristics of a wheel.
FIG. 8 is a diagram showing a surface tilt phenomenon of a conventional wheel.
FIG. 9 is a cross-sectional view of a conventional wheel.
FIG. 10 is a diagram schematically illustrating a vibration mode of a wheel.
[Explanation of symbols]
1 Wheel 2 Rim part 3 Spoke part 4 Wheel center part 5 Hub bolt hole 6 Reinforcement part B Base C Beam m Mass R Reinforcement

Claims (4)

In a vehicle wheel in which a wheel center portion and a rim portion are connected by a plurality of radial spoke portions, a pair of spoke portions are disposed on both sides of each hub bolt hole drilled in the wheel center portion, and these spokes The vehicle wheel is characterized in that the portion is thicker toward the wheel center portion and the natural frequency of the spoke portion is 400 HZ or more .   The vehicle wheel according to claim 1, wherein the spoke portion is formed in a substantially square cross section.   The vehicle wheel according to claim 1, wherein the spoke portion is formed in a substantially trapezoidal cross section to form a casting draft gradient. The cross-sectional second wheel center portion side of the spoke portion moment ^{I = bh 3/12 (b} : Spoke width, h: spokes thickness) of claims 1, characterized in that it is configured such that the maximum 3 The vehicle wheel according to any one of the above.

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