JP4114671B2 - Vehicle wheel structure - Google Patents

Description

  The present invention relates to an improvement in a wheel structure of a vehicle.

  FIG. 10 shows a schematic view of a conventionally used wheel. With reference to FIG. 10, conventionally, in a closed space 5 formed by the tire 1 and the wheel 10 during traveling of the vehicle. It is known that air column resonance is a cause of worsening road noise. Specifically, the air column resonance is a random vibration input to the tire 1 from the road surface vibrates the air in the closed space 5, and as a result, a resonance phenomenon occurs near the air column resonance frequency of the closed space 5. Resonance sound.

This air column resonance frequency is generally
f = c / 2πr
Where f: air column resonance frequency, c: speed of sound,
r: It is determined based on the formula shown by the length from the wheel center to the radial center portion 20 of the closed space, but the peak of the air column resonance frequency is actually due to the deformation of the tire ground contact surface 17 due to the vehicle weight. Divided into several. In any case, since the cross-sectional shape of the closed space 5 is always constant regardless of the rotation of the wheel 12, in the conventional wheel structure, r in the above formula is a constant value and always resonates at the same air column resonance frequency. However, it becomes an harsh sound with a high sound pressure level.

  By the way, as means for solving the noise from the wheel, Japanese Patent Laid-Open No. 9-11704 discloses a wheel by providing a substantially cylindrical ring including a layer made of at least one viscoelastic material on the outer peripheral surface of the tire wheel. Technology for absorbing the mechanical vibration of the wheel and reducing the noise of the wheel is disclosed. However, since this technology does not fundamentally suppress the generation of air column resonance, there is a problem that a sufficient noise reduction effect cannot be obtained.

  The present invention was devised in view of the above-mentioned problems, and provides a vehicle wheel structure that can effectively reduce noise generated by air column resonance in a closed space of the wheel. With the goal.

To achieve the above object, the vehicle wheel structure of the present invention according to claim 1 is a vehicle wheel structure comprising a wheel and a tire mounted on an outer periphery of the wheel. A plurality of bulkheads are arranged in the circumferential direction without partitioning the closed space in the enclosed and formed closed space, and the tire is grounded at a circumferential position where the bulkhead is not arranged as the wheel rotates. In order to reduce the noise level by periodically changing the air column resonance frequency of the closed space between the case and the case where the tire is grounded at the circumferential position where the bulkhead is disposed , The cross-sectional shape of the closed space is changed in the circumferential direction so that the circumferential length is equal to or greater than the circumferential length of the ground contact surface of the tire.

According to a second aspect of the vehicle wheel structure of the present invention, in the vehicle wheel structure according to the first aspect, the change in the cross-sectional shape of the closed space changes the cross-sectional area of the closed space in the circumferential direction. It is characterized by that.
The wheel structure of the vehicle of the present invention according to claim 3 is the wheel structure of the vehicle according to claim 2, wherein the cross-sectional area of the closed space is the bulkhead in the closed space in a portion where the tire is not in contact with the ground. The bulkhead is formed so that the cross-sectional area of the bulkhead is 2.5% or more with respect to the cross-sectional area of the portion having no gap.

The vehicle wheel structure according to a fourth aspect of the present invention is the vehicle wheel structure according to any one of the first to third aspects, wherein the change in the cross-sectional shape of the closed space is the same as the inner peripheral surface of the tire. The distance from the outer peripheral surface of the wheel facing the inner peripheral surface is changed in the circumferential direction.
The wheel structure of the vehicle of the present invention according to claim 5 is the wheel structure of the vehicle according to claim 4, wherein the distance is a portion where the bulk head is disposed and a portion where the bulk head is not disposed. The tire is set to 97% or less in a portion where the tire is not in contact with the ground.

The vehicle wheel structure according to a sixth aspect of the present invention is the vehicle wheel structure according to any one of the first to third aspects, wherein the bulkhead is disposed on a side surface in the vehicle width direction of the inner surface of the tire. It is characterized by that.
A vehicle wheel structure according to a seventh aspect of the present invention is the vehicle wheel structure according to any one of the first to fifth aspects, wherein the bulkhead is disposed on an inner peripheral surface of the tire. It is a feature.

The vehicle wheel structure according to an eighth aspect of the present invention is the vehicle wheel structure according to any one of the first to seventh aspects, wherein the bulkhead is substantially equal to a circumferential length of the bulkhead in a circumferential direction. It is characterized by being arranged at equal intervals at equal intervals.
A vehicle wheel structure according to a ninth aspect of the present invention is the vehicle wheel structure according to any one of the first to eighth aspects, wherein two of the bulkheads are arranged in the circumferential direction. It is said.

  A vehicle wheel structure according to a tenth aspect of the present invention is the vehicle wheel structure according to the ninth aspect, wherein the bulkhead has a length of approximately ¼ of the entire circumference.

  According to the vehicle wheel structure of the present invention, it is possible to reduce the time for resonating at a single air column resonance frequency and to reduce the noise level associated with air column resonance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 1 to 5 show a wheel structure of a vehicle as a first embodiment of the present invention, and FIG. 6 shows a vehicle as a second embodiment of the present invention. 7 shows the wheel structure of the vehicle as the third embodiment of the present invention, FIG. 8 shows the wheel structure of the vehicle as the fourth embodiment of the present invention, and FIG. 9 shows the wheel structure of the present invention. The wheel structure of the vehicle as other embodiment is shown. Description will be made based on these drawings. However, in FIGS. 1-9, the same code | symbol is provided to the same component as the above-mentioned prior art example.

  First, the vehicle wheel structure according to the first embodiment of the present invention will be described. As shown in FIG. 1, the outer peripheral surface 3 of the rim portion 6 of the vehicle wheel 10 has a length of about 1/8 of the entire circumference. 4 are arranged at equal intervals, and as shown in FIGS. 2 and 3, closed bulkheads 15 are formed surrounded by the tire 1 and the wheel 10 constituting the wheel 12. The cross-sectional shape of the space 5 is changed in the circumferential direction.

  Since the wheel structure of the vehicle according to the first embodiment of the present invention is configured as described above, there is no bulkhead 15 on the outer peripheral surface 3 of the rim portion 6 facing the tire ground contact surface 17 as shown in FIG. The air column resonance frequency is different between A and the state B in which the bulkhead 15 is located at the above-mentioned position as shown in FIG. 2 and 3, reference numeral 20 denotes the radial center of the closed space 5.

Specifically, when the portion immediately below the portion where the bulkhead 15 is disposed is grounded (state B), the tire inner peripheral surface 8 on the tire ground contact surface 17 and the outer peripheral surface of the wheel 10 facing the tire inner peripheral surface 8 are described. 3 distance H _B between the (surface 27 of the bulkhead 15), by the height of the bulkhead 15 as compared with the distance H _a if (condition a) where immediately below the site no bulkhead 15 is grounded Since it becomes short, the radial direction center part 20 of the closed space 5 is displaced to the wheel 12 outer peripheral side.

  For this reason, in the state A and the state B, the grounding section cross-sectional height of the closed space 5 is different, and the position of the radial center 20 in the grounding section of the closed space 5 is also different. As described above, since the air column resonance frequency is determined by the length r from the wheel center to the radial center 20, the air column resonance frequency is different in each state. As the wheel 12 rotates, as shown in FIG. 4, the air column resonance frequencies a and a ′ in the state A (see the solid line attached to the embodiment) and the air column resonance frequencies b and b ′ in the state B (the embodiment) (See the broken line attached).

  As a result, in the conventional wheel structure in which the air column resonance frequency in the closed space 5 is always constant regardless of the rotation of the wheel 12, even when the wheel 12 rotates, it always resonates at the same frequency (the one-dot chain line attached to the conventional example) On the other hand, according to the wheel structure of the present embodiment, the air column resonance frequency fluctuates with one quarter of the rotation of the wheel 12 as one cycle, so the time for resonance at a single frequency is shortened. As indicated by the solid and broken lines in FIG. 4, the noise level associated with the air column resonance frequency is low. In addition, since the air column resonance frequency is divided into a large number, the sound pressure level becomes low, and it is possible to make it difficult for passengers to feel noise.

Further, if the noise level of the air column resonance is lowered, the vibration amplitude in the air column resonance frequency region transmitted to the wheel 10 is also lowered, so that the noise accompanying the resonance of the wheel 10 due to the air column resonance can be reduced.
The wheel 10 has a bell mode in which both ends of the vehicle 10 in the longitudinal direction of the vehicle 10 are displaced in the opposite direction in the vehicle width direction around the spindle and a resonance at a higher frequency than the bell mode. There are two modes of natural frequency, the bending mode that resonates by displacing in the same direction in the vehicle width direction as the center. Of the frequencies that are input to the wheel 10, the frequency that is still larger than the other frequencies. If the two natural frequencies are present in the frequency region near the column resonance frequency, the resonance of the wheel 10 may be amplified and the noise level may not be effectively reduced.

  However, since the natural frequency of the bending mode described above is proportional to the bending rigidity of the wheel 10 and the natural frequency of the bell mode is inversely proportional to the weight of the wheel 10, the bulkhead 15 is provided on the outer peripheral surface 3 of the wheel 10. Then, the natural frequency of the bending mode increases as the bending rigidity of the wheel 10 increases, and the natural frequency of the bell mode decreases as the weight increases. Therefore, as shown by the solid line in FIG. 5, even if the natural frequency of the wheel 10 is in the air column resonance frequency region, both natural vibrations can be obtained by adjusting the plate thickness, material, weight, etc. of the bulkhead 15. Since the number can be removed from the air column resonance frequency region, it is possible to prevent the amplification of the resonance of the wheel 10 (see the one-dot chain line in FIG. 5), which has been easy to occur in the past.

Next, a vehicle wheel structure as a second embodiment of the present invention will be described. As shown in FIG. 6, in this wheel structure, a band 30 is wound around the outer peripheral surface 3 of the rim portion 6 of the wheel 10. Yes. The band 30 has attachment portions 28 at both ends thereof, and has a concave and convex shape that is continuous in a side view. The band 30 is wound around the outer peripheral surface 3 of the rim portion 6 of the wheel 10 and couples the attachment portions 28 at both ends. The band 30 changes the cross-sectional shape of the closed space 5 in the circumferential direction.
Since the vehicle wheel structure according to the second embodiment of the present invention is configured as described above, not only a noise reduction effect substantially similar to that of the above embodiment can be obtained, but also the manufacturing process can be simplified. In addition, there is an advantage that it can be retrofitted.

Next, a vehicle wheel structure as a third embodiment of the present invention will be described. As shown in FIG. 7, in this wheel structure, the shape of the outer peripheral surface 3 of the rim 6 of the wheel 10 is a shape other than a perfect circle. It is said.
The vehicle wheel structure according to the third embodiment of the present invention is configured as described above, and the cross-sectional shape of the closed space 5 is changed in the circumferential direction, so that a noise reduction effect substantially similar to that of each of the above embodiments is obtained. It is done.

Furthermore, the wheel structure of the vehicle as the fourth embodiment of the present invention will be described. As shown in FIG. 8, in this wheel structure, a bulkhead 15 'is partially provided on the tire inner peripheral surface 8 to provide a closed space 5 as shown in FIG. The cross-sectional shape is changed in the circumferential direction.
The vehicle wheel structure according to the fourth embodiment of the present invention is configured as described above, and the cross-sectional shape of the closed space 5 is changed in the circumferential direction. Therefore, a noise reduction effect substantially similar to that of each of the above embodiments is obtained. It is done.

  Furthermore, in the above embodiment, the length r (the length of the radial center line of the closed space 5) from the wheel center to the radial center 20 of the closed space 5 is changed with the rotation of the wheel 12, thereby The noise is reduced by the action of changing the air column resonance frequency in the inner space 5 with the rotation of the wheel 12, but the cross-sectional area of the closed space 5 is changed by the rotation of the wheel 12 according to the research by the developers according to the present invention. It has become clear that even if the cross-sectional shape of the closed space 5 is changed, the air column resonance frequency in the closed space 5 can be changed by the rotation of the wheel 12.

  Therefore, for example, as shown in FIGS. 9A and 9B, if a bulk head 15 ″ is provided on the side surface in the vehicle width direction of the tire inner surface, the bulk corresponding to the tire ground contact surface 17 in the closed space 5 is formed. Since the cross-sectional area of the part differs between the state where the head 15 ″ is present and the state where the bulk head 15 ″ is not present at the part, the air column resonance frequency is changed by the rotation of the wheel 12 in the same manner as in the above embodiment. Noise can be reduced.

In the present embodiment, four or two bulkheads 15, 15 ′, 15 ″ are arranged. However, the inner circumference of the tire or the rim 6 outer circumferential surface 3 of the wheel 10 is approximately ¼ of the entire circumference. If the two bulkheads having the length of 1 are arranged at equal intervals, the time for resonating at a single air column resonance frequency can be shortened most, and the noise can be minimized.
In addition, the shortest radial direction length of the closed space 5 other than the tire contact surface 17 is 97% or less (or substantially 97% or less) of the longest portion length, or the cross-sectional area of the portion without the bulkhead in the closed space 5 If the cross-sectional area of the bulkhead 15 is 2.5% or more (or about 2.5% or more), the air column resonance frequency can be effectively shifted, and a further noise reduction effect can be obtained. is there.

It is a wheel perspective view concerning a 1st embodiment of the present invention. It is a schematic side view explaining the effect | action of the wheel which concerns on 1st Embodiment of this invention. It is a schematic side view explaining the effect | action of the wheel which concerns on 1st Embodiment of this invention. It is a figure which shows the characteristic of the noise level with respect to the air column resonance frequency which concerns on 1st Embodiment of this invention compared with a prior art. It is a figure which shows the characteristic of the noise level with respect to the resonant frequency of the wheel which concerns on 1st Embodiment of this invention compared with a prior art. It is a perspective view of the wheel concerning a 2nd embodiment of the present invention. It is a schematic side view of the wheel which concerns on 3rd Embodiment of this invention. It is a schematic side view of the wheel which concerns on 4th Embodiment of this invention. It is the schematic of the wheel which concerns on other embodiment of this invention, (a) is a side view, (b) is a schematic diagram which shows the KK arrow cross section of (a). It is a schematic side view of the wheel which concerns on a prior art.

Explanation of symbols

3 Wheel outer peripheral surface 5 Closed space 10 Wheel 12 Wheel 15, 15 ', 15 "Bulk head 17 Tire contact surface 28 Mounting portion 30 Band

Claims (10)

In a wheel structure of a vehicle having a wheel and a tire mounted on the outer periphery of the wheel,
In the closed space surrounded and formed by the wheel and the tire, a plurality of bulkheads are arranged in the circumferential direction without partitioning the closed space,
The air column in the closed space when the tire is grounded at a circumferential position where the bulkhead is not disposed as the wheel rotates and when the tire is grounded at a circumferential position where the bulkhead is disposed Changing the cross-sectional shape of the closed space in the circumferential direction by setting the circumferential length of the bulkhead to be equal to or greater than the circumferential length of the ground contact surface of the tire so as to reduce the noise level by periodically changing the resonance frequency A wheel structure of a vehicle, characterized in that   The vehicle wheel structure according to claim 1, wherein the change in the cross-sectional shape of the closed space changes the cross-sectional area of the closed space in the circumferential direction.   The cross-sectional area of the closed space is set so that the cross-sectional area of the bulkhead is 2.5% or more with respect to the cross-sectional area of the portion of the closed space where the bulkhead is not present in the non-grounded portion of the tire. The vehicle wheel structure according to claim 2, wherein the vehicle wheel structure is formed as follows.   The change in the cross-sectional shape of the closed space changes a distance between an inner peripheral surface of the tire and an outer peripheral surface of the wheel facing the inner peripheral surface in a circumferential direction. The wheel structure of the vehicle according to any one of 1 to 3.   The distance is set to 97% or less in a portion where the bulkhead is not grounded, in a portion where the bulkhead is not grounded, with respect to a portion where the bulkhead is not disposed. Item 5. A vehicle wheel structure according to Item 4.   The vehicle wheel structure according to any one of claims 1 to 3, wherein the bulkhead is disposed on a side surface in the vehicle width direction of the inner surface of the tire.   The vehicle wheel structure according to any one of claims 1 to 5, wherein the bulkhead is disposed on an inner peripheral surface of the tire.   The vehicle wheel structure according to any one of claims 1 to 7, wherein the bulkheads are arranged at equal intervals in the circumferential direction at substantially equal intervals with the circumferential length of the bulkhead. .   The vehicle wheel structure according to any one of claims 1 to 8, wherein two bulkheads are arranged in a circumferential direction.   The vehicle wheel structure according to claim 9, wherein the bulkhead has a length that is approximately ¼ of a total circumference.

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