JP2009029348A - Vehicular wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular wheel capable of reducing road noise in travelling of a vehicle. <P>SOLUTION: A spoke portion 5 is formed hollow so as to form a spoke cavity part 20, and an inner end of the spoke cavity part 20 is communicated with an annular cavity part 21 provided along the peripheral edge of a hub fitting part 4, and a porous sound absorbing material 35 is embedded in a rim side opening part 22 of the spoke cavity part 20. With this structure, since the action of a Helmholtz resonant muffler and the action of the sound absorbing material 35 for absorbing energy of sound waves are effectively combined, the cavity resonant sound to be generated in a tire-inside cavity part 38 in travelling of a vehicle loaded with tires 9 can be reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle wheel that can reduce air column resonance sound (so-called cavity resonance sound) generated in a tire cavity closed by a tire and a rim during traveling of the vehicle.

  In vehicles such as automobiles, road noise caused by vibrations input from the road surface has become apparent during vehicle travel due to advances in engine noise reduction technology. As a cause of this road noise, a cavity resonance sound generated in a cavity portion in a tire sealed by a tire and a rim portion of a vehicle wheel has been pointed out. This cavity resonance sound generates a standing wave having a circumference of the cavity portion of the tire as one wavelength due to vibration input from the road surface while the vehicle is traveling, and this standing wave has a specific frequency band (180 Hz to 270 Hz). This is caused by the phenomenon of air column resonance.

  As a method for reducing the above-described cavity resonance sound, configurations such as applying a Helmholtz resonance silencer or applying a quinque interference silencer have been proposed.

  For example, as in Patent Document 1, a configuration has been proposed in which a plurality of auxiliary air chambers are formed in the circumferential direction in a rim portion of a vehicle wheel, and a hole that communicates the auxiliary air chamber and the airspace in the tire is provided. Yes. In this configuration, a Helmholtz resonance muffler is configured by the auxiliary air chamber, and the cavity resonance generated in the above-described tire cavity can be reduced.

  Further, as in Patent Document 2, a configuration has been proposed in which a sound wave passage having both ends opened on the outer surface of the rim portion is provided on the vehicle wheel. This configuration attenuates the sound by propagating the sound wave propagating through the sound wave path and the sound wave propagating through the tire cavity, thereby reducing the cavity resonance sound. So-called quinque type interference silencer It is the structure which applied. In particular, both ends of the sound wave passage are provided at positions opposed to each other by 180 degrees in the circumferential direction, and the length of the sound wave passage is set to the length between the both ends of the sound wave passage in the tire cavity. By setting the phase difference of the propagating sound wave to be ½ wavelength, the effect of reducing the cavity resonance sound due to the interference action of the sound wave can be maximized.

Furthermore, as disclosed in Patent Document 3, a configuration is proposed in which the spoke portion of the vehicle wheel has a hollow structure and the hollow portion is filled with a damping material. In this configuration, the vibration damping material filled in the hollow portion of the spoke portion can reduce the resonance phenomenon that occurs in the tire cavity when the vehicle is running.
JP 2003-326904 A JP 2006-111194 A JP 2005-186839 A

  By the way, in a vehicle wheel having a configuration including either a Hertzholm-type resonance silencer or a Quinke-type interference silencer as described in Patent Documents 1 and 2, tires are mounted in the laboratory. It was confirmed that the cavity resonance noise can be reduced by the flat plate vibration test. Here, the flat plate vibration test restrains the hub mounting portion of the vehicle wheel and applies a predetermined load to the tire tread through the flat plate. Then, this flat plate is vibrated in the surface direction and the radial direction of the tire (vehicle wheel), and the vibration response transfer function at the hub mounting portion is captured. In this flat plate vibration test, the vehicle wheel equipped with the tire is not rotated, and the hole of the Hertzholm type resonance silencer or the opening of the Quinke type interference silencer is used for the tire. The vehicle wheel is arranged so as to face the ground contact surface. Therefore, the effect of reducing the cavity resonance sound by the Hertzholm type resonance silencer and the Quinke type interference silencer is maximized, and as a result, the usefulness of the flat plate vibration test has been confirmed.

  However, as described in Patent Documents 1 and 2 above, a vehicle wheel having either a Hertzholm type resonance silencer or a quinque type interference silencer is mounted on a vehicle, and road noise during actual vehicle running As a result of performing a test to measure the road noise, the effect of reducing road noise was small regardless of the configuration, and the effect of reducing road noise expected from the flat plate vibration test was not exhibited. As a cause of this, while driving a real vehicle, the road contact surface of the tire contains a lot of road surface irregularities, so that the vibration force generated by the road surface is absorbed by the tire tread. It is conceivable that the reduction effect is not exhibited in such a high frequency band. From the results of this actual vehicle running, it can be said that the configuration of Patent Documents 1 and 2 to which the Hertzholm type resonance silencer and the Quinke type interference silencer are applied cannot sufficiently reduce road noise during actual vehicle running. all right.

  On the other hand, in the configuration of Patent Document 3 described above in which the vibration damping material is filled in the hollow portion of the spoke portion, labor and cost required for the work of filling the hollow portion with the vibration damping material are increased. Furthermore, since a relatively large amount of damping material is required to fill the hollow part of the spoke part, the cost also increases. The configuration of Patent Document 3 is based on the premise that the hollow portion of the spoke portion has an airtight structure, and the hollow portion is applied as a Helmholtz resonance muffler as in Patent Document 1 described above. Is different. That is, the configuration of Patent Document 3 is intended to reduce the resonance generated in the hollow portion of the spoke portion, and cannot reduce the cavity resonance generated in the tire cavity.

  The present invention proposes a vehicle wheel capable of sufficiently reducing road noise by reducing a cavity resonance generated in a cavity in a tire by vibration input from a road surface during traveling of the vehicle.

  The present invention provides a vehicle wheel including a hub mounting portion fixed to an axle, a rim portion for mounting a tire, and a plurality of spoke portions that connect the hub mounting portion and the rim portion. Each of the spoke cavities is formed along the outer peripheral edge of the hub mounting portion, and has a rim side opening portion that passes through the rim portion inward and outward and opens at the outer surface of the rim portion. And an annular cavity that communicates with the inner end of each part, and a porous sound absorbing material is embedded in the opening of the spoke cavity so as to close the spoke cavity. This is a vehicle wheel. Here, the sound-absorbing material closes the spoke cavity, which means that the sound-absorbing material is packed in the opening of the spoke cavity, and the spoke cavity and the tire are attached and sealed through the hole of the sound-absorbing material. The tire cavity is communicated.

  In such a configuration, a Helmholtz resonance silencer is applied to the spoke cavity and the annular cavity, and a sound absorbing material is embedded in the rim side opening of the spoke cavity. By combining the Helmholtz type resonance silencer and the sound absorbing material, it is possible to effectively reduce the cavity resonance generated in the tire cavity where the tire is mounted and sealed. Here, since the plurality of spoke cavities and the annular cavities communicate with each other to form an integrated relatively wide airspace, the Helmholtz resonance silencer is highly effective in reducing the cavity resonance. The sound absorbing material that closes the rim side opening of the spoke cavity can directly absorb the energy of sound waves (air vibrations) entering and exiting the rim side opening, thus reducing the cavity resonance noise. be able to. Furthermore, the porous sound-absorbing material reduces the air passage area at the rim-side opening of the spoke cavity, so that the effect of reducing cavity resonance as a Helmholtz-type resonance silencer is improved. As described above, in this configuration, the effect as a Helmholtz type resonance silencer and the action of the sound absorbing material are effectively combined, so that the effect of reducing the cavity resonance noise is excellent. .

  The present invention provides a tire that has a configuration in which only the above-described conventional Helmholtz resonance silencer is applied, a configuration in which only a Quinke interference silencer is applied, and a configuration in which a vibration damping material is filled in the spoke portion. The effect of reducing the cavity resonance generated in the inner cavity is significantly improved. Therefore, it is possible to sufficiently reduce the cavity resonance sound generated in the tire cavity even when the vehicle is traveling and the road surface condition changes every moment.

  Moreover, as a spoke cavity part, the structure which made the rim side opening part comparatively narrow can be used suitably. This is because the effect of reducing cavity resonance is enhanced as a Helmholtz type resonance silencer. In this case, for example, the spoke portion can be configured to become narrower in the radially outward direction.

  Further, the sound absorbing material is a porous material, and when sound waves propagate through the inside as vibrations of the air, the vibrations of the air are converted into thermal energy to exhibit a sound absorbing action. Specifically, those having high acoustic impedance such as urethane foam, glass wool, felt material and the like can be suitably used.

  In the vehicle wheel described above, it extends from the outer peripheral edge of the hub mounting portion into the spoke cavity along the radial center line of each spoke, and defines the annular cavity in the circumferential direction, and each spoke cavity A partition wall that bisects the inner part of the wall into two divided cavities in the circumferential direction is provided for each spoke part, and the spoke cavities and the annular cavities communicate with each other through the divided cavities, and the wall length of the partition wall The effective length is set by defining the radial direction length of the split cavity portion, and the sound wave propagating through the cavity communication path composed of each spoke cavity portion, the split cavity portion, and the annular cavity portion, and the rim portion A configuration is proposed in which sound waves propagating through a tire cavity sealed by a tire mounted on the tire interfere with each other and attenuate.

  In such a configuration, the sound wave propagating through the cavity communication path defined by the partition wall interferes with the sound wave propagating through the tire cavity to attenuate both of them, thereby generating a cavity generated in the tire cavity. Resonance noise can be reduced. That is, this configuration is a configuration in which a quinke type interference silencer is applied by a cavity communication path, and is combined with the Helmholtz silencer and the sound absorbing material described above, and each cavity resonance noise is reduced. By being exhibited, the effect of reducing cavity resonance generated in the tire cavity is further improved. In addition, the effect of reducing the cavity resonance generated during vehicle travel is further improved as compared with the conventional configuration described above.

  Here, the effective length of the cavity communication path may be set such that a sound wave propagating through the cavity communication path and a sound wave propagating through the cavity in the tire interfere with each other to attenuate each other. If this phase difference does not become an integral multiple, it can be attenuated by the interference of waves. Specifically, a phase difference such as ¼ wavelength or 波長 wavelength may be generated, and it is preferable to approximate the phase difference of ½ wavelength. And what is necessary is just to set the wall length of a partition wall so that it may be set as the effective length which produces such a phase difference. The wall length of the partition wall may be set so as to at least bisect the inner part of each spoke cavity, so that the divided cavity part divided by the partition wall is communicated in the spoke cavity part. Furthermore, it is also possible to constitute so as to extend to the vicinity of the outer end of the spoke cavity.

  Further, by providing the partition wall, the rigidity and strength of the portion where the spoke part and the annular cavity part are formed are improved. Thereby, the vibration during vehicle travel can be suppressed, and the effect of reducing the cavity resonance noise in the tire cavity portion as a whole can be achieved. And it exists in the tendency for rigidity and intensity | strength to improve by setting the wall length of a partition wall long. Therefore, it is preferable to set the wall length of the partition wall so that the interference action of the sound wave propagating through the hollow communication path described above and the vibration suppressing action by improving the rigidity and strength occur in a well-balanced manner. Similarly, the rigidity and strength can be improved by setting the width of the partition wall wide.

  In such a configuration, the partition wall is a predetermined wall length, the effective length of the cavity communication path communicating with the rim side opening of the spoke cavity facing each other, the sound wave propagating through the cavity communication path, and the tire A configuration is proposed in which the phase difference from the sound wave propagating through the inner cavity is set to a half wavelength.

  Here, basically, a standing wave having one wavelength around the circumference is generated in the tire cavity due to vibration transmitted from the road surface. For this reason, the half-wavelength travels at a site 180 degrees opposite in the circumferential direction from the site where the vibration is generated, so that the difference in pressure between the two sites becomes the largest. In this configuration, the portions where the rim side openings of the spoke cavities facing each other are located, and the portions where vibrations are caused by the interference of sound waves having a half-wave phase difference and the portions facing each other It is possible to reduce the difference between the pressure and the pressure. Thereby, the cavity resonance sound which generate | occur | produces in the cavity part in a tire can be reduced more effectively. That is, this configuration can be said to be a configuration in which the above-described quinque interference silencer is applied most appropriately.

  The spoke cavities facing each other are most preferably located 180 degrees opposite to each other, but may be spoke cavities as close as possible to the 180 degrees opposite positions. Can be fully exhibited. A vehicle wheel having an odd number of spoke portions may be applied to two spoke portions as close to 180 degrees as possible. For example, in a configuration having three spoke portions, it is preferable to apply this configuration to all three.

  In the vehicle wheel of the present invention, a spoke cavity formed in a hollow spoke part is opened to the outer surface of the rim part, and an annular formed at the inner end of the spoke cavity part along the outer peripheral edge of the hub attachment part. The hollow portion is provided so as to communicate with each other, and a porous sound absorbing material is embedded in the rim side opening of the spoke hollow portion. In this configuration, by effectively combining the Helmholtz type resonance silencer and the sound absorbing material, it is possible to effectively exhibit the action of reducing the cavity resonance sound that both have. Therefore, road noise can be remarkably reduced when traveling on any road surface such as a rough road having relatively rough surfaces or a smooth surface having a relatively smooth surface.

  In such a vehicle wheel, a partition wall extending from the outer peripheral edge of the hub mounting portion into each spoke cavity and partitioning the annular cavity and the inner part of each spoke cavity in the circumferential direction is provided. In the configuration in which the sound wave propagating through the cavity transmission path whose effective length is set by the wall length and the sound wave propagating through the tire cavity are mutually attenuated, the so-called Quinke type The configuration is an application of the interference silencer, and the cavity resonance can be reduced by the interference action of the sound wave propagating through the cavity transmission path and the tire cavity. Therefore, the effect of reducing road noise during vehicle travel is further improved by effectively combining the structure with the application of the Helmholtz resonance silencer and the sound absorbing material.

  Here, the effective length of the cavity communication path communicating with the rim side opening of the spoke cavity facing each other is the half-wavelength of the phase difference between the sound wave propagating through the cavity communication path and the sound wave propagating through the tire cavity. In such a configuration, by causing the sound waves having a half-wave phase difference to interfere with each other at the portions facing each other, it is possible to reduce the vibration pressure difference generated in the tire cavity and reduce the cavity resonance noise. obtain. Therefore, the effect of reducing road noise during vehicle travel is further improved.

Embodiments of the present invention will be described in detail with reference to the accompanying drawings.
1 and 2 show an automobile wheel 1 according to the present invention. The vehicle wheel 1 is formed by casting an aluminum alloy, and includes a hub attachment portion 4 to which an automobile axle is connected, a rim portion 3 to which a tire is attached, a hub attachment portion 4 and a rim portion 3. And a plurality of spoke portions 5 that connect the two. Here, the hub mounting portion 4 and the plurality of spoke portions 5 constitute the disk portion 2. In the present embodiment, 10 spoke portions 5 are provided.

  Here, the hub mounting portion 4 of the disk portion 2 has a substantially disk shape, and a hub hole 17 is formed in the center thereof, and is located radially outside the hub hole 17 and is evenly spaced in the circumferential direction. A plurality of bolt holes 18 are provided as described above. Further, a hub mounting surface 19 is provided on the rear surface of the hub mounting portion 4 to which the axle hub is crimped. An annular ridge 8 rising in the front direction is provided outside the outer peripheral edge of the hub mounting portion 4, and ten spoke portions 5 are provided radially outward from the annular ridge 8. ing. The spoke part 5 has an inner end that is thick in the circumferential direction and gradually narrows outward, and is provided at regular intervals in the circumferential direction. That is, the spoke portion 5 is joined to the hub attachment portion 4 via the annular ridge portion 8.

  On the other hand, the rim portion 3 is formed with flange portions 10a and 10b for holding the tire beads from both sides at the opening edges of both ends, and a beat seat for seating and supporting and fixing the tire beads on the flange portions 10a and 10b. The parts 11a and 11b are coupled to each other. Further, a drop portion 13 is provided between the bead sheet portions 11a and 11b on both sides for dropping the tire bead when the tire is mounted. Further, the front bead sheet portion 11 a and the drop portion 13 are coupled via the well portion 14. The rim portion 3 is joined to the outer end of each of the spoke portions 5 on the inner side from the front flange portion 10a to the front bead seat portion 11a.

  In the automobile wheel 1, a so-called design surface is constituted by the surface of the disk portion 2 that becomes the appearance of the wheel when mounted on the automobile. And each above-mentioned site | part of the wheel 1 for motor vehicles is each formed concentrically centering on the central axis L. As shown in FIG. Moreover, the vehicle wheel 1 of the present embodiment is a vehicle wheel according to the present invention.

  Further, when the predetermined tire 9 is mounted on the above-described automobile wheel 1, the annular air space sealed by the rim portion 3 and the tire 9 is the tire cavity 38 according to the present invention.

Next, the main part of this invention is explained in full detail.
As shown in FIGS. 2 and 3, the spoke part 5 has a hollow structure, and the inside thereof is a spoke cavity part 20. In the present embodiment, all the spoke portions 5 have the same configuration. Each spoke cavity 20 has an outer end penetrating the front bead sheet portion 11 a of the rim portion 3 inward and outward, and is open on the outer surface of the well portion 14. That is, the rim side opening 22 of the spoke cavity 20 is formed on the outer surface of the front bead sheet portion 11a. Further, even in the annular ridge 8 provided along the outer peripheral edge of the hub attachment portion 4 described above, a hollow structure is formed, and the inside is an annular cavity portion 21. The inner end of each spoke cavity 20 communicates with the annular cavity 21.

  From the respective portions of the inner peripheral end (outer peripheral edge of the hub mounting portion 4) of the annular cavity portion 21 that face the respective spoke cavity portions 20, along the radial center line M of each spoke cavity portion 20, A partition wall 25 reaching the inside of the spoke cavity 20 is formed. That is, the partition walls 25 are provided so as to cross the annular cavity 21 along the radial direction and extend into the spoke cavities 20. The partition wall 25 partitions the annular cavity 21 in the circumferential direction, and divides the air space in the spoke cavity 20 where the partition wall 25 is formed in the circumferential direction. Here, the spoke cavity 20 is composed of divided cavities 27 and 27 that are divided into two by a partition wall 25 and a body cavity 28 that is radially outward from the partition wall 25. The annular cavity 21 partitioned by the partition wall 25 communicates with the divided cavities 27 and 27 and the integral cavity 28.

  The radial lengths of the divided cavities 27 and 27 in the spoke cavity 20 are defined by the wall length of the partition wall 25. Then, the annular cavity 21, the divided cavities 27 and 27 of the spoke cavities 20, and the same-body cavity 28 form a cavity communication path 30 in which they communicate. The effective length X of the cavity communication path 30 is set by the radial lengths of the divided cavity portions 27 and 27 defined by the wall length of the partition wall 25 described above. That is, the effective length X of the cavity communication path 30 can be set by appropriately setting the wall length of the partition wall 25.

  Here, the effective length X of the cavity communication path 30 is attenuated by the sound wave propagating through the cavity communication path 30 and the sound wave propagating through the in-tire cavity 38 that is sealed with the tire 9 interfering with each other. Thus, it is set by determining the wall length of the partition wall 25. In the present embodiment, the effective length X of the cavity communication path 30 communicating with each rim side opening 22 of the spoke cavity 20 facing each other is the sound wave propagating through the cavity communication path 30 and the in-tire cavity 38. The partition wall 25 is set as a specific wall length so that the phase difference from the sound wave propagating through the half wave becomes a half wavelength. The spoke cavities 20 that face each other are configured so that the present embodiment includes ten spoke portions 5 at equal intervals, and therefore are opposite to each other by 180 degrees in the circumferential direction. Is provided. The effective length X of the cavity communication path 30 varies depending not only on the wall length of the partition wall 25 but also on the number of spoke cavities 20 and the diameter of the automobile wheel 1. It is necessary to set the wall length of 25 appropriately.

  In this way, the sound wave propagating through the rim-side opening 22 of the spoke cavity 20 facing each other through the cavity communication path 30 has a phase difference that is shifted by a half wavelength from the sound wave propagating through the tire cavity 38. By doing so, both sound waves interfere and attenuate. Here, the vibration received by the tire 9 from the road surface generates a standing wave having one wavelength around the circumference of the tire cavity 38 and vibrations between the ground contact portion with the road surface and a portion opposite to the ground contact portion by 180 degrees. The pressure difference is the largest. This oscillating pressure difference can be reduced by interfering with a half-wavelength sound wave propagating through the hollow communication path 30. As a result, the effect of reducing cavity resonance generated in the tire cavity 38 is further improved. The configuration in which the effective length X of the cavity communication path 30 is set in this way is a configuration in which a quinque interference silencer is most appropriately applied.

  Further, as described above, each of the spoke cavities 20 communicates with the in-tire cavity 38, so that each rim side opening 22 communicates with the cavity communication path 30. Therefore, the sound wave that propagates through the cavity communication path 30 and exits from each rim-side opening 22 interferes with the sound wave that propagates through the tire cavity 38. The sound wave propagating through the cavity communication path 30 also causes a phase difference with respect to the sound wave propagating through the tire cavity portion 38. The phase difference between the sound waves emitted from the rim-side openings 22 is smaller than the phase difference due to the spoke cavities 20 facing each other, and therefore does not become an integral multiple. Therefore, the damping action is also exerted by the phase difference of the sound wave emitted from the rim-side opening 22 of each spoke cavity 20, and the cavity resonance can be reduced.

  Further, the partition walls 25 described above improve the rigidity and strength of the spoke portions 5 and the annular ridge portions 8 each having a hollow structure. Thereby, since the wheel 1 for motor vehicles has sufficient rigidity and intensity | strength and the vibration which arises in the said wheel 1 can be suppressed, cavity resonance sound can be reduced.

  Each spoke cavity 20 communicates with the tire cavity 38 through the rim-side opening 22 as described above, so that a so-called Helmholtz resonance silencer is applied. That is, since the sound wave transmitted through the tire cavity 38 enters and exits (propagates) from the rim-side opening 22 into the spoke cavity 20, the propagation of the sound wave can be delayed. Reduce vibration energy. Thereby, the cavity resonance sound generated in the tire cavity 38 can be reduced. The spoke cavities 20 communicate with each other via the annular cavities 21, so that the spoke cavities 20 and the annular cavities 21 constitute a relatively wide air space. Since this relatively wide air region can exert a high effect as a Helmholtz type resonance silencer, it is excellent in the effect of reducing cavity resonance noise.

  On the other hand, foamed urethane having a continuous foam structure is embedded in the rim side opening 22 of each spoke cavity 20 to close the rim side opening 22. This urethane foam is the porous sound absorbing material 35 according to the present invention, and absorbs sound in the holes of the sound absorbing material (foamed urethane) 35 when sound waves (air vibration) propagate. Thereby, the cavity resonance generated in the tire cavity 38 is propagated to each spoke cavity 20 through the rim-side opening 22, so that the cavity resonance can be reduced. Further, since the rim side opening 22 is closed by the porous sound absorbing material 35, a desired acoustic impedance is obtained. Therefore, as the above-described Helmholtz type resonance silencer, the action of delaying the wavelength of the sound wave is increased, and the effect of reducing the cavity resonance sound is further improved. In addition, as an embedding amount embedded in the rim side opening 22 of the sound absorbing material 35, if the embedding amount is small, the sound absorbing force is reduced. On the other hand, even if the sound absorbing material 35 is excessively embedded, the effect of improving the sound absorbing force is reduced, and the problem of an increase in cost due to an increase in the usage amount of the sound absorbing material 35 occurs. Therefore, the amount embedded in the rim side opening 22 of the spoke cavity 20 is appropriately set. Specifically, a configuration in which the vehicle wheel 1 is embedded from the outer end of the rim-side opening 22 to about 2 to 4 cm inward is preferable.

  As described above, the vehicle wheel 1 according to the present embodiment includes a configuration in which a Helmholtz resonance silencer is applied, a configuration in which a Quinke interference silencer is applied, and a sound absorbing material that directly absorbs sound wave energy. 35 are appropriately combined so that the respective actions are effectively exhibited. And since the synergistic effect of these each action can also arise, the effect of reducing the cavity resonance sound which generate | occur | produces in the cavity part 38 in a tire is high.

  In the automobile wheel 1 of this embodiment, even when the vehicle is mounted on an automobile and travels on an actual vehicle, the resonance phenomenon caused by the vibration that the tire 9 receives from the road surface can be reduced, and road noise due to the resonance phenomenon can be reduced. Can be reduced. Below, the result of having implemented the road noise evaluation test by actual vehicle driving | running | working using the vehicle wheel 1 of a present Example is demonstrated. In the evaluation test of this example, an automobile having a performance for sufficiently reducing engine noise and the like is used.

  As an automobile wheel 1 to be mounted on such a test vehicle (high performance vehicle), a wheel having a rim diameter of 20 inches was used. The automobile wheel 1 has the configuration of the above-described embodiment, has 10 spoke portions 5, and includes a spoke cavity portion 20 and an annular cavity portion 21. A tire 9 having a tire width of 245 mm, a flatness ratio of 35%, and a rim diameter of 20 inches was attached to the automobile wheel 1. And the vehicle wheel 1 of the present Example was attached to all four wheels of the test vehicle.

  In addition, on the test vehicle, a position corresponding to the passenger's ear position was set as a sound pressure measurement point on the window side of the cockpit and the rear right seat, and a predetermined sound pressure measuring device was attached. In the evaluation test of this example, the sound wave measured by this sound pressure measuring device was processed in the 1/3 octave band.

  A road noise evaluation test was performed by driving such a test vehicle on a substantially straight road at a speed of about 60 km / h. This road was a relatively smooth road. In addition, for comparison with the automobile wheel 1 of the present embodiment, the automobile wheel having the conventional configuration, which has the same outer diameter as the automobile wheel 1 and the spoke portion 5 and the annular ridge portion 8 have a solid structure. (Not shown) was similarly used to perform a road noise evaluation test. The vehicle wheel of this comparative example has the same configuration as the vehicle wheel 1 of the example except that the spoke cavity 20, the annular cavity 21, the partition wall 25, the sound absorbing material 35, and the like are not provided. A test is carried out with the same tire 9 mounted on the vehicle.

  The results of the road noise evaluation test are shown in FIGS. FIG. 4A shows the measurement result of the sound pressure level at the window side ear position of the cockpit, and FIG. 4B shows the measurement result of the sound pressure level at the window side ear position of the rear right seat. In both the pilot seat and the rear right seat, in any frequency band of 400 Hz or less, the test vehicle equipped with the vehicle wheel 1 of this example has a sound pressure in the vehicle that is higher than that in the comparative example. It was confirmed that it was reduced. In particular, the sound pressure reduction effect is high in a frequency band of 200 Hz to 250 Hz which is considered as a main factor of cavity resonance sound. Further, even if the measurement result of the sound pressure level is secondarily processed with a narrow band, the effect of reducing the cavity resonance sound is clearly shown (not shown).

  From this road noise evaluation test result, it is clear that the vehicle wheel 1 of this embodiment is excellent in the effect of reducing road noise during actual vehicle travel. This road noise evaluation test is a case where the road surface condition is relatively smooth and travels on a substantially straight road at a constant speed, and can be said to be a test condition in which the effect of reducing road noise is relatively suppressed. Therefore, when the conditions are set when traveling on a rough road with relatively rough surfaces, when traveling on a curve, or when the speed changes greatly, the vehicle wheel 1 of this embodiment reduces the road noise. It is thought that can be demonstrated even higher.

  In the automobile wheel 1 of the present example, the effect of reducing the cavity resonance sound was also exhibited in the flat plate vibration test described above (not shown).

  In the vehicle wheel 1 of the above-described embodiment, the configuration is such that the 10 spoke portions 5 are provided and the spoke hollow portions 20 are formed in all of them, but as another configuration, the number of the spoke portions 5 is as follows. Various configurations such as three, four, or twelve can be employed. Furthermore, it is good also as a structure by which the spoke hollow part 20 is formed by making the predetermined number of spoke parts 5 into a hollow structure among all the spoke parts 5. FIG. In this case, the above-described road noise reduction effect during actual vehicle traveling can be stably exhibited by providing the plurality of spoke portions 5 in which the spoke hollow portions 20 are formed at equal intervals in the circumferential direction.

  Further, as the sound absorbing material 35, glass wool, felt material or the like can be used in addition to urethane foam. As the sound absorbing material 35, a material having a high acoustic impedance can be suitably used.

  Moreover, in the vehicle wheel 1 of the above-described embodiment, the cavity communication path 30 is configured by the spoke cavity 20 and the annular cavity 21, but as other configurations, for example, in the hub attachment part Alternatively, a hollow portion communicating with the spoke cavity or the annular cavity 21 may be provided.

  In this invention, it is not limited to the Example mentioned above, About another structure, it can change suitably within the range of the meaning of this invention. For example, it can be applied to steel wheels and magnesium alloy automobile wheels in addition to aluminum alloy automobile wheels, and other than cast automobile wheels, those formed by pressing or forged. It can also be applied to.

It is a top view of the wheel 1 for cars concerning the present invention. It is TT longitudinal cross-sectional view of the said wheel 1 for motor vehicles. It is PP sectional drawing in FIG. It is a graph which shows the result of having measured the sound pressure in a vehicle by the road noise evaluation test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automobile wheel 2 Disc part 3 Rim part 4 Hub attachment part 5 Spoke part 9 Tire 20 Spoke cavity part 21 Annular cavity part 22 Rim side opening part 25 Partition wall 27 Divided cavity part 28 Body cavity part 30 Cavity communication path 35 Sound absorbing material 38 Tire cavity X Effective length

Claims (3)

In a vehicle wheel comprising a hub mounting portion fixed to an axle, a rim portion for mounting a tire, and a plurality of spoke portions connecting the hub mounting portion and the rim portion,
A spoke cavity that includes a rim-side opening that is formed by hollowing the spoke and that passes through the rim inward and outward and opens at the outer surface of the rim;
An annular cavity portion provided along the outer peripheral edge of the hub attachment portion and communicating with the inner end of each spoke cavity portion;
A vehicle wheel, wherein a porous sound absorbing material is embedded in an opening of a spoke cavity and the spoke cavity is closed. From the outer peripheral edge of the hub mounting portion, it extends into the spoke cavity along the radial center line of each spoke, and the annular cavity is partitioned in the circumferential direction, and the inner part of each spoke cavity is divided into two in the circumferential direction. A partition wall that bisects the divided cavity is provided for each spoke part, and the spoke cavity and the annular cavity are communicated with each other through the divided cavity.
The effective length is set by defining the radial length of the divided cavity by the wall length of the partition wall, and propagates through the cavity communication path composed of each spoke cavity, the divided cavity, and the annular cavity. The vehicle wheel according to claim 1, wherein the sound wave and the sound wave propagating through the cavity in the tire sealed by the tire attached to the rim part interfere with each other and are attenuated.   With the partition wall as a predetermined wall length, the effective length of the cavity communication path that communicates with the rim side opening of the spoke cavity facing each other, the sound wave that propagates through the cavity communication path and the sound wave that propagates through the cavity in the tire The vehicle wheel according to claim 2, wherein the phase difference is set to be a half wavelength.

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