JP2004352245A - Rim wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a practical rim wheel that can improve driving comfort and calmness, which are major points of requirement for automobiles. <P>SOLUTION: A plural number of lid units 20 are installed in the circumference direction on the outer surface of a rim 16, while partition walls are formed inside lid members 20, so that a plural number of subordinate air chambers 32 are constituted in the circumference direction between the rim 16 and lid members 20. A main air chamber 18 of a tire is linked with lid members 20 through a gap, composed as a linkage channel, with lid members 20. Since a Helmholtz resonator is constituted by the subordinate air chamber 32 and the gap, it is possible to absorb vibration of specific frequencies. In addition, because the subordinate air chamber 32 is not in the form of a ring continuing in the circumference direction, the generation of cave resonance sound is curbed, so that the sound muffling effect is considerable. Further, since the rim 16 is equipped with a recessed well portion 30, the tire 14 can be combined with the rim 16 as heretofore. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rim wheel for a vehicle on which a tire is mounted, and more particularly to a rim capable of suppressing vibration transmitted to the vehicle while ensuring high steering stability, improving ride comfort, reducing vehicle interior noise, and the like. About the wheel.

  2. Description of the Related Art In recent years, advanced functions have been promoted in high-grade vehicles, in particular, in order to achieve both high driving stability, ride comfort, and quietness of a vehicle at a high level.

  In response to the above-mentioned problems, active control techniques for suspensions, techniques for improving anti-vibration rubber and tire structures, and the like have been developed in the categories of tires, rim wheels, and suspensions, which are so-called undercarriages.

  Regarding the rim wheel, in order to improve the riding comfort, an auxiliary air chamber is provided in the wheel disc in Patent Document 1 (Japanese Utility Model Publication No. 38-27102), and the rim wheel further communicates with the tire main air chamber through a through hole. A configured tire wheel with auxiliary air chamber is disclosed.

  In Patent Document 2 (Japanese Utility Model Laid-Open No. 2-30704), the auxiliary air chamber is arranged in the wheel base for the same purpose.

On the other hand, an auxiliary air chamber is provided in the rim wheel in the same manner as in Patent Document 1 (Japanese Utility Model Publication No. 38-27102) in order to suppress the tire cavity resonance sound which is a major factor in the in-vehicle noise. Patent Literature 3 (Japanese Utility Model Laid-Open No. 1-39103) and Patent Literature 4 (Japanese Utility Model Laid-Open No. 1-90601) disclose a technique for adjusting the dimensions of the chamber and the communication hole so as to function as a Helmholtz resonance sound absorber.
Japanese Utility Model Publication No. 38-27102 Japanese Utility Model Laid-Open No. 2-30704 No. 1-39103 No. 1-90601

  The present inventors have studied and found that some of the above-mentioned known technologies have a certain effect on improvement of riding comfort and reduction of in-vehicle sound because the basic technology of engineering is used. Was done.

  However, due to the problems described below, it has not been put to practical use yet.

  Japanese Utility Model Publication No. 38-27102 and Japanese Utility Model Application Laid-Open No. 1-90601 form an auxiliary air chamber in a disk or a spoke. However, in practice, a large air chamber is formed because it is necessary to secure a brake space. It is impossible.

  In particular, most of the front wheels are equipped with disc brakes, and the brake calipers are very close to the inside of the rim wheel spokes in the axle direction.

  In addition, there is a limit to reducing the plate thickness from the viewpoint of rim strength.

  Regardless of whether the tire spring is reduced or the cavity resonance noise is reduced, the effect is extremely reduced unless a certain volume of the auxiliary air chamber is secured.

  Further, as a method of forming the auxiliary air chamber in the spoke, for example, a casting method using a core can be cited, but due to the difficulty in ensuring the accuracy of the size and position of the auxiliary air chamber, rotation There is concern that the balance will deteriorate.

  Further, an increase in manufacturing cost and a decrease in yield are disadvantageous.

  In the technique of joining or welding a plurality of members as disclosed in Japanese Utility Model Laid-Open Publication No. 38-27102, increase in weight, air-sealing property of the joined portion, and securing rotation balance are problems.

  In Japanese Utility Model Unexamined Publication No. 1-309103 and Japanese Unexamined Utility Model Application No. 2-30704, the rim wheel has a double bottom. However, since the diameter is smaller than the bead baseline, there is no so-called rim bottom part. It is impossible for the tire bead to get over the rim flange, and the rim cannot be practically assembled.

  Further, the present inventors have studied and found that when the annular continuous air chambers described above were formed, no reduction in the cavity resonance sound was observed at all.

  The present invention has been made in view of the above circumstances, and has as its object to provide a practical rim wheel that improves ride comfort and quietness, which are great performance requirements of an automobile.

  The rim wheel according to claim 1, wherein the rim wheel is formed between a rim and a lid member disposed radially outward of the rim, and is divided by a plurality of partition walls provided at intervals in a circumferential direction. A secondary air chamber, a concave well portion provided on at least one of the rim or the lid member, and having a bottom located radially inward of the bead seat, and communicating with the tire main air chamber and the auxiliary air chamber; A sub-chamber and the communication section constitute a Helmholtz resonance sound absorber.

  Next, the operation of the rim wheel according to the first aspect will be described.

  In the rim wheel according to the first aspect, a secondary air chamber is formed between the rim wheel main body and the lid member by disposing a lid member radially outside the rim wheel, and the secondary air chamber is a tire main air chamber. And functions as a Helmholtz resonance sound absorber.

  Also, this rim wheel is provided with a concave well portion whose bottom position is located radially inward of the bead seat, so that the tire bead portion can be dropped into the well portion, and the tire can be attached to the rim as before. Can be assembled.

  The well portion of the rim wheel body may be wider in the axial direction than the conventional product, or may have a structure deeper in the radial direction.

  The structure deeper in the radial direction means that the diameter difference between the bead part and the wheel base part is large.If there is enough brake space, the diameter difference can be increased by reducing the diameter of the wheel base part, If there is no room, the diameter difference can be increased by increasing the diameter of the bead portion and decreasing the tire height (making the tire outer diameter the same), that is, the so-called inch-up method.

  There is no substantial restriction on the width of the well portion in the axial direction.

  However, although the required auxiliary air chamber volume can be obtained even when the well portion is widened, it is preferable that the auxiliary air chamber be deeper inward in the radial direction from the viewpoint that a larger volume can be secured.

  The rim wheel body can be manufactured by a conventional casting method or a forging method, and can be manufactured inexpensively as before.

  The profile of the rim wheel provided with the lid member on the tire mounting side can be, for example, a line conforming to a normal JATMA standard.

  The material of the lid member may be the same metal material as that of the rim wheel main body, or welding is preferably selected if the same metal material is used, but a fixing method using a bolt or an adhesive is used for a different member.

  The thickness of the lid member depends on the material, but it is important to reduce the weight as much as possible in a range that does not cause plastic deformation of the tire rim assembly and rigidity that does not significantly deform due to centrifugal force during traveling. preferable.

  In the present invention, since the lid member is disposed between the rim wheel main body and the tire to form the sub air chamber, there is no fear of air leakage.

  In addition, since only the lid member manufactured separately from the rim wheel body is connected, the number of manufacturing steps and cost increase are small.

  Further, after the rim wheel main body and the lid member are combined, the profile can be made the same as that of the conventional rim wheel, so that the rim assembly and the rim release of the tire can be performed by the conventional method.

  By mounting the tire on the rim wheel, a sealed main air chamber is formed between the tire inner surface and the rim wheel.

  Here, if the auxiliary air chamber is continuous (that is, annular) in the circumferential direction, the auxiliary air chamber does not function as a Helmholtz resonance sound absorber, and cavity resonance having a frequency corresponding to the peripheral length is generated. Although the cavity resonance sound is rather loud, a significant noise reduction effect can be obtained effectively by disposing the partition and dividing the sub air chamber into a plurality in the circumferential direction.

  Further, by providing a plurality of sub air chambers, the volume of each sub air chamber can be changed, and the resonance frequency of each sub air chamber can be changed.

  The frequency of the cavity resonance sound in the tire main air chamber is determined by the inner periphery of the tire tread and the outer periphery of the rim. Changes.

  Therefore, in order to provide versatility, it is preferable to set the resonance frequency of each sub air chamber to be shifted, for example, by about 10 to 30 Hz.

  In addition, even when a certain tire size is determined, the frequency of the cavity resonance sound may change, the peak may be broadened, or the peak may have two peaks, depending on the load condition and the like. It is preferable to shift the resonance frequency of the air chamber.

  The number of partitions, that is, the number of sub-air chambers is not particularly limited as long as it is plural, but is preferably about 3 to 6.

  Further, it is preferable that the positions of the partition walls are equally distributed on the circumference in terms of rotational balance.

  According to the present invention, the auxiliary air chamber and the communication portion are set so that the resonance frequency given by the following equation (1) matches the tire cavity resonance frequency, so that the auxiliary air chamber is connected to the tire main air chamber by Helmholtz resonance sound absorption. It can function as a container, and can reduce the noise inside the vehicle.

f ₀ (Hz): resonance frequency Vn (cm ³⁾ of the additional air chamber: a volume Ln of the sub air chamber (cm): length of the communicating section Sn (cm ^2): sectional area n of the communicating portion includes a plurality of additional air The number of each chamber in the room.

When a plurality of (i) connecting portions exist in each sub-air chamber, if the cross-sectional area of each connecting portion is Si and the length is Li,
Sn = ΣSi (i = 2 to i)
Ln = ΣSi ・ Li / ΣSi
It should be calculated as

  The cavity resonance frequency in the tire main air chamber is determined by the circumference of the tire and the rim. In a normal passenger car tire, the cavity resonance frequency is around 250 Hz. This frequency is high for a mini vehicle tire and low for a large truck tire.

  When the present inventors examined using a general passenger car tire having a cavity resonance frequency of 250 Hz, the cavity resonance sound reduction effect was confirmed when the setting was within a range of 100 to 500 Hz.

  Therefore, a relatively wide range setting is allowed in the closed space of the tire, but according to the current size configuration, it is approximately in the range of 180 to 300 Hz, and the resonance frequency of each sub-air chamber is set to a size adapted within this range. Therefore, it is preferable to adjust each dimension in accordance with the above equation (1), since a large noise reduction effect can be obtained.

  Also, in the present invention, the internal constant volume of air is larger than that of a normal rim wheel by the volume of the auxiliary air chamber, so that the spring constant of the tire is reduced.

  For this reason, for example, a mild ride comfort is obtained for a large input such as a step on a road surface or a protrusion.

  Further, when the tire is deformed, the resistance of the air to pass through the communication portion increases the vibration damping property, and the riding comfort is improved.

  Further, by providing a plurality of lid members, it becomes easy to form a sub air chamber on the outer peripheral surface of the rim. In the case where the lid member is a single product (ring shape), it is necessary to attach the rim wheel in a disassemblable structure such as a three-piece structure, for example, and assembly is complicated.

  According to a second aspect of the present invention, in the rim wheel according to the first aspect, a gap is provided between the lid members, and the gap is used as the communication portion.

  Next, the operation of the rim wheel according to the second aspect will be described.

  In the rim wheel according to the second aspect, the lid member is arranged with a gap in the circumferential direction to form a sub air chamber, and the gap is used as a communication part, so that a hole or the like as a communication part is formed in the lid member. No need to do.

  For example, a slit-shaped communicating portion can be formed by arranging the respective lid members while keeping a constant interval in the circumferential direction.

  In this case, it is preferable to take measures such as forming a fitting structure between the rim wheel main body and the lid member for positioning the lid member, and providing a spacer for forming a slit at a circumferential end of the lid member. However, the desired form can be obtained with a minimum number of steps.

  According to a third aspect of the present invention, in the rim wheel according to the first aspect, the lid member and the lid member are in close contact with each other, and the lid member and the rim are in close contact with each other. It is characterized in that each of the lid members communicates with only one or a plurality of holes as communication portions.

  Next, the operation of the rim wheel according to the third aspect will be described.

  With such a configuration, for example, the resonance frequency can be changed only by adjusting the diameter and the number of the holes, and the degree of freedom increases for tire sizes having different cavity resonance frequencies.

  Further, the influence of the dimensional error and the mounting error of the lid member can be reduced.

  Welding or sealing is performed between the lid members, or a step is provided at the end of the lid member so that a gap is not formed in the circumferential direction by forming a fitting structure.

  The number of holes may be one for one lid member, but it is preferable to use a plurality of holes because the air flow resistance increases and the vibration damping property improves when the total cross-sectional areas of the holes are compared equally.

  According to a fourth aspect of the present invention, in the rim wheel according to any one of the first to third aspects, the total volume of the sub air chamber is 2% or more and 25% or more of the volume of the tire main air chamber. It is characterized as follows.

  Next, the operation of the rim wheel according to claim 4 will be described.

  When the total volume of the auxiliary air chamber is less than 2% of the volume of the tire main air chamber, the effect of improving the riding comfort and the effect of reducing the cavity resonance sound are reduced. In particular, theoretically, the auxiliary air chamber volume ratio is substantially equal to the tire spring reduction ratio, so that the effect of improving ride comfort is reduced.

  On the other hand, if the total volume of the sub air chamber exceeds 25% of the volume of the tire main air chamber, the tire spring constant is too low, and the vibration damping and steering stability are undesirably reduced.

  In addition, the total volume of the sub air chamber is more preferably 3 to 15% of the volume of the tire main air chamber.

  According to a fifth aspect of the present invention, in the rim wheel according to any one of the first to fourth aspects, a muffler is included in the sub air chamber.

  Next, the operation of the rim wheel according to the fifth aspect will be described.

  It is more preferable to include a sound deadening material (sound absorbing material) in the sub air chamber since the sound deadening effect of the sub air chamber is increased. Although the material of the noise reduction material is not particularly limited, for example, a cotton-like material or a foam-like material can be used.

  According to a sixth aspect of the present invention, in the rim wheel according to any one of the first to fifth aspects, the communication portion includes a valve capable of electrically changing an opening area. .

  Next, the operation of the rim wheel according to claim 6 will be described.

  By changing the opening area by the valve, the air passage resistance can be changed, and the vibration absorption characteristics can be changed.

  In addition, since the valves can be electrically controlled, the opening area can be changed by a vehicle-mounted computer. Thus, for example, the opening area can be automatically changed so that the noise in the vehicle interior is minimized.

  The invention according to claim 7 is the rim wheel according to claim 6, wherein the valve is controlled based on a vibration detection result of a vibration detection sensor provided in the vehicle.

  Next, the operation of the rim wheel according to claim 7 will be described.

  In the rim wheel according to the seventh aspect, the valve is controlled based on a vibration detection result of a vibration detection sensor provided in the vehicle.

  For example, when the vibration detection sensor detects a large amplitude vibration at the time of a large input or the like, the opening area can be largely changed to reduce the spring constant, reduce the impact, and improve the riding comfort.

  The vibration detection sensor may be mounted at any position as long as the vibration can be detected. However, the vibration is preferably detected at a portion where the lower part of the suspension is close to the road surface.

  As described above, since the rim wheel of the present invention has the above-described configuration, tires can be assembled in the same manner as before, and it is possible to improve the ride comfort and quietness, which are great performance requirements of an automobile. Has the effect.

[First Embodiment]
A first embodiment of a rim wheel according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1, in the rim wheel 10 of the present embodiment, by mounting the tire 14 on the rim 16, a sealed main air chamber 18 is formed between the tire 14 and the rim 16.

  As shown in FIGS. 1 and 2, a plurality (four in the present embodiment) of lid members 20 are arranged on the outer peripheral portion of the rim 16 along the circumferential direction.

  The lid member 20 of the present embodiment is formed by pressing a substantially rectangular plate material (aluminum plate having a thickness of 2 mm) of the same metal as the rim wheel 10, and is formed in a circumferential direction along the outer peripheral surface of the rim 16. And a part thereof is also curved in the width direction.

  A projecting positioning spacer 22 is integrally formed at one circumferential end of the lid member 20.

  The ends of the positioning spacers 22 of the plurality of lid members 20 are abutted against the other end of the adjacent lid members 20, whereby a certain width (between the lid members 20 and 20) is provided between the lid members 20. In the present embodiment, a gap 24 of 1 mm) is formed.

  One end in the width direction of the lid member 20 is engaged with and welded to a step portion 28 formed on the bead sheet 26 on the back side (the arrow IN direction side) of the rim 16.

  The other end in the width direction of the lid member 20 is welded to the outer peripheral surface slightly closer to the rim front side (the arrow OUT direction side) from the widthwise center portion of the rim 16.

Here, on the rim front side of the other end portion of the lid member 20, a concave well portion 30 for dropping the tire bead portion when the tire is mounted is formed. Note that the bottom of the well 30 is located radially inward of the bead seat 26 in the tire radial direction.
The outer shapes of the outer peripheral surface of the lid member 20 and the outer peripheral surface of the rim 16 (portion not covered by the lid member 20) are set to, for example, the same shapes as those specified in the normal JATMA standard.

  At the center in the circumferential direction of each lid member 20, a partition wall 20 </ b> A having the same shape as the cross section perpendicular to the circumferential direction of the space between the outer peripheral surface of the rim 16 and the lid member 20 is screwed to the inner surface side.

  Thereby, a plurality (four) of sub air chambers 32 are formed between the rim 16 and the lid member 20, and each sub air chamber 32 forms one gap 24 with respect to the tire main air chamber 18. Communicated through

  In the present embodiment, a Helmholtz resonance sound absorber is constituted by the auxiliary air chamber 32 and the gap 24, and the resonance frequency is set to about 250 Hz in the present embodiment.

The total inner volume of the sub air chamber 32 with respect to one rim wheel 10 is preferably 2% or more and 25% or less of the volume of the tire main air chamber 18, and more preferably 3% or more and 15% or less.
(Action)
Next, the operation of the rim wheel 10 of the present embodiment will be described.

  Since the tire main air chamber 18 composed of the tire 14 and the rim wheel 10 is connected to the sub air chamber 32 through the gap 24, at least the volume of the sub air chamber 32 and the normal tire and rim wheel Since the internal volume into which the air enters becomes larger than that of the combination product of the above, the spring constant of the tire 14 mainly in the radial direction decreases.

  Therefore, it is possible to provide a mild ride comfort for a large input such as a step on a road surface or a climb over a protrusion.

  Further, since the gap 24 has a relatively narrow slit shape, the resistance of the gap 24 can make the internal volume close to the spring constant when the volume is equal to the volume of the tire main air chamber 18 due to the high frequency input.

  Therefore, during high-speed running, the characteristics are the same as those of a combination product of a normal tire and a rim wheel in which the sub air chamber 32 is not provided, and steering stability can be secured.

  Further, with respect to high-frequency vibrations, the auxiliary air chamber 32 that is divided by the partition wall 20A and does not have a continuous annular shape in the circumferential direction serves as a resonance sound absorbing structure called a Helmholtz resonance sound absorber. Vibration (around 250 Hz in the present embodiment) can be absorbed, and vehicle interior noise can be reduced.

  For a sound of a specific frequency to be reduced, the volume and shape of the auxiliary air chamber 32, the cross-sectional area of the gap 24, and the length (in the direction perpendicular to the opening) are appropriately selected. Can exhibit resonance sound absorption.

  When there are a plurality of vibrations at the frequency to be reduced (for example, when there are a plurality of peaks in the frequency characteristic), the volume and shape of each sub air chamber 32, the cross-sectional area and the length of each gap 24, etc. By making a selection, it is possible to cope with vibrations at a plurality of frequencies.

  In addition, the inside of the sub air chamber 32 can be filled with a cotton-like body such as glass wool or sponge or a foam-like sound absorbing material (sound absorbing material) or attached to the inner wall, thereby further enhancing the sound absorbing effect. You can also.

In addition, since the rim wheel 10 is provided with the concave well portion 30, the bead portion of the tire 14 can be dropped into the well portion 30 and the tire 14 can be assembled as usual.
[Second embodiment]
Next, a second embodiment of the rim wheel of the present invention will be described with reference to FIGS. The same components as those of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  In the rim wheel (aluminum wheel) 40 of the present embodiment, substantially the entire outer peripheral surface inside the rim flange 44 of the rim 42 is formed deeper inward in the radial direction than the normal rim wheel, and is disposed in the circumferential direction. It is covered with a lid member 46.

  The lid member 46 of the present embodiment is formed by press-molding an aluminum plate having a thickness of 2 mm, and is fixed to the rim 42 by welding.

  In addition, a concave well portion 47 is formed in the lid member 46.

  On the outer peripheral surface of the rim 42, five partition walls 48 extending along the width direction of the rim 42 from one rim flange 44 side to the other rim flange 44 side are formed at equal circumferential intervals. Are covered by the lid member 46, thereby forming five sub-air chambers 50.

  When the tire (185 / 65R15) is mounted on the rim wheel (6JJ15) 40 of the present embodiment, the volume of the tire main air chamber 52 is about 25 liters, and the total volume of the five sub air chambers 50 is 1.7 ( 0.34 liters x 5) liters, and the total volume of the five sub-air chambers 50 is 6.8% of the total volume of the tire main air chamber 52.

  In each lid member 46, three through holes 54 are formed at regular intervals in the circumferential direction.

In the present embodiment, one lid member 46 in which three through holes 54 each having a diameter of 4 mm are formed,
Three cover members 46 each having three through holes 54 each having a diameter of 5 mm are used, and one cover member 46 each including three through holes 54 each having a diameter of 6 mm are used. The resonance frequency of the sub air chamber 50 is set to 217 Hz, the resonance frequency of the sub air chamber 50 having the through hole 54 having a diameter of 5 mm is set to 250 Hz, and the resonance frequency of the sub air chamber 50 having the through hole 54 having a diameter of 6 mm is set to 279 Hz. .

  In the rim wheel 40 of the present embodiment, a plurality of sub air chambers 50 having different resonance frequencies are provided as described above, so that vibration in a wide frequency range can be absorbed.

Further, since the sub air chamber 50 does not have a ring shape that is continuous in the circumferential direction, it is possible to prevent the occurrence of cavity resonance in the sub air chamber 50.
[Third Embodiment]
Next, a third embodiment of the rim wheel of the present invention will be described with reference to FIG. The same components as those of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  This embodiment is a modification of the rim wheel 40 of the second embodiment.

  A valve 60 whose opening area can be changed by electric control is attached to the through hole 54.

  The wiring 62 used to control the valve 60 is connected to a computer 66 mounted on the vehicle via a slip ring 64 provided between the rim wheel 40 and an axle (not shown).

  A vibration detection sensor 68 connected to a computer 66 is attached to a lower part of a vehicle (for example, an axle mounting portion of a suspension).

  In the present embodiment, since the opening area can be changed by the valve 60, the vibration absorption characteristics can be changed, and the vehicle can be changed based on the vibration detection results (frequency, amplitude, acceleration, etc.) from the vibration detection sensor 68. The computer 66 can control the valve 60 so that room noise is minimized.

  Further, since the passage of air can be completely prevented, the spring constant of the tire 14 is changed by providing a plurality of sub air chambers 50 and communicating only necessary sub air chambers 50 with the tire main air chamber 18. You can also.

  Note that the position of the vibration detection sensor 68 may be provided at a portion other than the lower part of the spring.

  These controls can be performed simultaneously with the active suspension of the automobile, as well as the tires alone, and thereby a greater effect can be expected for improving the riding comfort, reducing the noise in the vehicle interior, and the like.

Further, it is also possible to change the spring constant of the tire by operating a switch or the like according to the driver's preference.
[Other embodiments]
In the above embodiment, the lid member is fixed to the rim by welding, but may be fixed by another method such as adhesion or screwing.

  In the above embodiment, the lid member is made of metal (aluminum), but may be made of another material such as a synthetic resin.

Further, a hollow pipe may be attached to the cover member instead of forming a through hole.
(Test Example 1)
In order to confirm the effects of the present invention, a control product (combination product of a conventional rim wheel and a tire), a combination product of a rim wheel and a tire to which the present invention is applied (example), A prototype was removed from the prototype, and road noise was measured using a drum tester.

Control product: 5.5 J normal aluminum wheels fitted with 185 / 70R14 size normal passenger car tires. The volume of the tire main air chamber is about 25 × 10 ³ cm ³ .

  Example: A rim wheel according to the second embodiment is provided with the same passenger car tire as the control product.

  Comparative product: The same tire was mounted on a rim hole from which only the partition was removed from the example.

  The internal pressure of each tire was 200 kPa.

  The road noise drum has a diameter of 3 m and has asphalt on the surface imitating a general road shape. When the tire was pressed against the drum with a load of 400 kgf and was run at a speed of 60 km / h, the axial force of the drum in each direction was measured, and frequency analysis was performed. This test is a test method for so-called road noise transmitted to the inside of a vehicle as vibration.

  FIG. 6 shows the frequency analysis result of the axial force in the vertical direction, and FIG. 7 shows the frequency analysis result of the axial force in the tire front-rear direction.

  As a result of the test, it was confirmed that the cavity resonance peak was significantly reduced in the examples in both directions.

On the other hand, it was confirmed that the comparative product without the partition wall was worse than the control.
(Test Example 2)
In order to confirm the effect of the present invention, a control product of Test Example 1 and an example to which the present invention was applied were prepared, and the tire axial force when running at a constant speed was pressed against a drum provided with a protrusion. Was measured.

  The drum has a diameter of 3 m and has a projection of 10 mm in height on the surface. When the tire was pressed against the drum with a load of 400 kgf and was run at a speed of 40 km / h, the vertical axial force of the drum was measured, and the frequency analysis was performed.

  FIG. 8 shows results of axial force analysis in the vertical direction. As a result of the test, it can be seen that the peak value of the axial force in the vertical direction is lower in the example than in the conventional product, and the damping property is increased.

  FIG. 9 shows the result of frequency analysis.

As a result of the test, it was confirmed that the peak at 80 Hz was reduced, and the cavity resonance peak was also significantly reduced in this test.
(Test Example 3)
In order to confirm the effect of the present invention, a control product similar to the above-described test example and an embodiment to which the present invention is applied are prepared, mounted on a passenger car, and two test drivers run on a test course on a real vehicle. A steering stability test and a vibration riding comfort test were conducted.

  Driving, braking, steering wheel responsiveness, and controllability during maneuvering are comprehensively evaluated for steering stability, and vibration riding comfort tests include vibration on good roads, vibration on bad roads, and bumps. The overall evaluation of the vibration and the noise inside the vehicle during running on a special road was shown as an index when the control product was set to 100.

  The higher the index, the better the performance. The results are as described in Table 1 below.

  As a result of the test, it was confirmed that the product of the present invention had the same or higher steering stability as the control, and the riding comfort was greatly improved.

  As for the riding comfort, it was confirmed that especially the riding comfort on special roads and the noise in the vehicle were significantly improved as intended.

(A) is a sectional view along a rotation axis showing a main part of the rim wheel and the tire according to the first embodiment of the present invention, and (B) is an enlarged sectional view near a lid member end. . (A) is a plan view showing a part of the lid member, and (B) is a side view seen from a direction perpendicular to the axis of the rim wheel. FIG. 5 is a cross-sectional view along a rotation axis showing a main part of a rim wheel and a tire according to a second embodiment of the present invention. FIG. 6 is a cross-sectional view perpendicular to the axis of a rim wheel according to a second embodiment of the present invention. It is a sectional view of a rim wheel concerning a 3rd embodiment of the present invention. 9 is a frequency analysis result of an axial force in a vertical direction in Test Example 1. 7 is a frequency analysis result of the axial force in the tire front-rear direction of Test Example 1. 9 is a vertical axial force analysis result of Test Example 2. 9 is a frequency analysis result of an axial force in a vertical direction in Test Example 2.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 10 Rim wheel 16 Rim 18 Tire main air chamber 20 Cover member 20A Partition wall 24 Gap (communication part)
Reference Signs List 30 well part 32 sub air chamber 40 rim wheel 42 rim 46 lid member 47 well part 50 sub air chamber 52 tire main air chamber 54 through hole (communication part)
60 valve (communication part)
68 Vibration detection sensor

Claims (7)

A plurality of sub-air chambers formed between the rim and a lid member arranged radially outward of the rim and divided by a plurality of partition walls provided at intervals in a circumferential direction;
A concave well portion provided on at least one of the rim or the lid member, and a bottom portion located radially inward of the bead seat;
A communication section that communicates with the tire main air chamber and the sub air chamber;
With
A rim wheel, wherein a Helmholtz resonance sound absorber is constituted by the sub air chamber and the communication portion. The rim wheel according to claim 1, wherein a gap is provided between the lid members, and the gap is used as the communication portion. The lid member and the lid member are in close contact with each other, and the lid member and the rim are in close contact with each other. The rim wheel according to claim 1, wherein the rim wheel is in communication. The rim wheel according to any one of claims 1 to 3, wherein a total volume of the sub air chamber is 2% or more and 25% or less of a volume of the tire main air chamber. The rim wheel according to any one of claims 1 to 4, wherein a muffling material is included in the sub air chamber. The rim wheel according to any one of claims 1 to 5, wherein the communication portion includes a valve capable of electrically changing an opening area. The rim wheel according to claim 6, wherein the valve is controlled based on a vibration detection result of a vibration detection sensor provided in the vehicle.

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