JP2002178727A - Core body for tires, rim wheel with core and tire and rim assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire and rim assembly whose silence and operation stability are improved and which can improve the safety when a tire is punctured. SOLUTION: A core body 16 for tires, which is equipped with an auxiliary air chamber 44, is secured to a rim 18. The auxiliary air chamber 44 is communicated with a tire air chamber 20 through a hole 46. Since the auxiliary air chamber 44 and the hole 46 take a part of a Helmholtz resonance sound absorber, they can absorb the vibration in a specific frequency range and can reduce the noise in a car cabin. In addition, when the tire is punctured, the core body 16 for tires supports the load and enables a run flat running.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire core used for a safety pneumatic tire (run-flat tire), a rim wheel with a core having the tire core mounted thereon, and a tire / rim assembly. In particular, it is possible to reduce the noise in the vehicle by suppressing the vibration transmitted to the vehicle, improve the steering stability, and further improve the safety in the event of a tire puncture while ensuring a particularly high ride quality. The present invention relates to a core for a tire, a rim wheel with a core, and a tire / rim assembly.

[0002]

2. Description of the Related Art In recent years, in order to ensure safety at the time of tire puncture, techniques of a run flat tire and a load support called a core have been disclosed.

[0003] With respect to run flat tires,
No. 2,229,316 discloses a tire in which a reinforcing rubber having a crescent cross section is arranged on a side portion thereof.

[0004] The core is disclosed in Japanese Patent Application Laid-Open No. Hei 2-24681.
As disclosed in Japanese Patent Application Laid-Open No. 1-No. 1 (1993), an arrangement in which an assembly is disposed in a well portion of a rim has been proposed.

[0005] Both of them have a certain effect in extending the running distance during puncturing, but the side reinforced tires have poor ride comfort due to the weight increase and the high vertical spring constant due to the reinforcing rubber. In addition, there is a problem that the core body tends to deteriorate ride comfort due to an increase in weight.

[0006] Therefore, although the safety at the time of puncture is improved, there is no merit to the user when the vehicle runs under normal internal pressure, and there are many disadvantages.

[0007] For a user who does not experience puncture, it is only disadvantageous to the end, which is an obstacle to the spread of run flat tires.

On the other hand, as a technique for overcoming the drawbacks related to the riding comfort of a tire / rim assembly having a core, a wheel provided with a support having an air chamber is disclosed in Japanese Patent Application Laid-Open No. 1-31.
No. 4,612,612.

The air chamber in the support portion and the main air chamber of the tire are connected by a communication portion provided with a directional element, and when an impact that causes a change in volume is applied to the tire, the flow resistance of the communication portion is reduced. This is intended to attenuate the impact.

[0010] Also, Japanese Patent Application Laid-Open No. 7-17222 discloses that
There has been disclosed a technology in which a porous material or a fibrous material is mounted on a core assembly to suppress cavity resonance in a tire and reduce in-vehicle noise.

[0011]

SUMMARY OF THE INVENTION Among the above known techniques,
In the rim wheel disclosed in JP-A-1-314612, a support portion having a diameter larger than that of the bead seat portion is formed integrally with the rim portion. It has fatal drawbacks that cannot be assembled beyond.

Further, the rim wheel disclosed in Japanese Patent Application Laid-Open No. 7-17222 has a problem that although the cavity resonance is reduced to some extent, its improvement effect is not sufficient.

Further, mounting the porous material or the fibrous material so that the porous material or the fibrous material does not come off during running or when assembling the rim causes an increase in the number of manufacturing steps, which is not preferable in industrial production.

In consideration of the above-mentioned facts, the present invention improves the quietness and handling stability, which are the major performance requirements of an automobile, without sacrificing other performances such as ride comfort, and provides safety during tire puncture. It is an object of the present invention to provide a practical core for a tire, a rim wheel with a core, and a tire / rim assembly capable of improving the tire.

[0015]

According to a first aspect of the present invention, there is provided a tire core body mounted on an outer peripheral portion of a rim in a tire chamber formed between a tire inner surface and a rim wheel. In the inside, there is a circumferentially discontinuous auxiliary air chamber connected to the tire air chamber via one or more communication parts, and at least the auxiliary air chamber and the communication part are Helmholtz. It is characterized by functioning as a resonance sound absorber.

Next, the operation of the tire core according to the first aspect will be described.

The tire core is mounted on the outer periphery of the rim of the rim wheel.

By mounting the tire on the rim wheel on which the core for a tire is mounted, a sealed tire chamber is formed between the inner surface of the tire and the rim wheel.

The tire air chamber is connected to the auxiliary air chamber of the tire core through one or a plurality of communication portions. Basically, even if the tire core enters, the tire air chamber is connected to a normal rim wheel. Since the internal volumes are almost the same, the spring constant of the tire does not change for a low-frequency slow input.

However, by setting the cross-sectional area of the communication portion to be relatively small, the internal volume is reduced by the flow resistance of the communication portion from the tire air chamber volume to the volume of the tire core for a higher frequency input. , Ie, a higher spring constant when equal to a smaller volume compared to the original tire chamber volume. Further, the vibration damping property is improved.

Therefore, for example, in a situation where a high-frequency input such as a sudden steering wheel operation or a high-speed running is applied, the apparent tire spring constant is increased, and a high steering stability can be ensured, and the tire can get over a projection on the road. It is possible to enhance the damping properties of vibrations that occur when, for example, the vehicle is damaged.

In addition, at least the auxiliary air chamber and the communicating portion can function as a Helmholtz resonance sound absorber against vehicle interior noise, thereby absorbing tire cavity resonance sound of a specific frequency.

That is, for the sound of the specific frequency to be reduced, the resonance sound absorbing effect is exhibited in the sub air chamber by appropriately selecting the volume of the sub air chamber, the cross-sectional area of the communicating portion, the length, and the like. be able to.

However, if the auxiliary air chamber is continuous in the circumferential direction,
In addition to not functioning as a Helmholtz resonance sound absorber, a new cavity resonance is generated in the sub-air chamber, and a sound reduction effect cannot be exhibited. Therefore, the shape of the sub-air chamber must be discontinuous in the circumferential direction.

For example, for a tire for a passenger car, about 2
There is a peak at about 50 Hz, which is considered to be cavity resonance, which contributes to the noise in the vehicle. However, by appropriately setting the above-mentioned factors, the cavity resonance can be significantly reduced.

The core for a tire has a function of suppressing the amount of deflection of the tire and supporting the load when the tire is punctured. As a result, it is possible to prevent the rim from coming off, or to reduce the heat generated by the tire, which may cause the tire to break. Preferably, the tire core has a structure that can be elastically deformed by a load in order to prevent breakage at the time of tire puncture, and the structure is not particularly limited. It is desirable that the rim radial cross section of the chamber is close to circular.

The material constituting the wall surface of the sub air chamber is not particularly limited. However, in consideration of load support at the time of puncturing and impact from a road surface, (iron) steel material, light metal material such as aluminum, fiber A high strength material such as a reinforced resin composite material or an engineering plastic is preferable.

According to a second aspect of the present invention, in the tire core body according to the first aspect, the total volume of the sub air chamber is 1% or more and 40% or less of the total air chamber volume in the tire. It is characterized by.

Next, the operation of the core for a tire according to the second aspect will be described.

When the total volume of the auxiliary air chamber is less than 1% of the total air chamber volume in the tire, the effect of improving the vibration damping property and reducing the cavity resonance is reduced.

On the other hand, if the total volume of the sub air chamber is larger than 40% of the total air chamber volume in the tire, the workability of mounting the rim deteriorates, which is not preferable.

The total volume of the auxiliary air chamber is more preferably 2 to 30% of the total air chamber volume in the tire.

According to a third aspect of the present invention, in the core for a tire according to the first or second aspect, the resonance frequency of the Helmholtz resonance sound absorber formed by the sub air chamber and the communication portion is adjusted. It is characterized in that it is set in the range of 100 to 500 Hz.

Next, the operation of the tire core according to the third aspect will be described.

The cavity resonance frequency in the tire chamber is determined by the circumference of the tire and the rim. This frequency is high for a small tire for a light vehicle and low for a large tire for a truck.

The present inventors assume that the cavity resonance frequency is 250H.
According to the examination using a general passenger car tire of z, it was confirmed that the cavity resonance noise reduction effect was obtained when the setting was within a range of 100 to 500 Hz.

Therefore, in a closed space of a tire, a relatively wide range setting as described above is allowed.

According to the current size configuration, the resonance frequency of each tire is approximately in the range of 180 to 300 Hz, and it is more preferable to adjust each dimension so that the set resonance frequency of the Helmholtz resonance sound absorber also falls within this range. It is preferable to obtain a large noise reduction effect.

The resonance frequency of the Helmholtz resonance sound absorber composed of the sub air chamber and the communicating portion is, for example, the following equation (1)
Can be determined by:

[0040]

(Equation 1)

F ₀ (Hz): resonance frequency Vn (cm ³ ): volume of the auxiliary air chamber Ln (cm): length of the communication portion Sn (cm ² ): cross-sectional area of the communication portion Is the number of each air chamber when there are sub air chambers.

When there are a plurality of (i) connecting portions in each sub-air chamber, the cross-sectional area of each connecting portion is S
Assuming that i and the length are Li, the calculation may be made as follows: Sn = ΣSi (i = 2 to i) Ln = ΣSi · Li / ΣSi

According to a fourth aspect of the present invention, there is provided a tire core according to any one of the first to third aspects, wherein:
It is characterized in that a plurality of the sub air chambers are provided.

Next, the operation of the tire core according to the fourth aspect will be described.

If the auxiliary air chamber has a continuous ring shape (annular shape), a new cavity resonance at a frequency corresponding to the diameter of the auxiliary air chamber should be avoided.

If a plurality of sub-air chambers are provided in the tire circumferential direction, and the shape of each sub-air chamber is not a continuous annular shape, the generation of the above-described cavity resonance can be avoided, and the air chambers can be arranged in a well-balanced manner.

When a plurality of sub air chambers are provided in the tire circumferential direction as described above, preferably, the size of the communicating portion of each sub air chamber or the volume of the sub air chamber is changed, and each sub air chamber is changed. Is preferably shifted.

The frequency of the cavity resonance sound in the tire chamber is determined by the inner circumference of the tire tread and the outer circumference of the rim. The frequency of the resonance changes. Therefore, in order to provide versatility, it is preferable to set the frequency of each sub air chamber to be shifted, for example, by about 10 to 20 Hz.

Even when a certain tire size is determined, the frequency 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 sub air chambers is not particularly limited as long as it is plural, but is preferably about 3 to 6.

In terms of rotational balance, the position of the auxiliary air chamber (or the position of the partition wall between the auxiliary air chambers) is preferably equally distributed on the periphery. It is necessary to appropriately select the position (or the size and position of the partition wall between the sub air chambers).

According to a fifth aspect of the present invention, there is provided a tire core according to any one of the first to fourth aspects, wherein:
A muffler is included in the sub air chamber.

Next, the operation of the tire core 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 sound deadening 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, there is provided a tire core according to any one of the first to fifth aspects, wherein:
The tire core sub-air chamber portion constituting the sub-air chamber, and a base portion integrally provided on the rim rotation shaft side of the tire core sub-air chamber portion and connected to the outer peripheral surface of the rim, A plurality of arcuate core pieces are provided, and the plurality of core pieces are attached to the rim by being annularly connected along the rim circumferential direction by connecting means.

Next, the operation of the tire core according to claim 6 will be described.

The base portion is a portion for connection (for example, contact fixation) to the rim. By connecting a plurality of core pieces by a connection means, an annular shape having an inner circumference substantially equal to the rim bottom circumferential length is formed. A core for a tire can be formed. Thereby, the tire core can be reliably fixed to the rim wheel by friction with the rim bottom.

To mount the tire on a normal rim wheel, first, the tire bead portion on one side is assembled to the rim according to a normal method, and thereafter, a plurality of core pieces are connected by connecting means and fixed to the rim bottom.

Thereafter, the tire bead portion on the other side is assembled to the rim according to a usual method.

The structure of the connecting means and the method of connecting the core pieces are not particularly limited, and examples thereof include a method of fixing with bolts and screws, and a method of fastening with a high elastic band.

According to a seventh aspect of the present invention, in the core for a tire according to the sixth aspect, an elastic layer made of an elastic material in contact with the outer peripheral surface of the rim is provided on a side surface of the base portion on the rim rotation axis side. It is characterized by being.

Next, the operation of the tire core according to claim 7 will be described.

When the tire core is mounted on the rim wheel, the tire core is fixed with an elastic layer having elasticity (compressibility) to the bottom surfaces of the rims having slightly different dimensions with close contact. be able to.

If there is a gap between the tire core and the rim, rattling vibration occurs during running, which is not preferable.

As the elastic material, rubber, synthetic resin, foam (for example, sponge) and the like can be used.

According to an eighth aspect of the present invention, in the tire core according to the sixth aspect, the base is formed of an elastic material.

Next, the operation of the tire core according to the eighth aspect will be described.

By forming the base portion with an elastic body, the same effect as in claim 7 can be obtained without an elastic layer.

Further, since the base portion made of the elastic material absorbs the impact at the time of tire puncture, the durability of the tire core and the riding comfort of the vehicle can be improved.

The tire / rim assembly according to claim 9 is
A tire is mounted on a rim wheel to which the core for a tire according to any one of claims 1 to 8 is fixed.

The operation of the tire / rim assembly according to the ninth aspect is the same as the operation described for the tire core body according to the first to eighth aspects.

According to a tenth aspect of the present invention, in the tire core body according to any one of the first to fifth aspects, the invention is integrated with an air valve for injecting gas into the tire chamber. The air valve is fixed to the rim wheel by fixing the air valve to a valve hole of the rim wheel.

Next, the operation of the core for a tire according to the tenth aspect will be described.

Since the tire core according to the tenth aspect has an air valve, the tire core can be fixed to the rim wheel by an existing valve fixing method.
It is not necessary to form an annular shape in the tire so as not to come off the rim wheel, and mounting can be easily performed.

However, if the tire core is fixed only at the valve hole, the load at the time of puncturing will be concentrated on the air valve and the valve hole, causing premature destruction. It is preferable to provide a base in contact with the rim bottom at the radially inner portion of the tire core.

According to an eleventh aspect of the present invention, in the tire core according to the tenth aspect, an elastic layer made of an elastic material in contact with the outer peripheral surface of the rim is provided on the bottom surface on the rim wheel side. Features.

The operation of the tire core according to the eleventh aspect is the same as that of the tire core according to the seventh aspect.

According to a twelfth aspect of the present invention, there is provided a rim wheel provided with a core, comprising: the tire core body according to the tenth or eleventh aspect; and a rim wheel. A valve hole through which the air valve is inserted is formed, the air valve is inserted into the valve hole, a seal is provided between the air valve and the valve hole with a sealing member, and the air valve is fixed to the rim wheel by fixing means. It is characterized by doing.

Next, the operation of the rim wheel with a core according to the twelfth aspect will be described.

In order to mount the tire core according to claim 10 or 11 on a normal wheel, first, the tire bead portion on one side is assembled to a rim according to a normal method, and then the air valve is mounted on the rim wheel. Through the through hole.

At this time, the space between the air valve and the through hole is sealed with a seal member.

Then, the air valve is fixed to the rim wheel using a fixing means as in the conventional case.

Thereafter, the tire bead portion on the other side is assembled to the rim according to a usual method.

With the above structure, the rim wheel with a core can be easily assembled.

Although there are several methods for fixing the air valve, a method of externally tightening with a nut is preferable in terms of stability and workability of the tire core.

According to a thirteenth aspect of the present invention, in the rim wheel with a core according to the twelfth aspect, the core for a tire is constituted by a plurality of core pieces, and the air valve is integrally provided. A fixing member is provided on a core piece other than the child piece, and a fixing hole for inserting the fixing member other than the valve hole is formed on the rim wheel, and the air valve is provided integrally. The core piece other than the core piece allows the fixing member to pass through the fixing hole and seals the space between the fixing member and the fixing hole with a seal member, and the fixing member is fixed to the rim wheel by fixing means. It is characterized by being fixed to the rim wheel by fixing.

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

When the core for a tire is composed of a plurality of core pieces, it is sufficient that the air valve is provided in one core piece. A core having a similar fixing member (for example, an axial portion having an external thread formed on the outer peripheral portion) and a fixing hole similar to a through hole for an air valve provided on the rim wheel is provided with a fixing member similar to the air valve. It is formed according to the number of pieces, and a fixing member similar to the air valve is inserted into a fixing hole and fixed in the same manner as the air valve.

With such a configuration, the volume of the auxiliary air chamber can be increased, the sound reduction effect and the like can be increased, and the rotational balance can be improved.

Further, similarly to the air valve, it is necessary to seal the space between the fixing member and the fixing hole similar to the air valve with a sealing member. When the gas is filled in the tire air chamber, the fixing member similar to the air valve seals. It is preferable that the sealing portion is configured such that the member is pressed so that the sealing member comes into close contact with the inner surface of the fixing hole and the fixing member (for example, the sealing portion structure of a normal air valve is preferable).

A tire / rim assembly according to a fourteenth aspect is characterized in that a tire is mounted on the rim wheel with a core according to the twelfth or thirteenth aspect.

The operation of the tire / rim assembly according to the fourteenth aspect is the same as that of the rim wheel with a core according to the twelfth or thirteenth aspect.

According to a fifteenth aspect of the present invention, in the tire / rim assembly according to the ninth or fourteenth aspect, the rim between the rim radial outermost surface of the tire core and the rim wheel bead seat is provided. The radial distance is in the range of 30 to 70% of the rim radial distance from the rim wheel bead seat to the inner surface of the tire tread portion.

Next, the operation of the tire / rim assembly according to claim 15 will be described.

At the time of tire puncture, the distance between the outermost surface in the rim radial direction of the tire core and the rim wheel bead seat portion;
That is, if the height of the tire core is less than 30% of the distance from the rim wheel bead seat to the inner surface of the tire tread, the crush deformation of the tire becomes extremely large, and the tire durability deteriorates. The travelable distance after puncturing becomes short, which is not preferable.

On the other hand, if the height of the core for the tire is greater than 70% of the distance from the rim wheel bead seat to the inner surface of the tire tread, the tire and the tire can be used during normal running with internal pressure when riding on a step. It is not preferable because the child body comes into contact and causes abnormal vibration or breakage of the tire core body.

Although depending on the tire size, the rim radial distance between the rim radial outermost surface of the tire core and the rim wheel bead seat is the rim radial distance from the rim wheel bead seat to the inner surface of the tire tread portion. 40-60% of
Is more preferred.

According to a sixteenth aspect of the present invention, in the tire core according to any one of the first to eighth, tenth, and eleventh aspects, the communication portion is electrically connected to the tire core. It is characterized by including a valve whose opening area can be varied.

Next, the operation of the tire core according to claim 16 will be described.

In the tire core according to the sixteenth aspect,
Since the communication portion is provided with a valve having an electrically variable opening area, the air passage resistance can be changed by, for example, an automobile computer, and the vibration absorption characteristics can be changed.

As a result, the opening area can be automatically changed so as to minimize the vibration and noise in the cabin.

According to a seventeenth aspect of the present invention, in the tire core body according to the sixteenth aspect, the valve is controlled based on a vibration detection result of a vibration detection sensor provided in the vehicle. And

Next, the operation of the tire core according to claim 17 will be described.

In the core for a tire according to the seventeenth aspect,
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.

Note that the vibration detection sensor is attached at
Any part can be used as long as vibration can be detected, but it is preferable that the lower part of the suspension can detect vibration at a portion near the road surface.

[0106]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] The first embodiment of the present invention
The embodiment will be described with reference to FIGS.

As shown in FIG. 1, the tire / rim assembly 1
0 is a rim wheel (in this embodiment, an aluminum wheel)
12, a tire 14, and a tire core 16 are provided.

The tire core 16 and the tire 14 are mounted on the rim 18 of the rim wheel 12, and the tire 14
A sealed tire air chamber 20 is formed between the rim 18 and the rim 18.

The size of the tire 14 of this embodiment is 185 / 60R14, and the size of the rim 18 is 6JJ.
14.

[0110] As shown in FIG.
Is a plurality (six in this embodiment) of arcuate core pieces 2
The core pieces 22 are assembled in an annular shape by connecting the ends of the core pieces 22 to each other.

The tire core 16 of this embodiment is made of a synthetic resin material.

As the synthetic resin material, a flexural modulus of 7
000~16000MPa (ISO170 (dry)) Izod impact value 9~25kg / cm ² (ISO 1
80 / 1A (dry state with notch) and heat deformation temperature 220
° C (18.5 kg / cm ² ) or higher can be used. Specifically, nylon 6.6, nylon 4
・ A thermoplastic resin containing 6 or the like can be used.

In order to improve the strength, various types of short fibers such as glass fiber, carbon fiber, graphite fiber and alumina fiber, and known fillers such as whisker and calcium may be mixed into the synthetic resin material. Use core 16
An RP (GFRP, CFRP, etc.) structure may be used. The tire core 16 may be formed of metal such as steel.

The tire core 16 of this embodiment is formed of nylon 66 containing 40% of glass fibers.

As shown in FIGS. 3 and 4, the core piece 22 includes an air tank 24 as a sub air chamber forming portion and a base portion 26.

As shown in FIG. 4, the base 26 has a substantially inverted T-shaped cross section in the radial direction. The base 26 has a wall 26A having a constant width in the radial direction and a radially inner portion of the wall 26A. It has a radially inner end 26B integrally formed and of constant width in the axial direction, and has a wall 26A and a radially inner end 26B.
26C.

On the rim-side inner peripheral surface of the radial inner end 26B,
An elastic layer 30 made of an elastic material and having a constant thickness is fixed by an adhesive or the like.

The elastic layer 30 of the present embodiment is formed of a rubber sheet having a thickness of 1 mm, a width of 30 mm, and a rubber hardness (JIS A) of 60 degrees. A foam (for example, sponge) may be used.

The elastic layer 30 is slightly compressed in the rim radial direction, and is in close contact with the outer peripheral surface of the well 18A of the rim 18 to which the bead 15 of the pneumatic tire 14 is fixed.

As shown in FIG. 3 and FIG. 4, the base 26 has a first end on one side in the circumferential direction (in the direction of the arrow CCW).
Is provided, and a second fitting portion 34 that fits with the first fitting portion 32 is provided at an end on the other circumferential side (the arrow CW direction side). .

The first fitting portion 32 has a counterbore having a circular portion having a depth approximately half the thickness of the wall 26A on one side of the base 26 (on the back side of the sheet of FIG. 3). A bolt through hole 38 is formed in the center of the arc.
Are formed.

Next, the second fitting portion 34 has the base 26
A circular spot facing 40 having a depth dimension substantially half the thickness dimension of the wall 26A is formed coaxially on the other side surface (the front side of the paper surface of FIG. 3), and the first arc is formed at the center of the circular arc. Bolt through hole 42 having the same diameter as the bolt through hole 38 of the fitting portion 32 of FIG.
Are formed.

The first fitting portion 32 of the core piece 22 and the second fitting portion 34 of the other core piece 22 are overlapped,
By screwing a nut (not shown) to the bolt 43 inserted through the bolt through hole 38 and the bolt through hole 42, the core pieces 22 are connected to each other as shown in FIG. The child body 16 is formed.

As shown in FIG. 3, the air tank 24 has a shape in which a round pipe is bent in an arc shape and both ends are closed, and the internal space is a sub air chamber 44.

A single circular hole 46 is formed in the longitudinal center portion of each air tank 24 on the side facing the crown of the tire 14, and the tire air chamber 20 is formed through the hole 46.
And the sub air chamber 44 communicate with each other.

The total internal volume of the air tank 24 with respect to one rim wheel 12 (the volume of six auxiliary air chambers 44 in this embodiment) is the total internal air chamber volume (the volume of the tire air chamber 20 + the auxiliary air volume). It is preferably 1% or more and 40% or less of the total volume of the chamber 44, and more preferably 2% or more and 30% or less.

It is preferable to apply a lubricant such as silicone oil to the surface of the air tank in order to suppress frictional heat between the tire and the air tank during puncturing.

As shown in FIG. 1, the rim radial distance A between the rim radial outermost surface of the tire core 16 (the rim radial outermost end of the air tank 24) and the rim wheel bead seat is equal to the rim radius. From the wheel bead seat to the inner surface of the tire tread portion (the portion facing the radially outer side of the radially outermost surface of the tire core 16 rim, the tire core 1
6 A part where the outermost surface of the rim is in contact. ) Is preferably within the range of 30 to 70% of the rim radial distance B to the rim, and more preferably within the range of 40 to 60%. (Operation) Next, the operation of the tire / rim assembly 10 of the present embodiment will be described.

When the tire / rim assembly 10 rotates on the road surface, the tire 14 vibrates due to input from the road surface.

When a particularly large input deforms the tire 14, air flows from the tire air chamber 20 to the auxiliary air chamber 44. However, since the hole 46 as the communication portion is narrowed, fluid resistance is generated. Vibration is damped and ride comfort is improved.

Further, since the auxiliary air chamber 44 and the hole 46 play a role of a resonance sound absorbing structure called a Helmholtz resonance sound absorber, vibration of a specific frequency can be absorbed, and noise in the vehicle can be reduced.

For example, a tire for a passenger car has about 2
Since a peak considered to be cavity resonance exists at around 50 Hz, which contributes to vehicle interior noise, the resonance frequency of the auxiliary air chamber 44 may be set to around 250 Hz.

For the sound of a specific frequency to be reduced, the desired resonance in the sub-air chamber 44 can be achieved by appropriately selecting the volume and shape of the sub-air chamber 44 and the cross-sectional area and length of the hole 46. Sound absorption can be exhibited.

When there are a plurality of vibrations of the frequency to be reduced (for example, when there are a plurality of peaks in the frequency characteristics), the volume and shape of each sub-air chamber 44, the cross-sectional area and the length of each hole 46, By appropriately selecting the above, it is possible to cope with vibrations at a plurality of frequencies.

Further, since the auxiliary air chamber 44 of the present embodiment is not formed in an annular shape by the partition wall, it is possible to avoid the generation of cavity resonance due to the annular shape.

The tire core body 16 of the present embodiment rotates integrally with the rim 18 due to friction between the elastic layer 30 at the radially inner end 26B and the well portion 18A of the rim 18 during running.

Further, the elastic layer 30 is provided between the radial inner end 26B of the tire core 16 and the rim 18, so that the bottom surface of each of the rims having slightly different dimensions can be adhered to the bottom of the rim. The core 16 can be securely fixed.

As a result, the running tire core 16
The rattling is suppressed. To do so, when the tire core 16 is assembled to the rim 18, the elastic layer 30
The thickness of the elastic layer 30 or the inner diameter of the tire core 16 is set in advance so that the pressure is slightly compressed.

In the present embodiment, the hole 46 of the air tank 24 is circular. However, the shape of the hole 46 may be other than circular. The tire air chamber 20 and the auxiliary air chamber 44 may be communicated with each other by using a tubular body such as a slit or a pipe instead of the hole 46.

Further, the inside of the sub air chamber 44 can be filled with a cotton-like body such as glass wool or sponge or a foam-like sound absorbing agent (sound absorbing material), or can be attached to the inner wall.
Thereby, the sound absorbing effect can be further enhanced.

When the internal pressure decreases due to puncture or the like, the tire 14 is crushed on the ground contact side, and the inner surface of the crown portion contacts the radially outer end of the tire core body 16 (air tank 24).

At this time, the tire core 16 is
Is supported from the inside to prevent its collapse, and the tire 14 can run in a state where the internal pressure is low.

Further, since the cross-sectional shape of the air tank 24 is circular, local stress hardly acts upon input from the road surface, and the durability of the air tank 24 is ensured.

Next, the procedure for mounting the tire 14 on the rim wheel 12 will be described.

First, the bead portion 15 on one side of the tire 14 is assembled to the rim 18 according to a usual method, and then, a plurality of core pieces 22 are joined together on the rim bottom portion with bolts 43 and nuts.

Next, the other-side bead portion 15 may be assembled to the rim 18 in a usual manner.

The distance A in the rim radial direction between the rim radial outermost surface of the tire core 16 and the rim wheel bead seat.
However, if it is smaller than 30% of the rim radial distance B from the rim wheel bead seat to the inner surface of the tire tread portion, the crush deformation of the tire 14 at the time of puncturing becomes extremely large, and the tire durability deteriorates. The travelable distance becomes short, which is not preferable.

On the other hand, if the distance A is greater than 70% of the distance B, the tire 14 and the tire core body 16 come into contact with each other at the time of running over a step during normal running with the internal pressure charged, causing abnormal vibration. Core 16 for tires
It is not preferable because it may cause the destruction of the film.

[Second Embodiment] Next, a rim wheel according to a second embodiment of the present invention will be described with reference to FIGS. The same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 5, the core piece 52 of the tire core body 50 of the present embodiment is obtained by removing the base portion 26 from the core piece 22 of the first embodiment, and replacing the core piece with a thick elastic piece. The elastic base 54 made of a material is bonded. The air tank 24 is made of aluminum.

The side of the elastic base portion 54 which contacts the air tank 24 is formed in an arc shape. , Elastic base 54
Has a thickness of 16 (center) to 13 (both ends) mm and a width of 30 m
m, is made of rubber having a rubber hardness (JIS A) of 65 degrees, but may be made of synthetic resin other than rubber, foam (for example, sponge) or the like as long as it has elasticity.

As shown in FIG. 6A, the core piece 52
A main body 58 of a snap lock (commonly known) 56 is fixed to the outer peripheral side of the air tank 24 at one end in the longitudinal direction, and a hook portion 60 combined with the main body 58 is fixed to the other end in the longitudinal direction. ing.

When the U-shaped portion 58A of the main body 58 is hooked on the hook 60A of the hook portion 60 of the other core piece 52 and the lever 58B of the main body 58 is lowered (see FIG. 6B), the core piece 52 Are connected and fixed.

By connecting the core pieces 52 annularly with the snap locks 56, each elastic base portion 54 is slightly compressed,
The tire core 50 is securely fixed to the rim 18.

The snap lock 56 is provided with a hook-shaped lock lever 62 which is rotatable in a plane substantially perpendicular to the direction of rotation of the lever 58B. A hole 58C is formed in the side surface of the lever 58. By inserting the tip of the lock lever 62 into the hole 58C, the lever 58 is prevented from being raised by vibration or the like.
B can be fixed.

The operation of the tire core body 50 of the present embodiment,
The effect is the same as that of the above-described embodiment except that the riding comfort at the time of tire puncturing becomes mild. The unique operation and effect of the present embodiment are that the core pieces 52 are connected by using the snap locks 56, so that the core pieces 52 can be connected without any tools, resulting in good workability. Can be

In this embodiment, an air valve (not shown) mounted on the rim 18 is mounted at a gap 64 (FIG. 5) between the elastic base portions 54.
), And provided at a portion corresponding to the gap 64, air can be filled without interfering with the elastic base portion 54. [Third Embodiment] Next, a third embodiment 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.

The core 70 for a tire according to this embodiment is constituted by a plurality of core pieces 72 as in the above-described embodiment.

As shown in FIG. 7, the core piece 72 is provided with a plurality of air tanks 74 each having a shape in which a square pipe is bent in an arc shape and both ends are closed (only one side is shown in the figure). As shown, a base portion 76 is integrally provided on the rim side surface of the air tank 74.

The base portion 76 is in contact with the well portion 18A of the rim 18 via an elastic layer 77 so as to support a load during a tire puncture.

As shown in FIG. 7, one circular hole 78 is formed in the center of the air tank 74 in the longitudinal direction on the side opposite to the crown of the tire 14. 20 communicates with the sub air chamber 79 in the air tank 74.

Here, one of the plurality of core pieces 72
As shown in FIG. 8, the air valve 80
Are fixed, and an air hole 81 is formed coaxially with the air valve 80.

The air valve 80 may have a normal structure for a tire.

The rim 18 has a stepped through hole 82 through which the air valve 80 is inserted.

A packing 84 with a flange for sealing between the air valve 80 and the through hole 82 and a packing 86 without a flange are interposed between the through hole 82 and the shaft portion of the air valve 80.

The flange-less packing 86 and the washer 8
8 and a nut 90 are attached, and the core piece 72 with the air valve 80 is fixed to the rim 18 by tightening the nut 90.

As shown in FIG. 9, to the core piece 72 without the air valve 80, a set screw 92 which is completely identical in appearance to the air valve 80 and has no valve structure is fixed.

The core piece 72 without the air valve 80
Is fixed to the rim 18 in the same manner as the fixing method of the core piece 72 with the air valve 80. In addition, set screw 9
The length of 2 may be shorter than the air valve 80.

The operation and effect of the tire core 70 of this embodiment are the same as those of the above-described embodiment. Also, since the core pieces 72 do not need to be connected to each other, they can be easily attached.

[Fourth Embodiment] The present embodiment is a modification of the first embodiment.

As shown in FIG. 10, the hole 46 is provided with a valve 94 whose opening area can be changed by electric control.

The wiring 96 for controlling the valve 94 is connected to a computer 100 mounted on the vehicle via a slip ring 98 provided between the rim wheel 12 and an axle (not shown).

The vibration detection sensor 102 connected to the computer 100 is mounted on the lower part of the vehicle (for example, the axle mounting part of the suspension).

In this embodiment, since the opening area can be changed by the valve 94, the vibration absorption characteristics can be changed, and the vibration absorption characteristics (frequency, amplitude, acceleration, etc.) from the vibration detection sensor 102 can be changed. Thus, the computer 100 can control the valve 94 so that the noise in the passenger compartment is minimized.

The position of the vibration detection sensor 102 may be provided at a portion other than the lower part of the spring.

These controls are performed not only for the tire itself, but also for
The control can be performed simultaneously with the active suspension of the vehicle, and thereby a greater effect can be expected for improving the riding comfort and reducing the noise in the vehicle interior. (Test Example 1) In order to confirm the effects of the present invention, one kind of a tire / rim assembly of a comparative example (control product: a product combining a conventional rim wheel, a tire core body and a tire) and the present invention A prototype of the applied core, the rim wheel and the tire, and one kind of tire / rim assembly according to the embodiment are prototyped, mounted on a passenger car, run by a test driver, and tested for steering stability and vibration riding comfort. Was carried out.

Comparative Example: An ordinary 185 / 70R14 size tire for a passenger car was mounted on an ordinary 5.5JJ14 aluminum wheel. The volume of the tire chamber is about 2
5 × 10 ³ cm ³ .

Example: Second Embodiment (see FIGS. 5 and 6)
A rim wheel equipped with a tire core having the structure shown in FIG. 1 is equipped with the same passenger car tire as the control product. The volume of the tire air chamber is about 25 × 10 ³ cm ³ , and the total volume of the auxiliary air chamber (for 6 chambers) is 2.7 × 10 ³ cm.
³ (six sub-air chambers with an inner diameter of 5 cm and 0.45 liters each).

The diameters of the holes formed in the sub-air chambers are different for each sub-air chamber, and are 0.95 cm and 1.0, respectively.
5cm, 1.10cm, 1.15cm, 1.20cm,
1.30 cm, the number of holes is one each. A / B is 55%
(See FIG. 1).

The internal pressure of each tire was 200 kPa.

The driving stability, braking performance,
Comprehensive evaluation of steering wheel responsiveness and controllability at the time of maneuvering, and for vibration riding comfort tests, comprehensive evaluation of vibration on good roads, vibration on bad roads, vibration on special roads such as steps, and vehicle interior noise The index was shown with the product as 100.

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

[0183]

[Table 1]

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.

[0185] It was also confirmed that the riding comfort, especially on special roads, and the noise inside the vehicle were significantly improved as intended. (Test Example 2) To confirm the effects of the present invention, Test Example 1
Using a tire rim assembly of the same comparative example and a tire rim assembly of an embodiment combining a rim wheel and a tire to which the present invention is applied, and pressing the same on a drum simulating a normal road surface, The tire axial force when running at a constant speed was measured.

The drum has a diameter of 3 m and has asphalt on its surface imitating a general road shape. The tire is pressed against the drum with a load of 400 kgf and the speed is 40 km /
h, the drum axial force 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. 11 (A) shows the results of the axial force analysis in the vertical direction, and FIG. 11 (B) shows the results of the axial force analysis in the tire longitudinal direction.

In both cases, it was confirmed that the cavity resonance peak near 250 Hz was greatly reduced.

In the tire / rim assembly of the example, the vibration was greatly reduced as compared with the control. (Test Example 3) In order to confirm the effect of the present invention, the tire / rim assembly of the control product and the tire / rim assembly of the embodiment were respectively mounted on the front wheels of an actual vehicle, and the internal pressure of the right front tire was set to zero. A puncture durability test was performed.

The running was performed at a speed of 90 km / h in a peripheral circuit having a straight line and a gentle curve, and the running distance up to tire failure was examined.

The running distance until the tire failure is as shown in Table 2 below.

[0192]

[Table 2]

The tire according to the embodiment to which the present invention is applied has a size of 2
It can be seen that the tires did not break down even after running for 00 km, and the durability was greatly improved.

[0194]

As described above, the core for a tire, the rim wheel with the core and the tire / rim assembly of the present invention have the above-mentioned structures, so that other performances such as ride comfort are sacrificed. In addition, the present invention has the excellent effects of improving quietness and steering stability, which are the major performance requirements of automobiles, and improving safety during tire puncture.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part in a cross section of a part of a tire / rim assembly according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view perpendicular to the rotation axis of the tire / rim assembly according to the first embodiment of the present invention.

FIG. 3 is a side view of a core piece.

FIG. 4 is a side view of the core piece as viewed from the circumferential direction side.

FIG. 5 is a perspective view of a main part in a cross section of a part of a tire / rim assembly according to a second embodiment of the present invention.

FIG. 6A is a perspective view showing the vicinity of the snap lock before connection, and FIG. 6B is a perspective view of the vicinity of the snap lock after connection.

FIG. 7 is a perspective view of a main part in a cross section of a part of a tire / rim assembly according to a third embodiment of the present invention.

FIG. 8 is a sectional view of the vicinity of an air valve of the rim.

FIG. 9 is a cross-sectional view of the vicinity of a set screw of the rim.

FIG. 10 is a perspective view of a main part in a cross section of a part of a tire / rim assembly according to a fourth embodiment of the present invention.

FIG. 11A is a vertical axial force analysis result,
(B) is the result of axial force analysis in the front-rear direction.

[Description of Signs] 10 Tire / rim assembly 12 Rim wheel (Rim wheel with core) 14 Tire 16 Core body for tire (Rim wheel with core) 20 Tire air chamber 22 Core piece 24 Air tank (Secondary air) Chamber) 26 base part 30 elastic layer 43 bolt (connection means) 44 auxiliary air chamber 46 hole (communication part) 50 core body for tire (rim wheel with core) 52 core piece 54 elastic base part (base part) 56 Snap lock (connection means) 70 core for tire (rim wheel with core) 72 core piece 74 air tank (sub air chamber) 76 base 77 elastic layer 78 hole (communication part) 80 air valve 82 through hole 84 flange Packing with seal (seal member) 86 Packing without flange (seal member) 94 Valve 90 Nut (fixing means) 102 Vibration detection sensor

Claims (17)

[Claims] 1. A tire core mounted on an outer peripheral portion of a rim in a tire chamber formed between an inner surface of a tire and a rim wheel, wherein one or more communicating portions with the tire chamber are provided therein. A tire core having a circumferentially discontinuous sub-air chamber connected through a hole, wherein at least the sub-air chamber and the communication portion function as a Helmholtz resonance sound absorber. body. 2. The tire core according to claim 1, wherein a total volume of the sub air chamber is 1% or more and 40% or less of a total air chamber volume in the tire. 3. The tire core according to claim 1, wherein a resonance frequency of the Helmholtz resonance sound absorber is set in a range of 100 to 500 Hz. 4. The core for a tire according to claim 1, wherein a plurality of the sub air chambers are provided. 5. The core for a tire according to claim 1, wherein a sound deadening material is included in the sub air chamber. 6. A core auxiliary air chamber for a tire, which constitutes the auxiliary air chamber, and provided integrally on the rim rotation axis side of the core auxiliary air chamber for the tire, and connected to an outer peripheral surface of the rim. A base portion, and a plurality of arc-shaped core pieces having a core portion, wherein the plurality of core pieces are attached to the rim by being annularly connected along the rim circumferential direction by a connecting means. Any one of claims 1 to 5
The core for a tire according to the above item. 7. The tire core according to claim 6, wherein an elastic layer made of an elastic material in contact with the outer peripheral surface of the rim is provided on a bottom surface of the base portion on the rim rotation axis side. 8. The tire core according to claim 6, wherein the base is formed of an elastic material. 9. A tire / rim assembly wherein a tire is mounted on a rim wheel to which the tire core according to claim 1 is fixed. 10. The rim wheel is integrated with an air valve for injecting gas into the tire chamber, and is fixed to the rim wheel by fixing the air valve to a valve hole of the rim wheel. Item 6. The core for a tire according to any one of items 5. 11. The tire core according to claim 10, wherein an elastic layer made of an elastic material is provided on the bottom surface on the rim wheel side to be in contact with the outer peripheral surface of the rim. 12. A rim wheel with a core, comprising: the tire core body according to claim 10 or 11; and a rim wheel, wherein the rim wheel has a valve hole through which the air valve is inserted. The air valve is inserted into the valve hole, a seal is provided between the air valve and the valve hole with a seal member, and the air valve is fixed to the rim wheel by fixing means. Rim wheel with child. 13. The rim wheel according to claim 1, wherein the tire core comprises a plurality of core pieces, and a core member other than the core piece integrally provided with the air valve is provided with a fixing member. Has a fixing hole through which the fixing member is inserted other than the valve hole, and a core piece other than the core piece integrally provided with the air valve allows the fixing member to be inserted through the fixing hole. 13. The device according to claim 12, wherein a seal member seals between the fixing member and the fixing hole, and the fixing member is fixed to the rim wheel by fixing means. Rim wheel with core as described in. 14. A tire / rim assembly comprising a core mounted rim wheel according to claim 12 and a tire mounted thereon. 15. A rim radial distance between a rim radial outermost surface of the tire core body and a rim wheel bead seat is:
The tire / rim assembly according to claim 9 or 14, wherein the distance from the rim wheel bead seat to the inner surface of the tire tread portion is within a range of 30 to 70% of a rim radial direction distance. 16. The communication device according to claim 1, wherein the communication portion includes a valve having an electrically variable opening area. Core for tires. 17. The core for a tire according to claim 16, wherein the valve is controlled based on a vibration detection result of a vibration detection sensor provided in the vehicle.