JP2002307905A - Assembly of pneumatic tire and rim - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance rim assembling performance while maintaining the effect of suppressing cavity resonance. SOLUTION: A tire interval void 4 is provided with a sound suppressing implement 10 formed of a strip sheet body 10 using a sponge material, and arranged in a storage groove 9 circumferentially recessed in a well part 7 of a rim 3. The volume S2 of the sound suppressing implement 10 is set to 0.4% to 20.0% of the whole volume S1 of the tire internal void 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembly of a rim and a pneumatic tire having improved rim assembling performance while exhibiting an excellent cavity resonance reducing effect.

[0002]

2. Description of the Related Art One of the tire noises is a so-called road noise that generates a "go" sound in a frequency range of 50 to 400 Hz when traveling on a road surface. Resonant vibration of air (cavity resonance)
There is.

Therefore, the present applicant has filed Japanese Patent Application No. 2000-26.
No. 3519, as schematically shown in FIG. 10, proposes to dispose a sound damper made of a band-shaped sheet body b using a sponge material in a tire cavity a, and the volume S2 of the band-shaped sheet body b is proposed. Is 0.4% of the total volume S1 of the tire bore a.
With the above, cavity resonance can be effectively suppressed.

[0004] The belt-shaped sheet member b may be freely disposed in the tire bore a without being fixed to either the tire or the rim, or at least a part thereof may be fixed to the rim c.

[0005]

However, when the belt-shaped sheet member b is previously wound around the well portion c1 of the rim c and fixed, the bead portion of the tire does not rub against the belt-shaped sheet member b during rim assembly. Care must be taken, and the efficiency of the rim assembly tends to be impaired. In addition, when the belt-shaped sheet member b is put into the tire when assembling the rim, it takes much time and effort to insert the band-shaped sheet member b, and the storage of the tire and the band-shaped sheet member b is required to be performed separately.

Therefore, the present invention is based on forming a receiving groove extending in a circumferential direction in a well portion of a rim and arranging a band-like sheet body in the receiving groove, and maintains the effect of suppressing cavity resonance in the above-mentioned application. However, an object of the present invention is to provide an assembly of a rim and a pneumatic tire, which can enhance the rim assembly performance to a level close to a normal rim assembly.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a sponge material is used in a tire cavity formed by a rim and a pneumatic tire mounted on the rim. A sound suppressor, which is formed of a belt-like sheet body and is disposed in a well recessed in the circumferential direction in a well portion of the rim, is provided, and a volume S2 of the sound suppressor is set to 0. It is characterized by being at least 4% and at most 20.0%.

[0008] In the invention according to claim 2, the accommodating groove extends in a wavy shape in the circumferential direction.

In the invention according to claim 3, the rim has at least one groove wall of the accommodation groove, and a bead portion of the pneumatic tire extends from the groove wall into the accommodation groove in a comb shape in the tire axial direction. It is characterized by a guard piece protruding to prevent it from falling into the groove.

According to the invention of claim 4, the noise suppressor has a fence-like or net-like protective body on at least a part of an upper surface thereof for preventing a bead portion of the pneumatic tire from falling into the accommodation groove. It is characterized by doing.

In the present specification, the "volume S2 of the sound suppressor" is the apparent total volume of the band-shaped sheet body, and is determined from the outer shape of the band-shaped sheet body including the pores of the sponge material. Refers to volume. The "total volume S1 of the tire lumen" is approximately obtained by the following equation (1) in the normal state of the assembly. S1 = A × {(Di−Dr) / 2 + Dr} × π (1) where “A” is the cross-sectional area of the tire lumen obtained by CT scanning the tire lumen in the normal state, “Di” Is the maximum outer diameter of the tire lumen in the normal state shown in FIG.
r ”is the rim diameter, and“ π ”is the pi.

The "normal state" refers to a state in which the assembly is filled with a normal internal pressure and no load is applied. “Normal internal pressure” is the air pressure specified for each tire in the standard system including the standard on which the tire is based. For JATMA, the maximum air pressure is used. For TRA, the table “TIRE LOAD LIMITS AT” is used. VARIOUS COLD INFLATION P
RESSURES ", the maximum value in ETRTO," INFL
ATION PRESSURE ", but when the tire is for a passenger car, the pressure is set to 200 kPa in consideration of the actual use frequency and the like.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described.
This will be described together with the illustrated example. FIG. 1 is a meridional sectional view of an assembly of a pneumatic tire and a rim (hereinafter, may be simply referred to as an “assembly”) of the present invention, and FIG. 2 is a schematic diagram of the assembly in a circumferential direction along a tire equatorial plane. FIG.

In FIG. 1, an assembly 1 includes a tire 2 and a rim 3 around a rim 3 by mounting a pneumatic tire (hereinafter sometimes simply referred to as a “tire”) 2 on the rim 3. A surrounding tire bore 4 is formed.

The tire 2 is a conventional tubeless pneumatic tire, and a so-called inner liner rubber, which is hardly permeable to air, is provided on the inner surface facing the tire cavity 4. It is kept airtight.

The rim 3 includes a rim body 3A for seating and holding the tire 2, and a disk portion 3B integrally connected to the rim body 3A and attaching the rim to an axle.

As shown in FIG. 3, the rim main body 3A has a pair of rim seats 5 on which the respective bead portions 2A of the tire 2 are seated, and a flange which rises radially outward from an outer end of each rim seat 5 in the tire axial direction. A part 6 and a well part 7 provided between the inner ends of the rim sheet 5 and concaved inward in the radial direction are integrally formed. In this example, the well 7
Is a deep deep rim, but the well portion 7 may be a shallow shallow rim.

In the present embodiment, the well 7
In addition, a housing groove 9 extending in the circumferential direction is recessed, and a band-shaped sheet body 10A using a sponge material is formed in the housing groove 9.
The sound suppressor 10 is arranged.

The accommodating groove 9 is provided in the belt-like sheet body 10A.
In this example, as shown in FIG. 4 (expanded view showing the outer peripheral surface of the rim developed in the circumferential direction), the present example illustrates a case in which the rim extends continuously in the circumferential direction. are doing.
The accommodation groove 9 may be a single discontinuous groove that is interrupted in the circumferential direction, or may be an intermittent groove that is formed by separating a plurality of interrupted grooves in the circumferential direction. Example continuous grooves are preferred.

Next, in the present embodiment, the belt-shaped sheet body 10A has a flat rectangular cross section, and extends in the tire circumferential direction in the accommodation groove 9 by forming a belt-like shape long in the tire circumferential direction.

The sponge material forming the belt-like sheet body 10A is a spongy porous structure, for example, a so-called sponge having open cells formed by foaming rubber or synthetic resin, and animal fibers, plant fibers or synthetic fibers. Includes those that are intertwined and connected together.

The term "porous structure" as used herein includes not only open cells but also those having closed cells. Since such a sponge material has a high vibration-proof property and a high sound-absorbing property, it is possible to effectively absorb sound energy generated in the tire lumen 4 and reduce road noise by suppressing cavity resonance. Further, the sponge material is easily deformed such as shrinkage or bending, so that it can be easily housed in the housing groove 9, and has a lower specific gravity than a solid rubber body, so that the adverse effect on the tire weight balance is low. Can be suppressed. In this example, a preferable example using an open-cell sponge material made of polyurethane is illustrated.

The sponge material is not particularly limited, but has a specific gravity of 0.005 to 0.06, more preferably 0.010 to 0.05, and still more preferably 0.016 to 0.05.
-0.05, particularly preferably 0.016-0.035. When the specific gravity is less than 0.005 or more than 0.06, the effect of sufficiently absorbing the cavity resonance tends to decrease.

What is important here is that the band-shaped sheet 1
In order to exert the effect of suppressing cavity resonance by 0A, that is, the effect of reducing road noise, the volume S2 (specified as described above) of the belt-shaped sheet body 10A is reduced to the total volume S1 of the tire lumen (specified as described above). It is necessary to secure 0.4% or more of the above.

This is based on the results of various experiments by the present inventors. FIG. 5 shows that the raw material and specific gravity of the sponge material of the belt-shaped sheet body 10A are the same, and the total volume S1 of the tire bore 4 is On the other hand, a test result when a road noise test is performed by changing only the volume S2 of the belt-shaped sheet body 10A is shown.

As shown in FIG. 5, there is a clear correlation between the ratio S2 / S1 and the road noise.
By setting the ratio to 04 or more, a necessary effect of reducing road noise is exhibited. For this road noise reduction effect,
The ratio S2 / S1 is preferably 0.01 or more, more preferably 0.02 or more, and further preferably 0.04. If the ratio S2 / S1 exceeds 0.2, not only does the road noise reduction effect level off, but also an unnecessary increase in weight or a decrease in weight balance is caused. Therefore, the upper limit is 0.2 or less, but in practice, there is a limit to the groove volume of the accommodation groove 9, and generally 0.04 or less.

From such a viewpoint, the band-shaped sheet 1
0A is not particularly limited in its thickness T1, width W1, and length L1 as long as its volume S2 satisfies the above range, but actually, the groove depth T2 of the accommodation groove 9 and the groove width are not limited. It is set according to W2. The groove depth T2 and the groove width W2 of the accommodation groove 9 depend on the rim size.
Generally, the groove width W2 is 0 mm or less and the groove width W2 is 60 mm or less.

It is also important for the band-shaped sheet body 10A not to impair the workability at the time of assembling the rim. Therefore, in the assembly 1 of this embodiment, the band-shaped sheet body 10A is arranged in the accommodation groove 9 and In the arrangement state, the amount H by which the upper surface of the belt-shaped sheet body 10A protrudes from the upper surface of the well portion 7
Is regulated to 15 mm or less, preferably so as not to protrude.

As described above, in the assembly 1, since the belt-shaped sheet member 10 A having a predetermined volume S 2 is disposed in the tire lumen 4, the vibration-proof and sound-absorbing properties of the belt-shaped sheet body 10 A in the tire lumen 4. Can be effectively suppressed.

On the other hand, since the band-shaped sheet member 10A is disposed in the accommodation groove 9 recessed in the well portion 7, the bead portion 2A of the tire 2 does not rub against the band-shaped sheet member 10A during rim assembly. Thus, it is not necessary to pay attention, and the rim assembly performance can be improved to a level close to that of a normal rim assembly while maintaining the effect of suppressing cavity resonance.

In this embodiment, the case where the band-shaped sheet body 10A is held by fitting into the accommodation groove 9 is exemplified. However, if the band-shaped sheet body 10A is held when storing the rim 3 or when assembling the rim. Good. Therefore, there is no problem even if the belt-shaped sheet body 10A comes off the accommodation groove 9 due to centrifugal force or the like during traveling, and therefore, a slight fitting input is sufficient. In addition, you may hold | maintain by adhesion | attachment with an adhesive agent, for example.

FIG. 6 shows another embodiment of the accommodation groove 9.
In the figure, the case where the accommodation groove 9 extends in a wavy shape (including zigzag) in the tire circumferential direction is illustrated. In this way, by forming the accommodating groove 9 in a wavy shape, the bead portion 2 can be formed when the rim is assembled.
A can be prevented from falling into the accommodation groove 9, and the rim assembling performance can be further improved. For this purpose, the amplitude H1 of the wave is preferably in the range of 0.3 to 1.0 times the groove width W2, and the number of repetition pitches N of the wave in one round is preferable.
Is preferably 4 to 20.

FIG. 7 shows still another embodiment of the accommodation groove 9. In the drawing, the housing groove 9 has a guard piece 20 projecting from at least one groove wall 9A in the tire axial direction into the housing groove 9 in a tire axial direction from the groove wall 9A. The upper end of the guard piece 20 is substantially flush with the upper surface of the well 7.
At this time, a cut 21 through which the guard piece 20 passes is formed in the strip-shaped sheet body 10A.

The guard pieces 20 are preferably provided on both groove walls 9A as in the present embodiment. At this time, the guard pieces 20 are arranged in a staggered manner, and the amount of protrusion H2 of each guard piece 20 is determined by the following formula. It is desirable that the width is not less than 0.3 times, more preferably not less than 0.5 times the groove width W2. Such a guard piece 20 can also prevent the bead portion 2A from falling into the accommodation groove 9 at the time of assembling the rim, similarly to the wavy accommodation groove 9, and can improve the rim assembly performance. The tip of the guard piece 20 is preferably formed in an arc having a radius of about 2.0 mm, for example, in order to prevent the bead portion 2A from being damaged when the rim is assembled.

FIGS. 8 and 9 show another embodiment of the sound suppressor 10. FIG. In the figure, a strip-shaped sheet body 10A has a fence-shaped or net-shaped protection body 22 having a small thickness on at least a part of the upper surface thereof. In this protective body 22, the side frame pieces 22A on both sides extending in the circumferential direction are fixed to the upper surface of the well portion 7 using an adhesive, a screw, or the like. Thereby, it is possible to reliably prevent the bead portion 2A from falling into the accommodation groove 9,
The rim assembly performance can be enhanced to the same level as a normal rim assembly.

Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the illustrated embodiment, but may be implemented in various forms.

[0037]

EXAMPLE An assembly of a tire (165 / 65R15) and a rim (15 × 5J) having the structure shown in FIG. 1 and having the specifications shown in Table 1 was prototyped, and the rim assembly performance and road noise performance were tested. The strip-shaped sheet was formed using a polyurethane sponge having a specific gravity of 0.022 and having open cells. The content of the test is as follows.

(1) Rim assemblage performance: The workability of the rim assemblage was displayed in five levels with Comparative Example 1 being 5. The higher the value, the better.

(2) Road noise performance; internal pressure 200 kP
The sound inside the front seat when the vehicle is mounted on all the wheels of a vehicle (domestic 1500 cc hybrid vehicle) with the rim assembled at a and travels on a road noise measurement road (asphalt rough surface) at a speed of 60 km / H with one passenger Was measured, and the sound pressure level of the peak value of the air column resonance near 248 Hz was evaluated by an increase / decrease value (dB (A)) based on Comparative Example 1. The-(minus) sign means a reduction in road noise.

[0040]

[Table 1]

As shown in the table, in Examples 1 to 7, although it differs to some extent depending on the volume S2 of the band-shaped sheet member, the rim assembly performance is reduced while the road noise reduction effect as shown in Comparative Example 2 is maintained. It can be confirmed that it can be raised to a level close to the set. Particularly, as in the fourth and fifth embodiments, the rim assembling performance can be improved to such a level that there is no problem in practical use by forming the accommodation groove in a wave shape or providing a guard piece. When the upper surface of the belt-like sheet is protected by a fence-like or net-like protector as in Examples 6 and 7,
It is possible to secure a rim assembling performance which is completely inferior to a normal level (Comparative Example 1) in which a belt-shaped sheet body is not used.

[0042]

As described above, according to the present invention, since the accommodating groove extending in the circumferential direction is formed in the well portion of the rim, and the band-shaped sheet member is arranged in the accommodating groove, the effect of suppressing the cavity resonance is enhanced. While maintaining the rim assembly performance, the rim assembly performance can be increased to a level close to or equal to that of a normal rim assembly.

[Brief description of the drawings]

FIG. 1 is a meridional sectional view showing an embodiment of an assembly of a pneumatic tire and a rim according to the present invention.

FIG. 2 is a circumferential sectional view along the tire equator.

FIG. 3 is an enlarged sectional view showing a rim main body.

FIG. 4 is a development view showing a rim outer peripheral surface developed in a circumferential direction.

FIG. 5 is a diagram showing a relationship between a volume ratio S2 / S1 and road noise.

FIG. 6 is a development view showing another embodiment of the accommodation groove developed in a plane.

FIG. 7 is a developed view showing still another embodiment of the accommodation groove developed in a plane.

FIG. 8 is a diagram showing an embodiment of a protection body.

FIG. 9 is a diagram showing another embodiment of the protection body.

FIG. 10 is a sectional view illustrating a problem to be solved by the invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 2 pneumatic tire 2A bead part 3 rim 4 tire bore 7 well part 9 accommodation groove 9A groove wall 10 sound suppressor 10A band-shaped sheet body 20 guard piece 22 protective body

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mami Nishikawa 3-6-9, Wakihama-cho, Chuo-ku, Kobe City, Hyogo Prefecture Within Sumitomo Rubber Industries Co., Ltd. (72) Chieko Aoki 3 Wakihama-cho, Chuo-ku, Kobe City, Hyogo Prefecture Sumitomo Rubber Industries Co., Ltd. (72) Inventor Hideaki Sugihara 3-6-9, Wakihama-cho, Chuo-ku, Kobe City, Hyogo Prefecture

Claims (4)

[Claims] An accommodating groove formed in a tire cavity formed by a rim and a pneumatic tire mounted on the rim, formed of a band-shaped sheet member using a sponge material, and concavely formed in a well portion of the rim in a circumferential direction. A pneumatic tire, wherein a volume S2 of the noise suppressor is set to 0.4% or more and 20.0% or less of the total volume S1 of the tire lumen. Assembly with rim. 2. The pneumatic tire and rim assembly according to claim 1, wherein said accommodation groove extends in a wave shape in a circumferential direction. 3. The rim is provided on at least one groove wall of the accommodation groove to prevent the bead portion of the pneumatic tire from extending into the accommodation groove in a comb-shape in the tire axial direction from the groove wall and falling into the accommodation groove. The pneumatic tire and rim assembly according to claim 1, wherein a guard piece for preventing the rim is provided. 4. The noise suppressor is characterized in that at least a part of an upper surface thereof is provided with a fence-shaped or net-shaped protection body for preventing a bead portion of a pneumatic tire from falling into a housing groove. An assembly of a pneumatic tire and a rim according to claim 1.