JP2012236521A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire having a sound absorbing tool convenient for treatment, and advantageous to improving work efficiency for repairing a puncture.SOLUTION: The pneumatic tire 10 includes the sound absorbing tool 14. The sound absorbing tool 14 is constituted by winding a belt-like member 30 in a plurality of times in a spiral shape. The belt-like member 30 is constituted of an elastically deformable spring member 32 wound in a plurality of times in a spiral shape, and a deformable sound absorbing member 34 installed in the spring member 32 and extending over the total length of the spring member 32 along an outside place in the radial direction of the spring member 32. The sound absorbing tool 14 is detachably fixed by being installed on a tire inner surface 24 by pressing a total length part of the sound absorbing member 34 to the tire inner surface 24 by an elastic force of the spring member 32. Assuming a tire grounding width as W1, a width W2 of the sound absorbing tool 14 in the tire axial direction installed on and fixed to the tire inner surface 24, satisfies the relationship of W1×0.5≤W2≤W1×0.8.

Description

  The present invention relates to a pneumatic tire provided with a sound absorbing tool.

In a pneumatic tire, one of the causes of noise (road noise) is a cavity resonance sound caused by vibration of air filled in the tire.
The cavity resonance sound is generated when the tread portion vibrates due to road surface irregularities when the tire rolls, and the vibration of the tread portion vibrates the air inside the tire.

  As a technique for reducing noise due to such a cavity resonance phenomenon, it is proposed to arrange a sound absorbing member along the inner surface of the tire located inside the tread portion and fix the sound absorbing member to the inner surface of the tire with an arc-shaped fixture. (See Patent Document 1).

JP 2009-46011 A

However, in the above-described conventional technology, two members, a sound absorbing member and a fixing tool for fixing the sound absorbing member, are required. Therefore, when the tire is punctured and repaired, the sound absorbing member and the fixing tool are removed and attached. There was a problem that troublesome work and workability of puncture repair were bad.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a pneumatic tire that is convenient in handling and advantageous in improving workability of puncture repair.

  In order to achieve the above object, the present invention provides a pneumatic tire including a sound absorbing tool mounted on the inner surface of a tire inside a tread portion, and the sound absorbing tool includes a belt-like member wound in a plurality of turns. The strip-shaped member is configured to be elastically deformable in a radial direction, and the elastically deformable spring member wound a plurality of times in a spiral shape and the radially outer side of the spring member attached to the spring member and exhibiting the spiral shape And a deformable sound absorbing member extending along the length of the spring member along the entire length of the spring member. The belt-like member is spirally attached to the tire inner surface and is detachably fixed, and when the tire ground contact width is W1, the width W of the sound absorbing tool in the tire axial direction attached and fixed to the tire inner surface. Is characterized in that it satisfies the relationship of W1 × 0.5 ≦ W2 ≦ W1 × 0.8.

  According to the pneumatic tire of the present invention, since the sound absorbing tool is composed of a single band member wound a plurality of times, the handling of the sound absorbing tool is convenient, and when the tire is punctured and repaired, the sound absorbing tool It is easy to remove and attach tools, which is advantageous for improving the workability of puncture repair.

(A) is a half sectional view of a pneumatic tire equipped with the sound absorbing tool of the present embodiment, and (B) is a plan view of the pneumatic tire equipped with the sound absorbing tool of the present embodiment. It is sectional drawing of the edge part of a strip | belt-shaped member. (A)-(F) are sectional drawings of a strip-shaped member. (A)-(C) are top views of the pneumatic tire with which the sound absorption tool of this Embodiment was mounted | worn. It is a figure which shows the experimental result of Example 1, 2 of the pneumatic tire with which the sound absorption tool was mounted | worn, the prior art example 1, and the comparative examples 1 and 2. FIG.

Next, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the pneumatic tire 10 according to the present embodiment includes a tire body 12 and a sound absorbing tool 14.
The tire body 12 includes a tread portion 18, a pair of sidewall portions 20 that extend inward in the tire radial direction from both side portions of the tread portion 18, and a pair of bead portions 22 that are continuous to the inner peripheral side of each sidewall portion 20. It has.
The tire body 12 has a carcass layer (not shown) spanned between a pair of bead portions, and a belt layer is disposed outside the carcass layer inside the tread portion 18 as in the prior art, and an inner liner is provided. It is arranged on the inner surface of the tire body 12. In the present embodiment, the tire inner surface 24 located inside the tread portion 18 is formed of an inner liner.
In FIG. 1B, reference sign CL indicates the tire equator plane.

The sound absorbing tool 14 suppresses cavity resonance noise when the tire rolls.
The sound absorbing tool 14 is composed of a strip-shaped member 30 that is wound a plurality of times in a spiral shape and can be expanded and contracted in the radial direction of the spiral.
The band-shaped member 30 includes a spring member 32 and a sound absorbing member 34.

The spring member 32 is elastically deformable and is wound a plurality of times in a spiral shape, and the sound absorbing member 34 is attached to the tire inner surface 24 and fixed by the elastic force.
The spring member 32 can be expanded and contracted in the radial direction of the spiral, and can also be expanded and contracted in the axial direction of the spiral.
A synthetic resin material is preferable as the spring member 32 from the viewpoint of reducing the weight of the sound absorber 14, but a metal material can of course be used.
As such a synthetic resin material, for example, various conventionally known synthetic resin materials such as polypropylene resin can be used.

Further, when the spring member 32 is formed of a synthetic resin material, the diameter of 5 mm or more and 10 mm or less is intended to reduce the weight of the sound absorber 14 while ensuring a pressing force for pressing the sound absorbing member 34 against the tire inner surface 24. Is preferable.
When the spring member 32 has a circular cross section, if the diameter of the spring member 32 is less than 5 mm, the pressing force for pressing the sound absorbing member 34 against the tire inner surface 24 is insufficient, and it is difficult to fix the tire inner surface 24 at the time of mounting. . When the diameter of the spring member 32 exceeds 10 mm, there is a disadvantage in reducing the weight of the sound absorbing tool 14.
The spring member 32 may have various cross-sections known in the art, such as a circular or rectangular cross section.
Further, if both ends in the longitudinal direction of the spring member 32 are not rounded and formed round as shown in FIG. 2, the sound absorbing member 34 is not damaged and the sound absorbing tool 14 is durable. This is advantageous for improving the performance.

The sound absorbing member 34 functions as a noise reducing material that suppresses cavity resonance noise during tire rolling.
The sound absorbing member 34 is attached to the spring member 32 and extends over the entire length of the spring member 32 along a radially outer portion of the spring member 32 having a spiral shape and is deformable.
As the sound absorbing member 34, various conventionally known deformable materials such as foamed urethane, sound absorbing felt, and foamed aluminum can be used. However, damage, compression, etc., such as chipping and tearing can be ensured while ensuring a sound absorbing effect. In order to effectively suppress the deformation, flexible polyurethane foam is preferable.
The sound absorbing member 34 is attached to the spring member 32 and extends over the entire length of the spring member 32 along a radially outer portion of the spring member 32 having a spiral shape. Therefore, the sound absorbing member 34 is also wound in a spiral shape with the spring member 32 a plurality of times.

Examples of the manner in which the sound absorbing member 34 is attached to the spring member 32 include the following. For example, as shown in FIGS. 3A, 3 </ b> B, and 3 </ b> C, the spring member 32 may be embedded in the sound absorbing member 34. In the case of FIG. 3A, the spring member 32 has a circular cross section, and the sound absorbing member 34 has an annular cross section. In the case of FIG. 3B, the spring member 32 has a rectangular cross section, and the sound absorbing member 34 has a rectangular frame shape. In the case of FIG. 3C, the cross section of the spring member 32 has a horizontally long rectangular shape, and the cross section of the sound absorbing member 34 has a horizontally long rectangular frame shape.
Further, as shown in FIGS. 3D and 3E, the spring member 32 is embedded in the sound absorbing member 34 so that the portion of the spiral inner radial spring member 32 exhibited by the spring member 32 is exposed. May be. In the case of FIG. 3D, the spring member 32 has a circular cross section, and the sound absorbing member 34 has a crescent shape. In the case of FIG. 3 (E), the spring member 32 has a rectangular cross section, and the sound absorbing member 34 has a horizontally long rectangular cross section.
Further, as shown in FIG. 3 (F), a sound absorbing member 34 may be attached with an adhesive to a location of the spring-shaped spring member 32 in the radial direction of the spiral shape exhibited by the spring member 32. In the case of FIG. 3F, the spring member 32 has a rectangular cross section, and the sound absorbing member 34 has a horizontally long rectangular cross section.
The cross-sectional shapes of the spring member 32 and the sound absorbing member 34 are not limited to the above shapes, and the sound absorbing member 34 is located at least on the outer side in the radial direction of the spiral shape exhibited by the spring member 32 and is attached to the tire inner surface 24. Sometimes the sound absorbing member 34 may contact the tire inner surface 24.

The band-shaped member 30 composed of the spring member 32 and the sound absorbing member 34 having the above configuration has an elongated band shape, and its cross-sectional shape is uniform except for both ends in the longitudinal direction of the sound absorbing member 34 where the spring member 32 is not located. .
The sound absorbing tool 14 is inserted into the tire body 12 through the rim hole and expanded in diameter by the elastic force of the spring member 32 in a state in which the band-shaped member 30 is reduced in diameter in the spiral radial direction. The inner surface 24 is helically mounted, and the entire length of the sound absorbing member 34 is pressed against the entire circumference of the tire inner surface 24 by the elastic force of the spring member 32 and is detachably fixed to the tire inner surface 24.
Depending on the number of turns of the spiral, the belt-shaped member 30 is mounted by being wound spirally in the direction orthogonal to the longitudinal direction of the belt-shaped member 30 (in the tire axial direction) or by the length of the belt-shaped member 30. It is wound and mounted spirally in a state in which it is in contact with the direction orthogonal to the direction (in the tire axial direction). In addition, when the belt-like member 30 is spirally wound and attached in a direction perpendicular to the longitudinal direction (in the tire axial direction), the entire length portion of the sound absorbing member 34 in the longitudinal direction is securely attached to the tire inner surface 24. This is advantageous in pressing and securely fixing the sound absorbing tool 14.

With the sound absorber 14 mounted on the tire inner surface 24, as shown in FIG. 1B, when the tire ground contact width is W1, the sound absorber 14 mounted and fixed on the tire inner surface 24 along the tire axial direction. The width W2 satisfies the relationship of W1 × 0.5 ≦ W2 ≦ W1 × 0.8.
When the width W2 of the sound absorbing tool 14 is less than 50% of the tire ground contact width W1, the volume of the sound absorbing member 34 is small, a sufficient sound absorbing effect cannot be obtained, and the fixing property of the sound absorbing tool 14 is poor. Further, it is assumed that the sound absorbing tool 14 is deviated with respect to the tire inner surface 24, the sound absorbing effect is lowered, vibration is considered, and the sound absorbing member 34 is peeled off from the spring member 32. This is because it is considered.
When the width W2 of the sound absorber 14 exceeds 80% of the tire ground contact width W1, the sound absorber 14 can be securely fixed to the tire inner surface 24, but the tire inner surface 24 exceeding 80% of the tire ground contact width W1. This is because the tire has a large deformation at the time of running, and the durability of the sound absorbing member 34 is deteriorated, for example, the sound absorbing member 34 is peeled off from the spring member 32.
The tire ground contact width W1 is a region where the tread surface of the pneumatic tire contacts the road surface when the pneumatic tire is assembled on a regular rim and filled with a regular internal pressure and 70% of the regular load is applied. It is the maximum width in the tire width direction in the tire contact area. Here, the regular rim is “standard rim” defined by JATMA, “Design Rim” defined by TRA, or “Measuring Rim” defined by ETRTO. The normal internal pressure is “maximum air pressure” defined by JATMA, the maximum value described in “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “INFLATION PRESSURES” defined by ETRTO. The normal load is “maximum load capacity” defined by JATMA, the maximum value described in “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “LOAD CAPACITY” defined by ETRTO.

As shown in FIG. 4A, when both ends of the belt-like member 30 are located at the same location in the circumferential direction of the tire inner surface 24, the weight of the sound absorbing tool 14 in the circumferential direction of the tire inner surface 24 is unbalanced. Therefore, it is advantageous to improve the riding comfort by suppressing the deterioration of the uniformity of the pneumatic tire 10 to reduce the vibration when the vehicle travels.
Further, when the sound absorbing tool 14 is mounted on the tire inner surface 24, as shown in FIG. 4B, when both end portions in the longitudinal direction of the band-shaped member 30 overlap in the circumferential direction of the tire inner surface 24, the overlap. As shown in FIG. 4C and FIG. 4C, when both ends in the longitudinal direction of the belt-like member 30 are separated in the circumferential direction of the tire inner surface 24, the distance L2 to be separated should be as small as possible. This is advantageous in suppressing the weight imbalance of the tool 14, and is advantageous in improving the riding comfort by suppressing the reduction in uniformity of the pneumatic tire 10 to reduce vibration during vehicle travel.
The number of spiral turns around which the belt-like member 30 is wound depends on the cross-sectional area and shape of the sound absorbing member 34 and the spring member 32, but is preferably 3 to 8 from the viewpoint of ensuring sound absorption.

As described above, according to the pneumatic tire 10 of the present embodiment, the sound absorbing tool 14 is configured by the single belt-like member 30 wound a plurality of times.
Therefore, it is of course possible to suppress the cavity resonance sound when the tire rolls, the handling of the sound absorbing tool 14 is convenient, and when the tire is punctured and repaired, the sound absorbing tool 14 can be easily removed and attached, This is advantageous in improving the workability of puncture repair.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
As the sound absorbing tool 14, as shown in FIG. 3A, a sound absorbing material made of urethane foam having an outer diameter of 10 mm and a wire made of polypropylene resin having a diameter of 6 mm are used. Note that the sound absorbing tool 14 is not mounted in the conventional example.
The pneumatic tire in which the sound absorbing tool 14 is mounted on a 195 / 65R15 PC tire (a tire for a general passenger car) was tested for noise, fixing, and durability.
The test conditions are as follows.
Evaluation vehicle: Domestic FR car Air pressure: 220kPa
Evaluation place: Test course Speed: 100km / h
Mileage: 20,000km

The evaluation items are the following three items.
(1) R / N (noise performance)
The measurement result of the conventional example is represented by an index of 100, and the higher the index value, the more noise (road noise) can be reduced.
(2) Fixing property of the sound absorbing tool 14 After running, the mounting state of the sound absorbing tool 14 is observed, and is indicated by an index with Comparative Example 1 being 100, and the higher the index value, the better the fixing property.
(3) Durability of the sound absorbing tool 14 After traveling, the sound absorbing tool 14 is observed and indicated by an index with Comparative Example 1 being 100, indicating that the higher the index value, the better the durability.
In FIG. 5, W2 is the width of the sound absorber 14 attached and fixed to the tire inner surface 24 and along the tire axial direction, and W1 is the tire ground contact width.

From Comparative Example 1, when the width W2 of the sound absorbing tool 14 is less than 50% of the tire ground contact width W1, a sufficient sound absorbing effect cannot be obtained because the volume of the sound absorbing member 34 is small. It is clear that the fixing property of the sound absorbing member 34 is poor, the sound absorbing effect is lowered, and the durability of the sound absorbing member 34 is deteriorated.
From Examples 1 and 2, when the width W2 of the sound absorber 14 is 50% or more and 80% or less of the tire ground contact width W1, noise (road noise) can be reduced, and the sound absorber 14 can be fixed and durable. It is clear that the nature is good.
From Comparative Example 2, when the width W2 of the sound absorbing tool 14 exceeds 80% of the tire ground contact width W1, noise (road noise) can be reduced and the fixability of the sound absorbing tool 14 can be improved, but the sound absorbing member 34 is a spring member. It is apparent that the durability of the sound absorbing tool 14 is deteriorated, such as being peeled off from 32.

  DESCRIPTION OF SYMBOLS 10 ... Pneumatic tire, 12 ... Tire main body, 14 ... Sound absorbing tool, 30 ... Band-shaped member, 32 ... Spring member, 34 ... Sound absorbing member.

Claims (5)

A pneumatic tire including a sound absorbing tool mounted on the inner surface of the tire inside the tread portion,
The sound absorbing tool is configured such that the band-shaped member is wound in a spiral shape a plurality of times and can be expanded or contracted in the radial direction.
The belt-shaped member includes an elastically deformable spring member wound a plurality of times in a spiral shape, and a total length of the spring member along a radially outer portion of the spring member attached to the spring member and exhibiting the spiral shape. Composed of a deformable sound absorbing member extending over,
The sound absorbing tool is detachably fixed by attaching the belt-like member spirally to the tire inner surface by pressing the entire length of the sound absorbing member against the tire inner surface by the elastic force of the spring member,
When the tire ground contact width is W1, the width W2 of the sound absorber in the tire axial direction attached and fixed to the tire inner surface satisfies the relationship of W1 × 0.5 ≦ W2 ≦ W1 × 0.8.
A pneumatic tire characterized by that. The attachment of the spring member and the sound absorbing member is performed by the spring member being embedded in the sound absorbing member.
The pneumatic tire according to claim 1. The attachment of the spring member and the sound absorbing member is performed by embedding the spring member in the sound absorbing member so that the location of the spring member inside the spiral radial direction of the spring member is exposed.
The pneumatic tire according to claim 1. The attachment of the spring member and the sound absorbing member is made by adhering the sound absorbing member with an adhesive to the location of the spring member outside the spiral in the radial direction of the spring member.
The pneumatic tire according to claim 1. Both ends in the longitudinal direction of the spring member are rounded without being squared,
The pneumatic tire according to any one of claims 1 to 4, characterized in that:

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