JP2001088506A - Assembly of tire and disc wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve riding comfortableness and road noise simultaneously with attaining low rolling resistance and weight reduction in an assembly of a tire and a disc wheel. SOLUTION: In this assembly of a pneumatic radial tire and a disc wheel, the disc wheel is provided with a disc 11 rigidly fixed to an axle hub, and a rim 13 for supporting the pneumatic radial tire. A reinforcing material of a carcass 3 has the modulus of elasticity of 250 kgf/mm2 or more, and cushioning members 14 are provided at least partially between the disc 11 and the rim 13.

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 tire and a disc wheel and a method of using the same, and more particularly, to deterioration of riding comfort and road load, which are disadvantages inherent in low rolling resistance tires or lightweight tires. The present invention relates to an assembly of a tire and a disc wheel capable of complementing and improving noise deterioration and a method of using the same.

[0002]

2. Description of the Related Art At present, energy saving has been called for, and in automobiles, studies have been made to improve fuel efficiency by reducing weight, and accordingly, tires have also been reduced in weight. Is increasing year by year, and this tendency is particularly remarkable in general-purpose pneumatic radial tires for passenger cars.

[0003] A pneumatic radial tire generally has a so-called cross belt in which at least two inclined belt layers are laminated on the outer periphery of a crown portion of a carcass so that their cords cross each other. is there. But,
From the viewpoint of reducing the weight of tires, as a tire having a belt composed of one inclined belt layer and a circumferential belt layer in which lightweight organic fiber cords are arranged substantially parallel to the tire equatorial plane is being developed. became. This type of tire is disclosed, for example, in JP-A-62-152904 and JP-A-4-152904.
No. 163212. Also, tires have been developed which have improved cornering properties and high-speed durability while reducing the weight of the tires (JP-A-8-3187).
06 publication).

[0004]

However, a tire which is reduced in weight as described above, a tire whose air pressure is increased to achieve a reduction in rolling resistance, and a highly elastic reinforcing material are applied to a carcass. Tires tend to have a higher longitudinal spring constant than normal tires, resulting in poor ride comfort. In addition, in a tire whose tire structure is simplified in order to reduce the weight, the natural frequency of the tire is increased as compared with a normal tire, so that deterioration of road noise is inevitable. It is considered difficult to realize such a problem only by tuning the tire, and there is a limit.

It is an object of the present invention to solve the above-mentioned problems in an assembly of a tire and a disc wheel, realize low rolling resistance and light weight, and at the same time improve riding comfort and road noise.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the simplest and most effective method is the disk method as compared with the countermeasures by reducing the rigidity of the suspension or wheel. The present inventors have found that a buffer member is inserted into the joint between the rim and the rim, and have completed the present invention. That is, the present invention is as described below.

(1) A carcass comprising at least one carcass ply folded back by a pair of bead cores and connected in a toroidal shape, a tread arranged at a crown portion of the carcass, and arranged between the tread and the carcass. A pneumatic radial tire (A) having a belt composed of at least one belt ply, a disk fixed to an axle hub, and a rim supporting the pneumatic radial tire (B). And the reinforcing material of the carcass is 250 kgf /
An assembly of a tire and a disk wheel, wherein the assembly has a modulus of elasticity of ² mm or more and has a buffer member at least in a part between the disk and the rim.

(2) In the assembly of the tire and the disc wheel of the above (1), the reinforcing material of the carcass is a steel cord, and the twisted structure is 1 × N or 1 × N.
+ N.

(3) The assembly of the tire and the disc wheel of (1), wherein the reinforcing material of the carcass is an aromatic aramid fiber.

(4) The assembly of the tire and the disc wheel of (1), wherein the reinforcing material of the carcass is a polyester fiber.

(5) An assembly of a tire and a disc wheel according to any one of the above (1) to (4),
An assembly in which the cushioning member is a rubber elastic body.

(6) When an assembly of any one of the above (1) to (5) and a disc wheel is mounted on a vehicle and used, an air pressure of 120% or more of the standard maximum air pressure is applied to the tire. A method of using an assembly of a tire and a disc wheel, characterized by being filled. Here, the standard maximum air pressure is defined as a standard (determined by an industrial standard effective in an area where a tire is manufactured or used. For example, in the United States, "The Tire and Rim
Association Inc. Year Book, and in Europe, "Th
e Tire and Rim Technical Organization Standards M
anual "and in Japan, the Japan Automobile Tire Association's" JAT
It is the air pressure corresponding to the maximum load (maximum load capacity) of a single wheel in the applicable size (priling) specified in the “MA Year Book”).

The pneumatic radial tire (A) according to the present invention can realize low rolling resistance and light weight. By the way, the cause of the deterioration of ride comfort in tires with low rolling resistance and weight reduction is that the unsprung resonance frequency increases with the increase of the vertical spring constant of the tire, and the amplitude level also increases, so that the feel is rugged. This is because it gets worse. In this case, by interposing a cushioning member at the joint between the rim and the disk, the longitudinal spring constant of the assembly of the tire and the wheel with low rolling resistance and light weight can be reduced. It is possible to improve the resonance level. In addition, the reason why road noise deteriorates in tires with low rolling resistance and light weight is due to an increase in the natural frequency of the tire, which is also reduced by using the elastic wheel according to the present invention. Because the part acts as a dynamic damper, 200
Improvement in a band of not less than Hz is realized, leading to reduction of in-vehicle sound in this band, and improvement of road noise is achieved.
Even if the tire is filled with an air pressure of 120% or more of the standard maximum air pressure in order to further reduce the rolling resistance, substantially the same improvement effect can be obtained.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 1 shows a cross section in the tire width direction of an assembly according to an embodiment of the present invention. The pneumatic radial tire 1 in FIG. 1 includes a carcass 3 formed of one carcass ply that is folded back by a pair of bead cores 2 and that continues in a toroidal shape. The crown 4 of the carcass 3 includes
An intersecting belt 6 is provided in which two belt layers inclined with respect to the tire equatorial plane 5 are laminated such that their cords intersect each other.

In the present invention, the reinforcing material of the carcass 3 is 250 kgf / mm ² or more, preferably 500 kgf / mm ^2.
It is a cord having an elastic modulus of ² mm or more. Examples of such a cord include polyester, typically polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyamide, aromatic polyamide, typically Kevlar (registered trademark, manufactured by Dupont, aramid) or vinylon (PVA). And steel fiber cords.

In the present invention, when a PET, nylon, PEN, or vinylon fiber cord is used as the cord for the carcass 3, it is preferable that the carcass 3 has a twin-twist structure and the total denier Dr is in the range of 1000d to 6000d. The twin-twist structure is used to improve the compression fatigue property of the cord itself and workability, and the total denier in the range of 1000d to 6000d is 1000 d.
If it is less than d, it is difficult to physically drive the cord. On the other hand, if it exceeds 6000 d, the cord becomes too thick, and the rubber amount has to be increased, and the tire weight increases. Because it is a result.

Since PET, nylon, PEN, and vinylon fibers have a large work loss and easily generate heat, in a high-speed durability test, there is a possibility that these fiber cords are melted to cause tire burst. For this reason, the tangent loss tan δ of the cord of the carcass 3 is reduced by the initial tension 1 kgf.
/ Line, strain amplitude 0.1%, frequency 20Hz, ambient temperature 2
It is preferable to prevent the melting of these fiber cords by controlling the temperature to 0.3 or less under the condition of 5 ° C.

When a steel cord is used as the cord for the carcass 3, the elastic modulus of the cord is preferably 3
000kgf / mm ² or more, more preferably 4000k
By setting the gf / mm ² or more and the cord twist structure to 1 × N or 1 + N, the tire weight is slightly increased as compared with the case where the organic fiber cord is used, but the rolling resistance is further reduced. Can be achieved. If the elastic modulus is less than 3000 kgf / mm ² , the rigidity cannot be improved more effectively, and if it is not a 1 × N or 1 + N twisted structure, it is advantageous in terms of weight and cost. It becomes difficult to enjoy. The number of cords is preferably 30 to 45 per 50 mm from the viewpoint of securing rigidity and reducing the weight.

From the above, the code of the carcass 3 is
Depending on the use or the like, an organic fiber cord of PET, nylon, PEN, Kevlar and vinylon or a steel cord can be appropriately selected.

The pneumatic radial tire according to the present invention relates to the improvement of the carcass structure, in particular, the reinforcing material thereof, as described above, and other structures and materials can be determined according to conventional usage.

In the disk wheel shown in FIG. 1, a disk 11 fixed to an axle hub (not shown) has a base rim 1
2 is provided. A rubber elastic body 14 is annularly interposed between the outer peripheral surface of the base rim 12 and the inner peripheral surface of the rim 13 supporting the tire 1 as a cushioning member. The rubber elastic body 14 is adhered to both the inner peripheral surface of the rim 13 and the outer peripheral surface of the base rim 12 by, for example, a bonding means such as a vulcanization bonding. The cushioning member is not limited to the rubber elastic body, and may be another means such as a spring.
Further, a combination thereof may be used.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. Various types of high-pressure tires (2.8 kPa) of the type shown in FIG. A group in which the manufactured tires are mounted on an elastic disc wheel of the type shown in FIG. 1 (Examples 1 to 8), and a group in which the tires are mounted on a normal disc wheel of the same type as that shown in FIG. (Comparative Examples 1 to 8), and an actual vehicle running test was performed on these assembled bodies. The content of the test was the measurement of unsprung vibration when traveling on a joint road and the sound inside the vehicle when traveling on a road noise road. In each case, the result of Comparative Example 1 was set to 100 and indexed. The higher the value, the better the result. The results obtained are shown in Tables 1 and 2 below.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

As described above, in the assembly of the tire and the disc wheel according to the present invention, low rolling resistance and light weight can be realized, and at the same time, riding comfort performance and road noise can be improved. . Even if the tire is filled with an air pressure of 120% or more of the standard maximum air pressure in order to further reduce the rolling resistance, substantially the same improvement effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial sectional view in the tire axial direction of an assembly according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pneumatic radial tire 2 Bead core 3 Carcass 4 Crown part 5 Tire equatorial plane 6 Belt 11 Disk 12 Base rim 13 Rim 14 Buffer member (rubber elastic body)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) B60C 9/00 B60C 9/00 D

Claims (6)

[Claims] 1. A carcass comprising at least one carcass ply folded back by a pair of bead cores and connected in a toroidal shape, a tread arranged on a crown portion of the carcass, and arranged between the tread and the carcass. A pneumatic radial tire (A) including a belt composed of at least one belt ply, a disc fixed to an axle hub, and a disc wheel (B) including a rim that supports the pneumatic radial tire. Wherein the carcass reinforcing material has an elastic modulus of 250 kgf / mm ² or more, and a cushioning member is provided at least in part between the disc and the rim. Assembly. 2. The assembly according to claim 1, wherein the reinforcing material of the carcass is a steel cord, and the twisted structure is 1 × N or 1 + N. 3. The assembly according to claim 1, wherein the reinforcing material of the carcass is an aromatic aramid fiber. 4. The assembly according to claim 1, wherein the reinforcing material of the carcass is a polyester fiber. 5. The assembly according to claim 1, wherein the cushioning member is a rubber elastic body. 6. When the tire and disk wheel assembly according to any one of claims 1 to 5 is mounted on a vehicle and used, an air pressure of 120% or more with respect to a standard maximum air pressure is applied to the tire. Use of an assembly of a tire and a disc wheel, characterized by being filled.