JPH0516610A - Pneumatic tire - Google Patents

Abstract

PURPOSE:To make even and increase the tread rigidity effectively, and to improve the light-weight and the running property of a tire. CONSTITUTION:As a belt layer 9 provided to the outer side of a carcass 7, a bioxial woven fabric ply 10 made by weaving the first belt cords 11A provided at the angle 15 to 30 deg. to the tire equator CO, and the second belt cords 11B provided at the angle 15 to 30 deg. to the tire equator CO and in the direction to cross with the first belt cords 11A each other is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a biaxial woven belt ply to uniformly and effectively increase belt rigidity, and to reduce the weight of tires and improve running performance. Containing tires.

[0002]

2. Description of the Related Art In recent years, as the road network has been improved and the performance of vehicles has improved, the outside of the crown of the carcass has been tightened with a strong belt layer to increase the rigidity of the tread, thereby improving rolling performance and maneuverability. Radial tires with improved running performance such as stability and high-speed durability are widely used.

Further, in order to exert a sufficient hoop effect, this product is conventionally composed of a fabric material in the shape of a blind comb, in which a belt layer A and belt cords B are aligned in parallel with each other, as shown in FIG. A plurality of belt plies D are formed, and each belt cord B is 2 with respect to the tire equator.
The plies are stacked in different directions so that the plies intersect each other at an angle of about 0 degree.

[0004]

However, in the conventional belt structure using the fabric material of the interlaced weave,
Adjacent belt cords move relatively freely, such as lacking restraining force between cords, and stress acts on each cord independently, resulting in poor reinforcement effect and insufficient tread rigidity, and reduced uniformity. It was

Therefore, in such a belt structure, in order to obtain the required tread rigidity, it is possible to increase the number of belt plies and further to form the belt cord with a metal cord having high elasticity such as steel. This is generally done, but this has the problem of causing an increase in tire weight and impairing fuel efficiency.In recent years, it has been possible to improve the belt rigidity evenly and efficiently, while reducing tire weight and improving running performance. The emergence of something that can be raised is strongly desired.

In the conventional belt structure, since the arrangement directions of the belt cords are different between the plies, when the tire is deformed,
There is also a problem that a large shearing force acts between the plies, which induces separation especially at the ends of the plies, and causes a one-way flow phenomenon of the vehicle due to the cord arrangement direction of the outermost belt ply.

That is, the present invention is based on the use of a biaxially woven belt ply for the belt layer, which can uniformly and effectively increase the tread rigidity, which leads to a reduction in the weight of the tire and an improvement in the running performance. The purpose is to provide measurable pneumatic tires.

[0008]

In order to achieve the above object, a pneumatic tire of the present invention comprises a carcass folded around a bead core of a bead part from a tread part to a sidewall part, and a carcass of the carcass. A first belt cord having a belt layer arranged radially outside and inside the tread portion, the belt layers being arranged in parallel with each other at an angle of 15 or more and 30 degrees or less with respect to the tire equator. And a second belt cord arranged in parallel with each other at an angle of 15 degrees or more and 30 degrees or less with respect to the tire equator and in a direction intersecting with the first belt cord. Includes woven belt ply.

[0009]

In the biaxial woven belt ply thus included in the belt layer, the belt cords arranged along the two axial directions are woven together, so that the movements of the belt cords are restrained by the weaving of the belt cords. The rigidity can be effectively improved. In addition, the load applied to the tire can be widely distributed to each belt cord, the stress acting on each belt cord can be reduced and the cord durability can be improved, and the uniformity of the belt rigidity can be improved and the running performance can be greatly improved. ..

In addition, since the stress concentrated on the belt ply end can be relaxed by the mutual restraint between the cords, the cord can suppress the occurrence of separation, and further, each cord is centered on the tire equator. The left-right symmetry can prevent one-way flow of the vehicle.

As a result, in addition to reducing the number of plies, the number of cords to be driven, etc., it is also possible to adopt a low-mass organic fiber cord, which is inferior in strength and tensile elastic modulus as compared with the conventional metal cord, to the belt cord. It is possible to greatly reduce the weight of tires while maintaining the running performance.

[0012]

In the drawings, a pneumatic tire 1 includes a pair of bead portions 3 through which a bead core 2 passes, a sidewall portion 4 extending outward from each bead portion 3 in a tire radial direction, and an outer end portion of the sidewall portion 4 between the bead portions 3. It has a tread portion 5 to be spliced.

Between the bead portions 3 and 3, the main body portion 7A extending from the tread portion 5 through the sidewall portion 4 to the bead portion 3 is folded around the bead core 2 from the inside to the outside of the tire. The carcass 7 having the folded-back portion 7B is bridged, and the belt layer 9 is provided outside the carcass 7 and inside the tread portion 5.

The carcass 7 has at least one carcass cord in which carcass cords are arranged at an angle of 70 to 90 degrees with respect to the tire equator CO, and in this example, two carcass plies 7a and 7b.
The inner carcass ply 7a has a folded end that covers the folded end of the outer carcass ply 7b and terminates near the maximum tire width position. Further, the bead core 2 is provided in each bead portion 3 by passing between the main body portion 7A and the folded portion 7B.
A tapered beat apex rubber 8 extending outward from the tire in the radial direction of the tire is provided to reinforce from the bead portion 3 to the sidewall portion 4 while improving the lateral rigidity of the tire together with the high turn-up structure of the carcass 7. ..

The belt layer 9 is formed by one or more, in this example, one belt ply 9a, which is placed on the outside of the crown portion of the carcass 7, and has a hoop effect over substantially the entire width of the tread portion 5. Have and reinforce.

In the present invention, the belt ply 9a
Is formed by the biaxial woven belt ply 10.

As shown in the enlarged view of FIG. 2, the biaxial woven belt ply 10 has one of two axes xy intersecting at an angle α in the range of 30 to 60 degrees in the same plane. And the first belt cords 11A arranged in parallel with each other,
A biaxial woven body in which second belt cords 11B arranged parallel to each other along the other axis y are woven together, and the bisector of the angle α is wound in the tire circumferential direction. To be done. Further, the first and second belt cords 11A and 11B of the biaxial woven belt ply 10 have the same arrangement pitch P, and the first and second belt cords 11A and 11B are vertically arranged at the intersection Q thereof. And they intersect alternately.

Therefore, the first and second belt cords 11
A and 11B are 15 to 30 with respect to the tire equator CO, respectively.
The belt layers 9 are arranged at an angle of degrees and in a direction intersecting with each other, and are restrained from each other by their weaving.
The rigidity strength can be efficiently and uniformly increased. Moreover, the belt cord 11 (hereinafter, referred to as the first and second
The belt cords 11A and 11B are collectively referred to as the belt cord 11). The stress acting individually can be reduced to improve the cord durability, while the rubber loose at the cord end is suppressed and the separation at the belt end is prevented. As a result, in addition to the high-speed durability, rolling performance such as rolling performance, wear resistance, and steering stability can be effectively and comprehensively improved.

Further, as the belt cord 11, an aromatic polyamide cord, a polyester cord, a steel cord, and a composite cord of steel and aromatic polyamide,
A composite cord of aromatic polyamide and nylon can be preferably used, and the tire weight can be reduced by reducing the cord mass, the cord diameter, the number of cords driven, the number of plies and the like while maintaining the running performance.

In this embodiment, a band layer 13 is provided outside the belt layer 9 to suppress lifting of the belt layer 9 during high speed running.

The band layer 13 is formed of one band ply 13A in which band cords made of organic fibers are arranged at an angle of approximately 0 degrees with respect to the tire equator CO in this example.
By making the belt layer 9 wider than the belt layer 9,
Both ends are covered. Also, the band ply 13A
In the present example, the band cord is formed in an endless shape by spirally winding the band cord from one end to the other end in the tire circumferential direction. The belt layer 13 may be formed by winding a belt-like body in the tire circumferential direction. In such a case, the band layer 13 is a pair of left and right narrow band plies that cover only both ends of the belt layer 9. You may comprise.

Incidentally, such a biaxial woven belt ply 10
As shown in FIGS. 3 to 5, is a conventional interwoven belt ply 1 in which a steel belt cord is interwoven.
In this case, the biaxial woven belt ply 10 is arranged on the outermost side in the tire radial direction to suppress the generation of cord looseness at the end of the interwoven weave belt ply 15 and to increase the tread surface. It is preferable to make the rigidity uniform and prevent one-way flow of the vehicle.

When the biaxial woven belt ply 10 is arranged on the inner side in the radial direction of the tire, as shown in FIG. 6, the biaxial woven belt ply 10 has a fold end structure and the folded portions 10A at both ends thereof. It is preferable to wrap the end portion of the interwoven belt ply 15 by

(Specific Example) A tire having a tire size of 185 / 70R14 and having the structure shown in FIG.

[0025]

[Table 1]

The steering stability, riding comfort, high-speed durability, wear resistance, and tire weight of each trial tire were measured, and the measurement results at that time were compared with the conventional tire as an index. Regarding the tire weight, a tire with a low index has a light weight, and other tires with a high index have excellent performance. Table 1
The specifications of the belt layer and band layer described in Tables 2 and 3
Is shown in.

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

INDUSTRIAL APPLICABILITY As described above, since the pneumatic tire of the present invention uses the biaxial woven belt ply in the belt layer, the belt rigidity can be uniformly and effectively increased, and the tire can be reduced in weight and run. The performance can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged partial plan view of a biaxial woven belt ply.

FIG. 3 is a schematic diagram showing another embodiment of the belt layer of the present invention.

FIG. 4 is a schematic diagram showing another embodiment of the belt layer of the present invention.

FIG. 5 is a schematic diagram showing another example of the belt layer of the present invention.

FIG. 6 is a schematic diagram showing another embodiment of the belt layer of the present invention.

FIG. 7 is a diagram illustrating a conventional technique.

[Explanation of symbols]

 2 bead core 3 bead part 4 sidewall part 5 tread part 7 carcass 9 belt layer 10 biaxially woven belt ply 11A first belt cord 11B second belt cord

Claims (1)

Claim: What is claimed is: 1. A carcass folded from a tread portion to a sidewall portion around a bead core of a bead portion, and a belt arranged radially outside the carcass and inside the tread portion. The belt layer comprises a first belt cord arranged parallel to each other at an angle of 15 or more and 30 degrees or less with respect to the tire equator, and a belt layer of 15 or more and 30 degrees or less with respect to the tire equator. A biaxial woven fabric-like 2 in which second belt cords arranged at an angle in parallel to each other and in a direction intersecting with the first belt cord are woven together.
A pneumatic tire comprising a shaft woven belt ply.