Steel cord for radial tire belt, and radial tire

Abstract

The utility model relates to the technical field of tire production, in particular to a steel wire cord for a radial tire belted layer and a radial tire, and the steel wire cord is formed by weaving and twisting four monofilaments; wherein in the cross section of the steel wire cord, the four monofilaments are distributed in a rhombus shape and comprise a first pair of monofilaments located on the lower portion and a second pair of monofilaments located on the upper portion, a gap is formed between the first pair of monofilaments and the second pair of monofilaments, a gap is formed between the two monofilaments of the first pair, and a gap is formed between the two monofilaments of the second pair. The steel wire cord is formed by processing the four monofilaments at one time, the cross section of the steel wire cord is distributed in a rhombus shape, the monofilaments are arranged at intervals, the formed steel wire cord is low in density and high in strength, the thickness of a calendering cord fabric can be reduced, and the using amount of calendering rubber materials is reduced, so that the purpose of light weight of the tire is achieved, the rolling resistance of the tire is reduced, and the wear resistance of the tire is improved; the service life of the tire is prolonged and the production cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of tire production, in particular to a steel cord for a radial tire belt layer and a radial tire. Background Art

[0002] The belt layer of a radial tire, also known as the support layer, hard buffer layer or stabilizing layer, is an important component of radial tires and belted bias tires. The belt layer is located under the tread base of the radial tire and tightens the carcass along the circumferential direction of the tread centerline. The belt layer should use high-strength, high-modulus and small-angle arranged cords as its reinforcement material, and at the same time be covered with high-elongation and high-hardness rubber.

[0003] At present, radial tires usually use 2+2*0.35HT steel cord as the belt layer. Its structure is twisted in two layers, with a twist direction of S and a twist pitch of 16 to 17 mm. The inner layer is not twisted during twisting, and the inner and outer monofilaments form point contact. The breaking strength and fatigue resistance of the steel cord are low, and the inner and outer monofilaments form an alternating twist. During use, the wear resistance and fatigue performance are greatly reduced. Due to the multi-layer structure, the glue penetration performance is poor, the processing technology is complicated, and the line density is large. The application in tires makes the tire weight heavy. Utility Model Content

[0004] In view of the technical problems existing in the steel cord for belt layer in the prior art, the first aspect of the utility model proposes a steel cord for the belt layer of a radial tire, which is formed by twisting four monofilaments;

[0005] Among them, in the cross-section of the steel cord, the four monofilaments are distributed in a diamond shape, including a first pair of monofilaments located at the bottom and a second pair of monofilaments located at the top, there is a gap between the first pair of monofilaments and the second pair of monofilaments, there is a gap between the two monofilaments of the first pair, and there is a gap between the two monofilaments of the second pair.

[0006] Preferably, the diameter of the monofilament is 0.21 mm.

[0007] Preferably, the twist length of the monofilament is controlled to be 16 to 18 mm.

[0008] Preferably, the length L1 of the outer contour formed by the four monofilaments is controlled to be 0.51 mm, and the height L2 is controlled to be 0.42 mm±0.02 mm.

[0009] Preferably, the pre-deformation interval of each monofilament is 3 mm.

[0010] Preferably, the linear density of the steel cord is 1.10 g / m.

[0011] Preferably, the breaking tension of the steel cord is 490N.

[0012] In the second aspect of the present utility model, a technical solution is proposed, a radial tire structure, comprising a belt layer and a carcass ply;

[0013] The belt layer includes the steel cord for the belt layer of the radial tire as described above, and a rubber layer coated outside the steel cord.

[0014] Preferably, the thickness of the carcass ply is 1.05 mm.

[0015] Preferably, the specific gravity of the rubber compound of the belt layer is 3.8 g / cm³.

[0016] Compared with the prior art, the advantages of the present utility model are as follows:

[0017] In the present utility model, the steel cord is formed by one-time processing of 4 single filaments, with a rhombic cross-sectional distribution, a spacing between the single filaments, and a low linear density and high strength of the formed steel cord, which can reduce the thickness of the calendered carcass ply and reduce the amount of calendered rubber compound, thereby achieving the purpose of tire lightweight, reducing the rolling resistance of the tire, improving the wear resistance of the tire, extending the service life of the tire, and reducing the production cost at the same time;

[0018] In the present utility model, the steel cord has a single-layer structure, and the single filaments are deformed synchronously, with a line contact, which increases the breaking strength and fatigue resistance of the steel cord. The test results show that the durability and load-carrying capacity of the tire have reached a relatively high level. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings are not intended to be drawn to scale. In the drawings, each identical or approximately identical component shown in each figure may be denoted by the same reference numeral. For the sake of clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the present utility model will be described by way of example and with reference to the drawings, wherein:

[0020] Figure 1 is a schematic structural view of the steel cord for the belt layer of the radial tire shown in the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to better understand the technical content of the present utility model, specific embodiments are hereby given and described in conjunction with the accompanying drawings as follows.

[0022] Combined with Figure 1 shown, in the first aspect of the present utility model, a steel cord for the belt layer of a radial tire is proposed, which is formed by twisting four single filaments 1.

[0023] Among them, in the cross-section of the steel cord, four single filaments 1 are distributed in a rhombus shape, including a first pair of single filaments located below and a second pair of single filaments located above. There is a gap between the first pair of single filaments and the second pair of single filaments, a gap between the two single filaments of the first pair, and a gap between the two single filaments of the second pair.

[0024] The four single filaments are limited by a straightener, and the four single filaments 1 are kept in the Figure 1 rhombus distribution position shown for rubber coating. In this way, the four single filaments 1 formed have gaps between each other, and the formed steel cord has strong rubber penetration ability, and the single filaments are in line contact with each other, which can increase the breaking strength and fatigue resistance of the steel wire.

[0025] Optionally, the outer contour length L1 formed by the four single filaments 1 is controlled to be 0.51 mm, and the height L2 is controlled to be 0.42 mm ± 0.02 mm.

[0026] Further optionally, the diameter of the single filament 1 is 0.21 mm. The twist pitch of the single filament 1 is controlled to be 16 - 18 mm.

[0027] The steel cord shown in the present utility model is a single-layer structure, and the single filaments deform synchronously and are in line contact, which increases the breaking strength and fatigue resistance of the steel cord.

[0028] In an optional embodiment, the single filament 1 is pre-compressed and deformed by a deformed gear, and the pre-deformation spacing of each single filament 1 is 3 mm. In this way, the opening degree of the steel cord can be increased, so that the rubber can penetrate more fully between the single filaments 1 during the calendering process, thereby improving the rubber penetration performance of the steel cord. Good rubber penetration performance helps to enhance the wear resistance, anti-fatigue performance and service life of the tire.

[0029] In the above embodiment, the linear density of the formed steel cord is 1.10 g / m. It is lighter than the linear density of 2 + 2 * 0.35HT steel cord, which is 3.03 g / m, and is only 1 / 3 of the linear density of 2 + 2 * 0.35HT steel cord. And the breaking tensile force is 490 N, which is only reduced by half compared with 980 N of 2 + 2 * 0.35HT steel cord. Therefore, under the same linear density, the breaking tensile force of the steel cord proposed in this application is higher.

[0030] In addition, through the rhombus arrangement, the thickness of the calendered cord fabric can be thinned, the amount of calendered rubber compound can be reduced, so as to achieve the purpose of tire light weight, reduce the rolling resistance of the tire, improve the wear resistance of the tire, and extend the service life of the tire.

[0031] Embodiment 1

[0032] Steel cord for the belt layer of a radial tire, which is twisted by 4 single filaments. The single filament is a steel wire single filament with a carbon content of 0.91%, the single filament is Z-twisted, the twist pitch is 17 mm, and the single filament diameter is 0.21 mm.

[0033] Example 2

[0034] Steel cord for the belt layer of a radial tire, which is twisted by 4 single filaments. The single filament is a steel wire single filament with a carbon content of 0.92%, the single filament is Z-twisted, the twist pitch is 18 mm, and the single filament diameter is 0.21 mm.

[0035] Example 3

[0036] Steel cord for the belt layer of a radial tire, which is twisted by 4 single filaments. The single filament is a steel wire single filament with a carbon content of 0.93%, the single filament is Z-twisted, the twist pitch is 16 mm, and the single filament diameter is 0.21 mm.

[0037] The steel cord for the belt layer of a radial tire is all twisted in one go.

[0038] The steel cords for the belt layer of a radial tire in Examples 1 to 3 are respectively tested and compared with the 2 + 2*0.35HT steel cord. The data is shown in Table 1 below.

[0039] Table 1. Comparison between the steel cords in Examples 1 to 3 and the 2 + 2*0.35HT steel cord

[0040]

[0041] As the steel cords in Examples 1 to 3 above have a lower linear density and higher strength compared to the 2 + 2*0.35HT steel cord, the calendered cord fabric thickness can be reduced, the amount of calendered rubber compound can be decreased, thereby achieving the purpose of tire lightweight, reducing the tire rolling resistance, improving the tire wear resistance, and extending the tire service life.

[0042]

Radial tire structure

[0043] In a second aspect of the present invention, a technical solution is proposed. A radial tire structure includes a belt layer and a cord fabric layer;

[0044] The belt layer includes the above-mentioned steel cord for the belt layer of a radial tire and a rubber layer coated outside the steel cord.

[0045] Preferably, the thickness of the cord fabric is 1.05 mm. Optionally, one or more layers of cord fabric and the number of layers of steel cord in the belt layer can be set according to needs.

[0046] Preferably, the specific gravity of the rubber compound of the belt layer is 3.8 g / cubic centimeter.

[0047] Combined with the above embodiments, in the utility model, the steel cord is formed by one-time processing of 4 single filaments, and the cross-section is in a diamond distribution. There is a spacing between the single filaments, and the formed steel cord has a low linear density and high strength, which can reduce the thickness of the calendered fabric and reduce the amount of calendered rubber, thereby achieving the purpose of tire lightweight, reducing the rolling resistance of the tire, improving the wear resistance of the tire, extending the service life of the tire, and at the same time reducing the production cost; in the utility model, the steel cord is a single-layer structure, and the single filaments are deformed synchronously and are in line contact, which increases the breaking strength and fatigue resistance of the steel cord. The test results show that the durability and load-carrying capacity of the tire have reached a relatively high level.

[0048] Although the present utility model has been disclosed above with preferred embodiments, it is not intended to limit the present utility model. Those with ordinary knowledge in the technical field to which the present utility model pertains can make various changes and modifications without departing from the spirit and scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to what is defined by the claims.

Claims

1. A steel cord for a radial tire belt layer, characterized in that: It is formed by twisting four monofilaments (1); In the cross section of the steel cord, the four monofilaments (1) are distributed in a rhombus shape, including a first pair of monofilaments located at the bottom and a second pair of monofilaments located at the top, there is a gap between the first pair of monofilaments and the second pair of monofilaments, there is a gap between the two monofilaments (1) of the first pair, and there is a gap between the two monofilaments (1) of the second pair.

2. The steel cord for a radial tire belt layer according to claim 1, characterized in that: The diameter of the monofilament (1) is 0.21 mm.

3. The steel cord for a radial tire belt layer according to claim 2, characterized in that: The twist length of the monofilament (1) is controlled to be 16-18 mm.

4. The steel cord for a radial tire belt layer according to claim 2, characterized in that: The length L1 of the outer contour formed by the four monofilaments (1) is controlled to be 0.51 mm, and the height L2 is controlled to be 0.42 mm±0.02 mm.

5. The steel cord for a radial tire belt layer according to claim 2, characterized in that: The pre-deformation interval of each monofilament (1) is 3 mm.

6. The steel cord for a radial tire belt layer according to claim 1, characterized in that: The linear density of the steel cord is 1.10 g / m.

7. The steel cord for a radial tire belt layer according to claim 1, characterized in that: The breaking tensile force of the steel cord is 490N.

8. A radial tire, characterized in that: Includes belt and ply; The belt layer comprises the steel cord for a radial tire belt layer according to any one of claims 1 to 7, and a rubber layer covering the steel cord.

9. The radial tire according to claim 8, characterized in that: The thickness of the cord fabric is 1.05 mm.

10. The radial tire according to claim 8, characterized in that: The specific gravity of the rubber material of the belt layer is 3.8 g / cubic centimeter.

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