Steel cord structure for all-steel radial tire carcass

Abstract

The utility model relates to the technical field of steel cords, in particular to a steel cord structure for a tire body of an all-steel radial tire, which comprises a core wire comprising two first monofilaments which are spirally assembled together at the lay length of L1; the middle layer comprises eight second monofilaments which are spirally assembled outside the core wire at a lay length L2; and the outer layer comprises fourteen third monofilaments which are spirally wound outside the middle layer at a lay length L3. The three-layer structure of 2 + 8 + 14 is adopted, the second monofilaments of the middle layer and the first monofilaments of the inner layer are kept in linear contact and form an oval outline, gaps used for glue permeation are formed between the second monofilaments of the middle layer, the structure is stable, the strength is high, the third monofilaments of the outer layer are in point contact with the middle layer, a larger glue permeation gap is formed, and the glue permeation effect is good. The whole steel cord has better rubber permeation performance and corrosion resistance, and the safety performance is high after the steel cord is made into a tire.

Description

Technical Field

[0001] The utility model relates to the technical field of steel cord, in particular to a steel cord structure for the carcass of all-steel radial tires. Background Art

[0002] When selecting the carcass cord of all-steel radial tires, in addition to considering the carcass strength, it is also necessary to consider that the carcass cord should have relatively high breaking force, fatigue resistance and wear resistance. At present, the 3+9+15+1 type of steel cord with three layers of steel wires + one outer winding wire structure is commonly used in the carcass of all-steel radial tires; with the progress of society, it is required that the carcass of load-carrying radial tires has corresponding load-bearing capacity and fatigue performance. Due to the 3+9+15+1 type with an outer winding structure, the diameter of the outer winding wire is 0.15, and the breaking force is only 60N. When the tire is repeatedly bent during use, the outer winding wire is prone to breakage. After the outer winding wire breaks, the 3+9+15+1 type structure will shift as a whole in the tire, resulting in a reduction in tire life.

[0003] The lay direction of the 3+9+15+1 type is the opposite lay SSZS. During the use of the tire, due to the different lay directions of the second layer structure and the third layer structure, interactive stress is likely to occur, resulting in a reduction in tire service life. Summary of the Utility Model

[0004] In view of the technical problems existing in the steel cord in the prior art, the first aspect of the present utility model provides a steel cord structure for the carcass of all-steel radial tires, including:

[0005] A core wire, the core wire includes two first single wires spirally assembled together with a lay pitch L1;

[0006] An intermediate layer, the intermediate layer includes eight second single wires spirally assembled outside the core wire with a lay pitch L2;

[0007] An outer layer, the outer layer includes fourteen third single wires spirally wound outside the intermediate layer with a lay pitch L3;

[0008] Wherein, the lay pitch L1 of the first single wire is less than the lay pitch L2 of the second single wire is less than the lay pitch L3 of the third single wire, and the lay directions of the first single wire, the second single wire and the third single wire are the same;

[0009] The intermediate layer is spirally assembled by eight second single wires to form an elliptical cross-section, and the outer layer is spirally wound by fourteen third single wires to form an elliptical cross-section.

[0010] Preferably, the diameter of the first single wire is D1, the diameter of the second single wire is D2, and the diameter of the third single wire is D3, wherein, D1 = D2 = D3.

[0011] Preferably, the diameters of the first monofilament, the second monofilament, and the third monofilament are 0.17 mm.

[0012] Preferably, the twist pitch L2 of the second monofilament is twice the twist pitch L1 of the first monofilament.

[0013] Preferably, the twist pitch L1 of the first monofilament is 5 ± 0.25 mm, the twist pitch L2 of the second monofilament is 10 ± 0.5 mm, and the twist pitch L3 of the third monofilament is 13.5 ± 0.68 mm.

[0014] Preferably, the outer diameter of the outer layer is controlled to be 1.02 ± 0.051 mm.

[0015] Preferably, the twist directions of the first monofilament, the second monofilament, and the third monofilament are all in the Z direction.

[0016] Preferably, the breaking force of the steel cord structure is 1680 N.

[0017] Compared with the prior art, the advantages of the present utility model are as follows:

[0018] The present utility model adopts a three-layer structure of 2 + 8 + 14. The second monofilaments in the middle layer and the first monofilaments in the inner layer maintain line contact and form an elliptical contour. Gaps for rubber infiltration are formed between the second monofilaments in the middle layer, and the structure is stable and has high strength. The third monofilaments in the outer layer are in point contact with the middle layer, forming larger gaps for rubber infiltration, so that the overall steel cord has better rubber infiltration performance and corrosion resistance. After being made into a tire, it has high safety performance. The three-layer structure adopts the same twist direction, is not prone to generate cross stresses, and has a long service life of the tire. 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 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 examples and with reference to the drawings, wherein:

[0020] Figure 1 is a schematic structural diagram of the steel cord structure for the carcass of an all-steel 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] As Figure 1As shown in the figure, the first aspect of the present utility model proposes a steel cord structure for the carcass of all-steel radial tires, which includes three layers: a core wire 1, an intermediate layer 2, and an outer layer 3. There is no outer winding wire, and the overall shape is oval. It has stable performance, high strength, and high load-carrying capacity.

[0023] As Figure 1 shown in the figure, the core wire 1 includes two first single wires helically assembled together with a twist pitch L1, and the core wire 1 forms an oval contour; the intermediate layer 2 includes eight second single wires helically assembled outside the core wire 1 with a twist pitch L2. The intermediate layer 2 covers the outer layer of the core body and maintains an oval contour. Four of the second single wires are closely attached to the outer wall of the first first single wire, and the other four second single wires are closely attached to the outer wall of the second second single wire. Therefore, multiple second single wires are supported by the first single wire, and there are gaps between adjacent second single wires that are not closely arranged; the outer layer 3 includes fourteen third single wires helically wound outside the intermediate layer 2 with a twist pitch L3. The fourteen third single wires of the outer layer 3 still maintain an oval contour, and the third single wires are in point contact with the second single wires. Therefore, there are larger gaps between the third single wires and the second single wires, which is beneficial for rubber penetration.

[0024] Preferably, the diameter of the first single wire is D1, the diameter of the second single wire is D2, and the diameter of the third single wire is D3, where D1 = D2 = D3. Optionally, the diameters of the first single wire, the second single wire, and the third single wire are 0.17 mm.

[0025] Among them, the twist pitch L1 of the first single wire is less than the twist pitch L2 of the second single wire which is less than the twist pitch L3 of the third single wire, and the twist directions of the first single wire, the second single wire, and the third single wire are the same; the intermediate layer 2 is helically assembled by eight second single wires to form an oval cross-section, and the outer layer 3 is helically wound by fourteen third single wires to form an oval cross-section.

[0026] In the three-layer structure formed in this way, there is a gap between the outer layer 3 and the intermediate layer 2, and there is a gap between the intermediate layer 2 and the core wire 1, so that the rubber penetration performance of the steel cord is good. The three-layer structure is oval, with high structural stability, high strength, and high safety after being made into a tire product.

[0027] In an alternative embodiment, the twist pitch L2 of the second single wire is twice the twist pitch L1 of the first single wire. In this way, the second single wire maintains line contact with the first single wire outside the first single wire, and the formed structure has strong load-bearing capacity and is not easily deformed.

[0028] Specifically, the twist pitch L1 of the first single wire = 5 ± 0.25 mm, the twist pitch L2 of the second single wire = 10 ± 0.5 mm, and the twist pitch L3 of the third single wire = 13.5 ± 0.68 mm.

[0029] In this way, the outer diameter of the formed outer layer 3 is controlled to be 1.02 ± 0.051 mm. The overall outer diameter of the steel cord structure is approximately 1.02 mm.

[0030] Optionally, the twist directions of the first monofilament, the second monofilament, and the third monofilament are all Z-direction. In this way, all three layers are twisted in the Z-direction, and the formed steel cord structure will not generate interaction stress. The contact surface between the steel cord monofilaments is large, the load-bearing capacity is strong, and the rubber penetration performance between the three layers is good, and the corrosion resistance is good.

[0031] In a specific embodiment, the steel cord structure with a 2+8+14 three-layer structure has the following parameters:

[0032] Item 2+8+14*0.17 Monofilament diameter 0.17mm Cord diameter 1.02mm Core wire pitch 5.0 Center layer pitch 10.0 Outermost layer pitch 13.5 Core wire lay direction Z Center layer lay direction Z Outermost layer lay direction Z

[0033] After the breaking force test, the breaking force of the above 2+8+14*0.17 steel cord structure is 1680N.

[0034] Combined with the above embodiments, the present utility model adopts a 2+8+14 three-layer structure. The second monofilaments in the middle layer and the first monofilaments in the inner layer maintain line contact and form an oval contour. Gaps for rubber penetration are formed between the second monofilaments in the middle layer, and the structure is stable and has high strength. The third monofilaments in the outer layer are in point contact with the middle layer, forming larger gaps for rubber penetration, so that the overall steel cord has better rubber penetration performance and corrosion resistance. After being made into a tire, the safety performance is high. The three-layer structure adopts the same twist direction and is not easy to generate interaction stress, and the service life of the tire is long.

[0035] 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 belongs 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 structure for an all-steel radial tire carcass, characterized in that: include: A core wire (1), the core wire (1) comprising two first monofilaments helically assembled together with a lay length L1; An intermediate layer (2), the intermediate layer (2) comprising eight second monofilaments helically assembled outside the core wire (1) at a twist length L2; An outer layer (3), the outer layer (3) comprising fourteen third monofilaments spirally wound outside the middle layer (2) at a twisting pitch L3; The twist length L1 of the first monofilament is smaller than the twist length L2 of the second monofilament, which is smaller than the twist length L3 of the third monofilament, and the twist directions of the first monofilament, the second monofilament and the third monofilament are the same; The middle layer (2) is assembled by eight of the second monofilaments in a spiral so as to have an elliptical cross-section, and the outer layer (3) is wound by fourteen of the third monofilaments in a spiral so as to have an elliptical cross-section.

2. The steel cord structure for an all-steel radial tire carcass according to claim 1, characterized in that: The diameter of the first monofilament is D1, the diameter of the second monofilament is D2, and the diameter of the third monofilament is D3, wherein D1=D2=D3.

3. The steel cord structure for an all-steel radial tire carcass according to claim 2, characterized in that: The diameters of the first monofilament, the second monofilament and the third monofilament are 0.17 mm.

4. The steel cord structure for an all-steel radial tire carcass according to claim 1, characterized in that: The lay length L2 of the second monofilament is twice the lay length L1 of the first monofilament.

5. The steel cord structure for an all-steel radial tire carcass according to claim 4, characterized in that: The lay length L1 of the first monofilament is 5±0.25 mm, the lay length L2 of the second monofilament is 10±0.5 mm, and the lay length L3 of the third monofilament is 13.5±0.68 mm.

6. The steel cord structure for an all-steel radial tire carcass according to claim 1, characterized in that: The outer diameter of the outer layer (3) is controlled to be 1.02±0.051 mm.

7. The steel cord structure for an all-steel radial tire carcass according to claim 1, characterized in that: The twist directions of the first monofilament, the second monofilament and the third monofilament are all in the Z direction.

8. The steel cord structure for an all-steel radial tire carcass according to claim 1, characterized in that: The breaking force of the steel cord structure is 1680N.

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