阅读说明：本技术 一种钢帘线、其制造方法及轮胎 (Steel cord, manufacturing method thereof and tire ) 是由 刘祥 姚海东 苗为钢 刘湘慧 于 2020-05-07 设计创作，主要内容包括：本发明公开了一种钢帘线、其制造方法及轮胎,所述钢帘线包含至少一个强度元件,所述强度元件具有周期性的不连续的凸形曲线,所述凸形曲线总是置于钢帘线的一侧或两侧或多侧。所述钢帘线在具有所述凸形曲线一侧或两侧或多侧由于具有更多的间隙和开度导致其刚度小,而所述钢帘线在其他侧的刚度大,从而使得所述钢帘线具有取向性。同时,凸形曲线可以增加组成钢帘线的强度元件之间的间隙,提高钢帘线的橡胶渗透性,减少强度元件的磨损,提高强度元件的抗腐蚀性能。(The invention discloses a steel cord, a method for manufacturing the same and a tire, the steel cord comprising at least one strength element having a periodic discontinuous convex curve, the convex curve being always placed on one or two or more sides of the steel cord. The steel cord has a small stiffness at one side or both sides or more sides having the convex curve due to more gaps and openness, and the steel cord has a large stiffness at the other side, thereby imparting orientation to the steel cord. Meanwhile, the convex curve can increase the gap between the strength elements forming the steel cord, improve the rubber permeability of the steel cord, reduce the abrasion of the strength elements and improve the corrosion resistance of the strength elements.)

1. A steel cord characterized by: the steel cord comprises at least one strength element having a periodic discontinuous convex curve, which is always placed on one or both or more sides of the steel cord.

2. A steel cord as claimed in claim 1, characterized in that: the ratio C/P of the periodic distance C of the discontinuous convex curve of the strength element to the twisting lay length P of the strength element at the twisting position of the steel cord is less than or equal to 1.

3. A steel cord according to any one of claims 1 to 2, said convex curve having a ratio L/C of length L to periodic distance C of the discontinuous convex curve of said strength element being less than or equal to 0.5.

4. A steel cord according to any one of claims 1 to 3, characterized in that: the ratio of the wave height H of the convex curve to the diameter d of the strength element is 1.02-2.50, and the convex curve has a plurality of wavelengths.

5. A steel cord according to any one of claims 1 to 4, characterized in that: all the strength elements constituting the same twist position of the steel cord have a periodic discontinuous convex curve and said convex curve is always placed on one or both or more sides of the steel cord.

6. A steel cord according to any one of claims 1 to 5, characterized in that: said convex curve is always placed on both symmetrical sides of the steel cord.

7. A steel cord according to claim 6, characterized in that: the ratio of the periodic distance C of the discontinuous convex curve of the strength element to the twisting lay length P of the strength element at the twisting position of the steel cord is C/P =0.5, and the ratio L/C of the length L of the convex curve to the periodic distance C of the discontinuous convex curve of the strength element is less than or equal to 0.5.

8. A steel cord according to any one of claims 1 to 7, characterized in that: the periodic discontinuous convex curve of the strength members is in a plane.

9. A steel cord according to any one of claims 1 to 7, characterized in that: the periodic discontinuous convex curve of the strength members is within a continuous curve.

10. A method for manufacturing a steel cord according to any one of claims 1 to 9, comprising:

-subjecting at least one of said strength members to a periodic, discontinuous bending operation, thereby imparting a periodic, discontinuous convex curve to said at least one strength member;

-making up said steel cord with at least one of said elements, together with other elements, said strength elements subjected to periodic discontinuous bending operations having periodic discontinuous convex curves periodically placed on one or both or more sides of the steel cord during the building up.

11. The manufacturing method according to claim 10, characterized in that: the periodic, discontinuous bending operation of at least one of the strength members is performed in a plane.

12. The manufacturing method according to claim 10, characterized in that: the periodic, discontinuous bending operation of at least one of the strength members is performed in a helical manner.

13. A tire, characterized by: comprising a steel cord according to any one of claims 1 to 9.

Technical Field

The invention belongs to the technical field of rubber products, and particularly relates to a steel cord, a manufacturing method thereof and a tire.

Background

The tire has a requirement for orientation of the steel cord with the belt layer during running, and it is desired that the steel cord be reduced in rigidity and increased in flexibility in the tire radial direction so as to be easily capable of crossing obstacles such as cobblestones with good ride comfort; it is desirable that the steel cord has increased rigidity and decreased flexibility in the tire axial direction, so that it is more stable in bending and has good steering performance. In general, a steel cord is always isotropic in a manufacturing process, and a steel cord having an orientation needs to be processed and manufactured in a special manner.

EP0264145a1 discloses a steel cord with an elongated cross section comprising flat steel wires as core. CN102482844B discloses a steel cord with an oval cross section comprising oval steel wires as core. The elongated cross section or the elliptical cross section allows the steel cord to be obtained with orientation, but the flat wire or the elliptical wire decreases mechanical properties of the wire during the manufacturing process, such as fatigue resistance and tensile strength, and the flat wire or the elliptical wire is manufactured by cold drawing using a forming die or by cold rolling, which is complicated and difficult in the manufacturing process and increases the production cost.

JP- ｃA-09-268485 discloses another method of manufacturing an oriented steel cord by arranging round steel filaments according to an elliptical geometric feature, but the process of manufacturing the steel cord is not easy to implement and the cost is high.

Disclosure of Invention

The purpose is as follows: in order to overcome the defects in the prior art, the invention provides a steel cord, a manufacturing method thereof and a tire.

The technical scheme is as follows: in order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a steel cord comprising at least one strength element having a periodic discontinuous convex curve, which is always placed on one or two or more sides of the steel cord.

In the present application, the term "steel cord" does not mean that all the constituent elements are steel elements, but only that most of them are steel elements. Other elements such as nylon or aromatic polyester amine elements or other materials may also be present as strength elements or filler elements in the steel cord.

The term "element" may refer to a single steel wire or a strand having a plurality of single steel wires.

Preferably, the ratio C/P of the periodic distance C of the discontinuous convex curve of the strength element to the twisting lay length P of the strength element at the twisting position of the steel cord is less than or equal to 1.

Preferably, the ratio L/C of the length L of the convex curve to the periodic distance C of the discontinuous convex curve of the strength member is less than or equal to 0.5.

The periodic distance C of the discontinuous convex curve of a strength element refers to the axial distance from the convex curve home position of an individual strength element to the next adjacent convex curve home position.

The length L of the convex curve refers to the axial distance from the initial position to the end position of the convex curve.

The twist position refers to the position where the strength elements are arranged in the steel cord.

Preferably, the ratio of the wave height H of the convex curve to the diameter d of the strength element is 1.02-2.50, and the convex curve has a plurality of wavelengths. Further, in some embodiments, the convex curve has 2-4 wavelengths.

The wave height H of the convex curve refers to the distance from the crest to the trough of the convex curve perpendicular to the axial direction of the element.

Wavelength refers to the axial distance between adjacent peaks (or valleys).

The difference in orientation of the steel cord cannot be exhibited significantly if the ratio of the wave height H of the convex curve to the strength member diameter d is less than 1.02; a ratio of the wave height H of the convex curve to the strength member diameter d of more than 2.50 results in a significant increase in the strength loss of the strength member.

Preferably, all the strength elements constituting the same twist position of the steel cord have a periodic discontinuous convex curve, and said convex curve is always placed on one or both or more sides of the steel cord.

Preferably, said convex curve is always placed on both symmetrical sides of the steel cord. More preferably, the ratio of the periodic distance C of the discontinuous convex curve of the strength element to the twist lay length P of the strength element at the twist position of the steel cord is C/P0.5, and the ratio of the length L of the convex curve to the periodic distance C of the discontinuous convex curve of the strength element is L/C0.5.

Preferably, the periodic discontinuous convex curve of the strength members is in a plane.

Preferably, the periodic discontinuous convex curve of the strength members is within a continuous curve.

The diameter of the strength member is generally 0.10mm to 0.80mm, and other diameters may be designed as necessary.

In the case of a strength member as a steel member, the carbon content is generally 0.60% to 1.02% in order to obtain a high strength.

The strength member may be a bare steel wire or a coated steel wire without any coating. Preferably, to improve the adhesion of the steel cord to the rubber, the strength members are coated with a brass or other metal alloy coating that promotes adhesion to the rubber.

The invention also discloses a manufacturing method of the steel cord, which comprises the following steps:

-subjecting at least one of said elements to a periodic discontinuous bending operation so that said at least one element has a periodic discontinuous convex curve;

-making up said steel cord with at least one of said elements, along with the other elements, said elements subjected to periodic discontinuous bending operations having periodic discontinuous convex curves periodically placed on one or both or more sides of the steel cord during the making up.

Preferably, the periodic discontinuous bending operation received by at least one of the strength members is performed in a plane.

Preferably, the periodic discontinuous bending operation to which at least one of the strength members is subjected is performed in a helical manner.

The invention also discloses a tire which comprises the steel cord.

Has the advantages that: the present invention provides a steel cord having an orientation, which has a small rigidity on one side or both sides or more sides having the convex curve due to more gaps and openings, and a large rigidity on the other side, a method of manufacturing the same, and a tire. The steel cord is arranged in the tire belt layer according to the orientation of the rigidity, the side with low rigidity is arranged in the radial direction of the tire, and the side with high rigidity is arranged in the axial direction of the tire, so that good comfort and steering of driving are realized. In addition, the convex curve may increase the gap between the strength members constituting the steel cord, thereby improving the rubber permeability of the steel cord, reducing the abrasion of the strength members, and improving the corrosion resistance of the strength members.

Drawings

Fig. 1 is a schematic structural view of a prior art steel cord: a conventional steel cord 10, a first element 11, a second element 12.

FIG. 2 is a schematic illustration of a strength member according to an embodiment of the present invention.

FIG. 3 is a schematic structural view of a steel cord of an embodiment of the present invention: a steel cord 20, a first strength member 21, a second strength member 22.

Fig. 4 is a schematic view of a double twister for manufacturing a steel cord of an embodiment of the present invention.

FIG. 5 is a schematic view of a male gear in an embodiment.

In fig. 4 and 5: steel cord 20, strength component 30, original strength component 40, paying-off I-shaped wheel 41, convex gear 42, double-twisting machine 43, over-twisting device 44 and take-up spool 45.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may also include different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

A method of manufacturing an oriented steel cord comprising:

-subjecting at least one of said elements to a periodic discontinuous bending operation so that said at least one element has a periodic discontinuous convex curve;

-making up said steel cord with at least one of said elements, along with the other elements, said elements subjected to periodic discontinuous bending operations having periodic discontinuous convex curves periodically placed on one or both or more sides of the steel cord during the making up.

The strength member may be subjected to periodic, discontinuous bending operations using the male gear 42 shown in fig. 5, with the male teeth of the male gear 42 being in a periodic, discontinuous arrangement, so that a strength member 30 as shown in fig. 2 may be obtained. The required wave height H of the strength element 30, the length L of the convex curve and the periodic distance C of the convex curve can be obtained by designing and adjusting the wheel diameter, the tooth number and the tooth number of the convex gear 42, and meanwhile, a plurality of wavelengths of the convex curve of the strength element 30 can be set according to the tooth shape of the convex gear 42.

The male gear 42 may be actively rotated to bend the strength members or passively rotated to bend the strength members.

The male gear 42 may perform a bending operation on the strength member in one plane, and may also perform a bending operation on the strength member in a spiral manner by rotating the strength member around the axial direction thereof.

The male gear is only one way of bending the strength member, and other ways of periodically deforming the strength member by deforming rollers, bearings, etc. may be used.

As shown in fig. 4, a green strength member 40 is paid off from a pay-off reel 41, past a male gear 42, to obtain a strength member 30 having a periodic, discontinuous male curve. When the strength members 30 are twisted into the steel cord 20 by the double twister 43, the strength members 30 constitute the steel cord 20 in a nearly spiral manner, and the strength members 30 themselves are twisted centering on the axial direction of the steel cord 20, and the strength members 30 are twisted by one turn each time a pitch is formed. The deformed position of the male gear 42 is adjusted to arrange each strength member 30 in order of the convex curves one another so that the positions where the convex curves of the twisted strength members 30 are spirally wound are always periodically placed on one side or both sides or more of the steel cord 20, and finally, the take-up is performed by the take-up spool 45, thereby obtaining the steel cord having the orientation of the embodiment of the present invention, as shown in fig. 3.