JPS5931759Y2 - steel cord - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the structure of a steel cord used as a reinforcing material for pneumatic tires for vehicles, belt conveyors, etc.

A conventional steel cord is composed of a plurality of wires 1 or strands 2 twisted together, as shown in FIG.

A plurality of these steel cords are lined up in parallel and covered with a rubber material, and are used as reinforcing materials for tires, belts, etc.

When such a steel cord is used as a reinforcing material, there is a risk of wear between the strands, and since the strands are in close contact with each other, the rubber does not penetrate into the center of the steel cord, and the steel cord and rubber do not get in contact with each other. There were disadvantages in that the adhesion was not sufficient, the strands rusted due to water in the rubber or drains that entered from the outside air, and the complicated structure made it difficult to reduce costs.

For this reason, a flat wire steel cord as shown in Figure 2 A has been devised that takes advantage of its flexibility in one direction, but with a single flat wire structure, for example, the width of the carcass of a large pneumatic tire cannot be designed. For the above reasons, it is necessary to keep the thickness to about 1.3 mm, which makes it impossible to obtain tensile strength, and if this is determined by the thickness, the original flexibility of the flat wire is lost.

Also, if two or more flat wires are overlapped as shown in Figure 2, the workability of the process of use will be reduced, flexibility will not be sufficiently improved, and there will be no gaps between the flat wires, resulting in poor rubber penetration. Therefore, there are disadvantages such as poor adhesion between the flat wire and the rubber, and irregular buckling of the inner flat wire when the flat wire is used in a curved manner as shown in FIG.

The present invention provides a flat steel cord that overcomes the above-mentioned conventional drawbacks.

An embodiment of the steel cord of the present invention will be described below based on the drawings.

Embodiment 1 FIG. 4 shows an embodiment of the steel cord of the present invention, in which a corrugated flat wire 4 processed with minute waves is provided on a smooth flat wire 3 processed by cold rolling or the like. It is a steel cord having a gap 5 between a flat wire 3 and a corrugated flat wire 4.

The pitch P and wave height of the corrugated flat line 4 depend on the radius of curvature R during use as shown in Figure 5 (the outer corrugated flat line is
It can be determined as appropriate to follow the inner flat line.

When the corrugated flat line is curved to a radius of curvature R, the length l of the curved portion of the outer corrugated flat line can be extended by Δl.

△1=txt/R 1: Cold rolled to a center distance width Q of 7 mm and a thickness of 0.2 mm, tensile strength 2
On top of the flat wire 3 processed to have a strength of 32 kg/mm2, a corrugated flat wire 4 is formed by corrugating small corrugations with a pitch of 5 mm and a wave height of 0.16 mm in a cold rolling process to form a laminated flat wire steel cord. , flexibility index, rubber penetration ratio Example 2 FIG. 6 shows a steel cord according to another example of the present invention.

This is shown in Fig. 7 and has a three-layer structure compared to steel cord, which requires more strength.

In other words, on top of the smooth flat line 3, two wavy flat lines 4.6
are stacked to form three layers and wrapped with a thin steel wire 7 to form a steel cord.

In addition, if small waves corresponding to the amount of elongation corresponding to the curvature during use are provided on each corrugated flat wire, the steel cord will have strong strength and flexibility, and will easily bend the steel cord. 3 Other embodiments of the present invention are shown in FIGS. 8 and 9.

A corrugated flat wire 4 is provided on the flat wire 3, and a corrugated flat wire 8 is also provided below the flat wire 3 to form a three-layer structure, and the steel cord is wrapped with the steel wire 7 to form a steel cord.

FIG. 9 shows a comparison of the usage conditions of the steel cord of the present invention with that of conventional products.

Rubber can be infiltrated into the gap 5 between the flat wires.

Cold rolled to a width of 1.5 mm and a thickness of 0.17 mm, 222
A wavy flat wire 4 with a small wave pitch of 5 mm and a wave height of 0.15 mm and a wavy flat wire 6 with a small pitch of 3 mm and a wave height of 0.18 mm are superimposed on the high-strength flat wire 3 that has been strongly processed at kg/mm2, and then A steel cord was constructed by wrapping a steel wire 7 with a diameter of 0.15 mm at a pitch of 5 mm, and the results of comparing the flexibility index, rubber penetration ratio, etc. with conventional products are as follows.

The corrugated flat wire 8 in the lower layer is evenly compressed by the provided small waves, so that it can be easily bent and exhibits excellent flexibility.

Cold rolled to a width of 1.1 mm and a thickness of 0.22 mm, 234
The corrugated flat wires 4 and 8 with a small wave pitch of 5 mm, wave height Q, and 16 mm, processed in a rolling process, are superimposed on the upper and lower layers of the high tensile strength flat wire 3, which has been processed to a strength of kg/mm2. A steel cord was constructed by wrapping the steel wire 7 at a pitch of 5 mm, and the results of comparison with conventional products in terms of flexibility index, rubber penetration ratio, etc. are as follows.

Furthermore, if an amorphous metal, which can only be made in the form of a flat ribbon due to the special manufacturing process, is used for the steel cord of the present invention, the wire will have less distortion, good fatigue resistance, and high strength, so it can withstand high loads. Ideal for applications that involve a lot of bending.

Since the present invention is a steel cord constructed by overlapping at least one corrugated flat wire as described above, it has the following effects.

(1) High flexibility can be imparted to a steel cord having a stacked flat wire structure.

(2) Since rubber can be infiltrated into the gaps between the flat wires of the laminated flat steel cord, rusting of the flat wires is prevented.

(3) By pre-wrapping the corrugated flat wire with thin steel wire, it is possible to incorporate two or three layers of flat wire into the tire with good workability, and it is effective for composite integration with the rubber inside the tire. There is.

(4) Laminated flat steel cords are more wearable and less expensive than twisted steel cords, which consume a lot of energy during processing, and can be distantly related to energy savings.

[Brief explanation of drawings]

Figure 1 A 1, C, and 2 are cross-sectional views of conventional stranded steel cords. Figure 2 A 9 is a perspective view of conventional flat steel cord. Figure 3 A 1 is a conventional flat steel cord. A side view showing the state of the cord before and after bending, FIG. 4 is a perspective view showing one embodiment of the steel cord of the present invention, FIGS. 6 and 8 are perspective views showing the same embodiment, and FIG. A 9th part, Figure 7 A 2th part, No. 9
Figure A9 is a side view showing the steel cord of the present invention before and after bending. 1...Element wire, 2...Strand, 3.
...Flat line, 4,6゜8...Flat line with waves, 5
...Gap, 7...Steel wire.

Claims (3)

[Scope of utility model registration request] (1) Among steel cords made of multiple layers of flat wires, a steel cord is formed by layering at least one layer of corrugated flat wires. (2) A steel cord according to claim 1, which is formed by wrapping overlapping flat wires with a thin metal wire. (3) The steel cord according to claim 1, which uses an amorphous metal ribbon as the overlapping flat wire.