Steel cord for rubber track main cord

Abstract

A steel cord for a rubber track main cord, where core filaments of a core strand is restricted from coming out of a rubber member. This is achieved by causing rubber to penetrate to core filament surfaces of the core strand without reducing a cord breaking load. A core strand (22) of a steel cord (10) is constituted of one core filament (22C) and five sheath filaments (22S) twisted around the core filament (22). Six sheath strands (26) are twisted around the core strand (22). A rubber member is highly penetratable into the core filament (22C) because sufficiently wide gaps are held between the sheath filaments (22S). The structure above realizes the steel cord (10) where the core filament (22C) is restricted from coming out.

Description

technical field [0001] The present invention relates to a steel cord for a main cord built into a rubber crawler. Background technique [0002] Steel cords are often used as reinforcing materials for jointless endless rubber tracks. In addition, in order to improve the load-bearing capacity of the steel cord, the structure of the steel cord is often adopted with a 7×7 structure that increases the cord cutting load. [0003] As the 7×7 structure, for example, Japanese Patent Laying-Open No. 11-093087 discloses such as Figure 5 Like the steel cord 80 shown, six sheath strands 86 are arranged around one core strand 82. The diameters of the core wire 86C and the sheath wire 86S of 86 are all the same. [0004] But when Figure 5 In the structure as shown, since the space between the sheath yarns 82S constituting the core strand 82 is narrow, penetration of the rubber into the core yarn 82C constituting the core strand 82 is low. For this reason, when the rubber crawler belt ...

AI Technical Summary

Problems solved by technology

[0004] But when Figure 5 In the structure as shown, since the space between the sheath yarns 82S constituting the core strand 82 is narrow, the penetration of the rubber into the core yarn 82C constituting the core strand 82 is low.

For this reason, when the rubber crawler belt having the steel cord 80 is used, a load is repeatedly applied, and as a result, such a defect occurs that the core wire 82C constituting the core strand 82 runs from the end of the steel cord 80 to the rubber crawler belt. side of the surface protruding

[0007] However, as disclosed in Japanese Patent Application Laid-Open No. 2001-20188 Image 6 In the case of a structure as shown, the diameter of the core wire 92C and the core wire 96C is large

For this reason, there arises a problem that the weight of the steel cord 90 itself increases

In addition, since the rigidity of the steel cord 90 is increased, it is difficult to bend when manufacturing rubber products using a rubber crawler having the steel cord 90, and there is also a problem that it is necessary to manufacture without peeling at the seam.

In addition, when using wire wound on a bobbin of the same shape as the core wire and the sheath wire, the winding lengths are different due to the difference in diameter of the wire, so when using wires with different diameters, a wire with a smaller diameter may be generated. Problems such as margin (loss) and unprofitable cost increase

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