JPH1193088A - Single ply laid steel cord for reinforcing rubber and multiply laid steel cord for reinforcing rubber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject steel cord improved in rubber reinforcing performances, reliability and further durability together with cord characteristics by forming impression recessed parts at an interval in wires, laying the resultant wires, specifying the depth of the impression recessed parts and pitch and providing a compact cord. SOLUTION: This steel cord is composed by forming many impression recessed parts 2 (2a to 2c) in at least one wire at an interval kept in the longitudinal direction, laying the wire, providing communicating gaps into the interior of the cord with the respective impression recessed parts 2, regulating the ratio (w/d) of the depth (w) of the impression recessed parts 2 to the wire diameter (d) to 0.02-0.5 and regulating the ratio (p1/p) of the pitch p1 of the impression recessed parts 2 to the lay pitch (p) to 1-0.1, in the single ply laid steel cord for reinforcing rubber prepared by laying 3-6 wires 1 into the single ply.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber-reinforced single-layer twisted steel cord and a rubber-reinforced double-layer twisted steel cord suitable for reinforcing rubber of various tires and conveyor belts.

[0002]

2. Description of the Related Art Conventionally, a steel cord for rubber reinforcement applied to various tires, conveyor belts and the like is formed by twisting a plurality of (three in the illustrated example) strands a as shown in FIG. 3A, for example. A single-layer twisted steel cord for rubber reinforcement of a compact type, an inner layer a1 made of the steel cord as shown in FIG.
This is a compact type rubber-reinforced multi-layer twisted steel cord consisting of an outer layer b1 in which strands b) are twisted together, but when embedded in rubber, a space is formed inside the cord where the rubber does not penetrate and corrosion occurs. Recently,
A structure in which a plurality of strands are pre-molded and twisted, and a gap is formed between the strands to increase the rubber permeability, or the strands are formed in a wave or spiral shape and twisted, and twisted between strands An open type rubber cord for reinforcing rubber having a structure in which a gap is formed to enhance rubber permeability has been developed and proposed.
(Not shown)

[0003]

The conventional open type rubber cord for rubber reinforcement has a structure in which a gap is formed between the strands by being formed as described above, or formed into a wave shape or a spiral shape and twisted. As a result, the cord diameter becomes larger than that of the compact type shown in FIG. 3, the flexural rigidity decreases, and the cord elongation increases. There are problems in cord characteristics, rubber penetration reliability, durability, and the like, such as reduced cord shape retention and easy variation in shape.

SUMMARY OF THE INVENTION The present invention has been developed to solve the above-mentioned problems. The object of the present invention is to provide a large number of indented recesses in a wire and twist the wires so that the depth and the depth of the indented recess are reduced. It is an object of the present invention to provide a single-layer reinforced steel cord for rubber reinforcement and a multi-layer reinforced steel cord for rubber reinforcement, which are improved in rubber reinforcement performance, reliability and durability as well as cord characteristics by specifying a pitch or the like.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a single-layer rubber cord for reinforcing rubber in which three to six strands are twisted into a single layer. It is characterized by a rubber-reinforced single-layer stranded steel cord in which a gap is provided between the adjacent strands by means of each indentation recess, and a gap is formed between the strands and the adjacent strands. Even if an indented recess is provided, its strength and linearity are not significantly reduced and it is tightly twisted and compactly formed, almost the same cord diameter, bending rigidity, cord elongation and cord shape as a compact type steel cord In addition to the characteristics such as the shape accuracy and the like, the indentation recesses form a communication gap between the adjacent wires with high precision, and the rubber penetration over the entire inside of the cord is remarkably enhanced.

Further, the ratio w / d of the depth w of the indented recess and the wire diameter d is set to 0.02 to 0.5, and the ratio p1 of the pitch p1 of the indented recess and the twisted pitch p of the wire is set. / P is set to 1 to 0.1 to further improve the accuracy of forming the communication gap, the rubber permeability inside the cord, etc., and further enhance the cord characteristics, rubber reinforcement performance, reliability, etc. It has rubber reinforcement performance, reliability and durability as well as cord characteristics.

[0007] A rubber-reinforced multi-layer twisted steel cord comprising an inner layer in which three to six strands are twisted into a single layer, and an outer layer in which seven to twelve strands are twisted around the inner layer, At least one strand of the inner layer is twisted with a number of indented recesses at intervals in the length direction to provide a communication gap between the adjacent strands to the inside of the inner layer and at least a part of the strand of the outer layer. It features a multi-layered steel cord for rubber reinforcement with a communication gap to the inner layer between the layers, and the outer layer wires are twisted relatively tight around the inner layer which is tightly twisted and formed compactly. It can be formed compactly and has almost the same characteristics as the conventional compact type multi-layer stranded steel cord, such as cord diameter, bending stiffness, cord elongation, cord shape retention and shape accuracy, as well as the communication gap between the outer layer and the inner layer. Linking gap to by connexion inner inside each indentation recess is accurately formed, the rubber penetration property is remarkably enhanced over code inside throughout.

[0008] In the above-described rubber-reinforced double-layered steel cord, an outer layer wire is twisted around the inner layer in the same twisting direction, and a number of indentation recesses are provided in a part of the outer layer wire. Formed in a wave shape or spiral shape and twisted, characterized by providing a communication gap to the inner layer between adjacent strands of the outer layer, with the same twisting direction, and providing an indented recess in the strand of the outer layer Alternatively, by forming a corrugated shape or a spiral shape, a tighter and more compact cord is obtained, and the forming accuracy of the communication gap into the inner layer is further enhanced.

Further, the ratio w / d of the depth w of the indented recess provided in the inner layer or the outer layer wire to the wire diameter d is 0.02 to 0.02.
0.5, and the ratio p1 / p of the pitch p1 of the indented concave portion to the twisted pitch p of the strand is 1 to 0.1.
In addition, the accuracy of forming the communication gap between the inner layer and the inside of the inner layer and the rubber permeability are further enhanced, and the rubber reinforcing performance, reliability, etc., as well as the cord characteristics, are further enhanced.

Furthermore, the wire diameter d of the inner layer and the wire diameter d of the outer layer
It is characterized in that the ratio d / d1 of 1 is configured to be 1.05 to 1.25, and the accuracy of forming a communication gap to the inner layer and the inside of the inner layer, rubber reinforcement performance such as rubber permeability, reliability and the like are improved. In the multi-layer reinforced steel cord for rubber reinforcement,
It has rubber reinforcement performance, reliability and durability as well as overall excellent cord characteristics.

[0011]

FIG. 1A shows an embodiment of a single-layer twisted steel cord for rubber reinforcement of the present invention, FIGS. 1B to 1D show each embodiment of a double-layer twisted steel cord for rubber reinforcement, and FIG. Each Example of the provided indentation recessed part is shown. In the figure, 1 is a strand of a single-layer twisted steel cord or an inner strand of a multi-layer twisted steel cord, 2 (2a to 2c) are indented recesses provided in the strand, and 5 is a rubber reinforcement formed of the strand 1 Single-layer twisted steel cord, 5a is an inner layer using a rubber-reinforced double-layer twisted steel cord, 6 is an outer layer element wire, 6a is an outer layer, 6b is a corrugated or spiral shape formed on the element wire 6, d is an element wire 1, the wire diameter of d1 is the wire diameter of the wire 6, w is the depth of the indented concave portion,
p1 is an indentation recess pitch, 10a, 10b and 10c are double-layered steel cords for rubber reinforcement.

The illustrated embodiment is a single-layer rubber cord for reinforcing rubber in which three to six strands 1 are twisted into a single layer, and at least one strand 1 has a large number of indented recesses 2 (2).
a to 2c) are provided at intervals in the length direction and twisted,
A single-layer twisted steel cord 5 for rubber reinforcement is characterized in that a communication gap to the inside of the cord is provided between each indentation recess and the adjacent element wire 1 and the inside of the cord.

Further, in the above-described single-layer twisted steel cord for rubber reinforcement, an indentation recess 2 (2a, 2a) provided in the strand 1 is provided.
b, 2c), the ratio w / d of the depth w to the strand diameter d is 0.0
The ratio p1 / p of the pitch p1 of the indented recess and the twisting pitch p of the strands (not shown) is set to 1 to 0.5.
The single-layer twisted steel cord 5 for rubber reinforcement is characterized in that the cord is configured as described above.

Multilayer twist for rubber reinforcement comprising an inner layer 5a in which 3 to 6 strands 1 are twisted into a single layer, and an outer layer 6a in which 7 to 12 strands 6 are twisted around the inner layer. In a steel cord, a large number of indentation recesses 2 (2a to 2c) are provided in at least one element wire 1 of the inner layer at a lengthwise interval and twisted, and a communication gap between the adjacent element wires 1 to the inside of the inner layer is formed. In addition, a multi-layered steel cord 10a for rubber reinforcement is characterized in that a communication gap to the inner layer is provided between some of the wires 6 adjacent to the outer layer.

[0015] In the above-described double-strand rubber cord for reinforcing rubber, the wires 6 of the outer layer 6a are twisted around the inner layer 5a in the same twisting direction, and a large number of wires 6 are attached to at least a part of the wires 6 of the outer layer. Indentation recess 2 (2a-2)
c) is formed or formed into a wave shape or a spiral shape 6b and twisted, and a communication gap to the inner layer is provided between the adjacent wires 6 of the outer layer, and a rubber-reinforced double-layer twisted steel cord 10b, 10c.

Further, the ratio w / d of the depth w of the indented concave portion 2 (2a to 2c) provided in the wire 1 or 6 of the inner layer 5a or the outer layer 6a to the wire diameter d is 0.02 to 0.5. And the ratio p1 between the pitch p1 of the indented concave portion and the twisting pitch p of the element wire.
/ P is set to 1 to 0.1 to provide a rubber-reinforced double-layer steel cord 10a, 10b, 10c.

Further, the wire diameter d of the inner layer 5a and the outer layer 6
The ratio d / d1 of a to the wire diameter d1 is 1.05 to 1.25.
The rubber reinforced double-layer stranded steel cords 10a, 10b, 10c are characterized in that:

More specifically, a part of the inner wire 1 and a part of the outer wire 6 of the single-layer twisted steel cord for rubber reinforcement are:
As shown in FIG. 2, a number of indented concave portions 2 (2a, 2b, 2)
c) is provided by an indent roll (not shown) or the like. The indentation recesses 2 are provided at pitches p1 at intervals in the length direction of the element wire, and are formed in concave indentation recesses 2a, groove-shaped indentation recesses 2b, and conical indentation recesses 2c shown in FIGS. 2B to 2D. And, if necessary, in a plurality of rows as shown in FIG. 2A. Further, preferably, the indentation recess 2 (2a, 2b, 2)
The ratio w / d between the depth w and the wire diameter d in c) is 0.02 to 0.02.
In addition, the ratio p1 / p of the pitch p1 of the indented concave portion and the twisting pitch p (not shown) of the element wire 1 (or 6) is set to 1 to 0.1.

FIG. 1A is a typical example of the single-layer twisted steel cord for rubber reinforcement, which is a typical example of the single-layer twisted steel cord. The single-layer twisted steel cord for rubber reinforcement is obtained by twisting three strands 1 into a single layer. In the code, at least one strand 1
A number of indented recesses 2 (2a to 2c) are provided at intervals in the longitudinal direction and twisted, and a communication gap to the inside of the cord is provided between each indented recessed portion and an adjacent element wire 1 by each indented recess. I'm sorry. Since the indented concave portions 2 (2a to 2c) are formed as indented portions by pressing them moderately strongly by an appropriate means (not shown) such as an indent roll, there is no particular change in the cross-sectional area in the portion where the indented concave portions are formed. It does not have a special effect on characteristics such as strand strength, bending rigidity, and linearity. If necessary, a plurality of wires 1 or a plurality of wires 1 can be provided in a plurality of rows, and a plurality of (three in the illustrated example) wires 1 are tightly twisted to form a compact type steel cord. Excellent cord retention, bending rigidity, low cord elongation characteristics, etc. are obtained, which are almost the same as the compact type steel cords, and the indented recesses provided at intervals in the length direction enable the The gap connected to the center of the cord is formed with high precision, and when embedded in rubber, the rubber penetrates well into the cord and effectively prevents corrosion. The properties are significantly enhanced.

Further, in the rubber reinforcing single-layer stranded steel cord 5 described above, the ratio of the depth w of the indentation concave portion 2 (2a, 2b, 2c) provided in at least one strand 1 to the strand diameter d. w / d is set to 0.02 to 0.5, and the ratio p1 / p of the pitch p1 of the indented concave portion to the twisted pitch p of the strand is set to 1 to 0.1. At different wire diameters, a large number of single-layer reinforced steel cords for rubber reinforcement were manufactured by changing the depth w of the indented concave portion, the pitch p1 of the indented recesses, and the twisting pitch p of the wires, and embedded and tested in rubber. As a result, when the ratio w / d is set to 0.02 to 0.5, characteristics such as strength, bending deformation, and linearity of the strand are not particularly affected. Further, when the ratio p1 / p is configured to be 1 to 0.1, there is an effect that the rubber is well penetrated into the inside of the entire cord by the indented concave portions and no space remains inside when embedded in the rubber. confirmed. That is, it has been confirmed that, by specifying the value within the above numerical range, the above-mentioned excellent cord characteristics, rubber reinforcing performance, and reliability can be obtained.

Further, the single-strand rubber cord 5 for rubber reinforcement shown in FIG. 1A is constituted by three strands 1 and one strand is provided with an indented recess. In accordance with the above, various structures can be provided by using four to six strands as necessary, or by providing indentation recesses in a plurality of strands. It has been confirmed that the operation and effect as described above can be obtained even with such a configuration.

The rubber reinforced multilayer stranded steel cord shown in FIGS. 1B to 1D is a typical example of the rubber reinforced multilayer stranded steel cord. The rubber reinforced multilayer stranded steel cord 10a shown in FIG. A single-layer rubber cord 5 for reinforcing rubber shown in FIG. 1A is used as an inner layer 5a, and an inner layer 5a in which three wires 1 are twisted into a single layer, and nine wires 6 around the inner layer.
In a rubber-reinforced double-layered steel cord provided with an outer layer 6a, a number of indented recesses 2 (2a to 2c) are provided in a single wire 1 at intervals in the length direction, and twisted. A communication gap to the inside of the cord is provided between the adjacent wires 1 by each indentation concave portion, and a communication gap to the inner layer 5a is provided between at least a part of the wires 6 of the outer layer 6a. The communication gap can be easily formed by appropriately reducing the number of strands 6 as shown in the figure or by applying a small wire diameter.

The above-described rubber-reinforced double-layered steel cord 10a (see FIG. 1B) relatively tightly twists the strand 6 of the outer layer 6a around the tightly twisted and compactly formed inner layer 5a. It can be formed to be compact and has almost the same cord diameter, bending rigidity, cord elongation, cord shape,
Code characteristics such as shape accuracy are obtained, and the outer layer 6a
The communication gap to the inside of the inner layer is accurately formed by the communication gap of the inner layer 5a and the indented concave portions of the inner layer 5a, so that the rubber permeability is remarkably increased over the entire area of the cord, and the cord corrosion is effectively prevented.

Further, the rubber twisted multi-layer twisted steel cord 10b shown in FIG. 1C has a larger number of indentation recesses 2 (2a to 2c) in two strands 1 than the rubber reinforcing double-layered twisted steel cord 10a. ) Are provided at intervals in the length direction and twisted together, and the inner layer 5a and one strand 6 of the outer layer 6a are provided with a number of indented recesses 2 (2a to 2c) at intervals in the length direction and twisted. The structure is characterized in that a communication passage to the inner layer is further provided by the indented concave portion, and the other structure is basically the same as that of the multi-layer twisted steel cord 10a for rubber reinforcement. Due to the indented concave portion provided in the strand 6, communication with the inner layer is further improved, and rubber penetration into the inside is further enhanced. Basically, the same operation and effect as those of the rubber-reinforced double-layer stranded steel cord 10a can be obtained.

Further, the multi-strand rubber cord 10c for rubber reinforcement shown in FIG. 1D has a larger number of indentation recesses 2 () on the three strands 1 of the inner layer 5a than the single-strand steel cord 10b for rubber reinforcement. 2a to 2c) are provided at intervals in the longitudinal direction and twisted, and one strand 6 of the outer layer 6a is formed into a wave shape or a spiral shape 6b and twisted to form a strand 6
It is characterized in that the corrugated or spiral shape 6b and the indentation recesses provided in the three strands 1 of the inner layer 5a provide a communication passage to the inside of the inner layer. It is formed in the same manner as the layer-twisted steel cord 10b.
Further, the communication between the inner layer and the inner layer is further improved by the indented concave portions, and the rubber permeability is further enhanced. Basically, the same operation and effect as those of the rubber-reinforced double-layer stranded steel cord 10a can be obtained.

Further, in each of the rubber reinforced multi-layer stranded steel cords 10a, 10b, and 10c, the depth w of the indented concave portion 2 (2a, 2b, 2c) provided in the strands 1 and 6 and the strand diameter d are determined. The ratio w / d is set to 0.02 to 0.5, and the ratio p1 / p between the pitch p1 of the indented concave portion and the twisting pitch p (not shown) of the strand is set to 1 to 0.1. . When the ratio w / d and the ratio p1 / p are within the above numerical ranges, the same operation and effect as described above can be obtained. It has been confirmed that the rubber reinforcement performance and reliability as well as the cord characteristics are further improved, such as better rubber penetration throughout the cord.

In the above-described rubber-reinforced double-layered twisted steel cords 10a, 10b and 10c, an inner layer 5a is constituted by 4 to 6 strands 1 in addition to the illustration as necessary in accordance with the mode of rubber reinforcement. Or the outer layer 6a is composed of 7 to 12 strands 6, and the pressing recess is 2 (2a, 2b, 2c).
Alternatively, the number of the wires 1 and the wires 6 forming the wave shape or the spiral shape 6b may be further varied. It has been confirmed that the functions and effects of the above-described multi-layer reinforced steel cord for rubber reinforcement can be basically obtained even with such various configurations. Also, if necessary, the outermost layer is twisted around the outer layer to form a rubber reinforcement 3.
It can also be implemented as a layered steel cord.

[0028]

According to the present invention, there is provided the above-mentioned configuration,
A single layer twisted steel cord for rubber reinforcement in which up to six strands are twisted into a single layer, characterized in that at least one strand is provided with a number of indentation recesses at intervals in the length direction and twisted. Even if the indented recess is provided, it is tightly twisted and compactly formed without significantly reducing the strength and linearity of the wire, and the cord diameter, bending rigidity, cord elongation,
Cord characteristics such as cord shape retention and shape accuracy are effectively enhanced. In addition, a communication gap into the cord is formed with high accuracy between each pressing recess and the adjacent element wire,
Rubber penetration throughout the cord is significantly improved. Further, the ratio w / d of the depth w of the indented recess and the wire diameter d is set to 0.02 to 0.5, and the pitch p of the indented recess is set.
The ratio p1 / p of 1 to the twisting pitch p of the strand is 1 to 1.
By setting it to 0.1, the rubber characteristics, the rubber reinforcement performance, the reliability and the durability are remarkably improved as well as the cord characteristics, such as further improving the accuracy of forming the communication gap and the rubber permeability into the cord.

In the multi-layered steel cord for reinforcing rubber, the above-described single-layered steel cord for reinforcing rubber is used as an inner layer, and a communication gap to the inner layer is provided between a part of wires of the outer layer twisted around the inner layer. As a result, the wire is tightly twisted and compactly formed, similarly the cord characteristics are effectively enhanced, and the communication gap between the outer layer and the indentation recesses of the inner layer is accurately formed to the inside of the inner layer. As a result, the rubber permeability is remarkably increased throughout the cord. In addition, the outer layer wires are twisted in the same twisting direction around the inner layer to form a more compact,
A number of indentation recesses are formed in a part of the wire of the outer layer or formed into a wave shape or a spiral shape and twisted, and the communication gap to the inner layer is further increased, and the rubber penetration into the inner layer is further improved. . Further, the ratio w / d of the depth w of the indented recess and the wire diameter d is set to 0.02 to 0.5, and the ratio p1 / p of the pitch p1 of the indented recess and the twisting pitch p of the wire is set to 1 to 1.
0.1, and the ratio of the wire diameter of the inner layer to the wire diameter of the outer layer d /
By configuring d1 to be 1.05 to 1.25, the accuracy of forming the communication gap and the rubber permeability are further improved. The properties and the durability are remarkably improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view (A) showing one embodiment of a single-layer twisted steel cord for rubber reinforcement of the present invention, and each cross-sectional view (B) (B) showing each embodiment of a multi-layer twisted steel cord for rubber reinforcement. C)
(D)

FIG. 2 is a side view showing each embodiment of an indented concave portion provided in a strand (A), (B), (C), and (D).

FIG. 3 is a cross-sectional view (A) showing an example of a conventional single-layer reinforced steel cord for rubber reinforcement and a cross-sectional view (B) showing an example of a multi-layer stranded steel cord for rubber reinforcement.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Element wire 2 (2a-2c) Indentation concave part 5 Single-layer twisted steel cord for rubber reinforcement 5a Inner layer 6 Element wire (outer layer) 6a Outer layer 6b Wave shape or spiral shape (outer layer) 10a, 10b, 10c Multi-layer twist for rubber reinforcement Steel cord d Element diameter (inner layer) d1 Element diameter (outer layer) p Twisting pitch of element wire p1 Pitch of indented recess w Depth of indented recess

Claims (6)

[Claims] In a single-layer rubber cord for reinforcing rubber, in which three to six strands are twisted into a single layer, at least one strand is provided with a number of indented recesses at intervals in the length direction and twisted. In addition, a single-layer twisted steel cord for rubber reinforcement is characterized in that a communication gap to the inside of the cord is provided between each of the indented recesses and an adjacent element wire by an indented recess. 2. The single-layer twisted steel cord for rubber reinforcement according to claim 1, wherein a depth w of the indented recess provided in the strand is provided.
The ratio w / d of the wire and the wire diameter d is set to 0.02 to 0.5, and the ratio p1 / p between the pitch p1 of the indented recess and the twisted pitch p of the wire is set to 1 to 0.1. A single-layer twisted steel cord for rubber reinforcement, characterized by the following features: 3. A rubber-reinforced double-layered steel cord comprising an inner layer in which three to six strands are twisted into a single layer, and an outer layer in which seven to twelve strands are twisted around the inner layer. In the method, a number of indentation recesses are provided in at least one element wire of the inner layer at a longitudinal interval and twisted to provide a communication gap between the adjacent element wires of the inner layer to the inside of the inner layer and the adjacent layer of the outer layer. A multilayer twisted steel cord for rubber reinforcement characterized in that a communication gap to the inner layer is provided between the element wires. 4. The multilayer twisted steel cord for rubber reinforcement according to claim 3, wherein the wires of the outer layer are twisted around the inner layer in the same twisting direction, and a number of indentations are formed on some of the wires of the outer layer. A multilayer reinforced steel cord for rubber reinforcement, wherein a concave portion is provided or formed into a wave shape or a spiral shape and twisted, and a communication gap to an inner layer is provided between adjacent wires of an outer layer. 5. The double stranded steel cord for rubber reinforcement according to claim 3 or 4, wherein a ratio w / a of a depth w of an indented concave portion provided in an element wire of an inner layer or an outer layer and a element wire diameter d. d
Characterized in that the ratio p1 / p between the pitch p1 of the indented recess and the twisting pitch p of the strand is set to 1 to 0.1, and the multilayered twisted steel for rubber reinforcement is 1 to 0.1. code. 6. The rubber reinforced multi-layer twisted steel cord according to claim 3, 4 or 5, wherein the ratio d / d1 of the wire diameter d of the inner layer to the wire diameter d1 of the outer layer is 1. .0
A multi-layer reinforced steel cord for rubber reinforcement, characterized in that the cord is comprised of 5-1.25.