JPH0545089U - Steel cord - Google Patents

Abstract

(57) [Summary] [Purpose] Moderately reduce the wire contact area between the wires, enhance the penetration of plastics, prevent cord rusting, effectively reduce wire wear, and bend fatigue characteristics. , To provide a steel cord having improved compression fatigue characteristics and life. [Structure] In a steel cord formed by twisting two strands (1, 2 or 1a, 2a), at least one strand (2 or 1a, 2a) is rolled to form a rectangular cross section (h , W or ha, wa), and in the steel cord, one strand 2 is rolled to obtain a size ratio of 0.90 to 0.50 of short side h and long side w. The steel cord is characterized in that it is formed in a rectangular shape (h, w) in cross section, and in the steel cord, two strands 1a, 2a are cross-sections having a size ratio of 0.90 to 0.65 of short side and long side, respectively. It is characterized in that it is formed in a rectangular shape (ha, wa).

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a steel cord suitable as a reinforcing material for rubber, that is, a plastic for tires and belts of various automobiles.

[0002]

[Prior Art]

 Steel cords embedded in the plastics of passenger tires (carcass, etc.) as reinforcing materials are required to have excellent bending fatigue properties and compression fatigue properties at the same time as tensile strength. In addition to the compression fatigue characteristics, it directly affects the penetration of plastics into the cord. The penetration of plastics prevents rusting of the cord due to moisture ingress during running, improves the service life, and improves fretting. It also contributes to the improvement of bending fatigue properties and compression fatigue properties associated with the ing phenomenon (wear). The conventional 1 × 2 steel cord has a simple structure in which two strands of wire are twisted together, and it has the characteristics described above and tends to be used more frequently than other structures.

[0003]

[Problems to be solved by the device]

 The conventional 1 × 2 steel cord has relatively excellent properties as described above, but the wire contact portions between the wires and the non-penetration portion of the plastic are formed over the entire length of the wire. Therefore, there are problems such as rusting of cords, abrasion of wires, that is, bending fatigue characteristics and compression fatigue characteristics due to fretting phenomenon, and shortening of life.

The present invention was developed in order to address the above-mentioned problems, and the purpose of the present invention is to reduce the wire contact area between the strands to a reasonable degree and to infiltrate the plastic material. The purpose of the present invention is to provide a steel cord which improves the bending fatigue property, compression fatigue property and life by improving cord fatigue, preventing cord rusting, and effectively reducing wire wear.

[0005]

[Means for Solving the Problems]

 In the present invention, in a steel cord formed by twisting two strands, at least one of the strands is rolled to form a rectangular cross section, thereby forming an appropriate gap between the strands. The wire contact area between the strands is moderately reduced and the penetration of plastics is enhanced. Further, in the above steel cord, one of the strands is rolled to form a rectangular cross section with a size ratio of the short side to the long side of 0.90 to 0.50, or each of the two strands is made short. By forming the rectangular shape in cross section with the size ratio of the side to the long side of 0.90 to 0.65, the gap between the strands is formed and the reliability thereof is further enhanced.

[0006]

[Action]

 In a steel cord formed by twisting two strands together, at least one of the strands is rolled to form an appropriate gap between adjacent strands by a smooth section with a rectangular cross section. , The wire contact area between the wires is moderately reduced, the friction or wear between the wires is reduced without causing a significant decrease in the bending rigidity of the cord, and the infiltration of plastics into the cord is effective. To prevent cord corrosion, extend the service life, and effectively reduce the accompanying wear, and obtain excellent bending fatigue properties and compression fatigue properties. Further, in the above steel cord, one wire is rolled to form a rectangular cross section with a size ratio of the short side to the long side of 0.90 to 0.50, or two wires are respectively formed. By forming a rectangular cross-section with a size ratio of the short side to the long side of 0.90 to 0.65, the gap between the wires is formed and its reliability is further enhanced.

[0007]

【Example】

 FIG. 1 is a first embodiment of the steel cord of the present invention, FIG. 2 is a second embodiment of the same, FIG. 3 is an example of a wire drawing machine for processing the steel cord, and FIG. 4 is a strand of the steel cord. An example of an apparatus is shown. The first embodiment shown in FIG. 1 is a steel cord formed by twisting two strands 1 and 2, in which one of the strands 1 and 2, that is, the strand 2 is rolled to form a short side. The steel cord has a rectangular cross section (h, w) consisting of h and a long side w. Further, in the steel cord, one of the strands 1 and 2, that is, the strand 2 is rolled to form a rectangular cross section (h, w with a size ratio of 0.90 to 0.50 of short side h and long side w). ) It has become a steel cord formed.

In the second embodiment of FIG. 2, in a steel cord formed by twisting two strands 1a, 2a, two strands 1a, 2a are rolled to obtain short sides ha and long sides wa. The steel cord has a rectangular cross section (ha, wa). Further, in the steel cord, two wires 1a and 2a are respectively rolled to form a rectangular cross section (ha, wa) with a size ratio of 0.90 to 0.65 between the short side ha and the long side wa. It has become a steel cord.

The steel cord of each of the above-described embodiments is manufactured by, for example, the wire drawing machine shown in FIG. 3 and the twisting wire machine shown in FIG. That is, in the wire drawing machine shown in FIG. 3, each of the wires 1, 2, 1 a, 2 a is drawn out from the supply bobbin 10 and is drawn by the wire drawing device 12 via the guide roller 11 and then the capstan 13 is drawn. It is rolled (rolled wires 2, 1a, 2a) by a rolling roll 14 via a guide roller 15 and wound on a winding bobbin 16 via a guide roller 15. Further, the drawn (and rolled) processed wires 1, 2, 1a, 2a are fed from the two supply bobbins 16a in the stranded wire machine of FIG. 4, and are guided by the guide roller 17 and the measuring roller 18. After passing through the tensioning device 19, the strands are attached to each strand by the attachment device 20 under a constant tension. The squeezing is adjusted by adjusting the diameter and spacing of the pins of the squeezing device in accordance with the twisted shape of each wire.

Next, each of the strands that have been stiffened next is twisted into a desired cord shape through the strand collecting device 21, the first twist turn roller 22, and the second twist turn roller 23, and the OT device 24, It is wound on the winding bobbin 27 through the capstan 25 and the guide roller 26, and is manufactured into a steel cord formed by twisting the two wires 1, 2 or the wires 1a, 2a.

[0011]

[Table 1]

Each of the samples shown in Table 1 is a steel cord manufactured by twisting the cord twist length (twist pitch) in the same S direction with a twist length of 14.0 mm. A structure formed by twisting two circular strands (circular cross section), Examples 1 to 3 and Comparative Examples 1 and 2 are one circular strand (circular cross section) and one rectangular strand (cross section rectangular). Shapes) are formed by twisting, and Examples 4, 5 and Comparative Examples 3 to 5 are structures formed by twisting two rectangular element wires (rectangular cross section), and steel cords thereof. Bending fatigue properties, compressive fatigue properties and bending stiffness of the rubber composites of above were tested, and the results as shown were obtained.

The steel cord of the present invention is a steel cord formed by twisting two strands of wire together and rolling one strand 2 to form a rectangular cross section (h, w) (Fig. 1)), or two strands 1a, 2a each rolled to form a rectangular cross section (ha, wa) (see FIG. 2). 1 and 2 respectively, an appropriate gap is formed between the adjacent strands by each smooth portion having a rectangular cross section formed on the strand 2 or 1a, 2a. The line contact area between the wires is reduced moderately, and the decrease in the line contact area reduces the friction or wear between the wires without causing a significant decrease in the bending rigidity of the cord and forms the gap between them. Effectively increases the penetration of plastics into the cord. The cord corrosion is prevented, the life is extended, and the accompanying wear is effectively reduced, and excellent bending fatigue characteristics and compression fatigue characteristics are obtained (see Examples 1 to 5).

Further, the steel cord of the present invention is obtained by rolling one of two strands of wire to form a rectangular cross section (h, w) having a size ratio of 0.90 to 0.50 of the short side h and the long side w. Or a structure in which two strands of wire are formed in a rectangular cross section (ha, wa) with a size ratio of 0.90 to 0.65 between the short side ha and the long side wa, respectively. As is clear from Table 1, when the size ratio of the short sides h, ha and the long sides w, wa of the cross-sectional shape of the strand exceeds 0.90, the smooth part is almost lost and the gap between the strands is small. Formation, improvement of wire contact between wires, that is, improvement of bending fatigue property and compression fatigue property of steel cord can hardly be expected, and when the size ratio of the short side and the long side is decreased, the bending rigidity is If the allowable limit is set to 80% or more and only one wire has a rectangular cross section (h, w), When the size ratio is 0.50 or more and only two strands have a rectangular cross section (ha, wa), the size ratio is preferably limited to 0.65 or more.

[0015]

[Effect of the device]

 The present invention has the above-described structure, and in a steel cord formed by twisting two strands together, a smooth portion having a rectangular cross section formed by rolling at least one of the strands, An appropriate gap is formed between the adjacent wires, and the wire contact area between the wires is also moderately reduced, so that the friction or wear between the wires does not cause a significant decrease in the bending rigidity of the steel cord. In addition, the penetration of plastics into the cord is effectively enhanced, cord corrosion is prevented, the life is extended, and the accompanying wear is effectively reduced, and bending fatigue characteristics and compression fatigue characteristics are improved. And the life is improved.

Further, in the above steel cord, one strand is rolled to form a rectangular cross-section with a short side to long side size ratio of 0.90 to 0.50, or two strands. Are formed in a rectangular cross section with a size ratio of 0.90 to 0.65 for the short side and the long side, respectively, to further improve the reliability of the gap formation between the wires.

[Brief description of drawings]

FIG. 1 is a side view and a sectional view of various parts showing a first embodiment of the present invention.

FIG. 2 is a side view showing a second embodiment of the present invention and a mechanical view of each section.

FIG. 3 is a side view mechanism diagram of a wire drawing machine for drawing and compressing the steel cord of the embodiment.

FIG. 4 is a side view mechanism diagram of the steel cord stranding machine of the embodiment.

[Explanation of symbols]

 1,1a, 2,2a strand h, ha short side w, wa long side (h, w) (ha, wa) rectangular cross section

Claims (3)

[Scope of utility model registration request] 1. A steel cord formed by twisting two strands together, wherein at least one of the strands is rolled to form a rectangular cross section. 2. A steel cord formed by twisting two strands together, one of the strands being rolled into a rectangular cross section with a size ratio of the short side to the long side of 0.90 to 0.50. A steel cord characterized by being formed. 3. A steel cord formed by twisting two strands together, wherein each of the strands has a rectangular cross-section with a size ratio of 0.90 to 0.65 between the short side and the long side. A steel cord that is characterized.