JPH06114974A - Fiber strip material with strip rubber cover for tire and production thereof - Google Patents

Abstract

PURPOSE:To prevent the damage of a cord even when a wide fiber strip material with a strip rubber cover is cut in the fiber direction with a slit knife. CONSTITUTION:A fiber strip material with a strip rubber cover 7 is constituted of a cord group 7a as a fiber strip material formed only from warp yarns and the rubber cover material 7b covering the cord group 7a and the weaving width of the cord group 7a is formed from two or more spans when one span is 1/10-1/20 the width of a steel breaker and at least two ultrahigh strength fiber cords 72 are arranged to the boundary part of the respective spans and usual strength fiber cords 71 are arranged in one span held between the ultrahigh strength fiber cords 72. As the ultrahigh strength fiber cord 72, a blended twist product of an aromatic polyamide fiber and a nylon fiber is employed. The ultrahigh strength fiber cord 72 and the usual strength fiber cord 71 are produced so as to have almost equal elongation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt-shaped rubber-attached fiber belt for reinforcing a tire of an automobile.

[0002]

2. Description of the Related Art An automobile tire is basically composed of rubber and various reinforcing materials to be installed therein. Particularly in the case of radial tires, a steel breaker is annularly mounted as a reinforcing material inside the tread portion.
In recent years, along with the increase in high-speed driving performance of automobiles, in addition to providing high-speed stability to the tire, in order to make the tire even stronger, a ring is formed along the outer peripheral surface of the steel breaker having the above ring shape. A fibrous strip is wrapped around. By doing this, the binding force in the circumferential direction of the tread portion is increased, and the tire dimensions are stabilized,
In addition, it is said that it will greatly contribute to improving the maneuverability and running stability of the automobile.

Usually, the above-mentioned fibrous belt is a cloth-like body in which cords made of synthetic fibers such as rayon, nylon or polyester are used as warps, and the force acting mainly only in the extending direction of the fibers is taken into consideration. The weft is not used because it is present. Therefore, in order to stabilize the state in which a large number of cords are arranged in parallel, the fiber strip is covered with rubber to form a fiber strip with rubber. Then, such a fiber-belt with rubber strip is wound around the outer peripheral surface of the annular steel breaker.

[0004] Such a fiber band with rubber is drawn out so that the cords mounted on a large number of reel stands are aligned in parallel with each other, and the molten rubber is supplied toward the cords aligned in parallel. Manufactured by.

Usually, the fiber band with rubber is formed into a plurality of spans, each span of which is 1/10 to 1/20 of the width of the steel breaker, and the plurality of spans are cut in the fiber extending direction to form a unit rubber. A fiber strip with an attached rubber, and this fiber strip with a unit rubber is actually spirally wound around the outer peripheral surface of the steel breaker.

[0006]

By the way, the fiber-rubber strip with a unit rubber as described above is manufactured by once producing a wide fiber-rubber strip with a rubber and cutting it into a plurality of fibers in the fiber direction. Since a slit knife is usually used for cutting, the cord made of synthetic resin is damaged at the tip of this knife, and in the worst case, the cord is often cut. Then, when the cord is cut, there has been a problem that the stress in the longitudinal direction of the unit strip with fiber rubber becomes non-uniform and the quality is deteriorated.

There is also a strong demand for the rubber-coated fiber band itself to be tougher.

The present invention has been made in order to solve the above problems, and provides a fiber band body with a rubber band for tires which is tougher than conventional ones, and has a wide rubber band. It is an object of the present invention to provide a method for producing a fiber-shaped belt strip with a rubber band for a tire, which does not damage the cord even if the fiber strip with a fiber is cut in the fiber direction.

[0009]

According to a first aspect of the present invention, there is provided a belt-shaped rubber-coated fiber belt for a tire, which is disposed on an outer peripheral surface of a steel breaker installed in a tire. However, this rubber-attached fiber strip has a large number of organic fiber cords arranged side by side, and at least one super-strength fiber cord is disposed on both sides thereof, and an organic fiber strip, It is characterized in that it is constituted by a rubber-made covering body which covers a part or all of the surface.

According to a second aspect of the present invention, there is provided a belt-shaped rubber-coated fiber belt for a tire according to the first aspect, wherein the super-strength fiber cord is an aromatic polyamide fiber and a nylon fiber. It is characterized in that a mixed twisted product with is used.

According to a third aspect of the present invention, there is provided a belt-shaped rubber-coated fiber belt for tires, wherein the super-strength fiber cord and the normal-strength fiber cord are the same as those of the first or second tire belt-shaped rubber-coated fiber belt. It is characterized in that it is prepared so as to have substantially the same elongation.

According to a fourth aspect of the present invention, there is provided a method for producing a belt-shaped rubber-coated fiber belt for a tire, which is arranged on an outer peripheral surface of a steel breaker installed in the tire. While a plurality of bundles of super-strength fiber cords consisting of at least two at a predetermined interval are interposed between a large number of organic fiber cords arranged side by side, at least one on both sides of the fiber belt. The super-strength fiber cord is arranged to form a fiber band, and a part or all of this fiber band is coated with rubber to form a fiber band with rubber.
A unit rubber-equipped fiber strip is obtained by cutting the rubber-provided fiber strip at the bundle portion of the super-strength fiber cord so that the super-strength fiber cord is separated into right and left.

According to a fifth aspect of the present invention, there is provided a method for producing a fiber strip with a rubber band for a tire according to the method for producing a fiber strip with a rubber band for a tire according to the fourth aspect, wherein the super-strength fiber cord is aromatic. It is characterized in that a mixed twisted product of a system polyamide fiber and a nylon fiber is used.

According to a sixth aspect of the present invention, there is provided a method for producing a fiber strip with a rubber band for a tire according to the method for producing a fiber strip with a rubber band for a tire according to the fourth or fifth aspect, wherein: The normal strength fiber cord is characterized by being prepared so as to have substantially the same elongation.

[0015]

According to the fiber strip with rubber band for tires of the above-mentioned claim 1, the rubber fiber strip has a large number of organic fiber cords arranged in parallel and at least one super-strength fiber cord on both sides thereof. Both sides of the organic fiber band, which are easily scratched by external force, because they are composed of the arranged organic fiber band and a rubber coating that covers part or all of the surface of the organic fiber band. The part is protected by the super-strength fiber cord, and the organic fiber cord is reinforced by the amount of the super-strength fiber cord used. Become tough.

According to the fiber strip with a rubber band for tires of the above-mentioned claim 2, the super-strength fiber cord is a mixed twist product of aromatic polyamide fiber and nylon fiber. In comparison, its strength is remarkably high, and damage by the blade edge of the knife during division is effectively suppressed.

According to the fiber strip with a rubber band for tires of the third aspect, the super-strength fiber cord and the normal-strength fiber cord have substantially the same elongation in the elongation range required during the manufacturing process. Since it is prepared so as to have, the elongation in the fiber direction of the unit band with the unit rubber due to the external force is uniform in the width direction, the internal stress caused by the imbalance of the elongation does not occur, and the durability of the tire is consequently increased. improves.

According to the method for producing a fiber-shaped belt-like body with a rubber band for tires according to claim 4, at least two high-strength super-strength fiber cords are arranged at a boundary portion of a plurality of fiber-like belt bodies with a unit rubber. Has been done. Therefore, even if the cutting edge of a slit knife is cut between adjacent super-strength fiber cords and cut in the fiber direction, since the super-strength fiber cord is extremely tough, it is damaged or cut at the knife edge. As a result, it is possible to obtain a uniform fibrous band with unit rubber.

According to the method for producing a fiber strip with a rubber band for tires according to claim 5, since the super-strength fiber cord is a mixed twist product of aromatic polyamide fiber and nylon fiber, the ordinary strength of the surroundings is high. Its strength is remarkably stronger than that of the fiber cord, and damage by the cutting edge of the knife during division is effectively suppressed.

According to the method for producing a fiber strip with a rubber band for tires as set forth in claim 6, the super-strength fiber cord and the normal-strength fiber cord are substantially equal to each other in the elongation range required during the manufacturing process. Since it is prepared so as to have an elongation, the elongation in the fiber direction of the unit band with the unit rubber due to an external force is uniform in the width direction, and internal stress caused by the imbalance of elongation does not occur, and as a result, the tire The durability is improved.

[0021]

EXAMPLE FIG. 1 is a cross-sectional view showing an example of a tire in which a belt-shaped rubber-attached fiber belt body for a tire according to the present invention is installed. As shown in this figure, a tire 1 includes a tread portion 11 that is a portion that directly contacts a road surface, sidewall portions 12 that form left and right sidewalls, and a bead portion 13 that is a portion that is fixed to a rim 2 of a wheel. , A carcass 3 made of a cord layer coated with rubber and uniformly attached to the inner surface of the tire 1.

Inside the bead portion 13, a so-called bead 13a, in which bead wires made of a metal cord are aligned and wound and covered with rubber, is embedded so that the strength of this portion is increased to the rim 2 of the tire 1. The joint is made strong. In addition, a tread pattern having irregularities is formed on the surface of the tread portion 11 to contribute to the improvement of the running performance of the automobile.

Inside the tread portion 11 of the tire 1 as described above, the steel breaker 5 is annularly formed in the circumferential direction of the tire 1.
Is buried. This steel breaker 5 is a steel cord arranged in parallel with rubber coating.
The steel breaker 5 is often used for high-performance tires that are compatible with recent speed increases.

A band layer 6 is formed on the upper surface of the steel breaker 5 in an annular shape. The band layer 6 is made of a band-shaped fiber band with rubber, and its width is 1/10 to 1/20 of the width of the steel breaker 5. The band layer 6 is formed by winding the rubber-attached fiber strip around the outer peripheral surface of the steel breaker 5 a plurality of times. The formation of the band layer 6 ensures that the steel breaker 5 is embedded and held in the tread portion 11. ,
The strength of the tire 1 is further increased.

FIG. 2 is an enlarged perspective view of a belt-shaped rubber-coated fiber belt used for forming the band layer 6 as described above. As shown in this figure, the fibrous strip 7 with a rubber strip is
The normal strength fiber cord 71 and the super-strength fiber cord 72 are composed of a cord group 7a as a fiber band formed only by warp yarns, and a covering body 7b in which the cord group 7a is covered with rubber. No weft is used for the cord group 7a.

The weaving width of the above-mentioned fiber-shaped belt-like body 7 with rubber-like belt is 1/10 to 1/20 of the width of the steel breaker 5.
Is defined as one span, and at least two super-strength fiber cords 72 are arranged at the boundary of each span. The normal-strength fiber cords 71 are arranged within one span held by the super-strength fiber cords 72. In this example, the super strength fiber cord 7
Two end portions of the two are one, and two intermediate portions are provided. The number of normal strength fiber cords 71 arranged side by side in one span is not particularly limited, and superstrength fiber cords 72 are arranged at both ends according to the required width of one span.

As the normal strength fiber cord 71, a nylon filament, a polyester filament, a vinylon filament or the like having an elastic modulus of 1000 kg is used.
/ Mm ² or less, preferably 700 kg / mm ² or less is suitably used, but in the present embodiment, 66 nylon filament is usually used as the base material as the strength fiber cord 71. A plurality of the filaments are twisted to form the normal strength fiber cord 71. The thickness of the normal strength fiber cord 71 is set to 840 to 1680 denier.

As the super-strength fiber cord 72, aromatic polyamide filaments, wholly aromatic polyester filaments, polyvinyl alcohol filaments having a strength of 15 g / d or more, or carbon fibers have an elastic modulus of 1000 kg / mm ² or more. , Preferably 1500 kg / m
Although m ² or more is preferably used, in the present embodiment, a filament made of an aromatic polyamide and 66 nylon are used as the super-strength fiber cord 72, and a hybrid made of a mixed twisted product of the filament and the nylon filament is particularly used. Code is being used. The thickness of the super-strength fiber cord 72 is also 840 to 16 similarly to the normal-strength fiber cord 71.
It is set to 80 denier.

The reason why a mixed twisted product of an aromatic polyamide filament and a 66 nylon filament is used as the super strength fiber cord 72 is that the super strength fiber cord 72 is used only when the aromatic polyamide filament is used. This is because the elongation of No. 1 is extremely smaller than that of the normal strength fiber cord 71, and the elongation becomes non-uniform, so that it is avoided by mixing twisting.

The number and thickness of each filament are appropriately selected so that the super-strength fiber cord 72 and the normal-strength fiber cord 71 have substantially the same elongation, and the super-strength fiber cord is spun by twisting them. 72 has been prepared.

These normal strength fiber cords 71 are juxtaposed between the super-strength fiber cords 72 as warp yarns and covered with rubber to form a cover 7b. A body 7 is formed. A unit strip-shaped rubber-coated fiber strip 70 is formed between one span of the strip-shaped rubber-coated fiber strip 7, that is, a pair of super-strength fiber cords 72 sandwiching the normal-strength fiber cord 71.

However, in the present embodiment, a mixed twist product of a 66 nylon filament and an aromatic polyamide filament is used as the super strength fiber cord 72, but the super strength fiber cord 72 of the present invention is 66 nylon. The twisted yarn is not limited to the mixed twisted product of the filament made of aromatic polyamide and the filament made of aromatic polyamide, and twisted yarn of only the filament made of aromatic polyamide may be used.

Since the fiber-shaped strip with rubber 7 of the present invention is constructed as described above, in order to use it as the band layer 6 of the tire 1, as shown in FIG. The slit knife 8 is inserted into the portion of the super-strength fiber cord 72 of the disposed belt-shaped rubber-coated fiber strip 7 and the portion is cut along the cord. that way,
A plurality of unit band-shaped rubber-coated fiber bands 70 are obtained from one band-shaped rubber-coated fiber band 7, and the unit band-shaped rubber-coated fiber band 70 is wound around the surface of the steel breaker 5 in an annular shape. The band layer 6 is formed.

Further, in the present invention, since the extremely tough super-strength fiber cord 72 as described above is used at the portion of the fiber strip 7 with the strip rubber to be cut by the slit knife 8, the slit knife 8 is used. Therefore, the super-strength fiber cord 72 is not scratched or cut, and as a result, the unit belt-shaped rubber band 70 with stable quality is obtained, which is convenient.

[0035]

As described above, the fiber strip with rubber band for tire of the present invention is composed of the fiber strip formed by only the warp and the rubber coating coated with the fiber strip, The woven width of the fiber strip is formed by a plurality of spans with the width of the steel breaker as one span, at least two super-strength fiber cords are arranged at the boundary portion of each span, and on both sides of the fiber strip. Since at least one super-strength fiber cord is disposed and the normal-strength fiber cord is disposed within one span sandwiched between these super-strength fiber cords, a slit knife is provided between adjacent super-strength fiber cords. Even if you cut the blade edge of and cut it in the direction of the fiber,
The super-strength fiber cord is extremely tough, and it is convenient that it is not damaged or cut by the cutting edge of a knife, and as a result, a homogeneous fiber band with unit rubber can be obtained.

If the above super-strength fiber cord is prepared as a mixed twist product of aromatic polyamide fiber and nylon fiber,
The strength is much stronger than the surrounding normal strength fiber cord, and damage by the blade edge of the knife during division is effectively suppressed.

Further, if the super-strength fiber cord and the normal-strength fiber cord are prepared so as to have substantially the same elongation, the elongation in the fiber direction of the unit band with the unit rubber by the external force becomes uniform in the width direction. In addition, the internal stress caused by the imbalance of elongation does not occur, and the durability of the tire can be improved. As a result, the tire lasts longer and is economically advantageous.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a tire in which a fibrous strip with rubber band for tire according to the present invention is embedded.

FIG. 2 is a perspective view showing an example of a fiber-shaped band body with a rubber band.

FIG. 3 is a perspective view exemplifying a state in which a unit belt-shaped fiber-belt with rubber is manufactured by dividing the belt-shaped with rubber-band.

[Explanation of symbols]

 1 Tire 11 Tread Part 12 Sidewall Part 13 Bead Part 13a Bead 2 Rim 3 Carcass 5 Steel Breaker 6 Band Layer 7 Fiber Strip with Rubber Band 7a Cord Group 7b Cover 70 Unit Fiber Belt with Unit 71 Rubber Nylon Cord 72 Ultra Strength fiber cord 8 slit knife

Claims (6)

[Claims] 1. A belt-shaped fiber band with rubber for a tire, which is disposed on the outer peripheral surface of a steel breaker installed in a tire, wherein the fiber band with rubber has a large number of organic fiber cords arranged in parallel. At least one super-strength fiber cord is disposed on both sides of the organic fiber strip, and a rubber coating covering a part or all of the surface of the organic fiber strip. Characteristic fiber strip with rubber strip for tires. 2. The fiber strip with a rubber band for a tire according to claim 1, wherein a mixed twist product of aromatic polyamide fiber and nylon fiber is used as the super-strength fiber cord. 3. The fiber strip with a rubber band for tire according to claim 1, wherein the super-strength fiber cord and the normal-strength fiber cord are prepared so as to have substantially the same elongation. . 4. A method for manufacturing a fiber strip with a rubber band for a tire, which is arranged on the outer peripheral surface of a steel breaker installed in a tire, wherein a predetermined interval is provided between a plurality of organic fiber cords arranged in parallel. In addition to interposing a plurality of bundles of at least two super-strength fiber cords, at least one super-strength fiber cord is arranged on both sides of the fiber strip to form a fiber strip. By covering a part or all of the body with rubber to form a fiber band with rubber, and cutting the fiber band with rubber by separating the super strength fiber cords into left and right parts at the bundle of the super strength fiber cords. A method for producing a belt-shaped rubber-coated fiber belt for a tire, comprising obtaining a unit rubber-backed fiber belt. 5. The method for producing a fiber strip with a rubber band for a tire according to claim 4, wherein a mixed twist product of aromatic polyamide fiber and nylon fiber is used as the super-strength fiber cord. 6. The fiber strip with a rubber band according to claim 4, wherein the super-strength fiber cord and the normal-strength fiber cord are prepared so as to have substantially the same elongation. Manufacturing method.