JPH10217352A - Production of reinforcing material for belt layer and production of pneumatic radial tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously mold a reinforcing material made of crushed spiral tube in an industrial production scale. SOLUTION: Strip materials (a) formed by lining a plurality of arranged reinforcing cords (f) with unvulcanized rubber are supplied to nip rollers 4 from a supply rollers 3a and the nip rollers 4 are rotated around the axis being the supply direction of the strip materials (a) to mold the strip materials (a) on the supply side into a spirally wound tube (b) which is, in turn, flatly crushed by the nip rolls 4 to be molded into a strip-like reinforcing material (c).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a reinforcing material for a belt layer used for a belt layer of a pneumatic radial tire and a method of manufacturing a pneumatic radial tire using the reinforcing material. The present invention relates to a method of manufacturing a reinforcing material for a belt layer and a method of manufacturing a pneumatic radial tire, which efficiently form a reinforcing material for a belt layer based on a spiral tube on an industrial scale.

[0002]

2. Description of the Related Art In general, a belt layer of a pneumatic radial tire is formed by bias-cutting a belt-shaped body calendered so that a plurality of aligned reinforcing cords are impregnated with unvulcanized rubber. The strip is joined in the width direction and wound up as a long belt material, pulled out at the time of green tire molding, cut to the length of the belt layer, and spliced so that the ends partially overlap, and the outer periphery of the carcass layer To be wrapped around.

[0003] In the belt layer thus formed, cut ends of the reinforcing cord are formed at both end portions, and separation of the rubber and the edge portion of the reinforcing cord is easily caused by stress concentration on the cut end. The problem becomes more pronounced at higher speeds, so that high-speed durability is poor. As a countermeasure, the present inventors made a spiral tube once wound spirally from a rubberized calender material of a plurality of aligned reinforcing cords, and flattened and squashed the reinforcing material in the tire circumferential direction. It has been found that by forming the belt layer by spirally winding it a plurality of times, there is no cut end of the reinforcing cord at the end of the belt layer, and a pneumatic tire having excellent edge separation resistance can be obtained.

However, a technique for manufacturing the above-mentioned reinforcing material obtained by crushing the spiral tube on an industrial production scale has not yet been established, and this has hindered the productivity of such excellent pneumatic tires. Was.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a reinforcing material for a belt layer, which enables the above-mentioned reinforcing material obtained by crushing the spiral tube to be continuously formed on an industrial production scale. Another object of the present invention is to provide a method for manufacturing a pneumatic radial tire using the above-mentioned reinforcing material for a belt layer.

[0006]

A method of manufacturing a reinforcing material for a belt layer according to the present invention, which achieves the above object, comprises a method of producing a strip material obtained by rubberizing a plurality of aligned reinforcing cords with unvulcanized rubber from a supply roller to a nip roller. The nip roller is rotated around the supply direction of the strip material as an axis to form the strip material on the supply side into a spiral wound spiral tube, and the spiral tube is crushed flat by the nip roller. It is characterized by being formed into a belt-like reinforcing material.

Further, in the method of manufacturing a pneumatic radial tire according to the present invention, the reinforcing material obtained by the above-described manufacturing method is continuously wound spirally in the tire circumferential direction a plurality of times around the outer periphery of the carcass layer to form a belt layer. It is characterized by forming. In forming the belt-like reinforcing material used for the belt layer in this manner, while supplying a strip material obtained by rubberizing a plurality of alignment reinforcing cords with unvulcanized rubber to the nip roller, the nip roller is moved in the strip material supply direction. By rotating as a shaft, the strip material is formed into a spiral-wound spiral tube and crushed flat, so that a belt-shaped reinforcing material can be efficiently formed on an industrial production scale.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an example of an apparatus for implementing the method for producing a reinforcing material for a belt layer according to the present invention. Reference numeral 1 denotes a calender device for forming a strip material a by impregnating a plurality of aligned reinforcing cords f with unvulcanized rubber supplied from a rubber tube 2, and 3 denotes a strip material a obtained by the calender device 1 with arrows. This is a supply device provided with a pair of left and right supply rollers 3a for sending out at a constant speed to the downstream side shown. The supply device 3 spirally winds a strip material a around a pair of left and right nip rollers 4.
The nip roller 4 flatly crushes the spiral tube b to form a belt-shaped reinforcing material c, and then winds the spiral tube b around the winding drum 6.

The nip roller 4 and the take-up drum 5 are both supported in a rotary frame 6, which is rotatably supported by a support frame 7 via a rotary shaft 8 and driven by a motor 9. It is designed to be driven to rotate about the rotation shaft 8. The nip roller 4 and the winding drum 5 are driven to rotate by a motor 10, and the winding drum 5 traverses left and right by a drive source (not shown) so that the reinforcing material c is evenly wound on the winding drum 5. It has become.

The support frame 7 is reciprocally movable along the supply direction of the strip material a, so that the relative distance between the supply device 3 and the nip roller 4 can be changed. By using the above-described device, the reinforcing material c for a belt layer for a pneumatic radial tire can be manufactured as follows.

While the unvulcanized rubber extruded from the rubber tube 2 is rubberized into the alignment reinforcing cords f in which a plurality of them are aligned in parallel with each other by the calender device 1, the strip material a is continuously formed. The nip roller 4 and the take-up drum 5 are rotated while rotating the rotary frame 6 about the rotary shaft 8 by driving the motors 9 and 10. A nip roller 4 that rotates the strip material a formed by the calender device 1 from a supply device 3 to a peripheral speed slower than the supply device 3
To supply. The strip material a is taken up by the nip roller 4 and changes from a nip roller 6 side to a spiral winding having a larger diameter sequentially from the upstream side to a spiral tube b. At this time, the supply direction of the strip material a sent out from the supply device 3 matches the rotation center of the rotating frame 6, that is, the axial direction of the rotating shaft 8.

When forming the spiral tube b, the tension between the supply device 3 and the nip roller 4 is kept constant so that the spiral tube b having a constant diameter is formed.
Is molded. This tension adjustment is performed by the support frame 7 when the supply device 3
This is performed by changing the relative distance between the supply device 3 and the nip roller 4 by being movable to the side. Further, in molding the spiral tube b,
It is desirable to make the direction of the spiral winding and the twisting direction of each reinforcing cord the same. By setting them in the same direction as described above, the reinforcing cord can be prevented from untwisting, and a reinforcing material having excellent durability can be obtained.

A spiral tube b continuously formed to have a substantially uniform diameter is crushed by a nip roller 4 and is flattened as shown in FIG. 2B from the cylindrical state of FIG. 2A. Of the reinforcing material a. The belt-shaped reinforcing material a is continuously wound up by the winding roller 5 and stocked. In this winding, the winding drum 5 traverses left and right in the axial direction, so that the whole is uniformly wound.

As described above, according to the present invention, a plurality of aligning reinforcing cords f are rubberized with unvulcanized rubber, and the strip material a is supplied to the nip roller 4 while being gripped by the supply device 3, and the nip roller 4 is stripped. Since the strip material “a” is continuously formed into a spirally wound spiral tube “b” by rotating about the material supply direction as an axis, and the strip material “a” is flattened and crushed by the nip roller 4 to form a strip-shaped reinforcing material “c”, the strip-shaped reinforcing material is formed. c can be continuously and efficiently molded on an industrial production scale.

In the present invention, in order to manufacture a pneumatic radial tire using the reinforcing material c, a set of bead cores and a side rubber are stuck, and then wound around the outer periphery of the expanded carcass layer as described above. The reinforcing material c wound up on the roller 5 is drawn out and continuously wound spirally plural times in the tire circumferential direction over the belt width to form a belt layer. Further, a green tire is formed by arranging a tread rubber on the belt layer, and the green tire is placed in a mold and vulcanized to obtain a pneumatic radial tire as shown in FIG.

In FIG. 3, reference numeral 11 denotes a tread portion, reference numeral 12 denotes a bead portion, reference numeral 13 denotes a sidewall portion, and a single carcass layer 14 is disposed inside the tire.
Are folded around the left and right bead cores 15 from the inside of the tire to the outside. A belt layer 16 having a two-layer structure in which a reinforcing material c crushed flat is spirally wound a plurality of times in the tire circumferential direction is embedded on the outer peripheral side of the carcass layer of the tread portion 11. There is no cut end of the reinforcing cord at the end of the belt layer, and the pneumatic radial tire has excellent edge separation resistance.

In the present invention, a steel cord or an organic fiber cord can be used as the alignment reinforcing cord f. For steel cord, wire diameter 0.1 ~
1 × N consisting of N steel filaments of 0.4 mm
A steel cord having a structure can be preferably used.
As the organic fiber cord, for example, a fiber selected from aromatic polyamide fiber, polyarylate fiber, polyparaphenylene benzobisoxazole fiber, polyvinyl alcohol fiber, rayon fiber, polyethylene terephthalate fiber, polyethylene 2,6-naphthalate fiber, nylon fiber A twisted yarn obtained by twisting one or two or more of the above can be preferably used. The twisting direction of each reinforcing cord is preferably the same as the spiral winding direction of the strip material a, and the twisting method may be any of S twisting and Z twisting.

The width of the strip material a in which the alignment reinforcing cord f is embedded is preferably 5 to 20 mm.
The width of the reinforcing material c can be 5 to 60 mm.
The inclination angle of the alignment reinforcing cord f with respect to the longitudinal direction of the reinforcing member is preferably set to 10 to 45 °. In the above-described embodiment, the spiral tube b is continuously formed by continuously rotating while simultaneously supplying the strip material a. However, instead of supplying the strip material a for a predetermined length, rotation is applied. And spiral spiral tube b
May be continuously formed.

Further, in the above embodiment, the spiral tube b is squashed flat to form the reinforcing material c in which the alignment reinforcing cord f has a spiral winding structure. By selecting the inclination angle and the strength of the cord f, the spiral tube b is crushed so as to be pushed down in the longitudinal direction so that the reinforcing cords located at both ends are maintained in a coiled shape without being bent. You may.

[0020]

As described above, according to the present invention, when a spirally wound spiral tube is crushed to form a flat belt layer reinforcing material, a plurality of aligned reinforcing cords are made of unvulcanized rubber. By supplying the pulled strip material from the supply roller to the nip roller and rotating the nip roller about the strip material supply direction as an axis, the spiral tube is continuously formed and crushed flat by the nip roller. The material can be efficiently and continuously formed on an industrial production scale.

[Brief description of the drawings]

FIG. 1 is a schematic elevational view showing a device for producing a reinforcing material for a belt layer of the present invention in a partially perspective view.

FIG. 2A is a perspective view of a main part of a spiral tube before being crushed, and FIG. 2B is a perspective view of a main part of a reinforcing member formed by crushing the spiral tube flat.

FIG. 3 is a perspective view showing an example of a pneumatic radial tire manufactured by using a reinforcing material for a belt layer manufactured by the method of the present invention, with a main part thereof partially cut away.

[Explanation of symbols]

Reference Signs List 1 calendar device 2 rubber tuber 3 supply device 3a supply roller 4 nip roller 5 take-up drum 6 rotating frame 7 support frame 8 rotating shaft 11 tread portion 12 bead portion 13 side wall portion 14 carcass layer 15 bead core 16 belt layer a strip material b spiral Tube c Reinforcement f Alignment reinforcement cord

Claims (6)

[Claims] 1. A method in which a strip material obtained by rubberizing a plurality of alignment reinforcing cords with unvulcanized rubber is supplied from a supply roller to a nip roller, and the nip roller is rotated about the supply direction of the strip material as an axis. A method for producing a reinforcing material for a belt layer, wherein a strip material on a supply side is formed into a spiral wound spiral tube, and the spiral tube is crushed flat by the nip roller to form a belt-shaped reinforcing material. 2. A spiral tube for feeding the strip material on the supply side while changing the relative distance between the supply roller and the nip roller to adjust the tension of the strip material supplied to the nip roller substantially constant. The method for producing a reinforcing material for a belt layer according to claim 1, wherein the reinforcing material is molded into a belt. 3. The method for manufacturing a reinforcing material for a belt layer according to claim 1, wherein the spiral winding direction of the spiral tube and the twist direction of each of the reinforcing cords are the same. 4. The reinforcing cord has a strand diameter of 0.1 to 0.4.
The method for producing a reinforcing material for a belt layer according to any one of claims 1 to 3, which is a steel cord having a 1 x N structure including N steel filaments of mm. 5. The method for producing a reinforcing material for a belt layer according to claim 1, wherein the width of the strip material is 5 to 20 mm. 6. A belt layer is formed by continuously winding the reinforcing material obtained by the manufacturing method according to any one of claims 1 to 5 around the outer periphery of the carcass layer spirally in the tire circumferential direction a plurality of times. Of manufacturing pneumatic radial tires.