JP2002361754A - Tire manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and conveniently form a short fiber reinforcing layer in which a short fiber material is orientated as originally expected. SOLUTION: There is provided a method for manufacturing a tire equipped with a short fiber reinforcing layer where the short fiber material 6 is orientated in a specified direction. When a green tire is molded, a rubber ribbon 5 containing the short fiber material 6 orientated in its own extension direction, is arranged by winding the rubber ribbon 5 around a belt 4 formed on a BT drum 3. The orientation direction of the short fiber material 6 inside the short fiber reinforcing layer is decided by selecting the rotary peripheral speed of the belt 4 on the BT drum 3 and the moving speed of the rubber ribbon 5, in the axial direction, of the BT drum 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a tire, especially a pneumatic tire, and more particularly to a method for easily forming a short fiber reinforcing layer in which a short fiber material is oriented in a required direction. is there.

[0002]

2. Description of the Related Art As a conventional technique proposed to achieve a good balance between low fuel consumption performance and durability performance, steering stability performance and ride comfort performance of a pneumatic radial tire, which once tended to be incompatible. Is Japanese Patent Laid-Open No. 6-191.
No. 208 is disclosed.

[0003] In this method, a belt made of a single spiral wound layer of an organic fiber cord coated with rubber or a ply of a predetermined length made of a rubber coating layer of a plurality of organic fiber cords arranged in parallel with each other is used. A belt comprising a single layer of winding in which the cord is extended in the circumferential direction is provided, and contains a short fibrous substance oriented in a predetermined direction with respect to the extending direction of the organic fiber cord. According to this, the reinforcing rubber layer containing the short fibrous substance is disposed on the belt, so that the belt cord made of organic fibers becomes the equator of the tire. 1 so that it is almost parallel to
Such a belt structure without the heat generated by the shear strain between the belt layers, which is peculiar to the tire having the belt structure in which only the layer is wound, and without impairing the advantageous effect of low rolling resistance when traveling straight. It is stated that the problems of reduced cornering power and reduced steering stability can be completely solved.

[0004]

However, in order to form a reinforcing rubber layer in which short fibrous substances are surely oriented in a predetermined direction as in this prior art, many steps and complicated work are required. There was a problem that became mandatory.

An object of the present invention is to solve such a problem, and an object of the present invention is to extrude from an extruder or the like, and to hold a required cross-sectional shape with a die, a die, and the like. Focusing on the fact that the short fiber material blended therein naturally inevitably orients in the extending direction of the rubber ribbon, the short fiber reinforcing layer in which the short fiber material is oriented as expected is included It is an object of the present invention to provide a method for manufacturing a tire that can easily and easily form a tire.

[0006]

According to the present invention, there is provided a tire manufacturing method comprising a short fiber reinforcing layer in which a short fiber material is oriented in a predetermined direction at at least one of an inner circumferential position and an outer circumferential position of a belt layer. In the molding of a green tire, a short fiber reinforcing layer in which a rubber ribbon containing a short fiber material oriented in its own extending direction is wound and arranged on a required layer formed on a rotating support. And the orientation direction of the short fiber material in the short fiber reinforcing layer is selected by selecting the rotational speed of the required layer on the rotary support and the moving speed of the rubber ribbon in the axial direction of the rotary support. Is determined by

Here, the rotary support may be a high-rigidity core having an outer peripheral surface shape corresponding to the inner peripheral surface shape of the product tire, a belt / tread drum, a molded drum whose central portion is expanded and deformed, or the like. it can.

This method is based on the fact that the short fiber material in the rubber ribbon is inevitably oriented in the extending direction of the ribbon by extrusion molding of a rubber composition containing the short fiber material. The extension angle of the rubber ribbon with respect to the circumferential direction of the rotating support is determined. As a result, the orientation angle of the short fiber material is determined. The relative relationship between the rotational peripheral speed and the moving speed of the rubber ribbon in the axial direction of the rotary support is selected. Therefore, here, while maintaining the selected state, the rubber ribbon is wound around the entire width direction and the circumferential direction without any gap in the predetermined width direction region, so that the inner circumferential position of the belt layer and the outer circumferential position are determined. In at least one of the side positions, a short fiber reinforcing layer in which the short fiber material is accurately oriented in a predetermined direction can be easily formed without a special step in advance, troublesome work, and the like.
And here, just change the relative relationship between the two speeds,
The orientation angle of the short fiber material can be easily controlled.

Here, the rubber ribbon can be wound and arranged in a zigzag manner while reciprocating the rubber ribbon in a required stroke in the axial direction of the rotating support that rotates steadily. Can be performed by helically winding around the rotating support while linearly moving in one direction from one end of the rotating support to the other end.

According to the former, since the short fiber material is inclined at a large angle with respect to the circumference of the rotary support, the short fiber reinforcing layer formed thereon is formed by the belt cord as described in the prior art. By using the reinforcing member for reinforcing the belt extending substantially in the circumferential direction of the tire, the above-described operation and effect can be effectively exhibited.

On the other hand, according to the latter, since the short fiber material is inclined at a small angle, the short fiber reinforcing layer formed on the short fiber material has a belt cord extending at a relatively large angle with respect to the tire circumference. When used as a reinforcement for a belt, it is possible to advantageously restrain swelling deformation of the tread during high-speed rotation of the tire.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the present invention, in which 1 denotes an extruder that can be an extruder, an injection extruder, a constant volume extruder, and the like, and 2 denotes an extruder 1 1 shows roller dies each consisting of a pair of rollers for forming a long strip extruded from the head of FIG. Reference numeral 3 denotes a belt tread drum (hereinafter referred to as “B
And a reference numeral 4 denotes a belt formed on the BT drum and comprising one or more belt layers.

Here, the extruder 1 is shown by arrows A and B in the figure.
As shown in the figure, the extruder 1 can be displaced as necessary together with the roller die 2 in the axial direction of the BT drum 3 and in the direction orthogonal thereto, and the extruder 1 is made of rubber containing a required amount of short fiber material. The composition functions to extrude from the head while gradually orienting the short fiber material in the direction of its movement as the extrusion proceeds under sufficient kneading.

The long strip extruded from the head in this manner is then shaped by a roller die 2 and has a width of, for example, about 5 to 20 mm and a width of 0.2 mm.
The rubber ribbon 5 has a thickness of about 5 mm. The rubber ribbon 5 is wound around a BT drum 3 rotating at a selected speed via a belt 4. in this case,
The extruder 1 and the roller die 2 are reciprocated in the axial direction of the BT drum 3 at a predetermined speed in relation to the selected rotation speed of the BT drum 3 so that the rubber ribbon 5 and thus the rubber ribbon 5 are contained therein. The short fiber material 6 to be
The BT drum 3 is stuck on the belt 4 in a zigzag shape, for example, as wide as the BT drum 3 is oriented in such a manner as to be inclined with respect to the circumferential line segment.

In this manner, the rubber ribbon 5 is
2A, the winding position of the rubber ribbon 5 is set in the circumferential direction of the belt 4 and the circumferential width of the rubber ribbon 5 with respect to the existing position, as shown in FIG. By changing the position by the corresponding amount and performing the next arrangement, and thereafter, performing the third and subsequent windings in the same manner, as shown in FIG.
Through the winding state shown in FIG. 5, the short fiber reinforcing layer 7 covering the belt peripheral surface with the rubber ribbon 5 over the entire inner and outer layers in the width direction and the circumferential direction thereof can be formed.

Here, the orientation angle of the short fiber material 6 with respect to the circumference of the BT drum is determined by the relative relationship between the peripheral speed of the short fiber material 6 and thus the peripheral speed of the belt and the moving speed of the roller die 2 in the axial direction of the BT drum. The selection can be made easily and easily by appropriate selection.

FIG. 3 shows that the roller die 2 is slowly and linearly moved from one end to the other end in the axial direction of the BT drum 3 toward one side.
By rotating the BT drum 3 at a relatively high peripheral speed and spirally winding the rubber ribbon 5 on the belt 4, for example, the short fiber reinforcing layer 7 covering the entire belt 4 in the width direction and the circumferential direction is provided. As a result, the short fiber material 6
Are oriented substantially in the circumferential direction of the belt 4.

Thus, the short fiber reinforcing layer in which the short fiber material is oriented as intended can be easily formed without the necessity of many working steps, complicated work, and the like. The layers can fully exhibit the required functions.

In the above description, the short fiber reinforcing layer is provided only on the outer peripheral side of the belt 4. However, in addition to or instead of this, the short fiber reinforcing layer is similarly provided on the inner peripheral side of the belt 4. You can also.

Further, according to the present invention, a high rigid core having an outer peripheral surface shape corresponding to an inner peripheral surface shape of a product tire is used as a rotating support, and a tire is formed by shaping a carcass band by expanding and deforming a central portion. The drum can be used as a rotating support. In the latter case, the rubber ribbon is wound around the green tire while the molding drum is in the shaping posture.

[0021]

As is apparent from the above description, according to the present invention, the short fiber reinforcing layer disposed at least at one of the inner peripheral position and the outer peripheral position of the belt layer is provided.
By forming the short fiber material in the winding direction of the rubber ribbon containing the short fiber material oriented in its own extending direction, the orientation direction of the short fiber material in the short fiber reinforcing layer is simply and easily as expected. The orientation direction can be easily changed as required.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a plan view illustrating a winding arrangement of a rubber ribbon.

FIG. 3 is a plan view illustrating another winding arrangement of the rubber ribbon.

[Description of Signs] 1 Extruder 2 Roller die 3 Belt / Tread drum 4 Belt 5 Rubber ribbon 6 Short fiber material 7 Short fiber reinforcement layer

Claims (3)

[Claims] 1. A method for manufacturing a tire comprising a short fiber reinforcing layer in which a short fiber material is oriented in a predetermined direction on at least one of an inner circumferential position and an outer circumferential position of a belt layer. A rubber ribbon containing a short fiber material oriented in its own extending direction is wound around a required layer formed on a rotary support to form the short fiber reinforcing layer, and the short fiber A method for manufacturing a tire, wherein the orientation direction of a short fiber material in a reinforcing layer is determined by selecting a peripheral speed of a required layer on a rotary support and a moving speed of a rubber ribbon in an axial direction of the rotary support. 2. The rubber ribbon is wound and arranged in a zigzag manner while reciprocating in the axial direction of the rotary support.
3. The method for producing a tire according to item 1. 3. The method for manufacturing a tire according to claim 1, wherein the rubber ribbon is spirally wound and arranged while linearly moving in one direction from one end of the rotary support to the other end.