JPH10296873A - Method and device for molding belt layer of pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely turn back the opposite ends of a strip material when the strip material is wound continuously in a zigzag manner to mold it. SOLUTION: When a strip material S, in which reinforcing cords are coated with unvulcanized rubber, is wound round a mold rotation body 1 continuously in a zigzag manner to form a belt layer B, a pair of an inner and outer guide rods 23, 24 is provided near the outer circumference of the body 1 so as to reciprocate in the axial direction of the body 1, so that the material S is fed onto the body 1 by being guided by the rods 23, 24, while the rods 23, 24 are turned by 180 degrees at the opposite locations of the reciprocating motion of the rods so that the rods are located reversely to fold beck the material S.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming a belt layer of a pneumatic radial tire, and more particularly, to forming a belt layer by forming a belt layer by continuously winding a strip material in a zigzag manner while folding the strip material. Method and apparatus.

[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. After splicing the strip to a length corresponding to the perimeter of the belt layer, it is wound around the outer periphery of the carcass layer and formed so that the ends are spliced. At least two belt layers are used to connect the reinforcing cord between the layers. It is configured to intersect.

[0003] However, in the belt layer configured as described above, since cut ends of the reinforcing cord are formed at both ends of the belt layer, separation easily occurs at the edge of the belt layer, and there is a problem in durability. Conventionally, as a countermeasure, a technique of forming an even-numbered belt layer by continuously winding a strip material obtained by rubberizing a plurality of aligned reinforcing cords in a zigzag shape while folding the strip material around the outer periphery of the forming drum at both ends is proposed. There is. By thus continuously winding the strip material to form a zigzag belt layer,
Since the cut ends of the reinforcing cord are not formed at both ends of the belt layer, the durability can be improved, and the uniformity can be improved because there is no splice in the circumferential direction.

However, since the strip material is continuously wound while being folded as described above, since the strip material is folded while applying tension, the strip material is easily pulled into the center in the width direction at the folded end, and the folding position is set. Has the drawback that it tends to be unstable. for that reason,
The bending angle of the reinforcing cord was not stable, and it was difficult to perform winding work with high accuracy.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for forming a belt layer of a pneumatic tire which enables both ends of a strip material to be folded with high precision when the strip material is continuously wound in a zigzag shape. It is to provide a device.

[0006]

According to the present invention, there is provided a method for forming a belt layer, comprising the steps of continuously winding a strip material obtained by rubberizing a reinforcing cord with unvulcanized rubber on a forming rotary body in a zigzag manner. In the method of forming a belt layer,
A pair of inner and outer guide rods that reciprocate in the axial direction of the forming rotator are provided at a position close to the outer periphery of the forming rotator, and the strip material is supplied onto the forming rotator while being guided by the guide rods. And a pair of the inner and outer guide rods respectively at both ends of the reciprocating traverse.
It is characterized in that the inside and outside positions are reversed by being inverted by 80 °.

In the belt layer forming apparatus of the present invention, a pair of inner and outer guide rods which reciprocate in the axial direction of the forming rotary body are provided at a position close to the outer periphery of the forming rotary body, and the reinforcing cord is made of unvulcanized rubber. The guide rods guide the rubberized strip material on the forming rotary body, and the pair of inner and outer guide rods are turned by approximately 180 ° at both ends of the reciprocating traverse, so that the inner and outer guide rods are mutually reciprocated. It is characterized in that the positions are interchanged.

[0008] While feeding the strip material onto the forming rotary body while guiding the strip material by a pair of inner and outer guide rods provided so as to reciprocate in the axial direction at a position close to the outer periphery of the forming rotary body, both ends of the traverse are provided. Since the guide rods are inverted by approximately 180 ° at the portion to exchange the positions with each other, the strip material can be continuously and precisely wound in a zigzag shape while being bent at a stable position and angle.

[0009]

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 used for a method of forming a belt layer of a pneumatic tire according to the present invention. 1 is a rotary-driven forming drum, 2 is 1
This is a traverser that reciprocates right and left in the axial direction of the forming drum 1 while guiding a strip material S obtained by rubberizing one or a plurality of alignment reinforcing cords with unvulcanized rubber.

The forming drum 1 is rotatably supported by a horizontally disposed rotary shaft 3, and is driven to rotate in the direction of arrow R by the rotary shaft 3. The rotating shaft 3 is connected to a drive source (not shown). In the traverser 2, the support box 21 is screwed into a ball screw 4 disposed above the forming drum 1 in parallel to the axial direction thereof, and the drive motor 5 drives the ball screw 4 alternately forward and reverse to traverse the traverser left and right. So that the rotating portion 2 is
2, two parallel guide lots 23 and 24 are provided so as to be in a direction orthogonal to the axial direction of the forming drum 1. The two guide rods 23 and 24 are vertically arranged in a direction perpendicular to the surface of the forming drum 1 and substantially every time the support box 21 comes to the turning point of the traverse, that is, the position of both ends E1 and E2 of the belt width. ° It is designed to be flipped and upside down. 6 is a guide provided in parallel with the ball screw 4.

While traversing left and right, FIG.
(A), (d), the upper and lower guide rods 2
3 and 24, the upper guide rod 23 (24) first guides the strip material S supplied from above on the back side in the traverse direction, and then the lower guide lot 24 (2).
3) The cloth is crossed so as to move to the front side in the traverse direction, and is attached to the surface of the forming drum 1 while being pressed.

[0012] The strip material S
When the strip material S is supplied from above, a pair of upper and lower guide rods 2 of the traverser 2 are formed.
When the strip material S is fed onto the forming drum 1 rotating in the direction of the arrow R while traversing left and right while being guided through the gaps 3 and 24, the strip material S is wound in a zigzag shape while being folded at both ends E1 and E2. Then, the belt layer is formed by winding the zigzag strips S in a layered manner.

FIG. 2 shows the effect of the pair of upper and lower guide rods 23, 24 when the traverser passes through the points a, b, c, d, e, f in FIG. Correspondingly, (a), (b), (c), (d), (e),
This is illustrated as (f). First, Traverser 2
At a point a in the process of moving the strip material S to the left in FIG.
After being guided to the rear side of the forming drum 1, it is sent to the front side of the lower guide rod 24, and the guide rod 24 is pressed onto the forming drum 1 and is adhered while being wound obliquely in the circumferential direction of the forming drum 1.

Next, when the traverser 2 moves to the left end E1 of the belt width at the point b in FIG.
However, as shown in FIG. 2 (b), the guide rods 23 and 24 are rotated counterclockwise by approximately 180 °, and at the point c where the traverse direction is reversed, the vertical positions of the guide rods 23 and 24 are switched as shown in FIG. 2 (c). By this switching operation, the upper guide rod 23 is turned downward, and the strip material S is bent while pressing the left folded portion S1 on the left side. Therefore, the strip material S is folded at the position of the end portion E1 without being dragged inward in the width direction, and the bending angle of the reinforcing cord can be accurately and accurately folded.

Next, the traverser 2 moves in the opposite direction, and at a point d in FIG.
As shown in (d), while the guide rod 23 is on the lower side and presses the strip material S onto the forming drum 1, the strip material S is circumferentially wound obliquely in a direction opposite to the path. Point e in FIG. 3,
That is, when the guide rods 23 and 24 are moved to the right end E2 of the belt width, the upper and lower guide rods 23 and 24 are reversed by about 180 ° in the opposite direction to the point b as shown in FIG.
As shown in (f), the guide rod 24 that has been switched downward is bent while pressing the right folded portion S2 of the strip material S onto the forming drum 1.

By continuously winding the strip material S in the circumferential direction of the forming drum 1 in a zigzag manner without gaps while repeating the above traversing operation, the even-numbered belt layers B accurately determine the positions of both ends and the bending angle. While being molded. In the present invention, it is preferable that the lower side of the pair of upper and lower guide rods traverse while pressing the strip material S onto the forming drum 1 as described above. In some cases, the pressing need not always be performed.
That is, in the case of a steel cord which has a high elastic modulus of the reinforcing cord of the strip material S and is difficult to bend, it is better that the lower guide rod presses the strip material S onto the forming drum 1. However, in the case of an organic fiber cord having a relatively low elastic modulus, the cord may be traversed only at a light contact or at a position very close to the surface of the strip S.

In the above embodiment, the pair of upper and lower guide lots 23 and 24 have been described as being not rotatable by themselves, but may be rotatable like rollers.
Although the pair of guide lots 23 and 24 are arranged vertically above and below the forming drum 1, they may be arranged right and left near the side of the forming drum 1.
What is necessary is just to extend the pair of 3 and 24 in the direction which intersects the drum axis direction, and to provide a pair so that it may be located in the radial inside and outside of the forming drum 1.

The forming drum may be a forming core formed in the internal space of the pneumatic tire, and may be a forming rotary body. In the above description, the strip material is wound on the forming drum for simplicity. However, it is needless to say that the strip material may be wound directly on the carcass layer wound on the forming drum.

[0019]

As described above, the present invention provides a method for forming a belt layer by continuously winding a strip material in a zigzag manner with a belt width in a circumferential direction of a forming rotating body such as a forming drum or a forming core. Using a pair of inner and outer guides as a traverser that traverses the surface of the forming rotating body reciprocally in the axial direction,
By alternately inverting the strip material at approximately 180 ° at both ends of the traverse, the strip material is folded back in a stacked manner, so that the bending position and angle of the strip material can be accurately performed so as not to be displaced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part showing an example of an apparatus used for a method of forming a belt layer of a pneumatic tire according to the present invention.

FIGS. 2 (a) to 2 (f) are explanatory views showing the operation of a guide rod at each position shown in FIG. 3 in the belt layer forming method of the present invention.

FIG. 3 is an explanatory view showing each position of the guide rod of FIG. 2;

[Explanation of symbols]

Reference Signs List 1 forming drum (forming rotating body) 2 traverser 3 rotating shaft 4 ball screw 6 guide 21 support box 22 rotating portion 23, 24 guide rod B belt layer E1, E2 belt width end S strip material

Claims (4)

[Claims] In a method of forming a belt layer by continuously winding a strip material obtained by rubberizing a reinforcing cord with unvulcanized rubber in a zigzag manner on a forming rotary body, a position close to an outer periphery of the forming rotary body is provided. A pair of inner and outer guide rods which reciprocate in the axial direction of the forming rotator are provided, and the strip material is supplied onto the forming rotator while being guided by the guide rods. A method for forming a belt layer of a pneumatic tire in which a pair of guide rods are inverted by about 180 ° to exchange the inner and outer positions of each other. 2. The method for forming a belt layer of a pneumatic tire according to claim 1, wherein the strip material is wound around the forming rotary body while being pressed by the guide rods inside the pair of inner and outer guide rods. 3. A pair of inner and outer guide rods which reciprocally traverse in the axial direction of the forming rotator are provided at a position close to the outer periphery of the forming rotator, and a strip material whose reinforcing cord is rubberized with unvulcanized rubber is used as the guide. A belt layer of a pneumatic tire in which a pair of inner and outer guide rods are inverted by approximately 180 ° at both ends of a reciprocating traverse to exchange their inner and outer positions with each other while being supplied onto the forming rotary body while guiding with a rod. Molding equipment. 4. The pneumatic tire belt layer forming apparatus according to claim 3, wherein a guide rod inside the pair of inner and outer guide rods is wound while pressing the strip material on the forming rotary body.