JPH1016081A - Method and apparatus for forming angle groove of low angle in continuous band material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for forming an angle groove of low angle on continuous band material wherein cutting workability in forming process can be made excellent, but joining sticking-together operation can be carried out without generating any difference in level in sticking components together to improve productivity of a tire, and defects after vulcanizing can be reduced. SOLUTION: A festoon device 3 controlling operation of a spreading device, a first conveying means 4, and a second conveying means 5 which are composed of a belt conveyor capable of turning regularly and reversely are in series installed between the spreading device 1 on which a band material W consisting of an unvulcanized rubber sheet is wound and a winding device 2. An embossing device 6 corresponding to total width in a width direction of the band material W which forms a conical groove Q of low angle (3 deg. to 15 deg.) at specific intervals of the continuous band material W is installed between the first conveying means 1 and the second conveying means 5.

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 low-angle chevron grooves at constant intervals in a continuous step in a continuous strip material such as an unvulcanized rubber sheet.

[0002]

2. Description of the Related Art Conventionally, in a tire molding process, an operation of attaching a thin unvulcanized rubber sheet on a molding drum of a molding machine has been performed, but an operator manually forms an angle on the molding drum. (30 ° to 45 °) Cutting requires skill in the work, and the cutting angle is limited to 30 ° even when using a circular cutter or an ultrasonic cutter in automatic cutting which does not require skill.

[0003]

Therefore, even if a thin unvulcanized rubber sheet is cut at a low angle in the molding step, the cutting angle is limited to 30 ° to 45 °. Butt joining is difficult, resulting in lap joining, and as shown in FIG. 6, a step h occurs at the joining portion 2 of the members 1a and 1b, which greatly affects vulcanization failure.

The present invention has been devised in view of such a conventional problem. In the manufacturing process of a member, a low-angle chevron groove corresponding to a cutting angle is continuously and automatically formed.
In addition to providing a member with a low-angle angled groove in the molding process, it facilitates low-angle cutting work, and because of the low angle, there is no step at the joints, so that the inner surface of the tire after vulcanization can be damaged or the members can be bonded together. A method and apparatus for forming a low-angle chevron groove in a continuous belt-like material capable of reducing failure due to air accumulation in a splice portion and thereby improving tire productivity. It is the purpose.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method in which a continuous strip material is transported at a predetermined speed between a first transport means and a second transport means in the width direction of the strip material. A stamping device consisting of an upper stamping die having a heating means capable of moving up and down corresponding to the entire width and a lower mold having a heating means having a flat surface is installed. The gist of the present invention is that it is formed in a higher semicircular shape.

Further, it is preferable that a belt conveyor capable of normal rotation and reverse rotation is used for the first conveying means and the second conveying means. The present invention is directed to a method of forming a low-angle chevron groove at a predetermined interval (peripheral length of a forming drum) on a thin continuous strip of rubber-like elastic material configured as described above and conveyed sequentially and continuously. In the belt material to be conveyed, a predetermined position in the longitudinal direction of the belt material, the upper pressing die formed in a semi-circular shape with a central portion higher than both sides over the entire width in the width direction, flat, By forming a low angle angled groove with uniform thickness by plastically deforming by holding and pressing while heating with the lower mold having a surface,
By pulling the band-shaped material before and after the chevron groove in the front-rear direction to secure the flatness of the band-shaped material and then transporting the band-shaped material to the next process, the cutting workability in the molding process can be facilitated, and the members can be bonded together. Can also perform the bonding work without generating a step, thereby improving the productivity of the tire, and also prevents the failure of the inner surface of the tire after vulcanization and the failure due to the air accumulation in the member bonding part (splice part). It can be reduced.

It is needless to say that the arrangement relationship between the upper die having a semicircular shape and the lower die having a flat surface may be changed as appropriate. The thickness of the band-shaped material is 1.0 to 2.5 mm, and the angle of the angled groove is 3 ° or more and 15 ° or more.
° or less, and the thickness of the bottom of the angled groove is 0.2 mm to 0.5
It is molded into mm. If the wall thickness is 1.0mm or less,
The effect of grooving is small, and if it is 2.5 mm or more, the pressing force for grooving becomes large, the device becomes huge, and the pressurizing time becomes long, which is not practical.

[0008] If the angle of the angled groove is 15 ° or more, not only butt joining becomes difficult, but also it is necessary to improve the precision of the pressing force at the time of forming the groove, which is not preferable. On the other hand, if it is less than 3 °, it is necessary to increase the pressing force at the time of grooving, and the pressurizing time becomes long, which is not practical. The thickness of the angle groove is 0.
If it is less than 2 mm, it is not preferable because it breaks or stretches in the middle of a molding machine when used in a continuous body. On the other hand, if the thickness of the angled groove is 0.5 mm or more, when a worker or a molding machine cuts along the groove, a relatively large step is generated, and the effect is undesirably reduced.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of a forming apparatus for performing a method of forming a low-angle chevron groove in a continuous strip material according to an embodiment of the present invention.
, A festoon device 3 for controlling the operation of the unwinding device, and a belt conveyor capable of normal and reverse rotation are provided between the unwinding device 1 and the winding device 2 which wind up the belt-shaped material W made of an unvulcanized rubber sheet. Transport means 4 and second transport means
A conveying means 5 is installed in series, and a low angle (5 ° or more and 15 ° or less) angled groove Q is provided between the first conveying means 4 and the second conveying means 5 at a predetermined interval of the continuous strip material W. The embossing device 6 corresponding to the entire width in the width direction of the strip-shaped material W that forms is installed.

The embossing device 6 includes an upper embossing die 8 having heating means (not shown) which can be raised and lowered via elevating means 7 such as a hydraulic cylinder, and a lower die 9 having heating means (not shown) having a flat surface. As shown in FIG. 2, the mold blade 8 a at the tip end of the upper pressing die 8 has a central portion P on both sides Pa.
It is formed in a higher semicircular arc shape. For example, the mold blade 8a at the tip of the upper pressing die 8 has a width of 900 mm corresponding to the width of the continuous strip material W, and the height of the central portion P of the mold blade 8a at the tip is 0.2 mm from both sides Pa. It is formed high and in an arc shape.

The reason why the mold blade 8a at the tip end of the upper pressing die 8 is formed in such a shape is that a straight-shaped (horizontal plane) mold blade has a low-angle chevron groove Q as shown in FIG. When formed, the thickness of the central portion P of the member is increased, and in order to form a uniform, thin, low-angle chevron groove Q, as described above, the central portion P is formed in a semicircular shape higher than both sides Pa. Need to be formed.

The temperature of the heating means of the upper pressing die 8 depends on the thickness of the continuous strip material, but in the case of the strip material W having a thickness of 2 mm as in this embodiment, 120 ° C.
The temperature of the heating means of the lower mold 9 is about ± 10 ° C.
The temperature is about 0 ° C. ± 5 ° C., and can be arbitrarily set depending on the thickness of the belt-shaped material W. The side on which the belt-shaped material is easily attached can be specified by the temperature difference between the upper and lower sides.

The pressing force (heating press) and time are as follows: 10 tons, 3 seconds,
It is 3.5 tons and around 30 seconds, but this can also be set arbitrarily. Next, a low-angle (3 ° or more and 15 ° or less) angled groove Q is formed in the continuous strip material W.
The method of forming during the transfer process of the above will be described.

First, the continuous band material W unwound from the unwinding device 1 is fed through a festoon device 3 onto a first conveying means 4 composed of a belt conveyor capable of normal rotation and reverse rotation. When a predetermined length, for example, a length corresponding to the peripheral length of a molding drum (not shown) is sent to the means 5 side, the conveyance drive of the first conveyance means 4 and the second conveyance means 5 is temporarily stopped.

The first transport means 4 and the second transport means 5
The upper pressing die 8 and the lower die 9 installed between them are sandwiched and pressed at a predetermined heating temperature to form a chevron groove Q having a low angle (3 ° or more and 15 ° or less). That is, when the embossed portion Wx of the continuous strip material W is positioned on the embossing device 6, the mold blade 8a at the tip end of the upper stamping die 8 is lowered via the elevating means 7, and the embossed portion Wx of the continuous strip material W is moved. While pressing it on the lower mold 9 as shown in FIG.
The angle groove Q is formed by hot pressing.

At this time, since both sides of the stamping portion Wx are wavy around the tip blade 8a and both ends of the band-shaped material W are pulled inward, the low angle as described above is obtained. After forming the angled groove Q (3 ° or more and 15 ° or less), the mold blade 8a at the tip of the upper pressing die 8 is raised, the first transporting means 4 is further reversed, and the second transporting means 5 is moved forward. Turn it over,
The flatness of the embossed portion Wx of the band-shaped material W is ensured by pulling the wavy portion generated in the embossed portion Wx in the left-right direction.

Actually, flatness can be ensured by moving the corrugated portion generated in the embossed portion Wx in the left-right direction by about 10 mm to 15 mm, respectively. By repeating the above method, the cutting workability in the molding process can be facilitated, and the band-shaped material W
Also, as shown in FIG. 5, the bonding of the end portions can be performed without causing a step difference.

[0018]

According to the present invention, as described above, the low-angle chevron groove corresponding to the cutting angle is continuously and automatically formed in the member manufacturing process, so that the cutting workability in the tire forming process is improved. In addition to being able to perform the bonding work of the cut surface butt joint without generating a step, the workability of the tire can be improved and the productivity of the tire can be improved. And vulcanization failure can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a forming apparatus for performing a method for forming a low-angle chevron groove in a continuous strip-shaped material according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a shape of a mold blade at a tip portion of an upper pressing die.

FIG. 3 is a perspective view of a low-angle chevron groove formed in a continuous strip material.

FIG. 4 is an explanatory view showing a method of correcting a wavy portion or a partially unbalanced portion of a chevron groove formed in a continuous belt-shaped material.

FIG. 5 is a cross-sectional view showing a cut end butt-bonded state of the end portion of the strip-shaped material of the present invention.

FIG. 6 is a cross-sectional view showing a conventional joining and bonding state of a terminal portion of a strip-shaped material.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 unwinding device 2 winding device 3 festoon device 4 first transport means 5 second transport means 6 die pushing device 7 elevating means 8 upper pushing die 8a die blade 9 lower die W continuous strip material Wx die pushing part P die blade Central part Both sides of Pa type blade Q Low angle angle groove

Claims (4)

[Claims] 1. A method for forming a low-angle chevron groove at a predetermined interval on a thin continuous strip of rubber-like elastic material conveyed sequentially. A predetermined position in the longitudinal direction of the band-shaped material is heated and sandwiched by a top mold having a semicircular shape with a central portion higher than both sides over the entire width in the width direction, and a lower mold having a flat surface, and pressurized while heating. Forming a low angle angled groove with a uniform thickness by deforming, and then pulling the band-shaped material before and after the angled groove in the front-rear direction to ensure the flatness of the band-shaped material and then transporting it to the next process A method of forming a low-angle chevron groove in a continuous strip material characterized by the following. 2. The thickness of the strip material is 1.0 to 2.5 mm.
The angle of the chevron groove is 3 ° or more and 15 ° or less, and the bottom portion of the chevron groove is formed to have a thickness of 0.2 mm to 0.5 mm. How to mold. 3. A heating means capable of moving up and down corresponding to the entire width in the width direction of the band material between a first conveyance unit and a second conveyance unit capable of rotating forward and backward for conveying the continuous band material at a predetermined speed. A stamping device consisting of an upper stamping die having a flat mold and a lower mold having a heating means having a flat surface is installed, and the tip of the upper stamping die is formed in a semicircular shape with a central portion higher than both sides. A forming apparatus for forming a low-angle chevron groove in a continuous strip material. 4. The first transporting means and the second transporting means,
4. The forming apparatus according to claim 3, wherein the belt conveyor is a belt conveyor capable of normal rotation and reverse rotation.