JPH0929858A - Manufacture of tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inner liner having a short molding time and high operating efficiency without using excess rubber without reducing the productivity by extruding a ribbon-like green rubber layer having a specified size, winding it and molding the liner. SOLUTION: A ribbon-like green rubber layer R having a thickness of about 2 to 20mm and a width of about 50 to 300mm is extruded from a rubber extruder, sequentially wound while deviating laterally on a molding drum D to mold an inner liner L. The unnecessary rubbers of starting and finishing ends of winding of the layer R are cut by a tilting cutter C to form sharp edges. The winding and lateral speeds of the layer R are set variably, the winding times of the layer R is increased at an arbitrary lateral position of the liner L from the other position to manufacture the liner L having a large thickness.

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, and more particularly to a method for manufacturing an inner liner which is one of intermediate members constituting a large tire for construction vehicles or industrial vehicles. Is.

[0002]

2. Description of the Related Art In general, an inner liner, which is one of the intermediate members constituting a tire, is made by mixing a natural or synthetic rubber with a rubber compounding agent such as a vulcanizing agent and a filler and kneading the rubber with a calender. , A predetermined width for each tire size and 1
It is rolled into a sheet with a uniform thickness of approximately 4 mm to 4 mm, and is temporarily wound with a non-adhesive sheet interposed and stored on a trolley, and this rubber sheet is unwound during the molding process, It is manufactured by cutting it to the required length for each size and winding it once or several times on a molding drum. As a result, when the tire size increases, the number of trucks increases and the truck storage space also increases. Furthermore, when manufacturing large or very large tires such as tires for construction vehicles or industrial vehicles, the width of the inner liner used is extremely large, which limits the rolling width of conventional calendars. May exceed capacity. With the increase in size of tires, it is a problem that can be easily solved by installing a new large calendar, but often investment more than the amount corresponding to the production volume of large tires is required, and also trolleys and non-adhesive sheets It is also necessary to change accessory-related items such as those to new large ones, and it may be difficult to adopt them on a commercial production basis. Therefore, conventionally, a method has been adopted in which the width of the inner liner, which is insufficient due to the increase in size of the tire, is supplemented by adding a narrow rubber sheet. However, such a method naturally causes problems such as an increase in cost due to an increase in manufacturing man-hours and a decrease in product accuracy.
In addition, since rubber sheets are usually partially overlapped in the width direction, there have been problems such as an increase in raw material costs and an increase in tire weight.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art, to eliminate the need for a trolley or a trolley storage space, reduce the investment cost for production, and improve productivity. It is an object of the present invention to provide a method for producing an inner liner that does not decrease the molding temperature and does not use extra rubber and that has a short molding time and high working efficiency.

[0004]

In order to achieve the above object, the method for producing a pneumatic tire according to the present invention comprises (1)
The inner liner is molded by extruding a ribbon-shaped green rubber layer with a thickness of 2 to 20 mm and a width of 50 to 300 mm from a rubber extruder and sequentially winding it on the molding drum while shifting it in the width direction. (2) A swing cutter is provided between the rubber extruder and the molding drum, and (3) winding and traverse speeds of the ribbon-shaped green rubber layer are variable. And a method for manufacturing a tire.

In order to achieve the above object, the method of manufacturing a pneumatic tire according to the present invention comprises
It is preferable to cut off unnecessary rubber at the beginning and end of winding of the ribbon-shaped green rubber layer to form a sharp edge.

In order to achieve the above object, in the method of manufacturing a pneumatic tire according to the present invention, the number of windings of the ribbon-shaped green rubber layer is set to be larger at any position in the width direction of the inner liner than at other positions. By doing so, it is preferable to manufacture an inner liner having a large thickness at any position in the width direction.

In the method for manufacturing a pneumatic tire according to the present invention, as described above, the ribbon-shaped green rubber layer is extruded from the rubber extruder and sequentially wound on the molding drum while being shifted in the width direction. Since the inner liner is molded, there is no need for a trolley and space for storing the trolley, and the width of the inner liner can be set as needed, so it is also necessary to newly install a large calendar as the tire gets larger. Absent.

In the method for manufacturing a pneumatic tire according to the present invention, as described above, the swing cutter is provided between the ribbon-shaped green rubber layer rubber extruder and the molding drum. With a cutter, unnecessary rubber at the beginning and end of the ribbon-shaped green rubber layer can be cut off to easily make the width of the inner liner circumferentially uniform. Further, since the edge of the inner liner is sharply cut by the swing cutter, manufacturing defects such as cracks in the inner liner and air entering can be prevented.

In the method for manufacturing a pneumatic tire according to the present invention, as described above, since the winding speed and the traverse speed of the ribbon-shaped green rubber layer are variable, the ribbon can be attached at any position in the width direction of the inner liner. It is possible to manufacture an inner liner having a large thickness at any position in the width direction by making the number of windings of the green rubber layer larger than at other positions. That is, it is possible to reduce the weight of the tire and the cost of raw materials by manufacturing the inner liner having the rubber of the required thickness at the required location. Further, since it is not necessary to stack thin wide sheets, a step of extracting air from the air pool generated in the step of stacking sheets becomes unnecessary, and a defect in tire manufacturing in which an air pool remains in a product (tire) is also eliminated.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is a drawing showing a manufacturing method according to the first embodiment of the present invention, in which a rubber extruder (not shown) A 3.5 mm wide, 200 mm wide ribbon-like green rubber layer R is extruded to form a molding drum D.
It is wound in the widthwise direction while being wound in order, and returned to the original position when reaching a predetermined width of 3000 mm, and the ribbon-shaped green rubber layer R is laminated on the already wound rubber layer, and the widthwise direction is the same as above. Winding sequentially while shifting, and repeating this lamination 4 times gives a thickness of 14 m.
An inner liner L having a width of m and a width of 3000 mm is molded. The tire size is 40.00R57. A swinging cutter C is provided between the rubber extruder and the molding drum D, and unnecessary rubber at the winding start and winding end of the ribbon-shaped green rubber layer R is cut off, and the width of the inner liner L is reduced. It becomes uniform on the circumference. Also, the swing cutter C
Since the edge of the inner liner L is sharply cut, manufacturing defects such as cracks in the inner liner and air entering are prevented.

FIG. 2 is a view showing a cross section of an inner liner L manufactured by a manufacturing method according to a second embodiment of the present invention, in which winding and traverse speeds of a ribbon-shaped green rubber layer R are variable. As a result, the number of windings of the ribbon-shaped green rubber layer R is increased at any position in the width direction of the inner liner L as compared with other positions, so that the inner liner L having a large thickness at any position in the width direction. Is manufactured.

FIG. 3 is a drawing showing a conventional manufacturing method, in which a wide sheet W having a thickness of 3.5 mm and a width of 2600 mm is used.
Then, a narrow sheet N having a thickness of 3.5 mm and a width of 500 mm is laminated on the molding drum while being overlapped by 100 mm, and four layers are laminated to form an inner liner L having a thickness of 14 mm and a width of 3000 mm. The tire size is 40.00R57 as in the example.

In order to compare the manufacturing method of Example 1 and the manufacturing method of the conventional example according to the present invention, the tire manufactured by the manufacturing method of Example 1 and the tire manufactured by the manufacturing method of the conventional example are the same. The condition was evaluated. The evaluation items are manufacturing defect repair rate and tire weight. Although the manufacturing defect repair rate of the tire manufactured by the conventional manufacturing method was 6%,
The manufacturing defect repair rate of the tire manufactured by the manufacturing method of Example 1 was 0.5%. The weight of the tire manufactured by the manufacturing method of Example 1 was 99% of the weight of the tire manufactured by the conventional manufacturing method.

From the above evaluation results, in the method of the first embodiment according to the present invention, the repair rate of manufacturing defects of the tire is improved and the weight of the tire is reduced as compared with the method of the conventional example. I understand.

[0015]

EFFECTS OF THE INVENTION According to the present invention, a trolley and a trolley storage space are not required, an investment cost for production is suppressed, productivity is not lowered, and an extra rubber is not used. It has become possible to provide a highly efficient inner liner manufacturing method.

[0016]

[Brief description of drawings]

FIG. 1 is a drawing showing a manufacturing method of the present invention.

FIG. 2 is an inner member manufactured by the manufacturing method of the present invention.
It is a cross section of a liner.

FIG. 3 is a drawing showing a manufacturing method according to a conventional example.

[Explanation of symbols]

 C Swing cutter D Molding drum L Inner liner N Narrow sheet R Ribbon-shaped green rubber layer W Wide sheet

Claims (3)

[Claims] 1. A method for manufacturing a tire, comprising: (1) about 2 to 20 mm in thickness and 50 to 3 in width from a rubber extruder.
Molding the inner liner by extruding a ribbon-shaped green rubber layer of about 00 mm and sequentially winding it on the molding drum while shifting it in the width direction, (2) the rubber extruder and the molding drum. (3) Manufacture of large tires for construction vehicles or industrial vehicles, characterized in that a swinging cutter is provided between them, and (3) winding of the ribbon-shaped green rubber layer and traverse speed are variable. Method. 2. The tire according to claim 1, wherein the swing cutter cuts off unnecessary rubber at the beginning and end of winding of the ribbon-shaped green rubber layer to form a sharp edge. Manufacturing method. 3. An inner liner having a large thickness at any position in the width direction by winding the ribbon-shaped green rubber layer at any position in the width direction of the inner liner more than at other positions. The method for manufacturing a tire according to claim 1, wherein a liner is manufactured.