JPH0443023A - Manufacture of pneumatic tire - Google Patents

Abstract

PURPOSE:To reduce the remaining of bubbles by sticking a tread, on which a squeegee rubber is stuck previously to a reinforcing layer, to the reinforcing layer when a tire is manufactured. CONSTITUTION:When a pneumatic tire in which a squeegee rubber 26 is arranged between a reinforcing layer 18 and a tread 14 is manufactured, the tread 14, on which the squeegee rubber 26 is pasted previously while being faced to the reinforcing layer 18, is stuck to the reinforcing layer 18. Accordingly, the remaining of bubbles between the tread 14 and the squeegee rubber 26 can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing pneumatic tires to be installed on automobiles, subways, etc.

[Conventional technology]

Conventionally, in pneumatic tires mounted on automobiles, subways, etc., a plurality of reinforcing layers for reinforcing the tread are provided between the carcass and the tread. These reinforcing layers are composed of organic fibers such as nylon, polyester aromatic polyamide, etc. and inorganic fibers such as steel, which are arranged in a direction intersecting the tire equatorial plane.

In addition, in pneumatic tires, squeegee rubber is installed between the carcass, reinforcing layer, and tread to protect the mutual contact surfaces of the carcass, reinforcing layer, and tread from internal distortion caused by tire transfer. There is.

However, in the above-mentioned conventional pneumatic tire, as shown in FIG. It was wider than the layer 50, and similarly the squeegee rubber 56 on the second reinforcing layer was also wider than the second reinforcing layer 52.

Furthermore, in the conventional pneumatic tire manufacturing method described above, the first reinforcing layer upper squeegee rubber 54 sandwiched between the first reinforcing layer 50 and the second reinforcing layer 52 is pasted to the first reinforcing layer lower squeegee rubber 55 in advance. . Therefore, the end portion 5 of the first reinforcing layer 50
0A and the first portion protruding from the end portion 52A of the second reinforcing layer 52.
Wrinkles were likely to occur at the end portion 54A of the squeegee rubber 54 on the reinforcing layer.

In addition, the squeegee rubber on the first reinforcing layer is attached near the end 54A of the squeegee rubber on the first reinforcing layer 54 and the end 56A of the squeegee rubber on the second reinforcing layer 56, because rubber is attached to the squeegee rubber on the first reinforcing layer during the pasting operation. 54 near the end 54A and the second
The air trapped in the wrinkles near the end 56A of the squeegee rubber 56 on the reinforcing layer cannot be sufficiently removed even if a large force is applied thereafter, and the air bubbles remain in the rubber.

Furthermore, when the tread 58 and the squeegee rubber 56 on the second reinforcing layer are attached, since the rubber is attached to the rubber, once the air is trapped between the rubbers, it will not be able to do so even if the air is subsequently applied with a large force. The air bubbles cannot be removed and remain in the rubber.

On the other hand, when a vehicle equipped with the pneumatic tire runs at high speed, internal distortion due to heat generation and tire displacement is concentrated in a portion of the shoulder of the tire (near the end of each reinforcing layer).

Therefore, if a tire molded with air bubbles remaining in a portion of the shoulder is used in such an environment, the tire will be damaged in a relatively short period of time.

[Problem to be solved by the invention]

The present invention takes the above-mentioned facts into consideration and aims to provide a method for manufacturing a pneumatic tire that can reduce the amount of residual air bubbles.

[Means and actions to solve the problem]

The method for manufacturing a pneumatic tire according to the present invention as set forth in claim (1) is a method for manufacturing a pneumatic tire in which a squeegee rubber is disposed between a reinforcing layer and a tread, and the method includes disposing a squeegee rubber between a reinforcing layer and a tread. It is characterized in that the tread with squeegee rubber attached to the facing side is attached to the reinforcing layer.

Therefore, the conventional work of attaching the tread to the squeegee rubber or attaching the rubbers to each other can be omitted, so that it is possible to reduce the amount of air bubbles remaining between the tread and the squeegee rubber.

Further, in the method for manufacturing a pneumatic tire according to the present invention described in claim (2), a first
A squeegee rubber under the reinforcing layer is provided, a squeegee rubber on the first reinforcing layer is provided between the first reinforcing layer and the second reinforcing layer, and a squeegee rubber on the second reinforcing layer is provided between the second reinforcing layer and the tread. A method for manufacturing a pneumatic tire, wherein a first reinforcing layer is provided, the first reinforcing layer facing the first reinforcing layer; 'It is a carcass ply to which the squeegee rubber under the first reinforcing layer, which is wider than the first reinforcing layer and which is wider than the second reinforcing layer, is attached in advance. After pasting the squeegee rubber on the first reinforcing layer sandwiched between the second reinforcing layer and the second reinforcing layer, the squeegee rubber on the second reinforcing layer is made wider than the first reinforcing layer and the second reinforcing layer facing the second reinforcing layer. It is characterized by attaching a tread that has been attached in advance.

Therefore, the first reinforcing layer sandwiched between the first reinforcing layer and the second reinforcing layer in advance
When attaching the squeegee rubber on the reinforcing layer, since the squeegee rubber on the first reinforcing layer is narrower than the first reinforcing layer,
It is possible to prevent the occurrence of wrinkles at the end of the squeegee rubber on the first reinforcing layer, and it is possible to reduce residual air bubbles. In addition, since the squeegee rubber on the second reinforcing layer is adhered to the reserved tread, wrinkles can be prevented from forming at the end of the squeegee rubber on the second reinforcing layer, and residual air bubbles can be reduced.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 2 shows a pneumatic tire 10 according to the present embodiment, in which a carcass ply comprising an organic fiber cord such as nylon 6 or nylon 66 is usually used, and the cord is arranged at an angle of 30° to 70° with respect to the tire's equatorial plane. A carcass 12 is formed by stacking 6 to 10 layers diagonally across each other in an angle range of 12° and rolling it up through both ends of each carcass ply and a bead ring 11, a tread 14 forming the road surface part of the tire, and a carcass. A first reinforcing layer 16 and a second reinforcing layer 18 are provided between the tread 12 and the tread 14.

These first reinforcing layer 16 and second reinforcing layer 18 are each made of the same material and structure as the carcass ply, and are arranged so that each cord forms an angle between the carcass ply and the road with respect to the tire equatorial plane. It is set up.

In addition, the carcass 12, the first reinforcing layer 16, the second reinforcing layer 18
And between each of the treads 14, damage due to tire deformation,
In particular, in order to prevent the cord from breaking, the thickness should be 0.
A squeegee rubber (not shown in FIG. 2) having a diameter of 5 to 0.8 is provided.

Further, as shown in FIG. 3, the first reinforcing layer 16 and the second
The coating thickness T of the coating rubber 19 covering each cord 17 of the reinforcing layer 18 is 4 mm or less. for example,
A nylon cord with a diameter of 0.51 mm is integrally covered with rubber sheets from the top and bottom to a thickness of 0.7 m, and the thickness of each attached rubber sheet is approximately equal to each other. shall be.

Therefore, recesses and protrusions are reliably formed alternately on the surfaces of the first reinforcing layer 16 and the second reinforcing layer 18, and the first reinforcing layer 16 and the second reinforcing layer 18 having the uneven surfaces and the squeegee rubber are placed facing each other. For this reason, the first reinforcing layer 1
6 and the second reinforcing layer 18 and the squeegee rubber, flat rubber surfaces are not disposed facing each other, making it possible to reduce residual air bubbles.

As shown in FIG. 1, in the state of a green tire, a first reinforcing layer lower squeegee rubber 20 is attached in advance to the upper surface of the carcass 12 (the side surface of the first reinforcing layer 1B). The width of the squeegee rubber 200 is made wider than the width of the first reinforcing layer 16.

A first reinforcing layer upper squeegee rubber 24 is attached in advance to the upper surface of the first reinforcing layer 16 (the side surface of the second reinforcing layer 18), and this first reinforcing layer upper squeegee rubber 24 has a width narrower than that of the first reinforcing layer 16. It is larger and wider than the second reinforcing layer 18. In this embodiment, the width of the squeegee rubber 24 on the first reinforcing layer is narrower by W (=30 mm) than the width of the first reinforcing layer 16, and
It is made wider by W (' = 30 mm) than the width of No. 8. The second reinforcing layer 18 is attached in advance to the upper surface of the first reinforcing layer squeegee rubber 24 .

Further, a second reinforcing layer top squeegee rubber 26 is attached in advance to the lower surface of the tread 14 (the side surface of the second reinforcing layer 18), and this second reinforcing layer top squeegee rubber 26 is attached to the first reinforcing layer 18.
6 and the second reinforcing layer 18. In this embodiment, the width of the squeegee rubber 26 on the second reinforcing layer is wider than the width of the first reinforcing layer 16 by W (#30 mm).

Next, a method for manufacturing the pneumatic tire 10 according to this embodiment will be explained.

In the method for manufacturing the pneumatic tire 10 of this embodiment,
An inner liner is placed on a molding drum, and a two-layer carcass 12 is pasted on the upper surface of the inner liner. Next, attach the bead ring and fold the carcass back. Repeat this process to obtain a double-ply structure.

Next, as shown in FIG. 1, the first reinforcing layer sandwiched between the first reinforcing layer 16 and the second reinforcing layer 18 is attached to the carcass 12 to which the first reinforcing layer lower squeegee rubber 20 has been previously attached to the upper surface. A squeegee rubber 24 is attached on the layer.

Thereafter, the trend 14 having the second reinforcing layer top squeegee rubber 26 stuck to the reserved lower surface is attached to the upper surface of the second reinforcing layer 18.

Therefore, on the upper surface of the first reinforcing layer lower squeegee rubber 20, the first
When attaching the first reinforcing layer top squeegee rubber 24 sandwiched between the reinforcing layer 16 and the second reinforcing layer 18, since the first reinforcing layer top squeegee rubber 24 is narrower than the first reinforcing layer 16, Wrinkling of the end portion 24A of the squeegee rubber 24 on the first reinforcing layer can be prevented from occurring, and residual air bubbles can be reduced.

In addition, the squeegee rubber 26 on the second reinforcing layer is applied to the tread 1 in advance.
4, it is possible to reduce the residual air bubbles between the tread 14 and the second reinforcing layer upper squeegee rubber 26, and wrinkles occur at the end portion 26A of the second reinforcing layer upper squeegee rubber 26. It is possible to prevent this and reduce the amount of remaining air bubbles.

In this case, in order to prevent the rubber thickness between the end 816A of the first reinforcing layer 16 and the tire surface from becoming thin in the product tire after vulcanization, as shown in FIG. The convex portion 28 is connected to the end portion 16 of the first reinforcing layer 16.
The end portion 16 of the first reinforcing layer 16 may be extended to the vicinity of A.
Preferably, A extends to the convex portion 28.

Furthermore, although the present embodiment has been described with reference to a bias tire, the present invention can also be applied to a radial tire.

(Experimental Example) When inspecting the prototype tire manufactured according to the present invention and the conventional tire manufactured by the conventional method shown in Fig. 4 for residual air bubbles after vulcanization using holography, it was found that the second breaker end In the conventional tire, it was confirmed that there were 1% of residual air bubbles, whereas in the prototype tire manufactured by the present invention, the air bubble generation rate was 0%. there were.

The experimental results revealed that the present invention is particularly superior.

In addition, the prototype tire and the conventional tire are respectively tire size: 6.00-16 12PR, carcass ply cord: 1890d/2 nylon 66, carcass ply cord angle: approximately 50° with respect to the equatorial plane of the tire. Number of carcass ply layers: 4 layers, cords of first and second reinforcing layers: 840d/2 nylon 66, angle of cords of reinforcing layers: mutually forming an angle of about 50° with respect to the tire equatorial plane It is an intersection.

〔Effect of the invention〕

Since the present invention has the above configuration, it has an excellent effect of being able to reduce residual bubbles.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the lamination state of a green tire of a pneumatic tire according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the upper half of the pneumatic tire according to an embodiment of the present invention, cut along the axial direction. FIG. 3 is a cross-sectional view showing a part of the reinforcing layer shown in FIG. 2 taken along the axial direction of the tire, and FIG. 4 is a cross-sectional view showing the stacked state of a conventional green tire. be. DESCRIPTION OF SYMBOLS 10... Pneumatic tire, 12... Carcass, 14... Tread, 16... First reinforcing layer, 18... Second reinforcing layer, 20... Squeegee rubber under first reinforcing layer, 24 ...First
Squeegee rubber on reinforcing layer, 26... Squeegee rubber on second reinforcing layer.

Claims (2)

[Claims] (1) A method for manufacturing a pneumatic tire in which a squeegee rubber is disposed between a reinforcing layer and a tread, in which the tread, on which the squeegee rubber is previously attached facing the reinforcing layer during tire manufacturing, is attached to the reinforcing layer. A method for manufacturing a pneumatic tire, characterized by: (2) disposing a first reinforcing layer lower squeegee rubber between the carcass ply and the first reinforcing layer, disposing a first reinforcing layer upper squeegee rubber between the first reinforcing layer and the second reinforcing layer, and Second
A method for manufacturing a pneumatic tire in which a squeegee rubber is disposed on a second reinforcing layer between the reinforcing layer and the tread, the first reinforcing layer having a width wider than the first reinforcing layer when facing the first reinforcing layer. A lower squeegee rubber is attached to the carcass ply in advance, and the first reinforcing layer is narrower than the first reinforcing layer and wider than the second reinforcing layer, and is sandwiched between the first reinforcing layer and the second reinforcing layer in advance. After pasting the squeegee rubber, attach the first layer facing the second reinforcing layer.
A method for manufacturing a pneumatic tire, comprising: pasting a tread on which a squeegee rubber has been pasted in advance on the reinforcing layer and the second reinforcing layer, the width of which is wider than that of the second reinforcing layer.