JPH04146121A - Manufacture of flat tire - Google Patents

Abstract

PURPOSE:To contrive an improvement in sticking accuracy of a tread of a flat tire, by a method wherein the tread is molded by dividing the same into three of a center tread and a right and left treads and the treads each are stuck in order onto a tire carcass and stitched. CONSTITUTION:A tread 5 divided into three is extrusion-molded beforehand into a center tread 5a, which is in almost a trapezoidal sectional form, and two shoulder treads 5b and in almost a uniform width. The treads 5b, 5b are stuck beforehand to side walls 6a, 6b and a casing is stuck onto a tire carcass 1 under a flat state. Then after a tread 5a is stuck through lamination onto a molded breaker 2 of the tire carrass by inflating a tire, stitching is performed respectively toward a shoulder part Wb from the central part of the tread 5a by a stitching roll 4. Then the treads 5b, 5b are stuck by turning up the tips of them and the stitching is performed respectively toward a tread 5a side from a tire bead 7 side by the sticking roll 4.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a flat radial tire.
More specifically, the present invention relates to a method for producing a flat tire, in which the tread is formed into three parts, a center tread, and left and right shoulder treads, and each tread is successively pasted and stitched onto a tire carcass.

[Conventional technology]

Conventionally, when molding an ultra-flat radial tire (with an aspect ratio of 50% or less), as shown in FIG. The stitching roll 4 is used to apply pressure while moving from the center 0 in the width direction of the tire in the left and right direction (in the direction of the arrow).

[Problem that the invention seeks to solve]

By the way, as mentioned above, the stitching roll 4 is of a type in which a plurality of rollers rotate while moving in the left-right direction from the center O in the tire width direction, so in the case of a wide tread, The elongation in the radial direction becomes uneven, causing deformation of the tire shoulder, which has a negative impact on tire uniformity.Also, because two treads are attached, air pockets occur in the shoulder, which impedes tire molding accuracy. There was a problem that it affected the

[Purpose of the invention]

This invention was devised in view of the above-mentioned conventional problems, and an object of the present invention is to provide a method for manufacturing a flat radial tire that improves the molding accuracy of ultra-flat tires, particularly the accuracy of tire tread attachment. It is something to do.

[Means to solve the problem]

In order to achieve the above object, the present invention first attaches a center tread of a tread divided into three parts, a center tread and a shoulder tread, to the crown part of a molded tire carcass, and then attaches the shoulder tread to the tire shoulder part. The gist of each is to be pasted.

Further, in the present invention, after a center tread is attached to the crown part of a formed tire carcass, stitching is performed from the center of the center tread toward a part of the shoulder using a stitching roll, and then the tire shoulder part is stitched. The gist of this method is to attach shoulder treads to the tires and stitch each shoulder tread from the tire bead side toward the center tread side using a stitching roll.

[Operation of the Invention] This invention is constructed as described above, and the tire tread is formed in advance by dividing it into three parts: a center tread that is attached to the crown part of the tire carcass, and a shoulder tread that is attached to a part of the left and right shoulders. By attaching the shoulder tread after attaching the center tread, even when attaching a wide tread, the radial elongation will not be uneven, and there will be no air pockets in the shoulder part. This method does not cause the problem of the occurrence of oxidation, and it is possible to improve the molding accuracy of the tire.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail based on the accompanying drawings.

Note that the same components as those in the conventional example are given the same reference numerals, and the description thereof will be omitted.

Figure 1 shows an ultra-flat radial tire T according to the present invention.
1 shows a formed tire carcass, on which a breaker 2 and a tread 5 divided into three parts are successively pasted and laminated.

The tread 5 divided into three parts is formed in the tire carcass 1 in advance.
A center tread 5a having a substantially trapezoidal cross section is attached to the crown part Wa of the tread, and two shoulder treads 5b are attached to the left and right shoulder portions wb, each of which has an approximately equal width and is extrusion-molded, as shown in FIG. As shown, after a center tread 5a is attached to the crown portion of the tire carcass, shoulder treads 5b, 5b are sequentially attached to the tire shoulder portions.

Next, a method for attaching the center tread 5a divided into three parts and the shoulder treads 5b, 5b on the tire carcass 1 will be specifically explained with reference to FIGS. 3 and 4.

First, the shoulder treads 5b, 5b are made in advance by side
It is pasted on the walls 6a and 6b, and the tire casing is pasted on the tire carcass 1 in a flat state. Next, as shown in FIG. 3, the center tread 5a is laminated and pasted on the breaker 2 of the tire carcass 1 formed by inflating the tire, and then a portion of the shoulder wb is pasted from the center of the center tread 5a. Stitching is performed by the stitching roll 4 toward each end.

Then, the tips of the shoulder treads 5b, 5b are turned and pasted, and each shoulder tread 5b, 5b is pasted.
b are stitched by the stitching roll 4 from the tire bead 7 side toward the center tread 5a side.

In addition, the center tread 5a and the shoulder tread 5
The splice portion G between b and 5b is removed from within the same ground plane.

FIG. 5 shows another embodiment in which the center tread 5a is formed into an inverted trapezoidal shape, and the shoulder treads 5b are formed to correspond to the shape of the end portion of the center tread 5a. In the above embodiment, when the tread 5 is pasted onto the tire carcass 1, the center tread 5a is pasted first, and then the left and right shoulder treads 5b, 5b are pasted. The left and right shoulder treads 5b, 5b are first attached to a part of wb, and the center tread 5a is attached later.

As described above, this embodiment includes a center tread 5a which is divided into three parts, and left and right shoulder treads 5b, 5.
b), and after pasting the center tread 5a, the shoulder treads 5b are pasted and spliced, resulting in uneven elongation in the radial direction even when a wide tread is pasted. Moreover, the problem of air pockets occurring in a part of the shoulder does not occur, and the molding accuracy of the tire can be improved.

〔Effect of the invention〕

Since this invention manufactures a flat tire using the method described above, even when a wide tread is attached, the radial elongation will not be uneven, and there will be no air pockets in a part of the shoulder. There are no problems that may occur, there is no deformation of part of the shoulder, and the molding accuracy of ultra-flat tires, especially the accuracy of tire tread attachment, can be improved, and the tire uniformity can be improved.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of an ultra-flat radial tire in which the present invention is implemented, Fig. 2 is an explanatory diagram showing the method for attaching the tread divided into three parts, and Figs. 3 and 4 are the steps for attaching the tread. FIG. 5 is a sectional view showing another embodiment of the center tread, and FIG. 6 is an explanatory view showing a conventional tread attachment method. 1... Tire carcass, 2... Breaker, 4...
Stitching roll, 5... Tread, 5a... Center tread, 5b... Shoulder tread, 6a
, 6b...side wall, T...super flat radial tire, Wa...crown part, wb...part of shoulder.

Claims (1)

[Claims] 1. After pasting the center tread of a tread divided into three parts, a center tread and a shoulder tread, on the crown part of a molded tire carcass, and then pasting each shoulder tread on the tire shoulder part. A method for manufacturing a flat tire, characterized by: 2. After attaching the center tread to the crown part of the formed tire carcass, stitch each part from the center of the center tread toward the shoulder part using a stitching roll, and then to the tire shoulder part.
A method for manufacturing a flat tire, comprising the steps of pasting each shoulder tread and stitching each shoulder tread from the tire bead side toward the center tread side using a stitching roll.