JPH04126603A - Emergency tire and manufacture thereof - Google Patents

Abstract

PURPOSE:To realize weight reduction without deteriorating performance or external appearance of an emergency tire by winding up edge parts of a sheet of carcass round bead cores, and arranging also a pair of right and left breakers outside the carcass. CONSTITUTION:In an emergency tire 1, a carcass 2 is set to be constituted only from a single ply, and edge parts of the carcass 2 are also wound up from the tire inside of bead cores 3 toward outside, and the winding edge parts 4 are also situated near the upper parts of the bead cores 3. A pair of right and left breakers 5a and 5b are arranged outside of the carcass 2, and both inner edges 6a and 6b of these are overlapped each other in the crown part 7, and outer edges 8a and 8b are arranged near the bead cores 3 so that folded edge parts or breaker edge parts of the carcass do not exist in sidewall parts 13. Further, sidewall rubbers 9 and a cap tread rubber 10 are arranged outside of respective breakers 5a and 5b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lightweight emergency tire and a method for manufacturing the same.

[Conventional technology]

An emergency tire is a tire that can be used in place of a regular tire to get to a repair location when the regular tire becomes flat.

In recent years, emergency tires have been designed with a smaller tire width and diameter than regular tires in order to avoid taking up too much storage space in the vehicle, and therefore are used with high internal pressure to balance with the regular tires, and the tire structure has been changed. The upper rigidity is increased.

Due to these structural requirements, conventional emergency tires are
As shown in FIG. 5, two or four carcass 2 are arranged so that the cords intersect with each other between the eyebrows, and both ends of the carcass 2 are folded around the bead core 3 from the inside of the tire to the outside. Section 12 to sidewall section 1
It was rolled up to position 3.

For this reason, conventional emergency tires inevitably have thick sidewalls and are extremely heavy. However, when the thickness of the sidewall rubber sheet is reduced in order to reduce weight, the folded end portion 12 of the carcass becomes a step in the sidewall portion 13 and appears uneven, which significantly deteriorates the appearance of the product. Another drawback is that separation is likely to occur at the folded end 12 of the carcass.

[Problem to be solved by the invention]

An object of the present invention is to provide an emergency tire and a method for manufacturing the same that make it possible to reduce the weight of a conventional emergency tire without degrading its performance or appearance.

[Means to solve the problem]

That is, in the emergency tire of the present invention, both ends of one carcass are rolled up from the inside of the tire to the outside of the bead core, and the rolled up ends are located near the top of the bead core, and a pair of left and right breakers are provided on the outside of the carcass. - are characterized in that their inner ends overlap each other at the crown portion, and their outer ends are arranged near the bead core, and sidewall rubber and cap tread rubber are arranged on the outside of these breakers. be.

On the other hand, in the method of manufacturing an emergency tire of the present invention, a pair of left and right breakers, to which a sidewall rubber sheet is preliminarily adhered to the outer end, is placed on a carcass formed into a cylindrical body with bead cores attached to both edges. , their inner ends are overlapped at the center of the cylindrical body, and their outer ends are wrapped so as to correspond to the bead cores, and then camp tread rubber is laminated on the upper surface of the overlapped part of the breaker. It is characterized by the following.

In this way, the rolled-up end of one carcass is located near the top of the bead core, and the inner ends of the pair of left and right players arranged outside the carcass overlap each other at the crown part, and the outer ends By arranging the tire near the bead core, the folded ends of a plurality of carcass are not concentrated on the sidewall part as in conventional tires, so the sidewall part can be made thinner and lighter. Furthermore, since the sidewall portion has neither the folded end of the carcass nor the one end of the breaker, even if the sidewall rubber is made thin, there will be no unevenness, resulting in a good product appearance. Furthermore, separation at the folded end of the carcass due to stress concentration is also eliminated.

The emergency tire according to the present invention will be explained below.

FIG. 1 is a sectional view of an emergency tire according to the present invention. In this emergency tire 1, the carcass 2 has only one ply, the ends of the carcass 2 are rolled up from the inside of the tire to the outside of the bead core 3, and the rolled up ends 4 are located near the top of the bead core 3. Further, a pair of left and right breakers 5a and 5b are arranged outside the carcass 2, and their inner ends 5a and 5b are overlapped with each other at a crown part 7.
In addition to having a multilayer structure, the outer ends 3a and 3b are arranged near the bead core 3, respectively, so that there is no folded end of the carcass or one end of the cutter in the sidewall portion 13.

In the above structure, the carcass 2 is biased so that its cords are inclined obliquely with respect to the tire radial direction, and the breakers 5a and 5b are arranged so that the cords are inclined in opposite directions with respect to the carcass 2 so that they intersect with each other. It is located in Furthermore, sidewall rubber 9 and cap tread rubber 10 are arranged outside these breakers 5a, 5b.

Next, a method for manufacturing an emergency tire configured as described above will be described.

First, as shown in FIG. 2, the sheet-like material of the carcass 2 is wrapped around a forming drum 15 in a cylindrical shape, and annular bead cores 3 are attached to both ends of the sheet, and then,
Both side parts of the carcass 2 are folded around the bead core 3 to form a cylindrical body 14.

Next, as shown in FIG. 3, a first breaker 5a, to which a sidewall rubber sheet 16 has been offset and adhered to the outside, is wound around the right side of the cylindrical body 14. At this time, the first breaker 5a connects the cord 20 of the carcass 2 and the cord 5 of the first breaker 5a between the layers of the carcass 2.
0 are arranged so that they intersect with each other.

Furthermore, as shown in FIG. 4, a second plaaker 5b, to which a sidewall rubber sheet 16 is offset and adhered to the outside in advance, is wound around the outer left side of the cylindrical body 14. At this time, the inner end 6b of the second breaker 5b and the first breaker 5
The inner end 6a of a and the inner end 6a of the cylinder overlap each other at the center of the cylindrical body, and
Create a layered structure. Like the first breaker 5a, the second breaker 5b is arranged so that the cord 20 of the carcass 2 and the cord 5o of the second breaker 5b cross each other between the layers of the carcass 2. That is, the cord of the second breaker 5b is biased in the same direction as the cord of the first breaker 5a.

Next, the breaker 5a has a double structure.

A cap tread rubber 1o is arranged around the outer periphery of the cap tread rubber 10 so that both ends of the cap tread rubber 10 are flush with the inner ends of the sidewall rubber sheets 16, 16, and the molding of the cylindrical laminate 17 is completed.

In this way, the first. Since the side wall rubber sheets 16 are bonded to the second breakers 5a and 5b in advance, there is no need to perform plying of the side rubber sheets again, and work efficiency is significantly improved. Furthermore, the first sidewall rubber sheet 16 is attached. 2nd player car 5
If a and 5b are polymerized in advance into one laminated pair and then wound around the cylindrical body 14, productivity can be further improved.

The cylindrical laminate 17 thus formed is deformed into an annular shape by a known method and vulcanized. When the tire is taken out of the mold after vulcanization molding, an emergency tire 1 is obtained in which the folded end of the carcass 2 and one end of the breaker are not present in the sidewall portion 13, as shown in FIG.

〔Example〕

Tire size T115 with the structure shown in Figure 1
/70DI 4 tires of the present invention were prototyped. carcass 2
, 1st. The cords of the second breakers 5a and 5b are made of nylon 1890d/2, and the sidewall rubber 9 is made of 2. I used a 0 Tsuru rubber sheet.

On the other hand, for comparison, a conventional tire of the same size as the tire of the present invention having a structure as shown in FIG. 7 was experimentally manufactured. The material of the carcass 2 was the same as that of the present invention, and the sidewall portion 13 was made of a 2.0 Tsuru rubber sheet.

The weight of the tire on a diameter of 1 was measured and expressed as an index, with the conventional tire being 100. The smaller the index, the lighter the weight.

The time required to manufacture a production tire is expressed as an index with the conventional tire set at 1°O. The larger the index, the higher the productivity.

(Hereinafter, blank spaces) From this "table", it can be seen that the emergency tire of the present invention can achieve weight reduction and also improve productivity.

In addition, the prototype tire was installed on a 14X4T rim, and the internal pressure was 4
．． Durability was examined by running for 48 hours under conditions of 2 kg/cm2 and a load of 500 kg (7).

Similar to the conventional tire, the tire of the present invention did not cause any failure. Furthermore, the appearance of the tire of the present invention when filled with air at 4.2 kg/cm2 was good, with no step in the sidewall portion due to the folded end of the carcass.

〔Effect of the invention〕

As described above, in the emergency tire of the present invention, the end of one carcass is rolled up from the inside of the tire to the outside of the bead core, the rolled up end is located near the top of the bead core, and a pair of left and right tires are placed on the outside of the carcass. The inner ends of the breakers overlap each other at the crown part, and the outer ends of the breakers are placed near the bead core, thereby reducing the weight of the tire without degrading the performance or appearance of conventional emergency tires. It became possible.

On the other hand, the method for manufacturing an emergency tire of the present invention includes a pair of left and right breakers in which a sidewall rubber sheet is preliminarily adhered to the outer end side on a carcass formed by attaching bead cores to both edges to form a cylindrical body. are wrapped so that their inner ends overlap at the center of the cylindrical body, and then the cap tread rubber is laminated on the top surface of the overlapped part of the breaker, so that the above-mentioned lightweight carcass material It is possible to efficiently produce emergency tires using

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an emergency tire according to the present invention, and FIG.
4 to 4 are explanatory diagrams showing the manufacturing process of the emergency tire according to the present invention, and FIG. 5 is a cross-sectional view of a conventional emergency tire. 2... Carcass, 3... Bead core, 5a, 5b.
...Breaker-17...Crown part, 1o-...Cap tread rubber, 14...Cylindrical body, 16...Side wall rubber sheet. Agent Patent Attorney Nobuo Ogawa −

Claims (1)

[Claims] 1. A carcass is rolled up with its both ends from the inside of the tire to the outside of the bead core, and the rolled up ends are positioned near the top of the bead core, and a pair of left and right breakers are installed on the outside of the carcass. An emergency tire in which the inner ends overlap each other at the crown part, the outer ends are arranged near the bead core, and sidewall rubber and cap tread rubber are arranged outside these breakers. 2. On a carcass formed into a cylindrical body with bead cores attached to each end edge, a pair of left and right breakers to which a sidewall rubber sheet has been glued in advance to the outer end side is attached, and the inner ends of the breakers are attached to the cylindrical body. A method for manufacturing an emergency tire, in which the central part is overlapped, the outer ends are wrapped so as to correspond to the bead core, and then a cap tread rubber is laminated on the upper surface of the overlapped part of the breaker.