JPH0891012A - Pneumatic tire - Google Patents

Abstract

PURPOSE: To correctly position the edge of a textile cord by constituting a belt layer from a steel ply and a kebler ply which is broader than the steel ply and positioning the edge on the outside in the width direction of the textile cord, between the edges of both the belt plies. CONSTITUTION: A belt layer 9 which is constituted of a steel ply 7 and a kebler ply 8 having the broader width is arranged outside in the radial direction of the crown part of a carcass 6 inside a tread part 1. Further, on the outside in the axial direction including the edge 9A of the belt layer 9, the edge 10A is positioned between the edges 7A and 8A of both the plies 7 and 8, covered by a textile cord 10 wound in the tire revolution direction. Accordingly, when lift is suppressed by the textile cord 10 and BEL is prevented, reducing the weight of the tire and improving the fuel consumption, the positioning of the cord 10A can be correctly performed, and the adverse influence given to the tire life can be reduced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a pneumatic tire.

[0002]

2. Description of the Related Art In FIGS. 4A and 4B, a conventional pneumatic tire T includes a carcass 101 which is arranged by folding back around a bead core of a bead portion from a tread portion 100 through a sidewall portion. A belt layer (breaker layer) 103 in which two steel plies 102 are sequentially stacked inside the tread portion 100 and outside the carcass 101 in the radial direction, and an edge 1 of the belt layer 103.
And a textile cord 104 which is wound in the rotational direction of the tire on the outer side in the radial direction including 03A. By covering the edge 103A with the cord 104, unnecessary movement such as lift of the edge 103A is suppressed. Improve the high speed (HSP) and prevent the separation (BEL) due to the edge of the edge 103A being broken.

In FIG. 4A, the cord 104 is arranged on a part of the belt layer 103 on the outer side in the width direction, whereas in FIG. 4B, the cord 104 is arranged on the entire width of the belt layer 103.

[0004]

In the conventional example shown in FIGS. 4A and 4B, since the textile cord 104 is wound in the tire rotation direction, the edge portion thereof has a width direction of the tire and Positioning in the radial direction is difficult, and due to the movement of rubber and the change in tire diameter during the vulcanization process during tire manufacturing, the edge 104A that should originally be at the positions shown in FIGS. 4 (A) and 4 (B) is shown in FIG. 4 (C). As shown in Fig. 4 (D), the ends vary in the width direction of the tire.
In some cases, the tires may slip inward in the radial direction, which adversely affects the life of the tire.

Therefore, an object of the present invention is to make it possible to accurately position an edge in a textile cord by providing an organic relationship between the material of the belt layer and the width dimension.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a tread portion 1
A carcass 6 which is disposed by folding back around the bead core 5 of the bead part 4 through the sidewall part 3 and two belt plies which are sequentially stacked inside the tread part 1 and on the outer side in the radial direction of the carcass 6. A pneumatic tire comprising: a belt layer 9 composed of 7 and 8; and a textile cord 10 wound in the tire rotation direction on the outer side in the radial direction including the edge 9A of the belt layer 9, The following technical measures are taken to achieve it.

That is, in the pneumatic tire according to the present invention, one of the belt plies 7 and 8 is the steel ply 7 and the other is the Kevlar ply 8, and the Kevlar ply 8 is wider than the steel ply 7. The edge 10A on the outer side in the width direction of the textile cord 10 is positioned between the edges 7A and 8A of the two belt plies 7 and 8.

In the present invention, steel plies can be placed inside or outside the Kevlar plies, and the textile cord can be single or multiple plies.

[0009]

Since the edge 7A of the steel ply 7 is covered with the Kevlar ply 8 or the textile cord 10, BEL is less likely to occur at the edge 7A. Since the Kevlar ply 8 generates almost no stress against the force in the compression direction, BEL is less likely to occur even at the edge 8A of the Kevlar ply 8.

Since the specific gravity of Kevlar is smaller than that of steel, the edge 8 of the Kevlar ply 8 during high speed running
The lift of A does not pose a problem compared to that of the steel ply 7, and the textile cord 10 only needs to suppress the lift of the edge 7A of the steel ply 7, and the edge 10A of the textile cord 10 is placed inside the edge 8A of the Kevlar ply 8. When the edge 10A of the cord 10 is brought into close contact with the Kevlar ply 8, the positioning becomes accurate.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 showing the right half of a pneumatic radial tire T, a sidewall portion 3 is provided from a tread portion 1 through a shoulder portion 2. The radial carcass 6 is arranged so as to be folded back around the bead core 5 of the bead portion 4 passing through
Is two plies in the figure, but it may be a single ply or two or more plies.

Inside the tread portion 1 and outside the crown portion of the carcass 6 in the radial direction, a belt layer 9 consisting of two belt plies 7 and 8 is provided. Is covered by the textile cord 10 wound in the tire rotation direction to suppress the lift and prevent the occurrence of BEL.

The first layer of the belt layer 9 is the steel ply 7, the second layer is the Kevlar ply 8, and the width of the Kevlar ply 8 is wider than that of the steel ply 7. The edge 10A of the textile cord 10 is positioned between the edges 7A and 8A of both plies 7 and 8.

Here, the edge 7 of the steel ply 7 is covered with the Kevlar ply 8 or the textile cord 10 to prevent BEL from being generated, and the Kevlar ply 8 is almost stressed against the force in the compression direction. Since it does not occur, BEL is less likely to occur in the edge 8A, and the specific gravity of the Kevlar is smaller than that of steel, so there is no problem. Therefore, the edge 10A of the textile cord 10 can be brought into close contact with the Kevlar and its positioning is accurate. it can.

In the illustrated example of FIG. 1, textile code 1
0 was partially covered on both outer sides of the belt layer 9, while the illustrated example of FIG. 2 is different in that the textile cord 10 covers the entire width of the belt layer 9,
Further, in the illustrated example of FIG. 3, the textile cords 10 of FIGS. 1 and 2 are combined to form a plurality of plies, and since the other configurations are common, portions common to FIGS. It is indicated by a symbol.

Further, in FIGS. 1 to 3, the first layer belt ply is made of steel ply and the second layer is made of Kevlar ply, but the width of the Kevlar ply is wider than that of the steel ply. The first layer may be Kevlar ply and the second layer may be steel ply.

[0017]

According to the present invention described in detail above, by using two belt plies, one of which is steel and the other of which is Kevlar, the weight and the fuel consumption of the tire can be reduced, and the textile cord suppresses lift and When the BEL is prevented, the edge of the cord can be positioned accurately, so that the life of the tire is not adversely affected.

[Brief description of drawings]

FIG. 1 is a right half sectional view showing a first embodiment of the present invention.

FIG. 2 is a left half sectional view showing a second embodiment of the present invention.

FIG. 3 is a right half sectional view showing a third embodiment of the present invention.

4A, 4B, 4C and 4D are cross-sectional views of four conventional examples.

[Explanation of symbols]

 T tire 1 tread portion 3 sidewall portion 4 bead portion 5 bead core 6 carcass 7 belt ply (steel ply) 8 belt ply (Kevlar ply) 10 textile cord

Claims (4)

[Claims] 1. A carcass (6) arranged so as to be folded back from a tread portion (1) through a sidewall portion (3) and around a bead core (5) of a bead portion (4), and the tread portion (1). Belt plies (7) that are sequentially stacked inside the carcass and radially outside the carcass (6)
Air comprising a belt layer (9) composed of (8) and a textile cord (10) wound in the tire rotation direction on the radially outer side including the edge (9A) of the belt layer (9). In the filled tire, one of the belt plies (7) and (8) is a steel ply (7) and the other is a Kevlar ply (8), and the Kevlar ply (8) is wider than the steel ply (7). The edge (10A) on the widthwise outer side of the textile cord (10) is positioned between the edges (7A) and (8A) of the two belt plies (7) and (8). Pneumatic tires. 2. The belt plies (7) (8) are arranged in the order of a steel ply (7) and a Kevlar ply (8) in the carcass (6) from the carcass side toward the radial outside. The pneumatic tire according to claim 1. 3. The pneumatic belt according to claim 1, wherein the belt plies (7) (8) are arranged in order of the Kevlar ply and the steel ply from the carcass (6) side toward the radially outer side. tire. 4. The pneumatic tire according to claim 1, wherein the textile cord (10) is a single ply or a plurality of plies.