JP2855329B2 - Pneumatic bias tire - Google Patents

Description

Description: TECHNICAL FIELD [0001] The present invention relates to a pneumatic bias tire that reduces heat generation and heat storage inside a tire during running and improves high-speed durability.

[Conventional technology]

Conventionally, a pneumatic bias tire is shown in FIGS.
As shown in the figure, the cords 6a of the carcass layer 6 cross each other between plies. This is because the direction of the force applied to each ply during running is offset between the adjacent plies and the uniformity of the entire ply is ensured. In these figures, 1 is a crown portion, 2 is a shoulder portion, 3 is a side portion, 4 is a bead portion, 5 is a tread,
7 represents a bead wire and 8 represents a breaker layer.

However, when code 6a is crossed in this way,
As the carcass layer 6 moves differently between adjacent plies during traveling, internal stress is generated because the rubber between the plies receives forces in different directions, thereby generating high heat in the carcass layer, There was a problem that separation occurred between plies. Therefore, in order to avoid this problem as much as possible, each ply is covered with a rubber having an appropriate thickness d1, d2, d3, d4,... Above and below the cord 6a as shown in FIG. It served as a buffer layer for relaxing the internal stress of each ply, thereby suppressing the occurrence of separation. However, in the case of a multilayer ply tire, these coated rubbers increase the thickness of the carcass layer as a whole and cause heat to accumulate, which is unfavorable for durability at high speed. In particular, as shown in FIG. 6, the shoulder portion 2 of the tire has a large heat storage due to the thick rubber, and is a portion where failure due to heat generation inside the tire is likely to occur.

[Object of the invention]

The present invention has been made in order to solve such a problem, and reduces heat generation and heat storage inside the tire during running, prevents separation between plies, and improves high-speed durability. It is an object of the present invention to provide a pneumatic bias tire that has been crushed.

[Configuration of the invention]

The present invention relates to a pneumatic tire having a carcass layer of a multilayer bias ply, wherein at least two of the plies have a carcass layer.
By arranging the cord arrangement of the adjacent plies of the layer in parallel with each other, it is possible to omit or thin the cord covering rubber between these plies, and to maintain the uniformity of the plies as a whole tire, Preferably, the plurality of parallel-arranged plies are stacked such that the cords intersect with the other plurality of parallel-arranged plies so that various characteristics during running of the tire are not hindered. That is, in summary, in the bias tire having three or more carcass layers, the present invention arranges the cords of at least two adjacent carcass layers parallel to each other between plies, and in the tread region, The gist of the present invention is a pneumatic bias tire formed of a single layer by indenting cords of at least two adjacent carcass layers arranged in parallel with each other and eliminating a covering rubber gauge between plies.

Hereinafter, the configuration of the present invention will be described in detail with reference to the drawings. Parts similar to those in FIGS. 5 and 6 are denoted by the same reference numerals.

FIG. 1 is a partially cutaway perspective view of an example of a pneumatic bias tire according to the present invention in a case where there are 12 carcass layers, and FIG. 2 is a half sectional view in the meridian direction.

FIG. 1 shows that in the tire, the cords 6a of the first, second, and third carcass layers 6 counted from the tire inner side to the outer side are parallel to each other between the plies, and the third and fourth numbers are the same. Intersect, make the 4th, 5th, 6th parallel, 6th and 7th
No. 7 and No. 8 and No. 9 are parallel,
The ninth and tenth cross each other, and the tenth, eleventh, and twelfth are parallel. As the cord 6a of the carcass layer 6, for example, an organic fiber cord such as a nylon cord or a polyester cord is used.

Also, the first cord 6a is made parallel to each other between plies.
No. 2, No. 3, No. 3 ply group, No. 4, No. 5, No. 6
No. ply group, No. 7, No. 8, No. 9 ply group, No.
For each of the 10th, 11th, and 12th plies,
As shown in FIG. 2, in the region of the tread 5, the cords are cut into each other, and a single layer is formed by eliminating the covering rubber gauge between the plies. Here, the carcass layer is represented by a solid line and a chain line, and the solid lines or the chain lines mean that the cords are parallel to each other between the plies, and the solid line and the chain line cross each other.

In this manner, the four parallel-arranged plies groups in which the cords 6a are located in parallel between the plies were stacked so that the cords crossed each other, so that a rubber buffer layer had to be provided only at the boundary surface of each group, Since the amount of rubber in the carcass as a whole can be reduced, which is advantageous for heat storage of the tire, and the plies of the parallel arrangement plies, the carcass layer 6 moves in the same manner between the plies during running. Concentration does not occur and heat generation can be suppressed. Further, since each of the four parallel-arranged plies is formed as a single layer in the region of the tread 5, the thickness of the carcass layer can be reduced as a whole in this region, thereby reducing internal heat generation and heat storage in this region. be able to.

The tire of the present invention was formed by laminating a group of parallel-arranged plies having a thinner coated rubber gauge as a part of a carcass when forming the tire, forming a cylindrical tire, forming this into an annular tire, and further vulcanizing. The tire is near the shoulder of the carcass as shown in Fig. 2.
Since 6b undergoes large deformation during the tire molding and vulcanization process, the cords of the adjacent ply groups are biting into each other, and the thickness of the entire carcass layer is reduced. Also, at this time, in the stacking of the plies of the parallel arrangement ply group, one ply is stacked in a cylindrical shape while shifting the pitch, and bonded.
Wrinkled spiral bonding becomes possible, and productivity can be improved.

FIG. 3 is a half sectional view in the meridian direction of another example of the pneumatic bias tire of the present invention. FIG. 3 shows a case where there are three carcass layers, and a case where two adjacent carcass layers are overlapped with each other to reduce the thickness of the coated rubber gauge.

To confirm the effects of the present invention, tire size 10.00-2
A heat generation test was carried out by an indoor rotation test under the conditions of a load of 2470 kg and a speed of 50 km / h using 14PR Y67 (a cord of a carcass layer: a nylon fiber cord). In this case, the temperature change was observed by elapse of the traveling time (minute) at the point A on the outermost carcass layer corresponding to the shoulder point 9 in FIG. The results are shown in FIG. 4 (measured on left and right tires with N = 1). In FIG. 4, a shows the tire of the present invention (the structure of FIGS. 1 and 2), and b shows the conventional tire (the structure of FIGS. 5 and 6). FIG. 4 shows that the tire of the present invention is excellent in heat resistance.

〔The invention's effect〕

As described above, according to the present invention, the cords of at least two adjacent carcass layers are arranged in parallel between the plies, and the cords of the at least two adjacent carcass layers arranged in parallel in the tread region. Are formed in a single layer by digging into each other and eliminating the coating rubber gauge between the plies, the following effects can be obtained.

Since the carcass layers move in the same manner between the parallel plies during running, heat generation and separation between the plies can be prevented, and the high-speed durability can be improved.

The rubber gauge between the plies can be eliminated, so the overall gauge from the crown to the shoulder of the tread, which generates heat in contact with the road surface, becomes thinner, which improves heat dissipation and lowers heat storage, resulting in heat resistance and high-speed durability Sex can be further improved.

Since the coating rubber gauge between the plies can be eliminated, the material cost can be reduced, and further, since the carcass layer can be so-called spirally applied at the time of molding the tire, the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of an example of a pneumatic bias tire of the present invention, FIG. 2 is a half-sectional explanatory view of the pneumatic bias tire of the present invention, and FIG. 3 is a meridian direction of another example of the pneumatic bias tire of the present invention. FIG. 4 is a diagram illustrating the relationship between the running time and the tire internal temperature. FIG. 5 is a partially cutaway perspective view of an example of a conventional pneumatic bias tire, FIG. 6 is a half sectional view in the meridian direction thereof,
FIG. 7 is an explanatory partial cross-sectional view of the carcass layer. 1 ... crown part, 2 ... shoulder part, 6 ... carcass layer, 6a ... cord, 7 ... bead wire, 8 ... breaker layer.

Claims (1)

(57) [Claims] 1. A bias tire having three or more carcass layers, wherein cords of at least two adjacent carcass layers are arranged parallel to each other between plies, and at least two layers of the parallel arranged carcass layers are arranged in a tread region. A pneumatic bias tire formed into a single layer by making the cords of adjacent carcass layers bite each other and eliminating the covering rubber gauge between the plies.