JPH085283B2 - Pneumatic tire - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pneumatic tire having improved durability at high speed running.

[Conventional technology]

There is a pneumatic tire in which a band layer is provided on the outer side of a belt layer using a metal or organic fiber cord in order to improve tire durability and steering stability. Furthermore, the actual development Sho 61-1560
As disclosed in No. 4, the applicant of the present invention has formed a band layer by winding a strip ply a plurality of times.

By providing a band layer formed by winding such a band-shaped ply, the tread portion has an increased hoop effect, and as a result of the centrifugal force generated in the tread portion as the tire rotates, the tread portion bulges outward in the tire radial direction, and It was possible to effectively prevent the so-called lifting phenomenon from occurring.

[Problems to be Solved by the Invention]

However, when the band layer is formed by winding the band ply a plurality of times, the band ply is spirally wound, and the cord forming the band ply cannot be parallel to the tire circumferential direction. It will be inclined by an angle corresponding to the lead angle of the spiral. As a result, the tire is deformed and the uniformity is deteriorated, so that the durability is reduced. This tendency is remarkable especially when traveling at high speed.

In order to solve the above-mentioned problems, the inventors of the present invention have conducted repeated research on winding a belt-shaped ply, and as a result, when winding the belt-shaped ply, the belt-shaped ply is arranged parallel to the tire equator in a majority of the tire circumferential surface. At the same time, they have found that the problem of the spiral winding described above can be solved by locally shifting to the next step.

An object of the present invention is to provide a pneumatic tire capable of improving durability at high speed running by increasing the uniformity of the tread portion.

[Means for solving the problem]

The present invention is a carcass consisting of one or more carcass plies that pass around a bead core of a bead part through a tread part, a side wall part, and two or more pieces arranged inside the tread part and on the outer side in the tire radial direction of the carcass. A belt layer consisting of the belt ply and a band layer disposed radially outside the belt layer and covering the belt layer,
The band layer is a long and narrow band-shaped ply having a plurality of band cords arranged in parallel and covered with a topping rubber, and a parallel region arranged parallel to and adjacent to the tire equator, and a parallel region. Continuous with the belt-shaped plies and inclined at an angle of 0.5 to 3 ° with respect to the tire equator, and has an inclined area continuous with the adjacent belt-shaped plies in the parallel area, and the inclined area is 0.2 More than double and 0.5
The band layer should start from one end in the tire width direction and end at the other end in the tire width direction, and at least at the tread shoulder portion, the band plies are wound in advance in the adjacent band plies in the radial direction. A pneumatic tire having an overlapping portion continuously formed on the outer side.

[Operation] Since the band layer in which the band-shaped ply is wound is provided on the outer side in the radial direction of the belt layer, the so-called lifting phenomenon in which the tread portion bulges outward in the tire radial direction due to the centrifugal force caused by the rotation of the tire is prevented. You can

Further, since the strip-shaped ply is wound with the parallel region and the inclined region and is local to the entire circumference of the inclined region, it enhances the uniformity of the tread portion and improves the durability at high speed running. can do.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In the figure, a pneumatic tire 1 has a sidewall portion 3 extending radially inward from both ends of a tread portion 2.
And a bead portion 4 located at the radially inner end of the side wall portion 3, and a toroidal carcass in which both ends pass from the tread portion 2 through the side wall portion and are folded back around the bead core 4A. 5 and tread part 2
And a belt layer 6 located inside and outside the carcass 5 in the radial direction. In this example, the band layer 7 is arranged on the outer side in the radial direction of the belt layer 6 over the entire width of the belt layer 6.

In the present example, the carcass 5 is composed of one carcass ply having a radial or semi-radial arrangement in which a carcass cord made of an organic fiber such as nylon or aromatic polyamide is inclined by 60 to 90 ° with respect to the tire equator C. .

The belt layer 6 comprises a plurality of layers, in this embodiment, upper and lower two layers of belt plies 6A and 6B, and the lower belt ply 6A is formed wider than the upper belt ply 6B.

The upper and lower belt plies 6A and 6B cross a highly elastic belt cord made of an organic fiber such as steel or aromatic polyamide at an angle of 15 to 40 ° with respect to the tire equator C and between the upper and lower belt plies. It is arranged in the direction.

The band layer 7 is formed by winding the band-shaped ply 10.

Band-shaped ply 10 consists of multiple band cords arranged in parallel
A cross section formed by covering 11 ... With a topping rubber 12 is a substantially rectangular and narrow elongated body.

In this embodiment, the band cord 11 is preferably an organic fiber cord having a heat shrinkability such as nylon 6.6. Such a heat-shrinkable organic fiber cord has a certain elongation during vulcanization and shrinks due to heat,
The strip ply 10 with high accuracy can be formed, and the uniformity of the finished tire is improved, while the strip ply 10 is easily manufactured.

Further, it is preferable that the band-shaped ply 10 has the band cords 11 ... Width of strip ply 10 (W1) for less than 6
Is small and the number of windings is large, which requires time and effort for manufacturing, resulting in high cost. On the contrary, if it exceeds 20 strips of ply 10
As a result of widening the width (W1) of the belt, the inclination angle of the belt-shaped ply 10 becomes large in an inclined region described later during winding, and the uniformity of the tire is impaired.

The band layer 7 is continuously wound so that the band-shaped ply 10 starts to be wound from one end F1 of the band layer 7 in the tire width direction as a starting point, and passes through the tire equator C to reach the other end F2 of the tire width direction and terminates. .

When the strip-shaped ply 10 is wound, as shown in FIG. 4 (a), the strip-shaped ply 10 is wrapped around the opposite side edges 10a of the strip-shaped ply 10 so as to have an overlapping portion 16.

Further, as shown in FIG. 2, the winding of the belt-shaped ply 10 is inclined at an angle α of 0.5 to 3 ° with respect to the parallel region J and the tire equator C which are arranged parallel to and adjacent to the tire equator C, and one end of which is inclined. An adjacent strip-shaped ply which is connected to one strip-shaped ply 10 in the parallel region and whose other end is adjacent to the one strip-shaped ply 10.
It is composed of a sloped region K in which strip-shaped plies 10B ...

The inclined region K is set to a range of 0.2 times or more and 0.5 times or less of the entire circumference of the tire. If the inclination region K is less than 0.2 times the entire circumference of the tire, the inclination angle of the belt-shaped ply 10, and thus the band cord.
While the inclination angle of 11 becomes large and manufacturing becomes difficult, when it exceeds 0.5 times, the parallel region J becomes small and the uniformity of the tire is not improved.

The inclination angle K of the strip ply 10 in the inclined region K
Is inclined beyond 3 °, the parallel region J and the inclined region K
The bending angle becomes large at the connecting portion Q with and, which makes the manufacture difficult.

Further, it is preferable that the seam of the tread portion 2 and the seam of the belt layer 6 which are easily broken during high speed running be located in the parallel region.

The overlapping portion 16 at the time of winding the strip-shaped ply 10 is the fourth
As shown in FIG. 6B, the overlap margin L may be made small in the central portion and gradually increased toward one end F1 and the other end F2 of the band layer. Further, a step may be formed so that the central portion is small and the tread shoulder portion is large.

When a tire travels at high speed, lifting is generally apt to occur in the tread shoulder region. Therefore, by increasing the rigidity near one end F1 and the other end of the band layer 7, the durability can be efficiently improved. Moreover, it is possible to suppress an unnecessary increase in tire weight.

The strip-shaped ply 10 may be wound so that the overlapping margin L is evenly distributed over the entire region, and the overlapping margin L may be O at the center and the overlapping margin L may be provided only on the tread shoulder portion. Thus, in the pneumatic tire of the present invention, the strip-shaped ply 10 has an overlapping portion 16 that continuously overlaps at the outer side in the radial direction of the adjacent strip-shaped plies 10 that are wound in advance at least in the tread shoulder portion. Let

Further, one end F1 and the other end F2 of the band layer 7 are lapped in parallel with the tire equator C for at least one revolution,
The winding start and winding end of the strip ply 10 can be reinforced,
It is possible to prevent the peeling and the growth thereof which are likely to occur at the end portions of the belt layer 6 and the band layer 7, and to further improve the durability.

The band layer 7 includes the winding of the band-shaped ply 10,
The outer double layer may be formed, and the present invention can be modified into various modes.

〔The invention's effect〕

As described above, in the pneumatic tire of the present invention, since the strip-shaped ply is wound with the parallel region and the inclined region having the above-mentioned constitution, the uniformity of the tire is enhanced and the durability in high speed running can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a developed plan view showing a combination of a carcass, a belt layer and a band layer, and FIG. 3 is a perspective view illustrating a band-shaped ply, and FIG. (A), (b) is sectional drawing which shows the winding of a strip ply. 2 ... Tread part, 3 ... Sidewall part, 4 ... Bead part, 4A ... Bead core, 5 ... Carcass, 6 ... Belt layer, 6A, 6B ... Belt ply, 7 ... Band layer, 10
…… Strip-shaped ply, 11 …… Band cord, 12 …… Topping rubber, J …… Parallel area, K …… Inclined area.

Claims (1)

[Claims] 1. A carcass consisting of one or more carcass plies that pass through a tread portion and a side wall portion and fold around a bead core of a bead portion, and two pieces arranged inside the tread portion and radially outside the tire. A belt layer formed of the above belt plies and a band layer disposed outside the belt layer in the radial direction and covering the belt layer, wherein the band layer includes a plurality of band cords arranged in parallel by a topping rubber. A long and narrow band-shaped ply covered with the parallel region is arranged parallel to and adjacent to the tire equator, and is connected to the belt-shaped plies in the parallel region and is inclined at an angle of 0.5 to 3 ° with respect to the tire equator. By this, there is an inclined region continuous with the adjacent strip-shaped plies in the parallel region, and the inclined region is a range of 0.2 times or more and 0.5 times or less of the entire circumference of the tire. At the same time, the band layer begins to wind from one end in the tire width direction and ends at the other end, and at least at the tread shoulder, the band ply continues radially outward to the adjacent band-shaped ply that is wound in advance. A pneumatic tire that has overlapping parts that are overlapped with each other.