JPH06115320A - Tire having shoulder block - Google Patents

Abstract

PURPOSE:To enhance the turning performance and/or the straight driving performance of a tire not only at a specific steering angle but also at other angles by arranging edges adjacent to each other in the circumferential direction of the tire, one of the edges being inclined at a desired angle to the axis of the tire and the other inclined at other than that angle. CONSTITUTION:A block pattern having a number of blocks 4 aligned in the circumferential direction C of the tire is formed in the center portion 2 and right and left shoulder portions 3 of a tread. Each block 4 has edges 5 formed at its front and rear ends extending in the circumferential direction C of the tire and at the front and rear ends of its surface on which sipes 6 are formed. Some of the blocks 4 have their edges 5 inclined at an angle A1 to the axis B of the tire and the blocks 4 located between have their edges 5 formed at angles A2-A5 other than angle A1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire having a shoulder block having a block pattern, such as a studless tire.

[0002]

2. Description of the Related Art Conventionally, in studless tires and the like, a block pattern has been used in order to improve running and drainage properties, and the blocks formed on the left and right shoulders have a shape shown in FIGS. There is one shown in. In the first prior art shown in FIG. 4, the edges 5 of all blocks 4 are parallel to the tire axial direction B (orthogonal to the tire circumferential direction C), and the second prior art shown in FIG.
The edges 5 of all the blocks 4 are inclined at an angle A1 with respect to the tire axial direction B.

Considering the running performance during straight running, it is most preferable that the edge 5 of the block 4 is at a right angle to the straight running direction, that is, the tire circumferential direction C, as in the first prior art. Since the tire tends to slip in the tangential direction D, it is preferable to keep the tire closer to a right angle to the tangential direction D as in the second conventional technique because the turning force becomes higher.

[0004]

However, the turning performance is deteriorated in the first prior art and the straight running performance is partially sacrificed in the second prior art, so that stable running performance is achieved in both straight running and turning. It is difficult to put out. That is, the first
In the prior art, as shown by the dotted line in FIG. 2, the turning force decreases in inverse proportion as the steering wheel angle increases, and in the second prior art, the edge 5 is perpendicular to the tangential direction as shown by the chain line. The turning force is high when the steering wheel angle is, and the turning force is low in other cases, making it difficult to obtain stable turning performance.

According to the present invention, by arranging an edge inclined at an angle A1 with respect to the axial direction of the tire and an edge having an angle other than the angle A1 adjacent to each other in the blocks of the left and right shoulder portions in the tire circumferential direction, the vehicle advances straight. Another object of the present invention is to provide a tire having a shoulder block capable of providing stable running performance on both sides of turning.

[0006]

The concrete means for solving the problem in the present invention is at least the left and right shoulder portions 3.
In the tire having the shoulder block having the block 4 in each side, the block 4 of each of the left and right shoulder portions 3 has an edge 5 inclined at an angle A1 with respect to the tire axial direction B.
And the edge 5 having an angle other than the angle A1 are arranged adjacent to each other in the tire circumferential direction C.

[0007]

When the vehicle body travels straight or makes a very gentle turn, the block 4 having the edge 5 with an extremely small inclination angle A5 has a running action to exert an effective straight running performance. Medium tilt angle A
The block 4 having the edge 5 of 2, A3 or A4 has a running action, and when turning at a steep angle, a large inclination angle A1
The block 4 having the edge 5 has a running action, and exhibits good turning performance according to each turning angle.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In the first embodiment shown in FIG. 1, 1 is a studless tire, and a tread is formed with a block pattern having a large number of blocks 4 in a tire circumferential direction C on a center portion 2 and left and right shoulder portions 3, and each block is formed. A plurality of sipes 6 which are long in the tire axial direction B are formed on the tire 4.

Each block 4 has edges 5 formed at the front and rear ends in the tire circumferential direction C and the front and rear edges of the surface forming the sipe 6, so that the edge action by the edge 5 kicks the ground at the time of ground contact. Has become. Blocks 4 located at intervals in the tire circumferential direction C of the left and right shoulder portions 3.
The edges 5 are inclined at an angle A1 with respect to the tire axial direction B, and in the other blocks 4 located between the blocks 4, the edges 5 have angles A2 to A5 other than the angle A1.
Is formed in.

The edge 5 of the sipe 6 of each block 4 is the edge 5 at the front and rear ends in the tire circumferential direction C of each block 4.
The edge 5 of the block 4 and the edge 5 of the sipe 6 are formed in parallel with each other and have the same effect on the running performance, although the degree is different. The angles A1 to A5 of the edge 5 are different from each other, and the steering angle of the steering wheel (usually 1 to 45).
1), which is set within 10 degrees and is used relatively often
A range of 5 degrees is preferred.

The angle A1 of the edge 5 is, for example, the same angle as in the second prior art, and is an angle that approaches a right angle with the tangential direction when the vehicle body turns when the steering wheel angle is steep (the steering wheel angle when turning). The angles A2 to A5 are smaller than the angle A1 and are angles approaching a right angle to the tangential direction of the vehicle body during a gentle curve, and the angle A5 may be 0 degrees. In this way, when the edge 5 inclined at the angle A1 with respect to the tire axial direction B and the edge 5 at the angles A2 to A5 other than the angle A1 are arranged adjacent to each other in the tire circumferential direction C, the steering wheel angle and the turning force are increased. As shown by the solid line in FIG. 2, a substantially constant turning force is obtained regardless of the steering wheel angle, and both the straight running performance and the turning performance become stable.

In the second embodiment shown in FIG. 3, blocks 4a, 4b, 4 having sipes 6 on the left and right shoulder portions 3 are provided.
Many c are arranged in the tire circumferential direction C, and block edges 5a, 5b, 5c of the blocks 4a, 4b, 4c are arranged.
Are set at angles different from each other with respect to the tire axial direction B, and are angles A0, A1, and A2, respectively. The angle A0 is 0 degree, that is, parallel to the tire axial direction B, and the angle A1 is an inclination angle larger than the angle A2.

The edges 5d, 5e, 5f of the sipes 6 in the blocks 4a, 4b, 4c have different angles with respect to the tire axial direction B, and the edge 5d has an angle A1.
The edge 5e is inclined at an angle A2, and the edge 5f is inclined at an angle A0. Therefore, in the block 4a, the block edge 5a having an angle of 0 and the sipe edge 5d having the inclination angle A1 are formed, and the block 4b is formed.
In, the block edge 5b having the inclination angle A2 and the sipe edge 5e are formed, and in the block 4c, the block edge 5c having the inclination angle A1 and the sipe edge 5f having the angle A0 are formed.

The angles of the block edges 5a, 5b, 5c and the sipe edges 5d, 5e, 5f are the same as the angle A.
Other than 0, A1, and A2, when the block edge has a large inclination angle, the inclination angle of the sipe edge is made small, the turning ability is made high at the block edge and the straightness is made high at the sipe edge, and the inclination angle is small at the block edge. In this case, it is preferable to increase the inclination angle of the sipe edge so that the block edge has high straightness and the sipe edge has high turning ability. Further, the three types of blocks 4a, 4b, 4c may be two types or four or more types.

[0015]

According to the present invention described in detail above, in a tire having a shoulder block having blocks 4 on at least each of the left and right shoulder portions 3, the block 4 of each of the left and right shoulder portions 3 has a tire axial direction B. The edge 5 inclined at an angle A1 with respect to the edge 5 and the edge 5 having an angle other than the angle A1
Since and are arranged adjacent to each other in the tire circumferential direction C, not only when the steering wheel angle is the angle A1, but also when the steering wheel angle is other than the angle A1, the turning performance and / or the straight running performance can be improved.
Driving stability is improved.

[Brief description of drawings]

FIG. 1 is a plan view showing a first embodiment of the present invention.

FIG. 2 is a graph showing a relationship between a steering wheel angle and a turning force according to the present invention and the related art.

FIG. 3 is a plan view showing a second embodiment of the present invention.

FIG. 4 is a plan view showing a first conventional technique.

FIG. 5 is a plan view showing a second conventional technique.

[Explanation of symbols]

 1 Studless tire 2 Center part 3 Shoulder part 4 Block 5 Edge 6 Sipe A Angle B Tire axial direction C Tire circumferential direction

Claims (1)

[Claims] 1. A tire having a shoulder block having blocks (4) on at least left and right shoulder portions (3), wherein the blocks (4) of the left and right shoulder portions (3) are in the tire axial direction (B). A shoulder block in which an edge (5) inclined at an angle (A1) and an edge (5) having an angle other than the angle (A1) are arranged adjacent to each other in the tire circumferential direction (C). With a tire.