JPH0733708U - Tire tread structure - Google Patents

Abstract

(57) [Summary] [Structure] A block 4 partitioned by a groove is formed in the tread portion 1, and each side surface 5 of the block 4 is adapted to move outward as it goes to the bottom portion. Four sipes 6, 7 are arranged in parallel with each other in the tire circumferential direction at equal intervals. In the ground contact surface 8 of the block 4, the distance L1 between the edge 9 on the tire circumferential direction side and the outer sipe 6 is
It is set to be smaller than the juxtaposed distance L2 of the sipes 6 and 7. The tire circumferential direction length L3 of the outer partition portion P1 and the tire circumferential direction length L of the inner partition portion P2 at any given height.
The value L3 / L4 of the ratio with respect to 4 can be made smaller than that of the conventional one, and the rigidity of the outer partition P1 can be made relatively smaller than that of the conventional one as compared with the rigidity of the inner partition P2. [Effect] It is possible to prevent a decrease in gripping force on the road surface due to uneven wear of the outer partition P1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to the structure of a tread portion of a tire.

[0002]

[Prior art]

 In the pneumatic studless tire, for example, as shown in FIG. 5, two vertical grooves 20 formed in the tire circumferential direction are arranged in parallel in the tire axial direction in the tread portion 19 and in the tire axial direction. A large number of the formed lateral grooves 21 are arranged side by side at equal intervals in the tire circumferential direction. As shown in FIG. 6, the tread portion 19 has a large number of blocks 22 defined by the longitudinal grooves 20 and the lateral grooves 21. Has been formed. Each side surface 23 of each block 22 is a curved surface that moves outward as it goes to the bottom. In addition, in order to improve the grip force on the road surface and to improve the traction, braking, cornering and climbing performance of the tire, the blocks 24, 25 formed in the tire axial direction are provided on each block 22, for example, 3 The books are arranged side by side at equal intervals in the tire circumferential direction.

By the way, the side surfaces 23 on both sides of the tire in the tire circumferential direction (side by side of the sipes) in the block 22 are separated from the outer sipes 24 toward the bottom portion. 26, the distance L5 between the edge 27 on the tire circumferential direction side and the outer sipe 24 was the same as the parallel distance L6 between the sipes 24, 25.

Therefore, in the above-mentioned conventional case, comparing the four partition portions P3 and P4 partitioned by the sipes 24 and 25 in the block 22, the same height (however, the height of the ground surface 26 is Except that the tire circumferential length L7 of the outer partition P3 is greater than the tire circumferential length L8 of the inner partition P4, and the vertical cross-sectional area of the outer partition P3 and the inner partition Although the area of the vertical cross section of the portion P4 is different, the depths of all the sipes 24 and 25 are the same in the above-described conventional case, regardless of this.

[0005]

[Problems to be solved by the device]

 Therefore, in the above-described conventional case, the rigidity of the outer partition P3 is higher than that of the inner partition P4, and as a result, the outer partition P3 is unevenly worn, and the outer partition P3 has the ground plane 26 side. As shown in FIG. 6, the outer corners 28 of the vehicle tend to be rounded, which reduces the grip on the road surface, resulting in the problems of reduced tire traction, braking, cornering, and climbing performance. Was there.

An object of the present invention is to provide a tire tread structure capable of solving the above-mentioned problems.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the first feature of the present invention is that a block divided by a groove is formed in a tread portion, and three or more sipes are arranged in parallel at equal intervals in the block. On the ground contact surface of the block, the distance between the sipe side-by-side edge and the sipe is smaller than the sipe side-by-side spacing.

A second feature of the present invention is that the tread portion is formed with blocks divided by grooves, and three or more sipes are juxtaposed at equal intervals in the block. The outer sipes are deeper than the inner sipes.

The first feature and the second feature may be combined.

[0010]

[Action]

 In claim 1, when comparing the partition parts partitioned by the sipes in the block, the length of the outer partition part in the same partition height in the juxtaposed direction and the inner partition part at the same height, The value of the ratio of the sipes to the length in the parallel installation direction can be made smaller than before. As a result, the rigidity of the outer partition can be made relatively smaller than that of the conventional one as compared with the rigidity of the inner partition.

According to the second aspect, at any same height, the length of the outer partition in the side-by-side arrangement direction of the sipes is the same as the length of the inner partition in the side-by-side direction. long. However, since the depth of the outer sipe is deeper than that of the inner sipe, the rigidity of the outer partition can be made relatively smaller than that of the conventional one as compared with the rigidity of the inner partition, as described above.

[0012]

【Example】

 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings of FIGS. 1 and 2. FIG. 1 shows a tread portion 1 of a pneumatic studless tire. In the tread portion 1, two longitudinal grooves 2 formed in the tire circumferential direction are arranged in parallel in the tire axial direction, and a plurality of lateral grooves 3 formed in the tire axial direction are arranged in parallel in the tire circumferential direction. As shown in FIG. 2, the tread portion 1 has a large number of blocks 4 defined by vertical grooves 2 and horizontal grooves 3. Each side surface 5 of each block 4 is a curved surface that moves outward as it goes to the bottom.

In each block 4, three sipes 6 and 7 formed in the tire axial direction are arranged side by side at equal intervals in the tire circumferential direction. The distance L1 between the end edge 9 on the (side by side direction of the sipes 7) side and the outer sipe 6 is smaller than the distance L2 between the sipes 6, 7 arranged side by side. Further, each of the sipes 6 and 7 is not formed over the entire length of the ground contact surface 8 of each block 4 with respect to the tire axial direction, and is formed on a part of the ground contact surface 8 excluding one end. The adjacent sipes 6, 7 are arranged such that the end portions where the sipes 6, 7 are not formed are on the opposite side in the tire axial direction. Further, although the depths of the sipes 6 and 7 are all the same, the width W1 of the outer sipe 6 is larger than the width W2 of the inner sipe 7. The widths W1 and W2 of the types 6 and 7 may be the same.

According to the embodiment configured as described above, the side surface 4 of the block 4 on the tire circumferential direction side is separated from the outer sipe 6 as it goes to the bottom, as in the conventional case. However, in the embodiment, the distance L1 between the edge 9 on the tire circumferential direction side and the outer sipe 6 on the ground contact surface 8 of the block 4 is set to be smaller than the juxtaposed distance L2 of the sipes 6, 7. ing . Therefore, when the four partition portions P1 and P2 partitioned by the sipes 6 and 7 in the block 4 are compared, the tire circumferential direction length L3 of the outer partition portion P1 and the inner partition portion P1 at the same arbitrary height are compared. The value L3 / L4 of the ratio of the partition portion P2 to the tire circumferential length L4 can be made smaller than in the conventional case.

Therefore, although the depths of the sipes 6 and 7 are all the same, the rigidity of the outer partition P1 is compared with the rigidity of the inner partition P2 as compared with the conventional case. Can be made small. As a result, the outer partition P1 is prevented from being unevenly worn and the outer corner 10 of the outer partition P1 on the ground surface 8 side is prevented from being rounded, the grip force on the road surface is reduced, and the tire traction, It is possible to prevent deterioration of braking, cornering, and climbing performance.

FIG. 3 shows a second embodiment of the present invention, in which the distance L1 between the edge 9 on the tire circumferential direction side and the outer sipe 6 on the ground contact surface 8 of the block 4 is the distance between the sipes 6 and 7 arranged in parallel. It is the same as L2, but the depth D1 of the outer sipe 6 is deeper than the depth D2 of the inner sipe 7.

According to the second embodiment, at any given height, the tire circumferential length L3 of the outer partition P1 is longer than the tire circumferential length L4 of the inner partition P2 as in the conventional case. . However, since the depth D1 of the outer sipe 6 is deeper than the depth D2 of the inner sipe 7, the rigidity of the outer partition P1 is relatively smaller than that of the conventional one as compared with the rigidity of the inner partition P2. it can.

FIG. 4 shows a third embodiment of the present invention, which is a combination of the first and second embodiments, in which an edge 9 on the tire circumferential direction side of the ground contact surface 8 of the block 4 and the sipe 6 are provided. The distance L1 is smaller than the juxtaposed distance L2 between the sipes 6 and 7, and the depth D1 of the outer sipe 6 is deeper than the depth D2 of the inner sipe 7. The width W1 of the outer sipe 6 is set to be larger than the width W2 of the inner sipe 7, but the widths W1 and W2 of the sipes 6 and 7 may be the same.

Although the number of sipes formed in the block is three in the embodiment, it may be four or more.

[0020]

[Effect of device]

 As described above in detail, according to the present invention, the rigidity of the outer partition can be made relatively smaller than that of the conventional one as compared with the rigidity of the inner partition. It is possible to prevent a decrease in grip on the road surface due to wear, and to prevent deterioration in tire traction, braking, cornering, and climbing performance.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along the line AA of FIG.

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

FIG. 4 is a sectional view showing a third embodiment of the present invention.

FIG. 5 is a plan view of a tread portion showing a conventional example.

6 is a sectional view taken along the line BB of FIG.

7 is a cross-sectional view showing a state after use of FIG.

[Explanation of symbols]

 1 Tread Part 4 Block 6 Outside Sipe 7 Inside Sipe 8 Grounding Surface 9 Edge P1 Outside Partition P2 Inner Partition

Claims (3)

[Scope of utility model registration request] 1. A tread portion in which a block partitioned by a groove is formed, and three or more sipes are juxtaposed at equal intervals in the block, and the side of the ground surface of the block in the juxtaposed direction of the sipes. The structure of the tire tread portion is characterized in that the distance between the end edge of the tire and the sipe is smaller than the distance between the sipes arranged side by side. 2. In the tread portion, a block partitioned by a groove is formed, and three or more sipes are arranged in parallel at equal intervals in the block, and the depth of the outer sipes is larger than that of the inner sipes. The structure of the tread portion of the tire characterized by being deepened. 3. The structure of the tread portion of the tire according to claim 2, wherein the distance between the edge of the ground contact surface of the block on the side in which the sipes are arranged in parallel and the sipes is smaller than the distance between the sipes arranged in parallel.