JPH11208217A - Pneumatic radial tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a difference in the lateral rigidity of the tread surface that instantly adapts to the lateral acceleration while turning at high speeds. SOLUTION: The tread surface 1 is composed of a block pattern 2 on the inside and a rib pattern 3 on the outside. The lateral rigidity of the outside is higher than that of the inside. The outside lateral rigidity is increased to be more than that of the inside by increasing or decreasing the surface area of the blocks and ribs, or increasing or decreasing the number of transverse grooves or the groove width. Furthermore, means for visual discrimination when the tire is mounted on the automobile is provided on the tread surface 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic radial tire, and more specifically, to an asymmetric pneumatic radial tire in which a block pattern and a rib pattern constitute a tread tread, the tread tread being laterally located on the tread tread. The present invention relates to a pneumatic radial tire having a rigidity relationship.

[0002]

2. Description of the Related Art For example, when a large lateral acceleration acts due to high-speed turning on a circuit or the like,
In the tread tread portion on the outside (outside) of the turn, a circumferential groove extending to the outside portion thereof is greatly crushed by the road surface reaction force, and the deformation of the tread surface at this time is caused by the deformation of the tire radius. The portion where the amount of ejection to the outside in the direction is large, in other words, the shoulder portion adjacent to the outside of the tread tread portion, which is the portion that will be particularly strongly grounded, and the outermost circumferential groove in the tire width direction The land-end portion adjacent to the inside of the ground carries a particularly large road surface reaction force, while the land-end portion adjacent to the outside of the circumferential groove rises from the road surface, and as a result, the contact pressure is particularly low. Abnormal wear occurs relatively early, in which both of the higher parts wear significantly, while the land-end part where the contact pressure hardly acts remains without being worn. Les was supposed to bring about decrease in tire life, occurrence of vibration, reduction of motion characteristics and the like.

[0003] The pneumatic radial tire disclosed in Japanese Patent Application Laid-Open No. 4-143105 is provided with two or more circumferential grooves extending in the tire circumferential direction on a tread tread portion.
A pneumatic radial tire having a block row formed between the circumferential grooves and the tread end, and a tire mounted on a vehicle, at least in a tread side region located outside the vehicle, This also at least, in the circumferential groove located closest to the tread end, on both groove walls,
From the radially outer position of the tire from its groove bottom, to the tread surface, the respective groove is gradually expanded toward the tread surface. A pneumatic radial tire in which the inclination angle of the inclined portion with respect to the tire normal is larger than the inclination angle of the expanded inclined portion provided on the groove wall near the center of the tread with respect to the tire normal. Side uneven wear was prevented.

[0004]

The technique disclosed in the above-mentioned publication is useful as such, but has the following problems. That is, the configuration of the tread tread portion is a so-called symmetric pattern in which the center portion is a rib pattern and the left and right are block patterns, and cannot be applied to an asymmetric pattern.

[0005] In addition, the tread portion of the tread tends to cause uneven wear due to lateral acceleration on the outside side when mounted on a vehicle, and it is necessary to improve dry grip during cornering. Since the side has a block pattern, the lateral rigidity is lower than that of the rib pattern, and therefore, uneven wear easily occurs,
Dry grip during cornering was just one step away.

According to the present invention, in order to solve the above-mentioned problems, the inside of the tread tread portion is constituted by a block pattern, and the outside is constituted by a rib pattern, and the lateral rigidity increases (increases) toward the outside. Accordingly, it is an object of the present invention to provide a pneumatic radial tire capable of preventing uneven wear to improve tire life and improving dry grip during cornering.

[0007]

SUMMARY OF THE INVENTION The present invention is a pneumatic radial tire having a tread tread portion formed of a block pattern and a rib pattern. In order to achieve the above object, the following technical means is provided. Have taken. That is, in the pneumatic radial tire according to claim 1, the block pattern is located on the inside side and the rib pattern is located on the outside side when the tire is mounted on an automobile. Is characterized in that the lateral rigidity on the outside side is set higher than that on the inside side.

[0008] By adopting such a structure, for example, when the vehicle is turning at high speed on a circuit or the like, the outside tends to wear unevenly compared to the inside due to the lateral acceleration acting on the tire due to the rib pattern. It is prevented by strengthening (enhancement) of rigidity, while improving dry grip and improving cornering performance,
The block pattern on the inside ensures drainage.

According to a second aspect of the present invention, there is provided the pneumatic radial tire according to the first aspect, wherein each of the blocks constituting the block pattern and each of the ribs constituting the rib pattern are arranged on the outside side from the inside side. Is set to have a high lateral rigidity. By adopting such a configuration, in the tread tread portion, the outside rigidity can be set more finely on the outside than on the inside, and the dry grip force at the time of cornering can be improved while reliably preventing uneven wear.

The means for setting the lateral stiffness on the outside side higher than the inside side is based on increasing or decreasing the land area of the blocks and ribs or increasing or decreasing the number of lateral grooves or the groove width. And it could be configured easily. Furthermore, when the tread tread portion is composed of the block pattern and the rib pattern, the orientation when mounted on the vehicle becomes important, and when this orientation is not appropriate, the function of the present invention is difficult to perform.

Therefore, the pneumatic radial tire according to the present invention is characterized in that the tread surface portion is provided with a visual identification means for mounting the tire on an automobile. By adopting such a configuration, a tire having a block pattern excellent in drainage performance on the inside side and a rib pattern excellent in grip performance on the outside side can be mounted on the automobile without error. In the past, the visual identification means was formed on the tire side, so it took time to attach while considering the pattern of the tread tread,
By forming it on the tread tread, the identification was good and the mounting error was eliminated.

Further, the visual identification means is also used for judging a tire running-in operation.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pneumatic radial tire according to the present invention will be described below with reference to the drawings. FIGS. 1A and 1B are partial plan views of a tread tread portion 1 of a pneumatic radial tire according to the present invention (FIG. 1).
(A)) and a plan view (FIG. 1 (B)) of a main part thereof. The tread tread portion 1 is composed of a block pattern 2 and a rib pattern 3, and an automobile (not shown) When mounted on a passenger car, a circuit car, or the like), the block pattern 2 is on the inside side (the right side in FIG. 1A).
And the rib pattern 3 is located on the outside side (FIG. 1).
(A) on the left).

More specifically, the tread tread portion 1 has a contact width TW, and the central portion of the tread tread portion 1 and three main grooves 4 extending in the tire circumferential direction on both left and right sides thereof are parallel to each other. The tread tread portion 1 is formed.
On the right side (right side of the center main groove 4), the sub-groove 5 is formed across the two main grooves 4 to form the block pattern 2. On the left side, the two main grooves 4 The rib pattern 3 is formed by forming the sub-groove 5 which does not cross the outer side, and the lateral rigidity on the outside side is set higher than that on the inside side.

Further, the inside side block pattern 2
With respect to A, by forming another sub-sub-groove 5A between two sub-grooves 5 in the tire circumferential direction, by dividing the block of the outside-side block pattern 2B into two, the lateral rigidity is changed. And the narrow groove 5B is formed in the divided block of the inside side block pattern 2A.
Is formed, the lateral stiffness of the block on the outside side is made higher than that of the block side on the inside side, and the sub-groove 5A is partially formed in the block pattern 2B on the outside side. Accordingly, the lateral rigidity of the outside side block pattern 2B is set higher than that of the inside side.

As for the rib pattern 3, the rib pattern 3A on the inside side (right side in FIG.
The lateral groove rigidity on the outside side is set higher than that on the inside side because the sub-groove 5 and the sub-sub-groove 5A are formed on the right edge of the rib and are not formed on the left edge of the rib. Is a sub-groove 5 formed on the right edge of the rib and a sub-groove 5 formed on the left edge of the rib.
The smaller groove 5C sets the lateral rigidity on the outside side higher than the inside side.

That is, the block patterns 2A, 2A
B and the rib patterns 3A, 3B are set to have higher lateral rigidity on the outside side than on the inside side, and more specifically, the individual blocks and the rib patterns 3A, 3B constituting the block patterns 2A, 2B. Is set to have a higher lateral rigidity on the outside side than on the inside side.

Here, as means for setting the lateral rigidity higher on the outside side than on the inside side, an increase / decrease in the land area of the blocks and ribs or an increase / decrease in the number of lateral grooves (sub-grooves and sub-sub-grooves) or the groove width are employed. can do. FIG.
1 (A) and 1 (B) show a tread portion 1 having the pattern configuration shown in FIG. 1 (A) provided with a visual identification means 6 when a tire is mounted on an automobile. Since (A) and (B) are common, common parts are indicated by common symbols.

In the illustrated embodiment, the visual identification means 6 is formed by forming an engraved arrow mark on the tire vulcanizing mold and having a height h of 0.2 mm to 1.5 mm from the surface of the tread tread portion 1. When the height h disappears, it is determined that the running-in operation (run-in running) has been completed, and this determination is also performed. The visual identification means 6 indicates that the tread portion 1 is recessed from the tread tread portion 1 in the illustrated arrow, but may be formed in a convex shape or may be a character display or the like. The indication may be provided, and the tread tread portion 1 is provided at 3 to 15 places at circumferential intervals.

FIG. 3 shows another useful embodiment of the present invention, wherein a center rib 7 is formed by a main groove 4 extending in a left and right zigzag shape at a central portion of the tread tread portion 1, and a block pattern 2 is formed on the inside side. On the outside side, a rib pattern 3 is formed, and by forming the sub-groove 5 and the sub-groove 5A, the lateral rigidity on the outside side is set higher than that on the inside side as shown by oblique lines in FIG. Other parts are common to FIGS. 1 and 2, and common parts are indicated by common reference numerals.

In the embodiment of the present invention, as long as the inside side is a block pattern and the outside side is a rib pattern and the lateral rigidity is set higher than the inside, the pattern can be freely changed.

[0022]

As described in detail above, according to the present invention, uneven wear can be ensured while sufficiently satisfying the dry performance and wet performance, and providing a difference in the lateral rigidity of the tread tread portion to cope with the lateral acceleration. Can be prevented.

[Brief description of the drawings]

FIGS. 1A and 1B show a first embodiment of the present invention, in which FIG. 1A is a plan view of a tread tread portion, and FIG.

FIGS. 2A and 2B show a second embodiment of the present invention, wherein FIG. 2A is a plan view of a tread tread portion, and FIG.

FIG. 3 is a plan view of a tread tread portion showing a third embodiment of the present invention.

[Explanation of symbols]

 1 tread tread 2 block pattern 3 rib pattern 4 main groove 5 sub groove

Claims (5)

[Claims] 1. A pneumatic radial tire having a tread tread portion formed of a block pattern and a rib pattern, wherein the block pattern is located on the inside side when mounted on an automobile, and the rib pattern is located on the outside. The pneumatic radial tire, wherein the lateral rigidity of the block pattern and the rib pattern is set higher on the outside side than on the inside side. 2. The pneumatic pneumatic pump according to claim 1, wherein the individual blocks constituting the block pattern and the individual ribs constituting the rib pattern are set to have a higher lateral rigidity on the outside side than on the inside side. Radial tire. 3. The method according to claim 1, wherein the means for setting the lateral rigidity higher on the outside side than on the inside side is an increase or decrease in the land area of the blocks and ribs or an increase or decrease in the number or width of the lateral grooves. 3. The pneumatic radial tire according to 2. 4. The pneumatic radial tire according to claim 1, wherein a visual identification means for mounting the tire on an automobile is provided on the tread tread portion. 5. The pneumatic radial tire according to claim 4, wherein the visual identification means also serves to determine whether the tire is running-in.