JP3850972B2 - Pneumatic radial tire - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pneumatic radial tire, and more specifically, in an asymmetric pneumatic radial tire in which a tread tread surface portion is configured by a block pattern and a rib pattern, the lateral rigidity of the tread tread portion has a magnitude relationship. The present invention relates to a pneumatic radial tire.
[0002]
[Prior art]
For example, when a large lateral acceleration is applied due to high-speed turning on a circuit or the like, a circumferential groove extending to the outer portion of the tread surface portion on the outside (outside) of the turn is a road surface reaction force. The deformation of the tread surface at this time is a portion where the amount of outward displacement of the tire in the radial direction is increased due to the deformation, in other words, a portion that is particularly strongly grounded. The shoulder portion adjacent to the outside of the surface portion and the land end portion adjacent to the inside of the outermost circumferential groove in the tire width direction will bear a particularly large road surface reaction force, on the outside of the circumferential groove. Adjacent land edges will float off the road surface, and as a result, both of these parts, where the contact pressure will be particularly high, will wear significantly, while the contact pressure will be much lower. Rikutan portion not throat action occurs abnormal wear relatively quickly that it remains without abrasion, it was supposed to result in 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 the tread surface, and at least between the circumferential groove and the tread end. A pneumatic radial tire formed of block rows,
The tire mounted on the vehicle, at least in the tread side section located outside the vehicle, and at least in the circumferential groove located closest to the tread end, on both groove walls, the groove bottom From each radially outer position of the tire, each of the expanded inclined portions inclined in the direction in which the groove width gradually expands toward the tread surface is provided, and the expanded inclined portion provided on the groove wall on the tread end side, This is a pneumatic radial tire that has an inclination angle with respect to the tire normal that is larger than the inclination angle with respect to the tire normal at the widened inclination portion provided in the groove wall near the center of the tread. Was preventing.
[0004]
[Problems to be solved by the invention]
Although the technique disclosed in the above publication is useful as it is, it has the following problems.
That is, the configuration of the tread surface is a so-called symmetrical pattern in which the central portion is a rib pattern and the left and right are block patterns, and cannot be applied to an asymmetric pattern.
In addition, the tread tread part tends to be unevenly worn due to lateral acceleration on the outside side in a state where it is mounted on a car, and it is necessary to improve the dry grip during cornering. Since it has a pattern, the lateral rigidity is lower than that of the rib pattern. Therefore, uneven wear is likely to occur, and the dry grip at the cornering is just one step away.
[0005]
In the present invention, in order to solve the above-described problems, the inside of the tread tread portion is configured as a block pattern, the outside is configured as a rib pattern, and the lateral rigidity is increased (increased) toward the outside, An object of the present invention is to provide a pneumatic radial tire that prevents uneven wear and improves the tire life and can improve dry grip during cornering.
[0006]
[Means for Solving the Problems]
The present invention is a pneumatic radial tire in which a tread tread surface portion is constituted by a block pattern and a rib pattern. In order to achieve the above-mentioned object, the following technical means are taken.
That is, in the pneumatic radial tire according to the present invention, the block pattern is located on the inside side and the rib pattern is located on the outside side in a state where the pneumatic tire is mounted on an automobile, and each of the block pattern and the rib pattern is The lateral rigidity on the outside side is set higher than that on the inside side.
[0007]
By adopting such a configuration, for example, when driving at a high speed on a circuit or the like, the lateral acceleration acting on the tires causes the outer side to wear more unevenly than the inside. This is prevented by (enhancement), and the dry grip is improved and the cornering performance is improved. On the other hand, the inside has a block pattern to ensure drainage.
The pneumatic radial tire according to the present invention is characterized in that the individual blocks constituting the block pattern and the individual ribs constituting the rib pattern are set to have higher lateral rigidity on the outside side than on the inside side. Is.
[0008]
By adopting such a configuration, in the tread tread portion, the outer side can be set finer and the lateral stiffness can be set larger than the inside, and the dry grip force at the cornering can be improved while ensuring the prevention of uneven wear.
The means for setting the lateral rigidity higher on the outside side than the inside side is to increase or decrease the land area of the blocks and ribs, or to increase or decrease the number of lateral grooves or the groove width. I was able to configure it.
Furthermore, when the tread tread portion is composed of a block pattern and a rib pattern, the direction when the tread is mounted on the automobile is important. When this direction is not appropriate, the function of the present invention is difficult to perform.
[0009]
Therefore, in the pneumatic radial tire according to the present invention, the tread tread portion is provided with visual identification means when the tire is mounted on an automobile, such a configuration. By adopting this, it is possible to install the tire with a block pattern with excellent drainage performance on the inside side and a rib pattern with excellent grip performance on the outside side without making a mistake. In the past, it was formed on the tire side, so it took time and effort to consider the tread tread pattern, but forming it on the tread tread makes it easy to identify and eliminate mounting mistakes. It was.
[0010]
In addition, the visual identification means also serves as a determination of a tire running-in operation.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a pneumatic radial tire according to the present invention will be described with reference to the drawings.
1 (A) and 1 (B) are a partial plan view (FIG. 1 (A)) of a tread tread surface portion 1 of a pneumatic radial tire according to the present invention, and a plan view (FIG. 1 (B)) of an essential part thereof. The tread tread portion 1 is composed of a block pattern 2 and a rib pattern 3, and the block pattern 2 is arranged on the inside side (shown in the figure) when mounted on a car (passenger car, circuit car, etc.) (not shown). 1 (A) is located on the right side), and the rib pattern 3 is located on the outside side (left side in FIG. 1 (A)).
[0012]
More specifically, the tread tread portion 1 has a ground contact width TW, and the central portion of the tread tread portion 1 and three main grooves 4 extending in the tire circumferential direction are formed in parallel to each other on the left and right sides. On the right side of the tread surface 1 (right side from the center main groove 4), a sub-groove 5 is formed across the two main grooves 4 to form the block pattern 2, and on the left side The rib pattern 3 is formed by forming the sub-grooves 5 that do not cross the two main grooves 4, and the lateral rigidity on the outside side is set higher than that on the inside side.
[0013]
Further, for the inside side block pattern 2A, by forming another sub-groove 5A between the two sub-grooves 5 in the tire circumferential direction, the block of the outside side block pattern 2B is divided into two. In addition to the change in the lateral rigidity, the narrow block 5B is formed in the divided block of the inside side block pattern 2A, so that the lateral rigidity of the block on the outside side of the inside side is also increased. As for the outside side block pattern 2B, by forming the secondary groove 5A partway, the outside side block pattern 2B also has a lateral rigidity on the outside side rather than the inside side. It is set high.
[0014]
Further, the rib pattern 3A on the inside side (right side in FIG. 1 (A)) of the rib pattern 3 is that the sub-groove 5 and the sub-groove 5A are formed on the rib right edge and not on the rib left edge. The lateral rigidity on the outside side is set higher than that on the inside side, and the left rib pattern 3B is formed with a secondary groove 5 on the right side edge of the rib and a groove 5C smaller than the secondary groove 5 formed on the left side edge of the rib. is the lateral rigidity of the outside side is set higher than the inside side by but is formed.
[0015]
That is, each of the block patterns 2A and 2B and the rib patterns 3A and 3B is set to have higher lateral rigidity on the outside side than on the inside side, and more specifically, each of the block patterns 2A and 2B constituting the block patterns 2A and 2B. The individual ribs constituting the block and rib patterns 3A and 3B are set to have 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, it is possible to adopt increase / decrease in land area of blocks and ribs or increase / decrease in the number of lateral grooves (sub-grooves and sub-grooves) or groove width. it can.
[0016]
2 (A) and 2 (B) include a tread tread portion 1 having the pattern configuration shown in FIG. 1 (A), and provided with visual identification means 6 when a tire is mounted on an automobile. Since it is common to FIGS. 1 (A) and 1 (B), common portions are denoted by common reference numerals.
In the illustrated embodiment, as the visual identification means 6, an inscription of an arrow is formed on the tire vulcanization mold and formed at a height h of 0.2 mm to 1.5 mm from the surface of the tread tread surface portion 1, thereby It is assumed that this judgment is combined with the fact that the running-in operation (run-in running) is completed when h disappears.
[0017]
The visual identification means 6 is shown as being recessed from the tread tread surface portion 1 by the arrow shown in the figure, but it may be formed in a convex shape, a character display, etc. It may be a display, and the tread surface portion 1 is provided at 3 to 15 places at intervals in the circumferential direction.
FIG. 3 shows another useful embodiment of the present invention, in which a center rib 7 is formed by a main groove 4 extending in a zigzag shape on the left and right sides in the central portion of the tread tread portion 1, and the inside side is a block pattern 2 on the outside side. The side is constituted by the rib pattern 3, and the lateral groove on the outside side is set higher than the inside side as shown by hatching in FIG. 3 by forming the sub groove 5 and the sub groove 5A. Since it is common with FIG. 1 and FIG. 2, the common part is shown with the common code | symbol.
[0018]
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 IN, the pattern can be freely changed.
[0019]
【The invention's effect】
As described above in detail, according to the present invention, uneven wear can be reliably prevented while sufficiently satisfying the dry performance and the wet performance, and having a difference in the lateral rigidity of the tread tread surface portion to cope with the lateral acceleration.
[Brief description of the drawings]
1A and 1B show a first embodiment of the present invention, in which FIG. 1A is a plan view of a tread surface portion, and FIG.
FIGS. 2A and 2B show a second embodiment of the present invention, in which FIG. 2A is a plan view of a tread surface portion, and FIG.
FIG. 3 is a plan view of a tread surface portion showing a third embodiment of the present invention.
[Explanation of symbols]
1 Tread surface 2 Block pattern 3 Rib pattern 4 Main groove 5 Sub groove

Claims (5)

A pneumatic radial tire in which the tread tread portion is composed of a block pattern and a rib pattern,
The block pattern is located on the inside side, the rib pattern is located on the outside side, and the individual blocks constituting the block pattern and the individual ribs constituting the rib pattern are inside. The pneumatic radial tire is characterized in that lateral rigidity on the outside side is set higher than that on the side, and each of the block pattern and rib pattern is set on the outside side with higher lateral rigidity than on the inside side. A pneumatic radial tire in which the tread tread portion is composed of a block pattern and a rib pattern,
The block pattern is located on the inside side and the rib pattern is located on the outside side in a state of being mounted on an automobile, and each of the block pattern and the rib pattern has higher lateral rigidity on the outside side than the inside side. Is set,
A pneumatic radial tire characterized in that a tread tread surface portion is provided with visual identification means for mounting a tire on an automobile, and this visual identification means also serves as a judgment of running-in of the tire. 2. The pneumatic radial 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 / decrease in the land area of the block and the rib, or an increase / decrease in the number or width of the lateral grooves. tire. The pneumatic radial tire according to claim 1 or 3, wherein the tread tread portion is provided with visual identification means for mounting the tire on an automobile.   The pneumatic radial tire according to claim 4, wherein the visual identification means also serves as a judgment of a running-in operation of the tire.

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