JP2002362113A - Atv tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the sliding property of a tire while minimizing the influences on other performances including traction. SOLUTION: This ATV tire having a plurality of blocks 4 sectioned by grooves 3 and formed on a tread portion 2 comprises a tapered surface 7 formed at the outside upper edges of the blocks 4b in a distance range of 40-70%, in the case that a distance outwardly from a tread center O of the tread portion 2 in the cross direction is represented by a percentage to a width from the tread center O to the outer end of the tread portion, in the state of sloping down from the tread center O toward the outer end of the tread portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buggy tire or other ATV (all terrain vehicle) for traveling on rough terrain such as sand, mud, snow, grassland, rocky terrain, and the like.
For tires.

[0002]

2. Description of the Related Art For ATV tires traveling on uneven terrain,
As the characteristics of the tire, it is required to have a good ride comfort, an excellent envelope property, and a running property on a board with a needle, a rocky place, a stair, and the like. In addition, the tire and the rim are separated for improved economy and maintenance, and the road surface is reinforced with tire cords for improved puncture resistance. Further, as the vehicle, a four-wheeled vehicle with a suspension is used, and the demand for high-speed, high-load heavy tires is increasing, so that a tire cord is used as a bias structure. In addition, air pressure is used at 15 to 45 kPa to maintain running ability on uneven soft ground, and it is necessary to secure bead drop resistance to maintain safety. The height is higher than that of passenger tires, and the beat wire is designed to have a winding diameter equal to or less than the rim hump diameter.

[0003] Conventionally, a large number of blocks formed by grooves are formed in a tread portion. With this block, during driving, braking or cornering, soil or snow is scraped off at the edge of the block, or the edge of the block is removed. By digging into the road surface, the grip is improved and the driving force and braking force are increased.

[0004]

By the way, it is necessary to improve the slidability of the tire in order to improve the maneuverability and the stability and to make the cornering smooth at the time of cornering. Slidability is one of the important factors in the maneuverability of a tire. However, the slidability, which is one of the important factors in the maneuverability of the tire as described above, is greatly affected by the tread pattern,
If the tread pattern is largely changed in order to improve the sliding property, other performances such as traction may be affected. Therefore, it is desired to improve the slidability without changing the tread pattern.

SUMMARY OF THE INVENTION In view of the above problems, the present invention improves the slidability of a tire by minimizing the influence on other performances such as traction.

[0006]

The technical means of the present invention for solving this technical problem is to provide an ATV tire in which a plurality of blocks 4 divided by grooves 3 are formed in a tread portion 2. When the distance away from the tread center O in the width direction is expressed as a percentage of the width from the tread center O to the outer edge of the tread portion, 40 to 40
The point is that a tapered surface 7 that is inclined downward from the tread center O side toward the outer end side of the tread portion is formed on the outer upper edge portion of the block 4b within a distance range of 70%.

Another technical means of the present invention is the
The point is that the tapered surface 7 is formed such that the height H2 from the bottom to the lower edge 7a of the tapered surface 7 is 60% or more of the depth L1 of the groove 3 forming the block 4b. Another technical means of the present invention is that the tapered surface 7 with respect to the outer surface 10 of the block 4b in the tire width direction.
Is set in the range of 10 ° to 30 °. Another technical means of the present invention is that the block 4
The point that the inclination angle α of the outer side surface 10 of the block 4b in the tire width direction with respect to the vertical line T facing the bottom surface 11 of the groove 3 forming b is set to 20 ° to 40 °.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. 1 and 2, 1 is sand,
An ATV tire that travels on rough terrain such as mud, snow, grassland, rocky terrain, etc. The tread portion 2 has a large number of blocks 4 (4a, 4b, 4c) divided by grooves 3. In the plurality of blocks 4, a row of first blocks 4a formed on the tread center O side of the tread portion 2,
There is a row of second blocks 4b formed on both sides of the first block 4a in the width direction, and a row of third blocks 4c formed on the outside of the second block 4b in the width direction. Each first block 4a is formed in a V shape in the circumferential direction (rotation direction) of the tire 1, and each second block 4b and each third block 4c are formed.
Are formed in a parallelogram shape inclined in the circumferential direction and the width direction of the tire 1.

When the distance of the tread portion 2 away from the tread center O in the width direction is expressed as a percentage with respect to the width A from the tread center O to the outer end of the tread portion 2,
The first block 4a is disposed in a range of 0% to 40% of the tread portion 2, and the second block 4b is disposed in a range of approximately 40% to 70% of the tread portion 2 in the left and right directions (width direction).
The third blocks 4c are arranged in two rows on the left and right in a range of 70% to 100% of the tread portion 2. A large number of the first blocks 4a, the second blocks 4b, and the third blocks 4c are arranged in rows at intervals in the circumferential direction (rotation direction) of the tire 1.

The outer upper edge of each of the second blocks 4b in the two rows in the width direction, that is, the outer upper edge of the block 4b in the tire width direction is disposed within a range of 40% to 70% of the tread portion 2. Have been. More specifically, in the illustrated example, it is arranged at a distance of about 65% of the tread portion 2. A tapered surface 7 is formed on the outer upper edge of each of the second blocks 4b (C chamfering), and each of the tapered surfaces 7 is
The block 4 is provided over the entire length in the tire rotation direction.
b is inclined so as to gradually descend from the tread center O side toward the outer end side of the tread portion.

The depth L2 from the upper surface (stepping surface) 9 of the block 4b to the lower edge 7a of each tapered surface 7 is
It is 40% or less, preferably 25% or less of the depth L1 of the groove 3 forming b. In other words, the bottom surface 1 of the groove 3
The height H2 from 1 to the lower edge 7a of each tapered surface 7 is:
It is 60% or more, preferably 75% or more of the depth L1 of the groove 3. Further, the inclination angle β of the tapered surface 7 with respect to the outer surface (groove rising surface) 10 in the tire width direction of each block 4b is set in the range of 10 ° to 30 °, and the bottom surface 11 of the groove 3 forming the block 4b. The inclination angle α of the outer surface 10 of the block 4b in the tire width direction with respect to the vertical line T toward

According to the above-described embodiment, the tapered surface 7 is formed at the outer upper edge of the block 4b which is located outside the tread center O in the range of 40% to 70% in the width direction. Therefore, in a situation where the traction is applied to the tire 1 during straight running, the surface where the tread portion 2 of the tire 1 is in contact with the tread center O of the tread portion 2 is about 40% outward from the tread center O in the width direction. Therefore, the influence of the tapered surface 7 on traction performance during straight running can be minimized. Also,
During cornering, the tread 2 of the tire 1 that touches the ground
The ground contact surface extends up to about 70% of the distance from the tread center O of the tread portion 2, and the tapered surface 7 acts greatly, so that the slidability during cornering traveling is improved and smooth cornering traveling can be achieved. Become.

In addition, the height H2 from the bottom surface 11 of the groove 3 to the lower end edge 7a of each tapered surface 7 is 6 times the depth L1 of the groove 3.
0% or more, the inclination angle β of the tapered surface 7 with respect to the outer surface 10 of each block 4b is set in the range of 10 ° to 30 °, and the bottom surface 11 of the groove 3 forming the block 4b.
The inclination angle α of the outer surface 10 of the block 4b with respect to the vertical line T toward
The gradual inclination by the inclination angle α of the block 4b and the inclination angle β of the tapered surface 7 can effectively enhance the slidability while appropriately suppressing the wear of the tapered surface 7 and the outer surface 10 of the block 4b. .

If tapered surfaces are formed on both the outer upper edge portion and the inner upper edge portion of each block 4b, the contact area of the block 4b becomes small, and the abrasion of the block 4b becomes large. When a tapered surface is formed at the upper edge of the front end side in the tire rotation direction of each block 4b, the edge of the block 4b is eliminated at the front end side in the tire rotation direction on the ground contact surface side, and traction is reduced. Although a problem that performance is deteriorated occurs, in the above embodiment, the tapered surface 7 is formed only on the outer upper edge of each block 4b.
The cornering responsiveness (sliding performance of the rear tire) is improved while reliably preventing the wear of the block 4b from becoming unnecessarily large and the traction performance being deteriorated as described above. Can be done. That is, when a tapered surface is not formed at the outer upper edge of each block 4b, the edge of the outer upper edge of the block 4b of the tire located at the rear during ATV cornering is caught, and the response of cornering ( Although the sliding performance of the rear tire is inferior, since the tapered surface 7 is formed only on the outer upper edge portion of each block 4b as described above, an increase in wear of the block 4b and an adverse effect on traction performance are prevented. While block 4b
The responsiveness of the cornering can be improved by the tapered surface 7 located at the outer upper edge of the.

FIG. 3 shows another embodiment in which a large number of blocks 4 (4a, 4b, 4c) are formed in a tread portion 2 of the tire 1, which are divided by grooves 3 in the circumferential direction and the width direction of the tire 1. Each of the first block 4a, the second block 4b, and the third block 4c is formed in a rectangular parallelepiped shape. The other points are the same as those of the above embodiment, and the outer upper edge of each of the second blocks 4b in the two rows is
The second block 4b is disposed at a distance of 0% to 70%, and a tapered surface 7 similar to that of the above-described embodiment is formed on the outer upper edge of each second block 4b. As a result, the influence on the traction performance when traveling straight ahead can be minimized, and at the same time, the slidability during cornering traveling is improved, and smooth cornering traveling can be achieved.

In the above embodiment, block 4
Is a square shape, but the shape of the block 4 is not limited to this, and may be, for example, a triangle, a pentagon or more polygon, an ellipse, or any other shape. Also, the pattern arrangement of the blocks 4 is not limited to the first to third block rows as in the above-described embodiment, and various arrangements may be considered, and a pattern arrangement that does not form a block row may be used.

[0017]

According to the present invention, the slidability of the tire can be improved while minimizing the influence on other performances such as traction.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a block portion showing one embodiment of the present invention.

FIG. 2 is a plan view of the tire.

FIG. 3 is a plan view of a tire showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ATV tire 2 Tread part 3 Groove 4 Block 7 Tapered surface 9 Outer surface 10 Top surface

Claims (4)

[Claims] An ATV tire in which a plurality of blocks (4) divided by grooves (3) are formed in a tread portion (2), wherein the tread portion (2) has a widthwise outward direction from a tread center O of the tread portion (2). When the separated distance is expressed as a percentage of the width from the tread center O to the outer end of the tread portion, 40 to 70%
At the outer upper edge of the block (4b) within the range of
An ATV tire characterized in that a tapered surface (7) is formed which is inclined downward from a tread center O side toward an outer end side of a tread portion. 2. The height H2 from the bottom surface (11) of the groove (3) to the lower edge (7a) of the tapered surface (7) is equal to the depth L1 of the groove (3) forming the block (4b). The ATV tire according to claim 1, wherein the tapered surface (7) is formed so as to be 60% or more. 3. The inclination angle β of the tapered surface (7) with respect to the outer surface (10) in the tire width direction of the block (4b) is set in the range of 10 ° to 30 °. The tire for ATV according to claim 1 or 2. 4. An outer surface (10) of the block (4b) in a tire width direction with respect to a vertical line T facing a bottom surface (11) of the groove (3) forming the block (4b).
The ATV tire according to any one of claims 1 to 3, wherein the inclination angle α of the tire is set to 20 ° to 40 °.