JPH09263110A - Pneumatic tire for four-wheel drive passenger car running on icy and snowy road - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire for running on the icy and snowy road which is excellent in braking performance and side-slip resistance on the icy and snowy road. SOLUTION: In a pneumatic tire provided with a block pattern as tread, in which a plurality of blocks are spacedly formed in the circumferential direction of the tire by many slant grooves spacedly arranged in the circumferential direction of the tire, the slant groove comprises a high slant groove extending at a relatively large slant angle to the circumferential direction and a low slant groove extending at a relatively small slant angle in the circumferential direction. A tread comprises the center area C with width of approximately 2/3 of tread width and both sides S positioned on both sides of the center area C. The high slant groove is arranged in the center area C and both sides S, forming a directional high slant groove 1 extending in a V-shape. The low slant groove is arranged in a center area C, forming an opposite directional low slant groove 2 extending in the right and left directions holding a pattern center E in a chevron-shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire for traveling on ice and snowy roads, and more particularly to a large number of blocks arranged at intervals in the tire circumferential direction by a large number of inclined grooves arranged at intervals in the tire circumferential direction. The present invention relates to a pneumatic tire for traveling on ice and snowy roads, in which a tread having a block pattern in which the above is formed.

In the present specification, the "V-shaped directional inclined groove" or the "V-shaped directional inclined groove" is a groove extending obliquely with respect to the circumferential direction, and the inclination of the groove. A so-called directional tread pattern in which the rotation direction (normal rotation direction) of the tire when the tire is mounted on the vehicle is specified so that the V-shaped tip of the extending portion is grounded first. It means a groove, and the "reverse-direction inclined groove extending in a V-shape" is a groove extending obliquely with respect to the circumferential direction,
The so-called reverse direction, in which the rotation direction (forward rotation direction) of the tire when the tire is mounted on the vehicle is designated so that the most open part in the V shape of the inclined extending part of the groove comes into contact with the ground first. Means the groove in which the sex tread pattern is formed, and the "negative ratio" means the ratio of the area of the apparent tread contact area that is not actually contacted with the groove and the like. .

[0003]

2. Description of the Related Art A typical conventional pneumatic tire for traveling on ice and snow roads has 4 to 5 circumferential grooves extending linearly or substantially linearly in the circumferential direction and about 45 degrees with respect to the circumferential direction. With a tread pattern in which a large number of blocks were formed at intervals in the tire circumferential direction by the inclined grooves extending at an inclination angle of, the negative ratio was about 45 to 50%.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to improve the performance of conventional pneumatic tires for traveling on ice and snow roads on ice and snow roads so that the tires can be safely run on ice burns and snow. In order to contribute to traffic safety in winter, it is an object of the present invention to provide a pneumatic tire for traveling on ice and snow roads, which is particularly excellent in braking performance and skid resistance on ice and snow.

[0005]

In order to achieve the above object, the pneumatic tire of the present invention has a large number of tires circumferentially spaced by a large number of inclined grooves arranged at intervals in the tire circumferential direction. In a pneumatic tire having a tread with a block pattern in which blocks of (1) are formed, (1) the inclined groove has a high inclined groove extending at a relatively large inclination angle with respect to the circumferential direction and a relatively high inclined groove with respect to the circumferential direction. (2) The tread has a central region having a width of about ⅔ of the tread width, and
Formed with both side regions located on both sides of the central region,
(3) The high-inclination groove is arranged over the central region and the both side regions to form a V-shaped directional high-inclination groove, and (4) the low-inclination groove is arranged in the central region, The pneumatic tire is characterized by forming a reverse low-inclination groove that extends in a V shape on both sides of the center.

To achieve the above object, in the pneumatic tire of the present invention, the high-inclination groove has an inclination angle of 50 to 80 degrees with respect to the circumferential direction in the central region and has a circumferential angle in the both-side regions with respect to the circumferential direction. It is preferable that the low inclination groove extends at an inclination angle of 80 to 90 degrees, and the low inclination groove extends at an inclination angle of 10 to 30 degrees with respect to the circumferential direction.

To achieve the above object, the pneumatic tire of the present invention preferably has a negative ratio in the central region of 30 to 40%, more preferably 32 to 38%.

In order to achieve the above object, the pneumatic tire of the present invention has a width of 4 to 7.5% of the tread width on the inner side in the tire axial direction of the both side regions, and is linear in the circumferential direction. Preferably, circumferential grooves are arranged which extend substantially linearly.

The pneumatic tire of the present invention has the above-described structure, and in particular, the low-inclination groove is arranged in the central region of the tread, and the reverse low-inclination extending in the left and right sides sandwiching the pattern center is provided. Since the groove is formed and preferably extends at an inclination angle of 10 to 30 degrees with respect to the circumferential direction, it exerts drainage and snow removal effects during booming during traveling on ice and snow, and when traveling on ice and snow roads. It is possible to obtain a pneumatic tire for traveling on ice and snow roads that has excellent braking performance. Although the presence of a water film or snow on the ice is a major obstacle to the tire's booting, in the pneumatic tire of the present invention, the low-slope groove arranged in the central region of the tread eliminates the water film and the snow on the ice. As a result, the contact area between the ice surface and the tread of the tire increases, and as a result, a pneumatic tire for traveling on ice and snow roads having excellent braking performance during traveling on ice and snow roads can be obtained. In addition, the low-sloping groove located in the central area of the tread forms a reverse low-sloping groove that extends in a left-right shape across the pattern center, so that it can be used when braking on ice / snow roads. It is easy to remove snow and snow.

The pneumatic tire of the present invention is constructed as described above, and in particular, the high-inclination groove is arranged over the central region and both side regions to form a V-shaped directional high-inclination groove, preferably , 50 in the central area in the circumferential direction
It is 8 degrees to the circumferential direction at both sides with an inclination angle of 80 degrees.
Since it extends at an inclination angle of 0 to 90 degrees and can firmly grasp snow when stepping on, it is possible to obtain a pneumatic tire for traveling on ice and snow roads, which has excellent traction performance during traveling on ice and snow roads. A large amount of edge components in the lateral direction with respect to the traction direction are formed by the high-sloping groove, so that a pneumatic tire for traveling on ice and snow roads having excellent traction performance can be obtained. The V-shaped directional high-inclination grooves formed by the high-inclination grooves are arranged in a zigzag pattern in the circumferential direction with the pattern center interposed therebetween, and the high-inclination grooves are 40 to 50.
It is preferable that they overlap by about mm in order to increase the edge component in the lateral direction with respect to the traction direction and improve the traction performance.

The pneumatic tire of the present invention has the above-mentioned structure, and in particular, has a width of 4 to 7.5% of the tread width on the inner side in the tire axial direction of both side regions, and has a linear shape in the circumferential direction. Since the circumferential grooves that extend substantially linearly are arranged, it is possible to obtain a pneumatic tire for traveling on ice and snowy roads having excellent snow discharge performance and skid resistance. Since this circumferential groove has an extremely large width corresponding to a width of 4 to 7.5% of the tread width, it is possible to bite snow widely and suppress or prevent skidding of the tire due to shear resistance of snow. it can.

The pneumatic tire of the present invention has the above-mentioned constitution, and in particular, the negative ratio in the central region is 30 to 40%, preferably 32 to 38%, so that the braking performance and traction on the snow and snow road are improved. It is possible to obtain a pneumatic tire for traveling on ice and snow roads having excellent performance.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment according to the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment 4 according to the present invention.
FIG. 3 is a partially enlarged front view of a tread pattern of a pneumatic tire for a wheel drive passenger car, the tire size is 265/7.
It is 0R15. 1 is a block in which a large number of blocks 3 are formed at intervals in the tire circumferential direction by a large number of inclined grooves 1 and 2 arranged at intervals in the tire circumferential direction.・ The tread has a pattern. The inclined grooves 1 and 2 are composed of a high inclined groove 1 extending at a relatively large inclination angle with respect to the circumferential direction and a low inclined groove 2 extending at a relatively small inclination angle with respect to the circumferential direction.
The tread is formed of a central region C having a width of about ⅔ of the tread width W and both side regions S located on both sides of the central region C. In the tire of this embodiment, the tread width W is 214 mm. Since the width of the central region C is 140 mm, C / W is about 65%. The high-inclination groove 1 is arranged over the central region C and both side regions S to form a directional high-inclination groove extending in a V shape, while the low-inclination groove 2 is arranged only in the central region C and has a pattern center E. Reverse direction low inclination grooves extending in a V shape are formed on both sides of the sandwich.
That is, the tire according to the present embodiment is a tire having a so-called directional tread pattern, the rotation (normal rotation) direction D of the tire when it is mounted on a vehicle is designated, and the inclination of the high-slope groove 1 is The V-shaped tip portion A of the extending portion is grounded first, and the most open portion of the low-angled groove 2 that extends obliquely is grounded first. The high-inclination groove 1 is formed of a high-inclination groove 11 located in the central portion of the central region C, a high-inclination groove 12 located outside the high-inclination groove 11 and high-inclination grooves 13 located in both side regions S. The high inclination groove 1 has an inclination angle of 50 to 80 degrees with respect to the circumferential direction in the central region C and 80 to 9 with respect to the circumferential direction in both side regions S.
It extends at an inclination angle of 0 degree, and the low inclination groove 2 is 1 with respect to the circumferential direction.
In the tire of this embodiment, the high-inclination groove 1 extends at an inclination angle of 0 to 30 degrees and is 6 in the central region C with respect to the circumferential direction.
In both side areas S, the inclination angle of 0 to 70 degrees extends at an inclination angle of 80 degrees with respect to the circumferential direction, and the low inclination groove 2 extends at an inclination angle of 17 degrees with respect to the circumferential direction. In the central region C, the negative ratio, that is, the ratio of the area of the portion not actually touching the ground, such as the groove, to the total apparent tread contact area is 30 to 40%, and preferably 3
In the tire of the present embodiment, the negative rate is 35% in the central region C and 40% in the entire tread including the both side regions S. A circumferential groove 4 having a width of 4 to 7.5% of the tread width and extending linearly or substantially linearly in the circumferential direction is arranged on the inner side of the both side regions S in the tire axial direction. In the example tire, circumferential grooves 4 are arranged that extend linearly and have a width of 6% of the tread width.

[0014]

The pneumatic tire of the present invention is a pneumatic tire for traveling on ice and snow roads, which is excellent in braking performance and skid resistance on ice and snow.

[Brief description of drawings]

FIG. 1 is a partially enlarged front view of a tread pattern of a tire according to the present invention.

[Explanation of symbols]

 1 Directional high inclination groove 2 Directional low inclination groove 3 Block 4 Circumferential groove A V-shaped tip C Central area D Tire rotation direction E Tire equatorial line (pattern center) S Both areas

Claims (5)

[Claims] 1. A pneumatic tire having a tread with a block pattern in which a large number of blocks are formed at intervals in the tire circumferential direction by a large number of inclined grooves arranged at intervals in the tire circumferential direction, (1) The inclined groove includes a high inclined groove extending at a relatively large inclination angle with respect to the circumferential direction and a low inclined groove extending at a relatively small inclination angle with respect to the circumferential direction, and (2) the tread is a tread. Width 2
It is formed of a central region having a width of about ⅓ and both side regions located on both sides of the central region. (3) The high-slope groove is arranged over the central region and the both side regions and extends in a V shape. Forming a directional high-inclination groove, and (4) forming a reverse directional low-inclination groove which is arranged in the central region and extends in a left-right shape across the pattern center. A characteristic pneumatic tire. 2. The high-inclination groove extends at an inclination angle of 50 to 80 degrees with respect to the circumferential direction in the central region, and extends at an inclination angle of 80 to 90 degrees with respect to the circumferential direction in the both side regions. The pneumatic tire according to claim 1, wherein the tire extends at an inclination angle of 10 to 30 degrees with respect to the circumferential direction. 3. The pneumatic tire according to claim 1, wherein the negative ratio in the central region is 30 to 40%, preferably 32 to 38%. 4. A circumferential groove having a width of 4 to 7.5% of the tread width and extending linearly or substantially linearly in the circumferential direction is arranged on the inner side in the tire axial direction of the both side regions. The pneumatic tire according to any one of claims 1 to 3, wherein. 5. The pneumatic tire according to claim 4, wherein the negative ratio is 30 to 40%, preferably 32 to 38% over the entire area of the tread in the central region and the both side regions.