JP2755995B2 - Pneumatic tire - Google Patents

Description

The present invention is applied to pneumatic tires, especially to passenger cars, and can be used in a vehicle interior with little sacrifice in steering stability on dry and wet road surfaces. The present invention relates to a high-performance radial tire that advantageously improves the performance.

(Prior Art) Conventional high performance radial tires for passenger cars include
Some have a tread pattern as shown in the figure.

This is because a pair of two circumferential main grooves 111 are provided in the center region of the tread tread portion T in parallel with each other, and also a pair of the circumferential intermediate grooves 112 and the circumferential narrow grooves 112 also form a pair. Each of the grooves 113 is sequentially provided at a predetermined interval to the outside in the width direction of the tire, and, from each circumferential main groove 111 toward each tread end, the intersection angle with respect to each circumferential groove is gradually increased. A plurality of wide inclined grooves 114 which are gradually changed and extended are provided at equal intervals in the tire circumferential direction, and further, each of the wide inclined grooves 114 located at both circumferential main grooves 111, The tire extends in a direction away from each other from the front side to the rear side in the rotation direction of the tire.

According to such a high-performance tire, the circumferential grooves 111, 112, 113
And the substantially parallelogram-shaped block defined by the inclined grooves 114 have a sufficiently high rigidity, and a high negative ratio is ensured. However, excellent steering stability is exhibited.

(Problems to be Solved by the Invention) However, in the conventional tire, since both the block rigidity and the groove volume are particularly increased with a view to improving the steering stability, vibration and pattern noise in the vehicle interior are reduced. The transmission cannot be effectively prevented, and as a result, the livability in the vehicle interior has been reduced.

Here, regarding the pattern noise, particularly in a tire having a curved inclined groove as shown in the illustrated example,
When it is new, the noise level is not high enough to cause a problem, but the level often increases with the progress of wear due to the occurrence of minute heel and toe wear on each block.

The present invention advantageously solves this problem of the prior art, and enhances the riding comfort and reduces the pattern noise without substantially impairing the steering stability on each of the dry road surface and the wet road surface. It is intended to provide a pneumatic tire capable of performing the following.

(Means for Solving the Problems) In the pneumatic tire of the present invention, in particular, a plurality of narrow-width inclined grooves having an opening width such that the groove walls are in contact with each other at the time of tire load rolling are formed with respect to the circumferential grooves. The wide inclined groove extends in the opposite direction to the wide inclined groove, and one narrow inclined groove intersects at least two wide inclined grooves.

Here, more preferably, the land portion which is partitioned by the circumferential groove and the wide inclined groove to form a substantially parallelogram, is divided into two substantially triangular shapes by the narrow inclined groove at the tread tread portion,
Also preferably, the wide wide inclined grooves located across the central region of the tread extend in a direction away from each other from the front side to the rear side in the rotation direction of the tire.

(Operation) In this tire, the circumferential groove and the wide inclined groove formed substantially in the same manner as the conventional tire mainly provide excellent drainage to wet road surfaces, and the narrow inclined groove mainly provides excellent drainage. While advantageously suppressing the decrease in rigidity of the land portion partitioned by the directional groove and the wide inclined groove, while improving the contact property of the land portion, the edge effect of the land portion on a wet road surface or other road surface with a small friction coefficient, That is,
The drainage effect on a wet road surface, the biting force on an ice and snow road surface, and the like can be greatly improved.

Also, here, the narrow inclined groove is extended in the direction opposite to the wide inclined groove with respect to the circumferential groove, and the above-described land portion, preferably a land portion having a substantially parallelogram shape, is moved in the rigid direction. By forming a small land portion in the direction of canceling the tire, the heel and toe wear is sufficiently prevented from occurring due to the uniform surface pressure in the land portion and the improvement of the ground contact property of the land portion, The pattern noise generated due to uneven wear can be reduced, and at the same time, the intersection angle of the wide inclined groove with respect to the circumferential groove is reduced while improving the grounding property, further reducing the pattern noise. Further, it is possible to further improve wet drainage.

For example, on a road surface with a small coefficient of friction, such as a just wet road surface with a water film thickness of zero, both edges of each continent have excellent sliding drag, so that sliding in any direction is possible. A high anti-slip function can also be exhibited.

In response to vibration input from the road surface during normal running, the narrow width inclined groove facilitates deformation of the land portion, so that vibration shock is reduced and riding comfort to the vehicle is improved.

In response to input from each direction during driving, braking, and turning, the opening of the narrow width inclined groove is closed and the land portion rigidity is maintained sufficiently high, so that a decrease in steering stability can be effectively prevented. .

In addition, by interposing the narrow inclined groove with at least two wide inclined grooves in relation to the extension angle of itself and the wide inclined groove, the arrangement pitch of the wide inclined groove, etc. The effect is effective. At a single intersection, the ratio of parallelogram land rows, which are divided into two triangular small lands, occupies a small portion of the road surface, and effects on pattern noise, vibration, and the like cannot be expected.

Furthermore, here, in order to increase the rigidity of the land portion and improve the steering performance, since the land portion shape is substantially a parallelogram, when dividing such a land portion into small land portions with narrow width inclined grooves, In order to maintain the rigidity balance of each of the divided continents, to make them function evenly, and to wear them, it is preferable that the shape of the continents be substantially triangular. In order to simultaneously improve the drainage performance on wet road surfaces and reduce the pattern noise, the extending direction of each wide inclined groove located across the tread central region is rotated from the front side in the tire rotation direction. It is preferable that the directions are separated from each other toward the rear side.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a tread pattern showing one embodiment of the present invention.

Note that the internal structure of the tire is the same as that of a normal radial tire, and is not illustrated here.

In the tire of this example, the circumferential main groove 1, the circumferential intermediate groove 2, the circumferential narrow groove 3, and the wide inclined groove 4 are formed on the tread tread portion T in the same manner as described for the conventional tire. A central block row 5 composed of substantially parallelogram-shaped blocks 5a between the circumferential main groove 1 and the circumferential intermediate groove 2;
In addition, between the circumferential intermediate groove 2 and the circumferential narrow groove 3, an intermediate block row 6, which is also a substantially parallelogram-shaped block 6 a, is partitioned, and the circumferential narrow groove 3 is formed.
From the outer tread edge to the tread end, each block 6 positioned outside the circumferential intermediate groove 2 in the width direction of the tire when the outer block row 7 composed of the blocks 7a is partitioned.
a, 7a, a plurality of narrow-width inclined grooves 8 having an opening width such that the groove walls are in contact with each other when the tire is rolling with a load; , And each of the narrow-width inclined grooves 8 intersects with the two wide-width inclined grooves 4.

Here, when forming each of the narrow-width inclined grooves 8 in this manner, in order to increase the block rigidity, the substantially parallelogram-shaped block 6a and the inner portion of the tread portion of the block 7a are subjected to the narrow-width slope. It is preferable to divide the small blocks into substantially triangular small blocks by the grooves 8 in order to balance the rigidity of each small block.
In order to simultaneously improve the drainage performance and reduce the pattern noise, the wide inclined grooves 4 are arranged so that each of the wide inclined grooves 4 is separated from the circumferential main groove 1 from the front side to the rear side in the tire rotation direction. Preferably, they are separated from each other.

According to such a tire, as described above, the narrow-width inclined groove 8 extends in the direction opposite to the wide-width inclined groove 4 with respect to the circumferential narrow groove 3, thereby reducing the pattern noise and improving the slip prevention function. In addition to improving the ride comfort of the vehicle and preventing a decrease in maneuverability, a narrow inclined groove 8 is formed by intersecting one narrow inclined groove 8 with two wide inclined grooves 4. Is effective.

2 to 4 each show a tread pattern showing another embodiment of the present invention. The tread pattern shown in FIG. 2 is mainly different from the tire shown in FIG. 2 in that two pairs of inner and outer circumferential narrow grooves 9 and 10 are provided on the outer side, and the portion of the wide inclined groove 4 near the tread end is extended upward in the drawing.

In the tread pattern shown in FIG. 3, the circumferential intermediate grooves 2 are provided near the ends of the tread tread portions 2 and two pairs of circumferential grooves are provided between the intermediate grooves 2 and the circumferential main grooves 1. The narrow grooves 11 and 12 are provided respectively,
Are extended from the circumferential main groove 1 toward the tread end, and one narrow-width inclined groove 8 intersects with three wide-width inclined grooves 4, so that all the blocks become small blocks having a substantially triangular shape. In the example shown in FIG. 4, a pair of a circumferential narrow groove 13, a circumferential intermediate groove 2 and a circumferential narrow groove 14 are formed at substantially equal intervals outside the circumferential main groove 1. The extending direction of the portion of the wide inclined groove 4 located outside the narrow circumferential groove 14 is set to the opposite direction to that shown in FIG. , Extending between the circumferential main groove 1 and the circumferential narrow groove 14.

Any of these embodiments can also provide the same effects as the tire shown in FIG. 1 based on satisfying the required requirements of the present invention.

(Comparative example)

Below, the vibration ride comfort of the inventive tire and the conventional tire,
A description will be given of a comparative test regarding pattern noise and steering stability on each of a dry road surface and a wet road surface.

◎ Test tires ・ Size PSR 205/60 R15 ・ Invention tire I In the tire having the tread pattern shown in FIG. 1, the circumferential width of each of the circumferential grooves 1 and 23 is 9 mm, 7 mm and 3 mm.
mm, the width of the wide inclined groove is gradually changed from 1 to 5 mm, and the width of the narrow inclined groove is 0.7 mm.

Inventive tire II A tire having the tread pattern shown in FIG. 2, in which the circumferential width of each of the circumferential grooves 1, 2, 9, 10 is 9 mm, 7 mm, 2 mm,
1 mm, and the groove width of each inclined groove was the same as that of the inventive tire I.

Inventive tire III A tire having the tread pattern shown in FIG. 3, wherein the circumferential width of each of the circumferential grooves 1, 11, 12, 2 is 9 mm, 3 mm, 2 m.
m, 7 mm, and the width of each inclined groove is the same as that of the inventive tire I.

Inventive tire IV A tire having the tread pattern shown in FIG. 4, wherein the circumferential width of each of the circumferential grooves 1, 13, 2, 14 is 9 mm, 2 mm, 7 m.
m, 2 mm, and the width of each inclined groove is the same as that of the inventive tire I.

・ Conventional tire Inventive tire I in which the narrow width inclined groove is omitted.

◎ Test method The tire internal pressure and load were set to normal conditions based on the JIS standard, and the riding comfort and pattern noise were evaluated by feeling when the vehicle was running on various road surfaces in general. In addition, the pattern noise after abrasion was evaluated by feeling after traveling 1000 km.

Driving stability on dry roads was evaluated by feeling evaluation of various driving on circuit courses on dry roads, and steering stability on wet roads was evaluated based on feelings of various driving on circuit courses on just wet roads at zero water depth. Each was determined by ring evaluation.

◎ Test results The results of the above various tests are compared with those of conventional tires
It is shown in the table below as 100.

The larger the index value, the better the result.

(Effects of the Invention) As is clear from the above table, according to the tire of the present invention, the vibration and noise in the vehicle interior are advantageously reduced without sacrificing the steering stability of the high performance radial tire, and the comfort is improved. Can be effectively improved.

[Brief description of the drawings]

1 to 4 are diagrams illustrating a tread pattern of a tire according to the present invention, and FIG. 5 is a diagram illustrating a tread pattern of a conventional tire. 1,2,3,9,10,11,12,13,14 circumferential groove 4 wide inclined groove 5,6,7 block row 5a, 6a, 7a block 8 Narrow width inclined groove.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-1-36506 (JP, A) JP-A-63-222907 (JP, A) JP-A-62-214004 (JP, A) JP-A-61-214 36002 (JP, A) JP-A-64-36508 (JP, A) JP-A-64-36507 (JP, A) JP-A-64-36505 (JP, A) JP-B-59-8562 (JP, B2) Tokiko Hei 5-23204 (JP, B2) Jiko Hei 7-55122 (JP, Y2)

Claims (3)

(57) [Claims] 1. A plurality of circumferential grooves extending parallel to each other in a circumferential direction of a tire, and an intersection angle with respect to the circumferential grooves is gradually changed from a central region of the tread to each tread end. A pneumatic tire having a plurality of wide inclined grooves extending on the tread tread portion, the plurality of pinches having an opening width such that the groove walls contact each other when the tire is rolling. The pneumatic injection device characterized in that the width-inclined groove extends in a direction opposite to the wide-width inclined groove with respect to the circumferential groove, and one narrow-width inclined groove intersects at least two wide-width inclined grooves. tire. 2. A land portion which is defined by a circumferential groove and a wide inclined groove and has a substantially parallelogram shape is divided into two substantially triangular shapes by a narrow inclined groove at a tread tread portion. Pneumatic tires. 3. The tire according to claim 1, wherein each of the wide inclined grooves located apart from the center region of the tread extends in a direction away from each other from the front side to the rear side in the rotation direction of the tire. The pneumatic tire as described.