JPH05294113A - Pneumatic tire - Google Patents

Abstract

PURPOSE:To reduce tread noise and vibration so as to improve interior comfortableness without decreasing maneuverability of a tire. CONSTITUTION:A pneumatic tire is provided with at least one main land zone 4 which is partitioned between a plurality of circumferential-direction main grooves 2, 3 in a tread and inclined main grooves 5 which are inclinedly extended mutually in the opposite direction in an each zone from the main grooves in the tread circumferential direction are extended beyond the central part of themain land part but completed without crossing each other. And two circumferential-direction narrow grooves 6 are provided, in the main land zone, extending almost parallel to the main grooves, inclined main grooves are shifted in their phases approximately 1/2 pitch mutually to the arranged pitch and extended to the circumferential-direction narrow grooves 6 which are situated on a far side from the main grooves, and inclined sub grooves 7 extending in the direction opposite to that of the inclined main grooves between respective circumferential-direction main grooves and respective circumferential- direction narrow grooves which are situated in a close side of them, are provided between respective inclined main grooves so that approximately trapezoidal blocks 8, 9 which alternately change their direction in the tread circumferential direction are partitioned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reduces the pattern noise without impairing the dynamic performance of pneumatic tires, especially tires, and also improves the vibration riding comfort and greatly improves the comfortability in the passenger compartment. It relates to high performance pneumatic tires.

[0002]

2. Description of the Related Art In a conventional high-performance pneumatic tire, a plurality of linear circumferential grooves extending in the circumferential direction are provided on the tread tread, and the tread tread has a center of the tread when viewed from the front when the tire is mounted on a vehicle. A unidirectional pattern in which a plurality of inclined grooves that extend obliquely upward from the area toward the tread edge is provided is widely and generally adopted.

[0003]

However, in such conventional high performance pneumatic tires, pattern design is performed with a focus on steering stability performance and wet performance, and as a result, the interior of the vehicle interior is It was forced to sacrifice habitability. The present invention has been made as a result of an examination to solve such problems of the conventional art, and an object of the present invention is to maintain high dry performance and wet performance of tires,
(EN) Provided is a pneumatic tire that effectively reduces pattern noise and sufficiently improves vibration riding comfort, and greatly enhances habitability in a vehicle interior.

[0004]

[Problems to be Solved by the Invention] A plurality of circumferential main grooves extending linearly in the tread circumferential direction are provided on a tread surface, and at least one main land area is defined between the circumferential main grooves. However, within the main land area, each of the circumferential main grooves extends in a direction opposite to the circumferential direction of the tread, and extends beyond the central portion of the main land area, but intersects with each other. In the main land area, each inclined main groove, which ends without being disposed at a predetermined interval in the circumferential direction of the tread, divides it substantially into three equal parts in the tread width direction. , Two circumferential narrow grooves that extend substantially parallel to the circumferential main groove and in which the groove walls contact each other in the ground plane, and inclined main grooves extending from the respective circumferential main grooves are provided. , Tread circumferential direction with respect to the pitch of the inclined main groove While mutually phase-shifting by approximately 1/2 pitch, extend from each circumferential main groove to the circumferential narrow groove on the far side, and between each inclined main groove extending from each circumferential main groove, Providing an inclined sub-groove extending in a direction opposite to those inclined main grooves with respect to the tread circumferential direction and extending between the circumferential main groove and the circumferential narrow groove on the side close thereto, with this, A substantially trapezoidal block whose direction alternates in the circumferential direction of the tread is defined between the circumferential grooves.

[0005]

The pneumatic tire of the present invention extends in the main land area from the respective circumferential main grooves while extending in the directions opposite to each other with respect to the circumferential direction of the tread, and at the center of the main land area. By providing continuous inclined main grooves that end without intersecting with each other even if they exceed the parts, it is possible to enhance the drainage effect of each inclined main groove and ensure excellent wet drainage performance. Approximately 1/2 of the pitch of their arrangement in the tread circumferential direction between the inclined main grooves.
By arranging with a pitch phase difference, it is possible to reduce pattern noise.

By the way, in the case where the respective inclined main grooves are interleaved and alternately arranged as described above,
Since the width of the main land area becomes wider by itself, the improvement of riding comfort is secured by providing the circumferential narrow groove in the main land area. In this case, since the circumferential narrow groove has a groove width such that the groove walls contact each other in the ground contact surface, especially for the force in the tread width direction during turning traveling,
It is possible to bring a plurality of blocks into contact in the tread width direction and sufficiently secure the required block rigidity.

Moreover, here, by providing the inclined sub-grooves between the inclined main grooves, the land portion between the circumferential main groove and the circumferential narrow groove located in the vicinity thereof is divided into two in the circumferential direction. As a result, the block rigidity necessary for ensuring the steering stability can be sufficiently ensured, and the block rigidity can be effectively reduced to improve the vibration riding comfort. In addition, the extension direction of the inclined sub-groove can be improved. By making the direction opposite to that of the inclined main groove, the variation effect can be enhanced and the pattern noise can be further effectively reduced.

The inclined sub-groove extending in the direction opposite to the inclined main groove has a negative effect on wet drainage, but the inclined main flow is longer and continuous, It controls the drainage effect, and the adverse effect of the short reverse tilt sub-groove can be ignored. And further, the trapezoidal block divided by each groove described above,
Rather than being inclined in one direction like parallel four-deformation, it has a substantially uniform and uniform rigidity, which can further improve both steering stability and vibration riding comfort, and good uneven wear resistance. Can bring

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a tread pattern showing an embodiment of the present invention, in which 1 is a tread surface portion, and 2 and 3 are two circumferential main grooves arranged with a tread center separated from each other. The four main circumferential grooves 2, 3 in total extend substantially linearly in the circumferential direction of the tread.

Here, a single main land area 4 is defined between two circumferential main grooves located in the vicinity of the tread center, and in each main land area, from the respective circumferential main grooves 2. , An inclination that extends in the directions opposite to each other with respect to the circumferential direction of the tread and crosses the center of the main land area 4, the tread center XX in the figure, but ends without intersecting with each other A main groove 5 is provided, and each of these inclined main grooves 5 is provided.
Of the inner circumferential end of each of the two circumferential narrow grooves 6 extending substantially parallel to the circumferential main groove 2 at each position substantially dividing the main land area 4 into three in the tread width direction. The narrow groove 6 on the side far from the direction main groove 2 is opened. Here, each circumferential narrow groove 6
Has a groove width such that the groove walls contact each other in the ground contact plane of the tire.

Further, here, between the respective inclined main grooves extending from the respective circumferential main grooves 2, the circumferential main grooves 2 extend in the direction opposite to the inclined main grooves 5 with respect to the tread circumferential direction.
And an inclined sub-groove 7 extending between it and a circumferential narrow groove 6 adjacent thereto, and by these, the respective circumferential grooves are alternately turned in the circumferential direction of the tread. Each of the trapezoidal blocks 8 and 9 is divided.

In addition, in the illustrated example, in each land portion 10 partitioned between each circumferential main groove 2 and each circumferential main groove 3, on the extension line of the above-mentioned inclined main groove 5, Alternatively, by providing inclined grooves 11 extending in the vicinity thereof and dividing grooves 12 extending in the direction opposite to the inclined grooves 11 with respect to the tread circumferential direction between these respective inclined grooves, the inside of those land portions is provided. Alternating with the circumferential direction of the tread, this also defines each block 13 of lateral trapezoidal shape.

Further, in this example, the land portion 14 between the outer circumferential main groove 3 and the tread end is provided with another inclined groove 15 extending on the extension line of the inclined groove 11 or in the vicinity thereof. Between these inclined grooves, another divided groove 16 extending in the direction opposite to the inclined groove 15 is provided to partition a lateral trapezoidal block 17 which is alternately opposite in the circumferential direction of the tread.

According to the pneumatic tire constructed as described above, in particular, the respective grooves 5, 6, 7 provided in the single main land area 4 and the respective blocks 8 defined in the area. As described above, under the action of Nos. 9 and 9, sufficient steering stability and wet drainage can be sufficiently ensured, yet pattern noise can be effectively reduced, and at the same time, vibration ride comfort can be greatly improved. .. Moreover, in this tire, each groove 1 provided in each land portion 10 and 14
Since 1, 12, 15, 16 and blocks 13, 17 also function in substantially the same manner as those of the main land area 4, the above-mentioned effects can be further improved.

FIG. 2 is a tread pattern showing another embodiment of the present invention, in which one circumferential main groove 21 is provided in the tread center portion, and each tread end from the circumferential main groove 21. Two main land areas divided between the circumferential main grooves 21 and 22 where other circumferential main grooves 22 are provided at positions with a predetermined distance to the side.
23, each groove similar to the above-described embodiment is provided. That is, in each main land area 23, the same inclined main groove 24, two circumferential narrow grooves 25 and inclined sub groove 26 as described above are formed, and by these, between the respective circumferential grooves. , Laterally trapezoidal blocks 27 and 28 are defined.

Here, in the land portion 29 between the circumferential main groove 22 and the tread end, the inclined groove 30 and the dividing groove 31 which are similar to those in the above-described example are also formed, respectively, to form a sideways trapezoid. A block 32 having a shape is defined. The pneumatic tire having such a pattern configuration can also bring about the same operational effects as the embodiment shown in FIG. 1 with respect to steering stability, wet drainage, pattern noise, and vibration riding comfort.

[0017]

[Comparative Example] A comparative test between the inventive tire and the conventional tire concerning steering stability on dry and wet road surfaces, low pattern noise, and good vibration riding comfort will be described below. ◎ Test tire size 205/50 R 15 with 160mm tread width. Invention Tire 1 A tire having the tread pattern shown in FIG.
The widths of the circumferential main grooves 2 and 3 are both 8.0 mm, the width of the main land area 4 is 42 mm, the angle of the inclined main groove 5 with respect to the tread circumferential direction is 30 to 40 °, and the groove width is 3.0 to 4.0 mm. The circumferential narrow groove 6 has a groove width of 1.0 mm, the inclined sub-groove 7 has an angle of 45 ° with respect to the circumferential direction of the tread, and the groove width is 3.0 to 3.5 mm. Invention tire 2 A tire having the tread pattern shown in FIG.
The width of the circumferential main groove 21 is 10.0 mm, the width of the circumferential main groove 22 is 9.0 mm
A tire having the same dimensions as the invention tire 1 except that Conventional tire A tire having a tread pattern shown in FIG. 3,
The width of the circumferential main groove is 8 mm and the width of the inclined groove is 4 mm,

◎ Test method Tires with a filling internal pressure of 2.2 kg / cm ² were mounted on an actual vehicle, and under the condition that a load equivalent to two occupants was loaded, the steering stability on dry road surface was dry. We evaluated the feeling when driving the circuit course in various driving modes, and the steering stability on wet road surface was
Evaluate the feeling when driving in a just wet state circuit course in various driving modes,
The low pattern noise is 100-40km / h on a smooth straight road.
The vehicle interior noise when running at the vehicle speed was evaluated by feeling, and the goodness of vibration riding comfort was evaluated by feeling when riding on several kinds of straight road surfaces with different surface roughness and unevenness.

◎ Test Results The results of the above tests are shown in Table 1 as an index, using the conventional tire as a control. The larger the index value, the better the result.

[Table 1] According to Table 1, each of the invention tires is capable of effectively reducing pattern noise and effectively improving vibration riding comfort while ensuring sufficient driving stability on dry and wet road surfaces. Is clear.

[0020]

As is apparent from the above comparative example, according to the present invention, the dynamic performance of the tire is improved due to the action of the various grooves provided in the main land area and the blocks partitioned by them. It is possible to effectively improve the habitability in the vehicle compartment while maintaining it.

[Brief description of drawings]

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

FIG. 2 is a tread pattern showing another embodiment of the present invention.

FIG. 3 is a diagram showing a tread pattern of a conventional tire. 1 Tread Tread 2,3,21,22 Circumferential main groove 4,23 Main land area 5,24 Inclined main groove 6,25 Circumferential narrow groove 7,26 Inclined auxiliary groove 8,9,27,28 Block

Claims (1)

[Claims] 1. A tread tread portion is provided with a plurality of circumferential main grooves linearly extending in the tread circumferential direction, and at least one main land area is defined between the circumferential main grooves, and each main In the land area, from each circumferential main groove, extending in a mutually opposite direction with respect to the tread circumferential direction,
A tire in which each inclined main groove that ends without intersecting with each other is arranged at a predetermined interval in the tread circumferential direction even if it exceeds the central portion of the main land area, , At each position that divides it substantially into three equal parts in the tread width direction, there are provided circumferential narrow grooves that extend substantially parallel to the circumferential main groove and in which the groove walls contact each other in the ground contact surface. The inclined main grooves extending from the circumferential main groove are phase-shifted from each other in the tread circumferential direction by about 1/2 pitch with respect to the pitch of the inclined main groove, and are far from each circumferential main groove. Between the inclined main grooves extending from the circumferential main groove to the circumferential narrow groove on the side, and extending in the direction opposite to the inclined main grooves with respect to the tread circumferential direction. The inclined sub-groove extending between the A pneumatic tire that is provided with a substantially trapezoidal block that alternates in the circumferential direction of the tread between the circumferential grooves.