JP3377291B2 - Pneumatic tire with directional tread pattern - Google Patents

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 passenger cars, and more particularly to a high athletic performance tire which emphasizes athletic performance capable of supporting sports running, and which is suitable for running on a wet road surface. The present invention relates to a pneumatic tire for a passenger vehicle, which prevents or suppresses wandering when traveling on a road surface provided with a rain groove without sacrificing wet performance.

[0002]

2. Description of the Related Art A typical conventional tread pattern of a pneumatic tire for a high-performance passenger car is shown in FIG. As shown in the figure, the conventional tire has several tires (four tires in the illustrated example,
The tread pattern is composed of circumferential grooves (generally about 2 to 8) and a large number of directional inclined grooves arranged at intervals in the circumferential direction. In the present specification, the circumferential groove means a straight groove or a substantially straight groove continuously extending in the circumferential direction, and the directional inclined groove is a groove extending obliquely with respect to the circumferential direction. Then, the side of the groove near the tire equatorial plane that extends obliquely contacts the ground first,
It means a groove in which a so-called directional tread pattern is formed, in which the direction of rotation of the tire when it is mounted on a vehicle is specified so that the side farther from the equatorial plane will come into contact with the ground later.

In order to improve steering stability and hydroplaning characteristics on a wet road surface in the conventional tire as described above, the number of circumferential grooves is increased and the inclination angle of the inclined grooves with respect to the circumferential direction is decreased. Is an effective and frequently adopted design method. However, it has been found that a pneumatic tire having a directional tread pattern excellent in wet performance designed by this method tends to cause wandering when traveling on a road surface having a rain groove. The rain groove is a small drain groove provided on the road surface at intervals of about 19 mm in order to enhance drainage performance on the road surface in the case of rain, and is provided along the traveling direction of the vehicle. Wandering is a phenomenon in which the grooves on the ground contact surface of a tire receive the reaction force due to being caught by the rain grooves, and the steering wheel is taken, or the vehicle sways.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high athletic performance tire which emphasizes athletic performance capable of supporting sports running, without sacrificing wet performance when traveling on a wet road surface. (EN) Provided is a novel tread pattern used for a pneumatic tire for a passenger vehicle, which prevents or suppresses wandering when traveling on a road surface provided with a rain groove.

[0005]

In order to achieve the above object, the pneumatic tire of the present invention comprises one or two circumferential main grooves and a circumferential groove provided at or near the center of the tread. A pneumatic tire having a directional tread pattern comprising a plurality of directional tilted grooves spaced in the direction and a plurality of crank-shaped grooves spaced in the circumferential direction as well. The crank-shaped groove is composed of a pair of circumferentially extending portions and an inclined and extending portion connecting one front end and the other rear end of the pair of circumferentially extending portions, and (2) the crank. The pair of circumferential grooves extending in the circumferential direction are arranged so that the side closer to the tire equatorial plane contacts the ground first, and the side farther from the equatorial plane contacts the ground later. The side closer to the equatorial plane of the tire touches down first A passenger high driving performance pneumatic tire for having a tread pattern, characterized in that arranged to the ground after the far side is the equatorial plane.

In order to achieve the above object, in the tread pattern of the pneumatic tire of the present invention, the lengths of the pair of circumferentially extending portions of the crank-shaped groove are not more than the tread contact length. The total length of the crank-shaped groove is preferably equal to or longer than the tread ground contact length.

To achieve the above object, in the tread pattern of the pneumatic tire of the present invention, the crank-shaped grooves adjacent to each other in the circumferential direction have a tire equatorial plane of a portion of one of the grooves extending in the circumferential direction. It is preferable that the near side and the side distant from the equatorial plane of the portion of the other groove extending in the circumferential direction are juxtaposed in the tire longitudinal direction.

In order to achieve the above object, in the tread pattern of the pneumatic tire of the present invention, the circumferentially adjacent portions of the crank-shaped grooves extending in the circumferential direction are arranged in parallel in the tire longitudinal direction. The width of the formed rib is 2
It is preferably 0 mm or more and 5% to 20% of the tread width.

To achieve the above object, in the tread pattern of the pneumatic tire of the present invention, the inclination angle of the pair of circumferentially extending portions of the crank-shaped groove with respect to the circumferential direction is 0 to 10 degrees, The inclination angle of the inclined extending portion of the crank-shaped groove with respect to the circumferential direction is preferably 40 to 60 degrees.

[0010]

Since the pneumatic tire for passenger cars of the present invention has the tread pattern as described above, the circumferential groove and the directional inclined groove provide a temporary drainage property. (See, for example, FIG. 4) is also the same. In the pneumatic tire for passenger cars of the present invention, in addition to the circumferential groove and the directional inclined groove, a large number of crank-shaped grooves are arranged at intervals in the circumferential direction, and (1) the crank-shaped grooves are arranged in a pair. (2) a portion extending in the circumferential direction and a portion extending inclining to connect one tip end portion and the other rear end portion of the pair of circumferentially extending portions, and (2) in the pair of circumferential directions of the crank-shaped groove. The extended portion is arranged so that the side closer to the tire equatorial plane comes into contact with the ground first, and the side farther from the equatorial plane comes into contact later, and (3) the portion of the crank-shaped groove extending obliquely closer to the tire equatorial plane comes first. It is arranged so that the side farther from the equatorial plane will come into contact with the ground later, so when driving on a wet road surface, water easily flows from the center to the side rear in the tire contact area, which is excellent in drainage. It is a tire.

In the tread pattern of the pneumatic tire for passenger cars according to the present invention, since the length of each of the pair of circumferentially extending portions of the crank-shaped groove is equal to or less than the tread contact length, the road surface provided with a rain groove. It is a tire with excellent drainage because it is possible to prevent or suppress wandering when traveling over, and the overall length of the rank-shaped groove is at least the tread contact length.

In the tread pattern of the pneumatic tire for a passenger car according to the present invention, the crank-shaped grooves adjacent to each other in the circumferential direction are provided with a groove extending in the circumferential direction of one of the grooves, which is closer to the tire equatorial plane and the other groove. Since the portion extending in the circumferential direction and the side far from the equatorial plane are juxtaposed in the tire longitudinal direction, the tire has excellent drainage.

In the tread pattern of the pneumatic tire of the present invention, the width of the rib formed by the circumferentially adjacent portions of the crank-shaped grooves extending in the circumferential direction being juxtaposed in the tire longitudinal direction is 20 mm or more. And tread width of 5
% To 20%, the rigidity of the rib portion is sufficiently secured.

To achieve the above object, in the tread pattern of the pneumatic tire for passenger cars of the present invention, the inclination angle of the pair of circumferentially extending portions of the crank-shaped groove with respect to the circumferential direction is 0 to 10 degrees. Therefore, it has excellent drainage,
Since the inclination angle of the inclined extending portion of the crank-shaped groove with respect to the circumferential direction is 40 to 60 degrees, the traction force and other road surface grasping performance are excellent.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to the drawings. FIGS. 1 to 7 are tread patterns of Examples 1 to 3 of a pneumatic tire for passenger cars according to the present invention. Both are 225 / 50R16
The tread width TW is about 200 mm.

The pneumatic tire of Example 1 shown in FIG.
Two circumferential main grooves (1 near the center of the tread)
1, 12) and a pair of left and right circumferential sub-grooves (13, 14) provided on both sides of the tread, and a large number of directional inclined grooves arranged at intervals in the circumferential direction. The width of the circumferential main groove (11, 12) is 8
In mm, the width of the circumferential sub-grooves (13, 14) is 2 mm.
The direction of the circumferential groove is the same as the circumferential direction, in other words, the inclination angle of these grooves with respect to the circumferential direction is 0 degree. The directional tilted groove is narrow enough to close the groove just below the load, and the wide directional tilted groove (2) has a width wide enough not to close even just below the load.
3, 24, 25, 26). In the first embodiment, the groove widths of the directional tilt slit grooves (21, 22) are both 1.2 mm, and the directional tilt wide grooves (23, 2).
The groove width of 4) is 3.5 mm, and the directional inclined wide groove (25,
The groove width of 26) is 4 m in the vicinity of the auxiliary grooves (13, 14) in the circumferential direction.
m, but gradually widened to 5 mm at both ends of the tread
Has become. The crank-shaped groove is a portion (31/33, 32/34) extending in the circumferential direction and an inclined extending portion (31) connecting the front end and the rear end of the other of the pair of circumferentially extending portions ( 35, 36), the side (31, 32) near the tire equatorial plane of the pair of circumferentially extending portions of the crank-shaped groove is grounded first and the side farther from the equatorial plane (33, 36).
34) is arranged so as to come into contact with the ground later, and parts of the crank-shaped grooves (35, 36) that extend obliquely are arranged so that the side closer to the tire equatorial plane comes into contact first and the side farther from the equatorial plane comes into contact later. ing. The groove width of the inclined extending portions (35, 36) of the crank-shaped groove is 5.5 mm, and the inclination angle with respect to the circumferential direction is 50 degrees. Sides of the pair of circumferentially extending portions of the crank-shaped groove near the tire equatorial plane (31, 32)
Has a groove width of 7 mm, the groove width on the side farther from the equatorial plane (33, 34) is 6 mm, and the inclination angle with respect to the circumferential direction is 0 degree. A pair of circumferentially extending portions (3
The length of 1/33, 32/34) is 50mm for both
The tread contact length (110 mm) or less. The total length of the crank-shaped groove is 120 mm, which is equal to or longer than the tread contact length. With respect to the crank-shaped grooves adjacent to each other in the circumferential direction, the side (31, 32) near the tire equatorial plane of the portion extending in the circumferential direction of one groove and the side (33 , 34) are juxtaposed in the tire longitudinal direction. The ribs formed by juxtaposing these tires in the longitudinal direction have a width of 14 mm and a tread width (2
It is 7% of 00 mm).

The pneumatic tire of Example 2 shown in FIG.
It is basically the same as the pneumatic tire of Example 1 shown in FIG. The main difference is that the pair of left and right circumferential sub-grooves (13, 14) provided in the first embodiment are eliminated, and the directional inclined slit grooves (21, 22) extend to the tread end as they are. It is that.

The pneumatic tire of Example 3 shown in FIG.
It is basically the same as the pneumatic tire of Example 2 shown in FIG. The main difference is that in Example 1, two 8 mm wide circumferential main grooves (11, 1) provided near the center of the tread were used.
2) is changed to a single circumferential main groove (10) having a width of 10 mm, and the crank-shaped grooves are connected to a substantially central portion on a side (31, 32) near a tire equatorial plane of a pair of circumferentially extending portions. That is, the grooves (43, 44) extending obliquely and the grooves (41, 42) further extending in the circumferential direction from the grooves (43, 44) are added.

The pneumatic tire of Example 4 shown in FIG.
It is basically the same as the pneumatic tire of Example 1 shown in FIG. The main difference is that in Example 1, two 8 mm wide circumferential main grooves (11, 1) provided near the center of the tread were used.
2) is changed into one 12 mm wide circumferential main groove (10), and a pair of two circumferential auxiliary grooves (13, 14) are moved on both sides thereof, and a pair of crank-shaped grooves extend in the circumferential direction. The inclination angle with respect to the circumferential direction is 5 degrees on both the side (31, 32) near the tire equatorial plane and the side (33, 34) far from the equatorial plane. However, one side (31, 33) of the tire equatorial plane is +5 degrees, and the other side (32, 34) is -5 degrees.

The pneumatic tire of Example 5 shown in FIG.
It is basically the same as the pneumatic tire of Example 4 shown in FIG. The main difference is that the side (31, 32) near the tire equatorial plane of the pair of circumferentially extending portions of the crank-shaped groove is slit groove (45, 46) and the side far from the equatorial plane (33, 34) is slit. That is, they are connected by the grooves (47, 48).

The Example 6 pneumatic tire shown in FIG. 6 is basically the same as the Example 4 pneumatic tire shown in FIG. The main difference is that the inclination angles (31, 34) of the pair of circumferentially extending portions of the crank-shaped groove with respect to the circumferential direction are −5 degrees and (32, 33) is +5 degrees.

The pneumatic tire of Example 7 shown in FIG.
It is basically the same as the pneumatic tire of Example 6 shown in FIG. The main difference is that the side (31, 32) near the tire equatorial plane of the pair of circumferentially extending portions of the crank-shaped groove is slit groove (45, 46) and the side far from the equatorial plane (33, 34) is slit. That is, they are connected by the grooves (47, 48).

The conventional pneumatic tire shown in FIG. 8 is a typical example of the tread pattern of the conventional pneumatic tire. As shown in the drawing, five circumferential grooves and a large number of directional inclined grooves are provided. Are arranged at intervals in the circumferential direction. The tire size is 225 / 50R16, and the tread width TW is about 200 mm, both of which are the same as those in the above embodiment. The circumferential groove (63) in the center of the tread has a width of 4
Although it is a narrow groove of mm, a pair of circumferential grooves (62, 64) with a groove width of 11 mm is provided on the left and right sides, and further, it is equivalent to about 1/4 of the tread width from both ends of the tread toward the center of the tread. A pair of circumferential grooves (61, 65) having a groove width of 10 mm are provided at the positions to be formed, and these four thick circumferential grooves and a large number of directional inclined grooves (71, 72, 73, 74, 75,
76) greatly contributes to drainage performance when the tire travels on a wet road surface.

1 to 7 of the present invention according to the present invention for passenger vehicle pneumatic tires and the conventional example of the conventional passenger vehicle pneumatic tire shown in FIG. 8 wet when running on a wet road surface. A wandering evaluation test was carried out when traveling on a road surface having performance (hydro planing) and a rain groove. The test conditions were a tire internal pressure of 2.3 Kg / cm ² , and hydro-planing characteristics were the result of a test driver's feeling evaluation by the response of the steering wheel when passing the wet road surface at a water depth of 10 mm, and wandering was free in California, USA.
It is a test driver's feeling evaluation result by the response of the steering wheel when traveling on the way. The evaluation results are shown in index representation with the result of the pneumatic tire of Conventional Example as 100, and the larger the number, the better the performance. Table 1 shows a summary of the evaluation results.

[0025]

[Table 1]

From the results shown in Table 1, the pneumatic tires for passenger cars of Examples 1 to 3 according to the present invention have the same or slightly better hydroplaning characteristics than the pneumatic tires for passenger cars of the conventional examples. However, it turns out that wandering is far superior.

[0027]

According to the pneumatic tire for passenger cars of the present invention,
In addition to the circumferential groove and the directional inclined groove, a large number of crank-shaped grooves are arranged at intervals in the circumferential direction, and (1) the crank-shaped grooves include a pair of circumferentially extending portions and the pair of circumferential grooves. (2) The side of the pair of crank-shaped grooves extending in the circumferential direction, which is closer to the tire equatorial plane, is first. It is arranged so that the side farther from the equatorial plane will come into contact with the ground later, and (3) the side of the crank-shaped groove extending obliquely closer to the tire equatorial plane will come into contact first, and the side farther from the equatorial plane will come later. Since the tire is arranged so as to be in contact with the ground, water easily flows from the center toward the rear side in the ground contact area of the tire when traveling on a wet road surface, and the tire has excellent drainage.

In the tread pattern of the pneumatic tire for passenger cars according to the present invention, since the length of each of the pair of circumferentially extending portions of the crank-shaped groove is equal to or shorter than the tread contact length, the road surface provided with a rain groove. It is a tire with excellent drainage because it is possible to prevent or suppress wandering when traveling over, and the overall length of the rank-shaped groove is at least the tread contact length.

In the tread pattern of the pneumatic tire for passenger cars according to the present invention, the crank-shaped grooves that are adjacent to each other in the circumferential direction are provided with a portion of one groove which extends in the circumferential direction and which is closer to the tire equatorial plane and the other groove. Since the portion extending in the circumferential direction and the side far from the equatorial plane are juxtaposed in the tire longitudinal direction, the tire has excellent drainage.

In the tread pattern of the pneumatic tire of the present invention, the width of the rib formed by the circumferentially adjacent portions of the crank-shaped grooves extending in the circumferential direction being parallel to each other in the tire longitudinal direction is 20 mm or more. And tread width of 5
% To 20%, the rigidity of the rib portion is sufficiently secured.

In the tread pattern of the pneumatic tire for passenger cars of the present invention, since the inclination angle of the pair of circumferentially extending portions of the crank-shaped groove with respect to the circumferential direction is 0 to 10 degrees, the drainage is excellent, Since the inclination angle of the inclined extending portion of the crank-shaped groove with respect to the circumferential direction is 40 to 60 degrees, the traction force and other road surface grasping performance are excellent.

[Brief description of drawings]

FIG. 1 is a tread pattern diagram of a pneumatic tire according to the present invention.

FIG. 2 is a tread pattern diagram of a pneumatic tire according to the present invention.

FIG. 3 is a tread pattern diagram of a pneumatic tire according to the present invention.

FIG. 4 is a tread pattern diagram of a pneumatic tire according to the present invention.

FIG. 5 is a tread pattern diagram of a pneumatic tire according to the present invention.

FIG. 6 is a tread pattern diagram of a pneumatic tire according to the present invention.

FIG. 7 is a tread pattern diagram of a pneumatic tire according to the present invention.

FIG. 8 is a tread pattern diagram of a conventional typical pneumatic tire.

[Explanation of symbols]

D tire rotation direction TW tread width 10 circumferential main groove 11 circumferential main groove 12 circumferential main groove 13 circumferential sub groove 14 circumferential sub groove 21 directional inclined groove (slit groove) 22 directional inclined groove (slit groove ) 23 directional tilted groove (wide width groove) 24 directional tilted groove (wide width groove) 25 directional tilted groove (wide width groove) 26 directional tilted groove (wide width groove) 31 portion extending in circumferential direction of crank-shaped groove (equatorial plane) 32 side portion extending in the circumferential direction of the crank-shaped groove (side closer to the equatorial plane) 33 portion extending in the circumferential direction of the crank-shaped groove (side farther from the equatorial plane) 34 portion extending in the circumferential direction of the crank-shaped groove (equator) The side farther from the surface) 35 Crank-shaped groove inclined extending portion 36 Crank-shaped groove inclined extending portion 41 Circumferentially extending groove 42 Circumferentially extending groove 43 Inclined extending groove 44 Inclined extending groove

Claims (5)

(57) [Claims] 1. A number of one or two circumferential main grooves provided at or near a central portion of a tread, and a large number of directional inclined grooves arranged at intervals in the circumferential direction, and also in the circumferential direction. In a pneumatic tire having a directional tread pattern consisting of a number of crank-shaped grooves spaced apart from each other, (1) the crank-shaped grooves have a pair of circumferentially extending portions and a pair of circumferential directions. A part that extends obliquely and connects one of the front end and the other rear end of the part,
(2) The pair of circumferentially extending portions of the crank-shaped groove are arranged so that the side closer to the tire equatorial plane comes into contact with the ground first and the side farther from the equatorial plane comes into contact with the ground later, and (3) inclination of the crank-shaped groove. The pneumatic tire with a tread pattern is characterized in that the side of the tire extending closer to the equatorial plane comes into contact with the ground first, and the side farther from the equatorial plane comes into contact with the ground later. 2. The length of each of the pair of circumferentially extending portions of the crank-shaped groove is equal to or less than the tread ground contact length,
The pneumatic tire according to claim 1, wherein the total length of the crank-shaped groove is equal to or longer than the tread contact length. 3. The crank-shaped grooves that are adjacent to each other in the circumferential direction include a side of one of the grooves extending in the circumferential direction near the tire equatorial plane and a side of the other groove extending in the circumferential direction far from the equatorial plane. 3. The pneumatic tire according to claim 1, wherein the tires are arranged side by side in the tire longitudinal direction. 4. The width of a rib formed by arranging circumferentially adjacent portions of the crank-shaped grooves extending in the circumferential direction in the tire longitudinal direction is 20 mm or more and 5% to 20% of the tread width. The pneumatic tire according to any one of claims 1 to 3, wherein: 5. The inclination angle of the pair of circumferentially extending portions of the crank groove with respect to the circumferential direction is 0 to 10 degrees, and the inclination angle of the diagonally extending portions of the crank groove with respect to the circumferential direction is 40 degrees. The pneumatic tire according to any one of claims 1 to 4, wherein the pneumatic tire has an angle of 60 to 60 degrees.