JPH0478483B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a tread structure for a vehicle tire, and more specifically to a tread structure for a so-called rally car tire that runs on unpaved roads, snowy roads, icy roads, etc. (Prior Art) On the outer surface of the tread portion of a tire, in pattern blocks such as center blocks and side blocks, the grounding edges of the blocks are formed in a stair-like shape that alternates in the tire axial direction and the tire rotational direction when viewed from above, thereby improving traction. A tire tread pattern designed to improve braking resistance and cornering performance during turning is known from Japanese Utility Model Application No. 58-45104. That is, as shown in FIGS. 5 and 6, the tire includes a center block S1 located on the tire equator and side blocks S2 arranged on both left and right sides of the center block S1, and a block grounding edge S3 of the side block S2.
This step-like structure improves traction, braking resistance, and cornering performance. (Problem to be Solved by the Invention) However, in the above-mentioned prior art, the pattern blocks are asymmetrical with respect to the tire equator line, as shown in FIGS. 5 and 6, and have no directionality. The following issues arose: That is, when turning the car to the right as shown in Fig. 5, with the rotation direction of the tires set as Q in Fig. 5,
Since the step-shaped block grounding edge S3 faces the direction of arrow F against tire skidding, it is possible to prevent skidding, but when turning left as shown in Fig. Since it does not face arrow F, it does not function effectively. Furthermore, the traction and braking resistance during straight traveling are unevenly applied on the left and right sides because the pattern blocks of the tire tread are asymmetrical. The present invention provides a vehicle tire in which the pattern blocks of the tire tread are given directionality, and moreover, the driving force and braking force when traveling straight are ensured equally on the left and right sides of the tire tread, while preventing skidding when turning at high speed. The purpose is to provide a treaded structure. (Means for Solving the Problems) The present invention includes a center block located on the tire equator line, a side block located on both sides away from the tire equator line, and a tire shoulder portion on both shoulder portions of the tire. The shoulder blocks located at In order to achieve the above-mentioned object in the tread structure of a vehicle tire, the following technical measures have been taken. That is, the present invention provides the center block 1
The outer shape of the center block 10 has a horizontally long part and a vertically long part, and is T-shaped in plan view, and each of the center blocks 10 has a vertically long part extending from the horizontally long part in the tire rotation direction Q, and extends in the tire circumferential direction. The side blocks 11 and shoulder blocks 12 are arranged in rows at intervals, and the outer shapes of the side blocks 11 and shoulder blocks 12 are formed by a vertical line segment 15A and a horizontal line segment 1.
The side blocks 11 are arranged between the center blocks 10 adjacent to each other in the tire circumferential direction and between the tire equator line O-O. The first side block 11A, which is arranged in a symmetrical position with respect to the tire circumferential direction, and the center block 10 on both left and right sides of the center block 10 are shifted in phase from each other in the tire circumferential direction, and are horizontally symmetrical with respect to the tire equator line O-O. and a second side block 11B arranged at symmetrical positions, and the shoulder block 12 has a length larger than the length of the center block 10 in the tire circumferential direction, and the shoulder block 12 has a length larger than that of the center block 10 in the tire circumferential direction. Block 1
The outer shape of the center block 10, the first and second side blocks 11A, 11B, and the shoulder block 12 is A lateral sea portion 13A that is substantially orthogonal to the tire equator line O-O at the tire ground contact portion through
The tire is characterized by having a diagonal portion 13B that is laterally symmetrical with respect to the tire equator line O-O and has a step-like shape that widens toward the tire rotation direction Q. (Function) In FIGS. 1 and 2, when the tire T rotates in the direction of the arrow Q and the vehicle travels straight, the tire equator line O-
Driving force and braking force are mainly exerted by the horizontal line segment 15B in the tire axial direction, which is substantially orthogonal to O, thereby ensuring driving force when traveling straight and sudden stopping. The oblique sea portion 13B, which extends symmetrically with respect to the equator line O-O, is connected to the center block 10 and the center block 13B so that its end is formed in the direction of rotation of the tire Q, as shown in FIG. 1・2
Since the side blocks 11A, 11B and the shoulder block 12 are arranged, the shoulder block 12, the first and second side blocks 11
A, 11B, and center block 10 are grounded in this order, and a large driving force is secured here. On the other hand, when turning at high speed while driving, it is necessary to prevent skidding.
If the car turns in the Y direction while the car is moving in the same direction, the tires will turn while slipping within the range of the X and Y line segments, and the car will turn while rolling to the left in the diagram, so the left half pattern of the tires will change. This will put a strain on the block. At this time, the first and second
Since the outer shape of the side blocks 11A, 11B and the shoulder block 12 is a step-like shape 15 that defines a vertical line segment 15A and a horizontal line segment 15B, the step-like part 15 is prevented from skidding by the arrow F.
Therefore, the shoulder block 12 ensures the rigidity of the tire shoulder section. This skidding prevention during turning is achieved by tire equatorial line O-
Since the pattern block is horizontally symmetrical with respect to O, the above-mentioned sideslip prevention is achieved when turning in either the left or right direction. (Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a tire T having a tread structure according to the present invention, which is mainly used for rallies, and is mounted so as to be rotationally driven in the direction of arrow Q. The tire T is a flat tire with an aspect ratio of 80, 70, 60, etc., and a center block 10, side blocks 11, and shoulder blocks 12 are provided on the outer surface of the tread portion at intervals in the tire circumferential direction. The blocks are arranged in a row at a distance to form a land portion, and a sea portion 13 is formed on the outer surface side of the tread portion via each of the blocks. To explain more specifically with reference to FIG. 2, the center block 10 is located on the tire equator line O-O, and has a T-shaped outer shape when viewed from above, having a horizontally long part and a vertically long part. Each of the center blocks 10 has a longitudinally elongated portion extending from a laterally elongated portion in the tire rotation direction Q, and is arranged in a row at intervals in the tire circumferential direction. The outer shape of the side block 11 and the shoulder block 12 consists of a vertical line segment 15A and a horizontal line segment 1.
5B are connected alternately to form a staircase shape 15 in plan view. Furthermore, the side blocks 11 are located between the center blocks 10 adjacent to each other in the circumferential direction of the tire, and are arranged at positions symmetrical to the left and right with respect to the tire equator line O-O, and are divided by a longitudinal seam 16. It consists of a block 11A and a second side block 11B which is arranged on both left and right sides of the center block 10, out of phase with the center block 10 in the circumferential direction of the tire, and at positions symmetrical with respect to the tire equator line O-O. . Further, the shoulder block 12 has a length larger than that of the center block 10 in the tire circumferential direction, for example, 1.5 to 2.5 times, so that it extends outside the left and right sides of the first and second side blocks 11A and 11B. In the left and right directions, the tires are arranged in symmetrical positions with respect to the tire equator line O-O. Through the outer shapes of the center block 10, the first and second side blocks 11A, 11B, and the shoulder block 12, a lateral sea area 13A that is substantially orthogonal to the tire equator line O-O at the tire ground contact area is formed.
The slanted sea portion 13B is horizontally symmetrical with respect to the tire equator line O-O and has a step-like shape that widens toward the tire rotation direction Q, and is formed with directionality. With the center block 10 on the line OO as a reference, the first and second side blocks 11A, 11B and the shoulder block 12 are arranged symmetrically on the left and right with respect to the equator line OO, and on the shoulder Block 12
From the first and second side blocks 11A and 11B,
Further, the first and second side blocks 11A and 11B are arranged ahead of the center block 10 in the tire rotation direction Q, respectively. As a result, the end of the oblique sea portion 13B is directed toward the tire rotation direction Q, and the lateral sea portion 13B is directed toward the tire rotation direction Q.
The length of A is said to be 15 to 30% of the tire's total ground contact width. The pair of left and right oblique sea portions 13B are substantially in the form of a so-called staircase in which longitudinal line segments (long line segments in the circumferential direction of the tire) and horizontal line segments are alternately connected, and in this embodiment, the first side block 11A and the second side block side block 11
B rising ground edge and shoulder block 12
The ground contact edges of the tire are configured by alternately connecting the ground contact edges extending in the tire axial direction and the ground contact edges extending in the tire rotational direction to form a step-like outline shape in plan view. Furthermore, the ratio of the actual ground contact area of the block pattern of the tread portion to the total ground contact area is 40 to 65%. In the illustrated embodiment, the length of the transverse portion 13A is set to 15% to 30% of the total ground contact width, because the horizontal line segment 15B of the center block 10 and the first side block 11A passes through the transverse portion 13A. This is because it provides driving force and braking force when traveling straight.
This is because if it is less than 15%, driving force etc. cannot be expected, and if it is 30% or more, excessive braking force etc. will result. Also, the length of the shoulder block 12 in the circumferential direction is determined relative to the length of the center block 10 in the same direction.
The shoulder block 1 was set at 1.5 to 2.5 times.
2 mainly ensures the rigidity of the shoulder portion 14, and therefore particularly contributes to ensuring the rigidity during cornering. In FIG. 2, 12A is a transverse portion between the shoulder blocks 12, and 12B is a recess formed on the ground surface of the shoulder block 12, which improves the edge effect of the shoulder block 12. Next, the feeling evaluation (10 point evaluation) of the tire T having pattern blocks according to the embodiment of the present invention is shown in FIG. Incidentally, the tires according to the embodiments of the present invention are as follows. Tire size: 165/80R13 Tire outer diameter: 600mm Tire width: 163mm Rim: 41/2J×13 Air pressure: 1.9Kg/cm ²

[Table] Number of circumferential pitches: 28 Land area/sea area ratio (%): 59.5/40.5 Ground contact width: 136.6 mm As is clear from Figure 4, the pattern blocks are symmetrical with respect to the equator line O-O. It can be seen that the tires of the examples of the present invention have significant advantages in cornering characteristics and stability. (Effects of the Invention) The present invention is as described above, and has the following advantages. If the vehicle is going straight, center block 1
0, the driving force and braking force are exerted by the horizontal line segment 15B in the tire axial direction such as the side block 11,
Since the side block 11 is symmetrical with respect to the equator line OO, it acts equally on the left and right sides, and there is no lateral wobbling. In addition, a diagonal sea portion 13 that is line symmetrical with respect to the tire equator line OO and widens towards the tire rotation direction Q.
Center block 10, 1st and 2nd to form B
Since the side blocks 11A, 11B and the shoulder block 12 are arranged, the road surface grip is sequentially transferred from the tire shoulder portion to the tire equator, and the straight running stability is good, and the initial response and grip force are large. Furthermore, since the oblique sea portion 13B is substantially constituted by the first and second side blocks 11A, 11B and the shoulder block 12 having a stepped shape 15 in a plan view, it is possible to perform high-speed turning. It works particularly effectively in the middle of the day. In other words, as shown in Fig. 3, if the current direction of the car is X, the car will turn to the right, so when the steering wheel is turned to the right, the tires will point in the direction Y, and the car's direction of travel, X, and the direction of the tires, Y. The angle α formed by
As the car turns while rolling to the left, this puts a strain on the left tire, especially the left half. At this time, the vertical line segment 15A of the staircase shape 15 in the tire rotation direction is
Since it faces the arrow F, it receives a large resistance force and reliably prevents skidding. In addition, since the staircase shape 15 is symmetrical with respect to the tire equator line O-O, skidding can be reliably prevented during both left and right turns. This is advantageous compared to a device that only has side skid prevention effect on either the left or right side. Further, since the shoulder blocks 12 on both shoulder portions 14 are made larger in length than the center block 10 in the tire circumferential direction, their lateral rigidity is increased and the deformation of the tire during cornering is increased. It can definitely be prevented.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a tire having a tread structure according to an embodiment of the present invention, FIG. 2 is a front view of the tread portion, FIG. Figs. 5 and 6 are explanatory diagrams of the effects of conventional tires during cornering. T... Tire, 10... Center block, 11...
Side block, 12...Shoulder block, 1
3...Ama, 13A...Yokoumi, 13...Slanted Sea, 15
…Stepped ground edge.

Claims (1)

[Scope of Claims] 1. A center block located on the tire equator line on the outer surface side of the tread portion of the tire, and side blocks located on both sides away from the tire equator line;
Shoulder blocks located on both shoulder portions of the tire are arranged in rows at intervals in the circumferential direction of the tire to form a land portion, and a sea portion is formed on the outer surface side of the tread portion through each of the blocks. In the tread structure of the vehicle tire thus formed, the outer shape of the center block 10 is T-shaped in plan view, having a horizontally long part and a vertically long part, and each of the center blocks 10 is longer in the vertical direction than the horizontally long part. The outer shapes of the side blocks 11 and shoulder blocks 12 are formed by vertical line segment 15A and horizontal line segment 1.
The side blocks 11 are arranged between the center blocks 10 adjacent to each other in the tire circumferential direction and between the tire equator line O-O. The first side block 11A, which is arranged in a symmetrical position with respect to the tire circumferential direction, is shifted in phase from the center block 10 on both the left and right sides of the center block 10, and is symmetrical with respect to the tire equator line O-O. and a second side block 11B disposed in symmetrical positions, and the shoulder block 12 has a length larger than the length of the center block 10 in the tire circumferential direction. Block 1
The outer shape of the center block 10, the first and second side blocks 11A, 11B, and the shoulder block 12 is A lateral sea area 13A that is substantially orthogonal to the tire equator line O-O at the tire ground contact area through
A tread structure for a vehicle tire, characterized in that it has a diagonal seam portion 13B that is laterally symmetrical with respect to the tire equator line O-O and has a step-like shape that widens toward the tire rotation direction Q.