JPS60169305A - Tread pattern of vehicle tire - Google Patents

Abstract

PURPOSE:To secure rationally the drain off power in circumferential direction and the drainage in lateral direction by forming center longitudinal grooves and longitudinal grooves arranged in a straight line and in the circumferential direction, and, by forming center lateral and shoulder lateral grooves crossing the line to the tire center obliquely. CONSTITUTION:Center blocks 21 are formed on the center of a tire being linked together over the full length of the circumference. Center lateral grooves 22, which obliquely cross the line to the tread center at an angle of alpha, are formed on both sides of this blocks 21 making zigzag patterns by shifting their phases in the circumferential direction. Longitudinal center grooves 23 are formed on both sides of the blocks 21 in a straight line over the full length of the circumference, and, side longitudinal grooves 24 are formed on the outer side of the longitudinal grooves 23, then, side lateral grooves 25 link the longitudinal grooves 23 and 24 mutually. Shoulder blocks 27 are formed on the outer side of the longitudinal grooves 24 and their shapes are represented by the longitudinal grooves 24 and shoulder lateral grooves 28, and besides, grooves 29 are formed at the outer side edges.

Description

[Detailed description of the invention] The present invention relates to a tread structure for a vehicle tire.

In order to explore strong grip, maneuverability, cornering limit performance, traction, and braking, not only the structure, material, and low profile of the tire are important factors, but also the shape of the tread pattern. It is essential.

To explain this with reference to Fig. 1 (fl) f21 (3) f41, if you make the trend l pattern slick as shown in Fig. 1 (11), you can maximize the grip force because the ground contact area is large. On the other hand, it has poor wet performance and is unsuitable for street use from the standpoint of high-speed maneuverability and controllability.

Therefore, as shown in Figure 1 (2), if half of Trend 1 is formed slick and vertical and horizontal grooves 2 are formed, Trend 1 becomes asymmetrical, resulting in poor wet performance, and the center of gravity also shifts from the center. be.

Therefore, as shown in FIG. 1 (3), if it is a general type with no directionality in which the length and width are formed throughout, it can be expected to have a certain degree of grip power, but there is a limit to its dry and wet performance.

By the way, as shown in FIG. 1 (4), if the horizontal grooves of the vertical and horizontal grooves a2 are given directionality, it is possible to increase the limits of both dry performance and wet performance, and it is possible to improve high-speed straight running stability. The proposition behind creating a low profile is that as the tire becomes ultra-flat, the shape of the contact patch changes from vertically to horizontally.If the pattern has directionality, wet grip performance can be improved and straight-line stability can be improved. It can be understood that this is an important factor that can be improved.

When considering the ratio of the ground contact part to the groove part with reference to Figure 2 (1) and (2), the ratio of the ground contact part to the groove part is 60:40 (the ground contact part is 60:40).
5:55 range), cornering performance A and braking performance B in the dry state are (1) in the same figure, and in the wet state (2) in the same figure. The area ratio of the pattern is increased as much as possible.

Therefore, it is recommended to increase the ground contact ratio by 10% as indicated by symbol C.

However, since this would be meaningless if the wet performance deteriorated, consideration should be given to the shape of the grooves, especially the lateral grooves.

To explain the lateral groove angle and performance with reference to Fig. 3 +11 to (6), fat in Fig. 3 (1) is a general block and the lateral groove angle is O, fbl is 25°, and (C) is 4
6°, (d) is 56°, both have directional patterns, and the wet cornering force is the third
Figure 3 (5) shows the overall wet performance, and Figure 3 (6) shows the overall wet performance.
and Fig. 4 (1) to (3).
Figure (1) shows the dry cornering force, Figure (2) shows the trial braking performance, Figure (3) shows the dry overall performance, and Figure 5 shows the dry and wet cornering force. The overall performance is shown. In Figures 3 to 5, D indicates normal tire rotation (forward) and E indicates reverse rotation. As is clear, the best lateral groove angle is within the range of 20° to 40°.

The above is based on actual vehicle tests conducted by the present inventors.

By the way, as a pneumatic tire in which longitudinal and lateral grooves are formed in the trend part, the lateral grooves are made to have an angle, and the respective area ratios of the grooves and the blocks formed by the grooves are considered, for example, Japanese Patent Laid-Open No. 140604/1984 discloses is proposed.

Although this conventional example has a certain degree of effectiveness,
There are the following problems.

In other words, in this conventional example, the center vertical groove is formed linearly in the tire circumferential direction at the center of the trend, and because of this, the ground contact area at the center is small, so the response when the steering wheel is turned at a small angle is There is a problem that sex becomes poor, and
There is a problem in that it cannot be expected to have a water film cutting function on the road surface.

In addition, some of the same conventional examples have vertical ribs formed in the center of the trend, but since the edges on both sides of this rib are not linear but have a so-called zigzag shape, There is a problem that drainage performance is poor, and furthermore, the water film cutting function is weak, resulting in a decrease in wet performance.

In view of the above-mentioned knowledge, the present invention has been made to optimize both dry and wet performance by giving the tread pattern directionality and also considering the tire structure, shape, material, etc. Therefore, in the present invention, a plurality of vertical grooves are formed on the outer surface side of the tread portion of the tire at intervals in the trend width direction and continue along the entire circumferential length, and a plurality of vertical grooves are formed that connect these vertical grooves in the trend width direction. The lateral grooves intersect at an angle with respect to the tread center and are arranged at intervals in the circumferential direction of the tire, forming a block defined by each of the vertical grooves and the lateral grooves, and the total area of the block in the ground contact area is In the trending structure of vehicle tires that are large in size and have a small total area of longitudinal and lateral grooves, a center block is formed continuously over the entire circumferential length of the tread at the center of the tread. On both sides of the center block, center horizontal grooves that intersect at an angle with respect to the center of the tread are formed with a phase shift in the circumferential direction, and on both sides of the center block, a linear center longitudinal groove is formed that spans the entire circumferential length. A side block is formed on each of the outer sides of both sides of the center longitudinal groove, and a linear shoulder groove parallel to the center longitudinal groove is formed on each outer side of the side block. A shoulder block is formed on each of the outer sides of the center lateral groove, and a side lateral groove and a shoulder lateral groove that communicate the longitudinal grooves extend outward on both sides with a portion having the same directionality as the longitudinal direction of the center lateral groove. The present invention provides a tread structure for a vehicle tire characterized by the following.

Embodiments of the present invention will be described in detail below with reference to the drawings.

6 and 7 show a cross-section of a tire having a trend pattern of the present invention, and 10 is the tire body;
The main body includes a bead portion 11, a sidewall portion 12, a shoulder portion 13, and a trend portion 14, and has a toroidal overall shape.

A bead wire 15 is provided in each of the bead portions 11, and a carcass ply 1 is provided over the bead wire 15.
The carcass ply 16 is a high modulus 2 polyester carcass, and the winding terminal 1
6A has a so-called high turn-up configuration located closer to the tread than the maximum width of the tire.

17 is an inside reinforcement, which extends from the outer circumferential surface of the bead handle (wire) to near the maximum width of the tire, and 18 is an ultra-hard filler, which is used for the aforementioned high turn amplifier and inside reinforcement. The reinforcement 17 and the filler 18 improve the lateral rigidity of the tire and contribute to increasing the steering stability.

19 is a steel belt layer, 20 is a nylon belt layer, and the steel belt layer 19 is made by twisting two steel cores 19A together and twisting seven steel outer members 19B around them, as shown in FIG. The steel belt layer 19 is wrapped with wires 19C, which are arranged in parallel across the entire tread width direction of the tire, forming two layers, the inner and outer layers, which intersect (intersect) with each other. Two nylon heald layers are fixed in parallel to each other.

Thereby, since the steel belt layer 19 and the nylon belt layer 20 are fixedly provided over the front surface of the trend part and a part of the shoulder, it is possible to prevent the tire from becoming stuck. In other words, it prevents the outer diameter of the tire from growing due to centrifugal force at high speeds.

The outer surface shape of the tread portion 14 has a radius R1 of its central band.
, the radius R2 of the side band is a so-called deal arc trend design, and in this example, R1 is 630 Tsuru and R2 is 3
17 dragons, Ll is 471, Ll is 20m1, L3 is 67+
am, and the radius of a portion of the shoulder is also shown as R3.

By the way, on the outer surface side of the trend portion 14, horizontal grooves having directionality are formed by intersecting the longitudinal grooves in one inclination direction of 25 degrees, 45 degrees, and 56 degrees with respect to the tire center line ○-0. At the same time, a block defined by longitudinal grooves and lateral grooves is formed, and each of the longitudinal grooves has a straight line shape continuous over the entire circumferential direction at intervals in the tread width direction, and each lateral groove has a continuous linear shape along the entire circumference. The longitudinal grooves are arranged at intervals in the circumferential direction so as to communicate with each other, and the ratio of the ground contact area of the block to the groove area is 70% to 30%, thereby improving dry and wet performance.

Each embodiment of the tread structure will be described in detail with reference to FIGS. 8 to 11. Each of these figures is partially developed and shown in plan view, and the center block 21 is located on the tire center line along the entire circumferential direction. On both sides of the center block 21, center lateral grooves 22 having an angle α that obliquely intersects with the center of the tread are formed in a so-called zigzag pattern with a phase shift in the circumferential direction. There is.

On both sides of the center block 21, center vertical grooves 23 are formed linearly over the entire circumferential direction, and side vertical grooves 11iI24 parallel to the interspace grooves 23 are formed on the outside of each center vertical groove 23. . The groove lJ of the side longitudinal groove 24 is formed wider than the center longitudinal groove 23, and side lateral grooves 25 that communicate the center longitudinal groove 23 and the side longitudinal groove 24 with each other are formed at intervals in the circumferential direction. In this example, the side lateral grooves 25 extend outward in the same direction as the center lateral grooves 22, and have a so-called tapered shape having a portion where the groove width increases in the direction of the extension. A side block 26 is formed on.

A shoulder block 27 is formed on the outside of each of the side vertical grooves 24, and is defined by the side vertical groove 24 and the shoulder horizontal groove 28. A groove 29 is formed at the outer end. 29 contributes to improving the ground contact of the block during limit running in corners.

In other words, by slightly weakening the block rigidity,
It has flexible movements.

The shoulder lateral groove 28 has the same directionality and angle as the side lateral a 25 (25°, 45°, 56°, preferably 30° to 35°).
and a groove having a directionality opposite to this groove and having an angle β of 15° to 20°,
The widths of the shoulder lateral grooves 28 are parallel to each other and extend outward.

Furthermore, a diamond cut gB6A 278 is formed on each of the side pro/reel 26 and the shoulder block 27.

Although the pattern is symmetrical with respect to the tire center line 0-0, the number of lateral grooves is set to be 30 to 50 with respect to the outer circumferential length of the tire. That is,
The tire outer circumference length/number of lateral grooves is set at 30 to 50.

In this case, the intervals between the lateral grooves (circumferential intervals) may be equal, but since this increases tire noise at a certain speed of the vehicle, it is desirable to arrange them at irregular intervals.

A commonly used pinch variation method can be used to provide this uneven spacing.

In the first embodiment shown in FIG. 8, the center lateral i22 has its starting end on the center center O-O, and in the second embodiment shown in FIG. 1st
In the third embodiment shown in Fig. 0, the starting end is located outside the center line 0-0, and in the fourth embodiment shown in Fig. 11, the starting end is formed in the shape of a "<" or "he" character. showing something.

A tire having the tread structure of the present invention (tubeless radial tire) is mounted on a vehicle, and the lateral groove moves forward in the direction in which the sharp side on the side facing the tire center first enters the road surface (
In terms of normal rotation, tires have the aforementioned curvature for driving performance, so the first contact with the ground is always at the center of the tire tread and throat, and the outer surfaces are only touched later.

become.

Therefore, when the road surface is wet, it is more rational to drain the water from the center line of the tire to the outside on both sides.

It is important to run on the road surface while cutting the water film, and the flatter the tire, the more horizontally egg-shaped the contact surface, so the flow of water across the entire contact surface is symmetrical. It is important that the

Therefore, in this embodiment, the center block 21 is used to ensure stability at small steering angles, while the center lateral WJ 22 cuts the water film, and the center vertical groove 23 is in a straight line so that water can be drained quickly. Good drainage is achieved in the central part, and the drainage direction is directed outward by the side horizontal groove 25 and merged with the side vertical groove a24.
Furthermore, while the side vertical grooves 24 allow linear drainage, the shoulder lateral grooves 28 further improve drainage.

Regarding wear during cornering, if the angle of the shoulder lateral groove 28 is the same as the angle of the other lateral grooves when cornering at the limit, the rigidity of the shoulder block 27 will decrease and wear will be severe, resulting in performance changes and The life of the tire will be shortened, and when wet, the larger the angle of the shoulder lateral groove 2B (30° to 35°).
The advantage is that by reducing the angle of the part that makes contact with the ground during cornering, this increases the rigidity, which, together with the grooves 29, provides a good balance of performance.

In addition, the width of the side lateral groove 25 is tapered and enlarged in the 71st! According to example 1, drainage to the outside in the horizontal direction is improved, and in combination with the diamond cut portions 26A and 27A, a synergistic effect is brought about to drainage in the vertical grooves 23 and 24.

In other words, for dry performance, Grisobka is improved by increasing the block's total ground contact area ratio to 70%, and for wet performance, the total area ratio of grooves is increased to 30%.
By keeping it in check, you can achieve the best results.

In summary, the present invention improves the drainage performance in the circumferential direction by the circumferentially straight vertical grooves including the center vertical groove and one or more side vertical grooves, and also improves drainage performance in the circumferential direction. The lateral grooves are directed toward the center of the tire, ensuring efficient drainage of water to the outside in the lateral direction, and the increased contact area with the center block, side blocks, and shoulder blocks improves grip performance in wet conditions. Both road and dry road surfaces can be secured.

Furthermore, since a center block is formed over the center of the tire that extends along the entire length in the circumferential direction, responsiveness at small steering angles can be sharpened. Since they are formed with the phases shifted, the water film can be cut well, and the so-called staggered arrangement with the phases shifted has advantages such as improved noise dispersion.

[Brief explanation of the drawing]

Figure 1 +11 to (4) are explanatory diagrams showing the thought process for understanding the present invention, Figure 2 +11 to +21 are explanatory diagrams also showing the ground contact area ratio and performance, and Figure 3 +11 to (6) are explanatory diagrams showing the thinking process for understanding the present invention. Similarly, an explanatory diagram showing the lateral groove angle and performance, FIGS. 4 and 5 are similar explanatory diagrams, FIG. 6 is a sectional view of a tire having the tread structure of the present invention, and FIG. 7 is an enlarged view of a part thereof. 8 to 11 are developed plan views showing four embodiments of the present invention. 14... Trend section, 21... Center block,
22...Center horizontal groove, 23...Center vertical groove, 2
4...Side vertical groove, 25...Side horizontal groove, 26...
・Side block, 27...Shoulder block, 2
8...Shoulder horizontal groove.

Claims (1)

[Claims] 1. A plurality of longitudinal grooves are formed on the outer surface of the trend portion of the tire at intervals in the tread width direction and continuous along the entire length in the circumferential direction, and these longitudinal grooves are communicated in the trend width direction. A plurality of horizontal grooves intersect at an angle with respect to the trend center and are arranged at intervals in the circumferential direction of the tire, forming a block defined by each of the vertical grooves and the horizontal grooves, and In a vehicle tire tread structure in which the area is large and the total area of longitudinal grooves and lateral grooves is small, a center block 2 is placed on the center of the tread of the trend part 14.
1 are formed continuously over the entire length in the circumferential direction,
Center lateral grooves 22 are formed on both sides of the center block 21 and are shifted in phase in the circumferential direction, intersecting each other with respect to the trend center.
A straight center longitudinal 6 extending the entire length in the circumferential direction on both sides of 1.
23 is formed, side blocks 26 are formed on each outer side of both sides of this center longitudinal groove 23, and linear shoulder longitudinal grooves 24 parallel to the center longitudinal groove 23 are formed on each outer side of both sides of the side block 26. A groove groove 27 is formed on each of the outer sides of the shoulder groove 24, and the side lateral groove 25 and the shoulder lateral groove 28, which communicate the longitudinal grooves 23 and 24, are connected to the center lateral groove 22. A tread structure for a vehicle tire, characterized in that a portion having the same directionality as the longitudinal direction extends outward on both sides.