JPS60169304A - Tread pattern of vehicle tire - Google Patents

Abstract

PURPOSE:To improve responsiveness to a narrow-angled manipulation of a steering wheel and efficiency in breaking water film by forming center blocks at the center of a tread and in the circumferential direction leaving spaces between them. CONSTITUTION:Center blocks 21 are formed on the center line of a tire in a straight line over the full length of the circumference leaving spaces between them, and these spaces between the adjoining blocks 21 in the circumferential direction form center grooves 22 which obliquely cross the line to the tread center at an angle of alpha. Center longitudinal grooves 23 are formed on both sides of the blocks 21 in a straight line over the full length of the circumference, and, on the outer side of the longitudinal grooves 23, side longitudinal grooves 24 are formed. Side lateral grooves 25, which link the longitudinal grooves 23 and 24 mutually, are formed in circumferential direction leaving spaces where side blocks 26 are formed. 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.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the trend structure of vehicle tires, and in particular,
It has a trend structure consisting of grooves formed in the tire tread and blocks defined by these grooves. By giving the grooves, especially the lateral grooves, directionality, it increases the limits of dry and wet performance and improves high-speed straight-line stability. The aim is to provide a street tire that has improved wet grip and straight-line stability, making it possible to enjoy circling and running.

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

Figure 1 +11 (2+ +31 (To explain this with reference to 41), if the pattern of tread 1 is made slick as shown in Figure 1 (1), the ground contact area is large - so the maximum grip force can be achieved. However, it has poor wet performance and is unsuitable for street use from the standpoint of high-speed maneuverability and stability.

Therefore, if half of the tread 1 is formed slick and vertical and horizontal grooves 2 are formed as shown in Fig. 1 (2), the tread 1 becomes asymmetrical, resulting in poor wet performance and the center of gravity being shifted from the center. .

Therefore, as shown in FIG. 1 (3), if it is a general type with no directionality in which the vertical and horizontal grooves 2 are formed over the entire surface, a certain degree of gripping force can be expected, but there is a limit in dry and wet performance.

By the way, as shown in FIG. 1 (4), if the horizontal grooves of the vertical and horizontal grooves 2 are given directionality, it is possible to increase the limits of both dry performance and wet performance, and there is also a possibility of increasing high-speed straight running stability. , The proposition of low profile is that as the tire becomes ultra-flat, the shape of the contact patch becomes longer than vertically long to horizontally, and 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 +11 +21, the average ratio of the ground contact part to the groove part is 60:40 (the ground contact part is 60:40).
5 to 55), cornering performance A and braking performance B in dry conditions are +11 in the same figure, and in wet conditions this is (2) in the same figure.From this, it is possible to increase dry grip performance. This means increasing the area ratio of the pattern as much as possible.

Therefore, it is recommended to increase the grounding portion ratio by 10% as shown 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 (1) to (6), a in Fig. 3 (1) is a general block and the lateral groove angle is 0, b is 25°, and C is When 46° and d are 56°, both have directional patterns, and the wet cornering force is shown in Figure 3 (2), the wet braking performance is shown in Figure 3 (3), and the wet circular turning performance is shown in Figure 3. Figure (4), wet traction is Figure 3 (5)
Also, the overall wet performance is shown in Figure 3 (6), and Figure 4 ill-(3) shows the same figure (
1) shows the dry cornering force, (2) the dry braking performance, and (3) the overall dry performance.Furthermore, Fig. 5 shows the overall performance in dry and wet conditions. has been done. 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 groove is formed linearly in the tire circumferential direction at the center of the tread, and because of this, the ground contact area at the center is small, resulting in poor response when the steering wheel is turned at a small angle. 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.

Also, in some of the same conventional examples, a vertical rib is formed in the center of the tread, but both side edges of the rib are not straight (they are in a so-called zigzag shape, so the center part There is a problem that the drainage performance is poor, and the water belly cutting function is weak, resulting in a decrease in wet performance.

In view of the above-mentioned knowledge, the present invention provides a tread pattern with directionality, and also takes into account the tire structure, shape, material, etc., thereby making it possible to optimize both dry and wet performance. They succeeded in developing a tread structure for a true sporty radial tire for street use with high margins.

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

6 to 9 show a first embodiment of the present invention,
10 is a tire body, and this body includes a bead portion 11,
It consists of a sidewall part 12, a shoulder part 13, and a trend part 14, and the overall shape is a toroidal 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.
6 is wound, the same carcass ply 16 is a high modulus 2 polyester carcass, and the winding fraction 1
The 68 has a so-called high-turn amplifier configuration located closer to the trend area than the maximum width of the tire.

17 is an inside reinforcement, which extends from the outer circumferential side 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 above-mentioned 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 heald layer, and the steel belt layer 19 is made by twisting two steel cores 19A together as shown in FIG. wire 19g
These are arranged in parallel across the entire trend width direction of the tire and are arranged intersecting each other (inside and outside 2N), and the outside of this Steelheld Ft19 consists of two layers. The nylon heald layers are arranged parallel to each other.

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

The outer surface shape of the trend part 14 is the radius R1 of its central band.
, the radius R2 of the side band is a so-called deal arc trend design, and in the first embodiment, R1 is 63011,
R2 is 317 mm, 11 is 47 mm, R2 is 20 mm, R
3 is shown as 67u+, and the radius of a portion of the shoulder is shown as R3.

By the way, on the outer surface side of the trend portion 14, directional lateral grooves are formed that intersect with the vertical groove in one direction of 25°, 45°, and 56° with respect to the tire center line 0-0. At the same time, a block defined by vertical grooves and horizontal grooves is formed, and each of the vertical grooves has a straight line shape that is continuous throughout the circumferential direction at intervals in the trend width direction, and each horizontal groove is 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.

The tread structure will be described in detail with reference to FIG. 7. This figure shows a partially unfolded plan view, in which center blocks 21 are formed linearly on the tire center line at intervals over the entire length in the circumferential direction. This center block 21
The center lateral grooves 22 are adjacent at intervals in the circumferential direction and intersect at an angle α obliquely with respect to the tread center.

Center vertical grooves 23 are formed in a straight line along the entire circumferential direction on both sides of the center block 21, and side vertical grooves 24 parallel to the intervening grooves 23 are formed on the outside of each center vertical groove 23. There is. The inside of the side longitudinal groove 24 is formed wider than the center longitudinal groove 23, and side lateral grooves 25 are formed at intervals in the circumferential direction to communicate the center longitudinal groove 23 and the side longitudinal groove 24 with each other. 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 a groove portion having the same directionality and angle (25°, 45°, 56°, preferably 30° to 35°) as the side lateral groove 25, and a directionality opposite to this groove portion, and an angle β of 15°. The groove widths of the shoulder width 'a28 are parallel to each other and extend outward.

Furthermore, the side block 26 and the shoulder block 2
Diacant portions 268 and 278 are formed in each of 7.

Although the pattern is symmetrical with respect to the tire center line OO, the number of lateral grooves is set to 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 to 30 to 50.

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

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

10 to 12 show a second embodiment of the present invention, in which the center block 21 has a circumferential length equivalent to two side blocks 26, and the center block 21 has a circumferential length equivalent to two side blocks 26.

26 has two side vertical grooves 24 and two side horizontal grooves 25.
Two rows of grooves are formed between the center block 21 and the shoulder block 27, and the inner side lateral grooves 25 extend outwardly into the groove. Narrow (formed,
A constricted portion 30 is formed in the middle of the outer side lateral groove 25, in this example closer to the inner side.

Since the other basic configuration is the same as the first embodiment described above, common parts are indicated by common symbols, and as shown in FIG. 11, <R1 is 9251111. R2 is 270 +au
Therefore, Ll shown in Fig. 8 is 52 recommendations - 1L2 is 30.
The difference is that the 5th gear and L3 are set to 82.5 fim.

That is, the tire of the second embodiment has a flatter shape than that of the first embodiment.

Furthermore, the tread pattern can also be configured by forming another center lateral groove 22^ in the longitudinal middle of the center protrusion 21 in the second embodiment, and a tire with this structure is similar to the embodiment shown in FIG. Part of it is shown in .

That is, another center lateral groove 22^ is formed, and the tire trend pattern having this center lateral groove 228 can be applied to tires with and without the constriction part 30 in the embodiment shown in FIG. On the contrary, the tread pattern of the tire of the present invention has a structure in which two center blocks 21 shown in FIG. This means that it includes a side lateral groove 25 having the shape shown in FIG. 7.

In FIG. 12, the widths of the two left and right side vertical grooves 24 are made slightly wider than Ill of the center vertical groove 23, and the widths of each side vertical groove 24 are the same.

A tire having a treadle structure according to the present invention (Tupres radial tire) is attached to a vehicle, and the center block 21
If we explain the direction in which the sharp side first enters the road surface as forward rotation (forward rotation), the tire has the aforementioned curvature for driving performance, so the first contact with the ground is always at the center of the tire trend section, The side will be grounded later.

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 horizontal groove 22 cuts the water film, and the center vertical groove 23, which is straight, quickly drains water. Good drainage is achieved in the central part, and the direction of drainage is directed outward by the side horizontal grooves 25 to merge with the side vertical grooves 24.Furthermore, while the side vertical grooves 24 allow water to drain in a straight line, the shoulder horizontal grooves 28 further improves 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 poor performance. In this case, when wet, the larger the angle of the shoulder lateral groove 28 (30 to 35 degrees).
The good thing is that by reducing the angle of the part that touches the ground when cornering, this increases the rigidity, which, together with the A29, improves the balance of performance.

In addition, according to the example shown in FIG. 7 in which the side lateral tJ25 has rlJ in a Taber expanded shape, drainage to the outside in the lateral direction is improved, and in combination with the diamond cut portions 268 and 27Δ,
This will have a synergistic effect on the drainage of the longitudinal grooves 23,24.

Further, when the embodiment shown in FIG. 12 has a constriction of 3 degrees, when the outward drainage in the lateral direction is too strong, the constriction 30 controls the drainage force in the lateral direction. This will improve the overall displacement and L7 displacement.

That is, the center block 21, side blocks 26, and shoulder blocks 27 constitute a so-called strong V-shaped formation block, and the large shoulder block 27 and its shoulder lateral grooves 28 are formed at an angle of 15 degrees instead of a 30-35 degree angle. High speed, stability,
This improves block performance, and each horizontal groove 22.25.
The symmetrical arrangement of 28 improves drainage outward in the lateral direction, improving grip on wet roads, controllability, and high-speed straight-line stability.In the example shown in Figure 7, 4
By forming the longitudinal grooves 23° and 24 of the book into straight lines,
This was done by further strengthening the drainage performance and widening the groove width in a tapered shape as the flow rate increased from the center to both outer sides.

Furthermore, according to the example in Fig. 12, it has an ultra-wide arc trend, excellent ground contact at the corner limit, strong dry grip, and lateral vR 22° 25 with drainage and slope by six straight vertical grooves 23, 24. .28 can create a smooth flow of water, improving wet grip and traction, and can control the vertical drainage efficiency from being hindered by the constriction 30, increasing the total drainage effect. It is.

In other words, for dry performance, the best effect can be achieved by increasing the total ground contact area ratio of the block to 70%, and for wet performance, by reducing the total area ratio of the grooves to 30%. be.

First embodiment (Fig. 7) with reference to Figs. 13 to 15
The following describes the performance test results of (1), the second embodiment (FIG. 12) (2), and the conventional product (2).

Figure 13 shows the dry performance cornering power, the test machine was a cornering force tester, and the air pressure was 2.0 kg/CIA.

Figure 14 shows the data for dry performance cornering force (maximum) under the same conditions, and Figure 15 shows the data for wet performance (braking performance (Figure 11)), steady circular turning, and maximum lateral G (lateral Acceleration) (30m radius)
This is test data on an asphalt road surface when also shows that the smaller the index, the better.

As described above, the inventors of the present invention have pursued a low profile, trendy pattern, material, and structure in order to pursue both dry and wet performance, and the structure of the tread part has been designed to achieve both dry and wet performance. By forming the blocks at intervals in the circumferential direction, it is possible to improve responsiveness when the steering wheel is turned at a small angle, and also to cut the water film well. The drainage performance is good and smooth in a straight line, and the center lateral groove, side lateral grooves, and shoulder lateral grooves also make the drainage performance to the outside in the lateral direction good. In fact, the directionality was different from that of each inner part, which made it possible to improve the rigidity of the shoulder block.

In addition, for those with a constricted part in the side horizontal groove,
This prevents the drainage from becoming stronger in the lateral direction, improving the overall drainage.If the length of the center block is increased by making the length of the two side blocks longer, the center This is of great practical benefit as it can improve the rigidity of the parts.

[Brief explanation of the drawing]

Figures 1 (1) to (4) are explanatory diagrams showing the thought process for understanding the present invention, Figures 2 (1) and (2) are explanatory diagrams also showing the ground contact area ratio and performance, and Figure 3 ( 11 to (6) are explanatory diagrams similarly showing the lateral groove angle and performance, FIGS. 4 and 5 are similar explanatory diagrams, FIG. 6 is a perspective view of a tire to which the first embodiment of the present invention is applied, and FIG. The figure is a plan view showing the developed tread pattern of the same tire, FIG. 8 is a sectional view of the same, FIG. 9 is an enlarged view of the belt layer, and FIG. 10 is a perspective view of a tire to which the second embodiment of the present invention is applied. , FIG. 11 is a cross-sectional view of the same tire, and FIG. 12 is a plan view showing an expanded trend pattern of the same tire.
FIGS. 13 to 15 are graphs showing test data of the embodiment of the present invention. 14-tread portion, 21-center block, 22.
22A- Center horizontal groove, 23- Center vertical groove, 24-
Side vertical groove, 25--Side horizontal groove, 26-Id block, 27-Shoulder block, 28-Shoulder horizontal groove, 3 (1-<Fin part. Fig. 73 Ippu heavy (tsu)-1 □ construction IQ> ----x □ I □ 1 Figure 75

Claims (1)

[Claims] 1. A plurality of longitudinal grooves are formed on the outer surface side of the trend portion of the tire at intervals in the tread width direction and are continuous along the entire length in the circumferential direction. The horizontal grooves of the book 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 the total area of the block at the ground contact part In the trending structure of vehicle tires in which the ratio of vertical grooves and horizontal grooves is large and the total area of longitudinal grooves and lateral grooves is small, a center block 2 is placed above the tread center of the tread portion 14.
1 are formed linearly at intervals over the entire length of the center block 21 in the circumferential direction, and adjacent intervals in the circumferential direction of the center block 21 intersect with the center of the tread.
Ia22, which connects the center longitudinal grooves 23 formed in a straight line on both sides of the center block 21 with each other, and has grooves parallel to the center longitudinal grooves 23 on the outer side of each of the center longitudinal grooves 23. At least one linear side vertical groove 24 is formed, and a side lateral groove 25 communicating each of the side vertical grooves 24 and the center vertical groove 23 is formed with the same directionality as the center lateral groove 22. , side blocks 26 defined by the center longitudinal groove 23, side longitudinal grooves 24 and side lateral grooves 25 are formed, and furthermore, shoulder blocks 27 are formed on the outer sides of the side longitudinal grooves 24, respectively. In the shoulder block 27, a portion communicating with the side vertical groove 24 has a groove portion having the same directionality as the side lateral groove 25 on the extension of the groove length, and a portion having a directionality opposite to this groove portion outwardly. A trending structure of a vehicle tire characterized in that a shoulder lateral groove 28 having an extended groove portion is formed. 2. On the outer surface of the trend area of the tire, multiple longitudinal grooves are formed that extend along the entire length of the circumference at intervals in the tread width direction, and multiple lateral grooves that connect these vertical grooves in the trend width direction form the trend area. Blocks are formed that are intersected obliquely with respect to the center and are spaced apart in the circumferential direction of the tire, each defined by the longitudinal grooves and the lateral grooves, and the total area of the block in contact with the ground is large. In the trend structure of vehicle tires in which the total area of the lateral grooves is set to a small ratio, a center block 2 is placed on the trend center of the tread portion 14.
1 are formed in a straight line at intervals over the entire length of the center block 21 in the circumferential direction, and adjacent intervals in the circumferential direction of the center block 21 are set as center horizontal a22 that intersect with the trend center about 1. Center longitudinal grooves 23 formed in a straight line on both sides of the block 21 are connected to each other, and linear side longitudinal grooves 2 parallel to the center longitudinal grooves 23 are formed on the outer side of each of the center longitudinal grooves 23.
4 are formed, and a side lateral a25 communicating each of the side vertical grooves 24 and the center vertical groove 23 is formed with the same directionality as the center lateral groove 22, and the center vertical groove 23 , a side block 26 defined by a side longitudinal i24 and a side lateral groove 25 is formed, and a shoulder block 27 is formed on each outer side of the side longitudinal groove a24, and the shoulder block 27 has the side longitudinal groove 25. Groove 2
A shoulder lateral groove in which a portion communicating with the side lateral groove 25 has a groove portion having the same directionality as the side lateral groove 25 on the extension of the groove length, and a groove portion extending outward with a directionality opposite to this groove portion. 28 is formed, and further, another center lateral 122A is formed in the middle part of the circumferential length of the center block 21.
is formed to have the same directionality as the center lateral groove 22, and the side lateral groove 25 and the shoulder lateral groove 28 are formed corresponding to this other center lateral '/m22A, and the side lateral groove 25 is formed in the same direction as the center lateral groove 22. A tread structure for a vehicle tire, characterized in that the width of the tread has a portion that widens outward. 3. A plurality of vertical grooves are formed on the outer surface of the tread of the tire at intervals in the tread width direction and continue along the entire length in the circumferential direction, and a plurality of lateral grooves that connect these vertical grooves in the trend width direction are formed. Blocks are formed that are intersected obliquely with respect to the center and are spaced apart in the circumferential direction of the tire, each defined by the longitudinal grooves and the lateral grooves, and the total area of the block in contact with the ground is large. In the tread structure of a vehicle tire in which the total area of the lateral grooves is set to a small ratio, a center block 2 is placed on the trend center of the trend part 14.
1 are formed in a straight line at intervals over the entire circumferential length, and adjacent intervals in the circumferential direction of the p center block 21 are center lateral grooves 22 that intersect at an angle with respect to the trend center. - Center vertical grooves 23 formed in a straight line on both sides of the hook 21 are connected to each other, and linear side vertical grooves parallel to the center vertical grooves 23 are provided on the outer side of each of the center vertical grooves 23. 2
At least one of 4 is formed, and the side vertical? A side horizontal groove 25 communicating each of the ta24 and the center vertical groove 23 is formed with the same directionality as the center lateral groove 22, and the side block is defined by the center vertical groove a23, the side vertical groove 24, and the side horizontal groove a25. Further, shoulder blocks 27 are formed on each of the outer sides of the side longitudinal grooves 24, and the portions of the shoulder blocks 27 that communicate with the side longitudinal grooves 24 correspond to the groove length of the side lateral grooves 25. A shoulder lateral groove 28 is formed which has a groove section extending in the same direction as this groove section and a groove section extending outwardly with a directionality opposite to this groove section. It has two lengths in the circumferential direction of the side blocks 26 formed on both sides via the center vertical groove 23, and each of the side lateral s25 has a constricted portion 3o.
A trendy structure of vehicle tires characterized by the formation of