JP2864359B2 - Tire tread structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a tread structure of a studless tire mainly used for snowy roads for automobiles.

[0002]

2. Description of the Related Art In general, in order to improve the running performance of a studless tire on an icy road surface, it is important to improve the low-temperature characteristics of the rubber of the tire to increase the coefficient of friction on ice, and to expand and activate the actual contact area. It is. In the latter case, in recent years, the combination of various blocks has been improved, and a notch groove has been formed in the block itself, thereby improving the adhesiveness of the block and enhancing the edge effect on an ice path.

[0003]

However, there is a limit in improving the block pattern and improving the driving force and the braking force by forming the cut grooves at the same tread width. In other words, since the blocks in the conventional tread structure are protruded in parallel to the surface while keeping the height slightly higher, there is a limit to what can be expected for the swaying and twisting effects. The only way to improve the exercise effect was to increase the tire and tread width. The present invention is intended to remarkably improve the effect of the actual ground contact portion without increasing the tire width.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to a tread structure for a tire in which a block having a notch groove is appropriately combined with a vertical groove, a horizontal groove or an inclined groove by focusing on the above points. The groove depth was gradually increased toward, and the ventilation holes penetrating from the bottom surface of the groove portion to both sides of the tread portion were appropriately arranged in a staggered manner to provide a tread structure of the tire. Things.

[0005]

The blocks on both sides of the tread portion are formed to have a height which is conventionally known, so that the groove depth gradually increases toward the center of the cross section of the tread width and the block height also increases. When the brake is applied on the icy road surface because the bottom has a ventilation hole, the compressed air in the groove between these blocks is exhausted from the ventilation hole, and the twisting action occurs when the block at the center part becomes more flexible. Following the road surface, the actual ground contact area is enlarged as shown in FIG. 2, and the braking force is exerted. Similarly, at the time of starting drive, the block is twisted in the protruding direction. At this time, the compressed air in the groove between the blocks is exhausted. Demonstrate. Also, when the tire gets on unevenness on the road, foreign matter, or the like, the central portion where the block height is large follows and follows the tire, and the adsorbability is exhibited without impairing it.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of a studless tire embodying the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of the present invention, in which a block 4 having a cut groove 6 on a surface of a tread portion 3 of a studless tire is provided with a vertical groove 5 and a horizontal groove,
Alternatively, it is a structure in which inclined grooves are appropriately combined.
Reference numeral 1 denotes a carcass portion, 2 denotes a sidewall portion, and 7 denotes a beat portion.

Reference numeral 5 denotes a vertical groove directed in the traveling direction, which keeps the straightness, and reference numeral 6 denotes a narrow cut groove arbitrarily formed in the block. Reference numeral 8 denotes an imaginary line connecting the noble portion of the block 4 and the groove bottom with respect to the tire cross section, and has a configuration in which the bottom of the tread 3 is cut into a substantially arc shape. The surface of the block 4 is formed to have a middle height in the cross section of the tread 3, and the blocks 4 at both ends have a conventionally known height. The height and depth of the block 4 and the vertical groove 5 or the horizontal groove (not shown) are gradually increased toward the center. Therefore, the cross section of the block 4 is arranged in a flat circular shape in which a circle is compressed, like the cross section of the tread portion in FIG.

Reference numerals 9 and 9 'denote ventilation holes which penetrate from the bottom surface of the groove to one side surface of the tread portion and are arranged in a circumferentially staggered manner with respect to the bottom surface of the groove between the middle and high blocks located at the center. ing.

FIG. 2 shows a large number of cut grooves 6 in the block 4.
Is a plan view schematically showing a state of deformation in the direction of F, that is, deformation due to kinking, torsion, and compression when braking is applied. Two-dot chain line 4
Indicates the original dimensions, and 4 'indicates a view enlarged by compression. F
In particular, at the deep center portion of the groove, the dispersed forces of f _{1 to} f ₃ act in the block 4 against the acting force of, and the surface area is significantly increased.

[0010]

As described above, the block height is formed to be middle toward the center of the tire tread width, and the vent holes are formed in a zigzag manner on the bottom of the groove. As compared with the case where the depth is provided in parallel, the center portion is deformed more abruptly and gently, so that the actual contact area is enlarged, and the braking force and the edge force are improved. Therefore, there is a benefit of significantly improving the exercise performance when climbing a hill or on a frozen road.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view embodying the present invention.

FIG. 2 is an explanatory diagram showing enlargement due to kinking and torsional compression during braking of a block.

[Explanation of symbols]

1 carcass 2 sidewall portion 3 teeth with respect to the tread portion 4 block 5 the vertical axis 6 notches 7 phantom lines 9,9 take over the beat section 8 block base 'vent F acting force direction f _{1, f} 2, _{f 3} blocks Nare, twist direction

Claims (1)

(57) [Claims] In a tire tread structure in which a block having a cut groove is appropriately combined with a vertical groove and a lateral groove or an inclined groove, the groove depth gradually increases toward the center of the tread width section and the block height increases. A tread structure for a tire, wherein the tread structure is formed so as to have a large size, and an appropriate number of ventilation holes penetrating from the bottom surface of the groove portion to both side portions of the tread portion are arranged in a staggered manner.