JP3822310B2 - Pneumatic tire - Google Patents

Description

【００３９】
試験の結果、本発明の適用された実施例タイヤは、ブロックに浅い切り込みが形成されていない従来タイヤに比較して、ヒール・アンド・トー摩耗の抑制効果が高く、また、耐摩耗性にも優れていることは明らかである。
【００４０】
【発明の効果】
以上説明したように、請求項１に記載の空気入りタイヤは上記の構成としたので、いわゆるハイ・アングルパターンの空気入りタイヤにおいて問題となる、ブロックの不均一摩耗を防止することができる、という優れた効果を有する。
【００４１】
また、周方向入力に対するブロック全体の捩じれ、動きを抑制することができる、という優れた効果を有する。
【００４２】
請求項２に記載の空気入りタイヤは上記の構成としたので、他性能を低下させることなくブロックの不均一摩耗を確実に防止することができる、という優れた効果を有する。
【図面の簡単な説明】
【図１】本発明の一実施形態に係る空気入りタイヤのトレッドパターンである。
【図２】浅い切り込みの断面図である。
【図３】従来タイヤのトレッドパターンである。
【符号の説明】
１０ 空気入りタイヤ
１２ トレッド
１４ 傾斜主溝
１６ 傾斜主溝
２２ 第１ブロック
２４ 第２ブロック
２６ 浅い切り込み
ＣＬ タイヤ赤道面[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pneumatic tire having an inclined groove in a tread, and relates to a pneumatic tire capable of preventing uneven wear of blocks defined by the inclined groove.
[0002]
[Prior art]
In the field of pneumatic tires, for the purpose of improving hydroplaning performance, the tread is inclined at a relatively small angle with respect to the tire circumferential direction on the tire equator side and relatively large with respect to the tire circumferential direction on the tread end side. There is a so-called high angle pattern pneumatic tire in which an inclined main groove inclined at an angle is formed.
[0003]
[Problems to be solved by the invention]
In this high-angle pattern pneumatic tire, as shown in FIG. 3, the blocks 104 and 106 defined by the inclined main grooves 100 and 102 extend in a substantially elongated triangular shape extending in a direction inclined with respect to the tire circumferential direction. It becomes.
[0004]
For this reason, due to the difference in rigidity between the narrow portion on the tire equatorial plane CL side of the block and the wide portion on the tire side portion side, when the side force is input, the block is twisted, and this causes a twist in the block. There is a problem of uniform wear.
[0005]
An object of the present invention is to prevent uneven wear of blocks in a so-called high angle pattern pneumatic tire in consideration of the above facts.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 is a tilted main groove that is inclined at a relatively small angle with respect to the tire circumferential direction on the tire equatorial plane side of the tread and is inclined at a relatively large angle with respect to the tire circumferential direction on the tread end side. A plurality of shallow incisions extending in the tire circumferential direction, and a distance between the shallow incisions and the shallow incisions is provided in the block. It is characterized by increasing density from sequel to the tread edge from the tire equator .
[0007]
In the pneumatic tire according to claim 1, the tread is inclined at a relatively small angle with respect to the tire circumferential direction on the tire equatorial plane side, and is inclined at a relatively large angle with respect to the tire circumferential direction on the tread end side. A plurality of shallow incisions extending in the tire circumferential direction are provided in an elongated, approximately triangular block partitioned by a main groove and a circumferential main groove, and the distance between the shallow incision and the shallow incision increases toward the tread edge from the tire equator plane. Since it is sparse, the following effects are obtained.
(1) Torsion of the block at the time of side force input is cut off and alleviated, and movement of one block causing uneven wear in the block is suppressed.
(2) Diffusion of non-uniform wear occurring in the block is suppressed.
(3) By causing the movement of the block on the ground contact surface to be independent within the range divided by the cut at the initial stage of wear with low block rigidity, nucleation of uneven wear is suppressed.
[0009]
(4) By arranging the interval between the shallow notch and the shallow notch from dense to sparse as it goes from the tire equatorial plane to the tread edge, the sub-blocks partitioned by the shallow notch can be elongated vertically in the tire circumferential direction, It is possible to suppress twisting and movement of the entire block with respect to circumferential input.
[0010]
The invention according to claim 2 is the pneumatic tire according to claim 1, characterized in that a depth of the shallow cut is 0.5 to 1.5 mm.
[0011]
In the pneumatic tire according to claim 2, by reducing the depth of shallow incision to 0.5 to 1.5 mm, it is possible to minimize a decrease in block rigidity due to incision.
[0012]
If the depth of cut is less than 0.5 mm, there is no effect of providing the cut. If the depth is greater than 1.5 mm, the block rigidity is lowered, and steering stability is affected.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the pneumatic tire of the present invention will be described with reference to FIGS. 1 and 2.
[0014]
The basic structure of the pneumatic tire 10 of the present invention is that a pair of sidewall portions and a crown portion interconnecting the sidewall portions are wound around a bead core embedded in a bead portion at the inner peripheral edge of the sidewall portion. Reinforced by a radial carcass composed of cord plies that are fastened back, and a belt composed of multiple layers of cords arranged in parallel to each other around the crown at a small angle with respect to the circumferential direction Is provided to reinforce the tread disposed in the crown portion.
[0015]
FIG. 1 is a plan view (pattern diagram) of a tread 12 of a pneumatic tire 10 (tire size: LVR31 × 10.50R156PR), CL indicates a tire equatorial plane, and E indicates a tread end.
[0016]
In the tread 12, a large number of inclined main grooves 14 and inclined main grooves 16 alternately arranged on both sides of the tire equatorial plane CL are alternately arranged in parallel along the tire circumferential direction (arrow A direction and arrow B direction). A circumferential main groove 18 that extends linearly along the tire circumferential direction and intersects the inclined main grooves 14 and 16 is disposed in the vicinity of both sides of the tire.
[0017]
These inclined main grooves 14 and 16 are inclined so as to gradually move away from the tire equatorial plane CL toward the arrow B direction side.
[0018]
The inclined main grooves 14 extend from the respective positions separated by a predetermined distance on both sides of the tire equatorial plane CL toward the respective tread ends E in opposite directions at a relatively shallow angle with respect to the tire circumferential direction. The vicinity of the end on the end E side extends at a relatively large angle with respect to the tire circumferential direction and opens to the tread end E.
[0019]
On the other hand, the inclined main groove 16 also has a relatively shallow angle with respect to the tire circumferential direction from each position separated by a predetermined distance on both sides of the tire equatorial plane CL to each tread end E side, in the same manner as the inclined main groove 14. The ends near the tread end E side extend at a relatively large angle with respect to the tire circumferential direction and open to the tread end E.
[0020]
As shown in FIG. 1, on the tire equatorial plane CL side, the inclined main groove 16 has a larger inclination with respect to the tire circumferential direction than the inclined main groove 14.
[0021]
The inclined main groove 14 and the inclined main groove 16 adjacent to the arrow A direction side are connected to each other on the tire equatorial plane CL side, and the vicinity of the tip of the inclined main groove 16 is a short connecting groove 20. Is connected to an intermediate portion of the inclined main groove 14 adjacent to the arrow A direction side.
[0022]
Therefore, the tread 12 includes a tilted main groove 14, a curved, elongated, substantially triangular first block defined by the tilted main groove 16 adjacent to the arrow A direction side and the circumferential main groove 18. 22 is formed, and the inclined main groove 16, the inclined main groove 14 adjacent to the inclined main groove 16 in the direction of arrow A, the elongated substantially triangular second block defined by the connecting groove 20 and the circumferential main groove 18 are formed. 24 is formed.
[0023]
Each of the first block 22 and the second block 24 is formed with a plurality of shallow notches 26 extending along the tire circumferential direction along the tire width direction.
[0024]
Further, the interval between the shallow notches 26 decreases from dense to sparse toward the tread end E from the tire equatorial plane CL, and the shapes of the sub-blocks 22A and 24A defined by the shallow notches 26 are each along the tire circumferential direction. It is preferable to elongate.
[0025]
As shown in FIG. 2, the groove width t of the shallow cut 26 may be zero or may have a groove width. However, when the groove width is zero, the groove depth D is preferably set to the main groove depth x 0.5 to 1.0. Otherwise (when it has a groove width), it is preferable to have a relationship of t / D = 0.1 to 1.0.
[0026]
Further, the groove depth D of the shallow notch 26 is preferably 5 to 20% with respect to the block height (main groove depth). In tires for passenger cars, light trucks, etc., the actual dimensions are 0.5 to 1%. .5 mm is preferred. These specifications are appropriately changed depending on the type of tire and the like, and the present invention is not limited to the above-mentioned specified range.
(Function)
Next, the effect | action of the pneumatic tire 10 of this embodiment is demonstrated.
[0027]
In the pneumatic tire 10 of the present embodiment, the first block 22 and the second block 24 are provided with a plurality of shallow notches 26 extending in the tire circumferential direction, and the blocks are divided into a plurality of blocks in the tire width direction. In both the two blocks 24, the twisting at the time of side force input is cut off and alleviated, the movement of one block causing uneven wear in the block is suppressed, and the diffusion of uneven wear generated in the block is suppressed.
[0028]
Furthermore, in the initial stage of wear with low block rigidity, the movement of the first block 22 and the second block 24 on the ground contact surface can be made independent within the range delimited by the cuts 26, thereby suppressing nucleation of uneven wear. can do.
[0029]
Further, the interval between the cuts 26 and 26 is arranged from dense to sparse from the tire equatorial plane CL toward the tread end E, and the shapes of the sub-blocks 22A and 24A partitioned by the cuts 26 are long in the tire circumferential direction. Therefore, the twisting and movement of the first block 22 and the second block 24 can be suppressed even in the circumferential direction input.
[0030]
In addition, by setting the depth of the shallow cut 26 to 0.5 to 1.5 mm, it is possible to minimize a decrease in block rigidity while suppressing twisting of the block.
[0031]
The shallow cut 26 may be inclined as long as it is within ± 45 ° with respect to the tire circumferential direction.
(Test example)
In order to confirm the effect of the present invention, the conventional tire and Example tires 1 and 2 to which the present invention was applied were prepared, and the heel and toe wear step and the wear resistance were compared.
[0032]
Both the conventional tire and the example tires 1 and 2 have a tire size of LVR31 × 10.50R156PR.
[0033]
The example tire 1 is a tire (see FIG. 1) in which the incision interval is increased from dense to sparse as it goes from the tire equatorial plane to the tread end, and the example tire 2 is a tire in which the incision interval is equal. is there.
[0034]
The conventional tire is a tire obtained by removing cuts from the blocks of the example tire 1 (see FIG. 1) (see FIG. 3).
[0035]
The test method will be described below.
Heel and toe wear step: A test tire was mounted on an actual vehicle (Hilux Surf: manufactured by Toyota Motor Corporation), and the amount of wear step generated before and after the block after traveling 10,000 km was measured. The result is an index display in which the conventional tire is 100, and the larger the value, the better the effect of suppressing heel and toe wear.
[0036]
Abrasion resistance: Applicable size in 1997 JATMA, maximum load capacity in ply rating, 58% front wheel, 47% rear wheel (equivalent to 5 passengers), 57% maximum air pressure corresponding to the maximum load capacity I went there.
[0037]
After traveling 10,000 km on the dry road surface, the amount of tire wear was measured. The result is an index display in which the conventional tire is 100, and the larger the value, the better the wear resistance.
[0038]
[Table 1]

[0039]
As a result of the test, the tire of the example to which the present invention was applied has a higher effect of suppressing heel and toe wear than the conventional tire in which the shallow notch is not formed in the block, and the wear resistance is also improved. It is clear that it is excellent.
[0040]
【The invention's effect】
As described above, since the pneumatic tire according to claim 1 has the above configuration, it can prevent uneven wear of the block, which is a problem in a pneumatic tire having a so-called high angle pattern. Has an excellent effect.
[0041]
Moreover, it has the outstanding effect that the twist of the whole block with respect to the circumferential direction input and a motion can be suppressed.
[0042]
Since the pneumatic tire according to claim 2 has the above configuration, it has an excellent effect that the uneven wear of the block can be surely prevented without lowering other performance.
[Brief description of the drawings]
FIG. 1 is a tread pattern of a pneumatic tire according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a shallow notch.
FIG. 3 is a tread pattern of a conventional tire.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Pneumatic tire 12 Tread 14 Inclined main groove 16 Inclined main groove 22 1st block 24 2nd block 26 Shallow notch CL Tire equatorial plane

Claims (2)

The tread has an inclined main groove that is inclined at a relatively small angle with respect to the tire circumferential direction on the tire equatorial plane side and is inclined at a relatively large angle with respect to the tire circumferential direction on the tread end side, and a circumferential main groove. A pneumatic tire having an elongated substantially triangular block,
A pneumatic tire characterized in that a plurality of shallow cuts extending in the tire circumferential direction are provided in the block, and the interval between the shallow cuts and the shallow cuts is made denser and sparser from the tire equatorial plane toward the tread end . The depth of the shallow notch is 0.5 to 1.5. mm The pneumatic tire according to claim 1, wherein

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