JP4198199B2 - Heavy duty pneumatic tire - Google Patents

Description

【００１１】
上記から明らかなように、切欠を設けた実施例１のタイヤは、比較例に対し石咬みを大幅に改良しており、さらに切欠の側壁の角度を大きくした実施例２では石咬みが見られなかった。
【００１２】
【発明の効果】
以上に述べたところから明らかなように、本初明によれば、重荷重用空気入りタイヤの石咬みを大幅に減少することができる。
【図面の簡単な説明】
【図１】本発明による重荷重用空気入りタイヤのトレッドパターン一部拡大正面囲である。
【図２】図1における重荷重用空気入りタイヤの溝断面図である。
【図３】従来の切欠のない重荷重用空気入りタイヤのトレッドパターン一部拡大正面図である。
【符号の説明】
１、２ 周方向溝
３、４、５ 横方向溝
６、７、８、９ 切欠
１０、１１、１２ ブロック
Ｎ トレッド法線
Ｅ タイヤ赤道線（トレッドパターン・センター）[0001]
[Technical field to which the invention belongs]
The present invention relates to a tread pattern of a heavy duty pneumatic tire, and particularly relates to prevention of stone bite.
[0002]
[Prior art]
Heavy duty pneumatic tires, especially tires traveling on rough roads, may damage the tires by biting stones in the grooves, or may cause danger to surrounding vehicles etc. if the stones once bited off during driving was there. Conventionally, in order to improve the biteability of the stone, the angle of the groove side wall with respect to the normal line standing on the tread surface in the cross section perpendicular to the direction in which the groove extends is increased, or a so-called stone ejector is installed in the groove. It was generally done.
[0003]
[Problems to be solved by the invention]
However, if the groove sidewall angle is simply increased as described above, the groove bottom R decreases, so that the rubber is cracked from the groove bottom due to deterioration of the rubber due to running, and the circumferential main No improvement has been made to the problem that it is easy to bite stones at the point where the groove and the lateral groove are connected. In addition, the present situation is that stone ejectors cannot solve the problem of reducing the wet performance of a tire.
[0004]
Therefore, an object of the present invention is to propose a heavy duty pneumatic tire that effectively prevents stone biting without deteriorating durability and wet performance.
[0005]
[Means for Solving the Problems]
To achieve the above object, the heavy-duty pneumatic tire of the present invention comprises at least two circumferential grooves and a plurality of lateral grooves that are connected to the circumferential grooves and spaced apart in the circumferential direction. In a heavy duty pneumatic tire having a tread, a stone bite is placed on the other groove side wall only at a position where one groove side wall is connected to the lateral groove of the pair of left and right groove side walls forming the circumferential groove. The notch that prevents the stone bite has a sidewall angle that is greater than the angle of the circumferential groove sidewall with respect to the normal to the tread surface in a cross section perpendicular to the direction in which the circumferential groove extends. Have.
[0006]
Further, it is preferable that the side wall angle of the notch is larger than the angle of the circumferential groove side wall with respect to the normal standing on the tread surface in the cross section perpendicular to the direction in which the circumferential groove extends, because the stone bite is further reduced.
[0007]
In heavy duty pneumatic tires having two circumferential main grooves and a large number of lateral directions connected to the circumferential main grooves and spaced apart in the circumferential direction, stone biting is the most problematic. Is the S portion of FIG. 3 where the lateral grooves are connected to the circumferential grooves. This part is a place where the block ends gather, and the rigidity around this block is lowered, so that the stone is easy to bite. In this case, if a notch is formed in the groove side wall of the circumferential groove where the lateral groove is connected to the circumferential groove as in the configuration adopted by the present invention, the space in this part becomes large and stone biting occurs. It becomes difficult. In addition, if the side wall angle of the notch is made larger than the angle of the groove side wall of the circumferential groove with respect to the normal standing on the tread surface in the cross section perpendicular to the direction in which the circumferential groove extends, it becomes difficult to bite the stone into the notch. Or big. Moreover, wet performance is also improved by providing a notch.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is a partially enlarged front view of a tread pattern of a pneumatic tire for trucks and buses according to an embodiment of the present invention, and the tire size is 10.00R20. It is.
As shown in the figure, the tread of the pneumatic tire of the embodiment is provided with four circumferential grooves 1 and 2 and a large number of lateral grooves 3, 4, 5 arranged at intervals on the circumference. A number of blocks 10, 11, 12 are formed on the tread circumference at intervals by these circumferential grooves 1, 2 and lateral grooves 3, 4, 5. And the notch 6, 7, 8, 9 is provided in the groove | channel side wall of the circumferential groove | channel of the location where a horizontal groove | channel is connected with the circumferential groove | channel.
[0009]
In order to confirm the effect of the present invention, tires with notches 6, 7, and 8 were made on the basis of the specifications shown in Table 1. For comparison, a tire without a notch shown in FIG. 3 was made as a prototype with the same structure except for the notch. These tires are mounted on a 7.50V rim with an internal pressure of 9.0kg / cm ² and mounted on the rear of a 10-ton dump truck. Table 1 also shows a comparison of the number of stones where the lateral grooves in the book are connected to the circumferential grooves.
[0010]
[Table 1]

[0011]
As is clear from the above, the tire of Example 1 provided with the notch has greatly improved the stone bite relative to the comparative example, and in Example 2 in which the angle of the side wall of the notch is further increased, the stone bite is seen. There wasn't.
[0012]
【The invention's effect】
As is apparent from the above description, according to the present initial description, the stone biting of the heavy duty pneumatic tire can be greatly reduced.
[Brief description of the drawings]
FIG. 1 is a partially enlarged front view of a tread pattern of a heavy duty pneumatic tire according to the present invention.
2 is a groove cross-sectional view of a heavy duty pneumatic tire in Fig.
FIG. 3 is a partially enlarged front view of a tread pattern of a conventional heavy duty pneumatic tire without a notch.
[Explanation of symbols]
1, 2, Circumferential groove 3, 4, 5 Lateral groove 6, 7, 8, 9 Notch 10, 11, 12 Block N Tread normal line E Tire equator line (tread pattern center)

Claims (1)

In a heavy duty pneumatic tire comprising at least two circumferential grooves and a plurality of lateral grooves connected to the circumferential grooves and arranged at intervals in the circumferential direction in a tread,
Of the pair of left and right groove sidewalls that form the circumferential groove, only one portion of the groove sidewall is connected to the lateral groove , and the other groove sidewall is formed with a notch that prevents stone biting ,
The notch for preventing stone biting has a sidewall angle larger than an angle of the circumferential groove sidewall with respect to a normal line standing on a tread surface in a cross section perpendicular to a direction in which the circumferential groove extends. Heavy duty pneumatic tire.

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