JP4316284B2 - Pneumatic tires for track vehicles - Google Patents

Description

表１から、本発明タイヤは、多角形摩耗やショルダー摩耗の問題を招くことなく、レール摩耗を改善できることがわかる。
【００３５】
【発明の効果】
上述したように本発明は、ショルダーリブ踏面のリブ外側端側にタイヤ周方向に延在する細溝を設け、該細溝によりリブ外側端側にサイプを設けない細リブを区分形成する一方、タイヤ幅方向に延在し最外側の主溝のジグザグ凹端及び細溝に開口するサイプをタイヤ周方向に所定の間隔で配置したので、多角形摩耗やショルダー摩耗の問題を招くことなくリブエッジのレール摩耗を改善することできる。
【図面の簡単な説明】
【図１】本発明の軌道走行車両用空気入りタイヤの一例を示すトレッド面の要部展開図である。
【図２】軌道走行車両用空気入りタイヤに作用する力を示す斜視説明図である。
【符号の説明】
１ トレッド面 １Ａ センター部
１Ｂ ショルダー部 ２ 主溝
２Ａ 最外側の主溝 ２ｘ ジグザグ凹端
３，３Ａ リブ ３Ａ１ 踏面
３Ｂ ショルダーリブ ３Ｂ１ 踏面
４ サイプ ５ 細溝
６ 細リブ ７ サイプ
Ｃ タイヤ周方向[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire for a track vehicle used for a monorail and the like, and more specifically, in a pneumatic tire for a track vehicle provided with a rib pattern, the rail vehicle air improved in rail wear. Related to tires.
[0002]
[Prior art]
In recent years, as a means of transportation between cities, a track traveling vehicle such as a monorail equipped with pneumatic tires, which is called new city traffic, has been used. Since this track traveling vehicle often travels in an area where houses are densely packed, a pneumatic tire used for the track traveling vehicle is required to have low noise.
[0003]
Also, when running on a curved track used under conditions of high load and high air pressure, a part of the vehicle body comes into contact with a guide provided on the track, and the direction of the tire is changed instantaneously. At the same time, since the motor is driven, a large torque acts on the tire in the early stage of acceleration / deceleration. Therefore, since it is used on the use conditions with which a tire is easy to wear, it is also necessary to have abrasion resistance. Therefore, a rib pattern is usually adopted as a tread pattern of a pneumatic tire for a track vehicle.
[0004]
However, as described above, when the tire direction changes momentarily during large torque action in the early stage of acceleration / deceleration under high load and high air pressure, a large slip occurs especially at the rib edge facing the main groove of the shoulder rib. There is a problem in that rail wear occurs along the surface.
[0005]
Therefore, conventionally, as a countermeasure described above, the main grooves in the tire circumferential direction that divide the ribs are formed in a zigzag shape, and the load applied to the rib edges is dispersed by reducing the load by increasing the edge length (for example, Patent Document 1).
[0006]
[Patent Document 1]
JP-A-4-43104 (1 page, FIG. 3)
[0007]
[Problems to be solved by the invention]
However, merely making the main grooves in the tire circumferential direction in a zigzag shape is not sufficient in reducing the effect of rail wear, and further improvement has been strongly demanded.
[0008]
An object of the present invention is to provide a pneumatic tire for a track vehicle that can improve rail wear in a pneumatic tire for a track vehicle provided with a rib pattern.
[0009]
[Means for Solving the Problems]
The present invention that achieves the above object is the pneumatic tire for a track vehicle in which a plurality of main grooves extending in a zigzag shape in the tire circumferential direction are provided on the tread surface, and ribs are sectioned by the main grooves. A narrow groove extending in the tire circumferential direction is provided on the outer rib side of both shoulder rib treads formed on the outer side of the tire from both main grooves, and a narrow rib without a sipe is formed on the outer rib side by the narrow groove. On the other hand, a zigzag concave end of the outermost main groove extending in the tire width direction and a sipe opening in the narrow groove are formed at a predetermined interval in the tire circumferential direction on the shoulder rib tread surface on the inner side in the tire width direction from the narrow groove. It is arranged.
[0010]
According to the present invention described above, the shoulder rib is divided by the sipe that opens into the groove at both ends, and the rigidity of the rib is reduced. Therefore, the tire orientation is instantaneous when a large torque is applied at the initial stage of acceleration / deceleration under high load and high air pressure. Since it is possible to avoid the occurrence of a large slip on the rib edge facing the main groove of the shoulder rib when the change is made, the occurrence of rail wear can be suppressed.
[0011]
When the rigidity of the shoulder rib is lowered in this way, the force applied to the outer edge of the shoulder rib of the shoulder rib due to a heavy load cannot be received, so the edge portion side is easily worn, but the sipe is divided into narrow grooves there. By disposing the thin ribs that are not provided, the thin ribs are subjected to a load to wear and the thin ribs are worn, thereby suppressing the shoulder wear that occurs at the tire outer edge portion of the rib body provided with the sipe inside the tire from the narrow groove. can do.
[0012]
In addition, if the ribs are divided by sipe, polygonal wear is likely to occur due to the difference in rigidity between the adjacent rib parts, but the sipe is opened in the zigzag concave end of the main groove so that it is predetermined in the tire circumferential direction. Therefore, it is possible to reduce the difference in rigidity between adjacent rib portions and suppress the occurrence of polygonal wear.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.
[0014]
FIG. 1 shows an example of a pneumatic tire for a track vehicle according to the present invention. A plurality of main grooves 2 extending zigzag along a tire circumferential direction C are provided on a tread surface 1. 2, a plurality of ribs 3 extending in the tire circumferential direction C are sectioned.
[0015]
On the tread surface 3A1 of the plurality of ribs 3A formed at the center portion 1A between the outermost main grooves 2A, a sipe that extends in the tire width direction and opens at the zigzag concave end 2x of the adjacent main groove 2 at both ends. 4 are arranged at predetermined intervals along the tire circumferential direction C.
[0016]
On the tread surface 3B1 of both shoulder ribs 3B formed in the shoulder portion 1B outside the tire from the outermost main grooves 2A, one thin line extending linearly along the tire circumferential direction C on the rib outer end side. A groove 5 is provided, and the narrow groove 5 divides and forms a thin rib 6 that does not have one sipe on the outer side of the rib.
[0017]
On the treads 3B1 of the shoulder ribs 3B, a sipe 7 extending in the tire width direction and opening in the zigzag concave end 2x of the outermost main groove 2A and opening in the narrow groove 5 along the tire circumferential direction C is provided. They are arranged at a predetermined interval.
[0018]
The sipes 4 and 7 are linearly formed and inclined with respect to the tire width direction. The sipes 4 and 7 of the adjacent ribs 3 are inclined and extended at substantially the same angle with the inclination direction with respect to the tire width direction being reversed, and the extension lines of the sipes intersect each other. Each sipe 4, 7 is provided so as to open to each zigzag concave end 2 x, and the shape of the rib section divided by the sipe 4, 7 is made uniform in each rib 3.
[0019]
Note that the sipes 4 and 7 referred to here are cuts having a width of 0.5 to 1.0 mm. The narrow groove 5 is a groove having a groove width of 2 to 5 mm. The groove width of the main groove 2 is in the range of 8 to 12 mm.
[0020]
As shown in FIG. 2, when the track vehicle travels on a curve, when the tire T momentarily changes, the force M due to a high load and high air pressure on the tire T, the force N due to a large torque at the initial stage of acceleration / deceleration, and the tire direction However, in the present invention described above, the shoulder rib 3B is divided by the sipe 7 having both ends opened in the groove to reduce the rigidity of the rib. Therefore, when the force shown in FIG. It is possible to suppress the occurrence of a large slip at the rib edge facing the main groove 2A of the shoulder rib 3B. As a result, occurrence of rail wear can be reduced.
[0021]
With such drop the rigidity of the shoulder rib 3B, the high load can not receive the force applied to the tire outer side edge of the shoulder portion 1B by, its edge portion is a problem that tends to wear occurs, sipes therein The thin ribs 6 not provided with the ribs are disposed, and the thin ribs 6 are worn by carrying the load by the thin ribs 6, so that they are generated at the tire outer edge portion of the rib main body provided with the sipe 7 on the tire inner side than the fine grooves 5. Shoulder wear can be suppressed.
[0022]
Further, when the rib is divided by the sipe, polygonal wear is likely to occur due to a difference in rigidity between adjacent rib portions divided by the sipe. However, the tire is formed by opening the sipe 7 at the zigzag concave end 2x of the main groove 2. Since they are provided at predetermined intervals in the circumferential direction, it is possible to reduce the difference in rigidity between adjacent rib portions divided by the sipe 7 and to suppress the occurrence of polygonal wear.
[0023]
In the present invention, the depth of the sipe 7 is preferably 70 to 90% of the groove depth of the adjacent main groove 2. If the depth of the sipe 7 is less than 70%, since the rigidity of the shoulder rib 3B increases after the middle stage of wear, rail wear is likely to occur. On the other hand, if it exceeds 90%, the movement of the rib portion divided by the sipe 7 becomes excessively large, and heel and toe wear is likely to occur in the rib portion, and cracks are likely to occur from the sipe edge.
[0024]
The depth of the sipe 4 is preferably set to the same depth as the sipe 7 in order to make the tread rigidity uniform.
[0025]
As described above, the sipe 4 is provided on the tread surface 3A1 of the rib 3A formed in the center portion 1A, so that the rigidity difference with the rib 3B of the shoulder portion 1B is reduced and the rigidity of the entire tread is made uniform. It is preferable for suppressing the occurrence of step wear.
[0026]
In addition, it is preferable that the sipe 4 and 7 arranged on the adjacent rib 3 as described above is inclined in the direction opposite to the tire width direction so that the extension lines of the sipe intersect each other. Movement can be suppressed, and rib punching resistance and polygonal wear resistance can be improved.
[0027]
The inclination angle of the sipes 4 and 7 with respect to the tire width direction is preferably 5 ° to 15 ° from the viewpoint of suppressing heel and toe wear.
[0028]
【Example】
In the tire 1 of the present invention configured as shown in FIG. 1 in which the tire size is the same for 11R22.5 and the sipe is provided in the center portion and shoulder portion of the tread surface, and in the tire 1 of the present invention, the sipe is provided in the rib of the center portion. In the present invention tire 2 and the present invention tire 1 which are not provided, in the present invention tire 3 and the present invention tire 2 in which the inclination direction of the sipe in the tire width direction is the same direction, the sipe is opened at a position away from the zigzag concave end. The comparative tire 1 and the comparative tire 2 in which the sipe was extended to the shoulder end without providing the narrow groove and the conventional tire in which the sipe was not provided on any of the ribs were produced.
[0029]
The sipe depth of the tire 1 of the present invention is 90% of the groove depth of the main groove, the sipe depth of the tire 2 of the present invention is 80% of the groove depth of the main groove, and the sipe depth of the tire 3 of the present invention is 70% of the groove depth of the main groove.
[0030]
Each of these test tires is mounted on a rim having a rim size of 22.5 × 8.25, the air pressure is set to 700 kPa, and the rail wear resistance, polygonal wear resistance, and shoulder wear resistance are evaluated under the following measurement conditions. When the test was conducted, the results shown in Table 1 were obtained.
[0031]
Measurement conditions Each test tire was run for 25 km based on the durability test conditions described in JIS D4230, and the width and depth of the generated rail wear were measured. The index value was evaluated. The larger this value, the better the rail wear resistance.
[0032]
Further, the width and depth of the step in the tire circumferential direction were measured, and the results were evaluated with an index value where the conventional tire was 100. The larger this value, the better the polygonal wear resistance. If the index value is 96 or more, it is an acceptable level.
[0033]
Further, the width and depth of the generated shoulder wear were measured, and the results were evaluated with an index value where the conventional tire was 100. The larger this value, the better the shoulder wear resistance.
[0034]
[Table 1]

From Table 1, it can be seen that the tire of the present invention can improve rail wear without causing problems of polygonal wear and shoulder wear.
[0035]
【The invention's effect】
As described above, the present invention provides a narrow groove extending in the tire circumferential direction on the rib outer end side of the shoulder rib tread surface, and the narrow groove does not provide a sipe on the rib outer end side. The zigzag concave end of the outermost main groove extending in the tire width direction and the sipe opening in the narrow groove are arranged at predetermined intervals in the tire circumferential direction, so that the rib edge can be formed without causing problems of polygonal wear and shoulder wear. Rail wear can be improved.
[Brief description of the drawings]
FIG. 1 is a development of a main part of a tread surface showing an example of a pneumatic tire for a track vehicle according to the present invention.
FIG. 2 is an explanatory perspective view showing a force acting on a pneumatic tire for a track traveling vehicle.
[Explanation of symbols]
1 tread surface 1A center portion 1B shoulder portion 2 main groove 2A outermost main groove 2x zigzag concave end 3, 3A rib 3A1 tread surface 3B shoulder rib 3B1 tread surface 4 sipe 5 narrow groove 6 narrow rib 7 sipe C tire circumferential direction

Claims (5)

In a pneumatic tire for a track traveling vehicle in which a plurality of main grooves extending zigzag in the tire circumferential direction are provided on the tread surface, and ribs are formed by division of the main grooves, the pneumatic tire is formed on the tire outer side from both outermost main grooves. A narrow groove extending in the tire circumferential direction is provided on the outer side of the ribs of the shoulder rib treads, and a thin rib without a sipe is provided on the outer side of the rib by the narrow groove, while extending in the tire width direction. A pneumatic tire for a track traveling vehicle in which zigzag concave ends of the outermost main groove and sipes opening in the narrow groove are arranged at predetermined intervals in the tire circumferential direction on the shoulder rib treads on the inner side in the tire width direction from the narrow groove. .   A sipe that extends in a tire width direction and opens at a zigzag concave end of a main groove adjacent to both ends is disposed at a predetermined interval in the tire circumferential direction on a rib tread formed between the outermost main grooves. The pneumatic tire for a track vehicle according to 1.   The pneumatic tire for a track vehicle according to claim 1 or 2, wherein the sipe is linear and inclined with respect to the tire width direction.   The pneumatic tire for a track vehicle according to claim 3, wherein the sipe of the adjacent ribs is reverse in the inclination direction with respect to the tire width direction.   The pneumatic tire for a track vehicle according to claim 1, 2, 3, or 4, wherein the depth of the sipe is 70 to 90% of the depth of the main groove.

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