JP2001010559A - Rubber crawler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To average the rigidity as the whole rubber crawler as much as possible so as to reduce the bending rigidity and also prevent the fatigue of a steel cord by forming one end of an ended steel cord into a protruding form and the other end into a recessed form in a joint part, and overlapping these ends. SOLUTION: A steel cord 2 is longitudinally buried in a lengthy ended rubber elastic body 1, and both ends 2a, 2b of the steel cord 2 are protruded from both ends of the rubber elastic body 1. The steel cord end 2a is cut so as to have a protruding form 2a1 in the lateral center area, and the other steel cord end 2b is cut into a recessed form 2b1 conformable to the protruding form 2a1. Both the steel cord ends 2a, 2b are overlapped as a part P0 with the steel cord end 2a side being on the inside of a rubber crawler to form a joint structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure when a rubber crawler is completed by making a long and elastic rubber body endless.

[0002]

2. Description of the Related Art In general, a rubber crawler is a rubber crawler made by embedding a steel cord in a long, endless rubber elastic body and forming an endless rubber crawler. It is overlapped and filled with unvulcanized rubber, which is vulcanized to be endless to complete the joint structure.

FIG. 5 is a view showing a joint structure of this endless portion. Normally, tips 22a and 22b of a steel cord 22 project from both ends of a rubber elastic body 21.
It is usually cut at right angles to the longitudinal direction. Then, both ends 22a and 22b are overlapped, and the unvulcanized rubber 23 is filled and vulcanized in this portion. Therefore, the portion where the steel cords 22a and 22b overlap is a portion having extremely high rigidity as viewed from the whole rubber track.

[0004] Therefore, when such a rubber crawler is wound around a sprocket or an idler and used for traveling, not only energy loss due to increased bending rigidity, but also vibration is generated from this joint portion, Furthermore, since the bending is not smooth, the occurrence of derailing cannot be denied. Further, there is a drawback such that the tip of the steel cord protrudes from the inside of the rubber, and the improvement of the joint portion has been demanded.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an improvement in a joint structure of a rubber crawler in which both ends of a steel cord as a tensile member are overlapped. An object of the present invention is to provide a joint structure that reduces bending rigidity and does not cause fatigue of a steel cord.

[0006]

SUMMARY OF THE INVENTION The gist of the present invention is to provide an endless rubber elastic body constituting a rubber crawler body, a steel cord embedded in a circumferential direction of the rubber elastic body, and the steel cord. And a joint that overlaps both ends of a steel cord with ends and makes it endless,
A rubber crawler having a rubber crawler, characterized in that the joint has a convex shape at one end of a steel cord having ends and a concave shape at the other end, and is formed by superimposing these. is there.

[0007] Preferably, the edge of the joint portion is disposed immediately above a rubber lug formed on the outer peripheral side of the rubber crawler or directly below a rubber projection for driving formed on the core metal or the inner peripheral side of the rubber crawler. More specifically, only one of the two end edges of the joint portion is disposed at the above position.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is based on the result of closely examining the running state of a conventional rubber crawler. In the conventional rubber crawler joint structure, such a joint portion as a whole rubber crawler has extremely high hardness. When it is used for traveling, it has a large winding resistance and cannot rotate smoothly, so that vibration is generated, and furthermore, it is a cause of occurrence of derailing. or,
The tip of the overlapped steel cord tends to splash out of the rubber elastic body, which has the disadvantage that the life of the rubber crawler is shortened. The purpose of the present invention is to solve this point.

With respect to the cutting shape of the tip of the steel cord of the present invention, it is possible to cut one or more steps, a V-shape, a trapezoid, or an arc. In this way, by shifting the overlap position of the sur cord between the center region and the left and right regions in the width direction, the overall rigidity of the rubber crawler becomes a direction of averaging, winding around a sprocket or an idler. The winding resistance at the time of being hung is reduced. In addition, it is preferable that the convex shape and the concave shape of the protruding portion of the steel cord are formed symmetrically to the left and right from the center in the width direction, since it is less affected by twisting or the like generated in the work place or the obtained rubber crawler.

Further, in order to prevent the steel cord end of the overlap portion from splashing, this portion is disposed immediately above the rubber lug. For this reason, the spring of the tip of the steel cord is prevented, and when the core metal is buried in the rubber crawler, it can be disposed immediately below the core metal. Furthermore, in a so-called inner drive type rubber crawler, a drive protrusion is formed on the inner peripheral side, but it is also possible to arrange the drive protrusion directly below the drive protrusion. That is,
The thickness of the rubber portion and the core portion of the rubber are smaller than those of the other portions in the degree of deformation of the rubber elastic body at the time of winding, and the tip of the steel cord is disposed here to prevent the rubber from jumping out of the rubber. . In addition, it is preferable to arrange only one edge of the both ends of the joint portion at the same position, and there is an effect of disposing both edges, but in this case, the inner steel cord buckles, This is because a peeling layer may be formed inside.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The rubber track of the present invention will be described in more detail with reference to particularly preferred examples. FIG. 1 is a plan view of the inner peripheral side when the structure of the present invention is applied to an inner drive type rubber crawler, in which a steel cord 2 is embedded in a long and end rubber elastic body 1 in the longitudinal direction thereof. Both ends 2a, 2b of the steel cord 2 project from both ends of the rubber elastic body 1. Then, as shown in FIG.
In the case of a, the central region in the width direction is cut as a convex shape 2a1, and in the other steely cord 2b, the cut is formed as a concave shape 2b1 corresponding to the convex shape 2a1. The steel cord 2a side is overlapped with the inner peripheral side of the rubber track so as to form a joint structure by overlapping P0.

The rubber crawler 10 is provided with rubber driving projections 11 at a constant pitch.
In this example, the edge 2a2 of the overlapped inner steel cord 2a1 is disposed immediately below the driving projection 11. In the illustrated example, the end 2b2 of the steel cord 2b1 on the other side is disposed between the driving projections 11, 11, but it is needless to say that it may be disposed immediately below the driving projection 11.

Although not shown, a rubber lug is formed on the rubber crawler on its outer peripheral side.
It goes without saying that a2 and / or 2b2 can be arranged directly below this. Further, when cores are embedded in the rubber track, they may be arranged immediately below this core.

The cutting shapes (2a1, 2b1) at the tips of the steel cords 2a, 2b are not particularly limited. However, as shown in FIGS.
1 may be formed, V-shaped, or bowed and cut.

[0015]

The features of the rubber crawler will now be further described with reference to FIG. 1. The overlap portion of the steel cord is structured so as to be shifted back and forth by a central region Sa and a left and right region Sb. As a result, there are no places where the rigidity of the rubber crawler is particularly high, and the rubber crawlers are averaged by the joints. Therefore, the winding resistance is relatively small, and energy loss, vibration and the like are reduced. Further, in this example, since the steel cord tips 2a1 and 2b1 are disposed immediately below the drive projection 11, the protrusion does not occur.

[Brief description of the drawings]

FIG. 1 is an inner peripheral plan view when the joint structure of the present invention is applied to an inner drive type rubber track.

FIG. 2 is an inner circumferential plan view showing only a steel cord in FIG. 1;

FIG. 3 is a plan view showing another example of cutting a steel cord protrusion.

FIG. 4 is a plan view showing still another example of cutting a steel cord protrusion.

FIG. 5 is an inner peripheral plan view showing a joint structure of a conventional rubber track.

[Explanation of symbols]

 1 ‥ Long and ended rubber elastic body, 2 ‥ Steel cord, 2a, 2b ‥ Protrusion of steel cord, 2a1 ‥ Protrusion of projection of steel cord, 2b1 ‥ Recession of projection of steel cord, 10 ‥ Rubber Crawler, 11 ‥ rubber drive protrusion, P0 ‥ overlap part.

Claims (4)

[Claims] An endless rubber elastic body constituting a rubber crawler body, a steel cord buried in a circumferential direction of the rubber elastic body, and both ends of a steel cord formed of the steel cord. A rubber crawler having an overlapped endless joint,
A rubber crawler characterized in that the joint portion has one end of a steel cord having an end formed in a convex shape and the other end formed in a concave shape, and these are overlapped. 2. An end edge of the joint portion is disposed immediately above a rubber lug formed on an outer peripheral side of the rubber crawler or directly below a core rubber or a driving rubber projection formed on an inner peripheral side of the rubber crawler. Item 4. A rubber track according to item 1. 3. A driving rubber projection formed directly on a rubber lug formed on an outer peripheral side of a rubber crawler, or on a core metal or an inner peripheral side of a rubber crawler, only one of the two end edges of the joint portion. 3. The device according to claim 1, which is disposed immediately below
The described rubber track. 4. The steel cord according to claim 1, wherein the protruding portion and the concave shape of the projecting portion are formed symmetrically left and right from the center in the width direction.
The described rubber crawler joint structure.