JP2000118451A - Endless structure of rubber crawler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent jumping up and down of the steel cord tip embedded in a rubber elastic body, and to uniformize lengthwise directional rigidity of a rubber crawler by filling unvulcanized rubber in the superposed part of steel cords. SOLUTION: A steel cord row 1 is embedded in an rubber elastic body constituting a rubber crawler, and is superposed with a prescribed width by projecting the tip. A bias cord 2 is embedded at a specific angle in the lengthwise direction of the rubber crawler on the outer peripheral side of the steel cord row 1. A breaker layer 3 is covered with a width not less than a width of the superposed part of the steel cord row 1. Thus, in the endless part, respective constitutive elements are arranged in upper/lower molds carved with the inner peripheral surface and the outer peripheral surface of the rubber crawler, the inside of the molds is filled with unvulcanized rubber, and this is vulcanized to be made endless. A sign 12 represents a rubber lug.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an endless portion of a rubber crawler, and more particularly, to a structure of an endless portion of a rubber crawler without a metal core.

[0002]

2. Description of the Related Art Since a coreless rubber crawler is used for relatively high-speed running, it is desired that the rubber crawler has a uniform rigidity in a longitudinal direction. Of course, the noise is also large. In particular, a row of steel cords is buried in the longitudinal direction to resist the tensile force applied to the rubber crawler, but this causes unevenness in rigidity.

That is, the coreless rubber cradle has a structure in which a steel cord row buried in the longitudinal direction thereof and two bias cords are superposed on the outer peripheral side thereof at a predetermined angle. I have. Such a steel cord row resists a tensile force, and a bias cord is buried to increase the lateral rigidity of the rubber crawler without increasing the winding rigidity. The endless rubber crawler is formed by first forming a rubber elastic body in an end shape, stacking steel cord rows protruding from both ends thereof, and filling the unfilled rubber with that portion. It is endless by vulcanization.

However, the rubber crawler is wrapped around a sprocket or an idler during running, and the end of the steel cord of the endless portion is formed by the moment of the wrapping around the outer peripheral surface of the rubber crawler. It also causes the rubber to jump off, leading to rubber cracks and peeling or cutting of steel cord, thereby reducing the life of the rubber crawler. Further, since the steel cord row is overlapped on the endless portion of the steel cord row, the winding rigidity sharply increases in this portion. This causes vibration and noise of the rubber crawler.

FIG. 3 is a cross-sectional view showing an endless portion of a core-barless rubber crawler that has been widely used in the prior art. A steel core is provided in a rubber elastic body 21 constituting the rubber crawler.
The nodes 22 are buried in rows in the width direction, and both ends are overlapped with a width W to be endless.
Therefore, when the tip 22a of the steel cord 22 is wound around a sprocket or an idler, there is a phenomenon that the tip 22a breaks through the rubber elastic body 21 constituting the rubber crawler and jumps to the outer peripheral side. Since only W is extremely increased in rigidity as a rubber crawler, it causes vibration and noise, particularly during winding. Since the steel cord 22 is buried in the longitudinal direction of the rubber elastic body 21, it hardly shows rigidity in the lateral force of the rubber crawler, and it may be laterally displaced by an external force to cause derailing or the like. Therefore, two bias codes 23 are buried.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is mainly to improve the endless portion of a coreless rubber crawler and to prevent the tip of a steel cord embedded in a rubber elastic body from jumping. The aim is to make the longitudinal rigidity of the rubber crawler uniform.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the gist of the present invention is to embed an end-like rubber elastic body in the longitudinal direction so that the rubber elastic body is buried. The protruding portions of the steel cord projecting from the both ends of the steel cord are overlapped, and the steel cords are arranged on the outer peripheral side in a direction perpendicular to the steel cord row and have a width larger than the overlapping width of the steel cord. It consists of a breaker layer arranged with a wide width,
These overlapping portions are filled with unvulcanized rubber and vulcanized to form an endless rubber crawler.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has an endless structure as described above, in which a breaker layer is buried to prevent the steel cord end from jumping. By embedding 20 mm or more wider than the endless portions of the row, the degree of winding rigidity in the longitudinal direction of the rubber crawler is reduced.

According to the present invention having such a structure, it is possible to reduce the winding resistance of the rubber crawler and prevent the occurrence of power loss. The breaker layer includes steel cord, Kevlar fiber, EPT fiber and the like.

[0010] In the case of a coreless rubber crawler, a stainless steel
A predetermined angle (3) with respect to the longitudinal direction of the rubber crawler is provided on the outer peripheral side and / or the inner peripheral side including the overlap portion of the records.
(About 0 to 60 degrees), it is preferable to dispose two bias codes in opposite directions to compensate for the lack of lateral rigidity of the rubber crawler caused by the fact that the core is not buried. Incidentally, synthetic fibers such as nylon fibers, polyester fibers, PET fibers and Kevlar fibers are usually used as the bias code.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an endless portion of a rubber roller according to the present invention. FIG. 1 is a sectional view of an endless portion of a coreless rubber crawler of the present invention, and FIG. 2 is an exploded view of each element in the endless portion. Reference numeral 1 denotes a steel cord row, which is embedded in a rubber elastic body 10 constituting a rubber crawler and has a tip protruding therefrom, and is superposed with a width W. is there. Reference numeral 2 denotes an angle (α) of ± 38 degrees with respect to the longitudinal direction of the rubber roller on the outer peripheral side of the steel cord row 1.
Bias cord made of embedded nylon fiber
Is.

Reference numeral 3 denotes a breaker layer made of steel code, which is covered with a width of 20 mm or more larger than the width W of the overlapping portion of the steel code 1. In the endless portion, the respective components are arranged in upper and lower molds on which the inner peripheral surface and the outer peripheral surface of the rubber crawler are engraved, and the interior of the mold is filled with unvulcanized rubber 11. Vulcanization results in complete endlessness. In the figure, reference numeral 12 denotes a rubber lug, and 13 denotes a rubber projection for transmitting a driving force.

[0013]

According to the rubber roller endless structure of the present invention, the jumping of the superposed steel cord tip 1a is prevented by the breaker layer 3, and the breaker layer 3 is further prevented from jumping. Since the steel cord 1 is present in a direction perpendicular to the steel cord 1 and wider than the overlapping width W of the steel cord 1 at the endless portion, the rigidity of the whole rubber crawler suddenly increases in this part. However, a relatively smooth winding around a sprocket or the like was obtained, so that the life of the rubber crawler was extended, vibration was reduced, and energy loss was small.

[Brief description of the drawings]

FIG. 1 is a sectional view of an endless portion of a coreless rubber crawler according to the present invention.

FIG. 2 is an exploded view of each element in an endless portion.

FIG. 3 is a cross-sectional view showing an endless portion of a conventional rubber roller without a metal core.

[Explanation of symbols]

 1 steel code row, 1a steel code tip, 2 bias code, 3 breaker layer, 10 rubber elastic body, 11 unvulcanized rubber, 12 rubber rug, 13 ‥ Rubber protrusion, α ‥ Angle of bias code with steel code, W ‥ Overlap width of steel code.

Claims (3)

[Claims] 1. A steel cord which is embedded in the longitudinal direction of an end-like rubber elastic body and has a tip end protruding from both ends of the rubber elastic body, the projecting portions of the steel cord are superimposed on each other. Braids arranged in a direction perpendicular to the steel code row and arranged with a width wider than the overlapping width of the steel code
A rubber layer, which comprises an unvulcanized rubber filled in these overlapping portions and vulcanized.
La endless structure. 2. A bias code is disposed on the outer periphery and / or the inner periphery of the steel cord in a direction opposite to each other at a predetermined angle with respect to the longitudinal direction of the rubber roller. 2. An endless structure of the rubber crawler according to claim 1. 3. The endless structure of a rubber roller according to claim 1, wherein the breaker layer is arranged to be wider by at least 20 mm before and after the superposed width of the tip of the steel cord.