JPH04110285A - Elastic caterpillar band - Google Patents

Abstract

PURPOSE:To reduce the rigidity of an orbital band body in a joint part by joining the terminal part on one side of a tensile member and the terminal part on the other side, in the state where one or several stripes are twisted and bound to a rope shape. CONSTITUTION:As for an orbital band body 10, twenty-four stripes of tensile members 30 are arranged in the peripheral direction on one side in the width direction of a lateral rigid member 20, and at the terminal edge part 31 on one side of the member 30 which is butt-joined in opposition in the peripheral direction and at the terminal part 32 on the other corresponding side, eight pieces of the bound parts 34, each of which is formed to a rope shape by twisting each three stripes around an another core member 36. The length of the twist of the tensile member 30 is set equal to the arrangement pitch P1 of the member 20 or more, and the edge parts 35a and 35b corresponding to the starting point and end point of twist at the bound part 34 are arranged in the plane projection region of the member 20. Further, the twisting pitch P2 of the member 30 is set equal to the arrangement pitch P1 of the member 20 or less.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an elastic endless track belt used as a traveling device for a vehicle such as a construction work machine.

[Conventional technology]

Conventionally, this type of elastic endless track belt has an endless track belt main body 1 made of rubber substance, as shown in FIGS. 4 and 5.
Base portions 21 of a horizontally rigid member 20 made of a metal body extending in the width direction are arranged at regular intervals in the circumferential direction, and a plurality of steel strips arranged in parallel in the circumferential direction are provided on the outer peripheral side of the horizontally rigid member 20. A tensile member 30 made of a cord or the like is arranged to surround both sides of the lateral rigid member 20 in the width direction, and is vulcanized and bonded integrally with the rubber substance.

The track belt main body 10 is provided with an engagement hole 11 penetrating the inner and outer circumferential surfaces thereof, into which teeth of a drive wheel (7) not shown are inserted, on the circumferential center line between the adjacent horizontal rigid members 20. Grounding lugs 12 are formed on the outer peripheral surface of the road belt main body 10 at positions corresponding to the lateral rigid members 20, respectively.

The lateral rigid member 20 is provided with a pair of wheel running guide protrusions 22 that are opposed in the width direction at the center of the base 21 and protrude inward from the inner circumferential surface of the track belt main body 10. An engaging portion 23 with which the tooth bottom of the drive wheel engages is provided at the center portion of the base portion 21 held between the guide projections 22.

The tensile member 30 of this elastic endless track belt consists of the track belt main body 10
Since it is a member that suppresses elongation in the zero circumferential direction, the tensile member 3
The end portions 31 and 32 on both sides to which 0 is joined in an endless manner are required to have sufficient joint strength against elongation in the circumferential direction.
As disclosed in Japanese Patent No. 6336, the tensile member 30
The both side end portions 31 and 32 of the track belt main body 1 are made to overlap each other by a circumferential length L in the thickness direction of the rubber substance over a plurality of horizontal rigid members 20 that make noise.
It is vulcanized and bonded together with 0.

[Problems to be Solved by the Invention] In an elastic endless track band in which the image-side end portions 31 and 32 of the tensile member 30 are joined by overlapping each other, the tensile member 30 Since the rigidity of the joint part 33 of the tensile member 30 is much higher than that of other parts, when the joint part 33 of the tensile member 30 is wrapped around the drive wheel and the guide wheel, the smoothness of the running condition is impaired. In addition to the drive torque increasing dramatically, the lateral rigid member 20 may fall off from the drive wheel, and furthermore, the lateral rigid member 20 may break due to stress concentration, or an accident may occur where the tensile member 30 is cut. , which causes harmful vibrations when the vehicle is running.

In addition, at the portion where the track belt main body 10 is connected to the drive wheel and the guide wheel, as shown in FIG. The elongation is restrained by the end portion 32 and the lateral rigid member 20, resulting in a wavy shape, so that both end portions 31, 32 of the tensile member 30
However, there is a problem in that it peels off due to wrinkles that occur between it and the rubber substance.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide an elastic endless track band in which the rigidity of the track band main body at the joint portion of tensile members is reduced.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides transversely rigid members extending in the width direction arranged at regular intervals in the circumferential direction in an endless track band main body made of rubber substance. and a plurality of tensile members arranged in parallel in the circumferential direction surrounding the outer circumferential side of the horizontally rigid member are integrally vulcanized and bonded. Of some or all of the end portions on both sides of the tensile members that are opposed to each other,
The end portion on one side and the corresponding end portion on the other side are twisted together one thread or a plurality of threads and joined together in a rope-like bundle.

[Embodiment] FIGS. 1 to 3 show an embodiment in which the present invention is applied to the elastic endless track belt shown in FIGS. 4 and 5.

The constituent members of the elastic track belt in this embodiment are the same as those shown in FIGS. 4 and 5 described above, so each constituent member will be described using the same reference numerals, but the structure other than the gist will be explained as follows. Identical parts should be given the same reference numerals.
The explanation will be omitted.

FIG. 1 shows a binding portion 34 in which both end portions 31 and 32 of the tensile member 30 are twisted and joined, in a cross section along the circumferential direction of the track belt main body 10, and FIG. A cross section in the width direction along line A-A in FIG. 1 is shown in the left half, and a cross section in the width direction along line B-B in FIG. 1 is shown in the right half.

In the track belt main body 10 shown in the above figure, 30 tensile members 30 are arranged on both sides of the horizontal rigid member 20 in the width direction, and all of the end portions 3132 on both sides of the tensile members 30 are arranged in the corresponding direction. Three bundles 34 are arranged in parallel in each row, each of which is twisted around a separately prepared core material 36 and joined into ten six-strand ropes.

With this configuration, the rigidity of the track belt main body IO at the binding portion 34 of the tensile member 30 is lowered compared to that of the conventional Ohara slab structure.

FIG. 3 is a plan view showing an example of the form in which both end portions of the tensile member are twisted together.

In the track belt main body 10 shown in the above figure, 24 tensile members 30 are arranged in the circumferential direction on one side in the width direction of the lateral rigid member 20.
An end portion 31 on one side of the tensile member 30 that is opposed and abutted against each other in the circumferential direction, and a corresponding end portion 3 on the other side
2, eight rope-like binding parts 34 are arranged in parallel, with each three threads twisted around another core material 36 (the core material 36 shown overlaps with the tensile member 30). ing.).

The length in the circumferential direction (twist length) of the bundled portion 34 of the tensile member 30 is equal to or longer than the arrangement pinch P of the lateral rigid member 20, and the length of the bundled portion 34 is equal to or greater than the twisting start point and end point of the bundled portion 34. Each corresponding end 35a35b is arranged on the plane projection area of the lateral rigid member 20.

Also, the twisting pins 1,000 P2 at both end portions 31 and 32 of the tensile member 30! Secondly, this should be equal to or smaller than the arrangement pitch P1 of the lateral rigid members 20. With this configuration, the twist of the binding portion 34 of the tensile member 30 is not unraveled by the lateral rigid member 20 at the portion where the track belt main body IO is wound around the drive wheel and the guide wheel.

Furthermore, regarding the direction of twisting of the both end portions 31 and 32 of the tensile member 300, Z-twist and S-twist are used for each binding portion 34.
They are arranged in a combination of alternating twists. With this configuration, twisting of the track belt main body 10 can be suppressed.

Further, the core material 36 inserted into the center of the bundled portion 34 of the tensile member 30 extends an appropriate length in the circumferential direction from the position of each end 35a, 35b of the bundled portion 34.

With this configuration, each end 35a, 35b of the binding portion 34 of the tensile member 30 does not protrude outward,
Separation from the rubber substance of the track belt main body 10 can be prevented.

The above-mentioned core material 36 is suitably a synthetic fiber rope coated with rubber, but instead of this core material 36, each end portion 31, 32 of the tensile member 30 itself may be used as the core material.

In addition, regarding the length of the twist between the end portion 31 on one side and the end portion 32 on the other side of the tensile member 30, the starting point of the twist is determined without making all the threads to be twisted the same length. The number of threads may be gradually reduced and twisted together as the tensile member 30 reaches the end point.
Since the rigidity of the track belt main body 10 at the binding portion 34 gradually changes in the circumferential direction, it is useful for stability and vibration prevention when the vehicle is running.

Moreover, each end 35a, 3 of the binding portion 34 of the tensile member 30
5b in the circumferential direction, in addition to arranging them on the straight line in the width direction of the track belt main body 10 as shown in the figure, the positions of the respective end portions 35a and 35b of each binding portion 34 are aligned in the circumferential direction. They may be shifted back and forth, and the lengths of the twists of the bundled portions 34 may not all be the same length, but may be different lengths. In this case, similar to the case where the number of twists in both end portions 31 and 32 of the tensile member 30 is gradually reduced between the twist start point and the end point, the number of twists in the binding portion 34 is reduced. The rigidity of the track belt main body 10 is relaxed.

In addition, the entire circumferential direction of the bundled portion 34 of the tensile member 30, or the inner peripheral side between the front and rear portions in the circumferential direction including each end 35a, 35b of the bundled portion 34 with the horizontal rigid member 20, or the outer peripheral side, A reinforcing layer of cloth or cord may be placed on both the inner and outer circumferential sides of the rib cage (if configured in this way,
A more effective function is obtained in preventing the ends 35a, 35b of the binding portion 34 of the tensile member 30 from springing out and separating from the rubber substance.

In the embodiment, both ends 31, 32 of the tensile member 30
Although the illustration shows a case where the binding portion 34 is constructed by twisting all of the tensile members 30, the present invention is not limited to such a case.
The two side end portions 31 and 32 of the two are twisted together, and the part of both side end portions 3132 can be formed into a conventional Ohara joint structure or any other arbitrary joint structure.

Further, regarding the number of twists of the end portions 31 and 32 on both sides of the tensile member 30, it is not necessarily necessary to set the number of twists to 6 twists of 3 twists each as in the above embodiment, for example, each end portion 31.
It is easy to twist only one thread of 32 without adding a core material,
In addition, any number of threads may be selected and twisted together.

[Effects of the Invention] As explained above, according to the present invention, the terminal portion on one side of the tensile member and the corresponding terminal portion on the other side are twisted together one thread or a plurality of threads, Since the structure is such that the parts are joined together in a rope-like manner, the rigidity of the track belt main body at the part where the tensile members are tied is reduced, and even when this part is wrapped around the drive wheel and the guide wheel,
Vehicle running becomes stable, a sudden increase in drive torque is suppressed, the state of engagement of the lateral rigid member with the drive wheel is ensured, and stress concentration at the wrapping part is alleviated. Therefore, breakage of the lateral rigid member and breakage of the tensile member do not occur, and it is possible to prevent vibrations caused by these while the vehicle is running.

Further, according to the present invention, when the binding portion of the tensile member of the track belt main body is wrapped around the drive wheel and the guide wheel, the expansion of the binding portion of the tensile member is not restricted.
An elastic endless track belt with high durability and excellent running stability of a vehicle can be obtained without causing wrinkles in the binding portion of the tensile member or peeling from the rubber substance.

[Brief explanation of the drawing]

FIG. 1 is a circumferential cross-sectional view showing an embodiment of the present invention, and FIG.
In the figure, the left half is a cross-sectional view taken along the line A-A in Figure 1, the right half is a cross-sectional view taken along the line B-B in Figure 1, and Figure 3 is a plane showing an example of twisting of the bundled portion of the tensile member. Figure 4 is a circumferential cross-sectional view showing the joint part of a conventional tensile member, and Figure 5 shows the left half of the fourth
The right half of the figure is a cross-sectional view taken along the line I--A in FIG. 4, and FIG. 6 is an explanatory diagram showing the load state at the winding portion of a conventional elastic endless track belt. In the figure, 10 is the track belt main body, 20 is a lateral rigid member, 30 is a tensile member, 31.32 is an end portion on both sides of the tensile member, 34 is a binding part of the tensile member, 36 is a core material, and Pl is a lateral member. P2, the arrangement pitch of the rigid member, is the twisting pitch of the end portions on both sides of the tensile member. ” ~ 3 Snow

Claims (4)

[Claims] (1) Inside the endless track belt main body made of rubber substance, there are horizontally rigid members extending in the width direction arranged at regular intervals in the circumferential direction, and horizontally rigid members that surround the outer peripheral side of the horizontally rigid members and are arranged in parallel in the circumferential direction. In an elastic endless track band formed by integrally vulcanizing and adhering a plurality of tensile members arranged in the same manner, a portion of both end portions of the tensile members facing each other in the circumferential direction of the track band main body or An elastic endless track belt characterized in that a terminal part on one side and a corresponding terminal part on the other side are twisted together one thread or a plurality of threads and joined together in a rope-like state. . (2) The elastic endless track belt according to claim 1, wherein the twisting pitch of both end portions of the tensile members is equal to or less than the arrangement pitch of the lateral rigid members. (3) The elastic endless track according to claim 1 or 2, in which binding portions in which the twist direction of both end portions of the tensile member is Z-twist and binding portions that are S-twist are arranged in alternating combinations. band. (4) Both end portions of the tensile member are twisted around a core material other than the tensile member, which is arranged so as to extend forward and backward in the circumferential direction from the position of the binding portion. or third
The elastic track belt according to any of the paragraphs.