JP2003267276A - Elastic crawler and crawler type traveling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve straight traveling stability by reducing twist at a wound-up part in an elastic crawler having plural layers of bias cords inclining in different directions against a crawler circumference direction embedded in a crawler body formed in an endless shape of rubber-like elastic body in addition to a main cord. <P>SOLUTION: Bias cord 8 having cords 8a inclining against the crawler circumference direction provided in parallel and another bias cord 9 arranged in a crawler outer circumference side of the bias cord 8 and having cords 9a inclining in a reverse direction to that of the bias cord 8 provided in parallel are embedded in a crawler body 2 in a crawler outer circumference side D of a rough center F in a thickness direction E. Bending stiffness of the bias cord 9 in outer circumference side of the crawler is lower than that of the bias cord 8 in an inner circumference side of the crawler. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic crawler used for a crawler type traveling device (trackless traveling device) used in a traveling portion of an automobile, an agricultural machine such as a combine or a tractor, or a construction machine such as a backhoe. The present invention relates to a crawler type traveling device.

[0002]

2. Description of the Related Art A crawler type traveling device has a crawler unit mainly constituted by winding an endless belt-shaped crawler belt (crawler belt) around, for example, a driving wheel, an idler (driven wheel) and a plurality of rolling wheels. The crawler belt is circularly circulated in the circumferential direction by rotating the driving wheels, and the crawler belt is thereby driven. As the crawler belt, there is an elastic crawler whose main body portion is formed of a rubber-like elastic body, and as this elastic crawler, there is a core bar-less elastic crawler.

In this coreless elastic crawler,
In the endless belt-shaped crawler body that constitutes the body portion, a main cord made of steel cord or the like arranged in the circumferential direction is embedded, and in addition to this main cord, in order to increase lateral rigidity, for example, A bias cord in which cords inclined with respect to the crawler circumferential direction are arranged side by side on the crawler outer peripheral side of the main cord in the crawler body, and the bias cord is arranged on the crawler outer circumferential side of the bias cord. And another bias cord formed by arranging cords in the opposite tilt direction side by side.

[0004]

In the elastic crawler, when the elastic crawler is wound around a drive wheel or an idler, among the bias cords arranged on the outer peripheral side of the crawler of the main cord, the bias on the inner peripheral side of the crawler is used. There is a problem that the bias cord on the outer peripheral side of the crawler has a higher tensile force than the cord, which causes twisting and deteriorates straightness. In order to solve this problem, there is a one-layer bias cord laminated on the main cord, which is formed by combining a plurality of cords having mutually opposite cord angles in the same plane. Then, there is a problem in that, when the vehicle runs on a rough road, due to the unevenness of the road surface, cracks are generated at the boundary surface between adjacent cords having opposite cord angles.

Further, in the above-mentioned bias cord, in the abutting portion of adjacent cords having opposite cord angles, an edge portion of one cord is overlapped with an edge portion of the other cord. As a result, the rigidity of only the lapped portion is increased, and the tension at the time of bending is concentrated on the lapped portion to generate heat, which causes a problem that the bias cord is peeled off. In view of the above problems, the present invention is an elastic crawler in which, in addition to the main cord, a plurality of layers of bias cords having different inclination directions with respect to the crawler circumferential direction are embedded in the crawler body, and twisting in the winding portion is prevented. The objective is to reduce the amount and to improve straightness.

[0006]

The technical means taken by the present invention to solve the technical problems is provided with a crawler main body formed in the shape of an endless belt by a rubber-like elastic body, and the thickness inside the crawler main body. A bias cord formed by juxtaposing cords inclined with respect to the crawler circumferential direction from the approximate center of the direction to the crawler outer circumferential side, and arranged on the crawler outer circumferential side of the bias cord, and in the crawler circumferential direction of the bias cord. Embedded with another bias cord formed by arranging cords in the inclination direction with respect to the crawler circumferential direction opposite to the inclination direction with respect to the crawler, and the bending rigidity of the bias cord on the outer peripheral side of the crawler is higher than that of the bias cord on the inner peripheral side of the crawler. It is characterized by being made smaller.

Further, by making the inclination angle of the bias cord on the outer peripheral side with respect to the crawler circumferential direction larger than the inclination angle of the bias cord on the inner peripheral side with respect to the crawler circumferential direction, the bending rigidity of the bias cord on the outer peripheral side of the crawler is kept within the crawler. It can be made smaller than the bias code on the circumference side. Another technical means includes a crawler main body formed of a rubber-like elastic body in an endless belt shape, and a cord inclined from the substantial center in the thickness direction inside the crawler main body to the crawler outer circumferential side with respect to the crawler circumferential direction. In addition to embedding the bias cords arranged in parallel, the cords are arranged in parallel in the inclination direction opposite to the inclination direction of the bias cords from the approximate center in the thickness direction inside the crawler body to the inner peripheral side of the crawler. With the bias cord embedded, the bending stiffness of the bias cord with the larger force of the compressive force acting on the bias cord on the inner circumference side of the crawler and the tensile force acting on the bias cord on the outer circumference side of the crawler is determined by the other bias cord. It is characterized in that it is made smaller than.

Further, the bending rigidity can be made different by changing the cord diameters of the bias cord on the inner peripheral side and the bias cord on the outer peripheral side. Further, the bending rigidity can be made different by changing the material of the cords of the bias cord on the inner peripheral side and the bias cord on the outer peripheral side. Further, the bending rigidity can be made different by changing the ends of the cords of the inner peripheral bias cord and the outer peripheral bias cord.
Another technical means is to provide a pair of left and right crawler units formed by wrapping an endless belt-shaped elastic crawler over a drive wheel and an idler, and the elastic crawler is formed by a rubber-like elastic body in an endless belt shape. In the crawler body, a main cord formed of cords arranged along the crawler circumferential direction and a bias cord formed by juxtaposing cords inclined with respect to the crawler circumferential direction are embedded. It is characterized in that the elastic crawlers have opposite left and right twisting characteristics so as to cancel out the twists generated in the wound portions of the elastic crawlers.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of the present invention. FIG. 1 is a view showing a cross section in a width direction B of an elastic crawler 1 used in a crawler type traveling device, and FIG. It is a bottom surface sectional view of the important section of a crawler.
The crawler type traveling device includes a drive wheel, an idler, and a plurality of rolling wheels. The elastic crawler 1 is wound around the driving wheel, the idler, and the rolling wheel to drive the driving wheel. By rotating, the elastic crawler 1 circulates in the circumferential direction.

The elastic crawler 1 is, for example, a high speed 4
Crawler car (Ommusubi type crawler type traveling device (crawler unit) is used instead of the front and rear tires of a four-wheel drive vehicle.
This is an elastic crawler 1 without a cored bar (no cored bar) that is adopted in a vehicle in which wheels are mounted independently, etc., and has a crawler main body 2 formed of a rubber-like elastic body in an endless belt shape. A lug 3 is integrally provided on the outer peripheral side D of the crawler body 2, and a drive protrusion 4 is integrally provided on the inner peripheral side C at the center of the crawler width direction B (horizontal direction). 3 and the drive protrusion 4 are arranged at appropriate intervals in the crawler circumferential direction A.

By engaging the engaging portion 5a of the driving wheel 5 with the driving projection 4, the driving force is transmitted from the driving wheel 5, and the driving projection 4 is driven by the driving wheel 5. , And has a function of engaging with idlers and rolling wheels to prevent wheel loss (disengagement of elastic crawler 1). A main cord 7 and a plurality of layers of bias cords 8 and 9 are embedded in the crawler body 2. The main cord 7 is composed of tensile strength cords 7a such as steel cords arranged along the crawler circumferential direction A and arranged in parallel in the crawler width direction B.

The bias cords 8 and 9 are constructed by arranging (arranged in parallel) cords 8a and 9a inclined with respect to the crawler circumferential direction A. Further, the inclination direction of the cord 9a of the bias cord 9 located on the outer side D of the crawler is different from the inclination direction of the cord 8a of the bias cord 8 located on the inner peripheral side C of the crawler (this is referred to as the bias cord on the inner peripheral side). However, when viewed from the crawler thickness direction E, the cord 8a of the bias cord 8 on the inner peripheral side and the cord 9a of the bias cord 9 on the outer peripheral side are provided so as to intersect with each other. If the inclination angle of the inner bias cord 8 with respect to the crawler circumferential direction A (with respect to the equator) (the cord angle α1) is a positive angle, the outer bias cord 9 is inclined with respect to the crawler circumferential direction A (with respect to the equator). The angle (code angle α2) is a negative angle (reverse code angle).

Therefore, in the portion where the elastic crawler 1 is wound around the drive wheel 5 and the like, the twist generated in the bias cord 8 on the inner peripheral side is suppressed (cancelled) by the bias cord 9 on the outer peripheral side. . The bias cord 8 on the inner peripheral side and the bias cord 9 on the outer peripheral side are arranged on the crawler outer peripheral side D with respect to the center F of the crawler body 2 in the crawler thickness direction E. By the way, in the portion where the elastic crawler 1 is wound around the drive wheel 5 or the like, a tensile force acts on the crawler outer peripheral side D rather than the center F of the crawler main body 2 in the crawler thickness direction E, and the crawler main body 2 crawler thickness. A compressive force acts on the inner peripheral side C of the crawler with respect to the center F in the depth direction E.

Therefore, in the example shown in the figure, in the portion where the elastic crawler 1 is wound around the drive wheel 5 and the like, the tension force of the bias cord 9 on the outer peripheral side is higher than that of the bias cord 8 on the inner peripheral side. Twisting occurs due to the difference in tensile force between the inner peripheral side bias cord 8 and the outer peripheral side bias cord 9, but in the present embodiment, with respect to the cord angle α1 of the inner peripheral side bias cord 8. By increasing the cord angle α2 of the bias cord 9 on the outer peripheral side, the bending rigidity of the bias cord 9 on the outer peripheral side is made smaller than that of the bias cord 8 on the inner peripheral side.

As a result, it is possible to reduce the twist caused by the difference in tensile force between the inner peripheral side bias cord 8 and the outer peripheral side bias cord 9 and to improve the straight running property. Also,
By making the bending rigidity of the bias cord 9 on the outer peripheral side smaller than that of the bias cord 8 on the inner peripheral side, the bending rigidity in the wound portion is reduced, and the bending resistance of the elastic crawler can be reduced. In the elastic crawler 1 having the above-described structure, the bias cord 8 on the inner peripheral side may be located at the center F of the crawler body 2 in the thickness direction E, and the main cord 7 may be located in the thickness direction of the crawler body 2. It may be located at E center F.

The bias cords 8 and 9 may be arranged on the inner peripheral side C of the crawler with respect to the main cord 7, and the bias cord 8 is arranged on the inner peripheral side of the crawler of the main cord 7. The bias cord 9 may be arranged on the outer peripheral side of the crawler of the main cord 7.
Further, in the above embodiment, the bias cords 8 and 9 are
The case where the crawler body 2 is provided on the outer peripheral side of the center F in the thickness direction E has been described as an example.
However, in the case where the elastic crawler 1 is provided on the inner peripheral side of the center F in the thickness direction E of the crawler body 2,
Since the compressive force of the bias cord 8 on the inner circumference side becomes higher than that of the bias cord 9 on the outer circumference side in the portion wound around the same, the bending rigidity of the bias cord 8 on the inner circumference side in this case. Is configured to be smaller than the bias cord 9 on the outer peripheral side.

Further, the bias cord 8 is the crawler body 2
When the bias cord 9 is provided on the inner peripheral side of the center F of the thickness direction E and on the outer peripheral side of the center F of the crawler body 2 in the thickness direction E, the bias cord 8 on the inner peripheral side is provided.
Is compared with the tensile force acting on the bias cord 9 on the outer peripheral side, and the bending stiffness of the bias cord having the larger force is configured to be smaller than that of the other bias cords. 3 to 5 show another means for making the bending stiffnesses of the bias cord 8 on the inner circumference side and the bias cord 9 on the outer circumference side different, and the arrangement configuration of the main cord 7 and the bias cords 8 and 9 is as follows. This is the same as the above embodiment.

In FIG. 3, the bending diameters of the bias cords 8 and 9 are made different from each other so that the bending rigidity is different. The cord diameter of the bias cord 9 on the outer peripheral side is the same as that of the bias cord on the inner peripheral side. By making the cord diameter smaller than the cord diameter of the cord 8, the rigidity is different. FIG. 4 shows that the bending rigidity is made different by changing the material of the cords 8a and 9a of the bias cords 8 and 9.
For example, the cord 8a of the bias cord 8 on the inner peripheral side is formed of a steel cord, and the bias cord 9 on the outer peripheral side is formed.
By configuring the cord 9 a of Nylon 6 or Nylon 66, the rigidity is different.

FIG. 5 shows that the bending rigidity is made different by changing the ends (number of driving) of the cords 8a, 9a of the bias cord 8 on the inner peripheral side and the bias cord 9 on the outer peripheral side. By making the end of the bias cord 8 on the inner circumference side larger than the end of the bias cord 9 on the outer circumference side, the rigidity is made different. By appropriately combining the means for making a difference in bending rigidity of the bias cords shown in FIGS. 2 to 5, the bias cords 8 and 9 on the inner and outer circumferences have a difference in rigidity, thereby reducing twisting and bending. The rigidity may be reduced.

FIGS. 6 and 7 relate to a crawler type traveling device according to another embodiment, and FIG. 6 shows a crawler unit U which constitutes the crawler type traveling device. The drive wheels 5 are arranged on the upper part of the above, and a plurality of rolling wheels 11 are arranged on the lower part between the idlers 10. This crawler unit U is, for example, 4
The crawler type traveling device according to the present embodiment, which is used in place of the left and right front and rear wheels, the left and right rear wheels, and the left and right front wheels, includes at least one pair of the crawler units U.

In this embodiment, the elastic crawlers 1 employed in the left and right crawler units U are basically constructed in the same manner as in the above-mentioned embodiments, and the main cord 7 is provided inside the crawler body 2. 2 layers of bias cord 8,
9 is different from the elastic crawler 1 in that the left and right crawler units U are formed so that the torsional characteristics of the elastic crawlers 1 are opposite to each other. By providing the left and right elastic crawlers 1
The twists generated in 1 are canceled by each other, and the straightness of the crawler type traveling device can be improved.

In the embodiments shown in FIGS. 6 and 7, at least one bias code is sufficient. Further, the crawler unit U may be of another type (for example, one having a plurality of rolling wheels between a drive wheel and an idler which are separated in the front-rear direction), and at least the crawler unit U may be used. It suffices to have a pair of left and right. In FIG. 8, the outer peripheral side bias cord 9 is brought closer to the inner peripheral side bias cord 8 so that the distance a between the main cord 7 and the inner peripheral side bias cord 8> the distance b between the bias cords 8 and 9. Bias cord 9 on the outer peripheral side
Is made closer to the bias cord 8 on the inner peripheral side to reduce the tensile force acting on the bias cord 9 on the outer peripheral side, thereby reducing the twist.

Incidentally, a tread pattern (lug pattern) that cancels the twist generated by the bias cord.
It is also possible to reduce the twist.

[0024]

EFFECTS OF THE INVENTION A bias cord formed by juxtaposing cords inclined with respect to the crawler circumferential direction from the approximate center of the crawler body in the thickness direction to the crawler outer circumferential side, and the bias cord is disposed on the crawler outer circumferential side. In the case of embedding another bias cord formed by arranging cords in a tilting direction opposite to the biasing direction of the bias cord, the bending rigidity of the bias cord on the outer peripheral side of the crawler is increased by the inner periphery of the crawler. By making the bias cord smaller than the side bias cord, it is possible to reduce the twist generated by the bending of the wound portion of the elastic crawler and improve the straightness.

Further, by making the inclination angle of the bias cord on the outer peripheral side with respect to the crawler circumferential direction larger than the inclination angle of the bias cord on the inner peripheral side with respect to the crawler circumferential direction, the bending rigidity of the bias cord on the outer peripheral side of the crawler is kept within the crawler. It can be made smaller than the bias code on the circumference side. In addition, a bias cord formed by arranging cords that are inclined with respect to the crawler circumferential direction from the approximate center of the crawler body in the thickness direction to the outer peripheral side of the crawler body is embedded. On the circumference,
In a case where another bias cord formed by arranging cords in the inclination direction opposite to the inclination direction of the bias cord is embedded, a compressive force acting on the bias cord on the inner peripheral side of the crawler and the outer peripheral side of the crawler are formed. Of the tensile force that acts on the bias cord of No. 2, the bending stiffness of the bias cord with the larger force is set to be smaller than that of the other bias cord, so that the twist generated by the bending of the wound portion of the elastic crawler is prevented. It can be reduced and the straightness can be improved.

Further, the bending rigidity can be made different by changing the cord diameters of the bias cord on the inner peripheral side and the bias cord on the outer peripheral side. Further, the bending rigidity can be made different by changing the material of the cords of the bias cord on the inner peripheral side and the bias cord on the outer peripheral side. Further, the bending rigidity can be made different by changing the ends of the cords of the inner peripheral bias cord and the outer peripheral bias cord.
In addition, a pair of left and right crawler units, which are formed by winding endless belt-shaped elastic crawlers around the drive wheels and the idler, are provided. A main cord constituted by cords arranged along the direction and a bias cord formed by arranging cords inclined with respect to the crawler circumferential direction are embedded, and the left and right elastic crawlers are the elastic crawlers. The straightness can be improved by having the opposite twisting characteristics on the left and right so that the twists generated in the winding portions of the two can be canceled out by each other.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an elastic crawler in a width direction.

FIG. 2 is a bottom cross-sectional view of a main part of an elastic crawler.

FIG. 3 is a bottom sectional view of a main part of an elastic crawler.

FIG. 4 is a bottom cross-sectional view of a main part of an elastic crawler.

FIG. 5 is a bottom cross-sectional view of a main part of an elastic crawler.

FIG. 6 is a side view of the crawler unit.

FIG. 7 is a bottom cross-sectional view of the main parts of the elastic crawlers of the left and right crawler units.

FIG. 8 is a cross-sectional view in the width direction of a main part of the elastic crawler.

[Explanation of symbols]

1 elastic crawler 2 crawler body 5 drive wheels 8 bias code 8a code 9 Bias code 9a code 10 idlers A crawler circumferential direction D crawler outer peripheral side E Crawler thickness direction F Crawler thickness direction center U crawler unit α1 inclination angle (code angle) α2 inclination angle (code angle)

Claims (7)

[Claims] 1. A crawler main body formed of a rubber-like elastic body in an endless band shape, wherein cords inclined with respect to the crawler circumferential direction are arranged in parallel from the approximate center of the crawler main body in the thickness direction to the outer side of the crawler. It is arranged on the outer side of the crawler of this bias cord and this bias cord,
Further, by embedding another bias cord formed by arranging cords in the inclination direction with respect to the crawler circumferential direction opposite to the inclination direction with respect to the crawler circumferential direction of the bias cord, the bending rigidity of the bias cord on the outer peripheral side of the crawler is improved. An elastic crawler characterized by being made smaller than the bias cord on the inner peripheral side of the crawler. 2. The elastic crawler according to claim 1, wherein an inclination angle of the bias cord on the outer peripheral side with respect to the crawler circumferential direction is larger than an inclination angle of the bias cord on the inner peripheral side with respect to the crawler circumferential direction. 3. A crawler main body formed of a rubber-like elastic body in an endless belt shape, and cords inclined in relation to the crawler circumferential direction are arranged in parallel from the approximate center in the thickness direction within the crawler main body. The bias cord is embedded, and another bias cord is formed by arranging the cords in the inclination direction opposite to the inclination direction of the bias cord in parallel from the approximate center of the crawler body in the thickness direction to the inner circumferential side of the crawler. However, of the compressive force acting on the bias cord on the inner circumference side of the crawler and the tensile force acting on the bias cord on the outer circumference side of the crawler, the bending stiffness of the bias cord having the larger force is made smaller than that of the other bias cord. An elastic crawler characterized by the above. 4. The bending rigidity is made different by changing the cord diameters of the bias cord on the inner peripheral side and the bias cord on the outer peripheral side.
Elastic crawler according to. 5. The elastic crawler according to claim 1 or 3, wherein the bending stiffness of the bias cord on the inner peripheral side is different from that of the bias cord on the outer peripheral side by changing the material of the cord. 6. The bending rigidity of the bias cord on the inner peripheral side and the bias cord on the outer peripheral side are changed by changing the ends of the cords.
Or the elastic crawler according to 3. 7. A left and right pair of crawler units each having an endless belt-like elastic crawler wound around a drive wheel and an idler, the elastic crawler being provided in a crawler body formed of a rubber-like elastic body in an endless belt shape. , A main cord composed of cords arranged along the crawler circumferential direction, and a bias cord formed by juxtaposing cords inclined with respect to the crawler circumferential direction are embedded, and the left and right elastic crawlers, A crawler type traveling device characterized by having opposite twisting characteristics on the left and right so as to cancel out the twists generated in the wound portion of the elastic crawler.