JP2021011128A - Elastic crawler - Google Patents

Abstract

To inhibit derailment attributable to bend or distortion while suppressing an increase in the weight of a core material.SOLUTION: An elastic crawler 1 has a core material 3 and a tension body 4 which is formed with a cord 11 extending in a crawler circumferential direction X through a crawler outer periphery Zo beyond the core material 3, the core material and the tension body being embedded in a crawler body 2. The core material 3 includes derailment prevention projections 8 that jut out in the crawler circumferential direction from flanks S on one side in the crawler circumferential direction X of a core material substance 7 and on the other side respectively. A crawler outer peripheral part 12 of the derailment prevention projection 8 includes a part 12a protruding toward the crawler outer periphery beyond the tension body 4.SELECTED DRAWING: Figure 3

Description

The present invention relates to an end band-shaped elastic crawler in which a core material is provided with a derailment prevention protrusion protruding in the circumferential direction of the crawler.

Conventionally, an elastic crawler in which a plurality of core materials and a tension body are embedded in a crawler body made of an elastic body such as rubber has been known. The core material functions as a reinforcing material in the crawler width direction, and is arranged at intervals in the crawler circumferential direction. Further, the tension body functions as a reinforcing material in the crawler circumferential direction, and is composed of a cord extending in the crawler circumferential direction through the crawler outer peripheral side from the core material.

In this type of elastic crawler, lateral displacement (deviation in the crawler width direction) is likely to occur between adjacent core materials. Then, due to the lateral displacement, the rolling wheel on the vehicle body side comes off from the guide protrusion on the core material side, causing a problem that the wheel is removed.

In Patent Document 1 below, in order to prevent derailment, the core material may be provided with a pair of first protrusions protruding on one side in the circumferential direction of the crawler and a pair of second protrusions protruding on the other side. Has been described. In this elastic crawler, the first protrusion of the core material on one side adjacent to each other in the circumferential direction of the crawler overlaps the second protrusion of the core material on the other side on the outside in the crawler width direction, so that lateral displacement between the core materials is suppressed. To.

Japanese Unexamined Patent Publication No. 2019-93878

However, if bending or twisting occurs between adjacent core materials due to an external force acting when riding on or turning a protrusion, the engagement between the first protrusion and the second protrusion is disengaged and the wheel is removed. May occur.

As a countermeasure against derailment caused by such bending and twisting, it is proposed to increase the size of the first protrusion and the second protrusion, but there is still room for improvement such as an increase in the weight of the core material. There is.

An object of the present invention is to provide an elastic crawler capable of suppressing derailment due to bending, twisting, etc., while suppressing an increase in the weight of the core material.

The present invention includes an endless band-shaped crawler body made of an elastic body and
A core material that is embedded in the crawler body at intervals in the circumferential direction of the crawler and is made of a material that is harder than the elastic body.
An elastic crawler that is embedded in the crawler body and includes a tension body made of a cord that is embedded in the crawler body and extends in the circumferential direction of the crawler through the outer peripheral side of the crawler from the core material.
The core material is
The core material body that extends in the crawler width direction and
The core material body includes a derailment prevention protrusion protruding in the crawler circumferential direction from one side and the other side surface in the crawler circumferential direction.
The crawler outer peripheral side portion of the derailment prevention protrusion includes a portion that projects toward the crawler outer peripheral side with respect to the tension body.

In the elastic crawler according to the present invention, the distance Lz in the crawler thickness direction between the center J1 of the derailment prevention protrusion in the crawler thickness direction and the center J2 of the tension body in the crawler thickness direction is the derailment prevention. It is preferably 1/2 or less of the height h in the crawler thickness direction of the protrusion.

In the elastic crawler according to the present invention, it is preferable that the crawler outer peripheral side portion of the derailment prevention protrusion includes an extension portion that rises from the crawler outer peripheral side surface of the core material main body and extends along the crawler circumferential direction.

In the elastic crawler according to the present invention, the extension portion preferably has a crawler circumferential length from the side surface of the core material body of 50 to 60% of the crawler circumferential width of the core material main body.

In the elastic crawler according to the present invention, the derailment prevention protrusions are a pair of first derailment prevention protrusions on both sides in the crawler width direction protruding from one side surface of the core material body, and the other side of the core material body. Including a pair of second derailment prevention protrusions on both sides of the crawler width direction protruding from the side surface of the crawler.
Each of the first derailment prevention protrusions of the core material on one side adjacent to each other in the crawler circumferential direction overlaps with each of the second derailment prevention protrusions of the core material on the other side on the outside in the crawler width direction. Is preferable.

In the elastic crawler according to the present invention, the inward surface of the first derailment prevention protrusion in the crawler width direction and the outward surface of the second derailment prevention protrusion in the crawler width direction are the crawler width direction and the outward surface, respectively. It is preferably composed of right-angled surfaces.

In the elastic crawler according to the present invention, the outward surface of the first derailment prevention protrusion in the crawler width direction is a V-shaped surface convex toward the outside in the crawler width direction, and the second derailment prevention protrusion. The inward facing surface in the crawler width direction preferably consists of a V-shaped surface that is convex inward in the crawler width direction.

In the elastic crawler according to the present invention, the outward surface of the first derailment prevention protrusion in the crawler width direction is an arc surface that is convex outward in the crawler width direction, and the crawler width of the second derailment prevention protrusion. The inward facing surface in the direction preferably consists of an arcuate surface that is convex inward in the crawler width direction.

In the elastic crawler according to the present invention, the core material includes a pair of guide protrusions on both sides in the crawler width direction protruding from the inner peripheral side surface of the crawler of the core material body, and the first derailment prevention protrusion is the said. It is preferably located inside the crawler width direction rather than the crawler width direction outer surface of the guide protrusion.

In the core material according to the present invention, in the derailment prevention protrusions protruding from one side and the other side of the crawler peripheral direction of the core material body, the crawler outer peripheral side portion of the derailment prevention protrusion is larger than the tension body. Includes a part that overhangs the outer circumference of the crawler. That is, the tension body passes through the central side of the derailment prevention protrusion in the crawler thickness direction.

Here, when bending or twisting occurs between the core members of the elastic crawler, the tension body is not stretched, so that the closer to the tension body, the smaller the displacement due to deformation. That is, the range in which the derailment prevention protrusions move in accordance with bending or twisting between the core materials is reduced, and the derailment prevention protrusions are less likely to come off. As a result, it becomes possible to suppress derailment while suppressing an increase in the weight of the core material.

It is a perspective view which shows one Embodiment of the elastic crawler of this invention. It is a perspective view of a core material. It is a front view which shows the half of the core material in the crawler width direction enlarged. (A) is a bottom view of the core material, and (b) is a sectional view taken along line AA. It is a schematic plan view which conceptually shows the arrangement state of a core material. (A) and (b) are cross-sectional views showing an example of the cross-sectional shape of the derailment prevention protrusion. It is a working figure of the derailment prevention protrusion which has a V-shaped surface.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a perspective view of the elastic crawler 1. As shown in FIG. 1, the elastic crawler 1 of the present embodiment is embedded in an endless band-shaped crawler body 2 made of an elastic body such as rubber, a plurality of core materials 3 embedded in the crawler body 2, and a crawler body 2. Including the tension body 4 to be made.

In the present specification, the crawler circumferential direction is the rotation direction of the elastic crawler 1, and corresponds to the direction indicated by the reference numeral X in FIG. Further, the crawler width direction is the axial direction of the drive wheels when the elastic crawler 1 is mounted on the vehicle, and corresponds to the direction indicated by the reference numeral Y in FIG. Further, the crawler thickness direction is a direction orthogonal to the crawler circumferential direction X and the crawler width direction Y, and corresponds to the direction indicated by the reference numeral Z in FIG. In the crawler thickness direction Z, the inside of the endless band-shaped elastic crawler 1 is the crawler inner peripheral side Zi, and the outside is the crawler outer peripheral side Z.

The crawler body 2 has a substantially constant width and extends continuously in the crawler circumferential direction X. A plurality of lugs 5 arranged at intervals in the crawler circumferential direction X project from the surface 2o of the crawler outer peripheral side Z of the crawler main body 2. The lug 5 extends in the crawler width direction Y to improve traction when traveling on rough terrain. On the surface 2i of the crawler inner peripheral side Zi of the crawler main body 2, two rows of protrusions 6 composed of a plurality of protrusions 6a and extending in the crawler circumferential direction X are formed. Drive wheels, idle wheels, rolling wheels, etc. on the vehicle body side are guided between the protruding rows 6 and 6. The protrusion 6a is reinforced by a guide protrusion 10 provided on the core material 3.

The core material 3 functions as a reinforcing material in the crawler width direction Y, and is arranged at intervals in the crawler circumferential direction X. The core material 3 is made of a material that is harder than the elastic body, and as the hard material, for example, a metal material such as steel or cast iron is preferably adopted. The entire core material 3 does not need to be embedded in the crawler body 2, and a part thereof, for example, the guide protrusion 10 may be exposed from the crawler body 2.

FIG. 2 is a perspective view of the core material 3. As shown in FIG. 2, the core material 3 includes a core material main body 7 extending in the crawler width direction Y, and one side of the core material main body 7 in the crawler circumferential direction X, and side surfaces S1 and S2 on the other side, respectively. Includes a derailment prevention protrusion 8 that protrudes toward the surface.

The core material main body 7 includes an engaging portion 7A arranged at the center of the crawler width direction Y and a wing portion 7B arranged on both outer sides of the engaging portion 7A in the crawler width direction Y. The surface of the crawler inner peripheral side Zi of the engaging portion 7A is formed by an arc surface 20 convex to the crawler inner peripheral side Zi so as to mesh with the tooth groove portion of the drive wheel, for example.

The core material 3 includes a pair of guide protrusions 10 and 10 protruding in the crawler thickness direction Z from the surface 7si of the crawler inner peripheral side Z of the core material main body 7. The guide protrusions 10 and 10 stand up on both sides of the engaging portion 7A in the crawler width direction Y. Then, the driving wheel, the floating wheel, and the rolling wheel are sandwiched between the guide protrusions 10 and 10 to guide the guide.

Next, in this example, the derailment prevention protrusions 8 are a pair of first derailment prevention protrusions 8A and 8A projecting from the one side surface S1 and a pair of second derailment prevention projections 8 projecting from the other side surface S2. Includes derailment prevention protrusions 8B and 8B. The pair of first derailment prevention protrusions 8A, 8A are arranged on both sides in the crawler width direction Y at intervals. Further, the pair of second derailment prevention protrusions 8B and 8B are also arranged on both sides in the crawler width direction Y at intervals.

FIG. 5 is a schematic plan view conceptually showing the arrangement state of the core members 3. In FIG. 5, the guide protrusion 10 is omitted. As shown in FIG. 5, the elastic crawler 1, a first derailing prevention protrusion 8A of the core 3 ₁ on one side adjacent the crawler circumferential direction X, the second derailing of the core 3 ₂ on the other side The prevention protrusion 8B is overlapped and engaged with the outside of the crawler width direction Y. Thus, lateral displacement between the core 3 _1, 3 ₂ (deviation of the crawler width direction Y) is suppressed.

As shown in FIG. 2, the tension body 4 is composed of a cord 11 extending in the crawler circumferential direction X from the core material 3 through the crawler outer peripheral side Z. The tension body 4 can be formed, for example, by winding a band-shaped cord array in which a plurality of cords 11 are arranged in the crawler width direction Y in the crawler circumferential direction X. Further, the tension body 4 can be formed by winding one or several cords 11 spirally a plurality of times in the crawler circumferential direction X. The tension body 4 is arranged outside the crawler width direction Y with respect to the first derailment prevention projection 8A.

As the cord 11, a metal cord such as a steel cord can be preferably adopted, but for example, an organic fiber cord such as aramid, polyester, nylon, or polyethylene naphthalate can also be adopted.

FIG. 3 is an enlarged front view showing a part of the core material 3. As shown in FIG. 3, in the present invention, the crawler outer peripheral side portion 12 of the derailment prevention protrusion 8 includes a portion 12a protruding from the tension body 4 to the crawler outer peripheral side Zo.

The crawler outer peripheral side portion 12 is defined as a portion of the derailment prevention protrusion 8 that exceeds the surface 7so of the crawler outer peripheral side Z of the core material main body 7 over the crawler outer peripheral side Zo. Further, the overhanging portion 12a is defined as a portion of the crawler outer peripheral side portion 12 that extends the tension body 4 over the crawler outer peripheral side Zo.

When the derailment prevention protrusion 8 includes the projecting portion 12a in this way, the tension body 4 passes through the central side of the derailment prevention projection 8 in the crawler thickness direction Z.

Here, when bending or twisting occurs between the core members 3 and 3 in the elastic crawler 1, since the tension body 4 is non-stretchable, the closer to the tension body 4, the smaller the displacement due to deformation. That is, the range in which the derailment prevention projection 8 moves in accordance with bending or twisting between the core members 3 and 3 becomes small, and disengagement between the derailment prevention projections 8A and 8B is less likely to occur. As a result, it becomes possible to suppress derailment while suppressing an increase in the weight of the core material.

From this point of view, the distance Lz in the crawler thickness direction between the center J1 of the derailment prevention protrusion 8 in the crawler thickness direction and the center J2 of the tension body 4 in the crawler thickness direction is the distance Lz of the derailment prevention protrusion 8. It is preferably 1/2 or less of the height h in the crawler thickness direction and as small as possible. In this example, the case where the center J1 and the surface 7so are arranged at the same height position is shown. However, the center J1 can be located on the outer peripheral side Zo of the crawler with respect to the surface 7so, and in such a case, the distance Lz can be set to 0.

Further, the closer the derailment prevention protrusion 8 is to the center Cy of the core material body 7 in the crawler width direction, the smaller the amount of deviation of the derailment prevention protrusion 8 in the crawler thickness direction Z due to twisting. As a result, disengagement between the derailment prevention protrusions 8A and 8B is less likely to occur. From such a viewpoint, it is preferable that the first derailment prevention protrusion 8A is located inside the crawler width direction outer surface 10so of the guide protrusion 10 in the crawler width direction. When the outer surface 10so is inclined, the first derailment prevention protrusion 8A is located at the intersection position P between the extension line of the outer surface 10so of the guide protrusion 10 and the extension line of the surface 7si of the core material body 7. , It is preferable to be located inside in the crawler width direction.

FIG. 4A is a bottom view of the core material 3, and FIG. 4B is a cross-sectional view taken along the line AA. As shown in FIGS. 4A and 4B, the crawler outer peripheral side portion 12 of the derailment prevention protrusion 8 rises from the crawler outer peripheral side surface 7so of the core material main body 7 and extends along the crawler circumferential direction X. Includes extension portion 12A.

The extension portion 12A enhances the strength of the derailment prevention protrusion 8 while suppressing an increase in the weight of the core material. In the extension portion 12A, the crawler circumferential length Lx from the side surface S of the core material main body 7 is preferably 50 to 60% of the crawler circumferential width Wx of the core material main body 7. If the length Lx is less than 50% of the width Wx, sufficient strength may not be obtained, and conversely, if it exceeds 60%, the weight of the core material is unnecessarily increased.

6 (a) and 6 (b) show preferable cross-sectional shapes of the first and second derailment prevention protrusions 8A and 8B. As shown in FIGS. 6A and 6B, the inward surface Ai of the first derailment prevention projection 8A in the crawler width direction Y and the outward direction of the second derailment prevention projection 8B in the crawler width direction Y. It is preferable that each surface Bo is composed of a surface 15 perpendicular to the crawler width direction Y.
As a result, the first and second derailment prevention protrusions 8A and 8B can be prevented from being disengaged.

Further, as shown in FIG. 6A, the outward surface Ao of the first derailment prevention protrusion 8A in the crawler width direction Y, the V-shaped surface 16 convex toward the outside in the crawler width direction, and the second It is preferable that the inward facing surface Bi of the crawler width direction Y of the derailment prevention protrusion 8B is formed by a V-shaped surface 16 that is convex inward in the crawler width direction.

As shown in FIG. 6B, the outward surface Ao of the first derailment prevention protrusion 8A in the crawler width direction Y, the arc surface 17 convex toward the outside in the crawler width direction, and the second derailment. It is also preferable that the inward facing surface Bi of the prevention protrusion 8B in the crawler width direction Y is formed by an arc surface 17 that is convex inward in the crawler width direction.

As represented by FIG. 7, when disengagement occurs between the first and second derailment prevention protrusions 8A and 8B, the slope 16s of the V-shaped surface 16 of the second derailment prevention protrusion 8B occurs. However, it becomes easy to move along the slope 16a of the V-shaped surface 16 of the first derailment prevention protrusion 8A. That is, the effect that the second derailment prevention projection 8B gets over the first derailment prevention projection 8A and easily returns to the original engaged state can be obtained. The same effect can be obtained in the case of the arcuate surface 17 shown in FIG. 6B.

Although the particularly preferable embodiments of the present invention have been described in detail above, the present invention is not limited to the illustrated embodiments and can be modified into various embodiments.

In order to confirm the effect of the present invention, an elastic crawler having the structure shown in FIGS. 1 and 2 was prototyped based on the specifications in Table 1. Then, each prototype was attached to the traveling device of the mini backhoe, and a traveling test including riding on a protrusion and turning was performed to evaluate the wheel removal resistance. In addition, the durability was evaluated in the actual vehicle durability test. In the comparative example and the embodiment, the cross-sectional shape and the cross-sectional size of the derailment prevention protrusion are the same, and the cross-sectional shape shown in FIG. 6A is used.

(1) Wheel resistance:
After running, the number of cases where the elastic crawler came off the rolling wheel and the wheel was removed was displayed in three stages. The higher the number, the better.

(2) Durability:
After running, the elastic crawler was disassembled, and the number of damages to the derailment prevention protrusion was displayed in three stages. The higher the number, the better.

As shown in the table, it can be confirmed that the elastic crawler of the example can exert an inhibitory effect on derailment.

1 Elastic crawler 2 Crawler body 3 Core material 4 Tension body 7 Core material body 8 Derailment prevention protrusion 8A 1st derailment prevention protrusion 8B 2nd derailment prevention protrusion 10 Guide protrusion 10so Outer side surface 11 Cord 12 Crawler outer circumference side Part 12a Overhanging part 12A Extension part 15 Right-angled surface 16V-shaped surface 17 Arc surface S1, S2 Side surface

Claims (9)

An endless band-shaped crawler body made of an elastic body,
A core material that is embedded in the crawler body at intervals in the circumferential direction of the crawler and is made of a material that is harder than the elastic body.
An elastic crawler that is embedded in the crawler body and includes a tension body made of a cord that is embedded in the crawler body and extends in the circumferential direction of the crawler through the outer peripheral side of the crawler from the core material.
The core material is
The core material body that extends in the crawler width direction and
The core material body includes a derailment prevention protrusion protruding in the crawler circumferential direction from one side and the other side surface in the crawler circumferential direction.
The crawler outer peripheral side portion of the derailment prevention protrusion is an elastic crawler including a portion protruding toward the crawler outer peripheral side with respect to the tension body. The distance Lz in the crawler thickness direction between the center J1 in the crawler thickness direction of the derailment prevention protrusion and the center J2 in the crawler thickness direction of the tension body is the height in the crawler thickness direction of the derailment prevention protrusion. The elastic crawler according to claim 1, which is ½ or less of h. The elastic crawler according to claim 1 or 2, wherein the crawler outer peripheral side portion of the derailment prevention protrusion includes an extension portion that rises from the crawler outer peripheral side surface of the core material body and extends along the crawler circumferential direction. The elastic crawler according to claim 3, wherein the extension portion has a crawler circumferential length from the side surface of the core material main body of 50 to 60% of the crawler circumferential width of the core material main body. The derailment prevention protrusions are a pair of first derailment prevention protrusions on both sides in the crawler width direction protruding from one side surface of the core material body, and a crawler width direction projecting from the other side surface of the core material body. Including a pair of second derailment prevention protrusions on both sides,
Each of the first derailment prevention protrusions of the core material on one side adjacent to each other in the crawler circumferential direction overlaps with each of the second derailment prevention protrusions of the core material on the other side on the outside in the crawler width direction. The elastic crawler according to any one of claims 1 to 4. The claim that the inward surface of the first derailment prevention protrusion in the crawler width direction and the outward surface of the second derailment prevention protrusion in the crawler width direction are each formed of a surface perpendicular to the crawler width direction. 5. The elastic crawler according to 5. The outward surface of the first derailment prevention protrusion in the crawler width direction is a V-shaped surface that is convex outward in the crawler width direction, and the inward surface of the second derailment prevention protrusion in the crawler width direction is The elastic crawler according to claim 5 or 6, comprising a V-shaped surface convex inward in the crawler width direction. The outward surface of the first derailment prevention protrusion in the crawler width direction is an arc surface that is convex outward in the crawler width direction, and the inward surface of the second derailment prevention protrusion in the crawler width direction is a crawler. The elastic crawler according to claim 5 or 6, which comprises an arcuate surface that is convex inward in the width direction. The core material includes a pair of guide protrusions on both sides in the crawler width direction protruding from the crawler inner peripheral side surface of the core material body.
The elastic crawler according to any one of claims 5 to 8, wherein the first derailment prevention protrusion is located inside in the crawler width direction with respect to the outer surface of the guide protrusion in the crawler width direction.

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