JP7310375B2 - elastic crawler - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end band-like elastic crawler provided with derailing prevention projections projecting in the circumferential direction of the crawler on a core material.

2. Description of the Related Art Conventionally, an elastic crawler is known in which a plurality of core members and tensile members are embedded in a crawler body made of an elastic material such as rubber. The core members function as reinforcing members in the width direction of the crawler and are arranged at intervals in the circumferential direction of the crawler. The tensile member functions as a reinforcing member in the crawler circumferential direction, and is composed of a cord extending in the crawler circumferential direction through the outer circumference of the crawler rather than the core member.

In this type of elastic crawler, lateral deviation (deviation in the crawler width direction) is likely to occur between adjacent core members. Then, due to the lateral shift, the rollers on the vehicle body side come off from the guide protrusions on the core material side, causing a problem of derailment.

In Patent Document 1 below, a pair of first projections projecting to one side in the crawler circumferential direction and a pair of second projections projecting to the other side may be provided on the core material in order to prevent derailment. Are listed. In this elastic crawler, the first projections of the core material on one side adjacent to each other in the crawler circumferential direction overlap the second projections of the core material on the other side on the outer side in the crawler width direction, thereby suppressing lateral displacement between the core materials. be.

JP-A-2019-93878

However, if bending or twisting occurs between adjacent core members due to external force acting when riding on a protrusion or turning, the engagement between the first protrusion and the second protrusion will be disengaged and the wheel will run off. may occur.

As a countermeasure against derailment caused by such bending and twisting, it has been proposed to increase the size of the first protrusion and the second protrusion, but there is still room for improvement, such as increasing 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 provides an endless belt-shaped crawler body made of an elastic body,
a core material embedded in the crawler body at intervals in the crawler circumferential direction and made of a material harder than the elastic body;
an elastic crawler comprising a cord embedded in the crawler body and extending in the crawler circumferential direction through the outer circumference of the crawler rather than the core material,
The core material
a core body extending in the width direction of the crawler;
Derailment prevention protrusions protruding in the crawler circumferential direction from one side and the other side of the core body in the crawler circumferential direction,
The crawler outer peripheral side portion of the derailment prevention projection includes a portion that protrudes further to the crawler outer peripheral side than the tensile 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 projection in the crawler thickness direction and the center J2 of the tensile body in the crawler thickness direction is the derailment prevention The height h of the projection in the thickness direction of the crawler is preferably 1/2 or less.

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

In the elastic crawler according to the present invention, it is preferable that the extended portion has a length in the crawler circumferential direction from the side surface of the core body that is 50 to 60% of the width of the core body in the crawler circumferential direction.

In the elastic crawler according to the present invention, the derailment prevention projections include a pair of first derailment prevention projections on both sides in the crawler width direction projecting from one side surface of the core body, and the other side of the core body. Including a pair of second derailment prevention projections on both sides in the crawler width direction that protrude from the side surface of
Each of the first derailment prevention projections of the core material on one side adjacent in the crawler circumferential direction overlaps each of the second derailment prevention projections of the core material on the other side on the outer side in the crawler width direction. is preferred.

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

In the elastic crawler according to the present invention, the outward surface in the crawler width direction of the first derailment prevention projection is a V-shaped surface convex outward in the crawler width direction, and the second derailment prevention projection It is also preferable that the inward surface in the crawler width direction is a V-shaped surface that protrudes inward in the crawler width direction.

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

In the elastic crawler according to the present invention, the core material includes a pair of guide projections on both sides in the crawler width direction projecting from the surface of the core body on the inner peripheral side of the crawler, and the first derailment prevention projections include the It is preferable that the guide protrusion is positioned inside in the crawler width direction of the outer surface of the guide protrusion in the crawler width direction.

In the core material according to the present invention, in the derailment prevention projections that protrude from the side surfaces of the core body on one side and the other side in the crawler circumferential direction, the crawler outer peripheral side portion of the derailment prevention projection is positioned more than the tensile body. It includes a portion that protrudes to the outer circumference of the crawler. That is, the tension member passes through the center side of the derailing prevention protrusion in the crawler thickness direction.

Here, when bending, twisting, or the like occurs between the core members of the elastic crawler, since the tensile member is non-stretchable, the closer the elastic crawler is to the tensile member, the smaller the displacement due to the deformation. That is, the derailing prevention projections have a smaller range of movement in accordance with bending, twisting, or the like between the core materials, and the detachment between the derailment prevention projections is less likely to occur. As a result, it is possible to suppress derailment while suppressing an increase in the weight of the core material.

It is a perspective view showing one embodiment of the elastic crawler of the present invention. It is a perspective view of a core material. It is a front view which expands and shows the half of the crawler width direction of a core material. (a) is a bottom view of the core material, and (b) is a sectional view taken along the line AA. FIG. 4 is a schematic plan view conceptually showing an arrangement state of core members; (a) and (b) are sectional views showing an example of a sectional shape of a derailing prevention projection. FIG. 10 is a working diagram of a derailing prevention projection having a V-shaped surface;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a perspective view of the elastic crawler 1. FIG. As shown in FIG. 1, the elastic crawler 1 of this embodiment includes an endless belt-like crawler body 2 made of an elastic material such as rubber, a plurality of core members 3 embedded in the crawler body 2, and and a tensile body 4 to be applied.

In this specification, the crawler circumferential direction is the direction of rotation of the elastic crawler 1 and corresponds to the direction indicated by symbol X in FIG. The crawler width direction is the axial direction of the drive wheels when the elastic crawler 1 is mounted on a vehicle, and corresponds to the direction indicated by symbol Y in FIG. Furthermore, the crawler thickness direction is a direction perpendicular to the crawler circumferential direction X and the crawler width direction Y, and corresponds to the direction indicated by symbol Z in FIG. In the crawler thickness direction Z, the inner side of the endless elastic crawler 1 is the crawler inner peripheral side Zi, and the outer side is the crawler outer peripheral side Zo.

The crawler body 2 extends continuously in the crawler circumferential direction X with a substantially constant width. A plurality of lugs 5 arranged at intervals in the crawler circumferential direction X protrude from a surface 2o of the crawler body 2 on the crawler outer peripheral side Zo. The lugs 5 extend in the width direction Y of the crawler to improve traction during running on rough terrain. Two rows of protrusions 6 each including a plurality of protrusions 6a and extending in the crawler circumferential direction X are formed on the surface 2i of the crawler body 2 on the crawler inner peripheral side Zi. A driving wheel, an idler wheel, a rolling wheel, and the like on the vehicle body side are guided between the projection rows 6,6. The protrusion 6a is reinforced by a guide protrusion 10 provided on the core member 3. As shown in FIG.

The core members 3 function as reinforcing members in the crawler width direction Y, and are arranged in the crawler circumferential direction X at intervals. The core material 3 is made of a material harder than the elastic body, and metal materials such as steel and cast iron are preferably used as the hard material. It should be noted that the entire core material 3 does not have to be embedded in the crawler body 2 , and a portion 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. FIG. As shown in FIG. 2, the core material 3 includes a core material main body 7 extending in the crawler width direction Y, and side surfaces S1 and S2 on one side and the other side of the crawler circumferential direction X of the core material main body 7, respectively. It includes a derailment prevention projection 8 that protrudes into the.

The core body 7 includes an engaging portion 7A arranged in the center in the crawler width direction Y, and wing portions 7B arranged on both outer sides in the crawler width direction Y of the engaging portion 7A. The surface of the engaging portion 7A on the inner peripheral side Zi of the crawler is formed with an arcuate surface 20 projecting toward the inner peripheral side Zi of the crawler so as to mesh with, for example, the tooth groove portion of the driving wheel.

The core material 3 includes a pair of guide protrusions 10, 10 projecting in the crawler thickness direction Z from a surface 7si of the crawler inner peripheral side Zi of the core material body 7. As shown in FIG. The guide protrusions 10, 10 rise on both sides of the engaging portion 7A in the crawler width direction Y. As shown in FIG. Between the guide projections 10, 10, the driving wheel, the idler wheel, and the rolling wheel are sandwiched and guided.

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

FIG. 5 is a schematic plan view conceptually showing how the core members 3 are arranged. In FIG. 5, the guide protrusion 10 is omitted. As shown in FIG. 5, in the elastic crawler 1, the first derailing prevention projection 8A of the core material ₃₁ on one side adjacent in the crawler circumferential direction X is the second derailment prevention projection of the core material ₃₂ on the other side. The prevention projection 8B overlaps and engages on the outer side in the crawler width direction Y. As shown in FIG. As a result, lateral deviation (deviation in the crawler width direction Y) between the core members 3 ₁ and 3 ₂ is suppressed.

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

As the cords 11, metal cords such as steel cords can be suitably used, but organic fiber cords such as aramid, polyester, nylon, and polyethylene naphthalate can also be used.

FIG. 3 is a front view showing an enlarged part of the core material 3. FIG. As shown in FIG. 3, in the present invention, the crawler outer peripheral side portion 12 of the derailing prevention projection 8 includes a portion 12a that protrudes 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 derailing prevention projection 8 that extends beyond the crawler outer peripheral side Zo surface 7so of the core material body 7 to the crawler outer peripheral side Zo. The overhanging portion 12a is defined as a portion of the crawler outer peripheral side portion 12 that extends beyond the tensile member 4 to the crawler outer peripheral side Zo.

When the derailment prevention projection 8 includes the overhanging portion 12a in this way, the tensile body 4 passes through the center side of the derailment prevention projection 8 in the crawler thickness direction Z.

Here, when the elastic crawler 1 is bent or twisted between the core members 3, 3, since the tensile member 4 is non-stretchable, the closer the elastic crawler 1 is to the tensile member 4, the smaller the displacement caused by the deformation. That is, the range of movement of the derailing prevention projections 8 according to bending, twisting, etc. between the core members 3, 3 becomes smaller, and disengagement between the derailment prevention projections 8A, 8B is less likely to occur. As a result, it is 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 projection 8 in the crawler thickness direction and the center J2 of the tension body 4 in the crawler thickness direction is It is preferably 1/2 or less of the height h in the crawler thickness direction and is as small as possible. This example shows the case where the center J1 and the surface 7so are arranged at the same height position. However, the center J1 can also be located on the crawler outer peripheral side Zo of the surface 7so, and in this case, the distance Lz can be set to zero.

Further, the closer the derailment prevention projection 8 is to the crawler width direction center Cy of the core material body 7, the smaller the amount of deviation of the derailment prevention projection 8 in the crawler thickness direction Z due to twisting. As a result, disengagement between the derailing prevention projections 8A and 8B is less likely to occur. From such a viewpoint, it is preferable that the first derailing prevention protrusion 8A be located inside the crawler width direction of the guide protrusion 10 relative to the crawler width direction outer surface 10so. In addition, when the outer surface 10so is inclined, the first derailment prevention protrusion 8A is located above the intersection point P of the extension line of the outer surface 10so of the guide protrusion 10 and the extension line of the surface 7si of the core body 7. , is preferably positioned on the inside in the width direction of the crawler.

FIG. 4(a) is a bottom view of the core member 3, and FIG. 4(b) 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 derailing prevention projection 8 rises from the crawler outer peripheral side surface 7so of the core material body 7 and extends along the crawler circumferential direction X. Includes extension 12A.

The extended portion 12A increases the strength of the derailing prevention projection 8 while suppressing an increase in the weight of the core material. The extended portion 12A preferably has a crawler circumferential length Lx from the side surface S of the core body 7 that is 50 to 60% of the crawler circumferential width Wx of the core body 7 . If the length Lx is less than 50% of the width Wx, sufficient strength may not be obtained.

6(a) and 6(b) show preferred cross-sectional shapes of the first and second derailment prevention projections 8A and 8B. As shown in FIGS. 6A and 6B, the inward surface Ai in the crawler width direction Y of the first derailment prevention projection 8A, and the outward in the crawler width direction Y of the second derailment prevention projection 8B It is preferable that each surface Bo consists of a surface 15 perpendicular to the crawler width direction Y. As shown in FIG.
This makes it difficult to disengage the first and second derailment prevention protrusions 8A and 8B.

Also, as shown in FIG. 6(a), the outward surface Ao of the first derailment prevention projection 8A in the crawler width direction Y is a V-shaped surface 16 that is convex toward the outside in the crawler width direction, and the second It is preferable to form the inward surface Bi of the derailing prevention projection 8B in the crawler width direction Y with a V-shaped surface 16 that protrudes inward in the crawler width direction.

In addition, as shown in FIG. 6(b), the outward surface Ao of the first derailment prevention projection 8A in the crawler width direction Y is formed by a convex arc surface 17 and a second derailment prevention projection toward the outer side in the crawler width direction. It is also preferable to form the inward surface Bi of the prevention protrusion 8B in the crawler width direction Y with an arcuate surface 17 that protrudes inward in the crawler width direction.

As representatively shown in FIG. 7, when disengagement occurs between the first and second derailment prevention projections 8A and 8B, the slope 16s of the V-shaped surface 16 of the second derailment prevention projection 8B However, it becomes easier to move along the slope 16a of the V-shaped surface 16 of the first derailment prevention projection 8A. In other words, the second derailing prevention projection 8B overcomes the first derailment prevention projection 8A to easily return to the original engagement state. A similar effect can be obtained with the arc surface 17 shown in FIG. 6(b).

Although the particularly preferred 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 in various ways.

In order to confirm the effect of the present invention, an elastic crawler having the structure shown in FIGS. Then, each prototype was mounted on a traveling device of a mini excavator, and a running test including riding on a protrusion and turning was conducted to evaluate the derailment resistance. In addition, durability was evaluated by an actual vehicle durability test. In the comparative example and the example, the cross-sectional shape and cross-sectional size of the derailing prevention projections are the same, and the cross-sectional shape shown in FIG. 6(a) is used.

(1) Derailment resistance:
After running, the number of cases in which the elastic crawler came off the wheel and derailed was displayed in three stages. The higher the number, the better.

(2) Durability:
After running, the elastic crawler was dismantled and the number of derailment prevention projections damaged was displayed in three stages. The higher the number, the better.

As shown in the table, it can be confirmed that the elastic crawlers of the examples can have an effect of suppressing derailment.

1 Elastic crawler 2 Crawler body 3 Core material 4 Tensile body 7 Core material body 8 Derailment prevention projection 8A First derailment prevention projection 8B Second derailment prevention projection 10 Guide projection 10so Outer surface 11 Cord 12 Crawler outer peripheral side Portion 12a Overhanging portion 12A Extension portion 15 Right-angled surface 16V Character-shaped surface 17 Arc surfaces S1, S2 Side surface

Claims (4)

an endless band-shaped crawler body made of an elastic body;
a core material embedded in the crawler body at intervals in the crawler circumferential direction and made of a material harder than the elastic body;
an elastic crawler comprising a cord embedded in the crawler body and extending in the crawler circumferential direction through the outer circumference of the crawler rather than the core material,
The core material
a core body extending in the width direction of the crawler;
derailment prevention protrusions protruding in the crawler circumferential direction from one side and the other side of the core body in the crawler circumferential direction;
a pair of guide projections on both sides in the crawler width direction projecting from the surface of the core body on the inner peripheral side of the crawler,
Among the derailment prevention protrusions, the crawler outer peripheral portion, which is the portion that extends the outermost crawler outer peripheral surface of the core material body to the crawler outer peripheral side, includes a portion that protrudes further to the crawler outer peripheral side than the tensile body. ,
The crawler outer peripheral side portion of the derailing prevention projection includes an extension portion that rises from the crawler outer peripheral side surface of the core body and extends along the crawler circumferential direction,
The length of the extended portion in the crawler circumferential direction from the side surface of the core body is 50 to 60% of the width of the core body in the crawler circumferential direction,
The derailment prevention projections include a pair of first derailment prevention projections on both sides in the crawler width direction projecting 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 projections on both sides,
Each of the first derailment prevention projections of the core material on one side adjacent in the crawler circumferential direction overlaps with each of the second derailment prevention projections of the core material on the other side on the outer side in the crawler width direction,
The first derailment prevention projection is located inside the crawler width direction of the crawler width direction outer surface of the guide projection ,
The outward surface in the crawler width direction of the first derailment prevention projection is a V-shaped surface convex outward in the crawler width direction, and the inward surface in the crawler width direction of the second derailment prevention projection is , consisting of a V-shaped surface convex toward the inner side in the crawler width direction ,
elastic crawler. an endless band-shaped crawler body made of an elastic body;
a core material embedded in the crawler body at intervals in the crawler circumferential direction and made of a material harder than the elastic body;
an elastic crawler comprising a cord embedded in the crawler body and extending in the crawler circumferential direction through the outer circumference of the crawler rather than the core material,
The core material
a core body extending in the width direction of the crawler;
derailment prevention protrusions protruding in the crawler circumferential direction from one side and the other side of the core body in the crawler circumferential direction;
a pair of guide projections on both sides in the crawler width direction projecting from the surface of the core body on the inner peripheral side of the crawler,
Among the derailment prevention protrusions, the crawler outer peripheral portion, which is the portion that extends the outermost crawler outer peripheral surface of the core material body to the crawler outer peripheral side, includes a portion that protrudes further to the crawler outer peripheral side than the tensile body. ,
The crawler outer peripheral side portion of the derailing prevention projection includes an extension portion that rises from the crawler outer peripheral side surface of the core body and extends along the crawler circumferential direction,
The length of the extended portion in the crawler circumferential direction from the side surface of the core body is 50 to 60% of the width of the core body in the crawler circumferential direction,
The derailment prevention projections include a pair of first derailment prevention projections on both sides in the crawler width direction projecting 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 projections on both sides,
Each of the first derailment prevention projections of the core material on one side adjacent in the crawler circumferential direction overlaps with each of the second derailment prevention projections of the core material on the other side on the outer side in the crawler width direction,
The first derailment prevention projection is located inside the crawler width direction of the crawler width direction outer surface of the guide projection,
The outward surface in the crawler width direction of the first derailment prevention projection is an arc surface convex outward in the crawler width direction, and the inward surface in the crawler width direction of the second derailment prevention projection is the crawler Consisting of an arc surface that is convex toward the inside in the width direction,
elastic crawler. The distance Lz in the crawler thickness direction between the center J1 of the derailing prevention projection in the crawler thickness direction and the center J2 of the tensile body in the crawler thickness direction is the height of the derailment prevention projection in the crawler thickness direction. The elastic crawler according to claim 1 or 2 , which is 1/2 or less of height h. The inward surface of the first derailment prevention projection in the crawler width direction and the outward surface of the second derailment prevention projection in the crawler width direction are each formed of a surface perpendicular to the crawler width direction. 4. The elastic crawler according to any one of 1 to 3 .

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