Rubber tracks and core metal

Abstract

To provide a rubber crawler which can enlarge a clearance between projections of adjacent core grids when the rubber crawler is bent around a sprocket or the like, and to provide the core grids.SOLUTION: In a rubber crawler, a pair of first projections of each core grid faces a pair of second projections of another core grid, located adjacent to the core grid at the first side in a crawler circumferential direction, in a crawler width direction. At least the first projection at the first side in the crawler width direction of the pair of first projections of each grid core has a first recessed part on a surface, which faces the second projection of the other core grid, of surfaces at both sides in the crawler width direction. In the first recessed part, a tip side end of the first projection in the crawler circumferential direction is located at the root side relative to a tip of the first projection in the crawler circumferential direction, and a length as seen in the crawler width direction of the first recessed part increases toward the root side in at least a portion including the tip side end of the first projection in the crawler circumferential direction. The first recessed part is open at the crawler inner periphery side and closed at the crawler outer periphery side and forms a substantially triangular prismatic shape.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a rubber crawler and a core metal.

Background Art

[0002] As a conventional rubber crawler, for the purpose of preventing lateral displacement and the like, there is one provided with a protrusion extending in the crawler circumferential direction from a base portion where the core metal extends in the crawler width direction (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional rubber crawler, when bending around a sprocket or the like, the core metals approach each other, and as a result, the clearance (gap) between the protrusions of adjacent core metals becomes too narrow, so that the bending rigidity of the rubber crawler becomes too high, and consequently, there is a risk that it becomes difficult to wrap around a rotating body and the loss of driving force increases.

[0005] An object of the present invention is to provide a rubber crawler and a core metal capable of expanding the clearance between the protrusions of adjacent core metals when the rubber crawler bends around a sprocket or the like.

Means for Solving the Problems

[0006] 〔1〕An endless crawler body made of rubber, a plurality of core metals embedded in the crawler body and arranged along the crawler circumferential direction, A rubber crawler comprising: Each of the core metals, A base portion extending in the width direction of the crawler, A pair of corners extending from the base portion toward the inner circumference of the crawler, A pair of first protrusions extending from the base portion toward the first side in the crawler circumferential direction, A pair of second protrusions extending from the base portion toward the second side in the crawler circumferential direction, Equipped with, Each of the pair of first projections on the core metal is positioned opposite to the pair of second projections on the other core metal adjacent to the core metal on the first side in the crawler circumferential direction, in the crawler width direction. Of the pair of first projections of each core metal, at least the first projection on the first side in the crawler width direction has a first recess on the surface on either side in the crawler width direction that faces the second projection of the other core metal. The first recess is such that the tip end of the first projection in the crawler circumferential direction of the first recess is located closer to the root of the first projection than the tip of the first projection in the crawler circumferential direction. The first recess, at least in the portion including the tip end of the first projection in the crawler circumferential direction, has a length in the crawler width direction that increases as it moves toward the root side of the first projection in the crawler circumferential direction. The first recess is open on the inner circumference side of the crawler and closed on the outer circumference side of the crawler. The first recess is a rubber crawler with a roughly triangular prism shape. This increases the clearance between adjacent core metal protrusions when the rubber track bends around the sprocket or other components.

[0007] [2] The rubber crawler according to [1], wherein the length of the first recess increases in the crawler thickness direction as it approaches the root side of the first projection in the crawler circumferential direction. This allows for increased clearance between adjacent core metal protrusions when the rubber crawler bends around sprockets, while suppressing a decrease in the rigidity of the protrusions.

[0008] [3] Of the pair of second projections of each core metal, at least the second projection on the second side in the crawler width direction has a second recess on the surface on either side in the crawler width direction that faces the first projection of the other core metal, The second recess is such that the end of the second recess on the tip side of the second projection in the crawler circumferential direction is located closer to the root side of the second projection than to the tip side of the second projection in the crawler circumferential direction. The second recess, at least in the portion including the tip end of the second projection in the crawler circumferential direction, has a length in the crawler width direction that increases as it moves toward the root side of the second projection in the crawler circumferential direction. The second recess is open on the inner circumference side of the crawler and closed on the outer circumference side of the crawler. The rubber crawler according to [1] or [2], wherein the second recess has a substantially triangular prism shape. This allows for a greater clearance between adjacent core metal protrusions when the rubber track bends around the sprocket or other components.

[0009] [4] The core metal used in any one of the rubber crawlers described in [1] to [3] above. This increases the clearance between adjacent core metal protrusions when the rubber track bends around the sprocket or other components. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a rubber crawler and a core metal that can increase the clearance between adjacent core metal protrusions when the rubber crawler bends around a sprocket or the like. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing a rubber crawler according to one embodiment of the present invention, viewed from the inner circumference side of the crawler. [Figure 2] Figure 1 shows the rubber crawler in a cross-sectional view along line AA in Figure 1. [Figure 3] It is a perspective view showing a plurality of adjacent core metals when the rubber crawler of FIG. 1 is in a flat state. [Figure 4] It is a B-B sectional view showing the plurality of core metals shown in FIG. 3 by a cross section along the line B-B of FIG. 3. [Figure 5] It is a perspective view showing the appearance of the core metal shown in FIG. 3 as viewed from the side of the first protrusion. [Figure 6] FIG. 6(a) is an enlarged view of the first protrusion shown in FIG. 5, FIG. 6(b) is a C-arrow view showing the state of viewing the first protrusion of FIG. 5 in the direction of arrow C, and FIG. 6(c) is a D-arrow view showing the state of viewing the first protrusion of FIG. 5 in the direction of arrow D. [Figure 7] It is a perspective view showing the appearance of the core metal shown in FIG. 3 as viewed from the side of the second protrusion. [Figure 8] FIG. 8(a) is an enlarged view of the second protrusion shown in FIG. 7, FIG. 8(b) is an E-arrow view showing the state of viewing the second protrusion of FIG. 7 in the direction of arrow E, and FIG. 8(c) is an F-arrow view showing the state of viewing the second protrusion of FIG. 7 in the direction of arrow F. [Figure 9] It is a perspective view showing a plurality of adjacent core metals when the rubber crawler of FIG. 1 bends around a sprocket or the like. [Figure 10] It is a G-arrow view showing the appearance of the plurality of core metals shown in FIG. 9 as viewed in the direction of arrow G. [Figure 11] It is a drawing corresponding to FIG. 4 and is a drawing for explaining a rubber crawler according to a modification of the present invention.

Embodiments for Carrying Out the Invention

[0012] The rubber crawler of the present invention is suitable for being mounted on the peripheral part of the running gear of any running machine such as construction machines (mini excavators, etc.) and agricultural machines (tractors, combines, etc.). Hereinafter, embodiments of the rubber crawler and the core metal according to the present invention will be exemplarily described with reference to the drawings. The same reference numerals are given to the common components in each figure.

[0013] Figure 1 is a schematic diagram showing a rubber crawler 1 according to one embodiment of the present invention as viewed from the inner circumference side of the crawler. Figure 2 is a cross-sectional view AA of the rubber crawler 1 of Figure 1, showing a cross-section along line AA in Figure 1. Line AA in Figure 1 extends along the width direction of the crawler. The rubber crawler 1 is preferably mounted on the undercarriage of running machinery such as construction machinery (mini excavators, etc.) and agricultural machinery (tractors, combine harvesters, etc.). Although not shown in the illustration, the undercarriage of running machinery includes a sprocket which is a drive wheel, one or more idlers which are driven wheels, and one or more rolling wheels. The sprocket has multiple pins on its outer circumference.

[0014] As shown in Figures 1 and 2, the rubber crawler 1 according to this embodiment comprises a crawler body 12, a plurality of lugs 14, one or more core layers 15, and a plurality of core metals 13 according to one embodiment of the present invention. Thus, the core metals 13 according to this embodiment are used in the rubber crawler 1 according to this embodiment.

[0015] The crawler body 12 is configured in an endless (ring-shaped) manner. The crawler body 12 is configured in a strip shape. The crawler body 12 is made of rubber.

[0016] In this specification, "crawler inner circumference IS", "crawler outer circumference OS", "crawler circumferential direction CD", "crawler width direction WD", and "crawler thickness direction TD" refer to the inner circumference, outer circumference, circumferential direction, width direction, and thickness direction of the crawler body 12, respectively, as indicated by the arrows in each figure. Furthermore, as indicated by the arrows in each figure, in this specification, one side in the crawler circumferential direction CD is referred to as the "first side CD1 in the crawler circumferential direction," and the other side in the crawler circumferential direction CD is referred to as the "second side CD2 in the crawler circumferential direction." Furthermore, as indicated by the arrows in each figure, in this specification, one side in the crawler width direction WD is referred to as the "first side WD1 in the crawler width direction," and the other side in the crawler width direction WD is referred to as the "second side WD2 in the crawler width direction." Furthermore, in this specification, "outer side of crawler width direction WD" refers to the side of the crawler body 12 that is farther from the center of the crawler width direction WD, and "inner side of crawler width direction WD" refers to the side of the crawler body 12 that is closer to the center of the crawler width direction WD. The direction of rotation of the rubber crawler 1 when the running machine is in motion may be the first side CD1 in the crawler's circumferential direction, or the second side CD2 in the crawler's circumferential direction.

[0017] The multiple lugs 14 on the rubber crawler 1 each protrude from the outer surface 122 of the crawler body 12 to the outer surface OS of the crawler. The shape and arrangement of the lugs 14 can be arbitrary. The end faces of the lugs 14 on the outer surface OS of the crawler are configured to make contact with the road surface. The lugs 14 are made of rubber.

[0018] In this embodiment, the core layer 15 has a plurality of cords 15C arranged along the crawler width direction WD. Each of these cords 15C extends around the entire circumference along the crawler circumferential direction CD. The core layer 15 is embedded inside the crawler body 12. The rubber crawler 1 may have the core layer 15 at only one location in the crawler thickness direction TD, as in the example of Figure 2 (in this case, the number of core layers 15 is one), or it may have the core layer 15 at multiple locations in the crawler thickness direction TD (in this case, the number of core layers 15 is multiple). The core layer 15 has the function of suppressing the crawler body 12 from extending in the crawler circumferential direction CD. Code 15C is made of, for example, metal (e.g., steel).

[0019] Figure 3 is a perspective view showing multiple adjacent core metals 13 when the rubber crawler 1 in Figure 1 is in a flat state. Here, "when the rubber crawler 1 is in a flat state" means that when only a part of the crawler circumferential direction CD of the rubber crawler 1 is viewed, that part is not bent by being wrapped around a sprocket or the like, but is in a flat state. Figure 4 is a BB cross-sectional view showing the multiple core metals 13 shown in Figure 3, with a cross-section along the BB line in Figure 3. Figure 4 corresponds to the view from the inner circumference IS of the crawler when each core metal 13 shown in Figure 3 is cut near the base of its corner 13C. As shown in Figures 1, 3, and 4, the multiple core metals 13 of the rubber crawler 1 are arranged along the circumferential direction CD of the crawler. The core metal 13 is made of metal (for example, iron or steel). At least a portion of the core metal 13 is embedded inside the crawler body 12. The core metal 13 is positioned on the inner circumference IS side of the crawler, relative to the core body layer 15 (Figure 2).

[0020] Figures 5 and 7 show the core metal 13 of this embodiment individually from different angles. The configuration of each core metal 13 is the same. In the following, when describing the core metal 13, each core metal 13 will be described individually. As shown in Figures 3, 4, 5, and 7, the core metal 13 comprises a base portion 13B, a pair of corner portions 13C, a pair of first projections (projections) 13P1, and a pair of second projections (projections) 13P2.

[0021] The base portion 13B extends in the crawler width direction WD. In this embodiment, the base portion 13B is configured in a substantially plate shape. In this embodiment, as shown in Figure 4, the base portion 13B has a substantially rectangular shape with the crawler width direction WD as its longitudinal direction when viewed from the inner circumference side IS of the crawler. However, the base portion 13B may have a shape different from that of this embodiment.

[0022] Each of the pair of corners 13C extends from the base portion 13B to the inner circumference IS of the crawler. Part or all of each corner 13C protrudes beyond the inner circumference surface 121 of the crawler body 12 to the inner circumference IS of the crawler (Figure 2). The pair of corners 13C are spaced apart from each other in the crawler width direction WD. The pair of corners 13C are located on both sides of the center of the crawler width direction WD of the base portion 13B. The pair of corner portions 13C of the core metal 13 have a guide function, which restricts the movement of each rotating body (sprocket, idler, road wheel) in the crawler width direction WD of the undercarriage of the running machine, either without or with the rubber, thereby preventing derailment. In this embodiment, the top surface 13Ca of the pair of corners 13C (the end surface of IS on the inner circumference side of the crawler) is configured such that the road wheels pass over it. However, the road wheels may be configured to travel on the outside of the pair of corners 13C in the crawler width direction WD, for example, rather than on the top surface 13Ca of the pair of corners 13C.

[0023] The portion of the base section 13B that connects the pair of corner sections 13C is the central section 13Bc. The portion of the base section 13B that is outside the pair of corner sections 13C in the crawler width direction WD is the pair of wing sections 13Bw. The central portion 13Bc of the base portion 13B of the core metal 13 has the function of transmitting the driving force from the sprocket to the rubber crawler 1 by engaging with the sprocket pin, either without or through the rubber.

[0024] The base portion 13B of the core metal 13 may be entirely covered by the crawler body 12, or a part of it (for example, the central portion 13Bc) may be exposed to the outside without being covered by the crawler body 12. Of the corner portions 13C of the core metal 13, the portion that protrudes toward the inner circumference IS of the crawler beyond the inner circumference surface 121 of the crawler body 12 may be covered in part or in whole with a film-like coating rubber, or it may be exposed to the outside without being covered with a film-like coating rubber.

[0025] As shown in Figures 1 to 3, a hole 16 is formed between the central portions 13Bc of adjacent core metals 13 in the circumferential direction CD of the crawler. The hole 16 is recessed toward the outer circumference of the crawler. The hole 16 is configured so that the pin of the sprocket can fit into it. As a result, the sprocket pin can engage with the central portion 13Bc of the core metal 13 while inserted into the hole 16, and thereby transmit the driving force to the rubber crawler 1. The hole 16 may be configured as a bottomless hole (through hole) that penetrates the crawler body 12 in the crawler thickness direction TD, or as a bottomed hole (recess) that does not penetrate the crawler body 12 in the crawler thickness direction TD.

[0026] As shown in Figures 3 to 5, the pair of first projections 13P1 each extend from the base portion 13B to the first side CD1 in the crawler circumferential direction. The pair of first projections 13P1 are spaced apart from each other in the crawler width direction WD. The pair of first projections 13P1 are located on both sides of the center of the base portion 13B in the crawler width direction WD. The pair of first projections 13P1 are located near the pair of corners 13C in the crawler width direction WD. A hole 16 is formed between the pair of first projections 13P1. As shown in Figures 3-4 and 7, the pair of second projections 13P2 each extend from the base portion 13B to the second side CD2 in the crawler circumferential direction. The pair of second projections 13P2 are spaced apart from each other in the crawler width direction WD. The pair of second projections 13P2 are located on both sides of the center of the base portion 13B in the crawler width direction WD. The pair of second projections 13P2 are located near the pair of corners 13C in the crawler width direction WD. A hole 16 is formed between the pair of second projections 13P2. As shown in Figures 3 and 4, each pair of first projections 13P1 of each core metal 13 faces each other in the crawler width direction WD with a pair of second projections 13P2 of another core metal 13 adjacent to that core metal 13 on the first side CD1 in the crawler circumferential direction. As a result, when adjacent core metals 13 move relative to each other in the crawler width direction WD, the pair of first projections 13P1 of each core metal 13 and the pair of second projections 13P2 of the other core metal 13 adjacent to that core metal 13 on the first side CD1 in the crawler circumferential direction engage (interfere) with each other, thereby restricting the movement of each other in the crawler width direction WD. This prevents misalignment (lateral displacement) of each core metal 13 in the crawler width direction WD, and consequently improves the rigidity of the rubber crawler 1 and suppresses wheel derailment.

[0027] As shown in Figures 3 and 4, in this embodiment, the pair of first projections 13P1 of the core metal 13 are located further outward in the crawler width direction WD than the pair of second projections 13P2 of other core metals 13 adjacent to the first side CD1 in the crawler circumferential direction of the said core metal 13. However, the pair of first projections 13P1 of the core metal 13 may be in any crawler width direction WD positional relationship with respect to the pair of second projections 13P2 of another core metal 13 adjacent to the said core metal 13 on the first side CD1 in the crawler circumferential direction.

[0028] As shown in Figure 4, when the rubber crawler 1 is in a flat state, a clearance (gap) g exists between a pair of first projections 13P1 of the core metal 13 and a pair of second projections 13P2 of another core metal 13 adjacent to the said core metal 13 on the first side CD1 in the crawler circumferential direction.

[0029] The first projection 13P1 and the second projection 13P2 have basically similar structures. For convenience, they will be described together in the following explanation.

[0030] As shown in Figures 3 to 5, in this embodiment, each of the pair of first projections 13P1 of the core metal 13 has a first recess R1 on the surface 13P1a on either side of the crawler width direction WD that faces the second projection 13P2 of the adjacent core metal 13 (in this embodiment, the surface on the inside of the crawler width direction WD). As shown in Figures 3-4 and 7, in this embodiment, each pair of second projections 13P2 of each core metal 13 has a second recess R2 on the surface 13P2a of the adjacent core metal 13 that faces the first projection 13P1 of the other core metal 13 (in this embodiment, the surface on the outside of the crawler width direction WD).

[0031] Figure 9 is a perspective view showing multiple adjacent core metals 13 when the rubber crawler 1 of this embodiment bends around a sprocket or the like. Here, "when the rubber crawler 1 bends around a sprocket or the like" refers to the state when, looking only at a part of the crawler circumferential direction CD of the rubber crawler 1, that part is wrapped around the sprocket or idler and is bent. Figure 10 is a view of the multiple core metals 13 shown in Figure 9 as seen in the direction of arrow G. Since the core metal 13 is located on the inner circumference IS of the crawler, as shown in Figure 9, when the rubber crawler 1 bends around the sprocket or idler, adjacent core metals 13 come closer together. Consequently, the clearance g between the first projection 13P1 and the second projection 13P2 of adjacent core metals 13 becomes narrower. However, in this embodiment, the first projection 13P1 and the second projection 13P2 have a first recess R1 and a second recess R2 on their opposing surfaces 13P1a and 13P2a, respectively, and the first recess R1 and the second recess R2 face each other. As shown in Figure 10, compared to the case where there are no first recess R1 and the second recess R2 (i.e., where substantially flat surfaces face each other), the clearance g when the rubber crawler 1 bends around a sprocket, etc. can be increased, and the risk of the first projection 13P1 and the second projection 13P2 contacting (interfering with) each other when the rubber crawler 1 bends around a sprocket, etc. can be reduced. Therefore, when the rubber crawler 1 bends around a sprocket, etc., it is possible to suppress the bending rigidity of the rubber crawler 1 from becoming too high, and consequently, the risk of the rubber crawler 1 becoming less likely to wrap around the sprocket, etc., and thus the risk of increased loss of driving force can be reduced.

[0032] Figure 6(a) is an enlarged view of the first projection 13P1 shown in Figure 5, Figure 6(b) is a view of the first projection 13P1 in Figure 5 as seen in the direction of arrow C, and Figure 6(c) is a view of the first projection 13P1 in Figure 5 as seen in the direction of arrow D. As shown in Figure 6, in this embodiment, the first projection 13P1 has, on the surface 13P1a of both sides of the crawler width direction WD that faces the second projection 13P2 of the adjacent core metal 13 (in this embodiment, the inner surface of the crawler width direction WD), a first section screen R11 facing the inner circumference IS of the crawler, a second section screen R12 facing the side of both sides of the crawler width direction WD that faces the second projection 13P2 of the other core metal 13 (in this embodiment, the inner side of the crawler width direction WD), and a third section screen R13 facing the first side CD1 of the crawler circumferential direction. The first recess R1 is divided into a first section screen R11, a second section screen R12, a third section screen R13, an opening surface in the first recess R1 that faces the second projection 13P2 of the other core metal 13 (in this embodiment, the inner surface in the crawler width direction WD) 13P1a of the surfaces on both sides of the first projection 13P1 in the crawler width direction WD, and an opening surface in the first recess R1 that faces the surface of the first projection 13P1 on the crawler inner circumference side IS. Figure 8(a) is an enlarged view of the second projection 13P2 shown in Figure 7, Figure 8(b) is a view of the second projection 13P2 in Figure 7 as seen in the direction of arrow E, and Figure 8(c) is a view of the second projection 13P2 in Figure 7 as seen in the direction of arrow F. As shown in Figure 8, in this embodiment, the second projection 13P2 has, on the surface 13P2a of both sides of the crawler width direction WD that faces the first projection 13P1 of the adjacent core metal 13 (in this embodiment, the outer surface of the crawler width direction WD), a first section screen R21 facing the inner circumference IS of the crawler, a second section screen R22 facing the side of both sides of the crawler width direction WD that faces the first projection 13P1 of the other core metal 13 (in this embodiment, the outer surface of the crawler width direction WD), and a third section screen R23 facing the second side CD2 of the crawler circumferential direction. The second recess R2 is divided by the first section screen R21, the second section screen R22, the third section screen R23, and an opening surface in the second recess R2 that faces the surface 13P2a of the second projection 13P2 on both sides of the crawler width direction WD of the other core metal 13 (in this embodiment, the surface on the outside of the crawler width direction WD) 13P2a, and an opening surface in the second recess R2 that faces the surface IS on the inner circumference side of the crawler of the second projection 13P2.

[0033] As shown in Figure 6, it is preferable that the first recess R1 has an end R1t on the tip 13P1t side of the first projection 13P1 in the crawler circumferential direction CD, which is located on the root 13P1r side of the first projection 13P1 rather than the tip 13P1t side of the first projection 13P1 in the crawler circumferential direction CD. As a result, the first recess R1 is positioned in a part where the first projection 13P1 and the second projection 13P2 are particularly likely to come into contact with each other when the rubber crawler 1 bends around a sprocket, etc., thereby suppressing contact between the first projection 13P1 and the second projection 13P2, and also suppressing a decrease in the ease with which the first projection 13P1 and the second projection 13P2 engage with each other and a decrease in the rigidity of the first projection 13P1 when adjacent core metals 13 move relative to each other in the crawler width direction WD, and consequently suppressing a decrease in the original function of the first projection 13P1 and the second projection 13P2, which is the lateral displacement prevention function (and consequently the wheel derailment prevention function). Here, "the tip 13P1t of the first projection 13P1" refers to the end of the first projection 13P1 on the first side CD1 in the crawler circumferential direction. Therefore, "the end R1t of the first recess R1 on the side of the tip 13P1t of the first projection 13P1 in the crawler circumferential direction CD" refers to the end of the first recess R1 on the first side CD1 in the crawler circumferential direction. Also, "the base 13P1r of the first projection 13P1" refers to the end of the first projection 13P1 on the second side CD2 in the crawler circumferential direction. The base 13P1r of the first projection 13P1 is connected to the end face of the base portion 13B on the first side CD1 in the crawler circumferential direction. As shown in Figure 8, it is preferable that the end R2t of the second recess R2 on the tip 13P2t side of the second projection 13P2 in the crawler circumferential direction CD is located on the root 13P2r side of the second projection 13P2 rather than the tip 13P2t of the second projection 13P2 in the crawler circumferential direction CD. As a result, the second recess R2 is positioned in a part where the first projection 13P1 and the second projection 13P2 are particularly likely to come into contact with each other when the rubber crawler 1 bends around a sprocket, etc., thereby suppressing contact between the first projection 13P1 and the second projection 13P2, and also suppressing a decrease in the ease with which the first projection 13P1 and the second projection 13P2 engage with each other and a decrease in the rigidity of the second projection 13P2 when adjacent core metals 13 move relative to each other in the crawler width direction WD, and consequently suppressing a decrease in the original function of the first projection 13P1 and the second projection 13P2, which is the lateral displacement prevention function (and consequently the wheel derailment prevention function). Here, "the tip 13P2t of the second projection 13P2" refers to the end of the second projection 13P2 on the second side CD2 in the crawler circumferential direction. Therefore, "the end R2t of the second recess R2 on the side of the tip 13P2t of the second projection 13P2 in the crawler circumferential direction CD" refers to the end of the second recess R2 on the second side CD2 in the crawler circumferential direction. Also, "the base 13P2r of the second projection 13P2" refers to the end of the second projection 13P2 on the first side CD1 in the crawler circumferential direction. The base 13P2r of the second projection 13P2 is connected to the end face of the base portion 13B on the second side CD2 in the crawler circumferential direction. Furthermore, if the end R1t of the first projection 13P1 on the tip 13P1t side of the first recess R1 in the crawler circumferential direction CD is located at the same position as the tip 13P1t of the first projection 13P1 in the crawler circumferential direction CD, the rigidity of the first projection 13P1 may be excessively reduced, and when the rubber crawler 1 bends around a sprocket or the like, twisting may occur between adjacent core metals 13, causing the first projection 13P1 and the second projection 13P2 to interlock undesirably. Similarly, if the end R2t of the second recess R2 on the tip 13P2t side of the second projection 13P2 in the crawler circumferential direction CD is located at the same position as the tip 13P2t of the second projection 13P2 in the crawler circumferential direction CD, the rigidity of the second projection 13P2 may be excessively reduced, and the first projection 13P1 and the second projection 13P2 may become undesirably interlocked when twisting occurs between adjacent core metals 13 when the rubber crawler 1 bends around a sprocket or the like.

[0034] As shown in Figure 6(c), it is preferable that the length L1 of the crawler width direction WD increases as the first recess R1 is directed toward the root 13P1r side of the first projection 13P1 in the crawler circumferential direction CD, at least in the portion including the end R1t on the tip 13P1t side of the first projection 13P1. As a result, the first recess R1 is positioned in a part where the first projection 13P1 and the second projection 13P2 are particularly likely to come into contact with each other when the rubber crawler 1 bends around a sprocket, etc., thereby suppressing contact between the first projection 13P1 and the second projection 13P2, and also suppressing a decrease in the ease with which the first projection 13P1 and the second projection 13P2 engage with each other and a decrease in the rigidity of the first projection 13P1 when adjacent core metals 13 move relative to each other in the crawler width direction WD, and consequently suppressing a decrease in the original function of the first projection 13P1 and the second projection 13P2, which is the lateral displacement prevention function (and consequently the wheel derailment prevention function). As shown in Figure 8(c), it is preferable that the length L2 of the crawler width direction WD increases as the second recess R2 is directed toward the root 13P2r side of the second projection 13P2 in the crawler circumferential direction CD, at least in the portion including the end R2t on the tip 13P2t side of the second projection 13P2. As a result, the second recess R2 is positioned in a part where the first projection 13P1 and the second projection 13P2 are particularly likely to come into contact with each other when the rubber crawler 1 bends around a sprocket, etc., thereby suppressing contact between the first projection 13P1 and the second projection 13P2, and also suppressing a decrease in the ease with which the first projection 13P1 and the second projection 13P2 engage with each other and a decrease in the rigidity of the second projection 13P2 when adjacent core metals 13 move relative to each other in the crawler width direction WD, and consequently suppressing a decrease in the original function of the first projection 13P1 and the second projection 13P2, which is the lateral displacement prevention function (and consequently the wheel derailment prevention function).

[0035] As shown in Figures 6(a) and 6(b), it is preferable that the first recess R1 is open on the inner circumference IS of the crawler (i.e., it opens to the surface of the inner circumference IS of the crawler of the first projection 13P1) and closed on the outer circumference OS of the crawler (i.e., it does not open to the surface of the outer circumference OS of the crawler of the first projection 13P1). When the rubber crawler 1 bends around a sprocket or the like, the clearance g between the first projection 13P1 and the second projection 13P2 tends to narrow particularly on the inner circumference IS of the crawler and conversely tends to widen on the outer circumference OS of the crawler. Therefore, by arranging the first recess R1 only on the inner circumference IS of the crawler as described above, the first recess R1 is positioned in a part where the first projection 13P1 and the second projection 13P2 are particularly likely to come into contact with each other when the rubber crawler 1 bends around a sprocket, etc., thereby suppressing contact between the first projection 13P1 and the second projection 13P2, and suppressing a decrease in the ease of engagement between the first projection 13P1 and the second projection 13P2 and a decrease in the rigidity of the first projection 13P1 when adjacent core metals 13 move relative to each other in the crawler width direction WD, and consequently suppressing a decrease in the original function of the first projection 13P1 and the second projection 13P2, which is the lateral displacement prevention function (and consequently the wheel derailment prevention function). As shown in Figures 8(a) and 8(b), it is preferable that the second recess R2 is open on the inner circumference IS of the crawler (i.e., it opens to the surface of the inner circumference IS of the crawler of the second projection 13P2) and closed on the outer circumference OS of the crawler (i.e., it does not open to the surface of the outer circumference OS of the crawler of the second projection 13P2). When the rubber crawler 1 bends around a sprocket or the like, the clearance g between the first projection 13P1 and the second projection 13P2 tends to narrow particularly on the inner circumference IS of the crawler, and conversely tends to widen on the outer circumference OS of the crawler. Therefore, by placing the second recess R2 only on the inner circumference IS of the crawler as described above, the second recess R2 is positioned in a part where the first projection 13P1 and the second projection 13P2 are particularly likely to come into contact with each other when the rubber crawler 1 bends around a sprocket, etc., thereby suppressing contact between the first projection 13P1 and the second projection 13P2, and suppressing a decrease in the ease of engagement between the first projection 13P1 and the second projection 13P2 and a decrease in the rigidity of the second projection 13P2 when adjacent core metals 13 move relative to each other in the crawler width direction WD, and consequently suppressing a decrease in the original function of the first projection 13P1 and the second projection 13P2, which is the lateral displacement prevention function (and consequently the wheel derailment prevention function). Furthermore, if the inner circumference IS side of the crawler is not open, the first recess R1 and the second recess R2 may be more likely to come into contact with each other when the rubber crawler 1 bends around a sprocket or the like.

[0036] As shown in Figure 6(a), the first recess R1 preferably has a roughly triangular prism shape. This roughly triangular prism shape has the first section screen R11 as the base and the crawler thickness direction TD as the height direction. The first section screen R11 has a roughly triangular shape. By giving the first recess R1 this shape, the first recess R1 is positioned in a part where the first projection 13P1 and the second projection 13P2 are particularly likely to come into contact with each other when the rubber crawler 1 bends around a sprocket, etc., thereby suppressing contact between the first projection 13P1 and the second projection 13P2, and also suppressing a decrease in the ease with which the first projection 13P1 and the second projection 13P2 engage with each other and a decrease in the rigidity of the first projection 13P1 when adjacent core metals 13 move relative to each other in the crawler width direction WD, and consequently suppressing a decrease in the original function of the first projection 13P1 and the second projection 13P2, which is the lateral displacement prevention function (and consequently the wheel derailment prevention function). As shown in Figure 8(a), the second recess R2 preferably has a roughly triangular prism shape. This roughly triangular prism shape has the first section screen R21 as its base and the crawler thickness direction TD as its height direction. The first section screen R21 has a roughly triangular shape. By shaping the second recess R2 in this way, the second recess R2 is positioned in a location where the first projection 13P1 and the second projection 13P2 are particularly likely to come into contact with each other when the rubber crawler 1 bends around a sprocket or the like. This suppresses contact between the first projection 13P1 and the second projection 13P2, and also suppresses a decrease in the ease with which the first projection 13P1 and the second projection 13P2 engage with each other and a decrease in the rigidity of the second projection 13P2 when adjacent core metals 13 move relative to each other in the crawler width direction WD. Consequently, it suppresses a decrease in the original function of the first projection 13P1 and the second projection 13P2, which is to prevent lateral displacement (and thus prevent wheel derailment). In this specification, the term "approximately triangular prism shape" includes the concept of an approximately truncated triangular prism shape. In this embodiment, the first recess R1 and the second recess R2 have first section surfaces R11 and R21 that form the bottom surface, which are inclined diagonally with respect to the height direction (crawler thickness direction TD), thereby forming an approximately truncated triangular prism shape.

[0037] As shown in Figure 6(b), it is preferable that the length M1 of the first recess R1 increases as it approaches the root 13P1r side of the first projection 13P1 in the crawler circumferential direction CD. This allows the first recess R1 to be positioned in a part where the first projection 13P1 and the second projection 13P2 are particularly likely to come into contact with each other when the rubber crawler 1 bends around a sprocket, thereby suppressing contact between the first projection 13P1 and the second projection 13P2. It also suppresses a decrease in the ease with which the first projection 13P1 and the second projection 13P2 engage with each other and a decrease in the rigidity of the first projection 13P1 when adjacent core metals 13 move relative to each other in the crawler width direction WD. Consequently, it is possible to suppress a decrease in the lateral displacement prevention function (and thus the wheel derailment prevention function), which is the original function of the first projection 13P1 and the second projection 13P2. Here, the "length M1 of the crawler thickness direction TD" of the first recess R1 refers to the maximum value when the length of the crawler thickness direction TD of the first recess R1 is not uniform along the crawler width direction WD, as in the example in Figure 6. In the example in Figure 6, the "length M1 of the crawler thickness direction TD" of the first recess R1 is the length of the crawler thickness direction TD measured at the end of the first recess R1 on the side facing the second projection 13P2 of the other core metal 13 (in this embodiment, the inside of the crawler width direction WD) on both sides of the crawler width direction WD. From a similar viewpoint, it is preferable that the first section screen R11 of the first recess R1 extends toward the outer circumference OS of the crawler as it moves toward the root 13P1r side of the first projection 13P1 in the crawler circumferential direction CD. As shown in Figure 8(b), it is preferable that the length M2 of the crawler thickness direction TD increases as the second recess R2 approaches the root 13P2r side of the second projection 13P2 in the crawler circumferential direction CD. This allows the second recess R2 to be positioned in a part where the first projection 13P1 and the second projection 13P2 are particularly likely to come into contact with each other when the rubber crawler 1 bends around a sprocket, thereby suppressing contact between the first projection 13P1 and the second projection 13P2. Furthermore, it is possible to suppress the decrease in the ease with which the first projection 13P1 and the second projection 13P2 engage with each other and the decrease in the rigidity of the second projection 13P2 when adjacent core metals 13 move relative to each other in the crawler width direction WD, and consequently, the decrease in the original function of the first projection 13P1 and the second projection 13P2, which is the lateral displacement prevention function (and consequently the wheel derailment prevention function). Here, the "length M2 of the crawler thickness direction TD" of the second recess R2 refers to the maximum value when the length of the crawler thickness direction TD of the second recess R2 is not uniform along the crawler width direction WD, as in the example in Figure 8. In the example in Figure 8, the "length M2 of the crawler thickness direction TD" of the second recess R2 is the length of the crawler thickness direction TD measured at the end of the second recess R2 on the side facing the first projection 13P1 of the other core metal 13 (in this embodiment, the outside of the crawler width direction WD) on both sides of the crawler width direction WD. From a similar viewpoint, it is preferable that the first section screen R21 of the second recess R2 extends toward the outer circumference OS of the crawler as it moves toward the root 13P2r side of the second projection 13P2 in the crawler circumferential direction CD.

[0038] When measured at the crawler width direction WD and crawler circumferential direction CD positions where the length M1 of the crawler thickness direction TD of the first recess R1 (Figure 6(b)) is maximum, it is preferable that the ratio of the length M1 of the crawler thickness direction TD of the first recess R1 to the length of the crawler thickness direction TD of the first projection 13P1 is 30-70%. As a result, the first recess R1 is positioned in a part where the first projection 13P1 and the second projection 13P2 are particularly likely to come into contact with each other when the rubber crawler 1 bends around a sprocket, etc., thereby suppressing contact between the first projection 13P1 and the second projection 13P2, and also suppressing a decrease in the ease with which the first projection 13P1 and the second projection 13P2 engage with each other and a decrease in the rigidity of the first projection 13P1 when adjacent core metals 13 move relative to each other in the crawler width direction WD, and consequently suppressing a decrease in the original function of the first projection 13P1 and the second projection 13P2, which is the lateral displacement prevention function (and consequently the wheel derailment prevention function). Here, in the example of Figure 6, the "crawler width direction WD and crawler circumferential direction CD position where the length M1 of the crawler thickness direction TD of the first recess R1 is maximized" specifically refers to the crawler width direction WD and crawler circumferential direction CD position of the first recess R1 on both sides of the crawler width direction WD that are facing the second projection 13P2 of the other core metal 13 (in this embodiment, the inside of the crawler width direction WD) and at the end of the second side CD2 in the crawler circumferential direction. When measured at the crawler width direction WD and crawler circumferential direction CD positions where the length M2 of the crawler thickness direction TD of the second recess R2 (Figure 8(b)) is maximum, it is preferable that the ratio of the length M2 of the crawler thickness direction TD of the second recess R2 to the length of the crawler thickness direction TD of the second projection 13P2 is 30-70%. As a result, the second recess R2 is positioned in a part where the first projection 13P1 and the second projection 13P2 are particularly likely to come into contact with each other when the rubber crawler 1 bends around a sprocket, etc., thereby suppressing contact between the first projection 13P1 and the second projection 13P2, and also suppressing a decrease in the ease with which the first projection 13P1 and the second projection 13P2 engage with each other and a decrease in the rigidity of the second projection 13P2 when adjacent core metals 13 move relative to each other in the crawler width direction WD, and consequently suppressing a decrease in the original function of the first projection 13P1 and the second projection 13P2, which is the lateral displacement prevention function (and consequently the wheel derailment prevention function). Here, in the example of Figure 8, the "crawler width direction WD and crawler circumferential direction CD positions where the length M2 of the crawler thickness direction TD of the second recess R2 is maximized" specifically refers to the crawler width direction WD and crawler circumferential direction CD positions of the second recess R2 on both sides of the crawler width direction WD that face the first projection 13P1 of the other core metal 13 (in this embodiment, the outside of the crawler width direction WD) and the end of the first side CD1 in the crawler circumferential direction.

[0039] As shown in Figure 6, it is preferable that the surface 13P1a of the first projection 13P1 facing the second projection 13P2 of the other core metal 13 (in this embodiment, the inner surface in the crawler width direction WD) of the crawler width direction WD on both sides of the crawler width direction WD extends toward the side facing the second projection 13P2 of the other core metal 13 (in this embodiment, the inner side in the crawler width direction WD) as it moves toward the base 13P1r of the first projection 13P1 in the crawler circumferential direction CD. It is also preferable that the surface of the crawler inner circumferential side IS of the first projection 13P1 is substantially perpendicular to the crawler thickness direction TD. Furthermore, it is preferable that the first section surface R11 of the first recess R1 extends toward the crawler outer circumferential side OS as it moves toward the side facing the second projection 13P2 of the other core metal 13 (in this embodiment, the inner side in the crawler width direction WD) of the crawler width direction WD. Furthermore, it is preferable that the second section screen R12 of the first recess R1 extends toward the side facing the second projection 13P2 of the other core metal 13 (in this embodiment, the inside of the crawler width direction WD) as it moves toward the base 13P1r side of the first projection 13P1 in the crawler circumferential direction CD. Furthermore, it is preferable that the third section screen R13 of the first recess R1 extends toward the side facing the second projection 13P2 of the other core metal 13 (in this embodiment, the inside of the crawler width direction WD) as it moves toward the base 13P1r side of the first projection 13P1 in the crawler circumferential direction CD. However, it is preferable that the acute angle of the third section screen R13 with respect to the crawler width direction WD is smaller than the acute angle of the second section screen R12 with respect to the crawler width direction WD. As shown in Figure 8, it is preferable that the second projection 13P2 has a surface 13P2a on either side of the crawler width direction WD that faces the first projection 13P1 of the other adjacent core metal 13 (in this embodiment, the surface on the outside of the crawler width direction WD) that extends towards the base 13P2r of the second projection 13P2 in the crawler circumferential direction CD, and that this extends towards the side facing the first projection 13P1 of the other core metal 13 (in this embodiment, the outside of the crawler width direction WD). It is also preferable that the surface of the crawler inner circumferential side IS of the second projection 13P2 is substantially perpendicular to the crawler thickness direction TD. Furthermore, it is preferable that the first section surface R21 of the second recess R2 extends towards the crawler outer circumferential side OS as it moves towards the side facing the first projection 13P1 of the other core metal 13 (in this embodiment, the outside of the crawler width direction WD). Furthermore, it is preferable that the second section screen R22 of the second recess R2 extends toward the side facing the first projection 13P1 of the other core metal 13 (in this embodiment, the outside of the crawler width direction WD) as it moves toward the base 13P2r side of the second projection 13P2 in the crawler circumferential direction CD. Furthermore, it is preferable that the third section screen R23 of the second recess R2 extends toward the side facing the first projection 13P1 of the other core metal 13 (in this embodiment, the outside of the crawler width direction WD) as it moves toward the base 13P2r side of the second projection 13P2 in the crawler circumferential direction CD. However, it is preferable that the acute angle of the third section screen R23 with respect to the crawler width direction WD is smaller than the acute angle of the second section screen R22 with respect to the crawler width direction WD.

[0040] In the embodiment described above, each of the pair of first projections 13P1 of the core metal 13 has a first recess R1, and each of the pair of second projections 13P2 of the core metal 13 has a second recess R2 (Figure 4). In this case, the clearance P between the first projections 13P1 and the second projections 13P2 when the rubber crawler 1 bends around a sprocket, etc., is increased, and consequently, the effect of suppressing contact between the first projections 13P1 and the second projections 13P2 when the rubber crawler 1 bends around a sprocket, etc. is greatest. However, as shown in the modified example in Figure 11, for example, only the first projection 13P1 on the crawler width direction side WD1 of the pair of first projections 13P1 of the core metal 13 may have the first recess R1, and only the second projection 13P2 on the crawler width direction side WD2 of the pair of second projections 13P2 of the core metal 13 may have the second recess R2. In this case, of the first projection 13P1 on the crawler width direction side WD2 of the pair of first projections 13P1 of the core metal 13, the surface 13P1a on both sides of the crawler width direction WD that faces the adjacent second projection 13P2 of the other core metal 13 will be a substantially flat surface, and of the second projection 13P2 on the crawler width direction side WD1 of the pair of second projections 13P2 of the core metal 13, the surface 13P2a on both sides of the crawler width direction WD that faces the adjacent first projection 13P1 of the other core metal 13 will be a substantially flat surface. Even in this case, the first recess R1 and the second recess R2 will each face a substantially flat surface, so compared to the case where the first recess R1 and the second recess R2 are not provided at all (i.e., substantially flat surfaces face each other), the clearance P between the first projection 13P1 and the second projection 13P2 when the rubber crawler 1 turns around a sprocket, etc., can be increased, and consequently, contact between the first projection 13P1 and the second projection 13P2 can be suppressed when the rubber crawler 1 turns around a sprocket, etc. Alternatively, only the first projection 13P1 on the crawler width direction side WD1 of the pair of first projections 13P1 of the core metal 13 may have the first recess R1, and neither of the pair of second projections 13P2 of the core metal 13 may have the second recess R2. Even in this case, on the crawler width direction side WD1, the first recess R1 and a substantially flat surface will face each other, so compared to the case where neither the first recess R1 nor the second recess R2 is provided at all, the clearance P between the first projection 13P1 and the second projection 13P2 can be increased when the rubber crawler 1 bends around a sprocket or the like, and consequently, contact between the first projection 13P1 and the second projection 13P2 can be suppressed. [Industrial applicability]

[0041] The rubber crawler of the present invention is preferably mounted on the undercarriage of any running machine, such as construction machinery (mini excavators, etc.) or agricultural machinery (tractors, combine harvesters, etc.). [Explanation of symbols]

[0042] 1: Rubber crawler, 12: Crawler body, 121: Inner surface of crawler body, 122: Outer surface of crawler body, 13: Mandrel, 13B: Base section, 13Bc: Central section, 13Bw: Wing section, 13C: Corner, 13Ca: Top surface, 13P1: First projection (projection), 13P1a: Of the surfaces on both sides in the crawler width direction, the surface facing the second projection of the other core metal, 13P1t: Tip, 13P1r: Base 13P2: Second projection (projection), 13P2a: Of the surfaces on both sides in the crawler width direction, the surface facing the first projection of the other core metal, 13P2t: Tip, 13P2r: Base R1: First recess, R11: First section screen, R12: Second section screen, R13: Third section screen, R1t: Tip end of the first projection in the crawler's circumferential direction, R1r: Base end of the first projection in the crawler's circumferential direction R2: Second recess, R21: First section screen, R22: Second section screen, R23: Third section screen, R2t: Tip end of the second projection in the crawler's circumferential direction, R2r: Base end of the second projection in the crawler's circumferential direction g: clearance, 14: Lag, 15: Core layer, 15C: Cord, 16: Hole, CD: Crawler circumferential direction, CD1: First side of the crawler circumferential direction, CD2: Second side of the crawler circumferential direction TD: Crawler thickness direction, WD: Crawler width direction, WD1: First side in the crawler width direction, WD2: Second side in the crawler width direction, IS: Inner circumference side of crawler, OS: Outer circumference side of crawler

Claims

1. An endless crawler body made of rubber, A plurality of core metals are embedded in the crawler body and arranged along the circumferential direction of the crawler, A rubber crawler equipped with, Each of the aforementioned core metals is A base portion extending in the width direction of the crawler, A pair of corners extending from the base portion toward the inner circumference of the crawler, A pair of first protrusions extending from the base portion toward the first side in the crawler circumferential direction, A pair of second protrusions extending from the base portion toward the second side in the crawler's circumferential direction, Equipped with, Each of the pair of first projections on the core metal is positioned opposite the pair of second projections on the other core metal adjacent to the core metal on the first side in the crawler circumferential direction, in the crawler width direction. Of the pair of first projections of each core metal, at least the first projection on the first side in the crawler width direction has a first recess on the surface on either side in the crawler width direction that faces the second projection of the other core metal. The first recess is such that the end of the first recess on the tip side of the first projection in the crawler circumferential direction is located closer to the root side of the first projection than to the tip of the first projection in the crawler circumferential direction. The first recess, at least in the portion including the tip end of the first projection in the crawler circumferential direction, has a length in the crawler width direction that increases as it moves toward the root side of the first projection in the crawler circumferential direction. The first recess is open on the inner circumference side of the crawler and closed on the outer circumference side of the crawler. The first recess is a rubber crawler with a roughly triangular prism shape.

2. The rubber crawler according to claim 1, wherein the length of the first recess increases in the crawler thickness direction as it approaches the root side of the first projection in the crawler circumferential direction.

3. Of the pair of second projections of each core metal, at least the second projection on the second side in the crawler width direction has a second recess on the surface on either side in the crawler width direction that faces the first projection of the other core metal. The second recess is such that the end of the second recess on the tip side of the second projection in the crawler circumferential direction is located closer to the root side of the second projection than to the tip of the second projection in the crawler circumferential direction. The second recess, at least in the portion including the tip end of the second projection in the crawler circumferential direction, has a length in the crawler width direction that increases as it moves toward the root side of the second projection in the crawler circumferential direction. The second recess is open on the inner circumference side of the crawler and closed on the outer circumference side of the crawler. The rubber crawler according to claim 1, wherein the second recess has a substantially triangular prism shape.

4. The core metal used in the rubber crawler according to any one of claims 1 to 3.

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