JP2005271874A - Elastic crawler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crawler which is superior in durability and suppresses the formation of a crack near the end of a core bar effectively. <P>SOLUTION: The crawler K comprises a crawler body 11 of an endless belt shape, core bars 12 embedded in the crawler body 11 longitudinally of the belt shape at every a prescribed distance, and lugs 13 projected on the crawler body 11 longitudinally of the belt shape at every a prescribed distance. The end 12a of each core bar 12 is formed into an end face 112a that has a radius of curvature of 3 mm or more. In addition, a reinforcing fiber layer 1 and an elastic layer 2 with high hardness are formed at the outside of the end 12a of the core bar 12 to be curved in correspondence to the end face 112a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an endless belt-like elastic crawler used in an infinite traveling device such as a construction machine or an agricultural machine.

  The elastic crawler is equipped with an endless belt-shaped crawler body made of an elastic material such as rubber and synthetic resin. Compared with an iron crawler, it has lower noise, better ride comfort, and higher road surface protection. It is widely used because of its advantages. In such an elastic crawler, a plurality of core bars are often embedded at predetermined intervals in the band longitudinal direction (circumferential direction) in order to improve the grounding supportability and strength.

When the elastic crawler with the core metal embedded is wound around various infinite traveling devices and used, for example, it rides on an obstacle such as a curb on the shoulder of a road, or is pressed from the side of the obstacle. If it is carried out, the elastic body which comprises a crawler main body will be compressed between a metal core and an obstruction. And when such compression is repeated, there exists a problem (a so-called ear-cut problem) that a crawler main body will crack. In particular, since stress concentration tends to occur near the end of the core bar, cracks are likely to occur.
In addition, the elastic crawler has a lug formed on the ground contact surface side to generate a predetermined traction force, but when this lug comes into contact with an obstacle, it is twisted backward and stress concentration occurs. As a result, there is a problem that an oblique crack occurs in the lug.

  In order to solve the above problems, a technique is proposed in which a high-hardness elastic layer having a higher hardness than other elastic bodies forming the elastic crawler body is interposed outside the longitudinal end (band width direction) end of the core metal. (For example, refer to Patent Document 1).

JP 2003-335275 A (Claim 1, FIG. 2)

However, in the above-described elastic crawler, since the tip of the cored bar has a shape with a small radius of curvature, there is a problem that the cored bar bites in from the inner side of the crawler main body and cracks occur starting from that part. In addition, there is a problem that a large crack is caused by being connected to a crack generated on the lug side, and the crack is broken.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide an elastic crawler excellent in durability capable of effectively suppressing the occurrence of cracks particularly in the vicinity of the end portion of the cored bar.

The elastic crawler of the present invention includes a crawler body made of an elastic material formed in an endless belt shape, a core bar embedded in the crawler body at predetermined intervals in the longitudinal direction of the belt, and a longitudinal band in the crawler body. An elastic crawler provided with a tensile body embedded along a direction and lugs projecting at predetermined intervals in the longitudinal direction of the band on the grounding surface side of the crawler body, A central portion extending in the width direction, and an end portion having an end surface with a radius of curvature set to 3 mm or more on the ground surface side, and in the end surface of the end portion of the cored bar inside the crawler body A reinforcing fiber layer having a curved portion corresponding to the curved surface shape is formed.
According to the above configuration, the cored bar end is formed in a large curved surface shape, and the reinforcing fiber layer having a curved part corresponding to the curved surface shape is formed. It is possible to relieve stress concentration. For this reason, it can suppress effectively that a crack generate | occur | produces in the crawler main body made from an elastic material in the vicinity of a metal core edge part.

  In the elastic crawler, it is preferable that a high-hardness elastic layer having a curved portion corresponding to a curved shape at the end face of the cored bar is formed outside the reinforcing fiber layer. In this case, the stress concentration generated in the vicinity of the end portion of the metal core can be further relaxed. Moreover, even if a crack occurs in the high-hardness elastic layer, the reinforcing fiber layer disposed on the end side of the cored bar causes the crack generated in the high-hardness elastic layer to progress to the vicinity of the end of the cored bar. It has the advantage that it can be effectively prevented.

In the above-described elastic crawler, it is preferable that a reinforcing fiber layer having a curved portion corresponding to the curved shape at the end portion of the core metal is also formed outside the high-hardness elastic layer. In this case, the stress concentration in the vicinity of the end of the cored bar can be further relaxed, and good durability can be exhibited against impact from the lateral direction (band width direction).
In the elastic crawler, it is preferable that at least one of the reinforcing fiber layer and the high-hardness elastic layer is extended to the grounding surface side so as to overlap the cored bar. In this case, the progress of the oblique crack from the end of the lug can be stopped, and even if a crack occurs in the vicinity of the end of the cored bar, there is a problem that both the cracks are connected and the elastic crawler is damaged. Can be effectively prevented.

  In the above-described elastic crawler, the both ends in the width direction of the crawler main body surface existing between the lugs adjacent in the longitudinal direction of the belt can be configured to bulge in a curved shape on the ground contact surface side. The both ends of the crawler body surface existing between the lugs adjacent to each other in the longitudinal direction may be configured to bulge out in a cross-sectional shape on the ground surface side.

In the elastic crawler, the crawler body surface and the lug surface are assumed to be virtual horizontal surfaces with respect to the surface closest to the ground contact surface, respectively, and the normal line is directed from the tip of the cored bar toward the ground contact surface. When the distance to the virtual horizontal plane of the crawler main body is A and the distance to the virtual horizontal plane of the lug is B when extended, the value (A / B) obtained by dividing the distance A by the distance B is 0.5. It is preferable to be set within the range of 0.75 or more and 0.75 or less. In this case, since the relationship between the burying position of the core metal and the thickness of the lug becomes appropriate, it can be used stably over a long period of time while ensuring good running performance.
Here, in the present invention, the elastic crawler has a surface closest to the ground contact surface among the surfaces of the crawler body when the normal is extended from the core metal tip toward the ground contact surface. The actual surface is also included in the “virtual horizontal surface of the crawler body”. Similarly, when the normal line extends from the tip of the mandrel toward the ground plane, the surface closest to the ground plane among the lug surfaces exists. It should be included in the “imaginary horizontal surface of the rug”.

  According to the present invention, it is possible to effectively suppress the occurrence of cracks particularly in the vicinity of the end portion of the cored bar. For this reason, the elastic crawler excellent in durability which suppressed generation | occurrence | production of what is called an ear piece effectively can be provided.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a belt longitudinal direction sectional view schematically showing an elastic crawler according to a first embodiment of the present invention, and FIG. 2 is a band width direction sectional view. The elastic crawler K according to the present embodiment is used by being wound around wheels such as a driving wheel and a driven wheel of an infinite traveling device such as a construction machine or an agricultural machine, and includes an endless belt-like crawler body 11 and a crawler body. 11 and a metal core 12 embedded in the interior of the crawler 11 and a lug 13 that protrudes integrally on the grounding surface side of the crawler body 11.

  The crawler main body 11 is formed in an endless belt shape using an elastic material such as rubber or synthetic resin that exhibits elasticity in consideration of low noise, good riding comfort, high road surface protection, and the like. As a material for forming the crawler body 11, for example, a material having a JIS-A hardness of 65 and a 200% modulus of 5.0 MPa is preferably used.

In the crawler body 11, a plurality of core bars 12 are embedded at equal intervals in the longitudinal direction of the band (the circumferential direction of the elastic crawler K) in order to increase the strength and ground contact support of the elastic crawler K. The cored bar 12 is formed in a symmetrical shape (see FIG. 2) with a rigid material such as metal or reinforced synthetic resin. Specifically, the cored bar 12 includes a central part 12b extending in the band width direction of the elastic crawler K, an end part 12a formed in a specific shape connected to the central part 12b, and the crawler body 12 above the central part 12b. And a protrusion 12c located in the vicinity of the center.
A tension member 14 made of a plurality of steel cords is banded on the grounding surface side (lower side in FIGS. 1 and 2) of the cored bar 12 along the band longitudinal direction (circumferential direction) of the crawler body 11. It is embedded in parallel in the width direction at predetermined intervals, increasing the tensile strength of the elastic crawler K in the longitudinal direction of the band.

  Referring to FIG. 3, the cored bar 12 is in contact with both end portions 12a (only one end is shown) of an end surface 112a having a large curved surface, specifically, an end surface 112a having a radius of curvature of 3 mm or more. It is provided on the ground side (lower side in the figure), so that stress concentration in the vicinity of the end 12a can be relaxed. Further, the core metal 12 is connected to the ground surface side of the end surface 112a, a horizontal bottom surface 112b formed over the core metal central portion 12b and the core metal end portion 12a, and the non-ground surface side of the end surface 112a (upper side in the figure). And an inclined surface 112d that is continuous with the end surface 112c and is inclined upward toward the center in the band width direction.

  Further, a reinforcing fiber layer 1 made of a fiber material such as a reinforcing fiber cord or a reinforcing short fiber is formed on the outer periphery of the end surface 112a of the cored bar 12 on the entire circumference in the circumferential direction of the elastic crawler K (also in FIG. 1). reference). The reinforcing fiber layer 1 is made of, for example, a canvas obtained by plain weaving or thick weaving of organic high-tensile fibers (polyester rayon, vinylon, aramid fiber, etc.), and corresponds to the curved shape of the end face 112a of the cored bar 12. It has a portion formed in a curved shape. Specifically, the reinforcing fiber layer 1 includes a concentric arcuate portion (curved portion) 1a formed substantially concentrically with the curved surface shape of the end surface 112a of the core metal 12, and two existing on both ends of the core metal 12. An extending portion that connects the concentric arcuate portions 1a and 1a (shown only on one end side in FIG. 3) and extends between the cored bar 12 and the tensile body 14 so as to face the bottom surface 112b of the cored bar 12. 1b.

Further, on the outside of the concentric arc-shaped portion (curved portion) 1a of the reinforcing fiber layer 1, a thick material made of an elastic material having a hardness higher than that of the elastic material of the crawler body 11 and having a high JIS-A hardness of 70 or more. An elastic layer 2 is formed. As a material for forming the high-hardness elastic layer 2, a polymer material such as rubber or synthetic resin, a material obtained by adding a reinforcing material such as cut fiber to the polymer material, or the like is used. In particular, those having a JIS-A hardness of 85 and a 200% modulus of 10.5 Mpa are preferably used.
The high hardness elastic layer 2 has a curved portion corresponding to the curved shape of the end surface 112 a of the core metal 12. More specifically, a concentric arcuate part (curved part) 2a formed substantially concentrically with the curved surface shape of the end surface 112a of the cored bar 12, and a bottom surface 112b of the cored bar 12 on the grounding surface side of the concentric arcuate part 2a. And an extending portion 2b extending so as to overlap a part of the. The high-hardness elastic layer 2 has a lapping margin (distance from a position that intersects the normal of the longitudinal end of the core 12 to a position extending toward the center of the extending portion 2 in the width direction) L1 is set to 10 mm or more. It is preferable.

  Returning to FIG. 1, lugs 13 extending in the width direction of the crawler main body 11 are integrally protruded at equal intervals in the longitudinal direction of the band (the circumferential direction of the elastic crawler K). Traction force can be generated by such lugs 13. The lugs 13 correspond to the embedded positions of the cored bar 12 and project at the same pitch as the cored bar 12. As shown in FIGS. 2 and 3, the surface (grounding surface side) 15 of the crawler body 11 existing between the lugs 13 adjacent in the belt longitudinal direction (circumferential direction) is formed in a horizontal plane.

  In the elastic crawler K according to the present embodiment configured as described above, the end 12a of the cored bar 12 is formed on a large curved end surface 112a and substantially concentric with the curved shape of the end surface 112a. Since the reinforcing fiber layer 1 and the high-hardness elastic layer 2 having the formed concentric arc-shaped portions 1a and 2a are formed, they can ride on an obstacle when used while being wound around a wheel, Even if it receives an impact from (band width direction), it can suppress effectively that a big crack generate | occur | produces in the crawler main body 11. FIG. Specifically, the large curved surface shape of the end surface 112a of the end portion 12a of the cored bar 12 and the reinforcing fiber layer 1 cause the elastic material constituting the crawler body 11 to bite into the end 12a of the cored bar 12. It can suppress effectively by letting it escape upward (non-grounding surface side). Further, since the reinforcing fiber layer 1 exists in the vicinity of the end portion 12a of the core metal 12, the stress concentration that has conventionally occurred in that portion can be relaxed. In addition, since the reinforcing fiber layer 1 is positioned on the end 12a side of the core metal 12 with respect to the high hardness elastic layer 2, even if a crack occurs in the high hardness elastic layer 2, the crack is detected at the end 12a of the core metal 12. Proceeding to the vicinity can be effectively prevented. Furthermore, in this embodiment, since the part on the ground contact surface side of the high hardness elastic layer 2 extends so as to overlap the bottom surface 112b of the cored bar 12, the progress of the oblique crack from the end of the lug 13 is prevented. It has the advantage that it can be stopped. Further, since the end portion 12a of the core metal 12 is not greatly raised to the inner peripheral side (non-grounding surface side), a crack is generated on the inner peripheral surface of the crawler main body 11 due to a reverse warping phenomenon when riding on an obstacle. There is also an advantage that a problem such as occurrence is effectively prevented.

(Second Embodiment)
FIG. 4 is a sectional view in the band width direction of an elastic crawler according to the second embodiment of the present invention, and FIG. 5 is a partial sectional view in which one end side is enlarged. This elastic crawler uses a cored bar having a different end shape from the elastic crawler according to the first embodiment, and changes the configuration of the reinforcing fiber layer and the high-hardness elastic layer on the end side.

  In the present embodiment, as shown in FIG. 5, the end 12a of the metal core 12 has a large curved end surface 112a, specifically, an end surface 112a having a curvature radius set to 3 mm or more on the ground surface side. ing. The metal core 12 has a horizontal bottom surface 112b formed on the grounding surface side of the end surface 112a over the end portion 12a and the central portion 12b, and is inclined downward from the end portion toward the center on the non-grounding surface side of the end surface 112a. The inclined surface 112c and the inclined surface 112d that is continuous with the inclined surface 112c and is inclined upward toward the center are formed, and the end surface 112a is formed in a large curved shape while ensuring grounding support and weight reduction. I can do it.

Reinforcing fiber layers 21 and 22 are formed outside the end surface 112 a of the core metal 12, and the reinforcing fiber layers 21 and 22 are curved corresponding to the curved shape of the end surface 112 a of the core metal 12. It has the part formed in. Specifically, the reinforcing fiber layer 21 closer to the end surface 112a of the two layers includes a concentric arcuate portion (curved portion) 21a formed substantially concentrically with the curved shape of the end surface 112a of the cored bar 12. The two concentric arcuate portions 21a and 21a (only one end side is shown in FIG. 5) existing on both ends of the core 12 are connected, and along the bottom surface 112b of the core 12 between the core 12 and the tension member 14. And an extending portion 21b extending so as to face each other. On the other hand, the reinforcing fiber layer 22 located closer to the grounding surface than the reinforcing fiber layer 21 has a concentric arcuate portion (curved portion) 22a formed substantially concentrically with the curved surface shape of the end surface 112a of the core metal 12; The concentric arcuate portion 22a is connected to the grounding surface side of the concentric arcuate portion 22a so as to overlap with a part of the bottom surface of the core metal 12 and extend to the vicinity of the tensile member 14. The reinforcing fiber layer 22 has a lapping margin (a distance from a position intersecting the normal of the longitudinal end of the core 12 to a position extending toward the center of the extending portion 22b in the width direction) L2 is set to 10 mm or more. It is preferable.

  Further, a thick high-hardness elastic layer 23 is formed outside the concentric arcuate portion (curved portion) 22a of the reinforcing fiber layer 22. The high-hardness elastic layer 23 has a curved portion corresponding to the curved shape of the end surface 112 a of the core metal 12. Specifically, a thick concentric arcuate part (curved part) 23a formed substantially concentrically with the curved surface shape of the end face 112a of the cored bar 12, and the cored bar 12 on the grounding surface side of the concentric arcuate part 23a. And an extending portion 23b extending so as to overlap with a part of the bottom surface 112b of the. The high-hardness elastic layer 23 has a lapping margin (distance from a position intersecting the normal of the longitudinal end of the core metal 12 to a position extending toward the center of the extending portion 23b in the band width direction) L1 is set to 10 mm or more. It is preferable.

  Furthermore, a reinforcing fiber layer 24 is formed outside the concentric arcuate portion (curved portion) 23 a of the high-hardness elastic layer 23, and the reinforcing fiber layer 24 is a curved shape of the end surface 112 a of the core metal 12. Corresponding to the curved portion. Specifically, the reinforcing fiber layer 24 is concentric with the end surface 112a of the core metal 12 and concentric arc-shaped portion 24a, and the grounding surface side of the concentric arc-shaped portion 24a overlaps a part of the bottom surface of the core metal 12. In this way, it has an extending portion 24b extending in a meandering manner. The reinforcing fiber layer 24 has a lapping margin (a distance from a position where it intersects the normal of the longitudinal tip of the core 12 to a position extending toward the center of the extending portion 24b in the width direction) L3 is set to 10 mm or more. It is preferable.

  In the elastic crawler according to the present embodiment, the surface (grounding surface side) 15 of the crawler main body 11 existing between the lugs 13 adjacent in the band longitudinal direction (circumferential direction) is formed in a curved shape at both ends in the band width direction. Has been. Specifically, the surface 15 has a horizontal plane 15b formed at the center in the band width direction, and curved surfaces 15a formed at both ends in the band width direction and connected to the horizontal plane 15b. Such a curved surface 15a Thus, the impact from the lateral direction can be dispersed.

  Even the elastic crawler according to the present embodiment configured as described above can achieve the same effects as those of the first embodiment. Furthermore, compared with the first embodiment, since two further reinforcing fiber layers 22 and 24 are formed at both ends in the band width direction, the stress concentration generated near the end 12a of the cored bar 12 is further alleviated. In addition, it is possible to exert a stronger durability against an impact from the lateral direction. Further, since the curved surfaces 15a are formed on both ends in the width direction of the surface 15 existing between the lugs 13 adjacent to each other in the band longitudinal direction (circumferential direction), it is possible to disperse the impact from the lateral direction. Also have.

(Third embodiment)
FIG. 6 is a partial cross-sectional view showing an elastic crawler according to the third embodiment of the present invention. This elastic crawler uses a cored bar different from the elastic crawler according to the first embodiment, and changes the configuration of the reinforcing fiber layer and the high hardness elastic layer on the end side.

  In the present embodiment, the end portion 12a of the core metal 12 has a large curved end surface 112a, specifically, an end surface 112a having a curvature radius set to 3 mm or more on the ground surface side. The metal core 12 includes a horizontal end bottom surface 112c extending toward the center of the band width on the grounding surface side of the end surface 112, an inclined surface 112d that is connected to the end bottom surface 112c and is inclined upward. It has a horizontal central bottom surface 112b that is continuous with the inclined surface 112d and extends toward the center.

  The reinforcing fiber layer 31 is formed outside the end surface 112a of the cored bar 12, and the reinforcing fiber layer 31 is formed in a curved shape corresponding to the curved shape of the end surface 112a of the cored bar 12. Has a part. Specifically, the reinforcing fiber layer 31 is connected to the concentric arc-shaped portion (curved portion) 31a formed substantially concentrically with the end surface 112a of the core metal 12, and the concentric arc-shaped portion 31a. An extending portion 31b that extends so as to face the bottom surface 112c, and an inclined portion 31c that is connected to the extending portion 31b and extends so as to face the inclined surface 112d of the cored bar 12. The central portion 31d is connected to the inclined portion 31c and extends between the cored bar 12 and the tensile body 14 so as to be opposed along the central bottom surface 112b of the cored bar 12.

  A reinforcing fiber layer 32 is formed outside the concentric arcuate portion (curved portion) 31 a of the reinforcing fiber layer 31, and the reinforcing fiber layer 32 has a curved shape on the end surface 112 a of the cored bar 12. Correspondingly, a curved portion is provided. Specifically, the reinforcing fiber layer 32 includes a concentric arcuate portion (curved portion) 32a formed substantially concentrically with the end surface 112a of the cored bar 12, and a width continuous to the grounding surface side of the concentric arcuate portion 32a. An extension part 32b that extends to a portion that partially overlaps the tensile body 14 toward the center in the direction, and a position on the grounding surface side across the high-hardness elastic layer 23, and an end face 112a of the cored bar 12 A concentric arcuate part (curved part) 32d formed substantially concentrically, and a connection part 32c that connects the concentric arcuate part 32a and the concentric arcuate part 32d on the non-grounding surface side. The reinforcing fiber layer 32 has a lapping margin (a distance from a position intersecting the normal of the longitudinal end of the core metal 12 to a position extending toward the center in the band width direction of the extending portion 32b) set to 10 mm or more. Is preferred.

  Further, a thick high-hardness elastic layer 23 is formed outside the concentric arc-shaped portion 32a of the reinforcing fiber layer 32. The high-hardness elastic layer 23 has a curved shape on the end surface 112a of the cored bar 12. Correspondingly, a curved portion is provided. Specifically, a thick concentric arcuate portion (curved portion) 23a formed substantially concentrically with the curved surface shape of the end surface 112a of the core metal 12 and the concentric arcuate portion 23a connected to the concentric arcuate portion 23a. On the ground side, there is a thick extending portion 23b extending so as to overlap a part of the bottom surface of the cored bar 12. The high-hardness elastic layer 23 has a lapping margin (a distance from a position that intersects the normal of the longitudinal end of the core metal 12 to a position that extends toward the center in the band width direction of the extending portion 23b) set to 10 mm or more. It is preferable.

  In the elastic crawler according to the present embodiment, as in the second embodiment, the surface (grounding surface side) 15 of the crawler main body 11 existing between the lugs 13 adjacent in the band longitudinal direction (circumferential direction) Both ends in the width direction are formed in a curved shape. Specifically, the surface 15 has a horizontal plane 15b formed at the center in the band width direction, and curved surfaces 15a formed at both ends in the band width direction and connected to the horizontal plane 15b. Such a curved surface 15a Thus, the impact from the lateral direction can be dispersed.

  Even the elastic crawler according to the present embodiment configured as described above can achieve the same effects as those of the first embodiment. Furthermore, since the reinforcing fiber layer 32 having the two concentric arcuate portions 32a and 32d is formed as compared with the first embodiment, the stress concentration generated in the vicinity of the end portion 12a of the core metal 12 is further relaxed. In addition, it is possible to exhibit stronger durability against impact from the lateral direction. Further, since the curved surfaces 15a are formed on both ends in the width direction of the surface 15 existing between the lugs 13 adjacent to each other in the band longitudinal direction (circumferential direction), it is possible to disperse the impact from the lateral direction. Also have.

(Fourth embodiment)
FIG. 7 is a partial sectional view showing an elastic crawler according to the fourth embodiment of the present invention. This elastic crawler is different from the elastic crawler according to the first embodiment in the configuration of the reinforcing fiber layer and the high-hardness elastic layer formed outside the end portion of the cored bar.

  In the present embodiment, a reinforcing fiber layer 41 is formed outside the end surface 112a of the cored bar 12, and the reinforcing fiber layer 41 is curved corresponding to the curved shape of the end surface 112a of the cored bar 12. It has a formed part. More specifically, the reinforcing fiber layer 41 connects the concentric arc-shaped portion (curved portion) 41a formed substantially concentrically with the end surface 112a of the core metal 12 and the concentric arc-shaped portions 41a at both ends, An extending portion 41 b extending so as to face the tensile member 14 along the bottom surface 112 b of the cored bar 12 is provided.

  A thick high-hardness elastic layer 42 is formed outside the concentric arc-shaped portion (curved portion) 41 a of the reinforcing fiber layer 41, and the high-hardness elastic layer 42 is an end surface 112 a of the cored bar 12. And a curved portion corresponding to the curved surface shape. Specifically, the high-hardness elastic layer 42 is connected to the concentric arc-shaped portion (curved portion) 42a formed substantially concentrically with the end surface 112a of the core metal 12, and the concentric arc-shaped portion 42a. It has an extended portion 42b that overlaps with a part of the bottom surface 112b and is formed so that the thickness gradually decreases toward the center in the band width direction. The high-hardness elastic layer 42 has a lapping margin (a distance from a position that intersects the normal of the longitudinal tip of the core metal 12 to a position extending toward the center of the extending portion 42b in the band width direction) set to 10 mm or more. It is preferable.

  Further, reinforcing fiber layers 43 and 44 are formed outside the concentric arcuate portion (curved portion) 42 a of the high-hardness elastic layer 42, and these reinforcing fiber layers 43 and 44 are both of the core metal 12. A portion formed in a curved shape corresponding to the curved shape of the end surface 112a is provided. Specifically, the reinforcing fiber layers 43 and 44 are both concentric arcuate portions (curved portions) 43a and 44a that are substantially concentrically formed with the end surface 112a of the core metal 12, and the concentric arcuate portions 43a, Each of the extending portions 43b and 44b extends so as to overlap with a part of the cored bar 12 toward the center in the width direction, continuing to the ground contact surface side of 44a. Each of the reinforcing fiber layers 43 and 44 has a wrap margin (a distance from a position intersecting with the normal of the longitudinal end of the core 12 to a position extending toward the center of the extending portion 43b or 44b in the band width direction). It is preferably set to 10 mm or more.

In the elastic crawler according to the present embodiment, the surface 15 of the crawler main body 11 existing between the lugs 13 adjacent in the belt longitudinal direction (circumferential direction) is formed to bulge in a curved shape toward the ground contact surface. Specifically, the surface 15 has a horizontal surface 15b formed at the center in the band width direction, and a curved surface 15a that is continuous with the horizontal surface 15b and bulges toward the grounding surface toward both ends in the width direction and is curved. Such a curved surface 15a can further disperse the impact from the lateral direction.
Further, regarding the surface of the crawler body 11 and the surface of the lug 13, a virtual horizontal plane is assumed on the basis of the surface closest to the grounding surface side, and a normal line is formed from the tip of the core metal 12 toward the grounding surface side. When the distance to the virtual horizontal plane of the crawler body 11 is A and the distance to the virtual horizontal plane of the lug 13 (the actual surface of the lug 13 in this embodiment) is B, the distance A is the distance B. The value (A / B) divided by is set within a range of 0.5 or more and 0.75 or less.

  Even the elastic crawler according to the present embodiment configured as described above can achieve the same effects as those of the first embodiment. In particular, compared with the first embodiment, two reinforcing fiber layers 43 and 44 are formed at both ends in the band width direction, so that stress concentration generated in the vicinity of the end portion 12a of the core metal 12 is further alleviated. In addition, it is possible to exert a stronger durability against an impact from the lateral direction. Further, since both ends of the surface 15 in the width direction of the surface 15 existing between the lugs 13 adjacent to each other in the longitudinal direction (circumferential direction) of the belt are formed on the curved surface 15a bulging to the grounding surface side, the impact from the lateral direction Can be further dispersed. Furthermore, since the relationship between the burying position of the core metal 12 and the thickness of the lug 13 is made appropriate, it also has an advantage that it can be used stably over a long period of time while ensuring good running performance. .

(Fifth embodiment)
FIG. 8 is a partial cross-sectional view showing an elastic crawler according to the fifth embodiment of the present invention. This elastic crawler is different from the elastic crawler according to the first embodiment in the configuration of the reinforcing fiber layer and the high-hardness elastic layer formed outside the end portion of the cored bar.

  In the present embodiment, reinforcing fiber layers 51 and 52 are formed outside the end surface 112a of the core metal 12, and each reinforcing fiber layer 51 and 52 is curved corresponding to the curved shape of the end surface 112a. It has the part formed in. More specifically, each of the reinforcing fiber layers 51 and 52 includes concentric arcuate portions (curved portions) 51a and 52a formed substantially concentrically with the end surface 112a of the end portion 12a of the core metal 12, respectively. The grounding surface side extending portions 51b and 52b extending so as to overlap a part of the bottom surface 112b of the cored bar 12 and the concentric arcuate portions 51a and 52a, and the concentric arcuate portions 51a and 52a. Non-grounding surface side extending portions 51c and 52c extending so as to overlap with a part of the upper surface of the surface.

  Further, a thick high-hardness elastic layer 53 is formed outside the concentric arc-shaped portion (curved portion) 52 a of the reinforcing fiber layer 52, and the high-hardness elastic layer 53 is an end face of the cored bar 12. It has a curved portion corresponding to the curved surface shape of 112a. Specifically, a thick concentric arcuate portion (curved portion) 53a formed substantially concentrically with the curved surface shape of the end surface 112a of the metal core 12, and the concentric arcuate portion 53a connected to the concentric arcuate portion 53a. On the ground side, there is a thick extending portion 53b extending so as to overlap a part of the bottom surface of the cored bar 12. The high-hardness elastic layer 53 has a lapping margin (a distance from a position where it intersects the normal of the longitudinal end of the band of the core metal 12 to a position extending toward the center in the width direction of the extending portion 53b) set to 10 mm or more. It is preferable.

  Reinforcing fiber layers 54, 55, 56 are formed outside the concentric arc-shaped portion (curved portion) 53a of the high-hardness elastic layer 53, and the reinforcing fiber layers 54, 55, 56 are respectively It has a portion formed in a curved shape corresponding to the curved surface shape of the end surface 112 a of the core metal 12. Specifically, each of the reinforcing fiber layers 54, 55, and 56 is a concentric arcuate portion (curved portion) 54a, 55a, and 56a formed substantially concentrically with the curved surface shape of the end surface 112a of the core metal 12. And ground surface side extending portions 54b, 55b, and 56b that are connected to the respective concentric arcuate portions 54a, 55a, and 56a and extend so as to overlap a part of the bottom surface 112b of the cored bar 12.

In the elastic crawler according to the present embodiment, the surface 15 of the crawler main body 11 existing between the lugs 13 adjacent in the longitudinal direction (circumferential direction) of the belt is formed to bulge in a cross-section in a cross-sectional shape toward the ground contact surface. ing. Specifically, the surface 57 bulges from an inclined surface 57a inclined toward the ground surface toward the center of the crawler body 11 from a lower side surface of the crawler body 11 and an inclined surface 57b inclined toward the non-ground surface. The crawler body 11 has a horizontal surface 57c at the center. Even the surface 57 bulged in the shape of a cross-section like this can further disperse the impact from the lateral direction.
Further, regarding the surface of the crawler body 11 and the surface of the lug 13, a virtual horizontal plane is assumed on the basis of the surface closest to the grounding surface side, and a normal line is formed from the tip of the core metal 12 toward the grounding surface side. When the distance to the virtual horizontal plane of the crawler body 11 is A and the distance to the virtual horizontal plane of the lug 13 (the actual surface of the lug 13 in this embodiment) is B, the distance A is the distance B. The value (A / B) divided by is set within a range of 0.5 or more and 0.75 or less.
Furthermore, in the elastic crawler according to the present embodiment, the bulging portion 13a is formed by bulging the side surface in the band width direction of the lug 13 outward.

  Even the elastic crawler according to the present embodiment configured as described above can achieve the same effects as those of the first embodiment. In particular, compared with the first embodiment, since many reinforcing fiber layers 51, 52, 54, 55, 56 are formed, the stress concentration generated in the vicinity of the end 12a of the cored bar 12 is further relaxed. In addition, it is possible to exhibit stronger durability against impact from the lateral direction. Moreover, since the both ends of the surface 57 in the width direction of the surface 57 existing between the lugs 13 adjacent in the longitudinal direction (circumferential direction) of the belt are formed in a cross-shaped bulge shape in which the both sides of the surface 57 are bulged toward the grounding surface. , It has the advantage that the impact from the lateral direction can be further dispersed. Furthermore, since the relationship between the burying position of the core metal 12 and the thickness of the lug 13 is made appropriate, it also has an advantage that it can be used stably over a long period of time while ensuring good running performance. .

The present invention is not limited to the above-described embodiments. For example, it is not necessary to form all of the plurality of reinforcing fiber layers in a curved portion corresponding to the curved shape of the core metal end face, and at least of the reinforcing fiber layers present on the core metal end side of the high hardness elastic layer. What is necessary is just to form in a curved part per layer. However, since a better result can be obtained when formed in a curved portion (particularly a concentric arc-shaped portion), when a plurality of reinforcing fiber layers are formed, it is preferable to form all of them with curved portions.
Further, in the present invention, depending on the use of the elastic crawler, etc., the cored bar 12 that does not have the protrusion 12c may be used, and the lug 13 may be arranged in an appropriate pattern. Good.

It is a belt longitudinal direction sectional view of an elastic crawler concerning a 1st embodiment of the present invention. FIG. 2 is a cross-sectional view in the band width direction of the elastic crawler shown in FIG. 1. It is sectional drawing to which some elastic crawlers shown in FIG. 2 were expanded. It is a band width direction sectional view of the elastic crawler concerning a 2nd embodiment of the present invention. It is a partial cross section figure of the elastic crawler shown in FIG. It is a partial cross section figure of the elastic crawler concerning the 3rd Embodiment of this invention. It is a partial cross section figure of the elastic crawler concerning the 4th Embodiment of this invention. It is a partial cross section figure of the elastic crawler concerning the 5th Embodiment of this invention.

Explanation of symbols

1 Reinforcing fiber layer 1a Concentric arcuate part (curved part)
1b Extension part 2 High hardness elastic layer 2a Concentric arcuate part (curved part)
2b Extension part 11 Crawler main body 12 Core metal 12a End part 13 Lug 112a End surface K Elastic crawler

Claims (7)

A crawler body made of an elastic material formed in an endless band shape, a core bar embedded in the crawler body at predetermined intervals in the longitudinal direction of the band, and embedded in the crawler body along the longitudinal direction of the band An elastic crawler comprising a tensile body and lugs protruding at predetermined intervals in the longitudinal direction of the belt on the grounding surface side of the crawler body,
The metal core has a central portion extending in the band width direction, and an end portion having an end surface on the ground surface side with a curvature radius set to 3 mm or more,
And inside the crawler body, a reinforcing fiber layer having a curved portion corresponding to the curved shape at the end surface of the cored bar end is formed.
An elastic crawler characterized by that.   The elastic crawler according to claim 1, wherein a high-hardness elastic layer having a curved portion corresponding to a curved shape at an end face of the cored bar is formed outside the reinforcing fiber layer.   The elastic crawler according to claim 2, wherein a reinforcing fiber layer having a curved portion corresponding to a curved shape at an end portion of the cored bar is formed on the outer side of the high-hardness elastic layer.   The elastic crawler according to any one of claims 1 to 3, wherein at least one of the reinforcing fiber layer and the high-hardness elastic layer is extended on the ground surface side so as to overlap the cored bar.   The elastic crawler according to any one of claims 1 to 4, wherein both ends of the crawler main body surface existing between the lugs adjacent to each other in the longitudinal direction of the belt bulge in a curved shape on the ground surface side. .   The both ends of the crawler main body surface which exists between the lugs adjacent to a strip | belt longitudinal direction are formed by bulging in the cross-sectional shape of the cross section on the grounding surface side. Elastic crawler. Regarding the surface of the crawler body and the surface of the lug, assuming a virtual horizontal plane with reference to the surface closest to the ground contact surface side,
When extending a normal line from the tip of the core bar toward the ground surface side, when the distance to the virtual horizontal plane of the crawler body is A, and the distance to the virtual horizontal plane of the lug is B,
The elastic crawler according to any one of claims 1 to 6, wherein a value (A / B) obtained by dividing the distance A by the distance B is set in a range of 0.5 or more and 0.75 or less.

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