JP2009234425A - Rubber crawler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber crawler capable of performing a subject such as improvement of lateral rigidity of the rubber crawler, prevention of edge cut, prevention of positional slippage of a steel cord, etc. <P>SOLUTION: This rubber crawler 10 includes a crawler body formed endless, a core bar 12 having wing parts 12b on both sides buried in the crawler body so as to extend in the cross direction of the crawler body and the steel cord 34 buried by extending in the circumferential direction of the crawler body on the grounding surface side U of the wing parts 12b in the crawler body, and projected parts 14 protruded to the grounding surface side U of the crawler body are formed in a state remaining protruded shape end edge parts 16 of the wing parts 12b on end parts 12c of the both wing parts 12b of the core bar 12. Additionally, the steel cord 34 is buried at a position nearer a center of the core bar 12 than the projected part 14 and a position nearer the core bar than a projection height position of the projected part 14. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a rubber crawler, in particular, a protrusion that protrudes toward the grounding surface with the end edge left at the end in the width direction of the cored bar for the purpose of improving lateral rigidity and preventing so-called edge cutting. It is related with the rubber crawler provided.

  The rubber crawler is an endless track made of rubber and has been actively researched and developed since it was first developed as an undercarriage part for agricultural equipment. There are a wide variety.

  FIG. 2 is a longitudinal sectional view in a width direction of a portion including a core bar of a conventional rubber crawler. However, it shows about half of the width direction of a rubber crawler. The rubber crawler 30 is embedded such that the core 32 has a predetermined interval in the circumferential direction of the rubber crawler 30 and the wing 32b extends in the width direction. On the ground surface side U, a steel cord 34 is extended and embedded in the circumferential direction. Then, the core metal 32 is covered with a rubber member, and an inner peripheral surface 36 and an outer peripheral surface 38 are formed. The outer peripheral surface 38 is on the ground contact surface side, and a lug 38a that contacts the ground is formed.

  The cored bar 32 has a guide protrusion 32a that secures a passage area 40 for a sprocket (not shown) and an idler (not shown) and through which the wheel passes. The grounding surface side (lower part) of the cored bar 32 is a first bottom surface part 32d on the grounding surface side of the passage region 40 such as a sprocket, a second bottom surface part 32e on the grounding surface side of the guide protrusion 32a, and a grounding surface of the wing part 32b. The third bottom surface portion 32f on the side has a height from the ground contact surface of the lug 38a of each bottom surface portion in the order of the first bottom surface portion 32d, the second bottom surface portion 32e, and the third bottom surface portion 32f. Yes. Each bottom surface portion is formed in parallel to the ground contact surface of the lug 38a. The connection portion between the first bottom surface portion 32d and the second bottom surface portion 32e and the connection portion between the second bottom surface portion 32e and the third bottom surface portion 32f are formed smoothly and continuously. The third bottom surface portion 32f extends longer in the width direction than the other bottom surface portions.

  The end portion 32c of the wing portion is formed in a convex shape at the tip in the width direction of the wing portion 32b, and the tip is rounded (R-shaped, R-processed). An appropriate distance L4 is provided between the end of the rubber crawler 30 in the width direction, that is, between the end P of the rubber crawler 30 in the width direction and the end 32c of the wing. When this L4 is set small, when a load is applied to the rubber crawler 30, stress concentrates on the end portion 32c, so that the so-called ear-cut is likely to occur, in which the rubber member surrounding the end portion 32c is torn. Further, if the length in the width direction of the cored bar 32 is increased and L4 is decreased, the weight of the cored bar 32 increases, so the length of the wing 32b and the end 32c of the cored bar 32 and the end of the rubber crawler 30 are increased. The interval L4 with P needs to be designed appropriately.

  The steel cord 34 is embedded on the ground contact surface side of the wing portion 32b with a distance D from the third bottom surface portion 32f. From the height H1 from the ground contact surface of the lug 38a of the outer peripheral surface 38 to the first bottom surface portion 32d. The lug 38a is buried at a position lower than the height H2 from the ground contact surface of the lug 38a to the third bottom surface portion 32f. Further, the length W in the width direction of the embedded steel cord 34 is configured to be shorter than the length in the width direction of the third bottom surface portion 32f. By this steel cord 34, stress due to the weight of the machine body applied to the wing portion 32b of the core metal 32 is distributed to the steel cord 34, and the rubber crawler 30 is prevented from being biased and reduced.

  The rubber crawler 30 having the above configuration has three problems. The first is the problem of lateral rigidity. That is, when traveling on a rough road surface or suddenly turning, there is a difference between the traveling direction of the machine body and the traveling direction of the rubber crawler 30, which causes the rubber crawler 30 to be derailed. This is a result of the core claw 32 that mainly transmits the driving force from the sprocket being independent from each other in the rubber crawler 30 and connecting them with a rubber elastic body having elasticity. Although the steel cord 34 is embedded as a tensile body in the longitudinal direction (circumferential direction), in the width direction of the rubber crawler 30, there is nothing particularly to prevent the elongation, and therefore the lateral rigidity is relatively low. It will be small. Therefore, for example, the core metal 32 may be laterally displaced or the rubber crawler 30 may be twisted with the expansion and contraction of the rubber elastic body.

  Secondly, there is a so-called ear-cut problem. This is a phenomenon in which, for example, when a load is applied from the side of the rubber crawler 30, the stress is concentrated on the end portion 32c of the wing portion 32b, and the rubber member in contact with the end portion 32c is cut. In FIG. 2, the convex end portion 32 c is rounded in order to alleviate the ear-cut problem as much as possible.

  The third problem is that the steel cord 34 is displaced when the rubber crawler is manufactured. In the vulcanization process at the time of manufacturing the rubber crawler, since the rubber member that has been kept to a certain degree until now becomes soft and flows, the flow acts on the steel cord 34, and the steel cord 34 It is a problem that it deviates from a predetermined position and height.

  In addition, in order to improve the lateral rigidity, it is necessary to provide a configuration in which some protrusions, hanging pieces or the like are provided on the ground plane side or the ground plane side on the wing part 32b or the third bottom face part 32f of the cored bar 32. It is. Patent Document 1 discloses a rubber crawler in which hanging pieces are formed on each core metal from the core metal toward the thickness direction of the rubber elastic body.

  According to the above-mentioned patent document 1, since the hanging piece is formed on the cored bar from the cored bar toward the thickness direction (ground surface side) of the rubber elastic body, it is effective in preventing the lateral displacement of the cored bar. There is. However, when the vertical piece is formed at both ends in the width direction of the core bar and toward the outer peripheral side, it is possible to prevent the position of the steel cord from being displaced when the rubber crawler is formed (Patent Document). 1 (see FIG. 5).

  Patent Document 2 discloses a configuration in which a wing portion of a core metal is bent in a round shape toward the crawler grounding side for the purpose of preventing an ear-cut by suppressing the occurrence of cracks on the inner peripheral surface of the crawler body. Is disclosed.

  Even with the configuration of the above-described Patent Document 2, it is considered that the lateral rigidity is improved to some extent because the width direction of the cored bar is not uniform, and it is possible to prevent the problem of positional deviation of the steel cord to some extent.

JP-A-4-243671 JP 2006-151140 A

  However, in the configuration of Patent Document 1, when a hanging piece is provided at the end of the core bar in the width direction, the lateral rigidity is improved, and the horizontal displacement of the steel cord can be prevented during the vulcanization process. When a load is applied from the lateral direction or from below, there is a problem that stress is likely to concentrate on the end of the hanging piece, and the end of the rubber crawler is likely to break, so-called ear cutting is likely to occur.

  Further, in the configuration of Patent Document 2, the wing portion of the core metal is bent so as to incline toward the ground contact surface side of the rubber crawler, and the lateral rigidity of the rubber crawler is improved to some extent, but to the tip portion of the wing portion. When the load is applied, the distribution of the generated stress becomes non-uniform, and there is a problem that the ear is easily cut off by the load from the lateral direction of the rubber crawler.

  In short, no rubber crawler that has solved all of the problems of lateral rigidity, the problem of cutting off the ears, and the problem of misalignment of the steel cord has been found so far.

  The present invention has been made in view of the above problems, and its purpose is to provide a rubber crawler capable of achieving problems such as improvement in the lateral rigidity of the rubber crawler, prevention of edge cutting and prevention of misalignment of the steel cord. It is to provide.

In order to achieve the above object, the rubber crawler according to claim 1,
An endless crawler body, a cored bar having wings on both sides embedded in the crawler body so as to extend in the width direction of the crawler body, and a ground contact surface from the wing part in the crawler body A rubber cord including a steel cord extending in the circumferential direction of the crawler body on the side, and a protrusion projecting toward the grounding surface side of the crawler body at the ends of both wings of the cored bar The portion is formed in a state where the convex edge portion of the wing portion is left.

  By adopting such a configuration, a protrusion projecting toward the grounding surface side of the crawler body is formed at the end in the width direction of the wing of the core metal, leaving the convex edge of the wing. Therefore, when a load is applied to the rubber member constituting the comb track from the lateral direction, the protrusion prevents the rubber member from moving, so that the lateral rigidity of the rubber track is improved. Furthermore, it is possible to disperse the stress due to the load applied to the end of the wing. In other words, the edge of the wing and the projection protrude in different directions, so that the stress from the ground contact surface side does not concentrate stress on the projection, and the edge of the wing Stress is dispersed in the part. Further, with respect to the load from the side portion of the rubber crawler, the stress is not concentrated only on the edge portion of the wing portion, and the stress is dispersed in the projection portion. In addition, since the protrusions can restrict the flow in the width direction of the rubber member during the vulcanization process, it is possible to prevent the displacement of the steel cord.

The rubber crawler according to claim 2 is the rubber crawler according to claim 1,
The steel cord is embedded in a position closer to the center of the cored bar than the protruding part and in a position closer to the cored bar than a protruding height position of the protruding part. Therefore, since the steel cord is embedded in the width direction inside the protrusion and in the height direction between the bottom surface and the tip of the protrusion, the flow of the rubber member in the width direction during the vulcanization process Therefore, it is possible to reliably prevent misalignment of the steel cord during the vulcanization process.

The rubber crawler according to claim 3 is the rubber crawler according to claim 1 or 2,
The tip of the projection and the edge of the core are rounded. Therefore, the load from the side of the rubber crawler and the load from the grounding surface side are such that the stress is concentrated on the tip of the wing, since the edge of the convex edge and the tip of the projection are rounded. Is effectively prevented, and thus ear cuts can be more effectively prevented.

The rubber crawler according to claim 4 is the rubber crawler according to any one of claims 1 to 3,
A rounded portion is provided at a rising portion of the protruding portion from the wing portion. Accordingly, when a load is applied from the side portion of the rubber crawler and the ground contact surface side, the protrusion is provided at the rising portion from the wing portion, so that the distortion of the rubber member can be effectively dispersed. As a result, so-called ear-cut prevention is achieved.

  According to the rubber crawler of the present invention, the protruding portion that protrudes toward the grounding surface side of the crawler main body is formed on the end portion in the width direction of the core bar in a state in which the convex edge portion of the wing portion remains. Therefore, it is possible to improve the lateral rigidity of the rubber track, and at the same time, it is possible to effectively disperse the stress due to the load applied to the end of the wing. In addition, the presence of the protrusions can prevent the steel cord from being displaced during manufacture.

  Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a longitudinal sectional view in a width direction of a portion including a core bar of a rubber crawler according to the present invention. However, it shows about half of the width direction of a rubber crawler. The rubber crawler 10 is embedded so that the metal core 12 extends in the width direction at a predetermined interval in the circumferential direction of the rubber crawler 10, and the wing 12 b of the metal core 12. On the ground surface side U, a steel cord 34 is extended and embedded in the circumferential direction. Then, the core metal 12 is covered with a rubber member, and an inner peripheral surface 36 and an outer peripheral surface 38 are formed. The outer peripheral surface 38 is on the ground contact surface side, and a lug 38a that contacts the ground is formed.

  The cored bar 12 has a guide protrusion 12a that secures a passage region 40 for a sprocket (not shown) and an idler (not shown) and through which the wheel passes. The grounding surface side (lower part) of the cored bar 12 is a first bottom surface part 12d on the grounding surface side of the passage area 40 such as a sprocket, a second bottom surface part 12e on the grounding surface side of the guide projection 12a, and a grounding surface of the wing part 12b. Side bottom surface portion 12f, and the height of each bottom surface lug 38a from the ground contact surface increases in the order of the first bottom surface portion 12d, the second bottom surface portion 12e, and the third bottom surface portion 12f. Yes. Each bottom surface portion is formed in parallel to the ground contact surface of the lug 38a. The connection portion between the first bottom surface portion 12d and the second bottom surface portion 12e and the connection portion between the second bottom surface portion 12e and the third bottom surface portion 12f are formed smoothly and continuously. The third bottom surface portion 12f extends longer in the width direction than the other bottom surface portions.

  A protruding portion 14 is formed on the end portion 12c of the wing portion 12b of the core metal 12 leaving the convex end edge portion 16 of the wing portion 12b. The protruding portion 14 is formed to protrude from the third bottom surface portion 12 f of the wing portion 12 toward the ground contact surface. Let the amount of protrusion be D2. The height of the tip 14a of the protrusion 14 from the ground contact surface of the lug 38a is configured to be substantially the same as or higher than the height H1 of the first bottom surface 12d.

  The steel cord 34 is embedded on the grounding surface side of the third bottom surface portion 12f of the cored bar 12 with an interval D1, and the protrusion amount D1 of the protrusion 14 has a relationship of D1 <D2. That is, the steel cord 34 is embedded at a position closer to the center of the core metal 12 than the protrusion 14 and closer to the core metal than the protrusion height position of the protrusion 14.

  The end edge portion 16 is formed in a convex shape on the end portion 12 c of the wing portion 12 b of the core metal 12. And the distance L3 from the edge part P of the width direction of the rubber crawler 10 to the edge part 16 is in the edge part 12c of the wing | blade part 12b of the metal core 12 in which the protrusion part 14 and the edge part 16 are provided. The predetermined interval is set so that stress is not concentrated by loads from below and from the side. Usually, it is at least 20 mm or more.

  The protrusion amount L2 in the width direction of the end edge portion 16 from the protrusion portion 14 is required to be 2 mm or more in terms of the manufacturing condition of the cored bar 12, but the protrusion amount D2 of the protrusion portion 14 toward the ground surface, Considering the thickness L1 in the direction and the distance L3 between the end edge portion 16 and the end portion P of the rubber crawler, it is optimally determined so that the stress is not concentrated. For example, it can be determined by performing a numerical analysis using a finite element method or the like. In an example of the analysis result, when there is no protrusion amount L2 of the end edge portion 16, the stress is concentrated on the protrusion portion 14 due to the load from the contact surface side, but the stress is dispersed by setting L2 to 2 mm. Can do. Other dimensions at this time are D2 = 7.5 mm, L1 = 4 mm, and L3 = 20 mm.

  Here, when the protrusion amount L2 of the end edge portion 16 is increased, the protrusion portion 14 and the end edge portion 16 exist independently from each other, and the effect of dispersing the stress is reduced. It is necessary to determine the installation position in the width direction of the protrusion 14 so that the end edge 16 is continuously present at the base of the protrusion 14, and to what extent the protrusion amount L2 can be increased accurately Is determined by performing numerical analysis by specifically determining the numerical value of each parameter.

  Further, the length of the wing portion 12b of the cored bar 12 is effectively dispersed by the steel coat 34 having a width W embedded in the grounding surface side of the third bottom surface part 12f, due to the weight of the machine body applied to the cored bar 12. It needs to be as long as possible. The longer the core 12 becomes, the higher the weight and the cost. Therefore, the weight of the machine body, the number of steel cords 34, the width W of the steel cords 34, the edge 16 and the ends P of the rubber crawler 30 are increased. It is important to decide appropriately in consideration of the interval.

  Here, the tip end 14a of the protrusion 14 and the tip end 16a of the end edge portion 16 are each rounded so that stress concentration can be further prevented. As an example, when D2 = 7.5 mm, L1 = 4 mm, L2 = 2 mm, and L3 = 20 mm, R = 2 mm is optimal for rounding. By these rounding processes, it is possible to effectively disperse the stress due to the load applied to the end portion 12c, and thus it is possible to more effectively prevent the ear cut.

  Furthermore, rounds are provided on the rising portions 18a and 18b of the protrusion 14 from the wing portion 12b. Accordingly, when a load is applied to the end portion 12c and a stress is generated in the end portion 12c, the rising portions 18a and 18b are provided with rounds, so that the distortion of the rubber member due to the generated stress is determined at a specific location. It becomes possible to disperse effectively without concentrating on, and the effect of preventing the ear-cut is further improved.

  Further, in the vulcanization process at the time of manufacturing the rubber crawler, since the rubber member that has been kept to a certain degree until now becomes soft and flows, the flow acts on the steel cord 34, and the steel cord 34 However, in the rubber crawler of the present invention, the protrusion 14 protrudes in the width direction of the rubber crawler 10, so that the rubber member becomes soft and flows. However, the flow is stopped by the protrusions 14 in the lateral direction. Therefore, the problem that the steel cord 34 is displaced from a predetermined position and height in the vulcanization process at the time of manufacturing the rubber crawler is solved.

  According to the rubber crawler 10 according to the above-described embodiment, the protruding portion 14 that protrudes from the third bottom surface portion 12f of the wing portion 12b toward the ground surface is provided on the end portion 12c of the wing portion 12b of the core metal 12. Since the protruding edge portion 16 is left on the end portion 12c of the 12b, it is possible to improve the lateral rigidity of the rubber crawler 10, and at the same time, disperse the stress caused by the load applied to the end portion 12c. Is possible. Further, the presence of the protrusions 14 can prevent displacement of the steel cord 34 during the vulcanization process.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the protruding portion protruding to the ground surface side has a uniform thickness, but the thickness may be changed toward the outer peripheral surface side.

It is a longitudinal cross-sectional view of the width direction which concerns on embodiment of the rubber crawler of this invention and contains a metal core. It is a longitudinal cross-sectional view of the width direction which concerns on the conventional rubber crawler and contains a metal core.

Explanation of symbols

10, 30 Rubber crawler 12, 32 Core metal 12a, 34a Guide projection 12b, 34b Blade 12c, 34c Blade end 14 Projection 16 Edge 34 Steel cord 36 Inner peripheral surface 38 Outer peripheral surface 38a Lug D2 end Amount of protrusion L2 toward the grounding surface side Amount of protrusion U toward the width direction of the edge portion U Grounding surface side

Claims (4)

An endless crawler body, a cored bar having wings on both sides embedded in the crawler body so as to extend in the width direction of the crawler body, and a ground contact surface from the wing part in the crawler body In a rubber crawler including a steel cord embedded in the crawler body extending in the circumferential direction on the side,
Protruding portions that protrude toward the grounding surface side of the crawler body are formed at the end portions of both wing portions of the core metal in a state where the convex edge portions of the wing portions remain. Rubber crawler. The steel cord is
2. The rubber crawler according to claim 1, wherein the rubber crawler is embedded at a position closer to the center of the core metal than the protrusion and at a position closer to the core metal than a protrusion height position of the protrusion.   The rubber crawler according to claim 1 or 2, wherein a tip end of the protruding portion and the end edge portion of the core metal are rounded.   The rubber crawler according to any one of claims 1 to 3, wherein a rounded portion is provided at a rising portion of the protruding portion from the wing portion.

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