JP2005212741A - Core bar for rubber crawler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance durability of a rubber crawler by preventing end-cutting phenomenon by crack generated at an end of a core bar in a crawler width direction of the core bar buried in the rubber crawler caused by the fact that the rubber crawler rides over curbstone at a road shoulder of a paved road and stones and obstacles of irregular ground and is pushed in a lateral direction. <P>SOLUTION: In the core bar constituting the rubber crawler and buried in the rubber crawler body, an enlargement width part is formed by elongating an end in a core bar longitudinal direction of the core bar to the outside than a width dimension of the core bar. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a rubber crawler mounted on an endless track traveling device used for an industrial vehicle such as an agricultural working machine, a construction machine, a civil engineering machine, and a transport vehicle, and more particularly, in the width direction of the rubber crawler. The present invention relates to prevention of an ear-cut phenomenon occurring at the end.

In an endless track traveling device used in traveling devices such as mobile construction machine vehicles, rubber crawlers are conventionally used in addition to iron crawlers.
The rubber crawler shown in FIG. 13 shows an example of a conventional rubber crawler. The rubber crawler C is composed of an endless belt H formed of a rubber elastic body, a core metal M and a tensile reinforcement S embedded in the belt.
And in the endless belt H which is a rubber crawler body, a tensile reinforcement layer in which a plurality of tensile reinforcing materials S are arranged in a line in a line by aligning them in the width direction of the rubber crawler along the circumferential direction of the crawler. Is formed. Further, the core metal M is embedded at regular intervals on the inner side of the tensile reinforcement layer in the rubber crawler body, and the guide protrusion K of the core metal M for preventing the crawler from being detached from the traveling device is provided on the inner side of the crawler. It is formed to protrude.
FIG. 13A is an overall side view of the rubber crawler C, and B is a partial cross-sectional perspective view for explaining the structure of the rubber crawler.
JP 2003-335275 A JP-A-11-105754

In recent years, construction machines and the like having a traveling device equipped with rubber crawlers are increasingly engaged in work on rough terrain where there are many stones or on the curb near the shoulder of paved roads. At this time, the rubber crawler rides on a stone, an obstacle, a curbstone, or the like (FIG. 14A) or is pressed laterally (FIG. 14B), whereby the length of the core metal embedded in the rubber crawler is increased. In the direction (crawler width direction), the central portion of the metal core is distorted, and the rubber elastic body at this portion is greatly deformed. By repeating this, the rubber elastic body may be damaged by fatigue. .
And whenever such a situation is repeated, destruction of a rubber elastic body advances, and the big crack F will finally generate | occur | produce in a rubber crawler main body. Conventionally, such a phenomenon is called “ear loss” and has become a problem.

  Further, when the rubber crawler travels in such a situation, the roller of the traveling device rolls on one side of the crawler circumferential direction (core metal width direction) from one side to the other side on the core claw guide protrusion of the rubber crawler. At this time, distortion tends to concentrate on the end portion in the core metal width direction (crawler circumferential direction), which causes a rubber crack in this portion.

The present invention improves the above-mentioned problem, that is, the concentration of strain generated around the end of the core metal in the longitudinal direction (crawler width direction), takes measures to alleviate the strain, and prevents the rubber crawler from being cut off.
The rubber crawler of the present invention is composed of an endless strip formed of a rubber elastic body or the like, a plurality of core bars and a tensile reinforcing material embedded therein.
The plurality of tensile reinforcement members are arranged in a line in the rubber crawler main body along the circumferential direction of the crawler along the circumferential direction of the rubber crawler to form a tensile reinforcement layer. Furthermore, core bars are embedded at regular intervals on the inner peripheral side of the tensile reinforcement layer in the rubber crawler body, and guide protrusions of the core bars are formed to protrude toward the inner peripheral side of the crawler to prevent the crawler from coming off the traveling device. Has been.
In the present invention, for the purpose of alleviating the concentration of distortion generated in the vicinity of the end portion in the longitudinal direction of the core metal, the end portion in the longitudinal direction (crawler width direction) of the core metal embedded in the rubber crawler body is set to the core width. The core metal is extended outward in the direction (crawler circumferential direction), and the longitudinal end portion of the core metal is widened in the core metal width direction.

Further, the rubber crawler of the present invention is such that the core metal embedded in the rubber crawler main body is widened by extending the end part of the core metal in the longitudinal direction (crawler width direction) and widening. The thickness of the outer wall is reduced toward the outer edge, and the inclined surface is formed by forming an inclined surface partially (preferably more than half the wall thickness) in the direction toward the ground contact surface side of the crawler or entirely. It is preferable to bend the core metal edge to the anti-grounding surface side so that the inclined surface faces the grounding surface side.
The core metal of the present invention is not limited to an integrated rubber crawler having an endless belt shape such as a rubber elastic body, but also a connected track link and block in which a base of the rubber crawler connects a pair of track links endlessly. It is composed of a skeleton formed by a body and a rod, and a crawler pad, and the crawler pad is composed of a core metal (crawler plate) and a crawler body part. It can also be used as gold, and similarly can prevent the ear-cut phenomenon.

  In the present invention, a cored bar longitudinal direction end (crawler width direction) end of a cored bar embedded in a rubber crawler main body is extended outwardly in a cored bar width direction (crawler circumferential direction), and the cored bar longitudinal direction end By increasing the width in the width direction of the core bar, the load per unit width (unit area) of the end part in the longitudinal direction of the core bar is reduced, thereby improving the cut resistance and preventing the occurrence of edge breaks occurring in the rubber crawler. As a result, the durability of the rubber crawler can be improved.

  The corners at the front and back in the width direction of the end of the core metal, which is the main cause of the ear cut, are widened so that the inclined surface faces the ground surface. Decrease the wall thickness of the end of the metal core toward the outer edge so that the inclined surface comes in the direction toward the ground, and provide the inclined portion in the direction toward the ground surface of the crawler, or the inclined surface is on the ground surface side. By making the structure bent to the anti-ground surface side so as to face, durability can be further improved.

The rubber crawler of the present invention is composed of an endless belt constituting the rubber crawler body, a plurality of core bars embedded in the belt, and a tensile reinforcing material.
The band is made of natural rubber, synthetic rubber (IR, SBR, BR, NBR, CR, IIR, EPDM, etc.) or raw rubber blended with these, reinforcing agent (carbon black, white carbon, etc.), anti-aging agent, Vulcanization accelerators, activators, tackifiers, rubber compositions (rubbers) containing vulcanization accelerators and crosslinking agents such as sulfur and organic peroxides, urethane rubber, semi-rigid and soft It is made of thermoplastic resin such as polyvinyl chloride resin.
Then, a plurality of tensile reinforcement members such as steel cords are aligned in the width direction of the rubber crawler along the circumferential direction of the crawler along the circumferential direction of the crawler, and are embedded in a line to form a tensile reinforcement layer in the band. ing.
Further, core bars are embedded at regular intervals on the inner peripheral side of the crawler of the tensile reinforcement layer, and guide protrusions of the core bars are formed to protrude toward the inner peripheral side of the crawler to prevent the crawler from being detached from the traveling device. .
The core metal embedded in the strap is formed with an engagement portion that engages with the driving device of the traveling device in the central region in the length direction of the core metal, and is removed from the outer side of the engagement portion in the length direction of the core metal. The guide protrusion for prevention is generally configured such that a wing portion is formed on the outer side thereof, and there is a structure in which a protrusion for preventing the rubber crawler from slipping out is formed.

The cored bar of the present invention is characterized in that the cored bar longitudinal direction end of the cored bar wing part is extended outward in the cored bar width direction, and the cored bar longitudinal direction end is widened in the cored bar width direction. It is said.
The rubber crawler of the present invention has a core that is a rubber crawler body, the core metal extending in the longitudinal direction in the longitudinal direction of the core metal in the longitudinal direction of the core metal, By embedding a core bar whose width is wide in the width direction of the core bar, when the rubber crawler rides on a stone or curbstone, it disperses the strain that occurs at the end of the core bar in the longitudinal direction and relaxes strain concentration Thus, it was possible to prevent rubber breakage, effectively reduce the ear cut caused by this, and improve the durability of the rubber crawler.

The present invention also reduces the wall thickness of the end of the metal core toward the outer edge so that the inclined surface comes in the direction of the ground contact surface of the crawler at the widened portion of the metal core end. It is preferable to provide a structure in which an inclined portion is provided in the direction toward the ground contact surface, or a widened portion of the end of the metal core is bent toward the anti-ground surface so that the inclined surface faces the ground contact surface.
The inclined part or the bent part obtained by bending the edge part of the metal core may be provided by either the metal bar width direction end part or the metal core longitudinal direction of the widened part of the metal core end part. However, it is preferable to provide the both ends of the core metal width direction end and the both ends of the metal core longitudinal direction, and it is desirable to provide the boat portion with an inclined portion or a bent portion.
As a result, the distortion of both corners in the front and rear direction in the width direction of the core bar with the wide core bar is alleviated, and the durability against the ear cut is further improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a core diagram used for a rubber crawler according to a first embodiment of the present invention, FIG. 1A is a plan view on the inner circumference (anti-ground surface) side, FIG. 1B is a front view, and FIG. 1C is a side view. is there. FIG. 2 is a rubber crawler showing a first embodiment of the present invention, and is a partial plan view on the outer peripheral (grounding surface) side showing a state where the core bar shown in FIG. 1 is embedded in the rubber crawler.
The metal core 1 of the first embodiment is formed with an engaging portion 1a that engages with the driving device of the traveling device in the center area, and the engaging portion is located on both the left and right outer sides of the metal core in the length direction. A pair of guide protrusions 1b for preventing wheel removal are arranged in a staggered manner across 1a, and wings 1c are formed on both outer sides thereof.
In the figure, reference numeral 1d denotes a detachment prevention protrusion provided to suppress the lateral displacement and twist of the rubber crawler.
The cored bar 1 of the present invention extends the cored bar wing part 1c tip part outward in the cored bar width direction and extends the cored bar blade part tip part outward in the cored bar width direction. The leading end region is wide, and both end edges of the cored bar in the longitudinal direction of the cored bar are formed as tail-shaped widened portions 2 longer than the width of the cored bar.

The metal core 1 is embedded in the rubber crawler main body 3a of the rubber crawler 3 as shown in FIG. When the core metal 1 is embedded in the rubber crawler, the core metal widened portion 2 of the core metal 1 is disposed at the end portion (ear portion) in the rubber crawler width direction. As a result, it is possible to reduce the load per unit width (unit area) of the longitudinal end of the cored bar, and when the rubber crawler rides on a stone or curbstone, the distortion generated at the longitudinal end of the cored bar is reduced. It is possible to disperse, and by reducing the concentration of strain, it is possible to prevent rubber breakage and to effectively reduce the ear-cut phenomenon due to this. As a result, the durability of the rubber crawler was improved.
In the figure, 3b is a lug.

At this time, the metal core width W ₂ of the core bar widened portion 2 is towards the wider is effective, becomes longer than the core metal buried spacing (1 pitch = 1P), a widened portion of the adjacent metal core since interference can not be embedded, it is necessary to shorten the width length W ₂ of the core widened portion 2 than the metal core embedded intervals. Moreover, the effect when the width W ₂ of the core bar widened portion 2 is too short is reduced, preferably, the core metal wings 1c width W _{1 {conventional} rubber crawler, a width W ₁ of the core metal wings 1c However, in many cases, the width is half (0.5 P) of the core metal burying interval. When a}, W2 is 1.1W ₁ ~1.8W _1, and it is preferably a 1.2W ₁ ~1.5W _1.
Further, the length L of the cored bar widened portion 2 is set to an appropriate length under the conditions of use, but if it is too short, the strength of the portion extended from the cored bar blade portion of the widened portion is maintained. On the other hand, if the length is too long, the weight of the metal core increases, the weight of the rubber crawler increases, and a large amount of material for the metal core is required.

FIG. 3 is a view showing a core bar according to a second embodiment of the present invention, FIG. 3A is an inner peripheral side plan view, FIG. 3B is a front view, and FIG. 3C is a side view. FIG. 4 is a view showing a rubber crawler in which a metal core according to a second embodiment of the present invention is embedded, FIG. 4A is a cross-sectional view in the crawler width direction, and FIG. 4B is a partial side view.
The cored bar 1 of the second embodiment forms a cored bar widened part 2 in which the tip end region of the cored bar wing part 1c is longer than the dimension of the central part of the cored bar outward in the width direction of the cored bar. The thickness of the metal core is reduced toward the outer edge, and partially (preferably a thickness of half (1/2 t) or more of the wall thickness t (1/2 t) in the present embodiment (3 in this embodiment). / 4t) or an entire inclined surface and an inclined portion (taper) 4 is provided.
As shown in FIG. 3, in the second embodiment, inclined portions 4 can be formed at both end edges of the core metal longitudinal direction edge a and the core metal width direction edge b of the core metal widened portion 2. Although desirable, a configuration may be adopted in which the inclined portions 4 having different inclination angles are provided at only one of them or at each edge.

FIG. 5 is a diagram showing a test method and a measurement result of measuring the distortion rate when the end portion in the width direction of the rubber crawler rides on the curb, FIG. 5A is a crawler cross-sectional view showing the test method, and FIG. 5B is a measurement. It is a graph which shows the distortion rate which shows a test result.
The level of the distortion test is disclosed in the rubber crawler shown in Example 2, the conventional general rubber crawler shown in FIG. 13 as a conventional example, and FIGS. 5 to 7 in Japanese Patent Laid-Open No. 11-105754 as a comparative example. Measurement was made on a rubber crawler in which a core bar (a core bar having a bent portion formed at the end of the end in the longitudinal direction of the core metal) in which the conventional technique for cutting off ears was taken.
As shown in FIG. 5A, a semicircular obstacle is placed on the corresponding portion of the rubber crawler that is directly below the position of W (10 mm) from the edge position in the longitudinal direction of the core metal, and a load F (500 kg) is applied to the core metal. The distortion rate when applied was measured.
As shown in the graph, the distortion rate of the conventional rubber crawler is 193%, and the distortion rate of the conventional rubber crawler of the comparative example using the conventional ear-cut countermeasure technology is 102%, whereas the second embodiment of the present invention. This rubber crawler has a distortion rate of 60%, which is 1/3 of that of the conventional example, and it can be seen that there is less distortion than the comparative example.
As described above, the present invention has a marked improvement in the distortion of the end portion in the width direction of the rubber crawler that occurs when riding on a foreign object, as compared with the conventional rubber crawler and the conventional rubber crawler using the anti-ear-cutting technique. Therefore, it is possible to reduce the occurrence of edge breaks occurring in the rubber crawler and improve the durability of the rubber crawler.

FIG. 6 is a view showing a core bar according to a third embodiment of the present invention, FIG. 6A is an inner peripheral side plan view, FIG. 6B is a front view, and FIG. 6C is a side view.
The cored bar 1 of the third embodiment is a cored bar widened part in which the cored bar wing part 1c tip is extended outward in the cored bar width direction, and the cored bar wing part tip is widened in the cored bar width direction. 2 and the bent portion obtained by extending the cored bar of the widened portion 2 is bent in the direction of the inner peripheral side of the crawler to form the bent portion 2a. The end portion of the core metal in the crawler circumferential direction is bent so as to face.
At this time, since by bending the metal core widened portion 2, the core metal width W ₃ of the core widened portion 2, since the leaving large toward the inner circumferential side of the steel cord is a base point winding of the rubber crawler, If it is not shorter than the core metal burying interval (1P), the adjacent widened portions 2 of the core metal will interfere with each other, and the rubber crawler will not wrap around the guide wheel or drive wheel of the traveling device.
That is, the core metal width W ₃ of the core widened portion 2, the core metal buried interval (1P), shorter than the dimension of the widened part 2 to each other of the core is pulled apart which do not interfere (p) (W ₃ < 1P-p).
In addition, the space | interval p where the wide parts 2 of a metal core do not interfere is when the dimension from a steel cord to the bending part 2a inner peripheral side front end of the metal core wide part 2 is h, and the number of teeth of a driving wheel is n , P = 2hsin (180 / n) °.

FIG. 7 is a view showing a core bar according to a fourth embodiment of the present invention, FIG. 7A is a plan view of the inner periphery side, FIG. 7B is a front view, and FIG. 7C is a side view.
The metal core 1 of the fourth embodiment has a metal core widened portion in which the metal core wing part 1c has its tip end extended outward in the metal core width direction, and the metal core wing part tip is wide in the metal core width direction. 2, the core metal longitudinal direction tip portion of the widened portion 2 is bent in the direction of the inner peripheral side of the crawler to form a bent portion 2 b, and the inclined surface formed by the bending is on the grounding surface side The core metal edge in the crawler width direction is bent so as to face.

FIG. 8 is a view showing a cored bar according to a fifth embodiment of the present invention, FIG. 8A is an inner peripheral side plan view, FIG. 8B is a front view, and FIG. 8C is a side view.
The metal core 1 of the fifth embodiment has a metal core widened portion in which the metal core wing part 1c has its tip end extended outward in the metal core width direction, and the metal core wing part tip is wide in the metal core width direction. 2 is bent, and the leading end in the core metal longitudinal direction of the widened portion 2 is bent toward the inner peripheral side of the crawler, and further bent from the corner in the core metal width direction to a part of the leading end in the core metal longitudinal direction. In this way, a bent portion 2a ′ is formed in which a bent portion is formed on the character.
As a result, the distortion of both corners in the front and rear direction in the width direction of the core bar with the wide core bar is alleviated, and the durability against the ear cut is further improved.
At this time, as shown in FIG. 9, the tip of the cored bar blade 1c is bent by bending the entire tip of the cored bar longitudinal direction of the widened part 2 so as to connect both bent parts formed at both ends of the cored bar width direction. As shown in Fig. 9, the boat-shaped bent portion 2c may be formed by bending the core metal edge of the crawler longitudinal direction and the crawler width direction and the corner portions in the crawler longitudinal direction and the crawler width direction so as to form a boat shape.

FIG. 10 and FIG. 11 are views showing a core bar used in a connection link type rubber crawler which is a track pad type rubber crawler adopting a structure in which a track pad is attached to a connection track link in which a pair of track links are connected endlessly. It is. 10A and 10B are views showing a cored bar according to a sixth embodiment of the present invention. FIG. 10A is a plan view of the outer periphery (grounding surface) side, FIG. 10B is a front view, and FIG. FIG. 11 is a view showing a core bar of another example of the sixth embodiment, FIG. 11A is a plan view of the outer periphery (ground plane) side, FIG. 11B is a front view, and FIG. 11C is a side view. FIG. 12 is a view showing a foot pad of a linked link type rubber crawler (crawler pad type rubber crawler) in which a core bar of another example of the sixth embodiment shown in FIG. 11 of the present invention is embedded, and FIG. FIG. 12B is a plan view of the ground plane, FIG. 12B is a longitudinal side view, and FIG. 12C is a width side view.
The cored bar 6 of the sixth embodiment shown in FIG. 10 has a cored bar widened by extending the end of the cored bar in the longitudinal direction of the cored bar and extending the cored bar end in the widthwise direction of the cored bar. Part 6a is formed. In addition, 6b in the figure is a through hole for passing a bolt into which a bolt for attaching the foot pad to the connecting track link is inserted.
Further, in another example of the sixth embodiment shown in FIG. 11, the cored bar 6 is formed by extending the cored bar end in the longitudinal direction of the cored bar and extending the cored bar in the widthwise direction of the cored bar. A widened cored bar 6a is formed, and a part wider than the cored bar of the widened part 6a is bent in a direction toward the inner periphery (anti-grounding surface) side of the crawler to form a bent part 6c and bent. The cored bar edge in the crawler circumferential direction is bent so that the inclined surface formed thereby faces the grounding surface.
Then, as shown in FIG. 12, the foot pad 5 of the connected link type rubber crawler which is a track pad type rubber crawler having a structure in which the track pad is attached to a connected track link (not shown) in which a pair of track links are connected endlessly. 11 shows a state where a cored bar (shoe plate) 6 which is another example of the sixth embodiment shown in FIG. 11 is embedded. The crawler belt main body 5a of the foot pad 5 is formed of a rubber elastic body, and the cored bar 6 is embedded in the foot pad main body 5a.
In the figure, reference numeral 5b denotes a bolt hole into which a bolt for attaching the foot pad to the connecting track link is inserted.

A is an inner peripheral side plan view, B is a front view, and C is a side view. (Example 1) It is an outer peripheral side top view which shows the state which embed | buried the metal core shown in FIG. 1 in the rubber crawler. (Example 1) A is an inner peripheral side plan view, B is a front view, and C is a side view. (Example 2) It is a crawler width direction sectional view of a rubber crawler. (Example 2) A is a cross-sectional view for explaining the state of a test in which the strain rate when the end portion in the width direction of the rubber crawler rides on the curbstone, and B is the strain rate when the end portion in the width direction of the rubber crawler rides on the curb. It is a graph which shows the measured test result. A is an inner peripheral side plan view, B is a front view, and C is a side view. Example 3 A is an inner peripheral side plan view, B is a front view, and C is a side view. (Example 4) A is an inner peripheral side plan view, B is a front view, and C is a side view. (Example 5) A is an inner peripheral side plan view, B is a front view, and C is a side view. (Another example of Example 5) A is a ground plane side plan view, B is a longitudinal side view, and C is a width side view. (Example 6) A is a ground plane side plan view, B is a longitudinal side view, and C is a width side view. (Another example of Example 6) A is a ground plane side plan view, B is a longitudinal side view, and C is a width side view. (Example 6) A is an overall side view of the rubber crawler, and B is a partial cross-sectional perspective view for explaining the structure of the rubber crawler. (Conventional example) It is a rubber crawler width direction sectional view explaining the situation where an ear piece occurs in a rubber crawler. (Conventional example)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Core metal 1a Metal core engaging part 1b Metal core guide protrusion 1c Metal core wing part 1d Detachment prevention protrusion 2 Metal core widening part 2a Metal core width direction bending part 2a'-shaped bending part 2b Core metal longitudinal direction bending part 2c Core metal boat-shaped bent part 3 Rubber crawler 3a Rubber crawler body (endless belt)
3b Lugs 3c Tensile reinforcement (steel cord)
4 Core metal inclined part 5 Foot pad 5a Foot pad body 5b Bolt hole 6 Core bar (track)
6a Core metal widened portion 6b Core metal through hole 6c Core metal bent portion

Claims (2)

  A rubber crawler body formed of a rubber elastic body or the like constituting a rubber crawler and a core metal embedded in the rubber crawler, and widening the core metal by extending the longitudinal end edge of the core metal outward from the core metal width dimension. A metal core for a rubber crawler characterized by forming a portion.   2. The rubber crawler core according to claim 1, wherein a thickness of the widened portion is reduced toward the outer edge, and an inclined surface is formed partially or entirely in a direction toward the grounding surface side of the crawler. Money.

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