JP2009262784A - Rubber crawler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a bend of a rubber crawler from causing the generation of cracks in a rubber body at an end of a core embedded in the rubber crawler and an end of a steel cord belt even if the rubber roller rides over a curb or is abraded by a side face of the curb, and an ear of the rubber crawler is bent. <P>SOLUTION: Only ends 30, 40 of a core 3 and a steel cord belt 4 are wound around and surrounded with a flexible and soft sheet material 9 composed of a material which is embedded in a rubber body 2 and hardly elongated more than rubber constituting the rubber body with a predetermined space from the ends. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an endless belt-like rubber body, a plurality of core bars embedded in the rubber body at a constant pitch in the circumferential direction of the rubber body, and a width direction of the rubber body on the outer peripheral side of the core bar in the rubber body It is related to a rubber crawler having a steel cord band composed of a plurality of steel cords arranged side by side, and in particular, it prevents cracks in the rubber body near the end of the core metal and the steel cord band. Related to the rubber crawler.

  The core metal and the steel cord band embedded in the endless rubber body have a length that does not reach the entire width of the rubber body. Therefore, the left and right sides of the rubber body constitute ears made of rubber material only. Yes.

  Therefore, since the ear part has the most flexibility in the rubber crawler as a whole, the structure is most likely to cause deformation distortion in the ear part from the viewpoint of how the rubber crawler is used.

  When this rubber crawler rides on, for example, a curbstone or the like, an upward or downward force is applied to the ear portion, and the rubber crawler is bent and deformed to the inner peripheral side or the outer peripheral side. When this deformation occurs repeatedly, the rubber part may crack near the end of the core bar or steel cord band.

  This crack tends to grow in the circumferential direction of the rubber crawler along the end of the core bar or steel cord band, so that the ear may be torn from the rubber crawler.

  As a measure for preventing the occurrence of such cracks, Japanese Patent Application Laid-Open No. 11-105754 (Patent Document 1) proposes forming a rib having a round cross section at the end of the core metal. . This round rib prevents the occurrence of cracks by increasing the contact area with the rubber material, increasing the adhesive strength, and acting so as not to concentrate the shearing force.

  Japanese Utility Model Laid-Open No. 06-061672 (Patent Document 2) discloses an endless belt-like shape in which the ground side of the steel cord band and the sides of the ends of the cored bar and the steel cord band are formed of reinforcing fibers such as Kepler. It is shown that the reinforcement body is uniformly surrounded by the reinforcement body of this type, and the reinforcement body installed in this way increases the rigidity of the rubber body in the vicinity of the end of the cored bar or steel cord band as well as other parts. The occurrence of cracks in the rubber body starting from the end is prevented.

JP-A-11-105754 Japanese Utility Model Publication No. 06-061672

  The countermeasure described in Patent Document 1 is effective in preventing the occurrence of cracks as described above, but there is a problem in that the round rib formed at the end of the core increases the weight of the core. is there. An extremely large number of cores are used in rubber crawlers. Therefore, an increase in the weight of each core metal leads to an increase in the weight of the rubber crawler, which in turn greatly increases the weight of the machine equipped with this rubber crawler. I will let you. In particular, such rubber crawlers are not suitable for lightweight aircraft. This is because an increase in the weight of the machine causes problems such as hindering conveyance.

  Further, as described above, the metal core described in Patent Document 1 suppresses the occurrence of cracks in the rubber main body at the end portion thereof, but this effect does not reach the end portion of the steel cord band, and tension is not applied. Cracks cannot be prevented from occurring at the end of the steel cord band that is hung and has high rigidity.

  The countermeasure described in Patent Document 2 extends an endless belt-shaped reinforcing body formed of reinforcing fibers such as Kepler by bending it from the ground side of the steel cord band toward the end of the steel cord band and the core metal. However, as one form of this extension, it has been shown to be performed up to the side of the ends of the cored bar and the steel cord band (see FIG. 1 of Patent Document 2). Thereby, for example, when the ear part of the rubber crawler rides on the curb and this ear part is bent inward, the rigidity of the rubber body is increased by the reinforcing body extending from the ground side of the steel cord band. The occurrence of cracks originating from the ends of the metal core and the steel cord band is prevented. However, for example, when the side portion of the rubber crawler rubs against the side surface of the curb and the ear portion is bent outward (on the ground side), the extension portion of the reinforcing body is Since the rubber body in the vicinity of the edge of the core bar cannot be provided with sufficient rigidity against such outward bending, cracks in the rubber body starting from the end of the core bar cannot be sufficiently prevented.

  Further, in FIG. 2 of Patent Document 2, as another form of reinforcing body extension, the reinforcing body is extended from the side of the end of the cored bar and the steel cord band to the inner peripheral side of the end of the cored bar. It has been shown.

  However, in the case of the form described at the beginning, the reinforcing body of Patent Document 2 extends from the periphery of the end of the core metal to the outer peripheral side of the core metal or the grounding side over almost half the range of the core metal. Because it is stretched long, the rubber crawler while driving is riding on a stone etc. and the rubber body is deformed, or the ear part is riding on a curbstone etc. and bent to the inner peripheral side of the rubber crawler, etc. Is rubbed against the curb or the like and bent to the outer peripheral side of the rubber crawler, shear stress is generated between the rubber body and the reinforcing body due to the difference in elongation between the rubber body and the reinforcing body, and the generation of this shear stress is repeated. In some cases, the rubber body and the reinforcing body may be separated. When this peeling occurs, the effect of imparting rigidity to the rubber body by the reinforcing body is lost, and when this peeling occurs near the end of the core metal, the rigidity of that part is lost, so the ear part of the rubber crawler is no longer present. It is impossible to prevent the bending deformation of the metal from spreading to the tip of the metal core, and the rubber main body will be cracked around the core metal tip.

  Therefore, the present invention does not cause the above-described peeling even if the above-mentioned ear portion is bent to the inside and the outside of the rubber crawler many times, and the rigidity of the rubber body around the end portion of the core metal and the steel cord band In such a case, the object is to perform the treatment without increasing the weight of the rubber crawler.

  In order to achieve the above object, the present invention provides an endless belt-shaped rubber body, a plurality of core bars embedded in the rubber body at a constant pitch in the circumferential direction of the rubber body, and the core bars in the rubber body. A rubber crawler having a steel cord band made of a plurality of steel cords embedded side by side in the width direction of the rubber main body on the outer peripheral side, and is made of a material that is less stretchable than the rubber constituting the rubber main body. A characteristic sheet material is embedded in the rubber body so as to surround and surround only the end portion at a predetermined interval from the end portions of the core metal and the steel cord band. To do.

  According to this configuration, since the sheet material has a portion that is wound on both the upper side and the lower side of the end portion of the cored bar and the steel cord band, a force from above and below is applied to the ear part. Even in this case, the core portion and the rubber portion around the end portion of the steel cord band are protected from cracking by the highly rigid portion. Furthermore, since the sheet material is embedded only in the area around the ends of the cored bar and the steel cord band, even if bending deformation occurs in the rubber body such as the ear part, the deformation occurs between the sheet material and the rubber body. Shear stress is hardly generated, and even if it is generated, its size is very small and does not cause separation between the two. Therefore, the rigidity imparting effect by the sheet material, and thus the crack generation preventing effect is permanently maintained.

  In addition, it is possible to efficiently and efficiently form a region with increased rigidity around the ends of the cored bar and the steel cord band, and in that case, by appropriately selecting the degree of difficulty in stretching the sheet material, The region stiffness can be adjusted to an optimum one. As a result, even if a bending force is applied to the ear portion, the bending does not reach the end of the cored bar and the steel cord band beyond the region where the rigidity has been increased, and starts at the end. Generation of rubber cracks (ear cuts) can be prevented. Since such an effect can be obtained without increasing the weight of the mandrel, the weight of the rubber crawler is not increased, and therefore, the weight of the body equipped with the rubber crawler is not increased.

  The rubber crawler according to claim 2 is characterized in that the amount of the sheet material to be wound is substantially equal on the inner peripheral side and the outer peripheral side of the end portion of the core metal and the steel cord strip.

  According to this structure, the area | region where rigidity was equally improved can be formed with sufficient balance in the inner peripheral side and outer peripheral side of the edge part of a metal core and a steel cord strip. It is more preferable that the amount of entrainment is equal on the inner peripheral side and the outer peripheral side.

  The rubber crawler according to claim 3 is characterized in that a distance in a rubber crawler width direction from the end of the end of the core metal and the steel cord band to the sheet material is 3 to 8 mm.

  If the interval is narrower than 3 mm, the rigidity of the portion surrounded by the sheet material becomes too high, and cracks are likely to occur on the outside of the sheet material. On the other hand, if the interval is wider than 8 mm, the rigidity of the portion surrounded by the sheet material becomes too low, and the core metal inside the sheet material and the rubber around the end portion of the steel cord band tend to crack.

  The rubber crawler according to claim 4 is characterized in that the sheet material is made of a canvas, a woven fabric, or a reinforcing fiber. The material is preferably nylon or vinylon.

  The canvas, the woven fabric, and the reinforcing fiber are embedded in the rubber body in a familiar manner, and the expansion of the rubber in the direction in which the fiber extends is regulated to effectively increase the rigidity of the surrounding rubber. Moreover, these canvases, woven fabrics, and reinforcing fibers are available at a relatively low cost.

  The rubber crawler of the present invention can sufficiently prevent the occurrence of cracks at the ends of the cored bar and the steel cord band with a relatively simple configuration in which the ends of the cored bar and the steel cord band are surrounded by a sheet material. In addition, since the crawler weight is not increased, the weight of the machine body on which the crawler is mounted can be sufficiently accommodated within a predetermined value.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partial perspective view of a rubber crawler according to the present invention, and FIG. 2 is a cross-sectional view of the rubber crawler of FIG.

  In FIG. 1, 1 is a rubber crawler, 2 is an endless belt-like rubber main body, 3 is a core metal embedded in the rubber main body 2 at a constant pitch in the circumferential direction of the rubber main body in a state of extending in the width direction of the rubber crawler, This is a steel cord band composed of a plurality of steel cords embedded in the rubber body 2 in the width direction of the rubber body on the outer peripheral side of the core metal 3. In the illustrated case, the steel cord band 4 is arranged in a state of being divided into one wing portion of the core metal 2 and the outer peripheral side of the other wing portion. In FIG. 1, reference numeral 5 denotes a drive wheel attached to a machine body (not shown) for driving the rubber crawler 1, and 6 denotes a roller wheel attached to the machine body for supporting the machine body with respect to the rubber crawler 1. , 7 is a protrusion formed in alignment with the inner peripheral surface of the rubber main body 2 to hold and guide the drive wheel 5 and the rolling wheel 6, and 8 is a lug formed on the outer peripheral surface of the rubber main body 2. .

  As shown in FIGS. 1 and 2, according to the present invention, the sheet material 9 is embedded in the rubber main body 2 so as to wind the ends of the cored bar 3 and the steel cord band 4. The sheet material 9 is flexible and flexible, and is made of a material that is less likely to stretch than the rubber constituting the rubber body 2. Specifically, the sheet material 9 is nylon, vinylon canvas, woven fabric, or reinforcing fiber.

  As is clear from FIG. 2, the sheet material 9 surrounds the core metal 3 and the ends of the steel cord band 4 so as to be wound. That is, the sheet material 9 is separated from the inner peripheral surface 31 and the distal end 32 of the end portion 30 of the core metal 3 and the outer peripheral surface 41 of the end portion 40 of the steel cord band 4 with a certain distance. The ends 30 and 40 of the belt 4 are surrounded in an inverted U shape. The opposite ends of the cored bar 3 and the steel cord band 4 are surrounded by a sheet material 9 in a U shape as shown in FIG.

  As an example of specific dimensions, the distance a between the tip 32 of the core metal 2 and the sheet material 9 is about 5 mm, and the sheet material 9 is wound from the tip 32 of the core metal 2 toward the central portion of the core metal 2. The length is about 1 cm on both the inner peripheral surface 31 side of the core end and the outer peripheral surface 41 side of the steel cord strip end. Moreover, the space | interval of the inner peripheral surface 31 of a metal core edge part, the outer peripheral surface 41 of a steel cord belt edge part, and the sealing material 9 is about 2-5 mm.

  Thus, since the sheet material 9 is included only in the periphery of the end portions of the cored bar 3 and the steel cord band 4, for example, the ear part 20 rides on a curbstone or the like, and the inside of the rubber crawler 1 (direction A). Even if it bends to the outside or is rubbed against the curb or the like and bent to the outside (in the direction of B), no shear stress is generated between the rubber main body 2 and the sheet material 9, and therefore Therefore, the effect of imparting rigidity by the sheet material 9 is permanently maintained. The bending in the B direction occurs, for example, when the ear portion 20 is rubbed against the side surface of the curb or the like when the rear side of the rubber crawler 1 turns upward during traveling.

  By embedding the sheet material 9 in this manner, the rigidity of the rubber main body 2 around the core end portion 30 and the steel cord band end portion 40 is increased, and the ear portion 20 is bent, for example, in the A direction or the B direction. However, the bending hardly affects the end portion 30 of the metal core and the end portion 40 of the steel cord due to the action of the rubber main body portion whose rigidity is enhanced. Generation of cracks in the main body 2 is prevented. In other words, the sheet material 9 has portions that are wound on both the upper side and the lower side of the end portions 30 and 40 of the cored bar 3 and the steel cord band 4, so Even when force is applied, the rubber portions around the end portions 30 and 40 of the core metal 3 and the steel cord band 4 are protected from cracking by the portion made highly rigid by the sheet material 9. . That is, close to the end portions 30 and 40, between the high rigidity portions 30 and 40 of the core metal 3 and the steel cord band 4 and the low rigidity ear portions 20 that are solid rubber, A layer with favorable rigidity enters, and the rigidity changes stepwise, so that the rubber distortion does not concentrate locally, so cracks are less likely to occur in the rubber part, effectively preventing the occurrence of ear cuts. . And since the sheet | seat material 9 is comparatively lightweight, the weight of the rubber crawler 1 is not increased significantly by the embedding. That is, the effect of preventing cracks at the end is achieved without increasing the weight of the rubber crawler.

  When canvas, woven fabric, or reinforcing fiber is used as the sheet material 9, an increase in the weight of the rubber crawler can be effectively prevented, and the rigidity of the rubber body in the direction in which the fiber extends increases, so that A rigid layer can be advantageously formed.

  The surroundings of the end portion of the metal core and the end portion of the steel cord band by the sheet material 9 may be performed individually. That is, the cored bar end portion 30 is surrounded by the sheet material 9 in an inverted U shape or a U shape, and the steel cord band end portion 40 is similarly surrounded by the sheet material 9. In this case, if the material of the sheet material 9 is selected to be suitable for the cored bar end 30 and the steel cord band end 40, respectively, the rigidity around the cored bar end 30 and the steel cord band end 40 is This is adapted to the rigidity of the core end portion 30 and the steel cord strip end portion 40 itself, and a more excellent cracking prevention effect is obtained.

1 is a partial perspective view of a rubber crawler according to the present invention. FIG. FIG. 2 is a partial cross-sectional view of the rubber crawler of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rubber crawler 2 Rubber | gum main body 20 Ear part 3 Core metal 30 Core metal end part 31 Inner peripheral surface of core metal part 32 Tip of metal core end part 4 Steel cord belt 40 Steel cord belt end 41 Steel cord belt end Outer peripheral surface 9 Sheet material

Claims (4)

Endless belt-like rubber body, a plurality of core bars embedded in the rubber body at a constant pitch in the circumferential direction of the rubber body, and embedded in the width direction of the rubber body on the outer peripheral side of the core metal in the rubber body In a rubber crawler having a steel cord band composed of a plurality of steel cords,
A flexible and flexible sheet material that is less likely to extend than the rubber constituting the rubber body is spaced apart from the end of the core metal and the steel cord band within the rubber body by a predetermined distance. The rubber crawler is embedded so as to enclose and surround only the end portion.   The rubber crawler according to claim 1, wherein the sheet material has substantially the same amount of winding on the inner peripheral side and the outer peripheral side of the end portions of the cored bar and the steel cord strip.   The rubber crawler according to claim 1 or 2, wherein an interval in a rubber crawler width direction from a tip of the end portion of the core metal and the steel cord band to the sheet material is 3 to 8 mm.   The rubber crawler according to any one of claims 1 to 3, wherein the sheet material is made of canvas, woven fabric, or reinforcing fiber.

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