JP5210619B2 - Rubber crawler manufacturing method - Google Patents

Description

  The present invention relates to a method of manufacturing a rubber crawler to be mounted on a construction machine such as a hydraulic excavator, an agricultural machine such as a combine or a tractor, or other crawler type vehicles, and is particularly generated at the end in the width direction of the rubber crawler. It is intended to effectively reduce “ear loss”.

  A crawler type vehicle is provided with a crawler configured by winding a belt-like body between a driving wheel connected to driving means such as a hydraulic motor and a non-driven type driven wheel. By rotating, the aircraft can run.

  The rubber crawler is gentle on the road surface (does not damage the soil in the field, etc., and rarely damages the road surface on asphalt or concrete roads), has low vibration and low noise, and uses a low ground pressure. Because it can run stably on snow and sand, it does not have a mechanical joint compared to an iron one, so there is no mud clogging and troublesome maintenance like an iron shoe is unnecessary. In recent years, this type of crawler has come to be used frequently, and due to the difference in the applicable machine body (excavator, agricultural machine, industrial machine, tractor, paving machine, etc.), the cored bar and the reinforcing layer are placed in the rubber layer. It is divided into a metal reinforcement type that is buried and fixed, a ply reinforcement type that is not provided with a cored bar, and only a reinforcement layer is provided.

  By the way, especially in the case of a metal reinforced rubber crawler, it extends from the width end of the core metal in a situation where it rides on a stone or curb or the edge in the width direction is strongly pressed by contact with the side wall. The rubber layer part (the crawler's width end) is greatly deformed (strain tends to concentrate on that part) starting from the width end of the mandrel (blade tip), and as a result of this repetition, the ear is cut. There was an inevitable bug.

As a prior art regarding this point, there is known a structure in which a high-hardness intermediate rubber layer is interposed from at least a contact surface side lower side of a longitudinal end portion of a core metal blade portion to an outer end portion of a rubber crawler width direction. (For example, refer to Patent Document 1) No proposal has been made regarding a specific manufacturing method.
JP 2003-335275 A

  The subject of this invention exists in the place which proposes the novel method which can manufacture a rubber crawler efficiently while suppressing generation | occurrence | production of an ear-cut.

The present invention, on the upper surface of the inner rubber sheet forming the inner peripheral surface of the crawler, established the core, further an outer rubber sheet forming the ground plane of the crawler on the said core placed, stacked, resulting In producing a rubber crawler by applying pressure and vulcanization treatment to the laminated body,
Prior to placing the core on the upper surface of the inner rubber sheet in the width direction end portion of the core body, sets a reinforcing member for囲撓the said width direction end portion, the widthwise end portion of the core member Is covered with the reinforcing member from the outside in the width direction of the core body .

  As the reinforcing member, it is desirable to use a member having a C-shaped cross-sectional shape preformed by unvulcanized extrusion molding.

  The reinforcing member is composed of a single member continuously extending along the longitudinal direction of the core body, or composed of a plurality of divided chips arranged at intervals along the longitudinal direction of the core body. Can be applied.

  Specifically, the core body corresponds to one consisting of at least one of a cored bar, a steel cord reinforcing layer, and a ply reinforcing layer, and is not only applied to a metal reinforced type crawler, but also has a cored bar. Application to non-ply reinforced crawlers.

  By pre-setting the reinforcing member pre-molded by unvulcanized extrusion molding at the end in the width direction of the core, displacement due to rubber flow during pressurization and vulcanization treatment is avoided, and The cross-sectional shape is stably maintained, and as a result, even if the rubber crawler rides on a stone or curbstone and a large strain occurs at the tip of the core body, the strain is effectively dispersed by the reinforcing layer. Then, the edge cut at the width end of the rubber crawler is suppressed.

  Incorporation of the reinforcing member is a simple operation of inserting the reinforcing member into the core body through the open end formed in the reinforcing member, so that the rubber crawler can be efficiently manufactured.

Hereinafter, the present invention will be described more specifically with reference to the drawings.
FIG. 1 is a diagram schematically showing a state in which a metal reinforced rubber crawler manufactured according to the present invention is wound between a driving wheel and a driven wheel, and FIG. 2 shows a cross section thereof. FIG.

  In the figure, reference numeral 1 denotes a rubber band constituting the main part of the crawler. This belt-like body 1 forms an endless track by winding between a driving wheel 2 and a driven wheel (not shown) and linking the ends thereof, and the inner peripheral side of the belt-like body 1 is driven. It is an arrangement area for the wheel 2, the rolling wheel 3, and the driven wheel (not shown), and the outer peripheral side is a grounding part that forms a land part such as a lug.

  Reference numeral 4 denotes a core body embedded and fixed in the rubber layer 1a of the strip 1 (hereinafter, this core body will be referred to as a core metal 4). A plurality of the core bars 4 are arranged at intervals along the belt-like body 1, and a base part 4a located at the center in the width direction and a base part 4a are integrally connected to project toward the inner peripheral side of the crawler. A pair of left and right protrusions 4b and 4c and a blade 4d and 4e extending from the base 4a to the edge in the width direction, and a path through which the driving wheel 2 and the driven wheel pass between the protrusions 4b and 4c. Each S is formed (see Fig. 2).

  Reference numeral 5 denotes a cord reinforcement layer disposed on the outer peripheral side of the core metal 4 and embedded and fixed in the rubber layer 1a together with the core metal 4. The cord reinforcement layer 5 is a steel cord extending along the belt-like body 1. It is composed of a plurality arranged in the width direction.

  6 is a flat surface provided adjacent to the protrusions 4b, 4c of the cored bar 4 on the inner peripheral side of the strip 1 and the rolling wheels 3 roll along the flat surface 6.

  Reference numeral 7 denotes a meshing hole penetrating from the inner circumference side to the outer circumference side of the strip 1 in the path S (see FIG. 1). The engagement holes 7 are provided at intervals over the entire circumference of the belt-like body 1 (formed between the cored bars 4), and the protrusions 2a of the drive wheels 2 are fitted in the engagement holes 7.

  Further, 8 is a reinforcing member (arranged in the rubber layer 1a) that surrounds a region from the lower end portion of the end portion in the width direction of the cored bar 4 to the upper end portion of the end portion in the width direction of the cord reinforcing layer 5. As the reinforcing member 8, a member having an external shape as shown in FIG. 3 preliminarily molded by unvulcanized extrusion molding is applied.

  Of the rolling wheels 3 interposed between the driving wheel 2 and the driven wheel, the rolling wheels 3 located on the lower surface (the side to be grounded) transmit the load of the fuselage to the rubber crawler to reliably ground the entire grounding part. A roller wheel (not shown) located on the upper surface has a function of supporting the tension of the rubber crawler so as to always keep constant between the driving wheel 3 and the driven wheel, When the driving wheel 2 is rotated by driving means such as a hydraulic motor, the rotational force is transmitted to the crawler through the engagement hole 7 that fits the protrusion 2a of the driving wheel 2, and the crawler rotates between the driven wheel and the driven wheel. It will be. If the crawler rides on a stone or curb when the crawler rotates, a large distortion will occur at the tip of the core 4 (tips of the blades 4d and 4e). Are distributed, and the edge cut at the width end of the crawler is suppressed.

  FIG. 4 is a view schematically showing an arrangement state of each member constituting the rubber crawler including the lower die 9. In manufacturing the rubber crawler, first, the inner rubber sheet 10 that forms the inner peripheral surface (inner peripheral side) of the crawler is set on the lower mold 9.

  Then, the core metal 4, the intermediate rubber layer 11, and the cord reinforcing layer 5 are installed on the upper surface of the inner rubber sheet 10, and the laminating member 8 is inserted at the end in the width direction as shown in FIG. The outer rubber sheet 12 that forms the part surface is disposed (assumed as a laminated body), and the upper mold (not shown) is matched with the lower mold 9, and inside the laminated body, a predetermined condition is satisfied. Originally, pressure and vulcanization are applied to integrate the members. Then, after the ends are bonded together to form a ring shape, the bonded portions are further vulcanized.

  As the reinforcing member 8, for example, synthetic resin such as nylon, polyethylene, polypropylene, or polystyrene, natural rubber, synthetic rubber, hard rubber or soft rubber mainly composed of butadiene rubber, or the like can be used.

  The cross-sectional shape is preferably a C-shaped cross-sectional shape from the viewpoint of misalignment prevention and moldability, but other cross-sections can be used as long as it is a groove-shaped shape that can reliably surround the widthwise end of the core body. You may apply what has a shape.

  The thickness is preferably about 3 mm. Further, it is desirable that the wrap margin L (the overlap margin in the core metal 4 and the cord reinforcing layer 5, see FIG. 5) is 30 mm.

  As shown in FIG. 6, the reinforcing member 8 may be used by extruding and integrating the back-to-back as shown in FIG. 6, and the reinforcing member 8 may be obtained by extruding into a tube shape as shown in FIG. It may be cut and used at the central portion, which enables efficient extrusion molding of the reinforcing member 8.

  When it is necessary to arrange the reinforcing member 8 only on the core metal 4, for example, as shown in FIG. 8, the pre-molded one is divided into a plurality of divided chips 8 'and used as the reinforcing member 8 in the width direction end of the core metal 4. Placed in each part.

  A rubber crawler with a size of 400 x 74 x 72.5 KS (W x L x PFS) with a cross section as shown in Fig. 2 is placed, with a hard rubber reinforcement member 8 with a thickness of 3 mm and a lapping allowance of 30 mm. A running test over a standard curbstone with a height of 150 mm was repeated, and a comparative survey was conducted with a rubber crawler without a reinforcing member (comparative example: other conditions are the same) with respect to the number of times until the ear was cut.

  As a result, in the rubber crawler where the reinforcing member (narrow sheet) is not installed, the number of times until the end of the ear is cut is five, whereas in the rubber crawler manufactured according to the present invention, the end of the ear is cut. It was confirmed that the life until the ear crush was further extended in the rubber crawler manufactured according to the present invention.

  In addition, regarding the manufacturing efficiency, the method according to the present invention can accurately position the narrow sheet only by folding the remaining area, although the process of laying the narrow sheet is added. It was confirmed that it was possible to manufacture the product.

  It is possible to provide a method in which ear cutting is suppressed and efficient production is possible.

It is the figure which showed typically the external appearance of the rubber crawler manufactured according to this invention. FIG. 2 is a view showing a cross section of the rubber crawler shown in FIG. It is an external appearance perspective view of a reinforcement member. It is explanatory drawing of the manufacturing method according to this invention. It is explanatory drawing of the manufacturing method according to this invention. It is an external appearance perspective view of the reinforcement member suitable for using for implementing this invention. It is an external appearance perspective view of the reinforcement member suitable for using for implementing this invention. It is an external appearance perspective view of the reinforcement member suitable for using for implementing this invention.

Explanation of symbols

1 Band
1a Rubber layer
2 Drive wheels
2a Protrusion
3 Rolling wheels
4 cored bar
4a base
4b Protrusion
4c protrusion
4d blade
4e blade
5 Cord reinforcement layer
6 Flat surface
7 Mating hole
8 Reinforcing member
9 Lower mold
10 Inner rubber sheet
11 Intermediate rubber layer
12 Outer rubber sheet

Claims (5)

The upper surface of the inner rubber sheet forming the inner peripheral surface of the crawler, established the core, further established the outer rubber sheet forming the ground plane of the crawler on the said core, laminated, the resulting laminate In manufacturing rubber crawlers by applying pressure and vulcanization,
Prior to placing the core on the upper surface of the inner rubber sheet in the width direction end portion of the core body, sets a reinforcing member for囲撓the said width direction end portion, the widthwise end portion of the core member Is covered with the reinforcing member from the outside in the width direction of the core body .   2. The manufacturing method according to claim 1, wherein the reinforcing member has a C-shaped cross-sectional shape preformed by unvulcanized extrusion molding.   3. The manufacturing method according to claim 1, wherein the reinforcing member is a single member that continuously extends along the longitudinal direction of the core body.   3. The manufacturing method according to claim 1, wherein the reinforcing member is composed of divided chips arranged at intervals along the longitudinal direction of the core body.   5. The manufacturing method according to claim 1, wherein the core body includes at least one of a cored bar, a steel cord reinforcing layer, and a ply reinforcing layer.

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