JP2000085028A - Method for molding rubber crawler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to easily remove a vulcanization rubber band from a space between projections of a rubber crawler obtd. by pinching in advance the projections with the vulcanization rubber band to make apparently them one projection. SOLUTION: In a method for molding a rubber crawler wherein an unvulcanized rubber member is vulcanized between an outer mold and an inner mold divided left and right, a vulcanization rubber band 2 is fitted between projections of a core metal 3 provided with a pair of projections 3A and it is embedded into an unvulcanized rubber to perform vulcanization molding and then, the outer mold is moved in the radial direction and the inner mold is moved and divided left and right to release the inner mold and the outer mold from the rubber crawler and then, the vulcanization rubber band 2 is peeled off from a pair of projections 3A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding an endless rubber crawler having a core bar having a pair of projections embedded therein.

[0002]

2. Description of the Related Art A rubber crawler is widely used as a traveling part of construction equipment and agricultural equipment. Usually, a metal core having a pair of projections is embedded in rubber and the projections are protruded from an inner peripheral surface. It has the following structure. FIG. 5 shows a basic method of molding a rubber crawler. As shown in FIG. 5, an end unvulcanized rubber band 32 having a main code 31 embedded therein is removed.
While holding the upper and lower molds (mold) 33, 34,
The unvulcanized belt-shaped rubber 32 is vulcanized under pressure and heat to obtain an end-shaped band-shaped rubber 35, and thereafter, the staggered ends 36 and 37 of the end-shaped band-shaped rubber 35 are polymerized to form an end. Both ends are vulcanized and joined by upper and lower molds 38 and 39 for joining to obtain an endless rubber crawler 30.

[0003] However, in such a rubber crawler molded by the conventional vulcanization method, a great deal of time was required for the manufacturing process. In addition, the molding die and the hot plate required for the molding are long, so that a large space is required for installation, and a joining and vulcanizing step of only an end portion for endlessness is required.

Further, both ends of the end-shaped rubber band must be vulcanized and joined, and it is impossible for the endless rubber crawler to have all the uniform characteristics on the circumference. Particularly, since both ends of the main code are overlapped and made endless, the rigidity in the length direction partially differs greatly, which causes noise, vibration, etc., which cannot withstand high-speed running. The appearance of a rubber crawler that has solved these problems has been awaited.

[0005] In view of the above, the present applicant has solved the problem in the conventional molding method, and embeds a spiral-shaped main code so as to have a uniform strength characteristic over its entire length and to cope particularly with high-speed running. A possible endless rubber crawler molding method was proposed. This molding method uses an inner mold that has the same shape as the inner peripheral surface of the rubber crawler and is divided into right and left in the width direction of the rubber crawler and an outer mold that has the same shape as the outer peripheral surface. On the outer periphery, lug rubber as a grounding part, inner peripheral rubber as an inner peripheral side, side rubber as a side part, protrusion rubber as a guide guide for a sprocket, a bias code, and a main code, which are components of a rubber crawler, are provided. It is placed and subjected to vulcanization by reducing the diameter of the outer mold. Then, the main code is formed by placing the protruding rubber and the inner peripheral rubber on the outer periphery of the inner mold, winding the spiral in a spiral shape, and then pressurizing and heating, and vulcanizing and molding between the inner and outer molds at once. Will be Next, the outer die is expanded in the radial direction to release the outer die from the outer peripheral surface of the rubber crawler, and then the inner die is moved and divided in the left-right direction to be released from the inner peripheral surface of the rubber crawler. It is.

However, when the inner die is divided and moved to the left and right, the inner peripheral surface of the rubber crawler must have a shape that can be easily divided into left and right, and one projection is formed at the center of the rubber crawler. The inner mold cannot be moved to the left or right except for the rubber mold, for example, a rubber clasp having a structure in which a metal core having a pair of protrusions is embedded in rubber and the protrusions protrude from the inner peripheral surface. -It was not possible to apply to the molding method of la.

[0007]

SUMMARY OF THE INVENTION The present invention is a further improvement of the method of molding a rubber crawler proposed above, and is applied to a rubber crawler having a core having a pair of projections embedded in the rubber crawler. An object of the present invention is to provide a method of molding an endless rubber crawler, which enables embedding of a spiral main code, and further allows provision of uniform circumferential strength characteristics. .

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and its gist is to divide the endless rubber crawler into a plurality of parts in a circumferential direction which defines the outer peripheral surface of the endless rubber crawler. In a method of molding a rubber crawler for vulcanizing an unvulcanized rubber member between an outer mold and an inner mold that defines an inner peripheral surface of a rubber crawler, a ring-shaped depression in which a pair of projections of a core metal fits in a central portion. The inner unvulcanized rubber sheet constituting the inner peripheral side of the rubber crawler is wound around the outer periphery of the inner die that can be divided into right and left parts in the width direction of the rubber crawler. A vulcanized rubber band having a pair of dents formed on the left and right is wound around the center, and a projection of a cored bar having a pair of projections is fitted into the depression of the vulcanized rubber band. -Spirally wound around the outer periphery of the rubber crawler. Periphery unvulcanized Gomushi - wrapped bets,
An outer die which is divided in the circumferential direction and is movable in the radial direction is disposed outside the rubber crawler component, and the outer die is radially contracted and pressurized to press the rubber crawler component. By heating this, the unvulcanized rubber is vulcanized, the outer mold is moved in the radial direction, the inner mold is moved right and left to separate the inner and outer molds from the rubber crawler, and then the vulcanized rubber is released. The present invention relates to a method of molding a rubber crawler for separating a band from between a pair of projections.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the rubber crawler molding method already proposed, the fact that the inner mold can be divided into left and right means that the rubber crawler has only one protrusion on the inner mold side due to its structure. The inner mold can be divided right and left around the center. However, in a rubber crawler having a structure in which a pair of protrusions are provided on the inner periphery of the rubber crawler, the protrusions of the rubber crawler have a pair of shapes protruding toward the inner mold. A recess to be fitted had to be formed, so that it could not be divided in the width direction of the rubber crawler.

However, in the present invention, the vulcanized rubber band is sandwiched between the pair of projections of the core bar, and the pair of projections temporarily become one projection, so that the inner mold can be divided into right and left. After vulcanization molding of a rubber crawler, the vulcanized rubber band fitted between the pair of projections is peeled off.

In general, it is known that applying higher heat to a vulcanized rubber makes the rubber brittle. Therefore, even if the vulcanized rubber is heated without using an adhesive even if the contact material is heated. Does not adhere, so that the vulcanized rubber band can be peeled off relatively easily from between the pair of projections, and a rubber crawler having a pair of projections can be obtained here. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for molding a rubber crawler according to the present invention will be described below with reference to the drawings. 1 to 3 are views showing a first embodiment of a rubber crawler molding method according to the present invention. FIG. 1 is a schematic side sectional view showing a vulcanizing step by movement of an outer mold, and FIG. 2 is a schematic front view thereof. FIG. 3 is a cross-sectional view of the rubber crawler component.

An outer mold 11 for defining a tread pattern or the like of a ground surface of the rubber crawler 1 to be vulcanized and molded is provided on the inner peripheral side of an inner frame 12 capable of reducing the diameter, and is divided in a circumferential direction. The inner frame 12 is formed in a width direction and a radial direction with respect to an inner peripheral inclined surface 15 of an outer frame 14 through a tapered inclined surface 13 on an outer periphery thereof. Movably fitted to These outer mold 11, inner and outer frames 12,
14 are all formed in an endless shape in a front view, and are preferably circular, but an appropriate shape such as an ellipse may be adopted.

On the other hand, an inner mold 16 which defines an inner peripheral side of a rubber roller having a pair of projections which engage with a track roller or the like to exhibit a detachment prevention function is also opposed to the outer mold 11. It is formed endless and has a ring-shaped recess 16C in which a pair of projections of the cored bar are accommodated at the center position in the width direction, and the center of the recess 16C is divided into two in the width direction (16A, 1A).
6B).

In FIG. 1, the inner frame 1
By pressing the outer frame 14 disposed on the outer circumference of the outer mold 2 to the left side, the divided pieces 11A to 11H of the outer mold 11 together with the inner frame 12 are reduced in diameter in accordance with the movement in the width direction, and the inner mold 16 is moved. The rubber crawler components placed on the outer periphery of the cradle are pressed uniformly and reliably.

When the outer die 11 is not mounted, the components of the rubber roller 1 are set on the outer peripheral surface of the inner die 16, but the inner peripheral unvulcanized rubber seal on the inner peripheral side is set. -G1
A is divided and wound right and left in the width direction. The vulcanized rubber band 2 is also wound around the central recess 16C.
Is provided with a pair of depressions 2A into which a pair of protrusions of the cored bar are fitted. Next, the core 3 having the pair of projections 3A is set by fitting the projections 3A into the recesses 2A. Then, surround the core bar 3 and
Is preferably wound spirally, and
Necessary members such as an outer unvulcanized rubber sheet 1B serving as a grounding portion and a side unvulcanized rubber sheet 1C serving as a side portion are wound. It will be vulcanized. 4a is a bias code.

Next, by moving the inner frame 12 in the width direction with respect to the outer frame 14, the inner frame 12 on which the outer mold 11 is installed expands in the radial direction, and the outer mold 11 is moved to the outer peripheral surface of the rubber roller 1. From the mold. Thereafter, the outer peripheral surface of one (right side) of the rubber crawler 1 is gripped with one of the right and left inner dies 16B, for example, the right inner die 16B interposed therebetween, to hold the other (left) inner die 16A. Is released in the width direction.
Similarly, the other side (left side) slightly released in the width direction
With the inner mold 16A interposed therebetween, the outer peripheral surface of the other (left) side of the rubber crawler 1 is gripped and the one (right) inner mold 1 is held.
Release 6B.

Finally, the vulcanized rubber band 2, which is still sandwiched between the projections 3A of the metal core 3, which protrudes from the inner periphery of the rubber crawler 1, is pulled out from between the projections 3A and peeled off. It is exposed and the molding is completed.

FIG. 4 shows a second embodiment of the crawler molding method according to the present invention. In this embodiment, an outer frame 14 is arranged directly on the outer periphery of an outer mold 11. is there. In the present embodiment, each divided part 11A in the outer mold 11 is used.
Slope surfaces 28, 28 are provided on the outer periphery of both end surfaces in the width direction of the divided parts 11A to 11H, and a pair of left and right outer frames 14A, 14B are arranged on the outer periphery of each of the divided pieces 11A to 11H. An inclined surface 29 corresponding to the inclined surface of the outer mold 11 is formed on each inner periphery of these outer frames 14A and 14B.
As the outer frames 14A and 14B move close to each other in the width direction, the divided pieces 11A to 11H are reduced in diameter in the radial direction through the inclined surfaces, and the rubber clamps mounted on the outer peripheries of the inner dies 16A and 16B. The vulcanization is performed by pressing and heating the rubber components. In the present embodiment, since the outer die 11 is directly reduced in diameter by the outer frame 14, it is possible to reduce the number of frame components, press plates, and the like. Of course, finally, the vulcanized rubber band 2, which is still sandwiched between the projections 3A of the metal core 3 projecting from the inner periphery of the rubber crawler 1, is pulled out from between the projections 3A and peeled off to expose the projections 3A. It goes without saying that the molding is completed.

[0020]

As described above, according to the present invention, in the molding of a rubber crawler using a metal core having a pair of projections, the projections are sandwiched in advance by a vulcanized rubber band and apparently one projection is formed. And a core metal and an unvulcanized rubber screen having such a configuration.
G. Further, after molding the rubber crawler component on the outer periphery of the inner mold capable of dividing the main code and the like in the width direction, the rubber crawler component is circumferentially divided outside the rubber crawler component and radially divided. A slidable outer mold is arranged, and the outer mold is configured to be vulcanized by radially reducing and pressurizing the outer mold. The vulcanized rubber band can be easily removed.

For this reason, a rubber clock having a pair of projections is provided.
The rubber crawler component can be uniformly and reliably pressed around the circumference by a plurality of outer molds between the endless outer mold and inner mold even if the rubber mold is vulcanized. The main code can be wound spirally, and the strength and rigidity characteristics can be uniform around the circumference. This provides a rubber crawler having improved properties and life.

[Brief description of the drawings]

FIG. 1 is a schematic side sectional view of a molding method of the present invention, particularly showing movement of an outer mold.

FIG. 2 is a schematic front view of FIG.

FIG. 3 is a sectional view of a rubber crawler component in the molding method of the present invention.

FIG. 4 is a schematic side sectional view showing another example of the crawler molding method of the present invention.

FIG. 5 is a schematic sectional view showing a conventional method of molding a rubber crawler.

[Explanation of symbols]

 1 rubber unrolled rubber sheet, 1A uncured rubber sheet on inner circumference, 1B uncured rubber sheet on outer circumference, 1C uncured rubber sheet on side, 2 cured rubber band, 2A cured rubber band Recess, 3mm core bar, 3A core bar projection, 4 main cord, 11mm outer die, 11A-11H outer die piece, 16mm inner die, 16A, 16B split inner die, 16C inner A ring-shaped depression in the center of the mold.

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Claims (1)

[Claims] 1. An unvulcanized rubber member is formed between an outer mold divided into a plurality of parts in a circumferential direction defining an outer peripheral surface of an endless rubber crawler and an inner mold defining an inner peripheral surface of the rubber crawler. In a method of molding a rubber crawler to be vulcanized, the center of the rubber crawler is provided with a ring-shaped recess in which a pair of protrusions of a metal core are accommodated, and the rubber crawler is formed on the outer periphery of an inner mold that can be divided into right and left in the width direction of the rubber crawler. An inner unvulcanized rubber sheet constituting the inner peripheral side is wound left and right in the width direction, a vulcanized rubber band having a pair of left and right recesses formed around the center of the inner mold, and a core bar having a pair of projections The main code is spirally wound around the cored bar, and the outer unvulcanized rubber sheet constituting the outer peripheral side of the rubber crawler is formed by fitting the projections into the recesses of the vulcanized rubber band. Wrapped around the rubber crawler component, and Place the outer mold that can move in the direction,
The outer mold is radially reduced and pressurized to pressurize the components of the rubber crawler, which is heated to vulcanize the unvulcanized rubber. Move the mold to the left and right and separate the inner and outer molds from the rubber crawler,
Thereafter, the vulcanized rubber band is peeled off from between the pair of projections.