JPS6119474B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an elastic endless track belt (hereinafter referred to as a crawler) that prevents deterioration of durability when traveling on rough terrain and alleviates the torque applied by impact. The present invention relates to a method for manufacturing a crawler that is unlikely to peel off even when such occurrences occur.

BACKGROUND ART Conventionally, a crawler is known in which a tension-retaining cord made of a steel cord and a core metal that receives a driving force transmitted from a sprocket wheel are embedded inside the vulcanized rubber of the crawler main body. In order to improve the adhesion between the mandrel and the tension-retaining cord, this crawler has a fibrous layer made of canvas interposed between the mandrel and the tension-retaining cord. However, if the fiber layer of this type of crawler comes into direct contact with the core metal or tension-retaining cord, there is a risk that the adhesive strength will be reduced. occurs, and when this reaches the fiber layer, it causes separation across the fiber layer, and eventually moisture infiltrates from the scratched area and penetrates into the interior of the crawler body through the fibers, causing the peeled part to grow, causing damage to the crawler body. It tends to promote and advance peeling.

The present invention eliminates the conventional drawbacks by interposing a thin rubber layer made of vulcanized or semi-vulcanized rubber between the mandrel and the tension-retaining cord instead of the fiber layer interposed between the mandrel and the tension-retaining cord. An improved method of manufacturing a crawler is provided.

The present invention consists of tension maintaining cords arranged and embedded in the rubber material of the crawler in the circumferential direction, and a mandrel that receives the driving force transmitted from the sprocket wheels embedded at regular intervals in the longitudinal direction. ,
A method for manufacturing an elastic endless track band in which an engagement hole for engaging a sprocket is provided between adjacent mandrels, and the mandrel is arranged in a rubber material on the inner circumferential side of a tension-retaining cord. The mandrel and the tension-retaining cord are arranged between the unvulcanized base rubber on the contact surface side and the unvulcanized rubber on the inner surface side, and a vulcanized rubber or semi-cured rubber having at least the same width as the tension-retaining cord is arranged between the core metal and the tension-retaining cord. A thin rubber layer made of vulcanized rubber is inserted and then heated to vulcanize each of the unvulcanized rubbers, thereby forming the engagement hole and separating the mandrel and the tension-retaining cord by the thin rubber layer. A method for manufacturing a crawler in which the main body of the crawler is formed of
Tension holding cords arranged at a constant width are placed at intervals on the left and right on the unvulcanized base rubber on the contact surface side, and vulcanized rubber or semi-vulcanized rubber having at least the same width as the tension holding cords is placed on the tension holding cords. The process of creating a bonded body by placing and pressing a thin rubber layer made of sulfur rubber, and placing the unvulcanized rubber on the inner circumferential side and the core metal, and placing the band-shaped inner circumferential side rubber on the lower mold. Then, the thin rubber layer side of the bonded body is placed on the unvulcanized rubber on the inner peripheral surface side at regular intervals in the circumferential direction. They are stacked one on top of the other so as to be joined, are brought into contact with an upper mold, are pressurized, and are heated and vulcanized.

Figures 1 to 4 show the structure of the crawler obtained by the manufacturing method of the present invention, and Figures 5 to 8 show details of the manufacturing method of the present invention. Tension holding cords 2 arranged in a constant width are placed on the ground side unvulcanized base rubber a with an interval L left and right, and the tension holding cords 2 have at least the same width as the tension holding cords 2 on top of the tension holding cords 2. A step of placing and pressing a thin rubber layer 4 made of vulcanized rubber or unvulcanized rubber to form a bonded body b, and placing a strip of unvulcanized rubber c on the inner circumference side on the lower mold d at intervals from left to right. and placing the mandrels 3 on the unvulcanized rubber c on the inner peripheral surface side at regular intervals in the circumferential direction, and the above-mentioned lamination on the mandrels 3 on the lower mold d. After overlapping the body b so that the thin rubber layer side is joined and staggered in a stepwise manner (see Fig. 7), the upper mold e is brought into contact with the upper mold e, pressurized, heated and vulcanized, and the contact surface side is unvulcanized. The base rubber, the tension holding cord 2, the thin rubber layer 4, the mandrel 3, and the unvulcanized rubber c on the inner circumference side are integrated, and the adjacent mandrels 3 are integrated.
An engagement hole 6 for engagement with a sprocket is provided between the two.
It also includes a step of protruding the lug 7 on the ground surface side during heating and vulcanization.

The main body of the belt-shaped crawler produced in this manner is made into an endless shape by overlapping and joining the stepped portions at both ends thereof.

A thin rubber layer 4 made of vulcanized or semi-vulcanized rubber placed and crimped on the tension-retaining cord 2 plays the role of preventing the tension-retaining cord 2 from being disturbed during molding and vulcanization and maintaining its position accurately. Although it is a thing,
If the coating rubber of the tension-maintaining cord 2 is also semi-vulcanized in advance, it is possible to further prevent it from becoming disordered.

As shown in FIG. 8, the lower mold d is attached to the base plate 9 and can be freely moved in and out of the upper mold e in the longitudinal direction by means of an appropriate guide device, so that the inner peripheral surface side rubber c and the center The gold 3 and the bonded body b can be easily assembled.

As mentioned above, the structure of the crawler manufactured by the manufacturing method of the present invention is shown in FIGS. 1 to 4, and the crawler main body 1 is made of vulcanized rubber, and the tension holding cord 2, which is flexible and made of steel cord, and the sprocket are included. Mandrel 3 that receives the driving force transmitted from the Tsuto wheel
are buried at regular intervals in the circumferential direction. The mandrel 3 is made of metal or plastic, and the one shown in FIG. 3 is provided with a retaining protrusion 5.

The mandrel 3 is arranged on the inner peripheral side of the tension-retaining cord 2, and a thin rubber layer made of vulcanized rubber or semi-vulcanized rubber is interposed between the tension-retaining cord 2 and the mandrel 3. By arranging the mandrel 3 on the inner circumferential side of the tension holding cord 2, when the crawler main body 1 is wound around the sprocket wheel, the mandrel 3 tightens around the sprocket wheel in a hoop shape, and the mandrel 3 tightens around the sprocket wheel. 3 is intended to restrict movements that attempt to secede. The thin rubber layer 4 made of vulcanized or semi-vulcanized rubber interposed between the mandrel 3 and the tension-retaining cord 2 has at least the same width as the tension-retaining cord 2, preferably wider than the width of the tension-retaining cord 2. The amount will be increased by 10% to 20%.

The thin rubber layer 4 prevents direct contact between the tension-retaining cord 2 and the mandrel 3 to increase adhesive strength, and also prevents disturbances during fatigue cutting of the tension-retaining cord 2 and molding and vulcanization. Unlike the conventionally used fiber layer, when the crawler main body 1 is wound around the sprocket wheel and runs, the core metal 3
The tension holding cord 2 elastically prevents the sprocket wheel from being pushed out by the driving force from the sprocket wheel.
It effectively reduces the impact during the transmission and prevents damage. Furthermore, when the crawler main body 1 is injured, the progress of separation is suppressed by preventing the injury from growing.

The thin rubber layer 4 made of vulcanized rubber or semi-vulcanized rubber is brushed to have a rough surface or used in combination with an adhesive in order to increase the adhesion between the tension maintaining cord 2 and the core metal 3. be able to. Further, short fibers such as cotton, synthetic fibers, glass fibers, rock wool, asbestos, and thin metal wires can be kneaded and used for the thin rubber layer 4.
Unlike a fiber layer woven with twisted yarn, these short fibers can reinforce the thin rubber layer 4 and increase its rigidity without introducing moisture into the woven fiber layer. Allows to maintain accuracy. In addition, when semi-vulcanized rubber is used for the thin rubber layer 4, the degree of vulcanization is preferably in the range of 0.5 to 0.9, where 1.0 is the degree of vulcanization when vulcanized under appropriate conditions. It is possible to facilitate bonding during sulfurization and to accurately position the tension maintaining cord 2. The thickness of the thin rubber layer 4 is preferably 0.5 mm to 3 mm.
By changing this rubber thickness, tension retention cord 2
The distance between the metal core 3 and the metal core 3 can be adjusted.

In the figure, 6 indicates the engagement hole with the sprocket, and 7 indicates the lug of the grounding part.

In the example shown in FIG. 4, a retaining protrusion 5 is provided on the inner peripheral surface of the rubber crawler main body integrally with the crawler main body 1, and the core bar 3 is made of a plate of metal or the like.

As described above, according to the present invention, the thin rubber layer 4 made of vulcanized rubber or semi-vulcanized rubber prevents the tension holding cord 2 from being disturbed, maintains the position of the tension holding cord 2 accurately, and It has the effect of being able to adjust the distance between the main body 1 of the crawler 2 and the mandrel 3, and in the case of manufactured crawlers, it is possible to reduce the impact of torque applied when traveling on rough terrain, and to prevent damage to the crawler main body 1. However, the thin rubber layer 4 interposed between the tension-retaining cord 2 and the mandrel 3 suppresses the growth of scratches and prevents the progress of separation by blocking moisture from entering from the outside. It exhibits excellent functions such as being able to prevent

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view of a crawler manufactured according to the present invention, FIG. 2 is a sectional view in the longitudinal direction of FIG. 1, FIG. 3 is a sectional view in the width direction of FIG. The figure is a cross-sectional view in the width direction of another example, Figure 5 is an explanatory diagram of the manufacturing method of the present invention and a cross-sectional view in the width direction, Figure 6 is a perspective view of the bonded body, and Figure 7 is the manufacturing method of the present invention. An explanatory diagram of the method is a longitudinal cross-sectional view, and FIG. 8 is a cross-sectional view of the vulcanization mold in the width direction. 1... Crawler main body, 2... Tension holding cord,
3... Mandrel, 4... Rubber thin layer, 5... Preventing protrusion, 6... Engagement hole, 7... Lug, a... Base rubber, b... Bonded body, c... Inner circumference Side rubber, d...
...lower mold, e...upper mold.

Claims (1)

[Scope of Claims] 1. Tension-retaining cords arranged and buried in the rubber material of the crawler in the circumferential direction, and a center receiving the driving force transmitted from the sprocket wheels buried at regular intervals in the longitudinal direction. An engagement hole for engaging with a sprocket is provided between the metal and adjacent core metals,
The core metal is a method of manufacturing an elastic endless track band placed in the rubber material on the inner circumferential side of the tension-retaining cord. Arranging the mandrel and the tension-retaining cord, interposing a thin rubber layer made of vulcanized rubber or semi-vulcanized rubber having at least the same width as the tension-retaining cord between them, and then heating each of the tension-retaining cords. A method of manufacturing an elastic endless track belt, which comprises vulcanizing unvulcanized rubber to form the engagement holes, and separating the core and tension holding cord with the thin rubber layer to form a crawler main body. 2. The unvulcanized base rubber on the contact surface side, the tension-retaining cord, and the thin rubber layer. A step of placing and pressing a thin rubber layer made of vulcanized rubber or semi-vulcanized rubber having at least the same width as the tension maintaining cord on the tension maintaining cord to form a bonded body; Place the core metal on the inner circumferential side of the rubber band on the lower mold,
A step of arranging mandrels at regular intervals in the circumferential direction on this unvulcanized rubber on the inner peripheral surface side, and a step of joining the thin rubber layer side of the bonded body onto the mandrel on the lower mold. 2. A method of manufacturing an elastic endless track belt according to claim 1, which comprises stacking the parts, pressing an upper mold into contact with each other, and heating and vulcanizing the parts.