JPH11300765A - Production of rubber crawler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a rubber crawler which enabled the production of a crawler in which a seamless spiral reinforcing code is embedded by feed vulcanization which is easy of handling and has stable quality. SOLUTION: In a method for producing a rubber crawler which produces the rubber crawler in which a cord 2 wound spirally is embedded by feed vulcanization, after unit unvulcanized rubber pieces 7A, 7B being formed on both sides of the cord 2, sheets which can be peeled easily after vulcanization and have uneven surfaces are fitted on the end part joining surfaces in the length direction of the unvulcanized pieces 7A, 7B and vulcanized. Next, immediately before the unvulcanized rubber pieces to be joined adjacently being joined, the sheets are peeled off and vulcanized with unvulcanized adhesive rubber placed between these joining surfaces so that the unvulcanized rubber pieces are feed-vulcanized in turn to mold an endless rubber crawler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an endless rubber crawler mounted on a high-speed snowmobile such as an RV vehicle or a construction vehicle.

[0002]

2. Description of the Related Art In recent years, there has been an increasing number of cases in which ordinary driving wheels of a leisure RV are removed, and an endless track driving device including a plurality of sprockets and rolling wheels is mounted and used as a snowmobile or the like. . A crawler composed of an endless rubber belt or the like is attached to such an endless track driving device, and it is urgently necessary to cope with an increase in traveling speed with the attachment of the crawler to an RV vehicle. I have. Further, in addition to ordinary snowmobiles and the like, construction vehicles and the like in which rubber crawlers that reduce noise, vibration, and the like are mounted are required to cope with high-speed crawlers. In general, a crawler mounted on such an endless track driving device, not shown, holds a crawler structure made of a band-like rubber or the like in which a reinforcing cord is embedded by an upper and lower mold (mold), and simultaneously holds the crawler structure. Further, the crawler structure is vulcanized by being sandwiched and heated by an external heat plate and an internal heat plate, and then the staggered both ends are polymerized to form upper and lower molds for joining the ends and the inner and outer heat plates. In this way, both ends are vulcanized and joined to obtain an endless crawler product.

However, in this vulcanization method, a mold and a hot plate become longer, so that a large space is required for installation, and a joining vulcanization step of only an end portion is required. It caused over-vulcanization and hardening, resulting in unstable quality. Therefore, the applicant of the present application has disclosed in Japanese Patent Laid-Open Publication No. Hei 9-277967 in order to prevent excessive vulcanization and the like due to double vulcanization at a joint portion of a rubber crawler and to ensure good adhesion. A vulcanization method was proposed.

Further, in order to avoid the use of the above-mentioned mold and hot plate which are long and require a device which requires a large space, a manufacturing method called feed vulcanization as shown in FIG. 5 is also employed. ing. In this feed vulcanization, a relatively long crawler 21 can be vulcanized by small equipment including upper and lower dies 25 and 26 each having a relatively short unit length. As shown in FIG. 5A, the crawler 21 is composed of a ground-side unvulcanized rubber 27 and an inner peripheral-side unvulcanized rubber 28 in which a cord 22 is embedded. Each time it is sequentially heated and vulcanized. FIG.
As shown in (B), the reinforcing cord 22 embedded in the crawler 21 is wound in a seamless spiral shape so as to cope with high speed.

[0005]

However, in order to manufacture a long crawler by such a conventional feed vulcanization method, the inner and outer unvulcanized rubbers 27 are provided on the front and back of the cord 22 wound in a spiral shape. , 28 had to be attached in advance over the entire circumference. For this reason, handling for setting a long crawler component composed of unvulcanized rubber, which is a long and heavy semi-finished product, in a vulcanization mold is troublesome.

Accordingly, the present invention employs a vulcanization method which prevents over-vulcanization and hardening due to double vulcanization at the joints proposed by the applicant of the present invention and which secures good adhesiveness. A rubber crawler that has solved the problem in the method of manufacturing a feed vulcanized crawler and has made it possible to manufacture a crawler embedded with a seamless spiral reinforcing cord by feed vulcanization with easy handling and stable quality. It is intended to provide a manufacturing method.

[0007]

According to the present invention, there is provided a rubber crawler manufacturing method in which a rubber crawler having a spirally wound cord embedded therein is manufactured by feed vulcanization. After adding the rubber, the unit unvulcanized rubber on the longitudinal end joining surface,
After vulcanization, a sheet material having an uneven surface is easily attached and vulcanized, and then immediately before the unit unvulcanized rubber to be joined adjacently is joined, the sheet material is detached. Then, by vulcanizing with an unvulcanized adhesive rubber interposed between these joining surfaces, the unit is successively fed and vulcanized to form an endless rubber crawler. . Further, the present invention is characterized in that the sulfur content of the unvulcanized adhesive rubber is larger than the sulfur content at the joint surface of the unit unvulcanized rubber. Further, the present invention is characterized in that the joining surface of the unit unvulcanized rubber is formed from the non-driving surface side of the grounding lug on the grounding side to the driving projection on the inner peripheral side, and solving these problems. Means.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a first embodiment of the rubber crawler manufacturing method of the present invention. FIG. 1 is a schematic explanatory view of the whole manufacturing apparatus, and FIG. 2 is an enlarged explanatory view of a main part. 1 (A) and 1 (B) are a plan view and a side view showing a first vulcanization step in a manufacturing process. First, an endless cord 2 spirally wound in a separate step in advance is set between a relatively short vulcanizing upper mold 5 and a lower vulcanizing mold 6 having a predetermined length. As the spiral code 2, A in FIG.
As shown in FIG. 4 (B), which is a cross section of FIG. 4 (A), an appropriate single wire or twisted cord 2W may be spirally wound and then the rubberized cord 2 covered entirely with rubber 2G may be used. As shown in FIG. 4 (C), a rubberized cord 2 in which a cord 2W for each turn is covered with rubber 2G and wound in a spiral shape may be employed. Further, a cord 2 woven by a horizontal cord 2W 'between cords 2W wound in a spiral shape as shown in FIG.
May be adopted. As a material for these cords, not only metal cords such as steel but also non-metal cords such as nylon and Kevlar (registered trademark) can be adopted.

[0009] The cord 2 wound and constructed in this manner is light in weight, so that the cord 2 is easy to handle and can be easily set in a vulcanizing apparatus without troublesome handling.
As shown in FIG. 1 (B), in the first step, the first unit unvulcanized rubber 7A (ground side), 8A ( After inner vulcanized rubbers 7A and 8A were pressurized and heated by vulcanizing upper and lower dies 5 and 6 to vulcanize them, FIG.
As shown in (C), the entire code 2 is sent by the unit length,
In the second step, the second unit unvulcanized rubber 7B, 8B is supplied between the vulcanizing upper and lower dies 5, 6, and the unit unvulcanized rubber 7A, 8A vulcanized in the first step is supplied. Vulcanization is performed in order to join with. The vulcanization and feeding for each unit are sequentially repeated to obtain an endless crawler. In addition, about the unit unvulcanized rubber 7 and 8 supplied to the front and back of the cord 2,
Those formed in a predetermined length and shape in a separate step may be supplied by a conveyor belt or the like, or vulcanized upper and lower dies 5,
6, an unvulcanized rubber injection device may be installed and supplied directly in close proximity.

FIG. 2 is an enlarged view for explaining the vulcanization bonding at the bonding surface of the unit unvulcanized rubber, which is an important component of feed vulcanization in the present invention. In FIG. 2A, the first unit unvulcanized rubbers 7A and 8A are the same as those in FIG.
When vulcanizing in the state shown in (B), peeling after vulcanization is easy on the end joining surface in the length direction and fine irregularities (R
max is 1 to 5000 μm, preferably 20 to 200 μm
The sheet material 9 on which m) is formed is attached. The sheet material 9 is, for example, an elastic canvas “Ox canvas” (250D) made of PET (polyethylene terephthalate).
/ 1 (203 / 5cm) × 250D / 2 (122 /
5 cm). Next, the first unit vulcanized rubbers 7A and 8A, which have been vulcanized with the sheet material 9 attached, are fed by the unit, and the second unit unvulcanized rubbers 7B and 8B are vulcanized. The vulcanization is performed by being set between the upper and lower molds 5 and 6, and the first unit vulcanized rubber 7
A, The sheet material 9 is pushed between the joining surfaces in 8A.

FIG. 2 (B) shows a state in which the sheet materials 9, 9 on the joint surfaces between the first and second unit vulcanized rubbers 7A, 7B and 8A, 8B are peeled off. It can be understood that fine irregularities on the surface of the sheet material 9 were transferred to the bonding surfaces. by this,
Normally, it is possible to omit the buffing performed on the rubber joint surface for improving the adhesive performance, and therefore,
By eliminating the troublesome labor of removing the buff powder, the working time can be significantly reduced and a sanitary working environment can be realized.

Next, as shown in FIG. 2 (C), the first and second unit vulcanized rubbers 7A, 7B and 8A, 8B between the first and second unit vulcanized rubber 7A, 8B from which the sheet materials 9, 9 have been peeled off are removed. The bonding surfaces are re-vulcanized with adhesive rubbers 10 and 10 interposed therebetween. Thereby, as shown in FIG. 2 (D), the first and second unit vulcanized rubbers 7A, 7B and 8
A and 8B are joined with the adhesive rubber 10 having a strong adhesion performance due to fine irregularities. This process is sequentially repeated to complete an endless rubber crawler. The adhesive rubber 10 has a sulfur content as a crosslinking material larger than the sulfur content of the unit unvulcanized rubbers 7 and 8 constituting the rubber crawler body. In particular, it has been found that a strong adhesive force can be obtained by using a rubber having a difference in sulfur content of 1 to 10 PHR.

The reason is that, due to a moderate difference in the amount of sulfur,
This is because during the vulcanization, sulfur moves from the side of the adhesive rubber 10 to the side of the unit vulcanized rubber 7 or 8, which is the rubber crawler body, and effectively acts as a cross-linking material to exert a strong adhesive force. When the amount of sulfur is equal to or less than that, sulfur migrates from the adhesive rubber 10 side to the unit vulcanized rubber 7 or 8 side, causing a decrease in elastic modulus and a decrease in adhesive force. On the other hand, if the difference in the sulfur amount exceeds 10 PHR, the physical properties of the adhesive rubber are reduced, and the adhesive strength is also reduced.

FIG. 3 shows a second embodiment of the method for manufacturing a rubber crawler according to the present invention. In this embodiment, the joint surface of the unit unvulcanized rubber is not driven by a ground lug on the ground side. It is characterized by being formed from the surface side to between the drive projections on the inner peripheral side. For example, in the rubber crawler 1 of FIG. 3, as described in the description of the first embodiment, for example, the second unit unvulcanized rubbers 7B and 8B, and the unit unvulcanized rubber 7B After vulcanization, the unit unvulcanized rubber 8 is placed on the grounding side where the grounding lug 4 is formed.
B is formed on the inner peripheral side where the driving projection 3 is formed after vulcanization. In the present embodiment, the joint surface 11 formed between the unit vulcanized rubber and the adjacent vulcanized rubber is provided between the non-driven surface side of the ground lug 4 on the ground side and the drive projection 3 on the inner peripheral side. , Formed between the three. Accordingly, when the vehicle travels in the forward direction (white arrow B), which is almost all traveling directions, the crawler 1 is driven in the direction of the black arrow C with respect to the vehicle, and the crawler 1 is driven at the time of the feed vulcanization. Since the joining surface 11 is formed from the non-driving surface side of the ground lug 4 to the driving protrusions 3 on the inner peripheral side, when the crawler 1 is driven, it does not receive excessive force from the ground or driving wheels. This contributes to improving the life of the crawler 1.

Although the embodiments of the present invention have been described in detail, within the scope of the present invention, the shape and material of the rubber track, the material of the cord and the form of rubberization and the winding form, the vulcanization method, The shape of the vulcanizing mold, the shape and material of the sheet material, the shape and material of the adhesive rubber, and the like can be appropriately adopted.

[0016]

As described above in detail, according to the present invention, it is possible to easily set a long crawler structure comprising a cord in a vulcanizing mold by utilizing the advantages of feed vulcanization. Handling is not troublesome, and it has become possible to increase work efficiency. In addition, a sheet material which is easy to peel off after vulcanization and has irregularities formed on the surface is added to the end joining surface in the longitudinal direction of the unit unvulcanized rubber provided on the front and back of the cord. Since it is configured to form irregularities on the bonding surface between the unit unvulcanized rubbers by vulcanizing, it is possible to omit the buffing performed on the bonding surface of the rubber to improve the adhesive performance,
By eliminating the troublesome labor of removing the buff powder, the working time can be significantly reduced and a sanitary working environment can be realized.

In addition, the sulfur content as a cross-linking material is larger than the sulfur content of the unit unvulcanized rubber constituting the rubber crawler body at the joint surface between the unit unvulcanized rubbers having the irregularities. The adhesive is re-vulcanized with the adhesive rubber interposed between them, so that the sulfur as the cross-linking material is appropriately transferred from the adhesive rubber to the rubber crawler body side during vulcanization, and the excess The crawler in which unit unvulcanized rubbers are sequentially joined by stable and good adhesive force without the risk of deterioration due to vulcanization and without fear of quality deterioration, and in which a seamless spiral reinforcing cord is embedded, It has become possible to manufacture by simple feed vulcanization.

Further, the joint surface between the unit unvulcanized rubbers in the rubber track formed by feed vulcanization is formed from the non-driving surface side of the ground lug on the ground side to the driving projection on the inner peripheral side. If you configure
When the crawler is driven when the vehicle travels in the forward direction, which is almost all the running directions, the joint surface does not receive an excessive force from the ground or the driving wheels, which contributes to the improvement of the life of the crawler. As described above, according to the present invention, there is provided a method of manufacturing a rubber crawler that enables a crawler in which a seamless spiral reinforcing cord is embedded to be manufactured by feed vulcanization with easy handling and stable quality. Is done.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a method for manufacturing a rubber crawler of the present invention, and is a schematic explanatory view of an entire manufacturing apparatus.

FIG. 2 is an enlarged view showing a first embodiment of the rubber crawler manufacturing method of the present invention and illustrating a vulcanization bonding step on a bonding surface of unit unvulcanized rubber during feed vulcanization.

FIG. 3 is a view showing a second embodiment of the method for manufacturing a rubber track of the present invention.

FIG. 4 is a view showing a form of a cord embedded in a rubber track of the present invention.

FIG. 5 is a side view and a plan view of a conventional method for producing vulcanized rubber by crawling by feed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crawler 2 Cord 3 Drive projection 4 Ground lug 5 Upper vulcanization mold 6 Lower vulcanization mold 7 Unit unvulcanized rubber (ground side) 8 Unit unvulcanized rubber (inner circumference side) 9 Sheet material 10 Adhesive rubber 11 Joining surface

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29K 21:00 105: 08 105: 24 B29L 29:00

Claims (3)

[Claims] 1. A method of manufacturing a rubber crawler, in which a rubber crawler embedded with a spirally wound cord is embedded and fed by vulcanization, a unit unvulcanized rubber is added to the front and back of the cord, and then the unit is uncured. The vulcanized rubber is bonded to the longitudinal end joint surface with a sheet material that is easily peeled off after vulcanization and has irregularities formed on the surface, and then vulcanized. Immediately before joining the vulcanized rubber, the sheet material is peeled off, and vulcanization is performed by interposing an unvulcanized adhesive rubber between these joining surfaces. A method of manufacturing a rubber crawler, comprising molding the rubber crawler of the above. 2. The method for producing a rubber crawler according to claim 1, wherein the sulfur content of the unvulcanized adhesive rubber is larger than the sulfur content at the joint surface of the unit unvulcanized rubber. . 3. The unit according to claim 1, wherein a joining surface of the unit unvulcanized rubber is formed from a non-driving surface of the ground lug to a driving protrusion on an inner peripheral side of the ground lug. Rubber crawler manufacturing method.