JPS6371339A - Preparation of flat belt - Google Patents

Abstract

PURPOSE:To obtain a flat belt generating no difference in level on the surface thereof and capable of being uniformly vulcanized under pressure, by arranging an unvulcanized belt preformed article between an inner mold and an outer mold both of which are composed of a cylindrical elastomer and expanding the cylindrical elastomer of the inner mold to uniformly pressurize the belt preformed article and vulcanizing said article under heating in this state. CONSTITUTION:An unvulcanized rubber tape and cloth are laminated to form a belt preformed article 2 which is, in turn, arranged between an inner mold 1 and an outer mold 3 and, thereafter, high pressure air is sent into the inner mold 1 from the high pressure medium introducing pipe 17 to expand the cylindrical elastomer 12 of the inner mold 1 and the belt preformed article is pressed to the outer mold 3 in the inside direction thereof by said expanding pressure and heated from a lower hot plate 4 and an upper hot plate 5 in this pressurized state to be vulcanized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a flat belt. More specifically, the present invention relates to a novel flat belt manufacturing method that utilizes expansion and pressure of a cylindrical elastic body.

[Prior Art] Flat belts are the most typical type of belt, and belts with various structures are produced. Among these, the manufacturing method for the most common flat belt consisting of a cloth layer on one side and a rubber layer on the other side is as follows.

First, a cloth serving as the core of the belt is inserted into the surface of a mandrel, and an unvulcanized rubber sheet is placed on top of the cloth to form a belt preform. Next, a tightening tape, such as canvas or a vulcanized rubber sheet, is wrapped around the outer periphery of the belt preform, which is then placed in a steam vulcanizer and vulcanized under predetermined conditions. After vulcanization is complete, the tape is untied and the surface is ground and polished. Finally, the belt molded product obtained is exposed to light so that it becomes a flat belt of a predetermined width.

However, flat belts manufactured by such conventional manufacturing methods have various drawbacks. First, since the unvulcanized belt preform is tightened by wrapping tape around it and vulcanized, traces of the tightening tape remain on the surface of the resulting vulcanized belt molded product, and it takes a considerable amount of time. It is necessary to perform grinding and polishing work. In this case, if the belt is tightened weakly so as not to leave any traces of the tightening tape, air will be bubbled into the belt, reducing its strength. Furthermore, this tightening tape pressing method has the disadvantage that it is not possible to uniformly press the outer periphery of the belt preform, making it difficult to manufacture a flat belt with uniform strength distribution.

Furthermore, in the case of special flat belts that have a rubber layer in the center and fabric layers on both sides, it has been difficult to manufacture industrially practical flat belts because of the significant level difference caused by the tightening tape.

[Problems to be Solved by the Invention] The present invention has been made based on the above points, and its purpose is to solve the above-mentioned drawbacks of the prior art, to eliminate steps on the surface, It is an object of the present invention to provide a method for manufacturing a flat belt that can be uniformly pressurized and vulcanized.

[Means for Solving the Problems] The gist of the present invention is to place an unvulcanized belt preform between a middle mold and an outer mold mainly composed of a cylindrical elastic body, and then The medium-sized cylindrical elastic body is expanded by sending a high-pressure medium into the area, and the belt preform is heated and vulcanized while uniformly pressurized by the expansion force of the expanded medium-sized cylindrical elastic body. A method of manufacturing a flat belt is provided.

In the present invention, the belt preformed product is a belt preformed product made of cloth and unvulcanized rubber.

This belt preform product can be vulcanized into a few to several dozen flat belts.

In the present invention, the medium size may be anything that can expand by feeding a high-pressure medium and pressurize the belt preform with the expansion force. For example, the medium size may be a cylindrical elastic body, a high-pressure medium inlet, a cylindrical elastic body fixture, etc. It consists of As the high-pressure medium, high-pressure air, high-pressure nitrogen, high-pressure steam, etc. can be used.

In the present invention, the outer mold is in contact with the outside of the bell 1 preform and is made of metal material.

[Function] In the method for manufacturing a flat belt of the present invention, an unvulcanized belt preform is placed between a middle mold mainly composed of a cylindrical elastic body and an outer mold made of a metal material, and then a high pressure is applied to the middle mold. A medium is introduced to expand the cylindrical elastic body, and the expansion force uniformly presses the belt preform while applying pressure! It is something to do. Therefore, according to the present invention, there is no need for the conventional tightening work using tightening tape, and as a result, it is possible to eliminate the step marks caused by the tightening tape, significantly reduce the number of grinding and polishing steps, improve product yield, and make quality uniform. Can be done.

[Example] Next, an example of the method for manufacturing a flat belt of the present invention will be described with reference to the drawings.

FIG. 1 is a new view of a vulcanizing device used in an embodiment of the flat belt manufacturing method of the present invention. In FIG. 1, reference numeral 33 designates a medium mold, 2 a belt preform, 3 an outer mold, 4 an upper heating plate, and 5 an upper heating plate. Here, the medium size 1 includes a high pressure medium inlet 11,
The cylindrical elastic body 12 includes a cylindrical elastic body fixture 13, an upper cylinder 14,
It is composed of an upper cylinder 15, a connecting rod 16, a pressure medium introduction pipe 17, and the like.

Note that the upper cylinder 14, the upper cylinder 15, and the connecting rod 16 are not necessarily necessary for the medium 1; for example, as shown in FIG. A medium size 1 with one hole may also be used.

In the present invention, the outer mold is a mold that abuts the outer surface of the belt preform and is made of a metal material.

Next, the method for manufacturing a flat belt of the present invention will be explained with reference to FIG.

First, in the present invention, a belt preform 2 is created by laminating an unvulcanized rubber tape and cloth. Then, the belt preform 2 obtained in this way is placed between the middle mold 1 and the outer mold 3, and then high pressure air is introduced from the high pressure medium introduction pipe 17 of the middle mold 1 to form the cylindrical elastic body 12 of the middle mold 1. is expanded, and the belt preform is pressurized inward of the outer mold 3 by the expansion pressure, and under the pressurized state, it is heated and vulcanized from the upper heating platen 4 and the upper heating platen 5.

[Effects of the Invention] According to the flat belt manufacturing method of the present invention, there is no tape tightening unlike the conventional manufacturing method, so no surface step root marks remain, and as a result, the grinding and VIII polishing steps can be significantly reduced. Not only can it be shortened, but it can also easily manufacture special belts whose inner thickness is made of rubber and both sides are made of cloth without deformation, and because the L pressure is uniform, flat belts of uniform quality can be produced. It is obtained and is industrially useful.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the flat belt manufacturing method of the present invention, and FIG. 2 is a sectional view of a medium size belt used in another embodiment. 1: Medium size, 2: Belt preform, 3: Outside, 4: Upper heating plate, 5: Upper heating plate, 11: High pressure medium inlet, 12: Cylindrical elastic body, 13: Cylindrical elastic body fixed Tools, 14: Lower cylinder, 15: Upper pipe, 16: Connecting rod, 17: High pressure medium introduction pipe, 18: Middle cylinder, 19: Pressure body blowout hole. Swearing 1st part 2nd part

Claims (1)

[Claims] (1) A middle mold 1 consisting of a high-pressure medium inlet 11, a cylindrical elastic body 12, and a cylindrical elastic body fixture 13, and an outer mold 3 made of a metal material.
The belt preform 2 is placed between the belt preform 2 and the cylindrical elastic body 12 is expanded by introducing a high pressure medium from the high pressure medium inlet 11, and the belt preform 2 is
A method for manufacturing a flat belt, which comprises heating and vulcanizing while applying pressure in the direction of the inner surface of the outer mold 3.