JPS60220713A - Manufacture of hollow rubber product - Google Patents

Abstract

PURPOSE:To vulcanize a product easily and effectively, causing core mold removing after vulcanizing to be unnecessary by filling the hollow part of a preform with heated and pressurized steam and vulcanizing it, after the core mold has been removed from the unvulcanized hollow preform. CONSTITUTION:Unvulcanized preforms 7, 8 are molded, pouring unvulcanized raw material into the cavities 5, 6 of a mold 1 composed of upper and lower outer molds 2, 3 and a core mold 4. After the core mold 4 has been removed, a hollow part 9 is filled wit heated and pressurized steam and is vulcanized. As the vulcanization is carried out after removing the core mold 4, there is not the complication such as conventional process in which the core mold is removed after vulcanization. The efficiency of vulcanization is also excellent, because the product is heated and pressurized directly from its inside.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method for manufacturing hollow rubber products.

BACKGROUND ART Conventional methods for manufacturing hollow rubber products include the following methods.

That is, Transferne uses an injection machine to inject dough into a mold equipped with a core mold to form a hollow part, or fills the dough inside the mold using a compression method, and then inserts the dough into the outer mold and Vulcanization molding is performed using a core mold, heating, and pressurizing. After vulcanization molding, the mold is opened and the product is taken out with the core mold attached. Air is then blown between the vulcanized rubber product and the core mold to form the rubber product. While sliding the core mold, the core mold is pulled out and the vulcanized rubber product is taken out.

However, in such conventional manufacturing methods, since a core mold is used even during vulcanization molding, it is necessary to pull out the core mold after the product is solidified. For this reason, the extraction work becomes complicated, and a very quick work cannot be expected.

OBJECTS OF THE INVENTION The present invention has been made in view of the conventional manufacturing method of hollow rubber products.
The purpose is to provide a method for manufacturing hollow rubber products that can speed up and simplify the work by maintaining shape retention using steam or the like instead of the core mold during vulcanization. That is.

Structure of the Invention In order to achieve the above object, the present invention includes a preforming process in which a molding die equipped with a metal core for forming a hollow part is used, and the molding die is filled with unvulcanized rubber. After the preforming step, the core mold is removed, and the hollow part is heated with steam or the like in the molding die.

It is equipped with a vulcanization molding process in which pressure gas is filled and curable.
Vulcanization molding is performed without using a core mold.

EXAMPLE An example of the present invention will be described below with reference to the drawings. In other words, the molding dies used in this embodiment include upper and lower outer molds λ, 3, and both molds λ1. ? It is composed of a hollow core mold interposed between them, which forms a hollow part.

During manufacturing, first, in the preforming step (-r), unvulcanized dough is poured into the divided cavity 5°6 formed between the core mold and the upper and lower molds λ, 3 by injection or compression. inject. At this time, at least the upper and lower outer molds λ.

3. Heat in advance. Through this preforming process, p1 unvulcanized preformed product7. You can get the best results. Next, in the vulcanization molding step (b) after this preliminary step, the preformed product 7 is placed in the upper and lower molds 2.3 as shown in the drawing.
．． Remove the core mold l with the male attached. This makes it possible to secure the hollow part. Then, the upper and lower molds 3 are closed, and the preformed product 7. Each edge 7a of the
Join the zaa. Thereafter, heated and pressurized gas such as steam is supplied to the hollow part, and the upper and lower outer molds 2.3 are continuously heated to carry out vulcanization molding. After the appropriate vulcanization time has elapsed, the heating and supply of JJu pressurized gas are stopped, and after reducing the pressure inside the hollow part 9, the upper and lower outer shells m-2゜3 are opened, and the parts are integrated by vulcanization molding. 100 tons of hollow rubber products can be obtained. Moreover, since the core mold l has already been removed during unvulcanization, there is no need for the complicated work of removing the core mold after molding, which simplifies the work.
It is possible to speed up the process.

In addition, when removing the core mold in the preforming process, the preformed product? , t may adhere to the core mold and be removed together with the core mold. Therefore, by providing a temperature difference between the upper and lower outer molds 2.3 and the metal core, the peelability of the metal core can be improved.

The temperature difference here means that the core metal V is from 0℃ to the top and bottom of the outer mold
A temperature 70°C lower is most suitable.

Detailed Description of the Invention As described above, the present invention removes the core mold during preforming, and heats the hollow part during vulcanization molding.

By filling with pressurized gas and curing 9 to 11 times, it is possible to complete the manufacture of hollow rubber products without the need for the complicated work of removing the core mt after vulcanization molding.
Therefore, it is possible to simplify and speed up the work process. In addition, during vulcanization molding, heat and pressure are applied from the hollow part, that is, from the inside of the product, so that the thermal efficiency during vulcanization can also be improved.

[Brief explanation of drawings]

The drawings are explanatory diagrams showing one embodiment of the present invention. l...Molding mold, 3...Upper outer mold, l...
Core type, 7. ♂...preformed product, ri...hollow part, 1
0...Hollow rubber product. Engraving of drawings (no change in content) Yari 1-day procedural amendment (method) % formula % 2. Name of invention Method for manufacturing hollow rubber products 3 Person making the amendment I! Relationship with 1 Applicant Kinugawa Rubber Industries Co., Ltd. 4, Agent Address: 1-29 Akashi-cho, Chuo-ku, Tokyo 104 This is a process explanatory drawing showing an example of the Yasai Building. ” 0(2) The drawing should be shown in red on a separate sheet.

Claims (1)

[Claims] (1) A preforming step of filling the unvulcanized dough into the mold using a molding mold equipped with a core mold for forming a hollow part, and removing the core mold after the preforming step. A method for manufacturing a hollow rubber product, comprising: a vulcanization molding machine that vulcanizes the hollow part in a molding die while filling the hollow part with heating heat such as steam and pressurized gas.