JPS6024931A - Manufacture of diaphragm - Google Patents

Abstract

PURPOSE:To raise the durability and general applicability of a diaphragm by a method in which a rubber is cast into each cavity formed between three split molds constituting a diaphragm mold to cause it to the molds, the intermediate rubber alone is taken out, and a base cloth is put between the upper and lower rubbers, followed by vulcanization. CONSTITUTION:A semi-vulcanized rubber is cast into each cavity formed between three split molds to form halved moldings of a final product. A base cloth is put between both the halved moldings of semi-vulcanized rubber, and the rubber is then completely vulcanized. The rubber molding to be taken out on the way of the former period of the process is made of a non-sticky semi-vulcanized rubber. In short, semi-vulcanized rubbers 15a and 15b are cast into the upper and lower cavities 11 and 12 and hardened, the molds are opened, the intermediate rubber molding 9 is separated, a preformed base cloth 16 is placed on the rubber 15b on the lower side, the upper and lower rubber moldings 8 and 10 are clamped together, and they are vulcanized. A diaphragm excellent in durability and general applicability can thus be formed in this procedure.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a 72-diameter diamond.

Traditionally, diaphragms have been shaped relatively flat (IO2) as shown in Figures 1 and 2, and those with a large step in the 4411 direction as shown in Figures 3 and 4. (3x4) and other various shapes are known, but these diaphragms (1)...(4)
Generally, a reinforcing base fabric (5) is embedded in the base. If this base fabric (5) is exposed on the surface (upper and lower surfaces) of the product diaphragm, it will first be cut due to contact abrasion with the case or center grate to which the diaphragm is assembled. Second, the rubber material and base fabric are likely to peel off and crack due to fatigue. Third, it is not appropriate to design the base fabric to be placed on the low-pressure side of the diaphragm in the atmosphere in which it is used. Because of this, it is not suitable for use under conditions where alternating pressure is applied, so it is not exposed on the surface of the product diaphragm but is embedded inside the rubber material, that is, located in the center of the diaphragm. is desirable. In this regard, the relatively flat shaped diaphragms (1) (2) shown above (Figs. 1 and 2)
As shown in Fig. 5, the base fabric (5) can be easily molded to a diameter of 72 mm by vulcanizing both sides of the base fabric (5) topped with unvulcanized rubber sheets (la) (lb). It can be positioned in the center of Figure I: p(6) is the upper rubber type, and (7) is the lower rubber type. On the other hand, if the 72 diamonds with large steps shown in Figures 3 and 4 were manufactured using the same method (see Figure 6), wrinkles would occur in the base fabric (5) and the position of the base fabric would be uniform. There was a problem in that it was not possible to obtain a normal product even if the product was no longer used.

In order to prevent wrinkles from forming on the base fabric (5),
As shown in Fig. 7, the preformed base fabric (5) is semi-vulcanized in the upper and lower rubber molds (6x7) in advance, and the lower rubber mold (6x7) is semi-vulcanized.
There is also a method of placing it on the rubber material (4b) adhered to 7) and placing the unvulcanized rubber sheet (4a) on top of it and vulcanizing it, but according to this method, the thickness of the rubber material (4b) The thickness already approximates the film thickness of the product diaphragm (4),
In addition, semi-vulcanized rubber material (4b) and unvulcanized rubber sheet (
It was still difficult to arrange the base fabric (5) at the center of the diaphragm (3×4), while leaving the drawback that the characteristics were different from those of 4a).

In view of the above points, the present invention has a mold for molding a diaphragm that is divided into three parts, upper, middle and lower, and semi-vulcanized rubber is poured into each of the two upper and lower cavities formed between each mold. With sulfur rubber adhered to the upper and lower rubber molds, remove only the middle rubber mold, then sandwich the base fabric between the upper and lower semi-vulcanized rubber and vulcanize. The present invention proposes a method for manufacturing a diaphragm in which the base fabric is placed in the center of a product diaphragm, and attempts to solve the problems of the above-mentioned conventional methods at once. That is, according to the method of the present invention, by pouring semi-vulcanized rubber into each of the upper and lower cavities formed between the three molds, the final product shape is divided into two parts by semi-vulcanized rubber. Formed with materials,
Next, the base fabric is inserted between the two vulcanized rubber parts and completely cured, so there is no wrinkles in the base fabric during the subsequent vulcanization process, and the center piece of the base fabric is carefully created. Not only is it easy to manufacture, but the properties of the upper and lower halves of the vulcanized rubber do not differ, and it is possible to provide a diamond with excellent durability and versatility. Furthermore, the present invention provides that the inner rubber mold, which is removed during the process, is made of a material to which semi-vulcanized rubber is difficult to adhere, or the front surface is coated with Teflon or the like in a state in which semi-vulcanized rubber is difficult to adhere. It is characterized by being processed. This results in
When the middle rubber mold is removed, the semi-pierced C rubber existing in the upper and lower cavities is not forced to follow the movement of the middle rubber mold.
It can be left securely in the cavity.

Next, an embodiment of the method for manufacturing a diaphragm according to the present invention will be described with reference to the drawings. In FIG.
The upper cavity (11) is shown between the upper rubber mold (8) and the middle rubber mold (9), and the middle rubber mold (c10) is clamped.
9) and the lower cavity (12) between the lower rubber mold (10)
is formed. Both cavities (11) (12)
When the middle rubber mold (9) is removed according to the procedure described later and the upper rubber mold (8) and lower rubber mold (lO) are directly fitted, the two (11X12) are combined to form a -diameter 72 mm. It is formed in the shape of The inner surface of the upper rubber mold (8) and the lower rubber mold (10) forming the cavities (11) and (12) is roughened by a mineral mold (glass mold), etc., and both cavities (11) and (12) are made rough. At the position corresponding to the periphery of the hook, there is a groove (13 x 14
) is formed, and the semi-vulcanized rubber (15&) (15b) described later is configured to be easily adhesive. On the other hand, the surface of the medium rubber (9) is coated with Teflon and semi-vulcanized rubber (9).
15a) and (15b) are configured to be difficult to stick to.

When manufacturing a diaphragm using the mold having the above configuration, semi-vulcanized rubber (15a) (15b) is poured into the upper and lower cavities (11) (12), and the rubber (15a)
) (15b) is solidified, the mold is opened once and the middle rubber mold (9) is completely removed (Fig. 8 (b)), and the preformed base fabric (16) is inserted into the lower semi-vulcanized rubber. (15b) Place the upper rubber mold (8) and the lower rubber! (10) After the molds are clamped so that they are directly fitted (Fig. 8 (c)), the diaphragm is vulcanized, and by this procedure, a diaphragm with superior durability and versatility than those described above can be manufactured. I can do it.

In addition, during the above process, if the middle rubber mold (9) cools down before being removed, the semi-vulcanized rubber (15a) (15b) may tend to stick to the middle rubber mold (9). When it is necessary to keep the middle rubber mold (9) warm, it is effective to mount a knife (not shown) inside the middle rubber mold (9).

The present invention has made it possible to manufacture a base cloth center piece of a diaphragm with a large step difference, which has been considered particularly difficult in the past, by the method described above, and its effects are extremely remarkable.

[Brief explanation of drawings]

Figures 1 to 4 are half-cut sectional views of the diaphragm;
Figures 7 through 7 are half-cut cross-sectional views of a mold and a molded product showing a conventional method for manufacturing a diaphragm, and Figure 8 is a half-cut cross-sectional view of a mold and a molded product showing the steps of a method for manufacturing a diaphragm according to an embodiment of the present invention. It is a diagram. (IX2X3X4) Diaphragm (5X16) Base fabric (
688) Upper rubber 1J (7) (10) Lower rubber mold (9) Middle rubber mold (11) (12) Cavity (13) (14) Hook is brocade (15 m) (15b) 1 mm for hand vulcanized rubber method 〉Su′/Dai Gaikai

Claims (3)

[Claims] (1) A middle rubber mold is inserted between the upper rubber mold and the lower rubber mold.
The semi-vulcanized rubber is poured into the upper and lower cavities formed between the upper rubber mold and the middle rubber mold and between the middle rubber mold and the lower rubber mold. is adhered to the upper rubber mold and the lower rubber mold, the mold is opened to remove the middle rubber mold, a base fabric is placed between the semi-vulcanized rubber, and the semi-vulcanized rubber is vulcanized. . A method for manufacturing a diaphragm, characterized in that the base fabric is placed in the center of a product diaphragm. (2) A method for manufacturing a diamond 72 as set forth in claim 1, characterized in that the middle rubber mold is made of a material to which semi-vulcanized rubber is difficult to adhere. (3) The method for manufacturing a diaphragm according to claim 1, wherein the inner rubber mold is surface-treated to make it difficult for semi-vulcanized rubber to stick by coating with Teflon or the like.