JPS60260325A - Manufacture of diaphragm with cloth therein - Google Patents

Abstract

PURPOSE:To produce efficiently a diaphragm having a cloth between rubber layers without biasing the location of the cloth, by vulcanizing a sheet having a cloth attached between rubber layers, molding it under pressure and heating, and quenching it immediately. CONSTITUTION:An adhesive is applied onto a base cloth, and rubber layers are calendered thereon followed by vulcanization to produce a vulcanized rubber sheet having a specified thickness with an intermediate layer of cloth. Then the rubber sheet is cut into a length 4 having a specified size, and the length of the sheet is pinched between molds 3, 3' located between press bodies 3, 8' having heaters 5, 5 and cooling water pipes 6, 6 and heated and pressed. Then the operation of the heaters 5, 5 is stopped, and cool water is passed through the cooling water pipes 6 6 to quench the length to normal temperatures to be set. After the cooling, the press bodies 8 8' are opened to remove the product. The thus molded product has the cloth wihtout the location thereof being biased and would not develop a crack or the like when being bent. The product can be used as a diaphragm of a pressure responsive apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a cloth intermediate diaphragm constituting a pressure operating part of a pressure-responsive device.

BACKGROUND OF THE INVENTION Conventionally, in order to prevent excessive elongation of a rubber diaphragm and increase mechanical strength, durability, etc., reinforcing cloth has been pasted or buried on one side or in the middle of a rubber diaphragm.

The conventional manufacturing method for fabric-filled diaphragms is as shown in Figure 2, where a fixed amount of unvulcanized rubber 2 is laminated on both sides with a base fabric 1 in the middle, which is then loaded into a press mold and pressed. It is common to perform molding.

At this time, the unvulcanized rubber causes a flow due to heating and flows to the periphery, and the excess flows through the metal touch part of the mold and into the rubber escape part, and then the rubber begins to vulcanize.
The diaphragm is molded, and the middle cloth is made of rubber 70-
It is difficult to keep the cloth stretched and buried uniformly in the middle of the diaphragm, especially when the diaphragm has a bend in its shape like a normal diaphragm, so that the cloth takes the shortest distance from the rubber flow. Since it is pulled linearly, at the bending point it is pushed to the front or back side as shown in Figure 3
Sometimes the rubber side is exposed.

When this diaphragm operates, the above-mentioned bending point becomes a recursion point, so stress is concentrated, and extremely trivial things such as wrinkles due to the difference in rigidity on both sides and slight peeling between cloth and rubber can be caused. However, this uneven portion often causes cracks, leaks, etc., and affects the durability of the product.

Problems to be Solved by the Invention The method for manufacturing a cloth intermediate diaphragm of the present invention reliably embeds the cloth in the middle of the rubber layers and makes the thickness of the upper and lower rubber layers uniform to a predetermined thickness. It is.

In the case of conventional methods, in order to obtain the desired results, it is desirable that the shape of the diaphragm be as flat as possible. Therefore, there are restrictions on the shape of the product, but when the method of the present invention is used, restrictions on the shape of the diaphragm can be largely relaxed and durability can also be improved.

Means for Solving the Problem In the present invention, a rubber layer is topped on both sides of the base fabric using a calender, or both sides are coated using a gluing machine to produce a rubber sheet of a desired thickness, which is then vulcanized in a can. By making a vulcanized rubber sheet by such a method, the position of the cloth in the rubber sheet is fixed in advance, and then cut, this rubber sheet is loaded into a diaphragm mold and pressed at high temperature.
Molded by heat-pressing. Next, the heating is stopped and water is passed through the press to rapidly cool it down, the formed diaphragm is fixed, and the product is removed from the press.

The rubber sheet of a desired thickness in which the working cloth is embedded is vulcanized by can vulcanization or the like, so that the cloth is fixed in the middle of the rubber.

When this is cut and heat-pressed at high temperature in a hot molding press, the rubber becomes flexible at the heating inflection temperature, and even at the bends of the mold, it stretches all over and adapts to the mold. , no change occurs in the positional relationship of the cloth in the rubber sheet.

Once the diaphragm has been molded, the heating is stopped and cooling water is passed through the press to rapidly cool it down, and the diaphragm is fixed in the hole of the press mold.

Example: Apply an adhesive to the base fabric, top it with calender mites or coat it with a sizing machine, and apply a layer of 0 thickness according to the specifications of the two editions while keeping it resistant to adhesion. Vulcanization is performed in a curing can or the like to produce a vulcanized rubber sheet with a predetermined thickness between the fabrics.

Next, this rubber sheet is punched or cut into required dimensions 4, as shown in FIG. The softened rubber sheet is pressed as shown in FIG. 1B by applying sufficient pressure to completely adhere to the mold. Next, the heat source is turned off, and cooling water is passed through the sample to quickly cool it down to room temperature.

For example, if the rubber material used is nitrile rubber, a heating temperature of about 180° C. and a pressure of about 10 h/cr/i are required, and in this case, the operation requires about 5 minutes of precision. After cooling, the press is opened and the product is taken out and finished.

Effects of the Invention According to the present invention, the cloth intermediate diaphragm has no unevenness of the cloth in the middle, is uniform on both sides, has less possibility of occurrence of bending cracks or leakage during operation, and is highly durable. Furthermore, since the rubber sheet used as the material can be obtained in a long length, preparation efficiency etc. are also significantly improved.

[Brief explanation of the drawing]

FIG. 1A shows a longitudinal section of press loading of a vulcanized rubber sheet using the heating/cooling press of the present invention. FIG. 1B shows a longitudinal section of the heating/cooling press of FIG. 1A in an operating state. FIG. 2 shows a longitudinal cross-section of a press-loading of an unvulcanized rubber sheet in the conventional cloth intermediate diaphragm manufacturing method. FIG. 3 is an enlarged view of a vertical cross section showing the state in which the cloth is buried in the bent portion of a conventional cloth intermediate diaphragm. 1... Base fabric, 2, 2'... Unvulcanized rubber sheet, 3,
3'... Mold, 4... Fabric intermediate vulcanized rubber sheet, 5...
...Heater, 6...Cooling water pipe, 7...Insulation material, 8
, 8'...Press body. Representative Patent Attorney Tadashi Takahashi Eloquent Attorney Masahiro Shiozaki Figure 1 (A) Figure 2

Claims (1)

[Claims] A rubber sheet with a rubber layer attached to both sides of the base fabric using a calendar or a gluing machine is vulcanized in advance in sheet form, cut, molded by heat and pressure using a heating and cooling press, and then crimped. A method for producing a fabric intermediate diaphragm, which is characterized by rapidly cooling the fabric while the diaphragm is still in place, and then removing it from the mold and finishing it.