JPH0523931B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing a dish-shaped rubber product.
This invention is particularly suitable for manufacturing methods for rubber products that require high precision in shape and dimensions, such as diaphragms and dust covers.

<Prior Art> Conventionally, a dish-shaped rubber product, such as a diaphragm, has been manufactured as follows.

Rubber molded product M having a dish-shaped portion D obtained by vulcanization molding a sheet-like rubber fabric using compression.
is set on the pedestal 1 of a punching machine having a convex surface 1a corresponding to the concave surface of the dish-shaped part, and the inner cutter (center hole punching blade) 3 and the outer cutter (outer periphery punching blade) 5 simultaneously cut the center hole and the outer periphery. The punching process was performed by punching (see Figure 4).

<Problems to be Solved by the Invention> However, when setting the rubber molded product on the pedestal 1, since the rubber molded product is dish-shaped, there is a gap between the concave surface of the rubber molded product and the convex surface 1a of the pedestal. Since the rubber molded product M does not get stuck and easily slides, it is difficult to accurately set the rubber molded product M in a predetermined position without causing eccentricity. For this reason, there is a possibility that punching by the outer cutter 5 and the inner cutter 3 may be performed in an eccentric state as shown in the illustrated example, and as a result, the rubber product is likely to suffer from center deviation defects.

In view of the above, it is an object of the present invention to provide a method for manufacturing a dish-shaped rubber product that is free from the possibility of centering defects occurring in the product.

<Means for Solving the Problems> The method for manufacturing a dish-shaped rubber product of the present invention solves the above problems with the following configuration.

A rubber molded product having a dish-shaped portion is vulcanized and molded by compression, and a center hole punching process is performed on the rubber molded product with a center hole punching machine built into the molding die while the mold is closed. A rubber molded product with punched holes,
A dish-shaped rubber product characterized in that the outer periphery of a rubber molded product is punched while the positioning convex portion formed on the pedestal of an outer periphery punching machine is fitted with the center hole and set on the pedestal. manufacturing method.

<Example> The present invention will be explained in detail based on an example. The same parts as in the conventional example are given the same reference numerals, and the explanation thereof will be omitted in whole or in part.

An example of a mold used in the manufacturing method of the present invention is shown in FIGS. 1 and 2.

Here, for the purpose of simplifying the explanation and the drawings, a single-cavity compression mold will be used as an example, but usually a plurality of compression molds (4 to 8 molds) are used.

The molds are female mold (fixed type) 11 and male mold (movable type).
It consists of 21. These female type 11 and male type 21
are upper and lower heating plates 12, 22 and insulation material 2, respectively.
It is used by being attached to a press (not shown) via 6 and 27.

Here, a concave portion 11a and a convex portion 21a are formed on the opposing surfaces of the female mold 11 and the male mold 21, respectively, and when the molds are matched, a rubber molded product M having a dish portion D is formed.
It is now possible to form a moldable product cavity. Up to this point, the configuration is the same as the conventional configuration.

In the mold used in the present invention, the female mold 11
It has a built-in center hole punching mechanism.

In the illustrated example, the punch 13 attached to the female die 11
Although a shearing mechanism consisting of a die 23 and a die 23 attached to the male die is built-in, it may also be a cut-off machine consisting of an upper blade and a pedestal.

Specifically, the punch 13 is urged upward by a return spring 14 and is moved by a stopper member 18 in which the punch head 13a slides in a guide hole 17 formed in the upper end of the spacer 16 and the female die 11. Retained. The punch 13 can be lowered through a stopper member 18 by a hammer 19 integrated with the piston rod of the air cylinder 20 against the force of a spring. Furthermore, an air passage 25 is formed in the male mold 21 and is connectable to a compressed air pipe and communicates with the die opening 23a, so that punching waste can be blown out of the mold.

Further, the peripheral punching machine is a push-cutting machine consisting of a pedestal 6 and a peripheral punching blade 5. and,
A molded product positioning convex portion 6b is formed at the center of a convex surface 6a corresponding to the concave surface of the tray portion of the rubber molded product of the pedestal 6.

Next, a method for manufacturing a rubber product according to the present invention will be explained using the above-mentioned mold and outer periphery punching machine (push cutting machine).

As shown in FIG. 1, a sheet of rubber dough R is inserted between the female mold 11 and the male mold 21, the mold is closed by operating a press (not shown), and the rubber molded product M is compressed. Vulcanization molding is performed using a tensioner. The vulcanization conditions at this time are, for example, 180
℃ x 3 minutes.

Next, a center hole punching process is performed on the rubber molded product M using a center punching device built into the molding die while the mold is closed.

That is, the hammer 1 is activated by operating the air cylinder 20.
By lowering the punch 9, the punch 13 is lowered against the spring force of the return spring 14. Then,
The center hole c is punched out by the shearing action of the punch 13 and the die 23 (second
(see figure). Subsequently, the air cylinder is operated to raise the hammer 19. Then, the punch 13 is raised by the action of the return spring 14. In addition, compressed air is passed through the air passage 25 to blow off and discharge punching waste that has been punched out and fallen at the die opening 23a to the outside of the mold.

Next, the rubber molded product with the center hole formed was
The mold is released, and the rubber molded product M is set on the pedestal 6 by fitting the center hole c of the rubber molded product M with the positioning convex portion 6b of the pedestal 6 of the outer periphery punching machine. At this time, the rubber molded product M
is set in the positioning convex portion 6b through the center hole c, so that the rubber molded product will not be set eccentrically with respect to the convex surface formed on the pedestal. Subsequently, when the outer periphery punching blade 5 is lowered in the same manner as in the conventional case, the outer periphery is punched by pressing. At this time, since the center hole c of the rubber molded product fits into the positioning convex portion 6b, the rubber molded product does not become eccentric, that is, deviate from its normal position due to shear movement during the punching process.

<Operations and effects of the invention> The method for manufacturing a rubber product of the present invention includes vulcanizing a rubber molded product having a dish-shaped portion by compression, and placing the rubber molded product in a molding die in a closed state. The built-in center hole punching device punches the center hole, and the rubber molded product with the center hole punched is
With a configuration characterized in that the outer periphery of the rubber molded product is punched while the positioning convex portion formed on the pedestal of the periphery punching machine is fitted with the center hole and set on the pedestal, the following can be achieved. It has the following effects.

When punching the outer periphery, the rubber molded product is set in the correct position through the center hole on the positioning convex part, so that the rubber molded product is eccentric to the convex surface of the pedestal when punching the outer periphery. It won't happen. Therefore, when manufacturing dish-shaped rubber products, there is no risk of center-shift defects occurring in the products.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of the mold used in the present invention immediately before molding, Fig. 2 is a schematic cross-sectional view when the mold is closed, and Fig. 3 is a punching used for punching the outer periphery of a rubber molded product in the present invention. Schematic cross-sectional view of the machine,
FIG. 4 is a schematic cross-sectional view of a conventional simultaneous punching machine for center hole and outer circumference of rubber molded products. DESCRIPTION OF SYMBOLS 1... Punching machine holder, 3... Center hole punching blade (punch/inner blade), 5... Peripheral punching blade (outer blade), 6... Punching machine holder, 6a... Positioning convex part, 11... …Female mold (fixed type), 21…Male mold (movable type), 23…Die, M…Rubber molded product, D
... Dish part, c ... Center hole of rubber product, l
...The outer periphery of a rubber product.

Claims (1)

[Scope of Claims] 1. A rubber molded product having a dish-shaped portion is vulcanized and molded by compression, and a center hole is punched into the rubber molded product using a center hole punching machine built in the molding die while the mold is closed. The rubber molded product with the center hole punched out is
A disk-shaped rubber article, characterized in that the outer periphery of a rubber molded product is punched in a state in which a positioning convex portion formed on a pedestal of an outer periphery punching machine is fitted with the center hole and set on the pedestal. How the product is manufactured.