JPH033381Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a molding device, and more specifically, it proposes a structure of a molding device that can ensure a degree of vacuum within a molding cavity.

When molding products made of plastic materials, a manufacturing method is widely used in which the air in the molding cavity is removed prior to molding in order to prevent air bubbles from remaining inside the product. . on the other hand,
In a molding device equipped with a means for releasing the product from the mold after completion of molding, the molding cavity is communicated with outside air between the product releasing means and a guide hole into which the product releasing means is movably inserted. Due to the formation of small gaps, it is difficult to maintain a high degree of vacuum within the molding cavity. That is, as shown in FIG. 1, a fixed side mounting plate 1 and a cavity plate 2, which cooperate with each other to form a molding cavity 3, are formed into a hollow body and are connected to the cavity plate 2 via a gasket 7. A spacer block 5, a moving side mounting plate 10 joined to the spacer block 5 via a gasket 9, a support plate 12 disposed in an axially movable manner within the internal cavity 6 of the spacer block 5, and a support plate with an end portion 12 and has a product ejection pin 13 that axially moves through the cavity plate 2 and a rod that axially moves through the movable side mounting plate 10, and is disposed in the internal cavity 6 and is attached to the support plate. It has a knock-out plate 15 that supports the spacer block 12, and is bored in the cavity plate 2, and has a minute gap formed between the product ejection pin 13 and the guide hole of the product ejection pin 13 and an internal cavity 6 of the spacer block 5. In a molding apparatus configured such that the vacuum conduit section 16 connected to the molding cavity 3 is connected to an external vacuum pump to exhaust the air inside the molding cavity 3, the rod of the knockout plate 15 is moved. A gasket 19 is arranged on a rod that passes through the side mounting plate 10 to shut off the internal cavity 6 and the outside air, but with repeated operation, the knockout plate 15
Since a gap is formed in the sliding portion of the packing 19, it is extremely difficult to maintain a high degree of vacuum within the molding cavity 3.

In view of the above-mentioned problems with the conventional molding apparatus, the present invention provides a structure in which the knock-out plate and the movable-side mounting plate are telescopically and airtightly connected to the knock-out plate and the movable-side mounting plate. The bellows are arranged so that the internal cavity of the spacer block is completely isolated from the outside.

The illustrated embodiment will be described below. In the embodiment shown in FIG. 2, the fixed side mounting plate 1, cavity plate 2, gasket 7, gasket 9, movable side mounting plate 10, support plate 12 and product ejecting pin 13 are the same as those in the molding apparatus shown in FIG. However, spacer block 5 and knockout plate 1
The rod passing through the moving side mounting plate 10 of No. 5 is the first rod.
The bellows 20 has a longer axial length than that of the molding device shown in the figure, and is formed to be expandable and contractible.
It is arranged between the knockout plate 15 and the moving side mounting plate 10, and each end is connected to the knockout plate 15 and the moving side mounting plate 10 via a gasket 21.
The spacer block 5 is connected to the spacer block 5 so that the inner cavity 6 of the spacer block 5 is completely isolated from the outside communicating with the space between the rod and the movable mounting plate 10.

As described above, the molding device of the present invention has a retractable bellows inserted between the knockout plate, which is placed in the internal cavity of the spacer block and moves the product ejecting pin, and the moving side mounting plate. Since the internal cavity of the spacer block is completely isolated from the outside, the vacuum created within the molding cavity by the suction of the vacuum pump is extremely high, and the degree of vacuum decreases as the molding process is repeated. There is no need to worry about doing so.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a molding apparatus according to the prior art, and FIG. 2 is a sectional view showing an embodiment of the present invention. 1... Fixed side mounting plate, 2... Cavity plate, 3
...Molding cavity, 5...Spacer block, 6...Internal cavity, 7...Gasket, 9...
Gasket, 10...Moving side mounting plate, 12...Support plate, 13...Product ejection pin, 15...Knockout plate, 16...Vacuum conduit section, 19...Packing, 20...Bellows, 21... Gasket.

Claims (1)

[Scope of utility model registration request] A fixed-side mounting plate 1, a cavity plate 2 that cooperates with the fixed-side mounting plate 1 to form a molding cavity 3, and are made into a hollow body and are joined to the cavity plate 2 to support the cavity plate 2. A spacer block 5, a movable mounting plate 10 that is joined to the spacer block 5 and supports the spacer block 5, and a product protrusion pin 1 that passes through the cavity plate 2 so as to be movable into the molding cavity 3.
3 and a knockout plate 15 which is provided with a rod passing through the moving side mounting plate 10 and is slidably disposed within the spacer block 5 and supports the product ejecting pin 13,
A molding device having a telescopic bellows 20 which surrounds the rod and whose end faces are hermetically coupled to the movable mounting plate 10 and the knockout plate 15.