JPS644494Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is based on a heat insulating board in which a dish-shaped seal plate forming the bottom of the material chamber is fixed, and synthetic resin sprue bushes are fitted in correspondence to each material injection hole of the seal plate. This relates to a transfer pot attached to the bottom of a pot block.

Transfer points of the above type, e.g.
As shown in the figure, it is used by being incorporated into a rubber transfer pot molding machine. Lower mold 2 and upper mold 3 heated by heating plate 1 during mold closing molding
Since heat conduction from the mold to the material chamber 5 is blocked by the heat insulating plate 6, the molds 2, 3 and the transfer pot 8 are raised by the press 7 and the rubber material is transferred to the relative position of the plunger 9. Due to the pressing action, the rubber material (cul) remaining in the material chamber 5 after press-fitting can be reused unvulcanized even after the vulcanization process is completed, and the yield of the rubber material can be greatly improved. Here, the sprue bush 11 has a substantially cylindrical shape as shown in FIG. It is made of a heat-resistant and slippery hard synthetic resin like resin, and is generally stronger than insulation materials made of asbestos hardened with heat-resistant phenol resin, polyimide resin, etc. Therefore, when press-fitting material, the squeezed portion 13a of the sprue 13
Under the influence of material pressure from above and through the seal plate 12, the bush 11 is pressed downward, and a large load is applied from the reinforcing plate 14 to the lower end surface 11a of the bush that faces the reinforcing plate (metal part) 14. act. As a result, the lower end of the bush 11 deforms and bulges inward as shown in FIG. 3, which adversely affects the flow of the material, and if the deformation is severe, the molding sprue is torn midway when the molding sprue is removed, resulting in the pinched portion 13a. There was a risk that material would remain between the deformed bulge 11b of the bush and the deformed bulge 11b. Note that the seal plate 12 is a pot block 15.
This serves to prevent material from entering between the lower surface and the upper surface of the insulation board, and to reinforce the insulation board.

In view of the above, the object of this invention is to provide a transfer pot in which the sprue bush is hardly deformed during press-fitting of material.

The transfer pot of this invention has a heat insulating plate fitted with a sprue bush corresponding to the material injection hole of the seal plate attached to the bottom of the pot block, and a flange is formed at the upper end of the sprue bush. In addition, the above object is achieved by fitting the sprue bush into the heat insulating board with a gap between the lower end surface and the opposing metal surface.

An embodiment of this invention will be described below based on the drawings.

As shown in FIGS. 4 to 6, in the transfer pot of the type described above, the sprue bush 21
A flange 21a is formed at the upper end, and the sprue bushing 21 is fitted to the heat insulating board with a gap α between the bushing lower end surface 21b and the reinforcing plate (metallic part) 14. It is said that Here, the gap α is set to about 0.1 to 0.3 mm, which is enough to prevent the rubber material from penetrating. In addition, the figure numerals in FIGS. 4-6 correspond to the above-mentioned FIGS. 1-2.

Next, how the above embodiment is used will be explained.

As in the conventional method, when the material is pressed into the mold, the sprue bushing 21 is pressed against the pinched portion 13 of the sprue 13.
a) The sprue bush 21 is subjected to the influence of material pressure from above and through the seal plate 12, i.e., a downward pressing force. However, most of the pressing force is absorbed by the heat insulating plate 6 through the flange portion 21a of the sprue bush 21. Therefore, even if the heat insulating plate 6 is compressed and the lower end surface 21b of the sprue bush 21 abuts against the reinforcing plate 14,
The load it receives is small and it hardly deforms at all.

Therefore, as shown in FIG. 4, when the molded sprue S is removed after completion of molding, the molded sprue S will not be torn and remain in the sprue bush 21 as in the conventional case. In addition, a rubber material R as shown in FIG.
After supplying the material to the supply chamber 5, the press 7 is raised to inject the material without adversely affecting the flow of the material. Incidentally, although C is cal, it is pre-vulcanized as described above, so it does not need to be removed every molding cycle and can be used as is as an injection material.

In the above embodiment, the case where one molded product is produced is taken as an example, but the invention can of course be applied to the production of multiple molded products. Further, if the reinforcing plate is not incorporated in the heat insulation board, the metal surface facing the lower end surface of the sprue bushing will be the upper surface of the upper mold 3.

Since the transfer pot of this invention has the above-mentioned configuration, it exhibits the following effects.

(a) Most of the pressing force applied to the sprue bush when material is injected is absorbed by the heat insulating plate through the flange, so there is almost no deformation of the sprue bush (particularly changing the sprue shape) during material press-in, and the material always flows. is good.

(b) For the same reason as (a) above, when removing the molded sprue after completion of molding, the molded sprue will not be torn off midway and remain in the sprue bushing.

(c) As a secondary effect, the formation of the flange at the upper end of the sprue bush increases the seal length between the seal plate and the upper surface of the sprue bush, increasing the effect of preventing material from flowing into the heat insulating part. .

[Brief explanation of the drawing]

Figure 1 is a partial cross-sectional view of the main parts of a molding machine equipped with a conventional transfer pot during closed molding.
Figure 2 is a sectional view of the installation of a conventional sprue bush, Figure 3 is a sectional view of the sprue bush in a deformed state in Figure 2, and Figure 4 is a molding machine in which the transfer pot of this invention is assembled. Fig. 5 is a cross-sectional view of the main part showing when the mold is opened after molding is completed, Fig. 5 is a cross-sectional view of the main part when the press is raised after supplying new material to the pot, and Fig. 6 is a cross-sectional view of the installation of the sprue bushing of this invention. It is a diagram. 5...Material chamber, 6...Insulation board, 8...Transfer pot, 9...Plunger, 11...Sprue bushing, 11a...Bushion bottom end surface, 11b
...Deformed bulge, 12...Seal plate, 12
a...Material injection hole, 13...Sprue, 14...
Reinforcement plate (metal part), 15...pot block, 21...sprue bush, 21a...flange, 21b...bottom end face of the bush, α...gap between the bottom end face of the bush and the opposing metal surface.

Claims (1)

[Scope of Claim for Utility Model Registration] A dish-shaped seal plate forming the bottom of the material chamber is fixed to the upper surface, and a sprue bush made of synthetic resin that is stronger than the heat insulating board material corresponds to each material injection hole of the seal plate. In a transfer pot in which a heat insulating board fitted with a heat insulating plate is attached to the bottom surface of a pot block, a flange is formed at the upper end of the sprue bush, and the sprue bush has a lower end surface and an opposing metal surface. A transfer pot characterized by being fitted into a heat insulating board with a gap between the transfer pots.