JPS63290632A - Knockout method in superplastic blowing press - Google Patents

Abstract

PURPOSE:To facilitate the knockout of a formed part out of a die body without the need for releasing material by forming a draft by shrinking one part of a formed part by cooling it with the air blowing out of a knockout pin after completion of a superplastic forming. CONSTITUTION:The plate stock 17 composed of a superplastic material is fitted to a die body 10 and press-fitted to the die 10' of the die body 10 by the superplastic deformation of the plate stock 17 by acting a gas pressure P on one side face of the plate stock 17. After completion of the superplastic forming a knockout pin 12 is descended to form an air pool 18. The bottom A' of a formed part A is shrinked by cooling it by blowing out slowly the air from the nozzle 14 of the knockout pin 12 to form a gap B between the side wall A'' of the forming article A and die 10'. The knockout of the formed part is thus facilitated by becoming of the same as having a draft. The formed part A is raised with the lifting of the knockout pin 12 with blowing out the air from the nozzle 14 of the knockout pin 12 and carried outside the furnace.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a knockout method for removing a superplastic molded product from a superplastic blow molding press.

[Conventional technology]

Superplastic blow molding is a method of gas pressure blow molding of a plate material by utilizing the large elongation and low deformation resistance of a superplastic material.

This superplastic blow molding involves mold forming shown in Figures 7 (1) and (2) and mold forming shown in Figures 8 (3), (4), (5).
, and male molding shown in (6).

For female mold forming, a plate material 2 made of superplastic material is placed inside the container 1.
The plate material 2 is pressed onto a female mold 3 by applying gas pressure to one side of the mold to form a superplastic molded product 4 (Fig. 7 (1),
(2)), male molding is the plate material 2 provided inside the container 1.
After applying gas pressure to one side of the plate material 2 to deform it,
A male die 5 is applied to the plate material 2, gas pressure is applied to the other side of the plate material 2, and the plate material 2 is pressed against the male die 5 to form a superplastic molded product 4 (Fig. 8 (3), ( 4) , (
5), see (6)).

[Problem that the invention seeks to solve]

Is the superplastic blow molding mentioned above expensive? n(A9500~60
0℃, steel 800-1000'C), but the workability of taking out the product after forming is poor, and the slope is 2 degrees or more (
aluminum) required.

■Requires graphite coating as a mold release material.

■It is difficult to handle because of the high temperature, and especially high-temperature steel threads need to be cooled down to a certain temperature in the furnace, which reduces productivity.

There were other problems.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to eliminate the need to prepare a drafting slope in advance, eliminate the need for a mold release material, and facilitate the removal of a molded product from a mold body. An object of the present invention is to provide an easy knockout method in a superplastic blow molding press.

[Means and effects for solving the problems] In order to achieve the above object, the present invention cools and shrinks a part of the molded product using air blown out from a knockout pin after the completion of superplastic molding of the molded product. A draft slope was formed in this molded product, and the knockout pin was raised while blowing out air, so that the molded product was extracted by an air cushion.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 6.

A superplastic blow molding press is shown in Figure 1. 10 in Figure 1
is a mold body, and a plurality of knockout pin holes 11 are formed in the bottom of this mold 10, and knockout pins 12 are inserted into these knockout pin holes 11 so as to be vertically movable.

The knockout pin 12 includes a pin body 13 as shown in FIG. 2, and a nozzle 14 is formed at the upper end of the pin body 13. It has a hole 16, and the chamber 15 communicates with a guide hole 16' provided in the pin body 13.

Since superplastic molding has the property of transferring fine details very well, there is a risk that the injection hole 16 of the knockout pin 12 and the like may be transferred to the product. However, there is a strong correlation between transferability, gas pressure, and plate thickness, and in the case of general blow molding (gas pressure of 1 to 2 kg/cd in AΩ), a hole diameter of 1710 or less of the plate thickness It has been empirically shown that there is no fear of transcription. Therefore, it is necessary to set the nozzle diameter to be 1110 mm or less than the thickness of the molded product in contact with the knockout pin 12. And the nozzle 14 is
During blow molding, it must be flush with the mold 10.

(a) superplastic blow molding A plate material 17 made of a superplastic material is attached to the mold body 10,
As shown in FIG. 1, gas pressure P is applied to one side of the plate 17 to cause superplastic deformation of the plate 17, thereby compressing the plate 17 to the mold 10' of the mold body 10.

(b) Local shrinkage by air cooling When superplastic molding is completed, the knockout pin 12 is lowered as shown in FIG. 3 to create an air reservoir 18.

Air is gently blown through the nozzle 14 of the front knockout bin 12 to cool and shrink the bottom A' of the molded product A, thereby forming a gap B between the side wall A'' of the molded product A and the mold lO'. This is equivalent to having more draft, and the molded product A can be taken out more easily.

(c) Although the material is cooled with knockout air, the deformation resistance of the material is extremely small, so pushing it up directly with the knockout pin 12 may cause scratches.

Therefore, as shown in FIG. 4, the molded product A is raised by raising the knockout pin 12 while blowing out air from the nozzle 14.

After molded product A is completely raised, it is transported out of the furnace.

Note that the location where the molded product A is cooled, that is, the knockout pin 12 is installed, must be at a position where the molded product A generates a draft angle when it shrinks on cooling.

For example, in the mold shape of the mold body 10 as shown in FIG.
can be easily taken out.

〔Effect of the invention〕

As described in detail above, the knockout method in the superplastic blow molding press according to the present invention involves cooling and shrinking a part of the molded product using air blown out from the knockout pin after the completion of superplastic molding of the molded product. This is characterized in that a draft angle is formed in the molded article, and the knockout pin is raised while blowing out air to extract the molded product using an air cushion.

Therefore, since the superplastic molded product formed at high temperature is locally cooled with air and contracted to obtain a draft angle, there is no need to obtain a draft angle in advance as in the conventional method, and there is no need to use a mold release agent.

Furthermore, since the molded product is extracted using an air cushion, the molded product, which has low deformation resistance, is not damaged.

Due to these features, the molded product can be easily taken out.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of superplastic blow molding using the knockout method according to the present invention, Fig. 21 is a longitudinal cross-sectional view of the nozzle of the knockout pin, and Fig. 3 is an explanatory diagram of the local shrinkage process by air cooling of the molded product. , Fig. 4 is an explanatory diagram of the air knockout process of molded products, Fig. 5 is an explanatory diagram of superplastic blow molding,
Figure 6 is an explanatory diagram of air knockout of molded products, Figure 7,
FIG. 8 is an explanatory diagram of different superplastic blow molding methods. 10 is a mold body, 11 is a knockout pin hole, 12 is a knockout pin, 13 is a pin body, 14 is a nozzle, A is a molded product,

Claims (1)

[Claims] After the superplastic molding of the molded product is completed, the air blown out from the knockout pin cools and contracts a part of the molded product to form a draft in the molded product, and the knockout pin is raised while air is blown out to create an air cushion. A knockout method in a superplastic blow molding press characterized by extracting a molded product.