WO1989007879A2

WO1989007879A2 - Diecasting process with two-stage control

Info

Publication number: WO1989007879A2
Application number: PCT/CH1989/000035
Authority: WO
Inventors: Adolf Auf Der Maur
Original assignee: Adolf Auf Der Maur
Priority date: 1988-02-26
Filing date: 1989-02-24
Publication date: 1989-09-08
Also published as: EP0357715A1; AU3053189A

Description

Die casting process with two-stage control

The present invention relates to a two-stage control of a casting process with two mutually independent casting speeds, the melt being driven by means of a pressure which can be changed twice, from an oven containing the melt, through a casting tube into the casting cavity of a mold. In the first stage, the casting furnace (15) automatically compensates for the discharge of the melt with pressure by means of the level display (23) each time the casting is carried out. That the melt reaches the level edge (18) at the pouring tube (19). And remains until the casting model (14) is pressed onto the casting tube (19). And at the moment the second stage (Flg. 2.) sets in motion. Their invention consists in that the casting model (14), once set, is always filled with exactly the same time. So that, for example, with ten casting processes, ten two-way valves (l) with manual operation and ten two-way valves (2) with motor operation. That are connected. So that the time opening, the through valves (2) from one to ten, the through valves (1) from one to ten, the loss of the melt in the casting furnace (15) from one to ten is always compensated for. And thus the pressure and thus the casting speed is always exactly the same once tuned. In the previous processes, the melt in the casting furnace is only pressurized when the model is pressed onto the casting tube, which has significant disadvantages. If the furnace is slowly pressurized, the casting process will be too slow. If the furnace is pressurized quickly, the flow rate cannot be controlled. And therefore the quality of the casting also varies.

For example, it is well known that if a molten metal is introduced too slowly into a permanent mold, the metal tends to solidify or harden too quickly, preventing proper filling of all parts of the mold and resulting in defective castings . On the other hand, entering the mold too quickly creates erosions and other damage such as cavities and cracks on the surface of the casting.

The purpose of the present invention is to provide a method without the disadvantages mentioned, in which a sensitive and precise control of the filling speed can be achieved in a relatively simple manner, so that a high, consistent casting quality is ensured. According to the invention, this is precisely described in the claims 1, 2 and 3 and with the plan.

Claims

Die casting process with two-stage control. Characterized by the intermediate pressure tank (16) via the pressure line Fig. 1, the two-way valve (8) with manual operation, the printing speed is set. Level indicator (23) with electrical contacts actuates motor valve (9) to shut off when the casting furnace (15) is pressurized until the melt through the pouring tube (19) at the level indicator (23) touches the edge of the level (l8) reached. Since there is a loss of material with every pouring process, the level indicator (23) has to influence the motor valve (9) in such a way that the melt always reaches the level edge (18) after each pouring process. The pressure registration (20) can be set manually in each casting model (14) in such a way that, for example, ten casting processes run without material refilling. The casting sequence counter (12) influences the casting quantity registration (13) and thus the casting quantity registration (13) influences the pressure registration (20) with each casting sequence. For example, if the melt does not reach the level edge (18) when the material is refilled when the casting furnace (15) is pressurized, the casting furnace (15) is automatically replenished with pressure until the level edge (18) is reached. The pressure gauges (10) and (3) are therefore also exposed to higher pressure. Which has the consequence. that automatically adjusts the pressure registration (20) and (21) the quantity count (12) and (5) and the quantity registration (13) and (6). For example, it only starts with the second or third pouring process. It can of course also be corrected manually. The pressure registration (20) thus takes over if there is a pressure loss in the casting furnace (15) automatically via the pressure manometer (10) and motor valve (9) the pressure compensation entered for him. The motor valve (11) is shut off at the moment when the casting model (14) is pressed onto the casting tube (19) and the control of FIG. 2 is started at the moment.

According to the invention, with ten casting processes, there are (l) ten two-way valves with manual actuation and (2) ten two-way valves with motor actuation, which are connected to one another from one to ten. So that the through valves (2) with motor actuation are open the same time for each pouring sequence from one to ten, once the time has been coordinated and then always the same. And you can compensate for one to ten loss of melt in the casting furnace (15) with the straight-through valves (1) with manual operation. So that each casting process from the level edge (18) to the upper edge casting model (14) is set once and always has the exact same speed. The two-way valve (4) with motor actuation closes with two-way valve (2) with motor actuation. Vent valve (7) with motor actuation opens when the melt in Giessmödsll (14) has solidified. Two-way valve (4) and two-way valve (11) open when the casting model (14) is lifted off the pouring tube (19). Vent valve (7) with motor actuation closes before the control of FIG. 1 is put into operation. According to the. 2-port valve block (1) with manual operation from one to ten and the 3-port valve block (2) sealed once with engine actuation from one to ten. And is exchanged with each casting model (14). So that each casting model (14) has its own valve block (1) and (2).

It is also dependent on this invention that the intermediate pressure tank (16) always has the exact same pressure and, when there is the slightest drop in pressure, is replenished with the two-way valve (22) via the compressor tank (17). So that no fluctuations can occur when printing.

According to the invention, the level display (23) is characterized by two n conductors, characterized in that an n conductor has contact with the melt in the casting furnace (15). Sodαss when the melt reaches the edge of the level (18), an n - wire contact is formed, and thereby shuts off the two-way valve (9) with motor actuation. According to the invention, the whole can also be done with alternating current (m phases and frequency f).