Low-pressure casting method and device thereof

Abstract

The invention relates to the technical field of casting and discloses a low-pressure casting method and a low-pressure casting device. The low-pressure casting method comprises the following steps: feeding, pressurizing, lifting liquid, keeping pressure, solidifying, decompressing and taking a mould. The low-pressure casting device comprises a temperature keeping chamber, a mould, a pressurizing chamber, a liquid lifting chamber, a plug rod, a liquid level pressurizing control system and a liquid level sensor, wherein the plug rod is used for controlling a feeding channel to open and close. The low-pressure casting method and device provided by the invention have the following advantages: the production efficiency is greatly increased; the continuous production is realized; the casting parameter is stable; the metal liquid level at each time of pouring is kept constant, so that the fluctuation of the pressurized pressure is small and athe control system is simplified; the quality of the metal liquid level is stable; and the degree of freedom of the technology is increased.

Description

technical field [0001] The invention relates to the field of casting technology, in particular to a low-pressure casting method and an adopted device. Background technique [0002] Low-pressure casting refers to a casting method in which liquid metal fills the mold from bottom to top and solidifies under pressure to obtain castings under pressure. Specifically: apply about 0.0098 to 0.049MPa on the metal liquid surface of the closed crucible The air pressure (dry air or inert gas) makes the molten metal rise along the pipe (riser) placed in the molten metal and flows into the mold above the chamber, until the molten metal is completely solidified from the upper part of the mold to the gate When the pressurization is stopped, the molten metal in the riser flows back to the crucible and the casting mold can be opened to take out the casting. Because the pressure applied on the liquid metal surface is very low, it is called low-pressure casting. [0003] The low-pressure cast...

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Problems solved by technology

[0005] However, the top-mounted low-pressure casting machine also has obvious disadvantages: 1) Low production efficiency, which is caused by the long pressurization process and long solidification time; All operations in the production cycle are carried out indoors, and most of the time for the heat preservation crucible is idle; the third is that when the molten metal in the crucible is used up for feeding, the entire production process must be stopped; 2) Control of pressurized pressure parameters The main reason for the low accuracy is that the metal liquid level in the crucible boiler decreases with the increase of the pouring times, and the height of the metal liquid surface from the mold is constantly changing, so the pressurized pressure needs to change with the change of the liquid level height, resulting in a The pressure fluctuation is large; the second is that the pressure feedback is slow, due to the large sealing area of ​​the heat preservation crucible, easy leakage, large volume, slow pressure rise, etc., the timeliness of the pressurization of the molten metal filling is poor; 3) the casting process of the parts is poor; 4) It is difficult to guarantee the stability of the quality of molten aluminum in the thermal insulation crucible. Because the thermal insulation crucible is sealed, refining in the furnace and removal of oxide slag cannot be implemented, and the quality of molten aluminum fluctuates greatly.

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