Metal mold gravity casting bottom air-exhaust method

Abstract

The invention discloses a metal mold gravity casting bottom air-exhaust method, comprising the following steps: (1) a sand core is arranged on a metal casting bottom plate, a first pushing plate and a second pushing plate are moved to lead the top parts of the first pushing plate and the second pushing plate to be leveled to the upper surface of the bottom plate, and then casting is carried out in the metal casting cavity; (2) after casting is carried out, the first pushing plate is fixed, the second pushing plate is pulled down to lead the second pushing plate to sink to cause an air-exhaustchannel on the bottom plate to be exposed, and then the air generated by heating of the sand core is exhausted outside through a through hole of the second pushing rod and the air-exhaust channel; (3) after a casting piece is solidified, the second pushing plate is pushed upwards until the casting piece is ejected out from the metal casting cavity by the first pushing rod and the second pushing rod. In the metal mold gravity casting bottom air-exhaust method, the air-exhaust channel is arranged on the bottom plate of the metal casting cavity, the air-exhaust channel has very good air-exhaust effect, the air-exhaust capacity can be greatly improved, and the quality of the casting piece cast by the metal mold gravity is improved.

Description

technical field [0001] The invention relates to a casting method, in particular to a bottom suction method in metal mold gravity casting. Background technique [0002] Nowadays, many parts of automobile engines are basically produced by metal gravity casting, especially the key parts such as cylinder head and cylinder block. Since the inner cavity shape of such parts is very complex, many sand cores are required to combine to form complex inner cavity shapes during the casting process of these parts. During the casting process, the sand core will generate a large amount of gas after being heated, causing defects such as pores and leakage in the casting. Therefore, in order to improve the qualified rate of castings, measures must be taken to discharge the gas of the sand core out of the casting cavity, or use sand cores with low gas generation for production. The use of sand cores with low air volume, in addition to increasing the cost, may also cause defects such as insuff...

AI Technical Summary

Problems solved by technology

This method has a certain effect, but the disadvantage is that for the left and right sliders without core heads, the air pumping effect will be greatly reduced

In addition, there is another situation that the sand core of the casting is allowed to have very little place to protrude, so that the forced exhaust system cannot be installed on the end mold and the slider, so it cannot achieve a good air extraction effect.

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