Low-pressure casting heat preserving furnace for molding filling of screw pump

Abstract

The invention discloses a low-pressure casting heat preserving furnace for molding filling of a screw pump. The furnace comprises a furnace body, a furnace cover and a mold filling pressure preserving system, wherein a round hole is formed in the furnace cover; the mold filling pressure preserving system consists of a motor, a belt wheel, a screw pump, a liquid rising pipe and a graphite washer; a pump shell of the screw pump and the liquid rising pipe are integrated; a screw rotor of the screw pump and the liquid rising pipe can vertically slide; the mold filling pressure preserving system realizes the liquid surface suspension through controlling the rotating speed of the motor; and the liquid level control is realized by using the graphite washer, mounted at the upper part of the liquid rising pipe, as a contact. The mold filling pressure preserving system is convenient to be installed; the pressure rise and the pressure preservation can be automatically finished after mold filling; and the working furnace body has no need to be sealed, so that the maintenance is convenient.

Description

technical field [0001] The invention belongs to the field of low-pressure casting, and in particular relates to a low-pressure casting holding furnace. Background technique [0002] At present, low-pressure casting is to add pressure to the sealed holding furnace to squeeze the aluminum liquid into the cavity. Due to the poor pressure bearing capacity of the metal furnace shell at high temperature, generally lower pressure is used for pressurization, so this molding method is called low pressure. Casting, its disadvantages are as follows: 1. During production, it is necessary to periodically inject cold air into the furnace to remove hot air, so the furnace temperature fluctuates greatly, and fresh oxygen-rich air impacts high-temperature aluminum water, accelerating the oxidation of aluminum water, slagging, and oxygen absorption , affecting the quality of aluminum water. 2. The furnace body must be sealed, which not only increases the cost but also makes it necessary to s...

AI Technical Summary

Problems solved by technology

[0002] At present, low-pressure casting is to add pressure to the sealed holding furnace to squeeze the aluminum liquid into the cavity. Due to the poor pressure bearing capacity of the metal furnace shell at high temperature, generally lower pressure is used for pressurization, so this molding method is called low pressure. Casting, its disadvantages are as follows: 1. During production, it is necessary to periodically inject cold air into the furnace to remove hot air, so the furnace temperature fluctuates greatly, and fresh oxygen-rich air impacts high-temperature aluminum water, accelerating the oxidation of aluminum water, slagging, and oxygen absorption , affecting the quality of aluminum water

2. The furnace body must be sealed, which not only increases the cost but also makes it necessary to stop production when adding aluminum water, which affects efficiency

3. Due to the frequent air leakage of the furnace body, it has a negative impact on the quality of the castings, and the anti-leakage function of the control system is very strict.

4. The main engine must be equipped with an expensive liquid level pressurization control system, and the furnace body must always drag the exhaust pipe

5. Due to the need for compressed air to alternately enter and exit the holding furnace during production, it is difficult to implement inert gas protection to improve the quality of aluminum water

[0003] In addition, there are many problems in the method of installing a mechanical pump from the bottom of the furnace to complete the filling of the low-pressure casting: first, when replacing the mechanical pump, the new pump must be installed after the furnace is stopped and the aluminum water is removed, and the refractory material needs to be knotted after installation. , it must be dried and baked for a long time before it can be used

Third, the connection between the riser pipe and the mechanical pump is cumbersome and unreliable, which will become a hidden danger

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