Sand negative pressure gravity casting die and casting method

Abstract

The invention relates to a casting die and a casting method for solving the technical problems that a sand box has low reuse efficiency and a vacuumizing system has complex structure and poor reliability in the conventional casting sand negative pressure casting method, and provides a sand negative pressure gravity casting die and a sand negative pressure gravity casting method with suitability of casting large hollow conical rotating body castings and high reuse efficiency of the sand box. The casting die comprises an upper box and a lower box; the lower box comprises a lower sand box, a vacuum pipe and a bottom cover barrel provide with vents; the lower sand box comprises a bottom plate, and the center of the bottom plate is provided with a vacuum pipe extending hole; the bottom cover barrel is backed off the bottom plate, the vacuum pipe comprises a vertical air inlet pipe and a horizontal communicating pipe, the free end of the vertical air inlet pipe passes through the bottom plate and extends to an air suction cavity formed by the bottom cover barrel and the bottom plate, the wall of the vertical air inlet pipe is provided with an air suction port, and the free end of the horizontal communicating pipe is connected with the vacuumizing system; and during casting, molten metal is cast when the air is extracted, the interior of the molding sand is in a negative pressure state, and the compactness and the mechanical performance of the obtained castings are higher than those of castings cast by using common molding sand.

Description

technical field [0001] The invention relates to the field of metal casting, in particular to a casting mold and a casting method suitable for large-scale hollow conical rotating body castings. Background technique [0002] The negative pressure casting method is a casting method invented and successfully developed in the late 1960s and early 1970s. The existing molding sand negative pressure casting method requires that the four walls of the sand box must be sealed, and a sand passing device must be provided to prevent sand from entering the vacuum pump and damaging the vacuum system. The sand filtering device includes a metal mesh of about 110 meshes arranged at the corresponding position of the air suction channel. These metal nets are easily blocked or damaged by sand grains during use, and the damaged metal nets must be cleaned or replaced when the sand box is reused. Therefore, in the negative pressure casting method of the prior art, the reuse efficiency of the sand ...

AI Technical Summary

Problems solved by technology

[0003] The present invention mainly solves the problem that the four walls of the sandbox need to be completely sealed in the existing sand negative pressure casting method, and the sand filter metal mesh must be installed on the suction channel of the sand box, and the sand filter metal mesh is easily blocked or damaged by sand particles during use. , so the reuse efficiency of the sand box is low, the vacuum system has complex structure, and the technical problems are poor reliability. It is suitable for large-scale hollow conical rotary casting. The four walls of the sand box do not need to be fully sealed, and the repeated Sand mold negative pressure gravity casting mold and casting method with high use efficiency

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