Mouldless cast forming method of frozen clay sand

Abstract

The invention belongs to the field of sand mould casting, and discloses a mouldless cast forming method of frozen clay sand. The mouldless cast forming method comprises the steps: crude sand and a clay binder are evenly mixed, moulding sand is manufactured and placed into a sand box to be compacted, a clay sand blank is manufactured and then placed into a low-temperature environment of minus 15-minus 40 DEG C to be sufficiently frozen, and after the strength and the surface hardness of the clay sand reach the index, a standby sand blank is manufactured; and a machining program is generated through a part model, a mouldless forming machine is driven to enable the frozen sand blank to be cut and assembled into a sand mould, and then the sand mould is cast under a normal-temperature or low-temperature environment. After the clay sand mould is frozen, air permeability is good, and the air hole defect in the metal liquid solidifying process is reduced; the compression-resisting (tensile) strength of the sand mould is high, the surface hardness is high, and the mouldless cast forming method is suitable for mouldless cutting forming; compared with traditional manual moulding, a mouldlessmanufacturing process of the frozen clay sand is high in efficiency and high in sand mould precision; and meanwhile, during casting, a high-temperature metal liquid melt is high in supercooling degree, thus in the metal solidifying process, the temperature gradient is large, a metal cast is compact in structure, and the mechanical property is good.

Description

technical field [0001] The invention belongs to the technical field of sand casting, in particular to a moldless casting forming method of frozen clay sand. Background technique [0002] Patternless casting technology mainly includes sand additive manufacturing technology based on selective laser sintering (SLS) or droplet jetting and subtractive manufacturing technology based on sand cutting. The frozen clay sand moldless casting forming method mainly involved in this paper is the cutting technology for clay sand blanks. [0003] The moldless casting forming method based on sand cutting technology is to use CAD-driven sand mold CNC machining system to directly cut and shape the sand blank. Compared with the traditional hand-turning mold, it has higher forming efficiency, lower production cost, better working environment, and higher sand mold accuracy (the sand mold / core size accuracy prepared by this method has been improved to CT6-7 level, and the surface roughness has re...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the problem that clay sand is currently used in a very large amount (more than 70%) in sand casting, but its own tensile (compressive) strength and surface hardness are low, and it is not suitable for the direct cutting of sand molds. Propose a method of cutting and forming frozen clay sand

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