Hollow-out printing method for composite manufacturing of frozen sand mold and resin sand mold

Abstract

The invention discloses a frozen sand mold and resin sand mold composite manufacturing hollow printing method. Firstly, the shell thickness and the hollow reinforcing structure are designed according to the casting requirement, and the design of the composite frozen hollow sand mold is completed. After design, pretreated casting crude sand is fed into a sand mixing device through a feeding machine and evenly stirred with a curing agent and a refrigerant. And then the two types of sand are fed into a sand paving device for 3D integrated printing. The control system controls the sand paving device to pave two types of molding sand as required according to section information of a current layer of a printing sand mold, resin molding sand is used for printing a shell, and freezing molding sand is used for printing a hollow structure; the double printing nozzles are controlled in a low-temperature environment, a resin binder or a water-based binder is sprayed as required, and the binder is in contact with premixed crude sand to react so as to solidify the molding sand. And sand is laid layer by layer according to needs, a binder is sprayed layer by layer according to needs, finally printing is completed, and redundant molding sand is cleaned after the sand mold is stored for a period of time in a low-temperature environment.

Description

technical field [0001] The invention belongs to the intersection field of additive manufacturing and casting technology, and in particular relates to a method for hollowing out and printing composite manufacturing of frozen sand molds and resin sand molds. Background technique [0002] Frozen sand casting technology is a casting technology in which water is used as a binder for sand casting, the sand is frozen in a low temperature environment to form a sand mold, and the casting is obtained after pouring the melt. The undercooling degree of the melt in the frozen sand mold is high, and the temperature gradient of the melt is large during the solidification process. The metal casting is strengthened by fine grains, the structure is dense, and the mechanical properties are good. The sand mold collapses naturally under the impact of high-temperature melt, and no strong irritating gas is generated during the pouring process. However, pure frozen sand molds have poor shape reten...

AI Technical Summary

Problems solved by technology

The traditional casting mold has a dense structure, which makes it difficult to control the cooling of the casting during the forming process of the casting. At the same time, the cooling efficiency of the casting after solidification is very low, and the production cycle is long.

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