Method for casting large-scale box type castings through precoated sand shell mold

Abstract

The invention belongs to the technical field of coated sand casting technology, in particular to a method for casting large-scale box castings with coated sand shell molds. Including mold making, molding sand preparation, core mold making, and core mold combination: After the shell molds and shell cores are combined according to the process card or drawing, the sand box is placed on the outside, the gating system is drawn out, and the gate and the gate are wrapped with plastic film. Riser, then between the shell mold and the sand box, add clay sand layer by layer and solidify, and finally lock the upper and lower boxes; pouring molding and cleaning. The invention has high casting precision, high yield and good surface finish, and is suitable for larger castings.

Description

technical field [0001] The invention belongs to the technical field of coated sand casting technology, in particular to a method for casting large-scale box castings with coated sand shell molds. technical background [0002] As we all know, the traditional coated sand casting process has many advantages such as good geometry, high surface finish, small machining allowance and small draft angle, but it is only suitable for the production of castings with a single weight of no more than a few kilograms to more than ten kilograms. (When pouring large-scale castings with shell casting, the shell will explode or stick to sand due to excessive molten iron pressure, resulting in waste products). Castings ranging from tens of kilograms to hundreds of kilograms have to rely on iron mold sand-coating technology and resin sand technology. The disadvantage of the sand-covered iron mold process is that the tooling is dedicated and the quantity is large, the mold and equipment are expens...

AI Technical Summary

Problems solved by technology

[0002] As we all know, the traditional coated sand casting process has many advantages such as good geometry, high surface finish, small machining allowance and small draft angle, but it is only suitable for the production of castings with a single weight of no more than a few kilograms to more than ten kilograms. (When pouring large-scale castings with shell casting, the shell will explode or stick to sand due to the excessive pressure of molten iron, resulting in waste products). Castings ranging from tens of kilograms to hundreds of kilograms have to rely on the iron mold sand-coating process and resin sand process.

The disadvantage of the sand-covered iron mold process is that the tooling is dedicated and the quantity is large, the mold and equipment are expensive, and assembly line production is required. It is not suitable for box products with many sand cores and small batches of multiple varieties.

The production of resin sand is often difficult to control due to the brushing of paint, which will affect the surface finish and precision of castings

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