Furan resin sand mold for producing heavy castings and sand core bumping method

Abstract

The invention relates to a furan resin sand mold for producing heavy castings and a sand core bumping method. According to the technical scheme of the invention, the bumping method comprises the following steps of: a, correcting a table-surface level of a bumper first when the bumper is arranged and then checking up accelerations at four corners of the table-surface by using a seismometer and keeping the numerical values of the accelerations of the four angles to between 20 and 30 m / s<2>; b, adding a furan resin and a furan self-hardening sulfuric curing agent into molding sand and stirring the mixture to obtain sand mud for making mold and core sands, wherein the added weight of the furan resin is 0.95 to 1.15 percent based on the added weight of the molding sand and the added weight of the furan self-hardening sulfuric curing agent is 35 to 45 percent based on the added weight of the furan resin and the sulfuric acid in the furan self-hardening sulfuric curing agent is 9 to 35 percent by weight; and c, pouring the sand mud into a box till the level of the sand mud is 100 to 150 millimeters higher than the box surface and then starting the bumper to perform bumping for 10 to 50 seconds. The method has the advantages of greatly improving the percent of pass, greatly improving the loosening conditions of the casting and greatly reducing the rejection rate.

Description

technical field [0001] The invention relates to a production method of large-scale high-toughness components and main components of high-power wind-driven generators, in particular to a method for producing furan resin sand molds and mud cores for large-scale castings. Background technique [0002] Due to its solidification characteristics, iron castings have high requirements on the compactness of the casting mold, especially for large ductile iron castings. The compactness of the casting mold has a great influence on the final quality of the casting. In actual production, it is often encountered that other process parameters do not change or change very little, but the internal shrinkage of the casting is very large, which is often caused by large fluctuations in the compactness of the mold. [0003] At present, many factories use furan resin sand to produce large-scale wind power ductile iron. For a long time, artificial wooden sticks have been used to obtain high mold co...

AI Technical Summary

Problems solved by technology

However, due to the shortcomings of this operation method, such as high labor intensity, large operation randomness, and uneven compaction, the internal quality of the casting after pouring is unstable, showing that sometimes there is little or no shrinkage porosity, and sometimes it is due to shrinkage. The pine was too large and scrapped. After inspection, it was found that the process parameters of these parts did not change much.

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