Production method for preventing evaporative pattern casting deformation

Abstract

The invention relates to an evaporative pattern casting method and in particular relates to a production method for preventing evaporative pattern casting deformation. The production method is characterized by comprising the following steps: designing a tie bar, adhering, modeling, smelting and casting, and mold dismantling. The method is unique, the product yield is improved, the production cost is reduced, iron liquid filling is not influenced, and the casting quality is guaranteed.

Description

technical field [0001] The invention relates to a casting method of lost foam, in particular to a production method for preventing deformation of lost foam castings. Background technique [0002] Lost foam casting has the advantages of short cycle, saving wood, reducing labor intensity, and reducing production costs. It plays an excellent role in the casting production of small batches, especially large pieces and complex cavities. However, due to the poor strength of EPS materials, Castings are easily deformed during the process of transportation, coating, drying, and molding, resulting in casting size problems. Especially for large castings, the size problems caused by deformation account for more than 30% of waste products. Therefore, the lost foam casting must first solve the deformation problem. [0003] The so-called lost foam casting deformation refers to: the geometric shape of the casting after pouring does not match the pattern, such as bending, depression, ellips...

AI Technical Summary

Problems solved by technology

However, the actual operation found that the molding process is cumbersome, and if the support frame and the pattern are not properly matched, the pattern will be damaged, causing the pattern to vibrate and deform. Moreover, for particularly complex parts, the support frame is difficult to clean after the casting is boxed, which increases the cleaning difficulty. ;3) Using lost foam stretching: following the idea of ​​wood mold reinforcement, we try to use lost foam stretching to increase the strength

However, it is actually found that the tensile strength of the lost foam is poor. For larger castings, the number of tendons is also large, resulting in a decrease in yield and difficulty in cleaning. During pouring, the tendons will also cause local molten iron to flow turbulently, causing casting inclusions Defects, at the same time, it will increase the gas volume of the pattern, which is easy to cause back-spray phenomenon

[0004] So far, there is no way to overcome the above drawbacks