1.问题的提出 既长又大的铸件变形对工件的加工余量及工件的加工质量等都带来很大影响。为了减少加工余量,提高工件的质量,采用一次反挠度,但还不能达到克服铸件变形的需要,并使铸件的平直度很不稳定。同一工件采用相同的铸造工艺,平直度相差很大,因此,对既长又大的铸件来说,我们采用二次反挠度新方法,对补偿工件的铸造变形又进了一步。 1. The question raised Both long and large castings deformation of the workpiece allowance and workpiece processing quality have a great impact. In order to reduce the machining allowance, improve the quality of the workpiece, the use of a reverse flexibility, but still can not meet the need to overcome the deformation of castings, and make the flatness of castings is very unstable. The same workpiece using the same casting process, the flatness vary greatly, therefore, for the long and large castings, we use the new method of secondary deflection, the workpiece deformation compensation for casting another step.