Analysis Of Machining Deformation For Thin-wall Parts And Design Of Fixture For Finishing Turning

Aluminum alloy material is widely used in lightweight design because of its character of lightweight and nice mechanical properties. Many structural members adopt aluminum alloy as cylinder body material, especially in defense science and technology industry. For instance, the Aircraft cabin used to be designed in thin-wall structure with aluminum alloy material in order to lower weight. But those thin-wall parts are easy to be deformed as their thin wall and low rigidity, which effects there manufacturing accuracy. So, how to reduce the reformation of controlling parts under pressure and how to improve their manufacturing accuracy and whole weapon performance have a great significance. This article focuses on the cabin parts of a spacecraft instrumentation, studies its clamping deformation during processing and how to control it, with the method of theoretical analysis and finite part simulation combined with experimentation. And it has made some achievement, the main contents are as following:1、The industrial analysis of thin-wall cabin components machining distortion. Because of the structural characteristics and technique requirement of cabin components, the article analyzes the controlling to the key technical parameters of thin-wall cabin components in detail according to the structural manufacturability of a product, selection of processing method of component side and machining sequence, and has gotten the feasible solution.2、Design a large clamping device of tensile spring, which is used to FT and turning. At the basis of the analysis of thin-wall cabin components machining distortion, according to the requirements of fine turning of outer cylinder, design a large clamping device of tensile spring which is with the tri –cone in one body, analyze the errors of the locating schemes of fixture, count the clamping force and the cutting force. Finally, finish the physical designof fixture.3、3-D contact problem of the thin-wall parts under the lamping state is analyzed with the method of FEA using ABAQUS software. Establish the finite element analysis model of the parts under the lamping state, get the stress and strain contours of the under pressure, and also get the relationship between the offset of mobile cones and the deformation of thin-wall components.4、At the basis of CK7525 CNC Lathe, program NC programming, do the machining experiments to FT of the thin-wall cabin components with the large clamping device of tensile spring. The processed cabin components passed the detection and every technical parameters meets the technological requirements. Finally the scheduled goal is achieved.This article provides a scientific technical method for the controlling of machining defo- rmation to the thin-wall cabin and the processing of thin-wall components.