Aspheric Design And Analysis Of Machine Tool Structure

With the development of space technology, the demand becomes more pressing that the aspheric optical elements become larger and the required accuracy is more stringent of late years. The lightweight requirements for optical components are more and more critical. It can' t keep up with the demand to the aspheric optical elements for the traditional optical materials and traditional methods. SiC aspheric mirrors have high lightweight extent and excellent optical performance. Accordingly, SiC turns to be the first of all optical materials which are made for space mirrors. Aiming at the machining features of SiC aspheric mirrors, this dissertation introduces processes to design an aspheric surface compound machine tool with both grinding and polishing. Main research subjects arc included as follow:1. The general planning of the machine tool is selected on the basis of the machining features of aspheric optical elements. The accuracy of the key parts is designed rationally and applied to the design process. A dual-rotors polishing tool is developed aiming at the machining manners characteristic in computer controlled optical surfacing (CCOS), and its removal function distributes as Gauss curve.2. The static characteristic of the beam is analyzed with the idea of finite element analysis. The maximum deformation is obtained. The result shows that the deformation of the beam has little influence on machining accuracy. The modal of the body section is analyzed, and the natural frequency and the modal shapes arc obtained. The suitable range of the spindle speed is given. Also the methods to improve the modal of the machine tool are studied.3. The straightness and verticality of the sevor-control system are tested. The influences on accuracy of the sevor-control system and grinding processs are analyzed. The methods are given to increase the accuracy of the machine tool during design and machining processes.