Simulation And Analysis Of 5-DOF Parallel Mechanism Adopted To Curved Face Forming Of Denture

In modern society, Dental health has drawn more and more attention from the public.Due to accelerated aging rate, the demand of tooth repair would be daily on the increase.With the maturity of CNC techniques, the method of denture making was gradually replaced by numerical control machining, thus improving the processing efficiency obviously. Foreign denture repair techniques has been becoming mature,which had formed a rounded system with regard to processing equipment,materials and software support.While domestic techniques had a large gap compared to foreign techniques, leading to the result that our country need to spend a lot of money to introduce the corresponding equipment from abroad to meet the domestic demand each year.So it is just around the corner that the denture repair system with independent intellectual property rights need to be researched and developmented, which could find a way out of this situation of depending on the introduction.A parallel mechanism of five degrees of freedom which could implement reciprocating line cutting trajectory for the purpose of processing and shaping of denture surface was designed.The mechanism had characteristics of small cumulative error, high rigidity, high bearing capacity and so on compared with traditional machine tools,which can implement high precision and high profile processing.In this thesis, the parallel mechanism which has outstanding performance was applied in the special environment of denture processing. Trajectory planning for denture processing,data selector of processing equipment,cutting force of cutter,the error magnification modeling,space planning and so on was researched. The structural parameters of parallel mechanism was designed and multi-objective optimization was implemented,and a prototype of parallel mechanism of five degree of freedom which could carry out denture surface forming was put up.Aiming at denture surface forming parallel mechanism of five degrees of freedom,dynamics modeling was carried out and analytical solution was decoupled.Jacobi matrix of parallel mechanism of deficient degree of freedom was deduced according to screw theory; by means of the research on denture surface forming parallel mechanism of five degrees of freedom, a universal decoupling method of acceleration which can solve analytical solutions of acceleration with regard to branched chain handspike was put forward;Dynamics modeling with respect to denture surface forming parallel mechanism of five degree of freedom was established via partial velocity and Kane’s equations,and analytical solution of the joint forces on various branched chain were solved.The denture surface forming parallel mechanism of five degrees of freedom was simulated and analysed.Correctness of dynamics modeling with regard to denture surface forming mechanism was verified, and the kinematics simulation of optimized mechanism was implemented according to planned tool trajectory, which were compared with the scheduled results.The deformation of various branched chain and error size of cutting tool end in circumstances that the mechanism was beared cutting force were simulated, and accuracy requirement of mechanism was validated.