Design And Optimization Of Parallel Machine Tool Oriented To Laser Cutting

In recent years, on account of less degrees of freedom parallel mechanism has the advantages ofsimple structure, fewer components, simple control, and it is cheap, thus become the focus in thecountries.Three degrees of freedom parallel mechanism is one of less degrees of freedom parallelmechanism, with great practical prospect in the category. It can satisfy the requirement of working inmost cases, also can be mixed with other institutions to complete various tasks. But in laser cutting,and other industrial production has not a very good application, But in laser cutting, and otherindustrial production has not been very good application, so the study of three degrees of freedomparallel mechanism has important strategic significance.Based on the3_PUU parallel mechanism,a kind of machine tool was proposed in this paper. Inthe meantime, theoretical modeling and simulation analyzes were utilized to study the3_PUU parallelmechanism in depth, and the design improvement of the original mechanism was carried on, the mainwork and innovations are as follows:1、With screw theory, we got that3_PUU parallel mechanism has three degrees of freedom. Andthen we set up kinematics model of3_PUU parallel mechanism, with closed-loop vector we got thepositive and negative solution of kinematics. This paper adopted a new simulation method forworkspace of3_PUU parallel mechanism, with SimMechanics we did not need to undertake thekinematics calculation, this simplify the operation process, and we could get better image.2、Kane method was expounded in detail, and based on the theory, the3_PUU mechanismdynamics equation was established. Virtual prototype model of the3_PUU parallel mechanism wascreated, then simulated the agency kinematics response, verified the correctness of the inversekinematic solution in the second chapter. Compared the positive solution of the kinematics simulationwith applying displacement drive, proving the validity of the model. The stress of the sliding blockwas simulated, then the dynamic inverse solution were obtained. Do process simulation, to ensure thereliability of the design.3、Static stiffness analysis was carried out on3_PUU parallel mechanism, which helped us knowthe poor direction of stiffness was Y, which was the first direction we should considered. Then didmodal analysis of the branch and the whole machine model respectively, so we got the agencyvibrational modes of natural vibration characteristics, we could consider these weak links tostrengthen to enhance overall kinematic characteristics.4、For the convenience of assembly, we improved the sliders’ structure. In addition to improve the strength, stiffness and vibration properties of the machine, the arrangement of hinge and linkdesign were improved, to some extent, those could prolong the service life of the machine tool.In this paper, we studied the3_PUU parallel machine tool, who had advantages of compactstructure, strong carrying capacity and high stiffness. Due to the characteristics of bar, the parallelmachine tool could avoid bar interference effectively. This parallel machine tool would have goodapplication prospects in mechanical processing, precision processing and handling work,etc.