Structure Design Of Rolling Linear Guide Connection And Bed

The enhancement of national comprehensive strength and competition between enterprises has created the need to high speed, high efficiency and high precision in process of modern machine tool. And the difficulty we encountered is how to meet the requirements of structure and performance with the lowest cost and shortest time. Currently, the structure forms and specific parameters of conjunction plane for machine tool rail are chosen in terms of machine tool manual and experience, and the local improvement of structure design for machine tool continues to follow the former experience. In view of the above problems, how to apply the reasonable and effective method to solve these problems is the key research in this paper.This subject comes from the National Science and Technology Major Project of China (grant number 2012ZX04010-011). Based on the research findings and this thesis studies, the structure layout of the guide rail plane is discussed, aiming at resolving the bottleneck of the conjunction plane of the machine tool. This research also puts forward a novel structure design method on characteristic parameters of the linear guide pair, handling the dilemma that the guide rail design lacks scientific evidence. Furthermore, the structure optimizing design method of the machine support parts is obtained by means of analyzing and researching the structure design and performance analysis. The main research contents have several aspects as follows:(1) According to the background of this research, this paper explained the research purpose and meaning. The rolling linear guide joint, supporting performance design of Machine tool and the research of structural design method were also reviewed, respectively. Moreover, it briefly summarized the achievement of the rolling guide joint and supporting performance design of Machine tool. This research introduced Finite Element Theory, Optimal Structure Theory, and Response surface method function fitting.(2) The basic structure and classification of profile connection for machine tools were introduced briefly. The characteristic parameters of connection face were defined through researching and summarizing the layout forms of rolling guides. Moreover, the composite load characteristics of position layout and structure layout for rolling guide could be discussed, through the research on the layout scheme of rolling linear guide.(3) The optimization design of characteristic parameters for rolling guides was studied based on Response Surface Methodology (RSM). First of all, the parameters model of rolling linear guide rail coupling could be established utilizing the Finite Element Method (FME). The static and dynamic performance database of characteristic parameters was obtained according to the results of FME analysis. Secondly, the RSM, referring to multi-objective genetic algorithm and orthogonal experiment coalesced admirably, could be employed to analysis the feature database of characteristic parameters, developing the optimization mathematical model under the typical working conditions. And then, the Pareto-optimal solutions of characteristic parameters were acquired based on the mixed influence of the significant impact of optimization targets for supporting parameters (rail span and slider spacing) and the results of sensitivity analysis.(4) Taking the vertical machining center as an example, the structure design and performance analysis of the bed were calculated. For one thing, the geometry model and physical model of bed were established under the simulation of the actual working load and constraints. Subsequently, with the Workbench platform and the topological optimization theory, the research of configuration on the bed was carried out, achieving the basic conceptual model of supporting part. Moreover, the structure conformation of bed could be obtained, through the selection of plate and stiffened plate. Then, the optimal bed structure was received adopting the software ANS YS Workbench to optimize the dimension of the bed structure. Finally, the contrastive analysis of the original and optimal bed in static and dynamic performance was carried out.The results indicated that the weight of optimal scheme decreased by 6.9% without compromising the static performance compared with the original project. With the basically same modes of vibration, the third order natural frequencies of the optimal scheme were increased by 18.3%,7% and 2.7%, respectively, satisfying the dynamic performance requirements.