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Based on the state-of-the-art of structural analysis of machine tool, considering the lower of process precision of surface grinder, the static and dynamic analysis were performed to components and complete of grinder, using ANSYS FEA software, improvement projects were proposed, also the optimization was carried out and has validated the feasibility of improvement projects.Firstly, according to the structure characteristics of grinder, the model of the main components of grinder was established by applying solid element, the static analysis was performed after the simplify load and constrains were given. The ribbed plates of the original grinder are too complicated, it’s inconvenient to manufacture, the result of planker and pillar analysis indicate that the planker has pitching distortion, effect the process precision of grinder. Therefore, alter the collocation and thickness of the ribbed plates, and change the plane fitting surface of planker and pillar to inclined one, and the result indicate that the ameliorative way could reduce the pitching distortion of planker effectively, it’s provided a novelty method to the amelioration of grinder.Secondly, modal analysis was performed to the original grinder and the improved one, after the improvement, the first natural frequency was change very little, also has similarly mode shape. Considering the result of static analysis, the improved projects of components not only decrease the weight, but also reduce the distortion, accordingly the improved projects is testified to be feasible. Based on the improved projects, lathe bed was optimized by using Sub-Problem method in ANSYS, after then, the weight of front lathe bed and was decreased separately 14.53% (448.5kg) and 15.18% (131.82kg) ,and the natural frequency and distortion shoe little change.The entire model of grinder was built with the improved components, and the static and modal analysis was accomplished. Compare with the original structure, the weight of the grinder was dropped 7.2% (553.6kg) ,the first natural frequency was increased 2.3%, mode characteristics was similarly with the original one, the pitching distortion of planker was decreased 82.8%, the goal of improvement was achieved on the whole, and the improved projects which proposed by this thesis was proved to be successful.In view of the effect of thermal distortion to grinder, we did temperature field analysis to lathe bed, the result show that, the structure displacement and stress was affected greatly by the rise in temperature, and the simulation of the temperature filed in the found process was performed, the result could provide reference for casting craft project.Lastly, we did field test experiment to original surface grinder, the result indicated the pitching distortion of grinding head in the process of its lateral movement is the primary factor which affect the process precision of surface grinder, and tally with the finite element analysis result. The result of static analysis, dynamic analysis and improved projects will provide significant reference for the design and structure improvement of surface grinder.
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