Study On Calculation Method About The Critical Preload Of Hydraulic Press With Combined Pre-Tight Structure

The specification and the equipment level of the large-scale forging hydraulic press is also a significant symbol indicating the product capacity, technical leave of heavy equipments, the economy and national defense strength of a country, having specific strategic significance. Whichever developed countries or development countries in the world pay attention to the development of heavy forging hydraulic press. In the present hydraulic press design, because its merit that has bigger rigidity, higher safety coefficients and ester controllably, the combines pre-tight structure has apply in the large-scale hydraulic press. Although the application of the combines pre-tight structure can solution many questions, it brings new problem that is integrity question.In this dissertation, the key question of design that about hydraulic press is analyzed. The article has put up the principle how the bending strain of beam and column have influence on integriy.Then inferred the computational method that contain bending strain of beam, which take the conventional mechanics computation as the foundation consideration.In this dissertation, the critical preloads of hydraulic press with combined pre-tight structure were proved when the design parameters have changed by the three dimensional finite element model.And the result indicatd that the calculation method about the critical preload hydraulic press with combined pre-tight structure was exacting.In this dissertation, the laws of the main effects for the 5MN Hydraulic press have been analysis by the method have been derived in this article.The information was shown that bias displacement was the most important element that affected hydraulic press's integrity. Bending's structure was one important elements also. Tension bar's structure had the smallest influence to hydraulic press's integrity.