Research On The Key Process Parameters Of Hydrodynamic Deep Drawing On The Oil Pan

With the rapid development of auto industry, the shape of auto covering parts is more and more diversified; enterprises have higher and higher demand for the shaping precision of auto covering parts due to precision shaping and the traditional stamping process can not meet the market requirement, so it is badly in need of a kind of advanced sheet metal forming process to adapt to the diversified production. As a kind of soft film forming, liquid deep drawing has simple shaping process, high precise of forming parts, low cost of molding development and short development cycle, therefore, there has a unique advantage for complex and larger drawing parts. However, due to the various objective conditions, liquid forming technology in the field of auto covering parts is not fully developed in our country. This thesis focuses on the tank pan to explore the influence of key process parameter on shaping in the liquid forming process.According to the characteristics of the tank pan shape, the numerical simulation software Dynaform is used to design the addendum and binder surface of model established by 3-D software. It utilizes common stamping deep drawing method to determine the reasonable drawbead layout method in the forming process. On the basis of process parameter determined by common drawing, it makes use of fixed gap to set friction coefficient between moulds so as to determine the appropriate liquid chamber pressure loading path; and determine the most reasonable way of liquid chamber pressure loading by analyzing the influence of different fluid chamber pressure load on the quality of the tank pan forming. By way of blank pressing of blank-holder force, it probes into the matching relationship between fluid chamber pressure loading path and blank-holder force loading. In order to conclude the effect of blank holder gap, it takes advantages of the influence of different blank-holder gap on the liquid deep drawing to undertake a further analysis.This thesis takes part thickness distribution, thinning ratio, forming limit diagram as the evaluation index to carry out the comparative research on piecewise equivalent drawbead ordinary deep drawing, blank-holder gap 1.32 mm liquid deep drawing in the four fluid chamber pressure load curve and liquid deep drawing of changing blank-holder force simulation in the four fluid chamber pressure load curve; Finally it concludes that liquid deep drawing process of fixed gap has its unique advantages under the reasonable fluid chamber pressure loading condition and parts forming defects get effective elimination, which can effectively reduce parts thinning and improve parts uniformity so as to gain parts of high precision. In the end, it carries out a further research on the drawbead layout which set real drawbead by utilizing process parameter determined by common drawing to undertake simulation and improve the simulation authenticity.