| During the stamping process of the tire mold steel sheet,due to the material properties,stamping process conditions,and processing environment,defects such as cracking,wrinkling,and Stamping springback will occur after the tire mold steel sheet is formed.The occurrence of process defects will affect the subsequent and The assembly of the blocks causes interference,which in turn affects the vulcanization molding quality of the tire pattern.This subject takes flat tire mold steel sheet as the research object,and uses the method of combining theoretical analysis and finite element simulation to explore the influence of process parameters of tire mold steel sheet on stamping forming quality during stamping forming.Process the material properties of SS304 stainless steel,and establish a stamping model of the tire mold steel sheet.Through finite element simulation software analysis,analyze the regularity of the forming quality of the tire mold steel sheet under different mold gaps,friction coefficients,blank holder forces and punching speeds,and predict Forming defects,optimizing process parameters.The main work of the thesis includes the following aspects:(1)Introduce the important role of tire mold steel sheet in tire vulcanization,and su mmarize the process defects and defect generation mechanism in the stamping process,and systematically introduce the finite element stamping theory,including the material model,Contact friction,and solving algorithms.(2)The main material performance parameters of SS304 stainless steel were obtained by using inductively coupled plasma mass spectrometer ICP-MS and Instron type material testing machine,the types of tire patterns and process requirements wereintroduced,and numerical control technology,electric spark technology and tire mold steel were introduced.The sheet forming technology process flow is analyzed.(3)Establish a typical flat tire mold steel sheet model,determine the forming limit map and the maximum thinning rate as the main method of judging the quality of stamping and forming,and use the finite element software simulation of the stress-strain distribution cloud diagram to analyze the stress-strain changes and obtain different The law of forming quality of tire mold steel sheet under mold clearance,friction coefficient,blank holding force and punching speed,the results show that the influence of process parameters on the quality of tire mold steel sheet stamping is different.When other process parameters are the same,With the increase of the punching speed,blank holding force and friction coefficient,the rupture process defects of the tire mold steel sheet will gradually appear,and the maximum thinning rate will also increase.When the mold gap is small,the tire mold steel sheet will be shaped.Fracture defects occur,and the maximum thinning rate increases.When the mold gap is large,more severe wrinkling occurs at the edge of the tire mold steel sheet,and the maximum thinning rate decreases.In su mmary,when the blank holding force is 20 kN,the die clearance is 15 %,the punching speed is 3000 mm / s,and the friction coefficient is 0.125,the forming quality of the tire mold steel sheet is the best.(4)Combining the mechanics of stamping Stamping springback mechanics and finite element simulation technology,the analysis of the iMPact of different process parameters on the Stamping springback of stamping forming,the results show that the Stamping springback amount,die clearance,and stamping speed of tire die steel sheet stamping are expressed as Proportional relationship,that is,the larger the mold clearance and punching speed,the greater the Stamping springback amount of the tire mold steel sheet after forming;it is inversely proportional to the friction coefficient and the blank holder force,that is,the larger the friction coefficient and blank holder force,the greater the tire mold steel The smaller the springback amount after the sheet is formed. |
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