Key Structure Design Of Die-casting Mould And The Research Of Forming Technology On Automobile Trailer Valve

Pressure casting is a kind of metal forming method with the remarked feature of high pressure and speed and realizes the continuous mass production of precision castings with uneven thickness and complex shape,so it is widely applied in industrial production.Die-casting mold occupies an important position in the whole die casting production.Weather the design of the pouring-exhausting-flooding system of die-casting mold is reasonable or not,it will determine the filling process of die casting in a great extent,and affect the quality of castings directly.This paper will take the trailer valve,a product of an auto parts casting enterprise in Zhejiang Quzhou as an example.To improve the rationality of the mold design,the distribution of the defects on the product and the Pass-Rate of products,the author conducts researches on the design of pouring-exhausting-flooding System,the mold’s important parts,numerical simulation analysis of die casting process and die casting experiments etc.The specific work and conclusions are as follows:1.The trailer valve is analyzed in details,and a preliminary design of pouringexhausting-flooding system is carried on according to the general design principle of pouring-exhausting-flooding system.Furthermore,design the key parts of the mold and determine the corresponding structural parameters.Finally,assemble the mold and put it into mold testing production.2.The mathematical model of alloy filling and solidification process is established,and the numerical simulation of die casting process of valve is carried on by using ProCAST.The paper also analyses the filling and solidification process of casting and observes the defects,then predicts the other potential defect types and regions.Contrast the simulation results with the casting of the defects found in the test phase and the results verify the accuracy of the numerical simulation.3.According to the results of numerical simulation and the defects generated in the testing production of castings,optimize the pouring-exhausting-flooding system and preliminary structure of the part.Adding reinforcement and three optimization schemes of pouring system which are simulated later are proposed,and the simulation results are compared and analyzed in order to determine the optimal scheme.4.Adopting the orthogonal test method,establish nine schemes of numerical simulation for die casting process parameters.The filling flow pattern,solidification rate and the result of the defect are analyzed synthetically,and the optimum technology parameters constitution is determined(The injection speed of 7m/s,the pouring temperature of 660℃ and the die preheating temperature of 220).5.According to the optimization results,modifying the corresponding structure of mold,and adjusting the parameters of die casting process for die casting experiments.Finally,the casting passed the quality tests of enterprise,and met the production requirements.At the same time,through metallographic test,the microstructures of the corresponding parts of the optimized casting are becoming uniform and compact.The internal defects are obviously improved.According to the theoretical simulation results and the defects in practical production,this paper optimized the mold structure and process parameters,and proved the accuracy of the numerical simulation optimization through physical experiments.The product’s quality has been improved,and can also bring economic and social benefits for the enterprise.The optimization design methods and ideas in this paper can provide reference for the optimization and process improvement of the same type of castings.