Die-Casting Mould Structure And Process Optimization Of Steering Valve Shell Based On Numerical Simulation

The valve body of steering gear is a key part of the automobile steering system,which has high requirements for product surface quality and mechanical strength.The topic of issue is aimed at the problem of many of the defects of shrinkage and porosity in the valve body produced by some company,which can result the low passing of the products of the valve body.By means of the casting simulation software-AnyCasting,which can simulate the die casting mold filling and solidification process to optimize the die structure and die casting process parameters so that the purpose of improving the quality of the valve shell casting can be achieved.Through numerical simulation of the flow field in the filling process and the temperature field in the Solidification process of the original project of the pressure casting.The original project is found that it isn't smooth.There are a lot of gas and eddy current phenomena.The distribution of temperature field in the solidification process is not balanced.The probability of shrinkage porosity at the final solidification and wall thickness is large.Through the observation of the typical cross section of the castings produced by the original project,a large number of defects of the shrinkage porosity were found and the accuracy of numerical simulation was verified.Based on the results of the numerical simulation,the structure of the original mold has been optimized.The eddy current phenomenon in filling process can be improved by means of improving feeding mode and flow passage size.The phenomenon of rolling gas during filling process can be improved by adding an exhaust slot and enlarging the thickness of the inner gate.The distribution of the temperature field in the die can be improved by adding the cooling water channel and the local cooling device,which can reduce the time needed for the solidification and improve the efficiency of the actual production.The orthogonal test of the factors affecting the quality of the casting was designed by pouring temperature,injection speed and preheating temperature of the mold.And through the analysis of simulation results,it is concluded that the optimal die casting process parameters are pouring temperature of 610 degrees Celsius,the injection speed of 1.2m/s,the mold preheating temperature of 170 degrees.The influence degree of the analysis on the quality of the casting from large to small is pouring temperature,preheating temperature of the mold,pressing speed.Through theincreased two sets of level simulation test aimed at each impact factors,the effect law of the three process parameters on the quality of the casting has been concluded.The actual production of the castings after the optimize the mold structure and process parameters has been done and then is compared with the typical section of the castings produced by the original method.The results show that the shrinkage cavity shrinkage porosity and the volume of gas in the castings have been improved greatly,which improves the quality of the valve shell casting.Therefore,the simulation theory research can be used to guide the actual production process of casting so that it can provide reference for the production of similar aluminum alloy die casting products.