Research On The Design Of Automotive Center Channel Shroud’s Injection Molding Structural Design And Systematic Optimization Research

With the rapid development of plastic industry,the application of plastic parts is more extensive,so the plastic mold design is put forward higher requirements.Taking the car central channel as the research object and using hot runner technology,CAE technology and injection molding processing optimization technology,the paper carries out the design of its gating,cooling system and the optimization of the forming process,which will lay the foundation for the material-saving design and efficient design of injection mold.Firstly,combined with the structural characteristics of plastic parts,Moldflow is used to analyze the mold flow.The results show that the gating system selects the way to combine multiple gate points,cold runner and hot runner,which can effectively solve the problems such as long filling time,large injection pressure,uneven filling and large warpage of plastic parts,etc.caused by the complex structure of plastic parts and the long filling process.The number of gates by program comparison is determined.Using rheology theory reveals the relationship between the each pipeline size of gating system and the gating equilibrium.Each pipeline size obtained from operation will provide a theoretical basis for efficient design of gating system.Secondly,with the principle that the cooling time is short and the forming quality is high,the cooling system is designed.The system selects a straight-through cooling method and heat transfer theory is used to calculate the diameter of the cooling pipe concave of die and punch.Cooling simulation is carried out by using Moldflow,combined with the appearance of plastic parts to optimize the layout of cooling pipe.Finally,the optimization of injection molding process is carried out,taking warpage as the optimization target.Firstly,the Taguchi orthogonal experimental design method is used to develop forming experiment so that local optimal solution of process parameters is obtained.Then the Taguchi orthogonal experimental matrix is used as the sample data.The BP neural network model of process parameters and warpage is established by Matlab.By using genetic algorithm,optimization is carried out to find out the global optimum solution of the process parameters.The main research conclusion is as follows:1.The four gates will have the best effect.Gating system takes the program with a main channel and four branch channels,by changing the diameter of pipeline of branch channels to solve gating unbalance problem caused by the asymmetry of a sprue gates.2.Because of the unequal heat transfer between concave and convex dies,the diameter of the cooling pipe is determined by the quantity of heat taken by the concave and convex die.Pipeline layout should also be closely distributed in heat concentrated area of plastic parts.3.By using optimization method of BP neural network model combined with genetic algorithm,the global optimal solution can be found quickly.Compared with traditional trial production,the development time of the mold is greatly shortened,development cost is saved,the production efficiency of the products is also improved and product quality is enhanced.