Studies On Thermal Equilibrium Analysis And Intelligent Optimal Design Of Injection Mold Hot Runner Based On Car Front Bumper

In hot runner of injection mould, the heat of plastic melt is directly affected by the thermal balance of hot runner temperature field. If plastic melt is in a very uneven temperature field for a period of time, it can be degraded. The product appearing defects is caused such as black spot, bubbles, and stripe. In the traditional process of hot runner design, although hot runner thermal balance is tightly controlled, most designs are done by experience. The production efficiency of hot runner can be received the most severe effect under lots of repeated modification and experiments. The frequency of repeated modifications and experiments can be reduced by the application of the Finite Element Analysis, but the determination of many variable parameters of hot runner still need a reasonable optimization method. The hot runner design and manufacturing the reference was provided by the application of combining with simulation, integration optimization, the algorithm fitting, data processing et al. and help its scientific design more efficient.Firstly an overview of the domestic and foreign research on hot runner thermal equilibrium analysis was made in this thesis. The intelligent optimization’s feasibility in the applications of thermal analysis of hot runner was discussed. The research emphasis and the main method in this thesis was put forward.Next, through the formula of heat transfer theory, the heat exchange relationships between the parts of the hot runner and between hot runner and the mold were respectively analyzed. On the basis of a partial simplified model, the heat coil’s and heat tube’s heating power were calculated. The proportion of each heat loss caused by heat conduction, the heat convection and the heat radiation was got through the analysis of the hot runner’s three heat loss methods.Then, the partial model of a car’s bumper hot runner was used in ANSYS software thermal analysis. Based on DOE, the three important factors, heat coil’s extreme circle number, hot mouth inner diameter and distance from heat pipes to runner, were studied about their impact on the thermal equilibrium analysis. After compared with Moldflow analysis of three solutions, a set of suitable for the bumper injection solution was pus forward and was used as a design reference of the preliminary hot runner.Finally, combining with ISIGHT and ANSYS software, an intelligent optimization process was completed. The three different arrangement ways of runner plate heat pipes were researched in intelligent optimization design, and then a global optimal solution was put forward. The hot runner was built to complete the parameters optimization design in the Workbench software DX design environment. The hot runner was used in simulation analysis and experimental verification for getting the optimum processing parameters. Through comparing with two of before and after optimization, the reliability and practicability of the proposed method was verified.In this thesis, through the example of a car’s bumper intelligent optimization design for the hot runner of injection mould, a set of effective and scientific method was provided, which had certain engineering practice guiding significance.