Design And Research Of Injection Molding Cold Runner For High Speed Train Rubber Inner Windshield

The rubber inner windshield is an important component of high-speed trains.Due to its complicated structure,thin wall,large volume,overall ring shape and U-shaped structure with an opening inward in cross section,and its aging resistance,tensile tear resistance,air tightness Special performance requirements such as flame retardancy,molded manufacturing methods cannot meet their production requirements due to problems such as high labor intensity,low production efficiency,unstable quality,and low product qualification rate.Therefore,injection molding is used to produce Inevitable choice for large and complex rubber products.However,at present,the injection molding technology for producing such large rubber products in China is not very mature,especially the key technologies such as special cold runners,molds,and processes need to be broken through.In-depth research is conducted to provide injection molding technology for such large and complex rubber products It is very necessary to provide a theoretical basis.Among them,the large rubber cold runner technology suitable for simultaneous injection of multiple injection heads is one of the keys of this technology.In this paper,based on the study of the numerical simulation theory of polymer fluid flow,the design and research of the cold runner of the high-speed train rubber injection molding.First,the Solidworks software is used to model the inner windshield of the rubber,the shape,volume and surface quality of the product are analyzed,and the cold runner model of the two structures is established based on the existing research results.The flow conditions of the model are simulated,and the pressure field,shear stress field and velocity field of the two models are analyzed,and the cold runner structure is determined according to the results.Based on this structural model,simulation analysis and optimization of main channel structures with different cone angles and different diameters are carried out.The specific research contents are as follows:(1)By referring to the relevant literature,the research status of injection molding runners at home and abroad is studied and summarized,and the flow mechanism of rubber injection molding is also studied.On this basis,the basic research plan and research route are determined.(2)The process parameters of injection molding were preliminarily determined according to the design requirements,and the three-dimensional model of two cold runner structures with 16 gates and 32 gates was preliminarily determined using Solidworks software;Simplify and suppose,the simplified model will be meshed with the software ICEM,and the meshed model will be used to set the material parameters and boundary conditions.(3)Using the CFD software Fluent to simulate the flow of rubber in the two cold runner models,the pressure field,the shear stress field and the velocity field of the rubber in the two models are obtained.Through comparative analysis,we can see that 16 gates The cold runner structure is an ideal structural design.(4)On the basis of the cold runner model,the main channel structure with different cone angles and different diameters is simulated and analyzed.By comparing and analyzing the flow field cloud diagram and curve chart,the influence law of the cone angle and diameter changes on the rubber flow is obtained.The analysis shows that when the cone angle is A=6°0 and the diameter is 7.92mm,it is the best mainstream channel structure.(5)According to the law of conservation of energy,the heat transfer mechanism of the rubber cold runner was studied,the scheme of the temperature control system was determined,the layout of the temperature control loop and the pore diameter of the temperature control loop and other parameters were designed,and the cold runner was controlled by finite element software The temperature field of the board was simulated.It can be seen from the simulation results that the temperature difference of the cold runner plate is within±3? the range,and the temperature uniformity meets the design requirements.