Research On Optimization Design Of Die Closing Mechanism For Horizontal Cold Chamber Die Casting Machine

The large complex light alloy structural parts widely used in today’s manufacturing industry are mainly made by pressure casting process.The horizontal cold chamber die casting machine,as the main equipment of the current die casting process,has a sophisticated structure.Mold clamping mechanism is one of the key components of die casting machine,its stability and accuracy directly affect the dimensional accuracy and material density of die casting,its die closing speed and stroke ratio and other factors will directly affect the efficiency and productivity of die casting,this paper takes the DM3000 horizontal cold chamber die casting machine of Guangdong Yizhi Precision Machinery Co.,LTD as the research object.The virtual prototype,finite element analysis and other modern design analysis techniques are used to systematically study and optimize the design of its mold closing mechanism.The main types and working principles of mold clamping mechanism are summarized in detail.Through the analysis of kinematics and mechanics characteristics of mold clamping mechanism,the key parameters such as stroke ratio,speed ratio and force-increase ratio of the mold clamping mechanism and their relationships are calculated.The size of the component was selected as the design variable,the constraint conditions were established,the appropriate force increase ratio and stroke ratio were selected as the objective function,and the impact of each design variable on the clamping force was analyzed.ADAMS was used to optimize the design of the mold clamping mechanism,and the strategy of reducing the stroke ratio in exchange for increasing the corresponding force increase ratio was adopted.In addition to increasing force increase ratio,the clamping force is improved.This paper summarizes the theory and application of modal analysis and introduces the method of modal analysis.Based on the theoretical basis of the finite element modal analysis technology,the modal frequency and modal shape of the assembly of the mold clamping mechanism were calculated and analyzed to determine the vibration characteristics of the structure,and then the sensitive parts and weak areas of vibration resistance were identified.Aiming at the problems of heavy weight and high manufacturing cost of moldboard in die casting machine mold clamping mechanism,lightweight design of die casting machine mold clamping mechanism was carried out in combination with practical engineering application.The topology optimization design method based on variable density method is introduced,and the relevant control parameters suitable for the lightweight design of die casting machine moldboard were determined.The optimal design of the static moldboard,the clamping moldboard and the dynamic moldboard of the mold clamping mechanism was carried out by the method of combining topology optimization and size optimization,which effectively reduced the quality of the whole machine.The energy consumption of the mechanism in actual operation is reduced.Compared with the formwork structure before optimization,the total weight of the three moldboards is reduced from 74.68 tons to 66.35 tons,with a weight reduction rate of11.5%,and the stress distribution is more uniform.