Four Casting Gates Of Float Type Low Pressure Casting For 4K Engine Head Research On Process Application

Aerospace Mitsubishi 4K series engine is independently developed by Shenyang Aerospace Mitsubishi Motors Engine Manufacturing Co.,Ltd,which has superior performance and good market prospect.However,the prototype was found to have water jacket leakage.In order to solve this problem,this paper studies the low pressure casting technology of four gate float type.In this paper,the feasibility of the four gate scheme is proved by theoretical calculation,and the casting structure and cylinder head structure are optimized.the numerical simulation of filling and solidification process of four gate float type low pressure casting for 4K engine cylinder head was carried out.The results show that the whole filling process is stable without obvious turbulence,and the solidification process can be solidified from top to bottom.Through production verification,the shrinkage cavity of 4K series engine cylinder head bolt table produced by four gate float type low pressure casting process has been improved obviously.This shows that it is feasible to use four gate float type low pressure casting for 4K engine cylinder head.BP artificial neural network was used to study the parameters affecting the qualification rate of four gate float type low-pressure casting of 4K series engine cylinder head: pouring temperature of aluminum liquid,falling speed of float,solidification and pressure holding time.The qualification rate of casting was further improved by simulation optimization.It is predicted from 343 combinations that when the temperature of liquid aluminum is 668 ?,the falling speed of float is 23 S,and the holding time is 390 s,the predicted qualified rate of output castings is the highest,98.2%.According to the optimized parameters,the cylinder head of 4K engine is produced continuously for six months,the average qualified rate is 98.14%,which is close to the predicted result,and the purpose of optimizing the process plan is achieved.the casting properties of the four gate float type low-pressure casting cylinder head of 4K series engine were tested.The results show that the porosity,hardness,tensile strength and metallographic structure of the casting have no obvious changes,which meet the requirements.The engine bench test of 4K series engine four gate float type low-pressure casting cylinder head was carried out.By comparison,the performance indexes of the engine,such as the maximum output power,maximum torque,low-speed torque,high-speed fuel consumption and low-speed fuel consumption,met the design performance requirements.Through theoretical analysis,numerical simulation,neural network optimization,and experimental verification,this paper studies the four gates process of the float type low-pressure casting of the 4K engine cylinder head,which improves the qualification rate of the cylinder head from 50% to 98%.It is of great significance to save the manufacturing cost and reduce the material and energy consumption.