Optimization And Simulation Of CNC Machining Process For Aluminum Flywheel Housing

The flywheel housing is an important connecting part between the automobile engine and the transmission.It is a porous thin-walled structure part made of cast aluminum or cast iron and the tolerance of key dimensions is higher.In recent years,CNC technology has been widely used as the main method of machining flywheel housing for its higher precision,efficiency and flexibility,which has replaced conventional machining technologies.However,there are still many unreasonable points in the existing CNC machining process,such as hole processing distortion,chip winding tool and flutter of the milling face,which seriously affect the product quality and production efficiency.Through analyzing the existing CNC machining process,it is found that the tools and the cutting parameters for boring 058 casting hole and Φ88.7 hole,reaming Φ18.02 hole,the material of taps,and the tool paths of milling cylinder mating surface and the side of flywheel housing are unreasonable,which is the key factor of affecting the machining quality and efficiency of the flywheel housing.By comparing the characteristics of PCD,carbide and high-speed steel,the material of the boring tools,reamers and taps are determined.The boring tools and reamers are designed,both the tool geometry angles and the structure and number of inserts are determined.A dynamic model of the surface milling system is established.An on-site hammering test for the milling process of the cylinder mating surface and side is carried out.The system flutter stability field is calculated by using CUTPRO cutting dynamics test software,and the spindle speed,feed speed and cutting depth without chatter vibration are obtained to provide reference for selecting the cutting parameters of the facing cutter.Based on the tools optimization on material and structure,the cutting parameters of each tool are determined to meet the requirements of surface roughness,precision and chip breaking,also considering the actual machine tool feature and performance and dynamic testing results.The optimum cutting-in angle and position are obtained for milling the cylinder joint surface and side according to the judgment condition of cutting approach,and the optimum tool path is proposed.The machining processes before and after optimization are simulated by using VERICUT software to show that the optimized machining cycle is decreased by 23.7s than the original machining cycle 381.3s.Finally,the machining process optimization is verified to be reasonable and flexible through a series of machining experiments.