The Structure Design Study Of Titanium Alloy Lightweight Piston

With the continuous improvement of velocity,compression ratio and power of the diesel,the heat load increasing,the thermal load of the heated parts in cylinder,especially that of the piston,has increased significantly.This leads to frequent high temperature failures of the piston.This paper aiming at design lightweight piston,high strengthened diesel engine piston,using Titanium Alloy material and proposing new type of piston structure to reduce the piston weight.From the perspective of the piston material,Aluminum Alloy has basically lost its carrying capacity under the high strengthen degree of the engine and thus cannot meet the reliability requirements of the piston.Therefore,adopt Titanium instead of Aluminum considering Titanium Alloy has properties like low density,high strength,tough corrosion,tough high temperature.And the piston has short skirt,two ring groove,low compression height,the cooling oil cavity.In order to do the analysis of the piston’s temperature,stress and strain state,this paper use Ricardo-Wave to performance simulation analysis and get the initial boundary conditions.Then the piston temperature and stress fields were gained which can lead the piston design to meet the standard,as well as cooling system.Owing to the short piston skirt,the movement,fray,oriented can be different.To solve this problem,this paper study cylinder gap to ensure it won’t be too big to tap the cylinder or too small to be stuck.Finally,list the machining program and crafts process according to the structure,manufacturing the new piston.Based on the research above,new piston was designed and produced.The results indicated that the new piston had a better high-temperature strength and fatigue resistance characteristics.Meanwhile,the reliability was greatly improved.