Analysis of gasoline engine failure by exhaust valve-piston collision and its optimization
MA Jingwei
CHANG Xuesong
YU Pengfei
WANG Chenxi
LIU Luping
WANG Jinlin
Abstract：In order to solve the export engine misfire fault caused by the collision of the exhaust valve with the piston during the operation of an engine,the chemical composition,metallographic structure,valve spring force,vehicle exhaust temperature,and driving habits of the valve guide and exhaust valve stem are analyzed,and the influence of the vehicle exhaust temperature and driving habits on the engine thermal load is determined.The cause of the fault is that the engine is prone to intense working conditions such as sudden acceleration and deceleration during operation,which lasts for a long time.The thermal load of the valve guide is increased,and the clearance of the valve guide is decreased,causing the valve to jam and impact the piston,resulting in engine misfire.The optimization is carried out by increasing the wrapping area of the valve guide.The simulation results show that the maximum temperature of the optimized guide is decreased from 245.3 ℃ to 208.5 ℃,and the maximum contraction of the valve guide is decreased from 0.026 1 mm to 0.014 3 mm.At the same time,the lower end diameter of the valve guide is reduced from 5.948 mm to 5.943 mm.A 300 hour rapid acceleration and deceleration test is conducted on the optimized engine,and no valve impact piston failure occurs,indicating normal engine operation.
Keywords：gasoline engineexhaust valveheat loadvalve guidepiston
Publication Date：2025-03-30
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：6( 73-77,85 )