Experimental analysis of maximum valve lift effects in cam-follower system for internal combustion engines

摘要

Designing valve lift of cam-follower system is very important for improving dynamic performance of internal combustion engines. Potential problems due to unwanted vibrations in high-speed engine are the follower jump, colliding surface of the valves, and seats which cause collide in a cam-follower system. The degree of collide depends on the valve lift value and valve closing velocity. Large forces and stresses are introduced when the cam and follower collide. This might cause early failure of the system due to unwanted vibration. The main purpose of present experimental study was to investigate and analyze the dynamic behavior of the cam-follower system for different valve lift values and operating speeds using time domain and frequency domain analysis technique. Two cases for maximum valve lift values of 8 and 10 mm were tested with corresponding operating speeds of 450, 930, 1440, 1950 and 2430 rpm. From the results, it was observed that the higher the operating speed, the higher amplitude values were obtained. Statistical analysis of obtained data showed that the 10 mm valve lift produced much more power than the 8 mm valve lift.