The Dynamics Analysis About Two Institutions Of Single-cylinder Diesel Engine

The two mechanisms of the single cylinder diesel engine are piston rod mechanism and gas distribution mechanism, the dynamic performance of the mechanisms directly affects the overall performance of the diesel engine, and the movement of the piston, connecting rod, valve and other parts in the two mechanisms especially affects the work efficiency of the engine. At present, the research of dynamic analysis of the mechanisms is one of the hot areas in the internal combustion engine research.The main research object of the paper is the main components for the two mechanisms of a diesel engine. In order to obtain the dynamic knowledge of the mechanisms, theoretic dynamic calculations are carried out for the main components in the mechanisms, dynamic models are built for the piston rod mechanism and main components in the gas distribution mechanism, and then 3D modeling work is finished for the single cylinder diesel engine with Solidworks. At the same time, a multi-body dynamic model l in ADAMS is built and its parameters are adjusted. With the multi-body dynamic model, the following are also obtained such as curves of the piston displacement, velocity and acceleration at different speed, curves of the rod displacement, velocity and acceleration in space at different speed, movement law of the gas distribution valve at a rated speed and the vibration contact force between the cam mechanism, hydraulic lifter, rocker arm and valve.Finally, with the maximum acceleration of the piston and the rod obtained from the dynamic model analysis as the given conditions for the subsequent finite element analysis, a finite element analysis is done for the piston and the rod respectively, and a finite element analysis is also done for the rocker and the valve with the given conditions obtained from the force between the rocker and the valve in the multi-body dynamic analysis. Through a series of studies, acceleration values of each piston and connecting rod at different speed are found. The motion continuity is not good when the speed is lower in the piston mechanism, while at rated speed the motion continuity is better. Analysis of the displacement, velocity, acceleration value of the piston mechanism at rated speed shows that the value flying off and rebound does not occur, and indicates that the gas distribution mechanism is working normally. Through finite element analysis, the location and value of the greatest stress for the piston and valve are found and so are the valve and the rocker. Comparison with the safety value proves the reliability of these components at working state. The research method and content of this paper have high application value for the development of the engine, and can provide a theoretical basis for the optimization of the single cylinder mechanism.