Dynamic Research Of Valve Tram In Diesel Engine

Valve train is important mechanism in indisel engine.The performance of thevalve train affects the economic, power, and wear performance of the engine. Thedynamic analysis of the valve train is one of the most important research directions inthe field of internal combustion engine. While the engine performance requirementscontinue to rise, valve train dynamic analysis is of great significance.With the camshaft valve train mounted under an internal combustion engine asthe study object, the paper carried out the dynamics simulation analysis of the valvetrain. In order to analyze the dynamic performance of the valve train from multipleangles, firstly,we established a traditional valve train of single-and multi-mass modeland analysised.Secondly, based on the multi-body system dynamics theory, multi-rigi-d-body dynamics of valve train, flexible-body dynamics model of a singlecomponent and flexible multi-body dynamics model were established.Based on thedynamic simulation analysis of the three models,we can know valve displacement,velocity is almost the same, while the other dynamic properties of valve-train hascertain difference from the obtained valve-train curve of dynamic characteristics,which provides a theoretical basis for future optimization design of valve train.Finally,studied the influence of the change of cam shaft speed, valve springstiffness size, whether applied pressure of gas explosion on dynamic characteristicsof the valve mechanism.We got valve fly off and component rebound phenomenon insome cases,from the valve traim curves of simulation results of different camshaftspeed;we found changing the valve spring stiffness between the valve components ofthe contact force is relatively large, while it almost has no effect for the valveseating velocity.Applied gas explosion pressure for the valve train,each componentdynamics performance change is not too large while it impact the force of valvetrain.The results of this study have wide application prospect and great practical valuefor practical engineering, which provides a reliable basis for the subsequentvalve-train system optimization and independent development of valve-train.