This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Engine Valve Train Dynamic Analysis using 1-D Simulation Approach
ISSN: 0148-7191, e-ISSN: 2688-3627
To be published on November 21, 2019 by SAE International in United States
Event: NuGen Summit
In order to reduce engine development timing and cost, a numerical calculation used to evaluate valve train systems. This paper discusses the work done on kinematic and dynamic analysis of Valve Train (VT) system of a diesel engine by using 1-D Ricardo Valdyn software. The goal is to meet optimum intake, exhaust valve timing requirement, maximize valve open area and 20% overspeed requirement. Valve train model is prepared and inputs like mass and stiffness are estimated from actual weighing and finite element approach respectively. Simulation model is used for predicting valve bounce speed, valve displacement, cam-follower contact stress and strain in the rocker arm. Initially, Kinematic analysis is carried out to study the change in valve motion characteristics such as cam contour radius, tappet contact eccentricity etc. Further to this, dynamic analysis is carried out to assess forces and stresses on valve train components. Effect of cam tappet contact stresses, buckling load on push rod, spring surge, ratio of spring force to inertia force, valve seating velocity at increased speed condition etc. are discussed in detail. The optimized cam profile and ramp have improved overall valve dynamics in terms of valve seating velocity and valve seating force. The dynamic vibration described in this paper has been fully validated by measurement.