MBD Simulation on IC Engine Valve Train
Aim : To study the multi body dynamics of IC engine valve train
Introduction :
We shall be discussing the various components of IC engine valve train and its multi body dynamics
It is a mechanism that controls the movement of intake and exhaust valve of IC engine.
CAM : It controls the opening and closing of valves. The motion is further transferred to the pushrod.
PUSHROD : It is a column member in this assembly. Its one end is connected to cam and other end is connected to the rocker arm
ROCKER ARM : The valves are actuated by the rocker arm and the motion is further transmitted to the valve
VALVE : The function of valves is to control the flow rate of air fuel mixture in the cylinder as well as flue gases outside the cylinder
VALVE MOUNT : Its functions to maintain the reciprocating motion of the valves
BASIC WORKING OF IC ENGINE VALVE TRAIN
First of all I coupled the constant speed 1500rpm motor to the cam ,due to this cam rotates on its axis. This motion is further transferred to the push rod,which is connected to the cam .This motion is transmitted to the rocker arm and then further to the valve which is mounted on the valve mount.
MOTION STUDY
I assembled all the parts in a proper manner . After that along with providing material I provided contacts between all the adjacent parts . I selected CAST CARBON STEEL as the material for all the components. Then I provided the spring of free length 45 mm and stiffness 15 N/mm on the valve.
Then I calculated the results and plotted the required graphs.
Animation
After calculating the results I ran the motion study at 0.1x speed . I felt too quick so changed the speed to 0.06x and for more clear understanding of the linear displacement of the push rod I changed the frames per second parameter to 7200 fps and then rerun the simulation .
Graphs
I plotted the results on a graph of linear displacement versus time of the pushrod for magnitude as well linear displacement in X direction
For magnitude graph I observed pattern similar to sinusoidal wave which is as shown in the attachment
For X direction graphs I observed straight line as their was no displacement in the X direction, which is as shown in the attached file