MBD Simulation on IC Engine Valve Train
Aim:- To model & do motion analysis of IC engine valve train.
Theory:-
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A valve train is a mechanical system that controls operation of the intake and exhaust valves in an internal combustion engine.The intake valves control the flow of air/fuel mixturebinto the combustion chamber, while the exhaust valves control the flow of spent exhaust gasses out of the combusion chamber once combustion is completed. The valvetrain consists of all the components responsible for transferring the rotational movement of the camshaft into the opening and closing of the intake and exhaust valves. Typical components are listed below in order from the crankshaft to the valves.
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Models:-
Cam Pushrod Rocker arm Valve Valve mount
Assembeled model:-
With cam lift of 3.5mm With cam lift of 6mm
Motion Analysis:-
- First the rotary motor is set at the axis of base circle of cam and rpm of 1500 is set.
- Then the solid body contacts are given and material is selected.
- Then the motion analysis is calculated and required plots are obtained.
Case 1:- Cam lift of 3.5mm, Speed (1500), Material- Cast carbon Steel.
- Linear displacement of Valve / Valve lift.
- The contact force between Cam and Pushrod.
- The contact force between Pushrod and Rocker arm.
- The contact force between Rocker arm and Valve.
Case 2:- Cam lift of 6mm, Speed (1500), Material- Cast carbon Steel.
- Linear displacement of Valve / Valve lift.
- The contact force between Cam and Pushrod.
- The contact force between Pushrod and Rocker arm.
- The contact force between Rocker arm and Valve.
Conclusion:-
Linear displacement of valve increases with the increase in lift of cam.
The contact force between the Rocker arm and Valve varies while measuring with respect to the X-direction and measuring with respect to magnitude. Because, the Rocker arm rotates about its axis hence, it develops force in all 3 directions so the value varies when measured with X-component & magnitude.
The X-component force is negative because of friction when it slides on valve head.
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