MBD Simulation on IC Engine Valve Train
IC Engine Valve train
Aim: To create an IC engine valve train and do motion analysis on it.
Objective:
- Create various parts of valve train.
- Assemble the parts created.
- Calculate the cam lift
- Study the motion analysis of the valve train at different cases.
- Study the plots obtained and explain it.
- Explain results.
Valve train is a mechanical system that controls operation of the intake and exhaust valves in an IC engine. The intake valves control the flow of air/fuel mixture (or air alone for direct-injected engines) into the combustion chamber, while the exhaust valves control the flow of spent exhaust gasses out of the combustion chamber once combustion is completed.
Here, the operation of a single valve from the valve train is studied.
Creating components of valve train
Cam
Push Rod
Valve
Rocker
Valve Stem
Assembling the components created
The study is done by applying the following conditions
|
Sr. No. |
Cam lift (mm) |
Speed (rpm) |
Material |
|
1. |
3.5 |
1500 |
Cast Carbon Steel |
|
2. |
6 |
1500 |
Cast Carbon Steel |
Formula to calculate the cam lift
Cam lift = (L-D1)+D2
Where, L = distance between the centers of two circles (mm)
D1 = diameter of the lower circle (mm)
D2 = diameter of the upper circle (mm)
Motion analysis:
Case 1:
Cam lift = (L-D1)+D5
3.5 = (L-25)+10
L = 18.5 mm
Plots obtained
Contact force between Cam and Push Rod
Contact force between Push Rod and Rocker
Contact force between Rocker and Valve (along X direction)
Contact force between Rocker and Valve (total magnitude)
Linear Displacement of valve
Case 2:
Cam lift = (L-D1)+D2
6 = (L-25)+10
L = 21mm
Plots obtained
Contact force between Cam and Push Rod
Contact force between Push Rod and Rocker
Contact force between Rocker and Valve (along X direction)
Contact force between Rocker and Valve (total magnitude)
Linear Displacement of valve
Results: As studied, there is not much difference in the respective contact forces of the two cam lifts taken for studying. The contact forces between the components in both the cases are nearby same. The difference present in the forces is very slight beacause the cam lift difference of both cases is small. If the difference between cam lifts is increased then the contact forces of bth cases posses more difference as compared to now.
G-Drive link to access the files attached
https://drive.google.com/drive/folders/1YtzPf_L5kqofGQImDsNcpXKn0mB3HLMt?usp=sharing
Animation video
Reference:
https://drive.google.com/file/d/1HYeX2n6wKf_phWrOLGxUlQeJPmaaww9x/view