MBD Simulation on IC Engine Valve Train
AIM
The aim of this challenge to model the parts of the IC engine valve train ie; (the cam, Pushrod, Rocker arm, Valve, Valve mount) and to assemble them in the right way to do the motion analysis and fetch the required results in form of plots with the different cam lift given and also as simulations.
INTRODUCTION
Each and every part of the assembly is modeled as per the given dimensions and also the constrains to make those sketches to be fully defined on, after which they are bought to assembly and they are set up in a way that each and every part is its position with respect to the other, checking it by selecting move parts in which physical dynamics is used so that the simulation and the motion study works fine in order to the get the results as expected.
MODELING PROCESS:
Part 1 - Cam
To sketch this cam, the front plane is selected and the sketch of the cam is drawn with the given dimensions and constraints in order to make the sketch fully defined, and the sketch is extruded by using midplane extrude option. Now to create the cam with respect to the cam-lift given in the challenge the dimensions of either the larger circle or the smaller one are changed and also at times the distance between them is edited to achieve the needed cam-lift parameter.
https://drive.google.com/file/d/1t4fRWh0JcpvJb-qb3AVy-fvJs1fPMGkX/view?usp=sharing
Part 2 - Pushrod
The front plane is selected for sketching the push rod, the sketch is then revolved by revolve boss base option where one of the lines is selected as the revolving axis of the sketch.
https://drive.google.com/file/d/10UZEEXhWXs6LNFlVwWyrucXjSsC_s-Ec/view?usp=sharing
Part 3 - Rocker arm
For sketching the rocker arm there are few types of which we choose the arc's to complete the sketch of the rocker arm. Where there are few or more constraints given to each and every point, arc, and also, the line to make the sketch more appropriate looking like a rocker arm and the dimensions and other constraints are given to the sketch to make it a fully defined one after which few fillets are provided at the corner points, then the sketch is extruded by midplane extrude option.
https://drive.google.com/file/d/1NnfnHKpUzN78Oj7d9Lo9HvTUXbDp3oqq/view?usp=sharing
Part 4 - Valve
The valve is an important component of this assembly, the front face is selected to create the sketch of this valve where the dimensions and constraints are given accordingly and there are few values to take into account which is to be given during dimensioning so that the sketch looks as expected, then the sketch is selected and revolved by selecting the line from the same sketch as the revolving axis.
https://drive.google.com/file/d/1co3SEkxZv2P0fGOzt48Rl1VtYpTDnkWV/view?usp=sharing
Part 5 - Valve mount
This valve mount is the part where the valve body is mounted, to sketch it the front plane is chosen where the required sketch is created by adding few lines provided with its dimensions from the origin and other parts, then in order to revolve this sketch a construction line from the origin is created and during revolve boss base option, the construction line is selected as the axis of revolution.
https://drive.google.com/file/d/1lwXi7E_UdRog9HrEGv_P2xkFv2fy0Vbf/view?usp=sharing
ASSEMBLY PROCESS:
This assembly firstly the rocker arm is brought in to the assembly and it is being mated with the planes of the assembly since all other parts are in relation with the rocker arm this part is kept first and followed by the push rod which is made to mate with a specific relationship so that it in the left side of the rocker arm where the small box-shaped extrusion is there, and the next part is the cam and this cam is placed in such a way that the pushrod is in the intersection or at its contact, which is done by giving distance and coincidence mate with respective planes of assemblies, after which the valve and the valve mount are placed in the right-hand side of the rocker arm so that the motion is transferred from the rocker arm to the valve. In this way, the assembly is perfectly fine and made to be in position by using physical dynamics, and then the assembly is ready for motion analysis.
https://drive.google.com/file/d/1XYDoPfBtzlnlsH-HwKpZyKgOgVFjd4js/view?usp=sharing
*Note; I have tried changing the names to RAHUL_Engine_valve_train_part_name, but that did not work I am not sure why, even if it has changes the assembly is throwing up errors, so I have left the name as it is. So please do consider fro this challenge alone.
MOTION STUDY SETUP:
The term motion study is referred to as the study of the behavioral aspects of any mechanism or machinery with respect to the inputs given the inputs can vary with respect to project or part, and also the analysis of the output is done at the same time it can be got as a plot from the entities we provide or from the outputs generated.
Now let's go into the procedure to do the motion study setup, Here we are going to perform this motion study on the IC engine valve train assembly for which firstly the motion addon is selected from Solidworks add-in's and then in the bottom bar we go to new motion study and select the motion analysis from the dropdown, then we proceed on, firstly the RPM for the cam is seated to the given value by selecting the temp axis of the cam, then the contact is given to all other parts. Now a linear spring is added in between the two edges of the valve and the edge of the valve mount, and few specs of which are changed according to our need. Now its the end of motion analysis setup now we shall proceed with the results ie plots obtained.
PLOT CAM Lift 3.5 (mm)
Valve Lift
The above plot is obtained from the motion study of IC engine valve train assembly where after the simulation of the working the results are made to be a plot with given specifications ie
-Displacement/velocity/acceleration
-linear Displacement
-Magnitude
and so we get the above plot where the axis is defined as
Y-axis(Linear Displacement in mm), X-axis(Time in sec)
OBSERVATION AND RESULT
The plot obtained here is the measure of valve lift using the linear displacement of the Pushrod part from the assembly since we have given the cam lift of 3.5mm, the displacement of the pushrod is also more or less 3.5 mm which is clearly noted from the plot above, and what the inference says is that, since the displacement of the pushrod is smoothly in a linear direction the curve formed is nearly a one-way sinusoidal curve but which is inverse direction.
The above plot is obtained from the motion study of IC engine valve train assembly where after the simulation of the working the results are made to be a plot with given specifications ie
-Displacement/velocity/acceleration
-linear Displacement
-Magnitude
and so we get the above plot where the axis is defined as
Y-axis(Linear Displacement in mm), X-axis(Time in sec)
OBSERVATION AND RESULT
The plot obtained here is the measure of valve lift using the linear displacement of the Valve part from the assembly since we have given the cam lift of 3.5mm, the displacement of the valve should give more or less 3.5 mm which is clearly noted from the plot above it is not so that's because the geometry of the rocker arm and also the positioning of the rocker arm, and what the inference says is that, since the displacement of the Valve is smoothly in a linear direction the curve formed is nearly a one-way sinusoidal curve.
*NOTE; Since it is asked for valve lift I first chose the valve linear displacement but it didn't show up well and that's why I have come up with two solutions with respect to the lift.
The contact force between Cam and Push Rod
The above plot is obtained from the motion study of IC engine valve train assembly where after the simulation of the working the results are made to be a plot with given specifications ie
-Forces
-Contact Force
-Magnitude
and so we get the above plot where the axis is defined as
Y-axis(Reaction force in newton), X-axis(Time in sec)
OBSERVATION AND RESULT
From the above graph, it is inferred that the linear lines are the points where the push rod is in contact with the lower circular profile of the cam, and the smaller linear lines are same as for upper circular part of the cam, and there are few ups and downs in the graph ie the ups are the point of contact where the push rod is getting higher in displacement and downs are the contact period where the pushrod is sliding down the cam, but there's a high peak during the lower part that is because of the spring we have provided which gives the additional reaction force that causes this high peaks.
The contact force between Pushrod and Rocker Arm
The above plot is obtained from the motion study of IC engine valve train assembly where after the simulation of the working the results are made to be a plot with given specifications ie
-Forces
-Contact Force
-Magnitude
and so we get the above plot where the axis is defined as
Y-axis(Reaction force in newton), X-axis(Time in sec)
OBSERVATION AND RESULT
From the above graph, it is inferred that the linear lines are the points where the contact of the pushrod is with the lower circular profile of the cam, and the smaller linear lines are same as for upper circular part of the cam, and there are few ups and downs in the graph ie the ups are the point of contact where the push rod is getting higher in displacement with the rocker arm and downs are the contact period where the pushrod is sliding down the cam or the lowering of rocker arm with a pushrod, but there's a high peak during the lower part that is because of the spring we have provided which gives the additional reaction force that causes this high peaks.
The contact force between Rocker Arm and Valve
The above plot is obtained from the motion study of IC engine valve train assembly where after the simulation of the working the results are made to be a plot with given specifications ie
-Forces
-Contact Force
-Magnitude
and so we get the above plot where the axis is defined as
Y-axis(Reaction force in newton), X-axis(Time in sec)
OBSERVATION AND RESULT
The above plot is the contact force between the rocker arm and the valve where similar to other contact forces we have the linear lines which clearly says that their period of contact is with the circular profile with a cam which creates a smooth force transfer on these parts, and there are also similar peaks and drops which are again the displacement of the valve and rocker arm but during the drop, there's a high peak point caused due to the reaction force provided by the linear spring added by us.
The contact force between Rocker Arm and Valve in X-Direction
The above plot is obtained from the motion study of IC engine valve train assembly where after the simulation of the working the results are made to be a plot with given specifications ie
-Forces
-Contact Force
-X component
and so we get the above plot where the axis is defined as
Y-axis(Reaction force in newton), X-axis(Time in sec)
OBSERVATION AND RESULT
The above plot is made in order to create a comparison between the normal magnitude contact force between the rocker arm and valve and go the x-directional contact force between the rocker arm and the valve.
So from the above plot, it is clear that there are linear lines, similar ups, and downs shown by the magnitude plot but the difference here is the appearance of the plot this plot is moving from positive value to negative value which is because of the measure of force in the one-directional component, where here is X direction.
PLOT CAM Lift 6 (mm)
Valve Lift
The above plot is obtained from the motion study of IC engine valve train assembly where after the simulation of the working the results are made to be a plot with given specifications ie
-Displacement/velocity/acceleration
-linear Displacement
-Magnitude
and so we get the above plot where the axis is defined as
Y-axis(Linear Displacement in mm), X-axis(Time in sec)
OBSERVATION AND RESULT
The plot obtained here is the measure of valve lift using the linear displacement of the Pushrod part from the assembly since we have given the cam lift of 6 mm, the displacement the pushrod is also more or less 6 mm which is clearly noted from the plot above, and what the inference says is that, since the displacement of the pushrod is smoothly in a linear direction the curve formed is nearly a one-way sinusoidal curve but which is inverse direction.
The above plot is obtained from the motion study of IC engine valve train assembly where after the simulation of the working the results are made to be a plot with given specifications ie
-Displacement/velocity/acceleration
-linear Displacement
-Magnitude
and so we get the above plot where the axis is defined as
Y-axis(Linear Displacement in mm), X-axis(Time in sec)
OBSERVATION AND RESULT
The plot obtained here is the measure of valve lift using the linear displacement of the Valve part from the assembly since we have given the cam lift of 6 mm, the displacement of the valve should give more or less 6 mm which is clearly noted from the plot above it is not so that's because the geometry of the rocker arm and also the positioning of the rocker arm, and what the inference says is that, since the displacement of the Valve is smoothly in a linear direction the curve formed is nearly a one-way sinusoidal curve.
*NOTE; Since it is asked for valve lift I first chose the valve linear displacement but it didn't show up well and that's why I have come up with two solutions with respect to the lift.
The contact force between Cam and Push Rod
The above plot is obtained from the motion study of IC engine valve train assembly where after the simulation of the working the results are made to be a plot with given specifications ie
-Forces
-Contact Force
-Magnitude
and so we get the above plot where the axis is defined as
Y-axis(Reaction force in newton), X-axis(Time in sec)
OBSERVATION AND RESULT
From the above graph, it is inferred that the linear lines are the points where the push rod is in contact with the lower circular profile of the cam, and the smaller linear lines are same as for upper circular part of the cam, and there are few ups and downs in the graph ie the ups are the point of contact where the push rod is getting higher in displacement and downs are the contact period where the pushrod is sliding down the cam, but there's a high peak during the lower part that is because of the spring we have provided which gives the additional reaction force that causes this high peaks.
The contact force between Pushrod and Rocker Arm
The above plot is obtained from the motion study of IC engine valve train assembly where after the simulation of the working the results are made to be a plot with given specifications ie
-Forces
-Contact Force
-Magnitude
and so we get the above plot where the axis is defined as
Y-axis(Reaction force in newton), X-axis(Time in sec)
OBSERVATION AND RESULT
From the above graph, it is inferred that the linear lines are the points where the contact of the pushrod is with the lower circular profile of the cam, and the smaller linear lines are same as for upper circular part of the cam, and there are few ups and downs in the graph ie the ups are the point of contact where the push rod is getting higher in displacement with the rocker arm and downs are the contact period where the pushrod is sliding down the cam or the lowering of rocker arm with a pushrod, but there's a high peak during the lower part that is because of the spring we have provided which gives the additional reaction force that causes this high peaks.
The contact force between Rocker Arm and Valve
The above plot is obtained from the motion study of IC engine valve train assembly where after the simulation of the working the results are made to be a plot with given specifications ie
-Forces
-Contact Force
-Magnitude
and so we get the above plot where the axis is defined as
Y-axis(Reaction force in newton), X-axis(Time in sec)
OBSERVATION AND RESULT
The above plot is the contact force between the rocker arm and the valve where similar to other contact forces we have the linear lines which clearly says that their period of contact is with the circular profile with a cam which creates a smooth force transfer on these parts, and there are also similar peaks and drops which are again the displacement of the valve and rocker arm but during the drop, there's a high peak point caused due to the reaction force provided by the linear spring added by us.
The contact force between Rocker Arm and Valve in X-Direction
The above plot is obtained from the motion study of IC engine valve train assembly where after the simulation of the working the results are made to be a plot with given specifications ie
-Forces
-Contact Force
-X component
and so we get the above plot where the axis is defined as
Y-axis(Reaction force in newton), X-axis(Time in sec)
OBSERVATION AND RESULT
The above plot is made in order to create a comparison between the normal magnitude contact force between the rocker arm and valve and go the x-directional contact force between the rocker arm and the valve.
So from the above plot, it is clear that there are linear lines, similar ups, and downs shown by the magnitude plot but the difference here is the appearance of the plot this plot is moving from positive value to negative value which is because of the measure of force in the one-directional component, where here is X direction.