Tài liệu Valve Cam Mechanism docx

Valve Cam Mechanism




1
ME-430 INTRODUCTION TO COMPUTER AIDED DESIGN
Valve Cam Mechanism
Pro/ENGINEER Wildfire 3.0
Dr. Herli Surjanhata


There are 6 parts that will be used in this mechanism analysis:
• shaft_mount.prt — the ground body.
• camshaft.prt (rotating body)
• rocker.prt (oscillating body)

2
• valve_guide.prt (ground body)
• valve.prt (sliding body)
• rocker_shaft.prt (rotating body)

PART: SHAFT_MOUNT.PRT








3
PART: CAMSHAFT.PRT




4
PART: ROCKER.PRT




PART: ROCKER_SHAFT.PRT




5
PART: VALVE.PRT

6
PART: VALVE_GUIDE.PRT







7
CREATE AN ASSEMBLY – rocker_arm.asm



Create a new assembly called
rocker_arm.
Uncheck Use default
template.
The New File Options dialog
box appears.

8


Select System of Units of
mmns_asm_design.

Under Parameters, fill
DESCRIPTION and
MODEL BY with Rocker
Arm Assembly and your
name.
OK.




The assembly should
have default datum
planes – ASM_FRONT,
ASM_RIGHT, and
ASM_TOP.



9
Click to open rocker_shaft.prt

Select
to assemble the
rocker_shaft.prt
at default
location.


Click
to finish the assembly operation.

Click
and open rocker.prt,



Keep default setup for
assembly.



Apply the following constraints between rocker_shaft and rocker – see below.
• Align the axis of the rocker.prt with the axis of the of rocker_shaft.prt
Align constraint.


• Align OFFSET the FRONT datum plane of the rocker.prt with the
ASM_FRONT datum plane of the rocker_arm.asm assembly Align
constraint. The offset distance is 25 mm.

10


The result of the assembly is shown below.


Save the assembly. The rocker_arm.asm will be sub-assembly for total
valve_cam assembly.



11
CREATE AN ASSEMBLY – valve_cam.asm



Create a new assembly called
valve_cam.
Uncheck Use default
template.
The New File Options dialog
box appears.

12


Select System of Units of
mmns_asm_design.

Under Parameters, fill
DESCRIPTION and
MODEL BY with Valve
Cam Mechanism and
your name.
OK.




The assembly should
have default datum
planes – ASM_FRONT,
ASM_RIGHT, and
ASM_TOP.



13

Bring in the part
shaft_mount.prt
and select
to
assemble the
shaft_mount.prt
at default
location.






Click
to complete the
assembly.


In order to install rocker_arm.asm and valve_guide.prt datum planes will be
created.

First create a datum plane that is 25 mm offset from ASM_FRONT.



Select Datum Plane Tool
.

Pick ASM_FRONT datum plane.


14


Click OK and ADTM1 is created.

15
Create a new datum plane through the axis of top hole of the shaft_mount. This
datum plane should be parallel with ASM_TOP.




16
Create a datum plane through the axis of the top hole and make a 20° angle with
ADTM2 – see figure below.




17
Create a datum plane through the axis of the top hole and normal with ADTM3 –
see figure below.




18

Create a datum plane that is - 52 mm offset with ADTM3 – see figure below.




19
Create a datum plane that is - 31 mm offset with ADTM4 – see figure below.





20
Click to create an axis through intersection between ADTM6 and ADTM1 –
see figure below.



Create a pin connection between rocker arm and shaft mount.
Click
, and open rocker_arm.asm.



From the list,
select Pin for
creating a pin
connection.

21
Apply the following constraints in creating pin connection between rocker arm and
shaft mount– see figure below:
• Align the axis A_2 rocker_shaft of the rocker_arm.asm with the axis A_3
of the top hole of shaft_mount.prt as Axis alignment constraint.


• Align the ASM_FRONT datum plane of the rocker_arm.asm with the
FRONT datum plane of the shaft_mount.prt as Translation constraint.



Pick and pick the rocker_shaft.

Drag-rotate the rocker shaft.

22


Create a pin connection for the camshaft and shaft_mount.
Open camshaft.prt in the assembly.



From the list, select Pin for creating a
pin connection.

Apply the following constraints for pin connection between camshaft and
shaft_mount – see below.
• Align the axis A_5 of the camshaft.prt with the axis A_4 of the bottom hole
of shaft_mount.prt as Axis alignment constraint.


• Align the FRONT datum plane of the camshaft.prt with the ADTM1 datum
plane of the valve_cam.asm assembly as Translation constraint.

23



Pick and pick the camshaft.

Try to rotate the camshaft about the shaft_mount.



Open valve_guide.prt and assemble the valve_guide to the assembly with the
following constraints:
• Align the TOP datum plane of the valve_guide.prt with the inclined
ADTM5 datum plane of the assembly.


24


• Align the axis A_2 of the valve_guide.prt with the axis AA_1 created at

the intersection between ADTM1 and ADTM6.




Create a slider connection for the valve and valve_guide.
Open valve.prt in the assembly.