Pro/Assembly

An assembly is a collection of parts oriented and positioned together. Creating an assembly involves telling Pro/E how the various components fit together. To do this, we specify assembly constraints. A component that is fully constrained in the assembly is called placed or assembled. Components in a movable assembly (a mechanism) are joined together by connections. This is a special type of constraint that allows motion along specific degrees of freedom. In the tutorial, we will create a four bar mechanism as shown in figure 1. The mechanism is an assembly composed of three components: PART1 (red), PART2 (green) and PART3 (yellow). First, we will place components using constraints and then connections.

Figure 1

A. Creating a Four-Bar Mechanism Using Constrains:

1. Placing the first part: a) Create a new assembly called Tutorial2a. Accept the default template.

b) Click or Insert > Component > Assemble. The Open dialog box opens.

c) Select part1.prt. The Component Placement dashboard appears as shown in figure 2.

Figure 2

d) Choose Default from the Constraint Type list to assemble the part at the default location. This defines part1 as the ground body as shown in figure 3.

Figure 3

e) Click .

2. Placing the second part: a) Click or Insert > Component > Assemble.

b) Choose part2.prt. The Component Placement dashboard appears.

c) Accept default Automatic from the Constraint.

d) Choose axis A-1 on part1.prt and A-1 on part2.prt to define axis alignment

e) Choose Surface F8 on part1 and surface F6 on part2 for alignment as shown in figure 4 and click .

Figure 4

f) Add one more constraint to make part2 perpendicular to part1 though the assembly is fully constraint. Open Placement panel and click on New Constraint. Pick 2 surfaces highlighted as shown in figure 5 for Align Angle Offset equal to zero as shown in figure 5.

Figure 5

3. Placing the second again as shown in figure 6 using the same instructions outlined

in 2.

Figure 6

4. Closing the Loop on the Four-Bar Mechanism

a) Click or Insert > Component > Assemble.

b) Choose part3.prt. The Component Placement dashboard appears.

c) Accept default Automatic from the Constraint.

d) Choose axis A-2 on part3 and A-1 on part2 to define axis alignment

e) Choose Surface F6 on part3 and surface F6 on part2 for mate as shown in figure 7 and click . The mechanism is fully constraint.

Figure 7

B. Assigning appearances to Components:

View Color and Appearance. The appearance Editor window will open as shown in figure 8. Pick red color and selection component part1 and click apply to change the color. Pick green for part2 and yellow for part3. The final mechanism is shown in figure 9.

Figure 8 Figure 9

C. Creating a Four-Bar Mechanism Using Joint Connections: 1. Placing the first part

a) Create a new assembly called Tutorial2b. Accept the default template.

b) Click or Insert > Component > Assemble. The Open dialog box opens.

c) Select part1.prt. The Component Placement dashboard appears.

d) Choose Default from the Constraint Type list to assemble the part at the default location. This defines part1 as the ground body.

e) Click .

2. Creating the first pin joint

a) Click or Insert > Component > Assemble.

b) Choose part2.prt. The Component Placement dashboard appears.

c) Choose Pin from the User Defined Connection Set list.

d) Choose axis A-1 on part1.prt and A-1 on part2.prt to define axis alignment

e) Choose Surface F8 on part1 and surface F6 on part2 for translation as shown in figure 10 and click .

Figure 10

3. Creating the Second Pin Connection

a) Click or Insert > Component > Assemble and choose part2.prt again. The Component Placement dashboard appears.

b) Choose Pin from the User defined Connection Set list.

c) Choose axis A-2 on part1.prt and A-1 on part2.prt to define axis alignment

d) Choose Surface F8 on part1 and surface F6 on part2 for translation as shown in figure 11 and click .

Figure 11

4. Closing the Loop on the Four-bar Mechanism

a) Click or Insert > Component > Assemble and choose part3.prt. The Component Placement dashboard box appears.

b) Choose Pin from the User Defined Connection Set list. Select axis A2 on part2.prt and axis A2 on part3.prt for Axis alignment.

c) Choose Surface F8 on part3 and surface F6 on part2 for translation

d) In the Placement slide-up panel, click New Set to add another pin connection. Select axis A2 on part2.prt and axis A1 on part3.prt for Axis alignment

e) Choose Surface F8 on part3 and surface F6 on part2 for translation as shown in figure 12 and click . The mechanism is fully connected.

f) Change components color using previous instruction outlined in B.

Figure 12

Pro/Mechanism Design

Mechanism design is used to define a mechanism, make it move, and analyze its motion. 1. Starting Mechanism design:

a) Start Pro/E and open tutorial2b.asm b) Click Applications > Mechanism. Mechanism Design begins.

2. Creating a Servo Motor: a) Click Mechanism > Servo Motors. The Servo Motors dialog box opens as

shown in figure 1.

Figure 1

b) Click New. The Servo Motor Definition dialog box opens as shown in figure 2.

Figure 2

c) On the Type tab, for the Driven Entity, select Motion Axis, and choose the pin joint connecting part1.prt to part2.prt (connection_2_axis_1) as shown in figure 3a.

d) On the Profile tab, change the Specification to Velocity as shown in figure 3b.

e) The Magnitude should be Constant. Enter the value 72 for A as shown in figure 3b.

Figure 3a Figure 3b

f) Select the Position check box and click . The plot shows that the servo motor will go through two full rotations in 10 seconds as shown in figure 4.

Figure 4

g) Click OK.

3. Creating and Running a Kinematic Analysis

a) Select Analysis > Mechanism Analysis or click . The Analysis Definition dialog box opens as shown in figure 5a.

Figure 5a Figure 5b

b) Under Type, select Kinematic. Accept the default name, AnalysisDefinition1.

c) On the Preferences tab, accept the default values.

d) On the Motors tab, be sure ServoMotor1 is listed. If it is not, click as shown in figure 5b.

e) Click Run. The progress of the analysis is shown at the bottom of the model window, and the model moves through the specified motion.

To view the analysis results in later sessions of Mechanism design, you must save them as a playback file.

4. Saving and Reviewing Results

a) Replay results. Select Analysis > Playback or click . The Playbacks dialog box opens as shown in figure 6a, click . The Animate dialog box opens as shown in figure 6b.

Figure 6a Figure 6b

b) Click to play or click Capture to save animation file as shown in figure 7.

Figure 7

c) On the Playbacks dialog box, click to save your results as a .pbk file. In the Save dialog box, accept the default name or change to another name. The default directory is the current working directory. You can also browse to find another directory to save your file. You can open the .pbk file in future sessions by

clicking and selecting the playback file. Click Close to quit.

d) Select Analysis > Measures or click . The Measure Results dialog box opens as shown in figure 8.

Figure 8 Figure 9

e) Click . The Measure Definition dialog box opens as shown in figure 9. Accept measure1 as the name.

f) Under Type, select Position.

g) Select a vertex on the part2 as shown in figure 10.

Figure 10

h) Select Y-component in the Component area, and accept the WCS for the Coordinate System. Under Evaluation Method, accept Each Time Step as shown in Figure 11.

Figure 11

i) Click OK.

j) On the Measure Results dialog box as shown in figure 12, select measure1 under Measures, and AnalysisDefinition1 under Result Set. (If you changed the result set name, select the appropriate name.) The Graph Type should be Measure vs. Time.

Figure 12 Figure 13

k) Click to see the plot of the measure. The plot should be a cosine curve as shown in figure 13.

l) Click to view animated simulation Tutorial2c.mpg

Pro_E Assembly4. Closing the Loop on the Four-Bar Mechanism3. Creating the Second Pin Connection4. Closing the Loop on the Four-bar Mechanism

ProE_Mechanism