Pro Engineer Mold Design

8/9/2019 Pro Engineer Mold Design

1/26

ASCENT - Center for Technical Knowledge

Pro/ENGINEER: Mold Design 61

Chapter 6 Mold Volumes from Parting

Surfaces

Objective This chapter introduces:

Mold Volumes Creating a Mold Volume from Parting Surfaces Classifying Mold Volumes Modifying Mold Volumes Splitting FailuresThe components that make up a mold are generated by creating moldvolumes that are then extracted to form the components. This chapter

teaches how to create the mold volumes. How to create the extractedfeature will be discussed later in the course.

Mold volumes are surface features and do not contain solid geometry.Mold volumes can include the core, cavity, sliders, lifters, inserts orany other component that are required to complete the mold. Anexample of a mold volume is shown in Figure 61.

Figure 61

Mold volumes can be either created by splitting the workpiece usingparting surfaces or using existing mold volume. In addition, you canalso create a volume directly without a parting surface. This directmethod will be discussed in the next chapter.
http://-/?-http://-/?-


2/26


62 Pro/ENGINEER: Mold Design

The following must exist in the model to create a mold volume using aparting surface:

Parting surface

Workpiece

Reference part

By default, Pro/ENGINEER creates two volumes; however, you cansplit the workpiece into one or two volumes if necessary. Figure 62shows a one-volume split.

Figure 62

Figure 63 shows a two-volume split.

Figure 63

One volume

Volumes

Reference

model
http://-/?-http://-/?-http://-/?-http://-/?-


3/26



6.1How to Split the Mold

When you use a parting surface to split a mold, the system begins byremoving the volumes of the reference part, or any gates, runners, orsprue from the workpiece. It then computes the volume of the

workpiece on each side of the surface and converts it into a volume.This creates a "vacuum" in the workpiece, which is filled with plasticduring the molding operation.

To create mold volumes using a parting surface, complete thefollowing steps:

1. Create the parting surface in the model. It must exist in themodel prior to splitting the mold volumes.

You can use the MOLD

VOUME menu to blankand shade volumes thatare created in the mold.Shading helps identify thecompleted volume andblanking can be used to

remove the volume fromthe display for clarity.

2. Click Mold Volume in the MOLD menu. The Split option is only

available if the Reference Model and Workpiece are not blankedfrom the display.

3. Click Split in the MOLD VOLUME menu. The SPLIT VOLUMEmenu appears as shown in Figure 64.

Figure 64

The SPLIT VOLUME menu options are described in Table 61.

Table 61

Option Description

Two Volume Splits the workpiece into two volumes.One Volume Splits the workpiece into only one volume.

All Wrkpcs Splits the workpieces. The geometry of all workpieces arejoined together and all reference parts are subtracted.

MoldVolume

Splits an existing volume.

Sel Comp Splits any part in the assembly.


4/26



4. Click Done in the SPLIT VOLUME menu. The Split dialog boxappears as shown in Figure 65.

Figure 65

5. Select the parting surface when prompted and select thebutton.

6. In some cases, the parting surface divides the mold into morethan two volumes. If so, you will be presented with an ISLANDLIST menu similar to that shown in Figure 66. All of the islandsare listed and must be assigned to either of the mold volumesbeing created. Selected islands are assigned to the first volumeand the remaining islands are included in the second volume.This is called classifying the mold volumes.

As you drag your cursor

over the island options, the

volume assigned to that

island highlights.

Figure 66

7. Select the button in the Split dialog box.

8. The first new volume is highlighted and you are prompted toenter name for the first volume. Enter a name and select the

button to create the volume. When prompted for the

name of the second volume, enter a name and select thebutton to create the second volume. A Refpart Cutout and twoSplit features are added to the model tree.


5/26



6.2Modifying Mold Volumes

To modify a mold volume, click Mold Volume > Modify and select thevolume to modify from the Selection Tools dialog box. The MOLD VOLmenu appears as shown in Figure 67.

Figure 67

The MOLD VOL menu options are described in Table 62.

Table 62

Option Description

Gather Creates a volume by selecting the mold assemblysurfaces.

Sketch Creates a volume by sketching.

RefPart Cutout Creates a reference part cutout in a selected volume.


6/26



Trim to Geom Trims the selected volume to a part, quilt, or plane.The volume shown in Figure 68 is trimmed to datumplane MOLD_FRONT.

Figure 68Round Creates rounds on selected mold volumes.

Offset Offsets the surfaces of a selected volume. You canoffset surfaces horizontally or tangentially.

Draft Drafts selected surfaces.

Draft Offset Creates an area offset with drafted surfaces. The

example in Figure 69 shows an offset area with 15

draft.

Figure 69

Option Description

Offset area with draft


7/26



Area Offset Offsets an area of a surface as shown in Figure 610.

Figure 610

ReplaceSurface

Replaces a volume surface up to a datum plane orquilt surface using the REPLACE SURFACE dialog

box, as shown in Figure 611.

Figure 611

Option Description

Offset area of a surface


8/26



6.3Splitting Failures

The most common causes of split failure include the following:

Gaps between the reference part and workpiece are not closed off

by a single parting quilt.

Mold components have different absolute accuracies.

A hole in reference part is not closed off by the parting surface.

The parting surface and volume do not intersect.

Irregular geometry in the intersecting curves.

Geometry checks in the model.

If a split fails to be created, select the Geom Option element in the

Split dialog box and select the button. The GEOM OPTION

menu appears as shown in Figure 612.

Figure 612

Be default, the MakeVolume option is usedwhen creating a split.

Select the Make Curves option and click Done/Return. This optionenables you to create intersection datum curves to investigate thecauses of the failure.
http://-/?-http://-/?-


9/26



Exercise 6a Football Stand

In this exercise, you will modify the workpiece part. You will createvolumes using the split feature, modify the parting surface, and shadethe volumes.

Goal After you complete this exercise, you will able to:

Redefine Workpiece Create Volumes Shade Volumes

Task 1: Open foot_mold manufacturing file.

1. Change the working directory to ch6 and ensure that all fileshave been erased from memory.

2. Open foot_mold.mfg. The model appears as shown inFigure 613.

Figure 613
http://-/?-http://-/?-


10/26



3. To display features in the model tree, select > TreeFilters. Select Features from the Model Tree Items dialog box

and select the button. The model tree appears as shownin Figure 614.

Figure 614

Task 2: Redefine the workpiece.

1. Select the FOOT_MOLD_WRK.PRT in the model tree and clickEdit Definition from the right-mouse button pop-up menu. TheAutomatic Workpiece dialog box appears.

2. Enter [6] for the overall dimension of the workpiece in the X- andY-directions, enter [2.1] for the +Z Cavity, and enter [0.5] for the-Z Core.

3. Select the button. The model appears as shown in

Figure 615.

Figure 615


11/26



Task 3: Create volumes.

1. Click Mold Volume > Split or select the button. The SPLITVOLUME menu appears.

2. Accept the defaults and click Done. The Split dialog box appearsand you are prompted to select the parting surface.

3. Select the parting surface shown in Figure 616 and select the

button.

Figure 616

Notice that the volumes are not created and the Troubleshooter dialogbox appears. The message for item 1 is:

Split feature has failed. Volume cannot be split due to a hole in theparting surface. The hole is highlighted in green. Redefine partingsurface to patch the hole.

4. Cancel the split operation and return to the MOLD menu.

5. Redefine the parting surface to intersect the workpiece.

6. Select the button. The SPLIT VOLUME menu appears.


Parting

surface
http://-/?-http://-/?-


12/26



8. Select the parting surface shown in Figure 617 and select the

button. The ISLAND LIST menu appears as shown inFigure 617. This enables you to assign the three separatevolumes in this model to either of the two split volumes.

Selected islands are

assigned to the firstvolume and islands thatare not selected areincluded in the second

volume.

Figure 617

9. Drag your cursor over the island options to highlight each island.10. Select the Island1 option and click Done Sel.

11. Select the button in the Split dialog box. The VolumeName dialog box appears as shown in Figure 618.

Notice the button

in the Volume Name dialogbox.

Figure 618

12. Enter [cavity] as the name and select the button.

13. The Volume Name dialog box reappears to name the second

volume. Enter [core] as the name and select the button.

The volumes appear as Split id # and Split id # in the model tree. Youcan use the Name option in the ASSEM SETUP menu to assign new

names for the features, or you can rename them directly in the modeltree.

14. Blank the reference part, workpiece, and parting surface.

15. Click Mold Volume > Shade. The Search Tool dialog boxappears as shown in Figure 619.
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-


13/26



Figure 619

16. Move CAVITY to the items selected area and close the dialogbox. The cavity volume appears as shown in Figure 620.
http://-/?-http://-/?-


14/26



Figure 620

17. Click Continue in the CntVolSel menu and select CORE usingthe Search Tool dialog box. The core volume appears as shownin Figure 621.

Figure 621

18. Click Done/Return in the MOLD VOLUME menu.

19. Unblank the reference part, workpiece, and parting surface.

20. Save the mold model and erase it from memory.
http://-/?-http://-/?-


15/26



Exercise 6b Scoop Model

In this exercise, you will modify the workpiece part. You will createvolumes using split feature, and shade the volumes.

Goal After you complete this exercise, you will able to:

Redefine workpiece Create Volumes Shade Volumes

Task 1: Open scoop_mold manufacturing file.

1. Open scoop_mold.mfg. The model appears as shown inFigure 622.

Figure 622

2. Display features in the model tree. The model tree appears asshown in Figure 623.

Figure 623


16/26



Task 2: Create volumes.

1. Click Mold Volume > Split or select the button. The SPLITVOLUME menu appears.


3. Select the button and select the button. From thelist of quilts that are returned in the items found section, selectMAIN_SURF, move it to the items selected area and close theSearch Tool dialog box.

4. Select the button in the Select dialog box. The volumescannot be created and the Troubleshooter dialog box appears.

5. Cancel the split operation and return to the MOLD menu. Themessage window reads, "Open geometry found in the results".

The Split feature has faileddue to problems in theintersection of partinggeometry with the moldvolume. Intersectioncurves are highlighted in

green, ends of gaps inintersection curves arehighlighted in red.

6. Select the Quit button from the FEAT FAILED menu.

7. Increase the workpiece dimension to [16] in Y-direction.


9. Accept the defaults and click Done.

10. The Split dialog box appears and you are prompted to select theparting surface.

11. Select MAIN_SURF and click Done Sel. The ISLAND LISTmenu appears.

Selected islands areassigned to the firstvolume and islands thatare not selected areincluded in the second

volume.

12. Drag your cursor over the island options to highlight each island.

13. Select the Island1 and Island3 options and click Done Sel.

14. Select the button in the Split dialog box. The VolumeName dialog box appears as shown in Figure 624.
http://-/?-http://-/?-


17/26



Figure 624

Notice the button

in the Volume Name dialog

box.

15. Enter [scoop_1] as the name and select the button.

16. The Volume Name dialog box reappears. Enter [scoop_2] as the

name and select the button.

The volumes appear as Split id # and Split id # in the model tree. Youcan use the Name option in the ASSEM SETUP menu to assign newnames for the features.


18. Click One Volume > Mold Volume > Done. The Split dialog boxand Search Tool dialog box appear.

19. Select SCOOP_1in the Search Tool dialog box. You areprompted to select the parting surface.

20. Select the button and select the button. Select

PART_SURF_1 in the Search Tool dialog box.

21. Select the button. The ISLAND LIST menu appears.

22. Drag your cursor over the island options to highlight each island.

23. Select the Island1 option and click Done Sel.

24. Select the button in the Split dialog box. The VolumeName dialog box appears.

25. Enter [scoop_3] as the name and select the button.


18/26



26. Shade each volume. They appear as shown in Figure 625.

Figure 625

27. Save the mold model and erase it from memory.
http://-/?-http://-/?-


19/26



Exercise 6c Outlet Strip Project

In this project, you will perform the following:

Perform a draft check on the outlet_strip part Apply a shrinkage ratio to all dimensions of the part Create the mold model, reference model, and parting

surface

Split the mold into two volumes

Task 1: Open outlet_strip.prt.

1. Open the outlet_strip.prt. The part appears as shown inFigure 626.

Figure 626
http://-/?-http://-/?-


20/26



Task 2: Perform a draft check on the model.

1. Perform a Draft Check on the model by clicking Analysis >Geometry > Draft. Select the top of the model and click Pickfrom list from the right mouse button pop-up menu. Click

SolidGeom and select .

2. Activate the Direction field in the References area of theDefinition tab on the Draft dialog box and select datum planeTOP as the pull direction.

3. Use the icons and angle value in the Draft Angle area to identifythe approximate draft angle of your model on different surfaces.

4. Select the draft features in the model tree and click Edit from theright mouse button pop-up menu. Determine the exact draftangles on drafted surfaces. Does this model have enough draft

to be molded?5. Add a shrinkage ratio value of [0.002] to all dimensions of the

model using the Shrinkage option in the PART SETUP menu.

Task 3: Create a manufacturing file.

1. Create a new manufacturing file to begin creating the mold forthis model. Name the file [OUTLET_MOLD].

2. Mate the bottom surface of the outlet_strip model to the

MAIN_PARTING_PLN datum plane. Align FRONT withMOLD_FRONT and RIGHT with MOLD_RIGHT. The modelappears as shown in Figure 627.
http://-/?-http://-/?-


21/26



Figure 627

By selecting the Same

Modeloption, you identifyyour reference model anddesign part as the samemodel. Any changes madeat the mold level takeseffect at the part level.

Task 4: Create a workpiece in the mold model.

1. Create the reference model using the Same Model option.

2. If you receive an absolute accuracy conflict, resolve it.

3. Change the mold direction using the Pull Direction option in theASSEM SETUP menu.

4. Create a rectangular workpiece using the Automatic Workpiecedialog box. Enter the rectangular dimensions shown inFigure 628.

Figure 628

5. Create a silhouette curve. The curve appears as shown inFigure 629. The reference model has been blanked for clarity.


22/26



Use Task 2 of exercise 5Bfor reference.

Figure 629

The Skirtoption is not

available in the SRF OPTSmenu unless allcomponents are displayed.

6. Create a skirt surface using the silhouette curve. Enter[OUTLET_PS] as the name of the skirt surface.

7. Click Shade in the PARTING SURF menu. The skirt surfaceappears as shown in Figure 630.

Use Task 4 of exercise 5Bfor reference.

Figure 630

Task 5: Split the model.

1. Split the mold into two volumes. Use OUTLET_PS as the partingsurface. Name the volumes [OUTLET_1] and [OUTLET_2].

2. Shade each volume. The volumes appear as shown inFigure 631.


23/26



Figure 631

3. Save the mold and erase all files from memory.

OUTLET_1OUTLET_2


24/26




25/26



Review Questions

Question 1 What is a mold volume?

Question 2 Does a mold volume contain solid geometry or surface geometry?

Question 3 How do you create a split?

Question 4 How do you specify which mold volume to assign a volume to if thereare more then two generated by the parting surface?

Question 5 Which option in the Split dialog box can be used to convert the moldvolume to curves to help resolve a split failure?

Question 6 Describe in a few short sentences the most common causes of splitfailure related to your work.


26/26


Pro Engineer Mold Design

Documents

Transcript of Pro Engineer Mold Design