Consumo energético y emisión de CO2

Continue to work with your mdp_cup3 project.

NOTE In a few minutes you will retrieve the parting part as it is now. If you did not save at the end of the last activity, Save All now.

NOTE Please do not save after this, until instructed to do so! Step 1 Only if needed, a staged assembly for this activity is in:

.../ moldwizd/ cup3_2 /

Procedure to open the staged assembly, if needed:

 Verify that no parts are open.

 Verify that Application  MoldWizard is active.  Open mdp_cup3_top in .../moldwizd/cup3_2

Step 2 Patch holes in the conical face.

The following two steps are done to learn how the Patch Surface feature works. Don't worry about the geometry configuration. We will take care of some problems in a few minutes.

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 Select and confirm the outer face of the cup".

A Select Holes dialog appears. Detected holes are pre-selected.

 Choose OK in the Select Holes dialog.

In a second or two, patch sheets are created.

 Cancel the Select Face dialog and the Tools dialog.

How Does it Work?

The system extracts a sheet body, the same as you would obtain using the tool Enlarge Surface. This sheet is the parent for one or more patch sheets, one for each hole being patched.

Creating a patch skin over the holes is sufficient to allow MoldWizard to calculate core and cavity regions; however, simply patching the holes with the easiest method may not meet engineering design intent for useful tooling.

The holes through the conical faces are patched, but a volume of

material will be left in the core area that will not permit removal of the plastic.

This part requires sliders" or draws", movable pieces of the mold that form the holes during injection and are withdrawn before the product is ejected.

In the following steps you will revert to the previously saved parting body, and patch the two conical faces of the cup with solid bodies that can be incorporated into slides.

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Step 3 Reopen your parting part.

 Choose File → Close → Reopen Selected Parts.

À

Á

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 Select your mdp_cup3_parting part from the list box.  Enable Force reopen if modified.

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Step 4 Patch the hole through multiple faces using Edge Patch.

 Zoom in on the hole passing through the cone and bottom

faces, as shown in the figure below:

À

 Reopen the Tools dialog and choose Edge Patch.  Select edge À as shown in the figure.

 Use the controls in the Curve/Edge Selection dialog to guide

the system to selecting the edges shown in the figure until the loop is closed.

When the loop is closed, the system displays an Add or remove faces dialog. The status line reads Found 3 faces to patch up."

 Choose OK to accept the highlighted faces.  Cancel the Tools dialog.

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How Does it Work?

Internally, MoldWizard creates a linked face and a scale feature for every one of the selected faces. The linked faces point to the original product model, hence the same scale used for the

shrink part is applied to each linked face. These new features are bundled together in a feature set named patch_set.

The original part must be open for this process to work properly. Be careful about using edge patch in an assembly that was reopened from the disk. The original part is represented by its empty reference set, and will not be opened.

Creating linked bodies and updating of the original model with link information takes measurable time. In this part, the time is negligible; however, in larger parts the delay can be significant. A user default is provided to set a maximum number of features in the original part. Beyond this maximum, edge patch will use an alternative curve mesh approach for Edge Patch:

MW_ToolsPatchFeatureNum: 150

The linked faces are sewn into a single sheet. The sewn sheet is then trimmed to the edge loop selected for the patch.

If the patch can not succeed by the method described above, and the loop consists of a single curve, MoldWizard might create a PATCH_THRU_CURVE_MESH feature. This behavior may be turned on or off in the mold_defaults file by:

MW_PartingMeshSurf

Sometimes a PATCH_THRU_CURVE_MESH will be perfectly acceptable. At other times, you may wish to model a new sheet and use EXISTING SURFACE to complete the patch.

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NOTE Warning Message

The original product part is modified" by extracting sheets. If that part is read only, you will receive a message when you save all parts, informing you that although the overall operation was successful, one part failed to save.

It is not good practice to ignore warnings and error messages unless you are confident that you understand the situation and can deal with the consequences.

The set up instructions for your classroom request that all your parts are read / write; however, work situations will arise when the original part is read only. At many companies, original parts are read only to prevent accidental changes by any one user. It does not matter if modified original parts are not saved. You can dismiss and ignore warnings about original product models only.

 If necessary, dismiss the above warning by choosing OK.

NOTE If your classroom is set up properly, you will not see the above warning. If the warning does appear, please inform your instructor.

NOTE You will continue to use this project in the next activity. This concludes Activity 3-3.

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MoldWizard Tools Dialog (continued)