Week 10 - Challenge 3 - Door Trim Lower with Engineering Features

AIM

To create a Door Trim Lower Plastic Component through a given Class A Surface, create the Heat Stakes, Locators considering design rules and perform Draft Analysis on the final plastic component.

OBJECTIVE

• To make sure that the model meets the requirements of the draft angle.
• To create the Tooling axis using bisecting method / suitable axis.
• To perform Draft analysis on the given Class A Surface.
• To create the required Class B and Class C surfaces.
• To obtain a solid body from the surface using Close Surface feature.
• To create the Heat stakes, Locators, considering design rules.
• To perform draft analysis on final plastic component.

CLASS A SURFACE

• Class ‘A’ surfaces are primarily used in the automotive environment and refer to those surfaces which are visible in a product. In other words: A - class surfaces are those aesthetic/free-form surfaces, which are visible to us (interior/exterior), and have an optimal aesthetic shape and high surface quality.
• The surfaces or regions which are visible nowadays are considered for Class-A modelling. It is one of the reasons why the importance of Class-A modelling is increasing day by day. Majority of the time this term is used in Plastic Part designs.

CLASS B SURFACE

• The Class B surface is created from the Class A surface, keeping the thickness of the component in check.
• The Class B surface resembles an offsetted surface from the Class A.

CLASS C SURFACE

• The Class C surface is used to bind the Class A and Class B surface together in order to form a closed surface.

PROCEDURE

Creating Tool Axis

• Initially the given Class-A surface was imported and checked for any discrepancies in the boundary and performed draft analysis on it at 3-degree draft.
• The ejection from the mould after manufacturing the interior trim must have the nominal 3-degree draft angle.
• The Y direction is suitable for creating the tooling axis because in the Y direction most of the surfaces are clearing while performing draft analysis.
• The base surface of the class-A was extracted to create a reference point on the surface using the point, create a line in the Y-direction.
• Generally tooling axis is created using above-described method, Bisecting method but here centre of gravity method is taken and A line normal to that point is created in the y direction and considered the tooling axis.

Creating Class B surface

• First offsetting entire class A surface to 3mm in the inward direction as 3mm is thickness of component.
• Some of errors were created in the offsetted surface like incomplete surfaces, gaps, small patches.

• These errors were solved by extracting surfaces, join by sub-elements to remove, extrapolating, sweep, multi-section surfaces etc commands.
• Joining patched surface to main surface, Class B surface was created.

Creating Class C surface

• We first extract the edges from the Class A surface with the help of the multi extract command which we create the path for a sweep for class C.
• Create a sweep with reference to the curve and the reference surface with a 90-degree angle and with draft direction where ever required and give the inside direction Check for the continuity of the surfaces if there is any gap go for extrapolated and trim all together now, we will get the class C surface.

• Joining class-A surface and class-C surfaces together.

Creating Solid Body

• Later, Joined Class A & Class C surface is trimmed with Class B surface to form the Door trim lower surface.

• Using the surface created, the solid plastic component was obtained using the Close surface feature present in the part workbench.

• The Tooling axis, Class A, B and C surfaces were published.

Engineering Features HEAT STAKES and LOCATORS

HEAT STAKES

Heat Staking is a pulsed-heat process to join two or more parts out of which one at least is made of plastic. The process is to deform the plastic material using heat and force at a set process time. The bond is made by partially de-forming the plastic part in order to fix the other. Heat Staking makes it easy to bond metal to plastic and is commonly used in high volume/low-cost applications such as automotive, IT and consumer appliances.

LOCATORS

Any workpiece has 12 degrees of freedom for movement in space that consists of 6 Axial and 6 Radial Degrees of Freedom. All 12 degrees of freedom must be restricted to ensure proper referencing of a workpiece. These 6 Axial Degrees of Freedom permit Straight-Line Movement in both directions along the 3-principal axis shown as X, Y & Z. The Radial Degrees of Freedom permit Rotational Movement, in both Clockwise & Counter clockwise radial directions around the same three axis.

2-Way Locator

These are the locators which arrests 2 degrees of freedom by a single rib.

4-Way Locator

These are the locators which arrests the 4 degrees of freedom by four ribs junctional together. These are of following type especially used for mould designs.

DRAFT ANALYSIS

• First, we should change model into material mode.
• Go to insert and in analysis select feature draft analysis.
• Align the compass along tooling axis and lock it.
• Next click on the surface and see that the surface is within the permissible limit of the values.
• The green colour area shows that it satisfies the 3-degree draft angle. If not satisfied then by using the Running point tool the area is measured and then altered to get a successful draft for the created tooling direction.

On given Class A surface

On obtained PART BODY

CONCLUSION

• The creation of Tooling axis and Draft analysis were performed.
• The solid component was created from the surface geometry.
• Engineering Features like Heat stakes and Locators were created as per design rules.
• The necessary screenshots and files were attached.
• The Class A, B, & C surfaces and also the Tooling Direction have been Published.