Aim: This project aims to create a switch bezel plastic component using the given class A surface following the OEM standard.

Class A-surface

Objective:

• Ensure Proper Tree Structure.
• Geometrical sets should have a proper name based on the sketches present inside them.
• All the sketches should be created under the Geometrical set.
• Use the Close Surface feature to make a solid body from the surface.
• To publish the Tooling Axis, Class A, B, and C surface.

Introduction:

CLASS-A SURFACE: the class-A surface is used in the automotive design industry. it describes the final production surface data for the aesthetic parts.

CLASS-B SURFACE: the class-B surface is the second surface that has a certain thickness from the class-A surface. this surface contains engineering aspects of a model. These must be smooth and "error-free" as well but are not held to the standards that class A surfaces are.

CLASS-C SURFACE: The Class C finish allows more imperfections than Class A or B. Class C is often specified for interior surfaces not readily visible, surfaces that will be covered by another part when assembled, or surfaces.

Design methodology:

Insert the class A surface of the switch bezel in CATIA software.

Determining the tooling axis for the switch bezel

Creation of class B surface.

Creation of class c surface.

Join the switch bezel's class A, class B, and class c surfaces and ensure all the surfaces are closed surfaces.

Use the Close Surface feature to make a solid body from the surface.

finally, Perform the Draft analysis on the switch bezel final plastic component.

Creating tooling axis:

The ejection from the mold after manufacturing the interior trim must have the nominal 3-degree draft angle.

hence the tooling directions created by considering the above factor and bisecting method is used.

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 z-direction and an axis system was inserted to the point

then using projection intersection along the yz plane is created and the two inclined lines were drawn inside the positioned sketch.

then bisecting lines with the two inclined lines were created.

DRAFT ANALYSIS ON CLASS-A SURFACE:

• Go to insert> analysis> feature draft analysis
• Align the tooling axis with the compass.
• Click on the surface and see that the surface is within the permissible limit of the draft values.
• The surface should be green and in the column nominal value 3deg given as input. hence the draft analysis on the class-A surface is successfully performed.

CLASS-B SURFACE CREATION:

• For creating the class-B surface the required surface except the offset surface have been extracted and then untrimmed all the surface.
• Then all the surfaces have been extrapolated to get intersections between them.
• Since the thickness of the Switch bezel is 2.5mm the B-Surface was offset to 2.5 mm and the required trim operations must be carried out.
• Finally, the required corners have been filleted to 12.5mm (15mm-2.5mm). [ 15mm - fillet value of the A-surface, 2.5mm – Thickness of the component ]

B SURFACE

CLASS-C SURFACE CREATION:

• The required outer edges of the A-Surface were extracted using Boundary. Then for avoiding the patches the curve is smoothened using the Curve Smooth option.
• Then by using the sweep command the surface was created with the following feature controls,

1. Profile type – Line
2. Subtype – With Draft Direction
3. Guide Curve – Smooth Curve
4. Draft Direction – Tooling Axis
5. Draft Computation Mode – Square
6. Angle – 3 Degree
7. Angle Sector – Positive Downward (1)
8. Length – 20mm

• Then by using extrapolate command the edges were intersected between the surface corners which eases the trimming operation.
• Now the required portion of the C – surface were trimmed out.

CONCLUSION

Finally the Class – A, B&C surfaces with the Tooling Direction have been Published and the Switch Bezel is moved on to the designing of the next operation – the creation of B-side features.