Week 9 - Challenge 2 - Switch Bezel Design

DESIGN AND DRAFT ANALYSIS OF SWITCH BEZEL

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

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 OF 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

Now the same procedure is done along the xz plane but on xz plane, we only have one surface line so the center point is used to extrude a line along the z-direction and gave a measurement of 6 degrees. from the surface line.

Bisecting these two lines sketch1 and sketch2 the bisecting line is created and published as a tooling axis.

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.

CREATION OF CLASS B SURFACE:

For creating the class-B surface the required surface except the offset surface have been extracted and then untrimmed all the surfaces.

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.

To get the radius of fillets the filleted surface is extracted and untrimmed the surface and then the radius is measure

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] and 11.5mm (14mm-2.5mm) [ 14mm - fillet value of the A-surface, 2.5mm – Thickness of the component].

CREATION OF CLASS C SURFACE:

The required outer edges of the A-Surface were extracted using Multiple Extract. 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,

Profile type – Line

Subtype – With Draft Direction

Guide Curve – Smooth Curve

Draft Direction – Tooling Axis

Draft Computation Mode – Square

Angle – 3 Degree

Angle Sector – Positive Downward (1)

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 was trimmed out.

CREATION OF CLOSED SURFACE:

Now the class – A and Class- C surfaces were joined together by removing the gaps in-between them with the help of extrapolation (tangent continuity) and Trim surface.

Then the exact surface of the Switch bezel was trimmed from the above-resulted trim surface with the class-B surface.

Then, by defining the part body by using the Closed Surface command in Part Design, the component's solid body is created.

PROCEDURE FOR DRAFT ANALYSIS:

• First the class – A surface is checked before creating the Class –B&C surface and finally the solid body must be analysed. Both can be done by following the below procedures.
• By changing the view mode to custom view parameters – Material mode then the feature draft analysis is enabled.
• Then the compass was activated and placed with the tooling axis by dragging the red pointer and then locked it.
• Then, by selecting the quick analysis mode, the nominal value will be 3 degrees and checked for the component's draft angle.
• 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.

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.