Week 8 - Challenge 4 - Bumper

DESIGN AND DRAFT ANALYSIS OF SWITCH BEZEL

Objective:

The objective of the project is to design the switch bezel and to do a draft analysis for it by creating the required tooling direction with the help of bisecting method.

Introduction:

The control panel bezel is the frame part of the window switch that holds its switch covers and buttons into place. Moulding is the method used to manufacture the plastic trims of an automotive by most OEM’s, hence by considering the manufacturing consideration the switch bezel is designed.

Design Consideraation:

• Class – A surface should be asethetically smooth and good.
• Class – B surface should have all the supporting features like ribs.
• Parting line should coincide with the B surface since flahing couldn’t affect the aesthetic of class – A.
• Class – C surface should also pass the draft analysis.

Procedure for creating the switch bezel:

• First, the given styling surfcae is checked for any irregularities and it found any then its is corrected by using trim, extrpolate, split and join commands.
• The below image shows that the class – A surface is clean and no irregularities present, so let’s move on to the next step.

Creation of tooling direction:

• Considering the ejection from the caavity of the mould after maunfacturing the interior trim must have the nominal 3 – degree draft angle.
• Hence the toooling direction is created by considering the above bfactor and bisecting method is used.
• The base surface of the class – A was extracted and a point at the centre is created and an axis system was inserted to the point with current feature is disabled.
• Then, bisecting lines with the two inclined lines were drawn.
• Now the same procedure is done along the XZ plane but on one side we don’t have inclined lines so the centre point is used to extrude a line along the z direction and gave a measurement of 5 degrees (tentatively).
• With these two lines from sketches 1 and 2, the bisecting line is crated and published as tooling axis (tooling direction).

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 surface.
• Then all the surface have been extrapolated to get intersections between them.
• Since the thickness of the switch bezel is 2.5mm the B – surface was offset to 2.5mm and the required trim operations must be carriednout.
• 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]

Creation of calss – C surface:

• The required outer edges of the A – surface were extracted using multiole extract. Then for avoiding the patches the curve is smoothened using curve smooth option.
• Then by using the sweep command the surface was created with 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 wereintersected between the surface corners which eases the trimming operqation.
• Now the required portion of the C – surface were 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 help of extrapolation (tangent continuity) and trim surface.
• Then the exact surface of the switch bezel was trimmed from the4 above resulted trim surface with class – B surface.
• Then by defining the part body by using the closed surface coomand 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 caan be done by following the below procedures.
• By changing the view mode to custom view paramters – material mode then the feaature draaft analysis is enabled.
• Then the compass was activated and place 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 – dregree draft angle. If not satisfied then by using the running point tool area is measured and then altereed to get a suuccessful draft for the created tooling direction.

Conclusion:

Finally the class – A, B & C surfaces with the tooling direction have been published and the swtich bezel is moved on to the designing of the next operation – the craetion of B side features.