Week 8 - Challenge 4 - Bumper

Title: Bumper Design Using CATIA V5

Objective: To create the Bumper Plastic component through the given Class-A surface. As well as, creating the tooling axis for the given Class-A Surface which is meeting the requirements of the draft angle and at the end perform the Draft analysis on the model.

Introduction: A bumper is a structure attached to or integrated with the front and rear ends of a motor vehicle, to absorb impact in a minor collision, ideally minimizing repair costs.

Specifications:

Bumper Thickness = 3 mm

Minimum Draft Angle = 3 Degrees

Definitions:

1. Class-A Surface: it is a surface created by the styling team which is then given as an input to the plastic designer to create the plastic component. It is the aesthetic surface and the outer most surface.
2. Class-B Surface: it is the surface below a certain thickness from the Class-A surface created by the plastic designer. This surface contains all the engineering aspects of a model.
3. Class-C Surface: it is the surface which joins the Class-A and Class-B surfaces together.
4. Draft: it is the amount of taper or slope given to cores or other parts of the die cavity to permit easy ejection of the casting from the die casting die.

Design Methodology:

Class A Given

1. Tooling Axis: for creation of the tooling axis, we follow the normal to surface line method.

1. First, ensure that the Class-A surface is properly joined and has no discontinuity. Select the boundary command from the toolbars and then select the Class-A surface. A boundary should only appear on the outer edges of the component.
2. Then, we decide the proper tooling axis direction with respect to the given component (in this case it is the Z-axis direction).
3. Generally, the tooling axis is created using bisecting lines method. But in this model, we observe that the side walls are not given any draft. Hence, we assume the axis normal to the base surface and parallel to side walls.
4. We create a line normal to base surface by creating a point first on that surface and then create the line using the Normal to Surface method and taking the base surface and the point as references. This new line is considered as the tooling axis.
   
   

Tooling Axis

2. Draft Analysis: to check whether our tooling axis is proper or not we do the draft analysis.

1. Go to insert > analysis > feature draft analysis.
2. Align the compass with the tooling axis.
3. Then, click on the Class-A surface to see if the it is within the permissible limit of the draft values.
4. The Class-A surface should turn green and then draft value should be given as 3 degrees.

Draft Analysis

3. Class-B: we create the Class-B surface by extruding the Class-A surface by 3 mm

1. First, we will use the Extract the total Class A surface by Offsetting it to a distance of 3 degrees.
2. After that, we see that some surfaces could not be extracted properly, thus leaving some small patches which we need to fix by using some surface creation tools like Multi-Sections Surface, Blends and Sweep.
   
   
   Class B Initial
   
3. After, closing all the small patches we use the Join command to ensure that the surface is properly joined.

Class B final

4. Class-C: we create the Class-C surface by extruding the edge boundaries of the Class-A surface by 3 mm.

1. First, we extract the outer boundary of the Class-A surface separately.
2. Then, we sweep this boundary using the sweep command. We select the Line option on the sweep command menu, the extracted boundaries as Guide curve 1 and the Class b surface as the Guide Surface. Also, we specify the draft angle as 90 degrees. We give this value because the Class C surface is perpendicular to the Tooling Axis direction.
3. After that, we join all the Class-C surface with the Class-B surface by using the Trim command.
4. Lastly, we use the Join command to join the Class A, B and C surfaces together and obtain the proper desired surface.
   
   

Class C Surface

e. Also, since the Class A we received was only the half surface of the bumper we Mirror the surface by using the symmetry command and create the full Bumper Surface.

Final Bumper Surface

5. Part Body: we create the final solid body using the Closed Surface command.

1. Go to Boundary command and click on the new surface. An error dialog-box should pop-up.
2. Go to the Part Design workbench.
3. Select the Closed Boundary option and then click on the generated surface.
4. A closed solid body is obtained.

Draft Analysis on the Final Solid:

Solid Body Views:

Isometric View:

Front View:

Top View:

Feature: