Week 8 - Challenge 2 - Switch Bezel Design

Aim

The aim of this project is to develop the product design of the switch bezel with the help of the class A surface following the OEM standards.

OBJECTIVE:

Create the Switch Bezel Plastic component through the given Class-A surface. To begin with, the tooling axis for the given Class-A Surface is created to meet the requirements of the draft angle and at the end perform the Draft analysis on the model. 

 The Thickness of the component is Considered as  2.5 mm

Introduction

Draft:

• A draft angle is a slant that is applied to each side of most features of an injection molded part. In other words Draft is providing tapers on the product features such as walls ribs posts and bosses that lie parallel to the direction of the release from the mold part ejection
• The nominal draft is 3mm for plastic components and for automotive sheet metal components is 7mm

Tooling axis :

• It is defined as the direction in which the molds opens or core and cavity, with the help of tooling axis created along x and Y axes are used for creating the Main Tooling axis by using bisecting method

Class A

Class A surface is the term mainly used in automotive design industry. It describes the final production surface data for the aesthetic parts of the car.

Class B

Class B surface is the secondary surfaces which is not visible normally. These must be smooth and "error-free" as well, but are not held to the standards that class A surfaces are.

Class C

Class C surfaces are the backside surfaces that can have tool marks, flash and other imperfections without hurting appearance, function, etc..

The steps involved in creation of this project are:

1. Bringing the class A surface of the switch bezel in Catia v5 software

2. Determining the tooling axis for the switch bezel

3. Creation of class B surface 

4. Creation of class C surface

5. Joining all the class A, class B and class C surfaces of the switch bezel

6. Building closed surface after joining all the surfaces

7. Draft analysis on the switch bezel

Procedure

Below is the class A surface which was incorporated in the Catia V5 work bench to work upon

Determination of Tooling axis for the above class A surface

Sketches

Main tooling axis

Creation of Class B surface

The class B surface is created by extracting each surface of class A surface and then untriming them.

After this an offset of 3 mm is given in the downward direction to generate the class B surface.

The surfaces are then extrapolated with a certain distance in order to create cross section among the surfaces to perform trim operation.

Surface trim option was used to give the class B surface required shape.

Creation of class C surface for switch bezel

For the creation of class B surface, first the boundary of the class A surface is extracted using Multiple extract feature.

After this sweep option is used to create the sweep along the tooling axis direction.

Class A surface and the class C surface are then joined together to get desired shape

After this operation, class B and class C surface are trimmed together to give the plastic product a mouldable shape.

After ensuring that the surfaces formed are completely closed, the closed surface feature is used to create the solid mould of the switch bezel

Draft Analysis

When the design is complete, draft analysis is done on the component.

After draft analysis is done we can observe that the green colour shows that the drafted walls of the switch bezel are above 2.9 degrees which is a permissible cirteria to manufacture in injection moulding.

Detailed tree structure for the creation of switch bezel is represented below

      

Conclusion

1. Class A, Class B and Class C surfaces are created following standards of automotive industry using Catia V5 software.

2. Draft analysis was performed on the switch bezel and it was observed that draft was under permissible limit for the manufacturing of the component using injection moulding process.