Project 2

 CAR BACKDOOR WIRING HARNESS DESIGN- PROJECT 2:

AIM:

       To route the Wiring harness on given car body back door and prepare flatten view drawing in CATIA V5.

INTRODUCTION

A wire harness, also commonly referred to as a wiring harness, is an exterior sheath used to cover some types of electronic wires. Generally, wiring harnesses are made of thermoplastic or thermoset materials that can help protect the cables from the environment.

Automobiles today come with some great features. Their design, though, calls for deft wiring considerations. An automotive wiring harness is an assembly of wires, connectors, and other electrical parts. You use it in a vehicle for the transmission of signals.

DOOR WIRING HARNESS:

                                In the case of car doors, as the door of the automobiles opens and closes, the wires bend. If you use the car every day, the door will open and close many times. In case of Back door, the trunk could be open and close many times in daily life. Backdoor wiring harness mainly introduced to connect the brake lights, number plate lights, rear wiper motor, defogger connections. The harness routing should be maintained properly with all the supporting components like clips, clamps with proper protective covers, rubber grommets.

Packaging rules and assumption made in the project

•    Avoid harness routing and clipping in blind zone 
•    Provide additional slack to the according to surroundings
•    Provide enough clearance for the wire harness
•    Provide guiding channel if required
•    Enough clamps to be provided to ensure positive  clearance with surrounding 
•    Distance between two clamp in same branch to 200 mm
•    Use rubber grommet for protection and vibration 
•    Branch length should be minimum 50 mm
•    Minimum distance between clip and branch point should be 23 mm
•    Maximum branches on a single point should be 4

OBJECTIVE

• Define all the mechanical connectors electrically and save it in the Catalogue.
• Place required Connecters on the Back door CAD data.
• Place Fir Tree clips at the required position by following the packaging rules.
• Create the Wiring Harness Routing with all the electrically defined connectors and mounting equipments.
• Create branching points at required locations to create sub branches and connect to various connectors in the geometrical bundle.
• Apply Protection coverings as required.
• Create Wiring harness flattening for the final geometrical bundle.
• Using the drafting workbench, create a drawing sheet with the flattened wiring harness.

Step 1- download the Back Door CAD data from the given source.

Step 2 define the connector into electrical define.

STEP 3 – Creating the context assembly

Context assembly is nothing but the product file which contains the back door 3D-CAD data and the back door geometrical bundle. Here the geometrical bundle product contains all the connectors and clips which are electrically defined for the assembly.

• Create new product file and rename it as Back door harness assembly context.
• Now add the back door CAD data into the context assembly and also creating the geometrical bundle product file inside the context assembly.
• Define the geometrical bundle product file electrically using the geometrical bundle command.

Step 4:Positioning the  Defined Clips as support.

Step 5: Bundle routing from interconnection connector to all the connectors arranged and all the mounting clips

The  dimensions assigned for bundles, like diameter and bend radius are assumed and actual values are provided at a later stage. From the below figure it is seen that the routing starts from the interconnection connector and goes through all the clips and then to the all the connectors.

The bend radius for all the bundles is assumed to be 1.4mm

Step 6: Creation of protection covering(COT Tubes) for the routing.

STEP 8 - ELECTRICAL CONTINUITY CHECK

We need to ensure that the entire bundle is fully connected.

• Go to edit and then click on search command.
• Go to advanced
• Select workbench as electrical, type as bundle segment and attribute as Fully connected
• The select result should be as TRUE or FALSE and the click search to see the connectivity analysis result

Step 9 - WIRING HARNESS FLATTENING

Wiring harness Bundle packaging process is done. Now we need to convert the geometrical bundle into a flattened wiring harness in the Electrical Harness Flattening Workbench.

• To create the Flattened Harness, we need to create a new product file and switch into the electrical harness flattening workbench.
• Now we need to define the Harness Flattening Parameters, save it in the same folder with all other files of back door harness  project and then Extract the geometric bundle from the wiring harness context product file.
• Then select all the branches and flatten the entire Geometric bundle.
• The bundles can be rotated and rolled with a proper radius in order to fit the drawing sheet.

STEP 10 – FLATTENED HARNESS VIEW IN THE DRAWING SHEET

Create a Drawing File for the flattened harness product.

First, we need to make sure that in the flatten parameter settings bundles and protective coverings have different graphical representation which are

Bundle Segments    – Single line representation

Protective coverings    – Double line representation.

• Create a new drawing file in the drafting workbench
• Insert the flattened harness product into the drawing sheet using view option and selecting the front view command.
• Modify the drawing sheet view with required parameters.

Conclusion

CAR back door wiring harness assembly has been successfully completed considering all the packaging rules and industry standards, Wiring harness flattening and Flattened view drawing preparations are also done using CATIA v5 software.