Project 2

Aim - Route the Wiring Harness on given Car body and prepare flatten view drawing in Catia V5.

Objective -

• To route the wiring harness for the given Backdoor.
• Application of all Packaging rules, Industry best practices studied in this course shall be demonstrated in design.
• Prepare flatten view drawing in Catia V5.

                                  

Methodology - 

1. Creating Context Assembly.
2. Defining required Connectors and Mounting devices electrically.
3. Addition of connectors and mounting devices in context assembly and positioning them.
4. Bundle routing.
5. Wire Harness flattening.
6. Drawing of flattened wire harness.

1.Creating Context Assembly -

                                      

• We have created context assembly for the backdoor of the car as main assembly as shown in above figure.
• This context assembly contains the 3D cad data for the backdoor of the car and harness geometrical bundle.

2.Defining required Connectors and Mounting devices electrically -

Following devices are required and after electrically defining taken into the cotext assembly.

2.1.Connectors - 

• C-1563689-1-b-3d   -  Quantity 3 - 2 for tail light and 1 for wiper motor 
• C-282080-1             -  Quantity 2 - For number plate light 
• C-776438-4             -  Quantity 1 - For Power connection and communication to Body Harness

2.2.Clamping Devices -

• Furr tree clip            -  Quantity 9 - For proper routing 

2.3.Protecting Devices

• COT tubes 

3.Addition of connectors and mounting devices in context assembly and positioning - 

                                   

• Above fig we can see the positioins of the connectors and mounting devices.

4.Bundle routing - 

• we have started bundle routing from interconnection connector and assumed diameter of main trunk is 10mm. 
• The diameter of bundle leading to 2 tail lights and 2 number plate lights is 5mm respectively.
• The bend ratio is assumed to be 154 and appropriate slack between 1-10% is given wherever needed.
• After routing check connectivity of the bundle.

                                                  

                                                                                 Fig. Bundle routing

  

           Fig.1.Bundle connectivity check                                                                   Fig.2.Bundle Connectivity check 

5.Wire Harness Flattening - 

• To create a flatten view of the harness assembly, we have to work in Electrical Harness Flattening workbench in Catia V5.
• Also, we have to make sure that the flattening file is saved into the same folder where we have all the parts of the harness assembly. 
• As shown in below image, while defining the wiring harness flattening parameters make sure to select Single line for bundle segment and Double line for protective covering.
• After that, we have to extract and bring the bundle assembly into the car tail gate flattening product file.
• To flatten the harness assembly, we have selected Face as an active plane and selected all the branches as shown in below image. 
• Now, we have a flatten view of the wiring harness geometrical bundle assembly as shown in below image.
• After creating flatten view, we have to rotate the connectors and clips in right direction along the selected plane using manipulation as shown in below image. 

                                 

6.Drawing of flattened wire Harness - 

• As shown in below image, we have to insert front view of the harness assembly into drawing file and define drawing properties.
• It should be noted that for the Dress-up feature 3D wireframe is always ON. If this setting is not selected then the bundle segments will not be visible on the drawing view. 

                                 

                                     

Rules followed for Routing -

1. Wiring harness should be routed in such way that it is easy to assemble and access.
2. Easy manufacturing, installation, removal and maintenance have to be considered while designing the wire harness.
3. Wiring Harness should be kept away from sharp environment like edges, corners etc.
4. Avoid harness routing and clipping in the blind zones or hard to reach areas during harness assembly or service.
5. Provide additional slack if needed according to the surrounding and harness bending requirement. If harness is passing through the closures/doors or tail gates then envelope dimensions during opening and closing of doors shall be considered to provide the slack. Check the harness slack requirements with open and close conditions to avoid excess slack.
6. Routing through small structural holes and openings shall be avoided. To minimize chaffing and handling of the wiring harness during installation.
7. It should be make sure that there is no case of fouling while designing the wiring harness in the CAD environment. Additional mounting equipments like clips/clamps may be used to avoid fouling.
8. Use of rubber grommet is recommanded if harness is passing through sheet metal panels. Example- firewall, passing to door, tail gate etc.
9. The branch length should be greater than 50mm.
10. The minimum distance between the two branch points should be at least 50mm.
11. Clips/clamps used for the wiring harness should be easily available in the market to avoid extra cost for custom mounting solutions.

Conclusion:

Routing of the wiring harness for the car backdoor assembly has done and prepared flatten-view drawing in Catia V5. Applied all the packaging rules while routing the wiring harness, implemented industry best practices in the harness design. Also, provided details like clearance, clipping selection, harness fixing requirements, harness continuity in order to design the harness