Project 2

AUTOMOTIVE WIRING HARNESS FOR BACKDOOR

Aim: To route the wiring harness on the given backdoor assembly and prepare the flatten view drawing in CATIA V5.

Objective: The objective of this project is to route the wiring harness and prepare flatten view drawing for the Backdoor of the car. All types of packaging rules have to be considered while routing the harness and industry based practices shall be demonstrated in harness design. All necessary details like clearance, clipping/clamping selection, harness fixing requirements, harness continuity should be provided in order to design the wiring harness.

Introduction:

The trunk or boot of a car is the vehicle's main storage or cargo compartment it also have a hatch at the rear of the vehicle. It is also called a tailgate. These doors can be operated manually or electric powered. here we design the trunk or back door wire harness using the Catia.The Backdoor is an assembly of many parts such as inner panel, outer panel upper, outer panel lower and Reinforcement. Inner panel is attached to the outer panel using mastic sealant.

Types of doors based on working position

1. Top Mounted Door
2. Side mounted Door
3. Bottom Door

Rules to be followed:

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 recommended 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 clip and branch point should be at least 25mm.
11. The minimum distance between the two branch points should be at least 50mm.
12. Clips/clamps used for the wiring harness should be easily available in the market to avoid extra cost for custom mounting solutions.

STEP 1 - Creating context assembly

Open the Backdoor assembly in the CATIA software making an assembly product file.

STEP 2 - Defining connectors electrically

Taking required components for the wire harness routing. Here we are using the components for backdoor upper and lower lights, wiper motor, sensors, and defogging equipment. The connectors used are first electrically defined and then added to the CATIA model.

The type of connectors used are given below-

1. Interconnection connector.

2. 2 pole connector used for light, sensors, and motors.

3. Clip and P-clamps are used to set the location of wire.

STEP 3 - Adding connectors and needed equipments

• The first part we position here is the interconnection connectors.

• We place the p clamps for the support in the needed positions.

• Proper connectors are positioned for different electrical equipments.

STEP 4 - Bundle routing

• The routing starts with interconnection connector placed on the Backdoor.
• It is continually routed to the following supports.
• The major routing supports used here are the p-clamps and furr tree clip.
• The back light connectors are routed.
• The connectors for the wiper motor equipment.
• The connectors for the number plate lights and the sensors.
• Now by using multi-branch bundle route all the connector with the clip and clamp.

STEP 5 - Bundle continuity check

• Now we check the bundle continuity check for the further process.
• The continuity checked of TRUE and FALSE conditions.

STEP 6 - Adding protective covering to the harness bundle

By using protection covering tool we protect the entire bundle. We have created a catalogue and we add the protection cover of 15mm diameter and 10 mm diameter. Here we Create a gap from the end and start extremity.

STEP 7 - Create flatten view

Now we open a new product file for the Electrical harness flattening. Here we save the already made geometrical bundle segment and we extract the geometrical bundle to flatten harness by apply flattening parameters we flatten the geometrical bundle.

Once the branches are flattened we do some modification in the branches using the rotate, bend, and straighten etc. tools in the Electrical harness flattening.

STEP 8 - Creating a flatten view drawing

Theabove image shows the 2D flattened imaged of backdoor wiring assembly.

Conclusion: Routing of the wiring harness for the Backdoor assembly has been successfully done and prepared flatten view drawing in CATIA V5 as per the design requirements.