Project 2

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

Given:

Car Tailgate Assembly

INTRODUCTION:

WIRING HARNESS OR CABLE HARNESS:

A cable harness, also known as a wire harness, wiring harness, cable assembly, wiring assembly, or wiring loom, is an assembly of electrical cables or wires which transmit signals or electrical power. The cables are bound together by a durable material such as rubber, vinyl, electrical tape, conduit, a weave of extruded string, or a combination thereof.

1. Wiring Harness

Cable harnesses are usually designed according to geometric and electrical requirements. A diagram is then provided (either on paper or on a monitor) for the assembly preparation and assembly.

The wires are first cut to the desired length, usually using a special wire-cutting machine. The wires may also be printed on by a special machine during the cutting process or on a separate machine. After this, the ends of the wires are stripped to expose the metal (or core) of the wires, which are fitted with any required terminals or connector housings. The cables are assembled and clamped together on a special workbench, or onto a pinboard (assembly board), according to design specification, to form the cable harness. After fitting any protective sleeves, conduit, or extruded yarn, the harness is either fitted directly in the vehicle or shipped.

DESIGN CRITERIA AND PACKAGING ASSUMPTIONS:

• Wiring harness routing shall provide ease in manufacturing, accessibility, easy removal, and easy maintenance of attached equipment and wiring harness.
• Routing through small structural holes and openings shall be avoided, minimize chaffing and handling of the wiring harness during installation.
• Avoid the harness routing and clipping in the Blind zone of the Operator during harness assembly or in service.
• Routing shall offer protection against possible damage through common misuses such as being handhold and temporary support for test equipment.
• Provide additional slack to the harness according to the surroundings and harness bending requirements.
• Ensure the routing meets the clearance requirements with different surrounding parts.
• Avoid routing over the bolts, near to the bolted joints. It may damage the harness or puncture the harness. Keep harness away from panel mounting screws.
• Avoid harness routing near sharp edges, if not possible provide protection to the harness.
• The maximum distance between two clips on a straight branch is 200mm.
• Provide Clips and clamps if the harness is going to bend at multiple locations.
• The use of too many sheet-metal brackets should be avoided.
• The branch length should be more than 50 mm.
• Min distance between clip and branching point to be 25 mm.
• Min distance between two branch breakouts should be 50 mm.

Routing the Wiring Harness:

1. First, we have to consider the components we need for the routing. Here we are only considering the taillights and the number plate lights.
   
   
2. Here we are considering 2 different types of connectors as follows
   
   Interconnection Connector:
   
   
   
   
   
   Light Connector
   
   
   
   
3. Clips used for routing the harness
   
   Fir tree clip 10mm Fir Tree clip 5 mm
   
   
   
   
4. Defining all the connectors as electrical components and the clips as the supporting equipment.
   
   
   
   
   
   
   
   
   
5. 
   
   
   
6. Routing of the wiring harness
   

1. Bundle Continuity Check
   
   
   
   
2. Application of protection coverings
   
   

Preparing the flattening view of the wiring harness assembly

Drafting of the Wiring Harness :

1. CONCLUSION:
   The wiring harness has been designed for the given tailgate assembly and the flattened view is drafted.