Wiring harness design in CATIA V5 - 3D modeling Week 2 Challenge

WIRING HARNESS DESIGN IN CATIA V5

INTRODUCTION

Wiring harness is the combination of electrical and mechanical CAD to connect all the electrical parts in the automotive at the optimum level. It mainly consists of an electrical harness and the mechanical harness in the design. CATIA V5 electrical workbench is used as the CAD tool for routing the wires.

Some basic terminology needs to be understood before designing the wiring harness:

1. Electrical Distribution System (EDS): It deals with physical (location of electronic components placed in the vehicle, front end to back end) and logical (different Electrical Control Units) architecture, schematic development, power distribution (set with fuses to check wiring harness is safe in various failure modes), wiring harness design and wiring harness component design of given electrical system.

2. E & E Architecture: It is the high-level logical connectivity diagram. It represents all the systems, sub-systems and logical connections between them. It shows the Control Area Network (CAN) between different electronic components.

3. Logical schematics: It is detailed design of E&E architecture which is extended to show the logical connectivity between different components and controls of different systems and sub-systems.
4. Electrical schematics: It is detailed design of logical schematics, which describe the pin-to-pin connectivity, properties, fusion distribution, grounding distribution, wire properties (wire type, colour, gauge), interconnects, circuit properties (circuit numbers, connector designation numbers, control device number), specification of component (rating od diode, resistors) etc., This is the end design of electrical core design of system and used as primary input for harness development.
   

5. Wiring harness topology: It is strategy to divide the harness between different pieces to achieve the best manufacturability, serviceability and cost-effective design. Ex: engine harness, door harness, tail gate harness.

6. Wiring harness routing: It is the desired path of wiring harness into given vehicle environment by applying set of design rules and industry best practices.

7. Wiring harness packaging: It deals with the fixing/mounting strategy of wiring harness routing to ensure the safe, reliable and durability of wiring harness by applying set of design rules and industry best practices.

WIRING HARNESS ASSEMBLY

The term Wiring Harness refers to the assembly of

• Wires: Various bundled wires together. Each individual wire is responsible for carrying the electrical signals and energy. Wires are made up of Cu conductors insulated with PVC insulation.
  

• Connectors: These are electro-mechanical device used to join electrical termination. Connectors create an electrical circuit. These are plastic moulded housing with locking and retention feature.
  

• Terminals: A device used to terminate a conductor that is to be affixed to post, stud, chassis, another tongue etc., to establish electrical connection. These are metal conductors with plating constructed in specific shape.

• Protection devices: Corrugated flexible tube and MCB/MCCB

• Insulation: Adhesive and non-adhesive tapes and sleeves. Polymer or cotton/polymer (very effective in high-temperature zone).

• Clips & Clamps: Plastic moulded parts with mounting /snapping features.

• Fuse and relay box: Plastic moulded parts used to package fuses and relays in systematic manner.

• Retention device: Plastic moulded parts to mount connector and other harness components. Connector backshells.

• Guiding channels: Plastic moulded parts or metal parts designed to guide harness bundle in given geometric area to secure and protect the harness
  

• Electronic components: Diodes, terminating resistors, flasher, Timer circuits are some parts of harness supply.

WIRING HARNESS DESIGN PROCESS:

DEFINING ELECTRIC PARAMETER FLOW CHART

WIRING HARNESS ASSEMBLY STRUCTURE — CONNECTOR DEFINITION

Following Parameters are required to defined for any connector —

• Geometry Parameters — Points & Co-ordinate system (Axis)
• Connector connection points - This point is used for the connection of one connector to another connector.
• Harness bundle entry point - This point defines where the harness bundle segment point will end when routed to the electrical connector.
• Cavity connection point (Optional) - This point is used to define the connection of a connector to a connector clip. This only applies to connectors which have the mounting feature for a connector clip.

CONNECTOR MODELING:

Download the specified connector from te.com. In the part design workbench provide the centre point and axis system to the wire inserting end and connection end. The axis must be given in a specified way:

X-axis: Towards the clamp

Y-axis: Towards the connection

Z-axis: left or right of the connector.

CONCLUSION:

The connector is successfully modelled in CATIA V5 and the same is added to the catalogue for further references.