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

'Wiring harness design in CATIA V5 - 3D modeling'

Introduction:

A wire harness is a system of insulated conducting wires bound together with insulating materials, used in the electrical system of a motor vehicle, complex machine or aircraft. Wire harness engineering is the development process of an electrical foundation for the safe and reliable distribution of power throughout a system. It forms the foundation of reliable, cost-effective and successful product design and manufacturing.

The purpose of a wire harness is to organize individual wires into a single unit to efficiently transmit electrical power and signals. A wire harness reduces labor time and potential for human error, enabling technicians to fit complex wiring assemblies into small or hard-to-reach spaces.

For example, in some modern vehicles there are approximately 40 different harnesses, comprised of roughly 700 connectors and more than 3000 wires. The bundling of wires and cables into a wire harness simplifies connection to larger components as a single unit for drop-in installation, instead of connecting every individual strand.

Wire harness design is the process by which an engineer evaluates the requirements of an electrical part of system, given available physical space to create an assembly of wires to deliver power and information as needed. The design must connect all necessary components and not interfere with other systems critical to the operation and purpose of the product.

For example, a wire harness in a car must power everything from drive controls to passenger comforts and safety The wire harness design must consider and account for mechanical systems, passenger, weight distribution, plumbing and more to ensure safe and efficient drive.

Some important terminologies used in Wiring harness design:

1) Electrical Distribution System: It runs from front end to rear end of the vehicle. It involves physical and logical architecture schematic development, power distribution, wiring harness design, wiring harness component design of given electrical system. It ensures the physical location of all electrical components placed in the vehicle. It provides the logical connectivity between electrical components. It has electrical controller unit for different sections like Airbag ECU, ABS and EBD ECU, Engine (ECU).

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.

While the distributed systems of vehicles have been practical and functional up until now, newer architectures, more data, and a movement toward centralized processing is challenging the limits of traditional automotive design. One such trend is the consolidation of domains into a centralized computer architecture. Instead of having several discrete ECUs, they are all housed in a centralized domain control. This model allows for greater software functionality, more code reuse, and easier remote management

3) Logical schematics: Detailed design of E&E architecture. It shows the logical connectivity between different components and controls of given systema and subsystem. It does not define any other parameter except electrical connectivity.

4) Electrical schematics: Detailed design of logical schematics, pin to pin connectivity, properties, fusing distribution, grounding distribution, interconnects, wire properties (wire gauge, color, type), circuit properties (circuit number, connector designation number, control device number), specification of components, end results of electrical core design of system and primary input for harness design.

5) Wiring harness topology: Strategy to split the harness between different pieces to achieve the best manufacturability, serviceability and cost-effective design.

6) Wiring harness routing: It provides the desired path of wiring harness into given vehicle environment by applying set of design rules and industrial standards.

7) Wiring harness packaging: 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 COMPONENTS:

The term Wiring Harness refers to the assembly of

1) Electrical Wires: An electrical wire is the electro technical component used to transport electricity to transmit energy and information. It is made of a conductive material, single or multiple strands, often surrounded by an insulating envelope. The inside of the electrical wire is called the “core” of the wire. The core can be made of copper, nickel-plated copper or nickel (white metal).

Each type of wire or cable is identified by a standard color.

• Neutral: blue.
• Earth: yellow/green striped.
• Phase: red or any other color (black, brown) except the previous ones.

Wires used in industry also comes with different codes such as :

H07 VU 1.5 mm2 wires ( CODE LETTERS OR PART NAME WITH SPECIFICATIONS)

• H or U: the first letter is a national or international reference point.
• 07: for 700 V, maximum tension supported by the wire.
• V: PVC insulating sheath (R for PRC).
• U: copper core; U and R indicate rigid cores, K a flexible core.
• 1.5 mm2: the wire cross-section.

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

There are different types of connectors available in market such as DT06-3S-PP01

Some of its specifications are:

DT06-3S is a 3pin Plug

• Connector Shape : Triangular

• Connector & Housing Type : Housing for Female Terminals

• Connector System : Component-to-Wire

• Contact Type : Socket

• Mating Pin Diameter : 1.59 mm [ .063 in ]

• Contact Current Rating (Max) (A): 13

• Product Length : 31.19 mm [ 1.228 in ]

• Product Width : 18.71 mm [ .737 in ]

• Connector Height : 23.89 mm [ .94 in ]

• Operating Temperature (Max) : 125 °C [ 257 °F ]

• Operating Temperature Range : -55 – 125 °C [ -67 – 257 °F ]

3) 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.;

4) Protection devices: Corrugated flexible tube is a protective covering over wire bundles

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

6) Clips & Clamps: These are Plastic molded parts with mounting or snapping features.

7) Retention device: A backshell (also known as an adapter) fits on to the back of a connector to provide strain relief and cable support to help from bending or over-flexing

DESIGN OF WIRING HARNESS IN CATIA V5:

Schematic Diagram for Wiring Harness Design Process:

Schematic Diagram for Connector definition Process:

Some more important terminologies with respect to connectors

1) CONNECTOR CONNECTION POINT: A connector connection point is used to specify how mating connectors are placed when making an electrical connection. We have to Open any document containing a single insert connector where we want to place a connector connection point. Then, we will place a Contact constraint. for example, a surface or a point.

2) BUNDLE CONNECTION POINT: To implement the transition of connections or cable connections from multi- to single-line representation, and vice-versa, so-called bundle connection points are used.

3) CAVITY CONNECTION POINT: A cavity connection point is used to specify how a device is placed in a cavity when making an electrical connection.

We have to define following component as Electrical Connector using Electrical Part design Workbench and also Define all the necessary properties to Connectors & Clip.

Deutsch DT06 : Connector

Tyco 174357-2 :Housing for Female Terminals

Tyco 85229-1 : Mounting Clip

Steps For Defining Connector:

1.Defined Geometrical Parameters :

Connector Connection point

Connector Cavity Axis System

In Connector cavity axis system following constraints must be followed:

• Y axis should point towards frontt face of the connector same direction as harness to the connector
• Z axis should be pointing across the connector from left to right
• X axis should be pointing in the direction towards the locking mechanism

Bundle Entry Point

Now we have to define part as connector by switching to electrical part workbench:

We have defined the component as a electrical part

2) Defined Bundle connection point

3) Defined Connector connection point

2) TYCO 174357-2

Geometrical parameters:

1) Connector connection point

2) Connector connection axis

3) Cavity connection point

4) Cavity connection axis system

Defined connector as electrical part'

Bundle connection point defined

Connector connection point defined

Cavity connection point defined

Tyco 85229-1:

Define it as mounting euipment

Define cavity:

Finally we will switch to Electrical assembly design of connector and mounting clip

There we will import connector and cavity/mounting clip and select electrical connection and then select cavity and then connector

Hence our product is defined and assembled using electrical workbench and electrical assembly design.

Thank You!