Project 2

                                          Design Automotive Wiring Harness for Backdoor Assembly

Reports by                                                                                                                                        Date: 06-Jul-2022

Ramkumar Kariyappan

PG program for Hybrid EV Design & simulation

Objective

 To Route the Wiring harness on Given car body and Prepare flatten view drawing in CATIA V5

1.Wiring Harness

                              A wire harness, often referred to as a cable harness or wiring assembly, is a systematic and integrated arrangement of cables within an insulated material. The purpose of the assembly is to transmit signal or electrical power. Cables are bound together with straps, cable ties, cable lacing, sleeves, electrical tape, conduit, or a combination thereof. The wire harness simplifies the connection to larger components by integrating the wiring into a single unit for “drop-in” installation.

1.1 Electrical Distribution System (EDS)

                                         An electrical distribution system is a series of electrical circuits that delivers power in the proper proportion to homes, commercial businesses and industrial facilities. Regardless of the size and applications, the ultimate goal remains universal: the economic and safe delivery of adequate electric power to electrical equipment.

1.1.1 Radial Distribution System

                                   Radial Distribution System has one power source for a group of customers. If there is a power failure, the entire group loses power. In addition, a circuit failure somewhere in the system could mean a power interruption for the entire system.

 1.1.2 Loop Distribution System

                                      Loop Distribution System loops through the service area and returns to the point of origin. The strategic placement of switches permits the electric company to supply power to customers from either direction. If one power source fails, switches are opened or closed to obtain power source.

1.1.3 Network Distribution System 

                                 The Network Distribution System is the most expensive, and the most reliable in terms of continuity of service. This system consists of a number of interconnecting circuits operating at the same utilization voltage.

The customer is connected to two or more power supplies. If one power source fails, the customer gets power from the other sources, without interruption.

 1.2 E&E Architecture

                   The term “electrical/electronic architecture” refers to the convergence of electronics hardware, network communications, software applications and wiring into one integrated system that controls an ever-increasing number of vehicle functions in the areas of vehicle control, body and security, infotainment, active safety, and other comfort, convenience, and connectivity functionality.

1.3 Logical Schematics

                  An Logical schematic is a diagram that shows how all of the wires and components in an electronic circuit are connected. They’re like a map for building or troubleshooting circuits, and can tell you almost everything you need to know to understand how a circuit works .

1.4 Electrical schematics

                   Electronic schematics are like recipes for electronics. They tell you what ingredients to use and how to mix the ingredients. But instead of using text to explain the recipe, a drawing is used.

1.5 Wiring Harness Topology

                 Strategy to divide and split between pieces to achieve the best manufacturability, cost efficient design

1.6 Wiring Harness Routing 

                Deals with desired path of wiring harness into given vehicle environment by applying set of design rules and industry best practices

 1.7 Wiring Harness Pacakging 

                Fixing/ mounting strategy of wiring routing to ensure the safety, reliability, durability

2. Terms Wiring Harness refers

                            Wires, Connectors, Terminals, Protacting Covering, Insulation, Seal grommets, clips and clamps

Wires

                             A wire is a flexible strand of metal.
                             Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Wire gauges come in various standard sizes, as expressed in terms of a gauge number.

 Connectors

                        A device that eliminates a section of cabling or implements a state of access for network devices, including PCs, hubs, and switches. Connectors can be famous for their physical presentation and mating features, including jacks and attachment (male connectors) or attachments and ports (female connectors).Connectors are used to connect the guided (wired) transmission media to devices like the hub, server, workstations etc.

Terminals

                     Terminals are yet another essential component in making electrical connections with wires. It is an electromechanical device with the help of which you terminate a wire. Usually, it is made up of a metal or an alloy, and however, carbon or silicon may also be used.

Protacting Covering

                  wire protection covers can also provide cable management and identification. Wrap similar groups of cables in protective expandable sleeving and separate your wires into recognizable groups while providing protection .

Seal grommets

                          A sealing grommet is a tube or ring that is used as a passage for an electrical cable. They are typically produced of rubber or metal. The sealing grommet is generally placed into holes in specific materials to protect sealing cables that run through them from any potential mechanical or chemical attack.

clips

                            A harness clip for clipping a wire to mounting supports of a vehicle includes a body and a tie-strap. The body includes a clip portion having a generally “U”-shaped channel for receiving the wire at an interior surface of body.

Wiring Harness Design Process

Pre Requirement to design Wiring Harness Design in CATIA V5

Before Entering to modeling we change some setting in CATIA software

Step 1 : Open CATIA V5 > new > part 

Step 2 : Start > Equipment & Systems > Electrical Harness Descipline > Electrical Part Design

Step 3 : Tool > Option > Infrastructure > chche management> click Cache Activation button 

Step 4 : Change cache size is 500 MB for work with large files

Design Wiring Harness Design in CATIA V5

Create Mechanical connector to Electrical Connector 

Step 1:

              

1. Create the point at the both sides point 1 and point 2
2. Then, create axis on point & point 2 ,aline axis like Y axis is perpedicular to the connector/ bundle face.

Step 2 :

1. This step we converted mechanical part to electrical component.
2. Start > Equipment & systems > Electrical Harness Discipline > Electrical part Design
3. First we input the connector and click the Define Connector symbol in tool bar.
4. Then we put no of terminals in connector.

Step 3                

1. Then, click connector connection point select the connector point.
2. Click bundle connection point select bundle area
3. Now our connector is converted into electrical part.

Note : here create Mechanical product coverted into electrical product same follow above steps.

Create fit tree clip

Step 1:

          1.Create the  referance point on fit tree clip

          2.Then, create Axis points on face using referance point we created

      3. Create plne Both side of the fit tree clip

      4 . Create bottom plane 

Step 2 :

1. This step we converted mechanical part to electrical component.
2. Start > Equipment & systems > Electrical Harness Discipline > Electrical part Design
3. Click the Define Support part in tool bar.
4. Then select parameters like Entry point and exit point on fit tree clip.
5. Save Electrical design in Local disk

Now our All Connectors and Supports are Coverted with Electrical properties 

Harness Routing and Pakaging:

Step 1 : Create a new Product file and name it  as<Backdoor Harness >

Step 2 : Go to Product tree right click the Backdoor Harness project click components then click Exiting component 

Step 3 : Now import our Backdoor model into Product workbench

Step 4 : Create a new product under context assembly and rename it <Number plate and tail gate harness>

Step 5 : Import all the required connectiors and supports with electrical property into the Number plate and tail gate harness

Step 6 : After imported connectors now we arranged the connector on suitable or already defined inter connection area

Step 10 : Now Switch to Electrical harness assembly workbech .click the  and click Geomerical bundle tool  now select the multibranchable bundle tool to routing the bundle 

Step 11 : Start routing start from the inter connected connector through fit tree clip.

Step 12 : check all the bundle are connected or not using Advance search option

now my all bundles are rounting properly and fully connected

Step 13 :Create the Electrical flattening of the Geometric bundle assembly

Open> New > Product > Electrical Harness Flattening work bench 

Step 14 : create Flettening parameters

Step 15 : Now our flattening parameters are fixed then use extract tool to pick the connector face then our 

is imported to flattening workbench.

Step 16 : Click flatten tool to flettening the Geometrical bundle 

Step 17 : Open> new > Drawing > A1 ISO ; this work bench we convert our bundle flattening to drawing 

Step 18 : Put all the details of Drawing like layout sheet ,annotation, BOM

Here CATIA was automatically get our Bill of Materials (BOM) Details from out part properties .

Finall output