Project 1

Wiring Harness Design Project 1-:

Aim

Design and develop the Wiring Harness on Given V6 Engine and Prepare Flatten View drawing in CATIA V5. Application of all Packaging rules, Industry best practices studied in this course shall be demonstrated in design.

INTRODUCTION

A wire Harness, also Commonly referred to as a Wiring Harness, is an exterior Sheet used to cover some types of electronic Wires. Generally, Wiring Harness are made of thermoplastic or thermoset materials that can help protect the cables from the environment.

Engine Harness

The given V-16 engine consist of following electrical components to which harness routing is required.

• 8+8 fuel injectors on the engine cylinders for both sides of the engine block (16 injectors), which are connected by a 12-pole connector with the wiring harness.
• 2 camshaft sensors on each engine block (4 camshaft sensors), which are connected by a 12-pole connector with the wiring harness.
• Engine coolant sensor at the center of the engine between the two blocks, which is connected by a 2-pole connector, with the wiring harness.
• Engine oil temperature and pressure sensor fitted at the oil sump of the engine on both engine cylinder blocks, which are connected by a 3-pole connector with the wiring harness.
• 1 sensor to measure vehicle speed, which is connected by a 3-pole connector, with the wiring harness.
• 1 sensor to sense neutral position of the transmission assembly, which is connected by a 2-pole connector, with the wiring harness.
• An interconnection connector to connect engine harness system to vehicle harness system.

Other equipment's required to complete the wiring harness routing

• Guiding channels to protect the harness routing from high heat zones of the engine wherever necessary.
• P-clamps to provide positive clamping and ensure clearance management for the routing wherever necessary.
• Sheetmetal brackets such as L-clips to mount the interconnection connector.
• Mounting clips to mount the connectors whenever required.
• Corrugated protection tubes to protect the wiring harness.

Assumptions and packing rules:

• Wiring harness routing shall provide ease in manufacturing, accessibility, easy removal and easy maintenance of attached equipment's and routing harness.
• Wiring harness should be routed in such a way that it is easy to assemble on a vehicle.
• Wiring harness should be kept away from sharp environments like sheet metal brackets, panel edges, corners etc.
• Avoid harness routing and clipping in blind zone of operator during harness during installation.
• Ensure that routing meets the clearance requirements with the different surrounding parts.
• Routing shall provide enough slack for each branch to avoid additional stress on wire and terminal crimping joints but ensure that extra slack does not cause wiring harness foul with surrounding parts and impact desired clearance requirements.
• Enough clamps should be provided to ensure the positive clearance with surrounding and safety of wiring harness.
• Use of plastic guided channels are recommended to meet the clearances in critical areas if it is difficult to achieve by use of clamps.
• Branch length should be minimum 50mm.
• Minimum distance between clip and nearest branching point should be 25mm.
• Minimum distance between two breakouts should be 50mm.
• Limit the no. of branches from single branch point to 4.
• Ensure that harness protection is provided according to surrounding temperature, manufacturability and expected reliability.
• The min. bend radius is to be 1.4.
• Consider min 5% slack in the wiring harness if needed.

DESIGN METHODOLOGY

Step 1- Download the Engine Cad Data and Required Connectors CAD data from the given Source.

Step 2- Download the required Connectors from the Source and Convert the Mechanical Connectors electrically by using the electrical part design work bench by following below steps.

. First download the Connectors and mounting clip from the given link source.

. Get into Mechanical part workbench to create required geometrical parameters. Create Connector Connection point and bundle connection point on the required sides of the CAD part.

. Create axis system on the Connector Connection point Such a Way that the Y Coordinate facing normal to the connector face, X co-ordinate facing towards the locking mechanism and Z Co-ordinates facing to the top.

. Create Cavity Connection Point for Connectors having the cavity for mounting clips.

Using the geometrical parameters Created.

. Define part as electrical connector.

. Define bundle connection point.

. Define connector connection point.

. Define Cavity Connection Point.

2 Pole Connector

3 Pole Connector

12 Pole Connector

Step 3- Download and define the plastic channel electrically.

. Procedure for electrically defining the Channel.

. Create bundle entry point and exit point.

. Create a line Curve between the main entry and exit points for creating the multi-blanchable using external curve inside the channel.

. Create 8 bundle entry points on the openings for connecting the injector connectors.

. Using the geometrical parameters define the channel electrical using the define mounting equipment option.

. Create define bundle entry points using the " define bundle connection point option. "

Step 4 - Download and define P-clamp, fir clip and cavity clip.

Step 5- Creating the Context assembly: -

Context assembly is nothing but the product file which contains the engine 3D-CAD data and the engine harness geometrical bundle. Here the geometrical bundle product contains all the connectors and other mounting equipment's, clips and clamps which are electrically defined for the assembly. Sheet metal L-clamp are added in the main context assembly. Then we need to switch into the Electrical Harness Assembly workbench and Geometrical Bundle Product file should be electrically defined using the Define Geometrical Bundle Option before adding any parts into it.

Step 6- Adding 12 pole connectors to all fuel injector sensors as well as for the camshaft sensors.

4 pole connectors should be added in the geometrical bundle using copy and paste connector. Connectors can be added again by copy pasting the 1st imported connector.

Place the Connectors on all the fuel injector sensors and cam-shaft sensors using the manipulation tools like move, smart move, snap tool and also using the compass.

Adding all the other Connectors for Sensors like Coolant heat Sensor, neutral position sensor, Speed Sensors.

Step 7 - Placing the Interconnection connector and L-clamp Support

However, Situation of interconnection connectors are not similar to device connectors. Interconnection connectors are not parked with any device but should be parked with the Help of clips/clamps/ Sheet metal Bracket etc. Possible to the Packaging conditions.

Un parked Connectors Can Create Following Issues: -

. Rattling Noise.

. Physical damage to Connectors.

. Uncontrolled Harness Routing.

. Manual errors during assembly because of undefined parking.

Step8-: Add P-clamps for proper Routing of the harness Bundle.

Adding supporting components like p-clamps and firtree clip Can help the harness bundle provide proper routing and also help to prevent the Harness bundles fouling from unwanted mechanical components.

. P- clamp and the Fir Tree can be placed at required locations to ensure best possible routing for the Harness Bundles.

. The p-clamp can be mounted to the holes provided on the Engine Block in which the Screws to tighten the Engine Block.

Step 9- Placement of Channels at the required locations. Use of plastic guiding channels are recommended to meet the clearance in critical areas if it is difficult to achieve by use of clamps.

Step 10- Routing the wiring harness to the connectors

Go to electrical harness assembly workbench and select geometrical bundle command and select the geometrical bundle in the model tree. Then select the multi-blanchable command to start the bundle routing and go to route definition.

I) The bundle routing starts from interconnection connector and then to the P-clamps and to the guiding channels

ii) Adding branching points wherever necessary using add branch point command as shown below.

iii) Adding branches wherever necessary to connect the various connectors to the main branch as shown below using add branches command and routing definition into it.

Step 11 - Harness Routing Procedure for the channel

. First, we need to create multi blanchable bundle using the External curve option and select the line which we created earlier.

. After Creating Bundle Segment Create 8 Branch points inside the Channel for Creating subbranches for the injector sensor connectors.

Final Harness Assembly for the Engine: -

Step 12 - Electrical Continuity check

We need to ensure that Entire Bundle is Fully Connected.

Go to edit and then click on Search command. Go to advanced. select workbench as Electrical, type as Bundle Segment and attribute as fully Connected.

Then select result should be as True or False and then click Search to see the connectivity analysis result.

Step13 - After finally Completing the wire Harness Routing by following the Packaging Rules we need to Provide Protection Parts Wherever necessary. Slit-COT tubes, cotton tapes are added on the wiring Harness Bundle as Shown below. The top part of the Plastic guiding channel will also be added at this stage.

Step 14 - Wiring Harness Flattening: -

Wiring Harness Bundle Packaging Process is done. Now we need to convert the geometrical bundle into a flattened wiring harness in the electrical Harness Flattening Workbench.

. To create the Flattened Harness, we need to create a new Product file and switch into electrical Harness flattening Parameters and then Extract the geometric bundle from the Wiring Harness Context product file.

. Then Select all the Branches and Flatten the entire Geometric Bundle.

. The Bundles Can be Rotated and Rolled with a Proper Radius in Order to Fit the Drawing Sheet.

Step 15 - Flattened Harness View in the Drawing Sheet

Create a Drawing File for the flattened harness product.

. First, we need to make sure that in the flatten parameter settings bundles and protective coverings have different graphical representation which are,

Bundle Segments - Single line representation.

Protective Coverings - Double line representation.

. Create a new drawing file in the drafting Workbench.

. Insert the flattened harness product into the drawing sheet using view option and selecting the front view command.

. Modify the Drawing Sheet with Required Parameters.

Conclusion: Thus, the engine harness routing is completed and the flatten view drawing is created.