Project 1

AIM -

To Route the Wiring harness on Given Engine and Prepare flattened view drawing in CATIA V5. Application of all Packaging rules, Industry best practices studied in this course shall be demonstrated in design. Apply Protection coverings.

INTRODUCTION

A wire harness is an exterior sheath used to cover some types of electronic wires. Generally, wiring harnesses are made of thermoplastic or thermoset materials that can help protect the cables from the environment.

The above figure shows the given V16 engine cad data.

OBJECTIVE

• Define all the mechanical connectors electrically.
• Place all the connectors to the required positions on the given engine 3D CAD model.
• Place P-Clamps and Fir Tree clips at the required position by following the packaging rules.
• Create the Wiring Harness Routing with all the electrically defined connectors and mounting equipments.
• Create branching points at required locations to create sub branches and connect to various connectors in the geometrical bundle.
• Apply Protection coverings as required.
• Create Wiring harness flattening for the final geometrical bundle.
• Using the drafting workbench, create a drawing sheet with the flattened wiring harness.

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 method.

• Download the connectors and mounting clip from the given link source.
• Get into the 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 coordinate facing towards the locking mechanism and Z coordinate facing to the top.
• Create cavity connection point for connectors having the cavity for mounting clips.
• Define part as electrical connector.
• Define bundle connection point.

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-branchable 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.

STEP 4- Download and define P-clamp, L-clamp 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 equipments, clips and clamps which are electrically defined for the assembly. Sheet metal L-clamp are added in the main context assembly and 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.

Important Rules to be consider for wiring harness routing-

• Distance between two clamps on a straight branch should be minimum of 200mm.
• The minimum branch length should be 50mm.
• Minimum distance between clip and nearest branching point should be 25mm.
• The minimum distance between two straight connection points should be 200mm.
• The minimum distance between two breakout points should be 50mm.
• To limit the number of branches from a single branch point to 4.
• Avoid routing wiring harness near the exhaust manifold and its components and also from other unshielded heat sources. If re-routing is not possible then maintain a minimum distance of 200mm.
• Try to avoid use of too many metal brackets on engine. Try to use the available threaded bosses on engine or demand for it.
• Enough clamps shall be provided to ensure positive clearance with surroundings and safety of wiring harness.
• P - Clamps, Fir tree clips and other clips can be added to the Geometric bundle as they are electrically defined and are part of the Wire harness routing and should be provided with the Wire bundle package.
• Enough slack should be provided to the wiring harness which help not to get damaged during the Engine rocking or starting condition.
• The wire harness routing should be done in such a way that it is easy in manufacturing and serviceability.
• The wire routing should be done keeping in mind the cost effectiveness of the bundle package.
• To avoid the harness routing and clipping in blind zones of the operator during the assembly and the service.
• To provide proper slack at end connectors so that there will be no tension on the wire bundle.
• To avoid sharp edges on the sheet metal parts and if it is not possible then provide protection parts to prevent damage of the wire bundle.
• To provide separate branch points for separate connectors to ensure Poka-Yoke.

Keeping all the above packaging rules we can start the routing of the wire and provide clipping and clamping wherever necessary during the routing process.We add all connector, sensor, interconnection connector. l clamp, p clamp and furr tree clip at the places where required. we can add more components like furr tre clips and p clamps aftrerwords if required.

STEP 6 - Placement of Channels at the required Locations

Use of plastic guiding channels are recommended to meet the clearances in critical areas if it is difficult to achieve by use of clamps.

STEP 7 - Wiring harness routing

Design criteria followed to route the wiring harness

• Wiring harness routed by considering the factors ease in manufacturing, accessibility, easy removal and easy maintenance of attached equipments 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 upto 4.
• Ensure that harness protection is provided according to surrounding temperature, manufacturabilty and expected reliability.
• The min. bend radius is to be 1.4.

First, we need to create multi-branchable bundle using the external curve option and select the line which we created earlier.

After creating the bundle segment, create 8 branch points inside the channel for creating sub branches for the injector sensor connectors.

Add branch points at minimum of 25mm distance from clips and clamps to create new sub branches connecting various connectors. After completing the routing, we need to check that if any of the bundles is interacting with the Engine part.

There must be proper clearance between the wire bundle and the engine part.

Additional slack or Fir tree can be placed to ensure proper routing.

• STEP 8 - Add protection covering

Add protective coverings on the wiring harness to protect wiring from high temperature . protective covering created by using define protection part command in the electrical part design workbench. Select part , and define the parameters as per the requirement.

The created corrugated tube can be added into the catalog by store device command and selecting the catalog file created for protective covering. then appropriate protective covering added to the bundle segments.

STEP 9 - Electrical coutinuity check

• We need to ensure that the 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
• The select result should be as TRUE or FALSE and the click search to see the connectivity analysis result.

STEP 10 - Wiring harness flattenning

Create a new product file for flatten the wiring harness and save as in the same folder where the wiring harness is saved. Then switch to Electrical harness flattening workbench and select harness flattening parameters and define harness flattening parameters. Before creating flatten view, Make sure that selecting 'Double line' for bundle segment and 'Double' line for protective covering.

STEP 11 - drawing of the flattened wiring harness

Open a new drawing file and Select front view command, then go to the flattened harness window and select a suitable face to create drafting of the harness.Tto make the bundle segments visible right click on the drawing sheet and go to properties, in the view tab, highlight '3D wireframe' and 'is always visible' in the dress up settings.

Conclusion

In this project i have successfully routed the wiring harness for the V16 Engine assembly and the flatten-view drawing was prepared in CATIA V5. Various packaging rules and constraints were considered while routing the harness. After finalizing the wire routing, we can request the corresponding Engine design team to provide additional holes for the mounting of Fir tree clips.