Project 1
AIM- Route the wiring harness for the Bugatti V16 Engine assembly and prepare flatten-view drawing in CATIA V5.
OBJECTIVE- The objective of this project is route the wiring harness and prepare flatten-view drawing for the Bugatti V16 engine. All types of packaging rules and constraints have to be considered while routing the harness. Industry best practices should be implemented in the harness design. All necessary details like clearance/ clamping selection, harness fixing requirements, harness continuity should be provided in order to design the wiring harness.
Figure A - Bugatti V16 Engine for which wiring harness has to be designed
BACKGROUND, TECHNICAL SPECIFICATIONS, AND ASSUMPTIONS-
The wiring harness packaging rules and the industry best practices that have been followed to complete this project are as follows:-
1. Provide additional slack if needed according to the surrounding and harness bending requirement. Generally, slack between 5-10% is sufficient.
2. It should be made sure that there is no case of fouling while designing the wiring harness in CAD software. Additional clips/ clamps may be used to avoid fouling.
3. Avoid routing over bolts, bolted joints, or screwed joints to avoid harness puncture.
4. Avoid harness routing near sharp edges or else provide protection over the harness.
5. Enough mounting equipment such as clips and clamps should be provided.
6. Keep away from heat generation components and follow clearance distance.
7. Avoid direct support for harness on fuel lines routed in the engine.
8. Avoid too many sheet metal brackets on the engine. Try to use available threaded bosses on the engine or demand for it.
9. Use plastic guiding channels if needed.
10. Branch Length should be greater than 50mm.
11. The minimum distance between Clip to the branch point should be at least 25 mm.
12. The minimum distance between two branch points should be at least 50mm
13. Protection should be provided as needed according to the surrounding temperature.
14. The wiring harness should be easy to assemble and easy to access.
The given Bugatti V16 Engine has 16 fuel injector sensors and 4 cam-shaft sensors. In total, we have 20 sensors that have to be connected electrically. Generally, 4-pole connectors are used for fuel injectors. Therefore, for the simplification of this project, we will be using same four-pole connector for all the 20 sensors.
The engine will also have an interconnection connector which will connect the engine to other parts of the vehicle. We will be using a 12-pole electrical connector with a mounting clip feature as an interconnection connector.
The plastic guiding channel used in this harness should be made of a material that can stand at least 150 degrees Celcius.
The bend ratio for all the bundle segments is considered to be 1.4
P-Clamp suitable for at least 20mm diameter wire is to be used for this project.
CONTENT-
STEP1- Creating context assembly
A context assembly has to be created which will serve as the main assembly for engine harness. The context assembly will contain the 3D-CAD data for the Bugatti V16 engine and the engine harness geometrical bundle. If any sheet metal brackets are required then they are added in this "ASSY ENGINE HARNESS CONTEXT".
STEP2- Defining the 4-pole connector electrically
The 4-pole connector used for this harness assembly is "C-156389-1". The 3D CAD data for this connector was downloaded from TE.com. To define the connector electrically we should define the geometrical parameters, bundle-connection point, and the connector-connection point for the downloaded connector.
STEP3- Adding connectors to all 16 fuel injector sensors and 4 cam-shaft sensors.
All the connectors have to be added inside the Engine harness geometrical bundle assembly. Manipulation tools along with a compass, snap, and smart move features should be used to locate all the 20 connectors in their desired locations. All the connectors are shown in red for clarity.
First, connectors are located for the first 8-fuel injector sensors which are on the left side of the engine. Then they are located for the 4-cam-shaft sensors. At last, the remaining 8 connectors are added to the 8 fuel-injectors on the right side of the engine.
STEP4 - Sheet-metal bracket for mounting interconnection connector
A sheet -metal bracket has to be created in order to provide mounting for the interconnection connector. We have to make sure that the bracket is placed inside the context assembly outside the engine and harness geometrical bundle assembly. The bracket can be mounted on the existing bolt located as shown below. It has to be made sure that in the real-world application if we are using any existing bolts or screws then the design idea has to be discussed and passed by the engine design engineering team in order to make sure the proper functioning of the engine. This bracket should have a locking feature in the clockwise-direction so it does not rotate freely. The current engine design has a rib feature as shown below which can be used to our advantage as a locking feature. The edge of the bracket will sit on the rib thus locking the bracket in place.
The assumed dimensions (in mm) for the required sheet-metal bracket is shown below. It can be noted that the mounting slot is provided for the interconnector. A slot in place of a hole will allow us to make sure the interconnection connector is secured properly and does not have any rotational motion.
STEP5- Defining the Interconnection connector and mounting clip electrically and then mounting it on the created bracket. Mounting P-clamps for wire harness.
A 12-pole "C-776438-4" connector and mounting cavity "C-1924487-2" is used as an interconnection connector. The 3D-CAD data file for the required connector and the cavity is downloaded from TE.com. Both the connector and the cavity are electrically defined and mounted on the sheet-metal bracket.
The above figure also shows a P-clamp mounted the existing bolt of the engine. The P-clamp is Hellermann Tyton - 211-60129. This P-clamp is good for the maximum diameter of 20.5 mm. Before mounting the P clamps we have to define them electrically. To do so we have to define geometrical parameters and bundle entry and exit points from both left and right side of the P-clamp.
A total of 3 P-clamps are used for this wiring harness. They are all mounted on the periphery of the casting on the already existing bolts.
STEP6 A- Plastic Guiding Channel
The Bugatti V16 engine has 8 fuel injectors on the left side and 8 fuel injectors on the right side of the engine. All these fuel injector sensors are located very close to each other. So, the best way to route the wires around them is by using a plastic guiding channel as they will help us organize all the wires very precisely and will reduce complex wiring harness routing. To mount the plastic guiding channels we would need some mounting provisions. The engine design team can be consulted and asked to provide mounting threaded holes or threaded bosses.
There will be two different plastic guiding channels for this engine. One for the left and the other for the right side of the engine. It has to be made sure that proper clearance (at least 50 mm) is provided between the plastic channel and the exhaust pipes. The total thickness of the these channels is 25 mm.
The plastic guiding channel will be a two-piece molded plastic that will protect the wiring harness from surrounding high temperatures, wear and tear while providing nice aesthetics to the engine.
Figure- Left Bottom Guiding Channel Dimensions
Figure- Left Top Guiding Channel Dimensions
Figure- Right Bottom Guiding Channel Dimensions
Figure- Right Top Guiding Channel Dimensions
STEP6 B- Drawing guiding sketch for the plastic guiding channel and defining channel electrically
Create an entry "point 1" at the channel entry face and "point 2" the endpoint at a distance of 550 mm from "point 1". Draw a line sketch joining the two points. This sketch will be used later as a route definition when routing the wire bundle inside the plastic guiding channel. The figure below shows the left bottom guiding channel. The same process have to be repeated for the right channel.
The next step is to define the guiding channel electrically. We have to define it as equipment and define 8 bundle entry points leading to the fuel-injectors connectors and 1 bundle entry point along the entry face of the channel.
STEP6 C- Locating the Guiding channel
Use manipulation, compass, snap and smart move commands to locate and move the guiding channels in place as shown below. These channels are added inside the engine harness geometrical bundle. At this stage, we will only add the bottom part of the left and right guiding channels.
STEP7- Engine with all mounting and guiding provisions
The image below shows all the 20 connectors, 2 plastic guiding channels, 3 P-clamps, and an interconnection connector mounted on the sheet-metal bracket.
STEP8- Bundle routing from interconnection connector to three P- clamps
At this stage, we are not using the exact value for bundle diameter. We will assign the bundle diameter values at a later stage. The bend ratio is assumed to be 1.4.
STEP9- Adding branches to 4 cam-shaft sensors located near the interconnection connector
Adding the branch point to the bundle segment shown below at a distance of 55 mm from the P- clamp.
Adding two branches from the created branch point to the cam-shaft connectors.
Completed routing to all the four cam-shaft connectors.
STEP10- Routing to the guiding channel
Another branch point is added at 55mm from the interconnection connector. From this branch point, the bundle is routed to the right side guiding channel. It can be noticed that there is no need of any additional mounting provisions for this bundle segment as the bundle path is practical and completely possible in the real world situation.
The bundle segment inside the guiding channel is made by using the pre-made sketch as the routing definition for the bundle.
STEP11- Defining bundle segment inside the guiding channel
From the entry side of the guiding channel create the first branch point at 100 mm and then subsequently create six branch points at 65 mm.
Route bundle segments from these newly created branch point to the 8 fuel-injectors connectors. Bundle diameter is assumed to be 1.5 mm.
Similarly, route bundle segments to the left 8 fuel injectors.
STEP12- Redefining all the bundle diameters appropriately
All the bundle segments connecting to the connectors are 1.5 mm in diameter. Bundle diameter of the segments leading to the plastic guiding channels is 12mm.
STEP13- Adding protective coverings, guiding channels top shell to the harness bundle.
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.
5mm and 15mm COT tubes (shown in orange) are added on top of the bundle segments as a protective covering. The start and end extremity for the COT tubes is assumed appropriately.
Adding cotton tubes on all the 16 bundle segments leading to the 16 fuel injector connectors.
Adding the top half of the left and right plastic guiding channel.
STEP14- Checking Bundle Continuity
First, we have to make sure that multi-branchable is selected and then we have to go in EDIT>SEARCH>ADVANCED>ELECTRICAL WORKBENCH>TYPE-BUNDLE SEGMENT>ATTRIBUTE-FULLY CONNECTED
Selecting the "TRUE" option will show all the connected bundle segments while the selecting "FALSE" will show all the non-connected bundle segments.
For now, we will select "TRUE" and search for results. All the bundle segments are highlighted and found showing that all the bundle segments are electrically connected.
STEP15- Creating flat-pattern of wiring harness bundle
To make a flattened view of any wiring harness we should be working in the Electrical Harness Flattening workbench of CATIA V5. We should also make sure that the flattening file is saved in the same folder where we have all the parts of the harness assembly.
Defining the Harness Flattening parameter. Make sure to use the "Single Line" for the Bundle segment and "Double Line" for Protective covering.
Extract and bring the bundle assembly into the Engine Harness Flattening product file and then flatten the file along the XY plane
At this stage, for clarity, the flattening diagram of the plastic guiding channels has been hidden from the drawing view. The drawings for the guiding channel will be provided separately from the flattening diagram of the harness bundle assembly. The drawings posted above in "STEP-6" have to be used with the wiring harness flatten-view drawing.
Rotate the bundle segments connecting to the four cam-shaft connectors by using the "Rotate" feature in the flattening workbench. It should be noted, that we have "XY-Plane" as the flattening plane so we should make sure that we rotate the bundle segment only along the "XY-Plane".
For a better representation, we can use some features like bend, roll to streamline the harness. At this stage, fake scaling can be done for few bundle segments if needed.
STEP16- Creating a flatten-drawing view for the wiring harness assembly
Make a new drawing file and define all the necessary drawing parameters. Insert the front-view of the harness assembly into the drawing file.
Define the drawing properties as shown below. It should be noted that for the "dress-up" settings 3D wireframe is always "ON". If this setting is not selected then the bundle segments will not be visible on the drawing view.
Final drawing of the flatten-view of the engine wiring harness assembly.
CONCLUSION-
Routing of the wiring harness for the Bugatti V16 Engine assembly was done and the flatten-view drawing was prepared in CATIA V5. The drawings posted above in "STEP-6" for the left and right guiding channels have to be used with the wiring harness flatten-view drawing. Various packaging rules and constraints were considered while routing the harness. Industry best practices were implemented in the harness design. All necessary details like clearance/ clamping selection, harness fixing requirements, harness continuity were provided in order to design the wiring harness.