AIM:

• To route the wiring harness for the given engine.
• Application of all Packaging rules, Industry best practices studied in this course shall be demonstrated in design.
• Apply Protection coverings as required.

INTRODUCTION:

WIRING HARNESS OR CABLE HARNESS:

A cable harness, also known as a wire harness, wiring harness, cable assembly, wiring assembly, or wiring loom, is an assembly of electrical cables or wires which transmit signals or electrical power. The cables are bound together by a durable material such as rubber, vinyl, electrical tape, conduit, a weave of extruded string, or a combination thereof.

1. Wiring Harness

Cable harnesses are usually designed according to geometric and electrical requirements. A diagram is then provided (either on paper or on a monitor) for the assembly preparation and assembly.

The wires are first cut to the desired length, usually using a special wire-cutting machine. The wires may also be printed on by a special machine during the cutting process or on a separate machine. After this, the ends of the wires are stripped to expose the metal (or core) of the wires, which are fitted with any required terminals or connector housings. The cables are assembled and clamped together on a special workbench, or onto a pinboard (assembly board), according to design specifications, to form the cable harness. After fitting any protective sleeves, conduit, or extruded yarn, the harness is either fitted directly in the vehicle or shipped.

PACKAGING RULES:

• Wiring harness routing shall provide ease in manufacturing, accessibility, easy removal, and easy maintenance of attached equipment and wiring harnesses.
• Routing through small structural holes and openings shall be avoided, minimizing chaffing and handling of the wiring harness during installation.
• Avoid the harness routing and clipping in the Blind zone of the Operator during harness assembly or in service.
• Routing shall offer protection against possible damage through common misuses such as being handheld and temporary support for test equipment.
• Provide additional slack to the harness according to the surroundings and harness bending requirements.
• Ensure the routing meets the clearance requirements with different surrounding parts.
• Avoid routing over the bolts, near the bolted joints. It may damage the harness or puncture the harness. Keep harnesses away from panel mounting screws.
• Avoid harness routing near sharp edges, if not possible provide protection to the harness.
• The maximum distance between two clips on a straight branch is 200mm.
• Provide Clips and clamps if the harness is going to bend at multiple locations.
• The use of too many sheet-metal brackets should be avoided.
• The branch length should be more than 50 mm.
• Min distance between the clip and the branching point is to be 25 mm.
• Min distance between two branch breakouts should be 50 mm.

Assumptions-

1. Provide clips/clamps as per requirement.
2. Make sure that there is no falling case while designing the wire harness. Additional clips/clamps may be used to avoid falling cases.
3. Give additional slack if needed. 5-10% slack is sufficient.
4. Avoid routing over the bolt and bolted joints to avoid harness puncture.
5. Avoid routing on sharp edges or else provide protection over the harness.
6. Follow the clearance distance and keep away the harness from heat generation components.
7. Protection should be provided as needed according to the surrounding temperature.
8. Avoid direct support for harnesses on fuel lines routed in the engine.
9. Use plastic guiding channels if needed.
10. The branch length should be greater than 50mm.
11. The minimum distance between two branch points should be at least 50mm.
12. The minimum distance between the clip and the branch point should be at least 25mm.
13. Avoid too many sheet metal brackets on the engine. Try to use available threaded bosses on the engine or demand for it.
14. The wiring harness should be easy to assemble and easy to access.
15. While using dummy connectors, ensure that whatever positions you are defining is practical. Bundle diameters and other placements can be defined properly for the wire harness routing.
16. If the packaging area is too tight and there are many packaging constraints then we can think of creating a harness channel that can be used to route and protect the wire harness effectively.

Channel Bottom Plate

Channel Top Plate

Fir tree Clip

L Section Joint

P- Clip

Multiple Branching

Project report:

The V16 engine CAD data is seen in the image above. The wire harness for
the following engine-attached electrical components is routed here.
• Each of our 16-cylindercylinder engines has a fuel injector.
• There are four camshaft sensors on each engine block.
• Engine coolant sensor between the two blocks in the middle of the engine.• Engine oil temperature and pressure sensors are installed on both cylinder
blocks' oil sumps.
• Sensors that detect the gearbox assembly's neutral position and gauge
vehicle speed
• An interconnection connector to link the vehicles and the engine's harness
systems

It is necessary to mount the wire harness and manage its routing to ensure
suitable wiring harness packaging. Additionally, clearance management and
1. manufacturability are addressed. P-clamps to offer effective routing clearance management and positiveclamping Corrugated tubes are used to shield the wiring harness from potentially dangerous substances and temperatures.
2. Mounting clips for mounting the connectors
3. Guiding channels provide thermal protection in high-temperature zones.Next, make an assembly wire harness context new product in the assembly workbench. The wire harness electrical bundle and geometrical bundle were constructed inside of this product file at the top level. Given that this context component now has V16 engine CAD data.All of the harness parts, such as connectors, clips, grommets, and actual physical bundle segments and branches, are included in the geometric bundle.Electrical definitions should be given to each component.Download the necessary connections and mountings 3D data from the website.

Connector 1:

Connector 3:

Connector 4:

1.Create the connector connection point, connector connection axis system, and bundle connection point by opening the CAD data for the connectors in the CATIA component design workbench. Then enter the connector
definition in the electrical part design workbench along with the connector
2. connection point and bundle connection point. Here, we have an interconnection connector that needs a mounting clip to be mounted. Therefore, the cavity connection point for this connector should be specified (for connector No. 1).
3. Every connector has been identified as an electrical connector, along with all of its necessary features. A catalog document is made in the connector family, and it is used to contain all of the connector data, as shown below.

P_Clamp:

Define geometrical parameters first, such as the base plane, exit plane, and entry plane. The P-clamps are then defined as support using the support command and the parameters set in the electrical part design workbench.

Fir Tree Clip:

Define geometrical parameters first, such as base plane, entry point, exit point, and entry plane. Then, move to the electrical part design workbench, and define the fur-tree clip as support. After that, identify the entry, base, and exit planes. Two entries and exits should be available. Therefore, define the second entry and exit

Plastic Guiding Channels

The supplied V-16 engine has 8 injectors that are close to one another on both the left and right side of the engine, therefore plastic guiding channels are employed to ensure that the wire harness is routed without incidents.

Additionally, it offers thermal protection from engine areas with high temperatures.

To route the wire harness into the guiding channel, first, create geometric features such as bundle entry points and an external reference line in the part design workbench. Then, using the identified equipment option, designate the guiding channel in the workbench as electrical equipment.

Sheet Metal Bracket:

To provide parking for the interconnection connector, add a sheet metal bracket. Additionally, we must ensure that the bracket is positioned outside of the engine and geometrical bundle assemblies and inside the context assembly.

Placement of Connectors:

Switch to the “Assembly Design” workbench, and start placing the connectors at the proper location.

Place the 4-pole connectors at the 16 fuel injector sensors

Place the 4-pole connectors at the 4 camshaft

Place 2-pole connectors on the coolant temperature and vehicle speed measurement sensors.

Collent Temperature Sensor:

Vehicle Speed Measurement Connector:

• Place connector 2 on the neutral sensor

Place the L-sheet bracket and the interconnection connector in the desired suitable position to assist in the wiring harness and routing.

Place the L-sheet bracket in a suitable location, to place the interconnection connector on it. Note that you need to connect the mounting clip electrically to the interconnection connector before being placed on the L-sheet bracket.

Place the P-clamps on the desired suitable position to assist in the wiring harness and routing.

Guiding channel:

For the electrical wiring to be connected to the fuel injectors, provide a guiding channel on both sides. These channel deal with the thermal shielding provided by the wiring harness at high-temperature zones and clearance control. Then ask the engine design team for more threaded holes so you can use bolts or screws for installing the guiding channels where they need to be.

Harness Routing and Packaging:

• Include all of the electrically defined components in the geometric Place the parts in a way that allows the harness to be routed through them.
• Use the provided Geometrical bundle option on the electrical harness assembly workbench to electrically specify the geometrical bundle product
• The geometric bundle contains the accessible connectors that are correctly mounted on the fuel injectors, camshaft sensors, engine coolant sensors, and camshaft A manipulation tool is used to position the connectors.
• The interconnection connector is where the bundle routing begins, followed by the P-clamps and guiding channels. Add branch points to direct the wire harness from the main branch to different
• Choose the external curve option, then click on the line that has been drawn in the guiding channel to route the wiring harness through it. After that, add branch points to the wiring harness to direct it to the connectors from the guiding To prevent tension on the wire, the bundle section is given the necessary bend radius and slack.

Checking The Bundle Segment Error:

• Verify the continuity of the bundle after routing the

Electrical Workbench Edit > Search > Advanced > Type: Fully Connected is a bundle segment attribute. When the attribute criterion's "FALSE" option is used, all of the related bundle segments are displayed

• To shield the wiring from high temperatures, add protective coverings to the wiring harness. The "define protection part" command in the "electrical part design" workbench creates a protective
• By using the store device command and choosing the catalog file prepared for protective covering, the created corrugated tube can be added to the Then, the bundle segments are given the proper protective coatings keeping 15mm distance from each connector.

Design Criteria to Follow for Routing the Wiring Harness

• The routing of the wiring harness took into account variables including ease of manufacturing, accessibility, convenience of equipment attachment and maintenance, and ease of equipment removal.
• The wiring harness should be laid out so that it is simple to install on a vehicle,
• Sharp surfaces, such as panel edges, corners, and sheet metal brackets, should be kept away from the wiring harness.
• When installing the harness, avoid routing and clipping in the operator's blind zone.
• Verify that the route satisfies the conditions for clearance with the various adjacent parts.
• When routing, each branch must have adequate slack to prevent further strain on the wire and terminal crimping joints, but the extra slack must not interfere with neighboring components or reduce the desired clearance with the Environment.
• Enough clamps should be available to guarantee the wiring harness's safety and positive clearance with the positive clearance with the environment.
• If using clamps to satisfy the clearances in crucial sections is challenging, using plastic guided channels is advised.
• The minimum branch length should be 50mm.
• There should be a minimum of 25mm between the clip and the closest branching points.
• There should be a minimum of 50mm between two breakouts.
• Check to see that harness protection is offered by the local temperature, manufacturing potential, and expected realiability.
• A minimum bend radius of 1.4 is required.

Wiring Harness Flattening

To flatten the wiring harness, create a new product file and save it with the desired name in the same folder as the wiring harness. Then select Harness Flattening Parameters and define Harness Flattening Parameters on the “Electrical Harness Flattening” Workbench. 'Double line' for the bundle segment and 'Double' line for the protective covering must be selected before producing the flattened view.