Project 1

Route the Wiring harness on the Given Engine and Prepare to flatten the 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 as required.

Prepare & Submit all necessary reports like clearance, Clipping/Clamping selection, Harness fixing requirements, Harness continuity, and Assumptions if any along with CATIA 3D data.

WIRING HARNESS FOR ENGINE

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.

STEP 1: CREATING CONTEXT ASSEMBLY

• A Context Assembly for Engine Harness has been created which will work as the main assembly as shown in the above figure.
• A Context Assembly will contain Engine Assembly data for Engine V16 and Engine Harness Geometrical Bundle Assembly.
• If any sheet metal bracket will require then they are added in the context assembly.

 

STEP 2: TO DEFINE THE 4-POLE CONNECTOR ELECTRICALLY.

Here, according to the requirement we are using 'C-1563689' which is a 4-pole connector. This CAD data is downloaded from te.com. Now, to define a connector electrically we should define the geometrical parameters like bundle connection point in the Electrical Part Design workbench for the downloaded connector.

The above figure shows the bundle connection point for the 4-pole connector 'C-1563689-4P'

STEP 3: ADDING CONNECTORS TO THE ALL 16 FUEL INJECTOR SENSORS AND 4 CAM-SHAFT SENSORS

In this step, we are placing connectors to fuel injector sensors and cam-shaft sensors. So, we will require total 20 connectors which have to be added in the Engine Harness Geometrical Bundle Assembly. We have to use manipulation tools along with a compass, snap and smart move features to locate all the 20 connectors at their desired locations.

STEP 4: ADDING SHEET METAL BRACKET

Now, we have to add sheet metal brackets in order to provide mounting for the interconnection connector. Also, we have to make sure that the bracket is placed inside the context assembly and outside of the engine and geometrical bundle assembly. The bracket should be mounted on the existing bolt as shown below. This bracket should have a locked system in a clockwise direction so that it can't be moved freely. Here in the below figure, the rib is performing the locking feature for the bracket. All the design ideas should be discussed with the engine designing team so that there won't be any disturbance to the smooth working of the engine in a real-world applications.

STEP 5: MOUNTING THE INTERCONNECTION CONNECTOR ON THE SHEET METAL BRACKET AND MOUNT THE P-CLAMPS FOR THE WIRE HARNESS

Here, a 12-pole connector "C-776438-4" and mounting cavity "C-1924487-2" is together used as an interconnection connector. The required cad data is downloaded from te.com. First, we have to define the 12 pole connector and mounting cavity electrically as below. 

Fig: 12 pole connector "C-776438-4"

Fig: Mounting cavity "C-1924487-2"

Now, we have to mount that electrically connected interconnection connector and cavity on sheet metal bracket as shown in above figure.

We have to mount 3 P-clamps also on the existing bolts of the engine so before that we have to define P-clamp electrically with geometrical parameters, entry and exit point on both left and right side of the P-clamp as shown in below figure.

Here, we have mounted 3 P-clamps on the existing bolts of the engine for the wire harness routing as shown in above figure.

In above figure, we have mounted fur tree clip also for the smooth path to wiring harness routing.

STEP 6: MOUNTING OF A PLASTIC GUIDING CHANNEL

We have to add now plastic guiding channel because Bugatti V16 engine has 8 injectors on right side and 8 injectors on left side which are very close to each other. Hence plastic guiding channel is best option for proper and easy routing of the wiring harness. It will reduce the complex wiring harness routing. We will require two different guiding channels for both right and left side of the engine. Now, before placing guiding channel, we have to define geometrical parameters of guiding channel as below.

In the above figure, we have created point 1 at the entry face and another point at the endpoint at a 550mm distance.

Now, join both points and create a line that will be later used for routing the wire harness bundle inside the guiding channel.

The above figure shows the left-side guiding channel and the same process will be repeated for the right-side channel.

 

After electrically defining of guiding channel, we have located the guiding channel at the desired place as shown in the above figure.

Here, we have used different commands like manipulation, snap, smart move, compass, etc. for placing of guiding channel.

Now at this stage, we have just located the bottom of the guiding channel.

In the above figure, the whole assembly is ready for the routing.

All 20 connectors, 3 P-clamps, 1 Interconnection connector, 2 fur tree clips, and 2 plastic guiding channels are mounted.

STEP 7: BUNDLE ROUTING FROM INTERCONNECTION CONNECTOR TO 3 P-CLAMPS

Here, we are routing the bundle segment from the interconnection connector to 3 P-clamps. The diameter for this routing path is 15mm and the bend radius ratio is assumed to be 1.4.

 

 

STEP 8: ADDING BRANCH POINTS TO 4 CAM-SHAFT SENSORS

Adding branch point to the bundle segment at a distance of 55mm from the P-clamp as shown the below figure.

In the above figure, two branches of 5mm are added from the created branch point to the cam-shaft sensors.

 

STEP 9: ROUTING TO THE PLASTIC GUIDING CHANNEL AND ADDING BRANCH POINTS TO BUNDLE SEGMENT INSIDE THE GUIDING CHANNEL

In the above figure, we can see that the bundle segment inside the guiding channel is created by using the pre-made sketch as the routing definition. The bundle diameter is assumed to be 15mm on the left side and 10mm on the right side

Here, from the entry side of the guiding channel, we have created the first branch point at 120mm and then subsequently created six branch points at 65mm as shown the below figure.

Similarly, we have done routing for the left-side guiding channel also as shown in the above figure.

ROUTING BUNDLE:

 CONNECTIVITY CHECKUP:

True value:

False Value:

HARNESS FLATTENING:

FLATTENING PARAMETER

EXTRACT:

 

 DRAWING SHEET:

VIEW PROPERTIES

 

CONCLUSION

3D representation and 2D drawing of the engine harness are implemented, Engine harness is taken as a case study, and developed the geometrical bundle assembly without fouling the bundle segments.