Challenge

Project 1

KKhushboo Kumari8 Mar 2023

WIRING HARNESS DESIGN PROJECT 1

AIM

Route the Wiring harness on Given 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. Apply Protection coverings as required.

Engine

The above figure shows the 16 valve Bugatti Engine where 8 cylinders are placed on the right side and 8 cylinders are placed on the left side.
There are total 16 injectors where 8 injectors are used for 8 cylinders on right side and 8 injectors are used for another 8 cylinders on left side.
Also there are 4 cam-shaft sensors, so there are total 20 sensors that we have to connected electrically.
Generally, 4-pole connectors are used for fuel injectors of the engine.
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 withstand at least 150 degree Celcius.
The bend ratio for the all bundle segmets should be 1.4

Assumptions-

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

INTRODUCTION

A wire harness, also commonly referred to as a wiring 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.

Engine Harness

Step 1: Creating Context Assembly

A Context Assembly for Engine Harness has created which will work as the main assembly as shown in above figure.
A Context Assembly will contain Engine Assembly data for Bugatti V16 Engine 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 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 and connector connection point in Electrical Part Design workbench for the downloaded connector.

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 compass, snap and smart move features to locate all the 20 connectors at their desired locations.

Step 4: Adding sheet metal bracket ( L- CLIP )

Now, we have to add sheet metal bracket 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 engine and geometrical bundle assembly. The bracket should be mounted on the existing bolt as shown below. This bracket should have locking system in clockwise direction so that it can't be move freely. Herein below figure, 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 for the smooth working of engine in real world application.

Step 5: Mounting the interconnection connector on the sheet metal bracket and mounting the p-clamps for wire harness

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

Inter Connection Connector (C-776438-4) electrically defined

mounting cavity "C-1924487-2 ( electrically defined )

both 12 pole connector and mounting cavity are electrically connected together in electrical assembly design workbench.

Now, we have to mount that electrically connected interconnection connector and cavity on sheet metal bracket

sensor connectors

2-pole connector

2-pole connector (C-173090-2)

2-pole connector (C-282080-1)

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

Here, we have mounted 3 P-clamps on the existing bolts of the engine for the wire harness routing

we have mounted furr tree clip also for the smooth path to wiring harness routing towards guiding channel on both right and left side.

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 channel for both right and left side of the engine. Now, before placing guiding channel, we have to define geometrical parameters of guiding channel

After electrically define of guiding channel, we have located guiding channel at desired place as shown in above figure.
Here, we have used different commands like manipulation, snap, smart move, compass etc. for placing of guiding channel

Some important packaging rules and best practices to be considered during wire harness routing and placing of the clips and clamps are as follows –

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.

Step 7: ROUTING CONNECTION in ELECTRICAL HARNESS ASSEMBLY workbench

Bundle routing from Interconnection connector to 3 P-clamps

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

Step8: Adding protective coverings ( from catloglogues )

we have done with whole wiring harness routing for the Bugatti V16 Engine. Now, we have to add protective coverings to all bundle segments and top shell of the guiding channel.

we have added all the slit COT tubes on bundle segments as a protective coverings. Also, we have added top of the both left and right side plastic guiding channel.

Step 9: Checking bundle continuity

In this step, first we have to make sure that multi-branchable is selected then we have to go in Edit>Search>Advanced>Workbench-Electrical>Type-Bundle Segment>Attribute-Fully Connected

here , we are not getting anything in false conditions, it means that our bundle has not any discontinuity means ready for FLattening.

Step 10: Creating flatten view of the engine harness geometrical bundle assembly ( TO check the exact length of the bundle )

In this step, for creating flatten view we have to work in Electrical Harness Flattening workbench of Catia V5. We should also make sure that the flattening file is saved in the same folder where other files of harness assembly are saved.

Before creating flatten view, first we have to define flattening parameters. Make sure that selecting 'Single line' for bundle segment and 'Double' line for protective covering.

procedure:

We have extracted the bundle assembly into Engine Harness Flattening Product file and then flattened the file along face of interconnection connector as shown in above figure.

We have to rotate bundle segments connecting to the 4 cam-shaft connectors using 'Rotate' feature in the flattening workbench as above figure.

It should be noted that we have 'face' of the interconnection connector as the flattening plane so we should make sure that we rotate the bundle segments along that plane only.

Step 11: Creating a flatten view drawing for the wiring harness assembly

we are creating new drawing file and defined all the necessary drawing parameters. We have to insert the front view of the Engine Harness Flattening Product file into the Drawing file.

We have to define drawing properties as shown in above figure. It should be noted that in 'Dress up' settings 3D wireframe is always ON. If this setting is not selected then th bundle segments won't be visible on drawing view.