Project 1

AIM

To route the wire harness of 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.

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.

An engine wiring harness is constricted wires, cables, terminals, and connectors controlling a vehicle’s electrical system. It relays electrical power and control information to components such as batteries, alternators, fuel injectors, fuses, audio systems, blower motors, fuel injectors, and computers. Wire harness companies customize it for every location, application, and design it interconnects. Also known as a cable harness, it is more than just a collection of multiple wires put together.

It manages the key functions around the engine including engine controller, oil controller gate, transmission plug housing, air pipe sensors, pressure sensors, and water temperature sensors.

An engine wiring harness is how each part of your vehicle gets electricity. It is crucial to help the vehicle run and it’s usually made of a heat-resistant rubber to handle the high and low temperatures that vehicles often experience. The vehicle needs more than the engine, and it requires a lot of electricity for certain things to function, like the radio or lights. Beyond that, battery, starter, and even alternator run on power, which is provided by the engine. Without an engine wiring harness, we couldn’t start your vehicle.

HOW DOES ENGINE WIRE HARNESS WORK

There are many cables in the engine wiring harness that work to connect electricity to your vehicle parts. This vehicle part has many sensors, and they work to ensure that everything in your vehicle is in working order. Some of these major systems in your car are fuel and transmission. When you get a check engine light, you have the engine wiring harness to thank.It works by using these cables and a fuse box. They wire the electricity produced by the engine to the various parts and sensors. It is created using high-temperature plastic or rubber because the engine heats up a lot. That could cause the engine wiring harness to melt over time. And while this is a rare occurrence, it does happen.Think of this part of the vehicle like the brain. Without it, it wouldn’t be possible to get the information your vehicle needs. It’s always working overtime to relay the data your vehicle needs to function correctly. Whenever a sensor goes off, it’s because the engine wiring harness alerted the sensor of the problem.The exciting thing is that as vehicles get more advanced, the engine wiring harness grows. Some say that new cars have over 100 pounds of wires, so imagine how many things could go wrong with that. In the past, there may not have been many issues. However, as things advance, there are more to go wrong. 

ENGINE HARNESS PROTECTION

Protecting the wires is crucial to the safety of the vehicle. Wires exposed to high temperatures, erosive chemicals and projectiles will be damaged leading to fires, brake failures and critical malfunctions. To prevent these issues, wires need to be bundled and covered.install wiring insulation or heat shield sleeve material that can withstand direct contact with high-temperature surfaces and is flameproof. It needs to be a material built specifically for under hood automotive applications and withstand constant temperatures up to 125°C, or 257°F.There are many options for protecting the wires in a vehicle’s harness. Zip ties securely bundle wire together but offer little protection or insulation. Plastic conduits offer protection from rough surfaces, although they can add weight and are not as flexible as other options. Heat-shrink tubing provides protection from heat, moisture and chemicals. However, the application is time-consuming.Tape is another option for bundling and protecting wires. Tapes are more flexible and cost-effective than other bundling options because they can be used for protective wrapping, bundling and sealing. With a wide variety of backings and adhesives, tape can offer sound dampening, thermal and electrical insulation and abrasion protection of the same quality of the other methods. Additionally, tapes are more flexible, lighter and easier to apply than tubing or plastic conduit.

OBJECTIVE

download the engine,connector,p clamp etc cad file from given link

give required points,plane and axis in part design workbench 

define the cad file electrically in electrical part design workbench

assemble them in required position for wire harness in mechanical assembly workbench

create a product file and bring engine cad file and wire harness product file

create bundle using wire harness assembly workbench

create flattening of the wire harness using harness flattening workbench

create the 2D drawing of the flattening in drawing workbench

PROCEDURE

step 1

first download the cad files from the link given.given neccessary point and axis to define each object in part design workbench.here we have connector,channel,p clamp,fir tree clip and connector clip.each object is given seperate things to define electrically.

this is a 2 pole connector.point and axis are given at mating region and point is given in bundle entry region

for connector - point and axis is given to define connector connection point,bundle connection point and cavity connection point if there.

this is also a 2 pole connector.point and axis are given at mating region and point is given in bundle entry region

this is a 4 pole connector.point and axis are given at mating region and point is given in bundle entry region.and this connector is widely used in this project

this is a 12 pole connector.point and axis are given at mating region and point is given in bundle entry region.here we define the connector clip point.because clip is used to attach this connector on a L clamp.

for connector clip - point and axis is given to define the cavity connection point

this connnector clip is used to fix the 12 pole connector in the L clamp.

 for channel - point and line is given to define

straight line is drawn inside the channel as shown and each sub channel passage points are given where bundles go out.

 for p clamp and fir tree clip - point and plane are given to define

points at the centre of each side of circular arch is given  and planes at each side faces and base of p vlamp is given.

 for fur tree clip- points and planes are used to define

it is defined in the same way like the p clamp.point and planes are given in each side faces and other plane is given in the base of the cylindrical surface inside.

there are some files like L clamp and channel's top surface which is no needed to be defined electrically.so no need to give points or axis to that body part.

 step 2

define the cad part with points,planes etc electrically using electrical part design workbench.

 for connector;first define the body as connector by using this tool

and giving number of terminals in open window displayed.then define connector connection point using

bundle connection point using

cavity connection point using

for connector clip; first define it as cavity using

then define the cavity connection point by filling appropriate tabs.

for channel;define it as equipment and then give bundle connection point details using

for p clamp and fir tree clip; define it as supporting parts by giving corresponding entry and exit planes and point.

after defining these body parts;create COT tube in the same workbench.when we click protection part; a window popup where we have to give inner diameter and thickness for the COT tube and save it it a catalog using store device option.

step 3

create a product file as context file and in that bring the engine cad file and create another product file in context file to create wire harness.in wire harness product file; bring the required connectors in appropriate position based on the mating region on the engine.use pclamp and fur tree clip on specific postion to avoid sharp edge contact on the engine for the bundles.

for fixing the 12 pole connector not on the engine;but required to take out the signals from each region of engine; L clamp is used.L clamp are placed on one side of the symmetry of the engine as shown.L clamp's hole is placed as exact position of the hole in the engine and also the clamp is supported on the ribs on the engine to avoid rotation while working or something.

step 4

for creating bundles change the workbench from mechanical assembly to electrical wire harness.first define the wire harness product file as geometry bundles.then start creating bundles using multi branch tool.

when it's window pop up;give required diameter,bend ratio and start route defining.in that; give we can tangency direction etc while selecting start and end of bundles.

for creating sub branch;first create branch point using create branch point option.

we have to select bundle and can give point on branch on basis of lenght and ratio of point with bundle lenght.then create sub branch from the branch point to required connectors or other body.we can give slack to the bundle inorder to avoid fouling of bundle with the surface of engine.

after creating the bundles;check the bundle continuity and bundle warning.for checking bundle continuity - select edit>search option.when that window popup; click advanced then  give electrical in workbench,bundle segment in type and full connected in attributes.give true for showing full connected bundle and click search.the fully connected bundle will showup.we can give false instead of true.then non continuity files will show.

the image shown is the bundle continuity checking and it shows no discontinuity or break in bundles.

 we can check bundle waring by checking any yellow warning sign like this logo ⚠ show up in any branches in multibranchable.if it show up in any branches; it will show up in multi branchables too.usually these warning happens whwn there is issue in bending radius.we should avoid these bundle warning by any mean while creating bundle.

this image shows that there is no bundle warning.so no problem in bundle bend radius and other.

step 5

after creating bundles and checked bundle continuity and bundle warning ;create protection to the bundle from hazardous situation and environment by forming COT tubes on the bundle which is one of the protective covering used over bundles.the COT tubes are created by clicking protective covering option.before that we have to create COT tube  and save them in a catlogue which is then used in future.we gave extrimity distance to free movement of bundle beacuse of protective covering.

here we have used 10,15 and 20 mm dia COT tubes for the protection of bundles.it is showned as the grey covering over the bundles.

bundles inside the channel is not having any protective covering beacuse it already inside the channel; which would protect from external heat and hazards.

step 6

clearance for the bundle with respect to each surface and region is checked.the clearance value for each region like exhaust line,turbo charger,screws, sharp ends etc would be different.so clearance value is also checked for the bundle in each region.the clearance distance from surface to surface is shown for engine region.

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

create another product file for flattening and change workbech to electrical harness falttening.first give flattening parameters.then extract the wire harness product file into the flattenign product file.after bringing wire harness product file into the flattening product file;the name of the wire harness product in flattenign product file is changed to ehf at the end of the name.ehf stands for electrical harness flattening.then flatten the wire harness using flattening tool.then the 3D wire harness would be displayed like 2D drawing on the plane which we gave while defining flattening parameters.we can change the drawing with tools like rotate,roll,scale etc.but scale tool won't be using much.

 also make sure that the flattening and wire harness file is saving in same location.

this is the flattened wire harness of this project.

step 8

the 2D drawing of the flatten is the next procedure.for that we should first create a blank A0  sheet and bring the flattened wire harness to the drawing sheet.since the drawing is large enough.it won't fit in the A0 sheet which is maximum in catia V5.

RESULT

 the wire harness for the engine is created by considering various packaging rules and constraints while routing the harness.wire harness's flattening is created and saved in same location.2D drawing of flattening is created and also saved in same location.