st20000442_training_report

INDUSTRIAL TRAINING REPORT

LEKAMGE M.S

ST20000442

ASIAN INSTITUTE OF TECHNOLOGY

SCHOOL OF ENGINEERING TECHNOLOGY

DEPARTMENT OF MECHATRONICS

INDUSTRIAL TRAINING REPORT_ST20000442 2

INDUSTRIAL TRAINING REPORT

TRAINEE

NAME : M.S LEKAMGE

STUDENT ID : ST20000442

TRAINING ORGANIZATION

NAME : General Motors Powertrain (Thailand)

BRANCH/DFEPARTMENT : Maintenance

SUPERVISING OFFICER : Mr. Tanate Somchantre

PERIOD OF TRAINING : from 12/05/2014 to 01/08/2014

TRAINING DURATION : 12 weeks

FIELD OF TRAINING : Mechatronics Engineering


ACKNOWLEDGEMENTS

I started my internship at GM powertrain right after finish the 3rd year of my

degree. I finished my 12 weeks of internship period with gaining a lot of knowledge

and experience. During the past 2 months I have realized that learning theoretical

is never the same when it comes to practice.

I would like to express my humble gratitude to Mrs. Sironart (Human resources

manager) for giving me this opportunity to do my internship program in General

Motors Powertrain (GM) and my supervisor Mr. Tanate Somchantra (Facilities

Engineer in GM Powertrain) for giving me valuable advices and patiently guiding

me through while I working here as a trainee. Also I would like to thank Miss. Aor

Wanlapa (Human resources in GM) for helping me in many ways and kindness. It

would not have been possible without the kind support and help of many

individuals and organizations. Not forgotten for all the staffs working at GM. I very

much appreciate for their entire kindness helping and teaching me when I’m

working there. I am highly indebted to GM for their guidance and constant

supervision as well as for providing necessary information regarding the training

period.


ABSTRACT

This report provides a brief description about the General Motors Company

and its Rayong plant. And also this is consist of history of the organization with

mainly focused on the GM Powertrain (Thailand). The discussion then focuses on

manufacturing processes in the Powertrain according to two main categories

which are Machining and Assembly.

This is the structure of the Powertrain

Machining

Head Machining

Crank Machining

Block Machining

Assembly

Assembly loop 1

Sub head

Turbocharger

Piston

Assembly loop 2

Cold testing

Hot test

Packaging

Furthermore this report contains about project what I have done during the

internship period under the Training Experience chapter. Mainly I have tried to

include things I have learnt newly about the industries as well as the product

(engines). And it has described those things highlighting the engineering aspects

and background.


CONTENTS

INTRODUCTION ........................................................................................................................... 7

1.1 Overview of General Motors ................................................................................................... 7

1.1.1 General Motors Mission Statement.................................................................................. 8

1.1.2 General Motors Vision Statement .................................................................................... 8

1.2 GM Powertrain ......................................................................................................................... 9

1.2.1 Factory layout of the Powertrain ...................................................................................... 9

TRAINING EXPERIENCE ......................................................................................................... 10

2.1 Training experience ................................................................................................................ 10

2.2 Project .................................................................................................................................... 11

2.2.1 Introduction of Intelligent Lighting System .................................................................... 11

2.2.2 Limitation (Effect of frequently switching for tube lights).............................................. 12

2.2.3 Solution (Replacing florescent lamps by LED tube lights) ............................................... 12

2.2.4 Motion detecting sensor ................................................................................................. 13

2.2.6 Testing and monitoring ................................................................................................... 16

2.2.7 Problem solving ............................................................................................................... 17

2.1.3 Cost analysis .................................................................................................................... 19

ENGINE ......................................................................................................................................... 20

3.1 History of Engine Operation................................................................................................... 20

3.2 Engine Operation ................................................................................................................... 20

3.2.2 Four Cycle Engines .......................................................................................................... 20

MCHINING SECTION ................................................................................................................ 24

4.1 Engine Head ........................................................................................................................... 24

4.1.1 Engine Head Machining Process ..................................................................................... 25

4.1.2 Machining layout ............................................................................................................ 26

4.2 Engine Crank .......................................................................................................................... 27

4.2.1 Engine crank machining process ..................................................................................... 28


4.3 Engine Block ........................................................................................................................... 29

4.3.1 Block machining process ................................................................................................. 30

ENGINE ASSEMBLY .................................................................................................................. 31

5.1 Engine Head Sub Assembly .................................................................................................... 31

5.1.1 Engine Head Sub Assembly process ................................................................................ 31

5.2 Assembly Loop 1 .................................................................................................................... 32

5.2.1 Assembly Loop 1 process ................................................................................................ 33

5.2.2 Important stations of loop 1 ........................................................................................... 34

5.3 Assembly Loop 2 .................................................................................................................... 38

5.3.1 Assembly loop 2 process ................................................................................................. 38

ENGINE TESTING ...................................................................................................................... 39

6.1 Engine Test History ................................................................................................................ 39

6.2 Engine Cold Test ..................................................................................................................... 40

Mist collector .............................................................................................................................. 42


CHAPTER 1 INTRODUCTION

1.1 Overview of General Motors

Today GM covers many countries in Southeast Asia including Fiji, Laos

Brunei, New Caledonia, Indonesia, Myanmar, Malaysia, Pakistan, Tahiti,

Philippines, Singapore, Japan, Vanuatu and Thailand. The headquarters which leads

GM’s growth in the Southeast Asia region situated in Bangkok, Thailand. The plant

in the Eastern Seaboard Industrial Estate in the Rayong province with a full

manufacturing facility opened on August 3, 2000. Its capacity of 180,000 and today

5,000 of employs team members. And that plant is the GM’s regional hub for

vehicle production.

Chevrolet Zafira MPV was the original product which manufactured in

Rayong plant by GM and in 2003 they have started introduce new models. The

Chevrolet Colorado midsize pickup truck has taken a good place among them.

Currently they produces Chevrolet Sonic, Chevrolet Captiva, Chevrolet Trailblazer

SUV and Cruze passenger cars.


1.1.1 General Motors Mission Statement

1.1.2 General Motors Vision Statement


1.2 GM Powertrain

GM’s first diesel engine plant in the region opened in September 2011 with

200million USD investment. That provides the powertrain facility with capacity of

130,000 engines per year to GM’s Rayong manufacturing plant. They produce new

family of Duramax four-cylinder diesel engines for the first time in the world.

Those engines power the Chevrolet Colorado midsize pickup truck and Trailblazer

SUV which are manufacturing in Rayong plant.

1.2.1 Factory layout of the Powertrain

As in the figure the head machining line, crank machining line and the block

machining line are in the Machining section. In the assembly section there is two

main loop as loop 1 and loop 2. The cold testing of the engine also do during the

assembly loop 2. Apart from that there is small sub head assembly line in that area.

There are few kitting loops also in the assembly section which assemble the piston

and the turbocharger for 2.5L and 2.8L engines. Also there is hot test room which is

doing the hot test as the final step of the manufacturing process.

They maintain the temperature in between 20c to 25c, humidity 50% to

80% RH and 6 to 12 ACH. That helps to keep away the factory from harmful flux for

machines as well as people.


CHAPTER 2

TRAINING EXPERIENCE

2.1 Training experience

Firstly I am very glad to have my internship in General Motors (GM)

Powertrain, Thailand. Actually it was one of my dreams work in an automobile

company.

I was assigned to GM Powertrain as an internship student for a period of 12

weeks starting from 12th of May to 1st of August, 2014. For the past 3 months in GM

Powertrain, I have been in difference section in the powertrain such as machining

section, assembly section, sub assembly section, cold test, hot test and maintenance

section. I have to do an energy saving project during my internship program. I have

implemented an energy saving lighting system successfully for part of the factory.

While my internship program I enjoyed well by studying, learning,

observing, meeting new people and seeing how they contribute to the factory. It

was great experience for my career.

This is my time durations for each sections

Training bay Time period Duration

Head machining 12/05/2014 to 16/05/2014 1 week

Crank machining 19/05/2014 to 23/05/2014 1 week

Block machining 26/05/2014 to 30/05/2014 1 week

Primary Assembly line 02/06/2014 to 13/06/2014 2 weeks

Secondary Assembly line 16/06/2014 to 27/06/2014 2 weeks

Cold testing 30/06/2014 to 11/07/2014 2 weeks

Hot testing 14/07/2014 to 18/07/2014 1 week

Maintenance section 21/07/2014 to 01/08/2014 2 weeks


2.2 Project

I have to do an energy saving project during my internship program. So I

proposed few energy saving projects and I selected an energy saving lighting

system project called ‘Intelligent Lighting System’. I presented my idea about the

project including the cost analysis, expected outcomes and future works. So my

project was in two main categories. First one is reduce energy conservation of

lighting system by installing intelligent lighting system. Second one is replacing

florescent lamps by LED tube lights. The main objective of this project was reduce

the energy consumption of the lighting system.

2.2.1 Introduction of Intelligent Lighting System

Non-operation time

Operation time

When the motion is detected by the motion sensor it send a signal to the

controlling unite which contains relays and timers. Then control unite will turn ON

the light/s. If there is no movement detected in the specific area the light/s will

turn off after a set period of time. And both motion sensor and controlling unite

should connect into a power source.


2.2.2 Limitation (Effect of frequently switching for tube lights)

There is a limitation for the Intelligent Lighting System with the frequently

switching florescent lamps. If going to frequently switch the florescent lamps, its

life time will be reduce according to that graph.

(Source: Lamptech, 2012)

To obtain 100% of rated life we should switch the lights lesser than 8 times

per day. If we switch the lights more than 8 time per day it will reduce the life time

of the lamp. But LED tube lights doesn’t depends on the switching frequency of the

lamp, and also LED tube light has more than 2 times of life time of florescent tube

lights.

2.2.3 Solution (Replacing florescent lamps by LED tube lights)

Currently they have use 56W florescent lamps in the whole factory. If we

can use LED tube lights instead of florescent lamps we need only 15W LED tube

lights to provide the same amount of light. Usually we can use only 50% amount of

light from the florescent lamps and by using reflection techniques we can increase

that amount around 70%. However more than 30% amount of light will be waste.

But from LED lamps we can get 100% efficiency. Because LED lights give the one

direction light. So there won’t be a waste. So that we can use 1350lm LED tube light

instead of 2500lm florescent lamps.


2.2.4 Motion detecting sensor

This sensor has an inbuilt timer and lux controller and it can switch more than

1000W. So we don’t need to use a timers and relays externally for that. We can

adjust the timer within 10 seconds to 10 minutes and we can adjust the lux

controller max or min according to day light or the night.

Recommended specs

Selected motion detector sensor

with inbuilt timer

Detection range and angle – 8m

and 180 angle

Time and Lux adjustment – 1min

to 10min

Switching capacity – more than 700W

Model specs

Selected motion detector sensor

with inbuilt timer

Detection range and angle – 12m

and 180 angle

Time and Lux adjustment – 3sec to

10min

Switching capacity – more than

1200W


2.2.5 Plan

Placing sensors

S1 S2

concrete beam

Side view

switc

h

stairc

ase

co

nc

rete

be

am

0 m

12

5cm

0 m

S2

S1

Top view

Expected area

covered by sensor 1

Expected area covered by sensor 2


Wiring diagram

D2

D1

Expected area covered by sensor 2


2.2.6 Testing and monitoring

I have attached and tested the both sensor and identify the problems

Detection length is not more than 3m

detection angle is about 110 degrees

Sensors can cover lesser than half of the full area


2.2.7 Problem solving

Allover in this project I have used the project implementation method called PDCA

(plan, do, check, action). According to that method I solved the problem by using

QC7 tool.

Fishbone diagram

From this I have sorted out the problem was in the Material which was motion

sensor.


Then I have to do a five why analysis to find a solution for the problem. The five

why analysis was in three main categories which were sensor adjustment, sensor

broken and sensor fault. So I have gave some solutions for all these categories as in

the diagram.

system is not working properly

lights are not switch ON for more than 3m

sensor cannot detect motion more than 3m

sensor adjustments sensor broken sensor fault

actio

n p

lan

rotate sensor

adjust angle

adjust timer

adjust lux

test in dark and light

test the sensor 1

test the sensor 2

check the specs

check the catalog

use more sensors

looking for ananother model ofsensor

manage the areaby these 2 sensors

increase the time delay

why

why

why

statusdetails result statusdetails result statusdetails result

N G

N G

N G

N G

N G

N G

N G

N G

N G

N G

N G

G

G

actio

n p

lan

actio

n p

lan

From this I got a better solutions. The solution was manage the whole area by two

sensors that we had already and increase the time delay. That was implemented

and I got a better result.


2.1.3 Cost analysis

Cost;

2 motion sensors 900 baht

Wires and other parts 200 baht

Total cost 1100 baht

Saving amount;

Wattage of a lamp 56*12 672 W

No of lamps 12 lamps

non-production time 5 hours

Amount pay for 1unit 3.7 baht

The saving amount is depends on how many days they will forget to turn

the lights off before the day-off

This amount of money can save if they forget to turn the lights off about 8

days per month as an average (assumption)

1193.472

0

500

1000

1500

2000

2500

0 2 4 6 8 10 12 14 16

savi

ng

amo

ut

per

yea

r (b

aht)

how many days they will forget to turn the lights off (days/month)

Saving amount

Payback period is 3 months


CHAPTER 3 ENGINE

3.1 History of Engine Operation

The fundamental operation of a reciprocating gasoline engine has not

changed since its birth over 100 years ago. Converting heat energy in hot

expanding gas into rotating mechanical energy is what it does. A reciprocating

engine is basically an air pump - the more air it can pump the more power it can

develop The two biggest areas of technological development that have led to the

development of modern day engines is materials and electronics.

3.2 Engine Operation

3.2.2 Four Cycle Engines

Main types of engines are petrol and diesel. Those are different types of fuel.

Diesel is heavy and dirtier fuel whereas petrol is comparatively high volatile fuel

and gets ignited very easily.

The both types of engines has 4 strokes

1. Inlet

2. Compression

3. Expansion

4. Exhaust


Main differences between Petrol engines and Diesel engines

Stroke Petrol engine Diesel engine

Inlet stoke mixture of air and petrol is

drawn in by the falling piston

only air is drawn in by the falling

piston

Compression

stroke mixture is compressed up to

about 1/8th to 1/12th of its

original size

only air is compressed up to about

1/14th to 1/25th of its original size

Expansion

stroke

the air and fuel mixture is

ignited using a spark plug

and burns expanding and

forcing the piston down

Fuel is injected at a high pressure

into the hot, compressed air in the

cylinder, causing it to burn and

force the piston down. No spark is

required

Exhaust

stroke

the burned mixture of air and fuel is pushed out of the cylinder by

the rising piston

A petrol engine is also known as a “spark ignition” engine. Since a spark plug

is require to ignite the mixture of petrol and air in the combustion chamber.

Whereas a Diesel engine is known as “compression ignition” engine. Since the air is

compressed to very high pressure raising its temperature and then diesel is

injected in very fine spray which causes the diesel to ignite and explode.

Diesel engine

http://article4ever.files.wordpress.com/2010/04/crdi.jpg


Petrol engine

A diesel engine is more easily turbocharged than a petrol engine. A petrol

engine cannot be easily turbocharged due to the fact that if the compression ratio

and the pressure in the cylinder is too high during the inlet stroke, the mixture

starts to burn too soon, while the piston is on its way up. The diesel engine has no

fuel in the cylinder, thus letting the turbocharger suck as much air as it can without

creating any problems. (A turbo charger is a simple air compressor which

compresses air in the combustion chamber for burning). Some diesel engines also

have an intercooler which helps in blowing cold and oxygen rich air in the

combustion chamber.

Electronic engine management not necessary in diesel engines. Some

modern diesel engines are gaining electronically controlled injection pumps, but

the vast majority of them out there have purely mechanical pumps. In fact no

electricity is required to make a diesel engine run, except for a simple fuel cut off

solenoid so that you can switch the thing off! If your alternator stops working, then

you’re going to get home in a diesel. This also means that a diesel engine does not

have any ignition breakers, ignition coils, distributors and ignition wires to go bad.

So a diesel engine should start no matter if it is dry or rainy or wet.

Petrol destroys lubrication and burns the engine whereas diesel doesn’t. So a diesel

engine would last longer than a petrol engine. Petrol engines are lighter than diesel

engines.

http://article4ever.files.wordpress.com/2010/04/petrol.jpg


Diesel engines have higher torque than petrol engines. Though the pickup of

a petrol engine would be much more than that of a diesel engine, the diesel engine

would be steady and carry heavier loads to longer distances. Diesel engines have

better fuel efficiency as compared to petrol due to the fact that they have higher

compression ratio. Diesel engines don’t need an ignition system, which reduces

their complexity. But they are noisier and may require frequent maintenance as

compared to petrol engines. Also they are more durable. Diesel engines may also

need glow plugs in extreme cold conditions which heat up the cylinder so that a

cold engine can start easily.


CHAPTER 4 MCHINING SECTION

4.1 Engine Head

This is the second biggest component of the engine. The main parts which

are connected to engine head are camshafts, fuel injectors and inlet/exhaust valves.

And if the engine has a turbocharger it is also connected to the engine head. Engine

head is the upper part of the engine which placed on the engine block.

Synchronization and the accuracy of the engine head should be perfect to achieve

best efficiency of the engine.


4.1.1 Engine Head Machining Process

This is the process of the engine head machining. CNC machining has taken a main

part of the engine head machining process. There are 6 CNC machines in a raw in

the machining line and each one has more than 7 tools. And finally machined head

part reaches the inspection station.

loading rawparts CNC machining

measuring final inspection

unloading


4.1.2 Machining layout


4.2 Engine Crank

Engine crank is place in the engine block which connected to pistons. Rotation of

the crank is the connected to the gear box of a vehicle.


4.2.1 Engine crank machining process

Engine crank machining is more complex than the engine head. Altogether there is

20 stations in this process. Finally it is wash and dry. Then it is going to final

inspection station.

loading rawpartsMill to lengh t,

centering, orital and hollow milling

Cheecking , rough milling mains and

pins, roughing gear ring seat

TT Broach mains incl. undercuts ,

post end and flange end

OD milling pins incl. undercuts,

topping incl. chamfer

Drill & chamfer oil holes

Washing, hardening, tempering

Hardness check

Rolling undercuts and straightening

Re-centering both ends and pre mill

slot at CW

TT Broach mains incl. post end, flange end and gear ring seat

Finish grinding mains, pins

Drill & tap flange bolt holes, drill & ream index holes,

milling keyway, finish mill slot

Finish grinding post end dia &

shoulder, thrust face (gear ring)

Finish grinding post end dia &

shoulder, thrust face (gear ring)

Brush & check

Heat & shrink gear ring

BalancingPolish mains, pins,

thrust face and flange

Wash & dry

Final inspection Unloading part


4.3 Engine Block

Engine block is the biggest part of the engine from the size as well as the weight.

This is the base of the engine. Pistons, crank, oil pan… etc. installed into the engine

block.


4.3.1 Block machining process

This process also have more than 15 stations. They are fully automated and

driven by a conveyers and pick and place robots. This machining line also have an

alarm system which can indicate any problem in the machine or the part. This

process includes a testing station in the final stage. This station operate by a kuka 5

axis robot and it automatically identifies defects.

loading rawparts CNC machining convayer

CNC machining convayer CNC machinig

washing convayer CNC machining

measuring cylinder honing finishing

measuring crank bar washig pressing plugs

leak testing unloading


CHAPTER 5 ENGINE ASSEMBLY

5.1 Engine Head Sub Assembly

5.1.1 Engine Head Sub Assembly process

This is a small process in the engine assembly section. In here they install

lower retainers, cam cover dowel pin, valve seals, springs, upper retainers,

intake/exhaust valves into the engine head and finally it is tested in leaks and laser

key check.

Load HeadInstall Lower Retainers, Cam

Cover Dowel PinInstall Valve Seals

Install Springs Install Upper Retainers & Keys Install Intake / Exhaust Valves

Laser Key Check Leak Test Cylinder Head Repair Station

Unload Head


5.2 Assembly Loop 1

Engine assembly loop 1 is the most important part from the engine

assembly process. All the main parts of engine such as engine block, engine crank

and engine head are assmble in this process. More than 80% percent of assembly

process done in loop 1. There is a special order to install the engine parts. And

there are work stations according to that order. This assembly line is also semi

automated as same as other assembly lines. There is a one worker for every and

each station and he has the responsible of the duty of his station. That assembly

loop assemble about 80% completed engine starting from the engine block. Kitting

loop 1 and loop 2 are also doing a effective job by suppling engine parts to related

stations.


5.2.1 Assembly Loop 1 process

Block Load Crank loadMain Bearing cap

install

Piston Install Rod caps install Water pump Install

Rear Seal Carrier Cover Install

Oil Buffle Install Upper Oil Pan Install

Head load Head Bolt Rundown Camshaft install

Cam Cap Bridge Install Timing Belt Install Cam Cover Install

Dust Cover Install Intake InstallHigh Pressure Fuel

Line Install

Water Pump Inlet Pipe Install

EGR InstallLow pressure fuel line

Install

Oil pick up tube install Lower Oil Pan Install Unloadinig


5.2.2 Important stations of loop 1

Crank load

Piston Install

Water pump Install


Oil Baffle Install

Head load

Camshaft install


Timing Belt Install

Intake Install

High Pressure Fuel Line Install


EGR Install

Lower Oil Pan Install


5.3 Assembly Loop 2

Final few steps of the engine assembly process are done in this loop. Cold

Test and the installation of Turbocharger have taken important part of this loop.

Apart from that prepare for cold test, punching the engine number, etc. done in

here. The cold test is done by fully automatically and result data of the test are

automatically update to the server. By the way defective engines which are failed

from the test rejects from the assembly loop by itself.

5.3.1 Assembly loop 2 process

Loading Cold TestInstall Shipping Cap to

Fuel return line

Install Shipping Cap to Fuel Pump Inlet

Flywheel/Flex Plate Install and Engrave

EUN#

Exhaust & Turbo Install

Turbo Oil Feed Tube Install

Turbo Leak Test Install Turbo brace

Turbo brace boltsTurbo Oil Drain Back

InstallUnloading


CHAPTER 6 ENGINE TESTING

6.1 Engine Test History

Before 1980 the hot test which was known as Bathtub test was in end of the

assembly line. There was no load test or cold test. And just look for leaks and listen

for noises. In 19th century new technologies have introduced for leak test and load

test. Those were fully automatic loaded dyno hot test. And snap shot data save to

server. In 1990 – 1995 the cold test was introduced and it performed end of the

assembly line instead of hot test. It was able to achieve excellent quality results.

And also it has the ability identify bad designs and the bad quality of suppliers.

Nowadays the hot test is implemented on all the launches and cold test has

taken a special place among the engine testing methods during the past few years

which has improved in several ways such as noise detection, vibration test. Main

thing which has changed in the modern engine testing process is distributing the

testing stages in machining and assembly processes. As an example, the leak test of

engine head is done by the ‘sub engine head’ section

Engine test

Cold test Hot test

loaded no load


6.2 Engine Cold Test

Cold test doesn’t identify the errors by itself, it is part of the whole process

to insure engines are built correctly. Cold test spins the engine with an external

driver while monitoring the following basic test signals:

intake pressure

exhaust pressure

oil pressure

motoring torque

vibration or noise

ignition signals

crankshaft sensor signal

camshaft sensor signal

The test stand computer generates control signals to operate engine

subsystems like the ignition and cam phases. The basic test signals are monitored

and analyzed by the cold test stand computer as the engine is motored and the

waveforms acquired have features that are used to establish test points. Data

acquisition is synchronized to the engine crankshaft (crank angle based sampling)

and test points are compared to high and low limits. That is based on limit

comparisons the engine is either accepted as normal or rejected as abnormal.

Test results and waveforms are stored on the test stand computer and sent

to the host computer for longer term storage also service functions or repairs are

logged into the host computer using repair codes and stored with the test record.

Rejected engines will go to a service loop or repair area for examination or repair

by a service person. The service loop computer retrieves the test history for the

engine being serviced from the host computer. The engine is retested in the cold

test stand after being in the service loop and reevaluated as normal or abnormal.

And the mechanical portion of a cold test stand is a precision machine tool with

details that accurately locate an engine for test. All locator and probe positions in a

cold test stand must be precise and repeatable from engine to engine. The

mechanical heart of the test stand is the drive line. It must be balanced, quiet,

smooth running and powerful enough to motor an engine at any speed from 0 to

2500 rpm with little to no speed variation. Mechanical clamps securely lock the

engine into the test stand mechanical fingers connect the test stand drive line to

the engine flywheel or flex plate.


Mechanical slides with seals probe the intake and exhaust ports of the

engine to be tested by blocking valves on the intake and exhaust probes allow

control of air flow in the engine during test. Mechanical slide with probe connects

to the engine oil pressure port and mechanical slides position vibrations sensors

(accelerometers) against the engine cylinder head and cylinder block. Mechanical

slides electrically connect the crankshaft sensors, ignition coils and cam phase oil

control valves (ocv) to the test stand computer. Mechanical slide positions

inductive sensors near the ignition coils to detect the spark plug firing signal. The

supercharging valves route compressed air to the engine intake to increase

cylinder pressure during testing. Some test stands use rigging harnesses and match

plates for electrical connections where automatic probes won’t work and some test

stand designs lift the engine from the pallet to improve noise and vibration testing.

The cold test drive line uses a mechanical overload or clutch to protect

against excessive overloads like an engine lock up. A cold test stand is basically a

machine tool and incorporates similar hardware like a PLC and I/O, relays,

solenoids, limit switches, power supplies, and fuses disconnects and power

distribution hardware. The PLC controls all machine motions, the drive motor and

rf tag operations and communicates with the test stand computer. The cold test

drive motor and drive controller spin the engine at desired speeds for the different

tests. The drive system has an encoder that supplies the test stand computer with

engine crankshaft speed and position information. The pressure transducers

monitor engine intake, exhaust and oil pressure sending electrical pressure signals

to the test stand computer. Oil temperature sensor allows for pressure

compensation due to variation in temperature and oil viscosity. Weather station

monitors air temperature, pressure and humidity to compensate intake and

exhaust pressure readings for changes in atmospheric pressure. Instrumentation

hardware conditions the transducer and sensor signals and it amplifiers isolate the

test stand computer from electrical noise and spikes. The test stand computer

controls all the test sequences and drive speeds via the PLC and it collects all the

test data, does the analysis and accepts or rejects the engine being tested.


CHAPTER 7 Mist collector


Documents

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