[a305] motor konstrüksiyonu ders notu (motor elemanları ve Çalışma prensipleri)

Temel Motor Elemanlar

ve alma Prensipleri

Bala

4 Stroklu ten Yanmal Motor

Krank mili

Fonksiyonu

Sonraki

Bileen?


Piston

Fonksiyonu

Sonraki

Bileen?


Egzoz Kanal

Fonksiyonu

Sonraki

Bileen?


KelebekFonksiyonu

Bileen?

Sonraki


Egzos

Supab

Fonksiyonu

Sonraki

Bileen?


Fonksiyonu

Emme Supab

Bileen?

Sonraki


Fonksiyonu

Su Ceketleri

Bileen?

Sonraki


Fonksiyonu

Biyel

Bileen?

Sonraki

4 Stroklu

ten Yanmal

Motor

Zamanlama aretiZamanlama areti

Fonksiyonu

Bileen?

Sonraki

4 Stroklu

ten Yanmal

Motor

Zamanlama areti

Fonksiyonu

Bu nedir?

Sonraki

4 Stroklu Motor

Emme Sktrmalk Devir

Hava/Yakt Karm

Fonksiyonu

Bu nedir?

Sonraki

4 Stroklu Motor

Emme Sktrmalk Devir

leri

Hava/Yakt Sktrma

Fonksiyon

Bu nedir?

4 Stroklu Motorkinci Devir

G Egzos

Fonksiyonu

leri

Hava/Yakt Yanmas

Bu nedir?

4 Stroklu Motorkinci Devir

Egzos

gazlar

Fonksiyonu

ileri

Bu nedir?

G Egzos

4 Stroklu Motor

Fonksiyonu

leri

KAM ML

KAM ML

MotorlarFonksiyonu

leri

Bileen?

Klbtr

KAM ML

KAM ML

Motorlar

leri

tici

Fonksiyonu

Bileent?

KAM ML

KAM ML

lk Aama Normal Yanma

Ateleme

Fonksiyonu

leri

Bu nedir?

First Stage

Normal Combustion

Alev n

Fonksiyonu

leri

Bu nedir?

kinci Aama Normal Yanma

Alevin yaylmas

Fonksiyonu

leri

Bu nedir?

Son aama Normal Yanma

Uniform basn

pistonu aa

iter

Tam Yanma

Function

ileri

Bu nedir?

Abnormal Combustion

Scak karbon noktas

Fonksiyonu

Next

Bu nedir?

Abnormal Combustion

Advanced Ignition Timing

Next

Function

What Is This?

stten Kaml Motor

ileri

Fonksiyonu

stten Kaml Motor

ileri

Fonksiyonu

Ya

Yksek srtnme nktalarna

Carburetor at Idle

CopyrightCIAT2009

Idle Air/Fuel mixture Adjusting Screw

Function

What Is This?

ileri

Carburetor at Off Idle

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Venturi

Area(Lower Pressure)

Function

What Is This?

Next

Feedback Carburetor

Function

Next

Fuel Injector

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Function

Next

Throttle Body Fuel Injection

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Function

Next

Multiport Fuel Injection

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Function

Next

Contact Point Distributor Ignition

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Function

Next

Distributor Ignition System(DI)

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Function

Next

Waste Spark Ignition System (EI)

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Function

Next

Coil on Plug Ignition

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Function

Next

Ignition Test

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Voltage requiredTo get spark plug to fire

Function

Next

Ignition Test

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Voltage requiredTo maintain spark

Function

Next

Throttle PlateThe throttle plate controls the amount of air

allowed into the combustion chamber of the engine. This in turn controls the speed and power of the engine. The driver of the vehicle controls the throttle plate. This is done by depressing the accelerator pedal with their foot. By depressing the accelerator pedal the throttle plate is rotated to allow more air to enter the intake system and thus the amount of air allowed into the combustion chamber.

CopyrightCIAT2009 Return

Krank Mili

ekilde 4 Stroklu

motorlarda kullanlan Krank Mili Grlmektedir.

Mavi eksen, dn

esnasnda tek eksende yeralan

krank ana muylularn

gstermektedir.

Pistonun aa-

Yukar hareketini kontrol eden Biyel

Muylular.

Geri

Pistonekilde Biyele bal

bir piston

grlmektedir. Biyel vastasyla ayrca krank miline de balanlacaktr.

Yanma odas

ierisinde yanma gerekletiinde, bunun sonucu olan kuvvet piston st yzeyine etki eder. Sonu

olarak Biyel aa

doru

hareket ettirilir. Krank mili dnmeye balar.

Geri

Piston tac

st Kompresyon segmanAlt Kompresyon Segman

Ya

kontrol kanal

Perno

segmanPiston etei

Biyel kolu

Biyel byk ba Biyel cvatalar

Yataklar

Egzos Kanal

Egzos

kanal

egzos

gazlarnn yanma

odasndan dar

atlmasn

salar. Bu durum egzos

strokunda

pistonun yukar

hareketinde gerekleir. Bu esnada egzos supab

da alm

olmaldr. Supap,

motorun dzgn almas

asndan doru zamanda alp kapanabilmelidir.

Geri

KelebekGrevi, yanma odasna giren hava miktarn

kontrol etmektir. Kelebek

aldka daha fazla miktarda hava ieri alnr. Daha fazla hava ve Yakt motor gcn

ve hzn

arttrr. Src

motor

hzn, hava kelebeini kontrol ederek ayarlar. Balant, gaz pedalna bal

kablo ile salanr.

Kelebek KontrolKelebek

Geri

EGR Valve

CopyrightCIAT2009

The EGR valve is used to help prevent the formation of NOx

during the combustion

process.

The EGR valve shown here is controlled by vacuum. This vacuum is controlled in various ways to allow the exhaust gases into the combustion process at the correct time and amount.

The valve allows a measured amount of exhaust gases to enter the combustion chamber before the ignition of the air fuel mixture. This lowers the peak combustion temperature, preventing the formation of NOx.

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Egzos SupabYanma odasn

egzost

kanalna kar

kapatr. Supaplarn

alp kapanmasn

kam mili kontrol eder.

4 strok

boyunca, egzost

strokunda

piston ykselmeye balayana kadar egzost

supab

kapal

konumda kalr. Bu

esnada kam mili vastasyla alan supap yoluyla gazlar egzos

kanalna doru sprlr. Sonrasnda emme stroku

balar. Egzost

supab

kapanarak emme supab

alr. Uygun miktarda hava/yakt karm

yanma odasna sevk

edilir. Bu esnada her iki supap da kapaldr ve sktrma sreci balar.

Geri

Emme SupabEmme strokunda

alr.

Pistonun aa

hareketi esnasnda yanma odasndaki basn

der. Dk basn, hava/yakt karmn

ieri alr.

Piston en alt noktaya ulatnda supap kapanr. Piston yukar

harekete balarken silindir ii basn

da artmaya

balar. Yanma odasndaki scaklk da artar. Piston strokunun

en st noktasna yakn ekilde ateleme

sistemi devreye girer ve yakt hava karm

atelenir.

Geri

Soutma SistemiSoutma amal

olarak silindir iinde

braklm

kanallardr. Ayrca silindir kafa konstrksiyonunda da bulunurlar. Soutucu akkan bu ceketler ve radyatr boyunca pompalanarak, snan svnn hava aracl

ile

radyatr kanatklarnda soutulmas

salanr

Geri

Biyel

Krank miline

Pistona

Piston ve Krank miline birbirine balar. Dorusal hareketin dnel harekete evrilmesinde ara yardmc

elemandr.

Geri

Kam mili zamanlamasZamanlama aretleri Kam milini krank miline gre ayarlamak son

derece nemlidir. Hem kam mili dilileri hem de blok yapda braklm

olan iaretler

mevcuttur ki bunlar uygunca denk getirilmelidirler.

Krank mili dilisi ayrca N

(st l

nokta) iaretine de sahiptir.

Bu ayarlarda reticinin direktifleri nem tar.

Geri

Supap Tolerans

CopyrightCIAT2009

The clearance between the stem of the valve and the rocker arm contact point is very important. If this clearance is not adjusted properly it could cause an engine running problem as well as an engine noise and or an emissions problem.

Some of these clearances are not adjustable and are controlled by hydraulics. In some cases there is a tolerance of up to .060in. The manufactures specifications should always be consulted with these issues of valve clearance and or adjustments.

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O2 Sensr Test

CopyrightCIAT2009 Next

Yava O2 Sensr

CopyrightCIAT2009

.080 secondMaximum to maximum Too Slow For

Modern-day Vehicle

Maximum .060 second

Next

Crossovers of .45V per second = 2

Minimum should = 3

O2 Sensr Test 2

CopyrightCIAT2009 Next

Proper Functioning O2 Sensor

CopyrightCIAT2009

.045 SecondMaximum to Maximum

Satisfactory ForModern-day Vehicle

Maximum .060 second

Crossovers of .45V per second = 4

Minimum should = 3

Air/Fuel MixtureAs the piston moves downward within

the cylinder, a low pressure is created. At this point the intake valve opens, allowing the air/fuel mixture to be forced into the low pressure area of the combustion chamber. The atmospheric pressure forces the air/fuel mixture into the low pressure area within the combustion chamber during the intake stroke.


Compressing Air/Fuel Mixture

As the piston moves up, within the cylinder, the air/fuel mixture is compressed. This compression causes the temperature of the mixture to increase. As the piston reaches near its highest point, the temperature is near the combustion point. Next the ignition ignites the air/fuel mixture by creating an arch

across the spark plug gap. CopyrightCIAT2009 Return

Heat and PressureThe combustion process produces high

pressure and temperature to the top of the piston. As the piston is in its downward stroke, it produces a pressure on the crankshaft. This produces the torque that is used to propel the vehicle down the road. The greatest torque is produced at about 12 degrees past top dead center, during the power stroke.


Exhaust GasesAs the piston moves up during the exhaust stroke, The exhaust valve must be open. The exhaust gases are what is left of the Air/Fuel mixture after the combustion process is completed. The ideal exhaust gases would consist of H2O vapor, CO2 and N2. However there is also some CO (carbon monoxide) HC (hydrocarbon) and Oxides on Nitrogen (NOx).


Valve SpringThe valve spring is used to properly seat the valve to prevent leakage. The seal is especially important during the compression and power stroke of the piston. If this spring is broken or is too week, it can cause drivability and or emissions problems. The proper seating can be check by conducting a cylinder leak down test.


Rocker ArmThe rocker is used to open the valve at

the proper time and allowing it to stay open for the proper length of time. In this case the rocker is controlled by a push rod which is controlled by the camshaft. Some rocker arms are adjusted to a specific clearance between the valve stem and the contact of the rocker arm.


Push RodThe push rod is used to control the opening and closing of the valve. The push rod is controlled by the cam shaft. As the rod is pushed up by the lob on the cam shaft, the push rod forces the rocker arm to open the valve into the combustion chamber. The push rod is used in engines where the camshaft is located in the block of the engine. CopyrightCIAT2009 Return

Fuel InjectorDoru miktarda yakt

, to create the

correct air/fuel ratio for the current demands on engine speed and power. The injector is turned on/off by the onboard computer (PCM). The fuel is broken up into a fine spray pattern by the injector. This spray is then vaporized by the low pressure in the combustion chamber during the intake stroke.

CopyrightCIAT2009 ReturnMalfunctions

Fuel Injector Malfunction

If the fuel injector should malfunction, it can cause driveabily

as well as emissions problems. If the injector

should not seat properly, it could cause a rich running condition (high CO). If the orifice should build up a carbon deposit, the spray pattern will be distorted and the results could be an incomplete vaporization of the fuel. This in turn could cause an incomplete combustion with a resulting high HC emission. Also, if the injector is not opening, it would cause a misfire. However, since there is no HC entering that combustion chamber, there would not be an increase in HC.


Ateleme ZamanlamasAteleme zamanlama iareti uygun olarak ayarlandnda , 1 nolu

piston st l

noktadadr. ekilde zamanlama zinciri muhafazasndaki iaret ile krank mili kasnandaki iaret bir hizaya getirilmitir. Genellikle bu izgiler st l

noktadan ok az

ndedirler.

GeriArzalar

Ignition Timing Malfunction

If the ignition timing is too far advanced, It can cause a pinging

problem within the

engine. This can also produce an elevated amount of both HC and NOx

exhaust

gases. By igniting the air/fuel mixture too early in the compression stroke, the result will be a higher peak pressure and temperature within the cylinder. This can produce elevated HC and or NOx

in the

exhaust gases. CopyrightCIAT2009 Return

Push RodThe push rod is the connection between the camshaft and the valve rocker arm. This push rod is used on the OHV (overhead valve) engine. In this case the camshaft is located within the engine block. The push rod is moved up and down as the camshaft lob comes in contact with it. This in turn opens and closes the corresponding valve, via the valve rocker arm.


Ignition SparkIgnition spark is used to ignite the air/fuel mixture within the combustion chamber. This is done when the piston reaches a proper point in its upward stroke. This position of the piston is determined by engine speed and load. This is termed as ignition timing. This was controlled by vacuum and centrifugal weights within the distributor in the older vehicles with mechanical ignition distributors. In the modern-

day vehicle spark timing is controlled by the PCM.


Initial Flame FrontWhen the ignition spark ignites the air/fuel mixture, a flame front is created in an area surrounding the spark plug. If the conditions for proper burning

of the

air/fuel mixture is correct, the flame front proceeds across the combustion chamber. If the air/fuel mixture is rich, the flame front will proceed faster. If the air/fuel mixture is lean, the flame front will move slower.


Second Stage Normal CombustionIf the combustion process is functioning normally, the flame front will proceed across the combustion chamber. It should be noted that the piston is still in its upward movement. This produces a higher pressure within the combustion chamber. Also, the burning

of the

air fuel mixture creates more heat and pressure. Thus the upward movement of the piston and the burning of the air/fuel mixture is creating a very high pressure, during the compression stroke of the piston.


Complete CombustionWhen the air/fuel mixture has burned to completion, The maximum pressure is produced within the combustion chamber. It should be noted the piston is in its downward movement at this point. The greatest torque produced on the crankshaft is when the piston is about 12 degrees past TDC. Now the piston will move to its bottom most position and then it will start moving up in the exhaust stroke.


Abnormal Combustion 1At times an engine will ping

or knock

during acceleration. One cause for this condition is carbon buildup on top of the piston or within the combustion chamber. Carbon retains heat. So when the piston moves up during the compression stroke, the carbon hot spot

can ignite the air/fuel

mixture. This will produce a second flame front and when the two collide, the result will be a ping

or knock.


Abnormal Combustion 2If the ignition timing is advanced too far, the results can be a pinging

during acceleration.

This is caused by the high pressure during the compression stroke. The flame front is proceeding across the combustion chamber. Meanwhile, the pressure is increasing causing the temperature within the chamber to increase. The air/fuel mixture will ignite at another point and cause a second flame front to be created. When these two flame fronts collide, It causes a ping.


Overhead Cam

CopyrightCIAT2009

The overhead cam engine has its camshaft located within the head. This eliminates the need for the pushrod which is used in the overhead valve engine. This type of valve function, at times, uses a rocker arm. However, some OHC systems control the opening and closing of the valves by directly positioning the valve stems next to the lobes of the camshaft. This eliminates the need for a rocker arm.

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Overhead Cam Engine

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The camshaft on this type of engine is located on the top portion of the cylinder head. This eliminates the need for a push rod

to control the

opening and closing of the valves. Nearly all modern-day vehicles have this type of camshaft operation. If there is only one camshaft per head, there is still a need for the rocker arm to control the opening and closing of the valves. If the vehicle has two camshafts per head, there is no need for a rocker arm. In this case, the camshaft lobes are in direct contact with the valve stem. In this case, there are some valve adjustments done with shims.

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Overhead Valve Engine

CopyrightCIAT2009

The camshaft, in an overhead valve engine, is located in the engine block. This requires a push rod

to

control the opening and closing of the valves at the correct time. The push rods fit into a cam follower which is in constant contact with the camshaft. Some of these cam followers were hydraulic controlled. This eliminated and valve adjustments. However, some were not hydraulic and these needed the proper valve clearance. Again, this adjustment must be performed on a warm engine for the proper clearance to adjust to a normal operating engine temperature.

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Push Rod

Cam Follower

Idle Air/Fuel AdjustmentThe proper air/fuel mixture, entering the engine at idle rpm, can be adjusted. The engine must be at the proper rpm and normal operating temperature. The mixture screw is turned clockwise to restrict the flow of fuel.With the engine running at proper idle speed and at normal operating temperature, the mixture screw is turned clockwise until the rpm starts to go down. The screw is then turned counter clockwise

turn. This should control the proper air/fuel mixture entering the engine at idle rpm.

CopyrightCIAT2009

Idle Air/Fuel mixture Adjustment Screw

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Carburetor Venturi AreaThe fuel is forced into the throat of the carburetor be the higher atmospheric pressure into the lower pressure within the carburetor. This lower pressure is created by the venturi

within the throat of the carburetor. The venturi

is like the shape of an airplane wing. In fact that is what causes an airplane to fly. As the air passes over the wing, a lower pressure is created on top of the wing. Thus the atmospheric pressure forces the wing up thus causing the plane to fly. The same thing happens within the venturi

area of the carburetor. The more air that passes over the venturi, the lower the pressure. The result is more fuel is forced into the carburetor throat. Thus the mixture stays balanced and the engine runs faster with more power.

CopyrightCIAT2009

Low PressureArea

Atmospheric Pressure

Return

Feedback CarburetorThe feedback carburetor is controlled by the on-board computer (PCM). It does so by controlling the mixture control solenoid within the carburetor. It either allows or disallows the fuel to enter the main discharge nozzle or the idle circuit. This controls the air/fuel ratio under various operating conditions. The technician can monitor the controlling signal to the discharge nozzle solenoid. This signal should be 30 degrees dwell under ideal air/fuel ratio. If the dwell reading is higher, the PCM is leaning out a rich mixture. The opposite is true, if the dwell reading is lower than 30 degrees, the PCM is richening up a lean running condition.


Fuel InjectorThe illustration on the left is of a fuel injector. The electrical terminals is when the injector is electrically connected to the PCM. The PCM controls the on time

of the injector by supplying

an electrical ground to the injector solenoid coil. The fuel in

shown in the illustration is

where the fuel is supplied to the injector at a constant pressure. When the solenoid coil is energized, the injector opens and the fuel is injected into the intake system.


Throttle Body Fuel Injection

This system of fuel injection is mounted on the intake manifold where the carburetor used to be. It should be noted the fuel pressure regulator controls the fuel pressure. Any fuel that is not required to maintain the correct fuel pressure is allowed to returned to the fuel tank. The idle speed is controlled by the PCM. It does so by controlling the amount of air allowed into the intake system below the throttle plate (idle air control valve). CopyrightCIAT2009 Return

Multiport Fuel InjectionThe multiport fuel injection system has one injector for each cylinder. Each of these injectors are controlled by the PCM. Each injector is located in the intake manifold next to the intake valve for that cylinder. The fuel pressure is maintained at a specific level. Any gasoline that is not needed to maintain this pressure is returned to the gas tank. The fuel pump can be located in the tank or any where along the line to the engine. CopyrightCIAT2009 Return

Contact Point Distributor Ignition

This type of ignition system uses a distributor with contact points. As these points close they provide a complete circuit for the coil primary circuit. As these points open, the magnetic field created by the current flow through the primary windings, collapse. This creates a very high voltage in the secondary windings of the coil. This is the voltage that is used to jump

the

sparkplug gap which begins the combustion process within the combustion chamber.


Distributor Ignition System (DI)

This ignition system uses a distributor that creates an electronic signal. This signal is sent to the control unit. This unit then opens and closes the coil primary circuit at the proper time. When the primary circuit is opened, the magnetic field created by the current flow through the primary windings, collapses and the high voltage is created in the secondary windings of the coil. This high voltage is directed to the cylinder sparkplug. This all happens at the correct time for the ignition of the air/fuel mixture within the combustion chamber.


Waste Spark Ignition System (EI)

This ignition system fires two sparkplugs at the same time. The secondary wire is connected to the cylinders that are on the opposite stroke when the piston is in its upward stroke. One plug fires on the compression stroke while the other fires on the exhaust stroke. This is called a waste spark

system, as when the coil fires, on sparkplug fires when there is no compression of air/fuel mixture to ignite. The opening and closing of the coil primary windings is controlled by the PCM.


Coil On Plug Ignition System (COP)

This type of ignition system uses one coil per sparkplug. The secondary of the coil is connected directly to the sparkplug. This system eliminates the need for sparkplug wires. This also eliminates the magnetic fields created by the sparkplug wires. These fields can cause computer control problems as it creates radio signals

which

can interfere with the computer sensor signals needed to fine tune the proper running of the engine. This ignition system is controlled by the PCM.CopyrightCIAT2009 Return

Slide Number 14 Stroklu ten Yanmal Motor4 Stroklu ten Yanmal Motor4 Stroklu ten Yanmal Motor4 Stroklu ten Yanmal Motor4 Stroklu ten Yanmal Motor4 Stroklu ten Yanmal Motor4 Stroklu ten Yanmal Motor4 Stroklu ten Yanmal Motor4 Stroklu ten Yanmal Motor4 Stroklu ten Yanmal Motor4 Stroklu Motor4 Stroklu Motor4 Stroklu Motor4 Stroklu Motor4 Stroklu MotorMotorlarMotorlarlk Aama Normal YanmaFirst Stage Normal Combustionkinci Aama Normal YanmaSon aama Normal YanmaAbnormal CombustionAbnormal Combustionstten Kaml Motorstten Kaml Motor Carburetor at IdleCarburetor at Off IdleFeedback CarburetorFuel InjectorThrottle Body Fuel InjectionMultiport Fuel InjectionContact Point Distributor IgnitionDistributor Ignition System(DI)Waste Spark Ignition System (EI)Coil on Plug Ignition Ignition TestIgnition TestThrottle PlateKrank MiliPistonEgzos KanalKelebekEGR ValveEgzos SupabEmme SupabSoutma SistemiBiyelKam mili zamanlamasSupap ToleransO2 Sensr TestYava O2 SensrO2 Sensr Test 2Proper Functioning O2 SensorAir/Fuel MixtureCompressing Air/Fuel MixtureHeat and PressureExhaust GasesValve SpringRocker ArmPush RodFuel InjectorFuel Injector MalfunctionAteleme ZamanlamasIgnition Timing MalfunctionPush RodIgnition SparkInitial Flame FrontSecond Stage Normal CombustionComplete CombustionAbnormal Combustion 1Abnormal Combustion 2Overhead CamOverhead Cam EngineOverhead Valve EngineIdle Air/Fuel AdjustmentCarburetor Venturi AreaFeedback CarburetorFuel InjectorThrottle Body Fuel InjectionMultiport Fuel InjectionContact Point Distributor IgnitionDistributor Ignition System (DI)Waste Spark Ignition System (EI)Coil On Plug Ignition System (COP)

[a305] motor konstrüksiyonu ders notu (motor elemanları ve Çalışma prensipleri)

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