This includes major type of engine fundamentals, assembly, Engine System, type of engines, Engines design according to fuels types used.Servicing Engines (Overhauling and troubleshooting, Transmissions types, hydraulic systems, Steering and brake systems and stereo systems and their servicing etc.
Saturday, May 7, 2011
Engine Systems comprise on the following;
1. Starting System
2. Fuel System
3. Ignition System
4. Cooling System
5. Lubrication System
6. Intake System
7. Exhaust system
8. Charging System
9. Engine Electronic Control System
These are the systems for petrol engines. Diesel Engines have similar systems except for fuel and ignition System. Some parts of the system are built into the engine, some parts are attached to the engine and other parts are located on the body panels in the engine compartment.
The functions of these systems are summarized below. Some systems have been covered in this volume and the later blogs.
1. Starting System
The starter is used to rotate the engine during starting. It consists of an electric motor and a drive, the drive has a small pinion that meshes with the ring gear on the flywheel during starting. The battery supplies the electric current (energy) to operate the starter and rotate the engine until it fires and runs on its own. For details check the videos links
All these systems operate in different ways, but they all have somewhere to store fuel (a fuel tank or a cylinder) and a way of supplying the engine with the fuel. They also have a way of supplying air and fuel mixed in the correct proportions so that it can be effectively burnt in the combustion chambers.
§Automotive gas fuels are liquefied petroleum gas (LPG) and natural gas for vehicles (NGV)
You can check the below given link to learn visually that how fuel System works in Dual Fuel System?
Petrol engines and engines operating on gas require an ignition system. This is needed to provide sparks that fires the charges in the combustion chambers. For this reason, petrol engines are sometimes referred to spark-ignition engines. This distinguishes them from diesel engines that do not need spark because they use compression-ignition.
Combustion in the diesel occurs when the fuel is sprayed into the combustion chamber. The air in the cylinder is at high temperature from being compressed - high enough to ignite the fuel that sprayed from the injector.
Watch the video below that how ignition system works in Gasoline powered engine known as SI (Spark Ignition) engine.
A considerable amount of heat is produced in an engine by the burning air-fuel mixture. Some of the heat is used to do useful work, some is transferred to other parts of the engine and some is carried away with the exhaust gases.
However there is still some heat to cause damage unless it is removed. This is the function of the cooling system, which removes about one-third of the heat that is produced.
The cooling system does not just remove the heat; it maintains the engine temperature at a desirable operating temperature. In a liquid cooled engine, this is done by circulating the coolant through the water-jackets. In an air-cooled engine cooling is air by passing through the cooling fins.
Below is the link given for the Engine cooling System.
The engine lubricating system consists of an oil pump, a relief valve and a filter; also pipes, passages and drilling in various parts of the engine through which the oil can flow.
A quantity of oil is held in the oil pan or sump. From this the oil is taken by the oil pump and circulated throughout the engine before returning to the oil pan. The oil lubricates all the moving parts and this not only reduces friction but prevents wear and damage also. The oil pump is directly driven by the crankshaft. The system has an oil cooler, located at the filter mounting under the filter.
Below is the link given for the Engine Lubrication System.
In petrol engines with electronic fuel injection, the intake system includes the air cleaner, ducting, the throttle valve assembly and the intake manifold. Nozzles of the fuel injectors spray fuel into the air passing from the intake manifold into the intake ports.
With carburetor fuel systems, a mixture of air and fuel is carried from the carburetor, through the intake manifold and into the engine through the intake ports.
For engines that operate on gas a mixture of air and gas is carried into the engine by the intake manifold. In petrol engines with fuel injection, and in diesel engines, clean air only is provided by the intake manifold.
Below is the link given for the Engine Air Intake System. In the video you will see the combustion chamber, but the initial entrance of the air is through air pre-cleaner, air cleaner , (turbocharger, if installed), intake manifold, carburettor and finally to combustion chamber through opened intake valves.
The exhaust system carries away the burnt gases away from the engine, and also reduces noise. The system consists of the exhaust manifold, exhaust pipes, catalytic converter and a muffler. Arrangements vary with different engines-there may be more than one muffler and more than one catalytic converter. Engines that run on lead replacement petrol (LRP) do not have a catalytic converter, neither do diesel engines.
Exhaust system works as in-taken air enters, in the same way exhaust gases are discharged from engine through valves, Exhaust manifold (collects the burnt gases from all cylinders at one place then exhausts through muffler, in automobiles a catalytic converter is installed to convert the most dangerous CO into CO2)
8. Charging System
The alternator, which is driven from the engine, converts mechanical energy into electrical energy. The battery supplies energy for the starter the ignition system and the electronic fuel pump during the starting period (petrol engine) but once the engine is running, the alternator supplies all the electrical energy. It also recharges the battery to replace the energy used during starting.
Below is the link given for the Engine charging System.
The engine electronic control system consists of sensors, a control unit and actuators. The control unit receives signals from the sensors and then sends the signals to various actuators. There are sensors on the engine, in the intake system and in the exhaust system; the injectors are the actuators that adjust the spray of fuel. There are also actuators in the ignition system that advance and retard the spark.
Below is the link given for the Engine ECU System. This is an entire system which includes ECM (Electronic control module), cable or chords, sensors and warning lamps etc. Main programmed component is ECM that stores the commands of components actuation and accuracy of fluids charge and atomizers (injectors).