08-03-2011, 12:28 PM
PRESENTED BY:
PRADEEP PATIL
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A PRESENTATION ON ENGINE COMPONENTS
ENGINE PURPOSE
• An engine is the power house of any vehicle
• An engine converts the fuel energy in to kinetic energy used to propell the vehicle on road
• Engine is also provided with the accessories and mountings for efficient working of the engine
• Engine components
WORKING OF ENGINE
• THE ENGINE WORK IN FOUR DIFFERENT STROKES
• SUCTION
• COMPRESSION
• POWER
• EXHAUST
• TYPES OF WORKING CYCLES
• TWO STROKE:- IN THIS TWO WORKING STROKES ARE COMPLETED IN SINGLE STROKE
• FOUR STROKE:- EACH STROKE IS COMPLETED IN DIFFERENT STROKE
MAIN COMPONENTS OF ENGINE
• ENGINE BLOCK
• ENGINE HEAD
• SUMP
• PISTON
• PISTON RINGS
• CRANK SHAFT
• CAM SHAFT
• CONNECTING ROD
• VALVE
• FLYWHEEL
• INTAKE MANIFOLD
• EXHAUST MANIFOLD
• TIMING CHAIN
• AIR FILTER
ENGINE BLOCK
• Engine block is the main part in the engine assembly.
• It comprises the moving parts.
• The block is provided with the provision for accessories and mountings.
• The engine block is casted as single in sand casting.
• The popular material for the engine block is cast iron, aluminum alloy etc
• The engine block is provided with the water jackets for circulating the coolant around the cylinder bore.
• The latest engine block materials contains alusil & nikasil
CYLINDER HEAD
• Cylinder head is the top portion of the engine it comprises the valve train.
• the cylinder head contains the poppet valves and the spark plugs, along with tracts or 'ports' for the inlet and exhaust gases
• The cylinder head also supports the spark plugs and fuel injectors.
• It also provided with the water jackets.
• The cylinder head is casted as single piece in cast iron casting or aluminum
• The aluminum is the most preferred material for the cylinder head as it is the lightest, corrosion resistant
Crank shaft
• Crank shaft is the rotating member in the engine assembly
• The reciprocating motion of the piston is transmitted into the rotary motion with the help of crank shaft.
• Crank shaft is roll forged or casted, but the roll forged crank shaft is most popular in commercial vehicles.
• The crank shaft is provided with journals
• It also provided with the oil holes for supplying oil
• The crank shaft is attached with the counter weights for proper balancing and smooth working of the engine during the idle strokes
GENERAL WORKING OF CRANK SHAFT
PISTON ASSEMBLY
• Piston is the reciprocating part inside the cylinder bore
• Piston is responsible for the suction and compression of the charge inside the cylinder cavity
• Pistons are die casted with aluminum alloy and sometimes with cast iron.
• They are provided with the spherical groove on top to achieve the max compression ratio with highest turbulence
• Pistons are provided with the piston rings usually three in nos. viz two compression and one oil control ring
• for improving the life of pistons they are coated with tin, graphite
CONNECTING ROD
• The connecting rod is the connecting member between piston and crank shaft
• The connecting rods are most usually forged of steel for production engines cast iron for applications such as motor scooters, aluminum alloys
• They are not rigidly fixed at either end, so that the angle between the connecting rod and the piston can change as the rod moves up and down and rotates around the crankshaft.
• The journal bearings are provided at crank end and other end is connected with the piston with the help of gudgeon pin.
• connecting rods made using powder metallurgy, which allows more precise control of size and weight with less machining and less excess mass to be machined off for balancing. The cap is then separated from the rod by a fracturing process, which results in an uneven mating surface due to the grain of the powdered metal
CAM SHAFT
• The cam shaft is the rotary component responsible for opening and closing of the inlet and exhaust valves
• The cam shaft is rotated with the help of timing chain or timing gear
• The cam shaft is provided with the cam lobes which causes the working of the valves
• The normal material for cam shaft is Chilled iron castings, Billet Steel
• The timing of crank shaft and cam shaft is so adjusted that the valves opens and closes at correct time
VALVES
• Valves are the gateways for the intake charge and exhaust gases
• The valves are operated with the help of cam shaft and cam lobes
• The opening and closing of the valve is done with the help of timing gear or timing chain
• The valves are cooled with coolant
• The sodium cooled valves are self cooled used for exhaust
• Valve seats made of improved alloys such as stellite
SPARK PLUG
• Spark plug is used to ignite the charge inside the engine cylinder
• Spark plugs are the electrical component in the engine assembly
• The spark plug produces the spark of about 10-15 thousand volts which produces 500-600̊ degree temperature
• The spark is produced in each cylinder during power stroke which is distributed with distributor according to firing order
FUEL INJECTORS
• Fuel injectors are used to inject the metered amount of fuel inside the cylinder during power stroke
• The fuel is metered with the solenoid
• The fuel is sprayed inside the cylinder in the form of little droplets formed due to pressurized fuel supply
• The injector is connected with the fuel pump
EXHAUST MANIFOLD
• The goal of performance exhaust headers is mainly to decrease flow resistance (back pressure), and to increase the volumetric efficiency of an engine, resulting in a gain in power output
• An exhaust manifold or header collects the exhaust gases from multiple cylinders into one pipe and delivers it into air
• Exhaust manifolds are generally simple cast iron or stainless steel units which collect engine exhaust from multiple cylinders and deliver it to the exhaust pipe
• The exhaust gases coming out from the exhaust manifold with high velocity thereby decreasing the temperature
• Ceramic paint is sprayed or brushed onto the manifold and then cured in an oven. These are usually thin, so have little insulatory properties however reduce engine bay heating by lessening the heat output via radiation.
• A ceramic mixture is bonded to the manifold via thermal spraying to give a tough ceramic coating with very good thermal insulation. This is often used on performance production cars and track-only racers.
• Exhaust wrap is wrapped completely around the manifold. Although this is cheap and fairly simple, it can lead to premature degradation of the manifold.
INTAKE MANIFOLD
• an intake manifold or inlet manifold is the part of an engine that supplies the fuel/air mixture to the cylinders
• The primary function of the intake manifold is to evenly distribute the combustion mixture (or just air in a direct injection engine) to each intake port in the cylinder head(s)
• Intake manifold is incorporated with the carburetor
• Intake manifold is generally fitted with air filters
• The intake manifolds are manufactured with venturi effect
