Internal Combustion Engine | Ic engine
- 1. INTERNAL COMBUSTION ENGINE By : Hamza Sudad & Saif Al-Din Ali
- 2. INTERNAL COMBUSTION ENGINE The internal combustion engine is an engine in which the burning of a fuel occurs in a confined space called a combustion chamber. This exothermic reaction of a fuel with an oxidizer creates gases of high temperature and pressure, which are permitted to expand.
- 3. MAIN DIFFERENCE – INTERNAL & EXTERNAL COMBUSTION ENGINE • The main difference between internal and external combustion engine is that in internal combustion engines, the working fluid burns inside the cylinder, whereas in external combustion engines, combustion takes place outside the cylinder and heat is then transferred to the working fluid. • internal combustion engine, the working fluid consists of a combustible fluid placed inside a cylinder. Four-stroke Diesel and petrol (gasoline) engines are internal combustion engines. In these engines, the fluid undergoes combustion inside the cylinder and expands. • external combustion engine, the combustion takes place outside the cylinder. Heat then needs to be transferred to the cylinder where work is done. Steam engines are an example of external combustion engines
- 4. THE MAIN COMPONENTS FOR IC ENGINE 1. Cylinder head 2. Cylinder block 3. Pistons 4. Piston rings 5. Piston pin 6. Connecting rod 7. Crank shaft 8. Cam shaft 9. Valves 10. Fly wheel 11. Fuel system 12. Ignition system 13. Cooling system 14. Lubrication system 15. Air cleaners
- 5. CYLINDER HEAD • The cylinder head is installed above the cylinder block where the top of the combustion chamber is formed • The cylinder head contains most parts of the combustion chamber such as valves, spark plugs or injectors. • It is placed between the head of cylinder and cylinder body (Gasket) to prevent leakage of gases, water and oil and makes the sides of the asbestos and steel or asbestos and red copper • Made of aluminum alloy
- 7. CYLINDER BLOCK • A cylinder block is the structure which contains the cylinder, plus any cylinder sleeves and coolant passages. • The main structure of an engine typically consists of the cylinders, coolant passages, oil galleries, crankcase and cylinder head(s) • Wet liner cylinder blocks use cylinder walls that are entirely removable, which fit into the block by means of special gaskets. • Engine blocks are normally cast from either a cast iron or an aluminum alloy. The aluminum block is much lighter in weight, and has better heat transfer to the coolant, but iron blocks retain some advantages and continue to be used by some manufacturers
- 8. ( CYLINDER BLOCK )
- 9. PISTON A piston is a moving disk enclosed in a cylinder which is made gas-tight by piston rings. The disk moves inside the cylinder as a liquid or gas inside the cylinder expands and contracts. A piston aids in the transformation of heat energy into mechanical work and vice versa. Because of this, pistons are a key component of heat engines
- 10. THE MAIN COMPONENTS OF PISTON 1. Piston Crown Piston crown forms the lower part of the combustion chamber in IC engine. It seals the cylinder and transmits the gas pressure to the connecting. As per the engine requirement, different types of crowns are used. The piston crown is subject to the high temperatures in the combustion space and the surface is liable to be eroded/burnt away. For this reason, the material from which the crown is made must be able to maintain its strength and resist corrosion at high temperatures. Steel, alloyed with chromium and molybdenum is used, and some pistons have a special alloy welded onto the hottest part of the crown to try and reduce the erosion caused by the burning fuel. The crown also carries the 4 or 5 piston ring grooves which may be chrome plated. It is basically has two type of shapes : Concave shape Convex shape
- 11. 2- PISTON RINGS A piston ring is a split ring that fits into a groove on the outer diameter of a piston in a reciprocating engine such as an internal combustion engine or steam engine. The main functions of piston rings in reciprocating engines are: 1. Sealing the combustion chamber so that there is minimal loss of gases to the crank case. 2. Improving heat transfer from the piston to the cylinder wall. 3. Maintaining the proper quantity of the oil between the piston and the cylinder wall 4. Regulating engine oil consumption by scraping oil from the cylinder walls back to the sump
- 12. 3- PISTON SKIRTS Piston skirt is fitted in both two stroke and four stroke engines. It has different function for different engines. In large cross head two stroke engines with uni-flow scavenging these skirts are short in length and are fitted to act as a guide and to stabilize the position of the piston inside the liner. It is generally made of nodular cast iron which have the following properties: Self lubricating Superior wear resistance
- 13. 4-PISTON PIN • The Piston pin is also called Gudgeon pin ,the gudgeon pin connects the piston to the connecting rod and provides a bearing for the connecting rod to pivot upon as the piston moves. • It’s a short hollow rod made of a steel alloy of high strength and hardness that may be physically separated from both the connecting rod and piston or crosshead.
- 14. CONNECTING ROD • A connecting rod is a rigid member which connects a piston to a crank or crankshaft in a reciprocating engine. Together with the crank, it forms a simple mechanism that converts reciprocating motion into rotating motion. • The connecting rod is under tremendous stress from the reciprocating load represented by the piston, actually stretching and being compressed with every rotation • Failure of a connecting rod is one of the most common causes of catastrophic engine failure. • To obtain minimal weight and high strength, connecting rods are made of the following materials:- Micro alloyed steels - Sintered metals - High-grade aluminum - CFRP and titanium (for high-performance engines) • Mass-produced connecting rods are forged, cast or sintered. Forged connecting rods exhibit a better strength-to-weight ratio and lower costs than sintered connecting rods. Die manufacture is however comparatively expensive.
- 15. CONNECTING ROD
- 16. CRANK SHAFT • mechanical part able to perform a conversion between reciprocating motion and rotational motion. In a reciprocating engine, it translates reciprocating motion of the piston into rotational motion • received the force affecting the pistons and transferred to the bearings • management of control gears and water pump, generator and fan The stresses affecting the column of the attachment: • 1 - stress of the bending. • 2. Torsion stress depends on torque, shaft length and dimeter. • 3- Torsional vibration depends on the column manufacturing material • 4 - friction in the locations of bearings Forging and casting • Crankshafts can be forged from a steel bar usually through roll forging or cast in ductile steel
- 17. CRANK SHAFT
- 18. CAMSHAFT A camshaft is a shaft to which a cam is fastened or of which a cam forms an integral part Timing - The relationship between the rotation of the camshaft and the rotation of the crankshaft is of critical importance. Since the valves control the flow of the air/fuel mixture intake and exhaust gases, they must be opened and closed at the appropriate time during the stroke of the piston. For this reason, the camshaft is connected to the crankshaft either directly, via a gear mechanism, or indirectly via a belt or chain called a timing belt or timing chain.
- 19. VALVES • A valve is a device that regulates, directs or controls the flow of a fluid (or gas) by opening, closing, or partially obstructing various passageways. • Valves form an integral component of an internal combustion engine and every cylinder in an engine at least has two of them, i.e. an intake (intake of fuel-air mixture) and an exhaust valve (exhaust gases). A multi-valve engine can have three, four and sometimes five valves. Multi-valve engines generally promise increased efficiencies for fuel combustion. • the intake valve open up at the start of the suction stroke and the exhaust valves open up during the exhaust stroke when the piston returns from BDC to TDC. The valves remain shut during compression and power strokes.
- 21. FLYWHHEL • A flywheel is a mechanical device specifically designed to efficiently store rotational energy. Flywheels resist changes in rotational speed by their moment of inertia. The amount of energy stored in a flywheel is proportional to the square of its rotational speed • a flywheel is used to smooth fast angular velocity fluctuations of the crankshaft in a reciprocating engine • Cast iron flywheels are used in old steam engines. Flywheels used in car engines are made of cast or nodular iron, steel or aluminum
- 22. FUEL SYSTEM • Components :- 1. Fuel Tank 2. Feed pumps 3. Fuel filter 4. Carburetor :This is the type for getting the air/fuel mixture into the combustion chambers. 5. Mechanical Fuel Injection
- 23. IGNITION SYSTEM • An ignition system is an array of components that are all involved in the process of igniting the air/fuel mixture in an internal combustion engine. • Compression ignition Diesel engines ignite the fuel-air mixture by the heat of compression and do not need a spark. They usually have glowplugs that preheat the combustion chamber to allow starting in cold weather.
- 25. . Radiator • To cool down the engine, a coolant is passed through the engine block, where it absorbs heat from the engine. The hot coolant is then fed into the inlet tank of the radiator (located either on the top of the radiator, or along one side), from which it is distributed across the radiator core through tubes to another tank on the opposite end of the radiator. As the coolant passes through the radiator tubes on its way to the opposite tank, it transfers much of its heat to the tubes which, in turn, transfer the heat to the fins that are lodged between each row of tubes. The fins then release the heat to the ambient air. Fins are used to greatly increase the contact surface of the tubes to the air, thus increasing the exchange efficiency. The cooled coolant is fed back to the engine, and the cycle repeats • Copper tubes and blades of aluminum
- 26. . WATER OR COOLANT PUMP • The Water pump is responsible for the flow of liquids through the cooling system, cooled water and coolant mix from the radiator is circulated into the middle of the pump and the centrifugal forces and spinning fins push the water and coolant mix to the outsides of the housing. There is a outlet pipe which then pumps this water to the cylinder head and engine block, to absorb the heat generated there. Water is then taken from the engine back to the radiator, ready to be cooled again and continue the cycle.
- 27. . RADIATOR FAN • The Radiator Fan is used when the vehicle is in a stationary position and there will not be enough air flowing through the radiator, as if it was in motion. With out this in place, the car will quickly exceed optimum operating temperatures and no doubt cause broken or damage to the engine. The fan is normally electronically operated via engine temperature sensors which monitor potential overheating, normal activation would only be while stationary, but in extreme conditions this will be fully automated to suit engine parameters
- 28. LUBRICATION SYSTEM • The engine lubrication system is to distribute oil to the moving parts to reduce friction between surfaces. Lubrication plays a key role in the life expectancy of an automotive engine . If the lubricating system fail, an engine would succumb to overheating and seizing very quickly. An oil pump is located on the bottom of the engine. The oil is pulled through a strainer, by the oil pump, removing larger contaminants from the mass of the fluid. The oil then forced through an oil filter under pressure to the main bearings and the oil pressure gauge. It is important to note that not all filters perform the same. A filter’s ability to remove particles is dependent upon many factors, including the media material (pore size, surface area and depth of filter), the differential pressure across the media, and the flow rate across the media. From the main bearings, the oil passes into drilled passages in the crankshaft and the big-end bearings of the connecting rod. The oil fling dispersed by the rotating crankshaft lubricates the cylinder walls and piston-pin bearings. The excess oil is scraped off by the scraper rings on the piston. The engine oil also lubricates camshaft bearings and the timing chain or gears on the camshaft drive. The excess oil in the system then drains back to the sump
- 30. AIR FILTER • A particulate air filter is a device composed of fibrous or porous materials which removes solid particulates such as dust, pollen, mold, and bacteria from the air. Filters containing an adsorbent or catalyst such as charcoal (carbon) may also remove odors and gaseous pollutants such as volatile organic compounds or ozone. Air filters are used in applications where air quality is important, notably in building ventilation systems and in engines. • Internal combustion engine air filters • The combustion air filter prevents abrasive particulate matter from entering the engine's cylinders, where it would cause mechanical wear and oil contamination. Most fuel injected vehicles use a pleated paper filter element in the form of a flat panel. This filter is usually placed inside a plastic box connected to the throttle body with duct work. Older vehicles that use carburetors or throttle body fuel injection typically use a cylindrical air filter,