4 stroke internal combustion engine work
Principle of operation of machines For a machine to work successfully, it must follow an orderly cycle of operation. The sequence is very rigid and cannot be changed. The working principle of SI and CI engines is described in the following sections. Although both engines have a lot in common there are some basic differences. Nicholas A. How does a 4 stroke internal combustion engine work is credited with inventing the spark-ignition engine. Otto (1876) while the compression-ignition engine was invented by Rudolf Diesel (1892). Hence, they are often referred to as otto engines and diesel engines. Mechanical components 4-stroke internal combustion engine work The main components of a cross-section engine of a single-cylinder spark-ignition engine with overhead valves and their functions are briefly described below. How does a 4 stroke internal combustion engine work Cylinder Block: The cylinder block is the main subsystem For different components. The cylinders of a multicylinder engine can assembled into a single unit called a cylinder block. The cylinder head and cylinder block are provided with water jacket when water cooled or cooling fins when air cooled. A cylinder head gasket can included between the cylinder block and the cylinder head. The cylinder head can rigidly attached to the cylinder block by a number of bolts or studs. How does a 4 stroke internal combustion engine work The lower part of the cylinder block can called the crankcase. Attached to the bottom of the crankcase can a cover called the crankcase which becomes the sump for the lubricating oil. The inner surface of the cylinder block can machined and precisely shaped into a cylindrical shape and can called the bore or face. How does a 4 stroke internal combustion engine work As the name suggests it is a cylindrical vessel or where the piston does the reciprocating motion. How does a 4 stroke internal combustion engine work During engine operation the various blocks formed in the cylinder can filled with working fluid and subjected to various thermodynamic processes. Piston: It is a cylindrical component that fits into the cylinder and forms the moving boundary of the combustion system. It fits perfectly into the cylinder and provides a gas-tight space with piston rings and lubricants. Combustion Chamber: The space at the top of the cylinder covered by the cylinder head and the top of the piston during the combustion process can called the combustion chamber. Combustion of fuel and release of heat energy creates pressure in this part of the cylinder. Inlet Manifold: The pipe that connects the intake system to the inlet valves of the engine and through which the air or air-fuel mixture can drawn into the cylinder can called the inlet manifold. How does a 4 stroke internal combustion engine work Exhaust Manifold: The pipe that connects the exhaust system to the exhaust valve of the engine and through which the combustion products can released into the atmosphere. Inlet and Exhaust Valves: Valves can usually mushroom-shaped poppet types. These are provided in the cylinder head or on the side of the cylinder to regulate the charge entering the cylinder (inlet valve) and exhaust the combustion products from the cylinder (exhaust valve). Spark Plug: This is the component that initiates the combustion process in sparkignition (SI) engines and is usually located in the cylinder head. Components Connecting Rod: It connects the piston and the crankshaft and transmits the gas forces from the piston to the crankshaft. How does a 4 stroke internal combustion engine work The two ends of the connecting wire can called the small end and the large end (Fig. 1.3). The smaller end can connected to the piston by the gudgeon pin and the larger end can connected to the crankshaft by the crankpin. Crankshaft: It converts the reciprocating motion of the piston into effective rotary motion of the output shaft. How does a 4 stroke internal combustion engine work The crankshaft of a single cylinder engine consists of a pair of crank arms and balance weights. Balance weights are provided for static and dynamic balance of rotating system. The crankshaft can attached to a crankcase. Piston Rings: Piston rings fitted in slots around the piston provide a strong seal between the piston and the cylinder wall, preventing leakage of combustion gases (see Figure 1.3). Gudgeon Pin: It connects the small end of the connecting rod and the piston. How does a 4 stroke internal combustion engine work Camshaft: The camshaft (not shown in the figure) and its associated parts control the opening and closing of the two valves. The parts involved are push rods, rocker arms, valve springs and tappets. This shaft provides the drive to the ignition system. The camshaft can driven by the crankshaft through the timing gear. Cams: These can formed as an integral part of the camshaft and can designed to open the valves at the right time and hold them open for the required duration (not shown in the figure). Flywheel: The net torque supplied to the crankshaft during a full cycle of engine operation causes fluctuations, How does a 4 stroke internal combustion engine work which cause angular changes, in the form of a wheel connected to the output shaft, this wheel can called a flywheel. (not shown in picture). Cylinder Bore (D): The nominal internal diameter of the working cylinder can called the cylinder bore and can denoted by the letter D and can usually expressed in millimeters (mm). Piston Area (A): The area of a circle with a diameter equal to the cylinder bore can called the piston area and can denoted by the letter A and can usually expressed in square centimeters (cm2). Stroke (L): The nominal distance that a working piston moves between two consecutive reversals of its direction of motion can called the stroke and can denoted by the letter L and can usually expressed in millimeters (mm). Stroke to Bore Ratio: L/T ratio is an important parameter in sizing an engine. If d < L, … Read more