The Engine and its parts
Automobiles, as discussed earlier, are powered by the engine and the magnitude of power produced depends on the size or capacity of the engine. The engine mainly works on 2 models ie either the engine works on 2 stroke engine models or 4 stroke engine models. But before we jump into these categories we need to understand various parts of the engine associated and what are their basic functions.
Various parts of an engine include
Engine Block
Cylinders
Pistons
Intake Valves
Exhaust Valves
Cam Shaft
Crankshaft
Connecting rod
Fuel injector
Spark plugs
Piston Rings
We shall discuss a brief below:
Engine Block
The engine block is a single casting block generally made up of Aluminum alloy. This is a single piece that has all the holes and space to include all the various parts of the engine along with coolant passages. This block is made high temperature resistant, high thermal conductivity to transfer heat into the coolant and strong enough at the same time. In short, the engine block is where the integration of all the other parts associated.
Cylinders
The cylinders are the most important part of an engine. The cylinders are basically described as a closed cylindrical hole in the engine block of some specific values that describes the capacity for an engine. The engine cylinders are the place where all the magic happens. Air and fuel mixtures are sprayed into the cylinders where when compressed combustion takes place due to high heat and pressure and the power is produced. Power and the capacity of an automobile depending on the number of cylinders along with some special arrangements. For example inline-four, V6. V8, W12, W16 are some of the cylinder arrangements.
Pistons
Pistons are a small light cylindrical component of an engine generally made up of aluminum alloy having high thermal conductivity. This component is placed inside a closed chamber, cylinder as discussed earlier. Piston reciprocated from one end to another inside the cylinder which sucks the air into the cylinder, compresses it, increases the temperature and pressure for combustion to take place, and then evacuates the burnt fuel.
Valves
For combustion to take place we need to allow the air-fuel mixture to enter the cylinder. This is done through the help of intake valves. Valves are nothing but just a small component that is triggered by spring action via camshafts. When the spring compresses it makes intake valve to move a little, making a small passage so that air can be sucked in and when spring relaxes the valve comes back to its original closed position. Exhaust valves also work in the same manner but used to remove the burnt gases after the combustion. Valve timing is the most important thing for proper combustion, efficient engine, and good fuel economy. Better the valve timing, efficient is the engine.
Camshaft
The camshaft is rotating shafts that are located on the top of the cylinder head. Camshafts include cams of different orientations which are used to change the orientations also called lobes. For example, camshafts with cam profile lobes, flat from one end, and a small outward protrusion on the other end are in contact with the valves, when the outward protrusion side rub against the valves it presses the valves and when the flat side comes in contact the valve comes back to its original position. So this is how the rotational motion of camshafts is changed into linear motion, and the main function of camshafts is to open and close valves at the right time.
Crank Shaft
Crankshafts are the rotating shafts located below the engine block that is used to convert reciprocating motion into rotational motion. Crankshafts are connected to the piston via a connecting rod. When the piston reciprocates the crankshaft rotates which is then connected to the flywheel.
Connecting Rod
The connecting rod is usually made of steel alloys. Connecting rods have 2 ends namely small end and big end. The small end is connected to the piston through a piston pin or gudgeon pin and the big end is connected to the crankshaft through the crank pin.
Fuel Injectors
Fuel injectors are the components that are responsible for the spray of fuel into the intake manifold. The main function of fuel injectors is to spray fuel in specific amounts at the right time and in atomized form.
Spark Plugs
Spark plugs are a part of the ignition system. These are placed on the top center of the cylinder which is controlled by ECU mainly in gasoline engines. Spark plugs are responsible to initiate the actual combustion process. When the air-fuel mixture compresses to a certain high temperature and pressure, the spark plug creates a small spark thus initiating the combustion.
Piston Rings
Piston rings are yet another important component in automobile engines. Piston rings are thing metallics clips which are attached to the outer diameter of the piston Without piston rings, the engines will not work for a minimum time even. Piston rings are basically used to isolated the combustion chamber from the piston. There are 3 types of piston rings, the top two rings are compression rings for sealing the combustion chamber and thirl is an oil ring to control the oil supply.
The main functions of piston rings are
- Airtight Sealing the combustion chamber so that there is minimal loss of gases into the crankcase.
- Improving thermal conduction from the piston to the cylinder wall.
- Maintaining the proper quantity of the oil between the piston and the cylinder wall to reduce wear and tear.
- Regulating engine oil consumption by scraping oil from the cylinder walls back to the oil sump
The engine is the most interesting component for an automobile and studying about the engine, its functioning is really very interesting.
