I.C ENGINE TERMINOLGOGY
The standard terms used in I.C Engines are
Inside diameter of the cylinder is termed as Bore.
2. Top Dead Center (TDC):
The extreme position reached by the piston at the top of the cylinder in the vertical engine is called Top Dead center.
3. Bottom Dead Center (BDC):
The extreme position reached by the piston at the Bottom of the cylinder in the vertical engine is called Bottom Dead center.
4. Stroke: The nominal distance travelled by the piston in the cylinder between the extreme upper and lower positions of the piston (TDC &BDC) is termed as stroke.
5. Compression ratio (r):
It is the ratio of Maximum cylinder volume to the Clearance volume.
6. Cylinder volume (v):
It is the sum of swept volume and the Clearance volume.
V = Vs + Vc
7. Swept volume (Vs):
It is the volume of space generated by the movement of piston
from one dead center to another dead center.
8.Clearance Volume( Vc):
It is the space in the cylinder, when the piston is at Top Dead
MAJOR PARTS OF AN IC ENGINE
• It is a round cylindrical casting in which a piston slides in and out to make strokes.
• Combustion take place inside the cylinder. The cylinder is closed by a cylinder head.
Material: Grey cast iron, Aluminium
2. Cylinder head
It is fitted to the top of the cylinder. It has inlet and outlet values, spark plug, Fuel injector, Water jackets.
Material: C.I, Aluminium 3. Piston
It is a device which transmits the energy (or) force of the expanding gas to the connecting rod. It slides up and down inside the cylinder.
Material: C.I, Aluminium alloy, Cast steel
4. Piston rings
Piston rings are inserted in the grooves of piston. There are two
types of rings.
1) Oil ring ( One ring is used)
2) Compression ring( Two ring is used)
5. Connecting rod
It converts the reciprocating motion of the piston into rotary motion of
crankshaft. The small end of the connecting rod is connected to piston and the big end is connected to the crankshaft.
Material: Plain carbon steel, Aluminium alloys
6. Crank shaft
It is the device used for getting power from the motion of the piston and connecting rod and this power is applied to the flywheel.
Material: Alloys steel.
It operates the opening and closing of the engine values. It has number of cams which are driven by crank shaft through timing gears. The function of the cam is to convert the rotary motion into the linear reciprocating motion
Material: Alloys steel
8. Crank case
It is the bottom portion of the I.C engine and holds the cylinder and the crank case. It also serves as a pump for the lubricating oil.
Material: Aluminium alloy, Cast iron 9. Flywheel:
It is a big wheel attached with crankshaft. It maintains the speed of the
10. Valves: The function of the value is to admit the fresh charge in the cylinder and to send the
exhaust gases out. There are two values namely inlet value and outlet value.
Material: Inlet value: Nickel chrome.
Outlet value: Nickel chrome, Stainless steel etc
11. Water Jackets
Water jackets are provided in the cylinder head. The purpose of water jackets is to keep the walls of the engine cool.