1.4. Engine

Engine

Machinery or motor vehicles is a source of energy. Views of its kind, the motor consists of electric motors, nuclear motor, motor fuels and others. Especially for the motor fuel, based on location of combustion, the engine is divided into two types, namely: external combustion engine (external combustion engines) such as steam engines and internal combustion engine (internal combustion engines) such as gasoline engines, diesel engines, and Wankel engine . Most engines in cars using internal combustion engine utilizing pistons, and which always developed is the gasoline engine and diesel engines.

To get the vehicle dynamics, the heat energy required is obtained from the combustion process. To generate the motion energy required some supporting elements, namely:

• The air, fuel, heat
• reciprocating motion & motion rotating
• Compression of the mixture of air - fuel
• Cycle engine

Terms happen include burning fuel (gasoline, diesel fuel, bio-diesel and other), oxygen and heat (ignition system of petrol engine or the heat of compression on diesel engines). This combustion process will take place sequentially in a cycle that will work repeatedly. This working cycle consists of:

1. Filling the cylinder with a combustible mixture (step suction)
2. Pressing the mixture until at a certain volume (the compression step)
3. Lit so that the mixture expands and produces power (step operation)
4. Removing the gas - a gas that has been burned from the inside cylinder (step flue)

Figure 1:18. Scheme 4 engine and the second step (not)

The fourth step is a step sequentially suction, compression, effort, wasted. Silkus machine itself is divided into two, namely four step cycle machine / no and engine two steps / no. Four steps in one machine cycle times there are four steps piston, two up and two down. Thus, in one cycle is reached in the second round of the crank shaft. Being two steps in one machine cycle pistons there are two time steps, one upstairs and one down, achieved in the first round of the crank shaft.

The amount of power generated by the motor power of a machine depends on:

• Cylinder volume
• Cylinder diameter
• Compression ratio
• Volumetric efficiency
• Thermal efficiency
• Mechanical efficiency

Engine capacity expressed in units of cc (cubic centimeters) or too liter. The capacity of this machine can also be used as indicators of the labor movement will be generated, however for the same cc not necessarily have the same power. There is a variable diameter of the piston, crank steps, as well as construction of the machine itself. Cylinder capacity obtained from the formula:



KS = (ʌ / 4) D2
L n, wherein:
KS = cylinder capacity
D = diameter of cylinder
L = step piston
n = number of cylinders




From the formula above, the diameter cylinder will cause a greater capacity (because D dikuadratkan) so that engine power will also increase. Based on the comparison of the diameter and the step, the machine is divided into three types, namely:
a. Square Engine = diameter equal to step
b. Over-square Engine = diameter greater than the step
c. Long stroke Engine = diameter smaller than the step

While the theoretical power (horse power indicator) can be calculated using the formula:
P L A N K
Dki = -------------- TK
60 x 75

• P = average effective pressure (kg/cm2)
• L = step piston (m)
• A = cross-sectional area of cylinder (cm2)
• N = rotation motor
• K = number of cylinders

Above formula is theoretical, because the actual motor power is also influenced by volumetric efficiency, losses to friction, heat and other losses. When these machines are constantly being developed there are two major groups, namely gasoline and diesel engines. The development of these machines continue to compete. In gasoline engines, components that support is the fuel system, ignition system, lubrication system, cooling system, charging system and electrical system. While the diesel engine is almost the same, only without the ignition system, utilizing combustion heat due to high pressure in the combustion chamber. Progress continues

done is increase the efficiency of fuel consumption and exhaust emission mines.

Figure 1:19. Increasingly compact car engine

BODY AUTOMOTIVE Vol 1