History and Development
Carburetor first invented by Karl Benz in 1885 and patented in 1886. In 1893 the Hungarian national engineer named János Csonka and Donat Banki also design a similar device. Was Frederick William Lanchester of Birmingham, England who first experimented using a carburetor on the car. In 1896 Frederick and his brother built the first car that uses gasoline in the UK, single cylinder-powered 5 hp (4 kW), and an internal combustion engine (internal combution). Not satisfied with the final result obtained, mainly due to the small power output, they are rebuilding the engine, this time they used two horizontal cylinders and also redesign their carburetors. This time they were able to finish the tour cars along 1,000 miles (1600 km) in 1900. This is a step forward in the field of automotive carburetors use
Carburetor berhahan commonly used for automobile gasoline until the late 1980s. After a lot of electronic controls used in cars, the use of carburetors being replaced by fuel injection system because it easily integrates with other systems to achieve fuel efficiency.
design
Carburetors can be grouped according to the direction of air flow, barrel and venturi type. Each carburetor combines all three in its design.
Direction of air flow
1. Flow down (downdraft), air enters from the top of the carburetor and then out through the bottom of the carburetor.
2. Flow TV (sidedraft), air enters from the side and flows out through the horizontal direction and then the next.
3. Flow rose (updraft), the inverse of the flow down, air enters from the bottom and out through the top.
Barrel
Barrels were airways in which there is a venturi.
Single barrel, only one barrel. Commonly used on motorcycles or cars with small engine capacity.
Multi barrel, memimiliki more than one barrel (generally two or four barrels), to meet the demand for greater air flow, especially for machines with large capacity engines.
Venturi
1. Venturi Still, in this type of venturi size is always fixed. Regulate gas pedal air valve which determines the amount of air flow through the venturi sehigga determine the amount of pressure to draw fuel.
2. Venturi move, in this type of gas pedal set venturi size by using a piston that can go up and down to form a venturi gap can be fickle. Venturi piston fluctuations are accompanied with fluctuations needle jet that regulates the amount of fuel that could be interested as well as the flow of air. This type is also called "constant pressure" due to the air pressure before entering the venturi is always the same.
Working Principle
Basically carburetor works using Bernoulli's principle: the faster air moves, the smaller its static pressure, but the higher its dynamic pressure. Gas pedal on a car actually does not directly control the amount of flow of fuel into the combustion chamber. Actual gas pedal control valve in the carburetor to determine the amount of air that can flow into the combustion chamber. The air is moving in the carburetor that has the pressure to attract and fuel into the combustion chamber.
Most machines berkarburator have only one carburetor, but some are using one carburetor for each cylinder owned. Even had a trend motorcycle modification in Indonesia the use of multi-carbu (many carburetors), but this is usually only used as decoration with no technical function. Early generation machines use carburetors upward flow (updraft), where the air enters through the bottom of the carburetor and then out through the top. The advantage of this design is to avoid the occurrence of engine flooding, the excess liquid fuel will spill out directly to the carburetor and into the intake mainfold; advantage is the bottom of the carburetor can be connected to the oil channels that are involved there is little oil into the air stream and are used to wash the air filter; however using air filters made of paper using oil washing is no longer needed now.
Beginning in the late 1930's, the flow carburetor down (downdraft) and flow laterally.
operational
At any time of the operation, the carburetor should be able to:
> Adjust the amount of airflow into the combustion chamber
> Deliver fuel with the right amount of air to flow into the combustion chamber so that the ratio of fuel / air is maintained.
> Mixing of air and fuel Airan flat and perfectly
The above items will be easier to do if only gasoline and air is an ideal fluid 'but in fact, by their nature, namely the viscosity, fluid friction, fluid inertia, and so karbrator become very complex in overcoming this situation is not ideal. Also carburetor must remain capable of producing a mixture of gasoline / air right under any circumstances, because the carburetor must operate in temperature, air pressure, engine speed, and centrifugal force is very diverse. Carburetor must be able to operate in a state :
> Start the engine in the cold
> Start in hot conditions
> Langsam or running at low speed
> Acceleration when the gas suddenly opened
> High speed with a fully open gas
> Steady pace with the gas partially open for long periods of time
Modern carburetor should also be able to reduce the amount of vehicle emissions.
base
Carburetor basically an open pipe on both ends, the pipe is moving toward the intake air into the engine mainfold head / combustion chamber. Venturi-shaped pipe, from one end of the wide surface and narrow in the middle and then widens again at the other end. This shape causes the air flow velocity increases when passing through a narrow passage.
In the fixed venturi type, tip carburetor equipped with air valve butterfly valve called the throttle (gas valve), a kind of disc that can rotate to close and open movement of air flow so it can adjust the amount of air / fuel in the combustion chamber. The number of the air / fuel is what determines the power and / or speed of motion machine. Gas pedal, or on motorcycles, gas grip is connected directly to the valve via cable. But the venturi type move, where the valve is not found as a set the size of the flow of air / fuel is the venturi size itself can vary. Gas pedal or grip connected to a piston that regulates the narrow gap in the venturi
Fuel sprayed the air flow through small channels contained in a narrow space inside the venturi. Low pressure of air moving in the venturi draw fuel from the carburetor bowl so that the fuel is ejected and follow the flow of air. These channels are called jets.
Open the gas from the throttle
When the handle is opened a little gas from the fully closed position, there is a venturi section having a lower pressure valve being closed due to spinning. This section provides a carburetor jet more than the other to smooth the distribution of fuel in the air stream.
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