Kaasuttimijärjestelmät

Kaasuttimijärjestelmät, commonly known as carburetors, are a type of engine fuel delivery system that mixes air and fuel for internal combustion engines. They were the primary method of fuel delivery in gasoline engines for many decades before being largely replaced by fuel injection systems. A carburetor operates on the principle of the Venturi effect, where a constriction in the airflow passage causes the air velocity to increase and its pressure to decrease. This low-pressure area draws fuel from a fuel bowl through a jet, atomizing it into the airflow.

The basic components of a carburetor include a float chamber that maintains a constant fuel level, a main jet that meters fuel flow at higher engine speeds, and a throttle valve that controls the amount of air entering the engine, thereby regulating engine speed and power. Various circuits, such as idle circuits and accelerator pumps, are incorporated to ensure proper fuel-air mixture across the entire operating range of the engine. For example, the idle circuit provides a richer mixture at low engine speeds, while an accelerator pump injects a small amount of extra fuel when the throttle is suddenly opened to prevent a lean condition.

While effective and relatively simple in design, carburetors have several limitations. They are sensitive to temperature and altitude changes, which can affect performance and emissions. Achieving precise fuel-air ratios, especially under varying engine loads and speeds, can be challenging, leading to less optimal fuel efficiency and higher emissions compared to modern fuel injection. Environmental regulations and the demand for improved performance and fuel economy have driven the widespread adoption of electronic fuel injection systems.