Vorfüllkammer

Vorfüllkammer is a German term that translates to "pre-chamber" in English. It refers to a small, separate chamber located in the cylinder head of some internal combustion engines, typically diesel engines. The primary function of the Vorfüllkammer is to facilitate a more controlled and efficient combustion process.

During the compression stroke, a portion of the air is compressed into the Vorfüllkammer. As the fuel is injected, it mixes with the hot, compressed air in the pre-chamber. An ignition source, such as a glow plug, is usually present in the Vorfüllkammer to initiate combustion. The initial combustion within the pre-chamber creates a rapid expansion of gases and a pressure wave. This pressure wave then forces the remaining fuel and air mixture from the main combustion chamber into the pre-chamber, where complete combustion occurs.

This two-stage combustion process offers several advantages. It helps to atomize the fuel more effectively and promote better mixing with air, leading to more complete combustion and reduced emissions. It can also contribute to smoother engine operation and reduce diesel knock, a characteristic knocking sound associated with diesel engines. While effective, pre-chamber designs are less common in modern diesel engines, with direct injection systems becoming more prevalent due to their higher efficiency and lower manufacturing complexity.