Yksikköruisku

Yksikköruisku is a Finnish term that translates to "unit injector" in English. It refers to a type of fuel injection system used primarily in diesel engines. In a unit injector system, each cylinder has its own injector unit, which combines the fuel pump and the injector nozzle into a single, compact assembly. This unit is typically driven by the engine's camshaft.

The operation of a unit injector involves the camshaft lobe pressing on a roller lever. This lever actuates a plunger within the injector body, creating the necessary pressure to inject fuel directly into the combustion chamber. The timing and duration of the injection are precisely controlled, contributing to efficient combustion and reduced emissions.

Compared to older mechanical injection systems, unit injectors offer advantages such as higher injection pressures, more precise control over the injection process, and improved fuel atomization. This can lead to better engine performance, increased fuel economy, and lower exhaust pollutant levels. However, unit injector systems can be more complex and expensive to manufacture and repair. They were a significant development in diesel engine technology, widely adopted in many commercial vehicles and some passenger cars before being superseded by common rail systems in many applications.