The Capability Of Forming Injection Rates For HSDI Diesel Engines With Unit Injector Systems

The development of future passenger car diesel engines has to be pointed in many directions. Present diesel techniques already set high standards on fuel economy, as the gasoline engines with catalytic converters did in passenger car application on performance, exhaust emissions, noise and vibrational emissions.

Unit Injectors for airborne mixing direct injection diesel combustion offer the flexibility necessary to form injection rate patterns and associated injection pressures for the sake of combustion tuning. The development steps of a small pilot injection of high cyclical precision which is load independend at lower speeds and which disappears into a high-rated injection at the upper speed range are discussed. Recent test results of a prototype engine indicate the high potential of HSDI engines with such Unit Injectors to meet standards on fuel economy in combination with performance and emissions far beyond today's serial diesel engines for passenger cars.