Fuel injection control system for internal combustion engine is used with double injectors with outer control needle for diffuse pilot injection and inner needle for conventional injection

摘要

The fuel injectors (14) are fed with high-pressure fuel from a common rail (16) supplied with fuel by a high-pressure pump (26). Each injector has an outer control needle which may be lifted to give a diffuse fuel spray and an inner control needle which may be lifted to give a concentrated fuel spray. A control circuit (36) regulates the operation of the injectors to give a diffuse pilot spray to give a lean homogenous mixture in the cylinder (11) as the piston (15) is rising on the compression stroke. A conventional concentrated spray is injected near top dead center to give a local rich mixture and ignition.