Accumulator fuel injection system

摘要

In a common rail system comprised of a first accumulator storing high-pressure fuel and a second accumulator storing low-pressure fuel, additional fuel is injected when a fuel pressure in a fuel passage or in the second accumulator (low inlet pressure of an injector) is reduced to a low pressure approximate to the pressure of the low-pressure fuel stored in the second accumulator after a switching valve is operated for disconnection from the fuel passage (switching valve drive signal OFF) at a point in time when a main injection control device finishes the injection of fuel (injector drive signal OFF) or after the main injection control device finishes the injection of fuel. This keeps the fuel pressure as low as possible during post injection to prevent the fuel from adhering to the wall surfaces of cylinder liners.