초록 ▼

An electronic engine management unit includes means for actuating each injector individually at a selected different time, and for a prescribed interval, during each cycle of the engine. A high pressure fuel supply pump having a high pressure discharge passage is fluidly connected to the common rail

An electronic engine management unit includes means for actuating each injector individually at a selected different time, and for a prescribed interval, during each cycle of the engine. A high pressure fuel supply pump having a high pressure discharge passage is fluidly connected to the common rail, and to a low pressure feed fuel inlet passage. A control subsystem controls the discharge pressure of the pump between injection events, by diverting the pump discharge so that instead of delivery to the common rail, the flow recirculates through the pump at a lower pressure. This is preferably accomplished by an inlet control passage fluidly connected to the low pressure feed fuel inlet passage, a discharge control passage fluidly connected to the high pressure discharge passage, and a non-return check valve in the high pressure discharge passage, between the discharge control passage and the common rail, which opens toward the common rail. A control valve is fluidly connected to the inlet control passage and to the discharge control passage, and switch means are coordinated with the means for actuating each injector. While the pump discharge passes through the control circuit but immediately before each injector actuation, the hydraulic circuit is substantially closed whereby the pump output pressure rises from the holding pressure to the high pressure. When the pump output pressure reaches the high pressure an injector is actuated.

대표청구항 ▼

1. A gasoline fuel injection system for an internal combustion engine comprising:a plurality of injectors for delivering fuel to a respective plurality of engine cylinders; a common rail conduit in fluid communication with all the injectors for exposing all the injectors to the same supply of high p

1. A gasoline fuel injection system for an internal combustion engine comprising:a plurality of injectors for delivering fuel to a respective plurality of engine cylinders; a common rail conduit in fluid communication with all the injectors for exposing all the injectors to the same supply of high pressure fuel; means for actuating each injector individually at a selected different time during each cycle of the engine; a high pressure fuel supply pump having a high pressure discharge passage fluidly connected to the common rail, and a low pressure feed fuel inlet passage; a discharge pressure control subsystem including, an inlet control passage fluidly connected to the low pressure feed fuel inlet passage, a discharge control passage fluidly connected to the high pressure discharge passage, a non-return check valve in the high pressure discharge passage, between the discharge control passage and the common rail, which opens toward the common rail, a control valve fluidly connected to the inlet control passage and to the discharge control passage, and switch means coordinated with the means for actuating each injector, for controlling the control valve between a substantially closed position for substantially isolating the discharge control passage from the inlet control passage and a substantially open position for exposing the inlet control passage to the discharge control passage.