A fuel supply system for an internal combustion engine may include a plurality of fuel injection pumps, each fuel injection pump being configured to pressurize fuel and provide the pressurized fuel to an associated fuel injector. The fuel supply system may further include a low-pressure fuel supply line fluidly connected to the plurality of fuel injection pumps and configured to provide fuel from a fuel supply tank to the plurality of fuel injection pumps. The fuel supply system may still further include a low-pressure fuel return line fluidly connected to the plurality of fuel injection pumps and configured to return remaining fuel from the plurality of fuel injection pumps to the fuel supply tank. The fuel supply system may include a first fuel cut-off valve disposed in the low-pressure fuel supply line and configured to stop a flow of fuel from the fuel supply tank to the plurality of fuel injection pumps.

A dual-fuel injector for a fuel injection device, including: a liquid fuel injector unit with a nozzle needle assigned to a liquid fuel nozzle arrangement of the dual-fuel injector and which is stroke controllable via a first control chamber; and a gas injector unit with a gas nozzle needle assigned to a gas nozzle arrangement of the dual-fuel injector and which is stroke controllable via a second control chamber. Each of the control chambers can be impinged with a control fluid to control the stroke of the respective nozzle needle. The control fluid from both the control chambers can be discharged. The dual-fuel injector has a control fluid reservoir in which discharged control fluid from the first control chamber can be introduced; the dual-fuel injector is configured to impinge the second control chamber with control fluid from the control fluid reservoir for the stroke control of the gas nozzle needle.

An energize-to-close solenoid operated spool type inlet control valve for a high pressure fuel pump is variably positionable relative to a sleeve having three inlet feed ports and the inlet check valve member, to implement three stages of pump operation: limp-home, low-pressure flow from the low-pressure feed pump to the common rail, no flow to the common rail, and metered quantity of flow to the common rail. The spool valve includes an axially extending internal passage fluidly connected to a fluid volume at the front end of the spool valve, and a control port at the back end of the spool valve, selectively alignable to fluidly connect the ports. Two springs of different lengths either alone or together, bias the spool valve toward opening of the inlet check valve.

The invention relates to a fuel-pumping device (1) for a fuel injection device of an internal combustion engine with a large high-pressure pump (16) and a small high-pressure pump (14) arranged in parallel, wherein fuel can be pumped by the large high-pressure pump (16) and by the small high-pressure pump (14) from a low-pressure region (13) into a high-pressure region (18). The high-pressure region (18) is connected to at least one injector (21). A control device (30) is provided, which can be used to conduct the entire pump output of the large high-pressure pump (16) or the small high-pressure pump (14) into the low-pressure region (13) via a discharge line (15).

An energize-to-close solenoid operated spool type inlet control valve for a high pressure fuel pump is variably positionable relative to a sleeve having three inlet feed ports and the inlet check valve member, to implement three stages of pump operation: limp-home, low-pressure flow from the low-pressure feed pump to the common rail, no flow to the common rail, and metered quantity of flow to the common rail. The spool valve includes an axially extending internal passage fluidly connected to a fluid volume at the front end of the spool valve, and a control port at the back end of the spool valve, selectively alignable to fluidly connect the ports. Two springs of different lengths either alone or together, bias the spool valve toward opening of the inlet check valve.

The pressure of the fuel is increased at a constant pressure intensification ratio after operating the pressure reducing device so that the pressure difference between the fuel passage and the control chamber after the operation has a value smaller than the predetermined pressure difference, if the required pressure of the fuel is higher than a reference pressure and lower than a pressure obtained by multiplying the reference pressure by a constant pressure intensification ratio.

The pressing part includes an abutment part capable of being in contact with the inner peripheral surface of the pressing passage, and a depressed opposite part that is opposed to the exhaust port at a position away from the exhaust port in a perpendicular direction perpendicular to the displacement direction due to an outer peripheral surface of the pressing part recessed from the abutment part even when the abutment part is in contact with the inner peripheral surface of the pressing passage. When the abutment part is in contact with the inner peripheral surface of the pressing passage, a depression dimension of the depressed opposite part relative to the abutment part is set, such that an amount of fuel discharged from the valve chest is defined by the exhaust throttle part instead of a gap between the depressed opposite part and the inner peripheral surface of the pressing passage.

A control valve arrangement includes a valve body with a filling chamber with a filling hole. A filling valve is arranged in the filling chamber for opening or closing a first fluid communication controlling filling of a first control chamber, the filling valve having a filling valve member with a moving valve seat, the filling valve member being normally biased open by a first spring. A control valve opens and closes a second fluid communication for controlling the emptying of the first control chamber, the control valve being normally biased closed by a second spring. A plug is arranged in the valve body for closing the filling chamber, the plug being provided with an opening which cooperates with the moving valve seat, the opening defining the first fluid communication between the filling chamber and the first control chamber.

A dual-fuel injector for a fuel injection device, including: a liquid fuel injector unit with a nozzle needle assigned to a liquid fuel nozzle arrangement of the dual-fuel injector and which is stroke controllable via a first control chamber; and a gas injector unit with a gas nozzle needle assigned to a gas nozzle arrangement of the dual-fuel injector and which is stroke controllable via a second control chamber. Each of the control chambers can be impinged with a control fluid to control the stroke of the respective nozzle needle. The control fluid from both the control chambers can be discharged. The dual-fuel injector has a control fluid reservoir in which discharged control fluid from the first control chamber can be introduced; the dual-fuel injector is configured to impinge the second control chamber with control fluid from the control fluid reservoir for the stroke control of the gas nozzle needle.