The fuel injection valve has a hydraulic control device for controlling the axial movement of the injection valve member. The stem of the intermediate valve member of mushroom-shaped configuration of the intermediate valve is guided in the guide recess of the intermediate part. In the open position, the intermediate valve member opens up a second connection between a high-pressure fuel inlet and a valve chamber and, in the closed position, the intermediate valve member shuts off the second connection between the high-pressure fuel inlet and the valve chamber. In the closed position of the intermediate valve member, the head of the intermediate valve member lies with a side facing toward the intermediate part against the intermediate valve seat via a first sealing surface, which runs around the stem or the guide recess at a first radial spacing so as to form a first annular sealing surface which is continuous in the circumferential direction.

A valve system includes a guide member having a passage, a seal member positioned relative to the passage, and a valve stem disposed within the guide member passage to move axially relative to the guide member and the seal member. The seal member has an inner circumferential surface defining a bore, an outer circumferential surface, and an intermediate seal portion therebetween. The intermediate seal portion includes a first axial end surface and a second axial end surface. The seal member further includes a ramp on at least one of the first axial end surface and the second axial end surface. The ramp is descending from the inner circumferential surface to one of the intermediate seal portion or the outer circumferential surface.

The subject matter of this specification can be embodied in, among other things, an apparatus that includes a high-pressure pump having a pump element, a regulating device positioned upstream of the high-pressure pump, a fuel channel defined between an inflow side of the regulating device and the pump element, and a safety device, actuatable to reduce a through-flowable cross section of the fuel channel.

A fuel pump for a liquid fuel injection system of a motor vehicle is provided. The fuel pump for a fuel injection system includes a low-pressure pump that provides liquid fuel from a fuel tank of the motor vehicle at a low pressure. A high-pressure pump in fluid communication with the low-pressure pump and compresses the liquid fuel from the low pressure to a high pressure for injecting the liquid fuel into an internal combustion engine of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.

A high pressure fuel pump includes an inlet metering valve arranged to control a quantity of fuel delivered to the pumping chamber during retracting motion of the pumping plunger. The inlet metering valve includes a metering valve member movable between a closed position and an open position, movement of the metering valve member from the closed position to the open position defining a variable flow area that increases as the metering valve member moves from the closed position toward the open position. An actuator piston in an actuator bore is exposed to pressure in the common rail. The actuator piston is biased toward a first position corresponding to low pressure in the common rail and movable toward a second position corresponding to maximum pressure in the common rail. The actuator piston includes a valve stop that determines a metering position of the metering valve member.

A high pressure fuel pump includes an inlet metering valve arranged to control a quantity of fuel delivered to the pumping chamber during retracting motion of the pumping plunger. The inlet metering valve includes a metering valve member movable between a closed position and an open position, movement of the metering valve member from the closed position to the open position defining a variable flow area that increases as the metering valve member moves from the closed position toward the open position. An actuator piston in an actuator bore is exposed to pressure in the common rail. The actuator piston is biased toward a first position corresponding to low pressure in the common rail and movable toward a second position corresponding to maximum pressure in the common rail. The actuator piston includes a valve stop that determines a metering position of the metering valve member.

A fuel pump for a liquid fuel injection system of a motor vehicle is provided. The fuel pump for a fuel injection system includes a low-pressure pump that provides liquid fuel from a fuel tank of the motor vehicle at a low pressure. A high-pressure pump in fluid communication with the low-pressure pump and compresses the liquid fuel from the low pressure to a high pressure for injecting the liquid fuel into an internal combustion engine of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.

The invention relates to a method for operating a fuel injector (10) and to a fuel injector (10) which is configured to carry out the method. The method comprises the steps of introducing a fuel under high pressure into a feed passage (78) and branching off a substream of the fuel under high pressure into a control space (74) in which an axial end face (70) of the nozzle needle (50) is loaded with the pressure such that the nozzle needle (50) is hydraulically loaded in the closing direction, and of opening a control valve (90) such that an outflow path arranged downstream of the control valve (90) in an outflow direction is freed and fuel flows out of the control space (74) in order to relieve the nozzle needle (50), wherein the fuel flowing out via the outflow path is divided into at least two substreams.

A fuel injection system for an aircraft engine has: a first fuel injector having a first actuation inlet, a first fuel inlet connected to a fuel source, and a first fuel outlet connected to the at least one combustion chamber, the first fuel injector defining a first pressure ratio; a second fuel injector having a second actuation inlet, a second fuel inlet connected to the fuel source, and a second fuel outlet connected to the at least one combustion chamber, the second fuel injector defining a second pressure ratio; and an actuation fluid system having a circuit connected to the first actuation inlet and to the second actuation inlet, the first outlet pressure different than the second outlet pressure by having one or both of the first pressure ratio different than the second pressure ratio and a first actuation pressure different than a second actuation pressure.

A dual-fuel fuel injection system for an internal combustion engine has a liquid fuel injection branch and a gas fuel injection branch, in which a gas injector assembly that is controllable via a control fluid is situated. The liquid fuel forms the control fluid of the gas injector assembly.