In a quantity limiting valve for a fuel injection system of an internal combustion engine including a cylinder with an inflow region and an outflow region separated by a piston axially movably disposed in the cylinder and a flow limiting fluid flow path extending along the piston between the inflow and outflow regions wherein the piston is biased with its front surface into contact with a stop element, the contact area between the front surface and the stop surface includes between the piston and the stop element a contact structure providing for an intermediate space which is in communication with the inflow region thereby to expose the front surface of the piston to the pressure of the fluid in the inflow region.

A fuel injector includes a nozzle having at least one nozzle outlet. A valve needle is moveable with respect to a valve needle seating through a range of movement between a closed position and an open position to control fuel delivery through the at least one nozzle outlet. The movement of the nozzle needle is controlled by fuel pressure within a control chamber. The injector has first and second nozzle control valves for controlling fuel flow into and out of the control chamber to pressurise and depressurise the control chamber, respectively. The first nozzle control valve can operate selectively to place the control chamber in fluid communication with a fuel drain or to place the control chamber in fluid communication with a high pressure supply line. The second nozzle control valve can operate selectively to place the control chamber in fluid communication with a fuel drain.

A fuel supply device includes a leaked fuel collection unit and a check valve. When fuel passes through a first seal member to leak out from a cam chamber into an inter-seal space, the leaked fuel collection unit sucks in this fuel to extract the fuel from the inter-seal space, then pressurizes and returns the fuel to a fuel tank. The check valve prevents the fuel from flowing in reverse from the fuel tank to the inter-seal space. Accordingly, regardless of the pressure in the fuel tank and the pressure in the inter-seal space, fuel that leaks into the inter-seal space may be actively returned to the fuel tank. Further, the check valve prevents pressure in the fuel tank from acting on seal members. Accordingly, fuel that leaks into the inter-seal space may be collected into the fuel tank.

A fuel injector that includes an injector control valve assembly. The injector control valve assembly includes a contact spring positioned between a fuel injector upper body and the injector control valve assembly to isolate a stator housing from clamping forces that occur during fuel injector assembly and clamping in an internal combustion engine. The injector control valve assembly further includes a cartridge configuration that permits preassembly of the injector control valve assembly prior to mounting in the fuel injector.

A flow limiting valve, comprising a valve body adjustable between a closed position and an open position, wherein in the open position a flow channel for a conveying fluid is opened in the flow limiting valve and in the closed position the flow channel is closed, whereby the adjustment of the valve body is subject to conveying fluid pressure; wherein a control valve is integrated into a housing of the flow limiting valve through which the valve body is adjustable between open and closed positions, regardless of the conveying fluid.