A high pressure plunger pump, having at least one plunger arrangement which comprises a working space connected to a valve seat suction line and a valve seat pressure line, in which a plunger is arranged in an axially reciprocable manner, wherein the valve seat pressure line is closeable by a pressure valve and the valve seat suction line by a suction valve, and the suction valve can be kept in an open position in a controlled manner as required by means of a counter-pressure device, is designed so that the counter-pressure device has a supply line via which a control fluid can be guided to the suction valve for keeping the suction valve open, wherein a low-pressure pump is connected to the supply line for generating pressure of the control fluid.

Methods and systems are provided for operating a lift pump of an engine fuel system. In one example, a method may comprise limiting a lift pump voltage to a lower first level when powering on a lift pump from off. The method may further comprise maintaining the lift pump voltage at the lower first level for a duration before increasing the lift pump voltage above the first level.

Methods and systems are provided for operating a lift pump of an engine fuel system. In one example, a method may comprise limiting a lift pump voltage to a lower first level when powering on a lift pump from off. The method may further comprise maintaining the lift pump voltage at the lower first level for a duration before increasing the lift pump voltage above the first level.

An object is to suppress cavitation generated at a distal end portion of a seat face when a valve body and a seat portion collide with each other. In a relief valve of a fuel pump, an intersection between the seat face and a flow channel hole is formed at a position more distant than the seat portion formed of the valve body in a valve closing state and the seat face in order to suppress generation of cavitation bubbles when the valve body improves and releases high-pressure fuel.

A fuel injection system is provided. The fuel injection system can have a fuel injector having a check valve with a plurality of fuel output ports, and a fuel injector body with an outer surface and an inner surface. The fuel injector body defines an inner volume to accommodate bi-directional movement of the check valve. The fuel injector body includes at least a first row of injection ports and a second row of injection ports extending from the inner surface to the outer surface. The check valve is bi-directionally controllable in the inner volume, during a single cycle, to output from the fuel injector body any one of a plurality of predefined pulse injection patterns.

A fuel injector control valve assembly is provided that comprises a valve actuating mechanism, a cage member that is operatively connected to the valve actuating mechanism, a poppet valve member that is operatively connected to the cage member and that defines a perimeter and a longitudinal axis, a valve sleeve member that is disposed about the poppet valve member, a shim that includes an upper surface that at least partially makes uninterrupted contact with the cage member and a lower surface that at least partially makes uninterrupted contact with the sleeve member, thereby providing a fluid seal about the perimeter of the poppet valve member, and a bounce limiting mechanism that is adjacent the shim and that is interposed between the cage member and at least one of either the poppet valve member and the valve sleeve member.

A hydraulic system includes a high pressure fluid source and a hydraulic actuator fluidly connected to the high pressure fluid source, and a low pressure fluid system fluidly connected to the hydraulic actuator via a fluid return line, and a hydraulic valve. The hydraulic valve includes a return spring and an elongate member, which is movably arranged in its longitudinal direction for controlling a fluid flow. The elongate member is biased to a closed position by the return spring. The elongate member forms a needle, the hydraulic valve includes a needle receiving body having a needle seat and the needle is engageable with the needle seat so as to control the fluid flow.

The invention relates to an injector for injecting fuel, preferably for injecting a gaseous fuel, in particular hydrogen, comprising a fuel supply line for introducing a highly pressurized gaseous fuel, an active valve which can be actively shut off and which is designed to close or release at least one passage on a first face of a valve plate in order to selectively release or interrupt a fluidic connection between the fuel supply line and a region which is downstream of the first face of the valve plate, and a passive valve which is arranged downstream of the valve plate and can be passively switched to a closing or releasing state as a result of different pressure ratios upstream and downstream of the passive valve.

A fuel injector including a flow balanced injector needle seal is provided. The fuel injector includes a needle in a fuel passage of the fuel injector body. The needle moves longitudinally in the fuel passage to selectively stop and start fuel injection from the fuel passage. The fuel injector includes a check valve assembly that maintains pressurized fuel in the fuel passage and permits fuel flow out of the fuel passage in response to a fuel injection event. The needle seal is provided between the check valve assembly and a sleeve that extends around the proximal end of the needle. The needle seal includes multiple inlet orifices for receiving a fuel flow into the needle seal that are positioned relative to one another so that net lateral forces on the needle are effectively offset from one another.

A sub out-orifice and an in-orifice are respectively formed in a low pressure passage and a high pressure passage of a fixed plate. A control valve is provided at an outlet port of the low pressure passage. In a normal control, the control valve starts its control-valve opening operation when a movable plate is in contact with the fixed plate. In an interval-shortening control, the control valve starts the control-valve opening operation at an earlier timing than that in the normal control, namely during a course in which a valve body is still in its valve-body closing operation.