A large two-stroke turbocharged compression-ignited internal combustion crosshead engine with a plurality of cylinders has at least one pressure booster for each cylinder for boosting fuel pressure, two or more electronically controlled fuel valves for each cylinder with an inlet of the two or more electronically controlled fuel valves being connected to an outlet of the at least one pressure booster. An electronic control unit is connected to the at least one pressure booster and the two or more electronically controlled fuel valves. The electronic control unit is configured to determine a start time for a fuel injection event, activate the at least one pressure booster ahead of the determined start time and pen the two or more electronically controlled fuel valves at the determined start time.

A fuel line check valve system and a fuel system that includes the fuel line check valve system are described. The fuel line check valve system may prevent flow into a fuel system that is generated via a vacuum in the fuel system. The fuel line check valve system may also remain in an open state after it is open via a reduced pressure.

A pump unit for supplying fuel, preferably diesel oil, to an internal combustion engine has at least two cylinders (10), which are formed in at least one head (9), are slidingly engaged by respective pistons (13), and communicate hydraulically with respective fuel inlets (11) in the cylinders (10) via respective interposed intake valves (15) provided with respective valve bodies (16) incorporated in the head (9); the inlets (11) of all the cylinders (10) being closed by a single cover (33) fixed to the head (9).

An object of the present invention is to obtain a high pressure fuel supply pump capable of reducing pressure pulsation that occurs in a low pressure pipe, preventing damage to the low pressure pipe, or reducing noise due to vibrations of the low pressure pipe. The present invention provides a high pressure fuel supply pump of a type in which, from a fuel suction port connected to a low pressure pipe provided upstream of a fuel, a low pressure passage, an electromagnetic suction valve driven by an electromagnetic force, a pressurizing chamber in which the volume thereof is increased or reduced by a plunger that is reciprocatingly moved by being guided by a cylinder, and a discharge valve provided at an outlet of the pressurizing chamber are sequentially arranged, a fuel is sucked to the pressurizing chamber through the electromagnetic suction valve, the amount of a part of the fuel, which is sucked to the pressurizing chamber, to be returned to the low pressure passage side is adjusted so that the amount of the fuel to be discharged through the discharge valve is controlled, and the high pressure fuel supply pump includes a backflow suppression mechanism for suppressing backflow of fuel from the fuel from the fuel suction portion to the low pressure pipe side.

An engine fuel delivery system includes a fuel pump having a pumping chamber to increase fuel pressure and a closeable inlet valve, and a fuel rail to communicate pressurized fuel received from the fuel pump to at least one engine cylinder. The engine fuel delivery system also includes a controller programmed to issue a control signal to periodically close the inlet valve to generate a setpoint fuel pressure within the pumping chamber. The controller is also programmed to adjust a control signal gain value in response to deviation in an outlet fuel pressure relative to the setpoint fuel pressure. The controller is further programmed to issue a warning message in response to the control signal gain being adjusted by more than a predetermined threshold from a calibrated gain value.

A manifold configured to inhibit air recirculation in an engine fueling system, the manifold comprising: a housing including an internal chamber in communication with a high pressure pump (“HPP”) port configured to receive drain fuel from a HPP; a drain port configured to return fuel to a fuel tank; an air bleed port configured to receive air bled from the fueling system; and a check valve positioned within the internal chamber, the check valve configured to inhibit air from flowing from the air bleed port to the HPP port, thereby inhibiting air recirculation into the engine fueling system.

In a fuel pump that includes a pump housing (10) that has fuel passages (11a, 11b), a plunger (17) that is movably housed in the pump housing (10), a fuel pressurizing chamber (15) that is formed in the pump housing (10) and draws in fuel via one of the fuel passages (11a) that is on the intake side of the fuel pressurizing chamber (15), pressurizes the fuel that has been drawn in, and discharges the pressurized fuel via the other fuel passage (11b) that is on the discharge side of the fuel pressure chamber (15), in response to movement of the plunger (17), and valve elements (12, 14, 16) that are arranged in the fuel passages (11a, 11b) near the fuel pressurizing chamber (15), each of the valve elements (12, 14, 16) has a reed valve body (41, 42, 43; 74, 75, 76) arranged in the fuel passage (11a) on the intake side of the fuel pressurizing chamber (15) or the fuel passage (11b) on the discharge side of the fuel pressurizing chamber (15); and an operating member (21) that applies operating force in at least one of a valve opening direction or a valve closing direction to the reed valve body (41, 42, 43; 74, 75, 76) is provided in the pump housing (10).

A fluid intake/discharge valve body for suction of a cryogenic liquefied gas fluid into a cylinder liner and discharge of the gas fluid with a piston, includes: a valve seat body including a fluid supply portion to supply the fluid and a fluid exhaust portion; an intake valve biased against the fluid supply portion; and a discharge valve biased against the fluid exhaust portion. The fluid supply portion includes a supply pathway connected to a supply pipe; a dividing wall including intake holes facing the intake valve; and a counterbore recessed portion on the dividing wall to surround the intake holes. The intake valve abuts an edge of the recessed portion when biased against the fluid supply portion. The discharge valve receives fluid pressure from a side of the discharge hole including a recessed portion disposed in a region wider than an outer periphery of the discharge hole.

Methods and systems are provided for delivering fuel to a port injector fuel rail in a port fuel direct injection (PFDI) engine. In one example, the port injector fuel rail may receive fuel from each of a compression chamber and a step chamber of a direct injection fuel pump coupled in the PFDI engine. In this way, pressurized fuel may be supplied to the port injector fuel rail during an entire cycle of the direct injection fuel pump.

The present invention relates to a fuel pump for pumping fuel, comprising a piston (2) and a diaphragm seal element (3), which seals on an inner annular seal seat (4) and an outer annular seal seat (5), wherein the following equation is satisfied: (Ra.sup.2−ra.sup.2)/(ri+L).sup.2=ra/ri, where ri is the inner radius of the inner seal seat (4), ra is the inner radius of the outer seal seat (5), Ra is the outer diameter of the piston (2) and L is a difference between an outer radius (Ria) of the inner seal seat (4) and the inner radius (ri) of the inner seal seat (4). The invention further relates to a method for operating a fuel pump.