A direct-injection, supercharged internal combustion engine having at least one cylinder, in which each cylinder is equipped with a direct injection apparatus, a fuel supply system comprising a high-pressure side and a low-pressure side, and a high-pressure piston pump comprising a piston displaceable in translational fashion between a bottom dead center and a top dead center of a pressure chamber of variable volume. The displaceable piston jointly delimits the pressure chamber with variable volume in such a way that a displacement of the piston causes a change in the volume of the pressure chamber via actuation of least one movable actuation element.

Provided is a fuel supply pump capable of improving welding quality while securing a function of a valve body. A fuel supply pump of the present invention includes a regulating member (discharge valve stopper 84) that guides movement of a valve body (discharge valve 82), a main body portion (body 1) provided with a valve chamber (discharge valve chamber 1d) that houses the regulating member, a sealing member (plug 85) that seals the valve chamber, and a welded portion (welded portion 86) that fixes the sealing member to the main body portion. An annular space portion (annular space portion 60) along an outer periphery of the regulating member is formed between the welded portion and the regulating member. The regulating member includes a positioning portion (fitting portion 84a) for positioning with respect to the main body portion on a side opposite to the sealing member, and a gap forming portion (gap forming portion 84c) forming an annular gap (annular gap 63) between the gap forming portion and the main body portion, and the annular gap allows a space on a side of the positioning portion in the valve chamber and the annular space portion to communicate with each other.

Provided is a discharge valve mechanism capable of improving responsiveness when a discharge valve is opened, and a high-pressure fuel supply pump including the discharge valve mechanism.

A discharge valve mechanism 500 includes a valve seat portion 51 having a primary-side flow path, a valve body 52 which can be seated on and separated from the valve seat portion 51, and a guide portion 542a which is formed to be slidable on an outer surface of the valve body 52 and guides movement of the valve body 52 in a contacting/separating direction with respect to the valve seat portion 51. The guide portion 542a includes a portion in which a gap from the outer surface of the valve body 52 is set to a predetermined value or less. A first secondary-side flow path 545 which allows an internal space 541a on an upstream side of the guide portion 542a to communicate with an external flow path 2g is formed to allow the fluid to flow out to a side in a moving direction of the valve body 52, and a second secondary-side flow path 546 which allows an internal space 543a on a downstream side of the guide portion 542a to communicate with the external flow path 2g is formed to allow the fluid to flow out to the side in the moving direction of the valve body 52.

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

Provided is a fuel supply pump capable of improving welding quality while securing a function of a valve body. A fuel supply pump of the present invention includes a regulating member (discharge valve stopper 84) that guides movement of a valve body (discharge valve 82), a main body portion (body 1) provided with a valve chamber (discharge valve chamber 1d) that houses the regulating member, a sealing member (plug 85) that seals the valve chamber, and a welded portion (welded portion 86) that fixes the sealing member to the main body portion. An annular space portion (annular space portion 60) along an outer periphery of the regulating member is formed between the welded portion and the regulating member. The regulating member includes a positioning portion (fitting portion 84a) for positioning with respect to the main body portion on a side opposite to the sealing member, and a gap forming portion (gap forming portion 84c) forming an annular gap (annular gap 63) between the gap forming portion and the main body portion, and the annular gap allows a space on a side of the positioning portion in the valve chamber and the annular space portion to communicate with each other.

A pumping element comprises a first flow chamber; a second flow chamber in fluid connection with the first flow chamber, the second flow chamber including a shoulder; a check valve including a first insert and a second insert, the first insert being movable between a first position wherein the first insert forms a seal that inhibits fluid flow between the first and second flow chambers and a second position wherein the first insert permits fluid flow between the first and second flow chambers, the second insert being inserted into the second flow chamber to an extent limited by the shoulder; and a spring having a first end engaging the first insert and a second end engaging the second insert; wherein the first insert moves from the first position to the second position against a biasing force of the spring in response to pressurized fluid in the first flow chamber.

Provided is a solution to a problem on a discharge valve mechanism disposed at an exit of a pressurizing chamber of a high-pressure fuel supply pump, that is, an occurrence of a backward flow of the fuel concentrates on a limited fuel passage, leading to a higher fuel flow rate, and this easily induces the occurrence of cavitation, and collapse of the generated cavitation might damage a seat surface, making it difficult to maintain valve functions. The present invention provides a valve mechanism including a seat member having a seat section, a valve body configured to attach to or detached from the seat section, and a housing member arranged on an outer peripheral side of the seat member. A first fluid flow-path is formed to connect an inner peripheral side and an outer peripheral side of the seat section in a case where the valve is detached from the seat section. A second fluid flow-path is formed to be connected with the first fluid flow-path, between an outer peripheral surface of the seat member and an inner peripheral surface of the housing member, or between an outer peripheral surface of the valve body and the inner peripheral surface of the housing member. The cross-sectional area along the axial direction of the valve mechanism of the second fluid flow-path is 0.18 mm square or above.

A fluid injection system can include a main flow line, a primary flow line connected to the main flow line, a primary flow valve disposed on the primary flow line and configured to selectively allow injectant flow to the primary flow line, a secondary flow line connected to the main flow line, and a secondary flow valve disposed on the secondary flow line and configured to selectively allow injectant flow to the secondary flow line. The system can include a primary purge branch in fluid communication with the primary flow line and connected to a purge gas line, a primary purge valve disposed in the primary purge branch between the primary flow line and the purge gas line, a secondary purge branch in fluid communication with the secondary flow line, and a secondary purge valve disposed between the purge gas line and both of the primary purge branch and the secondary purge branch.

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 valve seat member shared by an outlet valve and a pressure relief valve is provided between a pressurizing chamber and a high pressure path. A valve seat of the relief valve is provided on the side of the pressurizing chamber of the valve seat member. A valve seat of the outlet valve is provided in the valve seat member on the side of the high pressure path. One end of a relief path whose other end is open in the valve seat of the pressure relief valve is connected with the high pressure path, and one end of an outlet path whose other end is open in the valve seat of the outlet valve is connected with the pressurizing chamber.