Various embodiments include methods for operating a high-pressure pump comprising: driving a piston arranged in a compression chamber with a motor shaft; during movement of the piston toward the top dead center, closing the inlet valve so the fluid is then delivered by the piston through an outlet valve; applying a coil current to an electromagnet used to close the inlet valve during and/or after overshooting the top dead center; detecting a start time at which the coil current, on account of starting of an opening movement of the inlet valve, fulfills a predetermined change criterion; labelling a dead center rotation position of the motor shaft at which the piston is at the top dead center based at least in part on the ascertained start time; and adjusting operation of the pump based on the identified dead center rotation position.

A fuel injection pump includes a cylinder formed with a passage of fuel, a plunger, and a swirl flow generating par. The plunger slides along an inner wall of a sliding hole located in the cylinder and reciprocates between an uppermost point and a lowermost point to pressurize the fuel in a pressurizing chamber placed at an end of the sliding hole at a highest point. The plunger is movable downward to cause the pressurizing chamber to inhale the fuel from an intake passage in a fuel suction stroke. The intake passage is communicated to the pressurizing chamber at a lateral side of a plunger axis that is an axis of the plunger in a sliding direction. The swirl flow generating part guides the fuel to form a swirl flow around the plunger axis in the fuel suction stroke.

A damper spring structure of a high-pressure fuel pump includes: a housing of the high-pressure fuel pump in which a flow path for fuel is formed; a lid coupled to the housing and having an accommodation space between the housing and the lid; a damper spring installed in the accommodation space between the housing and the lid; and a damper installed in the damper spring so as to be supported by the damper spring, in which the damper spring is seated and supported on the lid and the housing in the accommodation space by contact points, and the lid is supported at a plurality of contact points.

A high-pressure pump has a metering valve and a valve stopper. The stopper has a regulation portion which an end surface of the valve is brought into contact with. An outer diameter of the regulation portion is equal to an outer diameter of the outer peripheral surface of the valve. A cylindrical sleeve is disposed around the regulation portion. When the end surface of the valve is in contact with the regulation portion, the sleeve covers a tapered surface of the valve.

A plunger is provided for reciprocating inside the barrel of a fuel pump. The plunger has a proximal end and a distal end. The proximal end of the plunger includes a cavity that defines a depressed volume within the plunger. A volume filler is disposed in the cavity, where the volume filler is constrained in the cavity by a retaining element.

A plunger is provided for reciprocating inside the barrel of a fuel pump. The plunger has a proximal end and a distal end. The proximal end of the plunger includes a cavity that defines a depressed volume within the plunger. A volume filler is disposed in the cavity, where the volume filler is constrained in the cavity by a retaining element.

An improved high-pressure fuel pump for a gasoline direct injection system is provided. The fuel pump includes a pump body defining a low-pressure side, a high-pressure side, and a pumping chamber therebetween. The pump body also defines a central bore and a drain port extending from the central bore to the low-pressure side. A slip-fit sleeve is clamped within the central bore, the slip-fit sleeve including upper and lower guide ribs. A plunger is moveable within the sleeve for compressing fuel within the pumping chamber. The plunger and the sleeve define a first diametral clearance, and the guide ribs and the central bore define a second diametral clearance. Fuel diverting around the upper guide rib during pumping operations can recirculate through the drain port to the low-pressure side. To accommodate thermal expansion of the sleeve, the second diametral clearance is at least 75% of the first diametral clearance.

A valve actuation system for an engine includes a rotatable camshaft, an injector actuation linkage, and a valve actuation linkage. The valve actuation linkage includes a valve lifter, a valve pushrod, and a rocker arm. At least one of a rocker arm center plane defined by the valve rocker arm or a lifter roller center plane defined by the valve lifter is spaced an offset distance from a pushrod axis, providing an increased contact width between an injector roller in the injector actuation linkage and one of a plurality of cam lobes of the camshaft. The valve lifter includes a fork defining a center plane spaced an offset distance from a center axis of the valve lifter. A rocker arm includes a screw bore offset relative to a rocker arm center plane.

The present disclosure generally relates to a pumping element of a fuel pump for an internal combustion engine wherein the 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.

The present disclosure generally relates to a pumping element of a fuel pump for an internal combustion engine wherein the 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.