The present disclosure relates to methods and fuel compositions for reducing cavitation-induced damage in common-rail injection engines operated at high fuel pressures. The fuel compositions include a gasoline-like fuel and one or more cavitation inhibitor additives.

A coil assembly in a fuel injector includes a magnetic core and; a winding wound around the core, the winding being overmoulded and forming a cylindrical overmoulding. An axial blind hole extends towards the interior of the coil assembly from a first surface to a distal end, the blind hole being suitable for housing at least one spring for loading a magnetic armature. The coil assembly is provided with a degassing hole passing through the core and the overmoulding from the blind axial hole to an axial outer cylindrical surface, the degassing hole being provided in the magnetic core and having a restriction that is arranged in a first section that is proximal to the blind axial hole.

The invention relates to a pump unit for feeding fuel, preferably diesel fuel, to an internal combustion engine, comprising at least one cylinder (14), a piston (15) which is displaceably arranged in the cylinder (14), and a pressure valve (30) for selectively controlling the supply of fuel to the internal combustion engine, wherein the pressure valve (30) has a closure part (38, 46, 51) provided with a cavity (44, 49, 53) that opens to the outside on an end surface (43, 48, 52) facing the piston (15) of the closure part (38, 46, 51).

There is provided a discharge valve mechanism provided at an outlet of a pressurizing chamber of a high-pressure fuel supply pump that aims to reduce a backflow amount of fuel from a discharge valve and to prevent cavitation erosion. There are provided a discharge valve disposed on a discharge side of a pressurizing chamber, a discharge valve seat that closes a discharge side flow passage of the pressurizing chamber by seating the discharge valve, and a discharge valve spring that presses the discharge valve toward the discharge valve seat. It is configured such that, in a case where a minimum seat diameter of a seat portion in which the discharge valve is seated on the discharge valve seat is set to D and a spring force of the discharge valve spring at a time of setting is set to F, a coefficient K obtained by dividing the spring force F by the minimum seat diameter D is set to be 0.2 or more.

This plunger pump includes a pressurization chamber that has a tubular inner circumferential wall and a plunger that has a substantially cylindrical outer circumferential surface. The inner circumferential wall has, in a part thereof in a circumferential direction about an axis of the plunger, a suction opening, which communicates with the pressurization chamber and is for introducing a fuel into the pressurization chamber. The inner circumferential wall is formed with an enlarged gap portion having a larger dimension than a dimension, at a position of the suction opening, from the outer circumferential surface of the plunger to an inner circumferential surface of the inner circumferential wall along a radial direction of the plunger, in at least a part of the inner circumferential wall at a position away from the position of the suction opening in the circumferential direction.

A nozzle assembly for a fuel injector includes an injector housing having a casing and a stack within the casing, an outlet check movable within a nozzle cavity in the injector housing, and having a stop positioned within a stop cavity. A clearance is formed between the outlet check and the injector housing and fluidly connects a spring cavity to a stop cavity, and an anti-cavitation vent is formed in the stack and fluidly connects the spring cavity to a low pressure space. The anti-cavitation vent limits pressure changes in the spring cavity during fuel injection such that production of cavitation bubbles in the spring cavity is limited.

A nozzle assembly for a fuel injector includes an injector housing having a casing and a stack within the casing, an outlet check movable within a nozzle cavity in the injector housing, and having a stop positioned within a stop cavity. A clearance is formed between the outlet check and the injector housing and fluidly connects a spring cavity to a stop cavity, and an anti-cavitation vent is formed in the stack and fluidly connects the spring cavity to a low pressure space. The anti-cavitation vent limits pressure changes in the spring cavity during fuel injection such that production of cavitation bubbles in the spring cavity is limited.

A filter for filtering hydraulic fluid in a hydraulically actuated fuel injector. The filter includes a first disc structure and a second disc structure disposed axially spaced apart from the first disc structure. The second disc structure is also disposed parallel to the first disc structure. The filter further includes an intermediate structure extending from the first disc structure to the second disc structure. The intermediate structure includes a first surface and a second surface disposed opposite and parallel to the first surface. The intermediate structure defines a plurality of passages extending from the first surface to the second surface. Each of the plurality of passages is perpendicular to a longitudinal axis of the filter.

There is provided a discharge valve mechanism provided at an outlet of a pressurizing chamber of a high-pressure fuel supply pump that aims to reduce a backflow amount of fuel from a discharge valve and to prevent cavitation erosion. There are provided a discharge valve disposed on a discharge side of a pressurizing chamber, a discharge valve seat that closes a discharge side flow passage of the pressurizing chamber by seating the discharge valve, and a discharge valve spring that presses the discharge valve toward the discharge valve seat. It is configured such that, in a case where a minimum seat diameter of a seat portion in which the discharge valve is seated on the discharge valve seat is set to D and a spring force of the discharge valve spring at a time of setting is set to F, a coefficient K obtained by dividing the spring force F by the minimum seat diameter D is set to be 0.2 or more.

A fuel injection system includes a fuel rail, and a damper that is disposed inside the fuel rail. The damper includes outwardly protruding first barbs formed integrally on one end of the damper and outwardly protruding second barbs formed integrally on an opposed end of the damper. The first barbs and the second barbs each engage the fuel rail inner surface, whereby the damper is located and retained within the fuel rail. The first barbs and the second barbs may be generally triangular in profile and each extend at an acute angle relative to the damper longitudinal axis. In addition, the first barbs and the second barbs are each oriented in the same direction relative to the longitudinal direction, whereby the damper is asymmetric when viewed in side view.