In a fuel injection valve that is inserted along a shape of an attachment hole formed in a cylinder head and that directly injects fuel supplied from a fuel supply section into a combustion chamber via a stepped section, the fuel supply section includes: a fuel cup, an end of which has a tapered section; a seal ring that prevents leakage of the fuel to the outside; and a support ring that supports the seal ring, the stepped section includes: a nozzle that injects the fuel into the combustion chamber; and an attachment shaft that has a larger radius than the nozzle, and a first gap in an axial direction between the tapered section and the support ring is larger than a second gap in the axial direction between the attachment hole and the attachment shaft.

The present disclosure relates to internal combustion engines. The teachings thereof may be embodied in injection valves with servo-valve control for injecting fuel into the combustion chamber. For example, an injection valve may include a valve pin connected to a valve body and an actuator preloaded by an actuator spring. The valve pin is fitted with a very small clearance to form a sealing gap between the valve pin and the valve body which includes bores. The lower end of the valve pin forms a coupling volume between the valve pin and the valve body, connected via the sealing gap and the bores to the valve chamber. The sealing gap provides a fluidic connection between the coupling volume and the valve chamber, but, during the short time of valve actuation, practically no exchange of fluid can take place between coupling volume and valve chamber so that the coupling volume does not substantially change in said short time.

A piezoelectric injector includes: a first piezo actuator and a second piezo actuator; a control valve connected to the first piezo actuator and the second piezo actuator through a control piston; at least one drain chamber in which the control valve and the control piston are movably received; a control chamber connected to the drain chamber through a first drain throttle and a second drain throttle having different diameters; and a needle movable by a change in fuel pressure of the control chamber to open and close at least one nozzle orifice. As at least one of the first piezo actuator and the second piezo actuator expands, a fuel is drained from the control chamber to the drain chamber through at least one of the first drain throttle and the second drain throttle.

A piezoelectric injector includes: a first piezo actuator and a second piezo actuator; a control valve connected to the first piezo actuator and the second piezo actuator through a control piston; at least one drain chamber in which the control valve and the control piston are movably received; a control chamber connected to the drain chamber through a first drain throttle and a second drain throttle having different diameters; and a needle movable by a change in fuel pressure of the control chamber to open and close at least one nozzle orifice. As at least one of the first piezo actuator and the second piezo actuator expands, a fuel is drained from the control chamber to the drain chamber through at least one of the first drain throttle and the second drain throttle.

An injection device for metering a fluid, having the following: a valve, which has a valve needle and a valve seat; a nozzle shaft, which surrounds the valve needle and which holds a volume of the fluid; and an inlet chamber, which adjoins the nozzle shaft on the side of the nozzle shaft facing away from the valve and which has a flow connection to the nozzle shaft. The injection device has at least one compressible volume compensation element, which is filled with a gas and which, within the injection device, is in contact with the fluid.

The teachings of the present disclosure describe an injector having an injector housing, an actuator, and a nozzle needle, wherein the actuator is arranged in an actuator space of the injector housing. The injector may include a control piston bore in the injector housing, in which a control piston is arranged, a leakage pin bore between the actuator space and the control piston bore, and a leakage pin coupling the control piston to the actuator, the leakage pin arranged in the leakage pin bore. The control piston may be hydraulically connected to the nozzle needle in order to open or close an outlet opening of the injector housing. The injector may include a high pressure line configured to convey a fuel under pressure to the nozzle needle and a feedline in the injector housing connecting the leakage pin bore to the high pressure line.

A method and system for determining remaining useful life of an in-use injector of a reciprocating engine is disclosed. The method includes determining nozzle wear relationship data for different duty cycles of the in-use injector, and using the nozzle wear relationship data together with operating parameters for the reciprocating engine, and emission relationship data to determine actual emission levels for the in-use injector based on the wear relationship data and the emission relationship data. The method and system further include determining remaining useful life of the in-use injector based on actual emission levels and the nozzle wear relationship data; and controlling an operation of the reciprocating engine based on the actual emission levels.

In a fuel injector, the temperature differential between a distributor plate, through which relatively cool fuel passes, and the manifold to which the distributor plate is bonded causes stresses and strains that can reduce the durability and longevity of the fuel injector. In disclosed embodiments, the distributor plate is bonded to an outer arm and inner arm. These arms act as levers to take up the stresses and strains caused by the temperature differential, thereby increasing the durability and longevity of the fuel injector.

A fuel pump includes a housing provided with an axial bore defining a compression chamber. The pump is further provided with a cylindrical piston slidably arranged in the bore, the piston extending from a top extremity that is inside the bore, defining a high pressure extremity, to a lower extremity, defining a low pressure extremity. The piston is able to reciprocally slide between a lower position where fuel at low pressure enters the compression chamber via an inlet and, a top position where fuel present in the compression chamber is pressurized before being expelled via an outlet. The piston is also provided with a recess surrounded by a peripheral wall arranged on its high pressure extremity, the recess and peripheral wall enabling the piston to expand radially when fuel in the compression chamber is pressurized.

A control valve assembly for controlling fuel pressure in a control chamber of a fuel injector. The control valve assembly comprising a valve member arranged in a bore provided in a valve housing, at least one of the valve member and the valve housing being moveable with respect to the other, wherein the valve member comprises a fuel-receiving cavity arranged to receive fuel that distorts at least a portion of the valve member so as to increase an external dimension thereof.