A vehicle fuel injector is configured to inject a high-pressure vehicle fuel received from a fuel rail into a combustion chamber. The vehicle fuel injector includes a nozzle which includes a plurality of discharge flow paths which are disposed to be spaced apart from each other in a circumferential direction and pass through the nozzle in a longitudinal direction, and outward flow paths formed on an inner circumferential surface of the nozzle, the nozzle having a hollow shape, and a needle bar which is formed to pass through the inner circumferential surface of the nozzle and vertically reciprocally moves on the inner circumferential surface of the nozzle, where rotation of the needle bar is adjusted in a left or right direction so that the nozzle is opened or closed.

A sealing cartridge (18) for an injector of an internal combustion engine seals a medium-filled first chamber (6) and a medium-filled second chamber (7). The chambers (6, 7) are between an injector (1) that is movable axially along an injector axis (9) and a housing (2) receives the injector (1). The sealing cartridge (18) is configured to receive the injector (1). The sealing cartridge (18) has at least one seal (11; 20) disposed in a receptacle housing (19) of the sealing cartridge (18). The receptacle housing (19) has a first housing portion (29) configured to receive the seal (11; 20) on the shell face (31) of the receptacle housing (19), and a second housing portion (30) configured to receive the seal (11; 20) on an internal face (25). An injector assembly (38) also is provided and has an injector (1) that is received in the sealing cartridge (18).

A fuel injector includes an injector body comprising an internal injector cavity, a flow passageway, and a drain conduit. The flow passageway is in fluid communication with at least one injector orifice. The fuel injector further includes a valve assembly comprising a valve seat and a valve member in fluid communication with the fuel circuit. The valve member is configured to move between an open position allowing fuel flow through the at least one injector orifice and a closed position inhibiting fuel flow through the at least one injector orifice. The fuel injector also includes a nozzle valve element fluidly coupled to the valve assembly, an actuator operably coupled to the valve assembly and the nozzle valve element, and a flexible member configured to elastically deform in response to pressure in the fuel injector. The flexible member is configured to inhibit flow to the drain circuit during an injection event.

Various embodiments may include a method for operating a diesel-common-rail piezo-operated servo injector comprising: partially charging the piezo-actuator from a non-charged state at 0 V (method a); partially discharging the piezo-actuator from an already charged state to a remaining limited charge (method b); measuring the piezo-voltage with both methods and comparing the results; when the comparison demonstrates correspondence within a predefined threshold, using method b in ranges in which method a cannot be carried out; and when the comparison does not demonstrate correspondence within the predefined threshold, using method a without using method b.

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 fuel injection valve includes a valve housing having an injection hole and a valve seat surface tapering toward a downstream side, a valve component that is accommodated in the valve housing and is coaxially separated from or seated on the valve seat surface, and an elastic component biasing the valve component toward the valve seat surface. The valve component includes an inner convex surface curved in a partial spherical shape with a predetermined curvature radius, and an outer convex surface that is provided continuously to the outer peripheral side of the inner convex surface and curved in a partial spherical shape having a smaller curvature radius than the inner convex surface. A boundary portion between the inner convex surface and the outer convex surface protrudes toward the valve seat surface so as to be able to be separated from or seated on the valve seat surface.

The disclosure relates to a circuit arrangement that includes a first DC-DC converter that is connected on the output side to a capacitor. A first terminal of the capacitor is a supply voltage terminal and a second terminal of the capacitor is a reference potential terminal. The circuit arrangement also includes a second DC-DC converter, which is connected on the input side with the capacitor and on the output side to a first terminal of a piezo actuator. The second terminal of the piezo actuator is connected to the first terminal of the capacitor.

There are provided a laminated piezoelectric element in which a stress applied to an interface between a cover layer and a stacked body is reduced, and an injection device and a fuel injection system provided with the laminated piezoelectric element. A laminated piezoelectric element includes a stacked body in which piezoelectric layers and internal electrode layers are alternately laminated; and a cover layer disposed so as to surround a side face of the stacked body, and the cover layer has a two-layer structure with an annular boundary when viewed in a section perpendicular to a stacking direction of the stacked body.

The invention relates to a method and a device for actuating an injection valve, which has a piezo actuator and a nozzle needle, of a fuel injection system of an internal combustion engine, in which method a control unit, in a manner dependent on a setpoint stroke height of the piezo actuator in successive injection cycles, outputs a control signal for changing the actual stroke height of the piezo actuator, characterized in that the control unit changes the setpoint stroke height of the piezo actuator, for compensation of the temperature dependency of the capacitance of the piezo actuator, in a manner dependent on the temperature of said piezo actuator.

Various embodiments may include a method for operating a piezo-actuator in a piezo-operated injector for a fuel injection system comprising: producing a measuring pulse at a position at which the usable signal which is to be measured is expected; then producing a reference pulse which corresponds to the measuring pulse, in the same cycle; subtracting a first actuator voltage measured during the reference pulse from a second actuator voltage measured during the measuring pulse; using a resulting voltage signal difference to calculate a force sensed by the piezo-actuator; and using the force sensed to correct an injection amount for the injector.