Continental Automotive Gmbh

Willibald Schuerz

Roman Etlender

Werner Reim

Janos Kerekgyarto

Ivan Krotow

Jignesh Jagani

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.

Injector

A piezo injector includes an actuator space in which a piezo actuator is arranged, a control piston bore in which a control piston with an end face is arranged, a leakage pin arranged between the piezo actuator and the end face to couple the piezo actuator with the control piston, and a union for fluidic communication with the control piston bore which union has a hydraulic throttle.

Piezo injector

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.

Piezo common rail injector with hydraulic clearance compensation integrated into the servo valve

A method is provided for pairing at least two injectors, e.g., two fuel injectors for a direct injection system of an internal combustion engine, wherein a criterion for the pairing of the at least two injectors is a total leakage and/or a pressure difference at a transfer pin of the respective injector. A method for producing an injector, e.g., a fuel injector for a direct injection system of an internal combustion engine, is also provided, wherein at least two instances of mechanical backlash, e.g., instances of pairing backlash, that are relevant to injection amounts, leakage amounts, and/or pressure differences of the injector are paired with each other.

Method for producing injectors, in particular fuel injectors

An injector includes an actuator arranged in an actuator space, a piston guide having a bore hole, and a piston arranged in the bore hole. The piston has a first end face facing the actuator and delimiting a first space in and/or on the bore hole, and a second end face lying opposite the first space and delimiting an adjoining second space in and/or on the bore hole. The piston is arranged between the first and second spaces, and a gap extends around the circumference of the piston between the piston and the bore hole. The piston includes a first material and the piston guide includes a second material, the first and second materials having different thermal expansion properties such that when the piston guide and/or piston are heated, the gap width of the gap decreases to limit fuel leakage between the first space and second spaces.

A piezo injector includes a piezo actuator arranged in an actuator chamber and a valve plunger arranged in a valve plunger bore and having a first end face facing the piezo actuator. The valve plunger is arranged between a first control chamber defined by a valve plunger bore portion delimited by the first end face and a spring chamber formed by a valve plunger bore portion opposite the first control chamber. A second control chamber is delimited by a second face of a nozzle needle and a sleeve guided by the nozzle needle. A leakage pin is arranged in a leakage pin bore between the piezo actuator and the first end face of the valve plunger. The leakage pin bore is formed in an intermediate plate arranged on a side of a control plate facing the piezo actuator, the valve plunger bore being formed in said control plate.

Piezo injector with hydraulically coupled nozzle needle movement

A piezo injector for direct fuel injection may comprise an injector body, an actuator unit having a piezoelectric actuator with a head plate and a base plate, a hydraulic coupler having a coupler piston, a coupler cylinder, and a coupler spring, and a nozzle unit having a nozzle needle arranged in a nozzle body. The piezoelectric actuator is surrounded by a corrugated tube braced between the head plate and the base plate such that the piezoelectric actuator has a preload imparted to it. The coupler spring forces the coupler piston against a face side, facing toward the coupler piston, of the nozzle needle.

Piezoelectric injector for direct fuel injection

A fluid injector has a solid state actuator and a control piston unit arranged in a recess of an injector body. A transmission pin mechanically couples the actuator to the control piston unit. A first control chamber, coupled hydraulically to a second control chamber, is delimited by the control piston unit and the injector body. A control piston of the control piston unit has an end surface that is coupled to the transmission pin and which delimits the first control chamber. The control piston unit has a control sleeve arranged coaxially with the control piston and an inwardly directed projection that provides a driving coupling between the control piston and the control sleeve after a predefined control stroke of the control piston. The driving coupling results in the control piston influencing a free volume of the first control chamber during an axial movement of the control piston.

Fluid injector

A solid actuator has an actuator structural unit, a top plate and a base plate. A hollow cylinder part made of maraging steel is heated to a predetermined first temperature at which the maraging steel is in an austenitic state. A corrugated tube is shaped from the hollow cylinder part by a shaping process, while the maraging steel is still in an austenitic state. The corrugated tube is cooled such that the maraging steel is in a martensitic state. The actuator structural unit is inserted into the corrugated tube. The top plate and the base plate are fixed to the corrugated tube such that the actuator structural unit is clamped between the top plate and the base plate at a predetermined pre-tension.

Method for producing a solid actuator

A piezo injector with an actuator chamber, in which a piezo actuator is arranged, includes an upper section (the injector body) and a lower section (the nozzle body). The piezo injector also has a control piston bore formed in the nozzle body, wherein a control sleeve, in which a control piston is received, is arranged in the control piston bore. The control sleeve seals against an intermediate plate with a first front face facing the piezo actuator. The control piston has a first side facing the piezo actuator, wherein the first front face of the control piston and the section of the control sleeve facing the piezo actuator form a first control chamber.

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Pielenhofen, Germany

Willibald Schuerz