Abstract: An injector with a double-switching control valve in which a valve body is guided in the housing of the control valve in a way that reduces the wear on a valve cone of the valve body and on a first valve seat in the housing of the control valve.

Abstract: An arrangement is proposed for forming a piezoelectric actuator, which has at least one piezoelectric element that in each case consists of a multi-layer structure of piezoelectric-layers, wherein internal electrodes arranged between the piezoelectric-layers in the direction of the build-up of the layers of the piezoelectric element, have an electrical voltage of different polarity alternately applied to them. Around the piezoelectric element, or in the case of multiple piezoelectric elements positioned in series in the activation direction, around the piezoelectric elements, and at least partially around the actuator head and the actuator foot there is arranged a covering system made from at least one layer of an insulating material. The at least one layer encloses the joints between the piezoelectric element or elements and the actuator head and the actuator foot, forming a seal.

Abstract: An injector with a double-switching control valve in which a valve body is guided in the housing of the control valve in a way that reduces the wear on a valve cone of the valve body and on a first valve seat in the housing of the control valve.

Abstract: A fuel injection device of an internal combustion engine includes a piezoelectric actuator and a valve element that are coupled to one another. The valve element has a pressure stage. An increase in the force acting on the piezoelectric actuator is interpreted as an actual opening of the valve element, and/or a decrease in the force acting on the piezoelectric actuator is interpreted as an actual closing of the valve element, and that these be taken into account at least part of the time in the controlling of the piezoelectric actuator.

Abstract: A fuel injector for an internal combustion engine is proposed having a directly actuatable injection valve element. The fuel injector has a nozzle needle, axially guided in a nozzle body, and an actuator accommodated in an injector housing. The nozzle needle is connected to a coupling piston on the nozzle-needle side and the actuator is connected to a coupling piston on the actuator side. The coupling piston on the actuator side acts on a coupling chamber and the coupling piston on the nozzle-needle side acts on a control chamber. The nozzle needle is lifted from a nozzle-needle sealing seat as a function of the pressure in the control space. An intermediate plate is provided between injector housing and nozzle body. The plate has a conduit hydraulically connecting the coupling chamber to the control chamber. The conduit contains a hydraulic throttle which has at least two sections having different cross sections of flow.

Abstract: A fuel injection valve with a valve member axially displaceable in a bore of a valve body comprises a valve stem, the combustion chamber end, with which it interacts with a valve face of the valve body, at least one injection opening downstream of the valve face and opening into the combustion chamber to be supplied with fuel, a guide section of the valve body guiding the valve member and being disposed axially between an annular gap connected to the high-pressure fuel line and an annular space leading to the valve face, a first throttle connection permanently interlinking the annular gap and the annular space, and a second throttle connection interlinking the annular gap and the annular space as of a defined opening stroke of the valve member and having a smaller throttle resistance than the first throttle connection. The guide section is configured by a guide sleeve that is fastened at the combustion chamber end of the valve body in the bore so as to be stationary.

Abstract: The invention relates to a fuel injector for injecting fuel into the combustion chamber of an internal combustion engine. The fuel injector has an injection valve member that can be actuated directly by a piezoelectric actuator. This injection valve member is contained in a nozzle body of the fuel injector and can be moved into its closed position by a spring element. A hydraulic boosting device is provided between the piezoelectric actuator and the injection valve member in order to adapt the force to be exerted by the piezoelectric actuator to the opening force curve of the injection valve member.

Abstract: An injector, in particular an injector for a combustion engine, includes at least one nozzle module which has an injection nozzle and a supply line for a fluid under a supply pressure, and a valve-control module, which is in operative connection with the nozzle module, and at least one valve-closure member on which the supply pressure acts, and includes a piezoelectric actuator which is used to activate the valve-closure member and which is prestressed by a spring in the direction facing away from the valve-closure member, the piezoelectric actuator being activated by a valve-control unit which specifies a control gradient. The control gradient is a variable that is dependent upon the supply pressure.

Abstract: A fuel injection device of an internal combustion engine includes a piezoelectric actuator and a valve element that are coupled to one another. The valve element has a pressure stage. An increase in the force acting on the piezoelectric actuator is interpreted as an actual opening of the valve element, and/or a decrease in the force acting on the piezoelectric actuator is interpreted as an actual closing of the valve element, and that these be taken into account at least part of the time in the controlling of the piezoelectric actuator.

Abstract: An injection nozzle for an internal combustion engine, in particular in a motor vehicle, the nozzle including a nozzle body having at least one injection port, a nozzle needle supported to execute a stroke inside the nozzle body to control an injection of fuel through the at least one injection port, a booster piston that is drive-coupled to an actuator and having a booster surface, the nozzle needle or a needle unit including the nozzle needle having a control surface that is hydraulically coupled to the booster surface. A bypass piston is supported to execute a stroke inside the booster piston, the bypass piston having a bypass surface that is hydraulically coupled to the booster surface, the bypass piston resting against a stop that is stationary in relation to the nozzle body, in an initial state in which the nozzle needle closes the at least one injection port, and the bypass piston having a reservoir surface that delimits a reservoir provided inside the booster piston.

Abstract: The invention relates to a fuel injector for injecting fuel into the combustion chamber of an internal combustion engine. The fuel injector has an injection valve member that can be actuated directly by a piezoelectric actuator. This injection valve member is contained in a nozzle body of the fuel injector and can be moved into its closed position by a spring element. A hydraulic boosting device is provided between the piezoelectric actuator and the injection valve member in order to adapt the force to be exerted by the piezoelectric actuator to the opening force curve of the injection valve member.

Abstract: The invention relates to an injection nozzle for an internal combustion engine having a nozzle needle or needle unit for controlling an injection of fuel through at least one injection orifice and an actuator for driving a coupling piston. The nozzle needle or needle unit has a control surface that at least partially delimits a control chamber which communicates with a coupling chamber that is at least partially delimited by the coupling piston. The control surface is situated at the end of the nozzle needle or nozzle unit oriented away from the at least one injection orifice and the actuator drives the coupling piston to open the nozzle needle in such a way that a volume of the coupling chamber increases.

Abstract: A fuel injector with a direct needle control for an internal combustion engine, having an actuator, a hydraulic booster, and a nozzle needle guided in a nozzle body and acting on a nozzle needle sealing seat. The hydraulic booster includes a booster piston connected to the actuator and a nozzle needle booster piston connected to the nozzle needle; a booster chamber in the form of an actuator coupler chamber is associated with a pressure surface of the actuator booster piston; and depending on the pressure in the actuator coupler chamber, the nozzle needle is lifted away from the nozzle needle sealing seat, thus initiating an injection. In addition to the actuator booster piston, a control element is provided that is able to execute a stroke motion, is hydraulically coupled to the actuator coupler chamber by means of a first control surface, and is associated with a control chamber by means of a second control surface.

Abstract: The invention relates to a valve for a fuel injection system, having a valve seat embodied in a valve housing, and having a valve member which is movable in the valve housing and has a sealing face that when the valve is closed rests sealingly against the valve seat and when the valve is open, together with the valve seat, defines a valve gap through which fuel flows. To prevent cavitation damage, the valve member has an encompassing hollow throat, which is disposed in the flow direction immediately downstream of the sealing face and is adjoined by an encompassing cross-sectional thickening of the valve member.

Abstract: The invention relates to a fuel injector with a piezoelectric actuator that actuates an injection valve member. This piezoelectric actuator acts on the injection valve member, which a spring element acts on in the closing direction. The fuel injector has a hydraulic coupling chamber that hydraulically couples a transmission piston to the injection valve member. A sleeve-shaped body rests against the injection valve member and cooperates with an edge that constitutes an intermediate stroke stop for the injection valve member.

Abstract: A fuel injector with a direct needle control for an internal combustion engine, having an actuator, a hydraulic booster, and a nozzle needle guided in a nozzle body and acting on a nozzle needle sealing seat. The hydraulic booster includes a booster piston connected to the actuator and a nozzle needle booster piston connected to the nozzle needle; a booster chamber in the form of an actuator coupler chamber is associated with a pressure surface of the actuator booster piston; and depending on the pressure in the actuator coupler chamber, the nozzle needle is lifted away from the nozzle needle sealing seat, thus initiating an injection. In addition to the actuator booster piston, a control element is provided that is able to execute a stroke motion, is hydraulically coupled to the actuator coupler chamber by means of a first control surface, and is associated with a control chamber by means of a second control surface.

Abstract: An injection valve for an internal combustion engine including at least a nozzle body, in which a nozzle needle is guided axially displaceably, and an at least one-piece retaining body, in which means for actuating the nozzle needle are disposed. On its circumferential surface, the nozzle body has means for engagement of a centering tool.

Abstract: The invention describes a method and an apparatus for charging a piezoelectric element, for example, used as an actuator in a fuel injection system of an internal combustion engine. The method and apparatus are characterized in that the piezoelectric element is activated by an activation voltage having a value set as a function of manufacturing characteristics of the particular piezoelectric element and based upon, for example, a correction value for injected fuel volume.

Abstract: An injection nozzle has a nozzle body, a nozzle needle that is supported displaceably in the nozzle body, a control chamber that communicates with a fluid inlet and a fluid outlet, and a valve element that can open and close the fluid outlet. The control chamber is laterally defined by a displaceable ring which rests on the nozzle needle, and a closing spring presses the ring against the nozzle needle in fluid-tight fashion.

Abstract: A valve for controlling fluids, having a piezoelectric actuator unit for actuating a valve member is proposed, which has at least one adjusting piston and at least one actuating piston that is guided in a valve body and actuates a valve closing body, which valve closing body cooperates with at least one valve seat embodied on the valve body and in the closing direction disconnects a control bore from an outlet chamber, from which a return conduit branches off, wherein between the adjusting piston and the actuating piston, a hydraulic chamber is disposed, which transmits a motion of the adjusting piston to the actuating piston. To keep the size of the actuator unit small, the actuating piston, at least when the valve closing body is closed, is supported essentially in a hydraulically force-balanced fashion.