Abstract: A flow rate control valve includes a base block and a valve opening/closing mechanism. The base block is provided with a valve chamber in which a valve seat through which a liquid raw material L flows, and a diaphragm that is brought into contact with or separated from the valve seat so as to close/open the valve seat are installed. The valve opening/closing mechanism includes a slide bearing part, a support post part, a piezoelectric actuator part, and a valve-actuating part. The slide bearing part is installed on the base block 1 and is provided with a bearing. The support post part includes a support post that is inserted slidably in the bearing and that moves upward and downward in a diaphragm direction.

Abstract: A device including a deformable shell delimiting an inner space, and a resilient band suspended in the inner space and including two ends secured to the deformable shell. The band includes a piezoelectric material to generate an electric voltage under the effect of the deformation of the shell and two electrodes for collecting the voltage. An electronic circuit for processing the voltage is arranged on the resilient band and connected to the electrodes of the resilient band.

Abstract: An air flow velocity calculating device of a internal combustion engine, has a cylinder, a spark plug, an air intake passage, an air flow controlling valve, an air flow velocity calculating portion, and an electric discharge current controlling portion. An electric discharge between a center electrode and a ground electrode is sustained during an electric discharge sustaining period. The electric discharge sustaining period is a period from when the electric discharge begins to when the electric discharge is intercepted by the air flow. Energy is supplied to the spark plug, so that the electric discharge current is sustained at a constant value by the electric discharge current controlling portion during an ignition period. The ignition period is a sum of an electric discharge sustaining period of a first electric discharge and electric discharge sustaining periods of second and subsequent electric discharges in one cycle of the internal combustion engine.

Abstract: The present disclosure relates to methods for operating an injection valve. An example method may include capturing ACTUAL quantities constituted by actuator current or actuator charge and/or actuator voltage continuously during an injection process; reconstructing a dynamic progression of the nozzle-needle stroke of an injection valve on the basis of a model structure for a motion of the nozzle needle of the injection valve, ascertaining the DESIRED quantities constituted by actuator current or actuator charge and/or actuator voltage therefrom, wherein the dynamic progression of the nozzle-needle stroke is reconstructed via a simplified model structure by introduction of at least one discrete measured value pertaining to the injection valve into a basic model of the nozzle-needle motion; comparing the DESIRED quantities with the ACTUAL quantities; and minimizing the difference between the DESIRED quantities and the ACTUAL quantities.

Abstract: A method for determining the opening for piezo servo-driven injectors may include measuring a voltage and a charge at an end of a charging process of the piezo actuator; determining a provisional scaling factor by calculating Q/U; determining the maximum of CVORL and using the instant at which the maximum occurs as an approximation value of the valve opening instant; measuring the charge and voltage at the approximation of the valve opening instant; solving the equation: 1.25×F2/E×C=(U×C?Q)2 Where F=force acting on the piezo actuator, E=electrical parameter of the piezo actuator; determining a new scaling factor from the solution of the equation; calculating the difference (U×C?Q) and determining a maximum of said value; and using the instant at which said maximum occurs as valve opening instant.

Abstract: A method for detecting error-containing components of a piezo-injector in an internal combustion engine fuel-injection system is disclosed. The piezo-injector has a piezoelectric actuator and an injection needle driven thereby, and is configured for operation in a partial-stroke mode and a full-stroke mode. First, the internal combustion engine is brought to a defined operational point. Then, the time for the injector needle to strike its stop when said injector needle is opened, as well as the time for the injector needle to strike its needle seat again when said injector needle is closed, are measured. The measured times are compared to normal values determined at the test stand. Parameter(s) for the fuel-injection system are calculated, using different calculation models, and the results are stored. Finally, the calculated parameters of the different calculation models are compared to norm values determined at the test stand, and compared to one another.

Abstract: An injector for a fluid, particularly for fuel, is provided having a valve housing, a fluid intake, a valve chamber having a spray-discharge orifice, a piezoelectric or magnetostrictive actuator situated in the valve housing and a fluid-guiding pipe connecting a fluid intake and a valve chamber, which is situated in the valve housing running along the actuator. In order to create structural space in the valve housing for guiding through the fluid-guiding pipe which has a sufficiently large diameter for reducing pressure drops in the intake region, a hollow cylinder surrounding the actuator and developed as a prestressed spring is provided with a cylinder wall opening that extends axially through the entire length, and the positioning of the fluid-guiding pipe in the valve housing is undertaken so that it extends radially into the cylinder wall opening.

Abstract: An injection nozzle has a nozzle needle that suppresses metering of fluid in a closed position and otherwise allows the metering of fluid. Furthermore, the injection valve has a solid-state actuator that acts on the nozzle needle. A first operating phase is performed for a closing operation in a first operating mode, during which first operating phase the solid-state actuator is discharged to a predefined part charge. Furthermore, a second operating phase is performed, during which the solid-state actuator is operated as a sensor. An operating duration of the second operating phase is predefined such that the closed position of the nozzle needle is reached during the operating duration. A third operating phase is performed, during which the solid-state actuator is discharged further to a predefined reference state. In a second operating mode, the first and second operating phases are carried out and the third operating phase is omitted.

Abstract: A method for determining the actual start of injection is performed by an actuating device for a piezo fuel injection valve and includes the following steps. First, a test injection is carried out with such a short actuation duration that a start of shut-off takes place at a time so early that the nozzle needle does not reach the open end position. Said time is predefined by the actuation and is therefore precisely known. Next, the closing time of the nozzle needle is then determined by measurement and evaluation of an electrical variable of the piezo direct drive. Once the closing time and the time of the start of shut-off are known, the actual start of injection is calculated back from the closing time via the start of shut-off. This permits an adequately precise determination of the actual injection quantity in almost every operating state of the internal combustion engine.

Abstract: In a fuel injector, a body has formed therein a spray hole and a fuel supply passage. Fuel supplied to the fuel supply passage is delivered to the spray hole. A fuel pressure sensor produces a signal indicative of a pressure of the fuel. First terminals are attached to the fuel pressure sensor and include a terminal for outputting the signal. The fuel pressure sensor is threadedly installed in the body while the first terminals are rotated. A connector includes a housing attached to the body, and second terminals supported by the housing for external electric connection of the fuel pressure sensor. Wires are operative to establish electrical connection between the first terminals and the second terminals. A wire holder is configured to hold each of the plurality of wires at least partly around the fuel pressure sensor.

Abstract: A multi-layer piezoelectric element includes a columnar stacked body including an active portion including piezoelectric layers and internal electrode layers alternately laminated, and inactive portions including piezoelectric layers laminated, the inactive portions arranged at both ends in a stacked direction of the active portion; and a pair of external electrodes arranged on side faces of the columnar stacked body, the pair of external electrodes electrically connected to the internal electrode layers alternately. In at least one interlayer portion of the inactive portions, there are metal particles having a particle size smaller than that of piezoelectric ceramic particles forming the piezoelectric layers of the inactive portions, and the metal particles are scattered in a range including a region in which the internal electrode layers overlap each other when viewed in the stacked direction of the columnar stacked body.

Abstract: Provided is a multi-layer piezoelectric element capable of achieving a high response speed and an increase in the displacement amount, ensuring sufficient mechanical strength, and suppressing deterioration of characteristics. A multi-layer piezoelectric element includes a stacked body in which piezoelectric layers and internal electrode layers are alternately laminated, and the piezoelectric layers include a polarization domain extending over a plurality of crystal particles. Since the piezoelectric layers include the polarization domain extending over the plurality of crystal particles, the multi-layer piezoelectric element can achieve a high response speed and an increase in the displacement amount, ensure sufficient mechanical strength, and suppress deterioration of characteristics.

Abstract: An injector for a fluid is provided, in particular for fuel, which has a valve housing, an intake nipple for the fluid disposed at one housing end, a nozzle body disposed at the other housing end, which has a valve seat surrounding a spray-discharge orifice, and a valve chamber disposed upstream therefrom, and a fluid-carrying pipe which extends in the valve housing and connects the valve chamber to the intake nipple. To achieve a connection of the fluid-carrying pipe to the valve chamber that is impervious to high operating pressures and is suitable in terms of production and convenient in terms of assembly, an axial blind hole which has an internal thread and is disposed at a radial offset to the housing axis of the valve housing, is formed in the nozzle body, and a fluid connection us established from the blind hole to the valve chamber.

Abstract: An injection valve is hydraulically coupled to a high-pressure accumulator in order to supply a fluid. The injection valve has a longitudinal axis, an injection needle, and an actuator. The actuator is designed to act on the injection needle. A pre-defined amount of electrical energy is supplied to the actuator in order to modify an axial length of the actuator in such a way that the injection needle moves out of the closed position. Once the pre-defined amount of electrical energy has been supplied, a first voltage value and a second voltage value are detected and/or determined by the actuator at respectively different pre-defined moments. On the basis of the first and second voltage values, a differential voltage value is determined, on the basis of which a first pressure is determined, which represents a pressure in the high-pressure accumulator.

Abstract: Provided is a highly durable multi-layer piezoelectric element wherein a conductive connection member is not broken even in the case of continuous driving for a long period in a high electric field under high pressure. A multi-layer piezoelectric element includes a stacked body configured so that piezoelectric layers and internal electrode layers are alternately laminated, an external electrode bonded to a side surface of the stacked body and electrically connected to the internal electrode layers, and a conductive connection member which is disposed on a surface of the external electrode and of which surface has projections and depressions formed repeatedly at least in a stacked direction of the stacked body.

Abstract: A programmable diesel fuel injector that increases frequency response and control precision over desired fuel flow rates throughout each injection event. All valve frequency and motional requirements are met by a compensated direct drive, which is enabled by the durable capability of a rare earth alloy to lengthen in a magnetic field. A continuously variable electrical input waveform is predetermined to result in the desired fuel injection rate shape. A magnetostrictive transducer converts voltage and current into continuously variable force and displacement of a master piston acting upon fuel within a closed chamber. A slave piston responds to the fuel pressure changes within the closed chamber and acts upon the spool of a spool valve to eject fuel.

Abstract: A fuel injector, in particular for the direct injection of fuel into the combustion chamber of a mixture-compressing internal combustion engine having externally supplied ignition, includes an armature which cooperates with a solenoid coil, and a valve needle which is joined to the armature by force-locking and on which a valve-closure member is provided which forms a sealing seat together with a valve-seat surface. The armature is swingingly supported on the valve needle by a spring.

Abstract: A piezoelectric-actuated fuel injector for injecting fuel into a combustion chamber of an internal combustion engine is provided which includes a piezoelectric actuator movable to expand in a first direction and movable to contract in a second direction opposite the first direction, and a hydraulic link assembly disposed within a nozzle cavity formed in a nozzle housing containing a nozzle valve element. The hydraulic link assembly is positioned close to the injector orifices to minimize needle valve element length and mass, thereby reducing seat impact forces and enhance response time. A refill valve operates to move into an open position to refill a hydraulic link chamber. An actuator power source operates to vary voltage to cause multiple injection pulses and to selectively maintain the voltage above a predetermined lower level between injection pulses to maintain the refill valve in a closed position to prevent refilling of the hydraulic link chamber.

Abstract: An injection valve has a valve body and a valve pin. The valve body has a metering orifice. In a closed position of the valve pin, the flow of fluid through the metering orifice is disabled and otherwise released. A control signal (ANS_SIG) for metering fluid with the injection valve is generated for a first valve pin actuator which is coupled to the valve pin to drive the valve pin. At least one first atomization signal (ZER_SIG—1) for the first and/or the second valve pin actuator is generated at least during a predetermined interval during the control of the first valve pin actuator with the control signal (AN_SIG) in such a manner that the valve pin is oscillatingly displaced relative to a position of the valve pin in response to the first atomization signal (ZER_SIG—1), the valve pin having said position in response to the control signal (ANS_SIG).

Abstract: The present invention provides an apparatus for enabling operation of a piezoelectric actuator, comprising a spring configured to provide a compressive force to a piezoelectric element of a piezoelectric actuator, wherein the compressive force varies with displacement of the piezoelectric element such that the compressive force is less at a first displacement than at a second displacement, and wherein the first displacement is greater than the second displacement.

Abstract: To provide a multi-layer piezoelectric element that is improved to mitigate the decrease in the amount of displacement under such harsh operating conditions, the multi-layer piezoelectric element, the multi-layer piezoelectric element comprising: a stacked body comprising a plurality of piezoelectric material layers and a plurality of internal electrodes, the stacked body being formed by stacking the plurality of internal electrodes and the piezoelectric layers alternately on each other; and an external electrode formed on a side face of the stacked body, wherein the external electrode comprises a base portion and a first protrusion protruding from the base portion toward an outside.

Abstract: The invention relates to an injector including a needle mounted in a nozzle and having an end defining a valve, the needle being connected at the other end to an actuator including first, second and third portions, the first and third portions being provided on either side of the second portion, the three portions being tightened together in order to form a block having two axially opposite limits, the first portion being connected with the needle at one of said limits, and an excitation means for vibrating the second portion according to setpoint period ?. According to the invention, the length between the two limits of the block is such that the propagation time T of the acoustic waves generated by the vibrations of the second portion of the actuator and running along that length meets the equation: T=n*[?/2], where n is an integer positive multiplication coefficient different from zero.

Abstract: A piezoelectric-actuated fuel injector for injecting fuel into a combustion chamber of an internal combustion engine is provided which includes a piezoelectric actuator movable to expand in a first direction and movable to contract in a second direction opposite the first direction, and a hydraulic link assembly disposed within said injector cavity. The hydraulic link assembly includes a hydraulic link barrel having an inner bore, a hydraulic link outer plunger positioned to slidably move in the inner bore, and a hydraulic link operatively connected to a needle valve to move the needle valve in the second direction toward the open position in response to movement of the piezoelectric actuator in the first direction. A hydraulic link inner plunger is attached to the needle valve and extends into a center bore of the hydraulic link outer plunger. Leakage control features and hydraulic link refill valves are also provided.

Abstract: A diesel engine fuel polishing system is provided that utilizes a piezoelectric pump to circulate fuel from a fuel tank and through a filter and then back to the fuel tank. The piezoelectric pump operates on ultra low power and can be utilized in continuous operation when the diesel engine is not in operation. The low power requirement allows the pump to be operated by a battery that is recharged by a solar energy panel.

Abstract: An apparatus for injecting fuel into a combustion chamber of an internal combustion engine. The apparatus includes a solid magnetostrictive material with a favored direction of magnetostrictive response formed into a shape with ends that are substantially parallel to each other and substantially perpendicular to the favored direction of magnetostrictive response. A fuel control valve element is located coaxial to the favored direction of magnetoelastic response of the magnetostrictive material, the element opening inwardly. A solenoid coil is located concentric with the magnetostrictive material and coaxial to the favored direction of magnetoelastic response, the solenoid coil adapted to excite the magnetostrictive material into mechanical motion. An excitation signal is provided within the solenoid coil consisting of a main current signal with a superposed alternating signal approximately the width of a hysteresis loop of the solid magnetostrictive material.

Abstract: A method of operating a fuel injector including a piezoelectric actuator having a stack of piezoelectric elements, and wherein in use the injector communicates with a fuel rail, the method comprises: applying a discharge current to the actuator for a discharge period so as to discharge the stack from a first differential voltage level across the stack to a second differential voltage level across the stack; maintaining the second differential voltage level for a period of time; and applying a charge current to the actuator for a charge period so as to charge the stack from the second differential voltage level to a third differential voltage level; wherein the third differential voltage level is selected in dependence on at least two engine parameters, the at least two engine parameters selected from: rail pressure; the electric pulse time; and the piezoelectric stack temperature.

Abstract: A return fuel passage is configured to communicate an outlet of a low-pressure fuel pump with a back pressure side of a fuel injection device. The return fuel passage is configured to partially return fuel from the back pressure side to the fuel tank to control fuel pressure at the back pressure side in response to fuel injection. In a starting operation a backpressure control valve communicates the outlet of the low-pressure fuel pump with the back pressure side and blocks the fuel tank from both the outlet of the low-pressure fuel pump and the back pressure side. In a normal operation, the backpressure control valve communicates the back pressure side with the fuel tank and blocks the outlet of the low-pressure fuel pump from both the fuel tank and the back pressure side.

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 module, direct fuel injector (10) includes a fuel side sub-assembly (78) having valve body structure (12, 14) defining a main flow passage (16) there-through, an outlet opening (26) and a seating surface (24). A needle (18) is in the main flow passage and has first and second ends. The second end (22) has a sealing surface (20). The needle is movable between a closed position with the sealing surface engaging the seating surface to prevent fuel from passing through the outlet opening, and an open position. A spring (30) biases the needle to the closed position. Manifold structure (36, 48) is coupled to the valve body structure. The injector also includes a dry side sub-assembly including a piezo stack (42) coupled to the manifold structure and changes length when voltage is applied thereto. The piezo stack is associated with the first end of the needle so that when the length of the piezo stack changes, the needle moves from the closed position to the open position thereof.

Abstract: A fluid injector has an actuator unit, a cartridge, which has a recess, which on one of its open ends forms an injection nozzle and takes in a needle. The needle has a first and a second part (15, 17). The first part (15) is inserted into the recess and closes or opens the injection nozzle depending on the position of the first part (15). The second part (17) is coupled to the actuator unit on one of its free ends and is coupled to the first part (15) via a coupling unit. The coupling unit is arranged in positive connection to the first part (15) and is joined to the second part. In that way the material for the first part may be chosen for being highly wear resistant. On the other hand the material of the second part (17) may be chosen for being well-suited for a joining process.

Abstract: To provide a multi-layer piezoelectric element that is improved to mitigate the decrease in the amount of displacement under such harsh operating conditions, the multi-layer piezoelectric element, the multi-layer piezoelectric element comprising: a stacked body comprising a plurality of piezoelectric material layers and a plurality of internal electrodes, the stacked body being formed by stacking the plurality of internal electrodes and the piezoelectric layers alternately on each other; and an external electrode formed on a side face of the stacked body, wherein the external electrode comprises a base portion and a first protrusion protruding from the base portion toward an outside.

Abstract: An actuator unit has a tube spring (32), a piezoelectric actuator (31), that is inserted into the tube spring (32), a first cap (33), that is connected to the tube spring (32) at a first free end of the tube spring (32) and which is adjoined by the piezoelectric actuator (31), a tube-shaped body 38, that is connected to the tube spring (32) by joining and is arranged in the area of a second free end (35) of the tube spring (32), and a device for pretensioning, that is supported by the tube-shaped body (38) and pretensions the piezoelectric actuator (31). The actuator unit is simple and cheap to manufacture.

Abstract: The piezo injector includes a piezo element expanding when electrical charges supplied from an external DC source are accumulated therein, and contracting when the electrical charges are discharged therefrom, an open/close valve opening and closing in accordance with expansion and contraction of the piezo element, a housing containing therein the piezo element and the open/close valve, and an inductor element through which the electrical charges are accumulated in and discharged from the piezo element.

Abstract: A method for injecting a fluid, in particular a fuel, performs the following steps: A nozzle (1) which can be actuated by a piezo element (5) is provided. A current pulse (12a) is supplied to the piezo element (5). The capacity (16) of the piezo element (5) is recorded at the time when the current pulse (12a) is supplied. An actual characteristic curve of the injection is recorded based on the capacity (16). The current pulse (12a) is regulated in order to optimize the injection based on the actual characteristic curve of the injection.

Abstract: An ultrasonic liquid delivery device has an elongate housing with an internal chamber, an inlet in fluid communication with the internal chamber of the housing, and an outlet in fluid communication with the internal chamber of the housing. An elongate ultrasonic waveguide is disposed at least in part within the internal chamber of the housing to ultrasonically energize liquid within the internal chamber prior to the liquid being exhausted from the housing through the outlet. The ultrasonic waveguide has an agitating member extending outward from the ultrasonic waveguide within the internal chamber of the housing intermediate the inlet and the outlet. The agitating member and the ultrasonic waveguide are constructed and arranged for dynamic motion of the agitating member relative to the ultrasonic waveguide upon ultrasonic vibration of the ultrasonic waveguide. An excitation device is operable to ultrasonically excite the ultrasonic waveguide and the agitating member.

Abstract: A valve has a piezo actuator, a valve element, a valve body and a valve seat. At a predeterminable point in time, the valve element is controlled by a discharging process of the piezo actuator from a position in which it rests against the valve seat to a predetermined position located at a distance from the valve seat. The discharging process is divided into a first discharging period during which a predetermined first amount of electrical energy is discharged from the piezo actuator, a subsequent holding time period during which the piezo actuator is not controlled, and a subsequent second discharging period during which a predetermined second amount of electrical energy is discharged. The holding time duration and/or the first discharging period are/is adapted according to the course of a value that is not characteristic of the oscillation behavior of the piezo actuator during the holding time period.

Abstract: A fuel injector for delivering fuel to an engine in which a housing of the injector has an internal fuel chamber and at least one exhaust port in fluid communication with the fuel chamber. A valve member is moveable relative to the housing between a closed position in which fuel within the fuel chamber is inhibited against exhaustion from the housing, and an open position in which fuel is exhaustable from the housing. An ultrasonic waveguide separate from the housing and valve member is disposed at least in part within the fuel chamber to ultrasonically excite fuel within the fuel chamber prior to the fuel exiting through the at least one exhaust port in the open position of the valve member. An excitation device is operable in the open position of the valve member to ultrasonically excite the ultrasonic waveguide.

Abstract: An ultrasonic liquid delivery device in which a housing of the device has an internal chamber and at least one exhaust port in fluid communication with the internal chamber of the housing. A valve member is moveable relative to the housing between a closed position in which liquid is inhibited against exhaustion from the housing via the at least one exhaust port, and an open position in which liquid is exhaustable from the housing via the at least one exhaust port. An ultrasonic waveguide separate from the housing and valve member is disposed at least in part within the internal chamber of the housing to ultrasonically energize liquid within the internal chamber prior to liquid being exhausted from the housing in the open position of the valve member. An excitation device is operable in the open position of the valve member to ultrasonically excite the ultrasonic waveguide.

Abstract: A combined injector and fuel pump suitable for high pressure direct injection of heavy fuels into Diesel engines, in particular small light weight Diesel engines as may be used in small aircraft. The injector utilizes a piezoelectric actuator driving a piston assembly comprising an inlet reed check valve disposed thereon. Fuel enters an inlet port coupled to an inlet chamber on a first side of the piston. Piezoelectric actuator contraction transfers fuel from the inlet chamber through the reed valve to the pressurization chamber on a second side of the piston. Piezoelectric actuator expansion drives the piston to pressurize the fuel in the pressurization chamber, which forces open a conical annular valve and nozzle assembly injecting a finely atomized mist of fuel into the cylinder.

Abstract: An electric circuit for triggering a piezoelectric element, a fuel injection system of a motor vehicle in particular, is described. A first measuring shunt connected in series to the piezoelectric element is provided. Provided are two transistors connected in series whose shared connecting point is connected to the piezoelectric element. A second measuring shunt is also provided. The two transistors and the second measuring shunt are connected in series.

Abstract: Injectors each having a piezo actuator are assigned to cylinders of an internal combustion engine. A regulator device is configured for furnishing a cylinder-specific controlled variable and a command variable to a controller whose primary manipulated variable is a variable representing an electrical power supplied to the piezo actuator during a control cycle. A manipulated variable splitting unit is provided whose input variable is a regulator-determined regulator value of the primary manipulated variable and is configured for determining a total value of the primary manipulated variable according to the regulator value. It is also configured for splitting the total value into a primary value of the primary manipulated variable and into a secondary value of a secondary manipulated variable according to a lower and/or upper threshold value of the total value.

Abstract: An piezo actuator loading signal is determined and generated according to an output value and a pilot control value which depends on at least one operational parameter. The loading signal causes that a valve member moves into a valve seat. A first value characteristic of the electric power fed to the actuator when the valve member hits the valve seat is determined while a second value characteristic of the energy delivered to the actuator is determined when the loading process of the actuator has been completed. A real value characteristic of a sealing force with which the valve member is pressed onto the valve seat is determined according to the first and second value. The real value and a predefined setpoint value are fed to the controller which accordingly adjusts a pilot control value assignment instruction which is used for determining the pilot control value if a predefined condition is met.

Abstract: The present disclosure is directed to a fuel injector. The fuel injector may include a casing substantially aligned along a central axis of the fuel injector. The fuel injector may also include a control valve configured to control a flow of fuel through the fuel injector. The fuel injector may also include a piezoelectric element disposed within the casing and associated with the control valve. The fuel injector may further include a motion coupler disposed between the control valve and the piezoelectric element the motion coupler configured to affect shock to reduce microscopic fractures within the piezoelectric element.

Abstract: An injector includes a nozzle hole, a needle, an actuator, a piston that is displaced in an axial direction according to extension or contraction of the actuator, an outer sleeve holding the piston slidably on its outer circumferential side and defining a pressure chamber expanded or shrunk according to displacement of the piston. When fuel pressure in the pressure chamber is increased upon extension of the actuator, the needle opens the nozzle hole. The injector further includes an inner sleeve slidably fitted around the needle and received in the pressure chamber, an urging device for urging the inner sleeve in the axial direction and for increasing or decreasing its urging force according to displacement of the piston, an engagement surface, and a fuel chamber. A gap between the fuel chamber and the pressure chamber is closed or opened when the inner sleeve annularly engages or disengages from the surface, respectively.

Abstract: In an injector, a first shaft portion of a needle is slidably supported by a first sleeves which is loosely received in a first internal chamber, and a second shaft portion of the needle is slidably supported in a body. Thereby, the first and second shaft portions are supported by the different members, and a relatively large clearance is formed on a radially outer side of the first sleeve.

Abstract: The present disclosure is directed to a fuel injector. The fuel injector may include a casing substantially aligned along a central axis of the fuel injector. The fuel injector may also include a control valve configured to control a flow of fuel through the fuel injector. The fuel injector may also include a piezoelectric element disposed within the casing and associated with the control valve. The fuel injector may further include a motion coupler disposed between the control valve and the piezoelectric element the motion coupler configured to affect shock to reduce microscopic fractures within the piezoelectric element.

Abstract: A method of operating an injector having an injector valve needle and a piezoelectric actuator for controlling movement of the injector valve needle, the method comprising reducing the voltage across the actuator at a first rate (RT1) in order to initiate an initial injection, increasing the voltage across the actuator in order to terminate the injection, and once the initial injection has terminated and before a subsequent injection is initiated, reducing the voltage across the actuator at a second rate (RT2; RT3), which is lower than the first rate (RT1), so as to de-energise the actuator but without initiating an injection. The invention ensures the injector spends a significantly reduced period of its life with a high voltage across its actuator.

Abstract: A fuel injection valve introduces a fuel into an engine and controlling fuel flow to reduce variability between injection events. The fuel injection valve employs an arrangement for a valve nozzle that cooperates with a valve needle to provide a range of needle movement within which the fuel mass flow rate is substantially constant. This can be achieved by providing a restriction with a constant flow area for a predetermined range of needle movement. The method comprises commanding a valve needle to a position within the predetermined range of needle movement to reduce variability in the fuel mass flow rate, particularly when the engine is idling or operating under low load conditions. Valve needle lift is variable during an injection event and from one injection event to another injection event.

Abstract: A first energy control unit has a pilot controller with an applied setpoint energy and outputs a pilot control signal, and a regulator outputting a regulator signal as a function of the setpoint energy and an actual energy of the piezo actuator. The energy control unit creates a control signal representative for a current threshold of a charge current, depending on the pilot control and regulator signals. Furthermore, there is a second energy control unit for another setpoint energy and another control signal. A power output stage sets a charge current for the piezo actuator as a function of the predetermined control signal and performs this for the predetermined time. A scheduling unit predetermines, for setting the setpoint energy, the control signal and the time to the power output stage, and for setting the another setpoint energy, the another control signal and the time to the another power output stage.

Abstract: A method for controlling a piezoelectric actuator of a fuel injector for controlling the quantity of fuel injected into the cylinders of an internal combustion engine controls the voltage across the injector in accordance with a voltage/charge vs. time profile in which the injector is driven at high current up to a level required to start injection, and then at lower current, resulting in a lower voltage/charge vs. time gradient, until the point where full charge is achieved. This results in a reduced variation in minimum delivery pulse and a reduction in the slope of the gain curve, as compared with conventional arrangements in which the voltage/charge vs. time gradient is constant. Alternatively, the injector may be driven at high current up to the charge level required to switch to hydraulic lift amplification. Any point of current change between these extremes may also be used with good effect.