Abstract: The invention relates to a drive circuit for an injector arrangement having a fuel injector, and a method of detecting faults in the drive circuit. The drive circuit includes a diagnostic tool that senses a measured voltage between the injector and a known voltage level. The measured voltage is biased with respect to the known voltage to a predicted voltage unless the drive circuit has a fault. A fault signal is provided on sensing of a measured voltage that differs from the predicted voltage. The drive circuit may additionally, or alternatively, include a diagnostic tool. The diagnostic tool senses a detected current to provide a fault signal upon detection of the fault when the detected current is at variance from a threshold current.

Abstract: A fuel injector, in particular for fuel injection systems of internal combustion engines. Such an injector is characterized by a magnetic circuit containing a core, a solenoid, an armature, and a movable valve needle having a valve closing body that cooperates with a fixed valve seat), the valve seat being formed on a valve seat body), and a valve seat carrier into which the valve seat body is introduced. The outer circumference of the valve seat body has a sawtooth-like structure for establishing a fixed connection to the valve seat carrier. The fuel injector is suitable in particular for use in fuel injection systems of mixture-compressing, externally ignited internal combustion engines.

Abstract: A method to improve the performance of an electrically controlled actuator is described. The method is capable of improving engine starting during at least some operating conditions.

Abstract: A control arrangement for a fuel injection apparatus of an internal combustion engine, the fuel injection apparatus comprising at lest two fuel injector nozzles, the injection action of which is controllable via a solenoid, and at least two control units arranged to control the solenoids controlling the injection action. According to the invention, each injector nozzle is provided with a first and second solenoid and the first and second solenoid are in connection with a different control unit.

Abstract: The invention relates to a drive circuit for an injector arrangement comprising a first fuel injector in parallel with a capacitive component. The drive circuit comprises: a selector means and diagnostic means. The selector means is operable to select the first fuel injector and/or the capacitive component into the drive circuit and to deselect the first fuel injector and/or the capacitive component from the drive circuit. When the capacitive component is selected and the first fuel injector is deselected, the diagnostic means is operable to sense a current through the first fuel injector. When the sensed current is at variance from a first threshold current the diagnostic means is operable to provide a first signal on detection of a stack terminal short circuit fault associated with the first fuel injector. The capacitive component may be a second fuel injector.

Abstract: In a voltage boost circuit for driving a fuel injector of an internal combustion engine, a high voltage developed in the voltage boost coil will be discharged into the battery power supply through the boost coil by electrically energizing a discharge switching element provided in parallel to the charging diode. If the overboost compensation overlaps a boost execution period, the end of the boost execution period will await starting of the overboost compensation.

Abstract: A method for controlling a piezoelectric actuator which displaces a control element of an injection valve includes the step of charging the actuator until a start voltage is reached. Subsequently, the actuator is discharged until a partial lifting voltage, which is maintained during a holding time, is reached. In the final step, the actuator is discharged until an off-load voltage is reached and a parameter which is dependent on the partial lifting voltage is used as a control variable. A desired value for the control variable is determined and the actuator is controlled in such a manner that the desired value of the control variable is maintained.

Abstract: The method and the device serve to adapt the valve characteristic of a fuel injection valve, which has a piezoelectrically driven nozzle needle and by which fuel is injected directly into the combustion chamber of an internal combustion engine, to production-related or age-related variations in the injection behaviour. The activation energy and the needle stroke of the fuel injection valve are controlled in such a way that the engine torque in the case of a fuel injection valve with a reference characteristic would not vary. Here, if an actually occurring variation in the engine torque is detected, then by varying the gradient of the activation-energy/valve-stroke characteristic curve of the fuel injection valve, the engine torque is matched to the engine torque generated with an injection valve with a reference characteristic.

Abstract: A fuel injector control method comprises determining a required separation time between a termination of an on signal associated with a first injection event and an initiation of an on signal associated with a second injection event. The method comprises calculating an overlap time between the separation time and the time to charge the piezoelectric stack to a first level; dividing the overlap time into first and second time periods as a function of the charge and discharge currents; applying the charge current to the piezoelectric stack for a charge time; and applying the discharge current to the piezoelectric stack for a discharge time so as to discharge the stack to a second level, wherein the discharge time is calculated on the basis of the second time period of the overlap time. Thus, first and second injection events are merged in a pulse mode of operation.

Abstract: A reduced cost dual fuel injection system and method is described. Port fuel injectors and direct fuel injectors may be operated by using common injector drivers.

Abstract: An accurate control of a solenoid-operated fuel injector in a Diesel or gasoline engine specifies that a pull-in voltage (Vpull-in) higher than the generally available battery voltage (Vbatt) is applied to the injector, and that the injection is ended as quickly as possible, in order that the fuel injection closely follows the solenoid current profile. When the initial pull-in voltage is lower than the expected nominal value, a deviation of the injected fuel quantity appears with respect to the nominal quantity. This inconvenience is overcome by monitoring the actual value of a selected parameter, such as the actual value of the initial pull-in voltage (Vpull-in), and the injection start time (te) and the solenoid energizing time (ET) are correspondingly modified.

Abstract: An internal combustion engine controller has: a voltage booster circuit for boosting a battery power source; a booster side driver element for flowing a current through the injectors by using the boosted voltage; a battery side driver element disposed in parallel with the booster side driver element to flow a current through the injectors by using the battery power source; a first downstream side driver element provided by controlling currents flowing through the injectors; current regeneration diodes for flowing currents from the downstream side to the upstream side of the injectors; a booster side current detector resistor for detecting currents flowing via the current regeneration diodes; and an injector control circuit for controlling and driving the booster side driver element, battery side driver element and first downstream side driver element.

Abstract: A fuel injection system for an internal combustion engine is provided which includes a fuel injector equipped with an actuator and a nozzle needle. The actuator works to lift the nozzle needle to inject fuel into an internal combustion engine. A controller controls an operation of the actuator to change an amount of lift of the nozzle needle a given number of times for a target injection duration, thereby ensuring the uniformity of size of atomized particles of the fuel sprayed from the fuel injector.

Abstract: A fuel injection system providing both fuel injection devices (5) and methods of fuel injection for internal combustion engines (1) in which a piezoelectric material (29) generates a current discharged to ignite fuel (8) delivered into the engine combustion chamber (2).

Abstract: A fuel injector with an injector body is disclosed which has at least two separate function units that are largely independent of one another. The function units are reversibly joined to one another by a connecting element and at least one positioning pin. The two function units can be produced and tested separately, which greatly simplifies both the production process and maintenance of the fuel injectors and lessens the vulnerability of the fuel injectors to malfunction.

Abstract: In a voltage boost circuit for driving a fuel injector of an internal combustion engine, a high voltage developed in the voltage boost coil will be discharged into the battery power supply through the boost coil by electrically energizing a discharge switching element provided in parallel to the charging diode. If the overboost compensation overlaps a boost execution period, the end of the boost execution period will await starting of the overboost compensation.

Abstract: A solenoid assembly is disclosed. The solenoid assembly has a housing having a cavity disposed therein. The solenoid assembly also has a unitary stator having a plurality of separated portions. The separated portions are held together by at least one lip located on an outer periphery of the stator. The stator is sized to fit within the cavity disposed in the housing.

Abstract: An electrical drive arrangement of a fuel injection system comprising a power supply operatively connected to an injector driver stage which, in turn, is operatively connected to at least one fuel injector. The electrical drive arrangement includes a voltage regulation device operatively connected between the power supply and the injector driver stage, wherein the voltage regulation device is arranged to regulate the voltage supply from the power supply to the injector driver stage.

Abstract: A common rail injection system for internal combustion diesel engines is provided which is designed to correct a limit of width of an ineffective injection command pulse signal which is to be applied to each fuel injector, but causes the injector to produce no spray of fuel in order to minimize a variation in quantity of fuel injected to the engine between the injectors arising from the individual variability or aging of the injectors. The system works to changes the width of a pilot injection command pulse signal to search a value thereof when an engine operation variation such as a change in speed of the engine exceeds or decreases below a threshold at which the injector may be viewed as having sprayed the fuel actually or stopped spraying the fuel actually and determines the limit of width of the ineffective injection command pulse signal using the searched value.

Abstract: An injector drive device includes a power supply unit that is supplied with power from a battery mounted in a vehicle and generates a voltage higher than the voltage of the battery, and EDU having a drive unit that is supplied with power from the power supply unit and drives an injector. The drive unit is housed in a housing. The power supply unit is placed externally to the EDU, that is, externally to the housing, so that the housing need not be made large against heat generation of the power supply unit.

Abstract: The invention relates to a drive circuit for an injector arrangement comprising a first fuel injector in parallel with a capacitive component. The drive circuit comprises: a selector means and diagnostic means. The selector means is operable to select the first fuel injector and/or the capacitive component into the drive circuit and to deselect the first fuel injector and/or the capacitive component from the drive circuit. When the capacitive component is selected and the first fuel injector is deselected, the diagnostic means is operable to sense a current through the first fuel injector. When the sensed current is at variance from a first threshold current the diagnostic means is operable to provide a first signal on detection of a stack terminal short circuit fault associated with the first fuel injector. The capacitive component may be a second fuel injector.

Abstract: Disclosed are a method and a device for more rapidly switching inductive fuel injection valves. According to the invention, the magnetic retaining forces generated by remanence in a bistable valve comprising an opening and closing coil or by eddy currents in a standard valve comprising an opening coil and a closing spring are eliminated with the aid of a negative current that flows through the coil in a direction running counter to the direction of the operating current. Additionally, the magnetic yoke and armature that are used are made of materials having different conductivities in order to be able to close the valve even more quickly.

Abstract: With reference to FIG. 1, the present invention provides an internal combustion engine (10) comprising a variable volume combustion chamber (13); an air intake system (18,20,21) for delivering charge air to the combustion chamber (13); an exhaust system (17) for relaying combusted gas from the combustion chamber (13) to atmosphere; and a fuel injection system (19, 21, 22, 23, 24, 25, 26) for delivering fuel into the charge air for combustion therewith in the combustion chamber (13). The fuel injection system (19,21,22,23,24,25,26) comprises a fuel injector (19) which functions as a positive displacement pump and dispenses an amount of fuel which is fixed for each and every operation of the injector (19); and a controller (23) which controls the operation of the fuel injector (19). In response to an increasing engine speed and/or load the controller (23) increases in amount the fuel delivered per engine cycle by increasing in number the occasions the fuel injector (19) is operated per engine cycle.

Abstract: An auxiliary electronic fuel injection control apparatus for enhancing engine performance includes an isolation circuit connectable to a main control switch having an output voltage pulse and a ground. A pass-through switch is in electrical communication with the isolation circuit and is connectable to a fuel injector, the isolation circuit designed to substantially render the pass-through switch transparent to the main control switch. A re-driver switch is in electrical communication with the pass-through switch and is connectable to the fuel injector and the ground. An auxiliary controller is in electrical communication with the isolation circuit, the pass-through switch, the re-driver switch, and to the ground. The output voltage pulse triggers the auxiliary controller to turn the pass-through switch and the re-driver switch on and off to effectively alter a duration of current to the fuel injector.

Abstract: An apparatus and a method for controlling a piezoelectric actuator are described. The voltage applied to the piezoelectric actuator is detected at a specified time. If certain variables are present, the detection of the voltage and/or the relaying of a detected voltage value is blocked.

Abstract: There is proposed a control unit for an internal combustion engine, which comprises a boost circuit, a switching element, a current detecting resistor and a controller and is designed to be actuated such that the boost circuit is used to boost a power source voltage to create a boosted voltage and the controller is used to control the switching element so as to enable the boosted voltage to flow to the injector solenoid coil. This control unit is designed such that, when the boost circuit goes out of order, the injector solenoid coil is excited by making use of the power source voltage without using the boosted voltage and without creating a peak current to thereby generate a first holding current required for opening the injector and a second holding current required for retaining the opened state of the injector, the second holding current being lower in intensity than the first holding current.

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: The invention relates to a drive circuit for an injector arrangement comprising a first fuel injector in parallel with a capacitive component. The drive circuit comprises: a selector means (SQ1, SQ2) and diagnostic means. The selector means (SQ1, SQ2) is operable to select the first fuel injector and/or the capacitive component into the drive circuit and to deselect the first fuel injector and/or the capacitive component from the drive circuit. When the capacitive component is selected and the first fuel injector is deselected, the diagnostic means is operable to sense a current (Isense) through the first fuel injector. When the sensed current (Isense) is at variance from a first threshold current (Ilimit) the diagnostic means is operable to provide a first signal on detection of a stack terminal short circuit fault associated with the first fuel injector. The capacitive component may be a second fuel injector.

Abstract: With a method for operating an internal combustion engine with a fuel injector (18) that is opened and closed electrically, a booster capacitor (BK) serving to increase the current intensity when the fuel injector (18) is opened, reliable fuel injection is ensured, even in extreme cases, such as resumption of fuel injection after an overrun condition, and in a starting procedure after a shutoff phase that is accompanied by an increase in pressure in the high pressure fuel system due to the fuel heating up, when booster capacitors are used that were designed for normal operation, by switching the current profile in certain operating states of the internal combustion engine from a standard value to an increased value and/or to a longer duration and, when the certain operating state ends, by resetting it to the standard value and the standard duration.

Abstract: A first module (1) has an injector housing (4) and a lifting actuating drive. A second module (2) has a nozzle body (16), an injection needle (18), and a restoring means. At least one value of at least one characteristic number for the first module is determined by appropriate control of the lifting actuating drive, and the first module (1) is associated with a plurality of categories (CL) according to the at least one value of the at least one characteristic number. At least one value of at least one characteristic number for the second module (2) is determined by appropriate actuation of the injection needle (18), and the second module (2) is associated with one of the plurality of categories according to the at least one value of the at least one characteristic number. In each case, a first module (1) and a second module (2) of the same category are paired and mounted.

Abstract: In a driving device for a piezoelectric actuator, when a driving signal is input, a charging switch is repetitively turned on/off to charge and expand the piezoelectric actuator under the state that a discharging switch is turned off. Thereafter, when the input of the driving signal is stopped, the discharging switch is repetitively turned on/off under the state that the charging switch is turned off, thereby discharging and contracting the piezoelectric actuator. Particularly, during the charging period, the charging switch is turned on at a fixed period, and the charging switch is turned off when an integration value of current flowing in a charging circuit at the ON-time of the charging switch reaches a target charge amount.

Abstract: A method for triggering solenoid valves assigned to gas-exchange valves in an electrohydraulic valve activation of an internal combustion engine having a plurality of combustion chambers. The solenoid valves assigned to the gas-exchange valves may be activated independently of each other. To this end, crankshaft-synchronous trigger signal for solenoid valves of the internal combustion engine are ascertained in a control unit and transmitted to an output stage. The output stage controls the solenoid valves on the basis of the transmitted trigger signals. Each combustion chamber of the internal combustion engine has at least one intake valve and at least one discharge valve as gas-exchange valve. All solenoid valves of all gas-exchange valves of a combustion chamber form a solenoid-valve set. One activation profile in each case is specified for all solenoid valves of a solenoid valve set.

Abstract: A voltage generator used to generate a voltage for driving a vehicle fuel injector includes a microcomputer, a coil, and a capacitor. The microcomputer calculates an interval at which the fuel injector is driven. When the interval is less than or equal to a predetermined time period, the microcomputer causes a first current to flow through the coil so that the capacitor is charged to a first level by counterelectromotive force produced in the coil. When the interval is greater than the time period, the microcomputer causes a second current less than the first current to flow through the coil so that the capacitor is charged to a second level less than the first level. The fuel injector is driven by the capacitor voltage.

Abstract: The invention relates to a system and method for detecting a closing of a solenoid. The system includes a capacitive charge circuit electrically coupled to the solenoid. The capacitive charge circuit conditions the current flow through the solenoid to increase the current in response to the closing of the solenoid. The invention also relates to a system and method that includes detecting a current through the solenoid and determining a current slope characteristic. The current slope characteristic is a function of the current and time. The method also includes conditioning an electrical characteristic of the solenoid such that the conditioning is in response to a current slope parameter. The current slope parameter defines a change in the current after removal of an electrical charge to the solenoid.

Abstract: An electrical drive arrangement of a fuel injection system comprising a power supply operatively connected to an injector driver stage which, in turn, is operatively connected to at least one fuel injector. The electrical drive arrangement includes a voltage regulation device operatively connected between the power supply and the injector driver stage, wherein the voltage regulation device is arranged to regulate the voltage supply from the power supply to the injector driver stage.

Abstract: A microcomputer calculates a fuel injection time. When the fuel injection time is longer than a predetermined specified time, the microcomputer sets a voltage level of a short-term injection signal to high and sets a peak current for coils in fuel injectors to a first peak current. When the fuel injection time is shorter than or equal to the predetermined specified time, the microcomputer sets a voltage level of the short-term injection signal to low and sets a peak current for the coils to a second peak current smaller than the first peak current.

Abstract: An internal combustion engine controller has: a voltage booster circuit for boosting a battery power source; a booster side driver element for flowing a current through the injectors by using the boosted voltage; a battery side driver element disposed in parallel with the booster side driver element to flow a current through the injectors by using the battery power source; a first downstream side driver element provided by controlling currents flowing through the injectors; current regeneration diodes for flowing currents from the downstream side to the upstream side of the injectors; a booster side current detector resistor for detecting currents flowing via the current regeneration diodes; and an injector control circuit for controlling and driving the booster side driver element, battery side driver element and first downstream side driver element.

Abstract: A fuel injector comprising: an injection valve provided with a mobile needle to regulate the fuel flow; an actuator adapted to shift the needle; an injection nozzle; a supporting body having a tubular shape and displaying a feeding channel; a sealing body provided with a valve seat of injection valve and comprising a disc-shaped capping element, which lowerly and fluid-tightly closes the feeding channel and is crossed by the injection nozzle, and a guiding element, which rises from the capping element, has a tubular shape, and accommodates the needle therein; an external fuel guiding channel defined between the feeding channel and the guiding element; a number of through feeding holes obtained in the lower part of the guiding element and leading towards valve seat; and a shutter head having an essentially spherical adjustment zone, which is integral with the needle, externally engages the guiding element.

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 is separate from the housing and valve member, with substantially the entire ultrasonic waveguide disposed 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: A method of operating a fuel injector including a piezoelectric actuator having a stack of piezoelectric elements, comprises applying a discharge current (IDISCHARGE) to the actuator for a discharge period so to discharge the stack from a first differential voltage level across the stack to a second, lower differential voltage level across the stack so as to initiate an injection event, and applying a charge current (ICHARGE) to the actuator for a charge period (T3 to T4?) so as to charge the stack from the second differential voltage level to a third differential voltage level so as to terminate the injection event. The method includes determining at least one engine parameter (e.g. common rail pressure) of the injection event prior to applying the charge current (ICHARGE) to the actuator and selecting the third differential voltage level in dependence on the at least one engine parameter.

Abstract: In a control circuit for at least one actuator, in particular for a capacitive actuator of an injection system of an internal combustion engine, a control current can be applied to the actuator. The control circuit has an inductor, e.g., having a core and having multiple windings, the windings being designed and connected to the control circuit such that a control current flowing into the actuator and a control current flowing out of the actuator each flow through different windings of the inductor, and a magnetic flux induced in the inductor or its core by the control current flowing into the actuator and a magnetic flux induced in the inductor or its core by the control current flowing out of the actuator mutually compensate one another.

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 solenoid valve driver is provided which may be employed in automotive fuel injection system. The solenoid valve driver includes a capacitor which is to be discharged to energize a coil of a solenoid valve and a controller. The controller determines a discharge start time that is a time when the capacitor is to be started to be discharged to energize the coil of the solenoid valve. When the discharge start time is reached in a condition that a charged voltage of the capacitor is out of a target voltage level, the controller advances the discharge start time to eliminate a lag of operation of the solenoid valve.

Abstract: A fuel injection device for an internal combustion engine including: an injector that injects fuel to be supplied to the internal combustion engine; a battery to which a DC converter that charges a capacitor of a capacitor discharge ignition circuit is connected as a load; a control portion that is provided to operate when a power supply voltage is provided from the battery through a power supply circuit, and generates an injection command signal when fuel injection timing is detected; and an injector drive circuit that applies a driving voltage from the battery to the injector while receiving the injection command signal, wherein the device further comprises converter operation stopping portion for stopping an operation of the DC converter during set load driving stop time when the injection command signal is generated.

Abstract: A control circuit (100) for at least one actuator (101, 102, 103, 201, 202, 203), in particular for a capacitive actuator (101, 102, 103, 201, 202, 203) of an injection system of an internal combustion engine (1) is described, in which a control current can be applied to the actuator (101, 102, 103, 201, 202, 203).

Abstract: A compact electromagnetic valve device for fuel injection apparatus for engines is provided with which occurrence of cavitation erosion due to rapid change in pressure in a small gap is prevented without increasing in size. Through holes are drilled in a platy armature connected to a poppet valve for opening and closing a fuel passage connecting a fuel feed/spill passage to a plunger room of a fuel injection apparatus, and a thin plate valve or check valve is provided to the armature to allow the holes to be opened or closed in accordance with upward or down ward movement of the armature connected with the popped valve.

Abstract: An injector driver and a drive method therefor wherein a reference current signal is generated that is synchronized to an injector valve signal for causing the injector to inject and that has a current increasing tendency substantially equivalent to an injector current waveform for the case in which a low voltage is applied to the injector, a current that flows in the injector is detected as a detected current signal, and the electrical powering of the injector is controlled by comparing the reference current signal with the detected current signal.

Abstract: A method for operating an internal combustion engine in which a valve needle of a fuel injector is adjusted from a closing position via an intermediate position to an opening position and back again. The adjustment is carried out with the aid of a piezoelectric actuator to which a trigger signal is applied. To reduce the contamination danger of the fuel injector and to keep wear of the valve needle low, the trigger signal for triggering the piezoelectric actuator has a greater slope steepness during the transition of the valve needle from the closing position to the intermediate position than during the transition of the valve needle from the intermediate position to the opening position.

Abstract: An eight-cylinder engine including fuel injection valves provided for each of the eight cylinders. A first valve drive unit for driving four of the eight fuel injection valves to open and close by energizing the four fuel injection valves and a second valve drive unit for driving the other four fuel injection valves to open and close by energizing the second-mentioned four fuel injection valves. Both of the valve drive units drive the fuel injection valves so that combustion and expansion strokes occur at equal intervals, thus allowing for a sufficient charging time for each valve drive unit. For example, the first valve drive unit energizes those fuel injection valves which are provided on a first, fourth, sixth and seventh cylinders, and the second valve drive unit energizes those fuel injection valves which are provided on a second, third, fifth, and eighth cylinders.

Abstract: In a method for operating an internal combustion engine with an electrically openable and closable fuel injector (18), the injectors are reliably held open in all operating conditions by the fact that the holding current for an open valve (18) is switched from a standard value to a higher value in certain operating states of the internal combustion engine, and it is reset to the standard value when the certain operating condition has ended.