Abstract: A common rail injector having an injector housing having a fuel supply line which communicates with a central high-pressure fuel source outside the injector housing and with a pressure chamber inside the injector housing, from which pressure chamber, as a function of the position of a 3/2-way control valve, fuel subjected to high pressure is injected. The 3/2 way control valve, includes a valve piston, movable back and forth in the injector housing between a position of repose and an injection position, which piston is coupled hydraulically with a piezoelectric actuator that is subjected to the pressure from the high-pressure fuel source.

Abstract: Within an injection nozzle for the injection of fuels into the combustion chamber of an internal combustion machine the injection nozzle (5) comprising an axially displaceable valve needle (7), which plunges into a control chamber (12) chargeable with pressurized fuel whose pressure is controllable by a control valve (16) opening or closing the at lest one inlet or outlet channel for fuel, channels are arranged in the region of the valve needle (7), which channels are connected with lubricant- or motor-oil lines respectively and can be passed through by lubricant- or motor-oil respectively. Also in the region of the control valve (16) and/or a solenoid actuating the control valve, channels are arranged which are connected with lubricant- or motor-oil lines respectively and can be passed through by lubricant- or motor-oil respectively.

Abstract: A seal for sealing the fuel injector from a valve mount opening of a cylinder head, the seal radially surrounding the region of the discharge-side end of a fuel injector, sealingly rests on the valve mount opening opening via a first section. By way of at least an axial partial section, which extends only across a portion of the axial height of the seal, the seal is fitted in the region of the discharge-side end of the fuel injector in integral fashion, by form-fit and/or force-locking.

Abstract: The invention relates to a fuel injection valve for intermittent fuel injection into the combustion chamber of internal combustion engines. A needle-shaped injection valve member (34) is arranged in the high-pressure fuel chamber (30) adjacent to the injection valve seat (32), said injection valve member co-operating with the injection valve seat (32) and defining, in a piston-type manner, the cylinder chamber (36) which is connected to the high-pressure inlet (26). The booster piston (28) is controlled by means of the control valve (34) embodied as a flat seat valve, increasing the pressure of the fuel in the high-pressure fuel chamber (30) for an injection, and thus lifting the injection valve member from the injection valve seat. In this way, the injection is carried out with increased pressure.

Abstract: A compensating element for supporting a fuel injector in a cylinder head of an internal combustion engine has an annular design and is situated between a valve housing of the fuel injector and a wall of a receiving bore of the cylinder head. The compensating element includes at least two side pieces, which are supported on the fuel injector and the cylinder head.

Abstract: A fuel injector (1) in an internal combustion engine, wherein an intermediate chamber control valve (26) operated by the fuel pressure in a common rail (2) is arranged in a fuel flow passage (25) connecting a two-position switching type three-way valve (8) and an intermediate chamber (20) of a booster piston (17). When the fuel pressure in the common rail (2) is in a high pressure side fuel region, the booster piston (17) is operated by this intermediate chamber control valve (26), while when the fuel pressure in the common rail (2) is in a low pressure side fuel region, the operation of the booster piston (17) is stopped by this intermediate chamber control valve (26).

Abstract: An arrangement in the fuel injection system for controlling the fuel injection, the arrangement comprising a body part with a space arranged therein, through which space the fuel to be injected flows during operation, the space further having an inlet opening and an outlet opening therein. The arrangement further comprises a piston means, arranged movably in the space and a flow path for creating a flow connection between the fuel inlet and the fuel outlet openings. The flow path comprises at least one throttling portion opening into the space of the body part, the cross-sectional flow area of the throttling portion being defined by the relative positions of the piston means and the body part.

Abstract: An accumulator fuel injection system working to energize fuel injectors to inject fuel at a sequence of injection timings into an internal combustion engine and also to control a fuel pump to feed the fuel to an accumulator at a sequence of controlled times for compensating for the amount of the fuel flowing out of the accumulator under feedback control. When having found a failure in operation of at least one of the fuel injectors, the system alters a mode of the feedback control to decrease the amount of fuel fed to the accumulator at one of the sequence of the controlled times which is at a selected interval away from one of the sequence of the injection timings at which the at least one of the fuel injectors is to be energized, thereby ensuring a steady balance between the amounts of fuel flowing into and out of the accumulator.

Abstract: A fuel injector for an internal combustion engine, the injector comprising an injector body having a tip portion defining at least one spray aperture; a pintle extending within the tip portion, the pintle having a head portion engageable with a valve seat to close the spray aperture, the pintle being axially moveable between a closed position wherein the head portion abuts the valve seat and an open position wherein the head portion is spaced from the valve seat; actuating means for selectively urging the pintle towards its open position; guide means being provided within the injector body guiding the pintle for axial movement between its closed and open positions; a fuel supply chamber being defined within the injector body between the spray aperture and the guide means, characterized in that the diameters of the guide means and valve seat are selected such that the pintle is substantially pressure balanced.

Abstract: A direct injection fuel injector system includes a fuel injector defining nozzle holes in an optimized cluster configuration. Each hole of a conventional multi-hole nozzle is replaced by two smaller, closely spaced holes in a two-hole-per-cluster configuration. The holes within a cluster are configured one above the other, in two horizontal planes or rows, spaced a distance apart from one another. The distance “d” between the nozzle holes in the cluster configuration, the clustered plume angle “?”, which is the angular separation between the centerlines of the nozzle holes, as well as the included spray angle “?”, are optimized through computational fluid dynamics and combustion modeling so that an optimal compromise can be found between liquid penetration, spray penetration and air entrainment, whereby to minimize soot emissions.

Abstract: A damper for damping pressure pulsations in a liquid includes an outer tube having an inner surface defining an interior cavity, and an inner tube positioned within the interior cavity of the outer tube. The inner tube includes an outer surface such that at least one chamber is formed between the inner surface of the outer tube and the outer surface of the inner tube for containing a gas. The damper includes an exterior surface configured to be surrounded by the liquid and an interior surface configured to define a passageway through the damper for the liquid. The damper can define at least two, and in one embodiment, four separate chambers for containing a gas. The damper can be part of a fuel rail assembly and is positioned within a fuel rail configured to contain pressurized fuel.

Abstract: Extremely high injection pressures are achieved in a common rail fuel injection system via a movable intensifier positioned in each fuel injector. The fuel injectors are individually controlled via a single electrical actuator that moves between positions that connect an intensifier control cavity either to the high pressure common rail or a low pressure reservoir. Leakage is avoided between injection events by maintaining opposing hydraulic surfaces of the intensifier and needle valve exposed to fluid pressure in the high pressure rail. This avoids pressure differentials and leakage associated with guide surfaces separating high and low pressure areas.

Abstract: A fuel injection system for an internal combustion engine includes a common rail, a plurality of accumulator injectors, and at least one accumulator controller separate from the accumulator injectors and connected to the common rail. Each accumulator controller includes a solenoid-controlled valve to control the fuel injection operations of one or more accumulator injectors.

Abstract: A fuel control system for an engine is disclosed. The fuel control system may have a source of pressurized fuel and at least one injector configured to receive and inject the pressurized fuel. The fuel system may also have a sensor configured to generate a signal indicative of an actual fuel pressure at the at least one injector, and a controller in communication with the sensor. The controller may be configured to determine a desired fuel pressure at the at least one injector, and compare the signal to the desired fuel pressure. The controller may also be configured to initiate a leak detection sequence in response to the comparison.

Abstract: Reducing leakage within fuel injectors is one way in which the efficiency of the overall fuel injection system can be improved. In most fuel injectors that include a direct control needle valve, the needle valve member is still biased toward a closed position by a spring that is located in a spring chamber connected to a low pressure vent. In many instances, the needle valve member is guided in a tight clearance region adjacent the spring chamber. Since the internal plumbing of the fuel injector is connected to a high pressure rail during and between injection events, static leakage across the guide region of the needle valve member can reduce efficiency. Static leakage is reduced in the present invention by connecting the spring chamber to the common rail instead of to a low pressure vent.

Abstract: A feed pump of a fuel supply system for a DME engine rotates in a normal direction to supply DME fuel in a fuel tank to a high-pressure supply pump through a low-pressure fuel supply passage. The high-pressure supply pump pressurizes the DME fuel and discharges the DME fuel therefrom. The discharged DME fuel is distributed by a high-pressure fuel supply passage and injected by a fuel injector. A first fuel recovery passage connects the high-pressure fuel supply passage to the low-pressure fuel supply passage. When the engine is operated, a first solenoid valve closes the first fuel recovery passage. When the engine is stopped, the first solenoid valve opens the first fuel recovery passage and the feed pump rotates in a reverse direction, thereby the DME fuel in the low-pressure fuel supply passage and in the high-pressure fuel supply passage is recovered into the fuel tank.

Abstract: A fuel injector for injecting fuel into a combustion chamber of an internal combustion engine, including a pressure booster, whose booster piston separates a work chamber, subjected to fuel via a pressure reservoir, from a pressure-relievable differential pressure chamber. A pressure change in the differential pressure chamber is effected via an actuation of a servo valve, which opens or closes a hydraulic connection of the differential pressure chamber to a first low-pressure-side return. The servo valve has a piston guided between a control chamber and a first hydraulic chamber. On this servo valve piston, a hydraulic face that positions the servo valve piston constantly in the opening direction when system pressure is applied and a first sealing seat that closes or opens a low-pressure-side return are embodied.

Abstract: The present invention relates to an injection nozzle (1) for an internal combustion engine, in particular in a motor vehicle. A first nozzle needle (3) controls at least one first injection opening (5). A second nozzle needle (4) controls at least one second injection opening (6). A control chamber (32) is connected via a throttle line (35) to a pressure chamber (34) in which it is possible to adjust the injection pressure. A first control piston (41) cooperates with a first needle unit (17) that includes the first nozzle needle (3) and the first control surface (43) of this first control piston (41) can be acted on by the control pressure prevailing in the control chamber (32). In the closed position of the first nozzle needle (3), there is an axial play (44) between the first control piston (41) and the first needle unit (17).

Abstract: A fuel injector 10 for a Diesel engine has a plunger 12 and two control valves 20 and 30 for controlling the injection of fuel from the main supply cavity to the discharge port 52. Each control valve 20 and 30 are actuated through piezo-electric stacks 34 and 74 connected to a electronic variable voltage supply 33.

Abstract: An injection unit has an injector arrangement connected to a pressure reservoir by a pressure line arrangement The injector arrangement has at least one servo injection valve and a control valve for the release of fuel from a control chamber into a fuel return line leading to the fuel tank The Valve may be operated by a piezoelectric actuator to cause a displacement of a nozzle body in the direction of an injection passage opening for initiating an injection process by pressure reduction in the control chamber. The fuel return line has a controllable valve, which restricts the fuel flow in the fuel return line in the actuated state. It is, thus, possible to reduce the effects of a change of length of the piezoelectric actuator, which exceeds the so-called tolerance gap in the servo injection valve, which are detrimental to the operation of the injection unit.

Abstract: A control device of a fuel injection system of an engine calculates command injection timing for starting an injection at target injection timing, and a command injection period for obtaining a target injection quantity. The control device monitors a charging voltage of a capacitor immediately before the command injection timing and estimates the charging voltage at the command injection timing based on the monitored value. If the estimated value is less than a specified value, the control device performs correction for advancing the command injection timing and correction for lengthening the command injection period in accordance with the decrease in the charging voltage. Thus, an injector can start the injection at the target injection timing and can inject the target injection quantity of fuel.

Abstract: A fuel injection system having an injection valve, a line supplying fuel at high pressure to the injection valve a control valve controlling the pressure in a control chamber communicating with the line. The control valve has a movable valve part is actuatable by an actuator via a hydraulic coupler having two pistons cooperating with a booster chamber of the coupler. A seat of the movable valve part has an inside cross-sectional area f3, with means for filling the booster chamber via guide gaps of the pistons with fuel under pressure. The pistons are located parallel to and inside one another and a booster chamber is located on the ends of the pistons toward the actuator. In the interior of the outer piston defines a filling chamber which communicates with the line and one of the pistons has a cross-sectional area f4 is mechanically coupled to the actuator via a rod having a cross-sectional area f5.

Abstract: A fuel pressure control device has a feedback control section for setting a feedback control amount (F/B control amount) in accordance with a deviation between target fuel pressure and actual fuel pressure and a feedforward control section for setting a feedforward control amount (F/F control amount) in accordance with a required fuel injection amount and engine rotation speed. When an engine operation state is an off-idling condition, F/F-F/B combination control for validating the F/F control amount and for setting a control amount of a high-pressure pump by adding the F/F control amount to the F/B control amount is performed. When the engine operation state changes from the off-idling condition to an idling condition, control is switched to F/B single control for invalidating the F/F control amount and for using only the F/B control amount.

Abstract: In a fuel supply arrangement for supplying fuel from a fuel tank to the fuel injectors of an internal combustion engine by an electrically operated fuel pump, a first fuel pressure level adequate for normal engine operation is provided by the fuel pump and means are provided for increasing the fuel injection pressure provided by the pump for supplying fuel at a higher pressure level to the fuel injectors during an engine start-up or warm-up phase.

Abstract: A servo valve for actuating a pressure booster of a fuel injector, the pressure booster having a work chamber separated by a booster piston from a differential pressure chamber and the pressure change in the differential pressure chamber of the pressure booster is effected via the servo valve, via switching valve. The control chamber of the servo valve can both be made to communicate with a high-pressure source and pressure-relieved into a low-pressure-side return, and for generating a fast closing motion at the valve piston, a pressure shoulder acting in the closing direction of the valve piston is embodied between the control chamber and the hydraulic chamber, and control edges without a common opening phase are embodied on the valve piston.

Abstract: A diaphragm valve having a first chamber and a second chamber, which is separated from the first chamber by means of a valve member which cooperates with a valve seat. A first connecting conduit situated in the vicinity of the valve seat feeds into the first chamber. To enable the diaphragm valve to be used as a pressure control valve, the valve member has a through conduit that connects the first connecting conduit to the second chamber of the pressure control valve when the pressure control valve is closed.

Abstract: A fuel injection device has an injection valve, a line that supplies highly pressurized fuel to the injection valve during operation, a control valve that controls the pressure in a control chamber of the injection valve, which chamber is connected to the line, and whose moving valve element is actuatable by an actuator via a hydraulic coupler having two pistons cooperating with a coupler volume of the coupler, the seat of the moving valve element having an inner cross-sectional surface area f3 and a conduit for filling the coupler volume with pressurized fuel via guidance gaps of the pistons.

Abstract: A fuel injection control system for a multi-cylinder internal combustion engine mounted in a vehicle is provided. The system works to schedule execution of a sequence of multiple injections of fuel into each of cylinders of the engine and determines whether events of any two of the injections scheduled to be executed in any two of the cylinders overlap in time with each other or not. If so, the system determines which of the two of the injections overlapping each other should be rescheduled based on operating condition of the vehicle and reschedules the execution of one of the two of the injections, as determined to be rescheduled, so as to eliminate overlap with any of the events of the injections. This avoids undesirable application of load on the system or the delay in activating fuel injectors which may arise from simultaneous activation of two of the injectors.

Abstract: A fuel injection system for internal combustion engines having a plurality of fuel injectors, in which the fuel injectors each have one high-pressure connection and one low-pressure connection, and the low-pressure connections discharge into at least one manifold line. The system has a means, located between the manifold line and a pressureless fuel return, for maintaining the fuel pressure; at least one throttle is located between the low-pressure connection of each fuel injector and the means for maintaining the fuel pressure.

Abstract: In a method for the pressure regulation in a common rail fuel injection system of an internal combustion engine wherein pressurized fuel is supplied to the various combustion chambers of the engine via injectors under the control of an electronic control unit, a first actual control pressure is determined from a measured rail pressure and compared with a desired rail pressure in order to form a first control deviation, whereupon a volume flow depending on the first control deviation is determined and, from the measured rail pressure, a second actual rail pressure is determined using overridingly the second actual rail pressure for the calculation of the controller parts of the high pressure controller.

Abstract: A fuel injection device for an internal combustion engine has a housing that contains a recess, which in turn contains two valve elements that are disposed coaxial to each other and each cooperating with a corresponding valve seat and are each associated with corresponding fuel outlet openings. In order for the fuel injection device to be as compact as possible, a shared valve device provided, which has at least three switched positions and influences the position of the valve elements.

Abstract: A fuel injection device for an internal combustion engine, having two valve elements each having a hydraulic control surface acting in the closing direction and associated with a hydraulic control chamber. A control valve influences the pressure in the control chamber, and loading devices act on the valve elements in the opening direction. The valve elements react at different hydraulic opening pressures prevailing in the control chamber. The control valve is able to set at least three different pressure levels in the control chamber: all of the valve elements are closed at a comparatively high pressure level; one valve element is open at a medium pressure level; and all of the valve elements are open at a comparatively low pressure level.

Abstract: A fuel injector for the direct injection of fuel into the combustion chamber of a mixture-compressing internal combustion engine having external ignition includes a valve housing formed by a nozzle body, and a seal which seals the fuel injector from a cylinder head of the internal combustion engine. The seal has a sleeve-type design with a structured cross section and extends across the axial length of the nozzle body.

Abstract: A fuel injection rail has a rail body formed by joining together a first body member having the shape of a trough and a second body member having the shape of a flat plate. Edges of the side walls of the first and the second body members are joined in folded seams by folding the edges of the first body member so as to crimp the edges of the second body member, and the folded seams are brazed.

Abstract: A fuel supplying apparatus of an internal combustion engine includes a first fuel supply system, a second fuel supply system, and a pulsation propagation suppressing unit. The first fuel supply system pressurizes a fuel by a low-pressure pump, and supplies the fuel pressurized by the low-pressure pump to a first fuel injection mechanism. The second fuel supply system is branched from the first fuel supply system, further pressurizes the fuel, pressurized by the low-pressure pump, by a high-pressure pump that is driven according to an operating state of the internal combustion engine, and supplies the fuel pressurized by the high-pressure pump to a second fuel injection mechanism. The pulsation propagation suppressing unit is provided in at least one of the first fuel supply system and the second fuel supply system, and suppresses propagation of a pulsation generated in the high-pressure pump to the first fuel injection mechanism.

Abstract: Prior art fuel line check valves remain closed after engine off and cool down. Diurnal heating and the resultant pressure increase in the fuel line causes fuel vapor emissions through small openings in the fuel line (e.g., at the injector tips). The invention provides a check valve for a vehicle fuel line which opens in response to engine cooling and remains open while the engine is off to relieve subsequent increasing pressure in the fuel line due to diurnal heating thereof.

Abstract: A fuel injector configured and arranged to inject fuel into a combustion chamber comprises a casing member, a fuel discharge valve and a micro nozzle. The casing member includes a hydraulic chamber configured to contain pressurized fuel and a flow rate regulating hole arranged to discharge the fuel from inside the hydraulic chamber. The fuel discharge valve is configured and arranged to open and close the flow rate regulating hole. The micro nozzle is disposed in a downstream part with respect to the fuel discharge valve, and has at least one through hole arranged to inject the fuel discharged from the flow rate regulating hole into the combustion chamber. The micro nozzle further includes a heating structure configured and arranged to selectively emit heat to raise temperature of the fuel that passes through the at least one through hole of the micro nozzle upon activation of the heating structure.

Abstract: A fuel injection apparatus has an accumulator, a booster, a nozzle, a hydraulic circuit, a hydraulic pressure valve and a control valve. At least one of a transmission path, which is connected to the hydraulic circuit, and the hydraulic piston is configured to generate a delay in an operation of the nozzle or the booster that is driven by one of fuel pressure in the control chamber and fuel pressure in the back pressure chamber that is directly controlled by the control valve, against an operation of the booster or the nozzle that is driven by the other of the fuel pressure in the back pressure chamber and the fuel pressure in the control pressure indirectly controlled by the hydraulic pressure valve.

Abstract: A method and apparatus for reducing or preventing hydrocarbon emissions from an air induction system of an automotive vehicle during diurnal periods opens the fuel line to ambient fuel tank pressure when fuel pressure in the fuel line decreases due to cooling of the fuel.

Abstract: An injector has a housing, a command piston, a control chamber, a needle, a nozzle chamber, a fuel inflow passage, a fuel discharge passage and an electric valve. The housing slidably supports the command piston and the needle. The housing and one end face of the command piston enclose the control chamber. The needle is disposed at the other end face side of the command piston. The housing and a leading end portion of the needle enclose the nozzle chamber to accumulate the high-pressure fuel therein. The housing is provided with an injection hole, which is opened and blocked by the needle. The fuel discharge passage opens at a fuel discharge port to the control chamber to discharge the high-pressure fuel out of the control chamber. The fuel discharge port is close to an uppermost position of the command piston.

Abstract: Engineers have come to learn that a fuel injection system with a variety of capabilities to produce a variety of injection strategies can better perform and reduce emissions at all engine operation conditions than a fuel injection system limited in its control over injection timing, number, quantity and rate shapes. According to the present invention, in order to increase the variability of available injection strategies, a fuel injection system includes at least one fuel injector fluidly connectable to at least a first common rail and a second common rail. By fluidly connecting the fuel injector to the first common rail, fuel can be injected at a first pressure. By fluidly connecting the fuel injector to the second common rail, fuel can be injected at a second pressure that is independent of the first pressure.

Abstract: A control servo valve (8) is housed inside the casing of an internal combustion engine fuel injector (1), and has an actuator (9), a control chamber (13) communicating with a fuel inlet (5) and with a fuel outlet passage (22), and a shutter (35) movable along an axis (3) by the actuator (9) between a closed position and an open position to close and open the outlet passage (22) respectively; the servo valve (8) also has a fixed axial rod (29) interposed between the actuator (9) and the control chamber (13); the outlet passage (22) comes out through an outer lateral surface (30) of the axial rod (29); and the shutter (35) is defined by a sleeve which slides axially on the outer lateral surface (30), and, in the closed position, closes the outlet passage (22) so as to be subjected to a zero axial resultant force by the pressure of the fuel.

Abstract: A servo-valve for a fuel injector equipped with a pressure booster whose working chamber is separated from a differential pressure chamber by a booster piston in which an actuator can connect a control chamber to a first low-pressure return and the differential pressure chamber can be connected to a second low-pressure return or to a return system in which the returns are connected to each other. A first servo-valve piston has a first sealing seat, and a second piston, embodied as a sealing sleeve, is accommodated on the first servo-valve piston and, together with a valve housing, constitutes a second sealing seat. When the pressure in the control chamber is relieved, this second sealing seat is closed with a shorter stroke, sooner than the first sealing seat. When the control chamber is subjected to pressure, the second sealing seat opens only after the first sealing seat is closed.

Abstract: An oil activated fuel injector which provides a pilot quantity of fuel prior to the main fuel injection event. A control system for a fuel injector includes a sensor for providing a signal to a control which is indicative of an opening motion of a spool. The control initiates a pull back of the spool, upon receipt of the signal, to eliminate a bounce back phenomenon of the spool during an injection of a pilot quantity of fuel. The signal may be representative of a pressure of working fluid or fuel, as well as a position or acceleration of the spool.

Abstract: A valve body surrounds a first passage connecting with a cylinder of an engine. A valve member is adapted to be seated on and lifted from the valve seat. An injector body connects with the valve body. The injector body has a pressure control chamber for controlling hydraulic pressure applied to the valve member thereby controlling a lift of the valve member. The injector body has a second passage through which fuel in the pressure control chamber is exhausted. An actuator is adapted to communicating the pressure control chamber with the first passage through the second passage and blocking the pressure control chamber from the first passage. The first passage introduces fuel from the pressure control chamber into the cylinder through the second passage.

Abstract: A flow damper is provided with a clearance to absorb a deformation occurring in proximate to a lower end of the valve body by the clearance on an entire outer circumference of a lower side of a large diameter portion of a piston. By the configuration in this manner, even if the slight deviation in the accuracy or the shape of the seat surface occurs a radially inward deformation of a lower portion of the valve body when the valve body is fastened to the common rail body at a large axial force, the clearance absorbs the deformation. Thus, the deformation of the valve body does not affect the piston sliding hole. Accordingly, a sliding clearance of the piston does not change, not to spoil a slide motion of the piston.

Abstract: A high pressure injection system comprises at least one fuel high pressure accumulator, a control chamber and a valve, in addition to an injection valve having a valve needle and a control piston. The control chamber is connected to the high pressure accumulator by means of an inlet throttle and to the valve by means of an outlet throttle. The control chamber controls the movement of the control piston and the valve needle connected thereto. To this end, flow conditions of the fuel flowing into and out of the control chamber are regulated by means of the inlet throttle and the outlet throttle. The inlet throttle is configured as a multi-stage throttle.

Abstract: A fuel injector having an injection valve connected to a high-pressure source and a control valve including a control piston guided in a valve body and comprising a pressure piston section having a first pressure surface guided in a bush and a control piston section with a sliding seal that has a control edge; the bush is contained in a pressure chamber of the valve body. In a first valve position, a sealing seat of the control piston disconnects a valve chamber from a low-pressure/return system and in a second valve position, the control edge of the control piston disconnects the pressure chamber from the valve chamber; in the second valve position, a connection is simultaneously produced between the valve chamber and the low-pressure/return system, thus initiating an actuation of the fuel injection valve. The control piston section with the control edge is guided in a control cylinder that is contained in the pressure chamber of the valve body and is separate from the bush.

Abstract: A fuel injector for injecting fuel into the combustion chamber of an internal combustion engine is equipped with a pressure booster that has a working chamber continuously connected to a common rail, and has a differential pressure chamber, which a piston part separates from the working chamber. The fuel injector also has an injection valve member. To actuate the fuel injector, a valve having a control valve in the form of a servo valve and an actuating valve that actuates this control valve. The multistage valve controls both the pressure booster and the injection valve member. The control valve and the actuating valve are hydraulically coupled to each other and different outlet throttles can be opened and closed in order to achieve different opening speeds of a servo valve piston.

Abstract: A fuel injector in injection systems for internal combustion engines having a valve body containing a control chamber that can be pressure-relieved and can be acted on with fuel via an inlet throttle and can be pressure-relieved via an outlet throttle. A first actuator can actuate a closing element. The valve body is connected to a holding body that has a nozzle body connected to it, which encompasses an injection valve element. In order to relieve the pressure in the control chamber, an additional, second outlet throttle is provided, whose closing element can be actuated either by an additional actuator or as a function of the power supply to a double-switching actuator.