Abstract: A fuel injection system for a piston engine, in which the piston engine comprises an engine block with cylinders arranged thereto and at least one fuel injector nozzle arranged for each cylinder and connected to the fuel injection system and in which the fuel injection system comprises at least one fuel pressure accumulator. The fuel injection system comprises a dedicated fuel pressure accumulator for each cylinder.

Abstract: A fuel rail assembly includes an integral pressure damper and an over-pressure stop to prevent the damper from flexing beyond it elastic limit. The rail assembly also includes injector cups formed outwardly relative to the rail to provide substantially unimpeded fuel flow to the injector. The fuel rail assembly further includes a damper cover to protect the damper from outside damage. The damper cover can be hermetically sealed to form an air chamber above the damper and opposite the fuel chamber in the fuel rail thereby providing a means for keeping the pressure differential between the chambers in an APDI fuel injection system substantially constant.

Abstract: The fuel injection apparatus has one fuel pump for each cylinder of the engine, which pump has a pump piston, driven by the engine in a reciprocating motion, that defines a pump work chamber, which communicates via a line with a fuel injection valve, disposed on the engine separately from the fuel pump, which valve has an injection valve member, by which at least one injection opening is controlled, and which is movable in the opening direction, counter to a closing force, by the pressure generated in the pump work chamber, and at least one first electrically triggered control valve is provided, by which a communication of the pump work chamber with a relief chamber is controlled, and which is disposed near the fuel pump.

Abstract: In a pressure-controlled fuel injection system, a nozzle needle is subjected to pressure in the closing direction by a nozzle spring. A nozzle chamber for opening the nozzle needle is connectable to a pressure reservoir via a pressure line. A hydraulic device is embodied to reinforce the closing performance of the nozzle needle. As a result, a faster closing performance of the nozzle needle is achieved.

Abstract: A fuel rail for an automotive vehicle with a spark-ignited, reciprocating piston internal combustion engine is provided. The fuel rail has a tubular body with a fuel inlet and a plurality of injector outlets. A damper is provided with a lower cup connected to the tubular body. The damper also has an upper cup with a diaphragm sealably separating the cups.

Abstract: End of injection rate shaping can be attained by controlling the flow rate into a check control cavity. Specifically, a flow control valve allows the check control cavity to vent at a first flow rate and to pressurize at a second slower flow rate. By pressurizing at a slower rate, end of injection does not occur as quickly, allowing injection pressure to decrease before injection is terminated.

Abstract: A fuel injection system is provided which includes a source of high pressure fuel, a low pressure fuel reservoir, and at least one fuel injector which has an injector body that defines a nozzle chamber, a needle control chamber, a needle control vent, a fuel inlet, and a nozzle outlet. A high pressure line extends between the source of high pressure fuel and the fuel inlet. A low pressure line extends between the low pressure fuel reservoir and the needle control vent. A needle control valve is positioned in the injector body and includes a poppet valve member with a first position in which the needle control chamber is fluidly connected to the fuel inlet but closed to the needle control vent. The poppet valve also has a second position in which the needle control chamber is closed to the fuel inlet but open to the needle control vent.

Abstract: For each cylinder of the internal combustion engine, the fuel injection apparatus has a high-pressure fuel pump and a fuel injection valve connected to it. A pump piston of the high-pressure fuel pump defines a pump working chamber connected to a pressure chamber of the fuel injection valve, which has an injection valve member which controls the injection openings and which the pressure prevailing in the pressure chamber can move in an opening direction counter to a closing force. A first control valve controls a connection between the pump working chamber and a relief chamber, and a second control valve controls a connection between the relief chamber and a control pressure chamber, which is connected to the pump working chamber.

Abstract: In an injection system with pressure intensification with a simple and space-saving design, control means are provided permitting a large range fuel injection pressure control, which also permits rapid adaptation of the fuel injection pressure to the various engine operating conditions.

Abstract: The invention relates to a method for injecting fuel, which is at high pressure, into air-compressing internal combustion engines employing an injection system which includes a compressor unit for compressing fuel and containing an actuating device for control valves with which device the nozzle needle of an injector is controlled. One of the two control valves is triggered multiple times or in clocked fashion via a piezoelectric actuator during individual injection phases or during the injection cycle.

Abstract: The present invention generally includes a composite fuel rail with integral damping provided by flat sections, molded into the rail conduit, that flex in response to a pressure pulsation and a co-injected composite laminate structure wherein the compounds of the laminates can be selectively varied to provide impact resistance, chemical resistance and a vapor permeation barrier, as needed.

Abstract: A high pressure fuel supply apparatus is constituted by a plunger reciprocating in a sleeve of a high pressure fuel pump so as to form a fuel pressurizing chamber between the plunger and the sleeve, a suction valve provided in a fuel suction port for sucking fuel into the fuel pressurizing chamber, and a discharge valve provided in a fuel discharge port for discharging fuel from the fuel pressurizing chamber into a high pressure fuel discharge passageway communicating with an internal combustion engine, the discharge valve reciprocating axially so as to perform an open/close operation, wherein the high pressure fuel supply apparatus further comprises a holder for regulating an axial reciprocating movement of the discharge valve in the open/close operation within a predetermined range.

Abstract: In a fuel injection system for internal combustion engines, including an electronically triggered control valve with an axial through bore, which is divided by two valve seats into three annular chambers, to which respectively a supply line for fuel at high pressure, a high-pressure line leading away to an injection valve, and a relief line are connected, and having a control piston, which is guided in the through bore and which has two valve sealing faces cooperating with the two valve seats, respectively, the control piston according to the invention has a further valve sealing face, which cooperates with the first valve seat and whose spacing from the first valve sealing face is at least equal to the spacing between the second valve sealing face and the second valve seat when the first sealing seat is closed. A communication between the supply line and the relief line is thus reliably prevented.

Abstract: A pressure booster for increasing the injection pressure in direct-injection internal combustion engines with a plurality of cylinders, in particular diesel engines, having a booster piston which has a relatively large end face that is subjected to a relatively low pressure and a relatively small end face at which in the pumping stroke an elevated injection pressure prevails, wherein on the side remote from the relatively large end face, because of the difference in size between the two end faces of the booster piston, an idle volume results. The idle volume is in communication with a cantilevered spring reservoir disposed locally for each individual cylinder or centrally for all the cylinders of the engine.

Abstract: An object of the present invention is to provide an accumulator fuel injection system comprising a pressure increasing unit 7 and a pressure increasing common rail 6, in which leaked fuel is recirculated from a high pressure side to a low pressure side, and which is capable of reducing the amount of fuel that must be delivered under pressure by a low pressure pump 3. The focus of the present invention is to return high pressure leaked fuel to between the low pressure pump 3 and a high pressure pump 5.

Abstract: A cylinder head for an internal combustion engine includes a spark plug 3, provided in combustion chamber 2, and an injection nozzle 1 that has a housing end face 27 and a closure element 6 which is movable by an actuator and has a closure member 10, the housing end face 17 of the injection nozzle 1 forming a common, planar surface with the closure member 10 in the closed state of the injection nozzle 1.

Abstract: A fuel pump comprising a plunger member reciprocable within a plunger bore, wherein the plunger member is cooperable with a drive arrangement to cause inward movement of the plunger member within the plunger bore to increase fuel pressure therein. The pump comprises an accumulator for fuel, and a valve arrangement controlling communication between the plunger bore and the accumulator to permit fuel under pressure to flow into the accumulator. The pumping plunger is moved in an outward direction under the action of the fuel pressure within the accumulator. The invention also relates to a fuel injection system comprising the fuel pump.

Abstract: An accumulator fuel injection apparatus is provided which may be employed in a common rail system for diesel engines. The fuel injection apparatus includes a pressure relief valve designed to relieve an unwanted rise in pressure of the fuel within an accumulator. The pressure relief valve includes a pressure pulsation minimizing mechanism designed to minimize pressure pulsations which are generated in a drain line and propagated to a valve mechanism of the pressure relief valve, causing a valve-opening pressure of the pressure relief valve to change. The pressure pulsation minimizing mechanism may be implemented by an orifice or a check valve.

Abstract: A fuel injector for fuel injection systems of internal combustion engines, in particular for the direct injection of fuel into a combustion chamber of an internal combustion engine, includes a solenoid coil, an armature that is acted upon in a closing direction by a resetting spring, and a valve needle that is in a form-locking connection with the armature for actuating a valve-closure member, which together with a valve seat surface forms a sealing seat. A cooperates with the resetting spring such that the spring forces of the resetting spring and of the are added together. In this context, the resetting spring is biased over a total lift of the armature and the is biased only over a residual lift of the armature, which is smaller than the total lift.

Abstract: A fuel rail is provided for delivering fuel to a plurality of fuel injectors for a reciprocating piston internal combustion engine. The fuel rail includes a sealed housing having an inlet for receiving fuel, the housing having at least first and second injector outlets for delivering fuel to fuel injectors. The fuel rail also includes first and second filling chambers formed within said housing fluidly connected with respective first and second injector outlets. A reserve pump chamber is provided which is fluidly connected with each said filling chamber, the reserve pump chamber has a volume approximately at least equal to or greater than a volume of one of the filling chambers. The reserve pump chamber dampens pressure pulsations generated in one of the filling chambers from progression to another filling chamber.

Abstract: The invention relates to a device for injecting fuel into the combustion chambers of an internal combustion engine, with a pump (2), which supplies highly pressurized fuel to a high-pressure accumulation chamber (3). Starting from this high-pressure accumulation chamber (3), a high-pressure supply line leads to an injector (5), which contains a metering valve (7) that acts on an injection nozzle (24) with fuel. The metering valve (7) is associated with a damping throttle (26), which is connected to a part of the high-pressure region.

Abstract: A method for optimizing the geometry of a line providing fluid communication between an outlet of a pump and an inlet, the pump and inlet each having a fixed location, where the pump imposes a periodic pressure pulse on the tubing composing the line. The method comprises the steps of identifying a basic design of the line using conventional industry practices for the specific application and making an initial determination as to the minimum number of bends which are required by the basic line design. If the tubing must be bent, the bend routing is established to best fit the installation constraints set by the design layout, the radii of the bends is maximized within installation constraints using one common radius, a finite element analysis is performed to determine the minimum and maximum loading on the tubing imposed by the expected pressure pulse and the material of the tubing is selected to satisfy design safety factors with the minimal material cost.

Abstract: In dual fuel engines, it is desirable to have injection of two distinct quantities of liquid fuel. Engines with these operating requirements have typically used two separate fuel injectors, or two separate nozzle assemblies, to satisfy this need. However, these systems can be rather complex and difficult to control. In addition, engineers have learned that fuel injectors having direct control have better performance which can increase engine efficiency. Therefore, the present invention addresses the needs of engines desiring injection of two distinct quantities of fuel, such as dual fuel engines, by utilizing a direct control fuel injector having a dual concentric check having separate orifices for the pilot and main injections.

Abstract: A flexible fuel rail system for fuel injection systems for internal combustion piston engines, particularly for engines having at least one or more banks of aligned cylinders. The fuel rail system incorporates two or more longitudinal fuel rails, connected by one or more crossover sections. The crossover section(s) include(s) one or more sections of enhanced flexibility, preferably corrugations. The fuel rails, crossover sections and sections of enhanced flexibility are preferably all fabricated from metal, preferably monolithically formed from a single piece of metal. The fuel rails preferably are provided with non-circular cross-sectional configurations, so that the walls of the fuel rails will flex, under the influence of fuel pressure pulsations caused by the fuel injectors, so as to substantially reduce or eliminate the negative impacts of such pulsations on the operation of the other injectors in the fuel injection system.

Abstract: A valve using a pressure control cavity to control valve position can implement a pressure to sensor to determine the pressure within the control cavity to determine whether pressure is presently acting upon the valve. The pressure sensor can provide a feedback signal to a control module allowing the control module to control timing of the valve.

Abstract: The present invention finds application in engines using mechanically actuated electronically controlled fuel injectors having direct control needle valves. In valves such as these, a spill control valve member controls fuel pressurization within the injector while a needle control valve member controls the timing and duration of the injection event. However, when the momentum of fuel exiting the fuel injector past the spill valve is greater than that of the tappet and plunger moving toward their downward positions, engine components upstream of the tappet can briefly separate and re-engage, which can result in increased mechanical noise levels. Therefore, the present invention is directed to maintaining sufficient contact force in the various engine components to reduce the mechanical noise levels by positioning a flow restriction between the fuel pressurization chamber of the fuel injector and a fuel source.

Abstract: A rail connection assembly includes an outer rail connection tube having a rail connection outlet, a component having a substantially centrally located bore that is fixed to the outer rail connection tube remote from said rail connection outlet, and a piston adapted for movement between a first position and a second position, with the second position being remote from said bore. A nipple having a predetermined cross section and extends from the piston and is slidably movable into and remote from said bore when the piston is moved between the first and second positions, respectively. A fluid communication path exists between the bore and the rail connection outlet. This provides a pilot injection of fuel when the piston moves into an intermediate position between the first and second positions and a full injection of fuel when the piston reaches the second position.

Abstract: A directly actuated injection valve comprises a hollow valve housing, a valve needle disposed within the hollow interior, a needle spring and a tubular magnetostrictive actuator assembly disposed in an annular space around a portion of the valve needle. A magnetic field activates the magnetostrictive material to change its length to cause a corresponding movement of the valve needle that actuates the valve. The valve needle is formed from a ferromagnetic material and extends through the tubular magnetostrictive actuator assembly without interfering with the flux field that is directed through the magnetostrictive member. A passive hydraulic link assembly is preferably employed to compensate for component wear, temperature effects and manufacturing variations within design tolerances.

Abstract: A fuel injection system for internal combustion engines essentially has a high-pressure injection pump, supplied with fuel from a low-pressure region, and a magnetic piston valve serving to control the injection pump. The magnetic valve having two coaxial valve chambers, communicating with one another through a valve opening but separable from one another by a valve seat, and an armature chamber. The armature chamber communicates with the inlet side via a pressure conduit, and the low-pressure valve chamber communicates with the outlet region of the injection pump. The low-pressure valve chamber has a fuel inlet conduit and a fuel outlet conduit, both of which have a gradually tapered cross section compared to the cross section of the remaining regions of the fuel inlet conduit and fuel outlet conduit. Maximal prevention of cavitation is successfully achieved in the region of the low-pressure valve chamber and hence cavitation erosion that is possible as a consequence of cavitation.

Abstract: A fuel rail for an automotive vehicle with a spark-ignited, reciprocating piston internal combustion engine is provided. The fuel rail has a tubular body with a fuel inlet and a plurality of injector outlets. A damper is provided with a lower cup connected to the tubular body. The damper also has an upper cup with a diaphragm sealably separating the cups.

Abstract: The invention relates to an arrangement for injecting fuel, which is at high pressure, into an internal combustion engine. An injector (25) encloses a pressure chamber (1), from which a high-pressure line (3) discharges into a control chamber (4) of a nozzle needle (5). Also contained in the injector (25) are two control valves (11, 12), which on the outlet side communicate with regions (9) of a lesser pressure level. One of the control valves (11, 12) that form the injection course (20) contains a pressure compensation system (34), by which the injection pressure course (20) can be varied by varying the stroke length (23) of the nozzle needle (5).

Abstract: A directly actuated injection valve comprises a hollow valve housing, a valve member disposed within the hollow interior, a biasing mechanism, an actuator assembly and a passive hydraulic link assembly. The valve member is movable between a closed position and an open position for governing the flow of fuel into the combustion chamber of an internal combustion engine. The biasing mechanism, preferably a spring, biases the valve member in the closed position. The actuator assembly generates an opening force that acts against the valve spring to open the valve. The hydraulic link assembly is interposed between the valve member and the valve spring and the actuator assembly. The hydraulic link assembly transmits respective closing and opening forces to the valve member. The hydraulic link preferably comprises a piston disposed within a cylinder that is filled with a hydraulic fluid.

Abstract: A fuel injection apparatus for internal combustion engines is proposed, which has a high-pressure fuel source from which fuel is supplied to an injection opening by means of a control valve unit. The control valve unit has a valve body, a valve member disposed in an axially mobile manner inside this valve body, and an actuator unit that actuates the valve member. A first high-pressure line connected to the high-pressure fuel source feeds into a first valve chamber of the control valve unit. In addition, a first valve seat is provided on an outer diameter of the valve body between the first valve chamber and a second valve chamber that communicates with the injection opening by means of a second high-pressure line. A second valve seat is formed on an inner diameter of the valve member and is engaged by a closing device.

Abstract: The present invention relates to common rail fuel injectors, and includes an example of such an injector, a fuel injection system employing such an injector, and a method of injecting fuel. The fuel injector includes an injector body, a fuel pressurization chamber, a nozzle chamber, a needle control chamber, a needle control spill outlet, a fuel inlet, and a nozzle outlet. The present fuel injection system includes a source of intermediate pressure fuel, a low pressure fuel reservoir, a needle valve, a flow control valve, and at least one of the present fuel injectors. The method of injecting fuel consists of the steps of injecting fuel at an intermediate pressure at least in part by fluidly connecting the injector's nozzle chamber to an intermediate fuel source, and injecting fuel at a high pressure at least in part by exposing a pressure intensifying element to the source of intermediate pressure fuel.

Abstract: A tubular fuel pressure damper for use in a fuel rail. The tubular fuel pressure damper includes a first and second end and an inner surface defining a cavity. The first and second ends of the fuel pressure damper are closed by crimping to form contact areas. The contact areas may be additionally sealed by welding, soldering or other means.

Abstract: A directly actuated injection valve comprises a hollow valve housing, a valve needle disposed within the hollow interior, a needle spring, and a magnetostrictive actuator assembly disposed in an annular space around a portion of the valve needle. A magnetic field actuates the magnetostrictive material to change its length to cause a corresponding movement of the valve needle that actuates the valve. The valve needle is comprises of a plurality of magnetostrictive actuator assembly is formed from a non-ferromagnetic material and the portion of the needle comprising the needle tip, which contacts the valve seat, is formed from a different material that has higher through-hardness than that the non-ferromagnetic material. The portion of the needle formed from a non-ferromagnetic material prevents interference with the flux field that is directed through the magnetostrictive member.

Abstract: The invention relates to a common rail injector for injecting fuel in a common rail injection system of an internal combustion engine, in particular a large diesel engine, having an injector housing which communicates with a central high-pressure reservoir and in which a nozzle needle can move axially counter to the initial stress of a nozzle spring which is contained in a nozzle spring chamber, in order to adjust the injection onset and the injection quantity as a function of the position of a 3/2-way valve. In order to improve the damping behavior in a common rail injection system, an injector pressure reservoir is integrated into the injector housing and communicates with the central high-pressure reservoir independent of the position of the 3/2-way valve.

Abstract: A fuel injector for an internal combustion engine has an injector housing having a pressure releasable control chamber for a vertical stroke movement and an annular chamber, an injector body closeable by the annular chamber, an inlet connectable to a high pressure collecting chamber and connected to and emptying into the annular chamber, an injection nozzle having a nozzle inlet and a nozzle chamber, with the nozzle inlet opened or closed by a sealing surface, a hydraulic spring associated with the injector body and including a control element impinged with high pressure via a volume of the hydraulic spring and via the inlet.

Abstract: A nozzle supply valve is positioned in the nozzle supply passage of a fuel injector, and is constructed to generate a boot shaped rate trace mechanically. The goal of the concept is to restrict the flow area during the first boot step and release the flow area restriction in the second step. During the first stage of injection, the flow to the nozzle only goes through a restricted orifice. When the line pressure is high enough to overcome the valve movement pressure spring preload, the nozzle supply valve moves to an unrestricted position, and the boot shaped rate trace is formed. Since this boot shape rate trace is generated mechanically, it can be combined with fuel injectors having a direct control needle valve in order to get different rate traces including, ramps, squares, pilots, posts and other split injections.

Abstract: An injection nozzle of a pressure-controlled fuel injection system has a control chamber for exerting pressure on a nozzle needle. The control chamber is connectable to a pressure reservoir via a pressure line that includes a 2/2-way valve. On the end of the nozzle needle that can be acted upon by pressure and is remote from the injection opening, a bore is embodied, by way of which the control chamber of the injection nozzle can be made to communicate with a leakage line as a function of the stroke of nozzle needle.

Abstract: An injector for injecting fuel in a combustion chamber of an internal combustion engine has a housing provided with a housing opening, a control valve body movable in the opening of the housing, a ring chamber which encloses the control valve body, an inlet connectable with a high pressure collecting chamber and opening into the ring chamber, a nozzle inlet arranged so that during the movement of the control valve body the nozzle inlet is connected with the inlet or separated from the latter, and 2/2-way control valves arranged inside the housing in series so that one of the 2/2-way control valves is force-equalized in an open condition.

Abstract: A fuel injection system for internal combustion engines, having a high-pressure accumulation chamber (7), which contains high-pressure fuel, having at least one fuel injection valve (15), which is connected to the high-pressure accumulation chamber (7). The fuel injection valve (15) can inject the highly pressurized fuel through injection openings (41, 42) into a combustion chamber of the engine. The fuel injection valve (15) has a control chamber (62), which is defined by a longitudinally mobile piston (60) and is operationally connected to the fuel injection valve (15) so that the injection cross section of the fuel injection valve (15) is controlled as a function of the hydraulic pressure in the control chamber (62). A low-pressure accumulation chamber (72) is provided, which can be connected to the control chamber (62), in which a predetermined fuel pressure is maintained in the low-pressure accumulation chamber (72) that is lower than the pressure in the high-pressure accumulation chamber (7) (FIG. 1).

Abstract: A hydraulically actuated fuel injector includes an injector body that defines an unobstructed biasing passage substantially fluidly isolated from a fuel pressurization chamber. A pumping element is positioned in the injector body and moveable between a retracted position and an advanced position. The pumping element has a biasing surface exposed to fluid pressure in the unobstructed biasing passage, and a fuel surface exposed to fuel pressure in the fuel pressurization chamber. A source of biasing fluid at a working pressure is fluidly connected to the unobstructed biasing passage. A source of fuel fluid at a supply pressure is fluidly connected to the fuel pressurization chamber.

Abstract: The nozzle body (5) of a fuel injection valve has a central bore (54) in which a nozzle needle (1) is guided. The tip (52) of the nozzle body (5) has a tapered valve seat (55) which forms together with the sealing edge (27) of the nozzle needle (1) a valve (27, 55) which controls the flow of fuel to the injection holes (9) in the nozzle tip (52). Underneath the sealing edge (27) a circumferential groove (33) is disposed in the truncatoconical needle tip (30, 35, 40, 45) at the level of which the injection holes (9) are disposed, so that when the valve (27, 55) opens the nozzle needle (1) is axially stabilized and the shaping of the injected jet is improved.

Abstract: A pressure limiter is connected fluid-tight between a common rail having an accumulator for storing high-pressure fuel delivered from a high-pressure fuel feed pump and a relief line. In a valve body of this pressure limiter, a damper chamber is provided on the downstream side of the sliding bore, for housing a large diameter portion of the piston and holding fuel, to thereby control the downward speed of the ball valve and the piston when the ball valve and the piston are shifted to the valve closing side by the force of the spring. Thus it becomes possible to prolong the downward-moving time of the ball valve and the piston.

Abstract: A fuel injection system includes a pressure storage chamber and one injector assigned to each cylinder, which injector can be connected to the pressure storage chamber via a pressure line that includes a metering valve. Using a single 2/2-way valve as a metering valve per cylinder makes for a more-economical manufacture of a fuel system, especially for small engines. The fuel injection is done under pressure control.

Abstract: In a fuel injection system for an internal combustion engine, in which fuel can be injected at least two different, high fuel pressures, via injectors, into the combustion chamber of the engine, having a central first pressure reservoir for the higher fuel pressure and a central second pressure reservoir, supplied from the first pressure reservoir, in which by regulation of its fuel delivery, the lower fuel pressure is maintained, and having a valve unit for switchover between the higher and the lower fuel, the valve unit for switchover between the higher and the lower fuel is provided locally for each injector. With this injection system, improved metering of the lower fuel pressure is possible.

Abstract: A fuel injector includes a body having a nozzle end and a connector end. The body defines a side feed opening disposed between said nozzle end and said connector end. An injection assembly is disposed in the nozzle end and includes an actuating coil, a value actuated by the coil, and a valve seat operably associated with the valve.

Abstract: The present invention relates to engines having common rail fuel injection systems. In traditional common rail fuel injection systems, each fuel injector utilized by the fuel system includes its own solenoid. These individual solenoids must cooperate to ensure that the proper amount of fuel is being injected from each injector at the proper time. Having individual solenoids requires a multiple number of moving electrical components. In contrast to the traditional common rail fuel injection system, the fuel injection system of the present invention includes fuel injectors that are controlled in operation by a common electronic actuator that is positioned remote from the fuel injectors. Therefore, the present invention reduces the number of moving electrical components in the fuel injection system by reducing the need for individual solenoids for each fuel injector.

Abstract: A fuel injection system has a pressure booster unit (1), disposed between a pressure reservoir chamber and a nozzle chamber, which unit has a displaceable piston unit (4) for boosting the pressure of the fuel to be supplied to the nozzle chamber. For controlling the pressure booster unit (1), the piston unit (4) has a transition from a larger to a smaller piston cross section and a differential chamber (2) formed thereby, which is connected to the pressure reservoir chamber via a filling path (13) having a filling valve (10). A reduction in the control quantity during the triggering of the pressure booster unit (1) and the performance of a rapid restoration of the piston unit (4) are attained.