Abstract: The injection system (1) comprises a pump (7) designed to send fuel at high pressure to an accumulation volume, for example formed by a common rail (6), for supplying a plurality of injectors (5). The pump (7) comprises at least one pumping element (18) actuated with reciprocating motion with a compression stroke (Pi-Ps) at a sinusoidal speed (24), in synchronism with each step of fuel injection. The injection system (1) comprises at least one by-pass solenoid valve (14), which is controlled by a chopper control unit (16, 28) for modulating the delivery of the pumping element (18) by varying both the instant of start (To) and the instant of end (T1) of delivery during the compression stroke (Pi-Ps), in such a way that the delivery is synchronous with the injection phase.

Abstract: An apparatus controls the quantity of fuel injection of an injector in accordance with the fuel pressure in the fuel rail of a direct injection type internal combustion engine. A reference value for controlling the injector is obtained on the basis of the difference and the fuel pressure in the fuel rail at the time of starting fuel injection out of injector.

Abstract: In a valve control unit for a ram jet propulsion system having a power unit space a valve for controlling a fuel quantity required to the propulsion system, and a valve adjusting unit which is constructed to be operable by means of an electronic control unit, the valve is combined with its valve adjusting unit and its electronic control unit to form a thermally insulated valve assembly. The valve assembly is configured for the arrangement in the power unit space.

Abstract: A fuel pressure relief valve includes a body defining a passageway having an inlet end in communication with a fuel pump and an outlet end in communication with a fuel rail. The valve also includes a seal member moveable between a first position in which the seal member is seated against the outlet end, and a second position in which the seal member is unseated from the outlet end. The valve further includes a biasing member biasing the seal member toward the second position. The seal member moves from the second position to the first position immediately after fuel pump shutoff to maintain pressure in the fuel rail. The seal member moves from the first position to the second position when fuel in the fuel rail drops to a residual pressure substantially less than the operating pressure to provide a leak path between the fuel pump and the fuel rail.

Abstract: A fuel control system for controlling the use of primary fuel and alternate fuel in an internal combustion engine without cross-contamination of fuel types. Cross-contamination of fuel types may eliminate the ability to receive certain benefits or financial incentives associated with use of alternate fuel, including but not limited to RINs, credits, and subsidies. In one embodiment, primary and/or alternate fuel are controllably delivered from sources to a flow cell. If blending is desired, both primary and alternate fuels are delivered to the flow cell. The engine is fed with the resulting primary fuel, alternate fuel, or blended mixture of fuel from the flow cell. The flow cell contains a bypass inlet port adapted to receive excess fuel not consumed by the engine in lieu of the excess fuel being returned to the primary and/or alternate fuel sources. In this manner, cross-contamination of the fuel sources can be avoided.

Abstract: A method and a device for supplying fuel to internal combustion engines comprise a regulated high-pressure system and a controlled low-pressure system, wherein an adaptation value for correcting the desired preliminary pressure is detected in an adaptation mode, in order to adjust a variable preliminary pressure in the low-pressure system. For this purpose, the preliminary pressure is specifically changed in the adaptation mode until vapor bubbles are detected by a regulator response of the high-pressure regulator of the high-pressure system. When vapor bubbles are detected, current process parameters of the fuel supply system are determined and the adaptation value is derived therefrom.

Abstract: The invention relates to a device for supplying fuel under high pressure in which the fuel is put under high pressure by a transfer pump, characterized by the fact that it comprises two identical transfer pumps (3, 4), powered by a control means, controlling the fuel feed rate of the two pumps, the latter supplying the same common rail (2).

Abstract: A shut off valve arrangement for use in a fuel injection system includes a shut off valve member operable between a closed position in which the shut off valve member is engaged with a shut off valve seating and an open position in which the shut off valve member is disengaged from the shut off valve seating to control the supply of fuel to the injector through a fuel supply passage. The shut off valve member includes a first surface that is exposed to fuel pressure within a shut off valve control chamber, a second surface exposed to fuel within the fuel supply passage and a third surface exposed to fuel pressure in a balance chamber, wherein the shut off valve arrangement is provided with a control valve for controlling the pressure of fuel within the shut off control chamber, thereby to control movement of the shut off valve member between the open and closed positions.

Abstract: A fuel injection system is equipped with a high-pressure supply pump driven by an output of an internal combustion engine to supply fuel to an accumulator, a low-pressure supply pump driven by a power source other than the engine to suck the fuel from a fuel tank and supply the sucked fuel to the high-pressure supply pump, and a pressure regulator working to regulate the pressure of the fuel supplied from the low-pressure supply pump to the high-pressure supply pump. The system also includes an abnormal pressure detector working to monitor a preselected parameter that bears a correlation to the energy held by the fuel at an inlet of the high-pressure supply pump to detect whether a pressure of the fuel at the inlet of the high-pressure supply pump is in an abnormal level or not without monitoring it directly.

Abstract: A fuel system for an engine is disclosed. The fuel system has a first source of fuel at a first pressure, and a second source of fuel at a second pressure. The fuel system also has a fuel injector configured to receive fuel from the first and second sources and inject fuel into a combustion chamber of the engine. The fuel system further has a valve operable to selectively direct fuel from the first and second sources to the fuel injector. The fuel system additionally has a controller in communication with the valve and being configured to affect operation of the valve and a resulting fuel pressure based on a desired injection pressure.

Abstract: A fuel injector has a piezoelectric or magnetostrictive actuator, which actuates a valve-closure member cooperating with a valve-seat surface to form a sealing seat. A hydraulic coupler includes a master piston, a slave piston, and a coupler volumeformed in-between. The master piston and the slave piston are axially displaceable with respect to one another. The coupler volume is connected to a compensating chamber via a throttle. A flexible section delimits the compensating chamber at least partially, and the coupler volume, the throttle, and the compensating chamber are filled with a hydraulic medium. At least one spring element directly or indirectly exerts pressure on the flexible section from the outside, via fixed components.

Abstract: A fuel injection system for an internal combustion system includes an Engine Management System (EMS), a fuel feed pump, a return line, a high-pressure pump, supplying fuel under pressure to a common rail, a hydraulically operated valve forming an outlet chamber connected to the common rail and a control chamber, the valve being designed such that, in its closed position, the valve prevents the flow out of the outlet chamber, and an electrically operated pilot valve. A nozzle with a resilient member that biases the nozzle towards closing is connected to the outlet of the hydraulically operated valve in such a way that pressure at the outlet of the hydraulically operated valve tends to overcome the force of the resilient member and open the nozzle. An electrically operated spill valve is connected between the outlet of the hydraulically operated valve and the return line.

Abstract: A fuel supply system for a motor vehicle has a sucking jet pump (6, 7) which is connected to a flow line (5). The valve (16, 17) reduces the cross-section of an opening (20) in a nozzle (14, 15) of the sucking jet pump (6, 7) with increasing pressure in the flow line (5). Hydraulic losses in supplying the sucking jet pump (6, 7) with fuel as a pump fluid are prevented and the conveying performance of the sucking jet pump (6, 7) is maintained, preferably, at a constant level.

Abstract: The invention can avoid an energy dissipation and a consumption of an apparatus by minimizing a driving amount of a fuel pump and maintain an improved fuel supply state, in a fuel supply system injecting a liquefied gas fuel by an injector and supplying to an engine.

Abstract: A fuel injection pump includes a pump housing, which has a cam chamber accommodating an eccentric cam of a camshaft, a plunger pump portion, which includes a plunger driven by the eccentric cam, and a feed pump driven by the camshaft for supplying fuel to the plunger pump portion. The camshaft has one end inserted in a through hole of an outer wall of the pump housing. A cover is fixed to the outer wall of the pump housing to close the through hole. The cover is coupled with a first pressure regulating valve for regulating pressure of fuel discharged from the feed pump. The longitudinal direction of the first pressure regulating valve is at a predetermined angle with respect to the longitudinal direction of the camshaft.

Abstract: A fuel injection system comprising an accumulator volume (10) arranged to be charged with fuel by means of a high pressure fuel pump (12) and for supplying fuel at a first injectable pressure level to a plurality of fuel injectors (22), wherein each injector (22) includes a delivery passage (16, 20), a valve needle (30), which is engageable with a seating to control fuel injection, and a control valve (26) for controlling fuel pressure within a control chamber (28) so as to control movement of the valve needle (30). The control valve (26) has a first operating position in which the control chamber (28) communicates with a low pressure drain and communication between the control chamber (28) and the delivery passage (16, 20) is prevented and a second operating position in which the control chamber (28) communicates with the delivery passage (16, 20) and communication between the control.

Abstract: A high-pressure fuel pump with a pressure relief valve which has improved hydraulic properties and a reduced number of high-pressure sealing points.

Abstract: The objective of the present invention is to dampen operating sounds of an electromagnetic drive mechanism used for a variable displacement control mechanism in a high-pressure fuel supply pump to reduce an individual difference depending on apparatus due to the change over time or installation tolerance. To achieve the above objective, the present invention is configured such that before the electromagnetic drive mechanism supplies a drive force to a plunger which is electromagnetically driven by the electromagnetic drive mechanism, another displacement force situates the plunger in a specific position. When compared to an occasion where the plunger is displaced all strokes by a magnetic biasing force, the above configuration is able to reduce the force of impact on a member (for example, valve body) mounted to the plunger and a restricting member, thereby damping the collision noise.

Abstract: Disclosed is a fuel metering unit for high-pressure pumps of fuel injection systems, whose leakproofness in zero delivery operation has been further improved and whose manufacture and assembly have been simplified.

Abstract: The invention provides a fuel injection pump comprising a pump housing and a pumping arrangement associated therewith, wherein the pumping arrangement includes a pumping plunger and a plunger drive arrangement, the pumping plunger having a first end reciprocably received within a plunger bore provided in the pump housing and a second end coupled to the plunger drive arrangement. A biasing spring is provided having first and second spring ends, the first spring end coupled to a spring plate member associated with the pump housing and the second spring end coupled the plunger drive arrangement. The pump housing includes first and second portions aligned on a common axis, the upper portion including a further bore in which at least an upper portion of a locking pin is receivable and wherein the spring plate member defines support means for supporting a lower end portion of the locking pin.

Abstract: The injection system comprises a high-pressure pump (7) with variable flowrate, having a number of pumping elements (18) actuated with reciprocating motion and provided each with a corresponding intake valve (22). An accumulation volume (28) is supplied with fuel at low pressure from an intake pipe (10) of the pump (7) through a solenoid valve (31) controlled as a function of the operating conditions of the engine (2). The accumulation volume (28) is in communication with the intake valves (22) through corresponding outlet holes (29), and the solenoid valve (31) is provided with nebulizer holes (36) such as to generate corresponding jets of fuel, each directed towards at least one of said outlet holes (29).

Abstract: A fuel delivery system for an internal combustion engine includes a piston pump with a work chamber and an inlet valve. An adjustable throttle restriction is disposed upstream of the inlet valve. It is proposed that an outlet of the throttle restriction be disposed immediately adjacent the inlet valve.

Abstract: A control system for controlling a device, the device having at least two functional elements, each functional element being controlled by a control signal, is disclosed in the present disclosure. The control system may include detecting means operatively connected to the device and configured to monitor the operation of the device, and to generate a signal indicative of an operating condition of the device. The control system may also include a control module operatively connected to the at least two functional elements and the detecting means, and configured to switch the two control signals applied to the respective functional elements in response to the signal generated by the detecting means.

Abstract: A fuel system for an engine is disclosed. The fuel system has a first source configured to pressurized fuel to a first pressure, and a second source configured to pressurized fuel to a second pressure. The fuel system also has a fuel injector configured to receive fuel at the first pressure and the second pressure, and a valve disposed between the fuel injector and the first and second sources. The valve is configured to modify the pressure of fuel from the first source based on a pressure of fuel from the second source.

Abstract: A fuel injection system for an internal combustion engine, comprises: a pump comprising a pumping plunger which is driven, in use, to cause pressurisation of fuel within a pump chamber, an accumulator volume for supplying fuel to a fuel injector, a fuel passage providing fluid communication between the pump chamber and the accumulator volume, and an inlet control valve operable to control fuel flow into the pump chamber from a low pressure reservoir; wherein the inlet control valve is a latching inlet valve. The fuel injection system may be a hybrid fuel injection system, having a rail valve located in the fuel passage between the pump chamber and the accumulator volume. The latching inlet valve may be a two-way electronic latching poppet valve, and the rail valve may be a non-return valve. A method of operating such a fuel injection system for an internal combustion engine is also described.

Abstract: Described herein is an electronic-injection fuel-supply system for an internal-combustion engine having at least one injector and a fuel pump; the fuel pump is provided with: a variable-volume pumping chamber; a one-way intake valve; a one-way delivery valve; a mobile piston that integrates within it the intake valve and is coupled to the pumping chamber to vary cyclically the volume of the pumping chamber itself; and an actuator device that impresses a reciprocating motion on the piston and has an electromagnetic actuator for actuating the piston during an intake phase and a spring for actuating the piston during a delivery phase.

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: A regulation valve has: a cylinder that has an inlet port at one end side thereof to introduce the fuel thereinto, and a relief port opening on a side face thereof; a piston that is reciprocatably inserted in the cylinder to vary an opening area of the relief port in accordance with a variation of the pressure of the fuel flowing in through the inlet port; and a spring that urges the piston in a direction against the pressure of the fuel acting on the piston to regulate the pressure to be a specific value. Further, the cylinder and/or the piston is formed so that the piston opens the relief port at a relatively small speed per a unit displacement thereof in starting opening the relief port and subsequently at a relatively large speed.

Abstract: A high-pressure fuel pump for an internal combustion engine is proposed, in which the regulating behavior in idling and lower partial-load operation is improved to such an extent that a separate pressure regulating valve in the high-pressure region of the fuel injection system can be dispensed with.

Abstract: An injector includes a boosting mechanism and a nozzle. The boosting mechanism boosts fuel, and the nozzle injects and supplies the fuel boosted by the boosting mechanism. The boosting mechanism includes a tubular piston and a column piston. The tubular piston has a bore, which extends through the tubular piston in a direction of a longitudinal axis of the tubular piston. The column piston is loosely received by the tubular piston and has an end portion, which projects from the tubular piston, and which is engaged with the tubular piston. The tubular piston is slidably received by a first cylinder. The end portion of the column piston is slidably received by a second cylinder, which is provided generally coaxially to the first cylinder, and which has a diameter different from that of the first cylinder.

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 control system for controlling a device, the device having at least two functional elements, each functional element being controlled by a control signal, is disclosed in the present disclosure. The control system may include detecting means operatively connected to the device and configured to monitor the operation of the device, and to generate a signal indicative of an operating condition of the device. The control system may also include a control module operatively connected to the at least two functional elements and the detecting means, and configured to switch the two control signals applied to the respective functional elements in response to the signal generated by the detecting means.

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: 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: A pumping system (10) for a fuel injection system including a pump body defining a pumping chamber, a plunger (14), a high-pressure outlet, a high-pressure fluid line (18) connecting the pumping chamber to the outlet and a trapped volume (20) in communication with either the fluid line (18) or the pumping chamber.

Abstract: A low-pressure delivery pipe provided with intake manifold injectors, a fuel pressure regulator, a high-pressure fuel pump, a high-pressure delivery pipe provided with in-cylinder injectors, and an electromagnetic relief valve are connected in series at the downstream of a low-pressure fuel pump that discharges a fuel within a fuel tank at a prescribed pressure. Since the low-pressure delivery pipe is arranged downstream of the low-pressure fuel pump, the fuel pressure within the low-pressure delivery pipe is lowered upon stop of vehicle operation, in response to stop of the low-pressure fuel pump. The fuel pressure within the high-pressure delivery pipe is also lowered in response to stop of the low-pressure fuel pump, by opening the electromagnetic relief valve upon stop of vehicle operation. Thus, oil tightness of the injectors during the stop of vehicle operation is ensured.

Abstract: A pumping arrangement for an internal combustion engine is disclosed. The pumping arrangement may have a first pumping chamber, a second pumping chamber, a first plunger, and a second plunger. The first and second plungers may be movable within the first and second pumping chambers between first and second spaced apart end positions to pressurize a fluid. The second plunger may move out of phase relative to the first plunger. The pumping arrangement may also have a single electronically controlled valve configured to meter the amount of fluid spilled from each of the first and second plungers.

Abstract: A common rail fuel pump for an internal combustion engine includes a pumping plunger (10) that is reciprocable within a plunger bore (14) provided in a pump housing (16) under the influence of a drive arrangement (18, 20) to cause fuel pressurisation within a pump chamber (12). An inlet metering valve (46) is operable to meter the quantity of fuel supplied to the pump chamber (12) during the return stroke of the plunger (10). An outlet valve (58) controls the supply of pressurised fuel from the pumping chamber (12) through an outlet passage (30) to the common rail fuel volume in circumstances in which the inlet metering valve is closed. The outlet passage (30) has a pump outlet (38), from where fuel is supplied to the common rail fuel volume. The inlet metering valve (46), the plunger (10) and the pump outlet (38) are arranged in axial alignment, providing a compact and lightweight pump for installation in existing and purpose-built engines.

Abstract: The pump (7) is provided with a body (16) having a compartment (17), and with at least one pumping element (13) that moves in a cylinder (12) in communication with the compartment (17), to raise the pressure of the fuel. The pump (7) comprises fluid-supply means (14, 22) for delivering the fuel to the pumping element (13), and an inlet mouth (26) made in the body (16) and supplied with the fuel coming directly from an external source (2). The inlet mouth (26) is fluidically connected to the compartment (17) to supply it with the fuel in order to lubricate and/or cool the pump (7) itself. Set between the inlet mouth (26) and the compartment (17) are: a non-return valve (33) to prevent in any case the pumping elements (13) from sucking the fuel from the compartment (17) of the body (16); and a flow regulator (29?), which allows an amount of fuel to pass such as to enable proper lubrication and cooling of the compartment (17) and of the parts present in the compartment (17).

Abstract: A fuel filter is located downstream of a feed pump to filter fuel discharged from the feed pump. An orifice is located between the fuel filter and a suction quantity control valve to restrict a flow rate of the fuel passing through the fuel filter. A positive pressure of the feed pump is applied to the fuel filter, and a passing pressure at the fuel filter increases. Even if viscosity of the fuel increases and the fuel becomes wax-like at low temperature, clogging of the fuel filter or an insufficient flow rate can be inhibited. The orifice restricts the flow rate of the fuel passing through the fuel filter. Accordingly, an increase in size of the fuel filter can be prevented even if the fuel filter is located downstream of the feed pump.

Abstract: A control valve module (14?) for a fuel injector assembly (10) has a conduit arrangement where a high-pressure passage (108) has a first portion (110) extending linearly between an annulus (106) surrounding the control valve cylinder (42) and an upper edge (34), and a second portion (112) extending linearly between the annulus (106) and a lower edge (35?).

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: 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 fluid pumping apparatus, system, and method are disclosed in which an apparatus according to one embodiment of the invention comprises a housing, an inlet through which the fluid enters the housing, an outlet through which the fluid leaves the housing, a valve comprising a valve member and a valve seat, the valve being positioned between the inlet and the outlet such that the fluid from the inlet must flow through the valve to reach the outlet, and a magnet mechanism, configured to exert a continuous magnetic force. The magnet mechanism is positioned to continuously urge the valve member into a first position. System and method embodiments are also disclosed.

Abstract: The invention relates to a fuel supply device pertaining to an internal combustion engine. Said fuel supply device has a regulating device comprising a first regulator, which is provided with at least one integral part and which produces, in a first mode of operation, a regulating signal for a volume flow control valve, and a second regulator that produces a regulating signal for an electromechanical pressure regulator in a second mode of operation. In the first mode of operation, an error in the fuel supply device is identified according to the integral part of the first regulator. In the second mode of operation, an error in the fuel supply device is identified according to a detected fuel pressure and the regulating signal for the electromechanical pressure regulator.

Abstract: A high-pressure fuel pump and methods for controlling this high-pressure fuel pump are described in which the pumping quantity regulation does not cause significant heating of the fuel to be pumped. The partial-load efficiency of the high-pressure fuel pump, triggered in accordance with the invention, is also very good.

Abstract: A high-pressure fuel pump control device is capable of reducing current consumption, increasing pump durability, and promoting a rise of fuel pressure from startup. The high-pressure fuel pump control device comprises a fuel injector valve for directly injecting fuel in a common rail into a combustion chamber and a high-pressure fuel pump for feeding the fuel under pressure to the common rail. The high-pressure fuel pump comprises a pressurization chamber, a plunger for pressurizing the fuel in the pressurization chamber, a fuel passage valve disposed in the pressurization chamber, and an actuator for actuating the fuel passage valve. The control device includes a control unit for executing output control of a drive signal for the actuator to vary a discharge rate of the high-pressure fuel pump.

Abstract: In an engine equipped with a common rail fuel injection system, the engine can sometimes experience an overspeed condition, and the pump may respond to this overspeed condition with self-actuation even in the absence of any control signal. In order to prevent an over pressurization condition, a liquid supply into a pumping chamber of the pump is limited during a retraction stroke of a pump plunger by energizing an electrical actuator coupled to a spill valve, to move the spill valve toward a closed position. The electrical actuator is de-energized during a pumping stroke of the pump plunger to allow the spill valve to more toward an open position. Liquid from the pumping chamber is discharged through the spill valve during the pumping stroke, but over pressurization is avoided by limiting the amount of liquid that can enter the pumping chamber during the retraction stroke.

Abstract: A fuel injection valve (10) with a pressure boosting unit is provided in an engine (1), and boosted pressure fuel injection is performed by increasing a pressure of fuel supplied to a fuel injection valve from a common rail (3). An ECU (20) decides a pressure boosting period that is defined as a time period from when the pressure of the fuel starts to be boosted until when the fuel injection is started using a numerical table in which a fuel injection amount and an engine rotational speed are used as parameters, and sets fuel injection control parameters such as a fuel injection period and pressure boosting starting timing, based on the pressure boosting period. Since the fuel injection control parameters are set based on the pressure boosting period, the control that is performed when the boosted pressure fuel injection is performed is simplified.

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.