Abstract: A fuel injector for an internal combustion engine is provided. The fuel injector has a simple structure that is easy to install and remove a piezoelectric valve actuator in and from the fuel injector and to adjust fuel injection characteristics finely and that allows an overall size of the fuel injector to be decreased. The fuel injector includes a housing to be installed in the engine and a structural element serving to install the piezoelectric valve actuator in the housing to be detachable easily. The piezoelectric valve actuator is retained in an actuator casing fitted in the housing so that it can expand or contract to move a needle valve. The actuator casing has an extensible portion in itself or is coupled to a bellows in alignment for enabling the piezoelectric valve actuator to expand, thereby allowing the size of the actuator casing to be minimized.

Abstract: A fuel injector comprising a valve needle slidable within a bore, a surface associated with the valve needle being exposed to the fuel pressure within a control chamber and an electromagnetically actuable control valve controlling communication between the control chamber and a low pressure chamber. The injector also comprises a damping arrangement arranged to damp pressure waves applied to the low pressure chamber.

Abstract: The injector has a control rod controlled by the fuel pressure in a control chamber, and a nozzle having an injection chamber supplied with pressurized fuel for injection. The nozzle has at least one injection orifice normally closed by a pin connected to the rod and activated by the fuel pressure in the injection chamber. The control chamber has a pressurized-fuel intake conduit, and a fuel discharge conduit which is normally closed and is opened for a variable length of time depending on the amount of fuel to be injected. The pin and the rod, and/or the intake conduit and the discharge conduit, are so sized as to keep the pin and the rod hydraulically balanced in the maximum-lift position to open the orifice.

Abstract: An injector for an injection system of an internal combustion engine, with an injector head (1), a nozzle (13) for injecting fuel, a control unit (12) for controlling the transfer of fuel from the injector head (1) to the nozzle (13) and an actuator (6) for the mechanical activation of the control unit (12) in order to control fuel injection, an injector housing (2), which receives at least the control unit (12), being integrally formed on the injector head (1) at the bottom.

Abstract: A high pressure gaseous fuel injector for injecting natural gas or other gaseous fuels at high pressures (eg. 300 to 700 psig more or less) into combustion engines for improved efficiency, better performance and reduced environmental emissions. The fuel injector is powered by hydraulic signals from an electrohydraulic valve. The fuel injector includes an outer cartridge housing and a universal valve cartridge mounted therein. The cartridge comprises an activator body and a valve body secured together, and the valve body has a gas valve slidable therein. The stroke of the valve is adjustable by controlling the size of shims in the valve body assembly, thereby providing a universal valve cartridge that can be easily adapted to differing fueling requirements for models and sizes of engines. The valve body includes a spring chamber between upper and lower valve guides.

Abstract: A fuel injector includes an injector body that defines a nozzle outlet. A needle valve member is mounted in the injector body and moveable a lift distance between an open position in which the nozzle outlet is open, and a closed position in which the nozzle outlet is blocked. A piezoelectric actuator is mounted in the injector body and is moveable a piezo distance between an off position and an on position. A coupling linkage interconnects the needle valve member to the piezoelectric actuator such that a movement of the piezoelectric actuator is multiplied into a larger movement of the needle valve member.

Abstract: A fuel injector for use in an injector arrangement including a fuel pump having a pump chamber and a spill valve arrangement including a spill valve member which is engageable with a spill valve seating to control communication between the pump chamber and a low pressure drain. The fuel injector further comprises a valve needle which is engageable with a valve needle seating, a control chamber arranged such that the fuel pressure therein urges the valve needle towards its seating, a control valve arrangement, including a control valve member, for controlling the fuel pressure within the control chamber, and an actuator arrangement for controlling movement of the spill valve member and the control valve member. The actuator arrangement comprises a double pole actuator having a first armature which is movable with the spill valve member and a single pole actuator having a second armature which is movable with the control valve member.

Abstract: A gasket for use in an electromotive diesel fuel injector. The gasket is made of a polymeric material and is adapted to be received by a filter nut of the fuel injector.

Abstract: An injector for a fuel injection system is provided with an injector housing in which a piezoelectric stack is located and with a valve housing connected with the injector housing in which a valve closing device with a jet needle is displaceably located. The valve closing device can be actuated by the piezoelectric stack. The valve closing device can be reset by a return device. A hydraulic following amplifier is located between the piezoelectric stack and the jet needle of the valve closing device. The amplifier has a displacement piston actuated by the piezoelectric stack. A control piston located downstream from the displacement piston and increases the displacement travel. A working piston that actuates the jet needle and increases the actuating force.

Abstract: An injection valve for a fuel injection system, for multistage control of the effective cross section of an injection opening. A spring/stop system with a first compression spring for a control valve for a control chamber, whose pressure determined the position of the valve shaft of an injection valve member. When a valve opens, the spring/stop system allows its valve tappet a first axial stroke, which is limited by a primary stop on an axially movable adapter. The axial mobility of the adapter allows the valve tappet, counter to the compressive force of a first compression spring, an additional, second axial stroke, which is limited by an end stop structurally connected to the housing. The valve tappet is urged in the closing direction of the control valve by a second compression spring braced against the housing of the injection valve, and in the closed state of the control valve the spring force of the second compression spring is less than that of the first compression spring.

Abstract: A lube oil and fuel blending system, pumping device and method are provided which effectively, inexpensively and controllably removes used lube oil from an engine and delivers the lube oil to the fuel system for consumption within the engine. The lube oil and fuel blending system includes a fuel pumping device or injector containing a bore and a plunger reciprocally mounted in the bore for movement through a retraction stroke and an advancement stroke, each having a predetermined stroke length. A fuel drain circuit communicates with the bore at a drain location spaced a predetermined seal length axially along the bore from an outer opening of the bore through which the plunger extends. The predetermined seal length is specifically designed less than the predetermined stroke length to cause lube oil on the outer portion of the plunger to be delivered by the plunger to the fuel drain circuit at the drain location.

Abstract: Disclosed is a fuel injection valve having at least two valve body parts, which each contact one another at a respective contact face and pressed against one another perpendicular to the contact face by a clamping device. An inflow conduit for fuel formed in both valve body parts passes through the contact faces, and a high fuel pressure prevails in it. At least one radially widened portion is embodied in the inflow conduit, near the contact face of at least one valve body part, so that this radially widened portion, as a result of the fuel pressure in the inflow conduit, undergoes an expansion in the axial direction. As a result, the region of the contact face surrounding the inflow conduit is pressed against the contact face of the contacting valve body part, so that the contact pressure of the contact faces increases, whereby the inflow conduit is thus better sealed off, and the force of the clamping device can be reduced.

Abstract: A fuel injection device for internal combustion engines, having a fuel injection pump, which can be inserted into a housing of the engine and is axially clamped together with a fuel injection valve by means of a clamping sleeve. The valve, with an end remote from the pump, protrudes into a combustion chamber of the engine. A fuel supply line to the fuel injection pump feeds into an annular chamber encompassing the clamping sleeve and, via through openings in the clamping sleeve and inlet conduits in the pump housing, the valve can be connected to a pump working chamber of fuel injection pump. According to the invention, the fuel filter in the inlet to the pump working chamber is constituted by the clamping sleeve, which has a multitude of filter openings for this purpose in its circumference wall, in the vicinity of the annular chamber.

Abstract: The present invention relates to fuel injectors having a free floating plunger. Traditional tappet assemblies include a plunger that is mechanically coupled to the tappet, and therefore, cannot be uncoupled over a portion of its movement during an injection event. In the event of a plunger seizure in a traditional tappet assembly, the tappet spring can be prevented from expanding, which can cause major valve train and engine damage. In addition, because the plunger in traditional tappet assemblies is moved to its upward position under the action of the tappet spring, the fuel passages can depressurize if fuel cannot refill the fuel pressurization chamber as quickly as the plunger retracts, causing cavitation bubbles. Therefore, the present invention utilizes a plunger that is not mechanically coupled to the tappet and can uncouple from the tappet during the injection event to address these and other problems related to plunger wear and failure.

Abstract: Pumps and injectors having a control valve spring arrangement configured to provide a force step when the control valve is at a rate shape position, and related methods for operating a control valve, are provided. The control valve is moveable over a stroke range between an open position and a closed position. The stroke range includes a rate shape position. The control valve spring arrangement is configured to provide a first spring force when the control valve is between the closed position and the rate shape position, and to provide a second spring force that is less than the first spring force when the control valve is between the rate shape position and the open position.

Abstract: An injection valve member for the closing and opening of injection orifices of a valve seat element is installed longitudinally adjustably in a central housing bore of a fuel injection valve. The opening and closing movement sequence of the injection valve member is controlled by a control device. A control piston operatively connected to the injection valve member is loaded, on the one hand, by the fuel system pressure prevailing in a high-pressure zone and, on the other hand, by the fuel control pressure in a control space. The high-pressure zone includes the central housing bore which is closed off sealingly by a control body fixed to the housing. The control space is arranged between the control body and a piston end face and is at least temporarily delimited radially by a control sleeve which is moveable transversely to the longitudinal axis of the housing.

Abstract: A fuel injection apparatus includes a valve closing unit provided for biasing a needle valve by a pressure of working fluid introduced into a pressure controlling chamber and a biasing force of a needle spring. A working fluid introducing/backing passage having a port is connected to the pressure controlling chamber. A throttle portion for imparting a fluidization resistance to the working fluid is provided in the port. The port is adapted to be kept in communication with the working fluid discharge passage only in a retracted position of a booster piston, to be in communication with a pressurizing chamber only in the case where the booster piston is advanced through a predetermined distance or longer, and to be in communication with none of the working fluid discharge passage and the pressurizing chamber from the retracted position to the advanced position through the predetermined distance.

Abstract: A high pressure gaseous fuel injector for injecting natural gas or other gaseous fuels at high pressures (eg. 300 to 700 psig more or less) into combustion engines for improved efficiency, better performance and reduced environmental emissions. The fuel injector is powered by hydraulic signals from an electrohydraulic valve. The fuel injector includes an outer cartridge housing and a universal valve cartridge mounted therein. The cartridge comprises an activator body and a valve body secured together, and the valve body has a gas valve slidable therein. The stroke of the valve is adjustable by controlling the size of shims in the valve body assembly, thereby providing a universal valve cartridge that can be easily adapted to differing fueling requirements for models and sizes of engines. The valve body includes a spring chamber between upper and lower valve guides.

Abstract: A fuel injector comprising a valve needle which is slidable within a bore, a surface associated with the valve needle defining, in part, a control chamber which communicates, through a restriction, with a supply passage. The fuel injector also includes an injection control valve controlling communication between the control chamber and a low pressure reservoir, and a drain valve controlling communication between the supply passage and the low pressure reservoir. The injection control valve and the drain valve include respective armatures moveable under the influence of a common electromagnetic actuator.

Abstract: A pump injector comprising a pumping chamber, a valve needle controlling communication between the pumping chamber and one or more outlet openings, and a spill valve controlling communication between the pumping chamber and a low pressure fuel reservoir, in use. The pump injector also comprises an inlet non-return valve arranged to permit fuel to flow from the fuel reservoir to the pumping chamber, in use, but substantially preventing fuel flow in the reverse direction. Alternatively, the pump injector may comprise an abutment piston engageable with the valve needle which defines, in part, a control chamber for fuel, and a control valve controlling communication between the pumping chamber and the control chamber.

Abstract: A high pressure gaseous fuel injector for injecting natural gas or other gaseous fuels at high pressures (eg. 300 to 700 psig more or less) into combustion engines for improved efficiency, better performance and reduced environmental emissions. The fuel injector is powered by hydraulic signals from an electrohydraulic valve. The fuel injector includes an outer cartridge housing and a universal valve cartridge mounted therein. The cartridge comprises an activator body and a valve body secured together, and the valve body has a gas valve slidable therein. The stroke of the valve is adjustable by controlling the size of shims in the valve body assembly, thereby providing a universal valve cartridge that can be easily adapted to differing fueling requirements for models and sizes of engines. The valve body includes a spring chamber between upper and lower valve guides.

Abstract: A fuel injector which has a double solenoid three-way or four-way spool valve that controls the flow of a working fluid that is used to move an intensifier piston of the injector.

Abstract: An actuator is operatively connected to a closing member via a tappet. The closing member is introduced in a valve chamber and forms, with a conically tapering valve seat as part of a servovalve, a seal resistant to high pressure. The cross section of the closing member is configured to be mushroom-shaped, a closing head being in the form of a part-sphere and having a central flattening, with the result that the tappet has an enlarged bearing surface. A stem of the closing member is surrounded by a valve spring. The closing member is preferably shaped out of a solid sphere.

Abstract: An injector assembly comprising an injector (3) and a wall (1) having an inner surface (2) defining a cavity receiving the injector (3). A peripheral surface portion of the injector (3) and a corresponding portion of the cavity inner surface (2) are configured to inter-engage such that force applied to the injector (3) in a predetermined direction causes mutually oppositely directed reaction forces perpendicular to the applied force which tend to laterally compress the injector (3), for relieving lateral stress within the injector (3). Additionally, an injector (3) for fitting in a cavity of an injector assembly, the injector (3) including an axially extending portion (10) comprising at least two peripheral irregularities in an otherwise substantially regular lateral cross-section.

Abstract: A fuel injector comprising a fuel inlet arranged, in use, to receive fuel under high pressure from a source of pressurised fuel, an outlet and an accumulator volume located between the inlet and the outlet. A piezoelectric actuator is located within the accumulator volume and is operable to move a control piston to modify the fuel pressure within a control chamber.

Abstract: A fuel injector comprises an injector body that defines a high pressure passage and a nozzle outlet. The injector body includes a nozzle valve member that is positioned between the high pressure passage and the nozzle outlet. The nozzle valve member is rotatable between a closed position in which the nozzle outlet is blocked and an open position in which the nozzle outlet is open.

Abstract: A valve comprises a valve body that includes an upper valve seat and a bore wall that defines a bore. A seat component is at least partially positioned in the bore and includes a lower valve seat. The seat component is radially out of contact with the bore wall. The upper valve seat and the lower valve seat are concentrically coupled via a valve member which is movable between the upper valve seat and the lower valve seat. The valve finds preferred application as a needle control valve in a fuel injector.

Abstract: An outwardly opening fuel injector comprises a valve needle movable within a bore and engageable with a seating to control the supply of fuel from the bore, the needle being moveable outwardly of the bore to move the needle away from its seating, the needle being biased towards its seating by a spring, the spring engaging a spring abutment arrangement associated with a part of the needle remote from the part thereof engageable with the seating, the spring abutment arrangement further acting to guide movement of the needle.

Abstract: A fuel injector includes a tappet assembly mounted on an injector body. At least one of the tappet assembly and the injector body define a retention opening therethrough. A retention member is positioned in the retention opening and concealed by at least one of the tappet assembly and the injector body. The tappet assembly is moveable with respect to the injector body an unadjustable displacement distance between an advanced position and an extended position. The height of the retention opening is less than the unadjustable displacement distance.

Abstract: The invention relates to a pump nozzle (1) for injecting fuel into an internal combustion engine, especially a single cylinder diesel engine, comprising a piston foot (3), a pump cylinder (8), a pump piston (7), an intermediate disk (16), and an injection nozzle with a pressure spring (14) a pressure spring plate (15) and a nozzle needle (20). The inventive pump nozzle has a reduced construction length by virtue of the pressure spring (14) being offset to the side of the nozzle needle axis.

Abstract: A fuel injector comprises a valve needle slidable within a bore and engageable with a seating to control the supply of fuel to an outlet opening, an end surface of the valve needle being exposed to the fuel pressure within a control chamber defined, in part, by a piston member moveable under the influence of a piezoelectric actuator. The control chamber may be supplied with fuel under pressure, in use, through a restricted flow path. The piston member may have an effective area exposed to the pressure within the control chamber which is greater than that of the needle.

Abstract: A fuel injection valve for internal combustion engines, having a valve member that is displaceable axially outward counter to a restoring force in a bore of a valve body. On an end toward the combustion chamber, the valve member has a closing head. The closing head protrudes from the bore and forms a valve closing member and on a side toward the valve body has a valve sealing face. The valve closing member cooperates with a valve seat face, disposed on a face end toward the combustion chamber of the valve body. The valve closing member at least one injection opening on the closing head. The injection opening originating at a pressure chamber and outlet opening being covered, in the closing position of the valve member, by the valve body and being uncovered upon an outward-oriented opening stroke. A two-stage hydraulic stroke stop, which limits the opening stroke of the valve member and is embodied as a hydraulic damping chamber with a relief line that can be opened.

Abstract: A hydraulically actuated fuel injector includes an injector body that defines a high pressure passage, a low pressure passage, a control passage, a fuel inlet, and a nozzle outlet. The injector body includes upper surface and a lower surface that partially define an armature cavity. The injector body also defines a fluid displacement passage that is separated from the upper surface and the lower surface and extends between the armature cavity and a low pressure area. The fluid displacement passage is positioned and sized such that an amount of oil is always maintained in the armature cavity at least to a level below the fluid displacement passage but above the lower surface. In addition, the fluid displacement passage is sized and positioned to ensure adequate drainage for cold start, yet provide a flow restriction especially at idle conditions to produce sufficient valve damping that a substantial reduction in impact noise occurs.

Abstract: A valve comprises a valve member which is engageable with a first seating to control communication between first and second ports and a second seating to control communication between second and third ports. The second seating is provided upon a separate seating member.

Abstract: A fuel injector nozzle has a housing defining a blind bore with at least one fuel injection spray orifice defined at a bottom portion of a spray tip and a guide passage defined at a top portion of the bore. An injection chamber of the bore is disposed between the orifice and the guide passage. A fuel injection passage intersects the guide passage. A needle check is slidably disposed in the blind bore for movement between a first position and a second position. In the first position, a seat portion of the check is disposed in the bore against the bottom portion of the tip while a guide portion of the check together with the guide passage define a first flow area restricting fluid flow therethrough. In the second position, the seat portion of the check is spaced from the bottom portion of the tip, and the guide portion and guide passage define a second flow area larger than the first flow area and less restrictive of flow therepast.

Abstract: A fuel injector which has check valve that is hydraulically controlled by a control fluid. A volume of fuel is pressurized within a fuel chamber of the injector by an intensifier. The check valve controls the flow of fuel from the fuel chamber through at least one nozzle opening of a valve body. The flow of control fluid is controlled by a control valve which can move between a first position and a second position. When the control valve is at its first position, the control fluid creates an hydraulic force which moves the check valve to a closed position. When the control valve is at its second position, the control fluid moves the check valve to an open position to allow the pressurized fuel to be ejected or sprayed from the nozzle opening(s). The intensifier can also be hydraulically controlled by a control valve.

Abstract: A fuel injector for use in a diesel engine which is equipped with an engine brake governed by a hydraulic circuit includes an injector body with a hollow interior, a plunger located within the injector body, a moveable coupling positioned within the injector body, a nozzle for the dispensing of fuel, and a variable rate return spring which is positioned between the injector body and the moveable coupling. The variable return spring is designed with a variable pitch between adjacent coils such that the pitch between coils near the end(s) of the spring is reduced over that near the center of the spring. The use of the variable rate spring is intended to address the problem of premature fatigue failures caused by the return spring oscillating at or above its natural frequency. The oscillations are induced due to the exhaust valve opening and closing events and are transmitted directly through the engine brake hydraulic circuit to the injectors by way of the injector push tube.

Abstract: An injector of intensified fuel injection type is disclosed in which a resin-made sealing member for sealing a clearance between a concave and a boosting piston fitted in the concave for reciprocating movement is protected from deterioration owing to high-pressure impulses occurring in the hydraulically actuating fluid in pressure chamber or in the fuel in the intensified chamber. The sealing member of resin-made O ring 44 prevents leakage of the hydraulically actuating fluid from the pressure chamber 8 to the spring chamber 30 through the clearance 27 between the enlarged concave and the boosting piston 119. A split metal ring 91 is arranged between the relatively sliding surfaces 49a, 49b of the enlarged concave 26 and the boosting piston 119 at any location between the pressure chamber 8 and the O ring 44.

Abstract: A fuel injector includes an injector body that defines a pressure relief passage with one end opening into a trapped volume, and a fuel pressurization chamber in fluid communication with a nozzle outlet. A needle valve member is positioned in the injector body and moveable between an inject position in which the fuel pressurization chamber is open to the nozzle outlet, and a closed position in which the nozzle outlet is blocked. The needle valve member has a closing hydraulic surface exposed to fluid pressure in the trapped volume. A pressure relief valve is positioned in the pressure relief passage, and has a valve member with an opening surface exposed to fluid pressure in the trapped volume, and a closing surface exposed to fluid pressure in the fuel pressurization chamber.

Abstract: A device and method for dosing fluid has a housing enclosing a lifting element and a primary drive hydraulically operable on the lifting element via a hydraulic chamber. The lifting element is disposed within a borehole with a leakage permitting fit. A fluid chamber in communication with the borehole contains a fluid to be dispensed in a dosed manner by controlled axial movement of the primary drive and lifting element.

Abstract: A hydraulically-actuated fuel injector includes an injector body that defines an actuation fluid inlet that is open to a first actuation fluid cavity, and a second actuation fluid cavity that is connected to the first actuation fluid cavity via a connection passage. The injector body also defines at least one actuation fluid drain. A source of relatively high pressure actuation fluid is connected to the actuation fluid inlet. A relatively low pressure reservoir is connected to the at least one actuation fluid drain. A control valve is attached to the injector body and is moveable between a first position in which the second actuation fluid cavity is open to the first actuation fluid cavity, and a second position in which the second actuation fluid cavity is open to the at least one actuation fluid drain.

Abstract: An electronically controlled device, such as a fuel injector, includes a first solenoid and a second solenoid attached to the injector body. An electrical circuit is attached to the injector body, and includes a positive terminal and a negative terminal connected to the first solenoid and the second solenoid. The electrical circuit permits energization of one of the first solenoid and the second solenoid when electrical current flows in either direction between the first terminal and the second terminal. However, the electrical circuit permits energization of the other of the first solenoid and the second solenoid only when current flows in a single direction between the first terminal and the second terminal.

Abstract: Existing poppet valves have a tendency to rebound or bounce during operation. This rebound or bounce adversely affects engine governability, high pressure injector fuel flow, noise and idle stability. The present invention reduces or nearly eliminates poppet valve (52) rebound or bounce. The apparatus (161) for compensating for the rebound of bounce overcomes the problem of variable injection. For example, as the poppet valve (52) rebounds the weight (174) strikes the bottom or contacting surface (168) preventing the poppet valve (52) from moving toward the first position (156). Thus, the variation in the injection of fuel is prevented or eliminated. Additionally, with the variation in the injection of fuel eliminated, the adverse affects of the bounce or rebound enables better engine governability, high pressure injector fuel flow and idle stability with reduced noise.

Abstract: A servo-controlled fuel injector is provided which includes a leakage limiting valve device for limiting the quantity of high pressure fuel available for leakage into the combustion chamber in the event the closed nozzle valve element fails to sealingly engage its seat between injection events. The servo-controlled fuel injector includes a control volume positioned adjacent an outer end of the nozzle valve element, a control volume charge circuit for supplying fuel to the control volume, a drain circuit for draining fuel from the control volume to a low pressure drain and an injection control valve positioned along the drain circuit for controlling the flow through the drain circuit so as to cause reciprocal movement of the nozzle valve element. The leakage limiting valve is integrated into the fuel injector body and positioned along a fuel transfer passage to block the flow of high pressure fuel to a nozzle cavity between injection events.

Abstract: A fuel injection valve for internal combustion engines, having a valve member that emerges outward from the valve body. At least two rows of injection ports one above the other are provided on the valve member, in the outward-oriented opening stroke of the valve member the injection parts are uncovered in secession. A two-stage hydraulic stroke stop, which limits the opening stroke travel of the valve member is embodied as a hydraulic damping chamber with openable relief. This relief is effected via at least two polished sections on the valve member which are openable in succession during the opening stroke motion of the valve member. At least one of the polished sections is connected to a low-pressure chamber, via a relief conduit containing a valve.

Abstract: An electrically controlled hydraulic actuated fuel injector wherein the amount of return fuel flow is substantially reduced without adversely affecting injection valve operation. An improved control valve armature valve disk of faster acting construction is also included. In one embodiment, dual pressurizing passages of differing diameters provide lower total fuel flow to a control chamber than the outflow through a depressurizing passage controlled by a control valve. Upon full opening of the injection valve, all return fuel flow is supplied to the control chamber through the smaller pressurizing passage, thereby reducing the requirement for pressure fuel flow. Upon closing of the control valve, cutting off discharge through the depressurizing passage, both of the dual pressurizing passages help fill the control chamber to quickly close the injection valve.

Abstract: A fuel injector includes an injector body that defines a low pressure space, a trapped volume and a fuel pressurization chamber in fluid communication with a nozzle outlet. A needle valve member is positioned in the injector body and moveable between an inject position in which the fuel pressurization chamber is open to the nozzle outlet, and a closed position in which the nozzle outlet is blocked to the fuel pressurization chamber. The needle valve member includes a lifting hydraulic surface exposed to fluid pressure in the fuel pressurization chamber, and a closing hydraulic surface exposed to fluid pressure in the trapped volume. At least one of the needle valve member and the injector body define a pressure release passage extending between the trapped volume and the low pressure space. A pressure regulating valve is positioned in the pressure release passage, and has a regulating valve member that is moveable to an open position when fluid pressure in the trapped volume is above pop-off pressure.

Abstract: A control valve assembly for use in a pump or injector of fuel injection systems is provided. A pump or injector body has a pumping chamber, and a valve chamber. The valve chamber defines a valve seat and has an axial guiding portion. A plunger is disposed in the pumping chamber. A valve body disposed in the valve chamber controls fuel. The valve body has a valve stem defining a seating surface. The valve body further has a valve guide in sliding engagement with the valve chamber guiding portion. The valve body is axially movable with respect to the valve chamber over a stroke range. The valve guide has an outer engagement surface that slidingly engages the valve chamber guiding portion with a clearance fit of at least about 5 micrometers in one embodiment. In another embodiment, the axial length of the engagement surface is at most about 7 millimeters. The reduced axial length and/or the clearance fit improve initial sealing performance and sealing performance over the life cycle of the product.

Abstract: An intensified fuel injector which has at least one lateral or side drain passage. The fuel injector may include a valve body which has longitudinal axis. The valve body may have a fuel chamber that is hydraulically coupled to a fuel supply port and at least one nozzle opening. An intensifier moves within the fuel chamber. The intensifier is hydraulically coupled to an intensifier chamber and also connected to a biasing spring. The spring is located within a spring chamber that is hydraulically coupled to the drain passage. The drain passage may extend through the valve body in a direction that is substantially perpendicular to the longitudinal axis of the body. The orientation and position drain passage minimizes the diameter or cross-sectional area of the fuel injector by eliminating a longitudinal passage typically found in fuel injectors of the prior art.

Abstract: A piezoelectric injector for fuel-injection systems of internal combustion engines has a piezoactuator guided with spring pretensioning in a valve housing. The actuator presses a sealing piece onto its valve seat through an actuating part, with the actuating part consisting of a pressure pin passing through the piezoactuator and having a head part resting on piezoactuator. The pressure pin and piezoactuator are of the same length and are made of the same ceramic material, in operation the sealing piece is lifted off its valve seat by piezoactuator which is expanded when in the charged state.