Abstract: A rapid-response solenoid-operated fuel injector for diesel engines is provided which includes a solenoid-operated valve member and a needle valve. The solenoid-operated valve member selectively establishes fluid communication between a fuel inlet and a fuel outlet. The needle valve is moved to selectively open and close a spray hole through which the fuel is sprayed. The solenoid-operated valve member is exposed at its head to the fuel pressure within a pressure control chamber supplied from the fuel inlet and has formed therein a pressure balancing chamber communicating with the pressure control chamber through a first orifice. The pressure of fuel within the pressure balancing chamber acting on the solenoid-operated valve member to block the fluid communication between the fuel inlet and outlet is balanced with the pressure of fuel within the pressure control chamber acting on the solenoid-operated valve member to establish the fluid communication between the fuel inlet and outlet.

Abstract: A hybrid hydraulic electronic unit injector (HEUI) assembly, having some characteristics of an accumulator-type assembly and some characteristics of a non-accumulator type assembly, is produced by designing the volume (V.sub.ACC) of the passageway downstream of an existing blowback prevention check valve of the assembly to be between 1.0 and 10.0 times the maximum quantity Q.sub.MAX of fuel injected during an injection event. The resulting hybrid assembly 1) exhibits a rising injection rate during at least the initial stages of the injection event and therefore exhibits benefits generally associated with non-accumulator type HEUI assemblies, and 2) exhibits a falling rate injection during at least the final stages of the injection event and therefore exhibits benefits generally associated with accumulator-type HEUI assemblies. The percentage of the injection event taking place under a falling rate increases generally proportionally with the ratio V.sub.ACC /Q.sub.MAX.

Abstract: A servo valve for an injection nozzle includes a housing having a valve chamber, a high-pressure opening, a connecting opening and a return opening. The valve chamber movably accommodates a valve member which can be displaced by actuating means to bear selectively against a first seat and a second seat. The valve member, when bearing against the first seat, closes the return opening and connects the high-pressure opening to the connecting opening. When bearing against the second seat it closes the high-pressure opening and connects the connecting opening to the return opening. The connecting opening is connected to a working chamber of the injection nozzle whose nozzle is closed when the working chamber is subjected to high pressure and opens upon a drop in pressure in the working chamber. The actuating means includes a component which varies in length when electrically actuated and which is connected to the valve member through the return opening by way of an actuating member.

Abstract: An electrohydraulically actuatable injection valve includes a control piston which divides an annular conduit from a control chamber disposed between the control piston and an actuator rod. A spring is disposed between the control piston and the actuator rod. The annular conduit also communicates through a control valve with a drain. If the control valve is closed with the injection valve open, the control piston opens a communication between the annular conduit and the control chamber, so that a nozzle needle is pressed onto an associated valve seat and abruptly stops the injection.

Abstract: A fuel system is disclosed which comprises a fuel pump, a spill valve and an injector provided in a single unit. The injector includes a valve member biased towards a seating by a coiled compression spring. The spring is engaged between a spring abutment of the valve member and a piston. The piston is arranged such that the face thereof facing away from the spring has fuel applied thereto when the spill valve is opened in order to assist movement of the valve member into engagement with the seating.

Abstract: An improved electronically-controlled heavy fuel oil (HFO) injection system comprises a pumping chamber for pressurizing fuel and a direct-operated check for controlling fuel injection. A control fluid different from the fuel is used to operate regulating apparatus for controlling the fuel injection pressure and fuel injection timing. The regulating apparatus isolate the HFO from sensitive mechanisms by appropriate exposure of the control fluid to flush intruding HFO from those mechanisms. Pressurization of fuel begins before the start of fuel injection. Fuel injection is initiated by exposing one end of the check to low pressure control fluid while the other end is exposed to high pressure fuel. Fuel injection is terminated by exposing the one end to high pressure control fluid to hydraulically balance the check and allow a biasing device to close the check.

Abstract: A hydraulically actuated fuel injector includes an injector body having a needle control chamber, a nozzle chamber, and a nozzle outlet that opens to the nozzle chamber. Fuel within the injector is hydraulically pressurized during each injection cycle. A needle valve is positioned to reciprocate in the nozzle chamber between an open position in which the nozzle outlet is open and a closed position in which the nozzle outlet is closed. The needle valve includes a closing hydraulic surface exposed to pressure in the needle control chamber. A needle control valve is mounted within the injector body and is moveable between an off position in which the needle control chamber is opened to a source of high pressure fluid and an on position in which the needle control chamber is opened to a low pressure passage.

Abstract: A fuel injection valve (1; 2) for the intermittent injection of fuel into the combustion chamber of an internal combustion engine is equipped with a hydraulic control device (15; 100). The opening or closing of a control bore (61; 109) is brought about by means of an electrically controlled solenoid valve (5; 6; 7), with the result that a control pressure in a control chamber (60; 114) is influenced, thus causing the opening or closing of injection ports into the combustion chamber via a control piston (30; 110) and an injection-valve member (24). The injection event is controlled additionally by controlling the movement of a solenoid-valve pilot-valve stem (70; 125) assigned to the control bore (61; 109). Means, by which the opening movement of the injection valve member (24) takes place in two successive phases, are provided.

Abstract: Fuel delivery to an engine from a cyclically pressurizable, electronically controlled accumulator-type fuel injector is controlled by "wasting" at least a portion of the pressurization stroke of the engine's high pressure pump so that a designated portion of the pressurization stroke of the pump does not result in accumulator cavity pressurization. Metering is effected simply by extending the period that the system's existing solenoid vent valve is open into a portion of the succeeding pressurization stroke of the pump so that a portion of the pumped fuel flows directly to vent. Additional electrical load on the engine can be minimized by using a latching type solenoid valve as the vent valve. The metering scheme 1) is more precise than metering schemes heretofore available for injectors of the disclosed type, 2) does not adversely effect injection timing or other injection parameters, 3) and requires no additional hardware.

Abstract: An improved hydraulically-actuated fluid injector system comprises a hydraulically-actuated fuel pressurization member, a fluid storage chamber, and a direct-operated check. Pressurization of fluid in the storage chamber begins before the start of fluid injection. Fluid injection begins by hydraulically unbalancing the check. Fluid injection ends by hydraulically balancing the check to allow a biasing device to close the check. Preferably, actuating fluid that is spilled from the fuel pressurization member (to end fuel injection) is communicated to a hydraulic motor which drives a source of pressurized hydraulically-actuating fluid.The present invention provides improved control of several fluid injection parameters, including higher peak fluid injection capability and less fluid injection pressure drop at the end of injection, resulting in improved engine performance and lower emissions, noise, and wear.

Abstract: A fuel injection device includes an injection hole for injecting fuel therethrough, a needle movable between a first position to open the injection hole and a second position to close the injection hole, and a back-pressure chamber. The fuel injection device further includes a two-way solenoid valve for opening and closing a flow passage between the back-pressure chamber and a drain side so as to change a pressure in the back-pressure chamber. The needle is movable between the first and second positions depending on the pressure in the back-pressure chamber. A first flow restrictor and a second flow restrictor are provided in a flow passage, which introduces high-pressure fuel into the back-pressure chamber, so as to restrict a flow of the high-pressure fuel passing therethrough. The first and second flow restrictors may be arranged in series to each other.

Abstract: A hydraulically actuated fuel injector includes an injector body having at least one actuation fluid inlet, a needle control chamber, a nozzle chamber, and a nozzle outlet that opens to the nozzle chamber. A hydraulic means within the injector pressurizes fuel in the nozzle chamber. The hydraulic means includes an actuation fluid control valve having a first solenoid and is moveable between an open position in which the actuation fluid inlet is open and a closed position in which the actuation fluid inlet is closed. A needle valve member is positioned to reciprocate in the nozzle chamber between an open position in which the nozzle outlet is open and a closed position in which the nozzle outlet is closed. A needle valve member includes a closing hydraulic surface exposed to pressure in the needle control chamber.

Abstract: A unit injector mounted to a cylinder head in a diesel engine includes a pump section and a nozzle section which are eccentrically connected to each other through a connecting portion. An axis of the nozzle section is disposed in alignment with an axis of a cylinder, and an axis is of the nozzle section disposed on the opposite side of a pair of intake valves from the axis of the nozzle section. A rocker arm for transmitting the rotation of an exhaust cam shaft to the pump section is pivotally carried at its intermediate portion on a rocker shaft supported above the nozzle section. Thus, it is possible to provide a reduction in size of the cylinder head, while maintaining the spray of a fuel into a cylinder uniform, by an improved layout of the unit injector in the cylinder head.

Abstract: In a fuel injection nozzle for an internal combustion engine with a fuel injection opening including a nozzle opening control needle with a body portion with discharge openings whose size depends on the axial displacement of the nozzle opening control needle and with means for limiting the axial displacement of the nozzle opening control needle, a hollow nozzle needle is disposed around the stem of the nozzle opening control needle and forms at its end a fuel control valve seat for controlling fuel flow to the fuel injection opening and a control space is provided at the end of the hollow nozzle needle opposite its valve seat which is in communication with a pressurized fuel supply for holding the hollow nozzle needle in a seated position but from which the pressure can be released to permit lifting of the hollow nozzle needle by pressurized fuel supplied to the seating area end of the hollow nozzle needle whereupon the pressurized fuel released through the fuel control valve displaces the nozzle opening cont

Abstract: In a fuel injection system for an internal-combustion engine which includes a dual-fluid nozzle which is supplied with fuel by a high-pressure pump and with water by a feed pump providing a substantially lower pressure than the high-pressure pump and which has disposed in a nozzle body a nozzle needle which is spring biased into a closing position where one end of the needle is seated on a valve seat, a fuel supply passage extends to an annular space around the valve needle and a branch passage leads to a control chamber formed at the other end of the valve needle and includes a solenoid valve for controlling the application of pressurized fluid to, and the release thereof from, the other end of the nozzle needle, an additional fluid line extends from the feed pump to the annular space and includes a check valve for permitting flow of additional fluid only toward the annular space and a pressure relief line in communication with the fuel supply passage via a control valve, and a control device is provided for

Abstract: An accumulator fuel injection apparatus in which a nozzle element is divided into a first nozzle having one end side of said nozzle element and a second nozzle having the other end side of the nozzle element. The accumulator fuel injection apparatus comprises a stopper for setting a maximum movement position of the first nozzle toward the second nozzle, a second pressure control chamber communicating with a first pressure control chamber and forming a predetermined space or interval through which the first nozzle and the second nozzle are spaced away from each other under a condition that the first nozzle is arranged at the maximum movement position, and delay apparatus for delaying reduction of pressure within the first pressure control chamber due to the fact that fluid flows into a low-pressure chamber from the first pressure control chamber upon communication of the first pressure control chamber and the low-pressure chamber with each other.

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: A fuel injection device for internal combustion engines having a high pressure fuel pump driven by the engine. The pump supplies high pressure fuel to a pressure storage chamber, which chamber, for its part, communicates with injection valves that protrude into the combustion chamber of the engine to be supplied. To achieve precise control of the injection times and injection quantities, the injection valve is directly triggered by a magnet valve, to which end the valve needle of the injection valve is embodied as the valve member of the magnet valve. In order to be able to precisely control very small injection quantities and times (for example pre-injection), the adjusting forces of the valve needle are minimized, to which end the valve needle is pressure balanced in every operating state of the injection valve by directing the high fuel pressure after the start of the valve needle opening stroke also onto the face end of the valve needle remote from the valve needle seat.

Abstract: A fuel injection system for internal combustion engines, having a high-pressure fuel pump and a feed line that feeds fuel from a low-pressure chamber into a pressure-regulatable high-pressure collection chamber. The high pressure collection chamber, which communicates with individual injection units via high-pressure lines. These injection units, which correspond in number to the injection locations in the combustion chamber of the engine to be supplied, are each composed of one injection valve and one three-way valve that controls the injection.

Abstract: In a two-way utility internal combustion engine, method and apparatus employing an accumulator-type fuel injector having an accumulator cavity and a control cavity both of which are pressurized with fuel to about the same pressure, fuel pressure in the accumulator cavity applying upward force on the needle, and fuel pressure in the control cavity applying opposing downward force on the needle. The accumulator and control cavities are pressurized by means of a reciprocating plunger pump wherein the plunger is driven by cam lobe means on the crankshaft, and injection is initiated by venting fuel from said control cavity through a two-way solenoid valve. Injection mass is varied by variation of the ignition timing relative to pump plunger top dead center. Engine power output is varied between full power and idle by skip-firing, which is caused by noninjection of fuel in the engine cylinder during one or more engine crankshaft cycles during a series of a predetermined number of crankshaft cycles.

Abstract: The invention relates to a fuel injection system for internal combustion engines, having a high-pressure feed pump that pumps fuel from a supply tank into a high-pressure common rail that communicates with the various injection valves via high-pressure lines. To increase the injection pressure to up to 2000 bar, the injection valves have a booster piston, which is guided axially on the valve member of the injection valve and with one end face defines an injection pressure chamber that communicates with the injection ports, and with its other end face defines a work chamber that can be made to communicate with the common rail.

Abstract: The valve comprises a shutter for the drain conduit of the control chamber f the injector; and an electromagnet having a fixed core with a seat for a coil which is energized to operate the armature controlling the shutter. The core presents two coaxial annular pole pieces, the outer one of which is shorter than the inner one and fitted with a ring of magnetic material partially closing the seat and enabling a substantial reduction in the diameter of the armature. The smaller diameter of the armature enables it to be fitted to the body of the injector by means of a larger-diameter threaded ring nut. The armature, together with a return spring, is fitted to a plate having a sleeve for guiding the stem; and the assembly is then fitted to the body independently of the electromagnet by screwing the ring nut inside a seat in the body.

Abstract: The body of a control valve is housed inside the hollow body of an injector y means of a fluidtight connection comprising a pair of precision ground mating surfaces, and a sealing ring compressed between a further two surfaces of the bodies adjacent to the aforementioned pair of surfaces. The ring may be made of rubber, may be fitted between two cylindrical surfaces, and is also pressed by the fuel on to a shoulder of the valve body. Alternatively, the ring may consist of a soft iron washer pressed axially between a flange on the valve body and a surface of the hollow body.

Abstract: The control valve of an injector comprises a plunger and a valve body having an axial control chamber connected to a drain conduit via a hole. The hole terminates at a flat surface of the valve body, which surface is perpendicular to the operating direction of the actuator of the plunger. The plunger consists of a pad element having a flat face engaging the surface of the valve body, while the opposite face may be flat or spherical, and is engaged by a complementary surface on the end of the actuator.

Abstract: A series of method and apparatus advances in the accumulator-type fuel injector art, applicable to both intensified and unintensified accumulator injectors, which cooperate to provide major improvements in internal combustion engine fuel economy, reduction of noise, and reduction of undesirable exhaust emissions, including smoke, oxides of nitrogen and hydrocarbons. According to the invention, injector needle closure speed is increased for sharper fuel cutoff and better atomization proximate closure, and needle closure bounce is minimized to minimize fuel dribble proximate closure by reducing both mass and length of the needle, which can be accomplished by a longitudinally divided needle. Hydraulic damping also damps and cushions both needle closing and needle opening.

Abstract: A control valve for an injector comprising a valve body having of a control chamber connected to a drain conduit via a hole terminating at a flat surface of the valve body. The plunger of the valve consists of a plate housed in a seat, the bottom wall of which arrests the travel of the plate after a travel "b". This is controlled by the armature of an electromagnet, which armature presents a rod arrested directly by an adjustable stop after traveling a distance "a" greater than travel "b". The opening and closing time of the valve is therefore unaffected by wear on the stop of the armature. The rod of the armature is in one piece with a stem activating the plate, and with a threaded portion screwed to the armature.

Abstract: The subject of the invention is an improvement in the pilot valve which is adapted to control the passage of fuel through a discharge aperture which communicates with a control chamber with which the device is provided; fuel is supplied under pressure into this control chamber and is discharged through the first mentioned discharge aperture to control the opening of a shutter needle with which the device is provided for the purpose of injecting a suitable quantity of fuel through at least one injection orifice. According to this improvement the armature of the pilot valve substantially comprises a rod which traverses an axial hole in the core of an electromagnet. The first end of the rod is fixed to the armature. A stop member, the position of which is adjustable with respect to the body of the device, is adapted to constitute an abutment for the second end of the rod. A ball is interposed between this second end and the stop member.

Abstract: An accumulator type fuel injector system including an arrangement for insuring that the injector will provide a relatively constant rate of fuel discharge under low speed low load conditions and a rate of discharge under high speed high load conditions that reaches its peak at the latter portion of the injection valve opening cycle. This is done by changing the effective areas of the various components of the valve, the preload of the biasing spring and the rate of the biasing spring.

Abstract: An accumulator type fuel injector system including an arrangement for changing the bias on the injector valve as the pressure of the fuel increases so as to reduce the sensitivity of the device to pressure variations as may occur under low speed operation. In the embodiments, the arrangement for changing the bias comprises either an elastomeric or a coil spring that acts against the main biasing spring of the injector valve and which are responsive to pressure in the accumulator chamber. In addition, a tapered discharge port arrangement is incorporated for the injector nozzle so that proportionately greater amounts of fuel will be discharged as the lift of the injection valve increases.

Abstract: A valve having a first valve body including a first contacting surface, a pressurized fluid supply path opening to the first contacting surface and a pressure-controlled chamber opening to the first contacting surface. A second valve body includes a second contacting surface contacting with the first contacting surface and a valve path whose ends open to the second contact surface, and which connects fluidly the pressurized fluid supply path to the pressure-controlled chamber. A valve is arranged in the second valve body and moved to a closed or open position at which the valve means does or does not cut off the fluidal connection between the pressurized fluid supply path and the pressure-controlled chamber. An actuator arranged on the second valve body moves the valve to the closed or opened position. A first drawing means presses the first contacting surface and the second contacting surface against each other. A second drawing means sets the actuator on the second valve body.

Abstract: A unit fuel injector adapted to receive fuel from a fuel supply at relatively low pressure and adapted to inject fuel at relatively high pressure into the combustion chamber of an internal combustion engine is provided, comprising an injector body having a first internal bore and an injector orifice and a plunger mounted for reciprocating movement within the first internal bore to define a variable volume fuel pressurization chamber including a cam actuated upper plunger portion and a lower plunger portion mounted in the first internal bore between the variable volume fuel pressurization chamber and the upper plunger portion. While the upper plunger portion is in its retracted position, low pressure fuel from the fuel supply is supplied to the variable volume fuel pressurization chamber.

Abstract: An accumulator type of fuel injection nozzle having an injection valve, a first electromagnet for initiating fuel injection, and a second electromagnet for controlling the lift amount of the injection valve is provided with an energizing arrangement which enables effective fuel injection control but which greatly reduces the risk of burning damage to the electromagnets. The amp-turn characteristics of the first electromagnet coil provide for a rapid start-up time wherein the peak magnetic flux is reached relatively quickly. In contrast, the amp-turn characteristics of the second electromagnet coil provide for a more gradual start-up time so that peak magnetic flux is reached more gradually. The second electromagnet coil is also adapted to achieve a relatively large magnetic flux without the need for large current supply. In operation, when the second electromagnet is energized, such energization is started before energization of the first electromagnet for a particular fuel injection cycle.

Abstract: An accumulator type of fuel injection nozzle having an injection valve that is controlled by an electromagnet within the accumulator chamber includes a feeder wire structure formed axially in the outer housing assembly of the injection nozzle for energizing the electromagnet. This feeder wire structure includes one or more axially extending wire passages formed in the outer housing assembly, preferably in a structure through which is formed a fuel inlet conduit, constructed so as to withstand the high pressure within the accumulator chamber, to provide a sufficient seal without increasing the outer diameter of the injection nozzle, and to provide easy installation of the injection nozzle without interference from the engine. One or more feeder wires are contained within the wire passages for energizing the electromagnet.

Abstract: In a device for controlling the lift of a hydraulically operated valve comprising an actuating element which is pressure-loaded or spring-loaded in closing direction and which acts as the boundary of an actuating chamber in the valve cage, and further comprising a pressure-generating unit, the valve lift is made continuously adjustable, independent of the control times of the valve, by providing that a flying setting plunger be used, which is guided in a cylinder, and which bounds a pressure from the actuating chamber in the valve cage, and by further providing that the pressure-generating unit have a high pressure line controlled by a valve and leading into the pressure chamber, as well as a low pressure line controlled by another valve and leading into the actuating chamber, the setting plunger being pressed against a stop in the cylinder during maximum valve lift.

Abstract: A perfected fuel injector comprising a plunger for controlling fuel passage between an injection chamber and at least an injection orifice formed in an injection nozzel; and an electromagnetic fuel metering valve for controlling fuel passage through a drain orifice between a control chamber, supplied with fuel under pressure, and a low-pressure chamber, so as to reduce to a given value the pressure of the fuel inside the control chamber and so displace the plunger. Pressurized fuel is supplied to the injection chamber and control chamber by means of a single fitting connected to a supply pipe and coming out inside a supply orifice formed in the injector body and communicating with the control chamber and with a duct supplying fuel to the injection chamber and comprising an annular chamber and a radial hole formed in a sleeve housed in a hole on the body.

Abstract: An accumulator type injection nozzle wherein a variable stop that is electrically actuated is provided for controlling the maximum degree of opening of the injection valve for controlling the amount of fuel discharged.

Abstract: An electromagnetically-controlled fuel injection valve for diesel engines includes an electromagnetic metering valve which controls communication between a control chamber supplied with fuel under pressure through an inlet hole, and a discharge hole. The solenoid metering valve includes a ball obturator movable in a cavity of the body defined by two annular valve seats of which the first defines the discharge hole and the second communicates with the inlet hole. The cavity is in communication with the control chamber through lateral passages. The ball obturator is kept in a closed position against the second seat by means of an electromagnetically-operated axial push rod.

Abstract: A fuel injector includes a needle valve body which is disposed in a sliding bore provided in a valve lower part and in which a needle valve portion abuts against a valve seat in the vicinity of an injection port, an upper portion of the needle valve body being pressed downwardly by a spring; an accululator formed above the needle valve body; a fuel passage communicating with the valve seat; a communicating passage bifurcating from the fuel passage and communicating with the accumulator; and an electromagnetic regulator valve which is disposed in the communicating passage and whose opening and closing timing can be adjusted.

Abstract: The invention provides means for controlling the rate of fuel injection of an accumulator injector of the type employing a pressure amplifying piston assembly. In one form of the invention, the injection rate is controlled by restricting the pressure decay in the amplifier chamber. In another form of the invention, means are provided for delaying the full opening of the injector valve needle after an initial valve opening.

Abstract: An electromagnetically-controlled fuel injection valve for diesel engines includes a body having an upper electromagnetic metering valve which controls communication between a control chamber supplied with the pressurized fuel and a discharge port. The metering solenoid valve, which itself constitutes a unit independent of the rest of the injection valve, is supported by a head element connected to the body of the injection valve by axial clamping means and has an appendage which carries the control chamber and the discharge port and is inserted in an axial seat in the body with the interposition of double sealing means.

Abstract: A fuel injector comprising a piston actuated by a piezoelectric element. A pressure control chamber is formed between the piston and the top face of the needle and connected to a high pressure fuel source via a fuel passage having a restricted flow area. The pressure control chamber is filled with fuel under pressure. The rear face of the piston, which is positioned opposite to the pressure control chamber, is exposed to a high pressure fuel chamber filled with fuel under pressure. The driving force acting on the piston due to the pressure of fuel in the pressure control chamber is cancelled by the driving force acting on the piston due to the pressure of fuel in the high pressure fuel chamber.

Abstract: A gasoline unit injector comprising an outer, electrically conductive bellows, defining a variable volume fluid chamber, for reciprocating a piston within a pressure chamber to increase the fuel pressure in various downstream cavities. Various bellows are disposed within such chambers and are deformable in response to the increased pressure, the bellows are operative to control the rate at which fuel flows out from a metering orifice upon activation of a coil assembly.

Abstract: In a pressure accumulation type of fuel injection device for an internal combustion engine, including a fuel injector which is adapted to temporarily store each incoming charge of highly pressurized fuel and inject the fuel under high pressure, a nozzle valve is provided within the pressure accumulation chamber defined in the fuel injector body. The upper end portion of the nozzle valve stem extends hermetically and slidably through a bore formed in the fuel injector body. Furthermore, a cylindrical check valve is provided so as to encircle the valve stem and is adapted to be biased towards an underside of an annular projection formed on the valve stem by a check valve spring mounted on the valve stem to close the check valve. The spring force for closing the check valve which controls the opening and the closing of the inlet portion of the pressure accumulation chamber is reduced and the pressure of the fuel stored in the pressure accumulation chamber can be increased greatly.

Abstract: In an apparatus for generating pre-injection quantities in unit fuel injectors for Diesel engines, including a pre-injection slide that generates a pronounced pressure intensification for a pre-injection in a pressure chamber closed off with respect to the high-pressure side and opens towards the injection line is slidably supported in a guide bore. The pre-injection slide is exposed to the injection pressure of an element chamber in such a way that after the execution of a partial stroke, which is responsible for the pre-injection quantity, upon further movement the pre-injection pressure chamber is opened toward the element chamber and thereby relieved, and by the ensuing movement of the pre-injection slide until the end of the stroke, a pre-determinable capacity that enables an injection pause is formed.

Abstract: The present invention relates to an accumulator fuel injector for a diesel engine, the device including first and second accumulators which are connected through a check valve and a relief valve. Fuel pressurized and delivered by a fuel injection pump is charged into the first accumulator so as to increase its pressure abruptly. When the fuel pressure in the first accumulator reaches a selected relief pressure, the fuel is charged into the second accumulator through the check valve and is accumulated therein. When fuel injection is started by opening of an injection valve, the fuel accumulated in the first accumulator is injected through the injection valve and at the same time the fuel accumulated in the second accumulator flows out to the first accumulator through the relief valve so as to also be injected through the injection valve.

Abstract: A gasoline unit injector comprising an outer, electrically conductive bellows, defining a variable volume fluid chamber, for reciprocating a piston within a pressure chamber to increase the fuel pressure in various downstream cavities. Various bellows are disposed within such chambers and are deformable in response to the increased pressure, the bellows are operative to control the rate at which fuel flows out from a metering orifice upon activation of a coil assembly.

Abstract: An air-assist fuel injection nozzle has an externally actuated plunger journaled for axial movement in the cylinder provided in a nozzle body. The plunger tip contains a central stepped bore which slidably supports a spring bias injection needle valve therein. The plunger, when it is in a raised position, allows a valve controlled supply passage to deliver a metered quantity of liquid fuel into a chamber defined by the cylinder and the valve and of the plunger. The cylinder at the chamber end is closeable by a gas valve disk which in turn has a central aperture defining a discharge passage flow through which is controlled by the inward opening injection needle valve.

Abstract: An electronically controlled fuel supply system for an internal combustion engine. The timing of the commencement of fuel injection into each combustion chamber is not fixed relative to the rotational position of the camshaft or other engine components. A unit injector assembly associated with each combustion chamber includes a control module and an accumulator type injector module. The control module contains a solenoid valve and, in some embodiments, a hydraulic pressure intensifier. The accumulator type injector module contains an injector nozzle, a hydraulic accumulator, and a non-return valve for admitting liquid fuel under pressure into the accumulator. In operation, an electrical control system supplies an electrical signal to the control module an appreciable portion of the engine cycle in advance of the time when fuel injection is to be initiated in the particular combustion chamber.

Abstract: An accumulator type of fuel injection nozzle having an injection valve that is controlled by an electromagnet within the accumulator chamber includes a feeder wire structure formed axially in the outer housing assembly of the injection nozzle for energizing the electromagnet. This feeder wire structure includes one or more axially extending wire passages formed in the outer housing assembly, preferably in a structure through which is formed a fuel inlet conduit, constructed so as to withstand the high pressure within the accumulator chamber, to provide a sufficient seal without increasing the outer diameter of the injection nozzle, and to provide easy installation of the injection nozzle without interference from the engine. One or more feeder wires are contained within the wire passages for energizing the electromagnet.

Abstract: An accumulator type of fuel injection nozzle having an injection valve, a first electromagnet for initiating fuel injection, and a second electromagnet for controlling the lift amount of the injection valve is provided with an energizing arrangement which enables effective fuel injection control but which greatly reduces the risk of burning damage to the electromagnets. The amp-turn characteristics of the first electromagnet coil provide for a rapid start-up time wherein the peak magnetic flux is reached relatively quickly. In contrast, the amp-turn characteristics of the second electromagnet coil provide for a more gradual start-up time so that peak magnetic flux is reached more gradually. The second electromagnet coil is also adapted to achieve a relatively large magnetic flux without the need for large current supply. In operation, when the second electromagnet is energized, such energization is started before energization of the first electromagnet for a particular fuel injection cycle.