Abstract: Disclosed herein is a two-stage fuel injection valve for a diesel engine. The valve includes a fuel valve block (110) having therein a passage (1701) into which fuel is supplied; a nozzle (140) having a low pressure nozzle hole (160) and a high pressure nozzle hole (161); a needle valve (130) differentially opening the low pressure nozzle hole and the high pressure nozzle; pressure booster spindles (141), (142) and (143) pressurizing the needle valve to boost pressure of low-load fuel; a shuttle valve (150) configured to supply a gauge pressure to the pressure booster spindles, thus raising the pressure of the fuel; a lifting bush valve (180) discharging fuel to a fuel discharge hole through a gap between the fuel discharge hole and a nozzle holder when a solenoid valve (201) is moved upwards; and the solenoid valve (201) controlling pressure applied to the lifting bush valve.

Abstract: A fuel injector for an engine is disclosed. The fuel injector may have a fuel nozzle with at least one injection orifice, and a needle element movable within the fuel nozzle between a first position at which the needle element inhibits fuel flow and a second position at which fuel flow is substantially uninhibited. The fuel injector may also have a control chamber located at a base end of the needle element, a body, and a control valve disposed within the body and movable to selectively drain the control chamber, thereby causing the needle element to move between the first and second positions. The fuel injector may further have an armature disposed within an armature cavity of the body and selectively energized to move the control valve, and a pressure reducer disposed within the body and configured to reduce a pressure of the armature cavity.

Abstract: A fuel injection device includes a nozzle needle, an actuator for actuating the nozzle needle, a force sensor for detecting a force applied by the actuator, and a control unit which is connected to the force sensor. The force sensor supplies signals to the control unit and the control unit is designed for determining a position of the nozzle needle and for precisely determining an injected fuel quantity, based on the supplied signal.

Abstract: The invention relates to a control chamber (7), the pressure of which determines the strokes or positions of a nozzle needle (6), and which is assigned to a force or pressure sensor (20) in order to detect the progression of the control chamber pressure. Because the control chamber pressure significantly changes during the closing of the nozzle needle (6), the operating phases of the injector can be exactly determined from the sensor data and supplied to an engine controller.

Abstract: A fuel injector for fuel ignition systems of internal combustion engines includes a magnetic circuit having a core, a magnetic coil and an armature, and a movable valve needle, which has a valve-closure member that cooperates with a fixed valve seat, the valve seat being shaped on a valve-seat member and being provided with a valve-seat support in which the valve-seat member is inserted. At least one metallic component of the fuel injector, in this context, has a serrated structure on its outer circumference for producing a solid connection to a corresponding component made of plastic. The plastic components may be the connection piece, the valve-seat support, the coil shell and the connecting pipe of the valve needle. The fuel injector is particularly suitable for use in fuel-injection systems of mixture-compressing internal combustion engines having externally supplied ignition.

Abstract: A method of controlling a fuel injection device that can control a small amount of injection is provided. A fuel injection device for use in an internal combustion engine, includes: a valve body that can open and close a fuel passage, a needle that transfers a force with the valve body, and executes valve opening/closing operation, and an electromagnet that includes a coil and a magnetic core provided as a driver for driving the needle, and a cylindrical nozzle holder disposed on an outer periphery of the magnetic core and the needle, in which a current is supplied to the coil to exert a magnetic attractive force between the magnetic core and the needle to open the valve body.

Abstract: An injection hole inlet is disposed at the upstream side face of the injection hole plate in such a way that, assuming that ? denotes the angle between respective lines obtained by vertically projecting a straight line that passes through the center of the injection hole inlet and the center of the valve seat and the major axis of the injection hole inlet onto a perpendicular plane that passes through the center of the injection hole inlet and is perpendicular to the center axis of the valve seat and assuming that ? denotes the angle between respective lines obtained by vertically projecting the straight line that passes through the center of the injection hole inlet and the center of the valve seat and the minor axis of the injection hole inlet onto the perpendicular plane, ?<? is satisfied.

Abstract: A main swirler of a triple annular configuration that is partitioned by a pre-filmer and a separator is installed in an inlet port of a main air flow channel. The vicinity of the inner wall of the main air flow channel provided with a main fuel injection port is bulged radially outward from the innermost surface (innermost surface of a small swirler) of a main swirler. Further, a distance from the main fuel injection port and the pre-filmer is set such that an effective opening area between the pre-filmer and “the inner wall of the main air flow channel provided with the main fuel injection port” is equal to an effective opening area of the small swirler. The swirling directions of the swirlers of the main swirler are “clockwise”-“counter-clockwise”-“clockwise” respectively along the radial outward direction when the swirling direction of the innermost swirler is taken as “clockwise”.

Abstract: A fuel injector includes: a pilot injector configured to spray fuel so as to form a first combustion region in a combustion chamber; and a main injector provided coaxially with the pilot injector so as to surround the pilot injector and configured to supply a fuel-air mixture that is a mixture of the fuel and air to form a second combustion region in the combustion chamber, wherein the pilot injector includes: a center nozzle configured to eject air jet flowing straight in an axial direction on a central axis of the pilot injector; an inside swirler provided on a radially outer side of the center nozzle and configured to cause inflow air to swirl around the central axis; and a pilot fuel injecting portion configured to inject the fuel from between the center nozzle and the inside swirler to air flow in the center nozzle.

Abstract: The invention relates to a fuel injector for a fuel injection system, in particular a common rail injection system, having a nozzle body (1) and having an injector body (2), wherein in the nozzle body (1) there is formed a high-pressure bore (3) for accommodating a nozzle needle (4) which can perform a stroke movement and by means of the stroke movement of which at least one injection opening (5) can be opened up or closed off, and wherein in the injector body (2) there is formed a low-pressure chamber (6) for accommodating a piezoelectric actuator (7), which low-pressure chamber can be or is hydraulically coupled via a coupling device (8) to the nozzle needle (4) in such a way that the nozzle needle (3) assumes the closed position thereof when the piezoelectric actuator (7) is electrically discharged.

Abstract: A fuel injector is described having a multi-orifice nozzle provided with a multitude of spray orifices through which fuel is injected, the multi-orifice nozzle having at least two spray orifices that have different spray-orifice diameters. Furthermore, a method is described for producing, by laser drilling, a multi-orifice nozzle having a multitude of spray orifices, at least two spray orifices having different spray orifice diameters.

Abstract: An injector apparatus for an engine, may include an injector body, an actuator mounted in the injection body, a rotary rod rotatably received in the injector body and selectively rotated by the actuator, wherein a fuel groove may be formed on outer surface of the rotary rod along a longitudinal direction thereof, and a nozzle hole formed at a nozzle of the injector body to selectively communicate with the fuel groove in accordance with rotation of the rotary rod, wherein the rotary rod slidably contacts with the nozzle in the injector body.

Abstract: A metallic fuel system component includes an internal surface and an external surface. The metallic fuel system component is made by inducing compressive residual stress in only a portion of the internal surface of the metallic fuel system component by transmitting a laser shock wave through the metallic fuel system component from the external surface to the internal surface.

Abstract: A dual fuel injector for a gas turbine engine includes a central cavity extending along a longitudinal axis from a first end to a second end, and a first fuel discharge outlet configured to direct a first fuel into the central cavity at the first end. The fuel injector may also include a first air discharge opening circumferentially disposed about the first fuel discharge outlet and configured to direct a first quantity of air into the central cavity, and a second air discharge opening circumferentially disposed about the central cavity and configured to discharge a second quantity of air into the central cavity downstream of the first air discharge outlet. The fuel injector may further include a second fuel discharge outlet circumferentially disposed about the central cavity and configured to discharge a second fuel therethrough. The second fuel may be different from the first fuel.

Abstract: The present invention concerns a nozzle with a nozzle body on the back of which a blind hole or seat hole is realized, whereby at least one spray hole leads outward from the blind hole or seat hole, in such a way that the spray hole displays a non-round cross section in the area of the spray hole aperture.

Abstract: To suppress clogging of an injection nozzle that supplies fuel to an exhaust passage of an engine, a controller executes intermittent addition of fuel from the injection nozzle. In executing the intermittent addition, the controller calculates a particulate discharge amount within the exhaust passage based on the engine operation state, and multiplies the exhaust gas temperature by the intake air rate to calculate the exhaust energy. Then, based on the particulate discharge amount and the exhaust energy, the controller calculates the amount of fuel to be added.

Abstract: A coupling device for mechanically coupling a fuel rail to a cylinder head of a combustion engine comprises a fuel injector cup designed to be hydraulically and mechanically coupled to the fuel rail and comprising a through hole extending between a first surface and a second surface of the fuel injector cup, the second surface arranged to face the cylinder head, and a fastening element designed to be fixedly coupled to the cylinder head, the fastening element comprising a head portion facing the first surface of the fuel injector cup and a shank portion partially arranged in the through hole and designed to be in engagement with the cylinder head. The coupling device comprises a first spring element arranged axially between the head portion and the first surface of the fuel injector cup, and a second spring element facing the second surface of the fuel injector cup and arrangeable axially between the second surface of the fuel injector cup and the cylinder head.

Abstract: The invention relates to a fuel injector, in particular a common rail injector, for injecting fuel into a combustion chamber of an internal combustion engine. The fuel injector has a multi-part injection valve element, which is adjustable between a closing position and an opening position and includes a first part and at least one second part that is adjustable relative to the first part. The first and second parts are coupled to one another via a hydraulic coupler volume. According to the invention, it is provided that the first part is guided in the second part, or the second part is guided in the first part, and that the coupler volume communicates with an injector volume via at least one throttle arrangement. The throttle arrangement is embodied such that the volumetric through flow increases only disproportionately little with an increasing pressure difference between the coupler volume and the injector volume.

Abstract: The invention relates to a method for producing a fuel injection element having channels, as well as to a fuel injection element. A fuel injection element according to the invention has helically extending channels and is produced with use of an extrusion tool.

Abstract: A fuel injector is provided with a fuel inlet, a fuel outlet, and a fuel passage for communicating fuel from the inlet to the outlet. A valve and valve seat assembly is provided for selectively preventing and permitting fuel to pass from the fuel inlet to the fuel outlet. The valve seat is defined by a tubular body and a valve seat that traverses an inside wall surface of the tubular body. An upstream face of the valve seat is downstream of an upstream end of the tubular body and a downstream face of the valve seat is upstream of a downstream end of the tubular body. At least one passage is provided through the tubular body beginning downstream of the downstream face of the valve seat and upstream of the downstream end of the tubular body. A cover may be disposed at the downstream end of the tubular body.

Abstract: Electromagnetic fuel injector for gaseous fuels comprising: an injection nozzle controlled by an injection valve; a movable shutter to regulate the flow of fuel through the injection valve; an electromagnetic actuator, which is suitable to move the shutter between a closed position and an open position of the injection valve and comprises a fixed magnetic pole, a coil suitable to induce a magnetic flux in the magnetic pole, and a movable anchor suitable to be magnetically attracted by the magnetic pole; an absorption element, which is made of an amagnetic elastic material and is arranged between the magnetic pole and the anchor; and a protective element, which is made of a magnetic metal material having high surface hardness and is interposed between the absorption element and the anchor.

Abstract: Provided is an injector having a plurality of micro-mixing nozzles having axes thereof pointing radially inwardly or outwardly with respect to a main axis of the injector and a plurality of micro-mixing nozzles having axes thereof extending axially with respect to the main axis of the injector. The arrangement of micro-mixing nozzles provides a means for fast and efficient mixing of fuels, such as highly reactive fuels including hydrogen. The arrangement of micro-mixing nozzles also achieves low NOx emissions.

Abstract: In certain embodiments, a fuel injector includes a wall separating a fuel passage from an air passage. The fuel injector also includes a fuel injection port extending from a first side of the wall to a second side of the wall for injecting a flow of fuel from the fuel passage into a flow of air in the air passage. In addition, the fuel injector includes first and second feedback lines extending from a downstream end of the fuel injection port to an upstream end of the fuel injection port. The first and second feedback lines are disposed on opposite sides of the fuel injection port. In addition, the first and second feedback lines are disposed entirely within the wall.

Abstract: The invention relates to a tool for the electrochemical machining of a fuel injection device, the tool having an electrode holder and an electrode element which forms a cathode during the machining operation in order to be able to electrochemically remove material from the fuel injection device in a machining region. The electrode element is arranged in such a way that it can be displaced in relation to the electrode holder.

Abstract: A hole axis of a communication hole is placed at a location, which coincides with a translated location of a hole axis of a connector hole that is translated toward an axial distal end portion of a main body in an axial direction of the main body. In this way, with respect to a high pressure flow passage, which is bent by 90 degrees and extends through the connector hole, the communication hole and an axial flow passage, the amount of projection of a projecting portion at an inner side area of this bent, which is located on the inner side of the bent, is reduced.

Abstract: An injector sleeve adapted to be mounted in a cylinder head of an internal combustion engine, where the injector sleeve comprises a tapered inner surface which constitutes a sealing surface for an injector, where the hardness of the tapered inner surface is higher than the hardness of the outer surface of the injector sleeve. The injector sleeve is produced in a cold forming process. The advantage of the invention is that the injector sleeve is provided with a sealing surface for an injector which is harder than the outer surface of the injector sleeve. In this way, a sealing surface for an injector having small tolerances is obtained without further machining, where the outer surface may be turned to the desired dimensions.

Abstract: The occurrence of leaks can be reduced by a fuel injection device (10) for injecting fuel into the combustion chamber of an internal combustion engine, wherein the fuel injection device (10) has an injection valve element (14) with a first section (26) on which a guide bearing element (20) is arranged, with provision being made for a first pressure chamber (22) in an area around the guide bearing element (20).

Abstract: Electromagnetic fuel injector for gaseous fuels comprising: an injection nozzle controlled by an injection valve; a movable shutter to regulate the flow of fuel through the injection valve; an electromagnetic actuator, which is suitable to move the shutter between a closed position and an open position of the injection valve and comprises a fixed magnetic pole, a coil suitable to induce a magnetic flux in the magnetic pole, and a movable anchor suitable to be magnetically attracted by the magnetic pole; an absorption element, which is made of an amagnetic elastic material and is arranged between the magnetic pole and the anchor; and a protective element, which is made of a magnetic metal material having high surface hardness and is interposed between the absorption element and the anchor.

Abstract: The method for manufacturing a solid housing, in particular a valve housing for an electromagnetically operable valve, is characterized in that the following method steps are used: a) providing a sheet metal strip made of a magnetic or magnetizable material, b) introducing an additive into a middle area of the sheet metal strip and fusing there for forming a non-magnetizable structure, c) cutting the sheet metal strip into a sheet metal piece of desired width, d) deforming the sheet metal piece into a sleeve shape, e) mutual fastening of the cut edges now facing each other and running in the longitudinal direction of the sleeve for forming a sleeve blank, f) final machining of the sleeve blank until a desired geometry of the housing is achieved. The housing is suitable in particular for use in fuel injectors in fuel injector systems of mixture-compressing spark-ignition internal combustion engines.

Abstract: The metering servovalve (7) includes a valve body (8, 30), a shutter (45), and an electromagnet (15), and is housed inside a casing (2) of the injector (1). The electromagnet (15) activates a movable armature (16) performing a travel defined by a stop member (19) carried by the electromagnet (15), which is fixed inside the casing by a threaded ring nut (40) with the interposition of at least one deformable shim (48). The ring nut (40) is screwed to a predetermined tightening torque to a thread (46) on the casing (2) to elastically deform the shim (48). And the shim (48) is defined by a metal ring with, for example, an L-, C-, S-, Z- or ?-shaped cross section.

Abstract: In a fuel injection nozzle for an internal combustion engine, a first cavity is disposed downstream of a valve seat in a direction in which fuel flows. A second cavity is disposed downstream of the first cavity in the direction in which the fuel flows. A fuel passage connects the first cavity to the second cavity. Fuel injection holes (24) lead to the second cavity. With this configuration, when the fuel flows through the first fuel passage, cavitation is induced. Cavitation bubbles flow into the second cavity along with the fuel. When the fuel is retained in the second cavity, the cavitation bubbles are uniformly mixed into the fuel. The fuel, which has been sufficiently mixed with the cavitation bubbles, is injected from the fuel injection holes.

Abstract: The invention relates to a fuel injector with an injector housing which has a high-pressure fuel connection which is connected to a central high-pressure fuel source outside the injector housing, and with a pressure chamber within the injector housing. According to the pressure in a coupling chamber, fuel under a high pressure is injected from the pressure chamber into a combustion chamber of an internal combustion engine when a nozzle valve opens. The nozzle valve has a combustion chamber-remote end with a control pressure surface which is acted upon in the coupling chamber by the coupling chamber pressure. In order to create a fuel injector which can be produced inexpensively, the nozzle valve has at least one low-pressure surface which is averted from the combustion chamber and acted upon with low pressure.

Abstract: A fuel injector assembly comprising an injector body having a leading end, a fuel inlet passage, a backleak passage and a trailing end that terminates in an end surface; a cap that fits over the trailing end of the injector body to define therebetween a chamber for receiving fuel from said backleak passage; and a seal for sealing said chamber to prevent the flow of fuel therefrom, wherein said seal is disposed between said end surface of the trailing end and an inlet end of said fuel inlet passage.

Abstract: A fuel injection device includes a cylinder that defines a pressure chamber at an end portion of a nozzle needle. A floating plate as a control member is placed in the cylinder. A cutout portion and multiple grooves are formed in the floating plate. The cutout portion and the grooves causes a gap between a large-diameter inner circumferential surface and an outer circumferential surface to communicate with the pressure chamber. The cutout portion and the grooves reduce a contact surface portion between the cylinder and the floating plate and divide the contact surface portion into multiple island portions. As a result, it is possible to reduce the contact surface portion.

Abstract: An anti-wear layer arrangement, in particular for components of a fuel injection system that are subjected to high pressures and high temperatures. The anti-wear layer arrangement has a protective layer formed from tetragonally bonded amorphous carbon or having a proportion of tetragonally bonded amorphous carbon, and also an adhesion promoter layer having titanium between the structural element and the protective layer. The adhesion promoter layer contains at least one oxidation-resistant element in addition to titanium.

Abstract: A fuel-injection system for direct injection of fuel into a combustion chamber through a combustion-chamber top arranged opposite a piston has a fuel injector which includes an actuable valve-closure member. The valve-closure member cooperates with a valve-seat surface to form a sealing seat. A multitude of spray-discharge orifices generates a spray cloud, each spray-discharge orifice generating a fuel jet, and the multitude of fuel jets generating the spray cloud in the combustion chamber. A first opening angle of the spray cloud in a first plane is greater than a second opening angle in a second plane extending perpendicular to the first plane.

Abstract: In one aspect, a fuel injector includes an injector body that defines a fuel inlet, a drain outlet and a nozzle outlet. A direct operated check valve is positioned in the injector body and includes a needle valve member with an opening hydraulic surface exposed to fluid pressure in a nozzle supply passage, and a closing hydraulic surface exposed to fluid pressure in a needle control chamber. The needle valve member is movable between a first position at which the nozzle supply passage is blocked to the nozzle outlet, and a second position at which the nozzle supply passage is open to the nozzle outlet. A needle control valve is positioned in the injector body and includes a control valve member movable between a first position at which the needle control chamber is fluidly connected to the drain outlet, and a second position at which the needle control chamber is fluidly blocked to the drain outlet.

Abstract: In an electromagnetic fuel injection valve including a magnetic coil housing (31) having a coil assembly (28) housed therein, the coil housing (31) includes the first and second coil housing half bodies (31a, 31b) whose cross sections are each shaped like an inferior arc, and which are oppositely disposed so as to interpose the coil assembly (28) and a coupler (34), each of the coil housing half bodies (31a, 31b) includes: a barrel portion (44) for covering an outer peripheral surface of the coil assembly (28); a front-end wall portion (45) and a rear-end wall portion (46) which are in contact with front-end and rear-end surfaces of the coil assembly (28); a front connection cylindrical portion (47) welded to the outer peripheral surface of the magnetic cylindrical body (4); and a rear connection cylindrical portion (48) welded to the outer peripheral surface of the fixed core (5); both the coil housing half bodies are formed symmetrically; and one half part and the other half part of each of the coil housing

Abstract: An actuator module including a piezoactuator, for example for a piezoinjector for metering fuel in an internal combustion engine, is proposed. The piezoactuator has piezoelements stacked one above another between an actuator head and an actuator foot and is provided with at least one elastomer layer enclosing the piezoelements. The elastomer layer is enveloped by a corrugated bellows or by telescopic tubes, composed of a material that is diffusion-impermeable with respect to a fuel to be metered by the piezoinjector. The corrugated bellows or the telescopic tubes have on their periphery grooves which can absorb expansions of the elastomer layer or of the piezoactuator.

Abstract: A method of assembling an ejector is provided, wherein the method includes providing a motive nozzle tip having a centerline axis and including a nozzle tip edge having at least one protrusion extending through a plane substantially normal to the centerline axis. The method also includes coupling the motive nozzle tip to the ejector.

Abstract: A fuel injector for fuel-injection systems of internal combustion engines includes a solenoid coil and an armature excitable by the solenoid coil, the armature being in operative connection with a valve-closure member, which forms a sealing seat together with a valve-seat body arranged in a valve sleeve. The valve-seat body is held in place in the valve sleeve by a clamping sleeve.

Abstract: An injector for vehicles improves utilization rate of air and mixing rate of air and fuel by disposing first and second nozzle holes having different K factors alternately. The injector for vehicles may include a housing of cylindrical shape, a plurality of nozzle holes communicating an inside of the housing with an outside thereof at a lower end of the housing, and a needle adapted to move reciprocally in the housing, and selectively opening or closing the nozzle hole, wherein the plurality of nozzle holes has a plurality of K factors.

Abstract: A monolithic fuel injection head for a fuel nozzle includes a substantially hollow vesicle body formed with an upstream end face, a downstream end face and a peripheral wall extending therebetween, an internal baffle plate extending radially outwardly from a downstream end of the bore, terminating short of the peripheral wall, thereby defining upstream and downstream fuel plenums in the vesicle body, in fluid communication by way of a radial gap between the baffle plate and the peripheral wall. A plurality of integral pre-mix tubes extend axially through the upstream and downstream fuel plenums in the vesicle body and through the baffle plate, with at least one fuel injection hole extending between each of the pre-mix tubes and the upstream fuel plenum, thereby enabling fuel in the upstream plenum to be injected into the plurality of pre-mix tubes. The fuel injection head is formed by direct metal laser sintering.

Abstract: A fuel injection valve for internal combustion engines has a valve housing composed of a first housing part and a second housing part which are connected to one another in a connecting region. In order to improve the strength of the connection in relation to the pressure of the fuel which prevails in an inner space, the housing wall of the first housing part is supported in the connecting region on the housing wall of the second housing part, and the housing wall of the second housing part is of reinforced design in the connecting region.

Abstract: A fuel injection system and method for injecting hydrocarbon fuel into a fuel reformer for generating hydrogen rich gas from hydrocarbon fuel are provided. The hydrocarbon fuel is injected into the fuel reformer as spray having a pulsating pressure.

Abstract: A fluid injector has a longitudinal axis (L) and a valve needle (12), which is axially moveable and operable to prevent a fluid injection in a closing position and to permit the fluid injection in further positions. The fluid injector also has an armature (14) which is mechanically coupled to the valve needle (12). Furthermore, the fluid injector has a solenoid assembly (30) which has at least a first and second coil (34, 36) and which is operable to magnetically actuate the armature (14) via an electrical signal (V) applied to at least one predetermined assortment of the at least two coils (34, 36).

Abstract: An annular two-phase spring has a plurality of first waves providing a first spring rate and a plurality of second waves providing a second spring rate. The two-phase spring can be used for installing a fuel injector in a fuel injector bore to improve sound performance.

Abstract: A direct injection injector for an engine includes a body forming the outer structure and having a space therein, a needle inserted to slide linearly in the body and having a hole therein forming a fuel channel, and a cylinder nozzle fitted on needle to communicate with hole and having a nozzle hole for injecting fuel, such that it is possible to prevent caulking in which the nozzle of the injector is clogged with soot while injecting fuel at relatively low pressure, change the spray type of the injected engine in various shapes, and sufficiently decrease the size of droplet of the fuel.

Abstract: There is provided a method by which a member having an undercut in the inner peripheral portion thereof can be formed readily. To form a material (1) formed with a recess (2) and the undercut (3) by using a swaging device, while the material (1) is first gripped by a clamper (11), and a mandrel (12) is inserted into the recess (2) of the material (1). The mandrel (12) used has an outside diameter equal to the inside diameter of a blind hole of an aimed product (fuel injection nozzle). Then, the material (1) is pushed in by the mandrel (12) to a position at which the material (1) abuts on a stopper (13), and the outside surface of the material (1) is struck by swaging dies (8) to perform a swaging operation. This swaging operation reduces the inside diameter of the recess (2) to the outside diameter of the mandrel (12), with the undercut (3) left.

Abstract: A movable core includes a through-hole, which receives a main body of a needle therethrough, and a receiving recess, which is axially recessed in a stationary core side end surface of the movable core. The receiving recess is configured into an annular form and radially outwardly extends from the through-hole to receive a flange of the needle. A movable plate is placed on an axial side of the movable core, which is opposite from the nozzle. An axial length of the flange is smaller than an axial distance between a contact surface of the movable plate, which is contactable with the needle, and a bottom wall of the receiving recess in a contact state where the movable core and the movable plate contact with each other.