EP1658427B1 - Fuel injection valve for internal combustion engines - Google Patents

Fuel injection valve for internal combustion engines Download PDF

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Publication number
EP1658427B1
EP1658427B1 EP04738755A EP04738755A EP1658427B1 EP 1658427 B1 EP1658427 B1 EP 1658427B1 EP 04738755 A EP04738755 A EP 04738755A EP 04738755 A EP04738755 A EP 04738755A EP 1658427 B1 EP1658427 B1 EP 1658427B1
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EP
European Patent Office
Prior art keywords
valve
control
needle
space
chamber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
EP04738755A
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German (de)
French (fr)
Other versions
EP1658427A1 (en
Inventor
Detlev Potz
Peter Boehland
Thomas Kuegler
Predrag Nunic
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Potz Wendelin
Sander-Potz Maike HF
Robert Bosch GmbH
Original Assignee
Potz Wendelin
Sander-Potz Maike HF
Robert Bosch GmbH
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Filing date
Publication date
Application filed by Potz Wendelin, Sander-Potz Maike HF, Robert Bosch GmbH filed Critical Potz Wendelin
Publication of EP1658427A1 publication Critical patent/EP1658427A1/en
Application granted granted Critical
Publication of EP1658427B1 publication Critical patent/EP1658427B1/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/0012—Valves
    • F02M63/0014—Valves characterised by the valve actuating means
    • F02M63/0015—Valves characterised by the valve actuating means electrical, e.g. using solenoid
    • F02M63/0026—Valves characterised by the valve actuating means electrical, e.g. using solenoid using piezoelectric or magnetostrictive actuators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • F02M45/02—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts
    • F02M45/04—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts with a small initial part, e.g. initial part for partial load and initial and main part for full load
    • F02M45/08—Injectors peculiar thereto
    • F02M45/086—Having more than one injection-valve controlling discharge orifices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • F02M45/02—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts
    • F02M45/10—Other injectors with multiple-part delivery, e.g. with vibrating valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
    • F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
    • F02M47/027—Electrically actuated valves draining the chamber to release the closing pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/46—Valves, e.g. injectors, with concentric valve bodies
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
    • F02M61/1806—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for characterised by the arrangement of discharge orifices, e.g. orientation or size

Definitions

  • the invention is based on a fuel injection valve for internal combustion engines, as for example from the document DE 102 22 196 A1 is known.
  • the known fuel injection valve has a housing in which a valve seat is formed, from which a plurality of injection openings emanates.
  • a valve outer needle and a valve inner needle slidably mounted therein are arranged in the housing, which interact with the valve seat with their valve seat-side end and thus control the opening of at least two injection openings.
  • an outer control chamber is formed by the pressure, at least indirectly, a closing force on the valve seat facing away from the end of the valve outer needle is exercised.
  • an inner control chamber is formed in the housing, by the pressure of which at least indirectly a closing force on the valve seat facing away from the end of the valve inner needle is exercisable. Both closing forces act in the direction of the valve seat and press the valve pins into contact with the valve seat.
  • the inner control chamber is connected via an inner outlet throttle with a control valve chamber of a control valve, and also the outer control chamber is connected via an outer flow restrictor with this control valve chamber.
  • the control valve chamber can be connected via a drain opening with a leakage oil space, wherein the various inlets are controlled by a valve member arranged in the control valve chamber, which can take various switching positions.
  • the inner control chamber is formed within a control piston against which the valve outer needle rests. This has the consequence that the pressure in the inner control chamber depends on the stroke of the valve outer needle. As a result, an independent control of valve outer needle and valve inner needle is no longer possible.
  • the pressure drop in the inner control room causes that a precisely balanced system of inlet throttles and outlet throttles must be present and beyond the pressure surfaces on the valve inner needle must be precisely adapted to the pressure conditions in order to accomplish the control can. This is technically complex and costly to implement.
  • an injection valve which has two nested valve needles.
  • the inner valve needle limits a first control chamber and the outer valve needle a second control chamber, wherein both control chambers - depending on the position of a control valve - with each other or with a drain are connectable.
  • the fuel injection valve according to the invention with the characterizing features of claim 1 has the advantage that an independent control of the valve outer needle and the valve inner needle is achievable, allowing greater freedom in the design of the corresponding component dimensions and also allows a more accurate metering of the injected fuel quantity.
  • the inner control chamber on an inner inlet throttle and the outer control chamber on an outer inlet throttle which are connected to a fuel-filled, formed in the housing high-pressure region.
  • the control valve space may be connected to a leakage oil space through the valve member which may occupy first, second and third shift positions, and in the first shift position, the drain port connecting the control valve space to the leakage oil space is closed by the valve member second switching position, both the inner outlet throttle and the outer outlet throttle are connected via the now open drain opening with the leakage oil space and in the third switching position, the outer outlet throttle connected to the leakage oil chamber and the inner drain throttle is closed by the valve member.
  • control valve which corresponds in its function to a 3/3-way valve, it is possible either to connect only the outer control chamber with the leakage oil space, which there leads to a pressure relief and thus causes an opening of the valve outer needle, or when the valve member is in its second shift position relieves both the inner and outer control chambers so that both valve pins open.
  • the inner control chamber and the outer control chamber are interconnected when both the valve outer needle and the inner valve needle are in their closed position, i. in contact with the valve seat.
  • This common control chamber is connected via two outlet throttles with the control valve chamber, which makes it possible, depending on the switching position of the valve member to relieve the common control chamber via one or both outlet throttles.
  • the valve member is movable via a piezoelectric actuator connected to the valve member.
  • the piezo plate allows the valve member to be inserted directly into any desired position Position between the first and the third switch position can be brought.
  • the valve member is advantageously in its first switching position on a first valve seat and in its third switching position on a second valve seat, wherein the valve member moves linearly between these two switching positions.
  • the second switching position of the valve member is located between the first and the third switching position.
  • valve seat facing away from the end faces of the valve needles do not directly limit the inner and the outer control chamber, but the valve needles are located on an inner and an outer valve piston, which limit the respective control chambers.
  • FIG. 1 a first embodiment of the fuel injection valve according to the invention is shown.
  • the fuel injection valve is shown in a section A and a section B, wherein the part between these two sections has been omitted for the sake of clarity.
  • the section B which represents the actual nozzle, is well known in the art, so that only its essential parts are described here, whereas section A contains the parts essential to the invention.
  • the fuel injection valve comprises a housing 1 comprising a holding body 9, a throttle plate 7, a control body 5, and a valve body 3 abutting each other in this order.
  • the valve body 3 is replaced by a Clamping nut 2, which bears against a shoulder of the valve body 3 and is screwed into a thread on the holding body 9, pressed against the control body 5, so that the control body 5 presses on the throttle plate 7 on the holding body 9.
  • a bore 11 is formed, which is designed as a blind bore and forms a conical valve seat 20 at its combustion chamber end.
  • a valve outer needle 17 is arranged longitudinally displaceably, which is sealingly guided in a bore 11 remote from the combustion chamber in the bore. Between the valve outer needle 17 and the wall of the bore 11, a pressure chamber 12 is formed which can be filled with fuel under high pressure via a feed channel 9, the throttle valve 7, the control body 5 and the valve body 3 extending inlet channel.
  • the inlet channel 8 opens into a radial extension of the pressure chamber 12, wherein this radial extension connects directly to the portion of the bore 11 in which the valve outer needle 17 is guided.
  • an outer valve sealing surface 22 is formed, which is at least approximately frusto-conical and which cooperates with the valve seat 20.
  • the valve outer needle 17 has a longitudinal bore 16, so that the valve outer needle 17 forms a hollow needle.
  • a valve inner needle 15 is longitudinally displaceable, which also has a conical valve sealing surface 24 at its valve seat end, with which the valve inner needle 15 cooperates with the valve seat 20.
  • the control of the outer injection openings 26 and the inner injection openings 28 takes place in such a way that at sufficiently high pressure in the pressure chamber 12, a force on the pressure shoulder 13 results, which is directed away from the valve seat.
  • the valve outer needle 17 moves away from the valve seat 20, so that the outer injection openings 26 are released and fuel is injected from the pressure chamber 12 through the outer injection openings 26 into the combustion chamber.
  • the valve inner needle 15 which by the hydraulic pressure on parts of the valve sealing surface 24 a directed away from the valve seat 20 Force learns from the valve seat 20, so the inner injection ports 28 are released and fuel is injected simultaneously through the outer injection ports 26 and the inner injection ports 28.
  • a piston chamber 32 is formed, which is open at both end faces of the control body 5.
  • an outer valve piston 34 and arranged in the outer valve piston 34 inner valve piston 36 is arranged in the piston chamber 32.
  • the outer valve piston 34 rests against the valve outer needle 17, while the inner valve piston 36 rests against the valve inner needle 15.
  • a closing spring 38 is arranged in the piston chamber 32, which is supported at one end to a shoulder formed in the piston chamber 32 and the other end on the outer valve piston 34, wherein the closing spring 38 is biased so that they the outer valve piston 34 and thus the valve outer needle 17 in Direction of the valve seat 20 presses.
  • Figure 3a and 3b each show an enlargement of the piston chamber 32.
  • the outer valve piston 34 bounded with its valve outer needle 17 facing away from an outer control chamber 56 which is bounded on the outside of the wall of the piston chamber 32 and the outer valve piston 34 opposite to the throttle plate 7.
  • the outer control chamber 56 is connected via an inlet throttle 47, via a formed in the throttle plate 7 connecting groove 53 with the inlet channel 8.
  • an outlet throttle 49 which opens into a control valve chamber 60 of a control valve 30, which is arranged in the holding body 9.
  • the inner valve piston 36 defines with its end facing away from the valve inner needle 15 an inner control chamber 54 which is connected via an inlet throttle 47, which is formed in the throttle plate 7, via the connecting groove 53 with the inlet channel 8.
  • the inner control chamber 54 is connected via an inner outlet throttle 51 with the control valve chamber 60.
  • a leakage oil chamber 40 is formed, which is connected to a fuel return system and in which always a low fuel pressure prevails.
  • a drain channel 42 which extends in the holding body 9 of the throttle plate 7 and the control body 5
  • the piston chamber 32 is connected to the leakage oil chamber 40, so that there is always a low fuel pressure in the piston chamber 32.
  • the leakage oil chamber 40 is likewise connected to the control valve chamber 60 via a drain opening 68.
  • FIG. 2a shows the closer structure of the control valve 30 and makes the operation clear.
  • a valve member 62 is arranged, which is connected to a piezoelectric actuator 66. With the help of the piezoelectric actuator 66, the valve member 62 can be moved in the longitudinal direction in the control valve chamber 60.
  • the valve member 62 has a first sealing surface 74, with which the valve member 62 in the in FIG. 2a shown first switching position is applied to a formed in the control valve chamber 60 first valve seat 70.
  • the drain opening 68 which is formed as an annular gap surrounding the valve member 62 and via which the control valve chamber 60 is connected to the leakage oil chamber 40, is closed.
  • FIG. 2b the second switching position of the valve member 62 is shown, this against the force of the closing spring 64 by movement by means of the piezoelectric actuator 66 can take.
  • the first sealing surface 74 of the valve member 62 has lifted from the first valve seat 70, so that the drain opening 68 is now open.
  • fuel flows from the control valve chamber 60 into the leakage oil chamber 40, so that the fuel pressure in the control valve chamber 60 decreases.
  • the third switching position of the valve member 62 is in Figure 2c illustrated and shows the valve member 62, as with its first sealing surface 74 opposite end face, which is formed as a second sealing surface 76, abuts the second valve seat 72 which is formed on the throttle plate 7.
  • the inner outlet throttle 51 is closed, so that now the outer control chamber 56 is connected to the control valve chamber 60.
  • the drain opening 68 remains open.
  • the operation of the fuel injection valve is as follows: at the beginning of the injection process, the valve member 62 of the control valve 30 in its first switching position, that is in abutment with the first valve seat 70. On the connection of the outer control chamber 56 and the inner control chamber 54 via the outer inlet throttle 45 and the inner inlet throttle 47 with the high-pressure region, ie the inlet channel 8, prevails in both control chambers 54, 56 the same fuel pressure as in the inlet channel 8.
  • the valve member 62 Due to the hydraulic force on the inner valve piston 36 and the outer valve piston 34, the valve outer needle 17 and the valve inner needle 15 against If an injection takes place only through the outer injection openings 26, the valve member 62 is moved via a corresponding energization of the piezoelectric actuator 66 from its first switching position to the third switching position, as described in US Pat Figure 2c is shown.
  • the outer outlet throttle 49 is in this case dimensioned such that the pressure in the two control chambers 54, 56 also drops when the inner outlet throttle 51 is closed by the valve member 62. Thus, less fuel flows via the inlet throttles 45, 47 into the control chambers 54, 56, than via the outer outlet throttle 49 in the Leakage oil chamber 40 drains off.
  • the pressure in the inner control chamber 54 does not drop further, but rises again via an appropriate fuel supply through the inner inlet throttle 47 to the level of the inlet channel 8.
  • the hydraulic force on the inner valve piston 36 and thus on the valve inner needle 15 remains so great that the valve inner needle 15 remains in its closed position and closes the inner injection openings 28.
  • the valve member 62 of the control valve 30 is driven by the piezoelectric actuator 66 back to the first switching position, as in FIG. 2a is shown. Overflowing fuel through the outer inlet throttle 45, the pressure in the outer control chamber 56 increases rapidly again, as no fuel flows through the outer outlet throttle 49.
  • the control valve 30 is actuated so that the valve member 62 moves to its second switching position, as in FIG. 2b is shown.
  • the common control space which is formed by the outer control chamber 56 and the inner control chamber 54, is connected to the control valve chamber 60 via the outer outlet throttle 49 and the inner outlet throttle 51.
  • the pressure in the control chambers 54, 56 drops rapidly and first it opens the valve outer needle 17 in the manner described above and, depending on the design of the pressure surface on the inner valve sealing surface 24 of the valve inner needle 15, with a short or slightly longer distance, the valve inner needle 15. In this case, the inner valve piston 36 moves so far until it comes to rest on the throttle plate 7. To complete the injection, the valve member 62 of the control valve 30 is moved back to its first switching position, as in FIG. 2a is shown.
  • the now closed drain opening 68 lacks the connection to the leakage oil chamber 40, which causes the pressure in the inner control chamber 54 and the outer control chamber 56 via fuel flow through the inner inlet throttle 47 and the outer inlet throttle 45 to rise rapidly again, so that on the corresponding hydraulic forces the outer valve piston 34 and the inner valve piston 36 both valve needles 15, 17 go back to its closed position.
  • valve member 62 moves first to the third switching position, so that, as described above, the valve outer needle 17 opens.
  • the valve member 62 can be moved to the second switching position, in which the inner control chamber 54 is relieved via the inner outlet throttle 51.
  • the valve member 62 is moved back to its first switching position, so that the valve needles 15, 17 close in the manner described above again.
  • FIG. 4 is a non-inventive fuel injection valve shown, in which case only the in FIG. 1 A labeled portion of the fuel injector is redrawn.
  • Section B of the FIG. 1 is identical to the combustion chamber end of the fuel injection valve, as in FIG. 4 is shown.
  • Fuel injection valve shown also has a housing 1, wherein a separate control body 5 is omitted and the holding body 9 directly adjacent to the throttle plate 7 and this in turn to the valve body 3.
  • the valve body 3 is characterized by a clamping nut 2 in the same manner as in the FIG. 1 shown embodiment pressed on the throttle plate 7 against the holding body 9.
  • a bore 11 is formed, in which also a valve outer needle 17 and a valve inner needle 15 are arranged, which are longitudinally displaceable in the bore 11.
  • a spring chamber 14 At the valve seat end facing away from the bore 11 is expanded to a spring chamber 14, in which the closing spring 38 is arranged.
  • the valve outer needle 17 is surrounded by a sleeve 18 which is arranged in the spring chamber 14 and between which and a support ring 19, the closing spring 38 is arranged under prestress.
  • the sleeve 18 abuts against the throttle plate 7, so that via the closing spring 38 and the support ring 19, a closing force is exerted on the valve outer needle 17.
  • the pressure chamber 12 continues as an annular space between the valve outer needle 17 and the wall of the bore 11 to the valve seat 20.
  • a bore 39 is formed, in which the valve inner needle 15 protrudes and in which it is guided.
  • the inner valve needle 15 is in this case formed longer than the valve outer needle 17, and it has a first annular groove 77, which is formed at the level of the sleeve 18, and a second annular groove 78 which is disposed within the throttle plate 7.
  • the first annular groove 77 and the second annular groove 78 are connected to each other via a connecting groove 79 on the outside of the valve inner needle 15 and the second annular groove 78 is connected via an in connected to the leakage oil chamber 40, so that there is always a low fuel pressure in both the first annular groove 77 and in the second annular groove 78.
  • the outer control chamber 56 is limited, which is connected via the outer outlet throttle 49 with the control valve chamber 60 of the control valve 30.
  • the control valve 30 corresponds here in its function and structure to the control valve 30, the in FIG. 1 respectively.
  • FIGS. 2a to 2c is shown.
  • the inner control chamber 54 is limited, which is connected via the inner outlet throttle 51 with the control valve chamber 60.
  • the inner control chamber 54 is connected to the outer inlet throttle 49, which in turn opens into the high-pressure region, ie into the inlet channel 8.
  • the control valve chamber 60 is via the drain opening 68 in the same manner as in FIGS. 2a to 2c shown connected to the leakage oil chamber 40.
  • the outer control chamber 56 is always separated from the inner control chamber 54.
  • the operation of the control chambers 54, 56 and their control by the control valve 30 are the same as in the FIG. 1 shown embodiment. If an injection is to take place only through the outer injection openings 26, then here too the valve member 62 is moved from the first to the third switching position, as in Figure 2c is shown. As a result, the valve member 62 comes with its second sealing surface 76 on the second valve seat 72, which is formed here in the throttle plate 7 to the plant.
  • the inner outlet throttle 51 is thus closed and the connection of the control valve chamber 60 with the leakage oil chamber 40 is opened via the drain opening 68.
  • the pressure in the outer control chamber 56 drops and the valve outer needle 17 opens in the known manner already described above.
  • the pressure shoulder 13, the in FIG. 4 is not shown, is formed closer to the valve seat than in the FIG. 1 illustrated embodiment.
  • the valve member 62 remains in the third switching position, the high pressure in the inner control chamber 54 is maintained, and a fuel flow through the annular gap between the wall of the bore 39 and the inner valve needle 15 is through the second annular groove 78, which is always depressurized via the drain passage 58 is prevented by any penetrating fuel is derived.
  • the valve member 62 is again quickly returned to the first switching position.
  • valve member 62 For injection via all injection openings 26, 28, the valve member 62 is moved to the second switching position, as in FIG. 2b is shown. As a result, both the inner outlet throttle 51, and the outer outlet throttle 49 are opened in the same manner, as already shown above, whereby the pressure drops both in the inner control chamber 54 and in the outer control chamber 56. As a result, the valve outer needle 17 and the inner valve needle 15 open in quick succession and release all the injection openings 26, 28. By moving the valve member 62 back to the first switching position, the control chambers 54, 56 again fill with fuel under high pressure, so that the valve outer needle 17 and the valve inner needle 15 slide back into its closed position.
  • the pressure drop in the outer control chamber 56 can not be varied, so that at each opening movement, the pressure drops there equally fast. As a result, the valve outer needle 17 always opens at about the same opening speed.
  • the movement of the valve member 62 can be done except by a piezoelectric actuator 66 by another drive, which allows the valve member 62 to move in the linear direction and to move in the first, second and third switching position.
  • piezo actuators are very suitable for this because they work very quickly and can approach any change in length between their maximum deflections.

Abstract

The invention relates to a fuel injection valve which comprises a housing (1) with a valve seat (20) configured therein and an interior valve needle (17) and an exterior valve needle (15). The pressure in an exterior control chamber (56) exerts a closing force onto the exterior valve needle (17) and the pressure in an interior control chamber (54) exerts a corresponding closing force onto the interior valve needle (15). The interior control chamber (54) is linked with a control valve chamber (60) of a control valve (30) via an interior outlet throttle (51) and the exterior control chamber (56) via an exterior outlet throttle (49), a valve member (62) being disposed in said control valve chamber (60). The interior control chamber (54) is linked with a high-pressure area (8) via an interior inlet throttle (47) and the exterior control chamber (56) via an exterior inlet throttle (45). The valve member (62) can assume a first, a second and a third switched position so that the pressure in the control chambers (54; 56) can be controlled to open only the exterior valve needle (17) as well as both valve needles (15; 17).

Description

Stand der TechnikState of the art

Die Erfindung geht von einem Kraftstoffeinspritzventil für Brennkraftmaschinen aus, wie es beispielsweise aus der Schrift DE 102 22 196 A1 bekannt ist. Das bekannte Kraftstoffeinspritzventil weist ein Gehäuse auf, in dem ein Ventilsitz ausgebildet ist, von dem eine Vielzahl von Einspritzöffnungen ausgeht. In dem Gehäuse ist eine Ventilaußennadel und eine in dieser gleitverschiebbar gelagerte Ventilinnennadel angeordnet, die mit ihrem ventilsitzseitigen Ende mit dem Ventilsitz zusammenwirken und so die Öffnung von wenigstens zwei Einspritzöffnungen steuern. Im Gehäuse ist ein äußerer Steuerraum ausgebildet, durch dessen Druck zumindest mittelbar eine Schließkraft auf das ventilsitzabgewandte Ende der Ventilaußennadel ausübbar ist. Darüber hinaus ist im Gehäuse ein innerer Steuerraum ausgebildet, durch dessen Druck zumindest mittelbar eine Schließkraft auf das ventilsitzabgewandte Ende der Ventilinnennadel ausübbar ist. Hierbei wirken beide Schließkräfte in Richtung des Ventilsitzes und drücken die Ventilnadeln in Anlage an den Ventilsitz. Der innere Steuerraum ist über eine innere Ablaufdrossel mit einem Steuerventilraum eines Steuerventils verbunden, und ebenso ist der äußere Steuerraum über eine äußere Ablaufdrossel mit diesem Steuerventilraum verbunden. Der Steuerventilraum ist über eine Ablauföffnung mit einem Leckölraum verbindbar, wobei die verschiedenen Zuläufe durch ein im Steuerventilraum angeordnetes Ventilglied gesteuert werden, welches verschiedene Schaltstellungen einnehmen kann.The invention is based on a fuel injection valve for internal combustion engines, as for example from the document DE 102 22 196 A1 is known. The known fuel injection valve has a housing in which a valve seat is formed, from which a plurality of injection openings emanates. A valve outer needle and a valve inner needle slidably mounted therein are arranged in the housing, which interact with the valve seat with their valve seat-side end and thus control the opening of at least two injection openings. In the housing, an outer control chamber is formed by the pressure, at least indirectly, a closing force on the valve seat facing away from the end of the valve outer needle is exercised. In addition, an inner control chamber is formed in the housing, by the pressure of which at least indirectly a closing force on the valve seat facing away from the end of the valve inner needle is exercisable. Both closing forces act in the direction of the valve seat and press the valve pins into contact with the valve seat. The inner control chamber is connected via an inner outlet throttle with a control valve chamber of a control valve, and also the outer control chamber is connected via an outer flow restrictor with this control valve chamber. The control valve chamber can be connected via a drain opening with a leakage oil space, wherein the various inlets are controlled by a valve member arranged in the control valve chamber, which can take various switching positions.

Beim bekannten Kraftstoffeinspritzventil ist der innere Steuerraum innerhalb eines Steuerkolbens ausgebildet, an dem die Ventilaußennadel anliegt. Dies hat zur Folge, dass der Druck im inneren Steuerraum vom Hub der Ventilaußennadel abhängt. Hierdurch ist eine unabhängige Steuerung von Ventilaußennadel und Ventilinnennadel nicht mehr möglich. Der Druckabfall im inneren Steuerraum bewirkt, dass ein genau austariertes System von Zulaufdrosseln und Ablaufdrosseln vorhanden sein muss und darüber hinaus die Druckflächen an der Ventilinnennadel genau an die Druckverhältnisse angepasst sein müssen, um die Steuerung bewerkstelligen zu können. Dies ist in der Umsetzung technisch aufwendig und kostenintensiv.In the known fuel injection valve, the inner control chamber is formed within a control piston against which the valve outer needle rests. This has the consequence that the pressure in the inner control chamber depends on the stroke of the valve outer needle. As a result, an independent control of valve outer needle and valve inner needle is no longer possible. The pressure drop in the inner control room causes that a precisely balanced system of inlet throttles and outlet throttles must be present and beyond the pressure surfaces on the valve inner needle must be precisely adapted to the pressure conditions in order to accomplish the control can. This is technically complex and costly to implement.

Aus der JP 2002-322970 A ist ein Einspritzventil bekannt, das zwei ineinander geführte Ventilnadeln aufweist. Hierbei begrenzt die innere Ventilnadel einen ersten Steuerraum und die äußere Ventilnadel einen zweiten Steuerraum, wobei beide Steuerräume - je nach Stellung eines Steuerventils - miteinander oder mit einem Ablauf verbindbar sind.From the JP 2002-322970 A is an injection valve is known which has two nested valve needles. In this case, the inner valve needle limits a first control chamber and the outer valve needle a second control chamber, wherein both control chambers - depending on the position of a control valve - with each other or with a drain are connectable.

Vorteile der ErfindungAdvantages of the invention

Das erfindungsgemäße Kraftstoffeinspritzventil mit den kennzeichnenden Merkmalen des Patentanspruchs 1 weist demgegenüber den Vorteil auf, dass eine unabhängige Steuerung der Ventilaußennadel und der Ventilinnennadel erreichbar ist, was größere Freiheiten bei der Auslegung der entsprechenden Bauteilabmessungen ermöglicht und darüber hinaus eine exaktere Zumessung der eingespritzten Kraftstoffmenge ermöglicht. Hierzu weist der innere Steuerraum eine innere Zulaufdrossel und der äußere Steuerraum eine äußere Zulaufdrossel auf, die mit einem kraftstoffgefüllten, im Gehäuse ausgebildeten Hochdruckbereich verbunden sind. Der Steuerventilraum kann durch das Ventilglied, das eine erste, eine zweite und eine dritte Schaltposition einnehmen kann, mit einem Leckölraum verbunden werden, wobei in der ersten Schaltposition die Ablauföffnung, die den Steuerventilraum mit dem Leckölraum verbindet, durch das Ventilglied verschlossen wird, in der zweiten Schaltposition sowohl die innere Ablaufdrossel als auch die äußere Ablaufdrossel über die jetzt geöffnete Ablauföffnung mit dem Leckölraum verbunden werden und in der dritten Schaltposition die äußere Ablaufdrossel mit dem Leckölraum verbunden und die innere Ablaufdrossel durch das Ventilglied verschlossen wird. Durch diese Ausgestaltung des Steuerventils, das in seiner Funktion einem 3/3-Wege-Ventil entspricht, ist es möglich, entweder nur den äußeren Steuerraum mit dem Leckölraum zu verbinden, was dort zu einer Druckentlastung führt und somit eine Öffnung der Ventilaußennadel bewirkt, oder, wenn das Ventilglied in seiner zweiten Schaltposition ist, sowohl den inneren als auch den äußeren Steuerraum entlastet, so dass beide Ventilnadeln öffnen.The fuel injection valve according to the invention with the characterizing features of claim 1 has the advantage that an independent control of the valve outer needle and the valve inner needle is achievable, allowing greater freedom in the design of the corresponding component dimensions and also allows a more accurate metering of the injected fuel quantity. For this purpose, the inner control chamber on an inner inlet throttle and the outer control chamber on an outer inlet throttle, which are connected to a fuel-filled, formed in the housing high-pressure region. The control valve space may be connected to a leakage oil space through the valve member which may occupy first, second and third shift positions, and in the first shift position, the drain port connecting the control valve space to the leakage oil space is closed by the valve member second switching position, both the inner outlet throttle and the outer outlet throttle are connected via the now open drain opening with the leakage oil space and in the third switching position, the outer outlet throttle connected to the leakage oil chamber and the inner drain throttle is closed by the valve member. Due to this configuration of the control valve, which corresponds in its function to a 3/3-way valve, it is possible either to connect only the outer control chamber with the leakage oil space, which there leads to a pressure relief and thus causes an opening of the valve outer needle, or when the valve member is in its second shift position relieves both the inner and outer control chambers so that both valve pins open.

Der innere Steuerraum und der äußere Steuerraum sind miteinander verbunden, wenn sich sowohl die Ventilaußennadel als auch die Ventilinnennadel in ihrer Schließstellung, d.h. in Anlage am Ventilsitz befinden. Dadurch entsteht ein gemeinsamer Steuerraum beider Ventilnadeln, der über zwei Zulaufdrosseln mit dem Hochdruckbereich verbunden ist. Dieser gemeinsame Steuerraum wird über zwei Ablaufdrosseln mit dem Steuerventilraum verbunden, was es ermöglicht, je nach Schaltstellung des Ventilglieds den gemeinsamen Steuerraum über eine oder beide Ablaufdrosseln zu entlasten. Dadurch kommt es zu einem schnellen oder weniger schnellen Druckabfall im gemeinsamen Steuerraum, so dass die äußere Ventilnadel entweder schnell oder etwas langsamer öffnet. Durch die Hubbewegung der Ventilaußennadel wird der äußere Steuerraum vom inneren Steuerraum getrennt, so dass nach Erreichen dieser Stellung der Ventilnadeln eine unabhängige Steuerung beider Ventilnadeln möglich ist, so dass die innere Ventilnadel geschlossen gehalten werden kann, während die äußere Ventilnadel geöffnet ist.The inner control chamber and the outer control chamber are interconnected when both the valve outer needle and the inner valve needle are in their closed position, i. in contact with the valve seat. This creates a common control chamber both valve needles, which is connected via two inlet throttles with the high pressure area. This common control chamber is connected via two outlet throttles with the control valve chamber, which makes it possible, depending on the switching position of the valve member to relieve the common control chamber via one or both outlet throttles. This leads to a rapid or less rapid pressure drop in the common control chamber, so that the outer valve needle opens either fast or slightly slower. By the lifting movement of the valve outer needle of the outer control chamber is separated from the inner control chamber, so that after reaching this position of the valve needles independent control of both valve pins is possible, so that the inner valve needle can be kept closed, while the outer valve needle is opened.

Durch die weiteren Ansprüche sind vorteilhafte Ausgestaltungen des Gegenstandes der Erfindung möglich. In einer ersten vorteilhaften Ausgestaltung ist das Ventilglied über einen mit dem Ventilglied verbundenem Piezosteller bewegbar. Der Piezosteller ermöglicht es, dass das Ventilglied direkt in jede gewünschte Position zwischen der ersten und der dritten Schaltstellung gebracht werden kann. Hierbei liegt das Ventilglied vorteilhafterweise in seiner ersten Schaltposition an einem ersten Ventilsitz und in seiner dritten Schaltposition an einem zweiten Ventilsitz an, wobei sich das Ventilglied linear zwischen diesen beiden Schaltpositionen bewegt. Die zweite Schaltposition des Ventilglieds befindet sich dabei zwischen der ersten und der dritten Schaltposition.By further claims advantageous embodiments of the subject invention are possible. In a first advantageous embodiment, the valve member is movable via a piezoelectric actuator connected to the valve member. The piezo plate allows the valve member to be inserted directly into any desired position Position between the first and the third switch position can be brought. In this case, the valve member is advantageously in its first switching position on a first valve seat and in its third switching position on a second valve seat, wherein the valve member moves linearly between these two switching positions. The second switching position of the valve member is located between the first and the third switching position.

In einer weiteren vorteilhaften Ausgestaltung begrenzen die ventilsitzabgewandten Stirnseiten der Ventilnadeln nicht direkt den inneren bzw. den äußeren Steuerraum, sondern die Ventilnadeln liegen an einem inneren und einem äußeren Ventilkolben an, welche die jeweiligen Steuerräume begrenzen. Dies bietet den Vorteil, dass die Steuerkolben separat gefertigt werden können, was es ermöglich, beispielsweise andere Materialien zu verwenden oder diese mit unterschiedlichen Verfahren zu fertigen.In a further advantageous embodiment, the valve seat facing away from the end faces of the valve needles do not directly limit the inner and the outer control chamber, but the valve needles are located on an inner and an outer valve piston, which limit the respective control chambers. This offers the advantage that the control pistons can be manufactured separately, which makes it possible, for example, to use other materials or to manufacture them with different methods.

Weitere Vorteile und vorteilhafte Ausgestaltungen des Gegenstandes der Erfindung sind der Beschreibung und der Zeichnung entnehmbar.Further advantages and advantageous embodiments of the subject matter of the invention can be taken from the description and the drawing.

Zeichnungdrawing

In der Zeichnung sind zwei Ausführungsbeispiele des erfindungsgemäßen Kraftstoffeinspritzventils dargestellt. Es zeigt

Figur 1
einen Längsschnitt durch ein erfindungsgemäßes Kraftstoffeinspritzventil, wobei der Mittelteil der Übersichtlichkeit halber weggelassen wurde,
Figur 2a bis 2c
eine Vergrößerung des Steuerventils in verschiedenen Schaltstellungen,
Figur 3a und 3b
eine Vergrößerung des mit III bezeichneten Ausschnitts von Figur 1 im Bereich der Steuerräume und
Figur 4
ein nicht erfindungsgemäßes Kraftstoffeinspritzventils, wobei hier nur der mit A bezeichnete Abschnitt des in Figur 1 gezeigten Kraftstoffeinspritzventils dargestellt ist.
In the drawing, two embodiments of the fuel injection valve according to the invention are shown. It shows
FIG. 1
a longitudinal section through a fuel injection valve according to the invention, the middle part has been omitted for clarity,
FIGS. 2a to 2c
an enlargement of the control valve in different switching positions,
Figure 3a and 3b
an enlargement of the III section of FIG. 1 in the field of tax rooms and
FIG. 4
a non-inventive fuel injection valve, in which case only the designated A section of the in FIG. 1 shown fuel injection valve is shown.

Beschreibung der AusführungsbeispieleDescription of the embodiments

In Figur 1 ist ein erstes Ausführungsbeispiel des erfindungsgemäßen Kraftstoffeinspritzventils dargestellt. Das Kraftstoffeinspritzventil ist in einem Abschnitt A und einem Abschnitt B dargestellt, wobei der Teil zwischen diesen beiden Abschnitten der Übersichtlichkeit halber weggelassen wurde. Der Abschnitt B, der die eigentliche Düse darstellt, ist aus dem Stand der Technik hinreichend bekannt, so dass hier nur seine wesentlichen Teile beschrieben sind, wogegen der Abschnitt A die für die Erfindung wesentlichen Teile beinhaltet.In FIG. 1 a first embodiment of the fuel injection valve according to the invention is shown. The fuel injection valve is shown in a section A and a section B, wherein the part between these two sections has been omitted for the sake of clarity. The section B, which represents the actual nozzle, is well known in the art, so that only its essential parts are described here, whereas section A contains the parts essential to the invention.

Das Kraftstoffeinspritzventil umfasst ein Gehäuse 1, das einen Haltekörper 9, eine Drosselplatte 7, einen Steuerkörper 5 und einen Ventilkörper 3 umfasst, die in dieser Reihenfolge aneinander anliegen. Der Ventilkörper 3 wird durch eine Spannmutter 2, die an einer Schulter des Ventilkörpers 3 anliegt und in ein Gewinde am Haltekörper 9 eingeschraubt ist, gegen den Steuerkörper 5 gedrückt, so dass der Steuerkörper 5 über die Drosselplatte 7 auf den Haltekörper 9 drückt. Dadurch bleiben sämtliche Teile des Gehäuses 1 in ihrer vorgesehenen Position. Im Ventilkörper 3 ist eine Bohrung 11 ausgebildet, die als Sackbohrung ausgeführt ist und die an ihrem brennraumseitigen Ende einen konischen Ventilsitz 20 bildet. Im konischen Ventilsitz 20 sind zwei Einspritzöffnungsreihen 26,28 ausgebildet, wobei die äußere Einspritzöffnungsreihe 26 stromaufwärts der inneren Einspritzöffnungsreihe 28 ausgebildet ist. Beide Einspritzöffnungsreihen 26, 28 münden in Einbaulage des Kraftstoffeinspritzventils in den Brennraum desselben. In der Bohrung 11 ist eine Ventilaußennadel 17 längsverschiebbar angeordnet, die an einem brennraumabgewandten Abschnitt in der Bohrung 11 dichtend geführt ist. Zwischen der Ventilaußennadel 17 und der Wand der Bohrung 11 ist ein Druckraum 12 ausgebildet, der über einen im Haltekörper 9, der Drosselklappe 7, dem Steuerkörper 5 und dem Ventilkörper 3 verlaufenden Zulaufkanal 8 mit Kraftstoff unter hohem Druck befüllbar ist. Der Zulaufkanal 8 mündet hierbei in eine radiale Erweiterung des Druckraums 12, wobei sich diese radiale Erweiterung direkt an den Abschnitt der Bohrung 11 anschließt, in der die Ventilaußennadel 17 geführt ist. Am ventilsitzzugewandten Ende der Ventilaußennadel 17 ist eine äußere Ventildichtfläche 22 ausgebildet, die zumindest näherungsweise kegelstumpfförmig ausgebildet ist und die mit dem Ventilsitz 20 zusammenwirkt. Die Ventilaußennadel 17 weist eine Längsbohrung 16 auf, so dass die Ventilaußennadel 17 eine Hohlnadel bildet. In der Längsbohrung 16 der Ventilaußennadel 17 ist eine Ventilinnennadel 15 längsverschiebbar angeordnet, die an ihrem ventilsitzseitigen Ende ebenfalls eine konische Ventildichtfläche 24 aufweist, mit der die Ventilinnennadel 15 mit dem Ventilsitz 20 zusammenwirkt.The fuel injection valve comprises a housing 1 comprising a holding body 9, a throttle plate 7, a control body 5, and a valve body 3 abutting each other in this order. The valve body 3 is replaced by a Clamping nut 2, which bears against a shoulder of the valve body 3 and is screwed into a thread on the holding body 9, pressed against the control body 5, so that the control body 5 presses on the throttle plate 7 on the holding body 9. As a result, all parts of the housing 1 remain in their intended position. In the valve body 3, a bore 11 is formed, which is designed as a blind bore and forms a conical valve seat 20 at its combustion chamber end. In the conical valve seat 20, two injection port rows 26, 28 are formed, with the outer injection port row 26 formed upstream of the inner injection port row 28. Both injection openings rows 26, 28 open into the combustion chamber in the installation position of the fuel injection valve. In the bore 11, a valve outer needle 17 is arranged longitudinally displaceably, which is sealingly guided in a bore 11 remote from the combustion chamber in the bore. Between the valve outer needle 17 and the wall of the bore 11, a pressure chamber 12 is formed which can be filled with fuel under high pressure via a feed channel 9, the throttle valve 7, the control body 5 and the valve body 3 extending inlet channel. The inlet channel 8 opens into a radial extension of the pressure chamber 12, wherein this radial extension connects directly to the portion of the bore 11 in which the valve outer needle 17 is guided. At the valve seat facing the end of the valve outer needle 17, an outer valve sealing surface 22 is formed, which is at least approximately frusto-conical and which cooperates with the valve seat 20. The valve outer needle 17 has a longitudinal bore 16, so that the valve outer needle 17 forms a hollow needle. In the longitudinal bore 16 of the valve outer needle 17, a valve inner needle 15 is longitudinally displaceable, which also has a conical valve sealing surface 24 at its valve seat end, with which the valve inner needle 15 cooperates with the valve seat 20.

Die Steuerung der äußeren Einspritzöffnungen 26 und der inneren Einspritzöffnungen 28 erfolgt in der Weise, dass sich bei genügend hohem Druck im Druckraum 12 eine Kraft auf die Druckschulter 13 ergibt, die vom Ventilsitz weg gerichtet ist. Hierdurch bewegt sich die Ventilaußennadel 17 vom Ventilsitz 20 weg, so dass die äußeren Einspritzöffnungen 26 freigegeben werden und Kraftstoff aus dem Druckraum 12 durch die äußeren Einspritzöffnungen 26 in den Brennraum eingespritzt wird. Hebt auch die Ventilinnennadel 15, die durch den hydraulischen Druck auf Teile der Ventildichtfläche 24 eine vom Ventilsitz 20 weggerichtete Kraft erfährt, vom Ventilsitz 20 ab, so werden die inneren Einspritzöffnungen 28 freigegeben und Kraftstoff wird gleichzeitig durch die äußeren Einspritzöffnungen 26 und die inneren Einspritzöffnungen 28 eingespritzt. Bei Anlage der äußeren Ventilnadel 17 oder der äußeren und der inneren Ventilnadel am Ventilsitz 20 werden sämtliche Einspritzöffnungen 26, 28 verschlossen und die Einspritzung ist beendet.The control of the outer injection openings 26 and the inner injection openings 28 takes place in such a way that at sufficiently high pressure in the pressure chamber 12, a force on the pressure shoulder 13 results, which is directed away from the valve seat. As a result, the valve outer needle 17 moves away from the valve seat 20, so that the outer injection openings 26 are released and fuel is injected from the pressure chamber 12 through the outer injection openings 26 into the combustion chamber. Also raises the valve inner needle 15, which by the hydraulic pressure on parts of the valve sealing surface 24 a directed away from the valve seat 20 Force learns from the valve seat 20, so the inner injection ports 28 are released and fuel is injected simultaneously through the outer injection ports 26 and the inner injection ports 28. Upon contact of the outer valve needle 17 or the outer and inner valve needle on the valve seat 20, all the injection openings 26, 28 are closed and the injection is completed.

Im Steuerkörper 5 ist ein Kolbenraum 32 ausgebildet, der an beiden Stirnseiten des Steuerkörpers 5 offen ist. Im Kolbenraum 32 ist ein äußerer Ventilkolben 34 und ein im äußeren Ventilkolben 34 angeordneter innerer Ventilkolben 36 angeordnet. Hierbei liegt der äußere Ventilkolben 34 an der Ventilaußennadel 17 an, während der innere Ventilkolben 36 an der Ventilinnennadel 15 anliegt. Im Kolbenraum 32 ist darüber hinaus eine Schließfeder 38 angeordnet, die sich einenends an einen im Kolbenraum 32 ausgebildeten Absatz und anderenends am äußeren Ventilkolben 34 abstützt, wobei die Schließfeder 38 so unter Vorspannung steht, dass sie den äußeren Ventilkolben 34 und damit die Ventilaußennadel 17 in Richtung des Ventilsitzes 20 drückt. Figur 3a und 3b zeigen jeweils eine Vergrößerung des Kolbenraums 32.In the control body 5, a piston chamber 32 is formed, which is open at both end faces of the control body 5. In the piston chamber 32, an outer valve piston 34 and arranged in the outer valve piston 34 inner valve piston 36 is arranged. In this case, the outer valve piston 34 rests against the valve outer needle 17, while the inner valve piston 36 rests against the valve inner needle 15. In addition, a closing spring 38 is arranged in the piston chamber 32, which is supported at one end to a shoulder formed in the piston chamber 32 and the other end on the outer valve piston 34, wherein the closing spring 38 is biased so that they the outer valve piston 34 and thus the valve outer needle 17 in Direction of the valve seat 20 presses. Figure 3a and 3b each show an enlargement of the piston chamber 32.

Der äußere Ventilkolben 34 begrenzt mit seiner der Ventilaußennadel 17 abgewandten Stirnseite einen äußeren Steuerraum 56, der außen von der Wand des Kolbenraums 32 und dem äußeren Ventilkolben 34 gegenüber von der Drosselplatte 7 begrenzt wird. Der äußere Steuerraum 56 ist über eine Zulaufdrossel 47, über eine in der Drosselplatte 7 ausgebildete Verbindungsnut 53 mit dem Zulauf kanal 8 verbunden. Darüber hinaus geht vom äußeren Steuerraum 56 eine Ablaufdrossel 49 ab, die in einen Steuerventilraum 60 eines Steuerventils 30 mündet, das im Haltekörper 9 angeordnet ist. Der innere Ventilkolben 36 begrenzt mit seiner der Ventilinnennadel 15 abgewandten Stirnseite einen inneren Steuerraum 54, der über eine Zulaufdrossel 47, die in der Drosselplatte 7 ausgebildet ist, über die Verbindungsnut 53 mit dem Zulaufkanal 8 verbunden. Auch der innere Steuerraum 54 ist über eine innere Ablaufdrossel 51 mit dem Steuerventilraum 60 verbunden.The outer valve piston 34 bounded with its valve outer needle 17 facing away from an outer control chamber 56 which is bounded on the outside of the wall of the piston chamber 32 and the outer valve piston 34 opposite to the throttle plate 7. The outer control chamber 56 is connected via an inlet throttle 47, via a formed in the throttle plate 7 connecting groove 53 with the inlet channel 8. In addition, from the outer control chamber 56, an outlet throttle 49, which opens into a control valve chamber 60 of a control valve 30, which is arranged in the holding body 9. The inner valve piston 36 defines with its end facing away from the valve inner needle 15 an inner control chamber 54 which is connected via an inlet throttle 47, which is formed in the throttle plate 7, via the connecting groove 53 with the inlet channel 8. Also, the inner control chamber 54 is connected via an inner outlet throttle 51 with the control valve chamber 60.

Im Haltekörper 9 ist ein Leckölraum 40 ausgebildet, der mit einem Kraftstoffrücklaufsystem verbunden ist und in dem stets ein niedriger Kraftstoffdruck herrscht. Über einen Ablaufkanal 42, der im Haltekörper 9 der Drosselplatte 7 und im Steuerkörper 5 verläuft, ist der Kolbenraum 32 mit dem Leckölraum 40 verbunden, so dass im Kolbenraum 32 stets ein niedriger Kraftstoffdruck herrscht. Aus dem Druckraum 12 austretender und zwischen der Ventilaußennadel 17 und der Wand der Bohrung 11 hindurchfließender Kraftstoff wird so abgeführt, so dass es zu keinem Druckanstieg im Kolbenraum 32 kommt. Der Leckölraum 40 ist über eine Ablauföffnung 68 ebenfalls mit dem Steuerventilraum 60 verbunden. Figur 2a zeigt den näheren Aufbau des Steuerventils 30 und macht die Wirkungsweise deutlich. Im Steuerventilraum 60 ist ein Ventilglied 62 angeordnet, das mit einem Piezosteller 66 verbunden ist. Mit Hilfe des Piezostellers 66 kann das Ventilglied 62 in Längsrichtung im Steuerventilraum 60 bewegt werden. Das Ventilglied 62 weist eine erste Dichtfläche 74 auf, mit der das Ventilglied 62 in der in Figur 2a dargestellten ersten Schaltposition an einem im Steuerventilraum 60 ausgebildeten ersten Ventilsitz 70 anliegt. Hierdurch wird die Ablauföffnung 68, die als ein das Ventilglied 62 umgebender Ringspalt ausgebildet ist und über den der Steuerventilraum 60 mit dem Leckölraum 40 verbunden ist, verschlossen. Über eine im Steuerventilraum 60 angeordnete Schließfeder 64 wird das Ventilglied 62 in Anlage an den ersten Ventilsitz 70 gepresst, so dass bei nicht bestromtem Piezosteller 66 das Ventilglied 62 in dieser ersten Schaltposition bleibt. In der ersten Schaltposition sind beide Ablaufdrosseln 49, 51, die in den Steuerventilraum 60 münden, geöffnet. Da der Steuerventilraum 60 jetzt keine Verbindung zum Leckölraum 40 hat, baut sich in diesem der hohe Kraftstoffdruck der im Hochdruckbereich des Kraftstoffeinspritzventils, also im Zulaufkanal 8, vorhanden ist, auf. Hierdurch herrscht auch im äußeren Steuerraum 56 und im inneren Steuerraum 54 ein hoher Kraftstoffdruck, der sowohl den äußeren Ventilkolben 34 und damit die Ventilaußennadel 17, als auch den inneren Ventilkolben 36 und damit die Ventilinnennadel 15 in Richtung des Ventilsitzes 20 drückt. In dieser Stellung der Ventilkolben 34, 36 sind die Steuerräume 54, 56 miteinander verbunden und bilden einen gemeinsamen Steuerraum. Da der äußere Ventilkolben 36 eine größere, den äußeren Steuerraum 56 begrenzende Fläche aufweist als die Druckschulter 13 der äußeren Ventilnadel 17, bleibt die äußere Ventilnadel 17 geschlossen, obwohl im Druckraum 12 stets ein hoher Kraftstoffdruck herrscht.In the holding body 9, a leakage oil chamber 40 is formed, which is connected to a fuel return system and in which always a low fuel pressure prevails. Via a drain channel 42, which extends in the holding body 9 of the throttle plate 7 and the control body 5, the piston chamber 32 is connected to the leakage oil chamber 40, so that there is always a low fuel pressure in the piston chamber 32. From the pressure chamber 12 exiting and flowing between the valve outer needle 17 and the wall of the bore 11 fuel is discharged so that there is no pressure increase in the piston chamber 32. The leakage oil chamber 40 is likewise connected to the control valve chamber 60 via a drain opening 68. FIG. 2a shows the closer structure of the control valve 30 and makes the operation clear. In the control valve chamber 60, a valve member 62 is arranged, which is connected to a piezoelectric actuator 66. With the help of the piezoelectric actuator 66, the valve member 62 can be moved in the longitudinal direction in the control valve chamber 60. The valve member 62 has a first sealing surface 74, with which the valve member 62 in the in FIG. 2a shown first switching position is applied to a formed in the control valve chamber 60 first valve seat 70. As a result, the drain opening 68, which is formed as an annular gap surrounding the valve member 62 and via which the control valve chamber 60 is connected to the leakage oil chamber 40, is closed. About a arranged in the control valve chamber 60 closing spring 64, the valve member 62 is pressed into abutment against the first valve seat 70 so that when not energized piezoelectric actuator 66, the valve member 62 remains in this first switching position. In the first switching position, both outlet throttles 49, 51, which open into the control valve chamber 60, are opened. Since the control valve chamber 60 now has no connection to the leakage oil chamber 40, the high fuel pressure which is present in the high-pressure region of the fuel injection valve, that is to say in the inlet channel 8, builds up in it. As a result, there is also a high fuel pressure in the outer control chamber 56 and in the inner control chamber 54, which presses both the outer valve piston 34 and thus the valve outer needle 17 and the inner valve piston 36 and thus the valve inner needle 15 in the direction of the valve seat 20. In this position of the valve piston 34, 36, the control chambers 54, 56 are connected to each other and form a common control chamber. Since the outer valve piston 36 has a larger, the outer control chamber 56 defining surface than the pressure shoulder 13 of the outer valve needle 17, the outer valve needle 17 remains closed, although there is always a high fuel pressure in the pressure chamber 12.

In Figur 2b ist die zweite Schaltposition des Ventilglieds 62 dargestellt, die dieses entgegen der Kraft der Schließfeder 64 durch Bewegung mittels des Piezostellers 66 einnehmen kann. In dieser Stellung hat die erste Dichtfläche 74 des Ventilglieds 62 vom ersten Ventilsitz 70 abgehoben, so dass die Ablauföffnung 68 nun geöffnet ist. Hierdurch fließt Kraftstoff aus dem Steuerventilraum 60 in den Leckölraum 40, so dass der Kraftstoffdruck im Steuerventilraum 60 sinkt. Da nach wie vor beide Ablaufdrosseln 49,51 geöffnet sind, fließt Kraftstoff sehr rasch aus dem äußeren Steuerraum 56 und dem inneren Steuerraum 54 über den Steuerventilraum 60 in den Leckölraum 40 ab, wobei die Zulaufdrosseln 45, 47 so bemessen sind, dass weniger Kraftstoff über diese Zulaufdrosseln 45, 47 in die Steuerräume 54, 56 nachfließt, als über die Ablaufdrossel 49, 51 abfließt. Hierdurch sinkt der Druck im äußeren Steuerraum 54 und im inneren Steuerraum 56 ab. Die dritte Schaltposition des Ventilglieds 62 ist in Figur 2c dargestellt und zeigt das Ventilglied 62, wie es mit seiner der ersten Dichtfläche 74 gegenüberliegenden Stirnseite, die als zweite Dichtfläche 76 ausgebildet ist, am zweiten Ventilsitz 72 anliegt, der an der Drosselplatte 7 ausgebildet ist. In dieser dritten Schaltposition wird die innere Ablaufdrossel 51 verschlossen, so dass nunmehr der äußere Steuerraum 56 mit dem Steuerventilraum 60 verbunden ist. Die Ablauföffnung 68 bleibt nach wie vor geöffnet.In FIG. 2b the second switching position of the valve member 62 is shown, this against the force of the closing spring 64 by movement by means of the piezoelectric actuator 66 can take. In this position, the first sealing surface 74 of the valve member 62 has lifted from the first valve seat 70, so that the drain opening 68 is now open. As a result, fuel flows from the control valve chamber 60 into the leakage oil chamber 40, so that the fuel pressure in the control valve chamber 60 decreases. Since both outlet throttles 49, 51 are still open, fuel flows very rapidly from the outer control chamber 56 and the inner control chamber 54 via the control valve chamber 60 into the leakage oil chamber 40, wherein the inlet throttles 45, 47 are dimensioned such that less fuel is present this inflow throttles 45, 47 flows into the control chambers 54, 56, as flows through the outlet throttle 49, 51. As a result, the pressure in the outer control chamber 54 and in the inner control chamber 56 decreases. The third switching position of the valve member 62 is in Figure 2c illustrated and shows the valve member 62, as with its first sealing surface 74 opposite end face, which is formed as a second sealing surface 76, abuts the second valve seat 72 which is formed on the throttle plate 7. In this third switching position, the inner outlet throttle 51 is closed, so that now the outer control chamber 56 is connected to the control valve chamber 60. The drain opening 68 remains open.

Die Funktionsweise des Kraftstoffeinspritzventils ist wie folgt: zu Beginn des Einspritzvorgangs ist das Ventilglied 62 des Steuerventils 30 in seiner ersten Schaltposition, d.h. in Anlage am ersten Ventilsitz 70. Über die Verbindung des äußeren Steuerraums 56 und des inneren Steuerraums 54 über die äußere Zulaufdrossel 45 und die innere Zulaufdrossel 47 mit dem Hochdruckbereich, also dem Zulaufkanal 8, herrscht in beiden Steuerräumen 54, 56 derselbe Kraftstoffdruck wie im Zulaufkanal 8. Durch die hydraulische Kraft auf den inneren Ventilkolben 36 und den äußeren Ventilkolben 34 werden die Ventilaußennadel 17 und die Ventilinnennadel 15 gegen den Ventilsitz 20 gedrückt und verschließen sämtliche Einspritzöffnungen 26, 28. Soll eine Einspritzung nur durch die äußeren Einspritzöffnungen 26 erfolgen, so wird das Ventilglied 62 über eine entsprechende Bestromung des Piezostellers 66 von seiner ersten Schaltposition in die dritte Schaltposition bewegt, wie sie in Figur 2c dargestellt ist. Die äußere Ablaufdrossel 49 ist hierbei so dimensioniert, dass der Druck in den beiden Steuerräumen 54, 56 auch dann abfällt, wenn die innere Ablaufdrossel 51 durch das Ventilglied 62 verschlossen wird. Es fließt also weniger Kraftstoff über die Zulaufdrosseln 45, 47 in die Steuerräume 54, 56 nach, als über die äußere Ablaufdrossel 49 in den Leckölraum 40 abfließt. Hierdurch sinkt der Druck im äußeren Steuerraum 56 und im inneren Steuerraum 54 so lange, bis die hydraulische Kraft auf die Druckschulter 13 der Ventilaußennadel 17 größer ist als die hydraulische Kraft und die Federkraft der Schließfeder 38 auf den äußeren Ventilkolben 34. Hierdurch bewegt sich die Ventilaußennadel 17 vom Ventilsitz 20 weg und öffnet die äußeren Einspritzöffnungen 26, durch die nun Kraftstoff in den Brennraum eingespritzt wird. Durch die Bewegung der Ventilaußennadel 17 bewegt sich auch der äußere Ventilkolben 34, bis er an der Drosselscheibe 7 zur Anlage kommt. Durch die Anschrägung der Stirnseite des äußeren Ventilkolbens 34 ist an diesem eine Dichtkante 37 ausgebildet, die durch ihre Anlage an der Drosselscheibe 7 den äußeren Steuerraum 56 vom inneren Steuerraum 54 trennt. Da der innere Steuerraum 54 nunmehr keine hydraulische Verbindung zum Steuerventilraum 60 und damit zum Leckölraum 40 hat, fällt der Druck im inneren Steuerraum 54 nicht weiter ab, sondern steigt über einen entsprechenden Kraftstoffzulauf durch die innere Zulaufdrossel 47 wieder auf das Niveau des Zulaufkanals 8 an. Dadurch bleibt die hydraulische Kraft auf den inneren Ventilkolben 36 und damit auf die Ventilinnennadel 15 so groß, dass die Ventilinnennadel 15 in ihrer Schließstellung verharrt und die inneren Einspritzöffnungen 28 verschließt. Zur Beendigung des Einspritzvorgangs wird das Ventilglied 62 des Steuerventils 30 durch den Piezosteller 66 wieder zurück in die erste Schaltposition gefahren, wie sie in Figur 2a dargestellt ist. Über zulaufenden Kraftstoff durch die äußere Zulaufdrossel 45 steigt der Druck im äußeren Steuerraum 56 rasch wieder an, da durch die äußere Ablaufdrossel 49 kein Kraftstoff mehr abfließt. Sobald der Kraftstoffdruck im äußeren Steuerraum 56 so weit angestiegen ist, dass die dadurch ausgeübte Kraft größer ist als die hydraulische Kraft auf die Druckschulter 13 der Ventilaußennadel 17, bewegt sich die Ventilaußennadel 17, angetrieben durch den äußeren Ventilkolben 34, zurück in ihre Schließposition, d.h. in Anlage an den Ventilsitz 20 und verschließt hierdurch die äußeren Einspritzöffnungen 26.The operation of the fuel injection valve is as follows: at the beginning of the injection process, the valve member 62 of the control valve 30 in its first switching position, that is in abutment with the first valve seat 70. On the connection of the outer control chamber 56 and the inner control chamber 54 via the outer inlet throttle 45 and the inner inlet throttle 47 with the high-pressure region, ie the inlet channel 8, prevails in both control chambers 54, 56 the same fuel pressure as in the inlet channel 8. Due to the hydraulic force on the inner valve piston 36 and the outer valve piston 34, the valve outer needle 17 and the valve inner needle 15 against If an injection takes place only through the outer injection openings 26, the valve member 62 is moved via a corresponding energization of the piezoelectric actuator 66 from its first switching position to the third switching position, as described in US Pat Figure 2c is shown. The outer outlet throttle 49 is in this case dimensioned such that the pressure in the two control chambers 54, 56 also drops when the inner outlet throttle 51 is closed by the valve member 62. Thus, less fuel flows via the inlet throttles 45, 47 into the control chambers 54, 56, than via the outer outlet throttle 49 in the Leakage oil chamber 40 drains off. As a result, the pressure in the outer control chamber 56 and in the inner control chamber 54 decreases until the hydraulic force on the pressure shoulder 13 of the valve outer needle 17 is greater than the hydraulic force and the spring force of the closing spring 38 on the outer valve piston 34. This causes the valve outer needle moves 17 away from the valve seat 20 and opens the outer injection openings 26 through which fuel is now injected into the combustion chamber. By the movement of the valve outer needle 17 and the outer valve piston 34 moves until it comes to the throttle plate 7 to the plant. By the bevel of the end face of the outer valve piston 34, a sealing edge 37 is formed on this, which separates the outer control chamber 56 from the inner control chamber 54 by their engagement with the throttle plate 7. Since the inner control chamber 54 now has no hydraulic connection to the control valve chamber 60 and thus to the leakage oil chamber 40, the pressure in the inner control chamber 54 does not drop further, but rises again via an appropriate fuel supply through the inner inlet throttle 47 to the level of the inlet channel 8. As a result, the hydraulic force on the inner valve piston 36 and thus on the valve inner needle 15 remains so great that the valve inner needle 15 remains in its closed position and closes the inner injection openings 28. To complete the injection process, the valve member 62 of the control valve 30 is driven by the piezoelectric actuator 66 back to the first switching position, as in FIG. 2a is shown. Overflowing fuel through the outer inlet throttle 45, the pressure in the outer control chamber 56 increases rapidly again, as no fuel flows through the outer outlet throttle 49. Once the fuel pressure in the outer control chamber 56 has risen so high that the force exerted thereby is greater than the hydraulic force on the pressure shoulder 13 of the valve outer needle 17, the valve outer needle 17, driven by the outer valve piston 34, moves back to its closed position, ie in abutment against the valve seat 20 and thereby closes the outer injection openings 26th

Da der Druck in dem vereinigten Steuerraum 54, 56 zu Beginn der Einspritzung nur über den Ablauf durch die äußere Ablaufdrossel 49 abfällt, ist dieser Druckabfall relativ langsam, so dass auch die Ventilaußennadel 17 nur langsam öffnet, was ein genaues Dosieren der Einspritzmenge ermöglicht. Da eine Einspritzung nur durch einen Teil der Einspritzöffnungen meist eine Vor- oder Nacheinspritzung ist, die eine nur sehr geringe Kraftstoffmenge aufweist, ist eine genaue Dosierung hier besonders wichtig.Since the pressure in the combined control chamber 54, 56 drops only at the beginning of the injection through the outlet through the outer outlet throttle 49, this pressure drop is relatively slow, so that the valve outer needle 17 opens only slowly, allowing accurate dosing of the injection quantity. Since an injection only by a part of the injection openings usually a pre- or post-injection is that has a very small amount of fuel, a precise dosage is particularly important here.

Wenn bei Volllast der Brennkraftmaschine sehr viel Kraftstoff im Brennraum benötigt wird, soll die Einspritzung durch sämtliche Einspritzöffnungen 26, 28 erfolgen. Hierzu wird das Steuerventil 30 so betätigt, dass das Ventilglied 62 in seine zweite Schaltposition fährt, wie es in Figur 2b dargestellt ist. Hierdurch wird der gemeinsame Steuerraum, der durch den äußeren Steuerraum 56 und den inneren Steuerraum 54 gebildet wird, über die äußere Ablaufdrossel 49 und die innere Ablaufdrossel 51 mit dem Steuerventilraum 60 verbunden. Da nun ein deutlich höherer Ablaufquerschnitt bereitsteht, fällt der Druck in den Steuerräumen 54, 56 sehr rasch ab und es öffnet zuerst die Ventilaußennadel 17 in der oben beschriebenen Art und Weise und, je nach Auslegung der Druckfläche an der inneren Ventildichtfläche 24 der Ventilinnennadel 15, mit kurzem oder etwas längerem Abstand auch die Ventilinnennadel 15. Hierbei verfährt der innere Ventilkolben 36 so weit, bis er zur Anlage an der Drosselscheibe 7 gelangt. Zur Beendigung der Einspritzung wird das Ventilglied 62 des Steuerventils 30 zurück in seine erste Schaltposition gefahren, wie es in Figur 2a dargestellt ist. Durch die nun verschlossene Ablauföffnung 68 fehlt die Verbindung zum Leckölraum 40, was den Druck im inneren Steuerraum 54 und dem äußeren Steuerraum 56 über Kraftstoffzufluss durch die innere Zulaufdrossel 47 und die äußere Zulaufdrossel 45 wieder rasch ansteigen lässt, so dass über die entsprechenden hydraulischen Kräfte auf den äußeren Ventilkolben 34 bzw. den inneren Ventilkolben 36 beide Ventilnadeln 15, 17 zurück in ihre Schließstellung fahren.If a lot of fuel in the combustion chamber is required at full load of the internal combustion engine, the injection should take place through all the injection openings 26, 28. For this purpose, the control valve 30 is actuated so that the valve member 62 moves to its second switching position, as in FIG. 2b is shown. As a result, the common control space, which is formed by the outer control chamber 56 and the inner control chamber 54, is connected to the control valve chamber 60 via the outer outlet throttle 49 and the inner outlet throttle 51. Since a significantly higher drainage cross-section is now available, the pressure in the control chambers 54, 56 drops rapidly and first it opens the valve outer needle 17 in the manner described above and, depending on the design of the pressure surface on the inner valve sealing surface 24 of the valve inner needle 15, with a short or slightly longer distance, the valve inner needle 15. In this case, the inner valve piston 36 moves so far until it comes to rest on the throttle plate 7. To complete the injection, the valve member 62 of the control valve 30 is moved back to its first switching position, as in FIG. 2a is shown. The now closed drain opening 68 lacks the connection to the leakage oil chamber 40, which causes the pressure in the inner control chamber 54 and the outer control chamber 56 via fuel flow through the inner inlet throttle 47 and the outer inlet throttle 45 to rise rapidly again, so that on the corresponding hydraulic forces the outer valve piston 34 and the inner valve piston 36 both valve needles 15, 17 go back to its closed position.

Neben diesen beiden Funktionsbeispielen sind auch andere Schaltmöglichkeiten des Steuerventils 30 denkbar. So kann eine Einspritzung auch in der Weise erfolgen, dass das Ventilglied 62 zuerst in die dritte Schaltposition fährt, so dass sich, wie oben beschrieben, die Ventilaußennadel 17 öffnet. Anschließend kann das Ventilglied 62 in die zweite Schaltposition gefahren werden, in der auch der innere Steuerraum 54 über die innere Ablaufdrossel 51 entlastet wird. Dadurch öffnet sich jetzt auch die Ventilinnennadel 15, so dass die Einspritzung zuerst nur durch die äußeren Einspritzöffnungen 26 und anschließend durch sämtliche Einspritzöffnungen 26, 28 erfolgt, so dass sich eine Einspritzverlaufsformung ergibt, deren genauer Verlauf auch noch über die Schaltgeschwindigkeit des Piezostellers 66 beeinflussbar ist. Anschließend wird das Ventilglied 62 in seine erste Schaltposition zurückgefahren, so dass die Ventilnadeln 15, 17 in der oben beschriebenen Art und Weise wieder schließen.In addition to these two functional examples, other switching options of the control valve 30 are conceivable. Thus, an injection can also take place in such a way that the valve member 62 moves first to the third switching position, so that, as described above, the valve outer needle 17 opens. Subsequently, the valve member 62 can be moved to the second switching position, in which the inner control chamber 54 is relieved via the inner outlet throttle 51. This now also opens the valve inner needle 15, so that the injection takes place at first only through the outer injection openings 26 and then through all the injection openings 26, 28, so that there is a Einspritzverlaufsformung whose exact course also on the switching speed of the piezoelectric actuator 66th can be influenced. Subsequently, the valve member 62 is moved back to its first switching position, so that the valve needles 15, 17 close in the manner described above again.

In Figur 4 ist ein nicht erfindungsgemäßes Kraftstoffeinspritzventils dargestellt, wobei hier nur der in Figur 1 mit A bezeichnete Abschnitt des des Kraftstoffeinspritzventils erneut gezeichnet ist. Der Abschnitt B der Figur 1 ist identisch mit dem brennraumseitigen Ende des Kraftstoffeinspritzventils, wie es in Figur 4 dargestellt ist. Das in Figur 4 dargestellte Kraftstoffeinspritzventil weist ebenfalls ein Gehäuse 1 auf, wobei ein separater Steuerkörper 5 entfällt und der Haltekörper 9 direkt an die Drosselscheibe 7 und diese wiederum an den Ventilkörper 3 grenzt. Der Ventilkörper 3 wird durch eine Spannmutter 2 in gleicher Art und Weise wie bei dem in Figur 1 gezeigten Ausführungsbeispiel über die Drosselscheibe 7 gegen den Haltekörper 9 gepresst. Im Ventilkörper 3 ist eine Bohrung 11 ausgebildet, in der ebenfalls eine Ventilaußennadel 17 und eine Ventilinnennadel 15 angeordnet sind, die in der Bohrung 11 längsverschiebbar sind. Am ventilsitzabgewandten Ende ist die Bohrung 11 zu einem Federraum 14 erweitert, in dem die Schließfeder 38 angeordnet ist. Die Ventilaußennadel 17 wird von einer Hülse 18 umgeben, die im Federraum 14 angeordnet ist und zwischen der und einem Stützring 19 die Schließfeder 38 unter Vorspannung angeordnet ist. Die Hülse 18 liegt an der Drosselscheibe 7 an, so dass über die Schließfeder 38 und den Stützring 19 eine Schließkraft auf die Ventilaußennadel 17 ausgeübt wird. In den Federraum 14 mündet der Zulaufkanal 8, so dass der Federraum 14 in seiner Funktion dem Druckraum 12 des in Figur 1 dargestellten Ausführungsbeispiels entspricht. Der Druckraum 12 setzt sich als Ringraum zwischen der Ventilaußennadel 17 und der Wand der Bohrung 11 bis zum Ventilsitz 20 fort.In FIG. 4 is a non-inventive fuel injection valve shown, in which case only the in FIG. 1 A labeled portion of the fuel injector is redrawn. Section B of the FIG. 1 is identical to the combustion chamber end of the fuel injection valve, as in FIG. 4 is shown. This in FIG. 4 Fuel injection valve shown also has a housing 1, wherein a separate control body 5 is omitted and the holding body 9 directly adjacent to the throttle plate 7 and this in turn to the valve body 3. The valve body 3 is characterized by a clamping nut 2 in the same manner as in the FIG. 1 shown embodiment pressed on the throttle plate 7 against the holding body 9. In the valve body 3, a bore 11 is formed, in which also a valve outer needle 17 and a valve inner needle 15 are arranged, which are longitudinally displaceable in the bore 11. At the valve seat end facing away from the bore 11 is expanded to a spring chamber 14, in which the closing spring 38 is arranged. The valve outer needle 17 is surrounded by a sleeve 18 which is arranged in the spring chamber 14 and between which and a support ring 19, the closing spring 38 is arranged under prestress. The sleeve 18 abuts against the throttle plate 7, so that via the closing spring 38 and the support ring 19, a closing force is exerted on the valve outer needle 17. In the spring chamber 14 of the inlet channel 8 opens, so that the spring chamber 14 in its function the pressure chamber 12 of the in FIG. 1 illustrated embodiment corresponds. The pressure chamber 12 continues as an annular space between the valve outer needle 17 and the wall of the bore 11 to the valve seat 20.

In der Drosselscheibe 7 ist eine Bohrung 39 ausgebildet, in die die Ventilinnennadel 15 hineinragt und in der sie geführt ist. Die Ventilinnennadel 15 ist hierbei länger als die Ventilaußennadel 17 ausgebildet, und sie weist eine erste Ringnut 77 auf, die auf Höhe der Hülse 18 ausgebildet ist, und eine zweite Ringnut 78, die innerhalb der Drosselscheibe 7 angeordnet ist. Die erste Ringnut 77 und die zweite Ringnut 78 sind über eine Verbindungsnut 79 an der Außenseite der Ventilinnennadel 15 miteinander verbunden und die zweite Ringnut 78 ist über einen in dem Leckölraum 40 verbunden, so dass sowohl in der ersten Ringnut 77 als auch in der zweiten Ringnut 78 stets ein niedriger Kraftstoffdruck herrscht.In the throttle plate 7, a bore 39 is formed, in which the valve inner needle 15 protrudes and in which it is guided. The inner valve needle 15 is in this case formed longer than the valve outer needle 17, and it has a first annular groove 77, which is formed at the level of the sleeve 18, and a second annular groove 78 which is disposed within the throttle plate 7. The first annular groove 77 and the second annular groove 78 are connected to each other via a connecting groove 79 on the outside of the valve inner needle 15 and the second annular groove 78 is connected via an in connected to the leakage oil chamber 40, so that there is always a low fuel pressure in both the first annular groove 77 and in the second annular groove 78.

Durch die ventilsitzabgewandte Stirnseite der Ventilaußennadel 17, die Hülse 18, die Drosselscheibe 7 und die Ventilinnennadel 15 wird der äußere Steuerraum 56 begrenzt, der über die äußere Ablaufdrossel 49 mit dem Steuerventilraum 60 des Steuerventils 30 verbunden ist. Das Steuerventil 30 entspricht hier in seiner Funktion und Aufbau dem Steuerventil 30, das in Figur 1 bzw. Figur 2a bis 2c dargestellt ist. Durch die ventilsitzabgewandte Stirnseite der Ventilinnennadel 15 und den Grund der Bohrung 39 wird der innere Steuerraum 54 begrenzt, der über die innere Ablaufdrossel 51 mit dem Steuerventilraum 60 verbunden ist. Der innere Steuerraum 54 ist mit der äußeren Zulaufdrossel 49 verbunden, die wiederum in den Hochdruckbereich, also in den Zulaufkanal 8 mündet. Der Steuerventilraum 60 ist über die Ablauföffnung 68 in gleicher Art und Weise, wie in Figur 2a bis 2c dargestellt, mit dem Leckölraum 40 verbindbar.By the valve seat facing away from the front end of the valve outer needle 17, the sleeve 18, the throttle plate 7 and the valve inner needle 15, the outer control chamber 56 is limited, which is connected via the outer outlet throttle 49 with the control valve chamber 60 of the control valve 30. The control valve 30 corresponds here in its function and structure to the control valve 30, the in FIG. 1 respectively. FIGS. 2a to 2c is shown. By the valve seat facing away from the end of the valve inner needle 15 and the bottom of the bore 39, the inner control chamber 54 is limited, which is connected via the inner outlet throttle 51 with the control valve chamber 60. The inner control chamber 54 is connected to the outer inlet throttle 49, which in turn opens into the high-pressure region, ie into the inlet channel 8. The control valve chamber 60 is via the drain opening 68 in the same manner as in FIGS. 2a to 2c shown connected to the leakage oil chamber 40.

Durch die Bauweise des Kraftstoffeinspritzventils ist hier der äußere Steuerraum 56 stets vom inneren Steuerraum 54 getrennt. Die Funktionsweise der Steuerräume 54, 56 und ihre Ansteuerung durch das Steuerventil 30 sind jedoch gleich wie bei dem in Figur 1 gezeigten Ausführungsbeispiel. Wenn eine Einspritzung nur durch die äußeren Einspritzöffnungen 26 erfolgen soll, so wird auch hier das Ventilglied 62 von der ersten in die dritte Schaltposition gefahren, wie sie in Figur 2c dargestellt ist. Dadurch kommt das Ventilglied 62 mit seiner zweiten Dichtfläche 76 am zweiten Ventilsitz 72, der hier in der Drosselscheibe 7 ausgebildet ist, zur Anlage. Die innere Ablaufdrossel 51 wird somit verschlossen und die Verbindung des Steuerventilraums 60 mit dem Leckölraum 40 über die Ablauföffnung 68 geöffnet. Der Druck im äußeren Steuerraum 56 fällt ab und die Ventilaußennadel 17 öffnet in der bereits oben beschriebenen bekannten Art und Weise. Die Druckschulter 13, die in Figur 4 nicht dargestellt ist, ist näher am Ventilsitz ausgebildet als bei dem in Figur 1 dargestellten Ausführungsbeispiel. Solange das Ventilglied 62 in der dritten Schaltstellung verharrt, bleibt der Hochdruck im inneren Steuerraum 54 erhalten, und ein Kraftstofffluss durch den Ringspalt zwischen der Wand der Bohrung 39 und der inneren Ventilnadel 15 wird durch die zweite Ringnut 78, die über den Ablaufkanal 58 stets drucklos ist, verhindert, indem gegebenenfalls eindringender Kraftstoff abgeleitet wird. Zur Beendigung der Einspritzung wird das Ventilglied 62 wiederum rasch in die erste Schaltposition zurückgefahren.Due to the design of the fuel injection valve here the outer control chamber 56 is always separated from the inner control chamber 54. However, the operation of the control chambers 54, 56 and their control by the control valve 30 are the same as in the FIG. 1 shown embodiment. If an injection is to take place only through the outer injection openings 26, then here too the valve member 62 is moved from the first to the third switching position, as in Figure 2c is shown. As a result, the valve member 62 comes with its second sealing surface 76 on the second valve seat 72, which is formed here in the throttle plate 7 to the plant. The inner outlet throttle 51 is thus closed and the connection of the control valve chamber 60 with the leakage oil chamber 40 is opened via the drain opening 68. The pressure in the outer control chamber 56 drops and the valve outer needle 17 opens in the known manner already described above. The pressure shoulder 13, the in FIG. 4 is not shown, is formed closer to the valve seat than in the FIG. 1 illustrated embodiment. As long as the valve member 62 remains in the third switching position, the high pressure in the inner control chamber 54 is maintained, and a fuel flow through the annular gap between the wall of the bore 39 and the inner valve needle 15 is through the second annular groove 78, which is always depressurized via the drain passage 58 is prevented by any penetrating fuel is derived. To end the Injection, the valve member 62 is again quickly returned to the first switching position.

Zur Einspritzung über sämtliche Einspritzöffnungen 26, 28 wird das Ventilglied 62 in die zweite Schaltposition gefahren, wie sie in Figur 2b dargestellt ist. Hierdurch werden in gleicher Art und Weise, wie oben bereits dargestellt, sowohl die innere Ablaufdrossel 51, als auch die äußere Ablaufdrossel 49 aufgesteuert, wodurch der Druck sowohl im inneren Steuerraum 54 als auch im äußeren Steuerraum 56 abfällt. Hierdurch öffnen rasch hintereinander die Ventilaußennadel 17 und die Ventilinnennadel 15 und geben sämtliche Einspritzöffnungen 26, 28 frei. Durch das Bewegen des Ventilglieds 62 zurück in die erste Schaltposition füllen sich die Steuerräume 54, 56 erneut mit Kraftstoff unter Hochdruck, so dass die Ventilaußennadel 17 und die Ventilinnennadel 15 in ihre Schließstellung zurückgleiten.For injection via all injection openings 26, 28, the valve member 62 is moved to the second switching position, as in FIG. 2b is shown. As a result, both the inner outlet throttle 51, and the outer outlet throttle 49 are opened in the same manner, as already shown above, whereby the pressure drops both in the inner control chamber 54 and in the outer control chamber 56. As a result, the valve outer needle 17 and the inner valve needle 15 open in quick succession and release all the injection openings 26, 28. By moving the valve member 62 back to the first switching position, the control chambers 54, 56 again fill with fuel under high pressure, so that the valve outer needle 17 and the valve inner needle 15 slide back into its closed position.

Bei dem in Figur 4 dargestellten nicht erfindungsgemäßen Kraftstoffeinspritzventil kann der Druckabfall im äußeren Steuerraum 56 nicht variiert werden, so dass bei jeder Öffnungsbewegung der Druck dort gleich schnell abfällt. Hierdurch öffnet die Ventilaußennadel 17 stets etwa mit der gleichen Öffnungsgeschwindigkeit.At the in FIG. 4 illustrated fuel injector not according to the invention, the pressure drop in the outer control chamber 56 can not be varied, so that at each opening movement, the pressure drops there equally fast. As a result, the valve outer needle 17 always opens at about the same opening speed.

Die Bewegung des Ventilglieds 62 kann außer durch einen Piezosteller 66 auch durch einen anderen Antrieb erfolgen, der es erlaubt, das Ventilglied 62 in linearer Richtung zu bewegen und in die erste, zweite und dritte Schaltposition zu bewegen. Piezosteller sind hierzu jedoch sehr geeignet, da sie sehr rasch arbeiten und jede beliebige Längenänderung zwischen ihren Maximalauslenkungen anfahren können.The movement of the valve member 62 can be done except by a piezoelectric actuator 66 by another drive, which allows the valve member 62 to move in the linear direction and to move in the first, second and third switching position. However, piezo actuators are very suitable for this because they work very quickly and can approach any change in length between their maximum deflections.

Claims (9)

  1. Fuel injection valve for internal combustion engines having a housing, in which a valve seat (20) is formed and a valve outer needle (17) and a valve inner needle (15) are arranged, and having an outer control space (56), by the pressure of which a closing force can be exerted on the valve outer needle (17) at least indirectly, and having an inner control space (54), by the pressure of which a closing force can be exerted on the valve inner needle (15) at least indirectly, the closing forces acting in the direction of the valve seat (20) and the inner control space (54) being connected via an inner outflow throttle (51) and the outer control space (56) being connected via an outer outflow throttle (49) to a control valve space (60) of a control valve (30), it being possible for the control valve space (60) to be connected to a leakage oil space (40) via an outflow opening (68) and a valve element (62) being arranged in the control valve space (60), the inner control space (54) being connected via an inner inflow throttle (47) and the outer control space (56) being connected via an outer inflow throttle (45) to a high-pressure region (8), and it being possible for the valve element (62) to assume a first, a second and a third switching position in the control valve space (60), such that the outflow opening (68) is closed in the first switching position, both the inner outflow throttle (51) and the outer outflow throttle (49) are connected to the leakage oil space (40) via the open outflow opening (68) in the second switching position and, in the third switching position, the outer outflow throttle (49) is connected to the leakage oil space (40) and the inner outflow throttle (51) is closed by the valve element (62), characterized in that the inner control space (54) and the outer control space (56) are connected to one another when both the valve outer needle (17) and the valve inner needle (15) are situated in their closed position in contact with the valve seat (20), the outer control space (56) being separated from the inner control space (54) by the stroke movement of the valve outer needle (17).
  2. Fuel injection valve according to Claim 1, characterized in that a low pressure always prevails in the leakage oil space (40).
  3. Fuel injection valve according to Claim 1 or 2, characterized in that the valve element (62) can be moved via a piezoelectric actuator (66).
  4. Fuel injection valve according to Claim 1, characterized in that the valve element (62) bears against a first valve seat (70) in its first switching position and against a second valve seat (72) in its third switching position, the valve element (62) moving linearly between the first and the third switching positions and being situated in its second switching position between the two valve seats (70; 72).
  5. Fuel injection valve according to Claim 1, characterized in that the valve outer needle (17) bears with its end which faces away from the valve seat against a movable, outer valve piston (34) which delimits the outer control space (56).
  6. Fuel injection valve according to Claim 5, characterized in that a sealing edge (37) which is formed by a chamfer is formed on the outer valve piston (34), which sealing edge (37) comes into contact with a sealing face during the opening stroke movement of the valve outer needle (17) and thus separates the outer control space (56) from the inner control space (54).
  7. Fuel injection valve according to Claim 5, characterized in that the outer valve piston (34) and the valve outer needle (17) are configured in one piece.
  8. Fuel injection valve according to Claim 1, characterized in that an inner valve piston (36) and the valve inner needle (15) are configured in one piece.
  9. Fuel injection valve according to one of Claims 1 to 8, characterized in that the outer control space (56), the inner control space (54) and the control valve space (60) are filled with fuel.
EP04738755A 2003-08-20 2004-06-22 Fuel injection valve for internal combustion engines Expired - Fee Related EP1658427B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2003138228 DE10338228A1 (en) 2003-08-20 2003-08-20 Fuel injection valve for internal combustion engines
PCT/DE2004/001306 WO2005019638A1 (en) 2003-08-20 2004-06-22 Fuel injection valve for internal combustion engines

Publications (2)

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EP1658427A1 EP1658427A1 (en) 2006-05-24
EP1658427B1 true EP1658427B1 (en) 2008-02-13

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EP04738755A Expired - Fee Related EP1658427B1 (en) 2003-08-20 2004-06-22 Fuel injection valve for internal combustion engines

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EP (1) EP1658427B1 (en)
DE (2) DE10338228A1 (en)
WO (1) WO2005019638A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102016285A (en) * 2008-04-23 2011-04-13 罗伯特·博世有限公司 Fuel injection valve for internal combustion engines

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Publication number Priority date Publication date Assignee Title
DE10357769B4 (en) * 2003-12-10 2007-06-21 Siemens Ag Fuel injection valve
DE102004030448A1 (en) * 2004-06-24 2006-01-12 Robert Bosch Gmbh Fuel injector
DE102004051756A1 (en) 2004-10-23 2006-04-27 Robert Bosch Gmbh Fuel injection valve for internal combustion engines
DE102004061800A1 (en) * 2004-12-22 2006-07-06 Robert Bosch Gmbh Injector of a fuel injection system of an internal combustion engine
DE102005020832A1 (en) * 2005-05-04 2006-11-09 Robert Bosch Gmbh Automotive fuel injection jet has two sliding needles both linked to a common fuel flow regulation chamber
DE102007002281A1 (en) 2007-01-16 2008-07-17 Robert Bosch Gmbh Injector for fuel injection system of internal-combustion engine in motor vehicle, has guidance for servo piston designed at separation element and limiting coupler space together with separation element and piston
DE102014209961A1 (en) * 2014-05-26 2015-11-26 Robert Bosch Gmbh Nozzle assembly for a fuel injector and fuel injector

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JP4221913B2 (en) * 2001-04-26 2009-02-12 トヨタ自動車株式会社 Fuel injection device
DE10122241A1 (en) * 2001-05-08 2002-12-05 Bosch Gmbh Robert Fuel injection valve for internal combustion engines
DE10210927A1 (en) * 2002-03-13 2003-10-02 Bosch Gmbh Robert Fuel injection valve for internal combustion engines

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102016285A (en) * 2008-04-23 2011-04-13 罗伯特·博世有限公司 Fuel injection valve for internal combustion engines

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DE10338228A1 (en) 2005-03-10
WO2005019638A1 (en) 2005-03-03
EP1658427A1 (en) 2006-05-24
DE502004006203D1 (en) 2008-03-27

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