EP1402174A1 - Fuel injection device for an internal combustion engine - Google Patents

Fuel injection device for an internal combustion engine

Info

Publication number
EP1402174A1
EP1402174A1 EP02742765A EP02742765A EP1402174A1 EP 1402174 A1 EP1402174 A1 EP 1402174A1 EP 02742765 A EP02742765 A EP 02742765A EP 02742765 A EP02742765 A EP 02742765A EP 1402174 A1 EP1402174 A1 EP 1402174A1
Authority
EP
European Patent Office
Prior art keywords
pump
chamber
fuel injection
pressure
injection valve
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.)
Granted
Application number
EP02742765A
Other languages
German (de)
French (fr)
Other versions
EP1402174B1 (en
Inventor
Herbert Strahberger
Serge Moling
Peter Voigt
Alain Amblard
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.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP1402174A1 publication Critical patent/EP1402174A1/en
Application granted granted Critical
Publication of EP1402174B1 publication Critical patent/EP1402174B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

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
    • F02M57/00—Fuel-injectors combined or associated with other devices
    • F02M57/02—Injectors structurally combined with fuel-injection pumps
    • 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
    • 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
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/20—Varying fuel delivery in quantity or timing
    • F02M59/36—Varying fuel delivery in quantity or timing by variably-timed valves controlling fuel passages to pumping elements or overflow passages
    • F02M59/366—Valves being actuated electrically
    • 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
    • F02M61/20—Closing valves mechanically, e.g. arrangements of springs or weights or permanent magnets; Damping of valve lift
    • F02M61/205—Means specially adapted for varying the spring tension or assisting the spring force to close the injection-valve, e.g. with damping of valve lift
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B3/00—Engines characterised by air compression and subsequent fuel addition
    • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
    • 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
    • F02M2200/50—Arrangements of springs for valves used in fuel injectors or fuel injection pumps
    • F02M2200/505—Adjusting spring tension by sliding spring seats

Definitions

  • the invention is based on one
  • Fuel injection device for an internal combustion engine according to the preamble of claim 1.
  • Such a fuel injection device is known from DE 39 00 763 AI.
  • This fuel injection device has a high-pressure fuel pump and a fuel injection valve for a cylinder of the internal combustion engine.
  • the high-pressure fuel pump has a pump piston which is driven by the internal combustion engine and delimits a pump work space, a connection of the pump work space to a relief space being controlled by an electrically controlled valve.
  • the fuel injection valve has an injection valve member, through which at least one injection opening is controlled and which can be moved in an opening direction against the force of a closing spring arranged in a spring chamber by the pressure prevailing in a pressure chamber connected to the pump work chamber.
  • the closing spring is supported on the one hand at least indirectly on the injection valve member and on the other hand at least indirectly on an evasive piston.
  • the evasive piston On its side facing away from the closing spring, the evasive piston delimits an anteroom connected to the pump working space via a throttle point and is thus acted upon by the pressure prevailing in the pump working space and can be moved in a stroke movement against the force of the closing spring.
  • the evasive piston can be moved from an initial position to a storage space at low pressure in the pressure space.
  • the pressure chamber of the fuel injector is over one Canal with the anteroom and indirectly connected to the pump work room.
  • the connection of the pressure chamber to the pump work chamber is thus also via the throttle point, the dimensioning of the throttle point as a compromise between that for the function of the
  • Dodge piston required dimensioning and the dimensioning required for the function of the fuel injector must be selected.
  • the fuel injection device with the features according to claim 1 has the advantage that the direct connection of the pressure chamber of the fuel injection valve with the pump working chamber via the at least one second throttle point, the first and the at least one second throttle point can be optimally selected independently of each other for the respective function ,
  • Fuel injection device for an internal combustion engine in a longitudinal section.
  • a fuel injection device for an internal combustion engine of a motor vehicle is shown.
  • the internal combustion engine has one or more cylinders, a fuel injection device having a high-pressure fuel pump 10 and a fuel injection valve 12 being provided for each cylinder.
  • the high-pressure fuel pump 10 and the fuel injection valve 12 are combined to form a so-called pump-nozzle unit.
  • High-pressure fuel pump 10 has a pump body 14, in which a pump piston 18 is tightly guided in a cylinder bore 16 and is driven in a stroke movement by a cam of a camshaft of the internal combustion engine against the force of a return spring 19.
  • the pump piston 18 delimits a pump working chamber 22 in the cylinder bore 16, in which fuel is compressed under high pressure during the delivery stroke of the pump piston 18.
  • fuel is supplied to the pump working chamber 22 from a fuel reservoir 24, for example by means of a feed pump.
  • the pump working chamber 22 has a connection to a relief chamber, which can serve as the fuel reservoir 24, for example, and which is controlled by an electrically controlled valve 23.
  • the electrically controlled valve 23 is connected to a control device 25.
  • the fuel injection valve 12 has a valve body 26 which, as will be explained in more detail below, is formed in several parts and which is connected to the pump body 14.
  • an injection valve member 28 is guided to be longitudinally displaceable in a bore 30.
  • the bore 30 runs at least approximately parallel to the cylinder 16 of the pump body 14, but can also run at an incline to the latter.
  • the valve body 26 has on its Combustion chamber of the cylinder of the engine end region facing at least one, preferably a plurality of injection openings 32.
  • the injection valve member 28 has at its end region facing the combustion chamber an, for example, approximately conical sealing surface 34 which interacts with a valve seat 36, for example also approximately conical in the valve body 26 in its end region facing the combustion chamber, from or after which the injection openings 32 lead away.
  • valve body 26 there is an annular space 38 between the injection valve member 28 and the bore 30 towards the valve seat 36, which in its end region facing away from the valve seat 36 merges into a pressure space 40 surrounding the injection valve member 28 by a radial expansion of the bore 30.
  • the injection valve member 28 has a pressure shoulder 42 facing the valve seat 36 at the level of the pressure chamber 40 due to a reduction in cross section.
  • a prestressed closing spring 44 engages, through which the
  • Injection valve member 28 is pressed toward the valve seat 36.
  • the closing spring 44 is arranged in a spring chamber 46 which adjoins the bore 30.
  • the spring chamber 46 is preferably connected to a relief chamber, for example the fuel reservoir 24.
  • the pressure chamber 40 is connected to the pump working chamber 22 via a channel 48 running through the valve body 26.
  • the closing spring 44 is supported on the one hand at least indirectly, for example via a spring plate, on the injection valve member 28 and on the other hand at least indirectly, for example likewise via a spring plate 51, on an evasive piston 50.
  • the evasive piston 50 is guided in a bore 80 of a housing part 81 and has at its end region facing the closing spring 44 a shaft part 52 which is connected through a connecting bore 53 in a partition 54 of the housing part 81 passes between the spring space 46 and a storage space 55 adjoining this in the housing part 81.
  • the spring plate 51 is supported on the end of the shaft part 52 which projects into the spring chamber 46.
  • the connecting bore 53 has a smaller diameter than the spring space 46 and the storage space 55.
  • the evasive piston 50 has an area 56 in the storage space 55 with a larger diameter than the connecting bore 53, so that a stroke movement of the evasive piston 50 into the spring space 46 is thereby limited is that the area 56 of the escape piston 50 comes to rest on the partition 54 as a stop.
  • the escape piston 50 is tightly guided with its area 56 in the bore 80 with a larger diameter than the connecting bore 53.
  • the spring chamber 46 is designed as a bore in a housing part 82 which forms part of the valve body 26.
  • the channel 48 runs through the housing part 82 offset to the spring chamber 46 approximately parallel to this.
  • a bore 58 leads from the end of the storage space 55 away from the spring space 46 to the pump working space 22 in the housing part 81.
  • the bore 58 has a smaller diameter than the bore 80.
  • the evasive piston 50 has a sealing surface 60 towards the bore 58 towards the region 56, which is, for example, approximately conical.
  • the sealing surface 60 interacts with the mouth of the bore 58 in the storage space 55 on the housing part 81 as a seat, which can also be approximately conical.
  • the evasive piston 50 has a shaft 62 which projects into the bore 58 and whose diameter is smaller than that of the region 56.
  • the shaft 62 initially has a substantially smaller diameter than the bore 58 and then towards its free end a shaft region 64 with a diameter that is only slightly smaller than that Diameter of the bore 58.
  • the sheep region 64 may have one or more flats 65 on its circumference, through which openings are formed between the shaft region 64 and the bore 58, through which fuel can get into the storage space 55.
  • an intermediate disk 83 is arranged, in which a bore 84 is formed, through which the bore 58 in the housing part 81 is connected to the pump working chamber 22.
  • the bore 84 represents a first throttle point, via which the bore 58 is connected to the pump work chamber 22.
  • the evasive piston 50 delimits an antechamber 85 in the bore 58 towards the intermediate disk 83, which is connected to the pump working chamber 22 via the first throttle point 84.
  • the dining space 55 is from the antechamber 85 and thus from
  • Accumulator piston 50 is less than the force of the closing spring 44th
  • the end portion of the injection valve member 28 is supported in the spring chamber 46 via a spring plate 88 on the closing spring 44.
  • the end region of the injection valve member 28 has a smaller diameter than the region guided in the bore 30.
  • the bore 30, the pressure chamber 40 and the annular chamber 38, at the lower end of which the valve seat 34 and the injection openings 32 are arranged, are formed in a valve housing 89 forming part of the valve body 26.
  • Valve housing 89 is an intermediate plate 90 with a small thickness.
  • the intermediate disk 90 has a bore 91 through which the end region of the injection valve member 28 passes.
  • the channel 48 runs from the pressure chamber 40 through the valve housing 89, the intermediate disk 90, the housing part 86, the housing part 82 and the intermediate disk 83.
  • the intermediate disk 83 has a groove 92 on its side facing the pump body 14, which leads to the pump working chamber 22 is open and into which the channel 48 opens.
  • the groove 92 can, for example, run approximately radially to the cylinder bore 16 and extends from the cylinder bore 16 outwards into the region of the intermediate disk 83 in which the channel 48 runs through it.
  • Throttle point 93 is provided. Damping of pressure vibrations in the channel 48 can be achieved by the second throttle point 93.
  • the second throttle point 93 can be formed by deliberately reducing the cross section of the channel 48. It can in particular be provided here that the channel 40 in the intermediate disk 83 and / or in the intermediate disk 90 is formed as a throttle bore with a defined cross section to form the throttle point 93.
  • the first throttle point 84 and the second throttle point 93 can be optimally selected independently of one another for the respective function.
  • the Kraf fuel injection valve 12 and the high-pressure fuel pump 10 are interconnected by means of an adapter sleeve 94.
  • the clamping sleeve 94 engages over the valve housing 89 and is screwed into a threaded bore 95 in the pump body 14.
  • the intermediate disk 83, the housing parts 81, 82, 86 and the intermediate disk 90 are clamped between the valve housing 89 and the pump body 14.
  • the function of the fuel injection device is explained below.
  • the pump working chamber 22 is filled with fuel during the suction stroke of the pump piston 18.
  • the control valve 23 is initially open, so that no high pressure can build up in the pump work space 22.
  • the control valve 23 is closed by the control device 25, so that the pump working space 22 is separated from the fuel reservoir 24 and builds up in this high pressure. If the pressure in the pump work chamber 22 and in the pressure chamber 40 is so high that the force acting on the injection valve member 28 via the pressure shoulder 42 in the opening direction 29 is greater than the force of the closing spring 44, the injection valve member 28 moves in the opening direction 29 and gives the at least one injection opening 32 free, through which fuel is injected into the combustion chamber of the cylinder.
  • the evasive piston 50 is in its initial position.
  • the pressure in the pump work chamber 22 subsequently increases further in accordance with the profile of the cam driving the pump piston 18.
  • the evasive piston 50 executes its evasive stroke movement and moves into the storage space 55 This causes a pressure drop in the pump working chamber 22 and also increases the pretension of the closing spring 44, which is supported on the accumulator piston 50 via the shaft part 52.
  • the pressure drop in the pump working chamber 22 and in the pressure chamber 40 results in a lower force in the opening direction 29 on the injection valve member 28 and as a result of the increase in the
  • Biasing the closing spring 44 results in an increased force in the closing direction on the injection valve member 28, so that it is moved again in the closing direction, with its sealing surface 34 comes into contact with the valve seat 36 and closes the injection openings 32, so that the fuel injection is interrupted.
  • the Fuel injection valve 12 is only open for a short period of time and only a small amount of fuel is injected into the combustion chamber as a pre-injection.
  • the amount of fuel injected is essentially determined by the opening pressure of the evasive piston 50, that is the pressure in the pump work chamber 22 and in the antechamber 85 at which the evasive piston 50 begins its evasive stroke movement.
  • the opening stroke of the injection valve member 28 during the pre-injection can be hydraulically limited by a damping device.
  • Such a damping unit is known from DE 39 00 762 AI and the corresponding US Pat. No. 5,125,580 and DE 39 00 763 AI and the corresponding US Pat. No. 5,125,581, the content of which hereby belongs to the content of the present patent application.
  • the stroke movement of the evasive piston 50 can also be damped by means of a damping device, as described in DE 39 00 762 AI, DE 39 00 763 AI, US Pat. No. 5,125,580 and US Pat. No. 5,125,581.
  • the pressure in the pump work chamber 22 subsequently increases further in accordance with the profile of the cam driving the pump piston 18, so that the pressure force acting on the injection valve member 28 increases again in the opening direction 29 and increases the closing force due to the increased preload of the closing spring 44, so that the
  • Fuel injector 12 opens again. A larger amount of fuel is injected over a longer period of time than during the pre-injection. The time period and the amount of fuel injected during this main injection are determined by the point in time at which the control valve 23 is opened again by the control device 25. After opening the control valve 23, the pump work chamber 22 is again with the
  • the evasive piston 50 with the shaft part 52 is moved back into its starting position by the force of the closing spring 44.
  • the time offset between the pilot injection and the main injection is mainly determined by the evasive stroke of the evasive piston 50.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)

Abstract

The fuel injection device comprises a fuel high pressure pump (10) and a fuel injection valve (12) for a cylinder of the internal combustion engine. The high pressure pump (10) has a pump working chamber (22) and the fuel injection valve (12) has an injection valve element (28), via which the at least one injection opening (32) is controlled and which can be displaced counter to the force of a closing spring (44) in an opening direction (29) by the pressure prevailing in a pressure chamber (40) connected to the pump working chamber (22). The closing spring (44) is supported on the injection valve element (28) on one side and on a displaceable pressure compensation plunger (50) on the other. Said pressure compensation plunger, on the side thereof facing away from the closing spring (44), delimits a vestibule (85) connected to the pump working chamber (22). The pressure compensation plunger (50) can be displaced counter to the force of the closing spring (44) and into a storage chamber (55). The vestibule (85) is connected to the pump working chamber (22) via a first throttle point (84), and the pressure chamber (40) of the fuel injection valve (12) is connected to the pump working chamber (22) via a second throttle point (93) while bypassing the vestibule (85).

Description

Kraf stoffeinspritzeinrichtunq für eine BrennkraftmaschineFuel injection device for an internal combustion engine
Stand der TechnikState of the art
Die Erfindung geht aus von einerThe invention is based on one
Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine nach der Gattung des Anspruchs 1.Fuel injection device for an internal combustion engine according to the preamble of claim 1.
Eine solche Kraftstoffeinspritzeinrichtung ist durch die DE 39 00 763 AI bekannt. Diese Kraftstoffeinspritzeinrichtung weist eine Kraftstoffhochdruckpumpe und ein Kraftstoffeinspritzventil für einen Zylinder der Brennkraftmaschine auf. Die Kraftstoffhochdruckpumpe weist einen durch die Brennkraftmaschine angetriebenen, einen Pumpenarbeitsraum begrenzenden Pumpenkolben auf, wobei durch ein elektrisch gesteuertes Ventil eine Verbindung des Pumpenarbeitsraums mit einem Entlastungsraum gesteuert wird. Das Kraftstoffeinspritzventil weist ein Einspritzventilglied auf, durch das wenigstens eine Einspritzöffnung gesteuert wird und das durch den in einem mit dem Pumpenarbeitsraum verbundenen Druckraum herrschenden Druck gegen die Kraft einer in einem Federraum angeordneten Schließfeder in einer Öffnungsrichtung bewegbar ist. Die Schließfeder stützt sich einerseits zumindest mittelbar am Einspritzventilglied und andererseits zumindest mittelbar an einem Ausweichkolben ab. Der Ausweichkolben begrenzt auf seiner der Schließfeder abgewandten Seite einen mit dem Pumpenarbeitsraum über eine Drosselstelle verbundenen Vorraum und ist somit vom im Pumpenarbeitsraum herrschenden Druck beaufschlagt und gegen die Kraft der Schließfeder in einer Hubbewegung bewegbar. Der Ausweichkolben ist von einer Ausgangsstellung bei geringem Druck im Druckraum in einen Speicherraum bewegbar. Der Druckraum des Kraftstoffeinspritzventils ist über einen Kanal mit dem Vorraum und über diesen mittelbar mit dem Pumpenarbeitsraum verbunden. Die Verbindung des Druckraums mit dem Pumpenarbeitsraum erfolgt somit ebenfalls über die Drosselstelle, wobei die Dimensionierung der Drosselstelle als Kompromiß zwischen der für die Funktion desSuch a fuel injection device is known from DE 39 00 763 AI. This fuel injection device has a high-pressure fuel pump and a fuel injection valve for a cylinder of the internal combustion engine. The high-pressure fuel pump has a pump piston which is driven by the internal combustion engine and delimits a pump work space, a connection of the pump work space to a relief space being controlled by an electrically controlled valve. The fuel injection valve has an injection valve member, through which at least one injection opening is controlled and which can be moved in an opening direction against the force of a closing spring arranged in a spring chamber by the pressure prevailing in a pressure chamber connected to the pump work chamber. The closing spring is supported on the one hand at least indirectly on the injection valve member and on the other hand at least indirectly on an evasive piston. On its side facing away from the closing spring, the evasive piston delimits an anteroom connected to the pump working space via a throttle point and is thus acted upon by the pressure prevailing in the pump working space and can be moved in a stroke movement against the force of the closing spring. The evasive piston can be moved from an initial position to a storage space at low pressure in the pressure space. The pressure chamber of the fuel injector is over one Canal with the anteroom and indirectly connected to the pump work room. The connection of the pressure chamber to the pump work chamber is thus also via the throttle point, the dimensioning of the throttle point as a compromise between that for the function of the
Ausweichkolbens erforderlichen Dimensionierung und der für die Funktion des Kraftstoffeinspritzventils erforderlichen Dimensionierung gewählt werden muß.Dodge piston required dimensioning and the dimensioning required for the function of the fuel injector must be selected.
Vorteile der ErfindungAdvantages of the invention
Die erfindungsgemäße Kraftstoffeinspritzeinrichtung mit den Merkmalen gemäß Anspruch 1 hat demgegenüber den Vorteil, daß durch die direkte Verbindung des Druckraums des Kraftstoffeinspritzventils mit dem Pumpenarbeitsraum über die wenigstens eine zweite Drosselstelle die erste und die wenigstens eine zweite Drosselstelle unabhängig voneinander optimal für die jeweilige Funktion gewählt werden können.The fuel injection device according to the invention with the features according to claim 1 has the advantage that the direct connection of the pressure chamber of the fuel injection valve with the pump working chamber via the at least one second throttle point, the first and the at least one second throttle point can be optimally selected independently of each other for the respective function ,
In den abhängigen Ansprüchen sind vorteilhafteIn the dependent claims are advantageous
Ausgestaltungen und Weiterbildungen der erfindungsgemäßen Kraftstoffeinspritzeinrichtung angegeben. Die Ausbildungen gemäß den Ansprüchen 2 bis 4 ermöglichen fertigungstechnisch einfache Anordnungen und Ausbildungen der Drosselstellen.Refinements and developments of the fuel injection device according to the invention are specified. The training according to claims 2 to 4 enable simple arrangements and training of the throttling points in terms of production technology.
Zeichnungdrawing
Ein Ausführungsbeispiel der Erfindung ist in der Zeichnung dargestellt und in der nachfolgenden Beschreibung näher erläutert. Die Figur zeigt eineAn embodiment of the invention is shown in the drawing and explained in more detail in the following description. The figure shows one
Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine in einem Längsschnitt.Fuel injection device for an internal combustion engine in a longitudinal section.
Beschreibung des Ausführungsbeispiels In der Figur ist eine Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine eines Kraftfahrzeugs dargestellt. Die Brennkraftmaschine weist einen oder mehrere Zylinder auf, wobei für jeden Zylinder eine Kraftstoffeinspritzeinrichtung mit einer Kraftstoffhochdruckpumpe 10 und einem Kraftstoffeinspritzventil 12 vorgesehen ist. Die Kraftstoffhochdruckpumpe 10 und das Kraftstoffeinspritzventil 12 sind zu einer sogenannten Pumpe-Düse-Einheit zusammengefaßt. DieDescription of the embodiment In the figure, a fuel injection device for an internal combustion engine of a motor vehicle is shown. The internal combustion engine has one or more cylinders, a fuel injection device having a high-pressure fuel pump 10 and a fuel injection valve 12 being provided for each cylinder. The high-pressure fuel pump 10 and the fuel injection valve 12 are combined to form a so-called pump-nozzle unit. The
Kraftstoffhochdruckpumpe 10 weist einen Pumpenkörper 14 auf, in dem in einer Zylinderbohrung 16 ein Pumpenkolben 18 dicht geführt ist, der durch einen Nocken einer Nockenwelle der Brennkraftmaschine entgegen der Kraft einer Rückstellfeder 19 in einer Hubbewegung angetrieben wird. Der Pumpenkolben 18 begrenzt in der Zylinderbohrung 16 einen Pumpenarbeitsraum 22 , in dem beim Förderhub des Pumpenkolbens 18 Kraftstoff unter Hochdruck verdichtet wird. Dem Pumpenarbeitsraum 22 wird beim Saughub des Pumpenkolbens 18 Kraftstoff aus einem Kraftstoffvorratsbehälter 24 zugeführt, beispielsweise mittels einer Förderpumpe. Der Pumpenarbeitsraum 22 weist eine Verbindung mit einem Entlastungsraum auf, als der beispielsweise der Kraftstoffvorratsbehälter 24 dienen kann, und die von einem elektrisch gesteuerten Ventil 23 gesteuert wird. Das elektrisch gesteuerte Ventil 23 ist mit einer Steuereinrichtung 25 verbunden.High-pressure fuel pump 10 has a pump body 14, in which a pump piston 18 is tightly guided in a cylinder bore 16 and is driven in a stroke movement by a cam of a camshaft of the internal combustion engine against the force of a return spring 19. The pump piston 18 delimits a pump working chamber 22 in the cylinder bore 16, in which fuel is compressed under high pressure during the delivery stroke of the pump piston 18. During the suction stroke of the pump piston 18, fuel is supplied to the pump working chamber 22 from a fuel reservoir 24, for example by means of a feed pump. The pump working chamber 22 has a connection to a relief chamber, which can serve as the fuel reservoir 24, for example, and which is controlled by an electrically controlled valve 23. The electrically controlled valve 23 is connected to a control device 25.
Das Kraftstoffeinspritzventil 12 weist einen Ventilkörper 26 auf, der wie nachfolgend noch näher erläutert wird mehrteilig ausgebildet ist, und der mit dem Pumpenkörper 14 verbunden ist. Im Ventilkörper 26 ist in einer Bohrung 30 ein Einspritzventilglied 28 längsverschiebbar geführt. Die Bohrung 30 verläuft zumindest annähernd parallel zum Zylinder 16 des Pumpenkörpers 14, kann jedoch auch geneigt zu diesem verlaufen. Der Ventilkörper 26 weist an seinem dem Brennraum des Zylinders der Brennkraftmaschine zugewandten Endbereich wenigstens eine, vorzugsweise mehrere Einspritzöffnungen 32 auf. Das Einspritzventilglied 28 weist an seinem dem Brennraum zugewandten Endbereich eine beispielsweise etwa kegelförmige Dichtfläche 34 auf, die mit einem im Ventilkörper 26 in dessen dem Brennraum zugewandtem Endbereich ausgebildeten, beispielsweise ebenfalls etwa kegelförmigen Ventilsitz 36 zusammenwirkt, von dem oder nach dem die Einspritzöffnungen 32 abführen.The fuel injection valve 12 has a valve body 26 which, as will be explained in more detail below, is formed in several parts and which is connected to the pump body 14. In the valve body 26, an injection valve member 28 is guided to be longitudinally displaceable in a bore 30. The bore 30 runs at least approximately parallel to the cylinder 16 of the pump body 14, but can also run at an incline to the latter. The valve body 26 has on its Combustion chamber of the cylinder of the engine end region facing at least one, preferably a plurality of injection openings 32. The injection valve member 28 has at its end region facing the combustion chamber an, for example, approximately conical sealing surface 34 which interacts with a valve seat 36, for example also approximately conical in the valve body 26 in its end region facing the combustion chamber, from or after which the injection openings 32 lead away.
Im Ventilkörper 26 ist zwischen dem Einspritzventilglied 28 und der Bohrung 30 zum Ventilsitz 36 hin ein Ringraum 38 vorhanden, der in seinem dem Ventilsitz 36 abgewandten Endbereich durch eine radiale Erweiterung der Bohrung 30 in einen das Einspritzventilglied 28 umgebenden Druckraum 40 übergeht. Das Einspritzventilglied 28 weist auf Höhe des Druckraums 40 durch eine Querschnittsverringerung eine zum Ventilsitz 36 weisende Druckschulter 42 auf. Am dem Brennraum abgewandten Ende des Einspritzventilglieds 28 greift eine vorgespannte Schließfeder 44 an, durch die dasIn the valve body 26 there is an annular space 38 between the injection valve member 28 and the bore 30 towards the valve seat 36, which in its end region facing away from the valve seat 36 merges into a pressure space 40 surrounding the injection valve member 28 by a radial expansion of the bore 30. The injection valve member 28 has a pressure shoulder 42 facing the valve seat 36 at the level of the pressure chamber 40 due to a reduction in cross section. At the end of the injection valve member 28 facing away from the combustion chamber, a prestressed closing spring 44 engages, through which the
Einspritzventilglied 28 zum Ventilsitz 36 hin gedrückt wird. Die Schließfeder 44 ist in einem Federraum 46 angeordnet, der sich an die Bohrung 30 anschließt. Der Federraum 46 ist vorzugsweise mit einem Entlastungsraum, beispielsweise dem Kraftstoffvorratsbehälter 24, verbunden. Der Druckraum 40 ist über einen durch den Ventilkörper 26 verlaufenden Kanal 48 mit dem Pumpenarbeitsraum 22 verbunden.Injection valve member 28 is pressed toward the valve seat 36. The closing spring 44 is arranged in a spring chamber 46 which adjoins the bore 30. The spring chamber 46 is preferably connected to a relief chamber, for example the fuel reservoir 24. The pressure chamber 40 is connected to the pump working chamber 22 via a channel 48 running through the valve body 26.
Die Schließfeder 44 stützt sich einerseits zumindest mittelbar, beispielsweise über einen Federteller, am Einspritzventilglied 28 und andererseits zumindest mittelbar, beispielsweise ebenfalls über einen Federteller 51, an einem Ausweichkolben 50 ab. Der Ausweichkolben 50 ist in einer Bohrung 80 eines Gehäuseteils 81 geführt und weist an seinem der Schließfeder 44 zugewandten Endbereich einen Schaftteil 52 auf, der durch eine Verbindungsbohrung 53 in einer Trennwand 54 des Gehäuseteils 81 zwischen dem Federraum 46 und einem an diesen im Gehäuseteil 81 anschließenden Speicherraum 55 hindurchtritt. An dem in den Federraum 46 ragenden Ende des Schaftteils 52 stützt sich der Federteller 51 ab. Die Verbindungsbohrung 53 weist einen kleineren Durchmesser auf als der Federraum 46 und der Speicherraum 55. Der Ausweichkolben 50 weist im Speicherraum 55 einen Bereich 56 mit größerem Durchmesser auf als die Verbindungsbohrung 53, so daß eine Hubbewegung des Ausweichkolbens 50 in den Federraum 46 hinein dadurch begrenzt ist, daß der Bereich 56 des Ausweichkolbens 50 an der Trennwand 54 als Anschlag zur Anlage kommt. Der Ausweichkolben 50 ist mit seinem Bereich 56 in der Bohrung 80 mit gegenüber der Verbindungsbohrung 53 entsprechend größerem Durchmesser dicht geführt. Der Federraum 46 ist als Bohrung in einem Gehäuseteil 82 ausgebildet, das einen Teil des Ventilkörpers 26 bildet. Der Kanal 48 verläuft durch das Gehäuseteil 82 versetzt zum Federraum 46 etwa parallel zu diesem.The closing spring 44 is supported on the one hand at least indirectly, for example via a spring plate, on the injection valve member 28 and on the other hand at least indirectly, for example likewise via a spring plate 51, on an evasive piston 50. The evasive piston 50 is guided in a bore 80 of a housing part 81 and has at its end region facing the closing spring 44 a shaft part 52 which is connected through a connecting bore 53 in a partition 54 of the housing part 81 passes between the spring space 46 and a storage space 55 adjoining this in the housing part 81. The spring plate 51 is supported on the end of the shaft part 52 which projects into the spring chamber 46. The connecting bore 53 has a smaller diameter than the spring space 46 and the storage space 55. The evasive piston 50 has an area 56 in the storage space 55 with a larger diameter than the connecting bore 53, so that a stroke movement of the evasive piston 50 into the spring space 46 is thereby limited is that the area 56 of the escape piston 50 comes to rest on the partition 54 as a stop. The escape piston 50 is tightly guided with its area 56 in the bore 80 with a larger diameter than the connecting bore 53. The spring chamber 46 is designed as a bore in a housing part 82 which forms part of the valve body 26. The channel 48 runs through the housing part 82 offset to the spring chamber 46 approximately parallel to this.
Vom Speicherraum 55 führt von dessen dem Federraum 46 abgewandtem Ende eine Bohrung 58 zum Pumpenarbeitsraum 22 hin im Gehäuseteil 81 ab. Die Bohrung 58 weist einen kleineren Durchmesser auf als die Bohrung 80. Der Ausweichkolben 50 weist zur Bohrung 58 hin an den Bereich 56 anschließend eine Dichtfläche 60 auf, die beispielsweise etwa kegelförmig ausgebildet ist. Die Dichtfläche 60 wirkt mit der Mündung der Bohrung 58 in den Speicherraum 55 am Gehäuseteil 81 als Sitz zusammen, die ebenfalls etwa kegelförmig ausgebildet sein kann. Der Ausweichkolben 50 weist einen in die Bohrung 58 ragenden Schaft 62 auf, dessen Durchmesser kleiner als der des Bereichs 56 ist. Der Schaft 62 weist an die Dichtfläche 60 anschließend zunächst einen wesentlich kleineren Durchmesser auf als die Bohrung 58 und zu seinem freien Ende hin anschließend einen Schaftbereich 64 mit einem Durchmesser, der nur wenig kleiner ist als der Durchmesser der Bohrung 58. Der Schaf bereich 64 kann an seinem Umfang eine oder mehrere Abflachungen 65 aufweisen, durch die Öffnungen zwischen dem Schaftbereich 64 und der Bohrung 58 gebildet werden, durch die Kraftstoff in den Speicherraum 55 gelangen kann.A bore 58 leads from the end of the storage space 55 away from the spring space 46 to the pump working space 22 in the housing part 81. The bore 58 has a smaller diameter than the bore 80. The evasive piston 50 has a sealing surface 60 towards the bore 58 towards the region 56, which is, for example, approximately conical. The sealing surface 60 interacts with the mouth of the bore 58 in the storage space 55 on the housing part 81 as a seat, which can also be approximately conical. The evasive piston 50 has a shaft 62 which projects into the bore 58 and whose diameter is smaller than that of the region 56. Following the sealing surface 60, the shaft 62 initially has a substantially smaller diameter than the bore 58 and then towards its free end a shaft region 64 with a diameter that is only slightly smaller than that Diameter of the bore 58. The sheep region 64 may have one or more flats 65 on its circumference, through which openings are formed between the shaft region 64 and the bore 58, through which fuel can get into the storage space 55.
Zwischen dem Gehäuseteil 81 und dem Pumpenkörper 14 ist eine Zwischenscheibe 83 angeordnet, in der eine Bohrung 84 ausgebildet ist, durch die die Bohrung 58 im Gehäuseteil 81 mit dem Pumpenarbeitsraum 22 verbunden ist. Die Bohrung 84 stellt eine erste Drosselstelle dar, über die die Bohrung 58 mit dem Pumpenarbeitsraum 22 verbunden ist. Der Ausweichkolben 50 begrenzt in der Bohrung 58 zur Zwischenscheibe 83 hin einen Vorraum 85, der über die erste Drosselstelle 84 mit dem Pumpenarbeitsraum 22 verbunden ist.Between the housing part 81 and the pump body 14, an intermediate disk 83 is arranged, in which a bore 84 is formed, through which the bore 58 in the housing part 81 is connected to the pump working chamber 22. The bore 84 represents a first throttle point, via which the bore 58 is connected to the pump work chamber 22. The evasive piston 50 delimits an antechamber 85 in the bore 58 towards the intermediate disk 83, which is connected to the pump working chamber 22 via the first throttle point 84.
Wenn sich der Ausweichkolben 50 in einer Ausgangsstellung befindet, in der dieser mit seiner Dichtfläche 60 am Dichtsitz an der Mündung der Bohrung 58 anliegt, so ist der Speieherräum 55 vom Vorraum 85 und damit vomIf the evasive piston 50 is in a starting position in which it rests with its sealing surface 60 on the sealing seat at the mouth of the bore 58, the dining space 55 is from the antechamber 85 and thus from
Pumpenarbeitsraum 22 getrennt. In der Ausgangsstellung des Ausweichkolbens 50 wirkt der im Pumpenarbeitsraum 22 herrschende Druck auf die Stirnfläche des Schaftbereichs 64 und durch die Öffnungen zwischen dem Schaftbereich 64 und der Bohrung 58 auf die Dichtfläche 60 des Speieherkolbens 50 entsprechend dem Durchmesser der Bohrung 58. Der Ausweichkolben 50 wird durch die Kraft der Schließfeder 44 gegen den im Pumpenarbeitsraum 22 und damit im Vorraum 85 herrschenden Druck in seiner Ausgangsstellung gehalten, wenn die durch den Druck im Pumpenarbeitsraum 22 auf denPump work room 22 separately. In the starting position of the escape piston 50, the pressure prevailing in the pump work chamber 22 acts on the end face of the shaft region 64 and through the openings between the shaft region 64 and the bore 58 on the sealing surface 60 of the feed piston 50 corresponding to the diameter of the bore 58 the force of the closing spring 44 is held in its initial position against the pressure prevailing in the pump work chamber 22 and thus in the antechamber 85 when the pressure in the pump work chamber 22 affects the pressure
Speicherkolben 50 ausgeübte Kraft geringer ist als die Kraft der Schließfeder 44.Accumulator piston 50 is less than the force of the closing spring 44th
Wenn der Druck im Pumpenarbeitsraum 22 und damit im Vorraum 85 so stark ansteigt, daß die auf den Ausweichkolben 50 erzeugte Kraft größer ist als die Kraft der Schließfeder 44, so bewegt sich der Ausweichkolben 50 und mit diesem der Schaftteil 52 in einer Ausweichbewegung in den Speicherraum 55, wobei sich der Schaftteil 52 in den Federraum 46 bewegt. Bei der Ausweichbewegung des Ausweichkolbens 50 wird Kraftstoff aus dem Speicherraum 55 in den Federraum 46 verdrängt, der durch einen Ringspalt zwischen dem Schaftteil 52 des Ausweichkolbens 50 und der Verbindungsbohrung 53 hindurchtreten muß. Hierdurch wird eine Dämpfung der Ausweichbewegung des Schaftteils 52 und damit des Ausweichkolbens 50 erreicht.If the pressure in the pump work chamber 22 and thus in the antechamber 85 increases so much that the force generated on the evasive piston 50 is greater than the force of the closing spring 44, so the evasive piston 50 and with it the shaft part 52 moves in an evasive movement into the storage space 55, the shaft part 52 moving into the spring space 46. During the evasive movement of the evasive piston 50, fuel is displaced from the storage space 55 into the spring space 46, which must pass through an annular gap between the shaft part 52 of the evasive piston 50 and the connecting bore 53. This results in damping the evasive movement of the shaft part 52 and thus the evasive piston 50.
Zum Kraftstoffeinspritzventil 12 hin anschließend ist an das Gehäuseteil 82 ein weiteres Gehäuseteil 86 als Teil des Ventilkörpers 26 angeordnet, das eine Bohrung 87 aufweist, durch die ein Endbereich des Einspritzventilglieds 28 hindurchtritt und in den Federraum 46 ragt. Das Einspritzventilglied 28 stützt sich mit seinem Endbereich im Federraum 46 über einen Federteller 88 an der Schließfeder 44 ab. Der Endbereich des Einspritzventilglieds 28 weist einen kleineren Durchmesser auf als dessen in der Bohrung 30 geführter Bereich. Die Bohrung 30, der Druckraum 40 sowie der Ringraum 38, an dessen unterem Ende der Ventilsitz 34 und die Einspritzöffnungen 32 angeordnet sind, sind in einem einen Teil des Ventilkörpers 26 bildenden Ventilgehäuse 89 ausgebildet. Zwischen dem Gehäuseteil 86 und demA further housing part 86 as part of the valve body 26, which has a bore 87 through which an end region of the injection valve member 28 passes and projects into the spring chamber 46, is arranged on the housing part 82 toward the fuel injection valve 12. The end portion of the injection valve member 28 is supported in the spring chamber 46 via a spring plate 88 on the closing spring 44. The end region of the injection valve member 28 has a smaller diameter than the region guided in the bore 30. The bore 30, the pressure chamber 40 and the annular chamber 38, at the lower end of which the valve seat 34 and the injection openings 32 are arranged, are formed in a valve housing 89 forming part of the valve body 26. Between the housing part 86 and the
Ventilgehäuse 89 ist eine Zwischenscheibe 90 mit geringer Dicke angeordnet. Die Zwischenscheibe 90 weist eine Bohrung 91 auf, durch die der Endbereich des Einspritzventilglieds 28 hindurchtritt.Valve housing 89 is an intermediate plate 90 with a small thickness. The intermediate disk 90 has a bore 91 through which the end region of the injection valve member 28 passes.
Der Kanal 48 verläuft vom Druckraum 40 aus durch das Ventilgehäuse 89, die Zwischenscheibe 90, das Gehäuseteil 86, das Gehäuseteil 82 und die Zwischenscheibe 83. Die Zwischenscheibe 83 weist auf ihrer dem Pumpenkörper 14 zugewandten Seite eine Nut 92 auf, die zum Pumpenarbeitsraum 22 hin offen ist und in die der Kanal 48 mündet. Die Nut 92 kann beispielsweise etwa radial zu der Zylinderbohrung 16 verlaufen und erstreckt sich von der Zylinderbohrung 16 nach außen bis in den Bereich der Zwischenscheibe 83, in dem der Kanal 48 durch diese verläuft. Die Verbindung des Druckraums 40 des Kraftstoffeinspritzventils 12 mit demThe channel 48 runs from the pressure chamber 40 through the valve housing 89, the intermediate disk 90, the housing part 86, the housing part 82 and the intermediate disk 83. The intermediate disk 83 has a groove 92 on its side facing the pump body 14, which leads to the pump working chamber 22 is open and into which the channel 48 opens. The groove 92 can, for example, run approximately radially to the cylinder bore 16 and extends from the cylinder bore 16 outwards into the region of the intermediate disk 83 in which the channel 48 runs through it. The connection of the pressure chamber 40 of the fuel injection valve 12 with the
Pumpenarbeitsraum 22 durch den Kanal 48 erfolgt somit direkt unter Umgehung des Vorraums 85, der vom Ausweichkolben 50 in der Bohrung 58 zur Zwischenscheibe 83 hin begrenzt wird. In dem den Druckraum 48 mit dem Pumpenarbeitsraum 22 verbindenden Kanal 48 ist wenigstens eine zweitePump working chamber 22 through channel 48 thus takes place directly bypassing antechamber 85, which is delimited by evasive piston 50 in bore 58 towards intermediate disk 83. There is at least a second one in the channel 48 connecting the pressure chamber 48 to the pump working chamber 22
Drosselstelle 93 vorgesehen. Durch die zweite Drosselstelle 93 kann eine Dämpfung von Druckschwingungen im Kanal 48 erreicht werden. Die zweite Drosselstelle 93 kann durch eine gezielte Verringerung des Querschnitts des Kanals 48 gebildet werden. Es kann hierbei insbesondere vorgesehen sein, daß der Kanal 40 in der Zwischenscheibe 83 und/oder in der Zwischenscheibe 90 zur Bildung der Drosselstelle 93 als Drosselbohrung mit definiertem Querschnitt ausgebildet ist. Die erste Drosselstelle 84 und die zweite Drosselstelle 93 können unabhängig voneinander für die jeweilige Funktion optimal gewählt werden.Throttle point 93 is provided. Damping of pressure vibrations in the channel 48 can be achieved by the second throttle point 93. The second throttle point 93 can be formed by deliberately reducing the cross section of the channel 48. It can in particular be provided here that the channel 40 in the intermediate disk 83 and / or in the intermediate disk 90 is formed as a throttle bore with a defined cross section to form the throttle point 93. The first throttle point 84 and the second throttle point 93 can be optimally selected independently of one another for the respective function.
Das Kraf stoffeinspritzventil 12 und die Kraftstoffhochdruckpumpe 10 sind mittels einer Spannhülse 94 miteinander verbunden. Die Spannhülse 94 übergreift das Ventilgehäuse 89 und ist in eine Gewindebohrung 95 im Pumpenkörper 14 eingeschraubt. Die Zwischenscheibe 83, die Gehäuseteile 81,82,86 sowie die Zwischenscheibe 90 sind zwischen dem Ventilgehäuse 89 und dem Pumpenkörper 14 eingespannt.The Kraf fuel injection valve 12 and the high-pressure fuel pump 10 are interconnected by means of an adapter sleeve 94. The clamping sleeve 94 engages over the valve housing 89 and is screwed into a threaded bore 95 in the pump body 14. The intermediate disk 83, the housing parts 81, 82, 86 and the intermediate disk 90 are clamped between the valve housing 89 and the pump body 14.
Nachfolgend wird die Funktion der Kraftstoffeinspritzeinrichtung erläutert. Der Pumpenarbeitsraum 22 wird während des Saughubs des Pumpenkolbens 18 mit Kraftstoff gefüllt. Beim Förderhub des Pumpenkolbens 18 ist das Steuerventil 23 zunächst geöffnet, so daß sich im Pumpenarbeitsraum 22 kein Hochdruck aufbauen kann. Wenn die Kraftstoffeinspritzung beginnen soll, so wird das Steuerventil 23 durch die Steuereinrichtung 25 geschlossen, so daß der Pumpenarbeitsraum 22 vom Kraftstoffvorratsbehälter 24 getrennt ist und sich in diesem Hochdruck aufbaut. Wenn der Druck im Pumpenarbeitsraum 22 und im Druckraum 40 so hoch ist, daß die über die Druckschulter 42 auf das Einspritzventilglied 28 wirkende Kraft in Öffnungsrichtung 29 größer ist als die Kraft der Schließfeder 44, so bewegt sich das Einspritzventilglied 28 in Öffnungsrichtung 29 und gibt die wenigstens eine Einspritzöffnung 32 frei, durch die Kraftstoff in den Brennraum des Zylinders eingespritzt wird. Der Ausweichkolben 50 befindet sich hierbei in seiner Ausgangsstellung. Der Druck im Pumpenarbeitsraum 22 steigt nachfolgend entsprechend dem Profil des den Pumpenkolben 18 antreibenden Nockens weiter an.The function of the fuel injection device is explained below. The pump working chamber 22 is filled with fuel during the suction stroke of the pump piston 18. During the delivery stroke of the pump piston 18, the control valve 23 is initially open, so that no high pressure can build up in the pump work space 22. When the fuel injection is to begin, the control valve 23 is closed by the control device 25, so that the pump working space 22 is separated from the fuel reservoir 24 and builds up in this high pressure. If the pressure in the pump work chamber 22 and in the pressure chamber 40 is so high that the force acting on the injection valve member 28 via the pressure shoulder 42 in the opening direction 29 is greater than the force of the closing spring 44, the injection valve member 28 moves in the opening direction 29 and gives the at least one injection opening 32 free, through which fuel is injected into the combustion chamber of the cylinder. The evasive piston 50 is in its initial position. The pressure in the pump work chamber 22 subsequently increases further in accordance with the profile of the cam driving the pump piston 18.
Wenn die durch den im Pumpenarbeitsraum 22 und damit im Vorraum 85 herrschenden Druck auf den Ausweichkolben 50 ausgeübte Kraft größer wird als die durch die Schließfeder 44 auf den Ausweichkolben 50 ausgeübte Kraft, so führt der Ausweichkolben 50 seine Ausweichhubbewegung aus und bewegt sich in den Speicherraum 55. Hierbei wird ein Druckabfall im Pumpenarbeitsraum 22 verursacht und außerdem die Vorspannung der Schließfeder 44 erhöht, die sich über den Schaftteil 52 am Speicherkolben 50 abstützt. Durch den Druckabfall im Pumpenarbeitsraum 22 und im Druckraum 40 ergibt sich eine geringere Kraft in Öffnungsrichtung 29 auf das Einspritzventilglied 28 und infolge der Erhöhung derIf the force exerted on the evasive piston 50 by the pressure prevailing in the pump work chamber 22 and thus in the antechamber 85 becomes greater than the force exerted on the evasive piston 50 by the closing spring 44, the evasive piston 50 executes its evasive stroke movement and moves into the storage space 55 This causes a pressure drop in the pump working chamber 22 and also increases the pretension of the closing spring 44, which is supported on the accumulator piston 50 via the shaft part 52. The pressure drop in the pump working chamber 22 and in the pressure chamber 40 results in a lower force in the opening direction 29 on the injection valve member 28 and as a result of the increase in the
Vorspannung der Schließfeder 44 ergibt sich eine erhöhte Kraft in Schließrichtung auf das Einspritzventilglied 28, so daß dieses wieder in Schließrichtung bewegt wird, mit seiner Dichtfläche 34 am Ventilsitz 36 zur Anlage kommt und die Einspritzöffnungen 32 verschließt, so daß die Kraftstoffeinspritzung unterbrochen wird. Das Kraftstoffeinspritzventil 12 ist dabei nur für eine kurze Zeitdauer geöffnet und es wird nur eine geringe Menge Kraftstoff als Voreinspritzung in den Brennraum eingespritzt. Die eingespritzte Kraftstoffmenge ist im wesentlichen vom Öffnungsdruck des Ausweichkolbens 50 bestimmt, das ist der Druck im Pumpenarbeitsraum 22 und im Vorraum 85, bei dem der Ausweichkolben 50 seine Ausweichhubbewegung beginnt. Der Öffnungshub des Einspritzventilglieds 28 während der Voreinspritzung kann durch eine Dämpfungseinrichtung hydraulisch begrenzt sein. Eine solche Dämpfungseinheit ist durch die DE 39 00 762 AI sowie die korrespondierende US-5,125,580 sowie die DE 39 00 763 AI sowie die korrespondierende US-5,125,581 bekannt, deren Inhalt hiermit zum Inhalt der vorliegenden Patentanmeldung gehört. Die Hubbewegung des Ausweichkolbens 50 kann ebenfalls mittels einer Dämpfungseinrichtung gedämpft werden, wie diese in der DE 39 00 762 AI, der DE 39 00 763 AI, der US-5,125,580 und der US-5,125,581 beschrieben ist.Biasing the closing spring 44 results in an increased force in the closing direction on the injection valve member 28, so that it is moved again in the closing direction, with its sealing surface 34 comes into contact with the valve seat 36 and closes the injection openings 32, so that the fuel injection is interrupted. The Fuel injection valve 12 is only open for a short period of time and only a small amount of fuel is injected into the combustion chamber as a pre-injection. The amount of fuel injected is essentially determined by the opening pressure of the evasive piston 50, that is the pressure in the pump work chamber 22 and in the antechamber 85 at which the evasive piston 50 begins its evasive stroke movement. The opening stroke of the injection valve member 28 during the pre-injection can be hydraulically limited by a damping device. Such a damping unit is known from DE 39 00 762 AI and the corresponding US Pat. No. 5,125,580 and DE 39 00 763 AI and the corresponding US Pat. No. 5,125,581, the content of which hereby belongs to the content of the present patent application. The stroke movement of the evasive piston 50 can also be damped by means of a damping device, as described in DE 39 00 762 AI, DE 39 00 763 AI, US Pat. No. 5,125,580 and US Pat. No. 5,125,581.
Der Druck im Pumpenarbeitsraum 22 steigt nachfolgend weiter an entsprechend dem Profil des den Pumpenkolben 18 antreibenden Nockens, so daß die auf das Einspritzventilglied 28 wirkende Druckkraft in Öffnungsrichtung 29 wieder zunimmt und die infolge der erhöhten Vorspannung der Schließfeder 44 erhöhte Schließkraft übersteigt, so daß dasThe pressure in the pump work chamber 22 subsequently increases further in accordance with the profile of the cam driving the pump piston 18, so that the pressure force acting on the injection valve member 28 increases again in the opening direction 29 and increases the closing force due to the increased preload of the closing spring 44, so that the
Kraf stoffeinspritzventil 12 wieder öffnet. Dabei wird eine größere Kraftstoffmenge über eine längere Zeitdauer eingespritzt als während der Voreinspritzung. Die Zeitdauer und die während dieser Haupteinspritzung eingespritzte Kraftstoffmenge werden durch den Zeitpunkt bestimmt, zu dem das Steuerventil 23 durch die Steuereinrichtung 25 wieder geöffnet wird. Nach dem Öffnen des Steuerventils 23 ist der Pumpenarbeitsraum 22 wieder mit demFuel injector 12 opens again. A larger amount of fuel is injected over a longer period of time than during the pre-injection. The time period and the amount of fuel injected during this main injection are determined by the point in time at which the control valve 23 is opened again by the control device 25. After opening the control valve 23, the pump work chamber 22 is again with the
Kraftstoffvorratsbehälter 24 verbunden, so daß dieser entlastet ist und das Kraftstoffeinspritzventil 12 schließt. Der Ausweichkolben 50 mit dem Schaftteil 52 wird durch die Kraft der Schließfeder 44 wieder in seine Ausgangsstellung zurückbewegt. Der zeitliche Versatz zwischen der Voreinspritzung und der Haupteinspritzung ist hauptsächlich durch den Ausweichhub des Ausweichkolbens 50 bestimmt. Fuel tank 24 connected so that this is relieved and the fuel injection valve 12 closes. The evasive piston 50 with the shaft part 52 is moved back into its starting position by the force of the closing spring 44. The time offset between the pilot injection and the main injection is mainly determined by the evasive stroke of the evasive piston 50.

Claims

Ansprüche Expectations
1. Kraftstoffeinspritzeinrichtung für eine Brennkraf maschine mit einer Kraftstoff ochdruckpumpe (10) und einem Kraftstoffeinspritzventil (12) für einen Zylinder der Brennkraftmaschine, wobei die Kraftstoffhochdruckpumpe / (10) einen durch die Brennkraftmaschine in einer Hubbewegung angetriebenen, einen Pumpenarbeitsraum (22) begrenzenden Pumpenkolben (18) aufweist, mit einem elektrisch gesteuerten Ventil (23), durch das eine Verbindung des1.Fuel injection device for an internal combustion engine with a high-pressure fuel pump (10) and a fuel injection valve (12) for a cylinder of the internal combustion engine, the high-pressure fuel pump / (10) being driven by the internal combustion engine in a stroke movement and defining a pump working chamber (22) pump piston ( 18), with an electrically controlled valve (23) through which a connection of the
Pumpenarbeitsraums (22) mit einem Entlastungsraum (24) gesteuert wird, wobei das Kraftstoffeinspritzventil (12) ein Einspritzventilglied (28) aufweist, durch das wenigstens eine Einspritzöffnung (32) gesteuert wird und das durch den in einem mit dem Pumpenarbeitsraum (22) verbundenenPump work space (22) is controlled with a relief chamber (24), the fuel injection valve (12) having an injection valve member (28) through which at least one injection opening (32) is controlled and which in one connected to the pump work space (22)
Druckraum (40) herrschenden Druck gegen die Kraft einer in einem Federraum (46) angeordneten Schließfeder (44) in einer Öffnungsrichtung (29) bewegbar ist, wobei sich die Schließfeder (44) einerseits zumindest mittelbar am Einspritzventilglied (28) und andererseits zumindest mittelbar an einem verschiebbaren Ausweichkolben (50) abstützt, der auf seiner der Schließfeder (44) abgewandten Seite einen mit dem Pumpenarbeitsraum (22) verbundenen Vorraum (85) begrenzt, wobei der Ausweichkolben (50) ausgehend von einer Ausgangsstellung bei geringem Druck im Pumpenarbeitsraum (22) gegen die Kraft der Schließfeder (44) in einen Speicherraum (55) verschiebbar ist, wobei der Vorraum (85) mit dem Pumpenarbeitsraum (22) über eine erste Drosselstelle (84) verbunden ist, dadurch gekennzeichnet, daß der Druckraum (40) des Kraftstoffeinspritzventils (12) direkt unter Umgehung des Vorraums (85) mit dem Pumpenarbeitsraum (22) verbunden ist und daß in der Verbindung (48) des Druckraums (40) mit demPressure chamber (40) prevailing pressure against the force of a closing spring (44) arranged in a spring chamber (46) can be moved in an opening direction (29), the closing spring (44) on the one hand at least indirectly on the injection valve member (28) and on the other hand at least indirectly supports a displaceable escape piston (50) which delimits an antechamber (85) connected to the pump work chamber (22) on its side facing away from the closing spring (44), the escape piston (50) starting from an initial position at low pressure in the pump work chamber (22) can be moved against the force of the closing spring (44) into a storage space (55), the antechamber (85) being connected to the pump work space (22) via a first throttle point (84), characterized in that the pressure space (40) of the fuel injection valve (12) directly bypassing the anteroom (85) with the Pump work chamber (22) is connected and that in the connection (48) of the pressure chamber (40) with the
Pumpenarbeitsraum (22) wenigstens eine zweite Drosselstelle (93) angeordnet ist.Pump work space (22) at least a second throttle point (93) is arranged.
2. Kraftstoffeinspritzeinrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die erste Drosselstelle (84) zwischen dem Vorraum (85) und dem Pumpenarbeitsraum (22) als eine Drosselbohrung in einer Zwischenscheibe (83) zwischen einem Pumpenkörper (14) , in dem der Pumpenkolben (18) geführt ist, und einem Gehäuseteil (81), in dem der Ausweichkolben (50) geführt ist, ausgebildet ist.2. Fuel injection device according to claim 1, characterized in that the first throttle point (84) between the vestibule (85) and the pump work chamber (22) as a throttle bore in an intermediate plate (83) between a pump body (14) in which the pump piston ( 18) is guided, and a housing part (81), in which the evasive piston (50) is guided, is formed.
3. Kraftstoffeinspritzeinrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die wenigstens eine zweite3. Fuel injection device according to claim 1 or 2, characterized in that the at least one second
Drosselstelle (93) in einem Gehäuseteil (86; 89) des Kraftstoffeinspritzventils (12) angeordnet ist.Throttle point (93) is arranged in a housing part (86; 89) of the fuel injection valve (12).
4. Kraftstoffeinspritzeinrichtung nach Anspruch 1 oder 2 , dadurch gekennzeichnet, daß die wenigstens eine zweite4. Fuel injection device according to claim 1 or 2, characterized in that the at least one second
Drosselstelle (93) in einer Zwischenscheibe (90) zwischen Gehäuseteilen (86,89) des Kraftstoffeinspritzventils (12) angeordnet ist. Throttle point (93) is arranged in an intermediate plate (90) between housing parts (86, 89) of the fuel injection valve (12).
EP02742765A 2001-06-19 2002-05-18 Fuel injection device for an internal combustion engine Expired - Lifetime EP1402174B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE20110130U 2001-06-19
DE20110130U DE20110130U1 (en) 2001-06-19 2001-06-19 Fuel injection device for an internal combustion engine
PCT/DE2002/001799 WO2002103197A1 (en) 2001-06-19 2002-05-18 Fuel injection device for an internal combustion engine

Publications (2)

Publication Number Publication Date
EP1402174A1 true EP1402174A1 (en) 2004-03-31
EP1402174B1 EP1402174B1 (en) 2006-04-12

Family

ID=7958262

Family Applications (1)

Application Number Title Priority Date Filing Date
EP02742765A Expired - Lifetime EP1402174B1 (en) 2001-06-19 2002-05-18 Fuel injection device for an internal combustion engine

Country Status (7)

Country Link
US (1) US6845757B2 (en)
EP (1) EP1402174B1 (en)
JP (1) JP2004521248A (en)
DE (2) DE20110130U1 (en)
HU (1) HUP0303548A2 (en)
PL (1) PL370296A1 (en)
WO (1) WO2002103197A1 (en)

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DE10119603A1 (en) * 2001-04-21 2002-10-24 Bosch Gmbh Robert Fuel injection arrangement has fuel pump with piston defining a pump operating chamber, balancing chamber, valve, piston with shaft part, connecting hole and gap
DE10119602A1 (en) * 2001-04-21 2002-10-24 Bosch Gmbh Robert Fuel injection unit consists of fuel pump with piston and chamber, control valve, closure spring, stop, shaft part, connecting hole and smaller and larger diameter shaft parts
DE10338081A1 (en) * 2003-08-19 2005-03-10 Bosch Gmbh Robert Fuel injector
JP3994990B2 (en) * 2004-07-21 2007-10-24 株式会社豊田中央研究所 Fuel injection device
US7287494B2 (en) * 2004-11-10 2007-10-30 Buck Supply Co., Inc. Multicylinder internal combustion engine with individual cylinder assemblies and modular cylinder carrier
US7287493B2 (en) * 2004-11-10 2007-10-30 Buck Supply Co., Inc. Internal combustion engine with hybrid cooling system
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DE102005055359A1 (en) 2005-11-21 2007-05-24 Robert Bosch Gmbh Intermediate plate for a fuel injector and fuel injector
US8316814B2 (en) * 2009-06-29 2012-11-27 Buck Kenneth M Toploading internal combustion engine

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Also Published As

Publication number Publication date
HUP0303548A2 (en) 2004-03-01
PL370296A1 (en) 2005-05-16
DE50206396D1 (en) 2006-05-24
US6845757B2 (en) 2005-01-25
WO2002103197A1 (en) 2002-12-27
DE20110130U1 (en) 2002-10-24
JP2004521248A (en) 2004-07-15
US20040099250A1 (en) 2004-05-27
EP1402174B1 (en) 2006-04-12

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