EP0070558B1 - Fuel-injection pump - Google Patents

Fuel-injection pump Download PDF

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Publication number
EP0070558B1
EP0070558B1 EP82106523A EP82106523A EP0070558B1 EP 0070558 B1 EP0070558 B1 EP 0070558B1 EP 82106523 A EP82106523 A EP 82106523A EP 82106523 A EP82106523 A EP 82106523A EP 0070558 B1 EP0070558 B1 EP 0070558B1
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EP
European Patent Office
Prior art keywords
fuel
distributor shaft
fuel injection
switching valve
control groove
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
Application number
EP82106523A
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German (de)
French (fr)
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EP0070558A1 (en
Inventor
Jean Leblanc
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
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Robert Bosch GmbH
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Publication date
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Publication of EP0070558A1 publication Critical patent/EP0070558A1/en
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    • 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
    • F02M59/205—Quantity of fuel admitted to pumping elements being metered by an auxiliary metering device
    • 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
    • F02M41/00—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor
    • F02M41/02—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor being spaced from pumping elements
    • F02M41/06—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor being spaced from pumping elements the distributor rotating
    • F02M41/063—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor being spaced from pumping elements the distributor rotating the distributor and rotary valve controlling fuel passages to pumping elements being combined
    • 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
    • F02M41/00—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor
    • F02M41/02—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor being spaced from pumping elements
    • F02M41/06—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor being spaced from pumping elements the distributor rotating
    • F02M41/063—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor being spaced from pumping elements the distributor rotating the distributor and rotary valve controlling fuel passages to pumping elements being combined
    • F02M41/066—Arrangements for adjusting the rotary valve-distributor

Definitions

  • the invention relates to a fuel injection pump according to the preamble of the main claim.
  • a known fuel injection pump of this type (DE-PS 1 303 637)
  • the distributor for quantity determination is axially displaced by a mechanical speed regulator and rotated relative to the drive shaft during its longitudinal displacement for the start of injection adjustment.
  • This relatively complex regulation has the disadvantage that, due to the rigid assignment of the control variables, an adaptation to the requirements of the engine manufacturers, inter alia, in the reduction of noise, fuel consumption and poisonous portion of the exhaust gas cannot be achieved.
  • the fuel injection pump according to the invention with the characterizing features of the main claim has the advantage of forming the basis for an extremely flexible injection pump control.
  • this basis almost all of the requirements of the internal combustion engine manufacturers can be met in consideration of engine parameters such as consumption, temperature, exhaust gas, etc.
  • the standard effort required for this is relatively small and extremely flexible.
  • the combination of the switching valve and the control edges of the control groove, which are guided synchronously with the pump speed, can substantially avoid an adverse, uncontrolled influence of the speed on the fuel metering, as is the case due to the constant switching times of fuel injection pumps controlled by solenoid valves, with extremely versatile influences on the injection.
  • a distributor shaft 2 and radially arranged pump pistons 3 are mounted in the housing 1 of a fuel injection pump.
  • the pump pistons 3 are driven via a cam ring 4, which surrounds the pistons in a pot-shaped manner and is firmly connected to the drive shaft of the fuel injection pump, not shown.
  • the distributor shaft 2 Via a clutch, not shown, the distributor shaft 2 is carried along by the drive shaft, but the distributor shaft 2 is axially displaceable in the housing 1.
  • an annular groove 5 is arranged, which delimits the pump working spaces 6 with the pistons 3.
  • longitudinal grooves are connected, of which a longitudinal groove 7 cooperates as a distributor groove with the delivery lines 8, which lead to the fuel injection nozzles 9 on the internal combustion engine and are opened one after the other through the distributor groove 7.
  • the distributor groove 7 can be designed as a long longitudinal groove branching off from the annular groove 5 or can be made shorter via a longitudinal channel 21 and two radial channels 22, 23 of the distributor shaft with the annular groove 5 (shown in dashed lines in FIG. 1).
  • 2 control grooves 10 are arranged on the lateral surface of the distributor shaft, which are connected to the annular groove 5 and extend slightly obliquely with respect to a surface line of the distributor shaft 2.
  • control grooves control a fuel supply opening 13 which opens into the cylinder 14 guiding the distributor shaft 2 and represents the end of a pressure channel 11 which is supplied with fuel by a fuel feed pump 12.
  • An electrically actuated switching valve 16 is arranged in the pressure channel, which preferably has a slide as a valve closing element and is therefore pressure-balanced. In particular, however, this valve should be of a type that can perform fast switching operations.
  • the delivery pressure of the fuel delivery pump is kept at a constant value by means of a pressure control valve 17.
  • the distributor shaft 2 is longitudinally displaceable, which is done with the aid of an electrical adjusting device 18.
  • This device is shown only schematically in the drawing and acts on the rotating distributor shaft via a point-like contact surface.
  • FIG. 2 For a more detailed explanation of the function, five different rotational positions A, B, C, D and E are shown in FIG. 2, each of which represents the rotational positions in the sectional planes I, 11 and 111 of the fuel injection pump according to FIG. 1 in a schematic juxtaposition.
  • the distributor shaft 2 is cut in the area of the pump pistons 3.
  • the sectional plane 11 passes through the fuel supply opening 13 and the sectional plane 111 lies in the confluence plane of the delivery lines 8.
  • a cam 24 of the cam ring 4 is also shown in its assignment to the pump piston 3, between the pumps piston 3 and the cam 24 a roller 25 is switched in a known manner.
  • the illustration A shows the rotational position of the distributor shaft 2 at the start of filling the pump work spaces 6 with fuel. At this point the roller 25 has reached the highest elevation of the cam 24 and is to be followed in the concept of the falling flank of the cam. The pump piston is moved outwards and the pump working space 6 is enlarged.
  • the switching valve 16 is at this time in the open position and the control groove 10 has just opened the connection to the pressure channel 11. Fuel can thus enter the annular groove 5 via the control groove 10 and from there into the pump work spaces 6. The fuel pressure ensures that the rollers 25 remain in contact with the cams 24.
  • the representation B shows the moment at which the switching valve 16 is closed. From this point in time, although the control groove 10 is still in connection with the pressure channel 11, the supply of fuel is stopped, so that the pump piston 3 maintains the position it has assumed at that point in time and lifts off the cam. This is the end of the metering.
  • the next cam 24 ' has now reached the roller 25, which in the course of the further movement of the cam 24' moves the pump piston 3 inwards.
  • the pump pistons 3 now carry out the delivery stroke and press the fuel via the longitudinal channel 21 and the radial channel 22 into the longitudinal groove 7, which is now connected to one of the delivery lines 8.
  • the delivered fuel is pressed into this and brought to the injection point at the internal combustion engine.
  • the pressure channel 11 is still blocked by the distributor shaft and the switching valve 16 is open.
  • the representation E shows the end of the injection, which is reached when the control groove 10 is brought back into connection with the pressure channel 11.
  • the distributor groove 7 is still connected to the delivery line 8
  • the fuel delivery is now interrupted, since the remaining fuel delivered by the pump piston 3 can flow off to the fuel supply side via the pressure channel.
  • a further channel 26 can be provided, which bypasses the switching valve 16 and contains a check valve 27. In this way, the control cross-section is enlarged and it is ensured that the injection is stopped suddenly. This last phase is then followed by phase A and the process described above is repeated.
  • the fuel injection quantity per stroke can be determined solely by the switching valve 16.
  • the metering phase is determined on the one hand by opening the pressure line 11 with a speed-controlled control edge of the control groove 10 and on the other hand by closing the switching valve 16.
  • This Control type leads to changing injection start times with variable injection quantity.
  • the end of the spray can be kept constant.
  • Another control option is that a constant amount of fuel is constantly metered through the switching valve 16, whereby a constant injection timing is achieved and that the distributor shaft 2 is shifted to vary the fuel injection amount.
  • the shift changes the point at which the control groove 10 is reconnected to the pressure line 11 at the end of the injection phase. The position of the end of injection is therefore variable.
  • This control also has the advantage that the metering is not dependent on the switching times of the switching valve.

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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)
  • High-Pressure Fuel Injection Pump Control (AREA)

Description

Die Erfindung geht aus von einer Kraftstoffeinspritzpumpe nach der Gattung des Hauptanspruchs. Bei einer bekannten Kraftstoffeinspritzpumpe dieser Art (DE-PS 1 303 637) wird der Verteiler zur Mengenbestimmung axial durch einen mechanischen Drehzahlregler verschoben und für die Spritzbeginnverstellung relativ zur Antriebswelle bei seiner Längsverschiebung verdreht. Diese verhältnismäßige aufwendige Regelung hat den Nachteil, daß infolge der starren Zuordnung der Regel- bzw. Steuergrößen eine Anpassung an die Forderungen der Brennkraftmaschinenhersteller unter anderem in der Verminderung von Geräusch, Kraftstoffverbrauch und Giftanteil des Abfases nicht erfüllbar sind.The invention relates to a fuel injection pump according to the preamble of the main claim. In a known fuel injection pump of this type (DE-PS 1 303 637), the distributor for quantity determination is axially displaced by a mechanical speed regulator and rotated relative to the drive shaft during its longitudinal displacement for the start of injection adjustment. This relatively complex regulation has the disadvantage that, due to the rigid assignment of the control variables, an adaptation to the requirements of the engine manufacturers, inter alia, in the reduction of noise, fuel consumption and poisonous portion of the exhaust gas cannot be achieved.

Die erfindungsgemäße Kraftstoffeinspritzpumpe mit den kennzeichnenden Merkmalen des Hauptanspruchs hat demgegenüber den Vorteil, die Grundlage für eine äußerst flexible Einspritzpumpenregelung zu bilden. In Ausgestaltung dieser Grundlage sind nahezu sämtliche Forderungen der Brennkraftmaschinenhersteller in der Berücksichtigung von Motorkenngrößen wie Verbrauch, Temperatur, Abgas usw. erfüllbar. Der hierzu erforderliche Regelaufwand ist verhältnismäßig gering und äußerst flexibel. Durch das gleichzeitige Steuern der Steuerpunkte der Steuernut und des der Zumessung dienenden Schaltventils ist es vorteilhaft möglich, die Phasen der Kraftstoffeinspritzung beliebig und unabhängig von Drehzahl und Einspritzmenge innerhalb des Förderhubbereiches des bzw. der Pumpenkolben vorzusehen. Die zur Steuerung vorgesehene elektrische Stellvorrichtung und das elektrische Schaltventil sind dabei nicht dem Einspritzdruck ausgesetzt. Durch die Kombination Schaltventil und pumpendrehzahlsynchron geführte Steuerkanten der Steuernut kann bei äußerst vielseitigen Einflußmöglichkeiten auf die Einspritzung ein nachteiliger unkontrollierter Einfluß der Drehzahl auf die Kraftstoffzumessung, wie das wegen den konstanten Schaltzeiten bei mit Magnetventilen gesteuerten Kraftstoffeinspritzpumpen der Fall ist, im wesentlichen vermieden werden.In contrast, the fuel injection pump according to the invention with the characterizing features of the main claim has the advantage of forming the basis for an extremely flexible injection pump control. In an embodiment of this basis, almost all of the requirements of the internal combustion engine manufacturers can be met in consideration of engine parameters such as consumption, temperature, exhaust gas, etc. The standard effort required for this is relatively small and extremely flexible. By simultaneously controlling the control points of the control groove and the switching valve used for metering, it is advantageously possible to provide the fuel injection phases as desired and independently of the speed and injection quantity within the delivery stroke range of the pump piston (s). The electrical control device provided for control and the electrical switching valve are not exposed to the injection pressure. The combination of the switching valve and the control edges of the control groove, which are guided synchronously with the pump speed, can substantially avoid an adverse, uncontrolled influence of the speed on the fuel metering, as is the case due to the constant switching times of fuel injection pumps controlled by solenoid valves, with extremely versatile influences on the injection.

Ein Ausführungsbeispiel des Gegenstandes der Erfindung ist in der Zeichnung vereinfacht dargestellt und im folgenden näher beschrieben. Es zeigt

  • F i g. 1 eine erfindungsgemäße Kraftstoffeinspritzpumpe im Längsschnitt und
  • Fig. 2 in den Darstellungen A, B, C, D und E fünf verschiedene Arbeitsstellungen jeweils gezeigt an den Querschnitten gemäß den Linien I, 11 und III in Fig. 1.
An embodiment of the object of the invention is shown in simplified form in the drawing and described in more detail below. It shows
  • F i g. 1 shows a fuel injection pump according to the invention in longitudinal section and
  • 2 in the representations A, B, C, D and E five different working positions each shown on the cross sections according to lines I, 11 and III in FIG. 1.

In dem Gehäuse 1 einer Kraftstoffeinspritzpumpe ist eine Verteilerwelle 2 sowie radial angeordnete Pumpenkolben 3 gelagert. Die Pumpenkolben 3 werden über einen Nockenring 4 angetrieben, der topfförmig die Kolben umgreift und mit der nicht dargestellten Antriebswelle der Kraftstoffeinspritzpumpe fest verbunden ist. Über eine nicht dargestellte Kupplung wird die Verteilerwelle 2 durch die Antriebswelle mitgenommen, wobei jedoch die Verteilerwelle 2 im Gehäuse 1 axial verschiebbar ist. Auf der Mantelfläche der Verteilerwelle 2 ist eine Ringnut 5 angeordnet, die mit den Kolben 3 die Pumpenarbeitsräume 6 begrenzt. Mit dieser Ringnut 5 sind Längsnuten verbunden, von denen eine Längsnut 7 als Verteilernut mit den Förderleitungen 8 zusammenwirkt, die zu den Kraftstoffeinspritzdüsen 9 an der Brennkraftmaschine führen und nacheinander durch die Verteilernut 7 aufgesteuert werden. Die Verteilernut 7 kann dabei als eine von der Ringnut 5 abzweigenden lange Längsnut ausgeführt sein oder kürzer ausgeführt über einen Längskanal 21 und zwei Radialkanäle 22, 23 der Verteilerwelle mit der Ringnut 5 verbunden sein (in Fig. 1 gestrichelt dargestellt). Außerdem sind auf der Mantelfläche der Verteilerwelle 2 Steuernuten 10 angeordnet, die mit der Ringnut 5 verbunden sind und bezogen auf eine Mantellinie der Verteilerwelle 2 leicht schräg verlaufen. Diese Steuernuten steuern eine Kraftstoffzuführöffnung 13, die in den die Verteilerwelle 2 führenden Zylinder 14 mündet und das Ende eines Druckkanals 11 darstellt, der von einer Kraftstofförderpumpe 12 mit Kraftstoff versorgt wird. In dem Druckkanal ist ein elektrisch betätigbares Schaltventil 16 angeordnet, das vorzugsweise als Ventilschließglied einen Schieber aufweist und somit druckausgeglichen ist. Insbesondere soll dieses Ventil jedoch von einer Bauart sein, die schnelle Schaltvorgänge ausführen kann. Der Förderdruck der Kraftstofförderpumpe wird mit Hilfe eines Druckregelventils 17 auf einem konstanten Wert gehalten.A distributor shaft 2 and radially arranged pump pistons 3 are mounted in the housing 1 of a fuel injection pump. The pump pistons 3 are driven via a cam ring 4, which surrounds the pistons in a pot-shaped manner and is firmly connected to the drive shaft of the fuel injection pump, not shown. Via a clutch, not shown, the distributor shaft 2 is carried along by the drive shaft, but the distributor shaft 2 is axially displaceable in the housing 1. On the lateral surface of the distributor shaft 2, an annular groove 5 is arranged, which delimits the pump working spaces 6 with the pistons 3. With this annular groove 5, longitudinal grooves are connected, of which a longitudinal groove 7 cooperates as a distributor groove with the delivery lines 8, which lead to the fuel injection nozzles 9 on the internal combustion engine and are opened one after the other through the distributor groove 7. The distributor groove 7 can be designed as a long longitudinal groove branching off from the annular groove 5 or can be made shorter via a longitudinal channel 21 and two radial channels 22, 23 of the distributor shaft with the annular groove 5 (shown in dashed lines in FIG. 1). In addition, 2 control grooves 10 are arranged on the lateral surface of the distributor shaft, which are connected to the annular groove 5 and extend slightly obliquely with respect to a surface line of the distributor shaft 2. These control grooves control a fuel supply opening 13 which opens into the cylinder 14 guiding the distributor shaft 2 and represents the end of a pressure channel 11 which is supplied with fuel by a fuel feed pump 12. An electrically actuated switching valve 16 is arranged in the pressure channel, which preferably has a slide as a valve closing element and is therefore pressure-balanced. In particular, however, this valve should be of a type that can perform fast switching operations. The delivery pressure of the fuel delivery pump is kept at a constant value by means of a pressure control valve 17.

Wie bereits erwähnt ist die Verteilerwelle 2 längs verschiebbar, was mit Hilfe einer elektrischen Stellvorrichtung 18 erfolgt. Diese Vorrichtung ist in der Zeichnung nur schematisch wiedergegeben und wirkt über eine punktförmige Berührungsfläche auf die rotierende Verteilerwelle. Bei der Verschiebung der Verteilerwelle entgegen der Kraft einer Feder 19 ändert sich die Lage der Steuernut 10 bezogen auf die Kraftstoffzuführöffnung 13 bei einer konstant angenommenen Drehstellung der Antriebswelle und somit ändern sich auch die Steuerzeiten, bei denen die Kraftstoffzuführöffnung 13 geöffnet ist.As already mentioned, the distributor shaft 2 is longitudinally displaceable, which is done with the aid of an electrical adjusting device 18. This device is shown only schematically in the drawing and acts on the rotating distributor shaft via a point-like contact surface. When the distributor shaft is displaced counter to the force of a spring 19, the position of the control groove 10 with respect to the fuel supply opening 13 changes when the rotational position of the drive shaft is assumed to be constant, and thus the control times at which the fuel supply opening 13 is opened also change.

Zur näheren Erläuterung der Funktion sind in Fig. 2 fünf verschiedene Drehstellungen A, B, C, D und E dargestellt, von denen jede in schematischer Nebeneinanderordnung die Drehstellungen in den Schnittebenen I, 11 und 111 der Kraftstoffeinspritzpumpe gemäß Fig. 1 wiedergibt. Beim Schnitt wird die Verteilerwelle 2 im Bereich der Pumpenkolben 3 geschnitten. Die Schnittebene 11 geht durch die Kraftstoffzuführöffnung 13 und die Schnittebene 111 liegt in der Einmündungsebene der Förderleitungen 8. Beim Schnitt I ist weiterhin auch ein Nocken 24 des Nockenrings4 in seiner Zuordnung zum Pumpenkolben 3 gezeigt, wobei zwischen dem Pumpenkolben 3 und dem Nocken 24 in bekannter Weise eine Rolle 25 geschaltet ist.For a more detailed explanation of the function, five different rotational positions A, B, C, D and E are shown in FIG. 2, each of which represents the rotational positions in the sectional planes I, 11 and 111 of the fuel injection pump according to FIG. 1 in a schematic juxtaposition. During the cut, the distributor shaft 2 is cut in the area of the pump pistons 3. The sectional plane 11 passes through the fuel supply opening 13 and the sectional plane 111 lies in the confluence plane of the delivery lines 8. In section I, a cam 24 of the cam ring 4 is also shown in its assignment to the pump piston 3, between the pumps piston 3 and the cam 24 a roller 25 is switched in a known manner.

Die Darstellung A zeigt die Drehstellung der Verteilerwelle 2 bei Beginn des Auffüllens der Pumpenarbeitsräume 6 mit Kraftstoff. Die Rolle 25 hat zu diesem Zeitpunkt die höchste Erhebung des Nockens 24 erreicht und ist im Begriff der abfallenden Flanke des Nockens zu folgen. Dabei wird der Pumpenkolben nach außen bewegt und der Pumpenarbeitsraum 6 vergrößert.The illustration A shows the rotational position of the distributor shaft 2 at the start of filling the pump work spaces 6 with fuel. At this point the roller 25 has reached the highest elevation of the cam 24 and is to be followed in the concept of the falling flank of the cam. The pump piston is moved outwards and the pump working space 6 is enlarged.

Das Schaltventil 16 befindet sich zu diesem Zeitpunkt in der geöffneten Stellung und die Steuernut 10 hat gerade die Verbindung zum Druckkanal 11 geöffnet. Somit kann Kraftstoff über die Steuernut 10 in die Ringnut 5 und von dort in die Pumpenarbeitsräume 6 gelangen. Der Kraftstoffdruck sorgt dafür, daß die Rollen 25 in Anlage an den Nocken 24 bleiben.The switching valve 16 is at this time in the open position and the control groove 10 has just opened the connection to the pressure channel 11. Fuel can thus enter the annular groove 5 via the control groove 10 and from there into the pump work spaces 6. The fuel pressure ensures that the rollers 25 remain in contact with the cams 24.

Bei der Darstellung B ist der Moment erfaßt, bei der das Schaltventil 16 geschlossen wird. Obwohl die Steuernut 10 noch in Verbindung mit dem Druckkanal 11 ist, wird ab diesem Zeitpunkt die Zufuhr von Kraftstoff gestopt, so daß die Pumpenkolben 3, die in diesem Zeitpunkt eingenommene Stellung beibehält und vom Nocken abhebt. Damit ist das Ende der Zumessung erreicht.The representation B shows the moment at which the switching valve 16 is closed. From this point in time, although the control groove 10 is still in connection with the pressure channel 11, the supply of fuel is stopped, so that the pump piston 3 maintains the position it has assumed at that point in time and lifts off the cam. This is the end of the metering.

Bei der Darstellung C ist die Verbindung zwischen Steuernut 10 und Druckkanal 11 unterbrochen. Ab diesem Zeitpunkt kann bereits wieder das Schaltventil 16 geöffnet werden, so daß keine Schaltverlustzeiten durch die endliche Schaltzeit des Magnetventils und kein durch die Schaltzeit des Magnetventils erzeugter Drehzahl-Einfluß auf die Kraftstoffmenge auftreten kann. Der Nocken 24 hat sich gegenüber dem Pumpenkolben bzw. der Rolle 25 weiterbewegt und die Pumpenkolben 3 befinden sich noch immer in der bei der Darstellung B fixierten Stellung.In the representation C, the connection between control groove 10 and pressure channel 11 is interrupted. From this point on, the switching valve 16 can be opened again, so that no switching loss times due to the finite switching time of the solenoid valve and no speed influence on the fuel quantity caused by the switching time of the solenoid valve can occur. The cam 24 has moved further with respect to the pump piston or the roller 25 and the pump pistons 3 are still in the position fixed in the representation B.

Bei der Darstellung D hat nun der nächste Nocken 24' die Rolle 25 erreicht, die im Laufe der Weiterbewegung des Nocken 24' die Pumpenkolben 3 einwärts bewegt. Die Pumpenkolben 3 führen nun den Förderhub aus und drücken den Kraftstoff über den Längskanal 21 und den Radialkanal 22 in die Längsnut 7, die nunmehr in Verbindung mit einer der Förderleitungen 8 steht. In diese wird der geförderte Kraftstoff gepreßt und zur Einspritzstelle bei der Brennkraftmaschine gebracht. Der Druckkanal 11 ist weiterhin durch die Verteilerwelle gesperrt und das Schaltventil 16 ist geöffnet.In the representation D, the next cam 24 'has now reached the roller 25, which in the course of the further movement of the cam 24' moves the pump piston 3 inwards. The pump pistons 3 now carry out the delivery stroke and press the fuel via the longitudinal channel 21 and the radial channel 22 into the longitudinal groove 7, which is now connected to one of the delivery lines 8. The delivered fuel is pressed into this and brought to the injection point at the internal combustion engine. The pressure channel 11 is still blocked by the distributor shaft and the switching valve 16 is open.

Die Darstellung E zeigt das Ende der Einspritzung, das dann erreicht ist, wenn die Steuernut 10 wieder in Verbindung mit dem Druckkanal 11 gebracht wird. Obwohl die Verteilernut 7 noch in Verbindung mit der Förderleitung 8 steht, wird jetzt die Kraftstofförderung unterbrochen, da der restliche vom Pumpenkolben 3 geförderte Kraftstoff über den Druckkanal zur Kraftstoffversorgungsseite abfließen kann. Zur Verbesserung der Absteuerung kann ein weiterer Kanal 26 vorgesehen werden, der das Schaltventil 16 umgeht und ein Rückschlagventil 27 enthält, Auf diese Weise wird der Absteuerquerschnitt vergrößert und es wird gewährleistet, daß die Einspritzung schlagartig beendet wird. An diese letzte Phase schließt sich dann danach wieder die Phase A an und der oben beschriebene Vorgang wiederholt sich. Wie man dieser Beschreibung entnehmen kann, kann die Kraftstoffeinspritzmenge pro Hub allein durch das Schaltventil 16 bestimmt werden. Dabei wird die Zumeßphase einerseits durch das Öffnen der Druckleitung 11 mit einer drehzahlsynchron geführten Steuerkante der Steuernut 10 bestimmt und andererseits durch das Schließen des Schaltventils 16. Es kommt somit nur einmal der Drehzahleinfluß bei der Kraftstoffzumessung zum Tragen aufgrund der konstanten Schaltzeit des Schaltventils 16. Diese Steuerungsart führt bei variabler Einspritzmenge zu sich ändernden Spritzbeginnzeiten. Das Spritzende kann dagegen konstant gehalten werden.The representation E shows the end of the injection, which is reached when the control groove 10 is brought back into connection with the pressure channel 11. Although the distributor groove 7 is still connected to the delivery line 8, the fuel delivery is now interrupted, since the remaining fuel delivered by the pump piston 3 can flow off to the fuel supply side via the pressure channel. To improve the control, a further channel 26 can be provided, which bypasses the switching valve 16 and contains a check valve 27. In this way, the control cross-section is enlarged and it is ensured that the injection is stopped suddenly. This last phase is then followed by phase A and the process described above is repeated. As can be seen from this description, the fuel injection quantity per stroke can be determined solely by the switching valve 16. The metering phase is determined on the one hand by opening the pressure line 11 with a speed-controlled control edge of the control groove 10 and on the other hand by closing the switching valve 16. Thus, the influence of the speed in fuel metering only comes into play once due to the constant switching time of the switching valve 16. This Control type leads to changing injection start times with variable injection quantity. The end of the spray, however, can be kept constant.

Eine andere Steuerungsmöglichkeit ist die, daß über das Schaltventil 16 ständig eine gleich große Kraftstoffmenge zugemessen wird, wodurch ein konstanter Einspritzzeitpunkt erzielt wird und daß zur Variation der Kraftstoffeinspritzmenge die Verteilerwelle 2 verschoben wird. Durch die Verschiebung ändert sich der Punkt bei dem die Steuernut 10 am Ende der Einspritzphase wieder mit der Druckleitung 11 verbunden wird. Die Lage des Einspritzendes ist somit veränderlich. Diese Steuerung hat weiterhin den Vorteil, daß die Zumessung nicht von den Schaltzeiten des Schaltventils abhängig ist. Durch Kombination von sowohl Verteilerwellenverschiebung als auch variabler Öffnungszeiten des Schaltventils 16 kann eine beliebige Kraftstoffmenge innerhalb eines beliebigen Bereiches des möglichen Förderhubs der Pumpenkolben 3 zur Einspritzung gelangen. Mit einer entsprechend ausgestalteten Steuereinrichtung lassen sich hier beliebige Spritzzeitpunkte und Spritzdauern in Abhängigkeit von Temperaturlast, Drehzahl und anderen Parametern der Brennkraftmaschinen erzielen.Another control option is that a constant amount of fuel is constantly metered through the switching valve 16, whereby a constant injection timing is achieved and that the distributor shaft 2 is shifted to vary the fuel injection amount. The shift changes the point at which the control groove 10 is reconnected to the pressure line 11 at the end of the injection phase. The position of the end of injection is therefore variable. This control also has the advantage that the metering is not dependent on the switching times of the switching valve. By combining both the distributor shaft displacement and the variable opening times of the switching valve 16, any quantity of fuel can be injected within any range of the possible delivery stroke of the pump pistons 3. With an appropriately designed control device, any desired spraying times and spraying times can be achieved depending on the temperature load, speed and other parameters of the internal combustion engines.

Claims (5)

  1. Fuel injection pump having at least one pump working chamber (6) enclosed by a pump piston (3) in a cylinder, which chamber is in constant communication with a distributor orifice on a distributor shaft (2) rotating in a cylinder, and can, through this orifice, be successively connected, upon rotation of the distributor shaft, during the conveying stroke of the pump piston, to one of the conveying lines (8) arranged in a distributed manner on the periphery of the cylinder and leading from the cylinder to the fuel injection point, the pump working chamber furthermore being in constant communication with a control groove (10) in the cylindrical surface of the distributor shaft, the said control groove (10) cooperating with a fuel feed orifice (13) opening into the cylinder and the distributor shaft (2) being axially displaceable so that the rotational position of the control groove (10) relative to the fuel feed orifice (13) and the drive of the distributor shaft can be varied, characterised in that the fuel feed orifice (13) can be connected via an electrically actuatable switching valve (16) to a fuel supply source and that the switching valve can be so controlled by an electrical control device that the said valve is opened after the fuel feed bore (13) has been closed by the following-up limiting edge of the control groove (10), and is closed at an instant at which the advancing control edge of the control groove (10) has again opened the fuel feed orifice (13), and that the distributor shaft (2) is displaceable by means of an electrical adjustment device (18).
  2. 2. Fuel injection pump according to claim 1, characterised in that the pressure of the fuel supply source can be set to a constant value by means of a pressure regulator (17).
  3. 3. Fuel injection pump according to claim 1, characterised in that the control groove (10) is inclined relative to the axial direction of the distributor shaft (2).
  4. 4. Fuel injection pump according to one of the preceding claims, characterised in that the switching valve (16) has a slide serving as a closing member.
  5. 5. Fuel injection pump according to one of the preceding claims, characterised in that a relief line (26) is provided parallel to the switching valve (16), the said line containing a non-return valve (27) opening in the direction of the fuel supply source.
EP82106523A 1981-07-22 1982-07-20 Fuel-injection pump Expired EP0070558B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3128975 1981-07-22
DE19813128975 DE3128975A1 (en) 1981-07-22 1981-07-22 FUEL INJECTION PUMP

Publications (2)

Publication Number Publication Date
EP0070558A1 EP0070558A1 (en) 1983-01-26
EP0070558B1 true EP0070558B1 (en) 1984-10-31

Family

ID=6137494

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82106523A Expired EP0070558B1 (en) 1981-07-22 1982-07-20 Fuel-injection pump

Country Status (5)

Country Link
US (1) US4501246A (en)
EP (1) EP0070558B1 (en)
JP (1) JPS5825565A (en)
BR (1) BR8204235A (en)
DE (2) DE3128975A1 (en)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3243348A1 (en) * 1982-11-24 1984-05-24 Robert Bosch Gmbh, 7000 Stuttgart FUEL INJECTION PUMP
DE3412834A1 (en) * 1984-04-05 1985-10-24 Robert Bosch Gmbh, 7000 Stuttgart FUEL INJECTION PUMP
DE3612942A1 (en) * 1986-04-17 1987-10-22 Bosch Gmbh Robert FUEL INJECTION PUMP FOR INTERNAL COMBUSTION ENGINES
DE3722265A1 (en) * 1987-07-06 1989-01-19 Bosch Gmbh Robert FUEL INJECTION PUMP
US5098260A (en) * 1990-04-23 1992-03-24 Cummins-Engine Company, Inc. Position-servo device for positioning a stop in a positive displacement fuel injection system
US5215449A (en) * 1991-12-05 1993-06-01 Stanadyne Automotive Corp. Distributor type fuel injection pump
US5954487A (en) * 1995-06-23 1999-09-21 Diesel Technology Company Fuel pump control valve assembly
WO1997001031A1 (en) 1995-06-23 1997-01-09 Diesel Technology Company Fuel pump and method of operating same
US6158419A (en) * 1999-03-10 2000-12-12 Diesel Technology Company Control valve assembly for pumps and injectors
US6089470A (en) * 1999-03-10 2000-07-18 Diesel Technology Company Control valve assembly for pumps and injectors
US6450778B1 (en) 2000-12-07 2002-09-17 Diesel Technology Company Pump system with high pressure restriction
DE602004002105T2 (en) * 2004-06-30 2007-02-08 C.R.F. S.C.P.A. High-pressure pump with variable delivery rate for a fuel injection system

Family Cites Families (13)

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Publication number Priority date Publication date Assignee Title
US2077259A (en) * 1931-05-22 1937-04-13 Joseph Schidlovsky Fuel injecting device for internal combustion engines
US2356627A (en) * 1940-06-27 1944-08-22 George A Rubissow Interruption injection pump
FR1387296A (en) * 1963-12-19 1965-01-29 Sigma Improvements made to rotary distributor fuel injection pumps
FR1449640A (en) * 1965-04-01 1966-05-06 Bosch Gmbh Robert Improvements made to rotary distributor fuel injection pumps
DE1919707A1 (en) * 1969-04-18 1970-11-12 Bosch Gmbh Robert Fuel injection pump for multi-cylinder internal combustion engines
DE2503346C2 (en) * 1975-01-28 1986-04-03 Robert Bosch Gmbh, 7000 Stuttgart Fuel distributor injection pump for internal combustion engines
JPS6032021B2 (en) * 1976-12-26 1985-07-25 株式会社デンソー Injection pump control device
GB1603415A (en) * 1977-04-30 1981-11-25 Lucas Industries Ltd Liquid fuel injection pumps
DE3000977A1 (en) * 1980-01-12 1981-07-23 Robert Bosch Gmbh, 7000 Stuttgart FUEL INJECTION DEVICE FOR INTERNAL COMBUSTION ENGINES, ESPECIALLY FOR DIESEL ENGINES
US4382751A (en) * 1980-02-14 1983-05-10 Lucas Industries Limited Fuel pumping apparatus
DE3017276A1 (en) * 1980-05-06 1981-11-12 Robert Bosch Gmbh, 7000 Stuttgart FUEL INJECTION PUMP FOR INTERNAL COMBUSTION ENGINES
DE3118669A1 (en) * 1980-07-01 1982-04-08 Robert Bosch Gmbh, 7000 Stuttgart "METHOD AND DEVICE FOR INJECTING FUEL IN COMBUSTION ENGINES, ESPECIALLY IN DIESEL ENGINES"
DE3024963A1 (en) * 1980-07-02 1982-01-28 Robert Bosch Gmbh, 7000 Stuttgart FUEL INJECTION DEVICE FOR INTERNAL COMBUSTION ENGINES, ESPECIALLY FOR DIESEL ENGINES

Also Published As

Publication number Publication date
US4501246A (en) 1985-02-26
JPH024780B2 (en) 1990-01-30
DE3128975A1 (en) 1983-02-10
EP0070558A1 (en) 1983-01-26
JPS5825565A (en) 1983-02-15
DE3261137D1 (en) 1984-12-06
BR8204235A (en) 1983-07-12

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