EP0318534B1 - Radial-piston-type dispensing injection pump - Google Patents

Radial-piston-type dispensing injection pump Download PDF

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Publication number
EP0318534B1
EP0318534B1 EP19880904479 EP88904479A EP0318534B1 EP 0318534 B1 EP0318534 B1 EP 0318534B1 EP 19880904479 EP19880904479 EP 19880904479 EP 88904479 A EP88904479 A EP 88904479A EP 0318534 B1 EP0318534 B1 EP 0318534B1
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EP
European Patent Office
Prior art keywords
pump
distributor
plunger
chamber
switching 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.)
Expired - Lifetime
Application number
EP19880904479
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German (de)
French (fr)
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EP0318534A1 (en
Inventor
André Brunel
Jean Paul Morel-Fourrier
Jean Leblanc
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Robert Bosch GmbH
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Robert Bosch GmbH
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Publication of EP0318534A1 publication Critical patent/EP0318534A1/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
    • F02M63/02—Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively
    • F02M63/0205—Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively for cutting-out pumps or injectors in case of abnormal operation of the engine or the injection apparatus, e.g. over-speed, break-down of fuel pumps or injectors ; for cutting-out pumps for stopping the engine
    • F02M63/0215—Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively for cutting-out pumps or injectors in case of abnormal operation of the engine or the injection apparatus, e.g. over-speed, break-down of fuel pumps or injectors ; for cutting-out pumps for stopping the engine by draining or closing fuel conduits

Definitions

  • the invention relates to a distributor fuel injection pump of the radial piston type of the type defined in the preamble of claim 1.
  • the displacement of the distributor piston serves to control the fuel injection quantity.
  • the point of the pump piston stroke, from which the amount of fuel delivered by the pump piston is interrupted to interrupt the fuel injection, is controlled via an inclined edge on the distributor piston that can be adjusted by the displacement.
  • the deactivated fuel is used to set a pressure in the control chamber with the help of an adjustable discharge throttle, by means of which the distributor piston is adjusted against the force of a control spring.
  • This fuel injection pump is very complex and offers no possibility of electrically controlling the fuel injection quantity taking into account various operating parameters. To adjust the start of spraying, a spray adjustment device is still required in a complex manner.
  • the pump work area is always completely filled with fuel during the suction stroke of the pump piston.
  • the amount of this fuel volume to be injected is determined as a function of parameters of the internal combustion engine, such as load and speed, by the time at which the electrical switching valve closes and opens.
  • the switching valve closes the fuel injection starts in the respective cylinder of the internal combustion engine, while when the switching valve is opened, the pump work chamber is connected to the relief chamber and the fuel injection is suddenly stopped.
  • the internal combustion engine is always supplied with the maximum fuel injection quantity regardless of the load, so that the speed of the internal combustion engine increases uninfluenced, the internal combustion engine "spins".
  • the object of the invention is to develop a generic distributor fuel injection pump so that it has the advantages of an easily and precisely feasible control of the fuel injection with the aid of an electrical switching valve and is further secured against spinning if a malfunction of the switching valve occurs. According to the invention, this object is achieved by the features of the characterizing part of patent claims 1 and 2.
  • the defect of the switching valve is recognized by a monitoring device, which then issues a closing command to the second switching valve.
  • a criterion for the defect of the first switching valve can be, for example, the increase in the speed of the internal combustion engine beyond a maximum speed.
  • the second switching valve is expediently designed such that it is normally closed and opens when actuated. The switching valve then closes when the control is omitted, so that the closing command consists in interrupting the excitation current for the electromagnet of the second switching valve. In this way, the fuel delivery is interrupted even when the control line of the second switching valve is disturbed.
  • the second switching valve can be much simpler and therefore cheaper than the first switching valve.
  • the radial piston type distributor fuel injection pump shown in longitudinal section in FIG. 1 has a cup-shaped housing 10 and a cover 11 closing it, which is pushed in from the open end of the housing 10 and delimits a pump interior 12 with a bottom 10a integral with the housing 10.
  • the pump interior 12 is filled with fuel at low pressure and is connected via a drain opening 13 with an upstream throttle 14 to a fuel return line leading to a fuel tank (both not shown).
  • a drive shaft 15 is passed through the bottom 10a of the housing 10 in a liquid-tight manner, which widens in a pot-shaped manner in the pump interior 12 and rotates with it along its edge connected cam ring 16 carries.
  • the cam ring 16 has on its inside in a known manner a cam track 17 with radially inwardly directed cams, the number and sequence of the number and sequence of radial pump pistons contained in the fuel injection pump and the number with these pump pistons per revolution of the drive shaft 15 piston strokes to be carried out are adapted.
  • a feed pump 18 sits on the drive shaft 15 and is connected to the fuel tank via an intake line 19 and to the pump interior 12 via a pressure line 20 and thereby ensures the fuel filling of the pump interior 12.
  • a distributor piston 21 is also connected to the drive shaft 15 in a rotationally fixed but axially displaceable manner, the axis of which is aligned with the axis of the drive shaft 15.
  • the distributor piston 21 is guided except for the end connected to the drive shaft 15 in the pump interior 12 in a distributor cylinder 22 which is held in a bore 23 of the cover 11 which is coaxial with the axis of the drive shaft 15.
  • Adjacent to the cam track 17, radially inward thereafter, guides 24 are provided in the cover 11 and in the distributor cylinder 22, which are evenly distributed over the circumference of the distributor cylinder 22 and extend close to the distributor piston 21.
  • FIG. 1 for supplying a total of three injection nozzles of an internal combustion engine, in particular a diesel engine, there are a total of three guides 24, of which only one can be seen in FIG. 1.
  • radial through bores 25 are provided in the distributor cylinder 22, in each of which a pump piston 26 is guided so as to be longitudinally displaceable.
  • a so-called roller plunger 27 is guided in a longitudinally displaceable manner, which consists of a roller or roller 28 and one Pusher cup 29 exists.
  • a plunger spring 31 which is basically supported on the one hand and on a spring plate 30 resting on the bottom of the plunger cup 29 on the other hand, presses the plunger cup 29 against the roller 28 and the latter against the cam track 17.
  • the spring plate 30 engages behind a protruding from the radial through bore 25 Collar 26a of the pump piston 26 and thus fixes the latter to the tappet cup 29.
  • Each pump piston 26 delimits a pump working chamber 32 in the radial through bore 25, the other limitation of which is formed by an annular groove 33 on the distributor piston 21.
  • a distributor groove 34 and a filling groove 35 open into the annular groove 33, each of which extends axially in opposite directions from the annular groove 33 on the distributor piston 21.
  • three injection bores 36 open in a cross-sectional plane, which are evenly distributed over the circumference of the distributor cylinder 22 and lead through the distributor cylinder 22 and the cover 11 to an injection nozzle 37 each. Of the three injection nozzles in total, one injection nozzle 37 is indicated schematically in FIG. 1.
  • the axial length of the distributor groove 34 is dimensioned such that it projects into the cross-sectional plane of the mouths of the injection bores 36 and thus connects one of the three injection bores 36 with the annular groove 33 depending on the rotational position of the distributor piston 21.
  • three filling bores 38 open out in the interior of the distributor cylinder 22 and are arranged uniformly distributed around the circumference of the distributor cylinder 22.
  • the axial length of the filling groove 35 is dimensioned such that it projects into this cross-sectional plane of the mouths of the filling bores 38 and thus one of the three, depending on the rotational position of the distributor piston 21 Filling holes 38 connects to the annular groove 33.
  • the coupling of the distributor piston 21 to the drive shaft 15 takes place via a pin-slot connection, in which a driving pin 39 on the drive shaft 15 positively engages in a longitudinal groove 40 in the distributor piston 21.
  • the basic position of the distributor piston 21 shown in FIG. 1 is determined by a helical compression spring 41 which presses the end of the longitudinal groove 40 against the driving pin 39, which thus forms a limit stop for the axial displacement movement of the distributor piston 21.
  • valve housing 42 of an electrical switching valve 43 On the outward-facing end face of the cover 11, the valve housing 42 of an electrical switching valve 43 is placed and fastened there in a corresponding manner.
  • the valve housing 42 engages with a centering pin in the inner cavity of the distributor cylinder 22 and, together with the end face 71 of the distributor piston 21 opposite it, delimits a control chamber 44.
  • the structure of the switching valve is known and is described, for example, in DE-OS 35 23 536.
  • the two valve connections 45, 46 of the switching valve 43 are connected to one another via a valve opening 47, which is controlled by a valve member 48.
  • the valve member 48 is actuated by an electromagnet 49, the valve member 48 opening the valve opening 47 in the non-energized state of the electromagnet 49 under the action of a return spring (not shown) and closing it in the energized state of the electromagnet 49.
  • the valve connection 45 covers a first bore section 51 of a relief line 50 opening into the end face of the cover, while the second valve connection 46 covers an opening in the end face of the cover 11 of a second bore section 52 of the relief line 50.
  • the pump work chamber 32 with the pump interior 12 is in via the relief line 50 Connection.
  • the pressure line 20 between the feed pump 18 and the pump interior 12 is guided via the control chamber 44 in the distributor cylinder 22, which divides the pressure line 20 into a first and second line section 53, 54.
  • a second electrical switching valve 55 is arranged, which controls a valve opening 57 integrated in the second line section 54 with a valve member 56.
  • the valve member 56 is actuated by an electromagnet 58, the valve member 56 closing the valve opening 57 in the non-energized state of the electromagnet 58 under the action of a valve closing spring 59 and releasing the electromagnet 58 in the energized state.
  • the second switching valve 55 is controlled by a monitoring device 60, which constantly monitors the proper functioning of the first switching valve 43 and issues a closing command in the form of switching off the excitation current for the electromagnet 58 to the second switching valve 55 as soon as the valve member 48 of the first switching valve 43 despite Elimination of the excitation of the electromagnet 49 does not open.
  • a monitoring device 60 can be designed, for example, as a speed detector that outputs the closing command to the second switching valve 55 when the speed of the internal combustion engine exceeds a predetermined maximum speed, which is a criterion for the no longer opening first switching valve 43.
  • the distributor piston 21 has a rotational position such that the filling groove 35 covers the filling bore 38.
  • the first switching valve 43 is open when de-energized and the second switching valve 55 is also open when energized.
  • the delivery stroke of the pump piston 26 begins, the pump piston 26 becoming more inclined due to the sliding of the roller tappet 27 Flank of the cam track 17 moved radially inwards.
  • Fuel is pumped back into the pump interior 12 from the pump work chamber 32 via the relief line 50 and the still open first switching valve 43.
  • the first switching valve 43 is closed.
  • the distributor piston 21 has reached a rotational position at the latest in which the distributor groove 34 covers an injection bore 36 and thus connects the pump working chamber 32 to the associated injection nozzle 37 via the injection bore 36.
  • fuel is now Injection nozzle 37 promoted and passes there for injection into the cylinder of the internal combustion engine.
  • the first switching valve 43 is de-energized, as a result of which the opening switching valve 43 connects the pump working chamber 32 to the pump interior 12 via the annular groove 33 and the relief line 50.
  • the pressure in the pump work chamber 32 suddenly drops below the opening pressure of the injection nozzle 37, and the latter closes.
  • the first switching valve 43 closes and / or opens the amount of fuel delivered to the injector 37 and injected there is metered.
  • 1b shows the fuel injection pump for the case in which the first switching valve 43 is defective in such a way that its valve member 48 does not open the valve opening 47 for the electromagnet 49 despite the absence of the excitation current.
  • the first switching valve 43 getting stuck in the closed state.
  • the entire amount of fuel contained in the pump working chamber 32 reaches the injection via the injection nozzle 37 for each delivery stroke of the pump piston 26.
  • the speed of the internal combustion engine thereby increases continuously. This excessive increase in the speed of the internal combustion engine is recognized by the monitoring device 60 and this issues a closing command to the second switching valve 55. This closing command causes the excitation current for the electromagnet 58 of the second switching valve 55 to be switched off.
  • the second switching valve closes under the action of the valve closing spring 59 55.
  • the control chamber 44 in the distributor cylinder 22 is thus separated from the pump interior 12.
  • the pressure in the control chamber 44 increases and causes the distributor piston 21 to be displaced into the axial displacement position shown in FIG. 1b. In this displacement position, it projects in the pump work space 32 opening filling groove 35 freely into the pump work space 12, whereby the pump work space 32 is connected to the pump interior 12.
  • the fuel will now flow out of the pump working chamber 32 via the filling groove 35 into the pump interior 12, so that no pressure exceeding the opening pressure of the injection nozzle 37 can build up in the pump working chamber 32.
  • the second exemplary embodiment of a radial piston type distributor fuel injection pump shown in FIG. 2 differs from the fuel injection pump in FIG. 1 only in that the annular groove 33 delimiting the pump working space 32 on the distributor piston 21 is divided by an annular web 62 which has an outer diameter of the distributor piston 21 has the corresponding outer diameter.
  • the annular web 62 is placed within the annular groove 33 in such a way that in the axial displacement position shown in FIG Separates annular groove 33 from the right part of the annular groove 33 and thus from the pump working space 32.
  • the filling groove 35 opens into this now sealed part of the annular groove 33, in the axial displacement position of the distributor piston 21, the filling groove 35 is separated from the pump working chamber 32 in each of its rotational positions and thus the latter relative to the fuel-filled pump interior 12 cordoned off.
  • the axial length of the filling groove 35 is shorter here or the filling bore 38 is made further away from the pump interior end of the distributor cylinder 22, so that the filling groove is in the axial displacement position of the distributor piston (Fig. 2b) 35 is not released from the distributor cylinder 22 to the pump interior 12.
  • annular groove 33 itself can be made so narrow that it is covered by the through holes 25 in the distributor cylinder 22 in the normal operating position of the distributor piston 21 (FIG. 2a) and in the axial displacement position of the distributor piston 21 (FIG. 2b ) is covered in its full length by the inner wall of the distributor cylinder 22.
  • FIG. 3 of a radial piston type distributor fuel injection pump differs from the fuel injection pump in FIG. 1 in that in the relief line 50 there is provided a bypass 63 which bridges the first switching valve and is opened or closed by the distributor piston 21.
  • a first bypass section 64 is connected to the first bore section 51 of the relief line 50 and a second bypass section 65 is connected to the second bore section 52 of the relief line 50.
  • Each bypass section 64, 65 opens into the interior of the distributor cylinder 22.
  • the orifices are placed in such a way that they are closed by the distributor piston 21 in the normal operating position of the distributor piston 21 (FIG. 3a) and in which the first switching valve 43 is defective by the distributor piston 21 assumed axial displacement position (Fig.
  • the exemplary embodiment of a distributor fuel injection pump of the radial piston type shown in FIG. 4 is modified somewhat more than the exemplary embodiments in FIGS. 2 and 3 compared to the fuel injection pump in FIG. 1.
  • the pressure line 20 leading away from the feed pump 18 is directly connected to the pump interior 12.
  • the control chamber 44 in the distributor cylinder 22 is connected to the pump interior 12 via an inlet line 66 and connected via an outlet line 67 with the interposition of a throttle 68 to a drain opening 69 provided in the cover 11, which in turn is connected to the fuel tank via a fuel return line.
  • the second switching valve 55 is arranged in the inlet line 66.
  • the connection of the drive shaft 15 and the distributor piston 21 is made such that the end face 70 of the distributor piston 21 projecting into the pump interior 12 is acted upon by the fuel pressure prevailing in the pump interior 12.
  • the first switching valve 43 remains stuck in its closed position, then, as with the fuel injection pump in FIG Monitoring device 60 controls the second switching valve 55. This closes so that no more fuel can flow into the control chamber 44 from the pump interior 12 via the feed line 66. Only the connection of the control room 44 via the drain line 67 to the drain opening 69 remains. The pressure acting on the end face 70 of the distributor piston 21 is now opposed to no counter pressure in the control chamber 44, as a result of which the distributor piston 21 is displaced to the right in FIG. 4a and assumes its axial displacement position shown in FIG. 4b.
  • the filling groove 35 is shifted to the right so far that it is no longer able to cover the filling bore 38 in the distributor cylinder 22 (FIG. 4b).
  • the pump working space 32 is thus separated from the pump interior 12 and can no longer be filled with fuel during the suction stroke of the pump piston 26. If the first switching valve 43 is defective, the fuel delivery to the injection nozzle 37 is interrupted.
  • FIGS. 2-4 differ from the fuel injection pump in FIG. 1 only in the modifications highlighted above. Otherwise, the structure and mode of operation are the same, so that the same reference numerals have been used for the same components. For the sake of clarity, the reference numerals in FIGS. 2-4 are only entered to the extent necessary to understand the deviations from FIG. 1.

Abstract

A dispensing fuel injection pump comprises at least one radial pump piston (26), which effects an intake stroke and a delivery stroke, with a rotary dispensing piston (18) which connects injectors (37) to the working chamber (32) of the pump limited by the piston (26), and with an electric switching valve (43) which controls the quantity of fuel injected and communicates with the working chamber (32) of the pump and with a fuel-filled inner chamber (12) of the pump. To effect an emergency stop of the engine in the event of defective operation of the switching valve (43), the dispensing piston (21) is movable axially in order to stop the feed of fuel to the injectors (37) when it is in a certain axial displacement position. The dispensing piston (21) limits, with its front face (71) a control chamber (44) connected to a second electric switching valve (55). When the second valve (55) is closed, an overpressure or underpressure in relation to the inner chamber (12) of the pump is generated, and causes the dispensing piston (21) to move to its axial displacement position.

Description

Stand der TechnikState of the art

Die Erfindung geht aus von einer Verteilerkraftstoffeinspritzpumpe der Radialkolbenbauart der im Oberbegriff des Anspruchs 1 definierten Gattung.The invention relates to a distributor fuel injection pump of the radial piston type of the type defined in the preamble of claim 1.

Bei einer solchen durch die US-A-3 485 225 bekannten Verteilerkraftstoffeinspritzpumpe, dient die Verschiebung des Verteilerkolbens dazu, die Kraftstoffeinspritzmenge zu steuern. Dabei wird über eine durch die Verschiebung verstellbare Schrägkante am Verteilerkolben der Punkt des Pumpenkolbenhubes gesteuert, ab dem die vom Pumpenkolben geförderte Kraftstoffmenge zur Unterbrechung der Kraftstoffeinspritzung abgesteuert wird. Der abgesteuerte Kraftstoff wird dazu verwendet, in dem Steuerraum mit Hilfe einer verstellbaren Abströmdrossel einen Druck einzustellen, durch den der Verteilerkolben gegen die Kraft einer Regelfeder verstellt wird. Wegen der intermittierenden Förderung der Kraftstoffpumpe durch den Pumpenkolben wird hierbei in der Verbindung zum Steuerraum ein Rückschlagventil benötigt, und wegen der ungeregelten Förderung von Kraftstoff durch den Pumpenkolben, vor allem beim Schubbetrieb und einer dabei auftretenden großen Absteuermenge aus dem Pumpenarbeitsraum wird eine Notvorrichtung nötig, durch die der Verteilerkolben über seine geringste Fördermengenstellung hinaus in die bestimmte axiale Verschiebestellung gebracht wird, in der der Pumpenarbeitsraum über eine Querbohrung direkt entlastbar ist. Der Pumpenkolben dient dabei zusammen mit der Regelfeder als Druckbegrenzungsventil und verhindert eine Überlastung des Steuerraumes.In such a distributor fuel injection pump known from US-A-3,485,225, the displacement of the distributor piston serves to control the fuel injection quantity. The point of the pump piston stroke, from which the amount of fuel delivered by the pump piston is interrupted to interrupt the fuel injection, is controlled via an inclined edge on the distributor piston that can be adjusted by the displacement. The deactivated fuel is used to set a pressure in the control chamber with the help of an adjustable discharge throttle, by means of which the distributor piston is adjusted against the force of a control spring. Because of the intermittent delivery of the fuel pump by the pump piston, a check valve is required in the connection to the control room, and because of the uncontrolled delivery of fuel by the pump piston, especially during overrun and a large amount of exhaust gas from the pump workspace, an emergency device is required which the distributor piston is brought beyond its lowest delivery position into the specific axial displacement position in which the pump work space can be relieved directly via a transverse bore. The pump piston, together with the control spring, serves as a pressure relief valve and prevents the control chamber from being overloaded.

Diese Kraftstoffeinspritzpumpe ist sehr aufwendig und bietet keine Möglichkeit, die Kraftstoffeinspritzmenge elektrisch zu steuern unter Berücksichtigung vielfältiger Betriebsparameter. Für die Einstellung des Spritzbeginns ist in aufwendiger Weise weiterhin eine Spritzverstelleinrichtung nötig.This fuel injection pump is very complex and offers no possibility of electrically controlling the fuel injection quantity taking into account various operating parameters. To adjust the start of spraying, a spray adjustment device is still required in a complex manner.

Durch die DE-A-35 23 536 und die WO 87/06307 ist es ferner bekannt, die Kraftstoffeinspritzung durch ein Schaltventil elektrisch zu steuern.From DE-A-35 23 536 and WO 87/06307 it is also known to control the fuel injection electrically by means of a switching valve.

Dort wird beim Saughub des Pumpenkolbens der Pumpenarbeitsraum immer vollständig mit Kraftstoff gefüllt. Die zur Einspritzung gelangende Menge dieses Kraftstoffvolumens wird abhängig von Parametern der Brennkraftmaschine, wie Last und Drehzahl, durch den Zeitpunkt des Schließens und Öffnens des elektrischen Schaltventils bestimmt. Mit Schließen des Schaltventils setzt die Kraftstoffeinspritzung in den jeweiligen Zylinder der Brennkraftmaschine ein, während mit Öffnen des Schaltventils der Pumpenarbeitsraum mit dem Entlastungsraum verbunden und damit die Kraftstoffeinspritzung schlagartig beendet wird. Bei einem Defekt des Schaltventils in der Weise, daß es in seiner Schließstellung hängen bleibt und nicht mehr öffnet, wird die Brennkraftmaschine lastunabhängig immer mit der maximalen Kraftstoffeinspritzmenge versorgt, so daß die Drehzahl der Brennkraftmaschine unbeeinflußbar anwächst, die Brennkraftmaschine "durchdreht".There, the pump work area is always completely filled with fuel during the suction stroke of the pump piston. The amount of this fuel volume to be injected is determined as a function of parameters of the internal combustion engine, such as load and speed, by the time at which the electrical switching valve closes and opens. When the switching valve closes, the fuel injection starts in the respective cylinder of the internal combustion engine, while when the switching valve is opened, the pump work chamber is connected to the relief chamber and the fuel injection is suddenly stopped. In the event of a defect in the switching valve in such a way that it gets stuck in its closed position and no longer opens, the internal combustion engine is always supplied with the maximum fuel injection quantity regardless of the load, so that the speed of the internal combustion engine increases uninfluenced, the internal combustion engine "spins".

Aufgabe der Erfindung ist es, eine gattungsgemäße Verteilerkraftstoffeinspritzpumpe so weiterzubilden, daß sie die Vorteile einer mit Hilfe eines elektrischen Schaltventils einfach und genau durchführbaren Steuerung der Kraftstoffeinspritzung aufweist und fernerhin gegen Durchdrehen bei Auftreten einer Fehlfunktion des Schaltventils gesichert ist. Diese Aufgabe wird erfindunsgemäß durch die Merkmale des Kennzeichens der Patentansprüche 1 und 2 gelöst.The object of the invention is to develop a generic distributor fuel injection pump so that it has the advantages of an easily and precisely feasible control of the fuel injection with the aid of an electrical switching valve and is further secured against spinning if a malfunction of the switching valve occurs. According to the invention, this object is achieved by the features of the characterizing part of patent claims 1 and 2.

Vorteile der ErfindungAdvantages of the invention

Im Falle des Hängenbleibens des Schalventils wird in seiner Schließstellung die Förderung von Kraftstoff aus dem Pumpenarbeitsraum zu der Einspritzdüse abgebrochen. Die Brennkraftmaschine kommt damit wegen fehlenden Zündgemisches zum Stillstand. Der Defekt des Schaltventils wird durch eine Überwachungseinrichtung erkannt, die dann einen Schließbefehl an das zweite Schaltventil gibt. Ein Kriterium für den Defekt des ersten Schaltventils kann beispielsweise das Anwachsen der Drehzahl der Brennkraftmaschine über eine maximale Drehzahl hinaus sein. Zweckmäßigerweise ist das zweite Schaltventil so ausgebildet, daß es normalerweise geschlossen ist und bei Ansteuerung öffnet. Das Schaltventil schließt dann bei Wegfall der Ansteuerung, so daß der Schließbefehl in einem Unterbrechen des Erregerstroms für den Elektromagneten des zweiten Schaltventils besteht. Auf diese Weise wird die Kraftstofförderung auch dann unterbrochen, wenn die Steuerleitung des zweiten Schaltventils gestört ist. Das zweite Schaltventil kann sehr viel einfacher und damit billiger als das erste Schaltventil sein.If the switching valve gets stuck, the delivery of fuel from the pump workspace to the injection nozzle is stopped in its closed position. The internal combustion engine comes to a standstill because of a missing ignition mixture. The defect of the switching valve is recognized by a monitoring device, which then issues a closing command to the second switching valve. A criterion for the defect of the first switching valve can be, for example, the increase in the speed of the internal combustion engine beyond a maximum speed. The second switching valve is expediently designed such that it is normally closed and opens when actuated. The switching valve then closes when the control is omitted, so that the closing command consists in interrupting the excitation current for the electromagnet of the second switching valve. In this way, the fuel delivery is interrupted even when the control line of the second switching valve is disturbed. The second switching valve can be much simpler and therefore cheaper than the first switching valve.

Durch die in weiteren weiteren Ansprüchen aufgeführten Maßnahmen sind vorteilhafte Weiterbildungen und Verbesserungen der im Anspruch 1 angegebenen Verteilerkraftstoffeinspritzpumpe möglich.The measures listed in further further claims are advantageous further developments and improvements in Claim 1 specified fuel injection pump possible.

Zeichnungdrawing

Die Erfindung ist anhand von in der Zeichnung dargestellten Ausführungsbeispielen in der nachfolgenden Beschreibung näher erläutert. Es zeigen jeweils in schematischer Darstellung:

Fig. 1 bis 4
jeweils einen Längsschnitt einer Verteilerkraftstoffeinspritzpumpe der Radialkolbenbauart in vier Ausführungsbeispielen, wobei die Verteilerkraftstoffeinspritzpumpe in den mit a bezeichneten Teilfiguren in der normalen Betriebsstellung und in den mit b bezeichneten Teilfiguren für den Störungsfall dargestellt ist.

The invention is explained in more detail in the following description with reference to exemplary embodiments shown in the drawing. Each shows in a schematic representation:
1 to 4
in each case a longitudinal section of a distributor fuel injection pump of the radial piston type in four exemplary embodiments, the distributor fuel injection pump being shown in the normal operating position in the partial figures labeled a and in the partial figures labeled b for the malfunction.

Beschreibung der AusführungsbeispieleDescription of the embodiments

Die in Fig. 1 im Längsschnitt dargestellte Verteilerkraftstoffeinspritzpumpe der Radialkolbenbauart weist ein topfförmiges Gehäuse 10 und einen dieses verschließenden Deckel 11 auf, der vom offenen Ende des Gehäuses 10 her eingeschoben ist und mit einem mit dem Gehäuse 10 einstückigen Boden 10a einen Pumpeninnenraum 12 begrenzt. Der Pumpeninnenraum 12 ist mit unter niedrigem Druck stehenden Kraftstoff gefüllt und über eine Abflußöffnung 13 mit vorgeschalteter Drossel 14 mit einer zu einem Kraftstofftank führenden Kraftstoff-Rücklaufleitung (beide nicht dargestellt) verbunden. Durch den Boden 10a des Gehäuses 10 ist eine Antriebswelle 15 flüssigkeitsdicht hindurchgeführt, die sich im Pumpeninnenraum 12 topfförmig erweitert und längs ihres Randes einen mit ihr drehfest verbundenen Nockenring 16 trägt. Der Nockenring 16 weist auf seiner Innenseite in bekannter Weise eine Nockenbahn 17 mit radial nach innen gerichteten Nocken auf, die in Zahl und Folge an die Zahl und Folge von in der Kraftstoffeinspritzpumpe enthaltenen Radial-Pumpenkolben und an die Zahl mit diesen Pumpenkolben pro Umdrehung der Antriebswelle 15 auszuführenden Kolbenhübe angepaßt sind. Auf der Antriebswelle 15 sitzt eine Förderpumpe 18, die über eine Ansaugleitung 19 mit dem Kraftstofftank und über eine Druckleitung 20 mit dem Pumpeninnenraum 12 verbunden ist und dadurch die Kraftstoffbefüllung des Pumpeninnenraums 12 sicherstellt.The radial piston type distributor fuel injection pump shown in longitudinal section in FIG. 1 has a cup-shaped housing 10 and a cover 11 closing it, which is pushed in from the open end of the housing 10 and delimits a pump interior 12 with a bottom 10a integral with the housing 10. The pump interior 12 is filled with fuel at low pressure and is connected via a drain opening 13 with an upstream throttle 14 to a fuel return line leading to a fuel tank (both not shown). A drive shaft 15 is passed through the bottom 10a of the housing 10 in a liquid-tight manner, which widens in a pot-shaped manner in the pump interior 12 and rotates with it along its edge connected cam ring 16 carries. The cam ring 16 has on its inside in a known manner a cam track 17 with radially inwardly directed cams, the number and sequence of the number and sequence of radial pump pistons contained in the fuel injection pump and the number with these pump pistons per revolution of the drive shaft 15 piston strokes to be carried out are adapted. A feed pump 18 sits on the drive shaft 15 and is connected to the fuel tank via an intake line 19 and to the pump interior 12 via a pressure line 20 and thereby ensures the fuel filling of the pump interior 12.

Mit der Antriebswelle 15 ist weiterhin ein Verteilerkolben 21 drehfest aber axial verschieblich verbunden, dessen Achse mit der Achse der Antriebswelle 15 fluchtet. Der Verteilerkolben 21 ist bis auf das mit der Antriebswelle 15 im Pumpeninnenraum 12 verbundene Ende in einem Verteilerzylinder 22 geführt, der in einer zur Achse der Antriebswelle 15 koaxialen Bohrung 23 des Deckels 11 gehalten ist. Der Nockenbahn 17 benachbart, radial nach innen anschließend, sind im Deckel 11 und im Verteilerzylinder 22 Führungen 24 vorgesehen, die über den Umfang des Verteilerzylinders 22 gleichmäßig verteilt sind und bis nahe an den Verteilerkolben 21 reichen. Für eine in Fig. 1 dargestellte Verteilerkraftstoffeinspritzpumpe zur Versorgung von insgesamt drei Einspritzdüsen einer Brennkraftmaschine, insbesondere eines Dieselmotors, sind insgesamt drei Führungen 24 vorhanden, von welchen in Fig. 1 nur eine zu sehen ist. Koaxial zu den Führungen 24 sind im Verteilerzylinder 22 radiale Durchgangsbohrungen 25 vorgesehen, in welchen jeweils ein Pumpenkolben 26 längsverschieblich geführt ist. In den Führungen 24 ist jeweils ein sog. Rollenstößel 27 längsverschieblich geführt, der aus einer Walze oder Rolle 28 und aus einer Stößeltasse 29 besteht. Eine im Grunde der Führung 24 einerseits und an einem am Boden der Stößeltasse 29 anliegenden Federteller 30 andererseits sich abstützende Stößelfeder 31 drückt die Stößeltasse 29 gegen die Rolle 28 und letztere an die Nockenbahn 17. Der Federteller 30 hintergreift dabei einen aus der radialen Durchgangsbohrung 25 herausragenden Bund 26a des Pumpenkolbens 26 und legt letzteren damit an der Stößeltasse 29 fest.A distributor piston 21 is also connected to the drive shaft 15 in a rotationally fixed but axially displaceable manner, the axis of which is aligned with the axis of the drive shaft 15. The distributor piston 21 is guided except for the end connected to the drive shaft 15 in the pump interior 12 in a distributor cylinder 22 which is held in a bore 23 of the cover 11 which is coaxial with the axis of the drive shaft 15. Adjacent to the cam track 17, radially inward thereafter, guides 24 are provided in the cover 11 and in the distributor cylinder 22, which are evenly distributed over the circumference of the distributor cylinder 22 and extend close to the distributor piston 21. For a distributor fuel injection pump shown in FIG. 1 for supplying a total of three injection nozzles of an internal combustion engine, in particular a diesel engine, there are a total of three guides 24, of which only one can be seen in FIG. 1. Coaxial to the guides 24, radial through bores 25 are provided in the distributor cylinder 22, in each of which a pump piston 26 is guided so as to be longitudinally displaceable. In the guides 24, a so-called roller plunger 27 is guided in a longitudinally displaceable manner, which consists of a roller or roller 28 and one Pusher cup 29 exists. A plunger spring 31, which is basically supported on the one hand and on a spring plate 30 resting on the bottom of the plunger cup 29 on the other hand, presses the plunger cup 29 against the roller 28 and the latter against the cam track 17. The spring plate 30 engages behind a protruding from the radial through bore 25 Collar 26a of the pump piston 26 and thus fixes the latter to the tappet cup 29.

Jeder Pumpenkolben 26 begrenzt in der radialen Durchgangsbohrung 25 einen Pumpenarbeitsraum 32, dessen andere Begrenzung von einer Ringnut 33 auf dem Verteilerkolben 21 gebildet wird. In der Ringnut 33 münden eine Verteilernut 34 und eine Füllnut 35, die sich jeweils auf dem Verteilerkolben 21 axial in entgegengesetzten Richtungen von der Ringnut 33 weg erstrecken. Im Innern des Verteilerzylinders 22 münden in einer Querschnittsebene drei Einspritzbohrungen 36, die über den Umfang des Verteilerzylinders 22 gleichmäßig verteilt sind und durch den Verteilerzylinder 22 und den Deckel 11 hindurch bis zu jeweils einer Einspritzdüse 37 führen. Von den insgesamt vorhandenen drei Einspritzdüsen ist in Fig. 1 eine Einspritzdüse 37 schematisch angedeutet. Die axiale Länge der Verteilernut 34 ist so bemessen, daß sie bis in die Querschnittsebene der Mündungen der Einspritzbohrungen 36 hineinragt und damit je nach Drehstellung des Verteilerkolbens 21 eine der drei Einspritzbohrungen 36 mit der Ringnut 33 verbindet. In einer weiteren Querschnittsebene nahe dem dem Pumpeninnenraum 12 zugekehrten Ende des Verteilerzylinders 22 münden im Innern des Verteilerzylinders 22 drei Füllbohrungen 38, die gleichmäßig am Umfang des Verteilerzylinders 22 verteilt angeordnet sind. Die axiale Länge der Füllnut 35 ist so bemessen, daß sie bis in diese Querschnittsebene der Mündungen der Füllbohrungen 38 hineinragt und damit je nach Drehstellung des Verteilerkolbens 21 eine der drei Füllbohrungen 38 mit der Ringnut 33 verbindet. Die Kopplung des Verteilerkolbens 21 an die Antriebswelle 15 erfolgt über eine Stift-Schlitz-Verbindung, bei welcher ein Mitnahmestift 39 an der Antriebswelle 15 formschlüssig in eine Längsnut 40 im Verteilerkolben 21 eingreift. Die in Fig. 1 dargestellte Grundstellung des Verteilerkolbens 21 wird durch eine Schraubendruckfeder 41 festgelegt, die das Ende der Längsnut 40 gegen den Mitnahmestift 39 drückt, der damit einen Begrenzungsanschlag für die axiale Verschiebebewegung des Verteilerkolbens 21 bildet.Each pump piston 26 delimits a pump working chamber 32 in the radial through bore 25, the other limitation of which is formed by an annular groove 33 on the distributor piston 21. A distributor groove 34 and a filling groove 35 open into the annular groove 33, each of which extends axially in opposite directions from the annular groove 33 on the distributor piston 21. In the interior of the distributor cylinder 22, three injection bores 36 open in a cross-sectional plane, which are evenly distributed over the circumference of the distributor cylinder 22 and lead through the distributor cylinder 22 and the cover 11 to an injection nozzle 37 each. Of the three injection nozzles in total, one injection nozzle 37 is indicated schematically in FIG. 1. The axial length of the distributor groove 34 is dimensioned such that it projects into the cross-sectional plane of the mouths of the injection bores 36 and thus connects one of the three injection bores 36 with the annular groove 33 depending on the rotational position of the distributor piston 21. In a further cross-sectional plane near the end of the distributor cylinder 22 facing the pump interior 12, three filling bores 38 open out in the interior of the distributor cylinder 22 and are arranged uniformly distributed around the circumference of the distributor cylinder 22. The axial length of the filling groove 35 is dimensioned such that it projects into this cross-sectional plane of the mouths of the filling bores 38 and thus one of the three, depending on the rotational position of the distributor piston 21 Filling holes 38 connects to the annular groove 33. The coupling of the distributor piston 21 to the drive shaft 15 takes place via a pin-slot connection, in which a driving pin 39 on the drive shaft 15 positively engages in a longitudinal groove 40 in the distributor piston 21. The basic position of the distributor piston 21 shown in FIG. 1 is determined by a helical compression spring 41 which presses the end of the longitudinal groove 40 against the driving pin 39, which thus forms a limit stop for the axial displacement movement of the distributor piston 21.

Auf der nach außen weisenden Stirnseite des Deckels 11 ist das Ventilgehäuse 42 eines elektrischen Schaltventils 43 aufgesetzt und dort in entsprechender Weise befestigt. Das Ventilgehäuse 42 greift dabei mit einem Zentrierzapfen in den Innenhohlraum des Verteilerzylinders 22 ein und begrenzt hier zusammen mit der ihm gegenüberliegenden Stirnfläche 71 des Verteilerkolbens 21 einen Steuerraum 44. Der Aufbau des Schaltventils ist bekannt und beispielsweise in der DE-OS 35 23 536 beschrieben. Kurzgefaßt sind die beiden Ventilanschlüsse 45, 46 des Schaltventils 43 über eine Ventilöffnung 47 miteinander verbunden, die von einem Ventilglied 48 gesteuert wird. Das Ventilglied 48 wird von einem Elektromagneten 49 betätigt, wobei das Ventilglied 48 die Ventilöffnung 47 im nicht erregten Zustand des Elektromagneten 49 unter der Wirkung einer nicht dargestellten Rückstellfeder freigibt und im erregten Zustand des Elektromagneten 49 verschließt. Der Ventilanschluß 45 überdeckt dabei eine in der Stirnseite des Deckels mündenden ersten Bohrungsabschnitt 51 einer Entlastungsleitung 50, während der zweite Ventilanschluß 46 sich mit einer in der Stirnseite des Deckels 11 befindlichen Öffnung eines zweiten Bohrungsabschnittes 52 der Entlastungsleitung 50 deckt. Über die Entlastungsleitung 50 steht der Pumpenarbeitsraum 32 mit dem Pumpeninnenraum 12 in Verbindung.On the outward-facing end face of the cover 11, the valve housing 42 of an electrical switching valve 43 is placed and fastened there in a corresponding manner. The valve housing 42 engages with a centering pin in the inner cavity of the distributor cylinder 22 and, together with the end face 71 of the distributor piston 21 opposite it, delimits a control chamber 44. The structure of the switching valve is known and is described, for example, in DE-OS 35 23 536. In short, the two valve connections 45, 46 of the switching valve 43 are connected to one another via a valve opening 47, which is controlled by a valve member 48. The valve member 48 is actuated by an electromagnet 49, the valve member 48 opening the valve opening 47 in the non-energized state of the electromagnet 49 under the action of a return spring (not shown) and closing it in the energized state of the electromagnet 49. The valve connection 45 covers a first bore section 51 of a relief line 50 opening into the end face of the cover, while the second valve connection 46 covers an opening in the end face of the cover 11 of a second bore section 52 of the relief line 50. The pump work chamber 32 with the pump interior 12 is in via the relief line 50 Connection.

Die Druckleitung 20 zwischen Förderpumpe 18 und Pumpeninnenraum 12 ist über den Steuerraum 44 im Verteilerzylinder 22 geführt, der die Druckleitung 20 in einen ersten und zweiten Leitungsabschnitt 53, 54 unterteilt. Im zweiten Leitungsabschnitt 54, der den Steuerraum 44 mit dem Pumpeninnenraum 12 verbindet, ist ein zweites elektrisches Schaltventil 55 angeordnet, das mit einem Ventilglied 56 eine im zweiten Leitungsabschnitt 54 integrierte Ventilöffnung 57 steuert. Das Ventilglied 56 wird von einem Elektromagneten 58 betätigt, wobei das Ventilglied 56 die Ventilöffnung 57 im nicht erregten Zustand des Elektromagneten 58 unter der Wirkung einer Ventilschließfeder 59 verschließt und im erregten Zustand des Elektromagneten 58 freigibt. Das zweite Schaltventil 55 wird von einer Überwachungsvorrichtung 60 gesteuert, die ständig die einwandfreie Funktion des ersten Schaltventils 43 überwacht und einen Schließbefehl in Form einer Abschaltung des Erregerstroms für den Elektromagneten 58 an das zweite Schaltventil 55 gibt, sobald das Ventilglied 48 des ersten Schaltventils 43 trotz Wegfall der Erregung des Elektromagneten 49 nicht öffnet. Eine solche Überwachungsvorrichtung 60 kann beispielsweise als Drehzahldetektor ausgebildet sein, der den Schließbefehl an das zweite Schaltventil 55 dann ausgibt, wenn die Drehzahl der Brennkraftmaschine eine vorgegebene maximale Drehzahl übersteigt, was ein Kriterium für das nicht mehr öffnende erste Schaltventil 43 ist. Schließt das zweite Schaltventil 55, so wird die Verbindung des Steuerraums 44 zu dem Pumpeninnenraum 12 gesperrt, und durch die Förderpumpe 18 wird im Steuerraum 44 ein Druck aufgebaut, der den Verteilerkolben 21 in eine in Fig. 1b dargestellte axiale Verschiebestellung überführt. In dieser axialen Verschiebestellung wird von dem Verteilerkolben 21 eine ansonsten verschlossene Mündung einer Bohrung 61 freigegeben, die nunmehr den Steuerraum 44 mit dem Pumpeninnenraum 12 verbindet. Wie Fig. 1b zeigt, wird außerdem das dem Pumpeninnenraum 12 zugekehrte Ende des Verteilerkolbens 21 so weit aus dem Verteilerzylinder 22 herausgeschoben, daß die Füllnut 35 zum Pumpeninnenraum 12 hin offen ist und eine ständige Verbindung zwischen dem Pumpenarbeitsraum 32 und dem Pumpeninnenraum 12 herstellt.The pressure line 20 between the feed pump 18 and the pump interior 12 is guided via the control chamber 44 in the distributor cylinder 22, which divides the pressure line 20 into a first and second line section 53, 54. In the second line section 54, which connects the control chamber 44 to the pump interior 12, a second electrical switching valve 55 is arranged, which controls a valve opening 57 integrated in the second line section 54 with a valve member 56. The valve member 56 is actuated by an electromagnet 58, the valve member 56 closing the valve opening 57 in the non-energized state of the electromagnet 58 under the action of a valve closing spring 59 and releasing the electromagnet 58 in the energized state. The second switching valve 55 is controlled by a monitoring device 60, which constantly monitors the proper functioning of the first switching valve 43 and issues a closing command in the form of switching off the excitation current for the electromagnet 58 to the second switching valve 55 as soon as the valve member 48 of the first switching valve 43 despite Elimination of the excitation of the electromagnet 49 does not open. Such a monitoring device 60 can be designed, for example, as a speed detector that outputs the closing command to the second switching valve 55 when the speed of the internal combustion engine exceeds a predetermined maximum speed, which is a criterion for the no longer opening first switching valve 43. If the second switching valve 55 closes, the connection of the control chamber 44 to the pump interior 12 is blocked, and a pressure is built up in the control chamber 44 by the feed pump 18, which transfers the distributor piston 21 into an axial displacement position shown in FIG. 1b. In this axial displacement position, an otherwise closed mouth of a bore 61 is made by the distributor piston 21 released, which now connects the control chamber 44 to the pump interior 12. As FIG. 1b shows, the end of the distributor piston 21 facing the pump interior 12 is also pushed out of the distributor cylinder 22 so far that the filling groove 35 is open towards the pump interior 12 and establishes a permanent connection between the pump working space 32 and the pump interior 12.

Die Wirkungsweise der vorstehend beschriebenen Kraftstoffeinspritzpumpe ist wie folgt:The operation of the fuel injection pump described above is as follows:

Beim Saughub des Pumpenkolbens 26 bewegt sich dieser infolge des Gleitens des Rollenstößels 27 auf einer abfallenden Flanke der Nockenbahn 17 radial nach außen. Der Verteilerkolben 21 hat eine solche Drehstellung, daß die Füllnut 35 die Füllbohrung 38 überdeckt. Das erste Schaltventil 43 ist stromlos offen und das zweite Schaltventil 55 ist durch Bestromung ebenfalls geöffnet. Kraftstoff fließt nunmehr über die Füllbohrung 38, die Füllnut 35 und die Ringnut 33 in den Pumpenarbeitsraum 32. Nach Durchlaufen der unteren Totpunktlage des Pumpenkolbens 26 setzt der Förderhub des Pumpenkolbens 26 ein, wobei sich der Pumpenkolben 26 infolge des Gleitens des Rollenstößels 27 auf einer ansteigenden Flanke der Nockenbahn 17 radial nach innen bewegt. Dabei wird Kraftstoff aus dem Pumpenarbeitsraum 32 über die Entlastungsleitung 50 und das noch offene erste Schaltventil 43 in den Pumpeninnenraum 12 zurückgefördert. Zu einem bestimmten Zeitpunkt während des Förderhubs wird das erste Schaltventil 43 geschlossen. Der Verteilerkolben 21 hat spätestens dann eine Drehstellung erreicht, in welcher die Verteilernut 34 eine Einspritzbohrung 36 überdeckt und damit den Pumpenarbeitsraum 32 über die Einspritzbohrung 36 mit der zugeordneten Einspritzdüse 37 verbindet. Aus dem Pumpenarbeitsraum 32 wird nun Kraftstoff zur Einspritzdüse 37 gefördert und gelangt dort zur Einspritzung in den Zylinder der Brennkraftmaschine. Zur Beendigung der Kraftstoffeinspritzung wird das erste Schaltventil 43 stromlos geschaltet, wodurch das öffnende Schaltventil 43 den Pumpenarbeitsraum 32 über die Ringnut 33 und die Entlastungsleitung 50 an den Pumpeninnenraum 12 anschließt. Der Druck im Pumpenarbeitsraum 32 fällt schlagartig unter den Öffnungsdruck der Einspritzdüse 37 ab, und letztere schließt. Durch den Zeitpunkt des Schließens und/oder Öffnens des ersten Schaltventils 43 wird die zur Einspritzdüse 37 geförderte und dort zur Einspritzung gelangende Kraftstoffmenge dosiert.During the suction stroke of the pump piston 26, it moves radially outwards due to the sliding of the roller tappet 27 on a falling flank of the cam track 17. The distributor piston 21 has a rotational position such that the filling groove 35 covers the filling bore 38. The first switching valve 43 is open when de-energized and the second switching valve 55 is also open when energized. Fuel now flows through the filling bore 38, the filling groove 35 and the annular groove 33 into the pump work chamber 32. After passing through the bottom dead center position of the pump piston 26, the delivery stroke of the pump piston 26 begins, the pump piston 26 becoming more inclined due to the sliding of the roller tappet 27 Flank of the cam track 17 moved radially inwards. Fuel is pumped back into the pump interior 12 from the pump work chamber 32 via the relief line 50 and the still open first switching valve 43. At a certain point in time during the delivery stroke, the first switching valve 43 is closed. The distributor piston 21 has reached a rotational position at the latest in which the distributor groove 34 covers an injection bore 36 and thus connects the pump working chamber 32 to the associated injection nozzle 37 via the injection bore 36. From the pump work space 32 fuel is now Injection nozzle 37 promoted and passes there for injection into the cylinder of the internal combustion engine. To end the fuel injection, the first switching valve 43 is de-energized, as a result of which the opening switching valve 43 connects the pump working chamber 32 to the pump interior 12 via the annular groove 33 and the relief line 50. The pressure in the pump work chamber 32 suddenly drops below the opening pressure of the injection nozzle 37, and the latter closes. By the time the first switching valve 43 closes and / or opens, the amount of fuel delivered to the injector 37 and injected there is metered.

In Fig. 1b ist die Kraftstoffeinspritzpumpe für den Fall dargestellt, daß das erste Schaltventil 43 in der Weise defekt ist, daß sein Ventilglied 48 trotz Wegfall des Erregerstroms für den Elektromagenten 49 die Ventilöffnung 47 nicht freigibt. Man spricht in diesem Fall von einem Hängenbleiben des ersten Schaltventils 43 im Schließzustand. Durch diesen Defekt gelangt bei jedem Förderhub des Pumpenkolbens 26 die gesamte im Pumpenarbeitsraum 32 enthaltene Kraftstoffmenge zur Einspritzung über die Einspritzdüse 37. Die Drehzahl der Brennkraftmaschine nimmt dadurch laufend zu. Dieses übermäßige Anwachsen der Drehzahl der Brennkraftmaschine wird von der Überwachungsvorrichtung 60 erkannt und diese gibt einen Schließbefehl an das zweite Schaltventil 55. Dieser Schließbefehl bewirkt eine Abschaltung des Erregerstroms für den Elektromagneten 58 des zweiten Schaltventils 55. Unter der Wirkung der Ventilschließfeder 59 schließt das zweite Schaltventil 55. Damit ist der Steuerraum 44 im Verteilerzylinder 22 vom Pumpeninnenraum 12 getrennt. Infolge der Kraftstofförderung durch die Förderpumpe 18 nimmt der Druck im Steuerraum 44 zu und bewirkt ein Verschieben des Verteilerkolbens 21 in die in Fig. 1b gezeigte axiale Verschiebestellung. In dieser Verschiebestellung ragt die im Pumpenarbeitsraum 32 mündende Füllnut 35 frei in den Pumpenarbeitsraum 12 hinein, wodurch der Pumpenarbeitsraum 32 mit dem Pumpeninnenraum 12 verbunden ist. Beim Förderhub des Pumpenkolbens 26 wird der Kraftstoff nun aus dem Pumpenarbeitsraum 32 über die Füllnut 35 in den Pumpeninnenraum 12 abströmen, so daß sich im Pumpenarbeitsraum 32 kein den Öffnungsdruck der Einspritzdüse 37 übersteigender Druck aufbauen kann. Es erfolgt damit keine Kraftstofförderung zur Einspritzdüse 37, und die Brennkraftmaschine kommt wegen Kraftstoffmangels zum Stillstand. In der axialen Verschiebestellung des Verteilerkolbens 21 wird die Bohrung 61 zum Steuerraum 44 hin freigegeben, so daß der von der Förderpumpe 18 noch geförderte Kraftstoff bei geschlossenem zweiten Schaltventil 55 über die Bohrung 61 wieder in den Pumpeninnenraum 12 abströmen kann.1b shows the fuel injection pump for the case in which the first switching valve 43 is defective in such a way that its valve member 48 does not open the valve opening 47 for the electromagnet 49 despite the absence of the excitation current. In this case, one speaks of the first switching valve 43 getting stuck in the closed state. As a result of this defect, the entire amount of fuel contained in the pump working chamber 32 reaches the injection via the injection nozzle 37 for each delivery stroke of the pump piston 26. The speed of the internal combustion engine thereby increases continuously. This excessive increase in the speed of the internal combustion engine is recognized by the monitoring device 60 and this issues a closing command to the second switching valve 55. This closing command causes the excitation current for the electromagnet 58 of the second switching valve 55 to be switched off. The second switching valve closes under the action of the valve closing spring 59 55. The control chamber 44 in the distributor cylinder 22 is thus separated from the pump interior 12. As a result of the fuel delivery by the feed pump 18, the pressure in the control chamber 44 increases and causes the distributor piston 21 to be displaced into the axial displacement position shown in FIG. 1b. In this displacement position, it projects in the pump work space 32 opening filling groove 35 freely into the pump work space 12, whereby the pump work space 32 is connected to the pump interior 12. During the delivery stroke of the pump piston 26, the fuel will now flow out of the pump working chamber 32 via the filling groove 35 into the pump interior 12, so that no pressure exceeding the opening pressure of the injection nozzle 37 can build up in the pump working chamber 32. There is therefore no fuel delivery to the injector 37, and the internal combustion engine comes to a standstill because of a lack of fuel. In the axial displacement position of the distributor piston 21, the bore 61 is released towards the control chamber 44, so that the fuel which is still being delivered by the feed pump 18 can flow back into the pump interior 12 via the bore 61 when the second switching valve 55 is closed.

Das in Fig. 2 dargestellte zweite Ausführungsbeispiel einer Verteilerkraftstoffeinspritzpumpe der Radialkolbenbauart unterscheidet sich von der Kraftstoffeinspritzpumpe in Fig.1 nur dadurch, daß die den Pumpenarbeitsraum 32 begrenzende Ringnut 33 auf dem Verteilerkolben 21 durch einen Ringsteg 62 unterteilt ist, der einen dem Außendurchmesser des Verteilerkolbens 21 entsprechenden Außendurchmesser aufweist. Der Ringsteg 62 ist innerhalb der Ringnut 33 so gelegt, daß in der in Fig. 2b dargestellten, vom Verteilerkolben 21 bei Defekt des ersten Schaltventils 43 eingenommen axialen Verschiebestellung der Ringsteg 62 zusammen mit der Innenwand des Verteilerzylinders 22 den in Fig. 2 linken Teil der Ringnut 33 von dem rechten Teil der Ringut 33 und damit vom Pumpenarbeitsraum 32 trennt. Da die Füllnut 35 in diesem jetzt abgedichteten Teil der Ringnut 33 mündet, ist in der axialen Verschiebestellung des Verteilerkolbens 21 in jeder seiner Drehstellungen die Füllnut 35 von dem Pumpenarbeitsraum 32 getrennt und damit letzterer gegenüber dem kraftstoffgefüllten Pumpeninnenraum 12 abgesperrt. Beim Saughub des Pumpenkolbens 26 kann damit kein Kraftstoff in den Pumpenarbeitsraum 32 gelangen, und die Förderung von Kraftstoff aus dem Pumpenarbeitsraum 32 zur Einspritzdüse 37 ist unterbunden. Im Gegensatz zu der Kraftstoffeinspritzpumpe in Fig. 1 ist hier die axiale Länge der Füllnut 35 kürzer bemessen bzw. die Füllbohrung 38 weiter entfernt von dem pumpeninnenraumseitigen Ende des Verteilerzylinders 22 eingebracht, so daß in der axialen Verschiebestellung des Verteilerkolbens (Fig. 2b) die Füllnut 35 nicht von dem Verteilerzylinder 22 zum Pumpeninnenraum 12 hin freigegeben wird.The second exemplary embodiment of a radial piston type distributor fuel injection pump shown in FIG. 2 differs from the fuel injection pump in FIG. 1 only in that the annular groove 33 delimiting the pump working space 32 on the distributor piston 21 is divided by an annular web 62 which has an outer diameter of the distributor piston 21 has the corresponding outer diameter. The annular web 62 is placed within the annular groove 33 in such a way that in the axial displacement position shown in FIG Separates annular groove 33 from the right part of the annular groove 33 and thus from the pump working space 32. Since the filling groove 35 opens into this now sealed part of the annular groove 33, in the axial displacement position of the distributor piston 21, the filling groove 35 is separated from the pump working chamber 32 in each of its rotational positions and thus the latter relative to the fuel-filled pump interior 12 cordoned off. During the suction stroke of the pump piston 26, no fuel can get into the pump work chamber 32, and the delivery of fuel from the pump work chamber 32 to the injection nozzle 37 is prevented. In contrast to the fuel injection pump in Fig. 1, the axial length of the filling groove 35 is shorter here or the filling bore 38 is made further away from the pump interior end of the distributor cylinder 22, so that the filling groove is in the axial displacement position of the distributor piston (Fig. 2b) 35 is not released from the distributor cylinder 22 to the pump interior 12.

Statt des Vorsehens eines Ringsteges 62 kann die Ringnut 33 selbst so schmal ausgebildet werden, daß sie in der normalen Betriebsstellung des Verteilerkolbens 21 (Fig. 2a) von den Durchgangsbohrungen 25 im Verteilerzylinder 22 überdeckt und in der axialen Verschiebestellung des Verteilerkolbens 21 (Fig. 2b) in ihrer vollen Länge von der Innenwand des Verteilerzylinders 22 abgedeckt wird.Instead of providing an annular web 62, the annular groove 33 itself can be made so narrow that it is covered by the through holes 25 in the distributor cylinder 22 in the normal operating position of the distributor piston 21 (FIG. 2a) and in the axial displacement position of the distributor piston 21 (FIG. 2b ) is covered in its full length by the inner wall of the distributor cylinder 22.

Das in Fig. 3 dargestellte weitere Ausführungsbeispiel einer Verteilerkraftstoffeinspritzpumpe der Radialkolbenbauart unterscheidet sich von der Kraftstoffeinspritzpumpe in Fig. 1 dadurch, daß in der Entlastungsleitung 50 ein das erste Schaltventil überbrückender Bypaß 63 vorgesehen ist, der durch den Verteilerkolben 21 geöffnet oder geschlossen wird. Hierzu ist ein erster Bypaßabschnitt 64 mit dem ersten Bohrungsabschnitt 51 der Entlastungsleitung 50 und ein zweiter Bypaßabschnitt 65 mit dem zweiten Bohrungsabschnitt 52 der Entlastungsleitung 50 verbunden. Jeder Bypaßabschnitt 64, 65 mündet im Innern des Verteilerzylinders 22. Die Mündungen sind dabei so gelegt, daß sie in der normalen Betriebsstellung des Verteilerkolbens 21 (Fig. 3a) von dem Verteilerkolben 21 abgeschlossen sind und in der bei Defekt des ersten Schaltventils 43 vom Verteilerkolben 21 eingenommenen axialen Verschiebestellung (Fig. 3b) in dem Steuerraum 44 münden. Damit wird in der axialen Verschiebestellung des Verteilerkolbens 21 in jeder seiner Drehstellungen der Pumpenarbeitsraum 32 über den den Bypaß 63 schließenden Steuerraum 44 und die Entlastungsleitung 50 mit dem Pumpeninnenraum 32 verbunden, so daß beim Förderhub des Pumpenkolbens 26 der im Pumpenarbeitsraum 32 befindliche Kraftstoff über die Entlastungsleitung 50 zum Pumpeninnenraum 12 gefördert wird. Auch in diesem Fall wird in der axialen Verschiebestellung des Verteilerkolbens 21, die durch das Schließen des zweiten Schaltventils 55 herbeigeführt worden ist, die Kraftstofförderung zur Einspritzdüse 37 unterbunden.The further exemplary embodiment shown in FIG. 3 of a radial piston type distributor fuel injection pump differs from the fuel injection pump in FIG. 1 in that in the relief line 50 there is provided a bypass 63 which bridges the first switching valve and is opened or closed by the distributor piston 21. For this purpose, a first bypass section 64 is connected to the first bore section 51 of the relief line 50 and a second bypass section 65 is connected to the second bore section 52 of the relief line 50. Each bypass section 64, 65 opens into the interior of the distributor cylinder 22. The orifices are placed in such a way that they are closed by the distributor piston 21 in the normal operating position of the distributor piston 21 (FIG. 3a) and in which the first switching valve 43 is defective by the distributor piston 21 assumed axial displacement position (Fig. 3b) in the Control room 44 open. Thus, in the axial displacement position of the distributor piston 21 in each of its rotational positions, the pump work chamber 32 is connected to the pump interior 32 via the control chamber 44 closing the bypass 63 and the relief line 50, so that during the delivery stroke of the pump piston 26 the fuel in the pump work chamber 32 is connected via the relief line 50 is promoted to the pump interior 12. In this case, too, the fuel delivery to the injection nozzle 37 is prevented in the axial displacement position of the distributor piston 21, which was brought about by the closing of the second switching valve 55.

Das in Fig. 4 dargestellte Ausführungsbeispiel einer Verteilerkraftstoffeinspritzpumpe der Radialkolbenbauart ist gegenüber der Kraftstoffeinspritzpumpe in Fig. 1 etwas weitergehender modifiziert als die Ausführungsbeispiele in Fig. 2 und 3. Hier ist die von der Förderpumpe 18 abführende Druckleitung 20 unmittelbar mit dem Pumpeninnenraum 12 verbunden. Der Steuerraum 44 im Verteilerzylinder 22 ist über eine Zulaufleitung 66 mit dem Pumpeninnenraum 12 verbunden und über eine Ablaufleitung 67 unter Zwischenschaltung einer Drossel 68 an eine im Deckel 11 vorgesehene Abflußöffnung 69 angeschlossen, die wiederum über eine Kraftstoff-Rücklaufleitung mit dem Kraftstofftank in Verbindung steht. Das zweite Schaltventil 55 ist in der der Zulaufleitung 66 angeordnet. Die Verbindung von Antriebswelle 15 und Verteilerkolben 21 ist so getroffen, daß die in dem Pumpeninnenraum 12 hineinragende Stirnseite 70 des Verteilerkolbens 21 von dem im Pumpeninnenraum 12 herrschenden Kraftstoffdruck beaufschlagt wird.The exemplary embodiment of a distributor fuel injection pump of the radial piston type shown in FIG. 4 is modified somewhat more than the exemplary embodiments in FIGS. 2 and 3 compared to the fuel injection pump in FIG. 1. Here, the pressure line 20 leading away from the feed pump 18 is directly connected to the pump interior 12. The control chamber 44 in the distributor cylinder 22 is connected to the pump interior 12 via an inlet line 66 and connected via an outlet line 67 with the interposition of a throttle 68 to a drain opening 69 provided in the cover 11, which in turn is connected to the fuel tank via a fuel return line. The second switching valve 55 is arranged in the inlet line 66. The connection of the drive shaft 15 and the distributor piston 21 is made such that the end face 70 of the distributor piston 21 projecting into the pump interior 12 is acted upon by the fuel pressure prevailing in the pump interior 12.

Bleibt nunmehr infolge eines Defekts das erste Schaltventil 43 in seiner Schließstellung hängen, so wird _ wie bei der Kraftstoffeinspritzpumpe in Fig. 1 _ durch die Überwachungsvorrichtung 60 das zweite Schaltventil 55 angesteuert. Dieses schließt, so daß kein Kraftstoff mehr aus dem Pumpeninnenraum 12 über die Zulaufleitung 66 in den Steuerraum 44 einströmen kann. Lediglich die Verbindung des Steuerraums 44 über die Ablaufleitung 67 zu der Abflußöffnung 69 bleibt bestehen. Dem auf die Stirnseite 70 des Verteilerkolbens 21 wirkenden Druck wird nunmehr kein Gegendruck im Steuerraum 44 entgegengesetzt, wodurch der Verteilerkolben 21 in Fig. 4a nach rechts verschoben wird und seine in Fig. 4b gezeigte axiale Verschiebestellung einnimmt. In dieser Verschiebestellung ist die Füllnut 35 soweit nach rechts verschoben, daß sie die Füllbohrung 38 im Verteilerzylinder 22 nicht mehr zu überdecken vermag (Fig. 4b). Damit ist der Pumpenarbeitsraum 32 von dem Pumpeninnenraum 12 getrennt und kann beim Saughub des Pumpenkolbens 26 nicht mehr mit Kraftstoff gefüllt werden. Bei defektem ersten Schaltventil 43 wird die Kraftstofförderung zur Einspritzdüse 37 abgebrochen.If, as a result of a defect, the first switching valve 43 remains stuck in its closed position, then, as with the fuel injection pump in FIG Monitoring device 60 controls the second switching valve 55. This closes so that no more fuel can flow into the control chamber 44 from the pump interior 12 via the feed line 66. Only the connection of the control room 44 via the drain line 67 to the drain opening 69 remains. The pressure acting on the end face 70 of the distributor piston 21 is now opposed to no counter pressure in the control chamber 44, as a result of which the distributor piston 21 is displaced to the right in FIG. 4a and assumes its axial displacement position shown in FIG. 4b. In this displacement position, the filling groove 35 is shifted to the right so far that it is no longer able to cover the filling bore 38 in the distributor cylinder 22 (FIG. 4b). The pump working space 32 is thus separated from the pump interior 12 and can no longer be filled with fuel during the suction stroke of the pump piston 26. If the first switching valve 43 is defective, the fuel delivery to the injection nozzle 37 is interrupted.

Die Ausführungsbeispiele der Verteilerkraftstoffeinspritzpumpen gemäß Fig. 2-4 unterscheiden sich von der Kraftstoffeinspritzpumpe in Fig.l nur durch die vorstehend hervorgehobenen Modifikationen. Im übrigen stimmen Aufbau und Funktionsweise überein, so daß auch für gleiche Bauteile gleiche Bezugszeichen verwendet worden sind. Der Übersichtlichkeit halber sind die Bezugszeichen in Fig. 2-4 nur soweit eingetragen, wie sie zum Verständnis der Abweichungen gegenüber Fig. 1 erforderlich sind.The exemplary embodiments of the distributor fuel injection pumps according to FIGS. 2-4 differ from the fuel injection pump in FIG. 1 only in the modifications highlighted above. Otherwise, the structure and mode of operation are the same, so that the same reference numerals have been used for the same components. For the sake of clarity, the reference numerals in FIGS. 2-4 are only entered to the extent necessary to understand the deviations from FIG. 1.

Claims (12)

1. Distributor fuel injection pump of the radial plunger type having a pump inner chamber (12), surrounded by a pump housing (10) and filled with fuel by a delivery pump, having a cam drive (16, 27), which is coupled to a drive shaft (15) and, upon rotation of the latter, drives at least one pump plunger (26), limiting a pump working chamber (32), for the execution of an intake and delivery stroke in a reciprocating movement radially with respect to the drive shaft (15), the pump working chamber (32) being filled with fuel during the intake stroke and the fuel being delivered from the pump working chamber (32) to a connected injection nozzle during the delivery stroke, having a distributor plunger (21), which is guided in a distributor cylinder (22), closed at one end and coaxial to the drive shaft (15), encloses with its end face a control chamber (44), can be displaced axially against the force of a spring (41) away from an initial position determined by contact against a stop by a pressure which can be controlled in the control chamber (44) by a control valve (55), which furthermore is coupled by its end protruding out of the distributor cylinder (22) and into the pump inner chamber (12) in a rotationally fixed manner to the drive shaft (15) and connects via channels (34, 35), which interact with bores (36, 38) in the distributor cylinder (22), the pump working chamber (32) to the pump inner chamber in at least a first rotational position, to the injection nozzle in at least a second rotational position and via a relief line (35, 38; 50, 64, 65, 52) to the pump inner chamber (12) in a certain axial displacement position, characterised in that the duration of delivery, and thus the quantity of fuel which is actually injected, is controlled by a first electrically controllable switching valve (43), which is connected on the one hand to the pump working chamber (32) and on the other hand to a relief chamber, in particular the pump inner chamber (12), and by closing fixes the beginning of delivery and by opening fixes the end of delivery, and in that the control chamber (44) is connected via a pressure line (53, 66) to the pressure side of the delivery pump (18) and via a pressure line (54, 67) to a relief chamber, the connection being maintained constantly via one (53, 66) of the pressure lines and the connection via the other (54, 67) of the pressure lines being able to be interrupted by the control valve designed as second electrically controlled switching valve (55) if the maximum speed of the distributor fuel injection pump is exceeded or if a defect in the first electrically controlled switching valve (43) occurs, with the result that the distributor plunger (21) can, by changing the forces acting on it, be brought from its initial position into the axial displacement position, in which the connection between pump working chamber (32) and pump inner chamber (12) is established.
2. Distributor fuel injection pump of the radial plunger type having a pump inner chamber (12), surrounded by a pump housing (10) and filled with fuel by a delivery pump, having a cam drive (16, 27), which is coupled to a drive shaft (15) and, upon rotation of the latter, drives at least one pump plunger (26), limiting a pump working chamber (32), for the execution of an intake and delivery stroke in a reciprocating movement radially with respect to the drive shaft (15), the pump working chamber (32) being filled with fuel during the intake stroke and the fuel being delivered from the pump working chamber (32) to a connected injection nozzle during the delivery stroke, having a distributor plunger (21), which is guided in a distributor cylinder (22), closed at one end and coaxial to the drive shaft (15), encloses with its end face a control chamber (44), can be displaced axially against the force of a spring (41) away from an initial position determined by contact against a stop by a pressure which can be controlled in the control chamber (41) [sic] by a control valve (55) into an axial displacement position, which furthermore is coupled by its end protruding out of the distributor cylinder (22) and into the pump inner chamber (12) in a rotationally fixed manner to the drive shaft (15) and connects via channels (34, 35), which interact with bores (36, 38) in the distributor cylinder (22), the pump working chamber (32) to the pump inner chamber in at least a first rotational position, to the injection nozzle in at least a second rotational position, characterised in that the duration of delivery, and thus the quantity of fuel actually injected, is controlled by a first electrically controllable switching valve (43), which is connected on the one hand to the pump working chamber (32) and on the other hand to a relief chamber, in particular the pump inner chamber (12), and by closing fixes the beginning of delivery and by opening fixes the end of delivery, and in that the control chamber (44) is connected via a pressure line (53, 66) to the pressure side of the delivery pump (18) and via a pressure line (54, 67) to a relief chamber, the connection being maintained constantly via one (53, 66) of the pressure lines and the connection via the other (54, 67) of the pressure lines being able to be interrupted by the control valve designed as second electrically controlled switching valve (55) if the maximum speed of the distributor fuel injection pump is exceeded or if a defect in the first electrically controlled switching valve occurs, with the result that the distributor plunger (21) can, by changing the forces acting on it, be brought from its initial position into the axial displacement position, and in this position the connection between pump working chamber (32) and pump inner chamber (12) is prevented, in particular in the first rotational position of the distributor plunger. (Figures 2 and 4).
3. Pump according to Claim 1 or 2, characterised in that the delivery line (20) connecting the delivery pump (18) and the pump inner chamber (12) is led via the control chamber (44) and in that the second switching valve (55) is arranged in the line section (54) between control chamber (44) and pump inner chamber (12) which has an outflow opening (13) provided with a throttle (14).
4. Pump according to Claim 3, characterised in that in the distributor cylinder (22) there is provided a bore (61), opening out on the one hand inside the said cylinder and on the other hand in the pump inner chamber (12), the mouth of which bore inside the distributor cylinder (22) is arranged in such a way that it is overlapped by the distributor plunger (21) and only released towards the control chamber (44) in the axial displacement position of the distributor plunger (21).
5. Pump according to one of Claims 1 and 3 or 4, characterised in that the distributor plunger (21) bears on its circumference a ring groove (33), which together with the pump plunger (26) limits the pump working chamber (32) and which, via an axial filling groove (35) on the distributor plunger (21), in the first rotational position of the latter overlapped a filling bore (38), opening out inside the distributor cylinder (22) and in the pump inner chamber (12), and in that the axial length of the filling groove (35) is dimensioned in such a way that, in the axial displacement position of the distributor plunger (21), it protrudes out of the distributor cylinder (22) into the pump inner chamber (12) (Fig. 1).
6. Pump according to Claims 2 and 3 or 4, characterised in that the distributor plunger (21) bears on its circumference a ring groove (33), which together with the pump plunger (26) limits the pump working chamber (32) and which, via an axial filling groove (35) on the distributor plunger (21), in the first rotational position of the latter overlaps a filling bore (38), opening out inside the distributor cylinder (22) and in the pump inner chamber (12), and in that the ring groove (33) is subdivided by a ring land (62) having an outside diameter corresponding to the diameter of the distributor plunger (21), which ring land is arranged in such a way that, in the axial displacement position of the distributor plunger (21), it shuts off the part of the ring groove (33) connected to the filling groove (35), together with the inside wall of the distributor cylinder (22), from the other part of the ring groove (33) (Fig. 2).
7. Pump according to Claim 1, characterised in that the distributor plunger (21) bears on its circumference a ring groove (33), which together with the pump plunger (26) limits the pump working chamber (32) and which, via an axial filling groove (35) on the distributor plunger (21), in the first rotational position of the latter overlapped a filling bore (38), opening out inside the distributor cylinder (22) and in the pump inner chamber (12), and is dimensioned in its axial length in such a way that, in the axial displacement position of the distributor plunger (21), it is overlapped by the inside wall of the distributor cylinder (22) lying between filling bore (38) and pump working chamber.
8. Pump according to Claim 1, characterised in that there opens out inside the distributor cylinder (22) a first bypass section (64), connected to the relief line section (51) between pump working chamber (32) and first switching valve (43), and a second bypass section (65), connected to the relief line section (52) between first switching valve (43) and pump inner chamber (12), of a bypass (63) to the first switching valve (43) and in that the mouths are arranged in such a way that the bypass (63) is blocked in the normal position of the distributor plunger (21) and is closed via the control chamber (44) in the axial displacement position of the distributor plunger (21) (Fig. 3).
9. Pump according to Claim 2, characterised in that the one pressure line (66) of the control chamber (44) is connected to the pump inner chamber (12), connected directly to the pressure side of the delivery pump, and the other pressure line (67) is connected to an outflow opening (69), provided with a throttle (68), in the pump housing (10, 11), in that the second switching valve (55) is arranged in the one pressure line (66) and in that the face (70) of the end of the distributor plunger (21) connected to the drive shaft (15) is subjected to the pressure in the pump inner chamber (12).
10. Pump according to Claim 9, characterised in that the distributor plunger (21) bears on its circumference a ring groove (33), which together with the pump plunger (26) limits the pump working chamber (32) and which, via an axial filling groove (35) on the distributor plunger (21), in the first rotational position of the latter overlaps a filling bore (38), opening out inside the distributor cylinder (22) and in the pump inner chamber (12), and in that the axial length of the filling groove (35) is dimensioned in such a way that, in the axial displacement position of the distributor plunger (21), it has been removed from the mouth region of the filling bore (38) in the distributor cylinder (22) (Fig. 4).
11. Pump according to one of Claims 1-10, characterised in that a device (60) for monitoring the function of the first switching valve (43) is provided, which emits a closing command to the second switching valve (55) if the valve element (48) of the first switching valve (43) remains in its closed position in spite of it no longer being actuated.
12. Pump according to one of Claims 1-11, characterised in that the second switching valve (55) is designed in such a way that it is closed [lacuna] its unexcited basic position and is open in its excited working position.
EP19880904479 1987-06-13 1988-05-28 Radial-piston-type dispensing injection pump Expired - Lifetime EP0318534B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3719807 1987-06-13
DE19873719807 DE3719807A1 (en) 1987-06-13 1987-06-13 RADIAL PISTON FUEL INJECTION PUMP

Publications (2)

Publication Number Publication Date
EP0318534A1 EP0318534A1 (en) 1989-06-07
EP0318534B1 true EP0318534B1 (en) 1991-07-10

Family

ID=6329656

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19880904479 Expired - Lifetime EP0318534B1 (en) 1987-06-13 1988-05-28 Radial-piston-type dispensing injection pump

Country Status (5)

Country Link
US (1) US4971012A (en)
EP (1) EP0318534B1 (en)
JP (1) JP2604841B2 (en)
DE (2) DE3719807A1 (en)
WO (1) WO1988009870A1 (en)

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Publication number Priority date Publication date Assignee Title
DE3900318A1 (en) * 1989-01-07 1990-07-12 Bosch Gmbh Robert DISTRIBUTION FUEL INJECTION PUMP FOR INTERNAL COMBUSTION ENGINES
GB8918429D0 (en) * 1989-08-12 1989-09-20 Lucas Ind Plc Fuel pumping apparatus
DE3927742A1 (en) * 1989-08-23 1991-02-28 Bosch Gmbh Robert FUEL INJECTION PUMP FOR INTERNAL COMBUSTION ENGINES
DE4032279A1 (en) * 1990-10-11 1992-04-16 Bosch Gmbh Robert Fuel injection pump for IC engine - has suction and delivery stroke controlled by electrically operated valve across fuel duct
US5103792A (en) * 1990-10-16 1992-04-14 Stanadyne Automotive Corp. Processor based fuel injection control system
US5215060A (en) * 1991-07-16 1993-06-01 Stanadyne Automotive Corp. Fuel system for rotary distributor fuel injection pump
DE4135595A1 (en) * 1991-10-29 1993-05-06 Robert Bosch Gmbh, 7000 Stuttgart, De FUEL INJECTION PUMP FOR INTERNAL COMBUSTION ENGINES
US5215449A (en) * 1991-12-05 1993-06-01 Stanadyne Automotive Corp. Distributor type fuel injection pump
DE59301885D1 (en) * 1992-04-25 1996-04-18 Bosch Gmbh Robert FUEL INJECTION DEVICE FOR INTERNAL COMBUSTION ENGINES
DE4243665C2 (en) * 1992-12-23 2003-11-13 Bosch Gmbh Robert Fuel injection device, in particular pump nozzle for internal combustion engines
FR2856007B1 (en) * 2003-06-11 2005-08-26 Essilor Int VALVE AND FEEDING DEVICE SUITABLE FOR FILLING, WITH A POLYMERIZABLE MATERIAL, A MOLDING CAVITY

Citations (1)

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DE3523536A1 (en) * 1984-09-14 1986-03-27 Robert Bosch Gmbh, 7000 Stuttgart Electrically controlled fuel injection pump for internal combustion engines

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US3485225A (en) * 1968-04-15 1969-12-23 Caterpillar Tractor Co Rotary distributor fuel pump
GB2108727B (en) * 1980-10-29 1985-02-06 Lucas Industries Ltd Fuel injection pumping apparatus
DE3243348A1 (en) * 1982-11-24 1984-05-24 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
DE3719831A1 (en) * 1987-06-13 1988-12-22 Bosch Gmbh Robert FUEL INJECTION PUMP

Patent Citations (1)

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Publication number Priority date Publication date Assignee Title
DE3523536A1 (en) * 1984-09-14 1986-03-27 Robert Bosch Gmbh, 7000 Stuttgart Electrically controlled fuel injection pump for internal combustion engines

Also Published As

Publication number Publication date
JP2604841B2 (en) 1997-04-30
WO1988009870A1 (en) 1988-12-15
US4971012A (en) 1990-11-20
DE3719807A1 (en) 1988-12-22
DE3863630D1 (en) 1991-08-14
JPH02500206A (en) 1990-01-25
EP0318534A1 (en) 1989-06-07

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