EP0167741B1 - Fuel injection pump for internal-combustion engines - Google Patents

Fuel injection pump for internal-combustion engines Download PDF

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Publication number
EP0167741B1
EP0167741B1 EP85105451A EP85105451A EP0167741B1 EP 0167741 B1 EP0167741 B1 EP 0167741B1 EP 85105451 A EP85105451 A EP 85105451A EP 85105451 A EP85105451 A EP 85105451A EP 0167741 B1 EP0167741 B1 EP 0167741B1
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EP
European Patent Office
Prior art keywords
channel
inflow
partial
flow
fuel
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.)
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EP85105451A
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German (de)
French (fr)
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EP0167741A1 (en
Inventor
Walter Häfele
Manfred Dipl.-Ing. Krämer
Dietmar Dipl.-Ing. Schmieder (Fh)
Johann Ing. Grad. Warga
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Robert Bosch GmbH
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Robert Bosch GmbH
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Priority to AT85105451T priority Critical patent/ATE56790T1/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
    • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
    • F02M55/001—Pumps with means for preventing erosion on fuel discharge
    • 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
    • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00

Definitions

  • the invention relates to a fuel injection pump for internal combustion engines according to the preamble of claims 1 and 3.
  • Injection pumps in which there is a separate pump element for each cylinder of the internal combustion engine and in which these pump elements are arranged in a row are referred to as inline injection pumps and have found widespread use, in particular for self-igniting internal combustion engines, so-called diesel engines.
  • diesel engines The technical development in diesel engines is that, because of stricter exhaust gas regulations, the combustion must leach optimally, along with a reduction in the specific power-to-weight ratio.
  • the metered amount of fuel must be very even and precise for each individual pump element. The metering of the fuel takes place in that the part of the fuel which does not reach the injection flows back under high pressure into the interior of a collecting space of the injection pump.
  • the overflow of the fuel under high pressure at the control edges of the pump pistons leads to its heating and thus physical properties such as density and compressibility change, so that the amount of fuel metered per pump stroke and its thermal energy content change, and this results in uneven cylinder outputs of the internal combustion engine .
  • a high-pressure injection pump designed for a peak pressure of 1,200 bar with a full-load injection quantity of 150 mm 3 / stroke results in a return flow quantity of 750 mm 3 / stroke, which is composed of the discharge quantity and the overflow quantity flowing back during the preliminary stroke.
  • This heated fuel mixes with the inflowing cold fuel, and this leads to the specified disadvantages in the case of conventional injection pumps which have a common suction space for all pump elements.
  • each partial suction chamber has a throttle connection between the outflow opening and the common outflow channel which forms a collector therewith and is fed by a common inflow channel provided with very large inflow openings to the partial suction chambers.
  • the fuel injection pump according to the invention with the characterizing features of patent claim 1 has the advantage that no heated outflow fuel mixes with the inflowing fuel because the flow divider divides the incoming fuel into partial flows by the appropriately dimensioned flow cross sections of its sections comprising the storage spaces, which divide each partial suction space with the Supply the required fuel flow. With the flushing achieved in this way, a precise and constant fuel metering for each combustion chamber of the internal combustion engine is possible at the same speed and load, and the thermal energy content of the fuel quantity metered per pump stroke is thus largely the same for all pump elements.
  • the flow divider and the collector are inserted into a longitudinal bore of the pump housing are set and have separate storage spaces upstream or downstream of the partial suction spaces for each partial suction space. These storage spaces serve as buffer spaces, so that heated outflow fuel from one of the pump elements cannot get into the inflowing fuel of one of the other pump elements due to the recoil effect that occurs during shutdown or is sucked in by one of the other pump elements during the suction stroke.
  • the generic fuel injection pump according to the characterizing features of this claim 3 is equipped with a pipe which contains both the flow divider and the collector and is inserted into a single longitudinal bore in the pump housing.
  • Such an injection pump has, in addition to the advantages already listed for claim 1, also advantageously the possibility of an easy-to-implement retrofit or reconstruction in large series of injection pumps equipped with only one longitudinal channel for the supply and discharge of the fuel.
  • the flow divider and the collector are each contained in a tube, both of which can be produced as components to be finished outside the pump.
  • a simplified assembly results if, according to the features of claim 4, the one containing the flow divider and collector pipe is divided in the longitudinal direction into chambers, with a separate, the storage space forming chamber for the inflow and outflow of the Fuel is connected.
  • the chambers in the interior of the tube, or when using two tubes configured in accordance with claim 5, the chambers in the interior of the tubes can be designed as multi-start helices and form large storage spaces with a uniform cross-section.
  • the coils inside the tubes can be made of fuel-resistant plastic, which makes production easier and good thermal insulation of the partial flows is achieved.
  • the advantages of an embodiment of the invention according to claim 8 consist in the fact that the inflowing and outflowing fuel is divided or brought together to form storage spaces by the pocket-like impressions in the two pipes containing the volume distributor and collector.
  • a precisely metered fuel partial flow which does not mix with other partial flows, thus runs through each partial suction chamber, which carries the heated outflow fuel with it and supplies fresh fuel for each pump stroke.
  • a preferred, particularly advantageous further development of the fuel injection pump according to the invention is achieved according to claim 9 by the production of the at least one tube assigned to the inflow channel from a non-metallic, poorly heat-conducting material, e.g. made of fuel-resistant plastic or ceramic.
  • this pipe has pocket-like recesses. Each of these recesses serves as the storage space upstream of the partial suction space for fuel flowing back from the overflow opening of the pump cylinder.
  • the longitudinal channel is formed as a stepped bore within the tube inserted into the inflow channel, the respective flow cross-section being reduced from channel section to channel section.
  • the throttling inflow openings opening into the storage spaces - as seen in the direction of flow - are always somewhat larger, so that the flow cross-section of each - from the inlet of the inflow channel, as seen in the flow direction — each subsequent inflow opening is larger by an amount that compensates for the flow losses compared to the flow cross section of the preceding inflow opening.
  • These inflow openings, which are equipped with different flow cross-sections, are, in and of themselves, already known from DE-A-33 26 045 cited at the beginning, but work here to achieve the desired uniform purging with the features of the stepped longitudinal channel.
  • the inner walls of the recesses forming the storage spaces can be reinforced according to the features of claim 13 in the case of highly loaded injection pumps.
  • the pipe inserted into the outflow channel according to claim 14 is made of a good heat-conducting material, preferably aluminum.
  • This tube like the tube located in the inflow channel, is also provided with recesses formed by impressions, each of which forms a storage space downstream of the associated partial suction chamber. So that the fuel does not heat up unevenly because of the different running times, the pipe inserted into the outflow channel can be arranged in the counterflow direction in a preferred manner.
  • GB-A-2 074 252 discloses a tube which is inserted into a longitudinal bore of the pump housing but only forms a collector.
  • the pipe shown there in FIG. 2, composed of individual segments, serves only as an impact protection pipe to prevent cavitation erosion on the outflow side, lies with the passage openings directly on the pump cylinder in the area of the overflow bores and, because of the lack of a partial suction chamber, only flows through during the shutdown. Because of the lack of a partial suction chamber and the non-existent volume division on the inflow side, a constant fuel temperature cannot be achieved in the area of the individual pump elements here because there is no continuous flow.
  • FIG. 1 shows a partial cross section through the first exemplary embodiment of a fuel injection pump with a first embodiment of the flow divider and collector
  • FIG. 2 shows a part of a longitudinal section along the section line FF in FIG. 1
  • FIGS. 3a and 3b each show a longitudinal and cross section of the flow divider according to the invention 1 and 2
  • FIG. 4 shows a partial cross section through an injection pump with a flow divider in a second embodiment
  • the partial figures 5a and 5b serve to explain the exemplary embodiment of the flow divider according to FIG. 4.
  • FIG 5a corresponding longitudinal Schmitt the third embodiment shown.
  • FIG. 1 there is a receiving bore 11 for a pump cylinder 12 within a pump housing 10, which bores upwards towards a fastening flange 13.
  • the fastening flange 13 is screwed to the pump housing 10 by means of fastening screws 14.
  • An intermediate disc 15, which is inserted between the mounting flange 13 and the pump housing 10, is used in a known manner to adjust the forward stroke.
  • a pump piston 16 operates within the pump cylinder 12, the control edge 17 of which cooperates with an overflow opening 18 around the pump cylinder 12 for fuel metering, the overflow opening 18 leading into a partial suction chamber 19 and at the same time serving as a suction opening.
  • the pump piston 16 carries out lifting and rotating movements and has a second control edge 20 which defines the start of the delivery of the fuel by covering the overflow opening 18.
  • a baffle ring 21 is provided so that the abraded outflow fuel, which is under high pressure and flows back into the partial suction spaces 19, does not cause any erosions on the wall of the receiving bore and surface of the pump cylinder 12 due to its high kinetic energy.
  • Fuel is supplied through an inflow channel 22 and excess fuel can flow away through an outflow channel 23.
  • Inflow channel 22 and outflow channel 23 each contain a tube 24 shown in FIG. 2 and in FIGS. 3a and b with pocket-like impressions 25 to form a flow divider 29 and a collector 30, respectively.
  • the pocket-like impressions 25 in the inflow channel 22 branch off a part of the fuel flow, guide them into the respective partial suction spaces 19 and form upstream additional storage spaces 26 for the fuel, so that a buffer effect occurs and no de-fueled fuel can be pushed back into the inflow channel 22 the partial suction chambers 19 is flushed through.
  • no heated fuel can be sucked back from the outlet channel 23, since the additional storage spaces 26 of the collector 30 in the outlet channel 23 are connected downstream of the partial suction chambers 19.
  • the amount of fuel flowing in and the flow cross-sections in the channels are to be dimensioned such that complete flushing of the partial suction spaces 19 is ensured and the entire overflow fuel is taken up by the drain channel 23.
  • FIG. 2 This purging effect is additionally illustrated in FIG. 2 by arrows for the fuel flow.
  • Figure 3a shows a longitudinal section of one of the tubes 24 with the pocket-like impressions 25
  • Figure 3b shows a cross section thereof.
  • the impressions 25 of the flow divider 29 in the inflow channel 22 and the collector 30 in the outflow channel 23, which are formed in the tubes 24, are constructed in the same way, but are used in opposite directions in accordance with the fuel flow.
  • the one tube 24 inserted into a longitudinal bore receiving the inflow channel 22 has an inflow opening 27 in the upstream end region 26a of the storage spaces 26, and in the other tube 24 receiving the outflow signal 23 the corresponding downstream, sheared edges also form there Impressions 25 comprising storage spaces 26 each have an outflow opening 28.
  • Figure 4 shows a half partial cross section through an injection pump with the features of the second embodiment.
  • Inflow channel 22 and outflow channel 23 (see also FIG. 5a) each contain, in the embodiment shown, a flow divider 129 or collector 130 formed by a tube 124, which in the flow direction of the fuel for each pump element has a separate chamber, forming a storage space 126 for each Have inflow and outflow of the fuel.
  • Figure 5a shows a partial longitudinal section corresponding to the section line E-E in Figure 4.
  • four separate flow areas are provided and designated by the numbers 1 to 4.
  • Each flow area belongs to a partial suction chamber 19 of a pump element of an in-line injection pump, the associated pump elements being shown in simplified form and also being designated by the numbers 1 to 4.
  • FIG. 5b shows the design of the cross sections of the tubes 124 to form the flow divider 129 or reservoir 130 according to FIG. 5a.
  • the sections A to D each show the cross sections through the one pipe 124 of the inflow channel 22 (see right row) and to the left the associated cross sections of the other pipe 124 of the outflow channel 23.
  • the flow arrows to the fuel flow to and from the partial suction chamber 19 are again indicated.
  • the partial cross section shown in FIG. 4 can also belong to another exemplary embodiment, not shown in more detail, in which e.g. only one tube 124 is used.
  • This tube 124 is divided in cross section into longitudinally extending chambers which are assigned to flow areas 1, 2, 3 and 4. These chambers are formed in the interior of the tube 124 as multi-start helices (helical channels), with each partial suction chamber 19 being assigned a helical path for the inflow and / or outflow of the fuel.
  • the multi-start coils inside the tube 124 or the tubes 124 can be made of fuel-resistant plastic and are used to create the sections forming the flow dividers 129 and collectors 130, e.g.
  • tube 124 if only one tube 124 is used, divided in the longitudinal direction into a first chamber separated by an intermediate wall and used for the inflow of the fuel, and a second chamber provided for the outflow of the fuel.
  • FIG. 6 shows a simplified longitudinal section, corresponding to Figure 5a, at the level of an inflow channel designated 222 and the outflow channel 23, but for a third embodiment of the fuel injection pump according to the invention.
  • This fuel injection pump is a six-cylinder injection pump, in which the pump cylinders 12 or partial suction spaces 19 assigned to the respective flow areas are continuously designated by the numbers 1 to 6.
  • the pump elements assigned to the flow areas 2 to 6 have been omitted in the sectional illustration.
  • a tube 224 receiving the inflow channel 222 consists of a non-metallic, poorly heat-conducting material, e.g. fuel-resistant plastic or ceramic, and the tube 24 containing the outflow channel 23 corresponds to the tube used in the first embodiment.
  • This tube 24 can also be made of plastic for thermal insulation, but for better heat dissipation it is made of a good heat-conducting material, preferably aluminum.
  • it has pocket-like impressions 25 which are tangentially adjacent to each partial suction space 19 and each form a storage space 26 connected downstream of the associated partial suction space 19. This space 26 opens into the interior of the tube 24 via the outflow opening 28 located in its downstream end region 26a.
  • this pipe 24 located in the outflow channel 23 is inserted in the counterflow direction to the flow direction of the pipe 224 inserted in the inflow channel 222 with its outflow openings 28 pointing to the housing section 10a receiving an inlet 222a of the inflow channel 222.
  • the tube 224 contains channel section 32 of the inflow channel 222 in the form of a longitudinal channel and recesses 31 which form storage spaces 226 and are connected to the longitudinal channel via inflow openings 227 1 , 227 2 , 227 z .
  • the longitudinal channel is in the form of a stepped bore with each inflow opening 227 1 , 227 2 to 227 z associated channel section 32 1 , 32 2 to 32 z formed.
  • the index numbers identify the assignment to the respective flow area, where Z stands for the last flow area as seen in the flow direction, that is to say for the flow area 6 in the exemplary embodiment according to FIG. 6.
  • Each of the channel sections preceding in the flow direction for example 32 1 , adjoining channel sections, eg 32 2 , has one compared to the flow cross-section of the preceding channel section reduced flow cross-section, and the flow cross-section of the last, most distant from the inlet 222a of the inflow channel 222 channel section 32 z is at least the same or slightly larger than the flow cross-section of the associated inflow opening 227 z .
  • the storage spaces 226 with the associated inflow openings 227 to 227 z form the flow divider 229 of the inflow channel 222.
  • a pipe 224 made of plastic and receiving the inflow channel 222 can cause erosion and flushing out on the inner walls of the recesses 31, designated 31a.
  • the inner walls 31a of the recesses 31 encompassing the storage spaces 226 on three sides can be reinforced by means of an erosion-resistant, preferably metallic lining 33.
  • Such a lining is shown for the storage space 226 assigned to the flow area 5.
  • the tube 224 is made of plastic by the injection molding process, the linings 33 can be inserted into the injection molding tool as sheet metal inserts and are then firmly connected to the tube 224. Such a method can also be used for ceramic materials.
  • the pocket-like recesses 31, which are tangentially adjacent to each partial suction chamber 19 and open to the partial suction chamber 19 and connected to the longitudinal channel 32 in the tube 224 via one of the throttling inflow openings 227, feed each partial suction chamber 19 to a partial flow derived from the inflowing fuel flow.
  • the recesses 31 each form one of the additional storage spaces 226 connected upstream of the associated partial suction space 19 for fuel flowing back from the overflow opening 18 of the pump cylinder 12.
  • An upstream end region 226a of each storage space 226 is connected to the longitudinal channel 32 by means of the inflow openings 227.

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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)

Description

Stand der TechnikState of the art

Die Erfindung bezieht sich auf eine Kraftstroffeinspritzpumpe für Brennkraftmaschinen nach der Gattung der Patentansprüche 1 und 3.The invention relates to a fuel injection pump for internal combustion engines according to the preamble of claims 1 and 3.

Einspritzpumpen, bei denen für jeden Zylinder der Brennkraftmaschine ein gesondertes Pumpenelement vorhanden ist und bei denen diese Pumpenelemente in einer Reihe angeordnet sind, werden als Reiheneinspritzpumpen bezeichnet und haben weiteste Verbreitung, insbesondere für selbstzündende Brennkraftmaschinen, sogenannte Dieselmotoren, gefunden. Die technische Entwicklung bei Dieselmotoren geht dahin, daß wegen verschärfter Abgasvorschriften die Verbrennung optimaler ablaugen muß, einhergehend mit einer Verringerung des spezifischen Leistungsgewichtes. Dabei muß bei stark erhöhten Einspritzdrücken die zugemessene Kraftstoffmenge bei jedem einzelnen Pumpenelement sehr gleichmäßig und genau sein. Des Zumessen des Kraftstoffes erfolgt dadurch, daß der Teil des Kraftstoffes, der nicht zur Einspritzung gelangt, unter hohem Druck in das Innere eines Sammelraumes der Einspritzpumpe zurückströmt. Das Überströmen des unter hohem Druck stehenden Kraftstoffes an Steuerkanten der Pumpenkolben führt zu seiner Erwärmung und damit verändern sich physikalische Eigenschaften wie Dichte und Kompressibilität, so daß sich die pro Pumpenhub zugemessene Kraftstoffmenge sowie sein thermischer Energiegehalt verändern, und das hat ungleichmäßige Zylinderleistungen der Brennkraftmaschine zur Folge. So ergibt sich z.B. bei einer für einen Spitzendruck von 1 200 bar ausgelegten Hochdruckeinspritzpumpe bei einer Vollasteinspritzmenge von 150 mm3/Hub eine aus Absteuermenge und während des Vorhubes rückströmender Überschiebemenge zusammengesetzte Rückströmmenge von 750 mm3/Hub. Dieser erwärmte Kraftstoff vermischt sich mit dem zufließenden kalten Kraftstoff, und das führt bei üblichen, einen gemeinsamen Saugraum für alle Pumpenelemente aufweisenden Einspritzpumpen zu den angegebenen Nachteilen.Injection pumps in which there is a separate pump element for each cylinder of the internal combustion engine and in which these pump elements are arranged in a row are referred to as inline injection pumps and have found widespread use, in particular for self-igniting internal combustion engines, so-called diesel engines. The technical development in diesel engines is that, because of stricter exhaust gas regulations, the combustion must leach optimally, along with a reduction in the specific power-to-weight ratio. At greatly increased injection pressures, the metered amount of fuel must be very even and precise for each individual pump element. The metering of the fuel takes place in that the part of the fuel which does not reach the injection flows back under high pressure into the interior of a collecting space of the injection pump. The overflow of the fuel under high pressure at the control edges of the pump pistons leads to its heating and thus physical properties such as density and compressibility change, so that the amount of fuel metered per pump stroke and its thermal energy content change, and this results in uneven cylinder outputs of the internal combustion engine . For example, a high-pressure injection pump designed for a peak pressure of 1,200 bar with a full-load injection quantity of 150 mm 3 / stroke results in a return flow quantity of 750 mm 3 / stroke, which is composed of the discharge quantity and the overflow quantity flowing back during the preliminary stroke. This heated fuel mixes with the inflowing cold fuel, and this leads to the specified disadvantages in the case of conventional injection pumps which have a common suction space for all pump elements.

Bei einer aus der DE-A-25 47 071 bekannten Kraftstoffeinspritzpumpe der gattungsgemäßen Bauart wurde bereits der bis dahin bekannte gemeinsame Saugraum, aus dem alle Pumpenelemente der Reiheneinspritzpumpe den zuzumessenden Kraftstoff ansaugen und zu den Einspritzdüsen fördern, in mehrere Teilsaugräume unterteilt, von denen jeder Teilsaugraum einem Pumpenelement zugeordnet ist. Dabei weist jeder Teilsaugraum eine Drosselverbinding zwischen der Abströmöffnung und dem mit dieser einen Sammler bildenden gemeinsamen Abströmkanal auf und wird vom einem gemeinsamen, mit sehr großen Zuströmöffnungen zu den Teilsaugräumen versehenen Zuströmkanal gespeist. Bei dieser bekannten Kraftstoffeinspritzpumpe kann jedoch nicht vermieden werden, daß sich in dem gemeinsamen Zuströmkanal der unter hohem Druck austretende und dadurch aufgeheizte Abströmkraftstoff mit zulaufendem Kraftstoff vermischt, und daß es dadurch zu unkontrollierbaren Streuungen bei den den Brennräumen der Brennkraftmaschine zugemessenen Kraftstoffmengen kommt.In a fuel injection pump of the generic type known from DE-A-25 47 071, the previously known common suction chamber, from which all pump elements of the in-line injection pump draw the fuel to be metered and deliver it to the injection nozzles, was divided into several partial suction chambers, each of which is a partial suction chamber is assigned to a pump element. In this case, each partial suction chamber has a throttle connection between the outflow opening and the common outflow channel which forms a collector therewith and is fed by a common inflow channel provided with very large inflow openings to the partial suction chambers. In this known fuel injection pump, however, it cannot be avoided that in the common inflow channel the outflow fuel escaping under high pressure and thus heated is mixed with incoming fuel, and that this leads to uncontrollable scattering in the fuel quantities metered into the combustion chambers of the internal combustion engine.

Um den vorgenannten Nachteil zu beheben, wurde in der DE-A-33 26 045, die nur bezüglich des in Figur 6 dargestellten Ausführungsbeispiels vorveröffentlicht ist, vorgeschlagen, die Teilsaugräume als einen den Pumpenzylinder vollständig umschließenden, nur über die Rücklauföffnung mit dem Rücklaufkanal und über eine gedrosselte Zulauföffnung mit dem Zulaufkanal verbundenen Hohlraum auszubilden. Dabei wurde der Durchströmquerschnitt der gedrosselten Zulauföffnungen kleiner ausgeführt als der Durchströmquerschnitt der zugehörigen Rücklauföffnungen. Da die Wärme der Pumpenelemente und Teilsaugräume auch auf das Pumpengehäuse übertragen wird, erwärmt sich der zufließende Kraftstoff bereits auf seinem Weg durch das Pumpengehäuse zu den einzelnen Teilsaugräumen. Der Kraftstoff nimmt also auf seinem Weg durch die Pumpe immer höhere Temperaturen an. Dies ist ebenfalls die Ursache von Mengenfehlern, vor allem infolge der Temperatureinflüsse bei Wechsel des Lastpunkts; d.h. der einzuspritzenden Fördermenge. Zur Reduzierung der Mengenfehler werden folgende Forderungen an das saugraumsystem gestellt:

  • -Da es sich nicht vermeiden läßt, daß die Temperatur in den Teilsaugräumen lastpunktabhängig, d.h. nicht konstant ist, ergibt sich die Forderung, in allen Teilsaugräumen jeweils die gleiche Temperatur zu erzielen.
  • -Das Einschwingverhalten der Temperatur soll für alle Teilsaugräume gleich sein.
  • -Der mit Hilfe der Spülmenge abgeführte Wärmestrom in den einzelnen Teilsaugräumen soll so groß sein, daß sich in allen Pumpenarbeitsräumen die gleiche Temperatur einstellt, und
  • -die Temperatur des Pumpengehäuses soll an jedem Pumpenelement gleich groß sein.
In order to remedy the above-mentioned disadvantage, it was proposed in DE-A-33 26 045, which was only published in relation to the exemplary embodiment shown in FIG. 6, that the partial suction chambers should be completely enclosing the pump cylinder, only via the return opening with the return channel and above to form a throttled inlet opening connected to the inlet channel. The flow cross-section of the throttled inlet openings was made smaller than the flow cross-section of the associated return openings. Since the heat of the pump elements and partial suction chambers is also transferred to the pump housing, the inflowing fuel heats up on its way through the pump housing to the individual partial suction chambers. The fuel therefore takes on ever higher temperatures on its way through the pump. This is also the cause of quantity errors, especially as a result of the temperature influences when the load point changes; ie the delivery rate to be injected. The following requirements are placed on the suction chamber system to reduce the quantity errors:
  • Since it cannot be avoided that the temperature in the partial suction chambers depends on the load point, ie is not constant, there is the requirement to achieve the same temperature in all partial suction chambers.
  • -The settling behavior of the temperature should be the same for all partial suction areas.
  • The heat flow dissipated with the aid of the flushing quantity in the individual partial suction spaces should be so large that the same temperature is set in all pump work spaces, and
  • -The temperature of the pump housing should be the same on each pump element.

Vorteile der ErfindungAdvantages of the invention

Die erfindungsgemäße Kraftstoffeinspritzpumpe mit den kennzeichnenden Merkmalen des Patentanspruchs 1 hat den Vorteil, daß sich kein aufgeheizter Abströmkraftstoff mit dem zuströmenden Kraftstoff vermischt, weil der Mengenteiler den zulaufenden Kraftstoff durch die entsprechend bemessenen Durchströmquerschnitte seiner die Speicherräume umfassenden Abschnitte in Teilströme aufteilt, die jeden Teilsaugraum mit dem erforderlichen Kraftstoffstrom versorgen. Mit der dadurch erzielten Durchspülung ist eine genaue und bei gleicher Drehzahl und Last gleichbleibende Kraftstoffzumessung für jeden Brennraum der Brennkraftmaschine möglich, und der thermische Energiegehalt der pro Pumpenhub zugemessenen Kraftstoffmenge ist somit bei allen Pumpenelementen weitgehend gleich. Weiterhin ist es für eine einwandfreie Wärmeabfuhr vorteilhaft, daß der Mengenteiler und der Sammler in je eine Längsbohrung des Pumpengehäuses eingesetzt sind und für jeden Teilsaugraum gesonderte, den Teilsaugräumen vor- bzw. nachgeschaltete Speicherräume aufweisen. Diese Speicherräume dienen als Pufferräume, so daß erhitzter Abströmkraftstoff eines der Pumpenelemente nicht durch die beim Absteuern auftretende Rückstoßwirkung in den zuströmenden Kraftstoff eines der anderen Pumpenelemente gelangen kann bzw. beim Saughub von einem der anderen Pumpenelemente angesaugt wird.The fuel injection pump according to the invention with the characterizing features of patent claim 1 has the advantage that no heated outflow fuel mixes with the inflowing fuel because the flow divider divides the incoming fuel into partial flows by the appropriately dimensioned flow cross sections of its sections comprising the storage spaces, which divide each partial suction space with the Supply the required fuel flow. With the flushing achieved in this way, a precise and constant fuel metering for each combustion chamber of the internal combustion engine is possible at the same speed and load, and the thermal energy content of the fuel quantity metered per pump stroke is thus largely the same for all pump elements. Furthermore, it is advantageous for proper heat dissipation that the flow divider and the collector are inserted into a longitudinal bore of the pump housing are set and have separate storage spaces upstream or downstream of the partial suction spaces for each partial suction space. These storage spaces serve as buffer spaces, so that heated outflow fuel from one of the pump elements cannot get into the inflowing fuel of one of the other pump elements due to the recoil effect that occurs during shutdown or is sucked in by one of the other pump elements during the suction stroke.

Bei einer zweiten, in Patentanspruch 3 niedergelegten erfindungsgemäßen Lösung ist die gattungsgemäße Kraftstoffeinspritzpumpe gemäß den kennzeichnenden Merkmalen dieses Patentanspruchs 3 mit einem in eine einzige Längsbohrung des Pumpengehäuses eingesetzten, sowohl den Mengenteiler als auch den Sammler enthaltenden Rohr ausgestattet. Eine solche Einspritzpumpe weist neben den bereits zu Patentanspruch 1 aufgeführten Vorteilen auch in vorteilhafter Weise die Möglichkeit einer einfach zu verwirklichenden Nachrüstung bzw. Umkonstruktion in Großserie gefertigter mit nur einem Längskanal für die Zu- und Abführung des Kraftstoffes ausgestatteter Einspritzpumpen auf.In a second solution according to the invention as set out in claim 3, the generic fuel injection pump according to the characterizing features of this claim 3 is equipped with a pipe which contains both the flow divider and the collector and is inserted into a single longitudinal bore in the pump housing. Such an injection pump has, in addition to the advantages already listed for claim 1, also advantageously the possibility of an easy-to-implement retrofit or reconstruction in large series of injection pumps equipped with only one longitudinal channel for the supply and discharge of the fuel.

Vorteilhafte Weiterbildungen und Ausgestaltungen der Erfindung können den abhängigen Ansprüchen entnommen werden. So sind bei einer Ausgestaltung der Erfindung gemäß Anspruch 2 der Mengenteiler und der Sammler in je einem Rohr enthalten, die beide als außerhalb der Pumpe fertig zu bearbeitende Bauteile herstellbar sind. Eine vereinfachte montage ergibt sich, wenn gemäß den Merkmalen des Anspruchs 4 das eine, den Mengenteiler und Sammler enthaltende Rohr in längsrichtung in Kammern unterteilt ist, wobei an jeden Teilsaugraum jeweils eine gesonderte, den Speicherraum bildende Kammer für den Zu- und für den Abfluß des Kraftstoffes angeschlossen ist. Bei dieser Ausgestaltung können gemäß Anspruch 6 die Kammern im Innern des Rohres, bzw. bei Verwendung zweier entsprechend Anspruch 5 ausgestalteter Rohre die Kammern im Inneren der Rohre, als mehrgängige Wendeln ausgebildet sein und große Speicherräume mit gleichmäßigem Querschnitt bilden. Die Wendeln im Innern der Rohre können dabei aus kraftstoffresistentem Kunststoff gefertigt sein, wodurch die Fertigung erleichtert und eine gute Wärmeisolierung der Teilströme erreicht wird.Advantageous further developments and refinements of the invention can be found in the dependent claims. Thus, in one embodiment of the invention, the flow divider and the collector are each contained in a tube, both of which can be produced as components to be finished outside the pump. A simplified assembly results if, according to the features of claim 4, the one containing the flow divider and collector pipe is divided in the longitudinal direction into chambers, with a separate, the storage space forming chamber for the inflow and outflow of the Fuel is connected. In this embodiment, the chambers in the interior of the tube, or when using two tubes configured in accordance with claim 5, the chambers in the interior of the tubes, can be designed as multi-start helices and form large storage spaces with a uniform cross-section. The coils inside the tubes can be made of fuel-resistant plastic, which makes production easier and good thermal insulation of the partial flows is achieved.

Die Vorteile bei einer Ausgestaltung der Erfindung gemäß Anspruch 8, bestehen darin, daß durch die taschenartigen Einprägungen in den zwei, den Mengenverteiler und Sammler enthaltenden Rohren der zu- und abströmende Kraftstoff unter Bildung von Speicherräumen aufgeteilt bzw. zusammengeführt wird. Somit verläuft durch jeden Teilsaugraum ein sich nicht mit anderen Teilströmen vermischender, genau dosierter Kraftstoffteilstrom, der den erhitzten Abströmkraftstoff mit sich transportiert und für jeden Pumpenhub frischen Kraftstoff zuführt.The advantages of an embodiment of the invention according to claim 8 consist in the fact that the inflowing and outflowing fuel is divided or brought together to form storage spaces by the pocket-like impressions in the two pipes containing the volume distributor and collector. A precisely metered fuel partial flow, which does not mix with other partial flows, thus runs through each partial suction chamber, which carries the heated outflow fuel with it and supplies fresh fuel for each pump stroke.

Eine bevorzugte, besonders vorteilhafte Weiterbildung der erfindungsgemäßen Kraftstoffeinspritzpumpe wird gemäß Anspruch 9 durch die Herstellung des mindestens einen, dem Zuströmkanal zugeordneten Rohres aus einem nichtmetallischen, schlecht wärmeleitenden Material, z.B. aus kraftstoffresistentem Kunststoff oder Keramik, erreicht. Um auch bei diesem, aus schlecht wärmeleitendem Material hergestellten Rohr eine Vermischung des erhitzten Abströmkraftstoffes mit dem zuströmenden Kraftstoff zu verhindern, weist dieses Rohr gemäß Anspruch 10 taschenartige Ausnehmungen auf. Jede dieser Ausnehmungen dient als der dem Teilsaugraum vorgeschaltete Speicherraum für aus der Überströmöffnung des Pumpenzylinders rückströmenden Kraftstoff.A preferred, particularly advantageous further development of the fuel injection pump according to the invention is achieved according to claim 9 by the production of the at least one tube assigned to the inflow channel from a non-metallic, poorly heat-conducting material, e.g. made of fuel-resistant plastic or ceramic. In order to prevent mixing of the heated effluent fuel with the inflowing fuel in this pipe, which is made of poorly heat-conducting material, this pipe has pocket-like recesses. Each of these recesses serves as the storage space upstream of the partial suction space for fuel flowing back from the overflow opening of the pump cylinder.

Damit außer der durchströmenden Menge auch deren Geschwindigkeit in allen Teilsaugräumen sich auf einen gleichen wert einstellt, wird gemäß den Ansprüchen 11 und 12 der Längskanal innerhalb des in den Zuströmkanal eingesetzten Rohres als Stufenbohrung ausgebildet, wobei sich der jeweilige Durchströmquerschnitt von Kanalabschnitt zu Kanalabschnitt vermindert.So that in addition to the flow rate, the speed in all partial suction spaces is set to the same value, the longitudinal channel is formed as a stepped bore within the tube inserted into the inflow channel, the respective flow cross-section being reduced from channel section to channel section.

Um non trotz der im Längskanal wirksam werdenden Strömungswiderstände eine gleichmäßige Durchspülung der Teilsaugräume zu gewährleisten, werden gemäß weiterer Merkmale in Anspruch 12 die in die Speicherräume mündenden drosselnden Zuströmöffnungen-in Strömungsrichtung gesehen-immer etwas größer, so daß jeweils der Durchströmquerschnitt der--vom Einlaß des Zuströmkanals her in Strömungsrichtung gesehen-jeweils nachfolgenden Zuströmöffnung gegenüber dem Durchströmquerschnitt der vorangehenden Zuströmöffnung um einen die Strömungsverluste ausgleichenden Betrag größer ist. Diese mit unterschiedlichen Durchströmquerschnitten ausgestatteten Zuströmöffnungen sind, für sich genommen, bereits aus der eingangs zitierten DE-A-33 26 045 bekannt, wirken hier zur Erzielung der angestrebten gleichmäßigen Durchspülung jedoch mit den Merkmalen des abgestuften Längskanals zusammen.In order to ensure a uniform flushing of the partial suction spaces in spite of the flow resistances becoming effective in the longitudinal channel, the throttling inflow openings opening into the storage spaces - as seen in the direction of flow - are always somewhat larger, so that the flow cross-section of each - from the inlet of the inflow channel, as seen in the flow direction — each subsequent inflow opening is larger by an amount that compensates for the flow losses compared to the flow cross section of the preceding inflow opening. These inflow openings, which are equipped with different flow cross-sections, are, in and of themselves, already known from DE-A-33 26 045 cited at the beginning, but work here to achieve the desired uniform purging with the features of the stepped longitudinal channel.

Zur Verbesserung der Dauerfestigkeit der vorerwähnten Rohre können bei hochbelasteten Einspritzpumpen die Innenwände der die Speicherräume bildenden Ausnehmungen gemäß den Merkmalen des Anspruchs 13 armiert werden.In order to improve the fatigue strength of the aforementioned pipes, the inner walls of the recesses forming the storage spaces can be reinforced according to the features of claim 13 in the case of highly loaded injection pumps.

Um nun aber eine zu starke Aufheizung des Pumpengehäuses zu verhindern, wird das gemäß Anspruch 14 in den Abströmkanal eingesetzte Rohr aus einem gut wärmeleitenden Material, vorzugsweise Aluminium, gefertigt. Dieses Rohr ist ebenfalls, wie das im Zuströmkanal befindliche Rohr, mit von Einprägungen gebildeten Ausnehmungen versehen, die jeweils einem dem zugehörigen Teilsaugraum nachgeschalteten Speicherraum bilden. Damit wegen der verschieden langen Laufzeit nicht doch noch eine ungleichmäßige Aufheizung des Kraftstoffes erfolgt, kann in bevorzugter Weise gemäß Anspruch 15 das in den Abströmkanal eingesetzte Rohr in Gegenstromrichtung angeordnet werden.However, in order to prevent excessive heating of the pump housing, the pipe inserted into the outflow channel according to claim 14 is made of a good heat-conducting material, preferably aluminum. This tube, like the tube located in the inflow channel, is also provided with recesses formed by impressions, each of which forms a storage space downstream of the associated partial suction chamber. So that the fuel does not heat up unevenly because of the different running times, the pipe inserted into the outflow channel can be arranged in the counterflow direction in a preferred manner.

Aus der FR-A-822 261 ist es bekannt, den Zuströmkanal als Mengenteiler durch mehrere, unterschiedlich lange Kanäle auszubilden. Außerdem sind auch diese Zuströmkanäle und der Abströmkanal voneinander getrennt auf gegenüberliegenden Seiten des Pumpenzylinders angeordnet, sie sind jedoch direkt an die von den Steuerkanten der Pumpenkolben gesteuerten Überströmöffnungen der Pumpenzylinder angeschlossen, separate Teilsaugräume sind demnach nicht vorhanden. Eine für einen gleichmäßigen Temperaturgang notwendige dauernde Durchspülung ist demnach wegen der fehlenden Teilsaugräume dort auch nicht vorgesehen und nicht möglich. Über einen getrennten Zuströmkanal wird lediglich jeweils eine Gruppe von Pumpenelementen mit Kraftstoff versorgt, die untereinander bezüglich ihrer Förderzeitpunkte so weit auseinanderliegen, daß die beim Vorhub sich aufbauenden Rückstoßwellen nicht mit dem Saughub des benachbarten Pumpenelements zusammenfallen. Dadurch werden Resonanzerscheinungen ausgeschlossen, welche ansonsten zu Mengenstreuungen führen würden. Aufgabe und konstruktive Ausgestaltungen dieser Einspritzpumpe weichen also stark von denen der vorliegenden Erfindung ab.From FR-A-822 261 it is known to divide the inflow channel as a flow divider by several to train channels of different lengths. In addition, these inflow channels and the outflow channel are also arranged separately from one another on opposite sides of the pump cylinder, but they are connected directly to the overflow openings of the pump cylinders controlled by the control edges of the pump pistons, so there are no separate partial suction spaces. A continuous flushing necessary for a uniform temperature response is therefore not provided and not possible because of the lack of partial suction spaces. Via a separate inflow channel, only one group of pump elements is supplied with fuel, which are so far apart from one another with respect to their delivery times that the recoil waves building up during the forward stroke do not coincide with the suction stroke of the adjacent pump element. This eliminates resonance phenomena that would otherwise lead to quantity scatter. The task and constructive designs of this injection pump thus deviate greatly from those of the present invention.

Ein in eine Längsbohrung des Pumpengehäuses eingesetztes, allerdings nur einen Sammler bildendes Rohr ist aus der GB-A-2 074 252 bekannt. Das dort in Figur 2 gezeigte, aus einzelnen Segmenten zusammengesetzte Rohr dient lediglich als Prallschutzrohr zur Verhinderung von Kavitationserosion auf der Abströmseite, liegt mit den Durchtrittsöffnungen direkt am Pumpenzylinder im Bereich der Überströmbohrungen an und ist wegen des fehlenden Teilsaugraums nur während der Absteuerung durchströmt. Wegen des fehlenden Teilsaugraums und der nicht vorhandenen Mengenteilung auf der Zuströmseite kann hier auch keine konstante Kraftstofftemperatur im Bereich der einzelnen Pumpenelemente erreicht werden, weil eine kontinuierliche durchströmung fehlt.GB-A-2 074 252 discloses a tube which is inserted into a longitudinal bore of the pump housing but only forms a collector. The pipe shown there in FIG. 2, composed of individual segments, serves only as an impact protection pipe to prevent cavitation erosion on the outflow side, lies with the passage openings directly on the pump cylinder in the area of the overflow bores and, because of the lack of a partial suction chamber, only flows through during the shutdown. Because of the lack of a partial suction chamber and the non-existent volume division on the inflow side, a constant fuel temperature cannot be achieved in the area of the individual pump elements here because there is no continuous flow.

Zeichnungdrawing

Drei Ausführungsbeispiele der erfindungsgemäß ausgestalteten Kraftstoffeinspritzpumpe sind in der Zeichnung dargestellt und werden nachfolgend näher beschrieben. Es zeigen: Figur 1 einen Teilquerschnitt durch das erste Ausführungsbeispiel einer Kraftstoffeinspritzpumpe mit einer ersten Ausführungsform des Mengenteilers und Sammlers, Figur 2 einen Teil eines Längsschnittes gemäß der Schnittlinie F-F in Figur 1 und die Figuren 3a und 3b je einen Längs- und Querschnitt des erfindungsgemäßen Mengenteilers gemäß Figuren 1 und 2, Figur 4 zeigt einen Teilquerschnitt durch eine Einspritzpumpe mit einem Mengenteiler in einer zweiten Ausgestaltung, und die Teilfiguren Figur 5a und Figur 5b dienen zur näheren Erläuterung des Ausführungsbeispiels des Mengenteilers gemäß Figur 4. In Figur 6 wird in einem der Figur 5a entsprechenden Längsschmitt das dritte Ausführungsbeispiel dargestellt.Three exemplary embodiments of the fuel injection pump designed according to the invention are shown in the drawing and are described in more detail below. 1 shows a partial cross section through the first exemplary embodiment of a fuel injection pump with a first embodiment of the flow divider and collector, FIG. 2 shows a part of a longitudinal section along the section line FF in FIG. 1, and FIGS. 3a and 3b each show a longitudinal and cross section of the flow divider according to the invention 1 and 2, FIG. 4 shows a partial cross section through an injection pump with a flow divider in a second embodiment, and the partial figures 5a and 5b serve to explain the exemplary embodiment of the flow divider according to FIG. 4. In FIG 5a corresponding longitudinal Schmitt the third embodiment shown.

Beschreibung der AusführungsbeispieleDescription of the embodiments

Bei dem in Figur 1 gezeigten Längsschnitt befindet sich innerhalb eines Pumpengehäuses 10 eine Aufnahmebohrung 11 für einen Pumpenzylinder 12, der sich nach oben hin zu einem Befestigungsflansch 13 verbreitert. Der Befestigungsflansch 13 ist mittels Befestigungsschrauben 14 am Pumpengehäuse 10 verschraubt. Eine Zwischenscheibe 15, die zwischen Befestigungsflansch 13 und Pumpengehäuse 10 eingelegt ist, dient in bekannter Weise der Einstellung des Vorhubes. Innerhalb des Pumpenzylinders 12 arbeitet ein Pumpenkolben 16, dessen Steuerkante 17 mit einer Überströmöffnung 18 um Pumpenzylinder 12 zur Kraftstoffzumessung zusammenarbeitet, wobei die Überströmöffnung 18 in einen Teilsaugraum 19 führt und zugleich als Sauföffnung dient. Der Pumpenkolben 16 führt Hub- und Drehbewegungen aus und weist eine zweite Steuerkante 20 auf, die den Förderbeginn des Kraftstoffes durch Verdecken der Überströmöffnung 18 festlegt. Damit der unter hohem Druck stehende abgesteuerte Abströmkraftstoff, der in die Teilsaugräume 19 zurückströmt, dort infolge seiner hohen kinetischen Energie keine Erosionen and der Wand der Aufnahmebohrung und Oberfläche des Pumpenzylinders 12 verursacht, ist ein Prallring 21 vorhanden. Durch einen Zuströmkanal 22 wird Kraftstoff zugeführt und überschüssiger Kraftstoff kann durch einen Abströmkanal 23 abfließen. Zuströmkanal 22 und Abströmkanal 23 enthalten zur Bildung eines Mengenteilers 29 bzw. eines Sammelers 30 je ein in Figur 2 und in den Figuren 3a und b dargestelltes Rohr 24 mit taschenartigen Einprägungen 25.In the longitudinal section shown in FIG. 1, there is a receiving bore 11 for a pump cylinder 12 within a pump housing 10, which bores upwards towards a fastening flange 13. The fastening flange 13 is screwed to the pump housing 10 by means of fastening screws 14. An intermediate disc 15, which is inserted between the mounting flange 13 and the pump housing 10, is used in a known manner to adjust the forward stroke. A pump piston 16 operates within the pump cylinder 12, the control edge 17 of which cooperates with an overflow opening 18 around the pump cylinder 12 for fuel metering, the overflow opening 18 leading into a partial suction chamber 19 and at the same time serving as a suction opening. The pump piston 16 carries out lifting and rotating movements and has a second control edge 20 which defines the start of the delivery of the fuel by covering the overflow opening 18. A baffle ring 21 is provided so that the abraded outflow fuel, which is under high pressure and flows back into the partial suction spaces 19, does not cause any erosions on the wall of the receiving bore and surface of the pump cylinder 12 due to its high kinetic energy. Fuel is supplied through an inflow channel 22 and excess fuel can flow away through an outflow channel 23. Inflow channel 22 and outflow channel 23 each contain a tube 24 shown in FIG. 2 and in FIGS. 3a and b with pocket-like impressions 25 to form a flow divider 29 and a collector 30, respectively.

Die taschenartigen Einprägungen 25 im Zuströmkanal 22 zweigen einen Teil der Kraftstoffströmung ab, leiten sie in die jeweiligen Teilsaugräume 19 und bilden vorgeschaltete zusätzliche Speicherräume 26 für den Kraftstoff, so daß eine Pufferwirkung entsteht und kein abgesteuerter Kraftstoff in den Zuströmkanal 22 Zurückgedrücktwerden kann, soldern vollständig durch die Teilsaugräume 19 hindurchgespült wird. Andererseits kann aus dem Abströmkanal 23 kein erwärmter Kraftstoff vom Element rückgesaugt werden, da die zusätzlichen Speicherräume 26 des Sammlers 30 im Abströmkanal 23 den Teilsaugräumen 19 stromabwärts nachgeschaltet sind. Dabei sind die Menge des Zuströmenden Kraftstoffes und die Durchströmquerschnitte in den Kanälen so zu bemessen, daß die vollständige Spülung der Teilsaugräume 19 gewährleistet ist und der gesamte Überströmkraftstoff von dem Abströmkanal 23 aufgenommen wird.The pocket-like impressions 25 in the inflow channel 22 branch off a part of the fuel flow, guide them into the respective partial suction spaces 19 and form upstream additional storage spaces 26 for the fuel, so that a buffer effect occurs and no de-fueled fuel can be pushed back into the inflow channel 22 the partial suction chambers 19 is flushed through. On the other hand, no heated fuel can be sucked back from the outlet channel 23, since the additional storage spaces 26 of the collector 30 in the outlet channel 23 are connected downstream of the partial suction chambers 19. The amount of fuel flowing in and the flow cross-sections in the channels are to be dimensioned such that complete flushing of the partial suction spaces 19 is ensured and the entire overflow fuel is taken up by the drain channel 23.

In der Figur 2 ist zusätzlich mit Pfeilen für die Kraftstoffströmung diese Spülwirkung verdeutlicht. Figur 3a zeigt einen Längsschnitt eines der Rohre 24 mit den taschenartigen Einprägungen 25, die Figure 3b zeigt einen Querschnitt davon. Dabei sind die in die Rohre 24 geformten Einprägungen 25 des Mengenteilers 29 im Zuströmkanal 22 und des Sammlers 30 im Abströmkanal 23 gleichartig aufgebaut, aber entsprechend der Kraftstoffströmung entgegengesetzt eingesetzt.This purging effect is additionally illustrated in FIG. 2 by arrows for the fuel flow. Figure 3a shows a longitudinal section of one of the tubes 24 with the pocket-like impressions 25, Figure 3b shows a cross section thereof. The impressions 25 of the flow divider 29 in the inflow channel 22 and the collector 30 in the outflow channel 23, which are formed in the tubes 24, are constructed in the same way, but are used in opposite directions in accordance with the fuel flow.

Das eine, in eine den Zuströmkanal 22 aufnehmende Längsbohrung eingesetzte Rohr 24 besitzt im stromaufwärts gerichteten Endbereich 26a der Speicherräume 26 je eine Zuströmöffnung 27, und bei dem anderen, den Abströmnal 23 aufnehmenden Rohr 24 bilden die entsprechenden stromabwärts gerichteten, abgescherten Kanten der dort auch die Speicherräume 26 umfassenden Einprägungen 25 je eine Abströmöffnung 28.The one tube 24 inserted into a longitudinal bore receiving the inflow channel 22 has an inflow opening 27 in the upstream end region 26a of the storage spaces 26, and in the other tube 24 receiving the outflow signal 23 the corresponding downstream, sheared edges also form there Impressions 25 comprising storage spaces 26 each have an outflow opening 28.

Figur 4 zeigt einen halben Teilquerschnitt durch eine Einspritzpumpe mit den Merkmalen des zweiten Ausführungsbeispieles. Zuströmkanal 22 und Abströmkanal 23 (siehe auch Figur 5a) enthalten bei der gezeigten Ausführungsform je einen von einem Rohr 124 gebildeten Mengenteiler 129 bzw. Sammler 130, die in der Strömungsrichtung des Kraftstoffes für jedes Pumpenelement eine gesonderte, je einen Speicherraum 126 bildende Kammer für den Zustrom und für den Abstrom des Kraftstoffes aufweisen.Figure 4 shows a half partial cross section through an injection pump with the features of the second embodiment. Inflow channel 22 and outflow channel 23 (see also FIG. 5a) each contain, in the embodiment shown, a flow divider 129 or collector 130 formed by a tube 124, which in the flow direction of the fuel for each pump element has a separate chamber, forming a storage space 126 for each Have inflow and outflow of the fuel.

Figure 5a zeigt entsprechend der Schnittline E-E in Figur 4 einen Teillängsschnitt. Um eine wirkungsvolle Spülung der Teilsaugräume 19 zu erhalten, sind vier getrennte Strömungsbereiche vorgesehen und mit den Ziffern 1 bis 4 bezeichnet. Dabei gehöhrt jeder Strömungsbereiche zu einem Teilsaugraum 19 eines Pumpenelementes einer Reiheneinspritzpumpe, wobei die zugehörigen Pumpenelemente vereinfacht dargestellt und ebenfalls mit den Ziffern 1 bis 4 bezeichnet sind.Figure 5a shows a partial longitudinal section corresponding to the section line E-E in Figure 4. In order to obtain an effective flushing of the partial suction spaces 19, four separate flow areas are provided and designated by the numbers 1 to 4. Each flow area belongs to a partial suction chamber 19 of a pump element of an in-line injection pump, the associated pump elements being shown in simplified form and also being designated by the numbers 1 to 4.

Die Gestaltung der Querschnitte der Rohre 124 zur Bildung des Mengenteilers 129 oder Speichers 130 gemäß Figur 5a zeigt die Figur 5b. Dort sind mit den Schnitten A bis D jeweils die Querschnitte durch das eine Rohr 124 des Zuströmkanals 22 (siehe rechte Reihe) und links daneben die zugehörigen Querschnitte des anderen Rohres 124 des Abströmkanals 23 gezeigt. Mit den Strömungspfeilen ist wiederum der Kraftstofffluß zu und von den Teilsaugräum 19 angedeutet.5b shows the design of the cross sections of the tubes 124 to form the flow divider 129 or reservoir 130 according to FIG. 5a. There the sections A to D each show the cross sections through the one pipe 124 of the inflow channel 22 (see right row) and to the left the associated cross sections of the other pipe 124 of the outflow channel 23. The flow arrows to the fuel flow to and from the partial suction chamber 19 are again indicated.

Der in Figur 4 dargestellte Teilquerschnitt kann auch zu einem anderen, nicht näher dargestellten Ausführungsbeispiel gehören, bei dem z.B. nur ein Rohr 124 verwendet wird. Dieses Rohr 124 ist im Querschnitt in in Längsrichtung verlaufende Kammern unterteilt, die den Strömungsbereichen 1, 2, 3 und 4 zugeordnet sind. Diese Kammern werden im Innern des Rohres 124 als mehrgängige Wendeln (schraubenförmige Kanäle) ausgebildet, wobei jedem Teilsaugraum 19 ein Wendelgang für den Zu- und/oder Abfluß des Kraftstoffes zugeordnet ist. Die mehrgängigen Wendeln im Inneren des Rohres 124 oder der Rohre 124 können aus kraftstoffresistantem Kunststoff gefertigt werden und sind zur Erstellung der die Mengenteiler 129 und Sammler 130 bildenden Abschnitte, z.B. bei verwendung nur eines Rohres 124, in Längsrichtung in je eine durch eine Zwischenwand getrennte, dem Zufluß des Kraftstoffes dienende erste Kammer und eine für den Abfluß des Kraftstoffes vorgesehene zweite Kammer unterteilt. Es können aber auch zwei, mit Wendeln versehene Rohre, wie bei den übrigen Ausführungsbeispielen, vorhanden sein, von denen eines dem Zufluß und das andere dem Abfluß des Kraftstoffes dient.The partial cross section shown in FIG. 4 can also belong to another exemplary embodiment, not shown in more detail, in which e.g. only one tube 124 is used. This tube 124 is divided in cross section into longitudinally extending chambers which are assigned to flow areas 1, 2, 3 and 4. These chambers are formed in the interior of the tube 124 as multi-start helices (helical channels), with each partial suction chamber 19 being assigned a helical path for the inflow and / or outflow of the fuel. The multi-start coils inside the tube 124 or the tubes 124 can be made of fuel-resistant plastic and are used to create the sections forming the flow dividers 129 and collectors 130, e.g. if only one tube 124 is used, divided in the longitudinal direction into a first chamber separated by an intermediate wall and used for the inflow of the fuel, and a second chamber provided for the outflow of the fuel. However, there may also be two helical tubes, as in the other exemplary embodiments, one of which is used for the inflow and the other for the outflow of the fuel.

Figure 6 zeigt einen vereinfachten Längsschnitt, entsprechend Figur 5a, in Höhe eines mit 222 bezeichneten Zuströmkanals bzw. des Abströmkanals 23, jedoch für ein drittes Ausführungsbeispiel der erfindungsgemäßen Kraftstoffeinspritzpumpe. Diese Kraftstoffeinspritzpumpe ist eine Sechszylinder-Einspritzpumpe, bei der die den jeweiligen Strömungsbereichen zugeordneten Pumpenzylinder 12 bzw. Teilsaugräume 19 fortlaufend mit den Ziffern 1 bis 6 bezeichnet sind. Zur deutlicheren Darstellung wurden in der Schnittdarstellung die den Strömungsbereichen 2 bis 6 zugeordneten Pumpenelemente weggelassen.Figure 6 shows a simplified longitudinal section, corresponding to Figure 5a, at the level of an inflow channel designated 222 and the outflow channel 23, but for a third embodiment of the fuel injection pump according to the invention. This fuel injection pump is a six-cylinder injection pump, in which the pump cylinders 12 or partial suction spaces 19 assigned to the respective flow areas are continuously designated by the numbers 1 to 6. For a clearer illustration, the pump elements assigned to the flow areas 2 to 6 have been omitted in the sectional illustration.

Ein den Zuströmkanal 222 aufnehmendes Rohr 224 besteht aus einem nichtmetallischen, schlecht wärmeleitenden Material, z.B. kraftstoffresistentem Kunststoff oder Keramik, und das den Abströmkanal 23 enthaltende Rohr 24 entspricht dem beim ersten Ausführungsbeispiel verwendeten Rohr. Dieses Rohr 24 kann ebenfalls zur Wärmedämmung aus Kunststoff gefertigt sein, zur besseren Wärmeableitung wird es aber aus einem gut wärmeleitenden Material, vorzugsweise Aluminium, gefertigt. Es weist ebenso wie das in dem zu den Figuren 1 bis 3 beschriebenen Beispiel verwendete Rohr 24 taschenartige, an jeden Teilsaugraum 19 tangential angrenzende Einprägungen 25 auf, die jeweils einen dem zugehörigen Teilsaugraum 19 nachgeschalteten Speicherraum 26 bilden. Dieser Raum 26 mündet über die in seinem stromabwärts gerichteten Endbereich 26a befindliche Abströmöffnung 28 in den Innenraum des rohres 24.A tube 224 receiving the inflow channel 222 consists of a non-metallic, poorly heat-conducting material, e.g. fuel-resistant plastic or ceramic, and the tube 24 containing the outflow channel 23 corresponds to the tube used in the first embodiment. This tube 24 can also be made of plastic for thermal insulation, but for better heat dissipation it is made of a good heat-conducting material, preferably aluminum. Like the tube 24 used in the example described in FIGS. 1 to 3, it has pocket-like impressions 25 which are tangentially adjacent to each partial suction space 19 and each form a storage space 26 connected downstream of the associated partial suction space 19. This space 26 opens into the interior of the tube 24 via the outflow opening 28 located in its downstream end region 26a.

Um die durch den verschieden langen Zuströmweg innerhalb des Rohres 224 entsprechend unterschiedliche Aufheizzeit des Kraftstoffes auszugleichen, wird der abströmende Kraftstoff in Gegenstromrichtung durch das Rohr 24 geführt. Deshalb ist dies im Abströmkanal 23 befindliche Rohr 24 in Gegenstromrichtung zur Strömungsrichtung des im Zuströmkanal 222 eingesetzten Rohres 224 mit seinen Abströmöffnungen 28 zu dem ein Einlaß 222a des Zuströmkanals 222 aufnehmenden Gehäuseabschnitt 10a hinweisend eingesetzt.In order to compensate for the different heating times of the fuel due to the differently long inflow path within the tube 224, the outflowing fuel is passed through the tube 24 in the counterflow direction. Therefore, this pipe 24 located in the outflow channel 23 is inserted in the counterflow direction to the flow direction of the pipe 224 inserted in the inflow channel 222 with its outflow openings 28 pointing to the housing section 10a receiving an inlet 222a of the inflow channel 222.

Das Rohr 224 enthält kanalabschnitt 32 des Zuströmkanals 222 in Form eines Längskanals und über Zuströmöffnungen 2271, 2272, 227z mit dem Längskanal verbundene, Speicherraume 226 bildende Ausnehmungen 31, Der Längskanal ist als Stufenbohrung mit einem jeder Zuströmöffnung 2271, 2272 bis 227z zugeordneten Kanalabschnitt 321, 322 bis 32z ausgebildet. Die Indexzahlen kennzeichnen die Zuordnung zu dem jeweiligen Strömungsbereich, wobei Z für den-in Strömungsrichtung gesehen-letzten Strömungsbereich steht, im Ausführungsbeispiel nach Figur 6 also für den Strömungsbereich 6. Jeder der sich in Strömungsrichtung einen vorangehenden Kanalabschnitt, z.B. 321, anschließenden Kanalabschnitte, z.B. 322, weist einen gegenüber dem Durchströmquerschnitt des vorangehenden Kanalabschnittes reduzierten Durchströmquerschnitt auf, und der Durchströmquerschnitt des letzten, vom Einlaß 222a des Zuströmkanals 222 entferntesten Kanalabschnittes 32z ist mindestens gleich oder geringfügig größer als der Durchströmquerschnitt der zugehörigen Zuströmöffnung 227z. Die Speicherräume 226 mit den zugehörigen Zuströmöffnungen 227, bis 227z bilden den Mengenteiler 229 des Zuströmkanals 222.The tube 224 contains channel section 32 of the inflow channel 222 in the form of a longitudinal channel and recesses 31 which form storage spaces 226 and are connected to the longitudinal channel via inflow openings 227 1 , 227 2 , 227 z . The longitudinal channel is in the form of a stepped bore with each inflow opening 227 1 , 227 2 to 227 z associated channel section 32 1 , 32 2 to 32 z formed. The index numbers identify the assignment to the respective flow area, where Z stands for the last flow area as seen in the flow direction, that is to say for the flow area 6 in the exemplary embodiment according to FIG. 6. Each of the channel sections preceding in the flow direction, for example 32 1 , adjoining channel sections, eg 32 2 , has one compared to the flow cross-section of the preceding channel section reduced flow cross-section, and the flow cross-section of the last, most distant from the inlet 222a of the inflow channel 222 channel section 32 z is at least the same or slightly larger than the flow cross-section of the associated inflow opening 227 z . The storage spaces 226 with the associated inflow openings 227 to 227 z form the flow divider 229 of the inflow channel 222.

Arbeitet die zugehörige Kraftstoffeinspritzpumpe mit sehr hohen Einspritzdrücken und entsprechend großen Abströmmengen und Abströmgeschwindigkeiten, dann kann es bei einem aus Kunststoff gefertigten, den Zuströmkanal 222 aufnehmenden Rohr 224 zu Erosion und Ausspülungen an den mit 31a bezeichneten Innenwänden der Ausnehmungen 31 kommen. Für solcher Fälle können die Innenwände 31a der die Speicherräume 226 dreiseitig umfassenden Ausnehmungen 31 mittels je einer erosionsfesten, vorzugsweise metallischen Auskleidung 33 armiert werden. Eine solche Auskleidung ist für den dem Strömungsbereich 5 zugeordneten Speicherraum 226 eingezeichnet. Ist das Rohr 224 im Spritzgießverfahren aus Kunststoff hergestellt, dann können die Auskleidungen 33 als Blecheinlegeteile in das Spritzgußwerkzeug eingelegt werden und sind danach fest mit dem Rohr 224 verbunden. Ein solches Verfahren kann auch bei Keramikwerkstoffen angewendet werden.If the associated fuel injection pump works with very high injection pressures and correspondingly large outflow quantities and outflow velocities, then a pipe 224 made of plastic and receiving the inflow channel 222 can cause erosion and flushing out on the inner walls of the recesses 31, designated 31a. In such cases, the inner walls 31a of the recesses 31 encompassing the storage spaces 226 on three sides can be reinforced by means of an erosion-resistant, preferably metallic lining 33. Such a lining is shown for the storage space 226 assigned to the flow area 5. If the tube 224 is made of plastic by the injection molding process, the linings 33 can be inserted into the injection molding tool as sheet metal inserts and are then firmly connected to the tube 224. Such a method can also be used for ceramic materials.

Die taschenartigen, an jeden Teilsaugraum 19 tangential angrenzenden, zum Teilsaugraum 19 hin offenen und mit dem Längskanal 32 im Rohr 224 über je eine der drosselnden Zuströmöffnungen 227 verbundenen Ausnehmungen 31 leiten jedem Teilsaugraum 19 einen vom zuströmenden Kraftstoffstrom abgeleiteten Teilstrom zu. Die Ausnehmungen 31 bilden dabei jeweils einen der dem zugehörigen Teilsaugraum 19 vorgeschalteten zusätzlichen Speicherräume 226 für aus der Überströmöffnung 18 des Pumpenzylinders 12 rückströmenden Kraftstoff. Mittels der Zuströmoffnungen 227 ist jeweils ein stromaufwärts gerichteter Endbereich 226a jedes Speicherraumes 226 an den Längskanal 32 angeschlossen. Durch diese Form und Lage der Speicherräume 226 kann auch bei hohem Einspritzdruck mit großer Strömungsgeschwindigkeit austretender Kraftstoff nicht soweit zurückgedrückt werden, daß er sich mit dem im Längskanal 32 zuströmenden Kraftstoff vermischen könnte. In den Einspritzpausen wird durch den überschüssigen, die Teilsaugräume 19 passierenden Kraftstoff der nach dem zuvor erfolgten Förderhub abgesteuerte Kraftstoff über den Speicherraum 26 des im Abströmkanal 23 befindlichen Rohres 24 zum Tank zurückgefördert.The pocket-like recesses 31, which are tangentially adjacent to each partial suction chamber 19 and open to the partial suction chamber 19 and connected to the longitudinal channel 32 in the tube 224 via one of the throttling inflow openings 227, feed each partial suction chamber 19 to a partial flow derived from the inflowing fuel flow. The recesses 31 each form one of the additional storage spaces 226 connected upstream of the associated partial suction space 19 for fuel flowing back from the overflow opening 18 of the pump cylinder 12. An upstream end region 226a of each storage space 226 is connected to the longitudinal channel 32 by means of the inflow openings 227. As a result of this shape and position of the storage spaces 226, fuel escaping at a high flow rate cannot be pushed back to such an extent that it could mix with the fuel flowing in the longitudinal channel 32 even at high injection pressure. In the injection pauses, the fuel that passes through the partial suction chambers 19 and that is pumped off after the delivery stroke previously carried is conveyed back to the tank via the storage chamber 26 of the pipe 24 located in the outflow channel 23.

Obwohl bereits durch die im Durchmesser in Strömungsrichtung größer werdenden Zuströmöffnungen 227, bis 227z eine weitgehend gleichmäßige Durchströmung der Teilsaugräume 19 erreicht wird, ist eine völlig gleichmäßige Erwärmung des Kraftstoffes und damit die geforderte Gleichförderung der Pumpenelemente erste durch die Kombination der zu Figur 6 beschriebenen Maßnahmen in vollem Umfang erzielbar. Es sind dies: Die Anordnung der vorgeschalteten Speicherräume 226, die im Durchmesse größer werdenden Bohrungen der Zuströmöffnungen 227, bis 227z und die in Strömungsrichtung gestuft kleiner werdenden Durchmesser der Kanalabschnitte 321 bis 32z des Längskanals 32 bei dem aus schlecht wärmeleitendem Material gefertigten Rohr 224 in Kombination mit dem gut wärmeleitenden Rohr 24 im Abströmkanal, der ebenfalls Speicherräume 26, die hier jedoch den Teilsaugräumen 19 nachgeschaltet sind, aufweist.Although a largely uniform flow through the partial suction spaces 19 is already achieved through the inflow openings 227 to 227 z, which are larger in diameter in the direction of flow, a completely uniform heating of the fuel and thus the required equal delivery of the pump elements is first through the combination of the measures described in FIG. 6 fully achievable. These are: The arrangement of the upstream storage spaces 226, the holes of the inflow openings 227, to 227 z which increase in diameter and the diameter of the channel sections 32 1 to 32 z of the longitudinal channel 32, which becomes smaller in the direction of flow, in the case of the tube made of poorly heat-conducting material 224 in combination with the good heat-conducting tube 24 in the outflow channel, which likewise has storage spaces 26, which, however, are connected downstream of the partial suction spaces 19 here.

Claims (15)

1. Fuel injection pump for internal-combustion engines, comprising a plurality of pump cylinders (12) arranged in a row in accommodation bores (11) of the pump housing (10), of which pump cylinders (12) each accommodates a pump plunger (16), driven by a camshaft and provided with control edges (17, 20) for metering the injection quantity, and is surrounded by partial-suction spaces (19) which are connected to the pump cylinders (12) by means of transfer ports (18) controlled by the control edges (17, 20) and an inflow channel (22) and an outflow channel (23) which extend in the longitudinal direction of the pump housing (10) essentially parallel to the camshaft and transversely to the longitudinal axis of the pump cylinders (12) and are intended for the fuel flow to and from the partial-suction spaces (19), in which arrangement one separate inflow port (27) each leads off from the inflow channel (22) to each partial-suction space (19), which inflow port (27) belongs to a flow divider (29), and one separate outflow port (28) each leads out into the outflow channel (23) from each partial-suction space (19), which outflow port (28) belongs to an accumulator (30), characterized in that the flow divider (29; 129; 229) is inserted into a longitudinal bore, accommodating the inflow channel (22), of the pump housing (10) and contains a number of storage spaces (26; 126; 226), corresponding to the number of partial-suction spaces (19), which are each provided with one of the inflow ports (27; 227), are separated from one another and are connected upstream from the partial-suction spaces, and in that the accumulator (30; 130) is inserted into a second longitudinal bore, accommodating the outflow channel (23), of the pump housing (10) and contains a corresponding number of storage spaces (26; 126) which are each provided with one of the outflow ports (28), are separated from one another and are connected downstream from the partial-suction spaces (19), in which arrangement the cross-sections of flow of at least the inflow ports (27; 227), belonging to the flow divider (29; 129; 229), or of the storage spaces are designed for in each case a partial fuel flow, separated off from the inflowing fuel and necessary for uniform injection-quantity metering, to the associated partial-suction space (19), and a backflow of fuel into the inflow channel is thereby prevented.
2. Fuel injection pump according to Claim 1, characterized in that the flow divider (29; 129; 229) and the accumulator (30; 130) are contained in one tube (24; 124; 224) each, the tube containing the flow divider (29; 129; 229) being inserted into the longitudinal bore accommodating the inflow channel (22), and the tube (24; 124) containing the accumulator (30; 130) being inserted into a second longitudinal bore, accommodating the outflow channel (23), of the pump housing (10).
3. Fuel injection pump for internal-combustion engines, comprising a plurality of pump cylinders (12) arranged in a row in accommodation bores (11) of the pump housing (10), of which pump cylinders (12) each accommodates a pump plunger (16), driven by a camshaft, and provided with control edges (17, 20) for metering the injection quantity, and is surrounded by partial-suction spaces (19) which are connected to the pump cylinders (12) by means of transfer ports (18) controlled by the control edges (17, 20), and an inflow channel (22) and an outflow channel (23) which extend in the longitudinal direction of the pump housing (10) essentially parallel to the camshaft and transversely to the longitudinal axis of the pump cylinders (12) and are intended for the fuel flow to and from the partial-suction spaces (19), in which arrangement one separate inflow port (27) each leads off from the inflow channel (22) to each partial-suction space (19), which inflow port (27) belongs to a flow divider (29), and one separate outflow port (28) each leads out into the outflow channel (23) from each partial-suction space (19), which outflow port (28) belongs to an accumulator (30), characterized in that a tube (124) containing the flow divider (129) and the accumulator (30) is inserted into a longitudinal bore, accommodating the inflow channel (22) and the outflow channel (23), of the pump housing (10), which tube (124), for forming the flow divider, comprises a number of storage spaces (126), corresponding to the number of partial-suction spaces (19), which are separated from one another and are connected upstream from the partial-suction spaces (19) and, for forming the accumulator (130), a corresponding number of storage spaces (26; 126) which are separated from one another and are connected downstream from the partial-suction spaces (19), in which arrangement the cross-sections of flow of at least the inflow ports belonging to the flow divider, or of the storage spaces are designed for in each case a partial fuel flow, separated off from the inflowing fuel and necessary for uniform injection-quantity metering, to the associated partial-suction space (19), and a backflow of fuel into the inflow channel is thereby prevented.
4. Fuel injection pump according to Claim 3, characterized in that the one tube (124) containing the flow divider (129) and, at the same time also the accumulator is subdivided both in cross-section and in the longitudinal direction into chambers forming the storage spaces (126), as a result of which in each case the separate storage space (126) for the inflow and the storage space for the outflow of the fuel are allocated to each partial-suction space (19) (Fig. 4).
5. Fuel injection pump according to Claim 2, characterized in that both tubes (124) are subdivided into sections identical in cross-section and having chambers which are of different length and form the storage spaces (126), so that in each case the separate storage space (126), allocated to the flow divider (129) and connected to the inflow channel (22), for the inflow and the storage space (126), allocated to the accumulator (130) and connected to the outflow channel (23), for the outflow of the fuel are connected to each partial-suction space (19) (Figs. 4, 5a and 5b).
6. Fuel injection pump according to Claim 4 or 5, characterized in that the chambers, forming the storage spaces, in the interior of the tube (124) or the tubes are formed by multi-start helices, in which arrangement either a single helix turn, subdivided into two chambers, for the inflow and outflow or a helix turn for the inflow and a helix turn for the outflow of the fuel are allocated to each partial-suction space (19).
7. Fuel injection pump according to Claim 6, characterized in that the multi-start helices in the interior of the tubes (24) are made of fuel-resistant plastic.
8. Fuel injection pump according to Claim 2, characterized in that the two tubes (24) have pocket-like impressions (25) which divide or collect the inflowing and outflowing fuel flow, the pocket-like impressions (25) being of such proportions that they form in each case the storage space (26), connected upstream, of the flow divider (29) for the fuel, discharged in a controlled. manner, on the inflow side or the storage space (26), connected downstream, of the accumulator (30) on the outflow side (Figs. 1, 2, 3a and 3b).
9. Fuel injection pump according to Claim 2, characterized in that at least the one tube (224) allocated to the inflow channel (222) is made of a non-metallic material which is a poor conductor of heat, e.g. fuel-resistant plastic or ceramic (Fig. 6).
10. Fuel injection pump according to Claim 2 or 9, characterized in that the tube (224) allocated to the inflow channel (222) has pocket-like recesses (31) which tangentially adjoin each partial-suction space (19), are open towards the partial-suction space (19), are connected to one channel section (32) each of the inflow channel (222) in the tube (224) via one restricting inflow port (227) each and form the storage spaces (226) for fuel flowing back from the transfer port (18) of the pump cylinder (12), which storage spaces (226) are allocated to the flow divider (229) and are in each case connected upstream from one of the associated partial-suction spaces (19), an enlarged end area (226a) directed upstream being provided in the storage space (226), into which end area (226a) the respective inflow port leads.
11. Fuel injection pump according to Claim 10, characterized in that the channel sections (32) inside the tube (224) allocated to the inflow channel (222) form a stepped bore having one channel section (311, 322, 32z) each connected to each inflow port (2271, 2272, 227z), so that each of the channel sections (323) adjoining a preceding channel section (322) in the flow direction has a cross-section of flow reduced relative to the cross-section of flow of the preceding channel section, and in that the cross-section of flow of the last channel section (32z) furthest away from the inlet (222a) of the inflow channel (222) is at least the same as or larger than the cross-section of flow of the associated inflow port (227z).
12. Fuel injection pump according to Claim 10, characterized in that the channel sections (32) inside the tube (224) inserted into the inflow channel (222) form a stepped bore having one channel section (321, 322, 32z) each allocated to each inflow port (227i, 2272, 227z), in that each of the channel sections (323) adjoining a preceding channel section (322) in the flow direction has a cross-section of flow reduced relative to the cross-section of flow of the preceding channel section, in that the cross-section of flow of the respectively following inflow port (2272)-viewed in the flow direction from the inlet (222a) of the inflow channel (222)-is slightly larger relative to the cross-section of flow of the preceding inflow port (2271), and in that the cross-section of flow of the last channel section (32z) furthest away from the inlet (222a) of the inflow channel (222) is at least the same as or larger than the cross-section of flow of the associated inflow port (227z).
13. Fuel injection pump according to Claim 10, characterized in that the inner walls (31a) of the recesses (31), forming the storage spaces (226), of the tube (224) allocated to the inflow channel (222) are reinforced in each case by means of an erosion-resistant, preferably metallic lining (33).
14. Fuel injection pump according to one of Claims 9 to 13, characterized in that the tube (24) accommodating the outflow channel (23) is made of a material which is a good conductor of heat, preferably aluminium, and has pocket-like impressions (25) which tangentially adjoin each partial-suction space (19), form in each case one of the storage spaces (26), connected downstream from the associated partial-suction space (19), of the accumulator (30) and lead into the interior space of the tube (24) via the outflow port (28) located in an end area (26a) directed downstream.
15. Fuel injection pump according to Claim 14, characterized in that the tube (24) containing the outflow channel (23), in the opposite flow direction to the tube (224) accommodating the inflow channel (222), is inserted in such a way as to point with its outflow ports (28) to the housing section (10a) accommodating the inlet (222a) of the inflow channel (222).
EP85105451A 1984-05-09 1985-05-04 Fuel injection pump for internal-combustion engines Expired - Lifetime EP0167741B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85105451T ATE56790T1 (en) 1984-05-09 1985-05-04 FUEL INJECTION PUMP FOR COMBUSTION ENGINES.

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE3417036 1984-05-09
DE3417036 1984-05-09
DE19853509536 DE3509536A1 (en) 1984-05-09 1985-03-16 FUEL INJECTION PUMP FOR INTERNAL COMBUSTION ENGINES
DE3509536 1985-03-16

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EP0167741A1 EP0167741A1 (en) 1986-01-15
EP0167741B1 true EP0167741B1 (en) 1990-09-19

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EP (1) EP0167741B1 (en)
DE (2) DE3509536A1 (en)

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Publication number Priority date Publication date Assignee Title
DE3546222A1 (en) * 1985-12-27 1987-07-02 Bosch Gmbh Robert FUEL INJECTION PUMP FOR INTERNAL COMBUSTION ENGINES
DE3844430A1 (en) * 1988-12-31 1990-07-05 Bosch Gmbh Robert FUEL INJECTION PUMP FOR INTERNAL COMBUSTION ENGINES
FI93985C (en) * 1991-04-17 1995-06-26 Waertsilae Diesel Int Mounting and coupling arrangements for a fuel injection pump
GB9823025D0 (en) * 1998-10-22 1998-12-16 Lucas Ind Plc Fuel system
DE10000876A1 (en) * 2000-01-12 2001-07-19 Deutz Ag Fuel system for internal combustion engine has second fuel line connection of each individual pump connected via further line connection to third fuel line connector
DE60319968T2 (en) * 2003-06-20 2009-04-16 Delphi Technologies, Inc., Troy Fuel system
DE102011004993A1 (en) * 2011-03-02 2012-09-06 Robert Bosch Gmbh Valve device for switching or metering a fluid
EP2667012B1 (en) 2012-05-25 2017-02-22 Caterpillar Motoren GmbH & Co. KG Baffle body with a wear resistant insert element and baffle body for a plunger operated fuel pump

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FR822261A (en) * 1936-05-29 1937-12-24 Fuel injection pump
FR975113A (en) * 1942-02-05 1951-03-01 Daimler Benz Ag Fuel injection pump for internal combustion engines with overflow adjustment and guidance in currents in the same direction
FR2242575B1 (en) * 1973-09-05 1978-11-10 Sigma Diesel
FR2243345B1 (en) * 1973-09-12 1979-02-09 Sigma Diesel
DE2547071A1 (en) * 1975-10-21 1977-05-05 Motoren Turbinen Union IC engine fuel injection pump - in which plungers have surrounding chambers joined to outlet and inlet fuel channels
DE2900874C2 (en) * 1979-01-11 1985-11-14 Robert Bosch Gmbh, 7000 Stuttgart Fuel injection pump for internal combustion engines
GB2074252B (en) * 1980-04-08 1983-09-21 Lucas Industries Ltd Fuel injection pumping apparatus
DE3136751A1 (en) * 1981-09-16 1983-03-31 Robert Bosch Gmbh, 7000 Stuttgart FUEL INJECTION PUMP FOR INTERNAL COMBUSTION ENGINES
DE3136749A1 (en) * 1981-09-16 1983-03-31 Robert Bosch Gmbh, 7000 Stuttgart FUEL INJECTION PUMP FOR INTERNAL COMBUSTION ENGINES
DE3326045A1 (en) * 1983-07-20 1985-01-31 Robert Bosch Gmbh, 7000 Stuttgart FUEL INJECTION PUMP FOR INTERNAL COMBUSTION ENGINES

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US4640255A (en) 1987-02-03
DE3579761D1 (en) 1990-10-25
DE3509536A1 (en) 1985-11-14
EP0167741A1 (en) 1986-01-15

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