EP4367381A1 - Pump, in particular fuel injection pump - Google Patents
Pump, in particular fuel injection pumpInfo
- Publication number
- EP4367381A1 EP4367381A1 EP22731211.3A EP22731211A EP4367381A1 EP 4367381 A1 EP4367381 A1 EP 4367381A1 EP 22731211 A EP22731211 A EP 22731211A EP 4367381 A1 EP4367381 A1 EP 4367381A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- pump
- lifting rod
- stop surface
- cylinder bore
- medium
- 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.)
- Pending
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 27
- 238000002347 injection Methods 0.000 title claims abstract description 11
- 239000007924 injection Substances 0.000 title claims abstract description 11
- 230000001050 lubricating effect Effects 0.000 claims abstract description 11
- 238000000926 separation method Methods 0.000 claims abstract description 8
- 238000002485 combustion reaction Methods 0.000 description 4
- 238000007789 sealing Methods 0.000 description 4
- 239000012530 fluid Substances 0.000 description 3
- 238000011161 development Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
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
- F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
- F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
- F02M59/442—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston means preventing fuel leakage around pump plunger, e.g. fluid barriers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
- F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
- F04B1/0404—Details or component parts
- F04B1/0448—Sealing means, e.g. for shafts or housings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
- F04B53/14—Pistons, piston-rods or piston-rod connections
- F04B53/144—Adaptation of piston-rods
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
- F04B53/14—Pistons, piston-rods or piston-rod connections
- F04B53/144—Adaptation of piston-rods
- F04B53/146—Piston-rod guiding arrangements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
- F04B53/16—Casings; Cylinders; Cylinder liners or heads; Fluid connections
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
- F02M2200/16—Sealing of fuel injection apparatus not otherwise provided for
Definitions
- the invention relates to a pump, in particular a fuel injection pump.
- Fuel injection pumps are used to supply an internal combustion engine with fuel. With the help of the internal combustion engine, for example, a vehicle can be driven.
- EP 1 722 098 A1 discloses a fuel injection pump with a piston that is guided in a cylinder so that it can move back and forth. Due to the movements of the piston, fuel is sucked into a pump work chamber and then compressed.
- a suitable engine can, for example, comprise a camshaft with a cam on which the piston is supported at its end facing away from the pump working chamber. The rotary movement of the camshaft is then converted into a linear movement of the piston. The provision can be effected with the help of the spring force of a piston spring. Irrespective of the specific design of the engine, the piston must be guided into the engine chamber, which is pressurized with a lubricating medium when the fuel injection pump is in operation. Since fuel is not usually used as a lubricating medium, measures must be taken to ensure media separation. For example, an annular sealing element can be arranged in the area of the guide of the piston.
- the object of the present invention is to reduce the loads on a rod seal used in a pump, in particular in a fuel injection pump, for media separation. As a result, the robustness and thus the service life of the pump should be increased in this way.
- the proposed pump in particular a fuel injection pump, includes a housing part with a cylinder bore in which a lifting rod is accommodated so that it can move back and forth.
- a rod seal is integrated into the cylinder bore for media separation, in particular for separating the fuel as the first medium from a lubricating medium as the second medium.
- the housing part forms a first stop surface which limits the stroke of the lifting rod and which interacts with a second stop surface formed on the lifting rod to form a stop.
- At least one relief groove is formed in at least one stop surface, via which the cylinder bore is connected to a medium-carrying pressure chamber when the lifting rod comes to rest on the stop surface of the housing part.
- a medium that is located between the two stop surfaces can escape into the medium-carrying pressure chamber via the at least one relief groove when the lifting rod reaches the stop.
- the at least one relief groove counteracts the formation of a fluid build-up in the stop area and in front of the rod seal within the cylinder bore.
- the at least one relief groove therefore leads to a Relief of the rod seal. Relieving the rod seal not only increases the life of the seal itself, but also increases the life of the pump.
- the relieving effect of the at least one relief groove increases with the size of the stop surfaces, since the displacement volume also increases with the size of the stop surfaces.
- the stop that the two stop surfaces form together can be a stop that defines an upper or lower dead center of the lifting rod.
- the medium that escapes into the medium-carrying pressure chamber via the at least one relief groove can in particular be the fuel to be injected.
- the at least one relief groove preferably runs radially in relation to a longitudinal axis of the cylinder bore and/or the lifting rod. If the at least one relief groove is formed in the stop surface of the housing part, it preferably runs radially in relation to the longitudinal axis A of the housing part. If the at least one relief groove is formed in the stop surface of the lifting rod, it preferably runs radially in relation to the longitudinal axis A of the lifting rod. Since the lifting rod is ideally aligned coaxially to the cylinder bore, the respective longitudinal axes coincide on a common longitudinal axis A. The radial course of the at least one relief groove corresponds to the shortest connection between the cylinder bore and the media-carrying pressure chamber, so that the medium located between the stop surfaces is at the shortest is displaced away into the pressure chamber.
- a plurality of relief grooves are arranged at the same angular distance from one another, for example in the shape of a cross or star, in at least one of the two stop surfaces.
- the arrangement at the same angular distance from one another leads to a uniform displacement of the medium located in the stop area into the medium-carrying pressure chamber, so that no pressure cushion can build up between the stop surfaces.
- the at least one relief groove can have an angular, for example triangular or quadrangular, trapezoidal or round cross-section.
- the Angular cross-sectional shape has the advantage that it is particularly easy to produce in a material-removing process and allows large flow cross-sections.
- the round cross-sectional shape is above all optimized for flow.
- the stop surface of the lifting rod is formed on an annular collar of the lifting rod, which is formed by a change in diameter of the lifting rod or by a separate body arranged on the lifting rod.
- the annular collar is firmly connected to the lifting rod, so that it can interact with the stop surface of the housing part to form a stop.
- the stop face of the housing part is formed on a plateau surrounding the cylinder bore.
- the at least one relief groove can then be created by a corresponding clearance in the plateau, so that it is easy to produce.
- the plateau preferably has a circular basic shape that is concentric with respect to the cylinder bore. In this way, an annular stop surface surrounding the cylinder bore is created, which has the same width all the way round and is only interrupted by the at least one relief groove.
- the medium-carrying pressure chamber with which the cylinder bore is connected via the at least one relief groove, is acted upon with fuel as the first medium during operation of the pump.
- the stop is therefore preferably arranged on the fuel side of the cylinder bore.
- the fuel can in particular be the fuel to be injected.
- the rod seal integrated into the cylinder bore prevents the fuel in the pressure chamber from mixing with another medium on the other side of the cylinder bore, in particular with a lubricating medium for lubricating an engine of the pump.
- the end of the cylinder bore facing away from the stop surface opens into a pressure chamber which is acted upon by a lubricating medium during operation of the pump.
- the fuel and the lubricating medium can be permanently and safely separated. This is because by providing the at least one relief groove in at least one stop surface, a fluid build-up in front of the rod seal and thus an increased load on the rod seal due to pressure peaks can be avoided.
- FIG. 1 shows a schematic longitudinal section through a pump according to the invention in the area of a rod seal integrated into a cylinder bore for media separation
- FIGS. 1 and 2 shows a schematic plan view of the housing part of the pump of FIGS. 1 and 2 having the cylinder bore
- the pump 1 shown in FIG. 1 can in particular be a fuel injection pump, with the aid of which fuel can be injected into a combustion chamber of an internal combustion engine.
- the pump 1 shown comprises a housing part 2 with a cylinder bore 3 in which a lifting rod 4 is accommodated or guided so that it can move back and forth.
- a first section of the lifting rod 4 dips into a first pressure chamber 9 to which a first medium, for example fuel, is applied when the pump 1 is in operation.
- a second section of the lifting rod 4 dips beyond the cylinder bore 3 into a second pressure chamber 12 which, when the pump 1 is in operation, is acted upon by another medium, for example a lubricating medium.
- a rod seal 5 is integrated into the cylinder bore 3 for reliable media separation.
- the housing part 2 forms a plateau 11 surrounding the cylinder bore 3 with a stop surface 6 which interacts with a stop surface 7 formed on an annular collar 10 of the lifting rod 4 to form a stop. If the lifting rod 4 moves in the direction of the stop while the pump 1 is in operation, fluid may accumulate in the stop area and within the cylinder bore 3 . The pressure peaks that occur lead to a high load on the rod seal 5, so that the sealing effect is endangered. In order to prevent this, the stop face 6 of the housing part 2 has a number of relief grooves 8 which are formed by openings in the plateau 11 . If the lifting rod 4 comes to rest against the stop, medium present between the stop surfaces 6 , 7 can escape into the pressure chamber 9 via the relief grooves 8 .
- the relief grooves 8 can be arranged in a cross shape and each extend radially outwards from the cylinder bore 3 .
- FIG. 2 shows four relief grooves 8 by way of example. However, the number can also be fewer than four, for example two or three, or more than four, for example five or six.
- any groove cross section can be selected. Exemplary embodiments are shown in FIGS. 3a) to 3c), with FIG. 3a) showing a round cross section, FIG. 3b) showing a square cross section and FIG. 3c) showing a trapezoidal cross section.
- the at least one relief groove 8 can also be formed in the stop surface 7 of the annular collar 10 of the lifting rod 4.
- the reference number 7 is therefore given in brackets after the reference number 6.
- the reference number 10 is given in brackets behind the reference number 11 .
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Fuel-Injection Apparatus (AREA)
Abstract
The invention relates to a pump (1), in particular a fuel injection pump, comprising a housing part (2) having a cylindrical bore (3) in which a reciprocating rod (4) is received so as to be movable back and forth, wherein a rod seal (5) is integrated into the cylindrical bore (3) for media separation, in particular for separating the fuel as first medium from a lubricating medium as second medium. According to the invention, the housing part (2) forms a first stop surface (6) which limits the stroke of the reciprocating rod (4) and which interacts in a stop-forming manner with a second stop surface (7) formed on the reciprocating rod (4), wherein at least one stop surface (6, 7) has at least one relief groove (8) formed therein, via which the cylindrical bore (3) is connected to a media-conducting pressure chamber (9) when the reciprocating rod (4) comes into contact with the stop surface (6) of the housing part (2).
Description
Beschreibung description
Titel: Title:
Pumpe, insbesondere Kraftstoffeinspritzpumpe Pump, in particular fuel injection pump
Die Erfindung betrifft eine Pumpe, insbesondere eine Kraftstoffeinspritzpumpe. Kraftstoffeinspritzpumpen dienen der Versorgung einer Brennkraftmaschine mit Kraftstoff. Mit Hilfe der Brennkraftmaschine kann beispielsweise ein Fahrzeug angetrieben werden. The invention relates to a pump, in particular a fuel injection pump. Fuel injection pumps are used to supply an internal combustion engine with fuel. With the help of the internal combustion engine, for example, a vehicle can be driven.
Stand der Technik State of the art
Aus der EP 1 722 098 Al geht beispielhaft eine Kraftstoffeinspritzpumpe mit einem Kolben hervor, der in einem Zylinder hin und her beweglich geführt ist. Durch die Bewegungen des Kolbens wird Kraftstoff in einen Pumpenarbeitsraum angesaugt und anschließend verdichtet. For example, EP 1 722 098 A1 discloses a fuel injection pump with a piston that is guided in a cylinder so that it can move back and forth. Due to the movements of the piston, fuel is sucked into a pump work chamber and then compressed.
Die Bewegungen des Kolbens erfordern ein Triebwerk. Ein geeignetes Triebwerk kann beispielsweise eine Nockenwelle mit einem Nocken umfassen, an dem der Kolben an seinem dem Pumpenarbeitsraum abgewandten Ende abgestützt ist. Die Drehbewegung der Nockenwelle wird dann in eine lineare Bewegung des Kolbens umgesetzt. Die Rückstellung kann mit Hilfe der Federkraft einer Kolbenfeder bewirkt werden. Unabhängig von der konkreten Ausführung des Triebwerks muss der Kolben bis in den Triebwerksraum geführt werden, der im Betrieb der Kraftstoffeinspritzpumpe mit einem Schmiermedium beaufschlagt wird. Da in der Regel kein Kraftstoff als Schmiermedium eingesetzt wird, müssen Maßnahmen ergriffen werden, die eine Medientrennung sicherstellen. Beispielsweise kann im Bereich der Führung des Kolbens ein ringförmiges Dichtelement angeordnet werden. Da dieses über die Bewegungen des Kolbens dynamisch belastet wird, ist ein besonders robustes Dichtelement vorzusehen. Üblicherweise werden daher sogenannte Stangendichtungen eingesetzt.
Ausgehend von dem vorstehend genannten Stand der Technik liegt der vorliegenden Erfindung die Aufgabe zugrunde, die Belastungen einer in einer Pumpe, insbesondere in einer Kraftstoffeinspritzpumpe, zur Medientrennung eingesetzten Stangendichtung zu verringern. Im Ergebnis soll auf diese Weise die Robustheit und damit die Lebensdauer der Pumpe gesteigert werden. The movements of the piston require an engine. A suitable engine can, for example, comprise a camshaft with a cam on which the piston is supported at its end facing away from the pump working chamber. The rotary movement of the camshaft is then converted into a linear movement of the piston. The provision can be effected with the help of the spring force of a piston spring. Irrespective of the specific design of the engine, the piston must be guided into the engine chamber, which is pressurized with a lubricating medium when the fuel injection pump is in operation. Since fuel is not usually used as a lubricating medium, measures must be taken to ensure media separation. For example, an annular sealing element can be arranged in the area of the guide of the piston. Since this is dynamically loaded by the movements of the piston, a particularly robust sealing element must be provided. So-called rod seals are therefore usually used. Proceeding from the prior art mentioned above, the object of the present invention is to reduce the loads on a rod seal used in a pump, in particular in a fuel injection pump, for media separation. As a result, the robustness and thus the service life of the pump should be increased in this way.
Zur Lösung der Aufgabe wird die Pumpe mit den Merkmalen des Anspruchs 1 vorgeschlagen. Vorteilhafte Weiterbildungen der Erfindung sind den Unteransprüchen zu entnehmen. To solve the problem, the pump with the features of claim 1 is proposed. Advantageous developments of the invention can be found in the dependent claims.
Offenbarung der Erfindung Disclosure of Invention
Die vorgeschlagene Pumpe, insbesondere Kraftstoffeinspritzpumpe, umfasst ein Gehäuseteil mit einer Zylinderbohrung, in der eine Hubstange hin und her beweglich aufgenommen ist. In die Zylinderbohrung ist zur Medientrennung, insbesondere zur Trennung des Kraftstoffs als erstem Medium von einem Schmiermedium als zweitem Medium, eine Stangendichtung integriert. Erfindungsgemäß bildet das Gehäuseteil eine den Hub der Hubstange begrenzende erste Anschlagfläche aus, die mit einer an der Hubstange ausgebildeten zweiten Anschlagfläche anschlagbildend zusammenwirkt. In zumindest einer Anschlagfläche ist dabei mindestens eine Entlastungsnut ausgebildet, über welche die Zylinderbohrung mit einem medienführenden Druckraum verbunden ist, wenn die Hubstange zur Anlage an der Anschlagfläche des Gehäuseteils gelangt. The proposed pump, in particular a fuel injection pump, includes a housing part with a cylinder bore in which a lifting rod is accommodated so that it can move back and forth. A rod seal is integrated into the cylinder bore for media separation, in particular for separating the fuel as the first medium from a lubricating medium as the second medium. According to the invention, the housing part forms a first stop surface which limits the stroke of the lifting rod and which interacts with a second stop surface formed on the lifting rod to form a stop. At least one relief groove is formed in at least one stop surface, via which the cylinder bore is connected to a medium-carrying pressure chamber when the lifting rod comes to rest on the stop surface of the housing part.
Über die mindestens eine Entlastungsnut kann ein Medium, das sich zwischen den beiden Anschlagflächen befindet, in den medienführenden Druckraum entweichen, wenn die Hubstange den Anschlag erreicht. Die mindestens eine Entlastungsnut wirkt auf diese Weise der Ausbildung eines Fluidstaus im Anschlagbereich sowie vor der Stangendichtung innerhalb der Zylinderbohrung entgegen. Das heißt, dass mit Hilfe der mindestens einen Entlastungsnut hohe Druckspitzen innerhalb der Zylinderbohrung vermieden werden, welche die Dichtfunktion und die Lebensdauer der Stangendichtung negativ beeinflussen könnten. Die mindestens eine Entlastungsnut führt demzufolge zu einer
Entlastung der Stangendichtung. Die Entlastung der Stangendichtung führt nicht nur zu einer erhöhten Lebensdauer der Dichtung selbst, sondern ferner zu einer erhöhten Lebensdauer der Pumpe. Die entlastende Wirkung der mindestens einen Entlastungsnut steigt mit der Größe der Anschlagflächen, da mit der Größe der Anschlagflächen auch das Verdrängervolumen größer wird. A medium that is located between the two stop surfaces can escape into the medium-carrying pressure chamber via the at least one relief groove when the lifting rod reaches the stop. In this way, the at least one relief groove counteracts the formation of a fluid build-up in the stop area and in front of the rod seal within the cylinder bore. This means that with the aid of the at least one relief groove, high pressure peaks within the cylinder bore, which could adversely affect the sealing function and the service life of the rod seal, are avoided. The at least one relief groove therefore leads to a Relief of the rod seal. Relieving the rod seal not only increases the life of the seal itself, but also increases the life of the pump. The relieving effect of the at least one relief groove increases with the size of the stop surfaces, since the displacement volume also increases with the size of the stop surfaces.
Bei dem Anschlag, den die beiden Anschlagflächen gemeinsam ausbilden, kann es sich um einen Anschlag handeln, der einen oberen oder unteren Totpunkt der Hubstange definiert. Bei dem Medium, das über die mindestens eine Entlastungsnut in den medienführenden Druckraum entweicht, kann es sich insbesondere um den einzuspritzenden Kraftstoff handeln. The stop that the two stop surfaces form together can be a stop that defines an upper or lower dead center of the lifting rod. The medium that escapes into the medium-carrying pressure chamber via the at least one relief groove can in particular be the fuel to be injected.
Die mindestens eine Entlastungsnut verläuft bevorzugt radial in Bezug auf eine Längsachse der Zylinderbohrung und/oder der Hubstange. Sofern die mindestens eine Entlastungsnut in der Anschlagfläche des Gehäuseteils ausgebildet ist, verläuft sich vorzugsweise radial in Bezug auf die Längsachse A des Gehäuseteils. Sofern die mindestens eine Entlastungsnut in der Anschlagfläche der Hubstange ausgebildet ist, verläuft sie vorzugsweise radial in Bezug auf die Längsachse A der Hubstange. Da im Idealfall die Hubstange koaxial zur Zylinderbohrung ausgerichtet ist, fallen die jeweiligen Längsachsen zusammen auf eine gemeinsame Längsachse A. Der radiale Verlauf der mindestens einen Entlastungsnut entspricht der kürzesten Verbindung zwischen der Zylinderbohrung und dem medienführenden Druckraum, so dass zwischen den Anschlagflächen befindliches Medium auf kürzestem Weg in den Druckraum verdrängt wird. The at least one relief groove preferably runs radially in relation to a longitudinal axis of the cylinder bore and/or the lifting rod. If the at least one relief groove is formed in the stop surface of the housing part, it preferably runs radially in relation to the longitudinal axis A of the housing part. If the at least one relief groove is formed in the stop surface of the lifting rod, it preferably runs radially in relation to the longitudinal axis A of the lifting rod. Since the lifting rod is ideally aligned coaxially to the cylinder bore, the respective longitudinal axes coincide on a common longitudinal axis A. The radial course of the at least one relief groove corresponds to the shortest connection between the cylinder bore and the media-carrying pressure chamber, so that the medium located between the stop surfaces is at the shortest is displaced away into the pressure chamber.
Vorteilhafterweise sind mehrere Entlastungsnuten in gleichem Winkelabstand zueinander, beispielsweise kreuz- oder sternförmig, in zumindest einer der beiden Anschlagflächen angeordnet. Die Anordnung im gleichen Winkelabstand zueinander führt zu einer gleichmäßigen Verdrängung des im Anschlagbereich befindlichen Mediums in den medienführenden Druckraum, so dass sich zwischen den Anschlagflächen kein Druckpolster aufbauen kann. Advantageously, a plurality of relief grooves are arranged at the same angular distance from one another, for example in the shape of a cross or star, in at least one of the two stop surfaces. The arrangement at the same angular distance from one another leads to a uniform displacement of the medium located in the stop area into the medium-carrying pressure chamber, so that no pressure cushion can build up between the stop surfaces.
Die mindestens eine Entlastungsnut kann einen eckigen, beispielsweise drei- oder viereckigen, einen trapezförmigen oder runden Querschnitt aufweisen. Die
eckige Querschnittsform besitzt den Vorteil, dass sie in einem materialabtragenden Verfahren besonders einfach herzustellen ist und große Strömungsquerschnitte ermöglicht. Die runde Querschnittsform ist vor allem strömungsoptimiert. The at least one relief groove can have an angular, for example triangular or quadrangular, trapezoidal or round cross-section. the Angular cross-sectional shape has the advantage that it is particularly easy to produce in a material-removing process and allows large flow cross-sections. The round cross-sectional shape is above all optimized for flow.
Gemäß einer bevorzugten Ausführungsform der Erfindung ist die Anschlagfläche der Hubstange an einem Ringbund der Hubstange ausgebildet, der durch einen Durchmesssersprung der Hubstange oder durch einen auf der Hubstange angeordneten separaten Körper ausgebildet wird. Der Ringbund ist in jedem Fall fest mit der Hubstange verbunden, so dass er anschlagbildend mit der Anschlagfläche des Gehäuseteils Zusammenwirken kann. Die gebaute Ausführung besitzt den Vorteil, dass die Herstellung der Hubstange sowie die Montage der Pumpe vereinfacht werden. According to a preferred embodiment of the invention, the stop surface of the lifting rod is formed on an annular collar of the lifting rod, which is formed by a change in diameter of the lifting rod or by a separate body arranged on the lifting rod. In any case, the annular collar is firmly connected to the lifting rod, so that it can interact with the stop surface of the housing part to form a stop. The built design has the advantage that the manufacture of the lifting rod and the assembly of the pump are simplified.
Gemäß einer weiteren bevorzugten Ausführungsform der Erfindung ist die Anschlagfläche des Gehäuseteils an einem die Zylinderbohrung umgebenden Plateau ausgebildet. Die mindestens eine Entlastungsnut kann dann durch eine entsprechende Freistellung im Plateau geschaffen werden, so dass sie einfach herzustellen ist. Das Plateau weist vorzugsweise eine kreisförmige Grundform auf, die konzentrisch in Bezug auf die Zylinderbohrung angeordnet ist. Auf diese Weise wird eine die Zylinderbohrung umgebende ringförmige Anschlagfläche geschaffen, die umlaufend die gleiche Breite aufweist und nur durch die mindestens eine Entlastungsnut unterbrochen wird. According to a further preferred embodiment of the invention, the stop face of the housing part is formed on a plateau surrounding the cylinder bore. The at least one relief groove can then be created by a corresponding clearance in the plateau, so that it is easy to produce. The plateau preferably has a circular basic shape that is concentric with respect to the cylinder bore. In this way, an annular stop surface surrounding the cylinder bore is created, which has the same width all the way round and is only interrupted by the at least one relief groove.
Des Weiteren wird vorgeschlagen, dass der medienführende Druckraum, mit dem die Zylinderbohrung über die mindestens eine Entlastungsnut verbunden ist, im Betrieb der Pumpe mit Kraftstoff als erstem Medium beaufschlagt ist. Der Anschlag ist demnach bevorzugt auf der Kraftstoffseite der Zylinderbohrung angeordnet. Bei dem Kraftstoff kann es sich insbesondere um den einzuspritzenden Kraftstoff handeln. Die in die Zylinderbohrung integrierte Stangendichtung verhindert, dass sich der im Druckraum befindliche Kraftstoff mit einem anderen Medium auf der anderen Seite der Zylinderbohrung, insbesondere mit einem Schmiermedium zur Schmierung eines Triebwerks der Pumpe mischt.
In Weiterbildung der Erfindung wird daher vorgeschlagen, dass die Zylinderbohrung an Ihrem der Anschlagfläche abgewandten Ende in einen Druckraum mündet, der im Betrieb der Pumpe mit einem Schmiermedium beaufschlagt ist. Mit Hilfe der in die Zylinderbohrung integrierten Stangedichtung können der Kraftstoff und das Schmiermedium dauerhaft sicher getrennt werden. Denn durch Vorsehen der mindestens einen Entlastungsnut in zumindest einer Anschlagfläche kann ein Fluidstau vor der Stangendichtung und damit eine erhöhte Belastung der Stangendichtung durch Druckspitzen vermieden werden. Furthermore, it is proposed that the medium-carrying pressure chamber, with which the cylinder bore is connected via the at least one relief groove, is acted upon with fuel as the first medium during operation of the pump. The stop is therefore preferably arranged on the fuel side of the cylinder bore. The fuel can in particular be the fuel to be injected. The rod seal integrated into the cylinder bore prevents the fuel in the pressure chamber from mixing with another medium on the other side of the cylinder bore, in particular with a lubricating medium for lubricating an engine of the pump. In a further development of the invention, it is therefore proposed that the end of the cylinder bore facing away from the stop surface opens into a pressure chamber which is acted upon by a lubricating medium during operation of the pump. With the help of the rod seal integrated in the cylinder bore, the fuel and the lubricating medium can be permanently and safely separated. This is because by providing the at least one relief groove in at least one stop surface, a fluid build-up in front of the rod seal and thus an increased load on the rod seal due to pressure peaks can be avoided.
Bevorzugte Ausführungsformen der Erfindung werden nachfolgend anhand der beigefügten Zeichnungen näher erläutert. Diese zeigen: Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings. These show:
Fig. 1 einen schematischen Längsschnitt durch eine erfindungsgemäße Pumpe im Bereich einer in eine Zylinderbohrung integrierten Stangendichtung zur Medientrennung, 1 shows a schematic longitudinal section through a pump according to the invention in the area of a rod seal integrated into a cylinder bore for media separation,
Fig. 2 eine schematische Draufsicht auf das die Zylinderbohrung aufweisende Gehäuseteil der Pumpe der Fig. 1 und 2 shows a schematic plan view of the housing part of the pump of FIGS. 1 and 2 having the cylinder bore
Fig. 3 a) bis c) verschiedene Querschnittsformen einer Entlastungsnut für eine erfindungsgemäße Pumpe. 3 a) to c) different cross-sectional shapes of a relief groove for a pump according to the invention.
Ausführliche Beschreibung der Zeichnungen Detailed description of the drawings
Bei der in der Figur 1 dargestellten Pumpe 1 kann es sich insbesondere um eine Kraftstoffeinspritzpumpe handeln, mit deren Hilfe Kraftstoff in einen Brennraum einer Brennkraftmaschine einspritzbar ist. Die dargestellte Pumpe 1 umfasst ein Gehäuseteil 2 mit einer Zylinderbohrung 3, in der eine Hubstange 4 hin und her beweglich aufgenommen bzw. geführt ist. Ein erster Abschnitt der Hubstange 4 taucht dabei in einen ersten Druckraum 9 ein, der im Betrieb der Pumpe 1 mit einem ersten Medium, beispielsweise Kraftstoff, beaufschlagt ist. Ein zweiter Abschnitt der Hubstange 4 taucht jenseits der Zylinderbohrung 3 in einen zweiten Druckraum 12 ein, der im Betrieb der Pumpe 1 mit einem weiteren Medium, beispielsweise einem Schmiermedium, beaufschlagt ist. Zur sicheren Medientrennung ist in die Zylinderbohrung 3 eine Stangendichtung 5 integriert.
Das Gehäuseteil 2 bildet ein die Zylinderbohrung 3 umgebendes Plateau 11 mit einer Anschlagfläche 6 aus, die mit einer an einem Ringbund 10 der Hubstange 4 ausgebildeten Anschlagfläche 7 anschlagbildend zusammenwirkt. Führt die Hubstange 4 im Betrieb der Pumpe 1 eine Bewegung in Richtung des Anschlags aus, kann es zu einem Fluidstau im Anschlagbereich sowie innerhalb der Zylinderbohrung 3 kommen. Die dabei auftretenden Druckspitzen führen zu einer hohen Belastung der Stangendichtung 5, so dass die Dichtwirkung gefährdet ist. Um dies zu verhindern, weist die Anschlagfläche 6 des Gehäuseteils 2 mehrere Entlastungsnuten 8 auf, die durch Freistellungen im Plateau 11 ausgebildet werden. Gelangt die Hubstange 4 zur Anlage am Anschlag, kann zwischen den Anschlagflächen 6, 7 vorhandenes Medium über die Entlastungsnuten 8 in den Druckraum 9 entweichen. The pump 1 shown in FIG. 1 can in particular be a fuel injection pump, with the aid of which fuel can be injected into a combustion chamber of an internal combustion engine. The pump 1 shown comprises a housing part 2 with a cylinder bore 3 in which a lifting rod 4 is accommodated or guided so that it can move back and forth. A first section of the lifting rod 4 dips into a first pressure chamber 9 to which a first medium, for example fuel, is applied when the pump 1 is in operation. A second section of the lifting rod 4 dips beyond the cylinder bore 3 into a second pressure chamber 12 which, when the pump 1 is in operation, is acted upon by another medium, for example a lubricating medium. A rod seal 5 is integrated into the cylinder bore 3 for reliable media separation. The housing part 2 forms a plateau 11 surrounding the cylinder bore 3 with a stop surface 6 which interacts with a stop surface 7 formed on an annular collar 10 of the lifting rod 4 to form a stop. If the lifting rod 4 moves in the direction of the stop while the pump 1 is in operation, fluid may accumulate in the stop area and within the cylinder bore 3 . The pressure peaks that occur lead to a high load on the rod seal 5, so that the sealing effect is endangered. In order to prevent this, the stop face 6 of the housing part 2 has a number of relief grooves 8 which are formed by openings in the plateau 11 . If the lifting rod 4 comes to rest against the stop, medium present between the stop surfaces 6 , 7 can escape into the pressure chamber 9 via the relief grooves 8 .
Wie beispielhaft in der Figur 2 dargestellt, können die Entlastungsnuten 8 kreuzförmig angeordnet sein und sich jeweils von der Zylinderbohrung 3 nach radial außen erstrecken. Figur 2 zeigt beispielhaft vier Entlastungsnuten 8. Die Anzahl kann aber auch weniger als vier, beispielsweise zwei oder drei, oder mehr als vier, beispielsweise fünf oder sechs, betragen. Ferner kann ein beliebiger Nutquerschnitt gewählt werden. Ausführungsbeispiele sind in den Figuren 3a) bis 3c) gezeigt, wobei Figur 3a) einen runden Querschnitt, die Figur 3b) einen viereckigen Querschnitt und die Figur 3c) einen trapezförmigen Querschnitt zeigen. As shown by way of example in FIG. 2, the relief grooves 8 can be arranged in a cross shape and each extend radially outwards from the cylinder bore 3 . FIG. 2 shows four relief grooves 8 by way of example. However, the number can also be fewer than four, for example two or three, or more than four, for example five or six. Furthermore, any groove cross section can be selected. Exemplary embodiments are shown in FIGS. 3a) to 3c), with FIG. 3a) showing a round cross section, FIG. 3b) showing a square cross section and FIG. 3c) showing a trapezoidal cross section.
Alternativ zu den Darstellungen der Figuren 1 bis 3 kann die mindestens eine Entlastungsnut 8 auch in der Anschlagfläche 7 des Ringbunds 10 der Hubstange 4 ausgebildet sein. In den Figuren 2 und 3 ist daher das Bezugszeichen 7 in Klammern hinter dem Bezugszeichen 6 angegeben. Analog ist in der Figur 2 hinter dem Bezugszeichen 11 das Bezugszeichen 10 in Klammern angegeben.
As an alternative to the illustrations in FIGS. 1 to 3, the at least one relief groove 8 can also be formed in the stop surface 7 of the annular collar 10 of the lifting rod 4. In FIGS. 2 and 3, the reference number 7 is therefore given in brackets after the reference number 6. Similarly, in FIG. 2, the reference number 10 is given in brackets behind the reference number 11 .
Claims
1. Pumpe (1), insbesondere Kraftstoffeinspritzpumpe, umfassend ein Gehäuseteil (2) mit einer Zylinderbohrung (3), in der eine Hubstange (4) hin und her beweglich aufgenommen ist, wobei in die Zylinderbohrung (3) zur Medientrennung, insbesondere zur Trennung des Kraftstoffs als erstem Medium von einem Schmiermedium als zweitem Medium, eine Stangendichtung (5) integriert, dadurch gekennzeichnet, dass das Gehäuseteil (2) eine den Hub der Hubstange (4) begrenzende erste Anschlagfläche (6) ausbildet, die mit einer an der Hubstange (4) ausgebildeten zweiten Anschlagfläche (7) anschlagbildend zusammenwirkt, wobei in zumindest einer Anschlagfläche (6, 7) mindestens eine Entlastungsnut (8) ausgebildet ist, über welche die Zylinderbohrung (3) mit einem medienführenden Druckraum (9) verbunden ist, wenn die Hubstange (4) zur Anlage an der Anschlagfläche (6) des Gehäuseteils (2) gelangt. 1. A pump (1), in particular a fuel injection pump, comprising a housing part (2) with a cylinder bore (3) in which a lifting rod (4) is accommodated so that it can move back and forth, being inserted into the cylinder bore (3) for media separation, in particular for separation of the fuel as the first medium from a lubricating medium as the second medium, a rod seal (5) is integrated, characterized in that the housing part (2) forms a first stop surface (6) which limits the stroke of the lifting rod (4) and which has a stop surface on the lifting rod (4) formed second stop surface (7) interacts to form a stop, at least one relief groove (8) being formed in at least one stop surface (6, 7), via which the cylinder bore (3) is connected to a media-carrying pressure chamber (9) when the Lifting rod (4) comes to rest on the stop surface (6) of the housing part (2).
2. Pumpe (1) nach Anspruch 1, dadurch gekennzeichnet, dass die mindestens eine Entlastungsnut (8) radial in Bezug auf eine Längsachse (A) der Zylinderbohrung (3) und/oder der Hubstange (4) verläuft. 2. Pump (1) according to claim 1, characterized in that the at least one relief groove (8) extends radially in relation to a longitudinal axis (A) of the cylinder bore (3) and/or the lifting rod (4).
3. Pumpe (1) nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass mehrere Entlastungsnuten (8) in gleichem Winkelabstand zueinander, beispielsweise kreuz- oder sternförmig, in zumindest einer der beiden Anschlagflächen (6, 7) angeordnet sind. 3. Pump (1) according to claim 1 or 2, characterized in that a plurality of relief grooves (8) are arranged at the same angular distance from one another, for example in a cross or star shape, in at least one of the two stop surfaces (6, 7).
4. Pumpe (1) nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die mindestens eine Entlastungsnut (8) einen eckigen, beispielsweise drei- oder viereckigen, einen trapezförmigen oder runden Querschnitt aufweist.
4. Pump (1) according to one of the preceding claims, characterized in that the at least one relief groove (8) has an angular, for example triangular or quadrangular, a trapezoidal or round cross-section.
5. Pumpe (1) nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Anschlagfläche (7) der Hubstange (4) an einem Ringbund (10) der Hubstange (4) ausgebildet ist, der durch einen Durchmesssersprung der Hubstange (4) oder durch einen auf der Hubstange (4) angeordneten separaten Körper ausgebildet wird. 5. Pump (1) according to one of the preceding claims, characterized in that the stop surface (7) of the lifting rod (4) is formed on an annular collar (10) of the lifting rod (4) which is caused by a change in diameter of the lifting rod (4) or is formed by a separate body arranged on the lifting rod (4).
6. Pumpe (1) nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Anschlagfläche (6) des Gehäuseteils (2) an einem die Zylinderbohrung (3) umgebenden Plateau (11) ausgebildet ist. 6. Pump (1) according to one of the preceding claims, characterized in that the stop surface (6) of the housing part (2) is formed on a plateau (11) surrounding the cylinder bore (3).
7. Pumpe (1) nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der medienführende Druckraum (9), mit dem die Zylinderbohrung (3) über die mindestens eine Entlastungsnut (8) verbunden ist, im Betrieb der Pumpe (1) mit Kraftstoff als erstem Medium beaufschlagt ist. 7. Pump (1) according to one of the preceding claims, characterized in that the media-carrying pressure chamber (9), with which the cylinder bore (3) is connected via the at least one relief groove (8), during operation of the pump (1) with fuel is acted upon as the first medium.
8. Pumpe (1) nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Zylinderbohrung (3) an Ihrem der Anschlagfläche (6) abgewandten Ende in einen Druckraum (12) mündet, der im Betrieb der Pumpe (1) mit einem Schmiermedium beaufschlagt ist.
8. Pump (1) according to one of the preceding claims, characterized in that the cylinder bore (3) at its end facing away from the stop surface (6) opens into a pressure chamber (12) which acts upon the operation of the pump (1) with a lubricating medium is.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102021207001.9A DE102021207001A1 (en) | 2021-07-05 | 2021-07-05 | Pump, in particular fuel injection pump |
PCT/EP2022/064850 WO2023280482A1 (en) | 2021-07-05 | 2022-06-01 | Pump, in particular fuel injection pump |
Publications (1)
Publication Number | Publication Date |
---|---|
EP4367381A1 true EP4367381A1 (en) | 2024-05-15 |
Family
ID=82100135
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP22731211.3A Pending EP4367381A1 (en) | 2021-07-05 | 2022-06-01 | Pump, in particular fuel injection pump |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP4367381A1 (en) |
JP (1) | JP2024522883A (en) |
KR (1) | KR20240026235A (en) |
CN (1) | CN117616195A (en) |
DE (1) | DE102021207001A1 (en) |
WO (1) | WO2023280482A1 (en) |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4098738B2 (en) | 2004-03-05 | 2008-06-11 | ボッシュ株式会社 | Fuel injection pump for internal combustion engines |
JP4825842B2 (en) * | 2008-06-09 | 2011-11-30 | トヨタ自動車株式会社 | Fuel pump |
DE102015201444A1 (en) * | 2015-01-28 | 2016-07-28 | Robert Bosch Gmbh | High pressure pump for conveying a medium |
DE102019208445A1 (en) * | 2019-06-11 | 2020-12-17 | Robert Bosch Gmbh | High pressure fuel pump |
-
2021
- 2021-07-05 DE DE102021207001.9A patent/DE102021207001A1/en active Pending
-
2022
- 2022-06-01 EP EP22731211.3A patent/EP4367381A1/en active Pending
- 2022-06-01 CN CN202280047926.9A patent/CN117616195A/en active Pending
- 2022-06-01 JP JP2023579491A patent/JP2024522883A/en active Pending
- 2022-06-01 KR KR1020247003655A patent/KR20240026235A/en unknown
- 2022-06-01 WO PCT/EP2022/064850 patent/WO2023280482A1/en active Application Filing
Also Published As
Publication number | Publication date |
---|---|
KR20240026235A (en) | 2024-02-27 |
CN117616195A (en) | 2024-02-27 |
WO2023280482A1 (en) | 2023-01-12 |
JP2024522883A (en) | 2024-06-21 |
DE102021207001A1 (en) | 2023-01-05 |
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