EP0091569A2 - Output regulator for a hydrostatic pump - Google Patents

Output regulator for a hydrostatic pump Download PDF

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Publication number
EP0091569A2
EP0091569A2 EP83102579A EP83102579A EP0091569A2 EP 0091569 A2 EP0091569 A2 EP 0091569A2 EP 83102579 A EP83102579 A EP 83102579A EP 83102579 A EP83102579 A EP 83102579A EP 0091569 A2 EP0091569 A2 EP 0091569A2
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EP
European Patent Office
Prior art keywords
pressure
pump
piston
line
acts
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP83102579A
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German (de)
French (fr)
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EP0091569A3 (en
EP0091569B1 (en
Inventor
Emil Knodel
Gerhard Dipl.-Ing. Nonnenmacher
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Robert Bosch GmbH
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Robert Bosch GmbH
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Publication of EP0091569B1 publication Critical patent/EP0091569B1/en
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04BPOSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/002Hydraulic systems to change the pump delivery
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04BPOSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B2201/00Pump parameters
    • F04B2201/12Parameters of driving or driven means
    • F04B2201/1203Power on the axis

Definitions

  • the invention is based on a power controller according to the preamble of the main claim.
  • a power controller according to the preamble of the main claim.
  • it is possible to place the operating points approximately on a hyperbola in a PQ diagram.
  • such a device has the disadvantage that points below the power hyperbola can only be controlled by means of auxiliary pressure, which can possibly lead to accidents, or that a lossy throttle must be arranged in the main flow.
  • the power controller according to the invention with the characterizing features of the main claim has the advantage that the pump can be reset via falling instead of rising control pressure. Points below the performance hyperbole can be targeted. With such a device the risk of accidents z. B. eliminated if the control pressure fails. In other losses are avoided by a common 'in the main conveyor line is arranged a throttle.
  • FIG. 1 shows a power control device with a variable displacement pump in a schematic illustration
  • FIG. 2 shows a second similar exemplary embodiment
  • FIG. 3 shows a detail.
  • 10 denotes a radial piston pump, the stroke ring 11 of which is set with the aid of two counteracting adjusting pistons 12, 13.
  • the actuating piston 12 has a much larger diameter than the actuating piston 13.
  • the radial piston pump 10 draws in pressure medium via a line 14 from a container 15 and conveys it into a delivery line 16.
  • a line 18 branches off from the delivery line 16 and leads to the pressure chamber 21 leads the actuating piston 13 receiving bore 20.
  • a line 22 continues from the delivery line 16, which leads to a control valve 23 which is designed as a 3/3-way valve with the switching positions I, II and III.
  • a line 25 extends from the control valve 23 and opens into the first pressure chamber 26 of a housing 27 into which a volumetric piston 28 is immersed.
  • a differential piston 30 Farther plunges into the pressure chamber 26 of the plunger 29 of a differential piston 30 which is guided in a bore 31 of the housing 27.
  • the piston part 30 has a much larger diameter than the plunger 29.
  • a pressure spring 32 acts on the piston part 30 and lies in the rear part of the bore 31 facing away from the plunger 29.
  • a line 35 opens, which starts from a line 37 connected to an auxiliary pump 36; the auxiliary pump sucks pressure medium from the container 15.
  • a preferably adjustable pressure relief valve 38 is arranged at the end of line 37, and a throttle 39 in line 37 behind the pump.
  • a line 40 leads from the control valve 23 to a pressure chamber 41 of a bore 42 which receives the actuating piston 12. Furthermore, a line 43 leads from the control valve 23 to the container 15.
  • Two pressure springs 45, 46 act on the control valve 23, which are shown symbolically in FIG. 1, but can be seen more clearly in FIG. 3. They act on the control slide 23 'of the control valve 23, one after the other.
  • the two springs 45, 46 are supported on a spring plate 47, which is fastened to a tracking rod 48, which supports itself again on the bottom of the actuating piston 12.
  • the control slide 23 ' is always in contact with the spring 45, but only after a certain adjustment path on the spring 46. These therefore come into engagement one after the other, which approximately results in a hyperbolic characteristic curve over pressure and volume. Such arrangements are known per se.
  • the tracking rod 48 penetrates through the hollow interior of the control slide 23 '.
  • an extension 50 to which the arm 51 of an angle lever 53 which is pivotable about a pivot point 52 fixed to the housing is articulated. At its end 53 'the volumetric flask 28 comes into contact.
  • the angle lever 53 has an extension 55 which interacts with a stop 56.
  • a similar stop 57 is located at the opposite end of the angle lever.
  • the control device works as follows: It is assumed that the larger-area actuating piston 12 has raised the stroke ring 11 of the pump and displaces pressure medium into the delivery line 16. The pressure prevailing in the delivery line propagates via line 18 into the pressure chamber 21 on the actuating piston 13, and via lines 22 and 25 to the pressure chamber 26 on the volumetric piston 28. It is further assumed that the auxiliary pump 36 delivers fully, as a result of which the differential piston 30 is pressed against the force of the spring 32 to the left and the plunger 29 now does not touch the measuring piston 28. Has the pressure in the delivery line 16 a certain one. Limit reached, then the angle lever 53 is pivoted by the force of the measuring piston 28 around the pivot 52 and brings the control valve 23 from its previous neutral position II to position III.
  • pressure medium can flow out of the pressure chamber 41 via the lines 40, 43 to the container 15.
  • the delivery pressure still prevails in the pressure chamber 21, so that the pump is now reset to a smaller delivery rate.
  • the springs 45 and 46 are tensioned more, and they return the control valve 23 to its neutral position II.
  • the angle lever 53 pushes the measuring piston 28 into its previous position.
  • the setpoint pressure generated in line 37 of auxiliary pump 36 depends on the cut-off pressure of pressure-limiting valve 38. If this control pressure is reduced compared to the normal value now present, e.g. B. by reducing the cut-off pressure at the pressure valve 38, then the pressure in the pressure chamber 33 falls. The spring 32 now presses the differential piston and thus its plunger 29 against the volumetric piston 28 and simulates a working pressure on this which is greater than that currently in the delivery line 16 ruling. As a result, the angle lever 53 is pivoted and the directional valve 23 is - as described above - adjusted so that the pump 10 is set to a smaller delivery rate. From this it can be seen that in the event of a failure or an arbitrary reduction in the control pressure in line 37, the resetting of the pump 10 takes place via falling instead of increasing control pressure. This can eliminate any possible risk of an accident.
  • the pump 10 is adjusted again the above performance hyperbole. This ensures that the pump 10 always adjusts to the smaller of the two setpoints from the working pressure in the delivery line 16 or control pressure in line 35. If the control pressure is reduced to a very low value or to zero, the force of the spring 32 on the differential piston and thus on the measuring piston 28 becomes so great that the pump is reset to zero.
  • the exemplary embodiment according to FIG. 2 differs from the previous one in that a line 60 branches off from the line 25 and leads to the end face of a 3/2-way valve 61 which is loaded by a spring 62 against this pressure force.
  • the directional control valve 61 is switched on in line 37.
  • the pressure in the line 37 from the control pressure prevailing in the conveying line 1 6 operating pressure can be influenced. If the latter has reached a certain size, the directional control valve 62 is switched from its flow position I to the position II, as a result of which pressure medium flows directly out of the line 37 to the container 15. As a result, the pressure in the pressure chamber 33 drops very quickly, so that the pump 10 is immediately reset (pressure cutoff).
  • the differential piston is also divided into a separate piston 30 'and a plunger 29' for manufacturing reasons.
  • the function remains the same as before.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)
  • Control Of Positive-Displacement Pumps (AREA)

Abstract

Der Leistungsregler nach Figur 1 dient für eine verstellbare Pumpe (10), die mit Hilfe zweier druckbeaufschlagter Stellkolben (12, 13) eingestellt wird. Von diesen wird wenigstens einer über ein Steuerventil (23) angesteuert, auf das einerseits zwei Federn (45, 46) einwirken, andererseits ein Hebel (53), auf den über einen Meßkolben (28) der Arbeitsdruck der Pumpe (10) einwirkt. Mit dem Meßkolben (28) wirkt auch ein Differentialkolben (29, 30) zusammen, der einerseits von einer Feder (32) belastet ist, andererseits von einem Steuerdruck, der von einer Hilfspumpe (36) erzeugt wird. Wird der Steuerdruck auf irgendeine Weise abgesenkt, dann wirkt die Feder (32) über den Differentialkolben derart auf den Meßkolben (28) ein, daß die Pumpe (10) zurückgestellt wird, d. h. dieser wird ein größerer als der von ihr erzeugte Arbeitsdruck simuliert. Auf diese Weise ist sichergestellt, daß sich die Pumpe (10) immer auf den kleineren der beiden Sollwerte aus Arbeits- bzw. Steuerdruck einstellt.The power regulator according to FIG. 1 is used for an adjustable pump (10) which is set with the aid of two pressurized control pistons (12, 13). At least one of these is controlled via a control valve (23), on which two springs (45, 46) act, on the one hand, and a lever (53) on which the working pressure of the pump (10) acts via a measuring piston (28). A differential piston (29, 30) interacts with the measuring piston (28) and is loaded on the one hand by a spring (32) and on the other hand by a control pressure generated by an auxiliary pump (36). If the control pressure is reduced in any way, then the spring (32) acts on the measuring piston (28) via the differential piston in such a way that the pump (10) is reset, i. H. this is simulated to be greater than the working pressure generated by it. This ensures that the pump (10) always adjusts to the smaller of the two setpoints from the working or control pressure.

Description

Stand der TechnikState of the art

Die Erfindung geht aus von einem Leistungsregler nach der Gattung des Hauptanspruchs. Mit einem derartigen bekannten Leistungsregler ist es möglich, die Arbeitspunkte angenähert auf eine Hyperbel in einem PQ-Diagramm zu legen. Eine derartige Einrichtung hat jedoch den Nachteil, daß Punkte unterhalb der Leistungshyperbel nur mittels Hilfsdruck angesteuert werden könnnen, was unter Umständen zu Unfällen führen kann, oder daß im Hauptstrom eine verlustbehaftete Drossel angeordnet werden muß.The invention is based on a power controller according to the preamble of the main claim. With such a known power regulator, it is possible to place the operating points approximately on a hyperbola in a PQ diagram. However, such a device has the disadvantage that points below the power hyperbola can only be controlled by means of auxiliary pressure, which can possibly lead to accidents, or that a lossy throttle must be arranged in the main flow.

Vorteile der ErfindungAdvantages of the invention

Der erfindungsgemäße Leistungsregler mit den kennzeichnenden Merkmalen des Hauptanspruchs hat demgegenüber den Vorteil, daß das Zurückstellen der Pumpe über fallenden anstatt über steigenden Steuerdruck möglich ist. Es können gezielt Punkte unterhalb der Leistungshyperbel angefahren werden. Durch eine derartige Einrichtung wird die Unfallgefahr z. B. bei Ausfallen des Steuerdrucks beseitigt. Im übrigen werden Verluste durch eine häufig' in der Haupt-Förderleitung angeordnete Drossel vermieden.The power controller according to the invention with the characterizing features of the main claim has the advantage that the pump can be reset via falling instead of rising control pressure. Points below the performance hyperbole can be targeted. With such a device the risk of accidents z. B. eliminated if the control pressure fails. In other losses are avoided by a common 'in the main conveyor line is arranged a throttle.

Durch die in den Unteransprüchen aufgeführten Maßnahmen sind Weiterbildungen der im Hauptanspruch angegebenen Merkmale möglich.The measures listed in the subclaims allow further developments of the features specified in the main claim.

Zeichnungdrawing

Zwei Ausführungsbeispiele der Erfindung sind in der Zeichnung dargestellt und in der nachfolgenden Beschreibung näher erläutert. Es zeigen Figur 1 eine Leistungsregeleinrichtung mit Verstellpumpe in schematischer Darstellung, Figur 2 ein zweites ähnliches Ausführungsbeispiel, Figur 3 eine Einzelheit .Two embodiments of the invention are shown in the drawing and explained in more detail in the following description. FIG. 1 shows a power control device with a variable displacement pump in a schematic illustration, FIG. 2 shows a second similar exemplary embodiment, and FIG. 3 shows a detail.

Beschreibung des ErfindungsbeispielsDescription of the invention example

In Figur 1 ist mit 10 ein Radialkolbenpumpe bezeichnet, deren Hubring 11 mit Hilfe zweier einander entgegenwirkender Stellkolben 12, 13 eingestellt wird. Der Stellkolben 12 hat einen wesentlich größeren Durchmesser als der Stellkolben 13. Die Radialkolbenpumpe 10 saugt Druckmittel über eine Leitung 14 aus einem Behälter 15 an und fördert dieses in eine Förderleitung 16. Von der Förderleitung 16 zweigt eine Leitung 18 ab, welche zum Druckraum 21 einer den Stellkolben 13 aufnehmenden Bohrung 20 führt. Von der Förderleitung 16 geht weiterhin eine Leitung 22 aus, die an ein Steuerventil 23 führt, das als 3/3-Wegeventil mit den Schaltstellungen I, II und III ausgebildet ist. Vom Steuerventil 23 geht eine Leitung 25 aus, die im ersten Druckraum 26 eines Gehäuses 27 mündet, in den ein Meßkolben 28 eintaucht. Weiterhin taucht in den Druckraum 26 der Stößel 29 eines Differentialkolbens 30 ein, der in. einer Bohrung 31 des Gehäuses 27 geführt ist. Der Kolbenteil 30 hat einen wesentlich größeren Durchmesser als der Stößel 29. Auf den Kolbenteil 30 wirkt eine Druckfeder 32 ein, die im hinteren, dem Stößel 29 abgewandten Teil der Bohrung 31 liegt. In den vorderen Teil der Bohrung 31, der als Druckraum 33 bezeichnet ist, mündet eine Leitung 35, die von einer an eine Hilfspumpe 36 angeschlossene Leitung 37 ausgeht; die Hilfspumpe saugt Druckmittel aus dem Behälter 15 an. Am Ende der Leitung 37 ist ein vorzugsweise verstellbares Druckbegrenzungsventil 38 angeordnet, in der Leitung 37 hinter der Pumpe eine Drossel 39.In FIG. 1, 10 denotes a radial piston pump, the stroke ring 11 of which is set with the aid of two counteracting adjusting pistons 12, 13. The actuating piston 12 has a much larger diameter than the actuating piston 13. The radial piston pump 10 draws in pressure medium via a line 14 from a container 15 and conveys it into a delivery line 16. A line 18 branches off from the delivery line 16 and leads to the pressure chamber 21 leads the actuating piston 13 receiving bore 20. A line 22 continues from the delivery line 16, which leads to a control valve 23 which is designed as a 3/3-way valve with the switching positions I, II and III. A line 25 extends from the control valve 23 and opens into the first pressure chamber 26 of a housing 27 into which a volumetric piston 28 is immersed. Farther plunges into the pressure chamber 26 of the plunger 29 of a differential piston 30 which is guided in a bore 31 of the housing 27. The piston part 30 has a much larger diameter than the plunger 29. A pressure spring 32 acts on the piston part 30 and lies in the rear part of the bore 31 facing away from the plunger 29. In the front part of the bore 31, which is referred to as the pressure chamber 33, a line 35 opens, which starts from a line 37 connected to an auxiliary pump 36; the auxiliary pump sucks pressure medium from the container 15. A preferably adjustable pressure relief valve 38 is arranged at the end of line 37, and a throttle 39 in line 37 behind the pump.

Vom Steuerventil 23 führt eine Leitung 40 zu einem Druckraum 41 einer Bohrung 42, die den Stellkolben 12 aufnimmt. Weiterhin führt vom Steuerventil 23 eine Leitung 43 zum Behälter 15.A line 40 leads from the control valve 23 to a pressure chamber 41 of a bore 42 which receives the actuating piston 12. Furthermore, a line 43 leads from the control valve 23 to the container 15.

Auf das Steuerventil 23 wirken zwei Druckfedern 45, 46 ein, die in Figur 1 symbolisch dargestellt , jedoch in Figur 3 deutlicher zu erkennen sind. Sie wirken auf den Steuerschieber 23' des Steuerventils 23 ein, und zwar nacheinander. Die beiden Federn 45, 46 stützen sich .an einem Federteller 47 ab, der an einer Nachführstange 48 befestigt ist, die sich selbst wieder am Boden des Stellkolbens 12 abstützt. Der Steuerschieber 23' liegt stets an der Feder 45 an, jedoch erst nach einem bestimmten Verstellweg an der Feder 46. Diese kommen also nacheinander in Eingriff, woraus sich angenähert ein Hyperbelkennlinie über Druck und Volumen ergibt. Derartige Anordnungen sind an sich bekannt. Die Nachführstange 48 dringt durch das hohle Innere des Steuerschiebers 23'.Two pressure springs 45, 46 act on the control valve 23, which are shown symbolically in FIG. 1, but can be seen more clearly in FIG. 3. They act on the control slide 23 'of the control valve 23, one after the other. The two springs 45, 46 are supported on a spring plate 47, which is fastened to a tracking rod 48, which supports itself again on the bottom of the actuating piston 12. The control slide 23 'is always in contact with the spring 45, but only after a certain adjustment path on the spring 46. These therefore come into engagement one after the other, which approximately results in a hyperbolic characteristic curve over pressure and volume. Such arrangements are known per se. The tracking rod 48 penetrates through the hollow interior of the control slide 23 '.

Am Steuerventil'23 und der Pumpe abgewandt befindet sich ein Fortsatz 50, an dem der Arm 51 eines um einen gehäusefesten Drehpunkt 52 schwenkbaren Winkelhebels 53 angelenkt ist. An dessen Ende 53' legt sich der Meßkolben 28 an. Der Winkelhebel 53 hat eine Verlängerung 55, die mit einem Anschlag 56 zusammenwirkt. Ein ähnlicher Anschlag 57 befindet sich am gegenüberliegenden Ende des Winkelhebels.On the control valve 23 and facing away from the pump there is an extension 50 to which the arm 51 of an angle lever 53 which is pivotable about a pivot point 52 fixed to the housing is articulated. At its end 53 'the volumetric flask 28 comes into contact. The angle lever 53 has an extension 55 which interacts with a stop 56. A similar stop 57 is located at the opposite end of the angle lever.

Die Regeleinrichtung arbeitet wie folgt: Es sei angenommen, daß der flächengrößere Stellkolben 12 den Hubring 11 der Pumpe ausgestellt hat und diese in die Förderleitung 16 Druckmittel verdrängt. Der in der Förderleitung herrschende Druck pflanzt sich über die Leitung 18 in den Druckraum 21 am Stellkolben 13 fort, sowie über die Leitungen 22 und 25 zum Druckraum 26 am Meßkolben 28. Es sei weiterhin angenommen, daß die Hilfspumpe 36 voll fördere, wodurch der Differentialkolben 30 entgegen der Kraft der Feder 32 nach links gedrückt wird und der Stößel 29 nun den Meßkolben 28 nicht berührt. Hat der Druck in der Förderleitung 16 einen bestimmten. Grenzwert erreicht, dann wird der Winkelhebel 53 durch die Kraft des Meßkolbens 28 um.den Drehpunkt 52 verschwenkt und bringt das Steuerventil 23 von seiner vorherigen Neutralstellung II in die Stellung III. Dadurch kann Druckmittel aus dem Druckraum 41 über die Leitungen 40, 43 zum Behälter 15 abströmen. Im Druckraum 21 herrscht nach wie vor der Förderdruck, so daß die Pumpe nun auf kleinere Fördermenge zurückgestellt wird. Dadurch werden die Federn 45 und 46 stärker gespannt, und sie stellen das Steuerventil 23 wieder in seine Neutralstellung II. Der Winkelhebel 53 schiebt dabei den Meßkolben 28 in seine vorherige Lage.The control device works as follows: It is assumed that the larger-area actuating piston 12 has raised the stroke ring 11 of the pump and displaces pressure medium into the delivery line 16. The pressure prevailing in the delivery line propagates via line 18 into the pressure chamber 21 on the actuating piston 13, and via lines 22 and 25 to the pressure chamber 26 on the volumetric piston 28. It is further assumed that the auxiliary pump 36 delivers fully, as a result of which the differential piston 30 is pressed against the force of the spring 32 to the left and the plunger 29 now does not touch the measuring piston 28. Has the pressure in the delivery line 16 a certain one. Limit reached, then the angle lever 53 is pivoted by the force of the measuring piston 28 around the pivot 52 and brings the control valve 23 from its previous neutral position II to position III. As a result, pressure medium can flow out of the pressure chamber 41 via the lines 40, 43 to the container 15. The delivery pressure still prevails in the pressure chamber 21, so that the pump is now reset to a smaller delivery rate. As a result, the springs 45 and 46 are tensioned more, and they return the control valve 23 to its neutral position II. The angle lever 53 pushes the measuring piston 28 into its previous position.

Fällt umgekehrt der Druck, dann bringen die Druckfedern 45 und/oder 46 das Steuerventil 23 in seine Schaltstellung I, so daß nun Druckmittel über die Leitungen 22 und 40 in den Druckraum 41 eindringen kann und die Pumpe 10 wieder auf größere Fördermenge einstellt. Dadurch sinkt die Kraft der Federn 45 und 46, der Meßkolben 28 verschwenkt den Winkelhebel 53, und dieser bringt das Steuerventil 23 wieder in seine Neutralstellung II. Durch die Anordnung der beiden nacheinander in Eingriff kommenden Druckfedern 45, 46 erhält man eine angenäherte Leistungshyperbel in einem PQ-Diagramm.Conversely, if the pressure drops, then the pressure springs 45 and / or 46 bring the control valve 23 into its switching position I, so that pressure medium can now enter the pressure chamber 41 via the lines 22 and 40 and the pump 10 adjusts to a larger delivery rate. As a result, the force of the springs 45 and 46 decreases, the measuring piston 28 pivots the angle lever 53, and this brings the control valve 23 back into its neutral position II PQ diagram.

Der in der Leitung 37 der Hilfspumpe 36 erzeugte Solldruck hängt ab vom Abschaltdruck des Druckbegrenzungsventils 38. Wird dieser Steuerdruck gegenüber dem jetzt vorliegenden Nörmalwert reduziert, z. B. durch Verminderung des Abschaltdrucks am Druckventil 38, dann fällt der Druck im Druckraum 33. Die Feder 32 drückt nun den Differentialkolben und damit dessen Stößel 29 gegen den Meßkolben 28 und simuliert an diesem einen Arbeitsdruck, der größer ist als der momentan in der Förderleitung 16 herrschende. Dadurch wird der Winkelhebel 53 verschwenkt, und das Wegeventil 23 wird - wie weiter oben beschrieben - so eingestellt, daß die Pumpe 10 auf kleinere Fördermenge eingestellt wird. Daraus ist zu erkennen, daß bei Ausfall oder willkürlicher Reduzierung des Steuerdrucks in der Leitung 37 das Rückstellen der Pumpe 10 über fallenden statt über steigenden Steuerdruck erfolgt. Hierdurch kann eine eventuell gegebene Unfallgefahr beseitigt werden.The setpoint pressure generated in line 37 of auxiliary pump 36 depends on the cut-off pressure of pressure-limiting valve 38. If this control pressure is reduced compared to the normal value now present, e.g. B. by reducing the cut-off pressure at the pressure valve 38, then the pressure in the pressure chamber 33 falls. The spring 32 now presses the differential piston and thus its plunger 29 against the volumetric piston 28 and simulates a working pressure on this which is greater than that currently in the delivery line 16 ruling. As a result, the angle lever 53 is pivoted and the directional valve 23 is - as described above - adjusted so that the pump 10 is set to a smaller delivery rate. From this it can be seen that in the event of a failure or an arbitrary reduction in the control pressure in line 37, the resetting of the pump 10 takes place via falling instead of increasing control pressure. This can eliminate any possible risk of an accident.

Ergibt der tatsächlich in der Förderleitung 16 herrschende Arbeitsdruck eine höhere Kraft auf den Meßkolben 28 als es durch die Wirkung von Federkraft 32 minus Steuerdruck 35 entspricht, folgt die Einstellung der Pumpe 10 wieder der oben genannten Leistungshyperbel. Damit ist sichergestellt, daß sich die Pumpe 10 immer auf den kleineren der beiden Sollwerte aus Arbeitsdruck in der Förderleitung 16 bzw. Steuerdruck in der Leitung 35 einstellt. Wird der Steuerdruck auf einen sehr niedrigen Wert oder auf Null abgesenkt, wird die Kraft der Feder 32 auf den Differentialkolben und damit auf den Meßkolben 28 so groß, daß die Pumpe nach Null zurückgestellt wird.If the working pressure actually prevailing in the delivery line 16 results in a higher force on the measuring piston 28 than corresponds to the action of spring force 32 minus control pressure 35, the pump 10 is adjusted again the above performance hyperbole. This ensures that the pump 10 always adjusts to the smaller of the two setpoints from the working pressure in the delivery line 16 or control pressure in line 35. If the control pressure is reduced to a very low value or to zero, the force of the spring 32 on the differential piston and thus on the measuring piston 28 becomes so great that the pump is reset to zero.

Das Ausführungsbeispiel nach Figur 2 unterscheidet sich von dem vorhergehenden dadurch, daß nun von der Leitung 25 eine Leitung 60 abzweigt, die an die Stirnseite eines 3/2-Wegeventils 61 führt, das entgegen dieser Druckkraft von einer Feder 62 belastet ist. Das Wegeventil 61 ist in die Leitung 37 eingeschaltet.The exemplary embodiment according to FIG. 2 differs from the previous one in that a line 60 branches off from the line 25 and leads to the end face of a 3/2-way valve 61 which is loaded by a spring 62 against this pressure force. The directional control valve 61 is switched on in line 37.

Bei diesem Ausführungsbeispiel kann der in der Leitung 37 herrschende Steuerdruck von dem in der Förderleitung 16 herrschenden Betriebsdruck beeinflußt werden. Hat letzterer eine gewisse Größe erreicht, so wird das Wegeventil 62 von seiner Durchflußstellung I in die Stellung II geschaltet, wodurch Druckmittel unmittelbar aus der Leitung 37 zum Behälter 15 abströmt. Dadurch sinkt der Druck im Druckraum 33 sehr schnell, so daß die Pumpe 10 sofort zurückgestellt wird (Druckabschneidung).In this embodiment, the pressure in the line 37 from the control pressure prevailing in the conveying line 1 6 operating pressure can be influenced. If the latter has reached a certain size, the directional control valve 62 is switched from its flow position I to the position II, as a result of which pressure medium flows directly out of the line 37 to the container 15. As a result, the pressure in the pressure chamber 33 drops very quickly, so that the pump 10 is immediately reset (pressure cutoff).

In diesem Ausführungsbeispiel ist außerdem der Differentialkolben aus fertigungstechnischen Gründen in einen getrennten Kolben 30' und einen Stößel 29' aufgeteilt. Die Funktion bleibt dadurch dieselbe wie zuvor.In this embodiment, the differential piston is also divided into a separate piston 30 'and a plunger 29' for manufacturing reasons. The function remains the same as before.

Claims (5)

1. Leistungsregler für eine hydrostatische Pumpe, deren hubveränderndes Glied mit Hilfe mindestens eines druckbeaufschlagten Kolbens entgegen einer Gegenkraft eingestellt wird, der von einem Ventil (23) gesteuert wird, auf das einerseits zwei Federn einwirken, andererseits eine dem Förderdruck proportionale Kraft über einen von diesem beaufschlagten Meßkolben und einen Hebel, dadurch gekennzeichnet, daß auf den Meßkolben (28) über ein Zwischenglied (29, 30) in derselben Wirkrichtung wie der Förderdruck zusätzlich eine Feder (32) einwirkt, und daß auf das Zwischenglied entgegen der Feder ein veränderbarer Steuerdruck aus einer zweiten Druckmittelquelle (36) einwirkt.1. Power regulator for a hydrostatic pump, the stroke-changing member of which is adjusted with the aid of at least one pressurized piston against a counterforce, which is controlled by a valve (23) on which, on the one hand, two springs act and, on the other hand, a force proportional to the delivery pressure via one of these acted upon piston and a lever, characterized in that a spring (32) acts on the measuring piston (28) via an intermediate member (29, 30) in the same direction of action as the delivery pressure, and that a variable control pressure acts on the intermediate member against the spring a second pressure medium source (36) acts. 2. Regler nach Anspruch 1, dadurch gekennzeichnet, daß das Zwischenglied ein Differentialkolben ist, auf dessen Ringfläche der Steuerdruck der zweiten Druckmittelquelle (36) einwirkt.2. Regulator according to claim 1, characterized in that the intermediate member is a differential piston, on the annular surface of which the control pressure of the second pressure medium source (36) acts. 3. Regler nach Anspruch 1 und/oder 2, dadurch gekennzeichnet, daß die Druckmittelquelle eine Hilfspumpe ist, an die parallel zum Zwischenglied ein Druckbegrenzungsventil (38) angeschlossen ist.3. Controller according to claim 1 and / or 2, characterized in that the pressure medium source is an auxiliary pump to which a pressure relief valve (38) is connected in parallel to the intermediate member. 4. Regler nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß in die Leitung der Hilfspumpe eine Drossel (39) eingeschaltet ist.4. Controller according to one of claims 1 to 3, characterized in that a throttle (39) is switched on in the line of the auxiliary pump. 5. Regler nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß dem Druckbegrenzungsventil (38) ein vom Arbeitsdruck der verstellbaren Pumpe beaufschlagtes Abschaltventil (61) vorgeschaltet ist, das Verbindung herzustellen vermag von der Förderleitung der Hilfspumpe (36) zum Behälter.5. Controller according to one of claims 1 to 4, characterized in that the pressure relief valve (38) is preceded by a shut-off valve (61) acted upon by the working pressure of the adjustable pump, which is able to establish the connection from the delivery line of the auxiliary pump (36) to the container.
EP83102579A 1982-04-10 1983-03-16 Output regulator for a hydrostatic pump Expired EP0091569B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3213377 1982-04-10
DE19823213377 DE3213377A1 (en) 1982-04-10 1982-04-10 PERFORMANCE CONTROLLER FOR A HYDROSTATIC PUMP

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EP0091569A2 true EP0091569A2 (en) 1983-10-19
EP0091569A3 EP0091569A3 (en) 1985-06-19
EP0091569B1 EP0091569B1 (en) 1987-07-15

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EP83102579A Expired EP0091569B1 (en) 1982-04-10 1983-03-16 Output regulator for a hydrostatic pump

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US (1) US4509902A (en)
EP (1) EP0091569B1 (en)
DE (2) DE3213377A1 (en)

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GB2215491A (en) * 1988-01-29 1989-09-20 Drum Eng Co Ltd Pump apparatus for discharging liquid

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DE3340332C2 (en) * 1983-11-08 1988-11-10 Hydromatik GmbH, 7915 Elchingen Power control device for a hydrostatic drive with flow rate adjustment
US4711616A (en) * 1984-12-13 1987-12-08 Nippondenso Co., Ltd. Control apparatus for a variable displacement pump
ITBO20030528A1 (en) * 2003-09-12 2005-03-13 Pierburg Spa PUMPING SYSTEM USING A PALETTE PUMP
US8123492B2 (en) * 2004-09-20 2012-02-28 Magna Powertrain Inc. Speed-related control mechanism for a pump and control method

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DE2208877A1 (en) * 1972-02-25 1973-09-13 Handtmann Metallguss Albert REGULATING DEVICE FOR REGULATING THE DELIVERY PRESSURE OF REGULAR PUMPS BY CHANGING THE DELIVERY QUANTITY
DE3200885A1 (en) * 1982-01-14 1983-07-21 Robert Bosch Gmbh, 7000 Stuttgart Output regulator for a hydrostatic pump

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2215491A (en) * 1988-01-29 1989-09-20 Drum Eng Co Ltd Pump apparatus for discharging liquid

Also Published As

Publication number Publication date
DE3372523D1 (en) 1987-08-20
US4509902A (en) 1985-04-09
EP0091569A3 (en) 1985-06-19
DE3213377A1 (en) 1983-10-13
EP0091569B1 (en) 1987-07-15

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