WO2010040708A1 - Hydraulic system for a user of a steering system - Google Patents

Hydraulic system for a user of a steering system Download PDF

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Publication number
WO2010040708A1
WO2010040708A1 PCT/EP2009/062889 EP2009062889W WO2010040708A1 WO 2010040708 A1 WO2010040708 A1 WO 2010040708A1 EP 2009062889 W EP2009062889 W EP 2009062889W WO 2010040708 A1 WO2010040708 A1 WO 2010040708A1
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WO
WIPO (PCT)
Prior art keywords
pressure
valve
hydraulic system
steering
pressure medium
Prior art date
Application number
PCT/EP2009/062889
Other languages
German (de)
French (fr)
Inventor
Johann Merz
Original Assignee
Zf Lenksysteme Gmbh
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Zf Lenksysteme Gmbh filed Critical Zf Lenksysteme Gmbh
Priority to EP09783732A priority Critical patent/EP2331827A1/en
Publication of WO2010040708A1 publication Critical patent/WO2010040708A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
    • B62D5/062—Details, component parts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
    • F04C14/18—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber
    • F04C14/22—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members
    • F04C14/223—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members using a movable cam
    • F04C14/226—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members using a movable cam by pivoting the cam around an eccentric axis
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
    • F15B11/05—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive
    • F15B11/055—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive by adjusting the pump output or bypass
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2/00—Rotary-piston machines or pumps
    • F04C2/30—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members
    • F04C2/34—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members
    • F04C2/344—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member
    • F04C2/3441—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation
    • F04C2/3442—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation the surfaces of the inner and outer member, forming the working space, being surfaces of revolution
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2270/00—Control; Monitoring or safety arrangements
    • F04C2270/18—Pressure
    • F04C2270/185—Controlled or regulated
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2270/00—Control; Monitoring or safety arrangements
    • F04C2270/20—Flow
    • F04C2270/205—Controlled or regulated
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/2053—Type of pump
    • F15B2211/20546—Type of pump variable capacity
    • F15B2211/20553—Type of pump variable capacity with pilot circuit, e.g. for controlling a swash plate
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/255—Flow control functions

Definitions

  • the invention relates to a hydraulic system with a stroke-controlled rotary pump for generating a pressure medium flow for a consumer of a steering system or an active chassis of a vehicle, according to the preamble of claim 1.
  • hydraulic systems with lift and volume flow controlled pump for a consumer such as a hydraulic power steering system of a vehicle, have a pilot operated pressure regulator, such as a flow control valve for a constant pressure medium flow.
  • a first valve chamber or high-pressure chamber of the flow control valve is fluidly connected via a first control line upstream of a first diaphragm in a supply line for the consumer.
  • a second valve chamber or low-pressure chamber of the flow control valve has in its interior a compression spring and is separated by a spring-loaded in the direction of the first valve chamber control piston, wherein the second valve chamber is connected via a second control line on the downstream side of the first panel to the supply line.
  • the control piston is adjusted in response to the pressure difference at an orifice in the second control line to dissipate a portion of the pressure medium from the supply line, or to control a pressurized actuator actuator for a cam ring of the rotary pump and thereby by the flow rate of the pressure medium to the consumer approximately to keep constant.
  • the disadvantage is that with this control method only a fixed predetermined valve characteristic and a defined manual torque curve on a steering handle is possible. An influencing a one of the driving speed of a vehicle, for example, dependent manual torque curve is not possible. Another disadvantage is that the rotary pump has to promote against a high idling pressure when not steered.
  • the invention has for its object to provide a hydraulic system with a constant current control, the pressure is regulated in terms of improving the energy balance.
  • the consumer-side pressurization of the control piston by a controllable pressure relief valve in the control piston or in a steering valve the hydraulic system preferably in the detuning of the pressure compensator formed by the control piston so changed in terms of the pressure of the pressure medium that both a constant current control, a maximum pressure limit and a very wide lowering of the pressure at low power consumption of the consumer and / or the rotary pump is possible.
  • the control piston moves in the direction of the second valve chamber or low pressure chamber and causes a discharge of pressure fluid from the first valve chamber into a pressure fluid reservoir and return to the rotary pump or an adjustment of a cam ring or the like, the stroke of Rotary pump determined.
  • the pressure relief valve may be formed as a controlled pressure relief valve and be controlled hydraulically, mechanically or electrically or electronically. It may be part of a hydraulic power steering system of a vehicle and regulate a pressure medium flow for a steering valve and a hydraulic actuator of the power steering. It is expedient to control the pressure relief valve in response to a, set to a steering handle of the vehicle steering angle or steering torque - such as when the steering angle is set to 0 °, preferably from 0 ° to ⁇ 3.5 °, thereby driving straight ahead of the vehicle the power consumption of the rotary pump is minimized.
  • there is the possibility of lowering the pressure as a function of the driving speed so that e.g. at low driving speed as in a parking operation of the vehicle, the pressure is increased and at high driving speed of the vehicle, the pressure is lowered.
  • the steering valve may have a closed or an open center, wherein in a steering valve with a closed center by installing a diaphragm some pressure fluid quiescent current may be passed through the steering valve to the response behavior of the control device when suddenly changing the steering angle - setpoint at the To improve the steering handle.
  • the flow control valve with pressure relief valve assumes a dual function, since the pressure medium for a
  • a hydraulic system according to the invention can preferably be used for consumers who are provided in vehicle chassis and are dependent on low energy consumption and high response speed.
  • Such a hydraulic system can be used advantageously in suspension systems as well as in stabilizers - such as in anti-roll bars - for vehicles.
  • Fig. 1 is a schematic diagram of a hydraulic system with electrically operated pressure relief valve of a hydraulic power steering.
  • FIG. 1st shows a cross section through a rotary pump with flow control valve of the hydraulic system in Fig. 1st
  • a hydraulic circuit 1 is shown in a schematic circuit diagram, which comprises a rotary pump 2 designed as an adjustable vane pump 18.
  • the hydraulic system 1 serves to supply pressure medium in a supply line 8 to a steering valve 13 designed as a rotary slide valve valve and a load 3 of a hydraulic power steering system 16 designed as a hydraulic servomotor 15.
  • a flow control valve 4 is arranged in a housing 19 of the vane pump 18, which serves to set the delivery rate of the pressure medium to a desired value.
  • the flow control valve 4 is executed in the figures 1 and 2 with a working as a pressure compensating control piston 10 which separates a first valve chamber 5 from a second valve chamber 9 and is slidably disposed in a bore of the flow control valve 4.
  • the first valve chamber 5 is fluidically connected via a first control line 6 upstream of a first aperture 7 in the supply line 8 to the supply line 8.
  • the second valve chamber 9 is connected via a second control line 1 1 downstream of the first aperture 7 to the supply line 8.
  • a second aperture 20 is disposed in the second control line 1 1 and generates a pressure difference to the second valve chamber 9.
  • a third Aperture 33 in the second control line 1 1 provides as a constant aperture for the constant pressure medium flow.
  • the control piston 10 is spring-loaded by a spring 21 in the second valve chamber 9 in the direction of the first valve chamber 5 and moves when a limit pressure is exceeded against the spring load of this spring 21. He acts on an adjusting device 12 for the flow control of the rotary pump 2 so that the delivery rate is reduced and so overall a constant flow rate is achieved.
  • the vane pump 18 has a variable stroke and, as shown in the exemplary embodiment, is suitable, for example, as a delivery unit in an external power or power steering system of a motor vehicle.
  • the vane pump 18 consists essentially of the housing 19, in which a cam ring 23 is arranged displaceably or pivotably in a recess which is defined by its walls 22. Eccentrically to the cam ring 23, a rotor 24, which carries radially displaceable wings 25 as displacement elements, is arranged in the recess. The rotor 24 is driven by a drive shaft 26. The wings 25 slide, applied by a hydraulic pressure to the inner contour of the cam ring 23, on the cam ring 23. Between the wings 25, pump chambers of different volume.
  • the pressurized actuator 12 is provided, which consists essentially of a first pressure chamber 27 extending between the outer side 28 of the cam ring 23 and the wall 22 of the recess in the housing 19 is formed, and from a second pressure chamber 29 which is approximately diametrically to the drive shaft 26 opposite the first pressure chamber 27 between the outer side 28 of the cam ring 23 and the wall 22 is formed.
  • the control piston 10 moves at a limit pressure is exceeded against the spring force of the spring 21 and acted on the first and second control line 6.1 the first and second pressure chamber 27, 29, so that the cam ring 23 of the rotary pump 2 at a pressure increase in the pressure medium supply line 8 gradually to the right in the sense of reducing the eccentricity of the rotor 24 and the delivery rate of the rotary pump 2 moves.
  • a built in the control piston 10 pressure relief valve 34 bridges a low pressure chamber 30, with spring 21, with a high pressure chamber 31st
  • Fig. 1 is formed as an electromechanically driven pressure relief valve 14 pilot valve of the second Venktilhunt 9 or low pressure chamber 30 downstream and thus allows for opening that the control piston 10 is moved in the direction of a reduction of the flow rate and the pressure of the pressure medium.
  • the opening pressure of the pressure limiting valve 14 is controlled and about a very small steering angle and / or steering torque and a relatively high driving speed reduced and vice versa, whereby a detuning of the pressure compensator formed by the flow control valve 4 is also achieved for example by short circuit of low pressure and high pressure chamber and a flow reduction and / or pressure reduction.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Power Steering Mechanism (AREA)
  • Details And Applications Of Rotary Liquid Pumps (AREA)

Abstract

The invention relates to a hydraulic system comprising a stroke-regulated rotary pump (2) for generating a flow of pressurizing medium for a user (3) of a steering system or active chassis of a vehicle, said pressurizing medium flow to the user (3) being regulated through a pilot-operated pressure regulator such that the flow rate of the pressurizing medium to the user (3) is approximately constant and the pressure is variable. In order to provide a hydraulic system with constant flow control, the pressure of said system being regulated to achieve an improvement in energy management, it is made possible for the pressure of the pressurizing medium to be modulated by a variable pressure limiting valve (14), said pressure being adjusted to a pre-determined pressure to the user (3).

Description

HYDROLIKSYSTEM FÜR EINEN VERBRAUCHER EINES LENKSYSTEMS HYDROLIC SYSTEM FOR A CONSUMER OF A STEERING SYSTEM
Die Erfindung betrifft ein Hydrauliksystem mit einer hubgeregelten Rotationspumpe zur Erzeugung eines Druckmittelstromes für einen Verbraucher eines Lenksystems oder eines aktiven Fahrwerks eines Fahrzeugs, nach dem Oberbegriff des Anspruchs 1.The invention relates to a hydraulic system with a stroke-controlled rotary pump for generating a pressure medium flow for a consumer of a steering system or an active chassis of a vehicle, according to the preamble of claim 1.
Hydrauliksysteme mit hub- und volumenstromgeregelter Pumpe beispielsweise für einen Verbraucher, wie eine hydraulische Servolenkung eines Fahrzeugs weisen einen vorgesteuerten Druckregler, wie etwa ein Stromregelventil für einen konstanten Druckmittelstrom auf. Dabei ist eine erste Ventilkammer oder Hochdruckkammer des Stromregelventils fluidisch über eine erste Steuerleitung stromauf einer ersten Blende in einer Versorgungsleitung für den Verbraucher verbunden. Eine zweite Ventilkammer oder Niederdruckkammer des Stromregelventils weist in ihrem Inneren eine Druckfeder auf und ist durch einen in Richtung auf die erste Ventilkammer federbelasteten Regelkolben getrennt, wobei die zweite Ventilkammer über eine zweite Steuerleitung auf der stromabwärtigen Seite der ersten Blende mit der Versorgungsleitung verbunden ist. Der Regelkolben wird in Abhängigkeit von dem Druckunterschied an einer Blende in der zweiten Steuerleitung verstellt, um einen Teil des Druckmittels von der Versorgungsleitung abzuführen, oder eine druckmittel-beaufschlagte Stelleinrichtung für einen Kurvenring der Rotationspumpe anzusteuern und um dadurch die Strömungsrate des Druckmittels zu dem Verbraucher etwa konstant zu halten.For example, hydraulic systems with lift and volume flow controlled pump for a consumer, such as a hydraulic power steering system of a vehicle, have a pilot operated pressure regulator, such as a flow control valve for a constant pressure medium flow. In this case, a first valve chamber or high-pressure chamber of the flow control valve is fluidly connected via a first control line upstream of a first diaphragm in a supply line for the consumer. A second valve chamber or low-pressure chamber of the flow control valve has in its interior a compression spring and is separated by a spring-loaded in the direction of the first valve chamber control piston, wherein the second valve chamber is connected via a second control line on the downstream side of the first panel to the supply line. The control piston is adjusted in response to the pressure difference at an orifice in the second control line to dissipate a portion of the pressure medium from the supply line, or to control a pressurized actuator actuator for a cam ring of the rotary pump and thereby by the flow rate of the pressure medium to the consumer approximately to keep constant.
Nachteilig ist, daß mit dieser Regelungsmethode nur eine fest vorgegebene Ventilcharakteristik und ein definierter Handmomentenverlauf an einer Lenkhandhabe möglich ist. Eine Beeinflussung eines von der Fahrgeschwindigkeit eines Fahrzeugs beispielsweise abhängigen Handmomentenverlaufs ist dadurch nicht möglich. Ein weiterer Nachteil ist, dass die Rotationspumpe auch gegen einen hohen Leerlauf-druck zu fördern hat, wenn nicht gelenkt wird.The disadvantage is that with this control method only a fixed predetermined valve characteristic and a defined manual torque curve on a steering handle is possible. An influencing a one of the driving speed of a vehicle, for example, dependent manual torque curve is not possible. Another disadvantage is that the rotary pump has to promote against a high idling pressure when not steered.
Der Erfindung liegt die Aufgabe zugrunde, ein Hydrauliksystem mit einer Konstantstromregelung anzugeben, deren Druck hinsichtlich einer Verbesserung des Energiehaushaltes geregelt ist.The invention has for its object to provide a hydraulic system with a constant current control, the pressure is regulated in terms of improving the energy balance.
Die Aufgabe wird mit einem Hydrauliksystem mit den Merkmalen des Anspruchs 1 gelöst.The object is achieved with a hydraulic system having the features of claim 1.
Gemäß der Erfindung wird die verbraucherseitige Druckbeaufschlagung des Regelkolbens durch ein regelbares Druckbegrenzungsventil in dem Regelkolben oder in einem Lenkventil des Hydrauliksystems vorzugsweise in Verstimmung der durch den Regelkolben gebildeten Druckwaage so hinsichtlich des Drucks des Druckmittels geändert, dass sowohl eine Konstantstromregelung, eine Maximaldruckbegrenzung und ein sehr weites Absenken des Druckes bei geringer Leistungsaufnahme des Verbrauchers und/oder der Rotationspumpe ermöglicht ist. Beim Öffnen des Druckbegrenzungsventils in dem Regelkolben des Stromregelventils bewegt sich der Regelkolben in Richtung auf die zweite Ventilkammer oder Niederdruckkammer und bewirkt ein Ableiten von Druckmittel aus der ersten Ventilkammer in einen Druckmittelbehälter und Rücklauf zur Rotationspumpe oder eine Verstellung eines Kurvenrings oder dergleichen, der den Hub der Rotationspumpe bestimmt.According to the invention, the consumer-side pressurization of the control piston by a controllable pressure relief valve in the control piston or in a steering valve the hydraulic system preferably in the detuning of the pressure compensator formed by the control piston so changed in terms of the pressure of the pressure medium that both a constant current control, a maximum pressure limit and a very wide lowering of the pressure at low power consumption of the consumer and / or the rotary pump is possible. When opening the pressure relief valve in the control piston of the flow control valve, the control piston moves in the direction of the second valve chamber or low pressure chamber and causes a discharge of pressure fluid from the first valve chamber into a pressure fluid reservoir and return to the rotary pump or an adjustment of a cam ring or the like, the stroke of Rotary pump determined.
Bevorzugte Ausführungen ergeben sich aus den Unteransprüchen.Preferred embodiments emerge from the subclaims.
Das Druckbegrenzungsventil kann als angesteuertes Druckbegrenzungsventil gebildet sein und hydraulisch, mechanisch oder elektrisch bzw. elektronisch angesteuert sein. Es kann Teil einer hydraulischen Servolenkung eines Fahrzeugs sein und einen Druckmittelstrom für ein Lenkventil und einen hydraulischen Aktuator der Servolenkung regeln. Dabei ist es zweckmäßig, das Druckbegrenzungsventil in Abhängigkeit von einem, an einer Lenkhandhabe des Fahrzeugs eingestellten Lenkwinkel oder Lenkmoment anzusteuern - etwa, wenn der Lenkwinkel um 0°, bevorzugt von 0° bis ± 3,5 ° eingestellt ist, wodurch bei Geradeausfahrt des Fahrzeugs die Leistungsaufnahme der Rotationspumpe minimiert ist. Zudem besteht die Möglichkeit einer Absenkung des Drucks in Abhängigkeit von der Fahrgeschwindigkeit, so, dass z.B. bei geringer Fahrgeschwindigkeit etwa bei einem Parkiervorgang des Fahrzeugs der Druck angehoben ist und bei hoher Fahr-geschwindigkeit des Fahrzeugs der Druck abgesenkt ist.The pressure relief valve may be formed as a controlled pressure relief valve and be controlled hydraulically, mechanically or electrically or electronically. It may be part of a hydraulic power steering system of a vehicle and regulate a pressure medium flow for a steering valve and a hydraulic actuator of the power steering. It is expedient to control the pressure relief valve in response to a, set to a steering handle of the vehicle steering angle or steering torque - such as when the steering angle is set to 0 °, preferably from 0 ° to ± 3.5 °, thereby driving straight ahead of the vehicle the power consumption of the rotary pump is minimized. In addition, there is the possibility of lowering the pressure as a function of the driving speed, so that e.g. at low driving speed as in a parking operation of the vehicle, the pressure is increased and at high driving speed of the vehicle, the pressure is lowered.
Das Lenkventil kann eine geschlossene oder eine offene Mitte aufweisen, wobei bei einem Lenkventil mit geschlossener Mitte durch Einbau einer Blende ein gewisser Druckmittel- Ruhestrom durch das Lenkventil geführt sein kann, um das Ansprech-verhalten der Regelvorrichtung bei plötzlichem Ändern des Lenkwinkel - Sollwertes an der Lenkhandhabe zu verbessern. Das Stromregelventil mit Druckbe-grenzungsventil übernimmt eine Doppelfunktion, da das Druckmittel für einenThe steering valve may have a closed or an open center, wherein in a steering valve with a closed center by installing a diaphragm some pressure fluid quiescent current may be passed through the steering valve to the response behavior of the control device when suddenly changing the steering angle - setpoint at the To improve the steering handle. The flow control valve with pressure relief valve assumes a dual function, since the pressure medium for a
Verbraucher mit dem Druck bereitgestellt wird, mit dem der Verbraucher im Hinblick auf ein bestimmtes Fahrverhalten des Fahrers und Fahrzeugs beaufschlagt werden soll, sodass die Notwendigkeit entfällt, diesbezüglich mit einem verbraucherseitigen, dem Stromregelventil nachgeordneten Druckregelventil zu arbeiten. Ein fest eingestellter, maximaler Druck an dem Druckbegrenzungsventil begrenzt den Druckmitteldruck in dem Hydrauliksystem.Consumers are provided with the pressure that is to be applied to the consumer with regard to a specific driving behavior of the driver and vehicle, so that eliminates the need to work in this regard with a consumer-side, the flow control valve downstream pressure control valve. A fixed set maximum pressure on the pressure relief valve limits the fluid pressure in the hydraulic system.
Ein erfindungsgemäßes Hydrauliksystem lässt sich vorzugsweise für Verbraucher einsetzen, die in Fahrwerken von Fahrzeugen vorgesehen sind, und auf einen niedrigen Energieverbrauch bei hoher Ansprechgeschwindigkeit angewiesen sind. Ein solches Hydrauliksystem lässt sich vorteilhaft in Federungssysteme wie auch in Stabilisierungseinrichtungen - etwa in Querstabilisatoren - für Fahrzeuge einsetzen.A hydraulic system according to the invention can preferably be used for consumers who are provided in vehicle chassis and are dependent on low energy consumption and high response speed. Such a hydraulic system can be used advantageously in suspension systems as well as in stabilizers - such as in anti-roll bars - for vehicles.
Die Erfindung wird nun näher anhand eines Ausführungsbeispiels beschrieben und anhand der beiliegenden Zeichnung wiedergegeben.The invention will now be described in more detail with reference to an embodiment and reproduced with reference to the accompanying drawings.
In der Zeichnung zeigt:In the drawing shows:
Fig. 1 ein schematisches Schaltbild eines Hydrauliksystems mit elektrisch betätigtem Druckbegrenzungsventil einer hydraulischen Servolenkung.Fig. 1 is a schematic diagram of a hydraulic system with electrically operated pressure relief valve of a hydraulic power steering.
Fig. 2 einen Querschnitt durch eine Rotationspumpe mit Stromregelventil des Hydrauliksystems in Fig. 1.2 shows a cross section through a rotary pump with flow control valve of the hydraulic system in Fig. 1st
In Fig. 1 ist in einem schematischen Schaltbild ein Hydrauliksystem 1 gezeigt, das eine als verstellbare Flügelzellenpumpe 18 ausgebildete Rotationspumpe 2 umfaßt. Das Hydrauliksystem 1 dient zur Druckmittelzufuhr in einer Versorgungsleitung 8 zu einem als Drehschieberventil ausgebildeten Lenkventil 13 und eines als hydraulischer Servomotors 15 ausgebildeten Verbrauchers 3 einer hydraulischen Servolenkung 16.In Fig. 1, a hydraulic circuit 1 is shown in a schematic circuit diagram, which comprises a rotary pump 2 designed as an adjustable vane pump 18. The hydraulic system 1 serves to supply pressure medium in a supply line 8 to a steering valve 13 designed as a rotary slide valve valve and a load 3 of a hydraulic power steering system 16 designed as a hydraulic servomotor 15.
Wie auch Fig. 1 in einem Querschnitt durch die verstellbare Flügelzellenpumpe 8 zeigt, ist in einem Gehäuse 19 der Flügelzellenpumpe 18 ein Stromregelventil 4 angeordnet, das zur Einstellung der Förderrate des Druckmittels auf einen gewünschten Wert dient. Das Stromregelventil 4 ist in den Figuren 1 und 2 mit einem als Druckwaage arbeitenden Regelkolben 10 ausgeführt, der eine erste Ventilkammer 5 von einer zweiten Ventilkammer 9 trennt und in einer Bohrung des Stromregelventils 4 verschiebbar angeordnet ist. Die erste Ventilkammer 5 ist über eine erste Steuerleitung 6 stromauf einer ersten Blende 7 in der Versorgungsleitung 8 mit der Versorgungsleitung 8 fluidisch verbunden. Die zweite Ventilkammer 9 ist über eine zweite Steuerleitung 1 1 stromab der ersten Blende 7 mit der Versorgungsleitung 8 verbunden. Eine zweite Blende 20 ist in der zweiten Steuerleitung 1 1 angeordnet und erzeugt eine Druckdifferenz zu der zweiten Ventilkammer 9. Eine dritte Blende 33 in der zweiten Steuerleitung 1 1 sorgt als Konstantblende für den konstanten Druckmittelstrom. Der Regelkolben 10 ist durch eine Feder 21 in der zweiten Ventilkammer 9 in Richtung auf die erste Ventilkammer 5 federbelastet und bewegt sich bei Überschreiten eines Grenzdruckes entgegen der Federbelastung dieser Feder 21. Er beaufschlagt dabei eine Stelleinrichtung 12 für die Fördermengenregelung der Rotationspumpe 2 so, dass die Förderrate reduziert wird und so insgesamt eine konstante Förderrate erzielt wird.As also shown in Fig. 1 in a cross section through the adjustable vane pump 8, a flow control valve 4 is arranged in a housing 19 of the vane pump 18, which serves to set the delivery rate of the pressure medium to a desired value. The flow control valve 4 is executed in the figures 1 and 2 with a working as a pressure compensating control piston 10 which separates a first valve chamber 5 from a second valve chamber 9 and is slidably disposed in a bore of the flow control valve 4. The first valve chamber 5 is fluidically connected via a first control line 6 upstream of a first aperture 7 in the supply line 8 to the supply line 8. The second valve chamber 9 is connected via a second control line 1 1 downstream of the first aperture 7 to the supply line 8. A second aperture 20 is disposed in the second control line 1 1 and generates a pressure difference to the second valve chamber 9. A third Aperture 33 in the second control line 1 1 provides as a constant aperture for the constant pressure medium flow. The control piston 10 is spring-loaded by a spring 21 in the second valve chamber 9 in the direction of the first valve chamber 5 and moves when a limit pressure is exceeded against the spring load of this spring 21. He acts on an adjusting device 12 for the flow control of the rotary pump 2 so that the delivery rate is reduced and so overall a constant flow rate is achieved.
Wie insbesondere Fig. 2 zeigt, weist die Flügelzellenpumpe 18 einen variablen Hub auf und eignet sich, wie in dem Ausführungsbeispiel gezeigt, beispielsweise als Förderaggregat in einer Fremdkraft- oder Hilfskraftlenkung eines Kraftfahrzeugs.As shown particularly in FIG. 2, the vane pump 18 has a variable stroke and, as shown in the exemplary embodiment, is suitable, for example, as a delivery unit in an external power or power steering system of a motor vehicle.
Die Flügelzellenpumpe 18 besteht im Wesentlichen aus dem Gehäuse 19, in dem in eine Ausnehmung, die durch ihre Wände 22 definiert ist, ein Kurvenring 23 verschiebbar oder verschwenkbar angeordnet ist. Exzentrisch zu dem Kurvenring 23 ist in der Ausnehmung ein Rotor 24, welcher radial verschiebliche Flügel 25 als Verdrängungselemente trägt, angeordnet. Der Rotor 24 ist von einer Antriebswelle 26 angetrieben. Die Flügel 25 gleiten, von einem hydraulischen Druck an die Innenkontur des Kurvenrings 23 angelegt, an dem Kurvenring 23. Zwischen den Flügeln 25 bilden sich Pumpenkammern unterschiedlichen Volumens. Um die Exzentrizität des Rotors 24 zu verändern und damit die Fördermenge der Rotationspumpe 2 zu verändern, ist die druckmittelbeaufschlagte Stelleinrichtung 12 vorgesehen, die im Wesentlichen aus einer ersten Druckammer 27, die sich zwischen der Außenseite 28 des Kurvenrings 23 und der Wand 22 der Ausnehmung in dem Gehäuse 19 befindet, und aus einer zweiten Druckammer 29, die sich etwa diametral zu der Antriebswelle 26 gegenüber der ersten Druckkammer 27 zwischen der Außenseite 28 des Kurvenrings 23 und der Wand 22 befindet, gebildet wird.The vane pump 18 consists essentially of the housing 19, in which a cam ring 23 is arranged displaceably or pivotably in a recess which is defined by its walls 22. Eccentrically to the cam ring 23, a rotor 24, which carries radially displaceable wings 25 as displacement elements, is arranged in the recess. The rotor 24 is driven by a drive shaft 26. The wings 25 slide, applied by a hydraulic pressure to the inner contour of the cam ring 23, on the cam ring 23. Between the wings 25, pump chambers of different volume. In order to change the eccentricity of the rotor 24 and thus to change the delivery rate of the rotary pump 2, the pressurized actuator 12 is provided, which consists essentially of a first pressure chamber 27 extending between the outer side 28 of the cam ring 23 and the wall 22 of the recess in the housing 19 is formed, and from a second pressure chamber 29 which is approximately diametrically to the drive shaft 26 opposite the first pressure chamber 27 between the outer side 28 of the cam ring 23 and the wall 22 is formed.
Zu der Stelleinrichtung 12 ist funktional das Stromregelventil 4 zu rechnen. Der Regelkolben 10 bewegt sich bei Überschreiten eines Grenzdruckes entgegen der Federkraft der Feder 21 und beaufschlagt dabei über die erste und zweite Steuerleitung 6,1 1 die erste und zweite Druckkammer 27, 29, so, dass sich der Kurvenring 23 der Rotationspumpe 2 bei einem Druckanstieg in der Druckmittel-Versorgungsleitung 8 allmählich nach rechts im Sinne einer Verringerung der Exzentrizität des Rotors 24 und der Fördermenge der Rotationspumpe 2 bewegt.To the adjusting device 12 is functionally the flow control valve 4 to be expected. The control piston 10 moves at a limit pressure is exceeded against the spring force of the spring 21 and acted on the first and second control line 6.1 the first and second pressure chamber 27, 29, so that the cam ring 23 of the rotary pump 2 at a pressure increase in the pressure medium supply line 8 gradually to the right in the sense of reducing the eccentricity of the rotor 24 and the delivery rate of the rotary pump 2 moves.
Ein in dem Regelkolben 10 eingebautes Druckbegrenzungsventil 34 überbrückt eine Niederdruckammer 30, mit Feder 21 , mit einer Hochdruckkammer 31. In Fig. 1 ist ein als elektromechanisch angesteuertes Druckbegrenzungsventil 14 gebildetes Vorsteuerventil der zweiten Venktilkammer 9 oder Niederdruckkammer 30 nachgelagert und ermöglicht so bei einem Öffnen, dass der Regelkolben 10 in Richtung einer Reduktion der Fördermenge und des Drucks des Druckmittels bewegt wird.A built in the control piston 10 pressure relief valve 34 bridges a low pressure chamber 30, with spring 21, with a high pressure chamber 31st In Fig. 1 is formed as an electromechanically driven pressure relief valve 14 pilot valve of the second Venktilkammer 9 or low pressure chamber 30 downstream and thus allows for opening that the control piston 10 is moved in the direction of a reduction of the flow rate and the pressure of the pressure medium.
In Abhängigkeit von einem Lenkwinkel und/oder Lenkmoment an einer Lenkhandhabe 17 und in Abhängigkeit einer Fahrgeschwindigkeit, die von einer Steuereinheit 32 gemessen und verarbeitet werden, wird der Öffnungsdruck des Druckbegrenzungs-ventils 14 geregelt und etwa bei einem sehr kleinen Lenkwinkel und/oder Lenkmoment und einer vergleichsweise hohen Fahrgeschwindigkeit herabgesetzt und umgekehrt, wodurch eine Verstimmung der durch das Stromregelventil 4 gebildeten Druckwaage auch beispielsweise durch Kurzschluß von Niederdruck- und Hochdruckkammer und eine Fördermengenreduktion und/oder Druckabsenkung erreicht wird. Depending on a steering angle and / or steering torque on a steering handle 17 and in response to a driving speed, which are measured and processed by a control unit 32, the opening pressure of the pressure limiting valve 14 is controlled and about a very small steering angle and / or steering torque and a relatively high driving speed reduced and vice versa, whereby a detuning of the pressure compensator formed by the flow control valve 4 is also achieved for example by short circuit of low pressure and high pressure chamber and a flow reduction and / or pressure reduction.
BezugszeichenlisteLIST OF REFERENCE NUMBERS
Hydrauliksystemhydraulic system
Rotationspumperotary pump
Verbraucherconsumer
StromregelventilFlow control valve
Ventilkammer, ersteValve chamber, first
Steuerleitung, ersteControl line, first
Blende, ersteAperture, first
Versorgungsleitungsupply line
Ventilkammer, zweiteValve chamber, second
Regelkolbencontrol piston
Steuerleitung, zweiteControl line, second
Stelleinrichtungsetting device
Lenkventilsteering valve
DruckbegrenzungsventilPressure relief valve
Servomotor, hydraulischServomotor, hydraulic
ServolenkungPower steering
LenkhandhabeSteering handle
FlügelzellenpumpeVane pump
Gehäuse, v. 18Housing, v. 18
Blende, zweiteAperture, second
Federfeather
Wandwall
Kurvenringcam ring
Rotorrotor
Flügelwing
Antriebswelledrive shaft
Druckkammer, erstePressure chamber, first
Außenseiteoutside
Druckkammer, zweitePressure chamber, second
NiederdruckkammerLow-pressure chamber
HochdruckkammerHigh-pressure chamber
Steuereinheitcontrol unit
33 Blende, dritte Druckbegrenzungsventil 33 aperture, third pressure relief valve

Claims

Patentansprüche claims
1. Hydrauliksystem mit hubgegelter Rotationspumpe (2) zur Erzeugung eines Druckmittelstromes für einen Verbraucher (3) eines Lenksystems oder aktiven Fahrwerks eines Fahrzeugs, deren Druckmittelstrom zu dem Verbraucher (3) durch einen vorgesteuerten Druckregler so geregelt ist, dass die Strömungsrate des Druckmittels zu dem Verbraucher (3) etwa konstant ist und der Druck variabel ist, d a d u r c h g e k e n n z e i c h n e t, dass der Druck des Druckmittels durch ein regelbares Druckbegrenzungsventil (14) in Anpassung an einen für die Beaufschlagung des Verbrauchers (3) vorgegebenen Druck veränderbar ist.1. Hydraulic system with lift-controlled rotary pump (2) for generating a pressure medium flow for a consumer (3) of a steering system or active chassis of a vehicle whose pressure medium flow to the consumer (3) is controlled by a pilot-operated pressure regulator so that the flow rate of the pressure medium to the Consumer (3) is approximately constant and the pressure is variable, characterized in that the pressure of the pressure medium by a controllable pressure relief valve (14) in adaptation to a predetermined for the application of the load (3) pressure is variable.
2. Hydrauliksystem nach Anspruch 1 , mit einer volumenstromgeregelten Rotationspumpe (2) zur Erzeugung eines Druckmittelstromes für den Verbraucher (3) des Fahrzeugs, deren Druckmittelstrom zu dem Verbraucher (3) über ein Stromregelventil (4) und eine Blende (33) geregelt ist, wobei eine erste Ventilkammer (5) des Stromregelventils (4) fluidisch über eine erste Steuerleitung (6) stromauf einer ersten Blende (7) in einer Versorgungsleitung (8) für den Verbraucher (3) verbunden ist und von einer zweiten Ventilkammer (9) durch einen in Richtung auf die erste Ventilkammer (5) federbelasteten Regelkolben (10) getrennt ist, wobei die zweite Ventilkammer (9) über eine zweite Steuerleitung2. Hydraulic system according to claim 1, with a volume-flow-controlled rotary pump (2) for generating a pressure medium flow for the consumer (3) of the vehicle whose pressure medium flow to the consumer (3) via a flow control valve (4) and a diaphragm (33) is regulated, wherein a first valve chamber (5) of the flow control valve (4) is fluidically connected via a first control line (6) upstream of a first orifice (7) in a supply line (8) for the consumer (3) and from a second valve chamber (9) a spring-loaded in the direction of the first valve chamber (5) control piston (10) is separated, wherein the second valve chamber (9) via a second control line
(11 ) auf der stromabwärtigen Seite der ersten Blende (7) mit der Versorgungsleitung (8) verbunden ist und der Regelkolben (10) in Abhängigkeit von dem Druckunterschied an einer zweiten Blende (20) in der Steuerleitung (11 ) verstellt wird, um einen Teil des Druckmittels von der Versorgungsleitung (8) abzuführen und/oder eine druckmittelbeaufschlagte Stelleinrichtung (12) für einen Kurvenring der Rotationspumpe (2) anzusteuern, um die Strömungsrate des Druckmittels zu dem Verbraucher (3) etwa konstant zu halten wobei dem Regelkolben (10) und/oder einem Lenkventil (13) an dem Hydrauliksystem (1 ) ein Druckbegrenzungsventil (14) zugeordnet ist, um den Druck des Druckmittels in Anpassung an einen für die Beaufschlagung des Verbrauchers (3) vorgegebenen Druck zu verändern.(11) on the downstream side of the first orifice (7) is connected to the supply line (8) and the control piston (10) is adjusted in response to the pressure difference at a second aperture (20) in the control line (11) to a Part of the pressure medium from the supply line (8) dissipate and / or a pressurized actuator control device (12) for a cam ring of the rotary pump (2) to keep the flow rate of the pressure medium to the consumer (3) about constant while the control piston (10) and / or a steering valve (13) on the hydraulic system (1) is associated with a pressure limiting valve (14) to change the pressure of the pressure medium in adaptation to a for the application of the load (3) predetermined pressure.
3. Hydrauliksystem nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass das Druckbegrenzungsventil (14) hydraulisch, mechanisch oder elektromagnetisch, oder elektronisch angesteuert ist. 3. Hydraulic system according to claim 1 or 2, characterized in that the pressure limiting valve (14) is hydraulically, mechanically or electromagnetically, or electronically controlled.
4. Hydrauliksystem nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass durch das Hydrauliksystem (1 ) ein Druckmittelstrom für ein Lenkventil (13) und einen hydraulischen Servomotor (15) einer Servolenkung (16) geregelt ist.4. Hydraulic system according to one of claims 1 to 3, characterized in that by the hydraulic system (1) a pressure medium flow for a steering valve (13) and a hydraulic servo motor (15) of a power steering (16) is regulated.
5. Hydrauliksystem nach Anspruch 4, dadurch gekennzeichnet, dass das Druckbegrenzungsventil (14) in Abhängigkeit von einem Lenkwinkel und/oder einem Lenkmoment an einer Lenkhandhabe (17) der Servolenkung (16) angesteuert ist.5. Hydraulic system according to claim 4, characterized in that the pressure limiting valve (14) in response to a steering angle and / or a steering torque to a steering handle (17) of the power steering (16) is driven.
6. Hydrauliksystem nach Anspruch 4 oder 5, dadurch gekennzeichnet, dass durch das Druckbegrenzungsventil (14) der Druck des Druckmittels in einem Lenkwinkelbereich von etwa 0 ± 3,5 ° auf etwa 1 bar abgesenkt ist.6. Hydraulic system according to claim 4 or 5, characterized in that is lowered by the pressure limiting valve (14), the pressure of the pressure medium in a steering angle range of about 0 ± 3.5 ° to about 1 bar.
7. Hydrauliksystem nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, dass das Druckbegrenzungsventil (14) in Abhängigkeit von der Fahrgeschwindigkeit des Fahrzeugs so angesteuert ist, dass mit zunehmender Fahrgeschwindigkeit der Druck des Druckmittels abgesenkt ist und umgekehrt.7. Hydraulic system according to one of claims 1 to 6, characterized in that the pressure limiting valve (14) is controlled in dependence on the driving speed of the vehicle so that with increasing driving speed of the pressure of the pressure medium is lowered and vice versa.
8. Hydrauliksystem nach einem der Ansprüche 4 bis 7, dadurch gekennzeichnet, dass das Lenkventil (13) eine offene oder geschlossene Mitte aufweist.8. Hydraulic system according to one of claims 4 to 7, characterized in that the steering valve (13) has an open or closed center.
9. Hydrauliksystem nach einem der Ansprüche 1 bis 8, dadurch gekennzeichnet, dass der Verbraucher (3) ein Aktuator für ein aktives Fahrwerk eines Fahrzeugs ist.9. Hydraulic system according to one of claims 1 to 8, characterized in that the consumer (3) is an actuator for an active chassis of a vehicle.
10. Hydrauliksystem nach einem der Ansprüche 1 bis 9, dadurch gekennzeichnet, dass die Rotationspumpe (2) eine verstellbare Flügelzellenpumpe (18) ist. 10. Hydraulic system according to one of claims 1 to 9, characterized in that the rotary pump (2) is an adjustable vane pump (18).
PCT/EP2009/062889 2008-10-10 2009-10-05 Hydraulic system for a user of a steering system WO2010040708A1 (en)

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DE200810042728 DE102008042728A1 (en) 2008-10-10 2008-10-10 hydraulic system

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DE102022118965A1 (en) 2022-07-28 2024-02-08 Pump Technology Solutions PS GmbH Device for regulating the delivery volume of a positive displacement pump, positive displacement pump and method for regulating the delivery volume of a positive displacement pump

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2952083A1 (en) * 1979-12-22 1981-06-25 Robert Bosch Gmbh, 7000 Stuttgart Control system for variable hydraulic pump - has output throttle and control valve permitting independent volume and pressure control
DE3143074A1 (en) * 1981-10-30 1983-05-11 Robert Bosch Gmbh, 7000 Stuttgart Device for controlling the pressure and flow of an adjustable pump

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2952083A1 (en) * 1979-12-22 1981-06-25 Robert Bosch Gmbh, 7000 Stuttgart Control system for variable hydraulic pump - has output throttle and control valve permitting independent volume and pressure control
DE3143074A1 (en) * 1981-10-30 1983-05-11 Robert Bosch Gmbh, 7000 Stuttgart Device for controlling the pressure and flow of an adjustable pump

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