WO2001019664A1 - Power-assisted steering system for motor vehicles - Google Patents

Power-assisted steering system for motor vehicles Download PDF

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Publication number
WO2001019664A1
WO2001019664A1 PCT/EP2000/008865 EP0008865W WO0119664A1 WO 2001019664 A1 WO2001019664 A1 WO 2001019664A1 EP 0008865 W EP0008865 W EP 0008865W WO 0119664 A1 WO0119664 A1 WO 0119664A1
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WO
WIPO (PCT)
Prior art keywords
steering
steering system
actuator
power steering
hydraulic
Prior art date
Application number
PCT/EP2000/008865
Other languages
German (de)
French (fr)
Inventor
Ünal GAZYAKAN
Hartmut Werries
Original Assignee
Zf Friedrichshafen Ag
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 Friedrichshafen Ag filed Critical Zf Friedrichshafen Ag
Priority to EP00962471A priority Critical patent/EP1212232A1/en
Publication of WO2001019664A1 publication Critical patent/WO2001019664A1/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
    • 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
    • B62D5/30—Safety devices, e.g. alternate emergency power supply or transmission means to ensure steering upon failure of the primary steering means

Definitions

  • the invention relates to an auxiliary power steering system for motor vehicles according to the kind defined in the preamble of claim 1.
  • steer-by-wire steering systems Power steering systems that work without mechanical coupling between the steering wheel and the steered vehicle wheels are called steer-by-wire steering systems.
  • These power steering systems have a steering wheel actuator coupled to the steering handwheel, which is composed, for example, of an electric motor, steering angle and / or torque sensor.
  • This steering wheel actuator is connected via electronic control to a steering actuator that can work electrically, hydraulically or pneumatically.
  • the difference between a predetermined target value and a measured actual value is detected by a sensor system and transmitted to a control unit.
  • An electronic unit calculates from this signal and depending on other factors such as Vehicle speed, lateral acceleration, road surface and loading condition a necessary auxiliary torque that is transmitted to the wheels of the motor vehicle to be steered via the steering actuator.
  • a corresponding signal is transmitted to the steering handwheel via the steering wheel actuator, so that the driver perceives the same steering feeling as he is accustomed to from conventional, mechanically coupled power steering systems.
  • a disadvantage of the prior art disclosed in DE 196 15 544 C1 is the fact that a relatively large number of different valves in the vehicle are spatially separated from one another and therefore have to be networked with one another in a complex manner. This large number of different valves carries a high risk of failure.
  • the present invention has for its object to present an auxiliary power steering system in which all necessary functions can be safely represented with as few simple valves as possible. Furthermore, the power steering system should have a fallback level, which makes it possible to bring the vehicle to a safe stop if the vehicle electronics fail.
  • the power steering system has a steering wheel actuator, which is used to transmit the driver a steering request applied via a steering handwheel and for generating a steering feeling is used as feedback for the driver.
  • the steering handwheel is connected by a torsionally elastic member and a gear to an electric motor, preferably designed as an asynchronous motor. Planetary or worm gears can be used as gears.
  • the steering handwheel is connected to a reversible hydraulic pump, which is preferably designed as a gear pump.
  • the steering wheel actuator is connected to a steering actuator via a controlled system. This steering actuator consists of a piston / cylinder unit which transmits the driver's steering request initiated via the steering wheel actuator to the wheels of the motor vehicle to be steered.
  • the integration of detection units in the connecting elements of the steering actuator and body structure means that tensile and compressive forces that act on the steering actuator via tie rods of the steered vehicle wheels can be measured directly.
  • the steering actuator can thus z. B. are attached to the body structure by means of force-measuring bolts, which can directly detect the forces occurring without being influenced by interference signals.
  • the steering actuator is connected to a further reversible hydraulic pump which is driven by an electric motor and a transmission. This second reversible hydraulic pump conveys a hydraulic medium via lines or hoses into the pressure chambers of the piston / cylinder unit.
  • a 4/2-way valve connects or separates the two hydraulic circuits, depending on the operating state.
  • the hydraulic fallback level can be activated by connecting a first hydraulic pump to the piston / cylinder unit.
  • the second hydraulic pump is located at its outputs Unlockable check valves are arranged, separated from the hydraulic circuit.
  • the hydraulic circuit is connected to an accumulator that compensates for any leaks and keeps the hydraulic circuit under constant preload.
  • a steering angle specified on the steering handwheel is an input variable for the steering actuator.
  • the electric motor drives the hydraulic pump until a displacement of the piston / cylinder unit corresponding to the measured steering angle has occurred.
  • the feedback transmitted from the steered vehicle wheels via the tie rods to the steering actuator is recorded and processed by detection units integrated in the suspension of the steering actuator.
  • the steering feel thus generated is thus a direct variable, which is formed from tie rod forces and torque on the steering handwheel. If the electronics or electric motor fails, the first hydraulic pump is connected to the piston / cylinder unit via the 4/2-way valve and the second hydraulic pump is separated from the piston / cylinder unit by two check valves. As a result, the first hydraulic motor can be driven manually via the steering handwheel and the vehicle can thereby be steered.
  • the single figure shows a schematic representation of an auxiliary power steering system according to the invention for motor vehicles.
  • ⁇ tem for motor vehicles consists of a steering actuator 1, which is connected to vehicle wheels 4 and 5 via track rods 2 and 3.
  • the tie rods 2 and 3 are firmly connected to one another via a connecting element 6.
  • the forces introduced via the vehicle wheels 4, 5 and the tie rods 2, 3 act directly through the connecting element 6 on fastening elements 7 and 8, which connect the steering actuator 1 to a body structure 9.
  • the fastening elements 7, 8 have detection units (not shown), for example in the form of strain gauges, which detect the forces which occur. With the help of these detected forces, a reaction is generated by a steering wheel actuator 10 on a steering handwheel 11 and thus gives the driver an artificially generated steering feeling that corresponds to the current driving situation.
  • the steering wheel actuator 10 is composed of a sensor unit 12, an electric motor 13, a hydraulic pump 14 and a mechanical assembly, not shown, consisting of a torsion bar spring and a gear, which is in operative connection with the steering handwheel 11.
  • the sensor unit 12 is used to record the steering angle and torque on the steering handwheel 11.
  • the steering actuator 1 is connected to an electric motor 15 and a hydraulic pump 16 via lines 17 and 18.
  • the hydraulic pump 16, which is driven by the electric motor 15, conveys pressure medium towards or away from the piston / cylinder unit 19.
  • drive state connects or disconnects a 4/2-way valve 20, the hydraulic pumps 14 and 16.
  • a central control unit 24 is connected via control lines to the electric motors 13 and 14, the sensor unit 12 on the steering handwheel 11, the 4/2-way valve 20, the check valves 21 and 22, the sensors integrated in the fastening elements 7 and 8, and a pressure sensor 25 and a position sensor 26 connected.

Abstract

The invention relates to a power-assisted steering system with at least one steering wheel actuator (11) and at least one steering actuator (1) and one hydraulic reactivation level wherein the steering actuator (1) can be locked or released via the check valves (21, 22).

Description

Hilfskraft-Lenksystem für Kraftfahrzeuge Power steering system for motor vehicles
Die Erfindung betrifft ein Hilfskraft-Lenksystem für Kraftfahrzeuge nach der im Oberbegriff von Anspruch 1 näher definierten Art.The invention relates to an auxiliary power steering system for motor vehicles according to the kind defined in the preamble of claim 1.
Hilfskraft-Lenksysteme, die ohne mechanische Kopplung zwischen Lenkhandrad und gelenkten Fahrzeugrädern arbeiten, werden als steer-by-wire-Lenksysteme bezeichnet. Diese Hilfskraft-Lenksysteme weisen einen mit dem Lenkhandrad gekoppelten Lenkradaktuator auf, der sich beispielsweise aus Elektromotor, Lenkwinkel- und/oder Drehmomentsensor zusammensetzt. Dieser Lenkradaktuator ist über eine elek- tronische Regelung mit einem Lenkaktuator verbunden, der elektrisch, hydraulisch oder pneumatisch arbeiten kann. Die Differenz zwischen einem vorgegebenen Soll-Wert und einem gemessenen Ist-Wert wird von einer Sensorik erfaßt und an ein Steuergerät übermittelt. Eine Elektronikeinheit berech- net dann aus diesem Signal und in Abhängigkeit von weiteren Faktoren wie z.B. Fahrzeuggeschwindigkeit, Querbeschleunigung, Fahrbahnoberfläche und Beladungszustand ein erforderliches Hilfsmoment, das über den Lenkaktuator auf die zu lenkenden Räder des Kraftfahrzeuges übertragen wird. Um dem Fahrer Rückmeldung über den momentanen Fahrzustand übermitteln zu können, wird über den Lenkradaktuator ein entsprechendes Signal auf das Lenkhandrad übertragen, sodaß der Fahrer ein gleiches Lenkgefühl wahrnimmt, wie er es von herkömmlichen, mechanisch gekoppelten Hilfskraft- Lenksystemen gewohnt ist.Power steering systems that work without mechanical coupling between the steering wheel and the steered vehicle wheels are called steer-by-wire steering systems. These power steering systems have a steering wheel actuator coupled to the steering handwheel, which is composed, for example, of an electric motor, steering angle and / or torque sensor. This steering wheel actuator is connected via electronic control to a steering actuator that can work electrically, hydraulically or pneumatically. The difference between a predetermined target value and a measured actual value is detected by a sensor system and transmitted to a control unit. An electronic unit then calculates from this signal and depending on other factors such as Vehicle speed, lateral acceleration, road surface and loading condition a necessary auxiliary torque that is transmitted to the wheels of the motor vehicle to be steered via the steering actuator. In order to be able to transmit feedback to the driver about the current driving state, a corresponding signal is transmitted to the steering handwheel via the steering wheel actuator, so that the driver perceives the same steering feeling as he is accustomed to from conventional, mechanically coupled power steering systems.
Aus der DE 196 15 544 Cl ist eine Fahrzeuglenkung bekanntgeworden, die nach dem Konzept „steer-by-wire* arbei- tet und ein hydraulisches Stellaggregat aufweist, welches über zwei separate Hydraulikkreise betätigt werden kann, die so miteinander vernetzt sind, daß Systemteile des einen Hydraulikkreises auch in dem anderen Hydraulikkreis verwen- det werden können. Dies wird durch umschaltbare Steuerventilaggregate bewerkstelligt, die elektromagnetisch gesteuerte Stellantriebe aufweisen.From DE 196 15 544 Cl a vehicle steering system has become known which operates according to the “steer-by-wire * concept”. tet and has a hydraulic actuating unit which can be operated via two separate hydraulic circuits which are networked with one another in such a way that system parts of one hydraulic circuit can also be used in the other hydraulic circuit. This is accomplished by switchable control valve assemblies that have electromagnetically controlled actuators.
Deren Stromversorgung übernimmt im Normalbetrieb die Fahrzeugbatterie, jedoch kann auch eine zusätzliche Stromver- sorgung vorgesehen werden.Their power supply is taken over by the vehicle battery in normal operation, but an additional power supply can also be provided.
Nachteilig an dem aus der DE 196 15 544 Cl bekanntgewordene Stand der Technik ist die Tatsache, daß relativ viele verschiedene Ventile im Fahrzeug räumlich weit von- einander getrennt untergebracht sind und deshalb aufwendig miteinander vernetzt werden müssen. Diese Vielzahl an verschiedenen Ventilen birgt ein hohes Ausfallrisiko.A disadvantage of the prior art disclosed in DE 196 15 544 C1 is the fact that a relatively large number of different valves in the vehicle are spatially separated from one another and therefore have to be networked with one another in a complex manner. This large number of different valves carries a high risk of failure.
Der vorliegenden Erfindung liegt die Aufgabe zugrunde ein Hilfskraft-Lenksystem darzustellen, bei dem mit möglichst wenigen, einfachen Ventilen alle erforderlichen Funktionen sicher dargestellt werden können. Weiterhin soll das Hilfskraft-Lenksystem eine Rückfallebene aufweisen, die es beim Ausfall der Fahrzeugelektronik ermöglicht, das Fahrzeug sicher zum Stillstand zu bringen.The present invention has for its object to present an auxiliary power steering system in which all necessary functions can be safely represented with as few simple valves as possible. Furthermore, the power steering system should have a fallback level, which makes it possible to bring the vehicle to a safe stop if the vehicle electronics fail.
Die der Erfindung zugrunde liegende Aufgabe wird durch ein, auch die kennzeichnenden Merkmale des Hauptanspruchs aufweisendes, gattungsgemäßes Hilfskraft-Lenksystem für Kraftfahrzeuge gelöst.The object on which the invention is based is achieved by a generic auxiliary power steering system for motor vehicles, which also has the characterizing features of the main claim.
Das erfindungsgemäße Hilfskraft-Lenksystem weist einen Lenkradaktuator auf, der zur Übertragung des vom Fahrer über ein Lenkhandrad aufgebrachten Lenkwunsches und zur Erzeugung eines Lenkgefühls als Rückmeldung für den Fahrer verwendet wird. Das Lenkhandrad ist durch ein drehelastisches Glied und ein Getriebe mit einem, vorzugsweise als Asynchronmotor ausgebildeten, Elektromotor verbunden. Als Getriebe können Planeten- oder Schneckengetriebe verwendet werden. Zusätzlich ist das Lenkhandrad mit einer reversierbaren Hydropumpe, die vorzugsweise als Zahnradpumpe ausgebildet ist, verbunden. Der Lenkradaktuator ist über eine Regelstrecke mit einem Lenkaktuator verbunden. Dieser Lenkaktuator besteht aus einer Kolben-/Zylinder-Einheit, die den über den Lenkradaktuator eingeleiteten Lenkwunsch des Fahrers an die zu lenkenden Räder des Kraftfahrzeuges weitergibt. Durch die Integration von Erfassungseinheiten in den Verbindungselementen von Lenkaktuator und Karosserieaufbau können auftretende Zug- und Druckkräfte, die über Spurstangen der gelenkten Fahrzeugräder auf den Lenkaktuator einwirken, direkt gemessen werden. Der Lenkaktuator kann somit z. B. mittels Kraftmeßbolzen am Karosserieaufbau befestigt werden, die die auftretenden Kräfte ohne Beeinflussung durch einwirkende Störsignale direkt erfassen können. Der Lenkaktuator ist mit einer weiteren reversierbaren Hydropumpe, die über einen Elektromotor und ein Getriebe angetrieben wird, verbunden. Diese zweite reversierbare Hydropumpe fördert ein Hydraulikmedium über Leitungen oder Schläuche in Druckräume der Kolben-/Zylinder-Einheit . Ein 4/2-Wegeventil verbindet beziehungsweise trennt die beiden Hydraulikkreise, abhängig vom jeweiligen Betriebszustand. So kann es bei einer Störung im steer-by-wire-Betrieb dazu kommen, daß die hydraulische Rückfallebene durch Verbinden einer ersten Hydropumpe mit der Kolben-/Zylindereinheit aktiviert wird. Beim aktivieren der hydraulischen Rückfallebene wird die zweite Hydropumpe, an deren Ausgängen entsperrbare Rückschlagventile angeordnet sind, vom Hydraulikkreis getrennt. Der Hydraulikkreis ist mit einem Speicher verbunden, der auftretende Leckagen kompensiert und den Hydraulikkreis unter konstanter Vorspannung hält. Ein am Lenkhandrad vorgegebener Lenkwinkel ist eine Eingangsgröße für den Lenkaktuator. Entsprechend dieser Vorgabe treibt der Elektromotor die Hydropumpe so lange an, bis sich eine dem gemessenen Lenkwinkel entsprechende Verschiebung der Kolben-/Zylinder-Einheit eingestellt hat. Die von den gelenkten Fahrzeugrädern über die Spurstangen auf den Lenkaktuator weitergeleitete Rückwirkung wird durch in der Aufhängung des Lenkaktuators integrierte Erfassungseinheiten aufgenommen und verarbeitet. Dadurch ergibt sich ein Drehmoment-Sollwert, der am Lenkra- daktuator eingestellt wird. Das dadurch erzeugte Lenkgefühl ist somit eine direkte Größe, die aus Spurstangenkräften und Drehmoment am Lenkhandrad gebildet wird. Beim Ausfall der Elektronik oder des Elektromotors wird die erste Hydropumpe über das 4/2-Wegeventil mit der Kolben-/ Zylinder-Einheit verbunden und die zweite Hydropumpe durch zwei Rückschlagventile von der Kolben-/Zylinder-Einheit getrennt. Dadurch kann der erste Hydromotor über das Lenkhandrad manuell angetrieben und dadurch das Fahrzeug gelenkt werden.The power steering system according to the invention has a steering wheel actuator, which is used to transmit the driver a steering request applied via a steering handwheel and for generating a steering feeling is used as feedback for the driver. The steering handwheel is connected by a torsionally elastic member and a gear to an electric motor, preferably designed as an asynchronous motor. Planetary or worm gears can be used as gears. In addition, the steering handwheel is connected to a reversible hydraulic pump, which is preferably designed as a gear pump. The steering wheel actuator is connected to a steering actuator via a controlled system. This steering actuator consists of a piston / cylinder unit which transmits the driver's steering request initiated via the steering wheel actuator to the wheels of the motor vehicle to be steered. The integration of detection units in the connecting elements of the steering actuator and body structure means that tensile and compressive forces that act on the steering actuator via tie rods of the steered vehicle wheels can be measured directly. The steering actuator can thus z. B. are attached to the body structure by means of force-measuring bolts, which can directly detect the forces occurring without being influenced by interference signals. The steering actuator is connected to a further reversible hydraulic pump which is driven by an electric motor and a transmission. This second reversible hydraulic pump conveys a hydraulic medium via lines or hoses into the pressure chambers of the piston / cylinder unit. A 4/2-way valve connects or separates the two hydraulic circuits, depending on the operating state. If there is a fault in steer-by-wire operation, the hydraulic fallback level can be activated by connecting a first hydraulic pump to the piston / cylinder unit. When the hydraulic fallback level is activated, the second hydraulic pump is located at its outputs Unlockable check valves are arranged, separated from the hydraulic circuit. The hydraulic circuit is connected to an accumulator that compensates for any leaks and keeps the hydraulic circuit under constant preload. A steering angle specified on the steering handwheel is an input variable for the steering actuator. In accordance with this specification, the electric motor drives the hydraulic pump until a displacement of the piston / cylinder unit corresponding to the measured steering angle has occurred. The feedback transmitted from the steered vehicle wheels via the tie rods to the steering actuator is recorded and processed by detection units integrated in the suspension of the steering actuator. This results in a torque setpoint that is set on the steering wheel actuator. The steering feel thus generated is thus a direct variable, which is formed from tie rod forces and torque on the steering handwheel. If the electronics or electric motor fails, the first hydraulic pump is connected to the piston / cylinder unit via the 4/2-way valve and the second hydraulic pump is separated from the piston / cylinder unit by two check valves. As a result, the first hydraulic motor can be driven manually via the steering handwheel and the vehicle can thereby be steered.
Vorteilhafte und zweckmäßige Ausgestaltungen der Erfindung sind in den Unteransprüchen angegeben. Die Erfindung ist aber nicht auf die Merkmalskombinationen der Ansprüche beschränkt, vielmehr ergeben sich für den Fachmann weitere sinnvolle Kombinationsmöglichkeiten von Ansprüchen und einzelnen Anspruchsmerkmalen aus der Aufgabenstellung. Nachfolgend ist anhand der Figur ein Ausführungsbeispiel der vorliegenden Erfindung prinzipgemäß beschrieben.Advantageous and expedient embodiments of the invention are specified in the subclaims. However, the invention is not limited to the combinations of features of the claims; rather, more sensible combinations of claims and individual claim features result from the task for the person skilled in the art. An exemplary embodiment of the present invention is described in principle below with reference to the figure.
Die einzige Figur zeigt eine schematische Darstellung eines erfindungsgemäßen Hilfskraft-Lenksystems für Kraftfahrzeuge.The single figure shows a schematic representation of an auxiliary power steering system according to the invention for motor vehicles.
Ein erfindungsgemäßes Hilfskraft-Lenk? ~tem für Kraftfahrzeuge besteht aus einem Lenkaktuator 1, der über Spur- stangen 2 und 3 mit Fahrzeugrädern 4 und 5 verbunden ist. Die Spurstangen 2 und 3 sind über ein Verbindungselement 6 fest miteinander verbunden. Die über die Fahrzeugräder 4, 5 und die Spurstangen 2, 3 eingeleiteten Kräfte wirken durch das Verbindungselement 6 direkt auf Befestigungselemente 7 und 8, die den Lenkaktuator 1 mit einem Karosserieaufbau 9 verbinden. Die Befestigungselemente 7, 8 weisen nicht dargestellte Erfassungseinheiten, beispielsweise in Form von Dehnmeßstreifen auf, die die auftretenden Kräfte erfassen. Mit Hilfe dieser erfaßten Kräfte wird eine Rückwirkung durch einen Lenkradaktuator 10 auf ein Lenkhandrad 11 erzeugt und so dem Fahrer ein künstlich erzeugtes Lenkgefühl vermittelt, das der momentanen Fahrsituation entspricht. Der Lenkradaktuator 10 setzt sich aus einer Sensor-Einheit 12, einem Elektromotor 13, einer Hydropumpe 14 und einer nicht dargestellten mechanischen Baugruppe, bestehend aus einer Drehstabfeder und einem Getriebe, zusammen, der mit dem Lenkhandrad 11 in Wirkverbindung steht. Die Sensor- Einheit 12 dient zur Erfassung von Lenkwinkel und Drehmoment am Lenkhandrad 11. Der Lenkaktuator 1 ist über Leitun- gen 17 und 18 mit einem Elektromotor 15 und einer Hydropumpe 16 verbunden. Die Hydropumpe 16, der von dem Elektromotor 15 angetrieben wird, fördert Druckmedium hin zu oder weg von der Kolben-/Zylinder-Einheit 19. Abhängig vom Be- triebszustand verbindet oder trennt ein 4/2-Wegeventil 20 die Hydropumpen 14 und 16. Ausgangseitig der Hydropumpe 16 befinden sich entsperrbare Rückschlagventile 21 und 22, die im Falle einer Aktivierung der hydraulischen Rückfallebene die Hydropumpe 16 vom Hydraulikkreis trennen.An assistant steering according to the invention? ~ tem for motor vehicles consists of a steering actuator 1, which is connected to vehicle wheels 4 and 5 via track rods 2 and 3. The tie rods 2 and 3 are firmly connected to one another via a connecting element 6. The forces introduced via the vehicle wheels 4, 5 and the tie rods 2, 3 act directly through the connecting element 6 on fastening elements 7 and 8, which connect the steering actuator 1 to a body structure 9. The fastening elements 7, 8 have detection units (not shown), for example in the form of strain gauges, which detect the forces which occur. With the help of these detected forces, a reaction is generated by a steering wheel actuator 10 on a steering handwheel 11 and thus gives the driver an artificially generated steering feeling that corresponds to the current driving situation. The steering wheel actuator 10 is composed of a sensor unit 12, an electric motor 13, a hydraulic pump 14 and a mechanical assembly, not shown, consisting of a torsion bar spring and a gear, which is in operative connection with the steering handwheel 11. The sensor unit 12 is used to record the steering angle and torque on the steering handwheel 11. The steering actuator 1 is connected to an electric motor 15 and a hydraulic pump 16 via lines 17 and 18. The hydraulic pump 16, which is driven by the electric motor 15, conveys pressure medium towards or away from the piston / cylinder unit 19. drive state connects or disconnects a 4/2-way valve 20, the hydraulic pumps 14 and 16. On the output side of the hydraulic pump 16 there are unlockable check valves 21 and 22, which separate the hydraulic pump 16 from the hydraulic circuit when the hydraulic fallback level is activated.
Der Hydraulikkreis wird durch einen Speicher 23 unter Vorspannung gehalten, um auftretende Leckagen zu kompensieren. Eine zentrale Steuereinheit 24 ist über Steuerleitungen mit den Elektromotoren 13 und 14, der Sensor-Einheit 12 am Lenkhandrad 11, dem 4/2-Wegeventil 20, den Rückschlagventilen 21 und 22, den in den Befestigungselementen 7 und 8 integrierten Sensoren, einem Drucksensor 25 und einem Lagesensor 26 verbunden. The hydraulic circuit is held under prestress by a reservoir 23 in order to compensate for leaks that occur. A central control unit 24 is connected via control lines to the electric motors 13 and 14, the sensor unit 12 on the steering handwheel 11, the 4/2-way valve 20, the check valves 21 and 22, the sensors integrated in the fastening elements 7 and 8, and a pressure sensor 25 and a position sensor 26 connected.
Bezugszeichenreference numeral
1 Lenkaktuator1 steering actuator
2 Spurstange2 tie rods
3 Spurstange3 tie rods
4 Fahrzeugrad4 vehicle wheel
5 Fahrzeugrad5 vehicle wheel
6 Verbindungselement6 connecting element
7 Befestigungselement7 fastener
8 Befestigungselement8 fastener
9 Karosserieaufbau9 body construction
10 Lenkradaktuator10 steering wheel actuator
11 Lenkhandrad11 steering handwheel
12 Sensor-Einheit12 sensor unit
13 Elektromotor13 electric motor
14 Hydropumpe14 hydraulic pump
15 Elektromotor15 electric motor
16 Hydropumpe16 hydraulic pump
17 Leitung17 line
18 Leitung18 management
19 Kolben-/Zylinder-Einheit19 piston / cylinder unit
20 4/2-Wegeventil20 4/2-way valve
21 Rückschlagventil21 check valve
22 Rückschlagventil22 check valve
23 Speicher23 memory
24 zentrale Steuereinheit24 central control unit
25 Drucksensor25 pressure sensor
26 Lagesensor 26 position sensor

Claims

P a t e n t a n s p r ü c h e Patent claims
1. Hilfskraft-Lenksystem mit mindestens einem Lenkra- daktuator (11) und mindestens einem Lenkaktuator (1) und einer hydraulischen Rückfallebene, dadurch g e k e n n z e i c h n e t , daß der Lenkaktuator (1) über eine Ventileinheit ge- bzw. entsperrt werden kann.1. Auxiliary power steering system with at least one steering actuator (11) and at least one steering actuator (1) and a hydraulic fall-back level, so that the steering actuator (1) can be locked or unlocked via a valve unit.
2. Hilfskraft-Lenksystem nach Anspruch 1, dadurch g e k e n n z e i c h n e t , daß die Ventileinheit aus Rückschlagventilen (21, 22) besteht.2. Power steering system according to claim 1, characterized in that the valve unit consists of check valves (21, 22).
3. Hilfskraft-Lenksystem nach Anspruch 1, dadurch g e k e n n z e i c h n e t , daß die Ventileinheit ein 4/2-Wegeventil aufweist.3. Auxiliary power steering system according to claim 1, characterized in that the valve unit has a 4/2-way valve.
4. Hilfskraft-Lenksystem nasch Anspruch 1, dadurch g e k e n n z e i c h n e t , daß durch Schalten der Rückschlagventile (21, 22) das Hilfskraft-Lenksystem in4. power steering system nasch claim 1, characterized g e k e n n z e i c h n e t that by switching the check valves (21, 22), the power steering system in
Mittenstellung blockiert und so eine Mittenzentrierung für einen exakten Geradeauslauf erzeugt werden kann.Center position blocked and thus a centering for an exact straight running can be generated.
5. Hilfskraft-Lenksystem nach Anspruch 1, dadurch g e k e n n z e i c h n e t , daß die Erfassungseinrichtung zur Bestimmung der auftretenden Kräfte gleichzeitig zur Befestigung des Lenkaktuators (1) am Karosserieaufbau (9) verwendet wird. 5. Power steering system according to claim 1, characterized in that the detection device for determining the forces occurring is used at the same time for fastening the steering actuator (1) to the body structure (9).
PCT/EP2000/008865 1999-09-16 2000-09-12 Power-assisted steering system for motor vehicles WO2001019664A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP00962471A EP1212232A1 (en) 1999-09-16 2000-09-12 Power-assisted steering system for motor vehicles

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE1999144459 DE19944459A1 (en) 1999-09-16 1999-09-16 Power steering system for motor vehicles
DE19944459.5 1999-09-16

Publications (1)

Publication Number Publication Date
WO2001019664A1 true WO2001019664A1 (en) 2001-03-22

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EP (1) EP1212232A1 (en)
DE (1) DE19944459A1 (en)
WO (1) WO2001019664A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2836671A1 (en) * 2002-03-04 2003-09-05 Messier Bugatti ARCHITECTURE OF ORIENTATION CONTROL HYDRAULIC SYSTEM
EP1657136A1 (en) * 2003-08-19 2006-05-17 Hitachi, Ltd. Power steering device and method of controlling the power steering device
CN1332843C (en) * 2003-12-11 2007-08-22 许倍强 Combination valve for locking up steering wheel of automobile

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DE4212184A1 (en) * 1992-04-10 1993-10-14 Bosch Gmbh Robert Hydraulic control unit for double acting working cylinder esp. in vehicle steering unit - controls both working volumes by one 4/3-way valve with hydraulic shut off valve connected between each working vol. and 4/3-way valve
DE19546942C1 (en) * 1995-12-15 1997-06-19 Daimler Benz Ag Hydraulic power steering
DE19615544C1 (en) 1996-04-19 1997-10-30 Daimler Benz Ag Vehicle steering

Patent Citations (3)

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Publication number Priority date Publication date Assignee Title
DE4212184A1 (en) * 1992-04-10 1993-10-14 Bosch Gmbh Robert Hydraulic control unit for double acting working cylinder esp. in vehicle steering unit - controls both working volumes by one 4/3-way valve with hydraulic shut off valve connected between each working vol. and 4/3-way valve
DE19546942C1 (en) * 1995-12-15 1997-06-19 Daimler Benz Ag Hydraulic power steering
DE19615544C1 (en) 1996-04-19 1997-10-30 Daimler Benz Ag Vehicle steering

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2836671A1 (en) * 2002-03-04 2003-09-05 Messier Bugatti ARCHITECTURE OF ORIENTATION CONTROL HYDRAULIC SYSTEM
EP1342645A1 (en) * 2002-03-04 2003-09-10 Messier-Bugatti Hydraulic steering system
US6769251B2 (en) 2002-03-04 2004-08-03 Messier-Bugatti Hydraulic system architecture for controlling steering
EP1657136A1 (en) * 2003-08-19 2006-05-17 Hitachi, Ltd. Power steering device and method of controlling the power steering device
EP1657136A4 (en) * 2003-08-19 2011-04-20 Hitachi Ltd Power steering device and method of controlling the power steering device
CN1332843C (en) * 2003-12-11 2007-08-22 许倍强 Combination valve for locking up steering wheel of automobile

Also Published As

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EP1212232A1 (en) 2002-06-12
DE19944459A1 (en) 2001-05-17

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