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WO2003047949A1 - Dual-circuit steer-by-wire steering system with two hydraulically operated actuators - Google Patents

Dual-circuit steer-by-wire steering system with two hydraulically operated actuators Download PDF

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Publication number
WO2003047949A1
WO2003047949A1 PCT/EP2002/013604 EP0213604W WO03047949A1 WO 2003047949 A1 WO2003047949 A1 WO 2003047949A1 EP 0213604 W EP0213604 W EP 0213604W WO 03047949 A1 WO03047949 A1 WO 03047949A1
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WO
WIPO (PCT)
Prior art keywords
steer
steering
actuating
wire steering
wire
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/EP2002/013604
Other languages
German (de)
French (fr)
Inventor
Karsten Sikora
Jochen Horwath
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ThyssenKrupp Presta Muelheim GmbH
Original Assignee
Mercedes Benz Lenkungen GmbH
ThyssenKrupp Presta Steertec 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 Mercedes Benz Lenkungen GmbH, ThyssenKrupp Presta Steertec GmbH filed Critical Mercedes Benz Lenkungen GmbH
Publication of WO2003047949A1 publication Critical patent/WO2003047949A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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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
    • B62D5/001—Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup
    • 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
    • B62D5/001—Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup
    • B62D5/003—Backup systems, e.g. for manual steering

Definitions

  • the present invention relates to a two-circuit steer-by-wire steering system with two hydraulically operated actuators.
  • Steering systems which have two actuating units for adjusting the steerable wheels.
  • the actuating units of these steering systems are dimensioned in such a way that both actuating units work together in normal driving operation, ie both actuating units exert approximately the same force. Due to the simultaneous operation of both actuators, the actuators and their steering circuits can be made smaller. In the event of a steering circuit failure or Actuating unit, the still functioning other actuating unit can just adjust the wheels, which means that restricted driving is still possible.
  • Such systems are either designed with one circuit or not completely with two circuits, so that there is no real redundancy.
  • the object of the present invention is to provide a steer-by-wire steering system which is as light as possible and has low energy consumption.
  • the steering circuits are not purely emissive. This means that two steering circuits are always activated simultaneously to adjust the steerable wheels, which results in a relatively high fuel requirement.
  • the steer-by-wire steering system according to the invention has the advantage that the two steering circuits are dimensioned in such a way that they can individually apply the forces required for steering the wheels during normal driving.
  • the parking or maneuvering mode differs from normal driving, in which the steering must exert relatively high forces to steer the wheels due to the higher frictional forces.
  • both steering circuits work together, provided the increased forces are to be applied in the parking or maneuvering mode.
  • the two steering circuits can be mechanically dimensioned smaller. This advantageously results in a lower volume flow requirement of the fluid medium of a steering circuit, as a result of which the pumps can be dimensioned smaller and advantageously a lower fuel requirement is established. Due to the smaller mechanical dimensioning, the steer-by-wire steering system according to the invention is advantageously very compact in structure and low in weight.
  • Both steering circuits advantageously have a valve with a “closed center” (closed enter), as a result of which a low energy consumption of the system can be achieved.
  • a simpler control can be achieved if a control valve with an "open center" is provided for the first steering circuit, which is provided for normal driving. As a result, it is not necessary to provide a pressure accumulator for this steering circuit.
  • the second steering circuit which is only switched on when required or is switched on as a fall-back level when the first steering circuit fails, advantageously uses a control valve which is designed as a valve with a "closed center".
  • the additional use of a pressure accumulator for this second steering circuit means that the pump used to build up pressure does not have to be in continuous operation. This results in further energy savings. Thanks to the pressure accumulator, the second steering circuit is always ready for use and can be activated immediately if required.
  • the volume flow peaks caused by strong steering maneuvers are also affected by the Pressure accumulator covered, which can advantageously be used with a pump with a lower delivery rate.
  • Actuating cylinders are advantageously used as actuating units in a hydraulic system, the actuating cylinders having displacement sensors with which the position of the piston in the actuating cylinder can be adjusted.
  • the force application points of the actuators can either be the tie rod or the steering lever.
  • the respective arrangement of the actuating units is in principle arbitrary and generally depends on the arrangement of other vehicle components. Because of the relatively small and compact design of the steer-by-wire steering system according to the invention, the actuating units can be arranged at different locations in the steering system as described.
  • Fig. 1 A steer-by-wire steering system according to the invention with two actuators, the
  • Fig.3 a parallel arrangement of the two
  • Actuating cylinder with a common point of force Fig. 4: two actuators with a common cylinder housing and piston rod.
  • FIG. 1 shows an inventive two-circuit steer-by-wire system with two actuating cylinders 2, which form the actuating units, the first ends 2a of which are articulated on the tie rod 3.
  • Sensors S monitor the deflection of the two actuating cylinders 2.
  • the tie rod 3 adjusts the steerable wheels 1 via steering levers 4.
  • the second ends 2b of the actuating cylinders 2 are arranged closer to the common vehicle axle A and are fixed there to the bodywork directly or via intermediate parts.
  • the fluid medium is pressed into the working spaces of the actuating cylinder 2 by pressure lines from the pump Pi of the steering circuit LKi via a control valve Vi, which is a valve with an "open center".
  • the steering circuit LK 2 has a valve V 2 , which is a valve with a "closed center". As long as the steering circuit LK 2 or its actuating cylinder 2 is not actively involved in the steering of the wheels 1, the valve V 2 is in the central position, as a result of which the pump P 2 transfers the fluid medium from the storage container 5 via a check valve R into a pressure accumulator D. inflated.
  • the pump P 2 As soon as a certain pressure has been built up in the pressure accumulator D and measured by means of the sensor SP, the pump P 2 is switched off. Through the check valve R, the fluid medium cannot get back from the pressure accumulator D into the storage container 5. By the built-up pressure in the pressure accumulator D of the fluid medium to the steering circuit LK 2 can be activated immediately by adjustment of the valve V2. Due to the pressure in the pressure container D, the pump P 2 does not immediately have to have the required pressure build up, as this is guaranteed by the pressure accumulator D at least for a short time.
  • the actuating cylinders 2 of the two steering circuits LKi and LK 2 can have different points of attack 2a.
  • the actuating cylinder 2 of the steering circuit LKi can act on the tie rod, whereas the actuating cylinder 2 of the steering circuit LK 2 can act on a steering lever 4.
  • the points of attack 2a of the two actuating cylinders 2 of the steering circuits LKi and LK 2 are interchanged in the embodiment described last.
  • the two actuating cylinders or actuating units 12, 22 can have a common force application point. This can be done according to the embodiments. of Figures 3 and 4 can be achieved.
  • the two actuating cylinders 12 are arranged parallel to one another, the two piston rods 13 and 17 being rigidly connected to one another by means of a connecting web 19, so that the pistons 14 and 18 carry out the same movements.
  • the actuating cylinders can have a common cylinder housing 15, a partition 16 then separating the working spaces from one another.
  • the actuating cylinders it is also possible for the actuating cylinders to have separate cylinder housings.
  • both pistons 24 and 25 of the two actuating cylinders 22 are on one common piston rod 23 and arranged in a common cylinder housing 26.
  • the working spaces 27, 28, 29 and 30 are separated from one another by the pistons 24 and 25 or the collar 31 formed or fastened on the cylinder 22 and the seal 32.
  • both the force application point 12a and 22a and alternatively the force application point 12b and 22b can be articulated on the common tie rod or on a steering lever.
  • a tie rod is also required so that the forces of the actuating cylinders 12 and 22 also act on both steered wheels 1.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Power Steering Mechanism (AREA)
  • Steering Control In Accordance With Driving Conditions (AREA)

Abstract

The invention relates to a steer-by-wire steering system that comprises a first and a second hydraulically operating actuator (2) which acts upon the steerable wheels (1). In the normal drive state, only the first actuator (2) adjusts the steerable wheels (1). The second actuator (2) only optionally assists the first actuator (2) in its power boost function and/or takes over its function if the first actuator (2) fails.

Description

Zweikreisiges Steer-by-wire-Lenksystem mit zwei hydraulisch betriebenen StellaggregatenDual-circuit steer-by-wire steering system with two hydraulically operated actuators

Die vorliegende Erfindung betrifft ein zweikreisiges Steer-by-wire-Lenksystem mit zwei hydraulisch betriebenen Stellaggregaten.The present invention relates to a two-circuit steer-by-wire steering system with two hydraulically operated actuators.

Es sind Lenksysteme bekannt, die über zwei Stellaggregate zur Verstellung der lenkbaren Räder verfügen. Die Stellaggregate dieser Lenksysteme sind derart dimensioniert, dass beide Stellaggregate im normalen Fahrbetrieb zusammen arbeiten, d.h. beide Stellaggregat in etwa die gleiche Kraft aufbringen. Durch den gleichzeitigen Betrieb beider Stellaggregate können die Stellaggregate und auch deren Lenkkreise kleiner dimensioniert werden. Bei Ausfall eines Lenkkreises bzw. Stellaggregats kann das noch funktionierende andere Stellaggregat die Rader gerade noch Verstellen, wodurch ein eingeschränkter Fahrbetrieb noch möglich ist. Derartige Systeme sind entweder einkreisig oder nicht vollständig zweikreisig ausgelegt, so dass keine echte Redundanz gegeben ist.Steering systems are known which have two actuating units for adjusting the steerable wheels. The actuating units of these steering systems are dimensioned in such a way that both actuating units work together in normal driving operation, ie both actuating units exert approximately the same force. Due to the simultaneous operation of both actuators, the actuators and their steering circuits can be made smaller. In the event of a steering circuit failure or Actuating unit, the still functioning other actuating unit can just adjust the wheels, which means that restricted driving is still possible. Such systems are either designed with one circuit or not completely with two circuits, so that there is no real redundancy.

Aufgabe der vorliegenden Erfindung ist es, eine Steer-by- wire-Lenkung bereitzustellen, die ein möglichst geringes Gewicht aufweist und einen geringen Energieverbrauch hat.The object of the present invention is to provide a steer-by-wire steering system which is as light as possible and has low energy consumption.

Diese Aufgabe wird mit einer Steer-by-wire-Lenkung mit den Merkmalen des Anspruchs 1 gelost. Weitere vorteilhafte Ausgestaltungen der Erfindung ergeben sich durch die Merkmale der Unteranspruche .This object is achieved with a steer-by-wire steering system with the features of claim 1. Further advantageous embodiments of the invention result from the features of the subclaims.

Bei den aus dem Stand der Technik bekannten Steer-By- Wire-Lenksystemen ist, wie bereits ausgeführt, keine reine Emkreisigkeit der Lenkkreise realisiert. Dies bedeutet, dass stets zwei Lenkkreise gleichzeitig zur Verstellung der lenkbaren Rader angesteuert werden, wodurch sich ein relativ hoher Kraftstoffbedarf ergibt. Im Gegensatz hierzu weist die erfmdungsgemaße Steer-By- Wire-Lenkung den Vorteil auf, dass die beiden Lenkkreise so dimensioniert sind, dass s e einzeln im normalen Fahrbetrieb die benotigten Kräfte zur Lenkung der Rader aufbringen können. Vom normalen Fahrbetrieb unterscheidet sich der Parkier- bzw. Rangierbetrieb, bei dem die Lenkung aufgrund der höheren Reibkrafte relativ hohe Kräfte zur Lenkung der Rader aufbringen muss. Bei der erfmdungsgemaßen Steer-By-Wire-Lenkung arbeiten beide Lenkkreise zusammen, sofern die erhöhten Kräfte im Parkier- bzw. Rangierbetrieb aufzubringen sind. Dagegen arbeitet nur ein Lenkkreis im normalen Fahrbetrieb. Hierdurch können die beiden Lenkkreise für sich kleiner mechanisch dimensioniert werden. Dadurch ergibt sich vorteilhaft ein geringerer Volumenstrombedarf des fluiden Mediums eines Lenkkreises, wodurch die Pumpen kleiner dimensioniert werden können und sich vorteilhaft ein geringerer Kraftstoffbedarf einstellt. Durch die kleinere mechanische Dimensionierung ist die erfindungsgemäße Steer-By-Wire-Lenkung vorteilhaft sehr kompakt in ihrem Aufbau und gering an Gewicht .In the steer-by-wire steering systems known from the prior art, as already stated, the steering circuits are not purely emissive. This means that two steering circuits are always activated simultaneously to adjust the steerable wheels, which results in a relatively high fuel requirement. In contrast to this, the steer-by-wire steering system according to the invention has the advantage that the two steering circuits are dimensioned in such a way that they can individually apply the forces required for steering the wheels during normal driving. The parking or maneuvering mode differs from normal driving, in which the steering must exert relatively high forces to steer the wheels due to the higher frictional forces. In the steer-by-wire steering system according to the invention, both steering circuits work together, provided the increased forces are to be applied in the parking or maneuvering mode. In contrast, only one steering circuit works in normal driving. As a result, the two steering circuits can be mechanically dimensioned smaller. This advantageously results in a lower volume flow requirement of the fluid medium of a steering circuit, as a result of which the pumps can be dimensioned smaller and advantageously a lower fuel requirement is established. Due to the smaller mechanical dimensioning, the steer-by-wire steering system according to the invention is advantageously very compact in structure and low in weight.

Vorteilhaft weisen beide Lenkkreise ein Ventil mit „geschlossener Mitte" (closed enter) auf, wodurch sich ein geringer Energieverbrauch des Systems erzielen lässt.Both steering circuits advantageously have a valve with a “closed center” (closed enter), as a result of which a low energy consumption of the system can be achieved.

Eine einfachere Steuerung lässt sich dagegen erzielen, wenn für den ersten Lenkkreis, welcher für den normalen Fahrbetrieb vorgesehen ist, ein Steuerventil mit "geöffneter Mitte" (open center) vorgesehen. Hierdurch ist es nicht erforderlich, einen Druckspeicher für diesen Lenkkreis vorzusehen. Der zweite Lenkkreis, welcher nur beim Bedarfsfall zugeschaltet oder aber bei Ausfall des ersten Lenkkreises für diesen als Rückfallebene zugeschaltet wird, verwendet vorteilhaft ein Steuerventil, welches als Ventil mit "geschlossener Mitte" (closed center) ausgebildet ist. Durch zusätzliche Verwendung eines Druckspeichers für diesen zweiten Lenkkreis wird erreicht, dass die zum Druckaufbau eingesetzte Pumpe nicht fortlaufend in Betrieb sein muss . Hierdurch wird eine weitere Energieeinsparung erzielt. Durch den Druckspeicher ist der zweite Lenkkreis stets einsatzbereit und kann bei Bedarf sofort zugeschaltet werden. Auch werden die Volumenstromspitzen, die durch starke Lenkmanöver hervorgerufen werden, durch den Druckspeicher gedeckt, wodurch vorteilhaft eine Pumpe mit geringerer Förderleistung zum Einsatz kommen kann.On the other hand, a simpler control can be achieved if a control valve with an "open center" is provided for the first steering circuit, which is provided for normal driving. As a result, it is not necessary to provide a pressure accumulator for this steering circuit. The second steering circuit, which is only switched on when required or is switched on as a fall-back level when the first steering circuit fails, advantageously uses a control valve which is designed as a valve with a "closed center". The additional use of a pressure accumulator for this second steering circuit means that the pump used to build up pressure does not have to be in continuous operation. This results in further energy savings. Thanks to the pressure accumulator, the second steering circuit is always ready for use and can be activated immediately if required. The volume flow peaks caused by strong steering maneuvers are also affected by the Pressure accumulator covered, which can advantageously be used with a pump with a lower delivery rate.

Vorteilhaft werden als Stellaggregate bei einem hydraulischen System Stellzylinder verwendet, wobei die Stellzylinder über Wegsensoren verfügen, mit denen die Stellung des Kolbens im Stellzylinder einregelbar ist.Actuating cylinders are advantageously used as actuating units in a hydraulic system, the actuating cylinders having displacement sensors with which the position of the piston in the actuating cylinder can be adjusted.

Die Kraftangriffspunkte der Stellaggregate können entweder die Spurstange oder aber die Lenkhebel sein. Die jeweilige Anordnung der Stellaggregate ist prinzipiell beliebig und hängt in der Regel von der Anordnung anderer Fahrzeugkomponenten ab. Aufgrund der relativ kleinen und kompakten Bauweise der erfindungsgemäßen Steer-By-Wire- Lenkung können die Stellaggregate wie beschrieben an verschiedenen Orten des Lenksystems angeordnet werden.The force application points of the actuators can either be the tie rod or the steering lever. The respective arrangement of the actuating units is in principle arbitrary and generally depends on the arrangement of other vehicle components. Because of the relatively small and compact design of the steer-by-wire steering system according to the invention, the actuating units can be arranged at different locations in the steering system as described.

Nachfolgend werden zwei Ausführungsformen einer erfindungsgemäßen Steer-By-Wire-Lenkung anhand von Figuren näher erläutert.Two embodiments of a steer-by-wire steering system according to the invention are explained in more detail below with reference to figures.

Es zeigen:Show it:

Fig. 1: eine erfindungsgemäße Steer-By-Wire-Lenkung mit zwei Stellaggregaten, derenFig. 1: A steer-by-wire steering system according to the invention with two actuators, the

Kraftangriffspunkte die Spurstange sind;Force application points are the tie rod;

Fig. 2: eine alternative Ausführungsform, bei der die Kraftangriffspunkte der Stellaggregate die Lenkhebel sind;2 shows an alternative embodiment in which the force application points of the actuating units are the steering levers;

Fig.3 : eine parallele Anordnung der beidenFig.3: a parallel arrangement of the two

Stellzylinder mit gemeinsamen Kraft- Angriffspunkt; Fig. 4: zwei Stellaggregate mit gemeinsamen Zylindergehäuse und Kolbenstange.Actuating cylinder with a common point of force; Fig. 4: two actuators with a common cylinder housing and piston rod.

Die Fig. 1 zeigt ein erfindungsgemäßes zweikreisiges Steer-By-Wire-System mit zwei Stellzylindern 2, die die Stellaggregate bilden, deren ersten Enden 2a an der Spurstange 3 angelenkt sind. Sensoren S überwachen die Auslenkung der beiden Stellzylinder 2. Die Spurstange 3 verstellt über Lenkhebel 4 die lenkbaren Räder 1. Die zweiten Enden 2b der Stellzylinder 2 sind näher zur gemeinsamen Fahrzeugachse A angeordnet und dort an der Karosserie direkt oder über Zwischenteile befestigt. Über Druckleitungen wird von der Pumpe Pi des Lenkkreises LKi über ein Steuerventil Vi, welches ein Ventil mit "offener Mitte" ist, das fluide Medium in die Arbeitsräume des Stellzylinders 2 gedrückt. Der Lenkkreis LK2 verfügt über ein Ventil V2, welches ein Ventil mit "geschlossener Mitte" ist. Solange der Lenkkreis LK2 bzw. dessen Stellzylinder 2 nicht aktiv an der Lenkung der Räder 1 beteiligt ist, befindet sich das Ventil V2 in der Mittenstellung, wodurch die Pumpe P2 das fluide Medium vom Vorratsbehältnis 5 über ein Rückschlagventil R in einen Druckspeicher D pumpt.1 shows an inventive two-circuit steer-by-wire system with two actuating cylinders 2, which form the actuating units, the first ends 2a of which are articulated on the tie rod 3. Sensors S monitor the deflection of the two actuating cylinders 2. The tie rod 3 adjusts the steerable wheels 1 via steering levers 4. The second ends 2b of the actuating cylinders 2 are arranged closer to the common vehicle axle A and are fixed there to the bodywork directly or via intermediate parts. The fluid medium is pressed into the working spaces of the actuating cylinder 2 by pressure lines from the pump Pi of the steering circuit LKi via a control valve Vi, which is a valve with an "open center". The steering circuit LK 2 has a valve V 2 , which is a valve with a "closed center". As long as the steering circuit LK 2 or its actuating cylinder 2 is not actively involved in the steering of the wheels 1, the valve V 2 is in the central position, as a result of which the pump P 2 transfers the fluid medium from the storage container 5 via a check valve R into a pressure accumulator D. inflated.

Sobald ein gewisser Druck im Druckspeicher D aufgebaut und mittels des Sensors SP gemessen wurde, wird die Pumpe P2 abgeschaltet. Durch das Rückschlagventil R kann das fluide Medium nicht zurück aus dem Druckspeicher D in das Vorratsbehältnis 5 gelangen. Durch den im Druckspeicher D aufgebauten Druck des fluiden Mediums kann der Lenkkreis LK2 sofort durch Verstellung des Ventils V2 aktiviert werden. Aufgrund des vorhandenen Drucks im Druckbehältnis D muss die Pumpe P2 nicht sofort den erforderlichen Druck aufbauen, da dies durch den Druckspeicher D zumindest für kurze Zeit gewährleistet ist.As soon as a certain pressure has been built up in the pressure accumulator D and measured by means of the sensor SP, the pump P 2 is switched off. Through the check valve R, the fluid medium cannot get back from the pressure accumulator D into the storage container 5. By the built-up pressure in the pressure accumulator D of the fluid medium to the steering circuit LK 2 can be activated immediately by adjustment of the valve V2. Due to the pressure in the pressure container D, the pump P 2 does not immediately have to have the required pressure build up, as this is guaranteed by the pressure accumulator D at least for a short time.

Die Fig. 2 zeigt eine alternative Anordnung der Stellzylinder 2, wobei diese nicht mehr an der Spurstange 3 mit ihren Kraftangriffspunkten 2a angreifen, sondern an den Lenkhebeln 4.2 shows an alternative arrangement of the actuating cylinders 2, whereby these no longer act on the tie rod 3 with their force application points 2a, but on the steering levers 4.

Alternativ ist auch möglich, dass die Stellzylinder 2 der beiden Lenkkreise LKi und LK2 unterschiedliche Angriffspunkte 2a besitzen. So kann zum Beispiel der Stellzylinder 2 des Lenkkreises LKi an der Spurstange angreifen, wohingegen der Stellzylinder 2 des Lenkkreises LK2 an einem Lenkhebel 4 angreift. Ebenso ist es möglich, daß die Angriffspunkte 2a der beiden Stellzylinder 2 der Lenkkreise LKi und LK2 im zuletzt beschriebenen Ausführungsbeispiel vertauscht sind.Alternatively, it is also possible for the actuating cylinders 2 of the two steering circuits LKi and LK 2 to have different points of attack 2a. For example, the actuating cylinder 2 of the steering circuit LKi can act on the tie rod, whereas the actuating cylinder 2 of the steering circuit LK 2 can act on a steering lever 4. It is also possible that the points of attack 2a of the two actuating cylinders 2 of the steering circuits LKi and LK 2 are interchanged in the embodiment described last.

Alternativ ist es auch möglich, dass die beiden Stellzylinder bzw. Stellaggregate 12, 22 einen gemeinsamen Kraft-Angriffspunkt besitzen. Dies kann mit den Ausführungsformen gem. der Figuren 3 und 4 erreicht werden. Bei der Ausführungsform gem. der Fig. 3 sind die beiden Stellzylinder 12 parallel zueinander angeordnet, wobei die beiden Kolbenstangen 13 und 17 mittels eines Verbindungsstegs 19 starr miteinander verbunden sind, so daß die Kolben 14 und 18 die selben Bewegungen durchführen. Die Stellzylinder können über ein gemeinsames Zylindergehäuse 15 verfügen, wobei dann eine Trennwand 16 die Arbeitsräume voneinander trennt. Es ist jedoch auch möglich, dass die Stellzylinder über separate Zylindergehäuse verfügen.Alternatively, it is also possible for the two actuating cylinders or actuating units 12, 22 to have a common force application point. This can be done according to the embodiments. of Figures 3 and 4 can be achieved. In the embodiment according to 3, the two actuating cylinders 12 are arranged parallel to one another, the two piston rods 13 and 17 being rigidly connected to one another by means of a connecting web 19, so that the pistons 14 and 18 carry out the same movements. The actuating cylinders can have a common cylinder housing 15, a partition 16 then separating the working spaces from one another. However, it is also possible for the actuating cylinders to have separate cylinder housings.

Bei der Ausführungsform gem. der Fig. 4 sind beide Kolben 24 und 25 der beiden Stellzylinder 22 an einer gemeinsamen Kolbenstange 23 und in einem gemeinsamen Zylindergehäuse 26 angeordnet. Die Arbeitsräume 27, 28, 29 und 30 werden durch die Kolben 24 und 25 bzw. den am Zylinder 22 angeformten oder befestigten Kragen 31 und der Dichtung 32 voneinander getrennt.In the embodiment according to 4, both pistons 24 and 25 of the two actuating cylinders 22 are on one common piston rod 23 and arranged in a common cylinder housing 26. The working spaces 27, 28, 29 and 30 are separated from one another by the pistons 24 and 25 or the collar 31 formed or fastened on the cylinder 22 and the seal 32.

Bei beiden Ausführungsformen der Figuren 3 und 4 können je nach Einsatz sowohl der Kraftangriffspunkt 12a bzw. 22a als auch alternativ der Kraftangriffspunkt 12b bzw. 22b an der gemeinsamen Spurstange oder an einem Lenkhebel angelenkt sein. Beim Anlenken an einem Lenkhebel ist zusätzlich noch eine Spurstange erforderlich, damit die Kräfte der Stellzylinder 12 bzw. 22 auch auf beide gelenkten Räder 1 wirken. In both embodiments of FIGS. 3 and 4, depending on the application, both the force application point 12a and 22a and alternatively the force application point 12b and 22b can be articulated on the common tie rod or on a steering lever. When articulating on a steering lever, a tie rod is also required so that the forces of the actuating cylinders 12 and 22 also act on both steered wheels 1.

Claims

P a t e n ta n s p rü ch e P aten ta nsp rü ch e 1. Steer-By-Wire-Lenkung, mit einem ersten und einem zweiten auf die lenkbaren Räder (1) wirkenden hydraulisch arbeitenden Stellaggregat (2, 12, 22), wobei im normalen Fahrbetrieb nur das erste Stellaggregat (2, 12, 22) die lenkbaren Räder (1) verstellt und das zweite Stellaggregat (2, 12, 22) nur hilfsweise zur Krafterhöhung das erste Stellaggregat (2, 12, 22) unterstützt und/oder bei Ausfall des ersten Stellaggregats (2) dessen Funktion übernimmt.1. Steer-by-wire steering, with a first and a second hydraulically operating actuating unit (2, 12, 22) acting on the steerable wheels (1), only the first actuating unit (2, 12, 22) in normal driving operation the steerable wheels (1) are adjusted and the second actuating unit (2, 12, 22) only supports the first actuating unit (2, 12, 22) and / or assumes its function if the first actuating unit (2) fails in order to increase the force. 2. Steer-By-Wire-Lenkung nach Anspruch 1, da du r ch ge ke nn z e i chne t , dass das Stellaggregat jeweils ein Stellzylinder (2, 12, 22) ist, wobei jedem Stellzylinder (2, 12, 22), jeweils mindestens eine Pumpe (Plf P2) zur Erzeugung eines2. Steer-by-wire steering according to claim 1, since you r ch ge ke nn zei chne t that the actuating unit is in each case an actuating cylinder (2, 12, 22), each actuating cylinder (2, 12, 22), in each case at least one pump (P lf P 2 ) for generating a Arbeitsdruckes des Fluids zugeordnet ist, wobei zwischen der mindestens einen Pumpe (Pi, P2) und demWorking pressure of the fluid is assigned, wherein between the at least one pump (Pi, P 2 ) and Stellzylinder (2, 12, 22) jeweils ein SteuerventilControl cylinders (2, 12, 22) each have a control valve (Vi, V2) angeordnet ist.(Vi, V 2 ) is arranged. 3. Steer-By-Wire-Lenkung nach Anspruch 1 oder 2, da du r ch ge ke nn z e i ch n e t , dass das Steuerventil (Vi) des ersten Stellzylinders (2, 12, 22) ein Ventil mit offener Mitte („open center") oder mit „geschlossener Mitte" („closed center") ist. 3. Steer-by-wire steering according to claim 1 or 2, since you r ch ge ke nn zei ch net that the control valve (Vi) of the first actuating cylinder (2, 12, 22) is a valve with an open center ("open center ") or with" closed center ". . Steer-By-Wire-Lenkung nach einem der Ansprüche 1 bis 3, d a d u r c h g e k e n n z e i c h n e t , dass das Steuerventil (V2) des zweiten Stellzylinders (2, 12, 22) ein Ventil mit geschlossener Mitte ("closed center") ist., Steer-by-wire steering system according to one of claims 1 to 3, characterized in that the control valve (V 2 ) of the second actuating cylinder (2, 12, 22) is a valve with a closed center ("closed center"). 5. Steer-By-Wire-Lenkung nach einem der vorhergehenden Ansprüche, da du r ch ge k e n n z e i chn e t , dass jeweils ein Stellzylinder (2, 12, 22), die dem Stellzylinder (2, 12, 22) zugeordnete mindestens eine Pumpe (Pi, P2) sowie das Steuerventil (Vi, V2) jeweils einen Lenkkreis (LKi, LK2) bilden, wobei bei Verwendung eines Steuerventils mit geschlossener Mitte ein zusätzlicher Druckspeicher (D) im Lenkkreis angeordnet ist.5. Steer-by-wire steering according to one of the preceding claims, since you r ch ge kennzei chn et that in each case an actuating cylinder (2, 12, 22), the actuating cylinder (2, 12, 22) assigned at least one pump (Pi, P 2 ) and the control valve (Vi, V 2 ) each form a steering circuit (LKi, LK 2 ), an additional pressure accumulator (D) being arranged in the steering circuit when using a control valve with a closed center. 6. Steer-By-Wire-Lenkung nach Anspruch 5, da du r c h ge ke n n z e i chne t , dass der erste Lenkkreis (LKi) derart dimensioniert ist bzw. ein derart großes Kraftniveau besitzt, dass er mit Ausnahme für den Parkierbetrieb bzw. Rangierbetrieb des gelenkten Fahrzeugs hinreichend große Kräfte für der Fahrbetrieb aufbringt.6. Steer-by-wire steering system according to claim 5, since you rch ge ke nnzei chne t that the first steering circuit (LKi) is dimensioned or has such a large level of force that it with the exception for the parking operation or shunting operation of the steered vehicle applies sufficiently large forces for driving. 7. Steer-By-Wire-Lenkung nach einem der vorhergehenden Ansprüche, da du r ch ge k e nn z e i ch n e t , dass der zweite Lenkkreis (LK2) ein gleiches oder niedrigeres Kraftniveau als der erste Lenkkreis (LKi) hat.7. Steer-by-wire steering according to one of the preceding claims, since you r ch ge ke nn zei ch net that the second steering circuit (LK 2 ) has an equal or lower power level than the first steering circuit (LKi). 8. Steer-By-Wire-Lenkung nach Anspruch 7, da du r ch ge k e n n z e i chn e t , dass der zweite Lenkkreis8. Steer-by-wire steering according to claim 7, since you r ch ge k e n z e i chn e t that the second steering circuit (LK2) ein Kraftniveau hat, derart, dass er alleine bei Ausfall des ersten Lenkkreises (LKi) die vorgeschriebenen Notlenkeigenschaften erfüllt. (LK 2 ) has a power level such that it only fulfills the prescribed emergency steering characteristics if the first steering circuit (LKi) fails. 9. Steer-By-Wire-Lenkung nach einem der vorhergehenden Ansprüche, dadu r ch ge k e nn z e i chn e t , dass das erste und/oder das zweite Stellaggregat (2, 12, 22) mit seinem einen ersten Ende (2a, 12a, 22a) an der Spurstange (3) befestigt bzw. angelenkt ist und auf diese zur Lenkung der Räder (1) eine Kraft ausübt .9. Steer-by-wire steering according to one of the preceding claims, that the first and / or the second actuating unit (2, 12, 22) with its one first end (2a, 12a , 22a) is fastened or articulated to the tie rod (3) and exerts a force thereon for steering the wheels (1). 10. Steer-By-Wire-Lenkung nach einem der vorhergehenden Ansprüche, da du r ch geke nn z e i chn e t , dass das erste Stellaggregat (2) mit seinem einen ersten Ende (2a) an einem Lenkhebel (4) eines ersten lenkbaren Rads (1) und das zweite Stellaggregat (2) mit seinem einen ersten Ende (2a) an einem Lenkhebel10. Steer-by-wire steering according to any one of the preceding claims, since you have chosen that the first actuating unit (2) with its one first end (2a) on a steering lever (4) of a first steerable wheel (1) and the second actuator (2) with its one first end (2a) on a steering lever (4) eines zweiten lenkbaren Rads (1) befestigt bzw. angelenkt ist.(4) a second steerable wheel (1) is attached or articulated. 11. Steer-By-Wire-Lenkung nach Anspruch 8 oder 9, da du r ch ge k e nn z e i ch n e t , dass das zweite Ende (2b) jedes Stellaggregats (2) in einem Bereich an der Fahrzeugkarosse befestigt bzw. angelenkt ist, der näher zur gemeinsamen Achse (A) der gelenkten Räder (1) ist als das jeweilige erste Ende (2a) der Stellaggregate (2) .11. Steer-by-wire steering according to claim 8 or 9, since you r ch ge ke nn zei ch net that the second end (2b) of each actuator (2) is attached or articulated in an area on the vehicle body, which is closer to the common axis (A) of the steered wheels (1) than the respective first end (2a) of the actuating units (2). 12. Steer-By-Wire-Lenkung nach einem der vorhergehenden Ansprüche, da du r ch ge ke nn z e i chn e t , dass die Pumpe (P2) des zweiten Stellaggregats (2, 12, 22) nur solange in Betrieb ist, bis sich ein bestimmter Druck im zugehörigen Druckspeicher (D) aufgebaut hat.12. Steer-by-wire steering according to one of the preceding claims, since you r ch ge ke nn zei chn et that the pump (P 2 ) of the second actuator (2, 12, 22) is only in operation until a certain pressure has built up in the associated pressure accumulator (D). 13. Steer-By-Wire-Lenkung nach einem der vorhergehenden Ansprüche, da du r ch ge ke n n z e i chn e t , daß jeweils ein Elektromotor die mindestens eine Pumpe (Pi, P2) eines Lenkkreises (LKi, LK2) antreibt.13. Steer-by-wire steering according to one of the preceding claims, since you r ch ge ke nnzei chn et, that an electric motor drives the at least one pump (Pi, P 2 ) of a steering circuit (LKi, LK 2 ). 14. Steer-By-Wire-Lenkung nach einem der vorhergehenden Ansprüche, da du r ch ge ke nn z e i chne t , dass der das Fahrzeug antreibende Motor über eine Kupplung die Pumpe (Pi, P2) mindestens eines Lenkkreises (LKi, LK2) antreibt.14. Steer-by-wire steering according to one of the preceding claims, since you r ch ge ke nn zei chne t that the motor driving the vehicle via a clutch, the pump (Pi, P 2 ) at least one steering circuit (LKi, LK 2 ) drives. 15. Steer-By-Wire-Lenkung nach einem der vorhergehenden Ansprüche, da du r ch ge ke nn z e i ch n e t , dass die beiden Stellzylinder (12, 22) einen gemeinsamen Kraftangriffspunkt auf die Spurstange oder einen Lenkhebel haben.15. Steer-by-wire steering according to one of the preceding claims, since you r ch ge ke nn z e i ch n e t that the two actuating cylinders (12, 22) have a common force application point on the tie rod or a steering lever. 16. Steer-By-Wire-Lenkung nach Anspruch 15, d a d u r c h g e k e n n z e i c h n e t , dass die beiden Stellzylinder (12) parallel zueinander angeordnet und die beiden Kolbenstangen (13,17) mittels eines Verbindungsstegs (19) starr miteinander verbunden fest sind.16. Steer-by-wire steering according to claim 15, so that the two actuating cylinders (12) are arranged parallel to one another and the two piston rods (13, 17) are rigidly connected to one another by means of a connecting web (19). 17. Steer-By-Wire-Lenkung nach Anspruch 15, d d u r c h g e k e n n z e i c h n e t , dass die beiden17. Steer-by-wire steering according to claim 15, which means that the two Stellzylinder (22) ein gemeinsames Zylindergehäuse (26) aufweisen, wobei die Kolben (24, 25) der beiden Stellzylinder (22) eine gemeinsame Kolbenstange 23 besitzen . Actuating cylinders (22) have a common cylinder housing (26), the pistons (24, 25) of the two actuating cylinders (22) having a common piston rod 23.
PCT/EP2002/013604 2001-12-04 2002-12-02 Dual-circuit steer-by-wire steering system with two hydraulically operated actuators Ceased WO2003047949A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2448914A (en) * 2007-05-03 2008-11-05 Jcb Landpower Ltd Vehicle with two fluid operated steering actuators
WO2020001736A1 (en) 2018-06-25 2020-01-02 Volvo Truck Corporation A steering assembly for a vehicle

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006019804B4 (en) * 2006-04-28 2009-01-15 Sauer-Danfoss Aps Hydraulic steering
DE102007057023A1 (en) 2006-12-18 2008-06-19 Sauer-Danfoss Aps Actuator control method e.g. for steering systems of motor vehicles or ships, involves generating desired movement of element and providing three channels for flow of liquid
DE102011009822B4 (en) * 2011-01-31 2012-12-06 Liebherr-Werk Ehingen Gmbh Mobile crane with active rear axle steering

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2579548A1 (en) * 1985-03-26 1986-10-03 Renault Dual-circuit power-assisted steering system
DE19615544C1 (en) * 1996-04-19 1997-10-30 Daimler Benz Ag Vehicle steering
DE19703846A1 (en) * 1997-02-01 1998-08-06 Claas Ohg Electro-hydraulic steering system for vehicles
DE19839953A1 (en) * 1998-09-02 2000-03-16 Daimler Chrysler Ag Steering system for non-track-bound motor vehicles
DE19946074A1 (en) * 1999-09-25 2001-04-26 Volkswagen Ag Electro-hydraulic steering gear of vehicle has majority discriminator making control of hydraulic adjusting device by electronic control device dependent on signals going out from sensors

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3730708A1 (en) * 1987-09-12 1989-03-23 Man Nutzfahrzeuge Gmbh AUXILIARY POWER STEERING SYSTEM FOR VEHICLES
JPH06500290A (en) * 1990-09-21 1994-01-13 ツェットエフ、フリードリッヒスハーフェン、アクチエンゲゼルシャフト Rack and pinion type power steering device especially for heavy vehicles
DK0551371T3 (en) * 1990-10-13 1995-03-13 Zahnradfabrik Friedrichshafen Hydrostatic steering device with hydraulic auxiliary power for motor vehicles
DE19546733C1 (en) * 1995-12-14 1997-03-27 Daimler Benz Ag Hydraulic servo steering for motor vehicle
DE19603270C1 (en) * 1996-01-30 1997-07-10 Daimler Benz Ag Hydraulic power steering for motor vehicles
DE19733032C1 (en) * 1997-07-31 1998-09-24 Mercedes Benz Lenkungen Gmbh Hydraulic servo-assisted steering arrangement for motor vehicle
DE19839951C2 (en) * 1998-09-02 2000-06-21 Daimler Chrysler Ag Steering system for non-track-bound motor vehicles
DE19855405B4 (en) * 1998-12-01 2005-03-03 Daimlerchrysler Ag Hydraulic power steering for motor vehicles
DE19935073A1 (en) * 1999-07-28 2001-02-01 Mercedes Benz Lenkungen Gmbh Steer-by-wire steering system with hydraulic pressure reservoir has two control motors as mutually independently operated associated units, each able to perform full steering function

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2579548A1 (en) * 1985-03-26 1986-10-03 Renault Dual-circuit power-assisted steering system
DE19615544C1 (en) * 1996-04-19 1997-10-30 Daimler Benz Ag Vehicle steering
DE19703846A1 (en) * 1997-02-01 1998-08-06 Claas Ohg Electro-hydraulic steering system for vehicles
DE19839953A1 (en) * 1998-09-02 2000-03-16 Daimler Chrysler Ag Steering system for non-track-bound motor vehicles
DE19946074A1 (en) * 1999-09-25 2001-04-26 Volkswagen Ag Electro-hydraulic steering gear of vehicle has majority discriminator making control of hydraulic adjusting device by electronic control device dependent on signals going out from sensors

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2448914A (en) * 2007-05-03 2008-11-05 Jcb Landpower Ltd Vehicle with two fluid operated steering actuators
US7837001B2 (en) 2007-05-03 2010-11-23 Jcb Landpower Limited Dual hydrostatic vehicle steering system
GB2448914B (en) * 2007-05-03 2012-03-07 Jcb Landpower Ltd Vehicle
WO2020001736A1 (en) 2018-06-25 2020-01-02 Volvo Truck Corporation A steering assembly for a vehicle
US11952060B2 (en) 2018-06-25 2024-04-09 Volvo Truck Corporation Steering assembly for a vehicle

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