WO1994020354A1 - Power-assisted steering for, in particular, motor vehicles - Google Patents
Power-assisted steering for, in particular, motor vehicles Download PDFInfo
- Publication number
- WO1994020354A1 WO1994020354A1 PCT/EP1994/000733 EP9400733W WO9420354A1 WO 1994020354 A1 WO1994020354 A1 WO 1994020354A1 EP 9400733 W EP9400733 W EP 9400733W WO 9420354 A1 WO9420354 A1 WO 9420354A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- steering
- valve
- spindle
- ball
- ball screw
- Prior art date
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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
- B62D5/08—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle characterised by type of steering valve used
- B62D5/081—Seat valves
-
- 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
- B62D5/20—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle specially adapted for particular type of steering gear or particular application
- B62D5/24—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle specially adapted for particular type of steering gear or particular application for worm type
Definitions
- the invention relates to an auxiliary power steering system, in particular for motor vehicles, according to the preamble of claim 1.
- an input member is rotatably mounted in a steering housing.
- An output member is guided axially displaceably in the steering housing as a function of the rotary movement of the input member.
- the output member is connected to a servo motor for auxiliary power support.
- a steering valve serves to control a pressure means to and from the servo motor and is adjustable as a function of a movement of the input member.
- the steering valve has an inlet seat valve and an outlet seat valve for each steering direction.
- Such an auxiliary power steering is the subject of the older German patent application P 42 03 335.7.
- This is a power assisted rack and pinion steering system, the input member of which is a pinion and the output member of which is a rack.
- the pinion is pivotally mounted, the pivoting movement taking place as a function of a rotation of the pinion and serving to adjust the steering valve.
- the power assisted rack and pinion steering system uses the movement of the pinion to adjust the steering valve.
- the application of a closed center tax system, ie of tax Systems in which the pressure medium line coming from the pressure medium source is blocked in the neutral position of the steering valve is therefore limited to power assisted-rack steering systems.
- the invention is based on the object of designing a control system with a closed center which can also be used for ball nut hydraulic steering systems.
- the solution is achieved in particular in that the input member is a ball screw that can be axially displaced within narrow limits and the output member is a ball nut.
- An actuating lever can be rotated on the ball screw, but is axially immovable relative to the ball screw.
- the actuating lever which serves to adjust the steering valve, is acted upon by the force of the centering spring in its axial neutral position.
- the ball screw is kept free of hydraulic, axially directed forces.
- FIG. 1 shows a longitudinal section through the power steering system according to the invention.
- FIG. 2 shows a partial section through the power steering system along the line II-II in FIG. 1st
- an input member in the form of a ball screw 2 is rotatably supported and axially displaceable in a radial bearing 3 within narrow limits.
- the ball screw 2 protrudes from the steering housing 1 and carries a steering spindle connection 4.
- the end 5 of the ball screw 2 opposite the steering spindle connection 4 projects into a bore 6 in the steering housing 1.
- the end 5 of the ball screw 2 is sealed off from the steering housing 1 by a seal 7.
- a space 10 is formed between the end face 8 of the ball screw 2 and the steering housing 1 and is pressurized with atmospheric pressure via a relief bore 11 or communicates with a pressure medium container 12 via this bore.
- the ball screw 2 is in a driving connection via a ball chain 13 with a ball nut 14, which is formed at one end as a servo piston 15.
- the servo piston 15 separates two working spaces 16 and 17 of a servo motor 18 arranged in the steering housing 1.
- An actuating lever 20 is rotatably connected to the ball screw 2, for example via a double-row ball bearing 21. At the same time, the actuating lever 20 is held against tilting and axially immovable relative to the ball screw 2.
- the actuating lever 20 is used to adjust a steering valve 22 which is used to control the pressure medium conveyed by a servo pump (not shown) and expediently stored in a memory to and from the working spaces 16 and 17 of the servo motor 18 in the steering housing 1 ⁇ is classified.
- the steering valve 22 contains two inlet seat valves 23 and 24 and two outlet seat valves 25 and 26.
- the inlet and outlet seat valves 23, 24, 25, 26 are arranged essentially parallel to the axis of the ball screw 2. In this case, an inlet seat valve 23 and 24 and an outlet seat valve 25 and 26 are arranged coaxially to each other.
- Inlet seat valves 23 and 24 closed.
- the play-free centering takes place on the one hand by two centering springs 30 and 31, which press a stop disk 32 against a stop 33 fixed to the housing and against the actuating lever 20, and on the other hand by means of a centering spring 34, which expediently acts directly on the actuating lever 20.
- the centering springs 30, 31 and 34 are expediently of the same size and have the same biasing forces.
- the actuating washer 32 is pressed upwards with a force twice as high - in FIG. 1 - while only the simple force of the centering spring 34 acts on the actuating lever 20 in the other direction. Since the adjustment paths of the actuating lever 20 and thus of the steering valve 22 are only very small, the centering forces are the same for both steering directions. (In the drawing, the adjustment paths of the exhaust seat valves 25 and 26 are shown exaggeratedly large in order to show the passages which are open when the steering valve 22 is in the neutral position.)
- the function of the power steering system according to the invention is described below: If the ball screw 2 is rotated, for example, by turning a steering handwheel (not shown) to the right, it screws into the ball nut 14 so that after overcoming the centering force of the two centering springs 30 and 31 (the force of the centering spring 34 has a reinforcing effect in this direction), the stop disk 32 is moved downward. As a result, the lower outlet seat valve 25 is closed and then the lower inlet seat valve 23 is opened. From an inlet port 35 via the then open inlet seat valve 23 pressure medium in the lower working space 16 is guided, whereby a movement of the ball nut 14 above the servo piston 15 is increased.
- the radial bearing 3 is expediently designed as a combined ball-roller bearing. By means of such a bearing, the friction of the spindle bearing can be practically neglected in normal operation of the power steering when the ball spindle 2 moves axially.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Mechanically-Actuated Valves (AREA)
Abstract
Described is a power-assisted steering unit, designed in particular for motor vehicles, in which a ball spindle (2) is mounted to rotate in the steering-unit housing (1) and to move within narrow limits along its longitudinal axis. The spindle (2) works in conjunction with a ball nut (14) connected to the piston (15) of a servo motor (18). In order to control the flow of hydraulic fluid between the two work spaces (16, 17) in the servo motor (18), a steering valve (22) is fitted which can be regulated as a function of the rotational motion of the spindle (2). The steering valve (22) has, for each steering direction, a seat-type inlet valve (23, 24) and a seat-type outlet valve (25, 26). The inlet valves (23, 24) are closed when the steering valve is in the neutral position. Regulation of the steering valve (22) is by means of a control lever (20) which is held on the spindle (2) so that it can rotate but not move along the longitudinal axis of the spindle (2) and which is acted on by centering springs (30, 31, 34) which keep it in the neutral longitudinal position. The spindle (2) is relieved of additional hydraulic forces acting in the longitudinal direction by virtue of the fact that one of its ends (5) is mounted in a seal in the steering-unit housing (1), forming a space (10) between the end surface (8) of the spindle (2) and the housing (1) which is exposed to the pressure of the atmosphere.
Description
Hilfskraftlenkunσ, insbesondere für Kraftfahrzeuge Power steering, especially for motor vehicles
Die Erfindung betrifft eine Hilfskraftlenkung, insbeson¬ dere für Kraftfahrzeuge, nach dem Oberbegriff des Anspruchs 1. Bei einer derartigen Hilfskraftlenkung ist in einem Lenkge¬ häuse ein Eingangsglied drehbar gelagert. Ein Ausgangsglied ist in dem Lenkgehäuse in Abhängigkeit von der Drehbewegung des Eingangsgliedes axial verschiebbar geführt. Zur Hilfs¬ kraftunterstützung ist das Ausgangsglied mit einem Servomotor verbunden. Ein Lenkventil dient zur Steuerung eines Druck¬ mittels zu und von dem Servomotor und ist in Abhängigkeit von einer Bewegung des Eingangsgliedes verstellbar. Das Lenkven- til weist für jede Lenkrichtung ein Einlaß-Sitzventil und ein Auslaß-Sitzventil auf.The invention relates to an auxiliary power steering system, in particular for motor vehicles, according to the preamble of claim 1. In such an auxiliary power steering system, an input member is rotatably mounted in a steering housing. An output member is guided axially displaceably in the steering housing as a function of the rotary movement of the input member. The output member is connected to a servo motor for auxiliary power support. A steering valve serves to control a pressure means to and from the servo motor and is adjustable as a function of a movement of the input member. The steering valve has an inlet seat valve and an outlet seat valve for each steering direction.
Eine derartige Hilfskraftlenkung ist Gegenstand der älte¬ ren deutschen Patentanmeldung P 42 03 335.7. Dabei handelt es sich um eine Zahnstangen-Hilfskraftlenkung, deren Eingangs¬ glied ein Ritzel und deren Ausgangsglied eine Zahnstange ist. Das Ritzel ist schwenkbar gelagert, wobei die Schwenkbewegung in Abhängigkeit von einer Drehung des Ritzels erfolgt und zur Verstellung des Lenkventils dient.Such an auxiliary power steering is the subject of the older German patent application P 42 03 335.7. This is a power assisted rack and pinion steering system, the input member of which is a pinion and the output member of which is a rack. The pinion is pivotally mounted, the pivoting movement taking place as a function of a rotation of the pinion and serving to adjust the steering valve.
Eine andere derartige Hilfskraftlenkung ist bekannt aus der DE-41 26 020 AI. Hierbei handelt es sich ebenfalls um eine Zahnstangen-Hilfskraftlenkung. Das Lenkventil wird hier jedoch durch eine begrenzte Axialbewegung des Ritzels verstellt.Another such power steering is known from DE-41 26 020 AI. This is also rack and pinion power steering. However, the steering valve is adjusted here by a limited axial movement of the pinion.
In beiden Fällen handelt es sich um Zahnstangen-Hilfs- kraftlenkungen, bei denen die Bewegung des Ritzels ausgenützt wird, um das Lenkventil zu verstellen. Die Anwendung eines Steuersystems mit geschlossener Mitte, d. h. von Steuer-
Systemen, bei denen in der Neutralstellung des Lenkventils die von der Druckmittelquelle kommende Druckmittelleitung ab¬ gesperrt ist, ist deshalb beschränkt auf Zahnstangen-Hilfs¬ kraftlenkungen.In both cases, the power assisted rack and pinion steering system uses the movement of the pinion to adjust the steering valve. The application of a closed center tax system, ie of tax Systems in which the pressure medium line coming from the pressure medium source is blocked in the neutral position of the steering valve is therefore limited to power assisted-rack steering systems.
Der Erfindung liegt die Aufgabe zugrunde, ein Steuer¬ system mit geschlossener Mitte auch für Kugelmutter-Hydrolen¬ kungen anwendbar zu gestalten.The invention is based on the object of designing a control system with a closed center which can also be used for ball nut hydraulic steering systems.
Diese Aufgabe wird durch die im Anspruch 1 gekennzeich¬ nete Hilfskraftlenkung gelöst. Die Lösung erfolgt insbesondere dadurch, daß das Eingangsglied eine in engen Grenzen axial verschiebbare Kugelspindel und das Ausgangsglied eine Kugel¬ mutter ist. Dabei ist an der Kugelspindel ein Betätigungs- hebel drehbar, aber gegenüber der Kugelspindel axial unver¬ schiebbar, gehalten. Der Betätigungshebel, der zur Verstel¬ lung des Lenkventils dient, wird durch die Kraft von Zentrier¬ fedem in seine axiale Neutralstellung beaufschlagt. Die Kugelspindel ist von hydraulischen, axial gerichteten Kräften freigehalten.This object is achieved by the power steering system characterized in claim 1. The solution is achieved in particular in that the input member is a ball screw that can be axially displaced within narrow limits and the output member is a ball nut. An actuating lever can be rotated on the ball screw, but is axially immovable relative to the ball screw. The actuating lever, which serves to adjust the steering valve, is acted upon by the force of the centering spring in its axial neutral position. The ball screw is kept free of hydraulic, axially directed forces.
Da die Abstimmung der Betätigungskräfte und der Zentrier¬ kräfte bei einem Lenksystem mit geschlossener Mitte sehr genau erfolgen muß, ist es besonders vorteilhaft, wenn die Kugel- spindel frei ist von zusätzlichen hydraulischen Kräften.Since the coordination of the actuating forces and the centering forces must be very precise in a steering system with a closed center, it is particularly advantageous if the ball screw is free of additional hydraulic forces.
Zweckmäßige und vorteilhafte Ausgestaltungen der Erfin¬ dung sind in den Unteransprüchen angegeben. Die Erfindung ist jedoch nicht auf die Merkmalskombinationen der Ansprüche be- schränkt. Für den Fachmann ergeben sich weitere sinnvolle Kom¬ binationsmöglichkeiten von Ansprüchen und einzelnen Anspruchs¬ merkmalen aus der Aufgabenstellung.
Eine besonders einfache und dennoch wirkungsvolle Mög¬ lichkeit, die Kugelspindel freizuhalten von zusätzlichen hydraulischen Kräften ist im Anspruch 2 angegeben. Dabei weist die Kugelspindel an ihrem einen Ende in bekannter Weise einen Lenkspindelanschluß auf und ist an ihrem anderen Ende in dem Lenkgehäuse dichtend geführt, so daß zwischen der Stirnfläche der Kugelspindel und dem Lenkgehäuse ein Raum ge¬ bildet wird, der mit atmosphärischem Druck beaufschlagt ist.Appropriate and advantageous refinements of the invention are specified in the subclaims. However, the invention is not limited to the combinations of features of the claims. For the person skilled in the art there are further useful combinations of claims and individual claim features from the task. A particularly simple yet effective possibility of keeping the ball screw free of additional hydraulic forces is specified in claim 2. The ball screw has a steering spindle connection at one end in a known manner and is sealingly guided in the steering housing at its other end, so that a space is formed between the end face of the ball screw and the steering housing, which is subjected to atmospheric pressure.
Im folgenden wird die Erfindung anhand eines in derIn the following the invention is based on one in the
Zeichnung dargestellten Ausführungsbeispieles näher erläutert. Es zeigt:Drawing illustrated embodiment explained in more detail. It shows:
Fig. 1 einen Längsschnitt durch die erfindungsgemäße Hilfskraftlenkung;1 shows a longitudinal section through the power steering system according to the invention.
Fig. 2 einen Teilschnitt durch die Hilfskraftlenkung nach der Linie II-II in Fig. 1.2 shows a partial section through the power steering system along the line II-II in FIG. 1st
In einem Lenkgehäuse 1 ist ein Eingangsglied in der Form einer Kugelspindel 2 drehbar und in engen Grenzen axial ver¬ schiebbar in einem Radiallager 3 gelagert. Bei dem Radial¬ lager 3 ragt die Kugelspindel 2 aus dem Lenkgehäuse 1 hervor und trägt einen Lenkspindelanschluß 4. Das dem Lenkspindelan- Schluß 4 gegenüberliegende Ende 5 der Kugelspindel 2 ragt in eine Bohrung 6 des Lenkgehäuses 1 hinein. Das Ende 5 der Kugelspindel 2 ist gegenüber dem Lenkgehäuse 1 durch eine Dichtung 7 abgedichtet. Dadurch wird zwischen der Stirn¬ fläche 8 der Kugelspindel 2 und dem Lenkgehäuse 1 ein Raum 10 gebildet, der über eine Entlastungsbohrung 11 mit atmosphäri¬ schem Druck beaufschlagt ist bzw. über diese Bohrung mit einem Druckmittelbehälter 12 in Verbindung steht.
Die Kugelspindel 2 steht über eine Kugelumlaufkette 13 in trieblicher Verbindung mit einer Kugelmutter 14, die an ihrem einen Ende als Servokolben 15 ausgebildet ist. Der Servokolben 15 trennt zwei in dem Lenkgehäuse 1 angeordnete Arbeitsräume 16 und 17 eines Servomotors 18.In a steering housing 1, an input member in the form of a ball screw 2 is rotatably supported and axially displaceable in a radial bearing 3 within narrow limits. In the radial bearing 3, the ball screw 2 protrudes from the steering housing 1 and carries a steering spindle connection 4. The end 5 of the ball screw 2 opposite the steering spindle connection 4 projects into a bore 6 in the steering housing 1. The end 5 of the ball screw 2 is sealed off from the steering housing 1 by a seal 7. As a result, a space 10 is formed between the end face 8 of the ball screw 2 and the steering housing 1 and is pressurized with atmospheric pressure via a relief bore 11 or communicates with a pressure medium container 12 via this bore. The ball screw 2 is in a driving connection via a ball chain 13 with a ball nut 14, which is formed at one end as a servo piston 15. The servo piston 15 separates two working spaces 16 and 17 of a servo motor 18 arranged in the steering housing 1.
Mit der Kugelspindel 2 ist ein Betätigungshebel 20 bei¬ spielsweise über ein doppelreihiges Kugellager 21 drehbar ver¬ bunden. Gleichzeitig ist der Betätigungshebel 20 gegenüber der Kugelspindel 2 kippsicher und axial unverschiebbar ge¬ halten.An actuating lever 20 is rotatably connected to the ball screw 2, for example via a double-row ball bearing 21. At the same time, the actuating lever 20 is held against tilting and axially immovable relative to the ball screw 2.
Der Betätigungshebel 20 dient zur Verstellung eines Lenk¬ ventils 22, das für die Steuerung des von einer nicht darge- stellten Servopumpe geförderten und zweckmäßigerweise in einem Speicher gespeicherten Druckmittels zu und von den Arbeits¬ räumen 16 und 17 des Servomotors 18 in dem Lenkgehäuse 1 ange¬ ordnet ist. Das Lenkventil 22 enthält zwei Einlaß-Sitzven¬ tile 23 und 24 und zwei Auslaß-Sitzventile 25 und 26. Die Einlaß- und Auslaß-Sitzventile 23, 24, 25, 26 sind im wesent¬ lichen parallel zur der Achse der Kugelspindel 2 angeordnet. Dabei sind jeweils ein Einlaß-Sitzventil 23 bzw. 24 und ein Auslaß-Sitzventil 25 bzw. 26 koaxial zueinander angeordnet.The actuating lever 20 is used to adjust a steering valve 22 which is used to control the pressure medium conveyed by a servo pump (not shown) and expediently stored in a memory to and from the working spaces 16 and 17 of the servo motor 18 in the steering housing 1 ¬ is classified. The steering valve 22 contains two inlet seat valves 23 and 24 and two outlet seat valves 25 and 26. The inlet and outlet seat valves 23, 24, 25, 26 are arranged essentially parallel to the axis of the ball screw 2. In this case, an inlet seat valve 23 and 24 and an outlet seat valve 25 and 26 are arranged coaxially to each other.
In der Neutralstellung des Lenkventils 22 sind die beidenThe two are in the neutral position of the steering valve 22
Einlaß-Sitzventile 23 und 24 geschlossen. Dies wird dadurch erreicht, daß deren Schließkörper durch die Kraft von Druck¬ federn 27 bzw. 28 gegen einen gehäusefesten Ventilsitz beauf¬ schlagbar sind.
Die spielfreie Mittenzentrierung erfolgt einerseits durch zwei Zentrierfedem 30 und 31, die eine Anschlag¬ scheibe 32 gegen einen gehäusefesten Anschlag 33 und gegen den Betätigungshebel 20 drücken, und andererseits durch eine Zentrierfeder 34, die zweckmäßigerweise direkt auf den Be¬ tätigungshebel 20 einwirkt.Inlet seat valves 23 and 24 closed. This is achieved in that the closing bodies can be acted upon by a force of compression springs 27 and 28 against a valve seat fixed to the housing. The play-free centering takes place on the one hand by two centering springs 30 and 31, which press a stop disk 32 against a stop 33 fixed to the housing and against the actuating lever 20, and on the other hand by means of a centering spring 34, which expediently acts directly on the actuating lever 20.
Die Zentrierfedem 30, 31 und 34 sind zweckmäßigerweise gleich groß und haben gleiche Vorspannkräfte. Dadurch wird die Ansehlagscheibe 32 mit einer doppelt so hohen Kraft - in Fig. 1 - nach oben gedrückt, während auf den Betätigungs¬ hebel 20 in der anderen Richtung nur die einfache Kraft der Zentrierfeder 34 wirkt. Da die Verstellwege des Betätigungs¬ hebels 20 und damit des Lenkventils 22 nur sehr klein sind, ergeben sich für beide Lenkrichtungen gleich große Zentrier¬ kräfte. (In der Zeichnung sind die Verstellwege der Auslaß- Sitzventile 25 und 26 übertrieben groß dargestellt, um die in der Neutralstellung des Lenkventils 22 offenen Durchgänge deutlicher darzustellen.)The centering springs 30, 31 and 34 are expediently of the same size and have the same biasing forces. As a result, the actuating washer 32 is pressed upwards with a force twice as high - in FIG. 1 - while only the simple force of the centering spring 34 acts on the actuating lever 20 in the other direction. Since the adjustment paths of the actuating lever 20 and thus of the steering valve 22 are only very small, the centering forces are the same for both steering directions. (In the drawing, the adjustment paths of the exhaust seat valves 25 and 26 are shown exaggeratedly large in order to show the passages which are open when the steering valve 22 is in the neutral position.)
Im folgenden wird die Funktion der erfindungsgemäßen Hilfskraftlenkung beschrieben: Wird die Kugelspindel 2 bei¬ spielsweise durch eine Rechtsdrehung eines nicht dargestell¬ ten Lenkhandrades gedreht, so schraubt sie sich in die Kugel- mutter 14 ein, so daß nach Überwindung der Zentrierkraft der beiden Zentrierfedern 30 und 31 (die Kraft der Zentrier¬ feder 34 wirkt in dieser Richtung verstärkend) die Anschlag¬ scheibe 32 nach unten bewegt wird. Dadurch wird das untere Auslaß-Sitzventil 25 geschlossen und danach das untere Ein- laß-Sitzventil 23 geöffnet. Von einem Zulaufanschluß 35 wird über das dann geöffnete Einlaß-Sitzventil 23 Druckmittel in
den unteren Arbeitsraum 16 geleitet, wodurch eine Bewegung der Kugelmutter 14 über den Servokolben 15 nach oben ver¬ stärkt wird.The function of the power steering system according to the invention is described below: If the ball screw 2 is rotated, for example, by turning a steering handwheel (not shown) to the right, it screws into the ball nut 14 so that after overcoming the centering force of the two centering springs 30 and 31 (the force of the centering spring 34 has a reinforcing effect in this direction), the stop disk 32 is moved downward. As a result, the lower outlet seat valve 25 is closed and then the lower inlet seat valve 23 is opened. From an inlet port 35 via the then open inlet seat valve 23 pressure medium in the lower working space 16 is guided, whereby a movement of the ball nut 14 above the servo piston 15 is increased.
Bei entgegengesetzter Drehrichtung ergibt sich ein sinn¬ gemäßer Ablauf.In the opposite direction of rotation there is a corresponding sequence.
Zweckmäßigerweise wird das Radiallager 3 als kombinier¬ tes Kugel-Rollen-Lager ausgebildet. Durch ein solches Lager kann im Normalbetrieb der Hilfskraftlenkung bei einer Axial¬ bewegung der Kugelspindel 2 die Reibung der Spindellagerung praktisch vernachlässigt werden.
The radial bearing 3 is expediently designed as a combined ball-roller bearing. By means of such a bearing, the friction of the spindle bearing can be practically neglected in normal operation of the power steering when the ball spindle 2 moves axially.
BezuσszeichenReference sign
1 Lenkgehäuse 31 Zentrierfeder1 steering housing 31 centering spring
2 Kugelspindel 32 Anschlagscheibe2 ball screw 32 stop disc
3 Radiallager 33 Anschlag3 radial bearings 33 stop
4 Lenkspindelanschluß 34 Zentrierfeder4 Steering spindle connection 34 centering spring
5 Ende von 2 35 Zulaufanschluß5 End of 2 35 inlet connection
6 Bohrung6 hole
7 Dichtung7 seal
8 Stirnfläche8 end face
99
10 Raum10 room
11 Entlastungsbohrung11 relief bore
12 Druckmittelbehälter12 pressure medium container
13 Kugelumlaufkette13 ball chain
14 Kugelmutter14 ball nut
15 Servokolben15 servo pistons
16 Arbeitsraum16 work space
17 Arbeitsräum17 work rooms
18 Servomotor18 servo motor
19 -19 -
20 Betätigungshebel20 operating levers
21 Kugellager21 ball bearings
22 Lenkventil22 steering valve
23 Einlaß-Sitzventil23 Inlet seat valve
24 Einlaß-Sitzventil24 Inlet seat valve
25 Auslaß-Sitzventil25 Exhaust seat valve
26 Auslaß-Sitzventil26 Exhaust seat valve
27 Druckfeder27 compression spring
28 Druckfeder28 compression spring
29 -29 -
30 Zentrierfeder
30 centering spring
Claims
1. Hilfskraftlenkung, insbesondere für Kraftfahrzeuge, mit folgenden Merkmalen: in einem Lenkgehäuse (1) ist ein Eingangsglied drehbar gelagert; ein Ausgangsglied ist in dem Lenkgehäuse (1) in Ab¬ hängigkeit von der Drehbewegung des Eingangsgliedes axial verschiebbar geführt; zur Hilfskraftunterstützung ist das Ausgangsglied mit einem Servomotor (18) verbunden; ein Lenkventil (22) zur Steuerung eines Druckmittels zu und von zwei Arbeitsräumen (16, 17) des Servomotors (18) ist in Abhängigkeit von einer Bewegung des Eingangs¬ gliedes verstellbar; das Lenkventil (22) weist für jede Lenkrichtung ein Ein¬ laß-Sitzventil (23, 24) und ein Auslaß-Sitzventil (25, 26) auf, wobei die Einlaß-Sitzventile (23, 24) in der NeutralStellung des Lenkventils (22) geschlossen sind, dadurch g e k e n n z e i c h n e t , daß das Eingangsglied eine in engen Grenzen axial ver¬ schiebbare Kugelspindel (2) und das Ausgangsglied eine Kugelmutter (14) ist; - daß an der Kugelspindel (2) ein Betätigungshebel (20) drehbar, aber gegenüber der Kugelspindel (2) axial un¬ verschiebbar, gehalten ist; - daß der Betätigungshebel (20), der zur Verstellung des Lenkventils (22) dient, durch die Kraft von Zentrier- federn (30, 31, 34) in seine axiale Neutralstellung be¬ aufschlagbar ist und daß die Kugelspindel (2) frei ist von hydraulischen, axial gerichteten Kräften. 1. power steering, in particular for motor vehicles, with the following features: an input member is rotatably mounted in a steering housing (1); an output member is guided axially displaceably in the steering housing (1) as a function of the rotary movement of the input member; the auxiliary member is connected to a servo motor (18) for auxiliary power support; a steering valve (22) for controlling a pressure medium to and from two working spaces (16, 17) of the servo motor (18) is adjustable as a function of a movement of the input member; the steering valve (22) has an inlet seat valve (23, 24) and an outlet seat valve (25, 26) for each steering direction, the inlet seat valves (23, 24) in the neutral position of the steering valve (22) are closed, characterized in that the input member is a ball screw (2) which can be axially displaced within narrow limits and the output member is a ball nut (14); - That on the ball spindle (2) an actuating lever (20) is rotatable, but axially non-displaceable relative to the ball spindle (2); - That the actuating lever (20), which serves to adjust the steering valve (22), can be loaded into its axial neutral position by the force of centering springs (30, 31, 34) and that the ball screw (2) is free of hydraulic, axially directed forces.
2. Hilfskraftlenkung nach Anspruch 1, dadurch g e ¬ k e n n z e i c h n e t , daß die Kugelspindel (2) an ihrem einen Ende einen Lenkspindelanschluß (4) aufweist und an ihrem anderen Ende (5) in dem Lenkgehäuse (1) dichtend geführt ist, so daß zwischen der Stirnfläche (8) der Kugelspindel (2) und dem Lenkgehäuse (1) ein Raum (10) gebildet wird und daß der Raum (10) mit atmosphärischem Druck beaufschlagt ist.2. Power steering according to claim 1, characterized ge ¬ indicates that the ball screw (2) at one end has a steering spindle connection (4) and at its other end (5) in the steering housing (1) is sealingly guided, so that between the End face (8) of the ball screw (2) and the steering housing (1) a space (10) is formed and that the space (10) is acted upon by atmospheric pressure.
3. Hilfskraftlenkung nach einem der Ansprüche 1 oder 2, dadurch g e k e n n z e i c h n e t , daß die Zentrier¬ fede (30, 31, 34) im wesentlichen gleiche Größe und gleiche Vorspannkraft aufweisen, wobei zwei der Zentrierfedern (30, 31) in der einen Richtung den Betätigungshebel (20) nur bis zu einem Anschlag (33) beaufschlagen und die dritte Zentrier- feder (34) in der anderen Richtung den Betätigungshebel (20) während seiner ganzen Bewegung beaufschlagt. 3. Power steering system according to one of claims 1 or 2, characterized in that the Zentrier¬ spring (30, 31, 34) have substantially the same size and the same biasing force, with two of the centering springs (30, 31) in one direction the actuating lever Actuate (20) only up to a stop (33) and the third centering spring (34) acts in the other direction on the actuating lever (20) during its entire movement.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19934307890 DE4307890A1 (en) | 1993-03-12 | 1993-03-12 | Power steering, in particular for motor vehicles |
| DEP4307890.7 | 1993-03-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1994020354A1 true WO1994020354A1 (en) | 1994-09-15 |
Family
ID=6482632
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP1994/000733 WO1994020354A1 (en) | 1993-03-12 | 1994-03-09 | Power-assisted steering for, in particular, motor vehicles |
Country Status (2)
| Country | Link |
|---|---|
| DE (1) | DE4307890A1 (en) |
| WO (1) | WO1994020354A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106394657A (en) * | 2016-10-09 | 2017-02-15 | 中国北方车辆研究所 | Input shaft locking device for steering gear and steering gear thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19603270C1 (en) * | 1996-01-30 | 1997-07-10 | Daimler Benz Ag | Hydraulic power steering for motor vehicles |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0001705A1 (en) * | 1977-10-17 | 1979-05-02 | CAM GEARS Limited | Power assisted steering gear assembly |
| WO1985001924A1 (en) * | 1983-11-05 | 1985-05-09 | Zahnradfabrik Friedrichshafen Ag | Rack servo-steering, particularly for motor vehicles |
| DE4126020A1 (en) * | 1991-08-06 | 1993-02-11 | Zahnradfabrik Friedrichshafen | AUXILIARY STEERING |
| DE4203335A1 (en) * | 1992-02-06 | 1993-08-12 | Zahnradfabrik Friedrichshafen | RACK AID AUXILIARY STEERING, ESPECIALLY FOR MOTOR VEHICLES |
-
1993
- 1993-03-12 DE DE19934307890 patent/DE4307890A1/en not_active Withdrawn
-
1994
- 1994-03-09 WO PCT/EP1994/000733 patent/WO1994020354A1/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0001705A1 (en) * | 1977-10-17 | 1979-05-02 | CAM GEARS Limited | Power assisted steering gear assembly |
| WO1985001924A1 (en) * | 1983-11-05 | 1985-05-09 | Zahnradfabrik Friedrichshafen Ag | Rack servo-steering, particularly for motor vehicles |
| DE4126020A1 (en) * | 1991-08-06 | 1993-02-11 | Zahnradfabrik Friedrichshafen | AUXILIARY STEERING |
| DE4203335A1 (en) * | 1992-02-06 | 1993-08-12 | Zahnradfabrik Friedrichshafen | RACK AID AUXILIARY STEERING, ESPECIALLY FOR MOTOR VEHICLES |
| WO1993015947A1 (en) * | 1992-02-06 | 1993-08-19 | Zf Friedrichshafen Ag | Power-assisted rack and pinion steering gear, especially for motor vehicles |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106394657A (en) * | 2016-10-09 | 2017-02-15 | 中国北方车辆研究所 | Input shaft locking device for steering gear and steering gear thereof |
| CN106394657B (en) * | 2016-10-09 | 2018-09-28 | 中国北方车辆研究所 | A kind of steering gear input shaft locking device and its steering gear |
Also Published As
| Publication number | Publication date |
|---|---|
| DE4307890A1 (en) | 1994-09-15 |
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