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EP0523065A1 - Direction assistee, notamment pour vehicules a moteur - Google Patents

Direction assistee, notamment pour vehicules a moteur

Info

Publication number
EP0523065A1
EP0523065A1 EP19910905009 EP91905009A EP0523065A1 EP 0523065 A1 EP0523065 A1 EP 0523065A1 EP 19910905009 EP19910905009 EP 19910905009 EP 91905009 A EP91905009 A EP 91905009A EP 0523065 A1 EP0523065 A1 EP 0523065A1
Authority
EP
European Patent Office
Prior art keywords
valve
check valve
power steering
pressure relief
working
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.)
Withdrawn
Application number
EP19910905009
Other languages
German (de)
English (en)
Inventor
Wilfried De Maight
Walter Kogel
Dieter Elser
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.)
ZF Friedrichshafen AG
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
Publication of EP0523065A1 publication Critical patent/EP0523065A1/fr
Withdrawn legal-status Critical Current

Links

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
    • B62D5/09—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 means for actuating valves

Definitions

  • the invention relates to an auxiliary power steering system, in particular for motor vehicles, with a servo motor, the two working spaces of which are connected to a control valve via working lines and can alternately be connected to a servo pump and a pressure medium container via the control valve, with a non-return valve and a parallel one in each of the two working lines Pressure relief valve are arranged such that the check valve opens in the direction of the work area and the pressure relief valve opens in the direction of the control valve.
  • Such an auxiliary power steering system is known from DE-C3 18 14 794.
  • a non-return valve and a pressure relief valve each form a preload valve.
  • the preload valves prevent vibrations and pendulum movements, which are excited by bumps or similar obstacles, with simple means that a certain, consistently high preload pressure is maintained in all pressure chambers of the servo motor. In certain applications, such as in commercial vehicle steering systems, a constantly maintained preload pressure is not desirable because this could slow down or delay the return of the axle.
  • the object of the invention is therefore to create an auxiliary power steering system in which the influence of a damping which is negative in terms of driving dynamics is reduced.
  • This object is achieved by the power steering system characterized in claims 1 and 2, respectively.
  • the damping effect can be defined so that the driver feels shock or vibrations only in a weakened form on the steering wheel. The impact of the impacts on the mechanical transmission parts is reduced.
  • the pressure relief valve can advantageously be arranged within the check valve. It is also possible to accommodate these two valves and the throttle in a common housing.
  • Figure 1 shows the first embodiment of the power steering system according to the invention in a schematic representation.
  • FIG. 2 shows a section from FIG. 1 with one and 3 valve combinations according to two further exemplary embodiments
  • FIG. 4 shows a longitudinal section through a valve combination of the exemplary embodiment according to FIG. 3;
  • FIG. 5 shows the cross section through the valve combination along the line V-V in Fig. 4.
  • Fig. 6 shows a longitudinal section as in Fig. 4, but in a constructive variant.
  • the power steering system according to the invention contains a servo motor 1, the working spaces 2 and 3 of which
  • Working lines 4 and 5 are connected to a control valve 6.
  • the control valve 6 can be adjusted via a steering handwheel (not shown) and controls the inlet from a servo pump 7 to the two working spaces 2 and 3 of the servo motor 1 and the return from the two working spaces 2 and 3 to a pressure medium container 8.
  • a check valve 10 which opens in the direction of the working space 2 or 3 of the servo motor 1 and prevents a return flow from this working space.
  • a pressure relief valve 12 that opens in the direction of the control valve 6.
  • the pressure limiting valve 12 limits the pressure in the working space 2 or 3 to a certain maximum value, for example 30 bar, and thereby prevents an excessive load on the mechanical steering parts.
  • FIG. 2 shows a valve combination in which the throttle 11 is omitted compared to the combination of FIG. 1. Instead of the simple one
  • Check valve 10 a check valve 13 is used, which is spring-loaded in the opening direction. It is thereby achieved that the check valve only closes when jerky movements of the piston 14 of the servo motor 1 cause higher oil ejection flows.
  • FIG. 3 shows a valve combination which corresponds to the combination from FIG. 2 but additionally contains the throttle 11.
  • This version is particularly suitable for steering systems in which the mechanical steering gear parts are heavily loaded from the steered vehicle wheels when driving over obstacles because the pressure builds up too slowly. Dynamic steering damping is avoided during normal steering movements.
  • FIG. 4 shows a longitudinal section through a structural design of the valve combination according to FIG. 3.
  • a valve piston 16 of the check valve 13 against the force of a compression spring 17 in a housing 15 guided axially displaceable.
  • the valve piston 16 acts as a closing body of the check valve 13 with a valve seat 18 fixed to the housing.
  • the compression piston 17 pushes the valve piston 16 away from the valve seat 18.
  • lateral flats 20 and radial bores 21 are provided on the valve piston 16.
  • the pressure relief valve 12 is arranged inside the valve piston 16 of the check valve 13.
  • the pressure limiting valve 12 has a valve piston 22 which is held in contact with a valve seat 24 by a compression spring 23.
  • the valve seat 24 is formed on the valve piston 16 of the check valve 13.
  • the compression spring 23 is supported on a stop ring 25 which is connected to the valve piston 16.
  • Further radial bores 26 are arranged in the valve piston 16, via which an annular piston surface 27 of the valve piston 22 is pressurized from the working space 2 or 3. When the pressure relief valve .12 is open, the bores 26 enable a connection from the working space 2 or 3 to the control valve 6.
  • the throttle 11 is in the valve piston 16 of the
  • FIG. 6 shows a design variant of the valve combination shown in FIG. 4. Parts that correspond to each other are the same in both figures Provide reference numerals.
  • the two compression springs of the pressure relief valve 12 and the check valve 13 are combined in a single compression spring 30. The rest of the structure corresponds to the structure in FIG. 4.
  • the servo pump 7 delivers pressure medium via the working line 4 into the working space 2 of the servo motor 1.
  • the pressure medium opens the check valve 10 and also flows through the throttle 11 in the direction of the
  • the pressure medium ejected from the working space 3 flows through the throttle 11 of the working line 5 into the pressure medium container 8.
  • the pressure relief valve 12 opens at pressures which occur during sudden movements of the

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Power Steering Mechanism (AREA)

Abstract

Direction assistée, notamment pour véhicules à moteur, comportant un servomoteur (1) dont les deux compartiments de travail (2, 3) sont reliés à une soupape de commande (6) par l'intermédiaire de conduites de travail (4, 5). Les compartiments de travail (2, 3) peuvent être reliés alternativement à une servopompe (7) et à un réservoir contenant un milieu hydraulique (8) par l'intermédiaire de soupape de commande (6). Un clapet anti-retour (10), un étranglement (11) et une soupape de limitation de pression (12) sont situés parallèlement les uns aux autres dans dans chacune des deux conduites de travail (4, 5). Le clapet anti-retour (10) s'ouvre en direction du compartiment de travail (2, 3). La soupape de limitation de pression (12) s'ouvre en direction de la soupape de commande (6).
EP19910905009 1990-02-28 1991-02-28 Direction assistee, notamment pour vehicules a moteur Withdrawn EP0523065A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4006233 1990-02-28
DE4006233 1990-02-28

Publications (1)

Publication Number Publication Date
EP0523065A1 true EP0523065A1 (fr) 1993-01-20

Family

ID=6401107

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19910905009 Withdrawn EP0523065A1 (fr) 1990-02-28 1991-02-28 Direction assistee, notamment pour vehicules a moteur

Country Status (3)

Country Link
EP (1) EP0523065A1 (fr)
DE (1) DE4106310C2 (fr)
WO (1) WO1991012985A1 (fr)

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4303204A1 (en) * 1992-02-29 1993-09-09 Teves Gmbh Alfred Hydraulically working servo linkage with pressure limiting valve - limits pump pressure and power when servo motor blockaded until pressure medium feed to damaged work chamber is interrupted
DE4323179C1 (de) * 1993-07-10 1994-11-17 Daimler Benz Ag Hydraulisch unterstützte Servolenkung
DE4338697C2 (de) * 1993-11-12 2000-03-23 Audi Ag Hydraulische Hilfskraftlenkung
DE4338847C1 (de) * 1993-11-13 1995-02-16 Hydraulik Nord Gmbh Hydraulische Lenkeinrichtung
ZA948197B (en) * 1993-12-14 1996-04-18 Hansen Inc Method and apparatus for controlling railway truck hunting and a railway car body supported thereby
DE4423658C2 (de) * 1994-07-06 2000-06-21 Daimler Chrysler Ag Hydraulische Servolenkung
DE4446123C2 (de) * 1994-12-22 2003-05-22 Man Nutzfahrzeuge Ag Vorrichtung zur Einwirkung auf die an der Lenkung eines Kraftfahrzeuges wirksamen Störkräfte
DE19617566C2 (de) * 1996-05-02 1998-04-02 Daimler Benz Ag Hydraulische Servolenkung eines Kraftfahrzeuges
DE19647130C1 (de) * 1996-11-14 1998-04-09 Daimler Benz Ag Dämpferventilanordnung
DE19649347A1 (de) * 1996-11-28 1998-06-04 Zahnradfabrik Friedrichshafen Hilfskraftlenkung für Kraftfahrzeuge
DE19650476C1 (de) * 1996-12-05 1998-05-07 Daimler Benz Ag Hydraulische Servolenkung
DE19651500C1 (de) 1996-12-11 1998-04-09 Daimler Benz Ag Dämpferventilanordnung
DE19729777C2 (de) * 1997-07-11 2003-06-12 Audi Ag Dämpfungsventil
DE19754011C1 (de) * 1997-12-05 1999-04-22 Daimler Chrysler Ag Hydraulische Servolenkung
DE19851678C2 (de) * 1998-11-10 2001-05-17 Daimler Chrysler Ag Hydraulische Servolenkung
DE10033531A1 (de) 2000-07-11 2002-01-24 Zf Lenksysteme Gmbh Hydraulische Lenkanlage für Nutzfahrzeuge

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1260096B (de) * 1964-11-11 1968-02-01 Demag Zug Gmbh Senkbremsventil fuer einen offenen hydraulischen Hub- bzw. Wippwerksarbeitskreis fuer hydraulisch betriebene Mobilkrane bzw. Bagger
DE1814794C3 (de) * 1968-12-14 1979-04-12 Zahnradfabrik Friedrichshafen Ag, 7990 Friedrichshafen Lenkeinrichtung mit hydraulischer Hilfskraft für Kraftfahrzeuge mit Knickgelenk
GB1303280A (fr) * 1970-12-23 1973-01-17
DE2143141A1 (de) * 1971-08-28 1973-03-01 Rudolf Bauer Zwei-wege-einstell-stromregelventil.
ES474738A1 (es) * 1978-11-02 1979-04-01 Bendiberica Sa Sistema de mando para servoaccionadores hidraulicos.
DE2927039A1 (de) * 1979-07-04 1981-01-15 Zahnradfabrik Friedrichshafen Hydraulische hilfskraftlenkung

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9112985A1 *

Also Published As

Publication number Publication date
WO1991012985A1 (fr) 1991-09-05
DE4106310C2 (de) 2002-10-24
DE4106310A1 (de) 1991-08-29

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