GB2233293A - Vehicle power steering system - Google Patents

Vehicle power steering system Download PDF

Info

Publication number
GB2233293A
GB2233293A GB9012244A GB9012244A GB2233293A GB 2233293 A GB2233293 A GB 2233293A GB 9012244 A GB9012244 A GB 9012244A GB 9012244 A GB9012244 A GB 9012244A GB 2233293 A GB2233293 A GB 2233293A
Authority
GB
United Kingdom
Prior art keywords
power
steering
electromotor
steering system
vehicle speed
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.)
Granted
Application number
GB9012244A
Other versions
GB2233293B (en
GB9012244D0 (en
Inventor
Hans-Christof Klein
Dr Manfred Kahrs
Peter Drott
Wilhelm Beer
Juergen Balz
Kurt Wollsiffer
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.)
Continental Teves AG and Co OHG
Original Assignee
Alfred Teves 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 Alfred Teves GmbH filed Critical Alfred Teves GmbH
Publication of GB9012244D0 publication Critical patent/GB9012244D0/en
Publication of GB2233293A publication Critical patent/GB2233293A/en
Application granted granted Critical
Publication of GB2233293B publication Critical patent/GB2233293B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
    • B62D6/02—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits responsive only to vehicle speed

Landscapes

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

Abstract

Electric power is supplied to the electromotor of a hydraulic pump unit (25) in response to steering demand and vehicle speed. Above a high speed threshold, eg 65 Km/h, the electric power supply is discontinued; in a medium speed range, eg 20 to 65 Km/h, the electromotor is energised at reduced power (stand-by) and below a low speed threshold. eg 20 Km/h, full electric power is supplied provided that there is demand from the steering input eg as sensed by movement of the steering control valve or driving pinion. The electric power supply may also depend on steering speed or acceleration, steering torque, pressure or motor current. <IMAGE>

Description

1 W.J.Grundherr 1 POWER STEERING SYSTEM FOR AUTOMOTIVE VEHICLES The
present invention is concerned with a power steering system for use with automotive vehicles.
More specifically the present invention is concerned with a power steering system comprising hydraulic pump means arranged to be actuated by an electromotor and connectable by a control valve and through hydraulic conduit means to at least one working chamber of hydraulic cylinder means coupled to a mechanical steering mechanism to support vehicle steering power, the power supplied to the electromotor during operation of the system being controlled by a signal dependant upon the vehicle speed.
A steering system of the afore-mentioned kind is taught by published West German Patent Specification DE-OS 3100067 wherein electric power is supplied to the electromotor in response to speed. However, this will apply only when the steering mechanism is actuated. Although a conventional power steering system as compared with a power steering system wherein a hydraulic pump is permanently operated, involves an energy saving advantage, it will not be capable in the event of a sudden demand to quickly provide its full servopower.
It is, therefore an olject of the present invention to provide a power steering system which is of the above- described kind for use with automotive vehicles and which is characterised by low energy requirements, low electromotor heating and an extremely short response time while and which 2 at the same time is of simple structural design.
According to the present invention a power steering system for use with automotive vehicles comprises hydraulic pump means arranged to be actuated by an electromotor and connectable by a control valve and through hydraulic conduit means to at least one working chamber of hydraulic cylinder means coupled to a mechanical steering mechanism to support vehicle steering power, the power supplied to the electromotor during operation of the system being controlled by a signal dependant upon the vehicle speed, characterised in that the electric power supply to the electromotor is discontinued above a first vehicle speed threshold, in that the electromotor is energised at reduced power below the first vehicle speed threshold and in that full electric power is supplied to the electromotor when the vehicle speed is below a second vehicle speed threshold lower than the first vehicle speed threshold and once the hydraulic cylinder support means is activated.
According to the system provided by the invention, the electromotor is switched off at high speeds, as is customary, for example, outside built-up areas.
In the speed range usually prevailing in urban traffic, the motor driven pump is operated in the so-called 11standby" mode, so that, on the one hand, electrical energy will be saved and on the other hand, the hydraulic fluid is not excessively heated which has a favourable effect on the life of the parts concerned and on the general degree of efficiency of the system. Within the speed range outside about 20 km/h,, the electromotor is also operated in the "stand-by" mode; however, in the event of suddenly occurring high hydraulic power requirements, such requirements can be satisfied after an extremely short response time since the pump is already rotating and within a very short period of time will be able to generate its full power.
According to a preferred form of embodiment of the invention, the hydraulic support to mechanical steering will be activated only after a predetermined steering torque C is 3 threshold having been exceeded, thereby causing the electromotor to run up only in the presence of a minimum support requirement. This will again improve the energysaving effect and will also minimise the noise development.
The power supply to the electromotor may be provided by a centre-tap battery or by a battery unit made up of two batteries. In the medium speed range, the voltage of a battery is then tapped, while in the event of high power requirements, at a low vehicle speed, the two batteries are connected in series.
According to another form of embodiment of the present invention, the electromotor comprises two excitation windings that can be excited in response to speed.
If the power steering system is to be operated on a standard vehicle battery and by a single-phase electromotor, employment of a pulse-pause actuation of a corresponding duration factor is suitable for attaining a particularly low-loss voltage reduction.
By way of example the present invention will know be described with reference to the accompanying drawings wherein:- Figure 1 shows a steering mechanism of a power steering system according to the invention comprising a control valve coupled to the steering shaft through a captivated spring element; Figure 2 shows an energising circuit for the electromotor of a hydraulic pump of the system; Figure 3 illustrates a different motor energising circuit to that shown in Figure 2; Figures 4,6 and 7 show an energising circUit for the electromotor of the power steering system; Figure 5 shows a motor speed vs. torque diagram of d.c.
electromotor of the power steering system, and; Figure 8 shows a power vs. time diagram during a steering operation of the system.
Referring to Figure 1, this shows a steering mechanism wherein the relative movement between a steering shaft 2 and Cli 4 a shaft housing 3 can be used to operate a control slide 1 of a control valve. For this purpose, the housing 3 will be.rigidly connected to the car body and the steering gear is configured as a rack-and-pinion provided with angular teeth.
Section 4 of the steering shaft 2 carrying the driving pinion 5 is axially displaceable within the housing 3 by arranging that the outer ring of a ball bearing 6 fixed in the axial direction to the steering shaft is displaceably guided by a cylindrical sliding face between stops 7 and 8.
Section 4 of the steering shaft 1 is pivotally connected at one end to a connecting member 9 by means of a spherical end 10 of section 4 which is received by an end socket of the member 9. Screwed into the connecting member 9 is a screw 11 in abutment with the control slide 1 of the control valve and in communication with housing 3 in resiliently preloaded manner through the captivated spring element 12.
To balance the axial stroke of section 4 of the steering shaft, the shaft is in communication with the steering wheel through an equilibrium means.
As the steering wheel is turned by the driver in one direction, the rotating movement of the driving.pinion 5 of the rack-and-pinion is converted into an axial movement of rack 14. Due to the angular teeth of the rack-and-pinion, depending on the direction of rotation of the steering wheel, an axial force component acting on section 4 of the shaft 2 will become effective resulting in an axial displacement of that section 4 until the outer ring of the ball bearing 6 is in abutment either with stop 7 or with stop B. In this way, pressure is applied to the control slide 1 in response to the steering directioh. Control slide 1, in known manner, regulates the application of pressure to a working cylinder (not shown) comprising a differential piston and coupled to the mechanical steering mechanism. The control slide 1 of the control valve regulates the communication between a pump connection 15, the chamber of the working cylinder having the larger pressure application surface - chamber connection 16 - and the non-pressurised - container - container connection 17.
Figure 2 schematically shows am energising circuit for the electromotor of the pump. The steering shaft 2 leads to a steering gear having a hydraulic cylinder coupled thereto and an integrated control valve generally of the construction shown in Figure 1. Provided on the control valve or on the driving pinion is a way sensor a signal output from which is supplied to an electronic control means 21 over a connection 20. Moreover, signals from a steering speed- and/or steering torque sensor 22 and from a vehicle speed sensor 23 are also applied as input signals to the electronic control means 21, the latter sensor being formed by an electronic speedometer or by wheel sensors of an antilocking brake system if provided. The electronic control means 21 can be connected to the car battery through the ignition lock and is connected with the electromotor of the motor pump assembly 25.
The electronic control means 21 actuates the electromotor in response to the speed, the steering torque and/or the steering speed in a manner continuously variable or, as in the case of a preferred embodiment of the invention, discretely in response to predetermined vehicle speed thresholds.
Once the vehicle speed sensor 23 indicates a vehicle speed of over 65 km/h, the power supply to the electromotor is interrupted. Since in the majority of cases at such vehicle speeds the steering torque will be so low that the pre-loaded control slide valve does not activate the hydraulic support, it will also be possible for the switch- off signal to be generated by the previously m6ntioned way sensor on the control slide of the control valve or on the driving pinion. This would involve the additional advantage that when the vehicle is negotiating long drawn out highway bends having comparatively low radii the hydraulic support can be activated at speeds of more than 65 km/h.
In the vehicle speed range of between 20 and 65 km/h, the motor/pump reswitches to the so-called ',stand-by" C 6 mode. The motor will increase its performance however, if, in that speed range, the perf ormance of the slow-running -pump is not sufficient, which will also be detected by the way sensor or the steering speed sensor. If, for example, the driver turns the steering wheel heavily in this speed range, the pump electromotor will accordingly increase its speed to make available from the pump a sufficiently large hydraulic fluid volume. If in that speed range, the performance of the slow-running pump is adequate, the motor will remain in the "stand-by" mode.
The electromotor, at a speed below 20 km/h, will maintain the "stand-by" mode until a steering operation is initiated. Once the sensors detect a steering movement, the electronic control means 21 will immediately switch the motor to the maximum performance.
The motor-pump speed/torque diagram as shown in Figure 5, illustrates the run-up of the electromotor from the "stand-by" mode to its full performance while operating the steering mechanism within a speed range under 20 km/h.
Once, in the speed range of between 20 km/h and 65 km/h, more hydraulic energy is required than delivered by the pump in the "stand-by" mode, it will also be run up from the "stand-by" mode, though not to the full performance but rather, as shown in broken lines, to a value of between "stand-by" and 100%.
Figure 3 shows schematically the controlled operation of the motor in response to the speed of the vehicle, to the steering speed and to the power take-up of the electromotor. The steering speed will be sensed by a steering speed sensor 32 coupled to the steering wheel 31 and the vdhicle speed will be indicated to the control device 30 by a signal Vs which is proportional to the vehicle speed. Motor current is sensed by the current sensor 33. As the pump load will increase when applying pressure to the working cylinder the power takeup of the motor will also rise. Hence, the power take-up is also indicative of the steering torque. The current sensor 33 can, therefore, take over the function of C 7 the way sensor on the control slide of the control valve or on the driving pinion, as shown in Figure 2, thereby simplifying the design of the general power steering system, as a current s ensor can be readily integrated into the electronic control unit. whereas a way sensor. in addition to the assembly thereof, also requires an additional electronic connection between the mechanical hydraulic part and the electronic unit.
The control of the energisation of the electromotor is achieved according to the same pattern as in the design of Figure 2.
A reduction in the excitation of the electromotor, through a pulse-pause energisation of an appropriate duration factor or ratio, can be realised in a particularly low-loss manner by employment of a so-called powerMOSFET switch forming an electronic circuit. An electronic circuit of that type is schematically shown in Figure 4. The Power MOSFET 27 and a power sensing resistor 26 are seriesconnected in the current supply circuit of the motor pump unit 25. The voltage at the power sensing resistor 26 which is in proportion to the motor current, is supplied through a filter 28 to a comparator 29 for comparing the input voltage thereto to a reference voltage. The Power MOSFET switch 27, in response to a comparator output signal received through a control device 30 is switched on/off in pulsating manner or is permanently in the switched-on condition. If the voltage at the current sensing resistor 26 is below the reference voltage, the motor 25 is operated in a pulsed manner but once that voltage exceeds the reference voltage, the motor is permanently eriergised. To ensure a saf e operation of the comparator 29, the comparator includes a hysteresis.
According to Figure 6, a voltage in proportion to the motor current and tapped from resistor 26 is applied to two comparators K1 and K2. The comparator K1 re-switches the pump motor from the pulse-pause excitation (stand-by) to permanent excitation once the actual input voltage to the 8 comparator exceeds the reference voltage U Refl associated with comparator K1.
If, after a steering operation, the input voltage to the comparators becomes lower than the reference voltage uR,f2 associated with comparator K2, the pump motor operation is switched back to the "stand-by" mode. The mode of operation of the two comparators, K1 and K2 is directionally dependant as otherwise there would be an undefined state between the two voltage thresholds.
In this respect, Figure 8 shows a power-versus -time diagram for a steering operation. Upon commencement of a steering action, the required steering torque will be raised, thereby causing the motor current to rise. Once a predetermined motor current value is reached, a first input or ACTUAL voltage at the current sensing resistor 26 exceeds the first reference voltage U R.fl so that the motor is, therefore, excited to provide higher performance. If, after termination of the steering operation, the motor torque drops, the input or ACTUAL voltage tapped from the current sensing resistor 26, will be less than the second reference voltage URCV The electromotor will accordingly. only run on stand-by performance. The control device 30 in Figure 6, shows a diagram of the pulse-pause excitation of the motor provided in the "stand-by" mode. The permanent excitation is shown diagrammatically above.
The circuit configuration according to Figure 7 is distinguished from the foregoing embodiments in that a variable or step-switched pulse-pause relationship can be additionally provided through the vehicle speed control.
Hence, from the pump motor standstill to thh permanent excitation, any desired characteristic can be adjusted.
9

Claims (13)

1. A power steering system f or automotive vehicles comprising hydraulic pump means arranged to be actuated by an electromotor and connectable by a control valve and through hydraulic conduit means to at least one working chamber of hydraulic cylinder means coupled to a mechanical steering mechanism to support vehicle steering power, the power supplied to the electro-motor during operation of the system being controlled by a signal dependant upon the vehicle speed, characterised in that the electric power supply to the electromotor is discontinued above a f irst vehicle speed threshold, in that the electromotor is energised at reduced power below the f irst vehicle speed threshold and in that full electric power is supplied to the electromotor when the vehicle speed is below a second vehicle speed threshold lower than the first vehicle speed threshold and once the hydraulic cylinder support means is activated.
2. A power steering system according to claim 1. characterised in that the hydraulic support means is activated only af ter a steering torque threshold has been exceeded.
3. A power steering system according to claim 1, characterised in that the reduced power is attained by a battery tapping arrangement.
4. A power steering system according to any one of the preceding claims, characterised in that the electromotor comprises different excitation windings that can be energised in dependence upon speed.
5. A power steering system according to any one of the preceding claims, characterised in that the excitation of the electromotor is through a pulse-pause excitation arrangement in which the duration factor and/or the pulse frequency are variable in dependence upon the vehicle speed.
6. A power steering system according to claim 5, characterised in that a Power-MOSFET and a current sensing resistor for pulse-pause excitation are provided in the electric power motor supply circuit.
7. A power steering system according to any one of the preceding claims, characterised in that a displacement of a resiliently pre-loaded component disposed in a manner displaceable relative to the vehicle body and caused by the steering power serves for the mechanical steering actuation of the control valve.
8. A power steering system according to claim 7. characterised in that a captivated spring element is provided for the resilient pre-loading.
9. A power steering system according to any one of the preceding claims, characterised in that the first vehicle speed threshold is at about 65 km/h while the second vehicle speed threshold is at about 20 km/h.
10. A power steering system according to any one of the preceding claims, characterised in that the electric power supplied to the electromotor is in dependence upon one or more of the following variables:
a) steering speed and/or steering acceleration; b) steering torque; c) control valve motion or motion of a component of the mechanical steering means displaceable in response to the steering power; d) pressure and/or change in pressure; e) power and/or change in power; f) speed and/or change in speed.
11. A power steering system according to any one of the preceding claims, characterised in that the speed- responsive change in the power supplied to the electromotor is continuous.
12. A power steering system according to any one of the preceding claims, characterised in that the speed-responsive 11 change in the power supplied to the electromotor is by a discrete change in power in response to marked vehicle speeds.
13. A power steering system substantially as hereinbefore described with reference to the accompanying drawings.
Published 1991 at The Patent Office. State House. 66171 High Holbom, InndonWC1R47P. Further copies may be obtained from The Patent office. Sales Branch. St Mary Cray. Orpington. Kent BR5 3RD. Printed by Multiplex techniques lid. St Mary Cray. Kent Con. 1187
GB9012244A 1989-06-26 1990-06-01 Power steering system for automotive vehicles Expired - Fee Related GB2233293B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE3920862A DE3920862A1 (en) 1989-06-26 1989-06-26 AUXILIARY STEERING FOR MOTOR VEHICLES

Publications (3)

Publication Number Publication Date
GB9012244D0 GB9012244D0 (en) 1990-07-18
GB2233293A true GB2233293A (en) 1991-01-09
GB2233293B GB2233293B (en) 1994-02-23

Family

ID=6383588

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9012244A Expired - Fee Related GB2233293B (en) 1989-06-26 1990-06-01 Power steering system for automotive vehicles

Country Status (8)

Country Link
JP (1) JPH0332980A (en)
CS (1) CS298990A2 (en)
DD (1) DD300360A5 (en)
DE (1) DE3920862A1 (en)
FR (1) FR2648776B1 (en)
GB (1) GB2233293B (en)
IT (1) IT1240896B (en)
PL (1) PL285726A1 (en)

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2266499A (en) * 1992-04-23 1993-11-03 Rover Group Hydraulic power-assisted steering system with input force sensor.
US5299650A (en) * 1991-09-18 1994-04-05 Mitsubishi Denki Kabushiki Kaisha Motor-driven power steering apparatus and method
GB2274434A (en) * 1993-01-22 1994-07-27 Rover Group Power-assisted steering valve
US6945351B2 (en) * 2001-08-06 2005-09-20 Koyo Seiko Co., Ltd. Power steering apparatus
US7363134B2 (en) 2004-06-01 2008-04-22 Favess Co. Ltd. Power steering apparatus
US7596441B2 (en) * 2005-08-22 2009-09-29 Hitachi, Ltd. Power steering device
CN100572167C (en) * 2003-06-06 2009-12-23 Trw汽车股份有限公司 Be used to control the method for the electric pump drive motor of power steering gear
US7837679B2 (en) 2000-10-17 2010-11-23 Asthmatx, Inc. Control system and process for application of energy to airway walls and other mediums
US7921855B2 (en) 1998-01-07 2011-04-12 Asthmatx, Inc. Method for treating an asthma attack
US7938123B2 (en) 1997-04-07 2011-05-10 Asthmatx, Inc. Modification of airways by application of cryo energy
US7992572B2 (en) 1998-06-10 2011-08-09 Asthmatx, Inc. Methods of evaluating individuals having reversible obstructive pulmonary disease
US8181656B2 (en) 1998-06-10 2012-05-22 Asthmatx, Inc. Methods for treating airways
US8251070B2 (en) 2000-03-27 2012-08-28 Asthmatx, Inc. Methods for treating airways
US8257413B2 (en) 2000-10-17 2012-09-04 Asthmatx, Inc. Modification of airways by application of energy
US8443810B2 (en) 1998-06-10 2013-05-21 Asthmatx, Inc. Methods of reducing mucus in airways
US8483831B1 (en) 2008-02-15 2013-07-09 Holaira, Inc. System and method for bronchial dilation
CN103481944A (en) * 2013-09-23 2014-01-01 湖南南车时代电动汽车股份有限公司 Power-assisted steering system for new energy bus and control method of power-assisted steering system
US8740895B2 (en) 2009-10-27 2014-06-03 Holaira, Inc. Delivery devices with coolable energy emitting assemblies
US8808280B2 (en) 2008-05-09 2014-08-19 Holaira, Inc. Systems, assemblies, and methods for treating a bronchial tree
US8911439B2 (en) 2009-11-11 2014-12-16 Holaira, Inc. Non-invasive and minimally invasive denervation methods and systems for performing the same
US9149328B2 (en) 2009-11-11 2015-10-06 Holaira, Inc. Systems, apparatuses, and methods for treating tissue and controlling stenosis
US9272132B2 (en) 2012-11-02 2016-03-01 Boston Scientific Scimed, Inc. Medical device for treating airways and related methods of use
US9283374B2 (en) 2012-11-05 2016-03-15 Boston Scientific Scimed, Inc. Devices and methods for delivering energy to body lumens
US9339618B2 (en) 2003-05-13 2016-05-17 Holaira, Inc. Method and apparatus for controlling narrowing of at least one airway
US9398933B2 (en) 2012-12-27 2016-07-26 Holaira, Inc. Methods for improving drug efficacy including a combination of drug administration and nerve modulation
US9592086B2 (en) 2012-07-24 2017-03-14 Boston Scientific Scimed, Inc. Electrodes for tissue treatment
US9770293B2 (en) 2012-06-04 2017-09-26 Boston Scientific Scimed, Inc. Systems and methods for treating tissue of a passageway within a body
US10478247B2 (en) 2013-08-09 2019-11-19 Boston Scientific Scimed, Inc. Expandable catheter and related methods of manufacture and use

Families Citing this family (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2688183B1 (en) * 1992-03-04 1997-06-13 Ecia Equip Composants Ind Auto STEERING ASSISTANCE DEVICE, ESPECIALLY A MOTOR VEHICLE.
DE4207668A1 (en) * 1992-03-11 1993-09-16 Teves Gmbh Alfred Vehicle hydraulic servo-assisted steering with steering torque sensor - has distribution of fluid to servo-valve chambers adjusted in accordance with torque-dependent displacement of sleeve around torsion bar
JPH05272466A (en) * 1992-03-27 1993-10-19 Toyoda Mach Works Ltd Hydraulic pump device
DE4227880A1 (en) * 1992-04-29 1993-11-04 Teves Gmbh Alfred HYDRAULIC POWER STEERING
DE4213980A1 (en) * 1992-04-29 1993-11-04 Teves Gmbh Alfred Vehicular hydraulic servo steering - has control valve designed as linear slide valve having axially movable sleeve and operating lever which transmits movement of sleeve by lever effect on slider valve
DE4307864A1 (en) * 1993-03-12 1994-09-15 Teves Gmbh Alfred Hydraulic power steering system with electrically operated pump which can be connected into circuit when required
DE4335390B4 (en) * 1993-10-16 2007-04-12 Trw Fahrwerksysteme Gmbh & Co Kg Power steering device
DE4418118C1 (en) * 1994-05-24 1995-07-06 Daimler Benz Ag Servo steering control for automobile
DE19623567C2 (en) * 1996-06-13 2000-06-08 Daimler Chrysler Ag Hydraulic servo control, in particular hydraulic power steering for motor vehicles
US6488673B1 (en) 1997-04-07 2002-12-03 Broncus Technologies, Inc. Method of increasing gas exchange of a lung
US6200333B1 (en) 1997-04-07 2001-03-13 Broncus Technologies, Inc. Bronchial stenter
US6283988B1 (en) 1997-04-07 2001-09-04 Broncus Technologies, Inc. Bronchial stenter having expandable electrodes
US6273907B1 (en) 1997-04-07 2001-08-14 Broncus Technologies, Inc. Bronchial stenter
US5972026A (en) 1997-04-07 1999-10-26 Broncus Technologies, Inc. Bronchial stenter having diametrically adjustable electrodes
DE19818139C2 (en) * 1998-04-23 2001-06-28 Trw Fahrwerksyst Gmbh & Co Method for limiting the maximum hydraulic pressure of a power steering system
JP3668614B2 (en) * 1998-07-13 2005-07-06 光洋精工株式会社 Power steering device
FR2782053B1 (en) 1998-08-07 2000-09-22 Renault STEERING METHOD OF A HYDRAULIC POWER STEERING ELECTRIC PUMP GROUP
DE10056588A1 (en) * 2000-11-15 2002-06-20 Zf Lenksysteme Gmbh Method for determining the target rotational speed of an electric motor for a hydraulic pump and steering device for a vehicle
JP4404700B2 (en) * 2004-06-24 2010-01-27 三菱電機株式会社 Electric hydraulic power steering device for vehicles
DE102008036261B4 (en) * 2008-08-04 2020-08-27 Zf Automotive Germany Gmbh Method for controlling a power unit of a vehicle steering system and vehicle steering system
DE102008054211A1 (en) 2008-10-31 2010-05-06 Daimler Ag Hybrid steering system for motor vehicle, has hydraulic device for producing hydraulic power steering support, and electrical device for producing electric motor power steering support
FR2950595B1 (en) * 2009-09-29 2019-07-05 Renault S.A.S. METHOD AND DEVICE FOR CONTROLLING AN ELECTRIC PUMP GROUP IN A MOTOR VEHICLE AND A MOTOR VEHICLE
DE102010045518A1 (en) * 2010-09-15 2012-03-15 Volkswagen Aktiengesellschaft Method for operating electromechanical power steering apparatus of i.e. motor car, involves producing support moment in dependence of guidance request in normal operation of power steering apparatus

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2079691A (en) * 1980-07-16 1982-01-27 Tokai Trw & Co Power steering device for a vehicle
GB2086323A (en) * 1980-10-03 1982-05-12 Tokai Trw & Co Electrically Driven Oil Pressured Power Steering Apparatus
GB2102751A (en) * 1981-05-29 1983-02-09 Tokai Trw & Co Electric-oil pressure power steering system

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1087826B (en) * 1977-10-28 1985-06-04 Magneti Marelli Spa ELECTRIC POWER STEERING FOR VEHICLES.
DE2915890A1 (en) * 1979-04-19 1980-11-06 Still Gmbh STEERING DEVICE FOR A VEHICLE WITH HYDRAULIC STEERING ASSISTANCE
DE3045428A1 (en) * 1980-12-02 1982-07-01 Lansing GmbH, 6712 Bobenheim-Roxheim STEERING DEVICE FOR CONVEYOR PRODUCTS
US4518055A (en) * 1982-04-08 1985-05-21 Nissan Motor Company, Limited Pump-drive device of power-assisted steering system
JPS59130780A (en) * 1983-01-17 1984-07-27 Aisin Seiki Co Ltd Motor-driven power steering device
GB2158788B (en) * 1984-05-05 1988-01-27 Trw Cam Gears Ltd Power assistance steering systems for vehicles
JPH0741842B2 (en) * 1985-10-18 1995-05-10 東海テイ−ア−ルダブリユ−株式会社 Vehicle speed sensitive power steering device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2079691A (en) * 1980-07-16 1982-01-27 Tokai Trw & Co Power steering device for a vehicle
GB2086323A (en) * 1980-10-03 1982-05-12 Tokai Trw & Co Electrically Driven Oil Pressured Power Steering Apparatus
GB2102751A (en) * 1981-05-29 1983-02-09 Tokai Trw & Co Electric-oil pressure power steering system

Cited By (69)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5299650A (en) * 1991-09-18 1994-04-05 Mitsubishi Denki Kabushiki Kaisha Motor-driven power steering apparatus and method
GB2266499A (en) * 1992-04-23 1993-11-03 Rover Group Hydraulic power-assisted steering system with input force sensor.
GB2274434A (en) * 1993-01-22 1994-07-27 Rover Group Power-assisted steering valve
GB2274434B (en) * 1993-01-22 1995-11-01 Rover Group A power-assisted steering valve
US8267094B2 (en) 1997-04-07 2012-09-18 Asthmatx, Inc. Modification of airways by application of ultrasound energy
US8161978B2 (en) 1997-04-07 2012-04-24 Asthmatx, Inc. Methods for treating asthma by damaging nerve tissue
US7938123B2 (en) 1997-04-07 2011-05-10 Asthmatx, Inc. Modification of airways by application of cryo energy
US9789331B2 (en) 1998-01-07 2017-10-17 Boston Scientific Scimed, Inc. Methods of treating a lung
US8584681B2 (en) 1998-01-07 2013-11-19 Asthmatx, Inc. Method for treating an asthma attack
US7921855B2 (en) 1998-01-07 2011-04-12 Asthmatx, Inc. Method for treating an asthma attack
US8534291B2 (en) 1998-06-10 2013-09-17 Asthmatx, Inc. Methods of treating inflammation in airways
US8443810B2 (en) 1998-06-10 2013-05-21 Asthmatx, Inc. Methods of reducing mucus in airways
US8181656B2 (en) 1998-06-10 2012-05-22 Asthmatx, Inc. Methods for treating airways
US7992572B2 (en) 1998-06-10 2011-08-09 Asthmatx, Inc. Methods of evaluating individuals having reversible obstructive pulmonary disease
US10561458B2 (en) 2000-03-27 2020-02-18 Boston Scientific Scimed, Inc. Methods for treating airways
US9358024B2 (en) 2000-03-27 2016-06-07 Asthmatx, Inc. Methods for treating airways
US8251070B2 (en) 2000-03-27 2012-08-28 Asthmatx, Inc. Methods for treating airways
US10278766B2 (en) 2000-03-27 2019-05-07 Boston Scientific Scimed, Inc. Methods for treating airways
US8459268B2 (en) 2000-03-27 2013-06-11 Asthmatx, Inc. Methods for treating airways
US8465486B2 (en) 2000-10-17 2013-06-18 Asthmatx, Inc. Modification of airways by application of energy
US7837679B2 (en) 2000-10-17 2010-11-23 Asthmatx, Inc. Control system and process for application of energy to airway walls and other mediums
US7854734B2 (en) 2000-10-17 2010-12-21 Asthmatx, Inc. Control system and process for application of energy to airway walls and other mediums
US9931163B2 (en) 2000-10-17 2018-04-03 Boston Scientific Scimed, Inc. Energy delivery devices
US9033976B2 (en) 2000-10-17 2015-05-19 Asthmatx, Inc. Modification of airways by application of energy
US8257413B2 (en) 2000-10-17 2012-09-04 Asthmatx, Inc. Modification of airways by application of energy
US8888769B2 (en) 2000-10-17 2014-11-18 Asthmatx, Inc. Control system and process for application of energy to airway walls and other mediums
US6945351B2 (en) * 2001-08-06 2005-09-20 Koyo Seiko Co., Ltd. Power steering apparatus
US7051834B2 (en) 2001-08-06 2006-05-30 Koyo Seiko Co., Ltd. Power steering apparatus
US10016592B2 (en) 2001-10-17 2018-07-10 Boston Scientific Scimed, Inc. Control system and process for application of energy to airway walls and other mediums
US10953170B2 (en) 2003-05-13 2021-03-23 Nuvaira, Inc. Apparatus for treating asthma using neurotoxin
US9339618B2 (en) 2003-05-13 2016-05-17 Holaira, Inc. Method and apparatus for controlling narrowing of at least one airway
CN100572167C (en) * 2003-06-06 2009-12-23 Trw汽车股份有限公司 Be used to control the method for the electric pump drive motor of power steering gear
US7363134B2 (en) 2004-06-01 2008-04-22 Favess Co. Ltd. Power steering apparatus
US7596441B2 (en) * 2005-08-22 2009-09-29 Hitachi, Ltd. Power steering device
US9125643B2 (en) 2008-02-15 2015-09-08 Holaira, Inc. System and method for bronchial dilation
US11058879B2 (en) 2008-02-15 2021-07-13 Nuvaira, Inc. System and method for bronchial dilation
US8731672B2 (en) 2008-02-15 2014-05-20 Holaira, Inc. System and method for bronchial dilation
US8483831B1 (en) 2008-02-15 2013-07-09 Holaira, Inc. System and method for bronchial dilation
US8489192B1 (en) 2008-02-15 2013-07-16 Holaira, Inc. System and method for bronchial dilation
US9668809B2 (en) 2008-05-09 2017-06-06 Holaira, Inc. Systems, assemblies, and methods for treating a bronchial tree
US10149714B2 (en) 2008-05-09 2018-12-11 Nuvaira, Inc. Systems, assemblies, and methods for treating a bronchial tree
US11937868B2 (en) 2008-05-09 2024-03-26 Nuvaira, Inc. Systems, assemblies, and methods for treating a bronchial tree
US8961508B2 (en) 2008-05-09 2015-02-24 Holaira, Inc. Systems, assemblies, and methods for treating a bronchial tree
US8808280B2 (en) 2008-05-09 2014-08-19 Holaira, Inc. Systems, assemblies, and methods for treating a bronchial tree
US8821489B2 (en) 2008-05-09 2014-09-02 Holaira, Inc. Systems, assemblies, and methods for treating a bronchial tree
US8932289B2 (en) 2009-10-27 2015-01-13 Holaira, Inc. Delivery devices with coolable energy emitting assemblies
US9017324B2 (en) 2009-10-27 2015-04-28 Holaira, Inc. Delivery devices with coolable energy emitting assemblies
US8740895B2 (en) 2009-10-27 2014-06-03 Holaira, Inc. Delivery devices with coolable energy emitting assemblies
US8777943B2 (en) 2009-10-27 2014-07-15 Holaira, Inc. Delivery devices with coolable energy emitting assemblies
US9649153B2 (en) 2009-10-27 2017-05-16 Holaira, Inc. Delivery devices with coolable energy emitting assemblies
US9005195B2 (en) 2009-10-27 2015-04-14 Holaira, Inc. Delivery devices with coolable energy emitting assemblies
US9675412B2 (en) 2009-10-27 2017-06-13 Holaira, Inc. Delivery devices with coolable energy emitting assemblies
US9149328B2 (en) 2009-11-11 2015-10-06 Holaira, Inc. Systems, apparatuses, and methods for treating tissue and controlling stenosis
US11389233B2 (en) 2009-11-11 2022-07-19 Nuvaira, Inc. Systems, apparatuses, and methods for treating tissue and controlling stenosis
US11712283B2 (en) 2009-11-11 2023-08-01 Nuvaira, Inc. Non-invasive and minimally invasive denervation methods and systems for performing the same
US9649154B2 (en) 2009-11-11 2017-05-16 Holaira, Inc. Non-invasive and minimally invasive denervation methods and systems for performing the same
US10610283B2 (en) 2009-11-11 2020-04-07 Nuvaira, Inc. Non-invasive and minimally invasive denervation methods and systems for performing the same
US8911439B2 (en) 2009-11-11 2014-12-16 Holaira, Inc. Non-invasive and minimally invasive denervation methods and systems for performing the same
US9770293B2 (en) 2012-06-04 2017-09-26 Boston Scientific Scimed, Inc. Systems and methods for treating tissue of a passageway within a body
US9592086B2 (en) 2012-07-24 2017-03-14 Boston Scientific Scimed, Inc. Electrodes for tissue treatment
US9572619B2 (en) 2012-11-02 2017-02-21 Boston Scientific Scimed, Inc. Medical device for treating airways and related methods of use
US9272132B2 (en) 2012-11-02 2016-03-01 Boston Scientific Scimed, Inc. Medical device for treating airways and related methods of use
US10492859B2 (en) 2012-11-05 2019-12-03 Boston Scientific Scimed, Inc. Devices and methods for delivering energy to body lumens
US9974609B2 (en) 2012-11-05 2018-05-22 Boston Scientific Scimed, Inc. Devices and methods for delivering energy to body lumens
US9283374B2 (en) 2012-11-05 2016-03-15 Boston Scientific Scimed, Inc. Devices and methods for delivering energy to body lumens
US9398933B2 (en) 2012-12-27 2016-07-26 Holaira, Inc. Methods for improving drug efficacy including a combination of drug administration and nerve modulation
US10478247B2 (en) 2013-08-09 2019-11-19 Boston Scientific Scimed, Inc. Expandable catheter and related methods of manufacture and use
US11801090B2 (en) 2013-08-09 2023-10-31 Boston Scientific Scimed, Inc. Expandable catheter and related methods of manufacture and use
CN103481944A (en) * 2013-09-23 2014-01-01 湖南南车时代电动汽车股份有限公司 Power-assisted steering system for new energy bus and control method of power-assisted steering system

Also Published As

Publication number Publication date
PL285726A1 (en) 1991-01-14
DE3920862A1 (en) 1991-01-03
FR2648776B1 (en) 1993-11-19
DD300360A5 (en) 1992-06-04
GB2233293B (en) 1994-02-23
CS298990A2 (en) 1991-11-12
IT9020341A1 (en) 1991-11-17
IT1240896B (en) 1993-12-20
JPH0332980A (en) 1991-02-13
GB9012244D0 (en) 1990-07-18
FR2648776A1 (en) 1990-12-28
IT9020341A0 (en) 1990-05-17

Similar Documents

Publication Publication Date Title
GB2233293A (en) Vehicle power steering system
KR890000443B1 (en) Power steering system
EP0091590A2 (en) Pump-drive device of power-assisted steering system
KR860003127A (en) Vehicle deceleration control system
GB2276596A (en) Steering system for forklift trucks.
JPS5996037A (en) Controller for braking force
US5067577A (en) Motor-driven type front and rear wheel steering apparatus
GB2125913A (en) Electromechanical brake booster
KR100469076B1 (en) Steering force control apparatus for power steering
KR100199758B1 (en) Length adjustable apparatus of steering column
JPH0241104Y2 (en)
KR0143591B1 (en) Power steering system for an automobile
JPH03281479A (en) Power steering device
KR910009491A (en) Automotive Continuously Variable Transmission
KR19980061217A (en) Speed Sensitive Steering Wheel Sensitivity Control Device
JPH0214539Y2 (en)
KR0140490Y1 (en) Electronic brake apparatus
KR0127066Y1 (en) Vibration type brake system
JPH0324457Y2 (en)
JPH03112776A (en) Controller for power steering device
JPH0446984U (en)
KR19990026684U (en) Electric proportioning valve device
KR960000584A (en) Electric automatic clutch control device
KR19980031085U (en) Steering wheel automatic control device
KR19980054246A (en) Automotive brake detection device and wheel reverse rotation control device

Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19980601