EP0038128A1 - Elektrohydraulisches Servosteuerungssystem - Google Patents

Elektrohydraulisches Servosteuerungssystem Download PDF

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Publication number
EP0038128A1
EP0038128A1 EP81301263A EP81301263A EP0038128A1 EP 0038128 A1 EP0038128 A1 EP 0038128A1 EP 81301263 A EP81301263 A EP 81301263A EP 81301263 A EP81301263 A EP 81301263A EP 0038128 A1 EP0038128 A1 EP 0038128A1
Authority
EP
European Patent Office
Prior art keywords
spool
valve
pilot
armature
force
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Withdrawn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
EP81301263A
Other languages
English (en)
French (fr)
Inventor
Gary Wills Sutton
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.)
SPX Corp
Original Assignee
General Signal Corp
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 General Signal Corp filed Critical General Signal Corp
Publication of EP0038128A1 publication Critical patent/EP0038128A1/de
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/0401—Valve members; Fluid interconnections therefor
    • F15B13/0402—Valve members; Fluid interconnections therefor for linearly sliding valves, e.g. spool valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure
    • F15B13/043—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with electrically-controlled pilot valves
    • F15B13/0435—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with electrically-controlled pilot valves the pilot valves being sliding valves
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
    • H01F7/13—Electromagnets; Actuators including electromagnets with armatures characterised by pulling-force characteristics

Definitions

  • This invention relates in general to hydraulic systems, and in particular, to a hydraulic system having an improved solenoid actuated pilot spool valve.
  • a typical electro-hydraulic servo system will include a main spool valve for controlling the direction and quantity of fluid from a source of pressurized fluid, such as a pump, to a fluid actuator, such as a motor.
  • a pilot valve is used to control the position of the main spool by selectively directing fluid from another pressurized source to the ends of the main spool.
  • the pilot valve is itself a spool valve, whose spool position is determined by a force motor, such as a solenoid, acting on one end of the pilot spool in order to control the fluid directed to the ends of the main spool.
  • Linear solenoids are designed to generate a near constant force over the entire distance that the plunger (armature) travels. In'other words, linear solenoids exert a constant force as the solenoid air gap changes.
  • the pilot spool is held in a central or neutral position by relatively light balance springs disposed on opposite ends of the pilot spool.
  • a solenoid acts on the pilot spool to displace it from its neutral position, a solenoid force is applied to one end of the spool.
  • the spool moves, it compresses a balance spring until the spring generates an equal and opposite spring force to counteract the solenoid force. Examples of such systems may be found in U.S. Patents Nos. 4,031,813; 3,874,269; and 3,763,746.
  • a solenoid is an inherently non-linear apparatus, one can be modified to operate over a linear range; see, e.g. U.S. Patent No. 3,740,594.
  • Linearly operating solenoids have been used to control pilot spools because such solenoids exert a near constant force over the full length of their air gap for a given electrical input.
  • a linear solenoid should yield a one-for-one correspondence between the operator input (an electrical signal), the displacement of the pilot spool (which is resisted by a spring with a linear spring constant), and the resulting displacement of the main spool and the motor.
  • a main feature of the present invention is the use of a solenoid having exaggerated, non-linear characteristics for acting upon a pilot spool.
  • Such non-linear characteristics are usually present for example in solenoids having sloped or slanted pole faces which are known per se, rather than the flat pole faces of linear solenoids.
  • FIG. 1 there is shown an electro- hydraulic servo actuated system 10.
  • That system includes a fluid motor, such as the cylinder 11 with a differential piston 12 which can be translated in either direction by selective application of fluid pressure and flow via service lines 13 and 14.
  • the direction and quantity of fluid applied to service lines 13 and 14 is controlled by main spool valve 15.
  • Hydraulic fluid is drawn from a reservoir 19 and is pressurized by a pump 16 that is in turn connected to spool valve inlet line 17.
  • An outlet line 18 carries fluid away from the spool valve 15.
  • a pressure relief valve 9 is connected between lines 17 and 18 in a manner well known in the art.
  • Main spool valve 15 operates in a conventional manner. To this end, when the spool valve is displaced to the right, service line 13 is connected with inlet 17 thereby displacing the piston 12 to the right. Likewise, fluid is exhausted from cylinder 11 via the service line 14 which is connected to drain or outlet 18. In a similar manner, the piston 12 can be driven in the opposite direction when spool valve 15 is shifted to the left.
  • main spool valve 15 The position of main spool valve 15 is hydraulically controlled by a pilot spool servo actuator system 20. Pilot service lines 21, 22 connect the ends of the main spool valve 15 with the pilot servo actuator system 20. Accordingly, main spool valve 15 is shifted to the left or the right depending upon the fluid pressure and flow applied via service lines 21, 22 which act against the centering springs 5 and 6 of the main spool.
  • the pilot actuator system 20 includes a pilot spool valve 24 which controls the direction and quantity of pilot fluid supplied via pilot lines 21 and 22.
  • the position of pilot spool 24 is itself determined by a centering spring 23 and a solenoid actuated force motor 25. Pilot fluid is drawn from the same reservoir 19 and is pressurized by a pilot pump 26 that is connected to pilot inlet line 27.
  • a pilot outlet line 29 is provided for exhausting return fluid through the pilot valves 24 to the reservoir 19.
  • a pilot relief valve 28 is connected between the inlet and outlet lines 27, 29 for relieving excessive pilot pressure in a manner well known in the art.
  • the pilot spool valve 24 includes a housing 30 having a cylindrical bore 35 with a cylindrical spool 31 slidably mounted therein.
  • a plurality of raised lands 32, 33, 34 on spool 31 are provided for controlling the direction of fluid from the inlet line 27 to the pilot service line ports 21a and 22a in a per se known manner.
  • the solenoid force motor 25 includes a ferromagnetic housing 40.
  • the housing includes an armature cavity 37 having a pair of oppositely disposed conical pole faces 38, 39.
  • An armature 42 is reciprocally and slidably mounted within the cavity 39.
  • Armature 42 has a central cylindrical body portion and two oppositely disposed, conically shaped end faces 48, 49 that face pole faces 38, 39, respectively.
  • a pair of electromagnetic coils 44, 45 are enclosed in the housing 40, closely adjacent to the armature 42.
  • the coils 44, 45 are separated near the middle of cavity 37 by an insulating disc 46.
  • the armature 42 will be urged towards the left when coil 44 is energized and to'the right when coil 45 is energized.
  • Electrode energy is supplied to the respective coils 44, 45 by a pair of leads 54, 55 (see Figure 1).
  • An actuator rod 41 axially mounted on the armature 42 extends from the force motor housing 40 through the pilot spool housing 34 to engage one end of pilot spool 31. Accordingly, the position of the armature 42 and thus the pilot spool 31 will be determined upon the net electromechanical force exerted on the armature 42 via the coils 44, 45.
  • the energizing circuit for coils 44 and 45 is schematically shown in Figure 5.
  • a supply voltage V is applied across a rheostat 51 and a parallel combination of three series resistors, R1, R2, and R3.
  • the output of rheostat 51 is applied to an oscillator 56 whose output is in turn a saw tooth shaped voltage signal whose amplitude is representative of the voltage drop between the wiper arm 51a of the rheostat and the ground.
  • the oscillator signal is applied to a comparator 57.
  • the comparator 57 will compare the input oscillator voltage with two fixed voltages, i.e., the voltages between resistors R1-R2 and R2-R3.
  • the output of the comparator 57 will be a modulated triangular pulse signal whose amplitude is representative of the relative displacement of the rheostat arm 51a from its mid or null point.
  • the comparator output is applied to a pair of pulse width modulating amplifiers 58, 59 whose outputs yield pulse width modulated current signals which are respectively proportional to the relative position of the wiper arm of rheostat 51.
  • the signals imposed upon coil lead 47, 48 will have the same relative width and hence the armature42 will be held in its central or neutral position.
  • the wiper arm is moved away from its null position, the relative width of the current pulse signals appearing on the respective lines 47, 48 will change and the armature will be moved in the general direction of the larger pulse width signal.
  • the Bernoulli forces Fd will generally reach peak Fd max after which they will fall off.
  • the Bernoulli forces can be related to the spool displacement which is the cause of the restriction of the fluid.
  • the Bernoulli forces will reach a maximum (Fd max.) at a given spool displacement, in this case, d max.
  • the length of air gap d on the solenoid is chosen to match the-spool displacement which will encounter the maximum Bernoulli forces.
  • the solenoid forces increase in a proportionate amount thereby cancelling one another out and leaving a net force at Fn which approximates a desired linear response.
  • the displacement of the pilot spool, and ultimately, of the main spool itself is directly proportional to the position of the wiper arm of rheostat 51. As the wiper arm is moved 10 percent from its null position, the pilot spool will move 10 percent from its null position and thereby displace the main spool 10 percent from its null position.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Electromagnetism (AREA)
  • Power Engineering (AREA)
  • Servomotors (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Magnetically Actuated Valves (AREA)
EP81301263A 1980-04-04 1981-03-24 Elektrohydraulisches Servosteuerungssystem Withdrawn EP0038128A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US13717180A 1980-04-04 1980-04-04
US137171 1980-04-04

Publications (1)

Publication Number Publication Date
EP0038128A1 true EP0038128A1 (de) 1981-10-21

Family

ID=22476120

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81301263A Withdrawn EP0038128A1 (de) 1980-04-04 1981-03-24 Elektrohydraulisches Servosteuerungssystem

Country Status (4)

Country Link
EP (1) EP0038128A1 (de)
JP (1) JPS56150603A (de)
KR (1) KR840001175B1 (de)
CA (1) CA1163897A (de)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4464978A (en) * 1981-03-23 1984-08-14 Hitachi, Ltd. Servovalve apparatus
WO1987004850A1 (en) * 1986-01-31 1987-08-13 Jakob Rothenberger Multi-chamber magnetic distributing valve
US4813339A (en) * 1984-11-09 1989-03-21 Hitachi, Ltd. Pulse-width-modulation control of parallel three-way valves to supply single-acting quick-response actuator
EP0354087A1 (de) * 1988-08-03 1990-02-07 Bennes Marrel Elektrohydraulisches Bauelement für Druckregelung
WO1990001615A1 (de) 1988-08-09 1990-02-22 Audi Ag Stelleinrichtung für ein gaswechselventil einer brennkraftmaschine
US4949741A (en) * 1989-01-10 1990-08-21 Vickers, Incorporated Power transmission
EP0809737B1 (de) * 1995-02-25 1999-06-16 Ultronics Limited Elektrohydraulische proportionale steuerventilvorrichtung
US9309900B2 (en) 2012-02-09 2016-04-12 Moog Inc. Electro-hydraulic servo valve
US10024444B2 (en) 2012-02-23 2018-07-17 Moog Inc. Integrated structure electro-hydraulic valve

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2436992A (en) * 1944-06-16 1948-03-02 Hpm Dev Corp Solenoid with plunger
GB656208A (en) * 1947-10-28 1951-08-15 United Aircraft Corp Improvements in or relating to magnetic devices
FR2121841A1 (de) * 1971-01-14 1972-08-25 Metz Gmbh Carl
US3740594A (en) * 1971-08-30 1973-06-19 Fema Corp Permanent-electromagnetic reciprocating device
US3858135A (en) * 1973-08-14 1974-12-31 S Gray Push-pull linear motor
FR2265162A1 (en) * 1974-03-21 1975-10-17 Griffet Ets M Remote control system for lorry mounted crane - uses potentiometer and position comparison signals
US4031813A (en) * 1973-10-10 1977-06-28 Sperry Rand Limited Hydraulic actuator controls
US4071042A (en) * 1975-05-16 1978-01-31 Regie Nationale Des Usines Renault Electromagnetic actuator, notably for hydraulic servo-control valve
US4144514A (en) * 1976-11-03 1979-03-13 General Electric Company Linear motion, electromagnetic force motor

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2436992A (en) * 1944-06-16 1948-03-02 Hpm Dev Corp Solenoid with plunger
GB656208A (en) * 1947-10-28 1951-08-15 United Aircraft Corp Improvements in or relating to magnetic devices
FR2121841A1 (de) * 1971-01-14 1972-08-25 Metz Gmbh Carl
US3740594A (en) * 1971-08-30 1973-06-19 Fema Corp Permanent-electromagnetic reciprocating device
US3858135A (en) * 1973-08-14 1974-12-31 S Gray Push-pull linear motor
US4031813A (en) * 1973-10-10 1977-06-28 Sperry Rand Limited Hydraulic actuator controls
FR2265162A1 (en) * 1974-03-21 1975-10-17 Griffet Ets M Remote control system for lorry mounted crane - uses potentiometer and position comparison signals
US4071042A (en) * 1975-05-16 1978-01-31 Regie Nationale Des Usines Renault Electromagnetic actuator, notably for hydraulic servo-control valve
US4144514A (en) * 1976-11-03 1979-03-13 General Electric Company Linear motion, electromagnetic force motor

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4464978A (en) * 1981-03-23 1984-08-14 Hitachi, Ltd. Servovalve apparatus
US4813339A (en) * 1984-11-09 1989-03-21 Hitachi, Ltd. Pulse-width-modulation control of parallel three-way valves to supply single-acting quick-response actuator
WO1987004850A1 (en) * 1986-01-31 1987-08-13 Jakob Rothenberger Multi-chamber magnetic distributing valve
EP0354087A1 (de) * 1988-08-03 1990-02-07 Bennes Marrel Elektrohydraulisches Bauelement für Druckregelung
FR2635203A1 (fr) * 1988-08-03 1990-02-09 Bennes Marrel Composant electro-hydraulique de regulation de pression
WO1990001615A1 (de) 1988-08-09 1990-02-22 Audi Ag Stelleinrichtung für ein gaswechselventil einer brennkraftmaschine
EP0357938A1 (de) * 1988-08-09 1990-03-14 Ag Audi Stelleinrichtung für ein Gaswechselventil einer Brennkraftmaschine
US5269269A (en) * 1988-08-09 1993-12-14 Audi Ag Adjusting device for gas exchange valves
US4949741A (en) * 1989-01-10 1990-08-21 Vickers, Incorporated Power transmission
EP0809737B1 (de) * 1995-02-25 1999-06-16 Ultronics Limited Elektrohydraulische proportionale steuerventilvorrichtung
US9309900B2 (en) 2012-02-09 2016-04-12 Moog Inc. Electro-hydraulic servo valve
US10024444B2 (en) 2012-02-23 2018-07-17 Moog Inc. Integrated structure electro-hydraulic valve

Also Published As

Publication number Publication date
KR840001175B1 (ko) 1984-08-16
KR830005508A (ko) 1983-08-20
CA1163897A (en) 1984-03-20
JPS56150603A (en) 1981-11-21

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PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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Designated state(s): DE FR GB

17P Request for examination filed

Effective date: 19820409

STAA Information on the status of an ep patent application or granted ep patent

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18D Application deemed to be withdrawn

Effective date: 19841109

RIN1 Information on inventor provided before grant (corrected)

Inventor name: SUTTON, GARY WILLS