US3596566A - Hydraulic valve - Google Patents

Hydraulic valve Download PDF

Info

Publication number
US3596566A
US3596566A US3596566DA US3596566A US 3596566 A US3596566 A US 3596566A US 3596566D A US3596566D A US 3596566DA US 3596566 A US3596566 A US 3596566A
Authority
US
United States
Prior art keywords
fluid
flow
pressure
motor
valve
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.)
Expired - Lifetime
Application number
Other languages
English (en)
Inventor
Robert D Krehbiel
Homer R Graber
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.)
Cessna Aircraft Co
Original Assignee
Cessna Aircraft Co
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 Cessna Aircraft Co filed Critical Cessna Aircraft Co
Application granted granted Critical
Publication of US3596566A publication Critical patent/US3596566A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • 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
    • F15B13/01—Locking-valves or other detent i.e. load-holding devices
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/87169—Supply and exhaust
    • Y10T137/87233—Biased exhaust valve
    • Y10T137/87241—Biased closed

Definitions

  • the flow-metering spool can also be positioned to afford floating movement of the motor plunger and rod in either direction in response to an applied external load.
  • the present invention solves the lockout instability problem by providing a separate pressure chamber and pressure responsive means: (I) for fully opening both lockout check valves before any pressure fluid is permitted to flow from the pressure source through either motor port to the controlled motor; (2) for maintaining both lockout checks fully open independent of any pressure variations which occur while the motor circuit is open; and (3) for affording closing of both lockout checks only after the flow paths to and from the motor have been closed.
  • valves embodying this invention the lockout check valves are held closed not only by spring pressure, but also by the pressure of fluid in the conduit between each lockout check and the respective adjacent end ofthe controlled motor.
  • a leakage path is provided to prevent accumulated internal leakage of pressure fluid from unseating or cracking either lockout. This makes it possible for the two lockouts to positively lock the plunger of the controlled motor in a selected position and to maintain it in that position indefinitely.
  • the invention also includes a means for opening both lockout check valves in case the hydraulic system pressure should drop to zero, and the load supported by the plunger rod of the motor happened to be in a dangerous position. The load can then be lowered to normal position.
  • FIG. 1 is an axial vertical section through a valve embodying the invention, the flow control spool being shown in its neutral position;
  • FIG. 2 is a transverse longitudinal section taken along the line 1-2 ofFIG. 1;
  • FIG. 3 is a fragmentary sectional view of the valve of FIG. 1, and shows details in the construction of a different type of lockout check valve than is shown in F I0. 1;
  • FIG. 4 is a view similar to FIG. I but shows the flow control spool moved slightly to the right of its neutral position to cause fluid pressure opening of both lockout check valves, while flow from the supply passage to either end of the motor remains blocked by the spool;
  • FIG. 5 is a view similar to FIG. 4 showing the spool moved slightly farther to the right in a position to meter fluid from the right end of the controlled motor, and to simultaneously afford flow of motive fluid from the supply passage to the left end ofthe motor;
  • FIG. 6 is an axial vertical section through a flow control valve embodying the invention in slightly different form, and schematically shows a simple hydraulic system in which such valves may be interposed.
  • the valve comprises a housing [0 having a fluid supply passage 11, fluid return passages 12 and I3, and two motor ports 14 and 15, connected to the respective opposite ends of a double acting hydraulic motor 16.
  • Extending through the housing is a spool bore 17 which is encircled by six longitudinally spaced bore communicating ducts 18 through 23, in addition to the return passages 12 and 13.
  • Ducts 21 and 22 communicate with each other and with the supply or inlet passage 11.
  • Ducts l9 and 22 communicate with each other by means of a longitudinal passage 24.
  • a slidable flow control spool 25 encircled by spaced grooves 26, 27 and 28 which define lands 29, 30, 31 and 32. Lands 29 and 31 are provided with recessed fluid metering notches 33 and 34, as clearly shown in FIG. 2.
  • spool 25 Internally, spool 25 is provided with a ball check valve 35 which closes one end of a duct 36.
  • the ball check chamber also communicates with the spool bore by means of longitudinally spaced lateral ducts 37 and 38.
  • Spool 25 has a second internal chamber 39 which communicates with the spool bore by longitudinally spaced lateral ducts 40 and 41.
  • Valve 10 houses opposed spring-closed lockout check valves 42 and 43, connected respectively to opposed lockout opening plungers 44 and 45 by means of spindles 46 and 47, respectively.
  • Lockout valve 42 is interposed between duct 18 and motor port 14, and when closed blocks flow from the motor port 14 into duct 18.
  • lockout valve 43 is interposed between duct 23 and motor port l5, and when closed blocks flow from motor port [5 into duct 23.
  • Lockout opening plungers 44 and 45 are reciprocable in a pressure chamber 48 which communicates with bore communicating duct 20. Internally, plungers 44 and 45 are provided respectively with ball check valves 49 and 50, which block communication in one direction between the chamber 48 and the flow ducts I8 and 23, respectively.
  • a conventional spool centering mechanism 51 which includes a coil spring 52, and which functions to return the spool to its neutral FIG. I position when the spool is released by the operator.
  • a spring-pressed ball-type detent 53 mounted in a recess in the housing cooperates with an annular groove 54 near the end of spool 15 to hold the spool in "float" position when the operator desires, as will be later explained in detail.
  • supply or inlet passage I1 is connected to a hydraulic pump, and return passages 12 and 13 are connected to a system reservoir, not shown. With the spool in neutral position, as in FIG. I, the supply and return passages are isolated from each other, as are the two motor ports, and the plunger and rod of motor I6 are locked against movement in either direction.
  • pressure chamber 48 remains in communication with supply passage II through ducts 36, 37 and 20, and that lockout checks 42 and 43 are thereby maintained fully open position entirely independent of any flow of fluid to or from the motor 16 through ducts I8 and 23.
  • the lockout checks are thus unaffected by variations in pressure in ducts 18 and 23, or in motor ports I4 and I5, and thus do not in any way affect precise metering of return fluid by spool 25, and consequent precise control by the operator over the speed of movement and positioning of the plunger of motor 16.
  • leakage ducts 57 and 58 are provided in the inner ends of spindles 46 and 47. Accumulated leakage fluid may pass through ducts 57 and 58, past ball checks 49 and 50, and enter chamber 48, from which it may travel to return duct I2, as previously described.
  • the spool In its detentcd position, the spool directs pressure fluid from supply I! to pressure chamber 48 through duct 36, past ball check 35, and through ducts 38 and 20, thus holding lockout checks 42 and 43 fully open.
  • Spool groove 26 connects duct I8 with return passage 12
  • spool groove 28 connects duct 23 with return passage 13.
  • Spool land 30 blocks flow of pres sure fluid from ducts II and 24 into duct I8, and spool land 3I blocks flow of pressure fluid from passage 11 into duct 23.
  • This detented spool position then, openly connects both ends of motor 16 with the low-pressure system return ducts 12 and I3, and permits the plunger and rod of motor I6 to be moved in either direction by an external load applied to the rod.
  • auxiliary lockout check valve opening mechanism may be included. It is useful only in case the fluid pressure source should fail, with consequent closing of the two lockouts under spring pressure, which in turn might lock the plunger of the motor at one end of its permitted stroke with the load on the plunger rod in an unstable or dangerous position.
  • Pin 59 is slidably mounted in the valve housing with suitable surrounding packing to prevent leakage.
  • Pin 59 has a generally wedge shaped or conical inner end which is normally positioned adjacent the inner ends of the two lockout opening plungers 44 and 45, as clearly shown in FIG. I.
  • the plungers are thereby forced outward, and the two lockouts are unseated, allowing the motor plunger to be moved in either direction by its load. Fluid displaced from either end of the motor 16 during such plunger movement passes through either duct 57 or 58 (FIG. I ⁇ , as the case may be, into chamber 48, and thence out of the valve through return passage I2, as previously described.
  • FIG. 3 LOCKOUT VALVE CONSTRUCTION
  • FIG. 3 An alternative lockout check valve and plunger construction is illustrated in FIG. 3.
  • the lockout valve 62 is mounted in a manner similar to the mounting of lockout 42, but it is not physically connected to the spindle 66 of the lockout opening plunger 64, although plunger spindle 66 opens the lockout in the same manner as does spindle 46.
  • Lockout 62 is reciprocable in a blind bore of a plug but the plug bore is not vented to the atmosphere, as is the case in the mounting of lockouts 42 and 43.
  • Lockout 62 is provided with a lateral duct 86 and a communicating axial duct 87 which pressure fluid from motor port I4 to enter the otherwise closed chamber 88 behind the lockout.
  • the closing force exerted on the lockout 62 by the pressurized fluid in chamber 88 is greater than any pressure created force exerted on the other end of the lockout through the lockout seat 89, because the seat exposed area is less than the total cross-sectional area of the lockout.
  • the lockout 62 is held in seated position not only by spring force but also by fluid-pressure-created force.
  • FIG. 6 EMBODIMENT In the valve illustrated in FIG. 6 the leakage ducts 57 and 58 of the FIG. I valve, and the ball check valves 49 and 50, and their respective leakage passages have been eliminated.
  • lockout check valve opening plungers 44 and 45 have been made solid, and all provision for leakage fluid passage from conduits l8 and 23 into chamber 48 has been omitted.
  • pressurized fluid which leaks from the supply duct 11 past spool 25 when the spool is in neutral position, and which accumulates in duct 18, is disposed of via an added spool port 90 (FIG. 6), spool chamber 39, port 40, into return passage 12.
  • leakage fluid which accumulates in duct 23 is disposed of via an added leakage duct 91, which directly communicates with return passage 13 when spool 25 is in neutral.
  • FIG. 6 valve Operation of the FIG. 6 valve is identical to the operation of the valve shown in FIGS. 1 to 5.
  • a hydraulic control valve assembly for controlling the flow of fluid between (a) a source of fluid pressure, (b) a hydraulic motor which has alternate inlet and discharge means, and (c) a reservoir for return fluid, said assembly having supply (I1) and return ports 12 8t 13), and comprising:
  • first and second passage means (14 8t 18 and 15 8t 23) in the valve body respectively connected to the alternate motor inlet and discharge means;
  • first and second check valves (42 8t 43) respectively mounted in the first and second passage means between the motor (16) and the supply (11) and return ports (12 81. 13), and biased against return of fluid from the motor;
  • a pressure chamber (48) in the body located between the opposed first and second check valves;
  • each check valve (62) is in the form of a plunger reciprocably mounted to project from one end of a blind cylinder (88), and the flow passage through the seat on which the projecting head of the check valve seats is of lesser cross-sectional area than the cross-sectional area of the blind cylinder;
  • each check valve affording communication between the respectively adjacent passage means (l4, l5) and the blind cylinder (88) behind the check valve
  • an elongated wedge-type element (59) slidably mounted in the valve assembly for longitudinal movement into said pressure chamber (48) along a line normal to the path of travel of the two check valve opening plungers (44, 45), and at a location and of a size to contact the adjacent inner ends of said plungers to force them to move respectively outward to open both check valves in the absence of pressure in said pressure chamber.
  • a check valve controlled duct in each of said plungers (44, 45, 64) effective when the flow control means (25) is in its flow-blocking position to afford flow of leakage fluid from the passage means (18, 23) into the pressure chamber (48), and to block flow of fluid from the pressure chamber into said passage means.
  • a hydraulic system comprising:
  • conduit means connected to said hydraulic motor
  • control valve means operatively connected to the conduit means and to the source of fluid pressure for selectively pressurizing or exhausting said conduit means;
  • a hydraulic cylinder including plunger means movable therein in response to pressure in said cylinder to open said check valve;
  • control valve means having a movable flow control means which has (a) a neutral position in which flow through said conduit means is blocked, (b) a second position in which fluid is directed from the source to said hydraulic cylinder to open said check valve, while flow through said conduit means remains blocked, and (c) a third position further spaced in the same direction from neutral position beyond said second position in which said conduit means is pressurized and said hydraulic cylinder is maintained pressurized independent of pressure fluid in said conduit means.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Multiple-Way Valves (AREA)
  • Valve Device For Special Equipments (AREA)
US3596566D 1967-05-15 1967-05-15 Hydraulic valve Expired - Lifetime US3596566A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US63822667A 1967-05-15 1967-05-15

Publications (1)

Publication Number Publication Date
US3596566A true US3596566A (en) 1971-08-03

Family

ID=24559138

Family Applications (1)

Application Number Title Priority Date Filing Date
US3596566D Expired - Lifetime US3596566A (en) 1967-05-15 1967-05-15 Hydraulic valve

Country Status (5)

Country Link
US (1) US3596566A (de)
DE (1) DE1750413C3 (de)
FR (1) FR1562719A (de)
GB (1) GB1177056A (de)
SE (1) SE341532B (de)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3944099A (en) * 1974-03-04 1976-03-16 Northwest Engineering Company Load holding device for mobile power crane excavators and the like
DE2852382A1 (de) * 1977-12-02 1979-06-07 Borg Warner Stroemungsmittelsystem
US4346733A (en) * 1980-07-29 1982-08-31 Fluid Controls, Inc. Control valve
US4545287A (en) * 1982-10-22 1985-10-08 The Cessna Aircraft Company Metered lockout valve
US4736672A (en) * 1986-04-07 1988-04-12 Cessna Aircraft Company Metered lockout valve
DE4123718A1 (de) * 1991-07-17 1993-01-21 Ford New Holland Gmbh Hydraulisches sperrventil
US5349818A (en) * 1993-08-11 1994-09-27 Teleflex (Canada) Limited Low deadband marine hydraulic steering system
US5481871A (en) * 1995-03-02 1996-01-09 Teleflex (Canada) Ltd. Hydraulic steering system with spool pressure equalization
US5613519A (en) * 1992-12-22 1997-03-25 Kabushiki Kaisha Komatsu Seisakusho Operating valve assembly with pressure compensation valve
US6131610A (en) * 1996-11-22 2000-10-17 Smc Kabushiki Kaisha Speed controller with pilot check valve
DE4436548C2 (de) * 1994-10-13 2000-12-21 Mannesmann Rexroth Ag Ventilanordnung zur Betätigung eines hydraulischen Verbrauchers
DE19957952A1 (de) * 1999-12-02 2001-06-07 Mannesmann Rexroth Ag Hydraulisches Wegeventil zur lastunabhängigen Steuerung eines hydraulischen Verbrauchers von insbesondere einer mobilen Arbeitsmaschine

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2080499B (en) * 1980-07-21 1984-03-07 Poclain Sa Fluid pressure-regulating valve

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3274902A (en) * 1965-10-22 1966-09-27 Deere & Co Hydraulic control system
US3381587A (en) * 1965-09-10 1968-05-07 Deere & Co Hydraulic control system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3381587A (en) * 1965-09-10 1968-05-07 Deere & Co Hydraulic control system
US3274902A (en) * 1965-10-22 1966-09-27 Deere & Co Hydraulic control system

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3944099A (en) * 1974-03-04 1976-03-16 Northwest Engineering Company Load holding device for mobile power crane excavators and the like
DE2852382A1 (de) * 1977-12-02 1979-06-07 Borg Warner Stroemungsmittelsystem
US4346733A (en) * 1980-07-29 1982-08-31 Fluid Controls, Inc. Control valve
US4545287A (en) * 1982-10-22 1985-10-08 The Cessna Aircraft Company Metered lockout valve
US4736672A (en) * 1986-04-07 1988-04-12 Cessna Aircraft Company Metered lockout valve
DE4123718A1 (de) * 1991-07-17 1993-01-21 Ford New Holland Gmbh Hydraulisches sperrventil
US5613519A (en) * 1992-12-22 1997-03-25 Kabushiki Kaisha Komatsu Seisakusho Operating valve assembly with pressure compensation valve
US5349818A (en) * 1993-08-11 1994-09-27 Teleflex (Canada) Limited Low deadband marine hydraulic steering system
USRE36342E (en) * 1993-08-11 1999-10-19 Teleflex (Canada) Ltd. Low deadband marine hydraulic steering system
DE4436548C2 (de) * 1994-10-13 2000-12-21 Mannesmann Rexroth Ag Ventilanordnung zur Betätigung eines hydraulischen Verbrauchers
US5481871A (en) * 1995-03-02 1996-01-09 Teleflex (Canada) Ltd. Hydraulic steering system with spool pressure equalization
US6131610A (en) * 1996-11-22 2000-10-17 Smc Kabushiki Kaisha Speed controller with pilot check valve
US6293180B1 (en) 1996-11-22 2001-09-25 Smc Kabushiki Kaisha Speed controller with pilot check valve
US6296015B1 (en) 1996-11-22 2001-10-02 Smc Kabushiki Kaisha Speed controller with pilot check valve
DE19957952A1 (de) * 1999-12-02 2001-06-07 Mannesmann Rexroth Ag Hydraulisches Wegeventil zur lastunabhängigen Steuerung eines hydraulischen Verbrauchers von insbesondere einer mobilen Arbeitsmaschine

Also Published As

Publication number Publication date
DE1750413B2 (de) 1977-12-29
SE341532B (de) 1971-12-27
DE1750413C3 (de) 1978-08-31
FR1562719A (de) 1969-04-04
DE1750413A1 (de) 1971-04-22
GB1177056A (en) 1970-01-07

Similar Documents

Publication Publication Date Title
US3613508A (en) Hydraulic valve
US4543875A (en) Electro-hydraulic directional control valve
US3411536A (en) Pilot operated control valve mechanism
US3722543A (en) Pressure compensated control valve
US3596566A (en) Hydraulic valve
US3304953A (en) Fluid power system and valve mechanisms therefor
US4066239A (en) Metering slot configuration for a valve spool
US2448532A (en) Automatic power position hold for control valves
JPH074403A (ja) 液圧アクチュエータ制御用液圧制御システム
EP0066151A2 (de) Hydrauliches Steuersystem mit vorgesteuertem Rückschlagventil
GB1045764A (en) Valve means for controlling operation of a fluid motor
US4352375A (en) Control valves
US2946347A (en) Control valve having a movable member containing combination check and relief valve unit
US3216448A (en) Spool valve assembly
US4080873A (en) Servoactuator
US3502109A (en) Quick response pilot operated valve
US3970108A (en) Priority hydraulic control valve
US3722541A (en) Control valve
US2954052A (en) Pressure fluid control system and valve
GB951528A (en) Improvements in fluid pressure control valves
US3685540A (en) Fluid flow controlling device for reversible fluid motors
US2954051A (en) Control valve for multiple valve banks
US3789739A (en) Remote hydraulic control
US4515181A (en) Flow control valve assembly wth quick response
US2816420A (en) Hydraulic system