EP0056369B1 - Druckminderventil für das lastabsenken ohne motorbetrieb - Google Patents

Druckminderventil für das lastabsenken ohne motorbetrieb Download PDF

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Publication number
EP0056369B1
EP0056369B1 EP81900355A EP81900355A EP0056369B1 EP 0056369 B1 EP0056369 B1 EP 0056369B1 EP 81900355 A EP81900355 A EP 81900355A EP 81900355 A EP81900355 A EP 81900355A EP 0056369 B1 EP0056369 B1 EP 0056369B1
Authority
EP
European Patent Office
Prior art keywords
fluid
spool
valve
pilot valve
pressure
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
Application number
EP81900355A
Other languages
English (en)
French (fr)
Other versions
EP0056369A4 (de
EP0056369A1 (de
Inventor
Kurt B. Melocik
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.)
Caterpillar Inc
Original Assignee
Caterpillar Tractor 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 Caterpillar Tractor Co filed Critical Caterpillar Tractor Co
Publication of EP0056369A1 publication Critical patent/EP0056369A1/de
Publication of EP0056369A4 publication Critical patent/EP0056369A4/de
Application granted granted Critical
Publication of EP0056369B1 publication Critical patent/EP0056369B1/de
Expired 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
    • F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure
    • F15B13/0422—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 manually-operated pilot valves, e.g. joysticks
    • 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
    • F15B20/00—Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
    • F15B20/004—Fluid pressure supply failure
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/365—Directional control combined with flow control and pressure control
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/635—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements
    • F15B2211/6355—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements having valve means
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/67—Methods for controlling pilot pressure
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/77—Control of direction of movement of the output member
    • F15B2211/7708—Control of direction of movement of the output member in one direction only
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/86—Control during or prevention of abnormal conditions
    • F15B2211/863—Control during or prevention of abnormal conditions the abnormal condition being a hydraulic or pneumatic failure
    • F15B2211/8633—Pressure source supply failure

Definitions

  • This invention relates to fluid systems and in particular to fluid systems for controlling the raising and lowering of a load.
  • a hydraulic control system having a load-lifting hydraulic motor, a source of pressurized fluid, and a pilot-operated directional control valve for directing fluid for operation of the motor.
  • the system is operative automatically upon failure of the main fluid pressure supply to provide pressurized fluid from the pressure side of the load-supporting motors for emergency pilot operation of the directional control valves.
  • US-A-3,840,049 shows a control system for a fluid motor wherein the direction control valve includes a spool and means for selectively shifting the spool in response to fluid pressure signals from a manually operated pilot valve.
  • the direction control valve includes make-up valve means for opening a bypass passage between the motor and the fluid return line when necessary to prevent cavitation of the motor such as due to an overrunning condition from the external load.
  • US-A-3,766,944 shows a pilot controlled fluid flow regulating valve.
  • the pilot valve has a body provided with inlet means connected to a pump or other suitable source of pressurized fluid, and port means connected to the chamber in the housing of the regulating valve.
  • a valve member of the pilot valve is movable to control the flow of fluid between the inlet means and the port means.
  • a control spring is mounted in the body of the pilot valve and is deformable to displace the valve member against the opposition of fluid pressure acting on the surface of the valve member.
  • US-A-3,698,415 shows a pressure regulating valve having a control member shiftable in a cylindrical bore of the bore housing by a manually operable lever.
  • a plurality of springs are provided for interconnecting the control member and the valve body. One of the springs comes into play only after the control member has been displaced at least a predetermined amount.
  • the present invention is directed to overcoming one or more of the problems as set forth above.
  • the fluid system of the present invention includes an improved pressure regulating pilot valve which permits the operator to control the movement of the spool of the pilot valve by the operator handle so as to control the lowering or closing of auxiliary apparatus by the fluid motor at the control of the operator.
  • pressure regulation is effected by the pilot valve.
  • the fluid control of the present invention is advantageously adapted for use in controlling the retraction of the apparatus as in the event of a dead engine, so that the normal pressurized fluid supply is de-energized.
  • the invention comprehends the provision of such a pilot valve wherein the same spool which is utilized for providing pressure regulated signals to the directional control valve is utilized in the event of a dead engine for controlling the movement of the load as desired by the operator.
  • the valve operates during the dead engine control to provide pressure regulation generally in the same manner as during normal operation of the fluid system.
  • the invention comprehends the provision in a fluid system having a reciprocable fluid motor, fluid supply means including a source of pressurized fluid, a pilot operated directional control valve for controlling delivery of the pressurized fluid to said motor for reciprocably operating the same, and a pilot valve for providing the pressurized fluid to the control valve at a predetermined regulated pressure.
  • the pilot valve includes an inlet port connected to the source and an outlet port connected to the directional control valve for conducting the pressure regulated fluid to the control valve to controllably move the fluid motor in one direction.
  • the pilot valve has a second inlet port connected to a load supporting end of the fluid motor.
  • a spool is movable between a first position at which fluid from the first inlet port to the outlet port is regulated at the predetermined pressure and a second position at which fluid from the second inlet port to the outlet port is regulated at the predetermined pressure.
  • the spool is movable from its first position to its second position only in the absence of pressurized fluid from said source.
  • the pilot valve in the illustrated embodiment includes a spool and the means associated with the pilot valve comprises flow passage means responsive to movement of the spool for selectively preventing communication between the fluid motor and the port when the source is providing the pressurized fluid.
  • the valve is arranged to provide the desired communication between the fluid motor and the port as a result of controlled movement of the spool when the source is not providing the pressurized fluid.
  • the means associated with the pilot valve includes a manually operable actuator for selectively positioning the pilot valve in a first disposition for controlling regulated pressure fluid flow to the port when the source is providing the pressurized fluid and in a second, disposition for controlling fluid flow from the fluid motor to the port when the source is not providing the pressurized fluid.
  • the valve is arranged to provide regulated pressure fluid flow in the second disposition.
  • the pressure regulating pilot valve is arranged to provide controlled fluid flow from the fluid motor of a fluid system under dead engine conditions, while at the same time providing pressure regulation of the fluid flow.
  • the apparatus of the present invention is extremely simple and economical of construction while yet providing the highly desirable features discussed above.
  • a fluid system generally designated 10 is shown to include a pressure regulating pilot valve 11 controlling a directional control valve 12 for controlling delivery of pressurized fluid from a pump 13 to a fluid motor 14.
  • the fluid motor illustratively may comprise a linear fluid motor including a piston 15 reciprocable in a cylinder 16 for lifting a load 17.
  • a first fluid supply line 18 is connected to one end of the cylinder and a second fluid supply line 19 is connected to the other end.
  • the system includes a reservoir tank 20 and a pressure regulating valve 21 for regulating the high pressure output of the pump 13.
  • Pilot valve 11 is controlled by a manually operable handle 22.
  • the handle is swingable about a pivot 23 so as to urge a first actuating arm 24 against a plunger 25 and a second actuating arm 26 against a plunger 27 of the pilot valve.
  • the handle is swingable within a housing 28 carried on wall means 29 defining the valve body.
  • Valve body 29 defines a first valve chamber 30 receiving a first movable valve member, or spool, 31, and a second valve chamber 32 receiving a second movable valve member, or spool, 33.
  • Spool 31 defines an axial, downwardly opening bore 34 communicating with an outlet port 35 connected to a transfer conduit 36.
  • Spool 33 defines a similar axial bore 37 opening to an outlet port 38 connected to a transfer conduit 39.
  • Valve body 29 further defines a cross bore 40 defining an inlet passage connected through a supply conduit 41 to the pump 13.
  • spool 31 is provided with a stem 42 which extends upwardly through a connector 43 into a recess 44 at the lower end of plunger 25.
  • spool 33 is provided with an upwardly extending stem 45 extending through a connector 46 into a recess 47 in the lower end of plunger 27.
  • a first coil spring 48 extends between connector 43 and a shoulder 49 on spool 31 for biasing the spool resiliently downwardly relative to the connector.
  • a coil spring 50 extends between connector 46 and a shoulder 51 on the spool 33 to bias the spool downwardly.
  • Connector 43 is biased upwardly by a coil spring 52 extending between the connector and a shoulder 53 on the valve body.
  • a second spring 54 biases the connector 46 upwardly, spring 54 extending between connector 46 and a shoulder 55 on the valve body.
  • connector 43 is normally urged against a shoulder 56 of a plug 57 slidably carrying the plunger 25, and connector 46 is urged against a shoulder 58 on a plug 59 slidably carrying plunger 27.
  • Spool 31 is provided with radial ports 60 opening to axial passage 34 and spool 33 is provided with radial ports 61 opening to passage 37.
  • ports 60 and 61 are normally spaced from the inlet passage 40.
  • the corresponding connector 43 or 46 is moved downwardly against the action of spring 52 or spring 54 respectively, so as to permit the spools 31 and 33 to be resiliently moved downwardly by the action of the biasing springs 48 and 50, respectively.
  • spool 31 may be moved sufficiently downwardly to provide communication between the inlet passage 40 and the radial ports 60, thereby conducting pressurized fluid from the pump and supply conduit 41 through ports 60 and passage 34 of spool 31, outlet 35 and transfer conduit 36 to the directional control valve 11.
  • the pressure of the fluid in outlet port 35 acting on the end of spool 31 opposes the bias of spring 48 to position the spool 31 to a first preselected position in response to fluid pressure in outlet port 35.
  • valve body 29 further defines an exhaust passage 62 connected through an exhaust port 63 and a conduit 64 to the tank reservoir 20.
  • ports 60 and 61 thereof are in communication with the exhaust passage so that conduits 36 and 39 are normally vented when the handle 22 is in the neutral, centered position of Figure 1A.
  • directional control va ⁇ ve 12 defines a spool valve having a body 65 defining a valve chamber 66 in which is reciprocally mounted a spool 67.
  • Conduit 36 opens through a closure 68 into one end of the chamber 66, and conduit 39 opens through a closure 69 into the opposite end of the chamber.
  • Spool 67 is centered in valve chamber 66 by a first biasing spring 70 extending between closure 68 and one end of the spool and a second biasing spring 71 extending between closure 69 and the opposite end of the spool.
  • a high pressure supply conduit 72 is connected from pump 13 through the valve body 65 to an annular recess 73 at the midportion of chamber 66.
  • a second annular recess 74 is spaced axially toward closure 68 from annular recess 73 and a second annular recess 75 is spaced axially in the opposite direction from the recess 73.
  • Recess 74 is connected through a passage 76 to the fluid supply line 18 and recess 75 is connected through a passage 77 to the fluid supply line 19.
  • valve body Outboard of annular recess 74, the valve body is provided with an exhaust annular recess 78 and outboard of the recess 75, the valve body is provided with a second annular recess 79.
  • the exhaust recesses are connected through an exhaust passage 80 and exhaust conduit 81 to the reservoir tank 20.
  • Spool 67 is provided with a first annular, radially outwardly opening recess 82 which is in communication with body recess 74 and spaced from body recess 73 in the centered arrangement of the control valve 12, as shown in Figure 1 B.
  • the spool is provided with a second annular, radially outwardly opening recess 83 in communication with recess 75 and out of communication with recess 73 when the spool is in the centered position of Figure 1 B.
  • Directional control valve 12 further defines a pair of make-up valves 84 and 85, respectively.
  • Make-up valve 84 is defined by a movable valve member 86 received in a valve chamber 87 in valve body 65 and is normally biased by a spring 88 into seated relationship with a valve seat 89 opening to the recess 78.
  • Valve member 86 defines a port 90 communicating the passage 76 with valve chamber 87 through a passage 91.
  • Make-up valve 85 is similar to make-up valve 84 and includes a valve member 92 biased by a spring 93 against a valve seat 94.
  • the valve member 92 is received in a valve chamber 95 and is provided with a port 96.
  • pilot control handle 22 is moved in a clockwise direction so as to provide communication between supply passage 40 and spool passage 37 through port 61, thereby providing pressurized fluid through the transfer conduit 39 to the righthand end of the directional control valve and thereby moving spool 67 to the left, positioning recess 83 so as to provide communication between recess 73 and recess 75 of the valve body, thereby providing pressurized fluid from conduit 72 through passage 77 to transfer conduit 19.
  • spool recess 82 is moved to provide communication between recesses 74 and 78 of the valve body to provide an exhaust passage from conduit 18 to the exhaust conduit 81 and tank 20.
  • valve 11 functions as a pressure regulating pilot valve for selectively moving spool 67 of directional control valve 12 as a function of the movement of handle 22 of the pilot valve.
  • Make-up valves 84 and 85 are provided for effectively preventing cavitation of fluid motor 14 such as when the load forces thereon tend to cause the piston 15 to move more rapidly than the flow of fluid from the pump 13 can provide through the lines 18, 19. If for example, the cylinder 14 is retracting rapidly as noted above during a lower condition, the pressure in line 18 and passage 76 would drop. This drop in pressure is also felt in valve chamber 87 via valve chamber 91 and port 90.
  • the improved pressure regulating pilot valve 11 is arranged to provide an improved means for permitting the system to provide a controlled retraction of a load as upon the occurrence of a failure of the high pressure fluid supply system with the load in an extended arrangement such as in a raised condition.
  • the control utilizes the pilot valve 11 to provide this desirable functioning in a novel and simple manner.
  • pilot valve body 29 is further provided with an annular recess 97 spaced below the inlet passage 40.
  • Pilot- valve member 31 is provided with a recess 98 which is normally disposed between passage 40 and recess 97 of the valve body during the normal operation of the pilot valve in controlling the raising and lowering of the load.
  • a conduit 99 is connected through a port 100 communicating with the recess 98, and as shown in Figure 1B, conduit 99 is connected to conduit 19.
  • the control system may nevertheless be utilized to provide a controlled lowering of the load 17 through suitable manipulation of handle 22. More specifically, under such conditions, the pressure in the lower end of cylinder 16 is communicated through conduit 99 and port 100 to the recess 98 of the pilot valve spool 31. Manipulation of handle 22 in a counterclockwise direction as seen in Figure 1A causes arm 24 to depress plunger 25 sufficiently to permit the pilot valve to move downwardly to a position wherein recess 98 communicates between port 100 and valve body recess 97.
  • This communication permits the high pressure fluid from the head end of cylinder 16 to be conducted through the port 35 and conduit 36 to the left hand end of control valve 12, as seen in Figure 1B, thereby moving the spool 67 to the right for controlling the lowering of the load.
  • the pilot valve spool 31 is spring biased in this operation, reciprocal movement of the spool 31 relative to the upper edge of recess 97 may occur so as to provide pressure regulation of the fluid being passed from port 100 through recess 98 to body recess 97 and discharge port 35.
  • the pressure reducing spool 31 functions to provide such desirable pressure regulation not only during the normal operation of the system as when the pump 13 is operative to provide the desired operating pressure, but also provides desirable control and pressure regulation in a dead engine condition wherein the pressurized fluid of the motor 14 resulting from an extended disposition of the load at the time of the occurrence of the dead engine condition is utilized to provide pressure regulated control of the directional control valve in a substantially similar manner so as to provide accurate controlled lowering of the load as well under such dead engine conditions.
  • the same spool that is utilized for controlling the pressure in normal operation is utilized in controlling the pressure and operation of the directional control valve in the dead engine condition and, thus, a substantially simplified and economical construction of the valving system is provided by the present invention.
  • the load may be any type of load desired to be positionally controlled by such a fluid system and while the invention is illustrated in connection with a raised load, as will be obvious to those skilled in the art, other forms of selectively extended loads, such as grasping jaw loads and the like, may be suitably controlled by system 10 in like manner.
  • fluid motor 14 may be utilized in connection with a wide range of load-displacing apparatuses.
  • the apparatus may comprise a loader having a bucket selectively raised by the motor 14.
  • the fluid system is advantageously adapted for use in any industrial application where it is desired to lower a raised load controlled by a pilot operated system in the event the pressurized fluid source fails.
  • the control system is utilized with a pilot valve for controlling the directional valve effecting the desired operation of the fluid motor and, thus, the system is advantageously adapted for use with a wide range of apparatuses utilizing such pilot controlled directional valves.
  • One group of apparatuses of such industrial applications is that of earthworking vehicles generally, one example of which is the loader discussed above.
  • the fluid system of the invention is advantageously adapted for use with auxiliary devices associated with such earthworking vehicles.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Multiple-Way Valves (AREA)
  • Fluid-Pressure Circuits (AREA)

Claims (4)

1. Ein Strömungsmittelsystem (10) mit einem umkehrbaren Strömungsmittelmotor (14), Strömungsmittelversorgungsmitteln einschließlich einer Quelle von Druckströmungsmittel (13), ein pilotbetätigtes Wegesteuerventil (12) zur Steuerung der Lieferung des Druckmittels an den Motor für den umkehrbaren Betrieb desselben und ein Pilotventil (11) zur Erzeugung des Druckströmungsmittels für das Wegesteuerventil (12) mit einem vorbestimmten regulierten Druck, wobei das Pilotventil (11) ein Einlaßöffnung (40) verbunden mit der Quelle (13) aufweist, eine Auslaßöffnung (35) und ferner Kolben (31) bewegbar in eine erste Position, in der der Strömungsmittelfluß von der ersten Einlaßöffnung (40) zu der Auslaßöffnung (35) auf den vorbestimmten Druck reguliert wird, wobei die Auslaßöffnung (35) mit dem Wegesteuerventil (12) verbunden ist, um das druckregulierte Strömungsmittel zum Wegesteuerventil (12) zu leiten, um so in steuerbarer Weise den Strömungsmittelmotor in einer Richtung zu bewegen, dadurch gekennzeichnet, daß das Pilotventil (11) eine zweite Einlaßöffnung (100) aufweist, und zwar verbunden mit einem lastunterstützenden Ende des Strömungsmittelmotors (14), daß der Koben (31) zwischen der ersten Position und einer zweiten Position bewegbar ist, in der Strömungsmittel von der ersten Einlaßöffnung (100) zur Auslaßöffnung (35) auf den vorbestimmten Druck reguliert wird, und daß der Kolben (31) aus seiner ersten Position in seine zweite Position nur beim Nichtvorhandensein von Druckströmungsmittel von der Quelle (13) bewegbar ist und die Verbindung des Strömungsmittels zwischen der zweiten Einlaßöffnung (100) und der Auslaßöffnung (35) in dessen erster Position blokkiert.
2. Strömungsmittelsystem nach Anspruch 1, wobei das Pilotventil (11) eine manuell betätigbare Betätigungsvorrichtung (22) aufweist, und zwar zur selektiven Positionierung des Kolbens (31) des Pilotventils (11).
3. Strömungsmittelsystem nach Anspruch 2, wobei Mittel vorgesehen sind, um selektiv den vorbestimmten, regulierten Druck zu variieren, und zwar einschließlich einer Feder (48), die zwischen der manuell betätigbaren Betätigungsvorrichtung (22) und dem Kolben (31) positioniert ist.
4. Strömungsmittelsystem nach einem der vorhergehenden Ansprüche, wobei das Pilotventil (11) eine Ausnehmung (97) in Strömungsmittelverbindung mit der Auslaßöffnung (35) definiert, wobei der Kolben (31) eine Ringausnehmung (98) in kontinuierlicher Strömungsmittelverbindung mit der zweiten Einlaßöffnung (100) aufweist, und wobei die Ringausnehmung (98) von der Strömungsmittelverbindung mit der Auslaßöffnung (35) an der ersten Position des Kolbens (31) blockiert ist, und zwar in Strömungsmittelverbindung mit der Auslaßöffnung (35) in der zweiten Position des Kolbens.
EP81900355A 1980-06-16 1980-06-16 Druckminderventil für das lastabsenken ohne motorbetrieb Expired EP0056369B1 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1980/000764 WO1981003685A1 (en) 1980-06-16 1980-06-16 Pressure reducing valve for dead engine lowering

Publications (3)

Publication Number Publication Date
EP0056369A1 EP0056369A1 (de) 1982-07-28
EP0056369A4 EP0056369A4 (de) 1983-10-06
EP0056369B1 true EP0056369B1 (de) 1985-08-07

Family

ID=22154398

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81900355A Expired EP0056369B1 (de) 1980-06-16 1980-06-16 Druckminderventil für das lastabsenken ohne motorbetrieb

Country Status (9)

Country Link
EP (1) EP0056369B1 (de)
JP (1) JPS57500840A (de)
BE (1) BE888846A (de)
BR (1) BR8009083A (de)
DE (1) DE3070963D1 (de)
IT (1) IT1189023B (de)
MX (1) MX153904A (de)
SG (1) SG17387G (de)
WO (1) WO1981003685A1 (de)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2557218B1 (fr) * 1983-12-21 1988-01-15 Bennes Marrel Emetteur hydraulique de commande a distance avec amplificateurs de debit
EP0775832A4 (de) * 1992-10-09 1998-02-25 Komatsu Mfg Co Ltd Hydraulisches pilotventil
US5433249A (en) * 1993-08-17 1995-07-18 Kubota Corporation Hydraulic pilot valve

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1939293A1 (de) * 1969-08-01 1971-02-11 Kracht Pumpen Motoren Druckregler
US3620129A (en) * 1970-07-15 1971-11-16 Gen Signal Corp Hydraulic power circuit with emergency lowering provisions
DE2152133B1 (de) * 1971-10-20 1973-02-22 Rexroth Gmbh G L Hydraulisch betaetigtes steuerventil
US3935792A (en) * 1973-02-26 1976-02-03 Caterpillar Tractor Co. Pilot pump bleed control for earthmoving scrapers
FR2236101A1 (en) * 1973-07-05 1975-01-31 Sigma Diesel Hydraulic actuator arm - spring system and valve ports gives balance and sense of feel to operator
US3840049A (en) * 1973-08-08 1974-10-08 Caterpillar Tractor Co Compact fluid motor control system with float position
US3987703A (en) * 1974-08-12 1976-10-26 Caterpillar Tractor Co. Combined restrictor and dead engine lowering valve
FR2376978A1 (fr) * 1977-01-06 1978-08-04 Rexroth Sigma Perfectionnements aux dispositifs distributeurs de fluide, notamment pour telecommande hydraulique

Also Published As

Publication number Publication date
WO1981003685A1 (en) 1981-12-24
MX153904A (es) 1987-02-16
JPS57500840A (de) 1982-05-13
IT8122313A0 (it) 1981-06-15
DE3070963D1 (en) 1985-09-12
EP0056369A4 (de) 1983-10-06
BE888846A (nl) 1981-11-19
EP0056369A1 (de) 1982-07-28
BR8009083A (pt) 1982-04-27
IT1189023B (it) 1988-01-28
SG17387G (en) 1987-07-24

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