EP0427165A1 - Système hydraulique, en particulier arrangement de valves pour un vérin alimenté par une pompe - Google Patents

Système hydraulique, en particulier arrangement de valves pour un vérin alimenté par une pompe Download PDF

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Publication number
EP0427165A1
EP0427165A1 EP19900121110 EP90121110A EP0427165A1 EP 0427165 A1 EP0427165 A1 EP 0427165A1 EP 19900121110 EP19900121110 EP 19900121110 EP 90121110 A EP90121110 A EP 90121110A EP 0427165 A1 EP0427165 A1 EP 0427165A1
Authority
EP
European Patent Office
Prior art keywords
valve
shut
pump
directional control
control 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.)
Withdrawn
Application number
EP19900121110
Other languages
German (de)
English (en)
Inventor
Douglas Millard Gage
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.)
Deere and Co
Original Assignee
Deere and 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 Deere and Co filed Critical Deere and Co
Publication of EP0427165A1 publication Critical patent/EP0427165A1/fr
Withdrawn legal-status Critical Current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
    • F15B13/01—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
    • Y10T137/2496—Self-proportioning or correlating systems
    • Y10T137/2544—Supply and exhaust type
    • Y10T137/2554—Reversing or 4-way valve systems

Definitions

  • the invention relates to a hydraulic system for a motor fed by a pump, which is connected via a first and a second line to a valve arrangement which has a directional control valve adjustable from a neutral position and two shut-off valves, the shut-off valves being related to those of liquid under pressure from the pump are arranged downstream of the directional control valve, can be brought into an open position via the pump pressure, and the pump sucks liquid from a collecting container and conveys it to the directional control valve.
  • the object to be achieved with the invention is seen in making such hydraulic systems or valve arrangements simpler.
  • This object has been achieved in that the hydraulic system is designed such that in the neutral position of the directional control valve and when a pressure builds up in a line, the shut-off valve associated with the line with the lower pressure is opened and the line with the lower pressure is connected to the collecting container becomes. In this way, no additional measures need to be taken on the engine or on the valve arrangement.
  • the object is achieved by a mechanical coupling of the shut-off valves in that the valve elements closing the shut-off valves cooperate with an adjustable unlocking slide which opens a shut-off valve when the other shut-off valve is closed.
  • One shut-off valve is closed by the fact that a pressure builds up in its line which presses the valve element, for example a ball, onto its seat, whereby the other shut-off valve is opened via the slide valve.
  • the unlocking slide can advantageously also rest with its ends against the valve elements and be adjustable via the pump pressure.
  • the unlocking slide thus has a length which corresponds to the distance between the two shut-off valves when one is closed and the other is open. If a shut-off valve now closes when the directional control slide is in the neutral position due to the pressure building up in its associated line, the closing valve element adjusts the unlocking slide and thus opens the other shut-off valve.
  • the unlocking slide can have two pistons arranged at a distance from one another, one of which is exposed to the pump pressure on one side when the directional control valve is adjusted from the neutral position.
  • the pistons also serve as a guide for the unlocking slide.
  • the directional control valve should be designed in such a way that, in its neutral position, it allows the liquid that is constantly pumped by the pump to flow back into the collecting container.
  • the directional control valve is designed in such a way that it blocks the liquid delivered by the pump in its neutral position.
  • the directional control valve can be connected to the two sides of a rotary motor of a work vehicle via the first and the second line, in each of which one of the shut-off valves in contact with one another via the unlocking slide is provided, the rotary motor being assigned to a gripping device.
  • pressure relief valves can be provided in a crossed manner between the two lines downstream of the shut-off valves.
  • the invention can be used particularly well in the work vehicle shown in FIG. 1 for forestry.
  • rotary motors the preferred use for rotating hydraulically driven motors, hereinafter referred to as rotary motors, takes place.
  • the work vehicle 10 shown in FIG. 1 has a frame 12 with articulated steering, for which vertical pins 14 are provided. It is supported on wheels 16, which also serve as drives.
  • a dozer or clearing blade 18 is connected to the front of the work vehicle.
  • At its rear end it has a gripping device 20 which is suspended on a boom 22 so as to be pivotable about a vertical axis.
  • the boom 22 is articulated on a support arch 24 and can be adjusted relative to this by a hydraulically actuated cylinder 26.
  • the support arch 24 is also hydraulically adjustable.
  • the gripping tools of the gripping device 20 can also be opened and closed using hydraulic cylinders located inside the gripping device.
  • a rotary motor 30, which is arranged at the outer end of the arm 22, serves to rotate the gripping device 20 about the vertical axis. Another arrangement of the rotary motor, e.g. B. inside the gripping device 20 is of course also possible.
  • the hydraulic system shown in Fig. 2 is used to drive the rotary motor 30. It is a so-called open system in which a control valve must be open in the central position so that the oil can flow back through the control valve to its reservoir.
  • the pumps used generally provide a constant flow of oil, which must have a return if the oil is not required to perform a function.
  • the hydraulic system according to FIG. 2 has a collecting tank 32, from which a pump 34 with a constant delivery rate sucks in hydraulic fluid via a line 36.
  • This liquid is conveyed by the pump 34 via feed lines 38 to a directional control valve 40, which is designed as a four-way and three-position valve and to which lines 42 and 44, which lead to the rotary motor 30, are connected.
  • the lines 42 and 44 mutually serve as feed or return lines.
  • the return oil passes back into the collecting tank 32 via a line connected to the directional control valve 40.
  • a pressure relief valve arrangement 46 is hydraulically coupled to the lines 42 and 44 and in particular consists of two spring-loaded pressure relief valves 48 and 50 arranged in a crosswise arrangement. They are each connected to the lines 42 and 44 via lines and sensor lines 52 which are not provided with a reference number. Since both pressure relief valves work identically, only a brief look at how the pressure relief works valve 48 received. In the position shown in FIG. 2, the flow from line 42 to line 44 is interrupted. However, as soon as the pressure in line 42 rises such that it exceeds the force of a spring 54 acting on the pressure relief valve, pressure relief valve 48 opens and connects line 42 to line 44. When the pressure in the line 44 rises, a connection of the line 44 to the line 42 then functioning as a return line can be established via the pressure limiting valve 50.
  • valve 3 shows a valve arrangement 56 with an integrated directional control valve 40 and a shut-off valve arrangement 60.
  • the valve arrangement is located in a valve housing 58, and the shut-off valve arrangement 60 is equipped with two shut-off valves 62 and 64.
  • Each of these shut-off valves has a valve seat 66, a valve element 68 and a spring 70.
  • the valve elements are designed as balls in the drawing. Other forms are of course possible.
  • the springs 70 are arranged such that they endeavor to press the valve elements 68 towards their valve seats 66 in order to block the liquid flow from the lines 42 and 44 to the collecting container 32. In the version shown in FIG.
  • unlocking slide 72 which is provided between the shut-off valves 62 and 64 and, with its ends designed accordingly, bears against both valve elements 68.
  • the unlocking slide 72 has a length such that it keeps a shut-off valve 62 or 64 open. This is always the one on the low pressure side.
  • the drain line 78 lies exactly opposite the mouth of the feed line 38 and is therefore not recognizable in FIG. 3.
  • the valve slide of the directional control valve 40 is adjusted to the right or to the left with reference to FIG. 3.
  • Pressurized liquid can then optionally act on one side of the rotary motor via line 42 or 44.
  • pressurized liquid will hit the shut-off valve 62 or 64 assigned to line 42 or 44 and open it.
  • the unlocking slide 72 is adjusted via this pressure in the direction of the other shut-off valve 64 or 62 and opens it so that return oil located in line 44 or 42 can get into the collecting container 32.
  • the adjustment of the unlocking slide 72 via the hydraulic pressure is effected by two pistons 79 lying on both sides of the mouth of the supply line 38, which simultaneously serve to guide the unlocking slide and are connected to it.
  • shut-off valve 64 will close and thereby adjust the unlocking slide 72 in the direction of the shut-off valve 62 and this will now open the lower pressure.
  • This reversal of the pressure conditions can occur when the boom 22 carrying a tree trunk is pivoted laterally or the tree trunk is lifted around a corner, as a result of which the gripping device and thus the rotary motor can be twisted.
  • one shut-off valve is always open and connects the corresponding line to the reservoir 32, while the other shut-off valve is always closed when the directional control valve 40 is in its neutral position. Since the side with the higher pressure is thus always blocked, the rotating mechanism is braked as soon as external forces occur.
  • the two lines 42 and 44 also include channels in the valve housing 58, and there the line 42 is divided by the shut-off valve 62 into an upstream channel part 80 and a downstream channel part 82.
  • the channel parts 82 and 86 are hydraulically coupled to the downstream side of the corresponding valve elements. With this arrangement, the hydraulic pressure always acts on the downstream side of the corresponding valve element, as a result of which the unlocking slide 72 is displaced in the direction of the other shut-off valve.
  • the shut-off valve arrangement 60 is shown in a closed hydraulic system which has a pump 90 with a variable delivery rate.
  • the pump can go into idle position as long as no pressure oil is required to perform a function.
  • the control valve is closed in its central or neutral position and blocks the oil flow coming from the pump.
  • the valve arrangement 56 used in the embodiment according to FIG. 4 corresponds to that according to FIG. 3 with the exception that the drain line 78 is no longer required.
  • the hydraulic system for the directional control valve 92 was adapted accordingly.
  • valve arrangements 95 and 96 were also provided in the lines 42 and 44 between the valve arrangement 56 and the pressure limiting valve arrangement 46. These each have a check valve with a bypass line, in which a throttle is provided. Hydraulic fluid directed to the pressure side of the rotary motor must fly over the bypass line and the throttle, while the return oil can flow back through the bypass line and the check valve.
  • valve arrangements 95 and 96 may also prove expedient to use the valve arrangements 95 and 96 in an open circuit.
  • open circuits usually use systems large amounts of liquid at low pressure, an open system may require additional pressure relief valves to allow the liquid to get back into the collection container.
  • the present invention works particularly well in closed hydraulic systems which generally have smaller amounts of liquid at high pressure. Therefore, the pressure relief valves must also be set higher. In addition, at higher pressures there is a risk of higher leakage oil proportions in the valve arrangement 56. With the present invention, leakage oil, which could cause the motor connected to lines 42 and 44 to creep, is returned to the reservoir. There is no need for drainage that was required and difficult to clean with conventional systems.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
EP19900121110 1989-11-09 1990-11-05 Système hydraulique, en particulier arrangement de valves pour un vérin alimenté par une pompe Withdrawn EP0427165A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US434941 1989-11-09
US07/434,941 US5018935A (en) 1989-11-09 1989-11-09 Automatic pressure relief system for a hydraulic motor

Publications (1)

Publication Number Publication Date
EP0427165A1 true EP0427165A1 (fr) 1991-05-15

Family

ID=23726337

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19900121110 Withdrawn EP0427165A1 (fr) 1989-11-09 1990-11-05 Système hydraulique, en particulier arrangement de valves pour un vérin alimenté par une pompe

Country Status (4)

Country Link
US (1) US5018935A (fr)
EP (1) EP0427165A1 (fr)
JP (1) JPH03189407A (fr)
CA (1) CA2029008A1 (fr)

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5349818A (en) * 1993-08-11 1994-09-27 Teleflex (Canada) Limited Low deadband marine hydraulic steering system
US5499503A (en) * 1994-09-22 1996-03-19 Iowa Mold Tooling Company, Inc. Hydraulic swing circuit
DE19500606C2 (de) * 1995-01-11 2001-03-15 Mannesmann Rexroth Ag Hydraulisches Senkbremsventil
US5481871A (en) * 1995-03-02 1996-01-09 Teleflex (Canada) Ltd. Hydraulic steering system with spool pressure equalization
US5743292A (en) * 1996-10-07 1998-04-28 Mcdonnell Douglas Corporation Pressure actuated check valve
DE19833489A1 (de) * 1998-07-24 2000-01-27 Mannesmann Rexroth Ag Hydraulische Schaltung
US6871574B2 (en) * 2003-05-28 2005-03-29 Husco International, Inc. Hydraulic control valve assembly having dual directional spool valves with pilot operated check valves
US6959726B2 (en) * 2003-10-01 2005-11-01 Husco International, Inc. Valve assembly for attenuating bounce of hydraulically driven members of a machine
US6996982B2 (en) * 2003-12-09 2006-02-14 The United States Of America As Represented By The Administrator Of The Environmental Protection Agency Method and device for switching hydraulic fluid supplies, such as for a hydraulic pump/motor
KR100590788B1 (ko) * 2003-12-26 2006-06-21 한국항공우주연구원 항공기 구조시험용 과하중 방지장치
JP2006283785A (ja) * 2005-03-31 2006-10-19 Nabtesco Corp 油圧回路およびその弁装置
US7415989B2 (en) * 2005-12-23 2008-08-26 Husco International, Inc. Spool activated lock-out valve for a hydraulic actuator load check valve
US7614843B2 (en) * 2007-01-05 2009-11-10 Caterpillar Inc. Freely rotatable closed grapple head and machine using same
US8904774B2 (en) * 2008-08-22 2014-12-09 Skyfuel, Inc. Hydraulic-based rotational system for solar concentrators that resists high wind loads without a mechanical lock
KR101088754B1 (ko) * 2009-10-20 2011-12-01 볼보 컨스트럭션 이큅먼트 에이비 유압 컨트롤밸브
JP5504423B2 (ja) * 2010-08-27 2014-05-28 日立建機株式会社 油圧作業機の油圧駆動装置
KR101624431B1 (ko) * 2011-09-09 2016-06-07 바르실라 핀랜드 오이 해양 선박의 스러스터용의 유압식 조타 장치
US9611871B2 (en) * 2013-09-13 2017-04-04 Norbert J. Kot Pneumatic valve assembly and method
CN106662245B (zh) * 2014-08-15 2019-05-10 博格华纳公司 用于自动变速器的多压力液压供给系统
DE102015204333A1 (de) * 2014-12-08 2016-06-09 Robert Bosch Gmbh Druckmitteleinspeisung für einen hydrostatischen Antrieb

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2720755A (en) * 1952-09-04 1955-10-18 Vickers Inc Power transmission
US3462122A (en) * 1967-08-21 1969-08-19 Cascade Corp Motor-operated load-handling apparatus with pressure-sensitive means controlling motor acceleration
US3795178A (en) * 1972-09-11 1974-03-05 R Roche Hydraulic actuator holding system
US4286432A (en) * 1979-08-30 1981-09-01 Caterpillar Tractor Co. Lock valve with variable length piston and hydraulic system for a work implement using the same

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3933167A (en) * 1974-02-20 1976-01-20 Tomco, Inc. Pilot operated check valve
US4005894A (en) * 1975-10-16 1977-02-01 J. I. Case Company Log grappling apparatus
JPS6155502U (fr) * 1984-09-17 1986-04-14
US4586332A (en) * 1984-11-19 1986-05-06 Caterpillar Tractor Co. Hydraulic swing motor control circuit

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2720755A (en) * 1952-09-04 1955-10-18 Vickers Inc Power transmission
US3462122A (en) * 1967-08-21 1969-08-19 Cascade Corp Motor-operated load-handling apparatus with pressure-sensitive means controlling motor acceleration
US3795178A (en) * 1972-09-11 1974-03-05 R Roche Hydraulic actuator holding system
US4286432A (en) * 1979-08-30 1981-09-01 Caterpillar Tractor Co. Lock valve with variable length piston and hydraulic system for a work implement using the same

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 8, no. 146 (M-307)(1583) 7 Juli 1984, & JP-A-59 43201 (HITACHI) 10 März 1984, *

Also Published As

Publication number Publication date
CA2029008A1 (fr) 1991-05-10
US5018935A (en) 1991-05-28
JPH03189407A (ja) 1991-08-19

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