EP1927759A1 - Double clapet de retenue doté d'une fonction de flottement - Google Patents

Double clapet de retenue doté d'une fonction de flottement Download PDF

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Publication number
EP1927759A1
EP1927759A1 EP07014738A EP07014738A EP1927759A1 EP 1927759 A1 EP1927759 A1 EP 1927759A1 EP 07014738 A EP07014738 A EP 07014738A EP 07014738 A EP07014738 A EP 07014738A EP 1927759 A1 EP1927759 A1 EP 1927759A1
Authority
EP
European Patent Office
Prior art keywords
check valve
hydraulic cylinder
flow paths
double check
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Withdrawn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
EP07014738A
Other languages
German (de)
English (en)
Inventor
Sung Bok Park
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.)
Volvo Construction Equipment AB
Original Assignee
Volvo Construction Equipment AB
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 Volvo Construction Equipment AB filed Critical Volvo Construction Equipment AB
Publication of EP1927759A1 publication Critical patent/EP1927759A1/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Withdrawn legal-status Critical Current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
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/024—Systems essentially incorporating special features for controlling the speed or actuating force of an output member by means of differential connection of the servomotor lines, e.g. regenerative circuits
    • 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
    • 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
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/20576—Systems with pumps with multiple pumps
    • 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
    • F15B2211/30505—Non-return valves, i.e. check valves
    • F15B2211/3051—Cross-check 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
    • 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
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3111—Neutral or centre positions the pump port being closed in the centre position, e.g. so-called closed centre
    • 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
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3122—Special positions other than the pump port being connected to working ports or the working ports being connected to the return line
    • F15B2211/3127—Floating position connecting the working ports and the return line
    • 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
    • F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
    • F15B2211/3157—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line
    • F15B2211/31576—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line having a single pressure source and a single output member
    • 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
    • F15B2211/32—Directional control characterised by the type of actuation
    • F15B2211/327—Directional control characterised by the type of actuation electrically or electronically
    • 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
    • F15B2211/32—Directional control characterised by the type of actuation
    • F15B2211/329—Directional control characterised by the type of actuation actuated by fluid 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
    • F15B2211/30—Directional control
    • F15B2211/35—Directional control combined with flow control

Definitions

  • the present invention relates to a double check valve having a floating function, whereby a working device (e.g., a dozer blade) that is used for a land readjustment work on a work surface can perform a floating function.
  • a working device e.g., a dozer blade
  • floating function means that a working device in a non-load state (that a large chamber and a small chamber of a hydraulic cylinder for operating the working device (e.g., a dozer blade) are connected to each other) is operated depending on the ruggedness of a work surface or road surface in a state that the supply of hydraulic fluid from a hydraulic pump to the hydraulic cylinder is temporarily intercepted.
  • a large chamber d1 and a small chamber d2 of a hydraulic cylinder d are connected to each other through a pipe h. Accordingly, when the equipment having a working device f mounted thereon travels along the rugged ground and is on a downhill road, the working device f descends due to its own weight, and thus the hydraulic cylinder d is driven to be extended. By contrast, when the equipment is on an uphill road, the hydraulic cylinder d is driven to be contracted.
  • the construction equipment having a conventional double check valve includes a hydraulic pump P; a hydraulic cylinder d connected to the hydraulic pump P to operate a dozer blade f; a control valve ⁇ installed in flow paths between the hydraulic pump P and the hydraulic cylinder d and shifted to control a start, a stop, and a direction change of the hydraulic cylinder d; and a double check valve k installed to open/close flow paths between the control valve ⁇ and the hydraulic cylinder d, and having a pair of check valves b and c supported by pressing members f1 and f2 that are elastically supported by first and second elastic members (e.g., compression coil springs) e1 and e2, respectively, and a plunger h slidably installed between the check valves b and c to prevent the dozer blade f from sinking.
  • first and second elastic members e.g., compression coil springs
  • the double check valve k serves as a check valve through the check valves b and c elastically supported by the first and second elastic members e1 and e2 and the pressing members f1 and f2.
  • the check valve b blocks first flow paths s1 and s3 that connect the control valve ⁇ to the small chamber d2 of the hydraulic cylinder d
  • the check valve c blocks second flow paths S2 and s4 that connect the control valve ⁇ to the large chamber d1 of the hydraulic cylinder d.
  • the hydraulic fluid bed from the hydraulic pump P is not supplied to the hydraulic cylinder d. Also, the hydraulic fluid fed from the hydraulic cylinder d is not returned to the hydraulic tank.
  • the dozer blade f is prevented from sinking.
  • the hydraulic fluid in the first flow path s1 acts upon a diaphragm n1 to shift the plunger h in the left direction, and presses the check valve b in the right direction as shown in the drawing to remove the check function (at this time, the first elastic member e1 receives the compression force). That is, the first flow paths s1 and s3 of the check valve k are connected to each other.
  • the plunger h is shifted to press the check valve c in the left direction as shown in the drawing to remove the check function (at this time, the second elastic member e2 receives the compression force). That is, the second flow paths S2 and S4 of the check valve k are connected to each other.
  • the hydraulic fluid fed from the hydraulic pump P is supplied to the small chamber d2 of the hydraulic cylinder d after passing through the control valve ⁇ and the first flow paths s1 and s3 of the check valve k in order.
  • the hydraulic fluid fed from the large chamber d1 of the hydraulic cylinder d is returned to the hydraulic tank after passing through the check valve c of which the check function has been removed, the second flow paths S2 and S4, and the control valve ⁇ in order.
  • the hydraulic cylinder d is driven to be contracted by the hydraulic fluid from the hydraulic pump P.
  • the hydraulic fluid in the second flow path s2 acts upon a diaphragm n2 to shift the plunger h in the right direction, and presses the check valve c in the left direction as shown in the drawing to remove the check function (at this time, the second elastic member e2 receives the compression force). That is, the second flow paths s2 and s4 of the check valve k are connected to each other.
  • the plunger h is shifted to press the check valve b in the right direction as shown in the drawing to remove the check function (at this time, the first elastic member e1 receives the compression force). That is, the first flow paths S1 and S3 of the check valve k are connected to each other.
  • the hydraulic fluid fed from the hydraulic pump P is supplied to the large chamber d1 of the hydraulic cylinder d after passing through the control valve ⁇ and the second flow paths s2 and s4 of the check valve k in order.
  • the hydraulic fluid fed from the small chamber d2 of the hydraulic cylinder d is returned to the hydraulic tank after passing through the check valve b of which the check function has been removed, the first flow paths S1 and S3, and the control valve ⁇ in order.
  • the hydraulic cylinder d is driven to be extended by the hydraulic fluid fed from the hydraulic pump P.
  • the construction equipment having the conventional double check valve has the problems that in the case where the control valve ⁇ is kept in a neutral state, the large chamber d1 and the small chamber d2 of the hydraulic cylinder d cannot be connected to each other through the check function of the check valves b and c installed in the double check valve k. Accordingly, in the case where the dozer blade f requires the floating function depending on the working condition, it is impossible to perform the floating function.
  • the present invention has been made to solve the above-mentioned problems occurring in the prior art while advantages achieved by the prior art are maintained intact.
  • One object of the present invention is to provide a double check valve having a floating function, whereby a working device that is operated by a hydraulic cylinder having a double check valve can perform a floating function when the working device performs land readjustment of a work surface, and thereby improving the workability.
  • a double check valve having a floating function which includes a hydraulic pump; a hydraulic cylinder connected to the hydraulic pump to operate a working device; a control valve installed to open/close flow paths between the hydraulic pump and the hydraulic cylinder and shifted to control a start, a stop, and a direction change of the hydraulic cylinder; and a double check valve installed in flow paths between the control valve and the hydraulic cylinder, and having a pair of plungers dividedly formed to be shifted in opposite directions to each other when a signal pressure is applied from an outside, and a pair of check valves being pressed to remove their check functions through a shifting of the plungers; wherein in the case where the control valve is shifted to a neutral state and a floating function mode of the working device is selected, a large chamber and a small chamber of the hydraulic cylinder are connected to each other by the double check valve.
  • the double check valve may further include a housing in which first flow paths connecting the control valve to the small chamber of the hydraulic cylinder and second flow paths connecting the control valve to the large chamber of the hydraulic cylinder are formed; a signal pressure flow path to which a signal pressure for shifting the plungers is supplied; a pressing member pressing the check valve for opening/closing the first flow paths; a first elastic member elastically supporting the pressing member so as to elastically bias the first flow paths, which have been blocked by the check valve, to their initial states; a pressing member pressing the check valve for opening/closing the second flow paths; and a second elastic member elastically supporting the pressing member so as to elastically bias the second flow paths, which have been blocked by the check valve, to their initial states.
  • a pilot signal pressure which is supplied from the hydraulic pump to the signal pressure flow path, is used as a signal pressure for shifting the plungers.
  • a double check valve having a floating function includes a hydraulic pump P; a hydraulic cylinder d connected to the hydraulic pump P to operate a working device; a control valve ⁇ installed in flow paths between the hydraulic pump P and the hydraulic cylinder d and shifted to control a start, a stop, and a direction change of the hydraulic cylinder d; and a double check valve k installed in first flow paths S1 and s3 and second flow paths S2 and s4 between the control valve ⁇ and the hydraulic cylinder d, and having a pair of plungers h1 and h2 dividedly formed to be shifted in opposite directions to each other when a signal pressure is applied from an outside to diaphragms n3 and n4, and a pair of check valves b and c (e.g., ball type or poppet valves) being pressed to remove their check functions through a shifting of the plungers h1 and h2.
  • a double check valve k installed in first flow paths S1 and s3 and second
  • a large chamber d1 and a small chamber d2 of the hydraulic cylinder d are connected to each other by the double check valve k.
  • the double check valve k may further include a housing m in which the first flow paths s1 and s3 connecting the control valve ⁇ to the small chamber d2 of the hydraulic cylinder d and the second flow paths S2 and s4 connecting the control valve ⁇ to the large chamber d1 of the hydraulic cylinder d are formed; a signal pressure flow path j to which a signal pressure for shifting the plungers is supplied from a pilot pump Pp; a pressing member f1 pressing the check valve b for opening/closing the first flow paths s1 and s3; a first elastic member e1 elastically supporting the pressing member f1 so as to elastically bias the first flow paths s1 and s3, which have been blocked by the check valve b, to their initial states; a pressing member f2 pressing the check valve c for opening/closing the second flow paths s2 and s4; and a second elastic member f2 elastically supporting the pressing member f2 so as to elastically bias the second flow paths s2
  • a pilot signal pressure which is supplied from the hydraulic pump Pp to the signal pressure flow path j, is used as a signal pressure for shifting the plungers h1 and h2.
  • the double check valve k may be driven by the hydraulic fluid fed from the hydraulic pump P or air pressure applied from a compressed air source (not illustrated).
  • the double check valve k serves as a check valve through the check valves b and c elastically supported by the first and second elastic members e1 and e2 and the pressing members f1 and f2.
  • the pair of plungers h1 and h2 dividedly formed are kept in close contact with each other.
  • the check valve b blocks the first flow paths s1 and s3 that connect the control valve ⁇ to the small chamber d2 of the hydraulic cylinder d
  • the check valve c blocks the second flow paths S2 and s4 that connect the control valve ⁇ to the large chamber d1 of the hydraulic cylinder d.
  • the hydraulic fluid bed from the hydraulic pump P is not supplied to the hydraulic cylinder d. Also, the hydraulic fluid fed from the hydraulic cylinder d is not returned to the hydraulic tank.
  • the dozer blade f is prevented from sinking.
  • the check valve b is pressed to remove the check function, and the first flow paths s1 and s3 are connected to each other. Accordingly, the hydraulic fluid fed from the hydraulic pump P is supplied to the small chamber d2 of the hydraulic cylinder d after passing through the control valve ⁇ and the first flow paths s1 and s3 in order.
  • the check valve c is pressed to remove the check function, and the second flow paths s2 and s4 are connected to each other. Accordingly, the hydraulic fluid fed from large chamber d1 of the hydraulic cylinder d is returned to the hydraulic tank after passing through the second flow paths s2 and s4 and the control valve ⁇ in order.
  • the check valve c is pressed to remove the check function, and the second flow paths s2 and s4 are connected to each other. Accordingly, the hydraulic fluid fed from the hydraulic pump P is supplied to the large chamber d1 of the hydraulic cylinder d after passing through the control valve ⁇ and the second flow paths s2 and s4 in order.
  • the check valve b is pressed to remove the check function, and the second flow paths s2 and s4 are connected to each other. Accordingly, the hydraulic fluid fed from small chamber d2 of the hydraulic cylinder d is returned to the hydraulic tank after passing through the first flow paths s1 and s3 and the control valve ⁇ in order.
  • FIG. 9 is a view illustrating the use state of the double check valve when the control valve ⁇ is shifted to a neutral state and the floating function of the dozer blade f is selected.
  • the check valve b is pressed in the right direction to remove its check function (at this time, the first elastic member e1 receives the compression force). That is, the first flow paths s1 and s3 of the check valve k are connected to each other.
  • the check valve c is pressed in the left direction to remove its check function (at this time, the second elastic member e2 receives the compression force). That is, the second flow paths s2 and s4 of the check valve k are connected to each other.
  • control valve ⁇ and the small chamber d2 of the hydraulic cylinder d are connected to each other by the first flow paths s1 and s3, and the control valve ⁇ and the large chamber d1 of the hydraulic cylinder d are connected to each other by the second flow paths s2 and s4.
  • the small chamber d2 and the large chamber d1 of the hydraulic cylinder d are connected to each other. That is, in the case where the hydraulic fluid fed from the large chamber d1 of the hydraulic cylinder d in a non-load state is transferred to the small chamber d2 of the hydraulic cylinder d (as indicated by an arrow) after passing through the second flow paths s4 and s2, the control valve ⁇ , and the first flow paths s1 and s3 in order, the hydraulic cylinder d is driven to be contracted.
  • the double check valve having a floating function has the following advantages.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Check Valves (AREA)
  • Operation Control Of Excavators (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Valve Device For Special Equipments (AREA)
EP07014738A 2006-11-29 2007-07-27 Double clapet de retenue doté d'une fonction de flottement Withdrawn EP1927759A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020060119035A KR100849500B1 (ko) 2006-11-29 2006-11-29 플로팅 기능이 구비된 더블 체크밸브

Publications (1)

Publication Number Publication Date
EP1927759A1 true EP1927759A1 (fr) 2008-06-04

Family

ID=39167691

Family Applications (1)

Application Number Title Priority Date Filing Date
EP07014738A Withdrawn EP1927759A1 (fr) 2006-11-29 2007-07-27 Double clapet de retenue doté d'une fonction de flottement

Country Status (5)

Country Link
US (1) US20080121101A1 (fr)
EP (1) EP1927759A1 (fr)
JP (1) JP2008138870A (fr)
KR (1) KR100849500B1 (fr)
CN (1) CN101191506A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2048372A2 (fr) * 2007-09-20 2009-04-15 Volvo Construction Equipment Holding Sweden AB Double clapet de retenue doté d'une fonction de flottation
EP2696080A1 (fr) * 2012-08-09 2014-02-12 HAWE Hydraulik SE Electro-hydraulic control

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5283862B2 (ja) * 2007-06-05 2013-09-04 三陽機器株式会社 油圧制御装置
FR2933471B1 (fr) * 2008-07-03 2013-02-15 Vianney Rabhi Vanne electro-hydraulique a levee de bille pour centrale hydraulique de moteur a taux de compression variable
KR100985814B1 (ko) 2010-02-18 2010-10-08 파카코리아 주식회사 캐비테이션 방지장치가 구비된 더블 파일롯 체크밸브
WO2011145759A1 (fr) * 2010-05-18 2011-11-24 볼보 컨스트럭션 이큅먼트 에이비 Double clapet anti-retour pour engin de travaux publics
KR101294673B1 (ko) * 2010-08-16 2013-08-09 국방과학연구소 자동 밀폐형 급속 유로전환 밸브
WO2012176314A1 (fr) * 2011-06-23 2012-12-27 株式会社ニレコ Dispositif d'entraînement hybride électrohydraulique
EP2937472A4 (fr) * 2012-12-20 2016-09-07 Volvo Constr Equip Ab Engin de chantier à fonction flottante
CA2905312C (fr) 2014-11-04 2021-03-30 Cnh Industrial Canada, Ltd. Dispositif hydraulique pour un chariot a air
KR101570390B1 (ko) 2015-05-12 2015-11-19 주식회사 에프피씨 자동 유량보상 밸브 유닛
FR3049663B1 (fr) * 2016-03-31 2018-03-16 Lohr Industrie Bloc de securite a double clapet pour verin hydraulique
JP6687992B2 (ja) * 2017-09-29 2020-04-28 株式会社日立建機ティエラ 建設機械
KR101835691B1 (ko) * 2017-11-06 2018-04-19 주식회사 에프피씨 유압작동 보조밸브

Citations (3)

* 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
US3908515A (en) * 1973-09-10 1975-09-30 Caterpillar Tractor Co Hydraulic circuit with selectively actuatable float control
DE19919014A1 (de) 1999-04-27 2000-11-09 Danfoss Fluid Power As Hydraulikventil mit einer Verriegelungs- und einer Schwimmfunktion

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4166506A (en) 1975-06-30 1979-09-04 Kabushiki Kaisha Komatsu Seisakusho Controlling apparatus for bulldozer blade
JPS56501057A (fr) * 1979-08-30 1981-07-30
US4506700A (en) 1983-10-07 1985-03-26 Deere & Company Poppet valve with float function
JPH06128984A (ja) * 1992-10-15 1994-05-10 Kubota Corp 作業車のドーザ装置
JPH10183674A (ja) 1996-12-25 1998-07-14 Toyo Umpanki Co Ltd 土工具昇降装置
US6477937B1 (en) * 1999-12-13 2002-11-12 Aladdin Engineering & Manufacturing Valve arrangement including release valve

Patent Citations (3)

* 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
US3908515A (en) * 1973-09-10 1975-09-30 Caterpillar Tractor Co Hydraulic circuit with selectively actuatable float control
DE19919014A1 (de) 1999-04-27 2000-11-09 Danfoss Fluid Power As Hydraulikventil mit einer Verriegelungs- und einer Schwimmfunktion

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2048372A2 (fr) * 2007-09-20 2009-04-15 Volvo Construction Equipment Holding Sweden AB Double clapet de retenue doté d'une fonction de flottation
EP2048372A3 (fr) * 2007-09-20 2012-05-30 Volvo Construction Equipment Holding Sweden AB Double clapet de retenue doté d'une fonction de flottation
EP2696080A1 (fr) * 2012-08-09 2014-02-12 HAWE Hydraulik SE Electro-hydraulic control

Also Published As

Publication number Publication date
KR20080048711A (ko) 2008-06-03
CN101191506A (zh) 2008-06-04
KR100849500B1 (ko) 2008-07-31
JP2008138870A (ja) 2008-06-19
US20080121101A1 (en) 2008-05-29

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