EP3786461A1 - Directional valve for a work vehicle and related hydraulic arrangement - Google Patents

Directional valve for a work vehicle and related hydraulic arrangement Download PDF

Info

Publication number
EP3786461A1
EP3786461A1 EP20193827.1A EP20193827A EP3786461A1 EP 3786461 A1 EP3786461 A1 EP 3786461A1 EP 20193827 A EP20193827 A EP 20193827A EP 3786461 A1 EP3786461 A1 EP 3786461A1
Authority
EP
European Patent Office
Prior art keywords
port
directional valve
valve
fluidly
piston
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Withdrawn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
EP20193827.1A
Other languages
German (de)
English (en)
French (fr)
Inventor
Peter Arbeithuber
Franz Haider
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.)
CNH Industrial Italia SpA
Original Assignee
CNH Industrial Italia SpA
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 CNH Industrial Italia SpA filed Critical CNH Industrial Italia SpA
Publication of EP3786461A1 publication Critical patent/EP3786461A1/en
Withdrawn legal-status Critical Current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
    • F15B13/0416—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor with means or adapted for load sensing
    • F15B13/0417—Load sensing elements; Internal fluid connections therefor; Anti-saturation or pressure-compensation valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
    • F15B11/05—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive
    • F15B11/055—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive by adjusting the pump output or bypass
    • 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
    • F15B2211/65—Methods of control of the load sensing pressure
    • F15B2211/651—Methods of control of the load sensing pressure characterised by the way the load pressure is communicated to the load sensing circuit
    • 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
    • F15B2211/76—Control of force or torque of the output member
    • F15B2211/761—Control of a negative load, i.e. of a load generating hydraulic energy
    • 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
    • F15B2211/8609—Control during or prevention of abnormal conditions the abnormal condition being cavitation

Definitions

  • the present invention concerns a directional valve, in particular a directional valve for a hydraulic cylinder of a work vehicle.
  • Work vehicles are usually provided with implements actuated by hydraulic cylinders; an example may be found in a front loader that carries a bucket lifted by a boom that is actuated by a hydraulic cylinder.
  • Figure 1 discloses a known hydraulic arrangement 1' for managing the lifting or lowering of a double acting cylinder 2' .
  • such known hydraulic arrangement 1' comprises a load sensing pump 3' and a directional valve 4', fluidly interposed between the load sensing pump 3', the hydraulic cylinder 2' and a discharge 5'.
  • directional valve 4' is configured to assume different position to allow a lowering, a lifting or a neutral stationary condition of the hydraulic cylinder 2'. Such positions may be assumed in function of a mechanical or electronic input given by the user of the work vehicle which needs to use the implement actuated by cylinder 2'.
  • pump 3' In lifting condition, pump 3' is configured to pump pressurized fluid towards piston chamber of cylinder 2' thereby lifting a load carried by the housing of the cylinder 2'and, at the same time, generating a load sensing signal x' which is proportional to the fluid sent to cylinder 2'.
  • load sensing signal x' is fluidly connected to pump 3', thereby controlling its operation.
  • valve 4' make communicate fluidly discharge 5' with piston chamber from which, thanks to the action on the load on cylinder 2', fluid flow out.
  • pump 3' can supply with pressurized fluid rod chamber of cylinder 2', however load sensing signal x" is very low and accordingly pump 3' is not controlled to supply fluid; therefore the movement of cylinder 2' is passive and actuated only by gravity acting on load M.
  • cavitation may arise in rod chamber of cylinder 2' thereby decreasing quality of cylinder 2' and, during use, filling rod chamber with air. Furthermore, such passive movement is low and cannot be actively hydraulically controlled.
  • An aim of the present invention is to satisfy the above mentioned needs in an economic and optimized way.
  • Figure 2 shows a hydraulic arrangement 1 for controlling the operation of an active cylinder 2 suitable for handling of a load M.
  • cylinder 2 is a standard double acting differential hydraulic cylinder comprising a body 3 defining a volume suitable for housing a piston 4 configured to slide in tight manner inside such volume and connected to a rod 5 configured to pass through body 3 in tight manner.
  • an extremity of rod 5 with respect to piston 4 is fixed to a portion of a work vehicle (not shown) while piston 4 subdivides the volume defined by body 3 in a piston chamber 6a and a rod chamber 6b.
  • Piston chamber 6a if fluidly connectable via a conduit 7a and a related hose 8 to a piston conduit 9a of hydraulic arrangement 1 and, similarly, rod chamber 6b is fluidly connectable to this latter via a conduit 7b and a related hose 8 to a rod conduit 9b.
  • Hydraulic arrangement 1 further comprises a pump 10 preferably a load sensing pump configured to suck fluid, e.g. oil, from a reservoir 11, increase its pressure and provide a pressurized fluid as output.
  • a pump 10 preferably a load sensing pump configured to suck fluid, e.g. oil, from a reservoir 11, increase its pressure and provide a pressurized fluid as output.
  • Such pump 10 is connectable to both piston and rod conduits 9a, 9b mentioned above as defined in the following.
  • Hydraulic arrangement 1 further comprises a directional valve 12 according to the present invention fluidly interposed between cylinder 2 and pump 10.
  • hydraulic cylinder 2 comprises a send conduit 13 fluidly connecting an output of pump 10 with a first port 12a of directional valve 12 and a return conduit 14 fluidly connecting directional a second port 12b of valve 12 with reservoir 11.
  • a directional third port 12c of valve 12 is fluidly connect to pump 10 via a conduit 15 carrying a load sensing signal configured to control pump 10.
  • a fourth and fifth ports 12d, 12e of directional valve 12 is fluidly connected to piston and rod conduits 9a, 9b mentioned above.
  • Directional valve 12 is configured to allow a lifting, a lowering, a neutral and a closed operational configuration by connecting in different manners piston and rod conduits 9a, 9b with send and return conduits 13, 14.
  • actuators means 16 configured to move directional valve 12.
  • such actuator means 16 are mechanical means and preferably acts against elastic means 17 configured to maintain directional valve in the neutral operational configuration.
  • directional valve is a five ways - four positions valve.
  • Hydraulic arrangement may further comprise a non return valve 18 fluidly interposed on send conduit 13 upstream with respect to directional valve 11, so as to allow passage only from pump 10 towards cylinder 2 and not vice versa.
  • hydraulic arrangement 1 may comprise a pressure compensator module 20, provided with a narrowing 21 and proportional ON-OFF valve 22 fluidly interposed in series upstream with the non-return valve 18.
  • pressure compensation module is per se known and therefore is not described for sake of brevity.
  • valve 12 of figure 3 may assume a first position I, i.e. rest neutral position wherein load signal conduit 15 is connected to return conduit 14, i.e. to reservoir 11. Accordingly, pump 10 does not provide any pressurized flow to cylinder 2 and piston and rod chambers 6a, 6b and pump 2 output are isolated. Accordingly, load M is maintained at a pre-set position since body 3 cannot be moved with respect to work vehicle. Indeed, pressure in piston and rod chambers 6a, 6b defines a stiffness of support given by cylinder 2 to mass M.
  • send conduit 13 is fluidly connected to piston conduit 9a and a portion X' of such fluid is spilled to load sensing conduit 15, while rod conduit 9b is fluidly connected to return conduit 14.
  • pump 10 can provide pressurized fluid to piston chamber 6a thereby moving body 3 and decreasing volume of rod chamber 6b. Fluid from such chamber may flow out via conduits 9b, 14.
  • the load sensing signal given by portion X' is collected by conduit 15 and sent to pump 10 which is controlled consequently.
  • send conduit 13 is fluidly connected to rod conduit 9b, while return conduit 14 is fluidly connected to piston conduit 9a; according to the invention, respective fluid portions X", X''' are spilled from both the fluid connection between conduits 9b and 13 and the fluid connection between conduits 9a, 14.
  • Such fluid portions are fluidly directed to a selection module 25, for example comprising a shuttle valve, configured to allow the passage of fluid to load sensing signal conduit 15 only to the portion X", X''' having the greater pressure.
  • send conduit 13 is open while both piston and rod conduits 9a, 9b and load sensing conduit 15 are fluidly connected to return conduit 14. Accordingly, pump 10 cannot provide pressurized fluid to cylinder 2, which is totally vent out to reservoir 11.
  • valve 10 In a lifting condition, i.e. second position II, fluid will flow from send conduit 13 towards piston conduit 9a to piston chamber 6a, thereby lifting body 3 and mass M accordingly. Operation of valve 10 is controlled by load sensing signal x' spilled to conduit 15 from the fluid flowing between conduits 9a and 13.
  • fluid will flow from piston conduit 9a, i.e. flowing out from piston chamber 9a under load acted by mass M, towards return conduit 14 and, in parallel, pump 10 may send pressurized fluid to rod chamber 6b via fluid connection between send conduit 13 and rod conduit 9b.
  • Fluid is spilled from both fluid connection between rod conduits 9b and send conduit 13 (X") and connection between piston conduit 9a and return conduit 14 (X''').
  • Such spilled fluid portions X", X''' then pass to selection module 25, e.g. to a shuttle valve, in which the one with greatest pressure will pass to pump 10 as loading sensing signal. In this way, a sufficient load sensing signal is always sent to pump 10 which can provide pressurized flow to rod chamber 6b, thereby avoiding cavitation and assuring a fast lowering of load M.
  • the proposed directional valve 12 allows to provide always a sufficient load sensing signal to control pump 10 thereby pressurizing road chamber 6b and avoiding cavitation.
  • pressure compensation module 20 may be optional, such as the non-return valve 18.
  • the pump 10 may be substituted by a hydraulic supply system of any known typology.
  • neutral position is optional and, accordingly, the present invention may apply to 5/3 way valves as known in the art.
  • fixation of cylinder 2 elements to work vehicle may be realized in specular or different way.
  • selection module 25 may comprise elements having the same function of the described shuttle valve.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Non-Deflectable Wheels, Steering Of Trailers, Or Other Steering (AREA)
EP20193827.1A 2019-09-02 2020-09-01 Directional valve for a work vehicle and related hydraulic arrangement Withdrawn EP3786461A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT102019000015363A IT201900015363A1 (it) 2019-09-02 2019-09-02 Valvola direzionale per un veicolo da lavoro e relativa disposizione idraulica

Publications (1)

Publication Number Publication Date
EP3786461A1 true EP3786461A1 (en) 2021-03-03

Family

ID=68988223

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20193827.1A Withdrawn EP3786461A1 (en) 2019-09-02 2020-09-01 Directional valve for a work vehicle and related hydraulic arrangement

Country Status (2)

Country Link
EP (1) EP3786461A1 (it)
IT (1) IT201900015363A1 (it)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3505623A1 (de) * 1985-02-19 1986-08-21 Robert Bosch Gmbh, 7000 Stuttgart Hydraulisches wegeventil fuer eine lastdruckkompensierte steuerung
US5211196A (en) * 1990-08-31 1993-05-18 Hydrolux S.A.R.L. Proportional seat-type 4-way valve
EP1143152A2 (en) * 2000-04-03 2001-10-10 Husco International, Inc. Auto-calibration of a solenoid operated valve
JP2002005107A (ja) * 1996-01-08 2002-01-09 Nachi Fujikoshi Corp 油圧駆動装置
EP2365226A1 (en) * 2010-03-12 2011-09-14 CNH Italia S.p.A. Hydraulic system
CN103062144B (zh) * 2012-12-30 2015-08-12 徐工集团工程机械股份有限公司江苏徐州工程机械研究院 一种具有抗饱和功能的负载敏感多路阀
CN105351278A (zh) * 2015-12-10 2016-02-24 上海新跃仪表厂 新型电液复合伺服控制***
EP3001042A1 (en) * 2014-09-25 2016-03-30 CNH Industrial Italia S.p.A. Hydraulic system
WO2016163926A1 (en) * 2015-04-10 2016-10-13 Volvo Construction Equipment Ab A load sensing hydraulic system for a working machine, and a method for controlling a load sensing hydraulic system

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3505623A1 (de) * 1985-02-19 1986-08-21 Robert Bosch Gmbh, 7000 Stuttgart Hydraulisches wegeventil fuer eine lastdruckkompensierte steuerung
US5211196A (en) * 1990-08-31 1993-05-18 Hydrolux S.A.R.L. Proportional seat-type 4-way valve
JP2002005107A (ja) * 1996-01-08 2002-01-09 Nachi Fujikoshi Corp 油圧駆動装置
EP1143152A2 (en) * 2000-04-03 2001-10-10 Husco International, Inc. Auto-calibration of a solenoid operated valve
EP2365226A1 (en) * 2010-03-12 2011-09-14 CNH Italia S.p.A. Hydraulic system
CN103062144B (zh) * 2012-12-30 2015-08-12 徐工集团工程机械股份有限公司江苏徐州工程机械研究院 一种具有抗饱和功能的负载敏感多路阀
EP3001042A1 (en) * 2014-09-25 2016-03-30 CNH Industrial Italia S.p.A. Hydraulic system
WO2016163926A1 (en) * 2015-04-10 2016-10-13 Volvo Construction Equipment Ab A load sensing hydraulic system for a working machine, and a method for controlling a load sensing hydraulic system
CN105351278A (zh) * 2015-12-10 2016-02-24 上海新跃仪表厂 新型电液复合伺服控制***

Also Published As

Publication number Publication date
IT201900015363A1 (it) 2021-03-02

Similar Documents

Publication Publication Date Title
US7614336B2 (en) Hydraulic system having augmented pressure compensation
EP2679735B1 (en) Construction machine with working attachment
US9206821B2 (en) Hydraulic switching mechanism for mobile hydraulics, mobile hydraulic machine and valve unit
US7204185B2 (en) Hydraulic system having a pressure compensator
US5490384A (en) Hydraulic flow priority system
JP6467515B2 (ja) 建設機械
US5802847A (en) Hydraulic system for a mobile work device, in particular a wheel loader
JP2009505013A (ja) 複動式油圧シリンダの油圧回路
AU2004276616A1 (en) Hydraulic control device of industrial machinery
US6370874B1 (en) Hydraulic control device for a mobile machine, especially for a wheel loader
CA2945219C (en) Device for recovering hydraulic energy in an implement and a corresponding implement
JP2008039184A (ja) 圧力動作型平衡バルブを有する油圧アクチュエータ制御回路
US20080295681A1 (en) Hydraulic system having an external pressure compensator
JP2017115992A (ja) 作業機の油圧システム
KR102535297B1 (ko) 유체 회로
EP3786461A1 (en) Directional valve for a work vehicle and related hydraulic arrangement
US7383682B2 (en) Hydraulic control arrangement for a mobile equipment
US8763388B2 (en) Hydraulic system having a backpressure control valve
JP2017015130A (ja) 流体回路
JP2008185098A (ja) 作業機械における制御システム
EP4112946A1 (en) Hydraulic arrangement for a work vehicle
CN111677704B (zh) 液压***和工程机械
EP4098808A1 (en) Construction machinery
CN112360833B (zh) 流量控制***及流量控制方法、起重机
EP2118385B1 (en) Fluid system and method of operating thereof

Legal Events

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

Free format text: ORIGINAL CODE: 0009012

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

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

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

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20210903

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

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

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20221114

RAP3 Party data changed (applicant data changed or rights of an application transferred)

Owner name: CNH INDUSTRIAL ITALIA S.P.A.

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20230325