DE102004005402A1 - Lifting cylinder raising and lowering system for utility vehicle uses hydraulic pump connected to 2/2-way valve connected to 2-way current regulation valve and cylinder - Google Patents

Lifting cylinder raising and lowering system for utility vehicle uses hydraulic pump connected to 2/2-way valve connected to 2-way current regulation valve and cylinder

Info

Publication number
DE102004005402A1
DE102004005402A1 DE200410005402 DE102004005402A DE102004005402A1 DE 102004005402 A1 DE102004005402 A1 DE 102004005402A1 DE 200410005402 DE200410005402 DE 200410005402 DE 102004005402 A DE102004005402 A DE 102004005402A DE 102004005402 A1 DE102004005402 A1 DE 102004005402A1
Authority
DE
Germany
Prior art keywords
valve
lifting cylinder
way
lowering
way 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.)
Granted
Application number
DE200410005402
Other languages
German (de)
Other versions
DE102004005402B4 (en
Inventor
Thomas Dipl.-Ing. Stolten
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.)
Jungheinrich AG
Original Assignee
Jungheinrich AG
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 Jungheinrich AG filed Critical Jungheinrich AG
Priority to DE200410005402 priority Critical patent/DE102004005402B4/en
Publication of DE102004005402A1 publication Critical patent/DE102004005402A1/en
Application granted granted Critical
Publication of DE102004005402B4 publication Critical patent/DE102004005402B4/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B66HOISTING; LIFTING; HAULING
    • B66FHOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075Constructional features or details
    • B66F9/20Means for actuating or controlling masts, platforms, or forks
    • B66F9/22Hydraulic devices or systems
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/04Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
    • F15B11/0413Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed in one direction only, with no control in the reverse direction, e.g. check valve in parallel with a throttle valve
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/20Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205Systems with pumps
    • F15B2211/2053Type of pump
    • F15B2211/20546Type of pump variable capacity
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/20Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/27Directional control by means of the pressure source
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/30Directional control
    • F15B2211/305Directional control characterised by the type of valves
    • F15B2211/3052Shuttle valves
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/30Directional control
    • F15B2211/315Directional control characterised by the connections of the valve or valves in the circuit
    • F15B2211/3157Directional 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
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/405Flow control characterised by the type of flow control means or valve
    • F15B2211/40515Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/405Flow control characterised by the type of flow control means or valve
    • F15B2211/40553Flow control characterised by the type of flow control means or valve with pressure compensating valves
    • F15B2211/40561Flow control characterised by the type of flow control means or valve with pressure compensating valves the pressure compensating valve arranged upstream of the flow control means
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/405Flow control characterised by the type of flow control means or valve
    • F15B2211/40576Assemblies of multiple valves
    • F15B2211/40584Assemblies of multiple valves the flow control means arranged in parallel with a check valve
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/41Flow control characterised by the positions of the valve element
    • F15B2211/413Flow control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional valves
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/42Flow control characterised by the type of actuation
    • F15B2211/426Flow control characterised by the type of actuation electrically or electronically
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/42Flow control characterised by the type of actuation
    • F15B2211/428Flow control characterised by the type of actuation actuated by fluid pressure
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/46Control of flow in the return line, i.e. meter-out control
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/47Flow control in one direction only
    • F15B2211/473Flow control in one direction only without restriction in the reverse direction
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/70Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/705Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
    • F15B2211/7051Linear output members
    • F15B2211/7052Single-acting output members
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/70Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/75Control of speed of the output member

Abstract

Valve arrangement for raising and lowering a lifting cylinder, in particular in a truck, with a directional control valve which selectively connects a pilot pump or a tank with the lifting cylinder with appropriate feedforward control and holds in a neutral position the lifting cylinder in the assumed position, the pump over a shuttle valve in its first position and a 2/2-way valve with the lifting cylinder and the lifting cylinder via the 2/2-way valve and the shuttle valve in its second position is connected to the tank, if a single pilot control means the 2/2-way valve the neutral position adjusted to a switching position.

Description

  • The The invention relates to a valve assembly for lifting and lowering a lifting cylinder, in particular in an industrial truck, according to the preamble of claim 1.
  • It is known in the way between a hydraulic pump and a Lift cylinder a 3/3-way valve or two separately separated valves to arrange. The valves are equipped with appropriate pilot control means equipped, z. B. electromagnet, which the valves for driving a desired one Adjust operating state. Among them is the lifting and lowering as well as the load attitude to understand. In the load attitude of the Lifting cylinders are held in the assumed position.
  • The Load is usually through a check valve realized. In a 3/3-way valve, the load is held in the neutral position of the valve, while the lifting process a Actuation in one direction and the lowering operation in the opposite Direction requires. The Senkzweig the well-known 3/3-way valve becomes common designed as an adjustable throttle to the lowering speed to set or limit.
  • Of the Invention is based on the object, a valve assembly for lifting and lowering a lifting cylinder, in particular in an industrial truck, which can be achieved with simpler means.
  • These The object is solved by the features of claim 1.
  • at inventive valve arrangement is the pump over a shuttle valve in its first position and a 2/2-way valve with the lifting cylinder and the lifting cylinder via the 2/2-way valve and the Shuttle valve in its second position connected to the tank, if a single pilot means the 2/2-way valve from the neutral position adjusted to a switching position.
  • The used according to the invention 2/2-way valve has a neutral or rest position, in the it realizes the load attitude. In its switching position it opens a passage for the flow rate of the pump to the lifting cylinder. At the same time is one Passage for created the lowering of the lifting cylinder to the tank. Switching from the pump to the tank, and vice versa, by means of a shuttle valve, whose one connection with the pump and its other connection is connected to the tank, while a connection in between connected to the input of the 2/2-way valve. The inventively provided Shuttle valve allows hence the flow of Hydraulic medium from the pump to the lifting cylinder in the lifting phase and the river of Medium from the lifting cylinder to the tank in the lowering phase by the valve member is distributed accordingly in the shuttle valve.
  • The Invention has the advantage that a simple 2/2-way valve is provided with only one active switching position. To control only a single pilot control is required such as in the form of an electromagnet, as common for hydraulic valves. It it goes without saying that too a control over a so-called pilot valve can be done, the hydraulic or works pneumatically. Thus, in the invention also decreases the effort for the feedforward control.
  • Becomes for the Lifting and lowering the same volume flow rate is needed a simple valve passage in both directions is sufficient. If, however, an adjustment of the opening cross-section in the valve passage desired is in one embodiment of the invention in the passage of the 2/2-way valve in its switching position adjustable by the pilot control throttle provided, depending on adjusted by a control signal controlling the pilot control means becomes.
  • Frequently becomes for the Lift a larger volume flow needed while the lowering speed is limited due to a standard definition. Therefore, it is provided according to an embodiment of the invention that in parallel a branch is connected to the throttle, which opens a lifting valve lifting the lifting cylinder contains. When lifting, therefore, an additional channel is opened, the sinking through the check valve due to the backflowing medium is closed. While of lowering, the volume flow can be proportional to a working Throttle be limited.
  • The Shuttle valve is in the invention preferably by suitable Medium biased against the connected to the pump port and that according to another embodiment either by gravity and / or with the help of a spring.
  • One embodiment The invention will be explained in more detail with reference to a drawing.
  • The only figure shows a circuit diagram of a valve assembly according to the Invention.
  • In the only figure feeds a hydraulic pump 10 in the first port P of a shuttle valve 12 , The second opposite connection T leads to the tank 14 for the pump 10 , A side port H leads to a 2/2-way valve 16 that with the outputs 2 and optionally with a line 18 connected is. This leads via a two-way current regulator 20 to a hydraulic lifting cylinder 22 , Parallel to the two-way current controller 20 lies a branch 24 , with a check valve 26 , The two-way current regulator 20 with the control lines 40 . 42 and the biasing spring 46 is a lowering brake that realizes a load-independent lowering speed, as known per se.
  • The slide of the 2/2-way valve, not shown, is at one end by a spring 28 biased and at the opposite end by an electromagnet 30 actuated, which can be acted upon by a voltage source with a different voltage (not shown), which is indicated by the arrow 32 is indicated.
  • In the neutral or de-energized position of the 2/2-way valve, the passage is blocked, and a check valve 34 takes over the load attitude.
  • The passage of the 2/2-way valve in the actuated position is from a throttle 36 and a branch connected in parallel to the throttle with a check valve 38 educated. In the mentioned switching position is the output 1 with the line 18 in connection.
  • For the lifting process, the 2/2-way valve 16 activated and brought into the switching position. The ball of the shuttle valve 12 closes the connection T to the tank 14 , and the medium passes from the pump via the shuttle valve 12 and via the parallel connection of the two branches in the 2/2-way valve and the check valve 26 to the lifting cylinder 22 ,
  • However, if the pump is inactive, the ball is in the shuttle valve 12 in the position shown in the figure. Hydraulic medium from the lifting cylinder 22 then flows via two-way current controller 20 and the throttle 36 over the shuttle valve 12 to the tank 14 , The lowering speed is over the adjustable cross section of the throttle 36 set.

Claims (7)

  1. Valve arrangement for raising and lowering a lifting cylinder, in particular in an industrial truck, with a directional control valve which selectively connects a pilot pump or a tank with the lifting cylinder with appropriate feedforward control and holds in a neutral position the lifting cylinder in the assumed position, characterized in that the pump ( 10 ) via a shuttle valve ( 12 ) in its first position and a 2/2-way valve ( 16 ) with the lifting cylinder ( 22 ) and the lifting cylinder ( 22 ) via the 2/2-way valve ( 16 ) and the shuttle valve ( 12 ) in its second position with the tank ( 14 ) is connected when a single pilot control means the 2/2-way valve ( 16 ) adjusted from the neutral position into a switching position.
  2. Valve arrangement according to claim 1, characterized in that the passage of the 2/2-way valve ( 16 ) in its switching position an adjustable by the pilot control throttle ( 36 ) and the pilot control means contains the throttle ( 26 ) adjusted in response to a pilot signal.
  3. Valve arrangement according to Claim 1 or 2, characterized in that the pilot control means is an electromagnet ( 30 ).
  4. Valve arrangement according to Claims 2 and 3, characterized in that the electromagnet ( 30 ) the throttle ( 36 ) in response to the applied control voltage.
  5. Valve arrangement according to one of claims 2 to 4, characterized in that the throttle ( 36 ) a branch is connected in parallel, the one when lifting the lifting cylinder ( 22 ) opening check valve ( 38 ) contains.
  6. Valve arrangement according to one of claims 1 to 5, characterized in that the valve member of the shuttle valve ( 12 ) against the pump ( 10 ) connected terminal (P) is biased.
  7. Valve arrangement according to claim 6, characterized that the Bias by gravity and / or a spring takes place.
DE200410005402 2004-02-03 2004-02-03 Valve arrangement for lifting and lowering a lifting cylinder Expired - Fee Related DE102004005402B4 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE200410005402 DE102004005402B4 (en) 2004-02-03 2004-02-03 Valve arrangement for lifting and lowering a lifting cylinder

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE200410005402 DE102004005402B4 (en) 2004-02-03 2004-02-03 Valve arrangement for lifting and lowering a lifting cylinder

Publications (2)

Publication Number Publication Date
DE102004005402A1 true DE102004005402A1 (en) 2005-08-18
DE102004005402B4 DE102004005402B4 (en) 2006-01-05

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
DE200410005402 Expired - Fee Related DE102004005402B4 (en) 2004-02-03 2004-02-03 Valve arrangement for lifting and lowering a lifting cylinder

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2786958A1 (en) * 2013-04-05 2014-10-08 Bosch Rexroth Oil Control S.p.A. Control device for the descent of a load
CN108561347A (en) * 2018-05-31 2018-09-21 武汉船用机械有限责任公司 A kind of oil cylinder hydraulic control system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007027567B4 (en) 2007-06-15 2018-03-01 Robert Bosch Gmbh Control arrangement with pipe rupture function

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3148852A1 (en) * 1981-12-10 1983-06-23 Dautel Emil Gmbh Electrohydraulic control circuit for a tailgate
DE20208577U1 (en) * 2002-06-03 2003-12-11 Hawe Hydraulik Gmbh & Co. Kg Electro-hydraulic lift control device for industrial trucks

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3148852A1 (en) * 1981-12-10 1983-06-23 Dautel Emil Gmbh Electrohydraulic control circuit for a tailgate
DE20208577U1 (en) * 2002-06-03 2003-12-11 Hawe Hydraulik Gmbh & Co. Kg Electro-hydraulic lift control device for industrial trucks

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2786958A1 (en) * 2013-04-05 2014-10-08 Bosch Rexroth Oil Control S.p.A. Control device for the descent of a load
CN108561347A (en) * 2018-05-31 2018-09-21 武汉船用机械有限责任公司 A kind of oil cylinder hydraulic control system

Also Published As

Publication number Publication date
DE102004005402B4 (en) 2006-01-05

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R119 Application deemed withdrawn, or ip right lapsed, due to non-payment of renewal fee