DE10045232B4 - Control device for a hydraulic volume flow - Google Patents

Control device for a hydraulic volume flow

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Publication number
DE10045232B4
DE10045232B4 DE2000145232 DE10045232A DE10045232B4 DE 10045232 B4 DE10045232 B4 DE 10045232B4 DE 2000145232 DE2000145232 DE 2000145232 DE 10045232 A DE10045232 A DE 10045232A DE 10045232 B4 DE10045232 B4 DE 10045232B4
Authority
DE
Germany
Prior art keywords
valve
control
pilot
pressure chamber
pressure
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
DE2000145232
Other languages
German (de)
Other versions
DE10045232A1 (en
Inventor
Wolfgang Koetter
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.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
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 Robert Bosch GmbH filed Critical Robert Bosch GmbH
Priority to DE2000145232 priority Critical patent/DE10045232B4/en
Publication of DE10045232A1 publication Critical patent/DE10045232A1/en
Application granted granted Critical
Publication of DE10045232B4 publication Critical patent/DE10045232B4/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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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
    • F15B20/00Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
    • F15B20/008Valve failure
    • 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
    • F15B13/01Locking-valves or other detent i.e. load-holding devices
    • F15B13/015Locking-valves or other detent i.e. load-holding devices using an enclosed pilot flow valve
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05DSYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D7/00Control of flow
    • G05D7/005Control of flow characterised by the use of auxiliary non-electric power combined with the use of electric means
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05DSYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D7/00Control of flow
    • G05D7/01Control of flow without auxiliary power
    • G05D7/0126Control of flow without auxiliary power the sensing element being a piston or plunger associated with one or more springs
    • G05D7/0133Control of flow without auxiliary power the sensing element being a piston or plunger associated with one or more springs within the flow-path
    • G05D7/014Control of flow without auxiliary power the sensing element being a piston or plunger associated with one or more springs within the flow-path using sliding elements

Abstract

Control device for a hydraulic volume flow (10, 22) of a loaded working fluid (12) with at least one main valve (14, 16) acting as a check valve and with a pressure chamber (40) connected to an inlet (48) and a drain for receiving pressurized fluid standing hydraulic means for controlling the main valve (14, 16), wherein the pressure in the pressure chamber (40) by a pilot valve (20, 36) is controllable, characterized in that the pressure chamber (40) shut-off by means of at least one further valve (60) is.

Description

  • State of the art
  • The The invention is based on a control device for a hydraulic volume flow according to the preamble of the claim 1
  • From the DE 196 34 319 A1 or the DE 41 40 604 A1 already a generic type control device with a check valve is known, in which a seat valve body is arranged. The poppet valve body cooperates with a housing-fixed main valve seat. In the seat valve body, a pilot valve body is arranged, which cooperates with a valve seat in the seat valve body. The seat valve body is pressed by the action of pressure in a pressure space on one of its end faces in the main valve seat.
  • In the control device according to the DE 196 34 319 is the pressure chamber on the outside of the seat valve body column located connected to a working cylinder. To open the shut-off valve, the pilot valve body is turned on at the beginning of an opening process by a proportional solenoid so far that the pressure chamber is completely relieved of pressure. After unlocking the check valve of the seat valve body is moved by the proportional solenoid mechanically against the force of a spring.
  • In the control device of the DE 41 40 604 A1 the pressure chamber is connected via a throttle of defined flow cross-section with a working cylinder. By means of a variable throttle point whose opening cross-section is controlled by the pilot valve body, the pressure in the pressure chamber and thus the position of the seat valve body in the check valve can be determined by means of a proportional magnet. The position of the seat valve body in the check valve determines the volume flow of the hydraulic fluid from the working cylinder in a return line.
  • If in the known control devices, for example, an abrasive metal chip blocked the valve seat, then the pilot valve can also at a Control signal for his closure not complete anymore shut down. There remains a small pilot volume flow of hydraulic fluid, so that the pressure slightly falls in the pressure room and so that the main control valve opens slightly. By this leakage conditionally, the working cylinder slowly loses hydraulic fluid, and the working piston descends into the working cylinder. At a working cylinder for the lifting fork of a forklift causes this hydraulic leakage, that yourself slowly lower the fork. This is undesirable because the fork lift itself should not move without control current specification.
  • Advantages of the invention
  • The The invention is based on a control device for a Volume flow of a hydraulic fluid at least one loaded working fluid with at least one check valve, which has a main valve and one with an inlet and outlet connected pressure chamber for receiving under Having pressurized hydraulic means for controlling the main valve, wherein the pressure in the pressure chamber controllable by a pilot valve is.
  • It It is suggested that the Pressure chamber drainage side by means of at least one other valve shut off is. Locks this further valve from the pressure chamber, so can in a leakage of the pilot valve described above, no hydraulic fluid drain from the pressure chamber. In the pressure room, therefore, the pressure prevails with him over the Feed connected loaded hydraulic circuit before. In this case becomes the main valve body pressed against the main valve seat and the main valve blocks the flow of hydraulic fluid from. The additional valve thus offers the advantage of a redundant safety shutdown. When switching off the control current, the pilot valve is closed, simultaneously the other valve is closed, so that the pilot control flow redundantly interrupted by two different valves, and the Main valve body is pressed into its main valve seat due to the build-up in the pressure chamber load pressure. Even if not complete closed pilot valve, a flow and, for example in a forklift, a movement under load can be avoided.
  • In an advantageous embodiment of the invention, the main valve a main valve body which interacts with a main valve seat. Training the main valve as a seat valve has the advantage that the flow the hydraulic means with the valve closed in the simplest way Completely is interrupted without losses due to leakage. The intension of the invention, a drain of Hydraulic fluid from the cylinder and thus a shift the working piston completely to prevent, is thus best achieved.
  • Preferably, the pilot valve has a pilot valve body, which is displaceable by a plunger of a proportional solenoid. By means of a proportional magnet can be implemented in a cost effective manner, an electrical signal in a travel of a pilot valve body. The pilot valve body in turn adjusts the position of a main valve body, which can control much larger volume flows of hydraulic fluid. in the de-energized state of the proportional solenoid pushes a return spring the pilot valve body in a the drain of the pressure chamber blocking position. The pressure in the pressure chamber causes - as described above - the main valve body, also to block the flow of hydraulic fluid. In the absence of drive current of the main valve body is pressed firmly into its seat due to the hydraulic pressure in the pressure chamber.
  • advantageously, is the pilot valve body in a bore of the main valve body for controlling a pilot flow rate displaceable. The check valve can be very compact in this way be built. Preferably, the pilot valve is on the drain side arranged the pressure chamber. When opening of the pilot valve body takes the pressure in the pressure chamber and thus in the closing direction acting force. After all the latter falls below the condition caused by the hydraulic pressure of the load Counterforce in opening direction. The main valve body is pushed in the direction of the pilot valve body and gives the Main valve seat free. By this succession of the main valve body is the pilot flow volume again smaller because the relative displacement between main valve body and pilot valve body becomes smaller. The pressure in the pressure chamber becomes larger again, and the main valve body shifts again in the closing direction. Ultimately a stable balance. Due to this compact design can they Hydraulic lines between pressure chamber and pilot valve body short being held. Pressure fluctuations are thus due to the immediate feedback largely avoided. The other valve is thus lower pressure fluctuations exposed and can be dimensioned cheaper become.
  • In an advantageous embodiment of the invention is the other Valve arranged between pressure chamber and pilot valve. This offers the advantage that the more valve on the static part of the check valve in easier Way, and the pilot flow rate and the main control volume flow are merged immediately after the valve seats can. Would be that another valve arranged after the pilot valve, would be a own, complicated discharge of the pilot flow volume from the Locking valve to the other valve needed.
  • Preferably the other valve is a seat valve. A seat valve stands out by its simple structure, but it is - more advantageous Way designed as a solenoid valve - his Determination quite fair, in the de-energized state, the pilot flow rate Completely shut off.
  • In an advantageous embodiment of the invention, the check valve and the other valve over a housing firmly connected. A composite unit of check valve and further valve is distinguished by its easy assembly and disassembly. The hydraulic connections run inside the housing. Separate hydraulic connection lines, which are cost-intensive and pose potential leakages, eliminated in this way.
  • Advantageous the check valve and the other valve are arranged coaxially with each other. It concludes the other valve directly to the pressure chamber. This arrangement offers the advantage that the Hydraulic connection between pressure chamber and further valve only off a short hole exists.
  • Preferably is at least part of the further valve in a bore in a housing arranged the check valve. The additional valve can thus save space in the case the check valve are integrated and in a simple manner, for example via a Screw connection to be connected to this. This shows that casing the check valve, a hydraulic connection between the other Valve and the pilot valve on. This will be - as above already executed - separate Hydraulic connection lines, which are cost-intensive and potential Leakage pose, saved.
  • Advantageous the other valve is electrically controlled and electrically parallel switched to a hydraulic pressure switch valve. The hydraulic fluid is in the operating state to the piston stroke in the working cylinder of a pressure supply pump put under pressure. With an inlet pressure balance, the pressure switched on the Hyrauliksystem. The inlet pressure balance in turn is actuated by the hydraulic pressure switch valve. The returning hydraulic fluid is collected in a tank before it comes from the pressure supply pump is returned to the hydraulic system. The hydraulic pressure switch valve When it is de-energized relieves a spring chamber of the inlet pressure compensator. This promotes the pressure supply pump of the hydraulic system even when switched on Actuator depressurizes the hydraulic fluid to the tank. That's all Load movements requiring hydraulic pressure are excluded. Im not energized State of Hydraulikdruckschaltaltventils are all in this way strokes switched off by working piston in working cylinders.
  • By the pilot valve and the invention further valve all lowering movements of working piston in working cylinders are interrupted with the safety of a redundant system in the de-energized state. The parallel connection of the hydraulic pressure switching valve on the one hand and the other valve on the other hand thus offers the advantage that in the disconnected, de-energized state, no movement is possible. A correspondingly operated hydraulic implement, such as a forklift, persists in motionlessness. There are no uncontrolled, unwanted movements instead.
  • Preferably the other valve is a 2/2 seat valve. This offers the advantage a simple, inexpensive Design and fulfilled nevertheless its purpose.
  • drawing
  • Further Advantages are shown in the following description of the drawing. In the drawing is an embodiment represented the invention. The drawing, the description and the Claims included numerous features in combination. The skilled person will become the characteristics appropriately also individually consider and summarize to meaningful further combinations.
  • Description of the embodiment
  • 1 shows a control device for a volume flow 10 . 22 a hydraulic means of a working cylinder 12 , about with a pump 28 and via a 3/2-way valve 30 lifted a load and controlled via a check valve can be lowered. The check valve has a main valve body 14 that with a main valve seat 16 interacts and via one of a proportional solenoid 18 actuatable pilot valve body 20 is controllable. The pilot valve body 20 is over a preloaded spring 34 in the closing direction 24 in his valve seat 36 in the main valve body 14 pressed. The feather 34 relies on one end 46 on a heel 54 inside a case 52 and acts on a second end 50 about one on the pilot valve body 20 attached spring plate 56 on the pilot valve body 20 in the closing direction 24 ,
  • Should a load with the working cylinder 12 be lowered, the proportional magnet 18 activated. One with the armature of the proportional magnet 18 connected plunger 32 shifts the pilot valve body 20 against the spring 34 , which is further biased. The pilot valve body 20 moves out of the valve seat 36 in the main valve body 14 in the opening direction 26 , so that a pilot flow volume 22 via a throttle point 38 , a feed 48 , a pressure room 40 , about one with the pressure room 40 connecting another valve 60 , two connection channels 58 . 62 and finally a fine control 66 and the valve seat 36 can drain into a return not shown. At the same time, the pressure in the pressure chamber becomes 40 reduced, with a force in the closing direction 24 on a surface 42 of the main valve body 14 acts. Exceeds the on a surface 44 acting pressure force in the opening direction 26 in the closing direction 24 acting pressure force, shifts the main valve body 14 in the opening direction 26 until an equilibrium position is reached. The load is over the working cylinder 12 lowered at a certain speed.
  • According to the invention, the pilot volume flow described above 22 through the other valve 60 shut off. If the pilot flow volume 22 interrupted, arises in the pressure room 40 the prevailing pressure in the loaded cylinder, as above the throttle point 38 builds up a pressure difference only with flowing hydraulic fluid. The pressure in the pressure chamber 40 causes a force in the closing direction 24 on a surface 42 of the main valve body 14 , This exceeds the one on a surface 44 acting pressure force in the opening direction 26 , because on both surfaces 42 . 44 when the other valve is sealed off, the same pressure acts and the force in the closing direction 24 receiving surface 42 is larger. The main valve body 14 So it's stuck in the main valve seat 16 pressed. The main valve blocks and the flow through the main valve 10 will be interrupted.
  • The other valve 60 is switched so that it is energized in the operating state and thus open. On the other hand, if the control device is switched off, this is the additional valve 60 de-energized and thus closed. A feather 68 pushes a valve cone 70 the further valve 60 in a valve seat 72 , In the undisturbed case of the normally closed control system locks the pilot valve, then follows the main valve body 14 as a result of the build-up in the pressure chamber closing force the pilot valve body 20 until he is in the main valve seat 16 comes to rest, and the main valve locks. But if the pilot valve blocked by any reason, for example by a Abriebspan from the hydraulic system, the pilot valve can not completely lock, and thus could without the other valve 60 the main valve also the volume flow 10 do not lock. In this accident, a load would be lowered, for example, in a forklift, the lifting fork, as from the associated working cylinder 12 Hydraulic fluid flows. This is extremely undesirable in a disconnected implement, as an uncontrolled movement of the possibly unguarded implement can cause personal injury and property damage. Due to the shut-off working device, respectively when de-energized control system, additionally blocking another valve 60 The safety of being able to exclude an unintentional movement of the disconnected implement, significantly increased.

Claims (12)

  1. Control device for a hydraulic volume flow ( 10 . 22 ) of a contaminated work equipment ( 12 ) with at least one main valve acting as a check valve ( 14 . 16 ) and one with a feed ( 48 ) and a drain connected pressure chamber ( 40 ) for receiving pressurized hydraulic fluid to control the main valve ( 14 . 16 ), whereby the pressure in the pressure chamber ( 40 ) from a pilot valve ( 20 . 36 Is controllable), characterized in that the pressure chamber ( 40 ) on the outlet side by means of at least one further valve ( 60 ) can be shut off.
  2. Control device according to claim 1, characterized in that the main valve ( 14 . 16 ) a main valve body ( 14 ) fitted with a main valve seat ( 16 ) cooperates.
  3. Control device according to claim 1 or 2, characterized in that the pilot valve ( 20 . 36 ) a pilot valve body ( 20 ), which via a plunger ( 32 ) of a proportional magnet ( 18 ) is displaceable.
  4. Control device according to Claims 1 to 3, characterized in that the pilot control valve body ( 20 ) in a bore of the main valve body ( 14 ) is displaceable for controlling a pilot flow volume.
  5. Control device according to one of the preceding claims, characterized in that the pilot valve ( 20 . 36 ) downstream of the pressure chamber ( 40 ) is arranged.
  6. Control device according to claim 1 and 5, characterized in that the further valve ( 60 ) between pressure chamber ( 40 ) and pilot valve ( 20 . 36 ) is arranged.
  7. Control device according to one of the preceding claims, characterized in that the further valves ( 60 ) is a seat valve.
  8. Control device according to one of the preceding claims, characterized in that the further valves ( 60 ) is a solenoid valve.
  9. Control device according to one of the preceding claims, characterized in that the main valve ( 14 . 16 ), the pilot valve ( 20 . 36 ) and the other valves ( 60 ) via a housing ( 52 ) are firmly connected.
  10. Control device according to one of the preceding claims, characterized in that the main valve ( 14 . 16 ), the pilot valve ( 20 . 36 ) and the other valves ( 60 ) are arranged coaxially to each other and the other valves ( 60 ) directly to the pressure chamber ( 40 ).
  11. Control device according to one of the preceding claims, characterized in that at least part of the further valve ( 60 ) in a bore in a housing ( 52 ) of the check valve is arranged and that the housing ( 52 ) a hydraulic connection between the further valve ( 60 ) and the pilot valve ( 20 . 36 ) having.
  12. Control device according to one of the preceding claims, characterized in that the further valves ( 60 ) is a 2/2-seat valve.
DE2000145232 2000-09-13 2000-09-13 Control device for a hydraulic volume flow Expired - Fee Related DE10045232B4 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE2000145232 DE10045232B4 (en) 2000-09-13 2000-09-13 Control device for a hydraulic volume flow

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2000145232 DE10045232B4 (en) 2000-09-13 2000-09-13 Control device for a hydraulic volume flow

Publications (2)

Publication Number Publication Date
DE10045232A1 DE10045232A1 (en) 2002-03-28
DE10045232B4 true DE10045232B4 (en) 2011-01-05

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DE2000145232 Expired - Fee Related DE10045232B4 (en) 2000-09-13 2000-09-13 Control device for a hydraulic volume flow

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Country Link
DE (1) DE10045232B4 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE20208577U1 (en) 2002-06-03 2003-12-11 Hawe Hydraulik Gmbh & Co. Kg Electro-hydraulic lift control device for industrial trucks

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4140604A1 (en) * 1991-12-10 1993-06-17 Bosch Gmbh Robert Control device for the volume flow of a hydraulic working agent
DE19634319A1 (en) * 1996-08-24 1998-02-26 Bosch Gmbh Robert Electro-hydraulic control device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4140604A1 (en) * 1991-12-10 1993-06-17 Bosch Gmbh Robert Control device for the volume flow of a hydraulic working agent
DE19634319A1 (en) * 1996-08-24 1998-02-26 Bosch Gmbh Robert Electro-hydraulic control device

Also Published As

Publication number Publication date
DE10045232A1 (en) 2002-03-28

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R020 Patent grant now final

Effective date: 20110405

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

Effective date: 20140401