EP1339988A1 - Element de blocage - Google Patents

Element de blocage

Info

Publication number
EP1339988A1
EP1339988A1 EP01969276A EP01969276A EP1339988A1 EP 1339988 A1 EP1339988 A1 EP 1339988A1 EP 01969276 A EP01969276 A EP 01969276A EP 01969276 A EP01969276 A EP 01969276A EP 1339988 A1 EP1339988 A1 EP 1339988A1
Authority
EP
European Patent Office
Prior art keywords
main piston
piston
block according
connection
locking block
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Withdrawn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
EP01969276A
Other languages
German (de)
English (en)
Inventor
Burkhard KNÖLL
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.)
Bosch Rexroth AG
Original Assignee
Bosch Rexroth 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 Bosch Rexroth AG filed Critical Bosch Rexroth AG
Publication of EP1339988A1 publication Critical patent/EP1339988A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/01—Locking-valves or other detent i.e. load-holding devices
    • F15B13/015—Locking-valves or other detent i.e. load-holding devices using an enclosed pilot flow valve
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/87169—Supply and exhaust
    • Y10T137/87233—Biased exhaust valve
    • Y10T137/87241—Biased closed
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/877—With flow control means for branched passages
    • Y10T137/87893—With fluid actuator

Definitions

  • the invention relates to a locking block according to the preamble of patent claim 1.
  • Lock blocks of this type are used, for example, in mobile hydraulics to control double-acting hydraulic cylinders, which are provided, for example, for actuating front linkages, rear linkages or other peripheral devices such as mowers, packers, etc.
  • the hydraulic cylinders are actuated, for example, via a valve arrangement, as is known from DE 197 34 479 A1.
  • This valve arrangement is disc-shaped and has a proportional valve with a directional and a speed section, via which a pressure connection can optionally be connected to two working connections.
  • the two working connections are connected to a cylinder space or an annular space of the hydraulic cylinder to be controlled.
  • a generic blocking block is assigned to each of the working connections and is designed as an unlockable check valve arrangement.
  • the blocking block In its non-return function, the blocking block allows pressure medium to be supplied from the proportional valve to the associated work connection, while the blocking block connected in parallel and assigned to the other work connection controls the return flow of the pressure medium from the hydraulic cylinder to a tank or low-pressure connection in its return function.
  • Each locking block has a main piston biased against a valve seat, which in the check function opens a connection between the pressure connection and the associated work connection.
  • an opening piston which can be acted upon by a control pressure is assigned to it, via which the main piston can be brought into its open position in order to open the connection between the working connection and the tank connection.
  • the opening piston opens a pre-opening of the main piston, so that the end face which is effective in the closing direction is relieved and the opening piston can lift the main piston from the valve seat due to the effect of the control pressure.
  • the push piston is supported by a spring on the adjacent end face of the main piston.
  • the pressure at the pressure connection ie the pump pressure
  • the non-return function extension of the hydraulic cylinder
  • the return function retract of the hydraulic cylinder
  • the load pressure is applied to the consumer in this pressure chamber.
  • the respective pressure in the pressure chamber must first be reduced before the respective other function can take effect.
  • a tank channel is opened via a control edge, so that the pressure chamber towards the tank is relieved.
  • the pump pressure still acts in said pressure chamber, so that the response behavior of the valve arrangement, in particular when switching quickly, does not meet the requirements under certain operating conditions.
  • the invention is based on the object
  • the pressure space between a main piston and a push-up piston is always relieved of pressure to a tank or a low-pressure connection, so that the delayed response behavior disadvantageous in the prior art due to the required pressure reduction in said
  • an end section of the push-up piston is sealingly guided in an end recess of the main piston, so that the pressure space is limited only by the push-up piston and the main piston designed with a pre-opening.
  • the latter is preferably designed as a stepped piston, the area difference being effective in the closing direction, so that the pushing piston can be moved back into its closed position as quickly as possible.
  • the pre-opening of the main cone is opened in the return function via the push-open piston, so that a rear space of the main piston towards the tank or low-pressure connection is relieved.
  • the annular space delimited by the radial shoulder of the main piston is hydraulically connected to a pilot channel downstream of the pilot valve seat on the one hand and to the working connection on the other.
  • a nozzle is provided in the pressure medium flow path from the annular space to the working connection, the effective diameter of which is substantially smaller than that of the pre-opening, so that an effective relief of the pressure in the annular space and in the pilot channel is possible.
  • this nozzle is formed by an axial groove on the outer circumference of the main piston.
  • the smaller diameter of the main piston preferably has the same diameter as the push-up piston.
  • the production of the locking block according to the invention is particularly simple if a channel is formed in the push-up piston, via which the pressure chamber is connected to the tank or low-pressure connection.
  • the hydraulic connection between the pilot channel and the annular space is controlled when the main piston is lifted from its valve seat and a larger opening cross-section is opened between the annular space and the associated working connection, so that pressure differences as a result of a leakage via the activated pre-opening and thus displacements of the Return characteristic can be prevented.
  • a connection between the working connection and the tank connection is opened, so that the pressure medium can flow out from the hydraulic cylinder to the tank.
  • a non-return spring arrangement which prestresses the main piston in the closing direction acts on the one hand as a non-return valve spring which enables the supply to the consumer in the non-return function and on the other hand as a control spring to control the return from the consumer to the tank.
  • this spring should be designed to be relatively weak so that there are no major pressure losses across the check valve.
  • the spring should have a steeper characteristic curve in order to enable a good response behavior in the return control.
  • the check valve arrangement is implemented by combining a weak check spring and a control spring with a steep characteristic curve, the comparatively weakly designed check spring determining the check function, while the control spring with a steep spring characteristic curve only after a predetermined axial movement of the main piston engages to control the return function.
  • the construction of the locking block is particularly simple if the main piston is guided in a sleeve inserted into a valve housing (valve disk), on the outer circumference of which a flange is provided for sealing.
  • a mechanical seal is preferably formed on the outer circumference of the main piston so that the leakage of the check valve is minimal even at high load pressures.
  • FIG. 1 shows a section through a locking block according to the invention and
  • FIG. 2 shows a variant of the locking block from FIG. 1.
  • FIG. 1 shows a longitudinal section through a locking block 1, which is inserted into a receiving bore 4 of a plate-shaped valve housing 2.
  • a sleeve 14 is inserted, in which a main piston 16 is guided axially.
  • the sleeve 14 extends from the end face of the valve housing on the right in FIG. 1 to the working channel A.
  • a flange 18 is formed on the outer circumference in the sleeve 14, which seals when the sleeve 14 is inserted abuts the peripheral wall of the receiving bore 4.
  • the main piston 16 is designed as a stepped piston, a portion 22 with a larger diameter D3 being guided in sections in a radially expanded area of an inner bore 20 of the sleeve 14.
  • This radially widened part 22 of the main piston protrudes axially from the sleeve 14 and, in the basic position shown, is biased against a valve seat 26 via a non-return spring arrangement 24 which is formed in the area between the pressure channel 12 and the working channel 10 on the receiving bore 4.
  • the main piston 16 is provided with a radially projecting annular collar 28 which is immersed in a correspondingly designed gradation of the receiving bore 4.
  • the annular collar 28 controls a further flow cross-section lying in series with a flow cross-section at the valve seat 26 between its one 360-degree edge and a 360-degree edge in the receiving bore 4 of the valve housing 2.
  • This additional flow cross-section begins to open when the flow area at the valve seat is already wide open.
  • the annular collar 28 also increases the area on the main piston 16 on which a pressure acting in the open direction can be present. Overall, the pressure drop is kept low in this way when the pressure medium flows from the pressure channel 12 via the main piston 16 to the working channel 10.
  • the part 22 of the main piston 16 with the diameter D3 is stepped down to the diameter D1 via a radial shoulder 32, this stepped end section 30 being guided in a corresponding radially recessed area of the inner bore 20.
  • the end section 30 has a mechanical seal 34 on its outer circumference, so that an annular space delimited by the radial shoulder 32 of the main piston 16 and the opposite shoulder of the inner bore 20 of the sleeve 14 is hydraulically sealed against a spring space 36 for the non-return spring arrangement 24.
  • This spring chamber (36) is closed in the axial direction by a screw plug 38 screwed into the sleeve 14.
  • the main piston 16 is designed with a pre-opening and has an end recess 40, in the bottom of which a pilot channel 42 which penetrates into the end section 30 of the main piston 16 opens.
  • a pilot valve seat 44 is formed, against which a pilot valve body 46 is biased by means of a weak pilot spring 48.
  • This is supported on a bolt 50 which is screwed into the pilot channel 42 and whose right end section in FIG. 1 protrudes axially from the main piston 16.
  • a non-return spring 52 of the non-return spring arrangement 24 which is supported on the locking screw 38, engages, so that the main piston 16 in the basic position shown in FIG. 1 is biased against its valve seat 26 via this comparatively weak return spring 52.
  • the non-return spring arrangement 24 also has a control spring 54 with a steeper spring characteristic than the aforementioned weak return spring 52.
  • This control spring 54 is supported on a spring plate 56 which is axially spaced from the right end face of the end section 30 in FIG. 1.
  • This spring plate 56 is on a radial shoulder in the NEN bore 20 of the sleeve 14 supported.
  • the other end portion of the control spring 54 abuts the screw plug 38.
  • the control spring 54 is only effective when the end portion 30 of the main piston 16 runs onto the spring plate 56.
  • a plurality of radial bores 58 which are connected to the annular space 34 in the closed position of the main piston 16, open into the pilot control channel 42.
  • the main piston 16 has a control edge 60 in the area of the radial bores 58, through which the connection between the annular space 34 and the radial bores 58 can be controlled when the main piston 16 is lifted off the valve seat 26.
  • the spring chamber 36 is connected to the space of the main piston 16 delimited by the end recess 40 via a bore 62, which is indicated by dashed lines and penetrates the end section 30.
  • axial grooves 64 are formed on the outer circumference of the part 22 of the main piston, these being narrowed towards the annular space 34 toward a nozzle 66.
  • the effective cross section of this nozzle 66 is significantly smaller than the diameter of the pilot valve seat 44.
  • an impact piston 68 is guided in the receiving bore 4, the right end section in FIG. 1 sealingly immersed in the end recess 40 of the main piston 16.
  • a spring 70 is supported on the bottom of the front recess 40, by means of which the pushing piston 68 is biased against an end surface 72 of the receiving bore 4 in the region of the control channel 6.
  • the push-up piston 68 has an axial projection 74 which, when the push-up piston 68 is axially displaced, runs onto the pilot valve body 46 and lifts it off its pilot valve seat 44.
  • the pressure chamber 76 formed between the pushing piston 68 and the main piston 16 is connected to the tank channel 8 via at least one angular bore 78 passing through the pushing piston 68 and extending from the right end face in FIG. 1 to the outside.
  • the outer circumference of the push piston 68 extends in the region of the tank channel 8.
  • the mouth area of the angle bore 78 in the area of the tank channel 8 is selected so that the pressure chamber 76 is always connected to the tank channel 8.
  • a control recess 80 is provided on the outer circumference of the pushing piston 68, which forms a further control edge 82, via which the connection between the tank channel 8 and the space 84 which extends from the mouth area of the pressure channel 12 to the valve seat 26 extends extends so that when the main piston 16 is lifted off, a hydraulic connection between the working channel 10 and the tank channel 8 is opened.
  • the axial position of the control edge 82 is selected such that the connection between the working channel 10 and the tank channel 8 is only opened when the larger opening cross section of the axial grooves 64 is open.
  • the outer diameter of the butt piston 68 has the same diameter D1 as the end portion 30 of the main piston 16.
  • the blocking block 1 is preceded by a proportional valve, via which the pressure channel 12 can be connected or blocked to the pump.
  • the pump pressure is present in the pressure channel 12, so that a resultant compressive force acting in the opening direction acts on the ring end face delimited by the diameters D3 and D1.
  • the main piston 16 then lifts off its valve seat 26 when the resultant compressive force in the opening direction is greater than the resultant compressive force in the annular space 34 in the closing direction and the force of the return spring 52 and the frictional force generated by the mechanical seal 35. Since the check spring 52 is designed to be relatively weak, the pressure loss in the check function is minimal.
  • the pressure chamber 76 is always connected to the tank channel 8 via the angular bore 78.
  • control oil located in the annular space 34 and in the pilot channel 42 can flow out through the pre-opening into the pressure chamber 76 and from there via the angular bore 78 to the tank channel 8, so that the pressure forces acting in the main piston 16 in the closing direction are reduced.
  • the push piston 68 then runs onto the main piston 16 so that it is lifted off its valve seat 26 due to the control pressure effective in the opening direction.
  • the effective nozzle 66 when lifting the main piston 16 and the diameter of the pilot valve seat 44 are designed so that the effective pressure in the annular space 34 can be reduced to the tank channel 8 even at a high pressure in the working channel 10.
  • connection between the radial bores 58 and the annular space 34 is controlled by the control edge 60 and, as a result, the larger opening cross section of the axial grooves 64 is opened, so that pressure differences due to leakages via the pilot valve arrangement and thus displacements of the return characteristic can be prevented.
  • the connection between the tank channel 8 and the working channel 10 is then opened via the further control edge 82, so that the pressure medium can flow out of the hydraulic cylinder to the tank channel 8.
  • the main piston 16 runs on the spring plate 56, so that the further opening in the return function takes place essentially against the force of the stronger control spring 54, which starts in an optimal manner this rule task is adapted.
  • FIG. 2 shows a simplified exemplary embodiment of the blocking block 1 from FIG. 1.
  • the nozzle 66 is not formed by one or more axial grooves 64 but by a jacket bore 86 which defines the sleeve 14 in the region between the flange 18 and the other side Working channel 10 passes through the adjacent end section.
  • the casing bore 86 opens on the one hand in the annular space 34 and on the other hand in an axial channel 88 which is formed between the outer circumference of the sleeve 14 and the inner circumferential wall of the receiving bore 4.
  • the main piston 16 has a control edge 90 in the region of the radial shoulder 32, via which the casing bore 86 is closed after the main piston 16 has been lifted off.
  • An additional control edge 92 then opens a larger opening cross section when the main piston 16 is axially displaced, which is realized by a radially recessed peripheral section 94 of the main piston 16.
  • the annular collar 28 of the main piston 16 in the region of the valve seat 26 was also dispensed with, so that the basic structure of the main piston 16 is simplified compared to the solution described at the beginning. Otherwise, the solution shown in FIG. 2 corresponds to the exemplary embodiment described at the beginning, so that further explanations can be dispensed with.
  • a blocking block for actuating a hydraulic consumer in which a main piston designed with a pre-opening can be lifted off a valve seat in a return function by means of an impact piston.
  • a pressure chamber delimited by the main piston on the one hand and by the control piston on the other is connected to a tank or low-pressure channel both in the return function and in the return function of the locking block, so that the changeover from the return function to the return function and vice versa can take place very quickly.
  • valve housings 68 push-up pistons
  • control channel 72 end face

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Safety Valves (AREA)
  • Fluid-Driven Valves (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

L'invention concerne un élément de blocage (1) destiné à la commande d'un consommateur hydraulique. Un piston principal (16) avec ouverture avancée peut, dans une fonction de retour, être soulevé d'un siège de soupape (26) par un piston de chasse (68). Un espace de pression (76) délimité par le piston principal, d'une part, et par le piston de réglage, d'autre part, est relié à un canal de réservoir ou basse pression (8) lors de la fonction de retour comme de la fonction de non-retour de l'élément de blocage, ce qui permet un transfert de la fonction de retour à la fonction de non-retour et vice-versa très rapide.
EP01969276A 2000-12-08 2001-09-07 Element de blocage Withdrawn EP1339988A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10061208 2000-12-08
DE10061208A DE10061208A1 (de) 2000-12-08 2000-12-08 Sperrblock
PCT/DE2001/003441 WO2002046622A1 (fr) 2000-12-08 2001-09-07 Element de blocage

Publications (1)

Publication Number Publication Date
EP1339988A1 true EP1339988A1 (fr) 2003-09-03

Family

ID=7666379

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01969276A Withdrawn EP1339988A1 (fr) 2000-12-08 2001-09-07 Element de blocage

Country Status (5)

Country Link
US (1) US6904938B2 (fr)
EP (1) EP1339988A1 (fr)
CA (1) CA2427290A1 (fr)
DE (1) DE10061208A1 (fr)
WO (1) WO2002046622A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5264115B2 (ja) * 2007-07-18 2013-08-14 キヤノン株式会社 反射型表示装置及びその駆動方法
DE102014101664A1 (de) * 2014-02-11 2015-08-13 Kendrion (Villingen) Gmbh Druckregelventil

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2309406C3 (de) * 1973-02-24 1980-01-10 Sauer Getriebe Kg, 2350 Neumuenster Sperrbremsventilanordnung
DE3420214A1 (de) * 1984-05-30 1985-12-05 Robert Bosch Gmbh, 7000 Stuttgart Wegeventil
PL333365A1 (en) * 1996-11-11 1999-12-06 Mannesmann Rexroth Ag Valving system and method of controlling operation thereof
DE19707722A1 (de) * 1996-11-11 1998-05-14 Rexroth Mannesmann Gmbh Ventilanordnung und Verfahren zur Ansteuerung einer derartigen Ventilanordnung
DE19646443A1 (de) * 1996-11-11 1998-05-14 Rexroth Mannesmann Gmbh Rückschlagventilanordnung
DE19813909B4 (de) * 1998-03-28 2007-02-15 Dbt Gmbh Hydraulisch aufsteuerbares Rückschlagventil für die Ausbauhydraulik in Bergbau-Untertagebetrieben

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0246622A1 *

Also Published As

Publication number Publication date
WO2002046622A1 (fr) 2002-06-13
US6904938B2 (en) 2005-06-14
DE10061208A1 (de) 2002-06-13
CA2427290A1 (fr) 2002-06-13
US20030167915A1 (en) 2003-09-11

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