EP0721067B1 - Vérin d'actionnement à fluide à capteur de champs magnétique - Google Patents

Vérin d'actionnement à fluide à capteur de champs magnétique Download PDF

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Publication number
EP0721067B1
EP0721067B1 EP95120518A EP95120518A EP0721067B1 EP 0721067 B1 EP0721067 B1 EP 0721067B1 EP 95120518 A EP95120518 A EP 95120518A EP 95120518 A EP95120518 A EP 95120518A EP 0721067 B1 EP0721067 B1 EP 0721067B1
Authority
EP
European Patent Office
Prior art keywords
permanent magnet
cylinder
piston arrangement
cylinder piston
magnetic field
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 - Lifetime
Application number
EP95120518A
Other languages
German (de)
English (en)
Other versions
EP0721067A2 (fr
EP0721067A3 (fr
Inventor
Albert Dipl -Ing. Beetz
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.)
Beetz Hydraulik GmbH
Original Assignee
Beetz Hydraulik 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 Beetz Hydraulik GmbH filed Critical Beetz Hydraulik GmbH
Publication of EP0721067A2 publication Critical patent/EP0721067A2/fr
Publication of EP0721067A3 publication Critical patent/EP0721067A3/fr
Application granted granted Critical
Publication of EP0721067B1 publication Critical patent/EP0721067B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/20—Other details, e.g. assembly with regulating devices
    • F15B15/28—Means for indicating the position, e.g. end of stroke
    • F15B15/2807—Position switches, i.e. means for sensing of discrete positions only, e.g. limit switches

Definitions

  • the invention relates to a pressure-operated cylinder-piston arrangement with a permanent magnet on the piston and a magnetic field sensor on the cylinder for querying a path signal, wherein the permanent magnet has a ring shape and is magnetized in the axial direction of the cylinder-piston arrangement, with ring discs made of ferromagnetic material for steering the Magnetic flux.
  • a pressure-actuated cylinder-piston arrangement of the above specified genus has become known, for example through DE 35 10 601 A1. It is on the piston rod ring-shaped, axially polarized permanent magnet pushed on. A ring disc made of ferromagnetic material, which also Piston forms, directs the magnetic flux against the cylinder wall. There is a magnetic field sensor on the outside of the cylinder arranged. In this way, the piston releases at one Position by the magnetic field sensor, a signal so that the Piston position is detected.
  • the invention is based on the arrangement of the genus specified at the beginning and beats the in the characterizing Features specified in the first claim in front.
  • the permanent magnet comes into direct contact Close to the inside wall of the cylinder without touching it.
  • the ring disk arranged on one side of the permanent magnet made of ferromagnetic material directs the magnetic Flow along the shortest route against the cylinder. In particular thereby avoiding scattering of the magnetic flux, so that the magnetic flux is confined to a narrow area becomes.
  • the outer diameter of the ring disk is made ferromagnetic material is slightly larger than that Outside diameter of the permanent magnet. This will do a suitable one due to the design of the washer or washers Redirection of the flow towards the cylinder wall achieved.
  • the axial dimensions of the washer made of ferromagnetic material at most half the size are as the axial dimensions of the permanent magnet. Thereby scatter is largely avoided and the magnetic flux is concentrated.
  • the washers can be axially on both sides of the permanent magnet to be ordered. In this case there is a magnetic flux essentially from one ring disc to the other Washer. However, it is better if only one ferromagnetic Washer on one side of the permanent magnet is applied so that only at this point the maximum of Field strength is achieved so that the sensor only this position displays. In special cases, however, it can be recommended be to also use two ferromagnetic washers, whereby then, depending on the arrangement, a somewhat wider area of the Maximum is obtained, or two peaks in the field of ferromagnetic Washers.
  • the outside diameter of the permanent magnet slightly smaller than the inside diameter of the cylinder. This ensures that the permanent magnet is not compatible with the Inner wall of the cylinder comes into contact, so that wear on the permanent magnet is prevented. The resulting a somewhat larger distance from the magnetic field sensor does not result Disadvantages because the ferromagnetic ring disk is sufficiently close can reach the inner wall of the cylinder.
  • the bushing consists in particular of austenitic steel and is welded into the recess and in a blind hole picks up the sensor. It is clear that in particular If, instead of welding, brazing is also sufficient can be. Through the welded socket and the blind hole the interior of the cylinder is separated from the sensor in the socket. The sensor can be easily replaced. The recess in the cylinder can go inside the cylinder pass. In this case, it is advantageous if the inner end machined the bushing together with the inner surface of the cylinder is. This procedure ensures that despite the used Bush the inner surface of the cylinder completely smooth is, so that no additional stress for the seals arise.
  • the invention also proposes that the piston be made of magnetic there is no or little conductive material. With this suggestion should be avoided that the permanent magnet in the piston finds its magnetic return, causing the magnetic field would be reduced in the recess or on the sensor. It was found that low magnetic conductivity for the Material of the piston is at least not disadvantageous.
  • the magnetic field sensor is usually fixed to the cylinder.
  • the arrangement can also be made such that the magnetic field sensor in a suitable recess along the Cylinder is slidable.
  • the job can of the piston in which the magnetic field sensor changes that emits the signal triggered by the permanent magnet of the piston.
  • the permanent magnet has relatively small dimensions. So the radial Thickness of the permanent magnet less than a third of the radius of the piston. In particular, it was found that the radial Thickness of the permanent magnet about the sixth part of the radius of the piston to achieve very good results.
  • the axial dimensions of the permanent magnet are same as the radial thickness or slightly larger.
  • the axial dimensions of the washer or washers Ferromagnetic material are in a preferred embodiment the invention at most half as large as that axial dimensions of the permanent magnet. This ensures one slightly axial expansion of the magnetic field and a corresponding Accuracy of the display by the magnetic field sensor.
  • the cylinder-piston arrangement 1 consists essentially of the Cylinder 10, the piston 11 and the piston rod 12.
  • the cylinder is closed on one side by the cover 13, which also carries the connecting line 14.
  • the piston rod guide 15 is provided is held by the locking ring 16.
  • the second hydraulic connection is designated 17.
  • a recess 20 is provided in the wall of the cylinder 10, in which the bushing 21 is inserted or welded is.
  • This bushing 21 takes the magnetic field sensor in the blind bore 22 2, the connections of which are designated by 23.
  • the Magnetic field sensor can be, for example, a reed switch which is housed in a protective tube. It is better however, to provide a magnetic field sensor that in particular has no moving parts and for example on inductive The magnetic field is determined and the corresponding one Emits signal.
  • the piston 11 consists essentially of the two parts 18 and 19.
  • the parts 18 and 19 are on the threaded pin 30 of the Piston rod 12 held. Due to the two-part training of Piston 11 can be in the annular groove 31 of part 19 of the annular Permanent magnet 3 are inserted.
  • the washers 32 and 33 are arranged on both sides of the permanent magnet 3, the washers 32 and 33 are arranged.
  • the Permanent magnet 3 is parallel to the central axis 39 of the cylinder-piston arrangement 1 magnetized. For example, the north pole shows towards the piston rod guide 15, the south pole against it towards the cover 13.
  • the permanent magnet 3 In the position shown of the piston 11 is the permanent magnet 3 arranged with respect to the recess 20 such that this permanent magnet is located at a point entirely within the Limits of the recess 20 is located, which receives the socket 21. In this way, the magnetic field of the permanent magnet Reach sensor 2 so that a path signal is obtained.
  • the Distance "s" indicates approximately how long the switching path is. there it doesn't matter whether the piston is off one or the other in the other direction towards the recess.
  • the two washers 32 and 33 can both be made of ferromagnetic Material. Better results or a more precise one However, the signal is received when one of the washers, for example, the washer 32, made of ferromagnetic Material exists while the other washer either is omitted, the width of the annular groove 31 then increasing would decrease, or if this other washer 33 made of aluminum, Brass or a similar material is made. at Such an arrangement will then only open the magnetic field sensor address the position of a ferromagnetic washer 32.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)

Claims (10)

  1. Ensemble cylindre-piston commandé par pression, comportant un aimant permanent (3) situé sur le piston (11), un détecteur de champ magnétique (2) placé sur le cylindre (10) afin de détecter un signal de déplacement, l'aimant permanent en forme d'anneau créant un champ magnétique parallèle à l'axe de l'ensemble cylindre-piston, et des rondelles (32, 33) constituées d'un matériau ferromagnétique permettant de guider le champ magnétique, caractérisé en ce que l'aimant permanent (3) est logé dans une rainure située au niveau de la surface externe (31) du piston (11) avec un diamètre extérieur légèrement inférieur au diamètre intérieur du cylindre (10), en ce que cette rainure (31) permet d'associer sur un côté de l'aimant permanent (3) une rondelle (32) constituée d'un matériau ferromagnétique dont les diamètres intérieur et extérieur correspondent respectivement aux diamètres intérieur et extérieur de l'aimant permanent et en ce qu'une perforation (20) de la parois du cylindre (10) reçoit une douille (21) faite d'un matériau non-magnétique destinée à la mise en place du détecteur de champ magnétique (2).
  2. Ensemble cylindre-piston selon la revendication 1, caractérisé en ce que le diamètre extérieur de la rondelle ferromagnétique (32) est légèrement supérieur au diamètre extérieur de l'aimant permanent (3).
  3. Ensemble cylindre-piston selon l'une ou les deux revendications précédentes, caractérisé en ce que les dimensions axiales de la rondelle ferromagnétique (32) ne dépassent pas la moitié des dimensions axiales de l'aimant permanent (3).
  4. Ensemble cylindre-piston selon l'une ou plusieurs des revendications précédentes, caractérisé en ce qu'une rondelle ferromagnétique (32) n'existe seulement que sur un côté de l'aimant permanent (3).
  5. Ensemble cylindre-piston selon l'une ou plusieurs des revendications précédentes, caractérisé en ce que la douille (21) est fabriquée de préférence en acier austénitique et en ce qu'elle est soudée au niveau d'une perforation (20) et contient le détecteur (2) dans un évidement (22).
  6. Ensemble cylindre-piston selon l'une ou plusieurs des revendications précédentes, caractérisé en ce que l'extrémité de la douille (21) est usinée en même temps que la surface intérieure du cylindre (10).
  7. Ensemble cylindre-piston selon l'une ou plusieurs des revendications précédentes, caractérisé en ce que le piston (11) est fabriqué dans un matériau ne conduisant que peu ou pas le flux magnétique.
  8. Ensemble cylindre-piston selon l'une ou plusieurs des revendications précédentes, caractérisé en ce que le détecteur de champ magnétique (2) peut être déplacé le long de l'axe de l'ensemble cylindre-piston (1).
  9. Ensemble cylindre-piston selon l'une ou plusieurs des revendications précédentes, caractérisé en ce que l'épaisseur de la parois de l'aimant permanent (3) n'excède pas un tiers du rayon du piston (11).
  10. Ensemble cylindre-piston selon l'une ou plusieurs des revendications précédentes, caractérisé en ce que l'épaisseur de la parois de l'aimant permanent (3) correspond approximativement au sixième du rayon du piston (11).
EP95120518A 1995-01-04 1995-12-23 Vérin d'actionnement à fluide à capteur de champs magnétique Expired - Lifetime EP0721067B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19500137A DE19500137A1 (de) 1995-01-04 1995-01-04 Druckmittelbetätigte Zylinder-Kolben-Anordnung mit einem Magnetfeldsensor
DE19500137 1995-01-04

Publications (3)

Publication Number Publication Date
EP0721067A2 EP0721067A2 (fr) 1996-07-10
EP0721067A3 EP0721067A3 (fr) 1998-02-11
EP0721067B1 true EP0721067B1 (fr) 2002-08-28

Family

ID=7750997

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95120518A Expired - Lifetime EP0721067B1 (fr) 1995-01-04 1995-12-23 Vérin d'actionnement à fluide à capteur de champs magnétique

Country Status (3)

Country Link
EP (1) EP0721067B1 (fr)
AT (1) ATE223002T1 (fr)
DE (2) DE19500137A1 (fr)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE29607993U1 (de) * 1996-05-03 1996-08-01 Festo Kg Kolben für einen Arbeitszylinder
DE19637296A1 (de) * 1996-09-13 1998-03-19 Wabco Gmbh Kolben/Zylinder-Anordnung
DE19712829B4 (de) * 1997-03-26 2005-02-17 Sick Ag Vorrichtung zur Erkennung der Position eines beweglichen Gegenstandes
DE19752671B4 (de) * 1997-11-28 2006-11-23 Ludwig Ehrhardt Gmbh Blockzylinder zur Aufnahme und Führung von Werkzeugen auf einer Werkzeugmaschine oder auf einem Arbeitstisch
DE19756639A1 (de) * 1997-12-19 1999-06-24 Zahnradfabrik Friedrichshafen Schalteinrichtung
DE19756637A1 (de) 1997-12-19 1999-06-24 Zahnradfabrik Friedrichshafen Schalteinrichtung
DE10053995A1 (de) 2000-10-31 2002-05-08 Continental Teves Ag & Co Ohg In einen Hauptzylinder integrierter Signalgeber mit Hall-Sensor
DE10304551A1 (de) * 2003-02-04 2004-08-12 Mann + Hummel Gmbh Stellelement mit Lageerkennung
DE10310428A1 (de) 2003-03-11 2004-09-30 Hydac Technology Gmbh Kolbenspeicher
DE102005030722A1 (de) * 2005-07-01 2007-01-04 Bosch Rexroth Teknik Ab Druckmittelzylinder
CN102943784B (zh) * 2012-11-19 2015-06-10 湖南特力液压有限公司 缸筒、液压缸及包含该液压缸的泵送设备
DE202013010056U1 (de) * 2013-11-07 2015-02-10 Bümach Engineering International B.V. Arbeitszylinder
DE102016210002A1 (de) * 2016-06-07 2017-12-07 Zf Friedrichshafen Ag Getriebe mit einer Schalteinheit

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE8209420U1 (de) * 1982-04-02 1983-09-15 Robert Bosch Gmbh, 7000 Stuttgart Kolben fuer beruehrungslose abtastung der kolbenstellung
DE3510601A1 (de) * 1985-03-23 1986-09-25 Wabco Westinghouse Steuerungstechnik GmbH & Co, 3000 Hannover Kolbeneinheit fuer einen arbeitszylinder mit einer einrichtung zum erfassen der kolbenposition
CH674058A5 (fr) * 1986-10-22 1990-04-30 Festo Kg
JPS63122902A (ja) * 1986-11-13 1988-05-26 Ckd Controls Ltd 移動体の位置確認装置
DE9010114U1 (fr) * 1990-07-03 1990-09-06 Festo Kg, 7300 Esslingen, De
DE4122481C2 (de) * 1991-07-06 1995-08-31 Kuhnke Gmbh Kg H Kolben-Zylinder-Anordnung
DE9305640U1 (de) * 1993-04-15 1994-08-25 Hydraulik Techniek Druckmittelbetätigter Arbeitszylinder

Also Published As

Publication number Publication date
EP0721067A2 (fr) 1996-07-10
DE19500137A1 (de) 1996-07-11
EP0721067A3 (fr) 1998-02-11
DE59510348D1 (de) 2002-10-02
ATE223002T1 (de) 2002-09-15

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