DE202004009637U1 - Hydraulic cylinders monitoring system e.g. for monitoring position of a piston, has ultrasonic sensors divided into segments, and located on cylinder walls and applied using self adhesive carriers - Google Patents
Hydraulic cylinders monitoring system e.g. for monitoring position of a piston, has ultrasonic sensors divided into segments, and located on cylinder walls and applied using self adhesive carriers Download PDFInfo
- Publication number
- DE202004009637U1 DE202004009637U1 DE200420009637 DE202004009637U DE202004009637U1 DE 202004009637 U1 DE202004009637 U1 DE 202004009637U1 DE 200420009637 DE200420009637 DE 200420009637 DE 202004009637 U DE202004009637 U DE 202004009637U DE 202004009637 U1 DE202004009637 U1 DE 202004009637U1
- Authority
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- Germany
- Prior art keywords
- segments
- piston
- cylinder
- sensors
- ultrasonic sensors
- 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
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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
- F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
- F15B1/02—Installations or systems with accumulators
- F15B1/04—Accumulators
- F15B1/08—Accumulators using a gas cushion; Gas charging devices; Indicators or floats therefor
-
- 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
-
- 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
- F15B15/2892—Means for indicating the position, e.g. end of stroke characterised by the attachment means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/48—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using wave or particle radiation means
-
- 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
- F15B2201/00—Accumulators
- F15B2201/20—Accumulator cushioning means
-
- 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
- F15B2201/00—Accumulators
- F15B2201/30—Accumulator separating means
- F15B2201/31—Accumulator separating means having rigid separating means, e.g. pistons
-
- 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
- F15B2201/00—Accumulators
- F15B2201/50—Monitoring, detection and testing means for accumulators
- F15B2201/515—Position detection for separating means
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)
Abstract
Description
Die Erfindung betrifft eine Vorrichtung zur Überwachung der Position eines in einem druckbeaufschlagten Zylinder bewegbaren Kolbens.The The invention relates to a device for monitoring the position of a piston movable in a pressurized cylinder.
Ein solches Messsystem wird beispielsweise für Druckspeicher (auch Energiespeicher) genutzt. Diese werden zum Beispiel bei Umformmaschinen benutzt.On Such a measuring system is used, for example, for pressure storage (also energy storage) used. These are used, for example, in forming machines.
Aber auch an herkömmlichen Hydraulikzylindern sind Positionsbestimmungen und Überwachungen der Endlagen notwendig.But also on conventional ones Hydraulic cylinders are position determination and monitoring of the end positions necessary.
Bisher gibt es eine Vielzahl von unterschiedlichen physikalischen Lösungen für dieses Problem. Einige Lösungen erfordern zusätzliche Anbauten, wie Messstangen, deren Bewegung erfasst wird (optisch, induktiv oder resistiv).So far there are a variety of different physical solutions to this Problem. Some solutions require additional Attachments, such as measuring rods, the movement of which is recorded (optically, inductive or resistive).
Magnetfeldsensoren auf dem Hydraulikzylinder erfordern aber zum Teil Umbauten am Kolben für zusätzliche Magnete. Es sind Systeme bekannt, die die Stellung des Kolbens überwachen und zur Erzielung der Wiederholgenauigkeit den Zylinder durchfahren müssen.magnetic field sensors on the hydraulic cylinder, however, sometimes require modifications to the piston for additional Magnets. Systems are known which monitor the position of the piston and drive through the cylinder to achieve repeatability have to.
Mechanische Endlagenschalter mit Schaltstange und Permanentmagnet erlauben nur eine maximale Kolbengeschwindigkeit bis etwa 0,5 m/s.mechanical Limit switches with switch rod and permanent magnet only allow a maximum piston speed of up to 0.5 m / s.
Darüber hinaus gibt es noch Vorrichtungen, welche die Kolbenposition kontinuierlich anzeigen.Furthermore there are still devices that keep the piston position continuously Show.
Dazu werden Seilzugmesssysteme mit Drehpotentiometern oder Magnetklappen verbunden. Auch hier gelten die Beschränkungen bezüglich der Kolbengeschwindigkeit.To wire rope measuring systems with rotary potentiometers or magnetic flaps connected. The restrictions regarding the piston speed also apply here.
Neuere Positionsmesssysteme erfassen die Position des Kolbens mit Ultraschall-Messsystemen. Derartige Systeme müssen meist in den Zylinderboden eingeschraubt werden. Durch spezielle Impedanzanpassungen für den Einsatz in Hydraulikölen werden die Ultraschallwandler für diese Systeme optimiert.newer Position measuring systems record the position of the piston with ultrasonic measuring systems. such Systems must usually screwed into the cylinder base. Through special Impedance adjustments for use in hydraulic oils the ultrasonic transducers for optimized these systems.
Die Zuverlässigkeit dieser System wird durch die Temperaturabhängigkeit stark eingeschränkt. Die Ultraschallgeschwindigkeit ist stark temperaturabhängig. Über den Einsatztemperaturbereich können Fehler bis zu 30% oder mehr auftreten. So ändert zum Beispiel eine Ölsorte ihre Schallgeschwindigkeit von 1550 m/s bei –20°C auf 1250 m/s bei +80°C. Weiterhin ist die Viskosität des Hydrauliköles auch stark temperaturabhängig. Die erhöhte Viskosität bewirkt wiederum eine erhöhte Dämpfung der Ultraschallwellen. Damit wird bei tiefen Temperaturen die Reichweite dieser Systeme eingeschränkt.The reliability this system is severely limited by the temperature dependence. The ultrasound speed is strongly temperature dependent. On the Operating temperature range can be errors up to 30% or more occur. For example, one type of oil changes its Speed of sound from 1550 m / s at –20 ° C to 1250 m / s at + 80 ° C. Farther is the viscosity of the hydraulic oil also strongly temperature-dependent. The increased viscosity in turn causes an increased damping the ultrasonic waves. So that the range at low temperatures of these systems restricted.
Zur Minimierung des Temperaturfehlers werden mehrere Maßnahmen vorgeschlagen.to Minimizing the temperature error will take several measures proposed.
So können Referenzmessstrecken mit in das Hydrauliköl eingebaut werden. Dazu wird ein fest mit dem Sensor verbundener Referenzreflektor in den Hydraulikkolben eingebaut. Andere Ultraschallmesssysteme verwenden einen zweiten Ultraschallsensor zur Kompensation. Auch mit einer zusätzlichen Temperaturmessung wird versucht diese Fehlermöglichkeit zu minimieren.So can Reference measuring sections must be built into the hydraulic oil. This will a reference reflector firmly connected to the sensor in the hydraulic piston built-in. Other ultrasonic measuring systems use a second one Ultrasonic sensor for compensation. Even with an additional one Temperature measurement tries to minimize this possibility of error.
In den Patentschriften JP 10-224946 und JP 10-241707 werden solche Positionsdetektoren für Hydraulkzylinder beschrieben.In JP 10-224946 and JP 10-241707 are such Position detectors for hydraulic cylinders described.
Nach der Patentschrift JP 11-240365 ist ein Temperatursensor über einen Analog-Digitalwandler mit dem Mikroprozessor verbunden, der aus der ermittelten Laufzeit den korrigierten Abstand des Kolbens zum Ultraschallsensor bestimmt.To JP 11-240365 is a temperature sensor over a Analog-to-digital converter connected to the microprocessor that made up the determined transit time the corrected distance of the piston to Ultrasonic sensor determined.
Der oben genannte Temperaturfehler der Ultraschallmessung ist aber bei schnell bewegten Hydrauliksystemen nur einer von mehreren Mängeln. Bedingt durch die Laufzeit der Ultraschallimpulse ergibt sich ein zusätzlicher Fehler für die genaue Positionierung der Hydraulikkolben.The the above-mentioned temperature error of the ultrasonic measurement is at rapidly moving hydraulic systems are just one of several shortcomings. conditioned the transit time of the ultrasonic pulses results in an additional one Error for the exact positioning of the hydraulic pistons.
Nachfolgend wird an einem Beispiel dieser grundsätzliche Mängel näher beschrieben. Gegeben sei ein Hydraulikzylinder oder auch ein Hydrospeicher mit einer Kolbengeschwindigkeit von 3,5 m/s und einer Fahrlänge des Kolbens vom Ultraschallsensor bis zum Messpunkt von 2,5 Metern. Das reflektierte Signal würde bei einer Öltemperatur von ca. 80°C und einer Ultraschallgeschwindigkeit von 1250 m/s eine Zeit von 4 Millisekunden vom Aussenden bis zum Empfang benötigen. Wenn die Wiederholfrequenz der Sendesignale zwischen 10 Hz und 100 Hz beträgt, kann der Kolben schon eine Weglänge von 35 mm bis 350 mm zurückgelegt haben.following is described in more detail using an example of these basic shortcomings. Be given a hydraulic cylinder or a hydraulic accumulator with a piston speed of 3.5 m / s and a driving length the piston from the ultrasonic sensor to the measuring point of 2.5 meters. The reflected signal would at an oil temperature of approx. 80 ° C and an ultrasonic speed of 1250 m / s a time of Take 4 milliseconds from sending to receiving. If the repetition frequency of the transmission signals is between 10 Hz and 100 Hz the piston is already a distance covered from 35 mm to 350 mm to have.
Zu diesem nur aus der Positionsmessung herrührenden Fehler kommen weitere Fehler, so die für die Signalverarbeitungszeit und die Reaktionszeit für das Hydraulikventil.To This error, which only results from the position measurement, comes with further errors Mistakes, so for the signal processing time and the response time for the hydraulic valve.
Die Positionierung des Kolbens ist damit auf jeden Fall mit einem erheblichen Fehler belastet.The Positioning the piston is definitely a significant one Error charged.
Wird die Weglänge für das Ultraschallsignal wesentlich verkürzt, kann dadurch auch der absolute Messfehler verringert werden.Becomes the path length for the The ultrasound signal can be significantly shortened absolute measurement errors can be reduced.
Wird die Positionsmessung seitlich am Zylinder ausgeführt, stehen die Positionssensoren üblicher weise seitlich nach außen ab. Bekannte Sensoren sind mechanisch bisher nur durch Schellen oder aufgeschweißte Befestigungspunkte zu montieren. Weiterhin sind sie durch ihre Abmessungen möglichen Beschädigungen ausgesetzt.If the position measurement is carried out on the side of the cylinder, the position sensors usually protrude laterally outwards. Known sensors have previously only been mechanically mountable using clamps or welded-on fastening points. Furthermore, their dimensions expose them to possible damage.
Die Messung dieser Sensoren erfolgt nur punktweise und ist meist nur auf eine Position beschränkt.The These sensors are only measured point by point and are usually only limited to one position.
Der Erfindung liegt die Aufgabe zugrunde die Bewegung des Hydraulikzylinders durch eine Vorrichtung zur Positionsmessung mit einem oder mehreren piezoelektrischen Elementen zu erfassen. Diese piezoelektrischen Elemente werden seitlich auf dem Hydraulikzylinder angebracht. Dabei sind diese Elemente flexibel und passen sich der Krümmung des Hydraulikzylinders an.The The invention is based on the movement of the hydraulic cylinder by a device for position measurement with one or more to detect piezoelectric elements. This piezoelectric Elements are attached to the side of the hydraulic cylinder. there these elements are flexible and adapt to the curvature of the Hydraulic cylinder.
Weitere vorteilhafte Ausgestaltungen der Erfindung ergeben sich aus den Merkmalen der Unteransprüche. Im Folgenden soll die Erfindung anhand von Ausführungsbeispielen beschrieben werden. Es zeigen:Further advantageous embodiments of the invention result from the Features of the subclaims. In the following, the invention is to be described on the basis of exemplary embodiments become. Show it:
In
Die
auf der Zylinderwand
Für die flexiblen
Ultraschallsensoren
Auch
codierte Matrixanordnungen von Ultraschallwandlern auf einer klebenden
PVDF-Folie können
ganzflächig
auf der Zylinderwand
Die
Ausgestaltung der positionsempfindlichen Ultraschallwandler erfordert
nur geringe Bauhöhen.
Somit sind keine konstruktiven Änderungen
der Hydraulikzylinder notwendig. Zum mechanischen Schutz dieser
Ultraschallwandler reicht ein der Krümmung der Hydraulikzylinder
angepasstes Schutzblech oder eine ähnlich gestaltete Schutzhülle, die über die
Trägerschicht
Zur
Verbesserung der Ortsauflösung
können die
Spuren
Claims (8)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE200420009637 DE202004009637U1 (en) | 2004-06-18 | 2004-06-18 | Hydraulic cylinders monitoring system e.g. for monitoring position of a piston, has ultrasonic sensors divided into segments, and located on cylinder walls and applied using self adhesive carriers |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE200420009637 DE202004009637U1 (en) | 2004-06-18 | 2004-06-18 | Hydraulic cylinders monitoring system e.g. for monitoring position of a piston, has ultrasonic sensors divided into segments, and located on cylinder walls and applied using self adhesive carriers |
Publications (1)
Publication Number | Publication Date |
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DE202004009637U1 true DE202004009637U1 (en) | 2004-09-23 |
Family
ID=33039609
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DE200420009637 Expired - Lifetime DE202004009637U1 (en) | 2004-06-18 | 2004-06-18 | Hydraulic cylinders monitoring system e.g. for monitoring position of a piston, has ultrasonic sensors divided into segments, and located on cylinder walls and applied using self adhesive carriers |
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DE (1) | DE202004009637U1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102005005965A1 (en) * | 2005-02-09 | 2006-08-17 | SONOTEC Dr. zur Horst-Meyer & Münch oHG | Ultrasonic compact sensor device for detecting pistons in hydraulic systems has ultrasonic sensor, fastened at cylinder from outside whereby several ultrasonic impulses are produced by ultrasonic sensor after electronic excitation |
DE102007062782A1 (en) | 2006-12-27 | 2009-04-02 | SONOTEC Dr. zur Horst-Meyer & Münch oHG | Proximity detector for use in piston or scrapper detection device utilized in liquid pipeline, has output device outputting communication signal during generation of predetermined signal form |
WO2013028092A1 (en) * | 2011-08-24 | 2013-02-28 | Dostiiari Nasir Nadir Ogly | Piezo-electric source of electrical energy for vehicles |
DE102012205363A1 (en) * | 2012-04-02 | 2013-10-02 | Marco Systemanalyse Und Entwicklung Gmbh | Positioning device |
WO2014033104A1 (en) * | 2012-08-28 | 2014-03-06 | Sensorlink As | Acoustic piston track |
-
2004
- 2004-06-18 DE DE200420009637 patent/DE202004009637U1/en not_active Expired - Lifetime
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102005005965A1 (en) * | 2005-02-09 | 2006-08-17 | SONOTEC Dr. zur Horst-Meyer & Münch oHG | Ultrasonic compact sensor device for detecting pistons in hydraulic systems has ultrasonic sensor, fastened at cylinder from outside whereby several ultrasonic impulses are produced by ultrasonic sensor after electronic excitation |
DE102007062782A1 (en) | 2006-12-27 | 2009-04-02 | SONOTEC Dr. zur Horst-Meyer & Münch oHG | Proximity detector for use in piston or scrapper detection device utilized in liquid pipeline, has output device outputting communication signal during generation of predetermined signal form |
EP2075594A2 (en) | 2007-12-27 | 2009-07-01 | SONOTEC Dr. zur Horst-Meyer und Münch OHG | Pig recognition device and method |
WO2013028092A1 (en) * | 2011-08-24 | 2013-02-28 | Dostiiari Nasir Nadir Ogly | Piezo-electric source of electrical energy for vehicles |
DE102012205363A1 (en) * | 2012-04-02 | 2013-10-02 | Marco Systemanalyse Und Entwicklung Gmbh | Positioning device |
US9546866B2 (en) | 2012-04-02 | 2017-01-17 | Marco Systemanalyse Und Entwicklung Gmbh | Position determination apparatus |
WO2014033104A1 (en) * | 2012-08-28 | 2014-03-06 | Sensorlink As | Acoustic piston track |
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R086 | Non-binding declaration of licensing interest | ||
R207 | Utility model specification |
Effective date: 20041028 |
|
R156 | Lapse of ip right after 3 years |
Effective date: 20080101 |