WO1997003912A1 - System for manoeuvring a magnetic load, in particular a ferromagnetic load - Google Patents

System for manoeuvring a magnetic load, in particular a ferromagnetic load Download PDF

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Publication number
WO1997003912A1
WO1997003912A1 PCT/EP1996/003206 EP9603206W WO9703912A1 WO 1997003912 A1 WO1997003912 A1 WO 1997003912A1 EP 9603206 W EP9603206 W EP 9603206W WO 9703912 A1 WO9703912 A1 WO 9703912A1
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WO
WIPO (PCT)
Prior art keywords
magnetic
load
force
maneuvering
weight
Prior art date
Application number
PCT/EP1996/003206
Other languages
German (de)
French (fr)
Inventor
Frank Jurisch
Original Assignee
Railfix N.V.
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 Railfix N.V. filed Critical Railfix N.V.
Priority to AU67352/96A priority Critical patent/AU6735296A/en
Publication of WO1997003912A1 publication Critical patent/WO1997003912A1/en

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/02—Permanent magnets [PM]
    • H01F7/04—Means for releasing the attractive force
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C1/00—Load-engaging elements or devices attached to lifting or lowering gear of cranes or adapted for connection therewith for transmitting lifting forces to articles or groups of articles
    • B66C1/04—Load-engaging elements or devices attached to lifting or lowering gear of cranes or adapted for connection therewith for transmitting lifting forces to articles or groups of articles by magnetic means
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
    • H01F7/16—Rectilinearly-movable armatures
    • H01F2007/1684—Armature position measurement using coils

Definitions

  • the invention relates to a system for maneuvering a magnetic, in particular ferromagnetic, load consisting of a movable device, in particular which can be suspended on a crane device, for maneuvering the magnetic load with at least one pair of magnetic poles, the pole faces of which have at least one air gap with the magnetic load to form a magnetic load Are connected in a circle, and with at least one detection coil arranged in the region of the pole faces, which is followed by an evaluation device which contains an integrator such that from the measurement signal of the at least one detection coil the magnetic flux prevailing in the air gap and from it the one acting on the magnetic load Magnetic force is detectable.
  • a system of the type mentioned at the outset is known from the magazine "Stahl und Eisen 114 (1994) No. 9, pages 69-71".
  • This is a lifting magnet that can be used to transport standing or lying sheet metal coils weighing up to 50 t.
  • Such a lifting magnet is also used for the crane transport of blocks, slabs or billets and has the advantage of a large-area load attack and greater economy compared to transport with pliers or hooks.
  • the device for maneuvering the magnetic load consists of four poles movable about axes, which can adapt to the lying coil.
  • the magnetic flux is generated by electrical windings through which current flows and runs through the magnetic poles into the load. In the area of the pole faces there are measuring loops with which the magnetic flux is measured according to the induction principle and from which the magnetic holding force is calculated.
  • the evaluation device contains a comparator device by means of which the detected magnetic force is comparable to the weight of the magnetic load, that the evaluation device is followed by a display device by means of which the operator can see a common display of weight and magnetic force , and that the evaluation device is followed by deactivation means via which the device for maneuvering the magnetic load at a for the weight under consideration of a Safety factor insufficient holding force can be deactivated.
  • the invention is characterized in that the conditions of the system with regard to occupational safety are checked by the constant comparison between the measured magnetic holding force and the weight force of the load, taking into account the required safety factor, and that if the conditions are not met, the Maneuvering device is automatically deactivated. Before this happens, the operator immediately looks over when the magnetic force comes below the minimum force required to maneuver the load and can react accordingly. If the counter reaction takes place before the deactivation condition is reached, uninterrupted operation can be realized, for example by the operator increasing the excitation current for the electromagnetic winding and thus the holding force. Without further aids, it is thus excluded that the operator maneuvers an impermissibly high load. This is of considerable importance in practice, since the loads usually have different weights, but the magnet system must be set so that it works optimally.
  • the display device is preferably an analog pointer instrument which has a scale, in particular linearly divided, in units of measurement of the magnetic load to be maneuvered. This gives the operator a quantitative measure of how far the magnetic force available for lifting the load is above the safety threshold.
  • the deactivation means can be coupled to an optical and / or acoustic warning device, by means of which a warning signal can be issued if the holding force is insufficient for the weight under consideration of a safety factor.
  • a force measuring device that can be integrated into the suspension of the maneuvering device is provided as the measuring device, for example a force measuring device by means of strain gauges. If this additionally has means for compensating for the dead weight of the maneuvering device, the measurement accuracy is correspondingly high.
  • the maneuvering system according to the invention can be used for several types of magnet systems.
  • the magnet system can be designed as a conventional electromagnet system with windings through which current flows.
  • Permanent magnet system be formed, which results in an economical solution, since no excitation current is required when maneuvering.
  • the system according to the invention is preferably used for an electropermanent system which has paired permanent magnets for generating the magnetic holding force on the magnetic load, one of the two permanent magnets of a pair being reversible from a parallel to an anti-parallel magnetization direction by means of an electrically excited magnetic field such that in the anti-parallel magnetization direction, the magnetic flux between the two permanent magnets of a pair short-circuited and in the parallel direction of magnetization the magnetic flux is conducted to the load via the pole faces of the magnet system.
  • This combines the advantages of the two systems mentioned above, on the one hand by generating an electroless maneuvering force and on the other hand facilitating the actuation of the magnetic circuit by the polarity reversal winding.
  • both the exclusive holding of the load and the transport of a previously raised load can be realized.
  • a preferred embodiment of the invention provides that a further detector device is provided, by means of which the respective working point of the magnetic circuit can be determined, wherein the further detector device can be a Hall probe arranged in the air gap of the magnetic circuit.
  • the further detector device can be a Hall probe arranged in the air gap of the magnetic circuit.
  • FIG. 1 is a sketch for explaining the function of the magnet system for the embodiment of the invention and FIG. 2 shows a block diagram relating to the connection of the electrical or electronic components according to the exemplary embodiment in FIG. 1.
  • two permanent magnets 1, 2 are provided, one of which, permanent magnet 1, carries an excitation winding 5 through which current flows.
  • the permanent magnets 1, 2 are arranged spatially parallel to one another and each end at their end faces at magnetic poles (flux guide pieces) 3, the pole faces 4 of which are arranged opposite the load 6 to be maneuvered.
  • the permanent magnets 1, 2 are polarized antiparallel to one another, that is to say that the south pole of the one with the north pole of the other magnet and the north pole of the one with the south pole of the other magnet short-circuit in a direct way without a magnetic flux through the load 6 runs.
  • the magnet system approaches the load 6 to be lifted.
  • the electrical or electronic device shown in FIG. 2 initially has a measuring coil 7 which consists of a few turns, for example 2 to 10 turns, of thermally stably insulated copper wire with a cross section of 0.25 to 0.5 mm 2 .
  • the winding which is thermally stable up to approx. 400 ° C., is inserted with an elastic, temperature-resistant insulating compound, for example made of silicone rubber, in a groove below the pole shoe edge of the pole shoes 4.
  • the measuring coil 7 is connected to an integrator 8, which operates on a display device 12 via an amplifier 9, a squarer 10 and a voltage-current converter 11.
  • the integrator 8 is designed as a Miller integrator, and its input resistance is selected to be very high at approximately 1 M ⁇ .
  • a switch S1 is provided, which is controlled via a distance sensor 19.
  • the output of the square 10 is connected to an input of a comparator circuit 14, the other input of which is connected to a measuring device 13, 15 for measuring the weight of the load 6.
  • a measuring device 13, 15 for measuring the weight of the load 6.
  • strain gauges 13 are located on the load, which measure the total force of the load and the maneuvering device.
  • the output of the force measuring device 13 works on a differentiating circuit 15, by means of which the weight force caused by the maneuvering device is subtracted and thus only the weight force of the load 6 is passed on to the input of the comparator circuit 14.
  • the comparator circuit 14 works on the central control device 16 of a crane on which the maneuvering device can be suspended.
  • the control device 16 also includes a deactivation device for stopping the crane drive.
  • the comparator device 14 controls an alarm device 17, which is formed from an acoustic and / or optical warning display.
  • the outputs of the crane controller 16, the distance sensor 19, the voltage current converter 11 and a control device for the magnets 20 are connected to the input of a shift register device 18, which operates as a memory.
  • the device according to the invention operates as follows:
  • the magnet system is activated from state I to state II by means of the magnet control 20.
  • the reset input of the integrator 8 is released via the switch S1, so that it receives its input signal via the measuring coil 7. This is defines the initial state.
  • the high input resistance results in a high integration time constant of the Miller integrator.
  • the integrated measurement signal is adjusted via the adjustable amplifier 9, adapted to the geometrical conditions of the magnet system, and processed in the squaring device 10 into a signal corresponding to the magnetic holding force.
  • a current signal which is proportional to the magnetic holding force is generated in the voltage-current converter circuit 11 and is brought to display on an analog pointer instrument (ammeter) 12 via trailing lines in the crane cabin.
  • the voltage signal corresponding to the magnetic force is compared in the comparator device 14 with the weight force associated with the load, the signal of which is obtained by the strain gauge device 13 on the suspension of the maneuvering device, the self-weight of the maneuvering device having been previously compensated for in the difference generator circuit 15.
  • the comparator device 14 now checks whether the magnetic holding force adequately applies the weight force. If this is the case, the crane controller 16 releases the maneuvering device, for example in order to lift the load or to carry out trolley or long journeys.
  • a signal is sent to the deactivation device (not shown) by means of which the crane control 16 is blocked.
  • a warning signal is output by the optical / acoustic crane device 17.
  • the voltage signal corresponding to the magnetic holding force is converted digitally and stored several times in a storage cycle 18 according to preselectable criteria during a load cycle. Several cycles can be saved so that operating errors can be clearly identified and differentiated from technical failures.

Abstract

A system for manoeuvring a magnetic load (6), in particular a ferromagnetic load, consists of a movable magnetic load manoeuvring device that may be suspended from a crane and has at least one pair of magnetic poles (3) whose pole faces (4) are connected to the magnetic load (6) through at least one air gap, closing a magnetic circuit. At least one detecting coil (7) is arranged in the area of the pole faces. Evaluating means (8-11) arranged downstream of the detecting coil (7) contain an integrator (8) so that the magnetic flux reigning in the air gap may be derived from the measurement signal generated by at least one detecting coil and the magnetic force acting on the magnetic load may be derived therefrom. In order to make the system safe to use even by unqualified persons for manoeuvring loads having a large range of different weights, the evaluating means (8-11) contain a comparator (14) that compares the detected magnetic force to the weight of the magnetic load, a display (12) mounted downstream of the evaluating means (8-11) visually displays both weight and magnetic force in a visible manner for the operator, and deactivating means are mounted downstream of the evaluating means (8-11) for deactivating the magnetic load manoeuvring device when the weight holding force is not sufficient, taking into account a safety factor.

Description

System zum Manövrieren einer magnetischen insbesondere ferromagnetischen LastSystem for maneuvering a magnetic, in particular ferromagnetic, load
Die Erfindung betrifft ein System zum Manövrieren einer magnetischen insbesondere ferromagnetischen Last bestehend aus einer bewegbaren, insbesondere an einer Kranvorrichtung aufhängbaren, Vorrichtung zum Manövrieren der magnetischen Last mit mindestens einem Paar von Magnetpolen, deren Polflächen über mindestens einen Luftspalt mit der magnetischen Last unter Ausbildung eines magnetischen Kreises in Verbindung stehen, und mit mindestens einer im Bereich der Polflächen angeordneten Detektierspule, der eine Auswerteeinrichtung nachgeordnet ist, die einen Integrator enthält derart, daß aus dem Meßsignal der mindestens einen Detektierspule der im Luftspalt herrschende magnetische Fluß und daraus die auf die magnetische Last wirkende Magnetkraft erfaßbar ist.The invention relates to a system for maneuvering a magnetic, in particular ferromagnetic, load consisting of a movable device, in particular which can be suspended on a crane device, for maneuvering the magnetic load with at least one pair of magnetic poles, the pole faces of which have at least one air gap with the magnetic load to form a magnetic load Are connected in a circle, and with at least one detection coil arranged in the region of the pole faces, which is followed by an evaluation device which contains an integrator such that from the measurement signal of the at least one detection coil the magnetic flux prevailing in the air gap and from it the one acting on the magnetic load Magnetic force is detectable.
Aus der Zeitschrift "Stahl und Eisen 114 (1994) Nr. 9, Seiten 69-71", ist ein System der eingangs genannten Art bekannt. Hierbei handelt es sich um einen Lasthebemagneten, der für den Transport stehender oder liegender Feinblechcoils mit bis zu 50 t Gewicht einsetzbar ist. Ein solcher Lasthebemagnet dient darüber hinaus zum Krantransport von Blöcken, Brammen oder Knüppeln und hat im Vergleich zu Transporten mit Zangen oder Haken den Vorteil eines großflächigen Lastangriffs und der größeren Wirtschaftlichkeit. Bei dem bekannten System besteht die Vorrichtung zum Manövrieren der magnetischen Last aus vier um Achsen beweglichen Polen, die sich dem liegenden Coil anpassen können. Der magnetische Fluß wird durch stromdurchflossene elektrische Wicklungen erzeugt und verläuft durch die Magnetpole in die Last. Im Bereich der Polflächen sind Meßschleifen untergebracht, mit denen nach dem Induktionsprinzip der magnetische Fluß gemessen wird und daraus die magnetische Haltekraft berechnet wird.A system of the type mentioned at the outset is known from the magazine "Stahl und Eisen 114 (1994) No. 9, pages 69-71". This is a lifting magnet that can be used to transport standing or lying sheet metal coils weighing up to 50 t. Such a lifting magnet is also used for the crane transport of blocks, slabs or billets and has the advantage of a large-area load attack and greater economy compared to transport with pliers or hooks. In the known system, the device for maneuvering the magnetic load consists of four poles movable about axes, which can adapt to the lying coil. The magnetic flux is generated by electrical windings through which current flows and runs through the magnetic poles into the load. In the area of the pole faces there are measuring loops with which the magnetic flux is measured according to the induction principle and from which the magnetic holding force is calculated.
Die Arbeitssicherheit dieses bekannten Systems ist jedoch dadurch eingeschränkt, daß für jede zu manövrierende Last aufgrund der Veränderung des Arbeitspunktes des Systems die Betriebsparameter neu eingestellt werden müssen und Testfahrten erforderiioh sind, um ein Herabfallen der Last im Betrieb zu verhindern.The operational safety of this known system is limited, however, by the fact that for each load to be maneuvered, the operating parameters have to be reset due to the change in the operating point of the system and test runs are required to prevent the load from falling during operation.
Daher liegt der vorliegenden Erfindung die Aufgabe zugrunde, ein System der eingangs genannten Art dahingehend weiterzuentwickeln, daß es auch von einer ungeschulten Bedienungsperson für einen weiten Bereich unterschiedlicher Lastgewichte sicher einsetzbar ist.It is therefore the object of the present invention to further develop a system of the type mentioned at the outset such that it can also be used safely by an untrained operator for a wide range of different load weights.
Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß die Auswerteeinrichtung eine Vergleichereinrichtung enthält, mittels der die erfaßte Magnetkraft mit der Gewichtskraft der magnetischen Last vergleichbar ist, daß der Auswerteeinrichtung eine Anzeigeeinrichtung nachgeordnet ist, mittels der für die Bedienungsperson sichtbar ein gemeinsame Anzeige von Gewichtskraft und Magnetkraft erfolgt, und daß der Auswerteeinrichtung Deaktivierungsmittel nachgeordnet sind, über die die Vorrichtung zum Manövrieren der magnetischen Last bei einer für die Gewichtskraft unter Berücksichtigung eines Sicherheitsfaktors nicht ausreichenden Haltekraft deaktivierbar ist.This object is achieved in that the evaluation device contains a comparator device by means of which the detected magnetic force is comparable to the weight of the magnetic load, that the evaluation device is followed by a display device by means of which the operator can see a common display of weight and magnetic force , and that the evaluation device is followed by deactivation means via which the device for maneuvering the magnetic load at a for the weight under consideration of a Safety factor insufficient holding force can be deactivated.
Die Erfindung zeichnet sich dadurch aus, daß durch den ständigen Vergleich zwischen der gemessenen magnetischen Haltekraft und der Gewichtskraft der Last unter Berücksichtigung des erforderlichen Sicherheitsfaktors bei jedem Lastfall die Voraussetzungen des Systems hinsichtlich der Arbeitssicherheit geprüft werden und daß dann, wenn die Voraussetzungen nicht vorliegen, die Manövriervorrichtung automatisch deaktiviert wird. Bevor dies geschieht, überblickt die Bedienungsperson jeweils sofort, wenn die Magnetkraft unter die mindestens erforderliche Kraft zum Manövrieren der Last gelangt und kann entsprechend gegenreagieren. Wenn die Gegenreaktion vor Erreichen der Deaktivierungsbedingung erfolgt, kann ein unterbrechungsfreier Betrieb realisiert werden, beispielsweise dadurch, daß seitens der Bedienungsperson der Erregerstsrom für die elektromagnetische Wicklung und damit die Haltekraft erhöht wird. Ohne weitere Hilfsmittel wird damit ausgeschlossen, daß die Bedienungsperson eine unzulässig hohe Last manövriert. Dies hat in der Praxis erhebliche Bedeutung, da die Lasten üblicherweise unterschiedliche Gewichte haben, das Magnetsystem aber so eingestellt werden muß, daß es optimal arbeitet.The invention is characterized in that the conditions of the system with regard to occupational safety are checked by the constant comparison between the measured magnetic holding force and the weight force of the load, taking into account the required safety factor, and that if the conditions are not met, the Maneuvering device is automatically deactivated. Before this happens, the operator immediately looks over when the magnetic force comes below the minimum force required to maneuver the load and can react accordingly. If the counter reaction takes place before the deactivation condition is reached, uninterrupted operation can be realized, for example by the operator increasing the excitation current for the electromagnetic winding and thus the holding force. Without further aids, it is thus excluded that the operator maneuvers an impermissibly high load. This is of considerable importance in practice, since the loads usually have different weights, but the magnet system must be set so that it works optimally.
Vorzugsweise ist die Anzeigeeinrichtung ein analoges Zeigerinstrument, welches eine insbesondere linear geteilte Skala in Maßeinheiten der zu manövrierenden magnetischen Last aufweist. Hierdurch erhält die Bedienungsperson ein quantitatives Maß dafür, wie weit die zum Heben der Last zur Verfügung stehende Magnetkraft oberhalb der Sicherheitsschwelle liegt. Eine weitere Erhöhung der Arbeitssicherheit ergibt sich dadurch, daß die Deaktivierungsmittel mit einer optischen und/oder akustischen Warneinrichtung koppelbar sind, mittels der bei einer für die Gewichtskraft unter Berücksichtigung eines Sicherheitsfaktors nicht ausreichenden Haltekraft ein Warnsignal ausgebbar ist.The display device is preferably an analog pointer instrument which has a scale, in particular linearly divided, in units of measurement of the magnetic load to be maneuvered. This gives the operator a quantitative measure of how far the magnetic force available for lifting the load is above the safety threshold. A further increase in occupational safety results from the fact that the deactivation means can be coupled to an optical and / or acoustic warning device, by means of which a warning signal can be issued if the holding force is insufficient for the weight under consideration of a safety factor.
Um eine jeweils momentane Erfassung der Gewichtskraft der Last zu erhalten, ist als Meßvorrichtung eine in die Aufhängung der Manövriervorrichtung integrierbare Kraftmeßeinrichtung vorgesehen, beispielsweise eine Kraftmeßeinrichtung mittels Dehnungsmeßstreifen. Wenn diese zusätzlich Mittel zur Kompensation des Eigengewichtes der Manövriervorrichtung aufweist, ergibt sich eine entsprechend hohe Meßgenauigkeit.In order to obtain a momentary detection of the weight of the load, a force measuring device that can be integrated into the suspension of the maneuvering device is provided as the measuring device, for example a force measuring device by means of strain gauges. If this additionally has means for compensating for the dead weight of the maneuvering device, the measurement accuracy is correspondingly high.
Das erfindsgemäße Manövriersystem ist für mehrere Arten von Magnetsystemen einsetzbar. Zum einen kann das Magnetsystem als ein herkömmliches Elektromagnetsystem mit stromdurchflossenen Windungen ausgeführt sein.The maneuvering system according to the invention can be used for several types of magnet systems. On the one hand, the magnet system can be designed as a conventional electromagnet system with windings through which current flows.
Zum anderen kann es aber auch als einOn the other hand, it can also be used as a
Permanentmagnetsystem gebildet sein, wodurch sich eine wirtschaftliche Lösung ergibt, da beim Manövrieren kein Erregerstrom benötigt wird.Permanent magnet system be formed, which results in an economical solution, since no excitation current is required when maneuvering.
Bevorzugt wird das erfindungsgemäße System jedoch eingesetzt für ein Elektropermanentsystem, welches paarweise angeordnete Permanentmagnete zur Erzeugung der magnetischen Haltekraft auf die magnetische Last aufweist, wobei einer der beiden Permanentmagnete eines Paars mittels eines elektrisch erregten Magnetfeldes von einer parallelen zu einer antiparallelen Magnetisierungsrichtung umkehrbar ist derart, daß in der antiparallelen Magnetisierungsrichtung der magnetische Fluß zwischen beiden Permanentmagneten eines Paars kurzgeschlossen und in der parallelen Magnetiεierungsrichtung der magnetische Fluß über die Polflächen des Magnetsystems zur Last geführt wird. Hierdurch werden die Vorteile von beiden zuvor genannten Systemen kombiniert, indem einerseits eine stromlose Manövrierkraft erzeugt und andererseits die Betätigung des magnetischen Kreises durch die Umpolungswicklung erleichtert wird.However, the system according to the invention is preferably used for an electropermanent system which has paired permanent magnets for generating the magnetic holding force on the magnetic load, one of the two permanent magnets of a pair being reversible from a parallel to an anti-parallel magnetization direction by means of an electrically excited magnetic field such that in the anti-parallel magnetization direction, the magnetic flux between the two permanent magnets of a pair short-circuited and in the parallel direction of magnetization the magnetic flux is conducted to the load via the pole faces of the magnet system. This combines the advantages of the two systems mentioned above, on the one hand by generating an electroless maneuvering force and on the other hand facilitating the actuation of the magnetic circuit by the polarity reversal winding.
Als Manövriertätigkeit der Vorrichtung kann sowohl das ausschließliche Halten der Last realisiert sein als auch das Transportieren einer zuvor angehobenen Last.As the maneuvering activity of the device, both the exclusive holding of the load and the transport of a previously raised load can be realized.
Eine bevorzugte Ausführungsform der Erfindung sieht schließlich vor, daß eine weitere Detektoreinrichtung vorgesehen ist, mittels der der jeweilige Arbeitspunkt des magnetischen Kreises bestimmbar ist, wobei die weitere Detektoreinrichtung eine im Luftspalt des magnetischen Kreises angeordnete Hallsonde sein kann. Durch diese Maßnahme wird der jeweilige Arbeitspunkt des Systems auf der Entmagnetisierungskurve bestimmt, so daß der Gefahr vorgebeugt werden kann, daß sich der Arbeitspunkt im Bereich des starken Abfalles auf der Hysteresekurve befindet oder sich diesem annähert. Dies ist insbesondere beim Einsatz von AlNiComagneten als Permanentmagnetmaterial von Bedeutung.Finally, a preferred embodiment of the invention provides that a further detector device is provided, by means of which the respective working point of the magnetic circuit can be determined, wherein the further detector device can be a Hall probe arranged in the air gap of the magnetic circuit. This measure determines the respective operating point of the system on the demagnetization curve, so that the danger can be prevented that the working point is in the area of the strong drop on the hysteresis curve or approaches it. This is particularly important when using AlNiComagnets as permanent magnet material.
Die Erfindung wird im folgenden anhand eines Ausführungbeispiels näher erläutert. Dabei zeigen:The invention is explained in more detail below using an exemplary embodiment. Show:
Fig. 1 eine Skizze zur Erläuterung der Funktion des Magnetsystems für das Ausführungsbeispiel der Erfindung und Fig. 2 ein Blockschaltbild betreffend die Verschaltung der elektrischen bzw. elektronischen Komponenten nach dem Ausführungsbeispiel in Fig. l.Fig. 1 is a sketch for explaining the function of the magnet system for the embodiment of the invention and FIG. 2 shows a block diagram relating to the connection of the electrical or electronic components according to the exemplary embodiment in FIG. 1.
In dem in Fig. 1 mit Zustand I bezeichneten Teilbild sind zwei Permanentmagnete 1,2 vorgesehen, von denen der eine, Permanentmagnet 1, eine stromdurchflossene Erregerwicklung 5 trägt. Die Permanentmagnete 1,2 sind räumlich parallel zueinander angeordnet und münden an ihren Endflächen jeweils an Magnetpole (Flußleitstücke) 3, deren Polflächen 4 der zu manövrierenden Last 6 gegenüber angeordnet sind.In the partial image labeled state I in FIG. 1, two permanent magnets 1, 2 are provided, one of which, permanent magnet 1, carries an excitation winding 5 through which current flows. The permanent magnets 1, 2 are arranged spatially parallel to one another and each end at their end faces at magnetic poles (flux guide pieces) 3, the pole faces 4 of which are arranged opposite the load 6 to be maneuvered.
Gemäß Zustand I sind die Permanentmagnete 1,2 antiparallel zueinander gepolt, d.h., daß sich der Südpol des einen mit dem Nordpol des anderen Magneten und der Nordpol des einen mit dem Südpol des anderen Magneten auf direktem Wege kurzschließen, ohne daß dabei ein magnetischer Fluß durch die Last 6 verläuft. In diesem Zustand nähert sich das Magnetsystem an die zu hebende Last 6 an.According to state I, the permanent magnets 1, 2 are polarized antiparallel to one another, that is to say that the south pole of the one with the north pole of the other magnet and the north pole of the one with the south pole of the other magnet short-circuit in a direct way without a magnetic flux through the load 6 runs. In this state, the magnet system approaches the load 6 to be lifted.
Befindet sich daε Magnetsystem gemäß Zustand II in der Nähe der Last, wirkt über die Erregerwicklung 5 auf den Permanentmagneten l ein impulsförmiger Strom einer Größe, die ausreicht, um ihn umzumagnetisieren. Hierdurch werden auf der einen Seite des Systems zwei Nordpole und auf der anderen Seite des Systems zwei Südpole gebildet, die jeweils gemeinsam so wirken, daß der magnetische Fluß entlang der gestrichelten Linien im Zustand II durch die Last 6' fließt. Auch nach Abschalten des elektrischen Feldes der Erregerwicklung 5, wie dies im Zustand III dargestellt ist, verläuft der Magnetfluß durch die Last β, so daß diese durch die magnetische Haltekraft bedingt gehalten wird. Wenn nun gemäß Zustand IV ein Lösen der Last von der Manövriervorrichtung gewünscht ist, erfolgt wiederum eine impulsförmige Beaufschlagung der Erregerwicklung 5, jedoch in umgekehrter Feldrichtung, so daß der Permanentmagnet 1 wieder ummagnetisiert wird, so daß er die Polung vom Zustand I annimmt. Hierdurch wird die Last freigegeben, da sich der magnetische Fluß, wie im Zusammenhang mit Zustand I erläutert wurde, wiederum zwischen den beiden Permanentmagneten 1,2 kurzschließt.If the magnet system according to state II is in the vicinity of the load, an impulsive current of a magnitude acts on the permanent magnet 1 via the excitation winding 5, which current is sufficient to re-magnetize it. As a result, two north poles are formed on one side of the system and two south poles are formed on the other side of the system, each of which together act in such a way that the magnetic flux flows through the load 6 ' along the dashed lines in state II. Even after switching off the electric field of the excitation winding 5, as shown in state III, the magnetic flux continues through the load β, so that it is held conditionally by the magnetic holding force. If, according to state IV, a release of the load from the maneuvering device is desired, the excitation winding 5 is again pulsed, but in the opposite direction of the field, so that the permanent magnet 1 is remagnetized so that it assumes the polarity from state I. As a result, the load is released since the magnetic flux, as explained in connection with state I, in turn shorts between the two permanent magnets 1, 2.
Die in Fig. 2 dargestellte elektrische bzw. elektronische Vorrichtung weist zunächst eine Meßspule 7 auf, die aus wenigen Windungen, z.B. 2 bis 10 Windungen, von thermisch stabil isoliertem Kupferdraht mit einem Querschnitt von 0,25 bis 0,5 mm2 besteht. Die bis ca. 400 C° thermisch stabile Windung ist mit einer elastischen temperaturbeständigen Isoliermasse, z.B. aus Silikonkautschuk, in einer Nut unterhalb der Polschuhkante der Polschuhe 4 eingelegt. Die Meßspule 7 iεt an einen Integrator 8 angeschlosεen, der über einen Verεtärker 9, einen Quadrierer 10 εowie einen Spannungε- Strom-Wandler 11 auf eine Anzeigevorrichtung 12 arbeitet. Der Integrator 8 ist als Millerintegrator ausgeführt, wobei sein Eingangswiderεtand mit etwa 1 MΩ sehr hoch gewählt ist.The electrical or electronic device shown in FIG. 2 initially has a measuring coil 7 which consists of a few turns, for example 2 to 10 turns, of thermally stably insulated copper wire with a cross section of 0.25 to 0.5 mm 2 . The winding, which is thermally stable up to approx. 400 ° C., is inserted with an elastic, temperature-resistant insulating compound, for example made of silicone rubber, in a groove below the pole shoe edge of the pole shoes 4. The measuring coil 7 is connected to an integrator 8, which operates on a display device 12 via an amplifier 9, a squarer 10 and a voltage-current converter 11. The integrator 8 is designed as a Miller integrator, and its input resistance is selected to be very high at approximately 1 MΩ.
Am Reseteingang des Integrators 8 iεt ein Schalter Sl vorgeεehen, welcher über einen Abεtandssenεor 19 geεteuert wird.At the reset input of the integrator 8, a switch S1 is provided, which is controlled via a distance sensor 19.
Der Ausgang des Quadrieres 10 ist mit einem Eingang einer Vergleicherschaltung 14 verbunden, deren anderer Eingang mit einer Meßeinrichtung 13,15 zur Messung der Gewichtskraft der Last 6 verbunden iεt. Hierzu befinden sich auf der Last 6 Dehnungsmeßstreifen 13, die die Gesamtkraft von Laεt und Manövriervorrichtung erfaεsen. Der Ausgang der Kraftmeßeinrichtung 13 arbeitet auf eine Differenzierschaltung 15, mittels der die durch die Manövriervorrichtung hervorgerufene Gewichtskraft abgezogen wird und somit nur die Gewichtskraft der Last 6 an den Eingang der Vergleicherschaltung 14 weitergegeben wird.The output of the square 10 is connected to an input of a comparator circuit 14, the other input of which is connected to a measuring device 13, 15 for measuring the weight of the load 6. For this purpose, strain gauges 13 are located on the load, which measure the total force of the load and the maneuvering device. The output of the force measuring device 13 works on a differentiating circuit 15, by means of which the weight force caused by the maneuvering device is subtracted and thus only the weight force of the load 6 is passed on to the input of the comparator circuit 14.
Die Vergleicherεchaltung 14 arbeitet auf die zentrale Steuereinrichtung 16 eineε Kranε, an dem die Manövriervorrichtung aufhängbar iεt. Die Steuereinrichtung 16 beinhaltet darüber hinauε eine Deaktivierungεeinrichtung zum Stillsetzen des Kranantriebs.The comparator circuit 14 works on the central control device 16 of a crane on which the maneuvering device can be suspended. The control device 16 also includes a deactivation device for stopping the crane drive.
Parallel hierzu steuert die Vergleichereinrichtung 14 eine Alarmeinrichtung 17 an, die aus einer akuεtiεchen und/oder optiεchen Warnanzeige gebildet ist.In parallel to this, the comparator device 14 controls an alarm device 17, which is formed from an acoustic and / or optical warning display.
Die Ausgänge der Kransteuerung 16, deε Abεtandεεenεorε 19, deε SpannungsStromwandlers 11 und einer Steuereinrichtung für die Magnete 20 sind am Eingang einer Schieberegistereinrichtung 18 angeschloεεen, welche alε Speicher arbeitet.The outputs of the crane controller 16, the distance sensor 19, the voltage current converter 11 and a control device for the magnets 20 are connected to the input of a shift register device 18, which operates as a memory.
Die erfindungεgemäße Vorrichtung arbeitet wie folgt:The device according to the invention operates as follows:
Sobald der Abεtandεsensor 19 detektiert, daß die Manövriervorrichtung in den Bereich der Last 6 gelangt, erfolgt eine Betätigung des Magnetsystemε auε dem Zustand I in den Zustand II mittels der MagnetSteuerung 20.As soon as the distance sensor 19 detects that the maneuvering device reaches the area of the load 6, the magnet system is activated from state I to state II by means of the magnet control 20.
Gleichzeitig wird der Reseteingang des Integrators 8 über den Schalter Sl freigegeben, εo daß dieεer über die Meßspule 7 sein Eingangεsignal empfängt. Hierdurch ist der Ausgangεzuεtand definiert. Durch den hohen Eingangswiderεtand ergibt εich eine hohe Integrationεzeitkonεtante deε Millerintegratorε.At the same time, the reset input of the integrator 8 is released via the switch S1, so that it receives its input signal via the measuring coil 7. This is defines the initial state. The high input resistance results in a high integration time constant of the Miller integrator.
Das aufintegrierte Meßsignal wird über den einstellbaren Verstärker 9 angepaßt an die geometrischen Bedingungen des Magnetsyεtemε verεtärkt und in der Quadriereinrichtung 10 zu einem der magnetischen Haltekraft entsprechenden Signal aufbereitet.The integrated measurement signal is adjusted via the adjustable amplifier 9, adapted to the geometrical conditions of the magnet system, and processed in the squaring device 10 into a signal corresponding to the magnetic holding force.
In der Spannungs-Stromwandler-Schaltung 11 wird ein der magnetischen Haltekraft proportionaleε Stromεignal erzeugt, welcheε über Schleppleitungen in der Krankabine zur Anzeige an einem analog anzeigenden Zeigerinstrument (Amperemeter) 12 gebracht wird.A current signal which is proportional to the magnetic holding force is generated in the voltage-current converter circuit 11 and is brought to display on an analog pointer instrument (ammeter) 12 via trailing lines in the crane cabin.
Das der Magnetkraft entsprechende Spannungsεignal wird in der Vergleichereinrichtung 14 mit der zur Laεt gehörigen Gewichtskraft verglichen, deren Signal durch die Dehnungεmeßεtreifeneinrichtung 13 an der Aufhängung der Manövriervorrichtung gewonnen wird, wobei zuvor das Eigengewicht der Manövriervorrichtung in der Differenzbildnerschaltung 15 kompensiert wurde.The voltage signal corresponding to the magnetic force is compared in the comparator device 14 with the weight force associated with the load, the signal of which is obtained by the strain gauge device 13 on the suspension of the maneuvering device, the self-weight of the maneuvering device having been previously compensated for in the difference generator circuit 15.
Die Vergleichereinrichtung 14 prüft nun unter Zugrundelegung des erforderten Sicherheitsfaktors, ob die magnetische Haltekraft die Gewichtεkraft hinreichend aufbringt. Ist dies der Fall, gibt die Kransteuerung 16 die Manövriereinrichtung frei, beispielsweise um die Last anzuheben oder um Katz- oder Langfahrten vorzunehmen.Based on the required safety factor, the comparator device 14 now checks whether the magnetic holding force adequately applies the weight force. If this is the case, the crane controller 16 releases the maneuvering device, for example in order to lift the load or to carry out trolley or long journeys.
Ist umgekehrt die magnetiεche Haltekraft unzureichend hoch, erfolgt ein Signal an die Deaktivierungεeinrichtung (nicht dargeεtellt) , mittels der die Kransteuerung 16 blockiert wird. Gleichzeitig wird ein Warnsignal von der optisch/akuεtiεchen Kraneinrichtung 17 auεgegeben. Zum Zwecke der besseren Kontrolle bzw. Verfolgung oder Aufklärung eines nicht vorhergesehenen Störfalls (Lastabwurf) wird das der magnetiεchen Haltekraft enεprechende Spannungssignal digital gewandelt und während eines Lastzykluε mehrfach nach vorwählbaren Kriterien in der Speichereinrichtung 18 abgeεpeichert. Dabei können mehrere Zyklen abgespeichert werden, wodurch Bedienungsfehler eindeutig erkannt und von technischen Ausfällen unterschieden werden können. Conversely, if the magnetic holding force is insufficiently high, a signal is sent to the deactivation device (not shown) by means of which the crane control 16 is blocked. At the same time, a warning signal is output by the optical / acoustic crane device 17. For the purpose of better control or tracking or clarification of an unforeseen accident (load shedding), the voltage signal corresponding to the magnetic holding force is converted digitally and stored several times in a storage cycle 18 according to preselectable criteria during a load cycle. Several cycles can be saved so that operating errors can be clearly identified and differentiated from technical failures.

Claims

PATENTANSPRÜCHE PATENT CLAIMS
1. System zum Manövrieren einer magnetischen insbeεondere ferromagnetischen Last (6) bestehend aus einer bewegbaren, insbesondere an einer Kranvorrichtung aufhängbaren, Vorrichtung zum Manövrieren der magnetischen Last mit mindestenε einem Paar von Magnetpolen (3) , deren Polflächen (4) über mindestens einen Luftspalt mit der magnetischen Last (6) unter Ausbildung eines magnetischen Kreises in Verbindung stehen, und mit mindestens einer im Bereich der Polflächen angeordneten Detektierspule (7) , der eine Auswerteeinrichtung (8-11) nachgeordnet ist, die einen Integrator (8) enthält derart, daß aus dem Meßsignal der mindestens einen Detektierspule der im Luftspalt herrschende magnetische Fluß und daraus die auf die magnetische Last wirkende Magnetkraft erfaßbar ist, d a d u r c h g e k e n n z e i c h n e t, daß die Auswerteeinrichtung (8-11) eine Vergleichereinrichtung (14) enthält, mittels der die erfaßte Magnetkraft mit der Gewichtskraft der magnetischen Laεt vergleichbar ist, daß der Auεwerteeinrichtung (8-11) eine Anzeigeeinrichtung (12) nachgeordnet iεt, mittels der für die Bedienungεperεon εichtbar ein gemeinεame Anzeige von Gewichtskraft und Magnetkraft erfolgt, und daß der Auεwerteeinrichtung (8-11) Deaktivierungεmittel nachgeordnet sind, über die die Vorrichtung zum Manövrieren der magnetischen Last bei einer für die Gewichtskraft unter Berücksichtigung eines Sicherheitsfaktors nicht ausreichenden Haltekraft deaktivierbar ist. 1. System for maneuvering a magnetic, in particular ferromagnetic load (6) consisting of a movable device, in particular which can be suspended on a crane device, for maneuvering the magnetic load with at least one pair of magnetic poles (3), the pole faces (4) of which have at least one air gap the magnetic load (6) is connected to form a magnetic circuit, and with at least one detection coil (7) arranged in the region of the pole faces, which is followed by an evaluation device (8-11) which contains an integrator (8) such that from the measurement signal of the at least one detection coil the magnetic flux prevailing in the air gap and therefrom the magnetic force acting on the magnetic load can be detected, characterized in that the evaluation device (8-11) contains a comparator device (14) by means of which the detected magnetic force and the weight force the magnetic load is comparable that the A A display device (12) is arranged downstream of the evaluation device (8-11), by means of which a visual display of the weight and magnetic force is made visible to the operating person, and that the evaluation device (8-11) is followed by deactivation means via which the device for maneuvering the magnetic Load can be deactivated at a holding force that is insufficient for the weight under consideration of a safety factor.
2. Vorrichtung nach Anspruch 1, d a d u r c h g e k e n n z e i c h n e t, daß die Anzeigeeinrichtung (12) ein analoges Zeigerinstrument ist, welches eine inεbesondere linear geteilte Skala in Maßeinheiten der zu manövrierenden magnetischen Last aufweist.2. Apparatus according to claim 1, d a d u r c h g e k e n n z e i c h n e t that the display device (12) is an analog pointer instrument which has an in particular linearly divided scale in units of measurement of the magnetic load to be maneuvered.
3. Vorrichtung nach einem der vorhergehenden Ansprüche, d a d u r c h g e k e n n z e i c h n e t, daß die Deaktivierungsmittel mit einer optiεchen und/oder akustiεchen Warneinrichtung (17) koppelbar sind, mittels der bei einer für die Gewichtskraft unter Berücksichtigung eines Sicherheitsfaktorε nicht auεreichenden Haltekraft ein Warnsignal ausgebbar ist.3. Device according to one of the preceding claims, that the deactivation means can be coupled with an optical and / or acoustic warning device (17), by means of which a warning signal can be output at a holding force that is not sufficient for the weight under consideration of a safety factor.
4. Vorrichtung nach einem der vorhergehenden Ansprüche, d a d u r c h g e k e n n z e i c h n e t, daß als Meßvorrichtung für die Gewichtskraft der magnetischen Laεt eine in die Aufhängung der Vorrichtung zum Manövrieren der magnetiεchen Last integrierbare lineare Kraftmesεeinrichtung vorgesehen ist.4. Device according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that a linear force measuring device which can be integrated into the suspension of the device for maneuvering the magnetic load is provided as the measuring device for the weight of the magnetic load.
5. Vorrichtung nach Anspruch 4, d a d u r c h g e k e n n z e i c h n e t, daß die Kraftmeßeinrichtung (13) Dehnungsmeßstreifen aufweist.5. Apparatus according to claim 4, d a d u r c h g e k e n n z e i c h n e t that the force measuring device (13) has strain gauges.
6. Vorrichtung nach Anspruch 4 oder 5, d a d u r c h g e k e n n z e i c h n e t, daß die Kraftmeßeinrichtung (13) Mittel zur Kompensation des Eigengewichtes der Vorrichtung zum Manövrieren der magnetischen Last aufweist. 6. Apparatus according to claim 4 or 5, characterized in that the force measuring device (13) has means for compensating for the dead weight of the device for maneuvering the magnetic load.
7. Vorrichtung nach einem der vorhergehenden Anεprüche, d a d u r c h g e k e n n z e i c h n e t, daß das mindestenε eine Paar von Magnetpolen von einem Elektromagnetεyεtem gebildet wird.7. Device according to one of the preceding claims, so that the at least one pair of magnetic poles is formed by an electromagnet system.
8. Vorrichtung nach einem der vorhergehenden Ansprüche, d a d u r c h g e k e n n z e i c h n e t, daß daε mindeεtenε eine Paar von Magnetpolen von einem Permanentmagnetsystem gebildet wird.8. Device according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that daε at least one pair of magnetic poles is formed by a permanent magnet system.
9. Vorrichtung nach einem der vorhergehenden Ansprüche, d a d u r c h g e k e n n z e i c h n e t, daß das mindeεtenε eine Paar von Magnetpolen von einem Elektro - Permanentmagnetsystem gebildet wird, welcheε paarweise angeordnete Permanentmagnete zur Erzeugung der magnetischen Haltekraft auf die Last aufweist, wobei einer der beiden Permanentmagnete eineε Paarε mittels eines elektrisch erregten Magnetfeldes von einer parallelen zu einer antiparallelen9. Device according to one of the preceding claims, characterized in that the at least one pair of magnetic poles is formed by an electro-permanent magnet system which has paired permanent magnets for generating the magnetic holding force on the load, one of the two permanent magnets being a pair by means of an electrical excited magnetic field from a parallel to an anti-parallel
Magnetisierungsrichtung umkehrbar ist derart, daß in der antiparallelen Magnetisierungsrichtung der magnetische Fluß zwischen beiden Permanentmagneten eines Paars kurzgeεchloεεen und in der parallelen Magnetiεierungεrichtung der magnetiεche Fluß über die Polflächen des Magnetsystems zur Last geführt wird.The direction of magnetization is reversible in such a way that the magnetic flux between the two permanent magnets of a pair is short-circuited in the antiparallel magnetization direction and the magnetic flux is conducted to the load via the pole faces of the magnet system in the parallel magnetization direction.
10.Vorrichtung nach einem der vorhergehenden Ansprüche, d a d u r c h g e k e n n z e i c h n e t, daß die Vorrichtung zum Manövrieren der magnetischen Last eine Haltevorrichtung ist. 10. Device according to one of the preceding claims, characterized in that the device for maneuvering the magnetic load is a holding device.
11. Vorrichtung nach einem der vorhergehenden Ansprüche, d a d u r c h g e k e n n z e i c h n e t, daß die Vorrichtung zum Manövrieren der magnetischen Last eine Transportvorrichtung iεt.11. Device according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that the device for maneuvering the magnetic load is a transport device.
12. Vorrichtung nach einem der vorhergehenden Anεprüche, d a d u r c h g e k e n n z e i c h n e t, daß eine weitere Detektoreinrichtung vorgesehen ist, mittels der der jeweilige Arbeitspunkt des magnetischen Kreises bestimmbar ist.12. The device as claimed in one of the preceding claims, namely that a further detector device is provided, by means of which the respective operating point of the magnetic circuit can be determined.
13. Vorrichtung nach Anspruch 12, d a d u r c h g e k e n n z e i c h n e t, daß die weitere Detektoreinrichtung eine im Luftspalt des magnetiεchen Kreiεeε angeordnete Hallsonde ist. 13. The apparatus of claim 12, so that the further detector means is a Hall probe arranged in the air gap of the magnetic circuit.
PCT/EP1996/003206 1995-07-24 1996-07-20 System for manoeuvring a magnetic load, in particular a ferromagnetic load WO1997003912A1 (en)

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DE102012009702A1 (en) * 2012-05-16 2013-11-21 Evertz Magnetbau Gmbh & Co. Kg Method for unpacking cast portion from mold, involves lifting upper portion of mold from base portion, and using electromagnet for converting upper portion and base portion
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EP2284340A3 (en) * 2009-08-13 2011-06-01 K.A. Schmersal Holding GmbH & Co. KG Magnetic catch for closure of an opening
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DE112013004264B4 (en) 2012-08-31 2023-03-09 Uttam Sarda Electropermanent magnetic holding device with magnetic flux sensor
US10787323B2 (en) 2017-05-15 2020-09-29 Prüftechnik Dieter Busch AG Apparatus and method for vibration measurement on a machine
DE102017110475B4 (en) 2017-05-15 2023-05-17 Prüftechnik Dieter Busch GmbH DEVICE AND METHOD FOR MEASUREMENT OF VIBRATION ON A MACHINE
EP3674249A1 (en) * 2018-12-21 2020-07-01 Tarkmet Oy Apparatus for magnetically attaching to a load
US11133124B2 (en) 2018-12-21 2021-09-28 Tarkmet Oy Apparatus for magnetically attaching to load

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