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WO1990004173A1 - Driving device for an ultrasonic train wheel control installation - Google Patents

Driving device for an ultrasonic train wheel control installation Download PDF

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Publication number
WO1990004173A1
WO1990004173A1 PCT/DE1989/000564 DE8900564W WO9004173A1 WO 1990004173 A1 WO1990004173 A1 WO 1990004173A1 DE 8900564 W DE8900564 W DE 8900564W WO 9004173 A1 WO9004173 A1 WO 9004173A1
Authority
WO
WIPO (PCT)
Prior art keywords
counter
distance
proximity switch
ultrasonic transducer
wheel
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.)
Ceased
Application number
PCT/DE1989/000564
Other languages
German (de)
French (fr)
Inventor
Rainer Neuschwander
Wilhelm Repplinger
Hans-Juergen Salzburger
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.)
Fraunhofer Gesellschaft zur Foerderung der Angewandten Forschung eV
Original Assignee
Fraunhofer Gesellschaft zur Foerderung der Angewandten Forschung eV
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 Fraunhofer Gesellschaft zur Foerderung der Angewandten Forschung eV filed Critical Fraunhofer Gesellschaft zur Foerderung der Angewandten Forschung eV
Publication of WO1990004173A1 publication Critical patent/WO1990004173A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G01N29/26—Arrangements for orientation or scanning by relative movement of the head and the sensor
    • G01N29/27—Arrangements for orientation or scanning by relative movement of the head and the sensor by moving the material relative to a stationary sensor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G01N29/24—Probes
    • G01N29/2412—Probes using the magnetostrictive properties of the material to be examined, e.g. electromagnetic acoustic transducers [EMAT]
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/04—Wave modes and trajectories
    • G01N2291/042—Wave modes
    • G01N2291/0423—Surface waves, e.g. Rayleigh waves, Love waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/10—Number of transducers
    • G01N2291/101—Number of transducers one transducer
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/26—Scanned objects
    • G01N2291/269—Various geometry objects
    • G01N2291/2696—Wheels, Gears, Bearings

Definitions

  • the invention relates to a device for controlling an ultrasonic wheel test system for railway wheels with a proximity switch arrangement which detects the position of the wheel to be tested and with a transceiver ultrasound transducer which are arranged in a section of a rail to be driven over by the wheel to be tested.
  • An electromagnetic ultrasonic transducer for such a device is described in DE-PS 32 18 453 and permits non-destructive testing of the running surface of railroad wheels by means of ultrasonic surface waves while driving over a rail section.
  • An inductive proximity switch for example, can be used to activate the ultrasonic transducer of the wheel test system at exactly the right moment.
  • Inductive proximity switches for automatic monitoring and control of the movement of rail vehicles are frequently used in the field of signaling and shunting technology as integrated proximity switches and are referred to as rail head contacts.
  • Such rail head contacts and also double rail head contacts are described in S + D - Signal und Draht, 72nd Year, September 1980, Issue 9, pages 166 to 172.
  • the known double contacts work in the differential method and, together with an interface module and a directional module, generate an electrical impulse that depends on the direction of travel and speed of the rail vehicle when the wheel that rolls over covers a minimum distance that depends on the wheel diameter, tire profile and distance of the wheel surface from the sensor as well as the size and the switching Characteristic of the sensor is dependent. In general, this minimum distance is between 60 and 120 mm.
  • there is a switching point inaccuracy which is sufficient when counting axes and when controlling signals and switches, but which leads to problems when ultrasonic wheel test systems are to be controlled which have a switching point accuracy of less than 5 mm desire.
  • the object of the invention is to provide a device for controlling an ultrasonic wheel testing system for railway wheels, which ensures high accuracy regardless of different disturbance variables, such as different speeds, wheel profiles and lift-offs .
  • a first and a second proximity switch connected to a time measuring device are arranged in the direction of travel upstream of the ultrasound transducer and that in the direction of travel between the second proximity switch and the ultrasound transducer in a second
  • a third proximity switch is provided, which is connected to a second time measuring device, by means of which an output signal can be generated after a delay time has elapsed, which is derived from the time recorded in the first time measuring device by dividing by the distance ratio from the first distance by the second distance.
  • the three proximity switches are controlled via a control logic with a direction serving first counter and are connected to a second counter serving as a second time measuring device, which count the clock pulses of an oscillator in opposite directions, the first counter being able to be reset before the start of the count and the second counter having the final count of the first counter.
  • the first counter is, for example, an up counter that can be reset at the start of a measurement, the counter reading of which can be transferred to the second counter at the end of the first time measurement, which counts down to zero. If the ratio of the distances is chosen so that the first distance is twice as large as the second distance, the arrangement is such that the number of cycles supplied to the second counter per unit of time is twice as high as the number of cycles supplied to the first counter per unit of time .
  • the first and the second proximity switches serve to detect a time, the measurement errors having a compensating effect on the delay time of the second counter.
  • FIG. 1 shows a cross section through the section of a rail in the region of the first proximity switch of the device according to the invention, together with a schematic representation of the wheel profile of a railway wheel
  • Fig. 3 is a block diagram of the device for controlling an ultrasonic wheel test system according to the invention.
  • FIG. 1 shows schematically a wheel tire profile 1 of a railway wheel that rolls on the running mirror of a rail 2, in which a first proximity switch 3 is provided in a receiving bore 4.
  • the first inductive proximity switch 3 is connected via a cable 5 to an electronic device shown in the block diagram in FIG. 3.
  • FIG. 2 shows a top view of the rail 2, which in its running mirror has a second inductive proximity switch 6 and a third inductive proximity switch 7 in addition to the first proximity switch 3 in the direction of travel or test direction. Furthermore, a transceiver ultrasound transducer 8 with a coil winding 9 can be seen in FIG. 2.
  • the ultrasound transducer 8 When the rail section shown in FIG. 2 is passed over, the ultrasound transducer 8 generates an ultrasound pulse precisely when the wheel axis is above the center of the ultrasound transducer 8 is located so that an ultrasonic inspection of the tread of the railroad wheel passing over can be carried out.
  • the rail 2, the associated second rail of which cannot be seen in the drawing, rests in the usual way on sleepers, of which a sleeper 10 is shown schematically in FIG. 2.
  • the center of the ultrasonic transducer 8 is illustrated in FIG. 2 by a line 11. Contrary to the direction of travel or test direction, the third proximity switch 7 is arranged to the left of the line 11 at a / 2 distance. The distance between the third proximity switch 7 and the line 11 is, for example, 20 mm.
  • the second proximity switch 6 is located approximately 100 mm in front of the line 11, above which the axis of the wheel to be tested should be at the time of the test.
  • the distance a between the first proximity switch 3 and the second proximity switch 6 is, for example, 40 mm, so that the first proximity switch 3 is approximately 14 cm in front of the line 11.
  • a contact signal K1 is first generated in the first proximity switch 3, the front edge of which acts on control logic 15 of an electronic circuit shown in FIG. 3.
  • the control logic 15 has 3 inputs 16, 17, 18, the input 16 having the contact signal K1 applied to it.
  • the proximity switch 6 generates a contact signal K2, which is fed to the control logic 15 via the input 17 and whose trailing edge is evaluated.
  • the third proximity switch 7 generates a contact signal K3 which acts on the input 18 of the control logic 15.
  • the control logic 15 is connected to a first counter 19, which is connected as an up counter, and to a second counter 20, which is connected as a down counter.
  • the second counter 20 has a clock input 21 which is supplied with the clock signal from a quartz-stable oscillator 22.
  • the clock output 23 of the oscillator 22 is also connected to a divider circuit 24, which reduces the clock signal in a ratio of 1: 2 and feeds it to the clock input 25 of the first counter 19.
  • the output 26 of the first counter 19 is connected to a memory 27, which makes it possible to temporarily store the counter reading at the output 26.
  • the data output of the memory 27 is connected to the counter input 28 of the second counter 20.
  • Both the first counter 19 and the second counter 20 are preferably a counter with a resolution of 16 bits, which is why the memory 27 is a memory with a single memory location for a word length of 16 bits.
  • the second counter 20 connected as a down counter has a zero output 29 which always delivers a signal when the current counter reading is zero.
  • the zero output 29 is connected to a driver 30, which is connected to a trigger output 31, to which a pulse signal is present when the center of the railway wheel to be tested is exactly above the line 11 in FIG. 2.
  • the first counter 19 is reset to zero using the control logic 15.
  • the control logic 15 When the leading edge of the contact signal K1 occurs, the control logic 15 generates a start signal at its first output 41 so that, starting with the leading edge of the contact signal K1, the first counter 19 begins to count the clock pulses of the oscillator 22 which are divided down 1: 2.
  • the control logic 15 in turn generates a stop signal with the trailing edge of the contact signal K2 and a takeover signal at the second output 42 which is connected to the takeover input of the memory 27, so that the memory 27 takes over the counter result present at the time of the trailing edge of the contact signal K2.
  • the counter result temporarily stored in the memory 27 is taken over into the second counter 20 until the contact signal K3 generated with the aid of the third proximity switch 7 occurs.
  • a start signal is transmitted to the second counter 20 via the third output 43 of the control logic 15, so that it begins to count down.
  • the clock input 21 receives clock signals whose frequency is twice as large as the clock signals at the clock input 25 of the first counter 19.
  • the distance a between the first proximity switch 3 and the second proximity switch 6 is twice as large
  • the second counter 20 comes to zero exactly when this is in Fig. 2 is from left to right evenly moving railway wheel exactly above the center of the ultrasonic transducer 8.
  • the ultrasound generation and the start of the ultrasound test is triggered by the signal occurring at the zero output 29 and amplified in the driver 30.
  • the distance ratios can be changed somewhat, but it is expedient if the distance between the first proximity switch 3 and the second proximity switch 6 is substantially greater than the distance between the third proximity switch 7 and the center of the ultrasonic transducer 8 illustrated by the line 11, because the various sources of error are then best compensated for.
  • the error sources are error sources resulting from the switching behavior of the inductive proximity switches, because the switching behavior of the proximity switches is dependent on the object speed, the different wheel profiles and the object distances.

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  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Electromagnetism (AREA)
  • Train Traffic Observation, Control, And Security (AREA)

Abstract

A driving device for an ultrasonic train wheel control installation has an arrangement with three proximity switches (3, 6, 7) and with an ultrasonic emitter-receiver transducer (8) arranged in a section of a track (2) along which the wheel to be inspected travels. Before the ultrasonic transducer (8), in the direction of travel, are arranged a first and a second mtually spaced (a) proximity switch (3, 8) connected to a timing device. On the path between the second proximity switch (6) and the ultrasonic transducer (8) is arranged a third proximity switch (7) at a second distance (a/2) from the middle of the ultrasonic transducer (8). The third proximity switch (7) is connected to a second timing device by means of which an output signal can be generated after a delay that is derived from the time measured by the first timing device devided by the ratio between the first distance (a) and the second distance (a/2).

Description

Vorrichtung zum Ansteuern einer Ultraschall-Radprüfanläge für Eisenbahnräder Device for controlling an ultrasonic wheel test system for railway wheels

Die Erfindung betrifft eine Vorrichtung zum Ansteuern einer Ultraschall-Radprüfanlage für Eisenbahnräder mit einer die Position des zu prüfenden Rades erfassenden Näherungsschalteranordnung und mit einem Sende-Empfän- ger-Ultraschall andler, die in einem vom zu prüfenden Rad zu überfahrenden Abschnitt einer Schiene angeordnet sind.The invention relates to a device for controlling an ultrasonic wheel test system for railway wheels with a proximity switch arrangement which detects the position of the wheel to be tested and with a transceiver ultrasound transducer which are arranged in a section of a rail to be driven over by the wheel to be tested.

Ein elektromagnetischer Ultraschallwandler für eine derartige Vorrichtung ist in der DE-PS 32 18 453 be¬ schrieben und gestattet eine zerstörungsfreie Prüfung der Lauffläche von Eisenbahnrädern mittels Ultraschall- Oberflächenwellen während des Überfahrens eines Schie¬ nenabschnittes. Um den Ultraschallwandler der Radprüf- anläge genau im richtigen Zeitmoment zu aktivieren, kann beispielsweise ein induktiver Näherungsschalter verwendet werden.An electromagnetic ultrasonic transducer for such a device is described in DE-PS 32 18 453 and permits non-destructive testing of the running surface of railroad wheels by means of ultrasonic surface waves while driving over a rail section. An inductive proximity switch, for example, can be used to activate the ultrasonic transducer of the wheel test system at exactly the right moment.

Induktive Näherungsschalter zur automatischen Über¬ wachung und Steuerung der Bewegung von Schienenfahr¬ zeugen werden im Bereich der Signal- und Rangiertechnik häufig als integrierte Näherungsschalter benutzt und als Schienenkopfkontakte bezeichnet. Der¬ artige Schienenkopfkontakte und auch Doppelschienen¬ kopfkontakte sind in S + D - Signal und Draht, 72. Jahrgang, September 1980, Heft 9, Seiten 166 bis 172 beschrieben. Die bekannten Doppelkontakte arbeiten im Differenzverfahren und erzeugen zusammen mit einer Anschaltbaugruppe und einer Richtungsbaugruppe einen von der Fahrtrichtung und Geschwindigkeit des Schienen¬ fahrzeuges abhängigen elektrischen Impuls, wenn das überrollende Rad eine Mindeststrecke zurücklegt, die vom Raddurchmesser, Reifenprofil, Abstand der Rad¬ oberfläche zum Sensor sowie der Größe und der Schalt- Charakteristik des Sensors abhängig ist. Im allgemeinen beträgt diese Mindeststrecke zwischen 60 und 120 mm. Bei den bekannten Anordnungen ergibt sich jedoch eine Schaltpunktungenauigkeit, die beim Zählen von Achsen sowie beim Steuern von Signalen und Weichen ausreicht, jedoch dann zu Problemen führt, wenn Ultraschall-Rad¬ prüfanlagen angesteuert werden sollen, die eine Schalt¬ punktgenauigkeit von weniger als 5 mm verlangen.Inductive proximity switches for automatic monitoring and control of the movement of rail vehicles are frequently used in the field of signaling and shunting technology as integrated proximity switches and are referred to as rail head contacts. Such rail head contacts and also double rail head contacts are described in S + D - Signal und Draht, 72nd Year, September 1980, Issue 9, pages 166 to 172. The known double contacts work in the differential method and, together with an interface module and a directional module, generate an electrical impulse that depends on the direction of travel and speed of the rail vehicle when the wheel that rolls over covers a minimum distance that depends on the wheel diameter, tire profile and distance of the wheel surface from the sensor as well as the size and the switching Characteristic of the sensor is dependent. In general, this minimum distance is between 60 and 120 mm. In the known arrangements, however, there is a switching point inaccuracy which is sufficient when counting axes and when controlling signals and switches, but which leads to problems when ultrasonic wheel test systems are to be controlled which have a switching point accuracy of less than 5 mm desire.

Ausgehend von diesem Stand der Technik liegt der Er¬ findung die Aufgabe zugrunde, eine Vorrichtung zum Ansteuern einer Ultraschall-Radprüfanläge für Eisen¬ bahnräder zu schaffen, die unabhängig von verschiedenen Störgrößen, wie unterschiedliche Geschwindigkeiten, Radprofile und Abhebungen, eine hohe Genauigkeit ge¬ währleistet.On the basis of this prior art, the object of the invention is to provide a device for controlling an ultrasonic wheel testing system for railway wheels, which ensures high accuracy regardless of different disturbance variables, such as different speeds, wheel profiles and lift-offs .

Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß in Laufrichtung vor dem Ultraschallwandler in einem ersten Abstand voneinander ein erster und ein zweiter mit einer Zeitmeßeinrichtung verbundener Näherungs¬ schalter angeordnet sind und daß in Laufrichtung zwi¬ schen dem zweiten Näherungsschalter und dem Ultra¬ schallwandler in einem zweiten Abstand vor der Mitte des Ultraschallwandlers ein dritter Näherungsschalter vorgesehen ist, der mit einer zweiten Zeitmeßeinrich¬ tung verbunden ist, durch die ein Ausgangssignal nach Ablauf einer Verzögerungszeit erzeugbar ist, die sich aus der in der ersten Zeitmeßeinrichtung erfaßten Zeit durch Dividieren durch das Abstandsverhältnis aus dem ersten Abstand durch den zweiten Abstand ergibt.This object is achieved in that a first and a second proximity switch connected to a time measuring device are arranged in the direction of travel upstream of the ultrasound transducer and that in the direction of travel between the second proximity switch and the ultrasound transducer in a second At a distance from the center of the ultrasonic transducer, a third proximity switch is provided, which is connected to a second time measuring device, by means of which an output signal can be generated after a delay time has elapsed, which is derived from the time recorded in the first time measuring device by dividing by the distance ratio from the first distance by the second distance.

Bei einem zweckmäßigen Ausführungsbeispiel der Er¬ findung ist vorgesehen, daß die drei Näherungsschalter über eine Steuerlogik mit einem als erste Zeitmeßein- richtung dienenden ersten Zähler und mit einem als zweite Zeitmeßeinrichtung dienenden zweiten Zähler verbunden sind, die in entgegengesetzten Richtungen die Taktimpulse eines Oszillators zählen, wobei der erste Zähler vor Zählbeginn jeweils rücksetzbar und der zweite Zähler jeweils mit dem Endzählwert des ersten Zählers beaufschlagbar ist. Bei dem ersten Zähler handelt es sich beispielsweise um einen zu Beginn einer Messung jeweils rücksetzbaren Aufwärtszähler, dessen Zählerstand am Ende der ersten Zeitmessung in den zweiten Zähler übertragbar ist, der bis Null abwärts zählt. Wenn das Verhältnis der Abstände so gewählt ist, daß der erste Abstand doppelt so groß wie der zweite Abstand ist, ist die Anordnung so getroffen, daß die pro Zeiteinheit dem zweiten Zähler zugeführte Taktzahl doppelt so hoch ist wie die pro Zeiteinheit dem ersten Zähler zugeführte Taktzahl.In an expedient embodiment of the invention, it is provided that the three proximity switches are controlled via a control logic with a direction serving first counter and are connected to a second counter serving as a second time measuring device, which count the clock pulses of an oscillator in opposite directions, the first counter being able to be reset before the start of the count and the second counter having the final count of the first counter. The first counter is, for example, an up counter that can be reset at the start of a measurement, the counter reading of which can be transferred to the second counter at the end of the first time measurement, which counts down to zero. If the ratio of the distances is chosen so that the first distance is twice as large as the second distance, the arrangement is such that the number of cycles supplied to the second counter per unit of time is twice as high as the number of cycles supplied to the first counter per unit of time .

Auf diese Weise dienen der erste und der zweite Nähe- rungsschalter zur Erfassung einer Zeit, wobei die Meßfehler sich auf die Verzögerungszeit des zweiten Zählers kompensierend auswirken.In this way, the first and the second proximity switches serve to detect a time, the measurement errors having a compensating effect on the delay time of the second counter.

Nachfolgend wird ein Ausführungsbeispiel der Erfindung anhand der Zeichnung näher beschrieben. Es zeigen:An exemplary embodiment of the invention is described in more detail below with reference to the drawing. Show it:

Fig. 1 einen Querschnitt durch den Abschnitt einer Schiene im Bereich des ersten Näherungs¬ schalters der erfindungsgemäßen Vorrichtung, zusammen mit einer schematischen Darstellung des Radprofils eines Eisenbahnrades,1 shows a cross section through the section of a rail in the region of the first proximity switch of the device according to the invention, together with a schematic representation of the wheel profile of a railway wheel,

Fig. 2 eine Draufsicht auf eine Schiene im Bereich der Näherungsschalter und des Ultraschall- wandlers der erfindungsgemäßen Vorrichtung und Fig. 3 ein , Blockschaltbild der Vorrichtung zum Ansteuern einer Ultraschall-Radprüfanlage gemäß der Erfindung.2 shows a plan view of a rail in the area of the proximity switches and the ultrasonic transducer of the device according to the invention and Fig. 3 is a block diagram of the device for controlling an ultrasonic wheel test system according to the invention.

In Fig. 1 erkennt man schematisch ein Radreifenprofil 1 eines Eisenbahnrades, das auf dem Laufspiegel einer Schiene 2 abrollt, in der ein erster Näherungsschalter 3 in einer Aufnahmebohrung 4 vorgesehen ist. Der erste induktive Näherungsschalter 3 ist über ein Kabel 5 mit einer in Fig. 3 im Blockschaltbild dargestellten elek¬ tronischen Einrichtung verbunden.1 shows schematically a wheel tire profile 1 of a railway wheel that rolls on the running mirror of a rail 2, in which a first proximity switch 3 is provided in a receiving bore 4. The first inductive proximity switch 3 is connected via a cable 5 to an electronic device shown in the block diagram in FIG. 3.

In Fig. 2 erkennt man in einer Draufsicht die Schiene 2, die in ihrem Laufspiegel zusätzlich zum ersten Näherungsschalter 3 in Fahrtrichtung oder Prüfrichtung einen zweiten induktiven Näherungsschalter 6 und einen dritten induktiven Näherungsschalter 7 aufweist. Wei¬ terhin erkennt man in Fig. 2 einen Sende-Empfänger- Ultraschallwandler 8 mit einer Spulenwicklung 9. Beim Überfahren des in Fig. 2 dargestellten Schienenab¬ schnitts erzeugt der Ultraschallwandler 8 genau dann einen Ultraschallimpuls, wenn die Radachse sich über der Mitte des Ultraschallwandlers 8 befindet, so daß eine Ultraschallprüfung der Lauffläche des überfahren- den Eisenbahnrades durchgeführt werden kann. Die Schie¬ ne 2, deren zugeordnete zweite Schiene in der Zeichnung nicht zu erkennen ist, ruht in üblicher Weise auf Schwellen, von denen eine Schwelle 10 in Fig. 2 sche¬ matisch dargestellt ist.2 shows a top view of the rail 2, which in its running mirror has a second inductive proximity switch 6 and a third inductive proximity switch 7 in addition to the first proximity switch 3 in the direction of travel or test direction. Furthermore, a transceiver ultrasound transducer 8 with a coil winding 9 can be seen in FIG. 2. When the rail section shown in FIG. 2 is passed over, the ultrasound transducer 8 generates an ultrasound pulse precisely when the wheel axis is above the center of the ultrasound transducer 8 is located so that an ultrasonic inspection of the tread of the railroad wheel passing over can be carried out. The rail 2, the associated second rail of which cannot be seen in the drawing, rests in the usual way on sleepers, of which a sleeper 10 is shown schematically in FIG. 2.

In Fig. 2 ist die Mitte des Ultraschallwandlers 8 durch eine Linie 11 veranschaulicht. Entgegen der Laufrich¬ tung oder Prüfrichtung ist links von der Linie 11 im Abstand a/2 der dritte Näherungsschalter 7 angeordnet. Der Abstand zwischen dem dritten Näherungsschalter 7 und der Linie 11 beträgt beispielsweise 20 mm.The center of the ultrasonic transducer 8 is illustrated in FIG. 2 by a line 11. Contrary to the direction of travel or test direction, the third proximity switch 7 is arranged to the left of the line 11 at a / 2 distance. The distance between the third proximity switch 7 and the line 11 is, for example, 20 mm.

Der zweite Näherungsschalter 6 befindet sich etwa 100 mm vor der Linie 11, über der sich die Achse des zu prüfenden Rades im PrüfZeitpunkt befinden soll. Der Abstand a zwischen dem ersten Näherungsschalter 3 und dem zweiten Näherungsschalter 6 beträgt beispielsweise 40 mm, so daß sich der erste Näherungsschalter 3 etwa 14 cm vor der Linie 11 befindet.The second proximity switch 6 is located approximately 100 mm in front of the line 11, above which the axis of the wheel to be tested should be at the time of the test. The distance a between the first proximity switch 3 and the second proximity switch 6 is, for example, 40 mm, so that the first proximity switch 3 is approximately 14 cm in front of the line 11.

Wenn in Fig. 2 von links nach rechts ein Eisenbahnrad die Schiene 2 überrollt, wird zunächst im ersten Nähe¬ rungsschalter 3 ein Kontaktsignal K1 erzeugt, dessen Vorderflanke eine in Fig. 3 dargestellte Steuerlogik 15 einer elektronischen Schaltung beaufschlagt. Die Steuerlogik 15 verfügt über 3 Eingänge 16, 17, 18, wobei der Eingang 16 mit dem Kontaktsignal K1 beauf¬ schlagbar ist.If a railroad wheel rolls over the rail 2 from left to right in FIG. 2, a contact signal K1 is first generated in the first proximity switch 3, the front edge of which acts on control logic 15 of an electronic circuit shown in FIG. 3. The control logic 15 has 3 inputs 16, 17, 18, the input 16 having the contact signal K1 applied to it.

Der Näherungsschalter 6 erzeugt ein Kontaktsignal K2 , das über den Eingang 17 der Steuerlogik 15 zugeführt und dessen Rückflanke ausgewertet wird. Der dritte Näherungsschalter 7 erzeugt ein Kontaktsignal K3 , das den Eingang 18 der Steuerlogik 15 beaufschlagt.The proximity switch 6 generates a contact signal K2, which is fed to the control logic 15 via the input 17 and whose trailing edge is evaluated. The third proximity switch 7 generates a contact signal K3 which acts on the input 18 of the control logic 15.

Wie man in Fig. 3 erkennt, ist die Steuerlogik 15 mit einem ersten Zähler 19, der als Aufwärtszähler ge¬ schaltet ist, und mit einem zweiten Zähler 20, der als Abwärtszähler geschaltet ist, verbunden. Der zweite Zähler 20 verfügt über einen Takteingang 21, der mit dem Taktsignal eines quarzstabilen Oszillators 22 beaufschlagt ist. Der Taktausgang 23 des Oszillators 22 ist weiterhin mit einer Teilerschaltung 24 verbunden, die das Taktsignal im Verhältnis 1 : 2 untersetzt und dem Takteingang 25 des ersten Zählers 19 zuführt.As can be seen in FIG. 3, the control logic 15 is connected to a first counter 19, which is connected as an up counter, and to a second counter 20, which is connected as a down counter. The second counter 20 has a clock input 21 which is supplied with the clock signal from a quartz-stable oscillator 22. The clock output 23 of the oscillator 22 is also connected to a divider circuit 24, which reduces the clock signal in a ratio of 1: 2 and feeds it to the clock input 25 of the first counter 19.

Der Ausgang 26 des ersten Zählers 19 ist mit einem Speicher 27 verbunden, der es gestattet, den Zähler¬ standswert am Ausgang 26 zwischenzuspeichern. Der Datenausgang des Speichers 27 ist mit dem Zählereingang 28 des zweiten Zählers 20 verbunden. Sowohl beim ersten Zähler 19 als auch beim zweiten Zähler 20 handelt es sich vorzugsweise,um einen Zähler mit einer Auflösung von 16 Bit, weshalb der Speicher 27 ein Speicher mit einem einzigen Speicherplatz für eine Wortlänge von 16 Bit ist.The output 26 of the first counter 19 is connected to a memory 27, which makes it possible to temporarily store the counter reading at the output 26. The data output of the memory 27 is connected to the counter input 28 of the second counter 20. Both the first counter 19 and the second counter 20 are preferably a counter with a resolution of 16 bits, which is why the memory 27 is a memory with a single memory location for a word length of 16 bits.

Der als Runterzähler geschaltete zweite Zähler 20 verfügt über einen Nullausgang 29, der immer dann ein Signal liefert, wenn der augenblickliche Zählerstand Null beträgt. Der Nullausgang 29 ist mit einem Treiber 30 verbunden, der an einen Triggerausgang 31 ange- schlössen ist, an dem ein Impulssignal anliegt, wenn sich die Mitte des zu prüfenden Eisenbahnrades genau über der Linie 11 in Fig. 2 befindet.The second counter 20 connected as a down counter has a zero output 29 which always delivers a signal when the current counter reading is zero. The zero output 29 is connected to a driver 30, which is connected to a trigger output 31, to which a pulse signal is present when the center of the railway wheel to be tested is exactly above the line 11 in FIG. 2.

Zu Beginn eines Meßvorgangs wird der erste Zähler 19 mit Hilfe der Steuerlogik 15 auf Null zurückgesetzt. Beim Auftreten der Vorderflanke des Kontaktsignals K1 erzeugt die Steuerlogik 15 an ihrem ersten Ausgang 41 ein Startsignal, so daß beginnend mit der Vorderflanke des Kontaktsignals K1 der erste Zähler 19 die im Ver- hältnis 1 : 2 heruntergeteilten Takte des Oszillators 22 zu zählen beginnt.At the beginning of a measuring process, the first counter 19 is reset to zero using the control logic 15. When the leading edge of the contact signal K1 occurs, the control logic 15 generates a start signal at its first output 41 so that, starting with the leading edge of the contact signal K1, the first counter 19 begins to count the clock pulses of the oscillator 22 which are divided down 1: 2.

Wenn das Eisenbahnrad den in Fig. 2 veranschaulichtenIf the railroad wheel illustrated in Fig. 2

Weg a zurückgelegt hat und das Kontaktsignal K2 durch den zweiten Näherungsschalter 6 erzeugt worden ist, erzeugt die Steuerlogik 15 ihrerseits mit der Rück¬ flanke des Kontaktsignals K2 ein Stoppsignal sowie ein Übernahmesignal am zweiten Ausgang 42, der mit dem Übernahmeeingang des Speichers 27 verbunden ist, so daß der Speicher 27 das zum Zeitpunkt der Rückflanke des Kontaktsignals K2 vorhandene Zählerergebnis übernimmt.Has traveled distance a and the contact signal K2 has been generated by the second proximity switch 6, The control logic 15 in turn generates a stop signal with the trailing edge of the contact signal K2 and a takeover signal at the second output 42 which is connected to the takeover input of the memory 27, so that the memory 27 takes over the counter result present at the time of the trailing edge of the contact signal K2.

Das im Speicher 27 zwischengespeicherte Zählerergebnis wird bis zum Auftreten des mit Hilfe des dritten Nähe- rungsschalters 7 erzeugten Kontaktsignals K3 in den zweiten Zähler 20 übernommen. Beim Auftreten der Vor¬ derflanke des Kontaktsignals K3 wird über den dritten Ausgang 43 der Steuerlogik 15 ein Startsignal zum zweiten Zähler 20 übermittelt, so daß dieser beginnt, abwärts zu zählen. Dabei erhält jedoch der Takteingang 21 Taktsignale, deren Frequenz doppelt so groß ist, wie die Taktsignale am Takteingang 25 des ersten Zählers 19. Im Hinblick darauf, daß der Abstand a zwischen dem ersten Näherungsschalter 3 und dem zweiten Näherungs- Schalter 6 doppelt so groß ist, wie der Abstand zwi¬ schen dem dritten Näherungsschalter 7 und der Linie 11 , über der sich die Achse des zu prüfenden Rades im PrüfZeitpunkt befinden soll, ergibt sich, daß der zweite Zähler 20 genau dann auf Null zu stehen kommt, wenn das sich in Fig. 2 von links nach rechts gleich¬ mäßig schnell bewegende Eisenbahnrad genau über der Mitte des Ultraschallwandlers 8 befindet. Die Ultra¬ schallerzeugung und der Beginn der Ultraschallprüfung wird dabei über das am Nullausgang 29 auftretende und im Treiber 30 verstärkte Signal ausgelöst.The counter result temporarily stored in the memory 27 is taken over into the second counter 20 until the contact signal K3 generated with the aid of the third proximity switch 7 occurs. When the leading edge of the contact signal K3 occurs, a start signal is transmitted to the second counter 20 via the third output 43 of the control logic 15, so that it begins to count down. However, the clock input 21 receives clock signals whose frequency is twice as large as the clock signals at the clock input 25 of the first counter 19. In view of the fact that the distance a between the first proximity switch 3 and the second proximity switch 6 is twice as large As the distance between the third proximity switch 7 and the line 11 over which the axis of the wheel to be tested is to be located at the time of the test, it follows that the second counter 20 comes to zero exactly when this is in Fig. 2 is from left to right evenly moving railway wheel exactly above the center of the ultrasonic transducer 8. The ultrasound generation and the start of the ultrasound test is triggered by the signal occurring at the zero output 29 and amplified in the driver 30.

Es leuchtet ein, daß die Abstandsverhältnisse etwas geändert werden können, jedoch ist es zweckmäßig, wenn der Abstand zwischen dem ersten Näherungsschalter 3 und dem zweiten Näherungsschalter 6 wesentlich größer ist als der Abstand zwischen dem dritten Näherungsschalter 7 und der durch die Linie 11 veranschaulichten Mitte des Ultraschallwandlers 8, weil dann die verschiedenen Fehlerquellen am besten kompensiert werden. Bei den Fehlerquellen handelt es sich um sich aus dem Schalt¬ verhalten der induktiven Näherungsschalter ergebende Fehlerquellen, weil das Schaltverhalten der Näherungs¬ schalter von der Objektgeschwindigkeit, den unter- schiedlichen Radprofilen und den Objektabständen ab¬ hängig ist. It is obvious that the distance ratios can be changed somewhat, but it is expedient if the distance between the first proximity switch 3 and the second proximity switch 6 is substantially greater than the distance between the third proximity switch 7 and the center of the ultrasonic transducer 8 illustrated by the line 11, because the various sources of error are then best compensated for. The error sources are error sources resulting from the switching behavior of the inductive proximity switches, because the switching behavior of the proximity switches is dependent on the object speed, the different wheel profiles and the object distances.

Claims

PATENTANSPRÜCHE PATENT CLAIMS 1. Vorrichtung zum Ansteuern einer Ultraschall-Rad¬ prüfanlage für Eisenbahnräder mit einer die Po- sition des zu prüfenden Rades erfassenden Nähe¬ rungsschalteranordnung und mit einem Sende-Emp- fänger-Ultraschallwandler, die in einem vom zu prüfenden Rad zu überfahrenden Abschnitt einer Schiene angeordnet sind, dadurch gekenn- zeichnet , daß in Laufrichtung vor dem Ultra¬ schallwandler (8) in einem ersten Abstand (a) von¬ einander ein erster und ein zweiter mit einer ersten Zeitmeßeinrichtung (19) verbundener Nähe¬ rungsschalter (3) angeordnet sind und daß in Laufrichtung zwischen dem zweiten Näherungsschal¬ ter (6) und dem Ultraschallwandler (8) in einem zweiten Abstand (a/2) vor der Mitte (11) des Ultraschallwandlers (8) ein dritter Näherungs¬ schalter (7) vorgesehen ist, der mit einer zweiten Zeitmeßeinrichtung (20) verbunden ist, durch die ein Ausgangssignal (29 bis 31) nach Ablauf einer Verzögerungszeit (27) erzeugbar ist, die sich aus der in der ersten Zeitmeßeinrichtung (19) erfaßten Zeit durch Dividieren (24) durch das Abstandsver- hältnis aus dem ersten Abstand (a) durch den zweiten Abstand (a/2) ergibt.1. Device for controlling an ultrasonic wheel test system for railway wheels with a proximity switch arrangement which detects the position of the wheel to be tested and with a transceiver ultrasonic transducer which is in a section of a rail to be driven over by the wheel to be tested are arranged, characterized in that a first and a second proximity switch (3) connected to a first time measuring device (19) are arranged at a first distance (a) from one another in the direction of travel in front of the ultrasonic transducer (8) and that a third proximity switch (7) is provided in the running direction between the second proximity switch (6) and the ultrasonic transducer (8) at a second distance (a / 2) in front of the center (11) of the ultrasonic transducer (8), which is connected to a second time measuring device (20), by means of which an output signal (29 to 31) can be generated after a delay time (27) has elapsed, which can be derived from the first Itmeßeinrichtung (19) recorded time by dividing (24) by the distance ratio from the first distance (a) by the second distance (a / 2). 2. Vorrichtung nach Anspruch 1, dadurch ge¬ kennzeichnet , daß die drei Näherungsschal- ter (3, 6, 7) über eine Steuerlogik (15) mit einem als erste Zeitmeßeinrichtung dienenden ersten Zähler (19) und einem als zweite Zeitmeßeinrich¬ tung dienenden zweiten Zähler (20) verbunden sind, die in entgegengesetzten Richtungen die Taktim- pulse (21 bis 25) eines Oszillators (22) zählen, wobei der Erstzähler (19) vor Zählbeginn jeweils rücksetzbar und der zweite Zähler (20) jeweils mit dem Endzählwert (27) des ersten Zählers (19) beaufschlagbar ist.2. Apparatus according to claim 1, characterized ge indicates that the three proximity switches (3, 6, 7) via a control logic (15) with a first time measuring device serving as a first counter (19) and a second time measuring device serving second counters (20) are connected which count the clock pulses (21 to 25) of an oscillator (22) in opposite directions, wherein the first counter (19) can be reset before the count begins and the second counter (20) can be loaded with the final count (27) of the first counter (19). 3. Vorrichtung nach Anspruch 2, dadurch ge¬ kennz eichnet , daß der erste Zähler (19) ein Aufwärtszähler ist, dessen Zählerstandsausgang (26) mit dem Eingang (28) des als Abwärtszähler gespalteten zweiten Zählers (20) verbunden ist.3. Apparatus according to claim 2, characterized ge¬ mark that the first counter (19) is an up counter, the counter reading output (26) with the input (28) of the split counter as a down counter (20) is connected. 4. Vorrichtung nach Anspruch 3, dadurch ge¬ kennzeichnet , daß zwischen den beiden Zählern (19, 20) ein Pufferspeicher (27) für den zu übertragenden Zählerstand vorgesehen ist.4. The device according to claim 3, characterized ge indicates that between the two counters (19, 20) a buffer memory (27) is provided for the counter reading to be transmitted. 5. Vorrichtung nach einem der Ansprüche 2 bis 4, dadurch gekennzeichnet , daß das Aus¬ gangssignal (31) für die Ansteuerung des Ultra- schallwandlers (8) am Nullausgang (29) des zweiten Zählers (20) abgreifbar ist.5. Device according to one of claims 2 to 4, characterized in that the output signal (31) for controlling the ultrasonic transducer (8) at the zero output (29) of the second counter (20) can be tapped. 6. Vorrichtung nach einem der Ansprüche 2 bis 5, dadurch gekennzeichnet , daß der Aus- gang des Oszillators (22) über eine Teilerschal¬ tung (24) an den Takteingang (25) des ersten Zählers (19) und unmittelbar an den Takteingang (21) des zweiten Zählers (20) angeschlossen ist.6. Device according to one of claims 2 to 5, characterized in that the output of the oscillator (22) via a divider circuit (24) to the clock input (25) of the first counter (19) and directly to the clock input ( 21) of the second counter (20) is connected. 7. Vorrichtung nach Anspruch 6, dadurch ge¬ kennz eichnet , daß die Teilerschaltung (24) eine Teilung im Verhältnis 1 : 2 vornimmt und der zweite Abstand (a/2) halb so groß ist wie der erste Abstand (a) . 7. The device according to claim 6, characterized ge indicates that the divider circuit (24) makes a division in the ratio 1: 2 and the second distance (a / 2) is half as large as the first distance (a). 8. Vorrichtung nach einem der vorstehenden Ansprüche, dadurch gekennze ichnet , daß die Nähe¬ rungsschalter (3, 6, 7) entlang einer in Lauf¬ richtung verlaufenden Gerade im Schienenkopf eingebettet sind.8. Device according to one of the preceding claims, characterized in that the proximity switches (3, 6, 7) are embedded along a straight line in the running direction in the rail head. 9. Vorrichtung nach Anspruch 8, dadurch ge ¬ kennzeichnet , daß der Sende-Empfänger- Ultraschallwandler (8) seitlich versetzt gegenüber der Geraden durch die Näherungsschalter (3, 6, 7) angeordnet ist.9. The device according to claim 8, characterized ge ¬ indicates that the transceiver ultrasonic transducer (8) is laterally offset from the straight line through the proximity switch (3, 6, 7). 10. Vorrichtung nach einem der vorstehenden Ansprüche, dadurch gekennzeichnet , daß der Ultra- schallwandler (8) ein elektromagnetischer Ultra¬ schallwandler mit einer Senderwicklung und einer Empfängerwicklung (9) ist. 10. Device according to one of the preceding claims, characterized in that the ultrasonic transducer (8) is an electromagnetic ultrasonic transducer with a transmitter winding and a receiver winding (9).
PCT/DE1989/000564 1988-10-13 1989-08-29 Driving device for an ultrasonic train wheel control installation Ceased WO1990004173A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DEP3834828.4 1988-10-13
DE19883834828 DE3834828C1 (en) 1988-10-13 1988-10-13

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