EP0283688A1 - X-ray emitter - Google Patents

X-ray emitter Download PDF

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Publication number
EP0283688A1
EP0283688A1 EP88101814A EP88101814A EP0283688A1 EP 0283688 A1 EP0283688 A1 EP 0283688A1 EP 88101814 A EP88101814 A EP 88101814A EP 88101814 A EP88101814 A EP 88101814A EP 0283688 A1 EP0283688 A1 EP 0283688A1
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EP
European Patent Office
Prior art keywords
ray emitter
housing
pressure
liquid pressure
pressure sensor
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.)
Granted
Application number
EP88101814A
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German (de)
French (fr)
Other versions
EP0283688B1 (en
Inventor
Günther Appelt
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.)
Siemens AG
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Siemens AG
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Publication date
Application filed by Siemens AG filed Critical Siemens AG
Publication of EP0283688A1 publication Critical patent/EP0283688A1/en
Application granted granted Critical
Publication of EP0283688B1 publication Critical patent/EP0283688B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05GX-RAY TECHNIQUE
    • H05G1/00X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/02Constructional details
    • H05G1/04Mounting the X-ray tube within a closed housing
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05GX-RAY TECHNIQUE
    • H05G1/00X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/08Electrical details
    • H05G1/26Measuring, controlling or protecting
    • H05G1/54Protecting or lifetime prediction

Definitions

  • the invention relates to an X-ray emitter which has a housing filled with an electrically insulating liquid and provided with a radiation passage window and an X-ray tube arranged therein, and a protective device which prevents the operation of the X-ray emitter when the liquid pressure in the housing exceeds a limit value.
  • the safety device is provided in order to keep the pressure rise inside the housing that occurs as a result of the heat loss emitted by the X-ray tube during operation into the interior of the housing within acceptable limits.
  • the protective device which is provided per se for safety reasons, can in turn trigger dangers during medical examinations, namely if the protective device responds during the examination of a patient and unexpectedly puts the x-ray emitter out of operation. In the case of catheterizations, life-threatening situations for the patient could occur.
  • the invention is based on the object of designing an X-ray emitter of the type mentioned at the outset in such a way that risks to the patient from the response of the protective device are excluded.
  • the x-ray emitter has a warning device which emits a warning signal when the threshold value of the liquid pressure is below the limit value which is decisive for the protective device.
  • the threshold value is dimensioned such that the warning signal is emitted a sufficient period of time, for example 30 minutes, before the protective device is expected to respond follows, so that the operating personnel or the examining doctor can assess whether an started examination can be completed in the remaining period or should be terminated for safety reasons. Danger to the patient from an unexpected response of the protective device is therefore excluded.
  • the warning device has a pressure sensor for measuring the threshold value of the liquid pressure. Under certain circumstances this can be a pressure sensor which is also part of the protective device and is used there to measure the limit value of the liquid pressure.
  • the threshold value can be set. It is therefore possible to adapt the period of time between the issue of the warning signal and the response of the protective device to the respective needs.
  • Such a setting of the threshold value is particularly easy to implement if the pressure sensor continuously emits a signal corresponding to the instantaneous value of the pressure and the warning device has means for comparing the signal corresponding to the instantaneous fluid pressure with a desired value corresponding to the threshold value of the fluid pressure, since in this If only the setpoint has to be changed to change the threshold value.
  • the pressure sensor emits an output signal which changes abruptly when the threshold value of the liquid pressure is reached.
  • the output signal of the pressure sensor can be the supply voltage of an optical or acoustic signal device which is applied to the signal device when the threshold value is reached.
  • the pressure sensor is expediently designed as a pressure-sensitive switch.
  • the pressure sensor can be directly exposed to the liquid pressure in the housing or, if the housing of the x-ray emitter has a flexible wall section to compensate for temperature-related changes in volume of the coolant, can be actuated indirectly by the flexible wall section, which can be formed by a membrane.
  • the pressure sensor can be formed by a simple switch which causes the warning signal to be emitted, the position of which can be adjusted relative to the flexible wall section in order to change the threshold value.
  • Another variant of the invention provides, in the event that the pressure sensor continuously emits a signal corresponding to the liquid pressure in the housing, that the warning devices have means for determining and displaying the time remaining until the limit value of the liquid pressure is reached.
  • the operating personnel is therefore constantly provided with information about the operating time of the X-ray emitter remaining until the protective device responds.
  • Fig. 1 shows an X-ray emitter according to the invention, which is coated with an electrically insulating liquid, e.g. Insulating oil, filled housing 1, in which an X-ray tube 2 is arranged.
  • an X-ray tube 2 is arranged.
  • This is designed as a rotating anode X-ray tube, which contains an anode plate 3, a cathode 4 and a motor for driving the rotating anode, which has a rotor 5 and a stator 7 arranged outside the glass body of the X-ray tube 2 on an insulator 6.
  • the housing 1 has a radiation passage window 8 for the X-rays emanating from the anode plate 3.
  • a transverse wall 9 on which there is provided a resilient membrane 10, which closes the interior of the housing 1 in a liquid-tight manner, and which serves to absorb temperature-related volume fluctuations of the liquid in the interior of the housing 1.
  • the supply voltages required to operate the X-ray tube namely the cathode heating voltage, the high voltage and the voltage required to drive the rotating anode, are provided by a generator device 11, with only a single line 12 between the generator device 11 and 11 in FIG. 1 for reasons of clarity the X-ray tube 2 is shown.
  • the generator device 11 has a control panel 11a, by means of which the operating data of the x-ray tube 2 can be set and the x-ray emitter can be put into operation.
  • the X-ray emitter In order to keep the rise in the liquid pressure in the housing 1 due to the heating of the liquid in the housing 1 due to the heat loss emitted by the X-ray tube 2 in operation below the limit value to be observed for safety reasons, the X-ray emitter has a protective device which prevents it from operating the liquid pressure in the housing 1 exceeds the limit value.
  • the protective device comprises a pressure-sensitive switch 13 with a pressure sensor 13a and a switch contact 13b, which is attached to the housing 1 in such a way that the pressure sensor 13a actuating the switch contact 13b directly detects the liquid pressure inside the housing 1 a contactor 14 for connecting the X-ray tube 2 to the generator device 11, the contacts 14a, of which only one is shown for clarity, and an excitation winding 14b, and a voltage source 15 to which the excitation winding 14b of the contactor 14 is connected of the switch contact 13b of the pressure-sensitive switch 13 can be switched on.
  • the protective device works in such a way that as long as the liquid pressure in the housing 1 is below the limit value, the contact 14a of the contactor is closed and the X-ray tube 2 is thus connected to the generator device 11 and can be operated with operating data set by means of the control panel 11a. As soon as the liquid pressure inside the housing 1 exceeds the limit value, the switch contact 14b of the pressure-sensitive switch 13 opens, whereupon the contactor 14 drops out and its contact 14a opens, so that the operation of the X-ray emitter is prevented.
  • the switch contact 13b of the pressure-sensitive switch closes again, whereupon the contactor 14 picks up and the X-ray emitter is ready for operation again.
  • the X-ray emitter has a warning device which emits a warning signal when the threshold value of the liquid pressure in the housing 1 is less than the limit value which is decisive for the protective device.
  • the warning device has a second pressure-sensitive switch 16, the pressure sensor 16a of which is also attached to the inner wall of the housing 1 and is directly exposed to the liquid pressure prevailing in the housing 1 and the double-pole switch contact 16b when the threshold value of the liquid pressure is reached inside the housing 1 closes, so that a warning lamp 17 and an acoustic signal generator 18 are connected to the voltage source 15.
  • the threshold value at which the warning device responds is dimensioned, depending on the area of application of the x-ray emitter, in such a way that the warning signal is emitted at a point in time which is sufficiently long before the protective device responds in order to enable the operating personnel to decide whether an intended examination is to be carried out can still be started, or an examination that is already being carried out can still be ended or has to be stopped for safety reasons.
  • a pushbutton switch 19 is provided as the pressure sensor of the warning device, which is actuated by means of the membrane 10, which bulges outward with increasing fluid pressure in the housing 1, namely such that the membrane 10 acts on a plunger 20 of the pushbutton switch 19, which closes the switching contact 21 of the pushbutton switch 19 when the membrane bulges corresponding to the threshold value of the liquid pressure, with the result that the acoustic signal transmitter 18 is switched on to the voltage source 15 .
  • the pushbutton switch 19 has a threaded attachment 22 surrounding the plunger 20, which is held in a bore 23 of a housing part 24 by means of the nuts 25.
  • the position of the pushbutton switch 19 relative to the diaphragm 10 can be changed in its direction of movement by adjusting the nuts 25.
  • the threshold value of the liquid pressure at which the warning device responds is the lower the further the pushbutton switch 19 is adjusted in the direction of the membrane 10.
  • the X-ray emitter shown in FIG. 4 differs from the ones described above in that the pressure sensor 27 of the warning device, which works, for example, according to the piezoelectric principle, continuously emits a signal corresponding to the instantaneous value of the liquid pressure in the housing 1.
  • the warning device has a comparator 28, which can be formed, for example, by an operational amplifier connected as a comparator.
  • a voltage source 29 with a potentiometer 30 connected to it is provided, it being possible to tap a voltage by means of the slider of the potentiometer 30, which represents a desired value corresponding to the threshold value of the liquid pressure. This voltage is supplied to one and the signal voltage supplied by the pressure sensor 27 to the other input of the comparator 28.
  • the output signal of the comparator 28 changes.
  • This controls a switching stage 31, by means of which a warning lamp 17 connects to the is supplied from the voltage source 29 supplied supply voltage.
  • the switching stage 31 can be designed, for example, as a conventional electromechanical relay or as a semiconductor switch. If this is necessary, an amplifier for the signal emitted by the pressure sensor 27 can be provided between the pressure sensor 27 and the corresponding input of the comparator 28.
  • the voltage which can be set by means of the potentiometer 30 and serves as a setpoint value is dimensioned such that it is always below a voltage which corresponds to the limit value of the liquid pressure in the interior of the housing 1 which is decisive for the response of the protective device. This can be done either by a suitable choice of the voltage supplied by the voltage source 29 or by a suitably dimensioned one, not shown in FIG. 4 set series resistance for the potentiometer 30 can be achieved. It is clear that by means of the described design of the warning device, the threshold value at which it responds or the period of time that elapses between the response of the warning device and the protective device can be easily adapted to the respective needs.
  • FIG. 5 An X-ray emitter according to the invention is shown in FIG. 5, in which a single pressure sensor 32 is provided, which is both part of the warning and the protective device.
  • a data processing device 33 is provided, which is also part of both the warning and the protective device, i.e. triggers the issuance of a warning signal when the liquid pressure inside the housing 1 exceeds the threshold value, and prevents the operation of the X-ray emitter when the liquid pressure in the Inside the housing 1 exceeds the limit.
  • the data processing device 33 comprises a multiplexer 34, an analog / digital converter 35, a computing device 36, a memory 37, an output unit 38 and a keyboard 39.
  • the keyboard 39 connected to the computing device 36, it is possible to enter the limit and the threshold value of the liquid pressure in the housing 1. These are then stored in the memory 37 by the computing device 36 and are available there.
  • the operating data for the X-ray emitter can be selected using the keyboard 39, the computing device 36 acting on the generator device 11 via the output unit 38 and causing the latter to provide the corresponding voltages for the X-ray tube 2.
  • the voltages actually emitted by the generator device 11 are fed to a multiplexer 34, to which the signal emitted by the pressure sensor 32 is also fed.
  • the multiplexer 34 From the multiplexer 34, they arrive at the analog / digital converter 35 and from there to the computing device 36 continuously compares the liquid pressure currently prevailing in the interior of the housing 1 with the values stored in the memory 37 for the limit or threshold value of the liquid pressure. As soon as the liquid pressure in the housing 1 exceeds the threshold value, the computing device 36 acts via the output unit 38 on the switching stages 40 and 41 in such a way that a signal lamp 17 and an acoustic signal generator 18 are connected to a voltage source 42.
  • the computing device 36 acts via the output unit 38 on the switching stage 43 in such a way that the excitation coil 14b of the contactor 14 is disconnected from the voltage source 42, with the result that the contact 14a of the contactor opens and the X-ray tube 2 is separated from the generator device 11, so that the operation of the X-ray emitter is prevented.
  • the computing device 36 continuously calculates from the instantaneous value of the liquid pressure and the values supplied to it via the multiplexer 34 and the analog / digital converter 35 for the operating data of the X-ray tube 2 and the stored limit value of the liquid pressure and shows the period of time until it is reached this via the output device 38 on a time display 44.
  • the time remaining in the currently set operating data of the X-ray tube 2 until the protective device responds appears on the time display 44. If the operating data of the X-ray tube 2 is changed in a way that affects the heat loss emitted by the X-ray tube 2 per unit of time, this is immediately taken into account in the calculation of the time remaining until the protective device responds, so that changes in the operating data of the X-ray tube also occur 2 correct information can always be found on the time display 44 during the examination.

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  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • X-Ray Techniques (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

Die Erfindung betrifft einen Röntgenstrahler, welcher ein mit einer elektrisch isolierenden Flüssigkeit gefülltes, mit einem Strahlendurchtrittsfenster (8) versehenes Gehäuse (1) und eine in diesem angeordnete Röntgenröhre (2) sowie eine den Betrieb des Röntgenstrahlers bei einem einen Grenzwert überschreitenden Flüssigkeitsdruck im Gehäuse (1) unterbindende Schutzeinrichtung (13, 14) aufweist. Um dem Bedienpersonal einen Hinweis auf das bevorstehende Ansprechen der Schutzeinrichtung (13, 14) zu geben, weist der Röntgenstrahler außerdem eine Warneinrichtung (16, 17, 18, 19) auf, welche bei einem unterhalb des für die Schutzeinrichtung (13, 14) maßgebenden Grenzwertes liegenden Schwellwert des Flüssigkeitsdruckes ein Warnsignal abgibt.The invention relates to an x-ray emitter which comprises a housing (1) filled with an electrically insulating liquid and provided with a radiation passage window (8) and an x-ray tube (2) arranged therein, and an operation of the x-ray emitter at a liquid pressure in the housing which exceeds a limit value ( 1) has a protective device (13, 14). In order to give the operating personnel an indication of the impending response of the protective device (13, 14), the x-ray emitter also has a warning device (16, 17, 18, 19), which is located below the one relevant to the protective device (13, 14) Threshold value of the fluid pressure emits a warning signal.

Description

Die Erfindung betrifft einen Röntgenstrahler, welcher ein mit einer elektrisch isolierenden Flüssigkeit gefülltes, mit einem Strahlendurchtrittsfenster versehenes Gehäuse und eine in die­sem angeordnete Röntgenröhre sowie eine den Betrieb des Rönt­genstrahlers bei einem einen Grenzwert überschreitenden Flüs­sigkeitsdruck im Gehäuse unterbindende Schutzeinrichtung auf­weist.The invention relates to an X-ray emitter which has a housing filled with an electrically insulating liquid and provided with a radiation passage window and an X-ray tube arranged therein, and a protective device which prevents the operation of the X-ray emitter when the liquid pressure in the housing exceeds a limit value.

Bei derartigen bekannten Röntgenstrahlern ist die Sicherheits­vorrichtung vorgesehen, um den infolge der von der Röntgenröhre im Betrieb an die Flüssigkeit abgegebene Verlustwärme auftre­tenden Druckanstieg im Innern des Gehäuses innerhalb zulässiger Grenzen zu halten. Die an sich aus Sicherheitsgründen vorgese­hene Schutzeinrichtung kann aber bei medizinischen Untersuchun­gen ihrerseits Gefahren auslösen, und zwar wenn während der Untersuchung eines Patienten die Schutzeinrichtung anspricht und den Röntgenstrahler unerwarteterweise außer Betrieb setzt. Dabei könnten im Falle von Katheterisierungen durchaus lebens­bedrohliche Situationen für den Patienten auftreten.In such known X-ray emitters, the safety device is provided in order to keep the pressure rise inside the housing that occurs as a result of the heat loss emitted by the X-ray tube during operation into the interior of the housing within acceptable limits. However, the protective device, which is provided per se for safety reasons, can in turn trigger dangers during medical examinations, namely if the protective device responds during the examination of a patient and unexpectedly puts the x-ray emitter out of operation. In the case of catheterizations, life-threatening situations for the patient could occur.

Der Erfindung liegt die Aufgabe zugrunde, einen Röntgenstrahler der eingangs genannten Art so auszubilden, daß Gefährdungen des Patienten durch das Ansprechen der Schutzeinrichtung ausge­schlossen sind.The invention is based on the object of designing an X-ray emitter of the type mentioned at the outset in such a way that risks to the patient from the response of the protective device are excluded.

Nach der Erfindung wird diese Aufgabe dadurch gelöst, daß der Röntgenstrahler eine Warneinrichtung aufweist, welche bei einem unterhalb des für die Schutzeinrichtung maßgebenden Grenzwertes liegenden Schwellwert des Flüssigkeitsdruckes ein Warnsignal abgibt. Dabei ist der Schwellwert so bemessen, daß die Abgabe des Warnsignales einen ausreichenden Zeitraum, z.B. 30 Minuten, vor dem zu erwartenden Ansprechen der Schutzeinrichtung er­ folgt, so daß das Bedienpersonal bzw. der untersuchende Arzt beurteilen kann, ob eine begonnene Untersuchung in dem verblei­benden Zeitraum abgeschlossen werden kann oder sicherheitshal­ber abzubrechen ist. Gefährdungen des Patienten durch ein uner­wartetes Ansprechen der Schutzeinrichtung sind somit ausge­schlossen.According to the invention, this object is achieved in that the x-ray emitter has a warning device which emits a warning signal when the threshold value of the liquid pressure is below the limit value which is decisive for the protective device. The threshold value is dimensioned such that the warning signal is emitted a sufficient period of time, for example 30 minutes, before the protective device is expected to respond follows, so that the operating personnel or the examining doctor can assess whether an started examination can be completed in the remaining period or should be terminated for safety reasons. Danger to the patient from an unexpected response of the protective device is therefore excluded.

Zur Messung des Schwellwertes des Flüssigkeitsdruckes weist die Warneinrichtung nach einer Variante der Erfindung einen Druck­fühler auf. Bei diesem kann es sich unter Umständen um einen Druckfühler handeln, der zugleich Bestandteil der Schutzein­richtung ist und dort zur Messung des Grenzwertes des Flüssig­keitsdruckes dient.According to a variant of the invention, the warning device has a pressure sensor for measuring the threshold value of the liquid pressure. Under certain circumstances this can be a pressure sensor which is also part of the protective device and is used there to measure the limit value of the liquid pressure.

Da je nach Einsatzgebiet des Röntgenstrahlers die Zeitdauer, für die dieser während einer Untersuchung in Betrieb sein muß, stark schwanken kann, ist nach einer Ausführungsform der Er­findung vorgesehen, daß der Schwellwert einstellbar ist. Es ist somit möglich, den zwischen der Abgabe des Warnsignales und dem Ansprechen der Schutzeinrichtung liegenden Zeitraum den jewei­ligen Bedürfnissen anzupassen. Eine solche Einstellung des Schwellwertes ist dann besonders einfach zu realisieren, wenn der Druckfühler kontinuierlich ein dem momentanen Wert des Druckes entsprechendes Signal abgibt und die Warneinrichtung Mittel zum Vergleichen des dem momentanen Flüssigkeitsdruck entsprechenden Signales mit einem dem Schwellwert des Flüssig­keitsdruckes entsprechenden Sollwert aufweist, da in diesem Fall zum Verändern des Schwellwertes lediglich der Sollwert verändert werden muß.Since, depending on the field of use of the x-ray emitter, the length of time for which the x-ray emitter must be in operation during an examination can vary greatly, it is provided according to one embodiment of the invention that the threshold value can be set. It is therefore possible to adapt the period of time between the issue of the warning signal and the response of the protective device to the respective needs. Such a setting of the threshold value is particularly easy to implement if the pressure sensor continuously emits a signal corresponding to the instantaneous value of the pressure and the warning device has means for comparing the signal corresponding to the instantaneous fluid pressure with a desired value corresponding to the threshold value of the fluid pressure, since in this If only the setpoint has to be changed to change the threshold value.

Nach einer anderen Ausführungsform der Erfindung ist vorgesehen, daß der Druckfühler ein Ausgangssignal abgibt, das sich bei Er­reichen des Schwellwertes des Flüssigkeitsdruckes sprunghaft ändert. Dabei kann es sich bei dem Ausgangssignal des Druckfüh­lers im einfachsten Fall um die Speisespannung einer optischen oder akustischen Signaleinrichtung handeln, die beim Erreichen des Schwellwertes an die Signaleinrichtung angelegt wird. Der Druckfühler ist in diesem Falle zweckmäßigerweise als druckemp­findlicher Schalter ausgeführt.According to another embodiment of the invention it is provided that the pressure sensor emits an output signal which changes abruptly when the threshold value of the liquid pressure is reached. In the simplest case, the output signal of the pressure sensor can be the supply voltage of an optical or acoustic signal device which is applied to the signal device when the threshold value is reached. The In this case, the pressure sensor is expediently designed as a pressure-sensitive switch.

Nach Varianten der Erfindung kann der Druckfühler dem Flüssig­keitsdruck im Gehäuse unmittelbar ausgesetzt oder, sofern das Gehäuse des Röntgenstrahlers einen nachgiebigen Wandabschnitt zum Ausgleich temperaturbedingter Volumenänderungen des Kühl­mittels aufweist, durch den nachgiebigen Wandabschnitt, der durch eine Membran gebildet sein kann, mittelbar betätigt sein. Im Falle der mittelbaren Betätigung des Druckfühlers durch einen nachgiebigen Wandabschnitt des Gehäuses kann der Druck­fühler durch einen einfachen, die Abgabe des Warnsignales be­wirkenden Schalter gebildet sein, dessen Lage zur Veränderung des Schwellwertes relativ zu dem nachgiebigen Wandabschnitt einstellbar ist.According to variants of the invention, the pressure sensor can be directly exposed to the liquid pressure in the housing or, if the housing of the x-ray emitter has a flexible wall section to compensate for temperature-related changes in volume of the coolant, can be actuated indirectly by the flexible wall section, which can be formed by a membrane. In the case of indirect actuation of the pressure sensor by a flexible wall section of the housing, the pressure sensor can be formed by a simple switch which causes the warning signal to be emitted, the position of which can be adjusted relative to the flexible wall section in order to change the threshold value.

Eine weitere Variante der Erfindung sieht für den Fall, daß der Druckfühler kontinuierlich ein dem Flüssigkeitsdruck in dem Ge­häuse entsprechendes Signal abgibt, vor, daß die Warneinrich­tungen Mittel zur Bestimmung und Anzeige der bis zum Erreichen des Grenzwertes des Flüssigkeitsdruckes verbleibenden Zeit auf­weist. Dem Bedienpersonal steht somit neben dem Warnsignal ständig eine Information über die bis zum Ansprechen der Schutzeinrichtung verbleibende Betriebszeit des Röntgenstrah­lers zur Verfügung.Another variant of the invention provides, in the event that the pressure sensor continuously emits a signal corresponding to the liquid pressure in the housing, that the warning devices have means for determining and displaying the time remaining until the limit value of the liquid pressure is reached. In addition to the warning signal, the operating personnel is therefore constantly provided with information about the operating time of the X-ray emitter remaining until the protective device responds.

In den beigefügten Zeichnungen sind Ausführungsbeispiele der Erfindung dargestellt. Es zeigen:

  • Fig. 1 und 2 erfindungsgemäße Röntgenstrahler in schematischer Darstellung,
  • Fig. 3 eine Einzelheit des erfindungsgemäßen Röntgenstrahlers nach Fig. 2 im Längsschnitt, und
  • Fig. 4 und 5 erfindungsgemäße Röntgenstrahler in schematischer Darstellung.
Exemplary embodiments of the invention are shown in the accompanying drawings. Show it:
  • 1 and 2 X-ray emitter according to the invention in a schematic representation,
  • 3 shows a detail of the X-ray emitter according to the invention according to FIG. 2 in longitudinal section, and
  • 4 and 5 X-ray emitter according to the invention in a schematic representation.

Die Fig. 1 zeigt einen erfindungsgemäßen Röntgenstrahler, der ein mit einer elektrisch isolierenden Flüssigkeit, z.B. Iso­lieröl, gefülltes Gehäuse 1 aufweist, in dem eine Röntgenröhre 2 angeordnet ist. Diese ist als Drehanoden-Röntgenröhre ausge­bildet, die einen Anodenteller 3, eine Kathode 4 und einen Mo­tor zum Antrieb der Drehanode enthält, der einen Rotor 5 und einen außerhalb des Glaskörpers der Röntgenröhre 2 auf einem Isolator 6 angeordneten Stator 7 aufweist. Das Gehäuse 1 be­sitzt ein Strahlendurchtrittsfenster 8 für die vom Anodenteller 3 ausgehende Röntgenstrahlung. Innerhalb des Gehäuses 1 ist eine Querwand 9 vorgesehen, an der eine den Innenraum des Ge­häuses 1 flüssigkeitsdicht verschließende, nach außen gewölbte nachgiebige Membran 10 vorgesehen ist, die dazu dient, tempera­turbedingte Volumenschwankungen der Flüssigkeit im Inneren des Gehäuses 1 aufzunehmen. Die zum Betrieb der Röntgenröhre erfor­derlichen Versorgungsspannungen, nämlich die Kathoden-Heizspan­nung, die Hochspannung und die zum Antrieb der Drehanode erfor­derliche Spannung, gibt eine Generatoreinrichtung 11 ab, wobei in Fig. 1 aus Gründen der Übersichtlichkeit nur eine einzige Leitung 12 zwischen der Generatoreinrichtung 11 und der Rönt­genröhre 2 dargestellt ist. Die Generatoreinrichtung 11 weist ein Bedienpult 11a auf, mittels dessen die Betriebsdaten der Röntgenröhre 2 eingestellt werden können und der Röntgenstrah­ler in Betrieb gesetzt werden kann.Fig. 1 shows an X-ray emitter according to the invention, which is coated with an electrically insulating liquid, e.g. Insulating oil, filled housing 1, in which an X-ray tube 2 is arranged. This is designed as a rotating anode X-ray tube, which contains an anode plate 3, a cathode 4 and a motor for driving the rotating anode, which has a rotor 5 and a stator 7 arranged outside the glass body of the X-ray tube 2 on an insulator 6. The housing 1 has a radiation passage window 8 for the X-rays emanating from the anode plate 3. Provided within the housing 1 is a transverse wall 9, on which there is provided a resilient membrane 10, which closes the interior of the housing 1 in a liquid-tight manner, and which serves to absorb temperature-related volume fluctuations of the liquid in the interior of the housing 1. The supply voltages required to operate the X-ray tube, namely the cathode heating voltage, the high voltage and the voltage required to drive the rotating anode, are provided by a generator device 11, with only a single line 12 between the generator device 11 and 11 in FIG. 1 for reasons of clarity the X-ray tube 2 is shown. The generator device 11 has a control panel 11a, by means of which the operating data of the x-ray tube 2 can be set and the x-ray emitter can be put into operation.

Um den infolge der Erwärmung der in dem Gehäuse 1 befindlichen Flüssigkeit durch die von der Röntgenröhre 2 im Betrieb abge­gebenen Verlustwärme auftretenden Anstieg des Flüssigkeitsdruk­kes im Gehäuse 1 unterhalb eines aus Sicherheitsgründen einzu­haltenden Grenzwertes zu halten, weist der Röntgenstrahler eine Schutzeinrichtung auf, die dessen Betrieb bei einem den Grenz­wert überschreitenden Flüssigkeitsdruck im Gehäuse 1 unterbin­det. Im einzelnen umfaßt die Schutzeinrichtung einen druckemp­findlichen Schalter 13 mit einem Drucksensor 13a und einem Schaltkontakt 13b, der derart an dem Gehäuse 1 angebracht ist, daß der den Schaltkontakt 13b betätigenden Drucksensor 13a dem Flüssigkeitsdruck im Inneren des Gehäuses 1 unmittelbar aus­ gesetzt ist, ein Schütz 14 zur Anschaltung der Röntgenröhre 2 an die Generatoreinrichtung 11, das Kontakte 14a, von denen der Übersichtlichkeit halber nur einer dargestellt ist, und eine Erregerwicklung 14b aufweist, und eine Spannungsquelle 15, an die die Erregerwicklung 14b des Schützes 14 mittels des Schalt­kontaktes 13b des druckempfindlichen Schalters 13 anschaltbar ist.In order to keep the rise in the liquid pressure in the housing 1 due to the heating of the liquid in the housing 1 due to the heat loss emitted by the X-ray tube 2 in operation below the limit value to be observed for safety reasons, the X-ray emitter has a protective device which prevents it from operating the liquid pressure in the housing 1 exceeds the limit value. In detail, the protective device comprises a pressure-sensitive switch 13 with a pressure sensor 13a and a switch contact 13b, which is attached to the housing 1 in such a way that the pressure sensor 13a actuating the switch contact 13b directly detects the liquid pressure inside the housing 1 a contactor 14 for connecting the X-ray tube 2 to the generator device 11, the contacts 14a, of which only one is shown for clarity, and an excitation winding 14b, and a voltage source 15 to which the excitation winding 14b of the contactor 14 is connected of the switch contact 13b of the pressure-sensitive switch 13 can be switched on.

Die Wirkungsweise der Schutzeinrichtung ist derart, daß, solan­ge der Flüssigkeitsdruck im Gehäuse 1 unterhalb des Grenzwertes liegt, der Kontakt 14a des Schützes geschlossen und die Rönt­genröhre 2 somit an die Generatoreinrichtung 11 angeschaltet ist und mit mittels des Bedienpultes 11a eingestellten Be­triebsdaten betrieben werden kann. Sobald der Flüssigkeitsdruck im Inneren des Gehäuses 1 den Grenzwert überschreitet, öffnet der Schaltkontakt 14b des druckempfindlichen Schalters 13, wo­rauf das Schütz 14 abfällt und dessen Kontakt 14a öffnet, so daß der Betrieb des Röntgenstrahlers unterbunden ist.The protective device works in such a way that as long as the liquid pressure in the housing 1 is below the limit value, the contact 14a of the contactor is closed and the X-ray tube 2 is thus connected to the generator device 11 and can be operated with operating data set by means of the control panel 11a. As soon as the liquid pressure inside the housing 1 exceeds the limit value, the switch contact 14b of the pressure-sensitive switch 13 opens, whereupon the contactor 14 drops out and its contact 14a opens, so that the operation of the X-ray emitter is prevented.

Fällt infolge der Abkühlung des Röntgenstrahlers der Flüssig­keitsdruck im Gehäuse 1 unter den Grenzwert, schließt der Schaltkontakt 13b des druckempfindlichen Schalters wieder, worauf das Schütz 14 anzieht und der Röntgenstrahler wieder be­triebsbereit ist.If the liquid pressure in the housing 1 falls below the limit value as a result of the cooling of the X-ray emitter, the switch contact 13b of the pressure-sensitive switch closes again, whereupon the contactor 14 picks up and the X-ray emitter is ready for operation again.

Um auf das bevorstehende Ansprechen der Schutzeinrichtung auf­merksam zu machen, weist der erfindungsgemäße Röntgenstrahler eine Warneinrichtung auf, welche bei einem unterhalb des für die Schutzeinrichtung maßgebenden Grenzwertes liegenden Schwell­wert des Flüssigkeitsdruckes im Gehäuse 1 ein Warnsignal ab­gibt. Im Falle des in Fig. 1 dargestellten Ausführungsbeispie­les besitzt die Warneinrichtung einen zweiten druckempfind­lichen Schalter 16, dessen Drucksensor 16a ebenfalls an der Innenwand des Gehäuses 1 angebracht und dem im Gehäuse 1 herr­schenden Flüssigkeitsdruck unmittelbar ausgesetzt ist und des­sen doppelpoliger Schaltkontakt 16b bei Erreichen des Schwell­wertes des Flüssigkeitsdruckes im Inneren des Gehäuses 1 schließt, so daß eine Warnlampe 17 und ein akustischer Signal­geber 18 an die Spannungsquelle 15 angeschaltet sind. Der Schwellwert, bei dem die Warneinrichtung anspricht, ist je nach Einsatzgebiet des Röntgenstrahlers so bemessen, daß das Warn­signal zu einem Zeitpunkt abgegeben wird, der ausreichend lange vor dem Ansprechen der Schutzeinrichtung liegt, um dem Bedien­personal eine Entscheidung darüber zu ermöglichen, ob eine be­absichtigte Untersuchung noch begonnen werden bzw. eine bereits in der Durchführung begriffene Untersuchung noch beendet werden kann oder aus Sicherheitsgründen abzubrechen ist.In order to draw attention to the impending response of the protective device, the X-ray emitter according to the invention has a warning device which emits a warning signal when the threshold value of the liquid pressure in the housing 1 is less than the limit value which is decisive for the protective device. In the case of the exemplary embodiment shown in FIG. 1, the warning device has a second pressure-sensitive switch 16, the pressure sensor 16a of which is also attached to the inner wall of the housing 1 and is directly exposed to the liquid pressure prevailing in the housing 1 and the double-pole switch contact 16b when the threshold value of the liquid pressure is reached inside the housing 1 closes, so that a warning lamp 17 and an acoustic signal generator 18 are connected to the voltage source 15. The threshold value at which the warning device responds is dimensioned, depending on the area of application of the x-ray emitter, in such a way that the warning signal is emitted at a point in time which is sufficiently long before the protective device responds in order to enable the operating personnel to decide whether an intended examination is to be carried out can still be started, or an examination that is already being carried out can still be ended or has to be stopped for safety reasons.

Das in Fig. 2 dargestellte Ausführungsbeispiel unterscheidet sich von dem zuvor beschriebenen dadurch, daß als Druckfühler der Warneinrichtung ein Tastschalter 19 vorgesehen ist, der mittels der Membran 10, die sich mit zunehmendem Flüssigkeits­druck im Gehäuse 1 stärker nach außen wölbt, betätigt wird, und zwar derart, daß die Membran 10 auf einen Stößel 20 des Tast­schalters 19 einwirkt, der bei einer dem Schwellwert des Flüs­sigkeitsdruckes entsprechenden Auswölbung der Membran den Schaltkontakt 21 des Tastschalters 19 schließt, was zur Folge hat, daß der akustische Signalgeber 18 an die Spannungsquelle 15 angeschaltet ist.The embodiment shown in Fig. 2 differs from that previously described in that a pushbutton switch 19 is provided as the pressure sensor of the warning device, which is actuated by means of the membrane 10, which bulges outward with increasing fluid pressure in the housing 1, namely such that the membrane 10 acts on a plunger 20 of the pushbutton switch 19, which closes the switching contact 21 of the pushbutton switch 19 when the membrane bulges corresponding to the threshold value of the liquid pressure, with the result that the acoustic signal transmitter 18 is switched on to the voltage source 15 .

Wie aus der Fig. 3 ersichtlich ist, weist der Tastschalter 19 einen den Stößel 20 umgebenden Gewindeansatz 22 auf, der in ei­ner Bohrung 23 eines Gehäuseteiles 24 mittels der Muttern 25 gehalten ist. Um den Schwellwert des Druckes, bei dem die Schaltkontakte 21 des Tastschalters 19 geschlossen werden und damit die Abgabe eines Warnsignales erfolgt, einstellen zu kön­nen, kann die Lage des Tastschalters 19 relativ zur Membran 10 in deren Bewegungsrichtung durch Verstellen der Muttern 25 ver­ändert werden. Dabei liegt der Schwellwert des Flüssigkeits­druckes, bei dem die Warneinrichtung anspricht, umso niedriger, je weiter der Tastschalter 19 in Richtung auf die Membran 10 verstellt wird.As can be seen from FIG. 3, the pushbutton switch 19 has a threaded attachment 22 surrounding the plunger 20, which is held in a bore 23 of a housing part 24 by means of the nuts 25. In order to be able to set the threshold value of the pressure at which the switch contacts 21 of the pushbutton switch 19 are closed and thus a warning signal is given, the position of the pushbutton switch 19 relative to the diaphragm 10 can be changed in its direction of movement by adjusting the nuts 25. The threshold value of the liquid pressure at which the warning device responds is the lower the further the pushbutton switch 19 is adjusted in the direction of the membrane 10.

Um Beschädigungen bzw. Verschleiß der Membran zu vermeiden, ist diese in demjenigen Bereich, in dem sie mit dem Stößel 20 des Tastschalters 19 in Eingriff kommt, mit einem Druckstück 26 versehen.To avoid damage or wear of the membrane provide this with a pressure piece 26 in the area in which it comes into engagement with the plunger 20 of the pushbutton switch 19.

Der in der Fig. 4 dargestellte Röntgenstrahler unterscheidet sich von den zuvor beschriebenen dadurch, daß der Druckfühler 27 der Warneinrichtung, der z.B. nach dem piezoelektrischen Prinzip arbeitet, kontinuierlich ein dem momentanen Wert des Flüssigkeitsdruckes im Gehäuse 1 entsprechendes Signal abgibt. Außer dem Druckfühler 27 weist die Warneinrichtung einen Ver­gleicher 28 auf, der z.B. durch einen als Komparator geschal­teten Operationsverstärker gebildet sein kann. Desweiteren ist eine Spannungsquelle 29 mit daran angeschlossenem Potentiometer 30 vorgesehen, wobei mittels des Schleifers des Potentiometers 30 eine Spannung abgegriffen werden kann, die einen dem Schwellwert des Flüssigkeitsdruckes entsprechenden Sollwert darstellt. Diese Spannung wird dem einen und die von dem Druck­fühler 27 gelieferte Signalspannung dem anderen Eingang des Vergleichers 28 zugeführt wird. Sobald der Flüssigkeitsdruck im Inneren des Gehäuses 1 den Schwellwert und somit die von dem Druckfühler 27 gelieferte Spannung den mittels des Potentio­meters 30 eingestellten Sollwert übersteigt, ändert sich das Ausgangssignal des Vergleichers 28. Dieses steuert eine Schaltstufe 31 an, mittels derer eine Warnlampe 17 an die von der Spannungsquelle 29 abgegebene Speisespannung gelegt wird. Die Schaltstufe 31 kann z.B. als gewöhnliches elektromechani­sches Relais oder auch als Halbleiter-Schalter ausgeführt sein. Sofern dies erforderlich ist, kann zwischen dem Druckfühler 27 und dem entsprechenden Eingang des Vergleichers 28 ein Verstär­ker für das von dem Druckfühler 27 abgegebene Signal vorgesehen sein. Die mittels des Potentiometers 30 einstellbare, als Soll­wert dienene Spannung ist so bemessen, daß sie stets unterhalb einer Spannung liegt, die dem für das Ansprechen der Schutzein­richtung maßgebenden Grenzwert des Flüssigkeitsdruckes im Inne­ren des Gehäuses 1 entspricht. Dies kann entweder durch geeig­nete Wahl der von der Spannungsquelle 29 gelieferten Spannung oder durch einen geeignet bemessenen, in Fig. 4 nicht darge­ stellten Vorwiderstand für das Potentiometer 30 erreicht wer­den. Es wird deutlich, daß mittels der beschriebenen Ausbildung der Warneinrichtung der Schwellwert, bei dem diese anspricht bzw. der Zeitraum, der zwischen dem Ansprechen der Warneinrich­tung und der Schutzeinrichtung verstreicht, auf einfache Weise den jeweiligen Bedürfnissen angepaßt werden kann.The X-ray emitter shown in FIG. 4 differs from the ones described above in that the pressure sensor 27 of the warning device, which works, for example, according to the piezoelectric principle, continuously emits a signal corresponding to the instantaneous value of the liquid pressure in the housing 1. In addition to the pressure sensor 27, the warning device has a comparator 28, which can be formed, for example, by an operational amplifier connected as a comparator. Furthermore, a voltage source 29 with a potentiometer 30 connected to it is provided, it being possible to tap a voltage by means of the slider of the potentiometer 30, which represents a desired value corresponding to the threshold value of the liquid pressure. This voltage is supplied to one and the signal voltage supplied by the pressure sensor 27 to the other input of the comparator 28. As soon as the liquid pressure in the interior of the housing 1 exceeds the threshold value and thus the voltage supplied by the pressure sensor 27 exceeds the target value set by means of the potentiometer 30, the output signal of the comparator 28 changes. This controls a switching stage 31, by means of which a warning lamp 17 connects to the is supplied from the voltage source 29 supplied supply voltage. The switching stage 31 can be designed, for example, as a conventional electromechanical relay or as a semiconductor switch. If this is necessary, an amplifier for the signal emitted by the pressure sensor 27 can be provided between the pressure sensor 27 and the corresponding input of the comparator 28. The voltage which can be set by means of the potentiometer 30 and serves as a setpoint value is dimensioned such that it is always below a voltage which corresponds to the limit value of the liquid pressure in the interior of the housing 1 which is decisive for the response of the protective device. This can be done either by a suitable choice of the voltage supplied by the voltage source 29 or by a suitably dimensioned one, not shown in FIG. 4 set series resistance for the potentiometer 30 can be achieved. It is clear that by means of the described design of the warning device, the threshold value at which it responds or the period of time that elapses between the response of the warning device and the protective device can be easily adapted to the respective needs.

In Fig. 5 ist ein erfindungsgemäßer Röntgenstrahler darge­stellt, bei dem ein einziger Druckfühler 32 vorgesehen ist, der sowohl Teil der Warn- als auch der Schutzeinrichtung ist. Aus­serdem ist eine Datenverarbeitungseinrichtung 33 vorgesehen, die ebenfalls Bestandteil sowohl der Warn- als auch der Schutz­einrichtung ist, also die Abgabe eines Warnsignales veranlaßt, wenn der Flüssigkeitsdruck im Inneren des Gehäuses 1 den Schwellwert übersteigt, und den Betrieb des Röntgenstrahlers unterbindet, wenn der Flüssigkeitsdruck im Inneren des Gehäuses 1 den Grenzwert überschreitet.An X-ray emitter according to the invention is shown in FIG. 5, in which a single pressure sensor 32 is provided, which is both part of the warning and the protective device. In addition, a data processing device 33 is provided, which is also part of both the warning and the protective device, i.e. triggers the issuance of a warning signal when the liquid pressure inside the housing 1 exceeds the threshold value, and prevents the operation of the X-ray emitter when the liquid pressure in the Inside the housing 1 exceeds the limit.

Im einzelnen umfaßt die Datenverarbeitungseinrichtung 33 einen Multiplexer 34, einen Analog/Digital-Wandler 35, einen Rechen­einrichtung 36, einen Speicher 37, eine Ausgabeeinheit 38 und eine Tastatur 39.In particular, the data processing device 33 comprises a multiplexer 34, an analog / digital converter 35, a computing device 36, a memory 37, an output unit 38 and a keyboard 39.

Mittels der mit der Recheneinrichtung 36 verbundenen Tastatur 39 besteht die Möglichkeit, den Grenz- und den Schwellwert des Flüssigkeitsdruckes im Gehäuse 1 einzugeben. Diese werden dann von der Recheneinrichtung 36 in dem Speicher 37 abgelegt und stehen dort zur Verfügung. Außerdem können mittels der Tastatur 39 die Betriebsdaten für den Röntgenstrahler gewählt werden, wobei die Recheneinrichtung 36 über die Ausgabeeinheit 38 auf die Generatoreinrichtung 11 einwirkt und diese veranlaßt, die entsprechenden Spannungen für die Röntgenröhre 2 bereitzustel­len. Die tatsächlich von der Generatoreinrichtung 11 abgegebe­nen Spannungen werden einem Multiplexer 34 zugeführt, dem aus­serdem das von dem Druckfühler 32 abgegebene Signal zugeführt wird. Von dem Multiplexer 34 gelangen diese zu dem Analog/Digi­tal-Wandler 35 und von dort zu der Recheneinrichtung 36. Diese vergleicht ständig den momentan im Inneren des Gehäuses 1 herr­schenden Flüssigkeitsdruck mit den in dem Speicher 37 abgespei­cherten Werten für den Grenz- bzw. Schwellwert des Flüssig­keitsdruckes. Sobald der Flüssigkeitsdruck im Gehäuse 1 den Schwellwert übersteigt, wirkt die Recheneinrichtung 36 über die Ausgabeeinheit 38 auf die Schaltstufen 40 und 41 derart ein, daß eine Signallampe 17 und ein akustischer Signalgeber 18 mit einer Spannungsquelle 42 verbunden sind. Übersteigt der im Ge­häuse 1 herrschende Flüssigkeitsdruck den Grenzwert, wirkt die Recheneinrichtung 36 über die Ausgabeeinheit 38 auf die Schalt­stufe 43 derart ein, daß die Erregerspule 14b des Schützes 14 von der Spannungsquelle 42 getrennt wird, was zur Folge hat, daß der Kontakt 14a des Schützes öffnet und die Röntgenröhre 2 von der Generatoreinrichtung 11 getrennt ist, so daß der Be­trieb des Röntgenstrahlers unterbunden ist.Using the keyboard 39 connected to the computing device 36, it is possible to enter the limit and the threshold value of the liquid pressure in the housing 1. These are then stored in the memory 37 by the computing device 36 and are available there. In addition, the operating data for the X-ray emitter can be selected using the keyboard 39, the computing device 36 acting on the generator device 11 via the output unit 38 and causing the latter to provide the corresponding voltages for the X-ray tube 2. The voltages actually emitted by the generator device 11 are fed to a multiplexer 34, to which the signal emitted by the pressure sensor 32 is also fed. From the multiplexer 34, they arrive at the analog / digital converter 35 and from there to the computing device 36 continuously compares the liquid pressure currently prevailing in the interior of the housing 1 with the values stored in the memory 37 for the limit or threshold value of the liquid pressure. As soon as the liquid pressure in the housing 1 exceeds the threshold value, the computing device 36 acts via the output unit 38 on the switching stages 40 and 41 in such a way that a signal lamp 17 and an acoustic signal generator 18 are connected to a voltage source 42. If the liquid pressure prevailing in the housing 1 exceeds the limit value, the computing device 36 acts via the output unit 38 on the switching stage 43 in such a way that the excitation coil 14b of the contactor 14 is disconnected from the voltage source 42, with the result that the contact 14a of the contactor opens and the X-ray tube 2 is separated from the generator device 11, so that the operation of the X-ray emitter is prevented.

Außerdem berechnet die Recheneinrichtung 36 aus dem momentanen Wert des Flüssigkeitsdruckes und den ihr über den Multiplexer 34 und den Analog/Digital-Wandler 35 zugeführten Werten für die Betriebsdaten der Röntgenröhre 2 sowie dem gespeicherten Grenz­wert des Flüssigkeitsdruckes ständig den bis zu dessen Errei­chen verbleibenden Zeitraum und zeigt diesen über die Ausgabe­einrichtung 38 auf einem Zeitdisplay 44 an.In addition, the computing device 36 continuously calculates from the instantaneous value of the liquid pressure and the values supplied to it via the multiplexer 34 and the analog / digital converter 35 for the operating data of the X-ray tube 2 and the stored limit value of the liquid pressure and shows the period of time until it is reached this via the output device 38 on a time display 44.

Bei der Ermittlung der bis zum Ansprechen der Schutzeinrichtung verbleibenden Zeit wird von der Erkenntnis Gebrauch gemacht, daß dem momentan im Gehäuse 1 herrschenden Flüssigkeitsdruck und dem Grenzwert des Flüssigkeitsdruckes bestimmte Temperatu­ren zugeordnet sind, wobei der Differenz dieser Temperaturen eine bestimmte Wärmemenge zugeordnet werden kann, die erforder­lich ist, um das in dem Gehäuse 1 befindliche Isolieröl von der dem momentanen Flüssigkeitsdruck entsprechenden Temperatur auf die dem Grenzwert des Flüssigkeitsdruckes entsprechende Tempe­ratur aufzuheizen. Da außerdem aus den Betriebsdaten der Rönt­genröhre 2 die pro Zeiteinheit anfallende Verlustwärme errech­net werden kann, besteht somit die Möglichkeit, den bis zum Er­reichen des Grenzwertes des Flüssigkeitsdruckes, also bis zum Ansprechen der Schutzschaltung verbleibenden Zeitraum zu be­rechnen. Die Verlängerung dieses Zeitraumes infolge der von dem Röntgenstrahler an die Umgebung abgegebene Wärmemenge kann durch einen einfachen Iterationsvorgang ebenfalls berücksich­tigt werden.When determining the time remaining until the protective device responds, use is made of the knowledge that certain temperatures are assigned to the liquid pressure currently prevailing in the housing 1 and the limit value of the liquid pressure, the difference between these temperatures being able to be assigned a certain amount of heat that is required is to heat the insulating oil located in the housing 1 from the temperature corresponding to the instantaneous liquid pressure to the temperature corresponding to the limit value of the liquid pressure. Since, in addition, the heat loss per unit time can be calculated from the operating data of the X-ray tube 2, there is thus the possibility of reaching the limit value of the liquid pressure, ie until Response of the protection circuit to calculate the remaining period. The extension of this period due to the amount of heat given off by the X-ray emitter to the surroundings can also be taken into account by a simple iteration process.

Auf dem Zeitdisplay 44 erscheint somit der bei den momentan eingestellten Betriebsdaten der Röntgenröhre 2 bis zum Anspre­chen der Schutzeinrichtung verbleibende Zeitraum. Werden die Betriebsdaten der Röntgenröhre 2 in einer Weise verändert, die sich auf die von der Röntgenröhre 2 pro Zeiteinheit abgegebene Verlustwärme auswirken, wird dies umgehend bei der Berechnung des bis zum Ansprechen der Schutzeinrichtung verbleibenden Zeitraumes berücksichtigt, so daß auch bei Veränderungen der Betriebsdaten der Röntgenröhre 2 während der Untersuchung dem Zeitdisplay 44 stets eine korrekte Information zu entnehmen ist.The time remaining in the currently set operating data of the X-ray tube 2 until the protective device responds appears on the time display 44. If the operating data of the X-ray tube 2 is changed in a way that affects the heat loss emitted by the X-ray tube 2 per unit of time, this is immediately taken into account in the calculation of the time remaining until the protective device responds, so that changes in the operating data of the X-ray tube also occur 2 correct information can always be found on the time display 44 during the examination.

Claims (10)

1. Röntgenstrahler, welcher ein mit einer elektrisch isolieren­den Flüssigkeit gefülltes, mit einem Strahlendurchtrittsfenster (8) versehenes Gehäuse (1) und eine in diesem angeordnete Rönt­genröhre (2) sowie eine den Betrieb des Röntgenstrahlers bei einem einen Grenzwert überschreitenden Flüssigkeitsdruck im Ge­häuse (1) unterbindende Schutzeinrichtung (13, 14, 32, 33) auf­weist, dadurch gekennzeichnet, daß der Röntgenstrahler eine Warneinrichtung (16, 17, 18, 19, 27, 28, 30, 32, 33, 44) aufweist, welche bei einem unterhalb des für die Schutzeinrichtung (13, 14, 32, 33) maßgebenden Grenz­wertes liegenden Schwellwert des Flüssigkeitsdruckes ein Warn­signal abgibt.1. X-ray emitter, which has a housing (1) filled with an electrically insulating liquid and provided with a radiation passage window (8) and an X-ray tube (2) arranged in the latter, and an operation of the X-ray emitter at a liquid pressure in the housing (1) that exceeds a limit value. protective device (13, 14, 32, 33), characterized in that the X-ray emitter has a warning device (16, 17, 18, 19, 27, 28, 30, 32, 33, 44), which at a below the for the protective device (13, 14, 32, 33) of the threshold value of the liquid pressure is a warning signal. 2. Röntgenstrahler nach Anspruch 1, dadurch ge­kennzeichnet, daß die Warneinrichtung zur Messung des Schwellwertes des Flüssigkeitsdruckes einen Druckfühler (16, 19, 27, 32) aufweist.2. X-ray emitter according to claim 1, characterized in that the warning device for measuring the threshold value of the liquid pressure has a pressure sensor (16, 19, 27, 32). 3. Röntgenstrahler nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß der Schwellwert einstellbar ist.3. X-ray emitter according to claim 1 or 2, characterized in that the threshold value is adjustable. 4. Röntgenstrahler nach Anspruch 2 oder 3, dadurch gekennzeichnet, daß der Druckfühler (27, 32) kontinuierlich ein dem momentanen Wert des Flüssigkeitsdruckes entsprechendes Signal abgibt und die Warneinrichtung Mittel (28, 33) zum Vergleichen des dem momentanen Flüssigkeitsdruck entsprechenden Signales mit einem dem Schwellwert des Flüssig­keitsdruckes entsprechenden Sollwert aufweist.4. X-ray emitter according to claim 2 or 3, characterized in that the pressure sensor (27, 32) continuously emits a signal corresponding to the instantaneous value of the fluid pressure and the warning device means (28, 33) for comparing the signal corresponding to the instantaneous fluid pressure with a Has threshold value of the liquid pressure corresponding setpoint. 5. Röntgenstrahler nach Anspruch 2 oder 3, dadurch gekennzeichnet, daß der Druckfühler (16, 19) ein Ausgangssignal abgibt, das sich bei Erreichen des Schwell­wertes des Flüssigkeitsdruckes sprunghaft ändert.5. X-ray emitter according to claim 2 or 3, characterized in that the pressure sensor (16, 19) emits an output signal which changes abruptly when the threshold value of the liquid pressure is reached. 6. Röntgenstrahler nach einem der Ansprüche 2 bis 5, da­durch gekennzeichnet, daß der Druckfühler (16, 27, 32) dem Flüssigkeitsdruck im Gehäuse (1) unmittelbar ausgesetzt ist.6. X-ray emitter according to one of claims 2 to 5, characterized in that the pressure sensor (16, 27, 32) is directly exposed to the liquid pressure in the housing (1). 7. Röntgenstrahler nach einem der Ansprüche 2 bis 5, dessen Ge­häuse (1) einen nachgiebigen Wandabschnitt (10) zum Ausgleich temperaturbedingter Volumenänderungen des Kühlmittels aufweist, dadurch gekennzeichnet, daß der Druck­fühler (19) durch den nachgiebigen Wandabschnitt (10) mittelbar betätigt ist.7. X-ray emitter according to one of claims 2 to 5, the housing (1) of which has a flexible wall section (10) to compensate for temperature-related changes in volume of the coolant, characterized in that the pressure sensor (19) is indirectly actuated by the flexible wall section (10). 8. Röntgenstrahler nach Anspruch 7, dadurch ge­kennzeichnet, daß der nachgiebige Wandabschnitt des Gehäuses (1) durch eine Membran (10) gebildet ist.8. X-ray emitter according to claim 7, characterized in that the resilient wall section of the housing (1) is formed by a membrane (10). 9. Röntgenstrahler nach Anspruch 7 oder 8, dadurch gekennzeichnet, daß der Druckfühler durch einen durch den nachgiebigen Wandabschnitt (10) des Gehäuses (1) be­tätigten Schalter (19) gebildet ist, dessen Lage relativ zu dem nachgiebigen Wandabschnitt (10) einstellbar ist.9. X-ray emitter according to Claim 7 or 8, characterized in that the pressure sensor is formed by a switch (19) actuated by the flexible wall section (10) of the housing (1), the position of which can be adjusted relative to the flexible wall section (10). 10. Röntgenstrahler nach einem der Ansprüche 2 bis 4 und 6 bis 8, dadurch gekennzeichnet, daß der Druckfühler (32) kontinuierlich ein dem Flüssigkeitsdruck in dem Gehäuse (1) entsprechendes Signal abgibt und die Warnein­richtung Mittel (33, 44) zur Bestimmung und Anzeige der bis zum Erreichen des Grenzwertes des Flüssigkeitsdruckes verbleibenden Zeit aufweist.10. X-ray emitter according to one of claims 2 to 4 and 6 to 8, characterized in that the pressure sensor (32) continuously emits a signal corresponding to the liquid pressure in the housing (1) and the warning device means (33, 44) for determination and display the time remaining until the limit of the liquid pressure is reached.
EP88101814A 1987-02-20 1988-02-08 X-ray emitter Expired - Lifetime EP0283688B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3705544 1987-02-20
DE3705544 1987-02-20

Publications (2)

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EP0283688A1 true EP0283688A1 (en) 1988-09-28
EP0283688B1 EP0283688B1 (en) 1992-11-11

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EP88101814A Expired - Lifetime EP0283688B1 (en) 1987-02-20 1988-02-08 X-ray emitter

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US (1) US4862489A (en)
EP (1) EP0283688B1 (en)
JP (1) JPH0515760Y2 (en)
DE (1) DE3875764D1 (en)

Cited By (3)

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EP0397562A1 (en) * 1989-05-10 1990-11-14 General Electric Cgr S.A. Safety device for X-ray installation
EP0526319A1 (en) * 1991-07-31 1993-02-03 General Electric Cgr S.A. Safety device in an x-ray apparatus
DE102015212393A1 (en) 2015-07-02 2017-01-05 Siemens Healthcare Gmbh Container for an X-ray generator with a pressure compensation device and X-ray generator with a container

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Publication number Priority date Publication date Assignee Title
US5056129A (en) * 1989-09-12 1991-10-08 The United States Of America As Represented By The United States Department Of Energy Apparatus for monitoring X-ray beam alignment
DE19707726C1 (en) * 1997-02-26 1998-09-24 Siemens Ag X-ray source with safety device
DE19707996A1 (en) * 1997-02-27 1998-09-10 Siemens Ag Warning device for X-ray source
DE10314538A1 (en) * 2003-03-31 2004-10-28 Siemens Ag X-ray tube pressure monitoring method in which the pressure inside the tube is measured, based on measurements of heating and tube currents and their comparison with calibration values, to predict remaining tube service life
CN109646029A (en) * 2019-01-15 2019-04-19 麦默真空技术无锡有限公司 A kind of control method and system of CT bulb fault pre-alarming

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DE738296C (en) * 1937-02-28 1943-08-10 Electricitaetsgesellschaft San Device to avoid local overheating in spatially adjustable containers for X-ray tubes filled with an insulating and coolant
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GB834719A (en) * 1957-11-04 1960-05-11 William Warren Triggs Safety x-ray tube housing
GB2018019A (en) * 1978-03-31 1979-10-10 Philips Nv Cooling x-ray tubes

Cited By (8)

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Publication number Priority date Publication date Assignee Title
EP0397562A1 (en) * 1989-05-10 1990-11-14 General Electric Cgr S.A. Safety device for X-ray installation
FR2646982A1 (en) * 1989-05-10 1990-11-16 Gen Electric Cgr SAFETY DEVICE FOR A RADIOGENIC ASSEMBLY
US5008916A (en) * 1989-05-10 1991-04-16 General Electric Cgr S.A. Safety device for radiogenic unit
EP0526319A1 (en) * 1991-07-31 1993-02-03 General Electric Cgr S.A. Safety device in an x-ray apparatus
FR2679762A1 (en) * 1991-07-31 1993-02-05 Gen Electric Cgr SAFETY DEVICE IN A RADIOLOGY APPARATUS.
US5285492A (en) * 1991-07-31 1994-02-08 General Electric Cgr S.A. Safety device in a radiology machine
DE102015212393A1 (en) 2015-07-02 2017-01-05 Siemens Healthcare Gmbh Container for an X-ray generator with a pressure compensation device and X-ray generator with a container
DE102015212393B4 (en) 2015-07-02 2021-08-12 Siemens Healthcare Gmbh Container for an X-ray generator with a pressure compensation device and X-ray generator with a container

Also Published As

Publication number Publication date
US4862489A (en) 1989-08-29
JPS63133098U (en) 1988-08-31
DE3875764D1 (en) 1992-12-17
JPH0515760Y2 (en) 1993-04-26
EP0283688B1 (en) 1992-11-11

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