JP2007080568A - X-ray generation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact X-ray generation device which can be continuously used for a long time. <P>SOLUTION: The X-ray generation device comprises an enclosure 4 which contains an X-ray tube 1 and insulation oil 2. A heat transferring component 3 made of aluminum nitride is disposed in close contact between an anode electrode 10 of the X-ray tube 1 and the enclosure 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an X-ray generator, and more particularly to a small X-ray generator used for medical examinations and the like.

  The X-ray generator applies high voltage between the anode (anode) and cathode (cathode) sealed in an X-ray tube, which is a vacuum glass container, and collides the thermoelectrons emitted from the cathode with the anode. To generate X-rays.

  At this time, most of the energy of the thermoelectrons that collide with the anode is converted into heat, so that the X-ray tube is heated to a high temperature and eventually breaks. For this reason, a general X-ray generator is provided with a cooling system for cooling the X-ray tube.

  FIG. 3 shows a structure of a small-sized apparatus used for medical examination or the like among conventional X-ray generation apparatuses. FIG. 3 is a cross-sectional view from the side of the X-ray generator.

  This X-ray generator is mainly composed of an X-ray tube 40 and a metal enclosure 42 containing insulating oil 41, and both electrodes of the X-ray tube 40 are provided by a high voltage generator 48 installed in the lower part. A high voltage is applied to the target to irradiate the object placed above through the X-ray emission port 43 with X-rays.

  The side surface of the X-ray tube 40 is covered with a cylindrical insulating sleeve 44 for insulating a high voltage except for the X-ray radiation port 43 and a cylindrical shielding body 45 for shielding scattered X-rays. They are installed so as to be immersed in the insulating oil 41 as a whole.

  In addition, an insulating plate 46 for insulating high voltage is provided on the inner surface of the enclosure 42, and a shielding plate 47 for shielding scattered X-rays is provided on the outer surface.

  In such an X-ray generator, the heat generated in the anode electrode 49 and the like of the X-ray tube 40 is first transmitted to the insulating oil 41 filled in the surroundings, and the insulating oil 41 heated up thereby is partially By causing convection and transferring heat to the enclosed container 42, it is discharged to the outside.

  In order to prevent the X-ray tube 40 from being damaged due to a high temperature, the X-ray generator is provided with an interlock mechanism (not shown), and the temperature of the X-ray tube 40 has a predetermined threshold value. If it exceeds, the high voltage generator 48 is shut off and the X-ray generator is automatically stopped.

  In the recent medical examination field, there is a need to use a small X-ray generator continuously for a long time due to a significant increase in the number of patients and the introduction of examination methods that continuously pulse X-rays. It is growing.

  However, in the conventional X-ray generator, when a new cooling system is not provided outside, the cooling performance is limited because the X-ray tube is cooled through the insulating oil as described above. If the X-ray tube exceeds the threshold temperature due to long-term use, etc., the interlock will be applied and the device will stop, and you will have to wait for a while until the temperature of the X-ray tube drops. There was a problem.

  The present invention has been made in view of such problems, and it can be used continuously for a long time by improving the cooling performance without greatly changing the size of the conventional X-ray generator. A wire generator is provided.

In order to achieve the above object, the present invention provides an X-ray generator in which an X-ray tube having an anode electrode is housed in a metal enclosure, and the enclosure is filled with insulating oil.
The X-ray generator is characterized in that a heat transfer device for transferring heat generated in the anode electrode is provided in close contact with the anode electrode and the inner surface of the enclosure.

  According to the invention configured as described above, since the heat is directly transferred from the anode electrode that generates most of the heat of the X-ray tube to the enclosure via the heat transfer device, the entire apparatus is more than conventional. The cooling performance can be greatly improved with almost no change in size.

  Moreover, this invention is an X-ray generator of Claim 1 with which the said heat exchanger was formed with aluminum nitride.

  Aluminum nitride is preferable as a material for the heat exchanger because it is excellent in thermal conductivity and insulation resistance.

Furthermore, the present invention provides an X-ray tube having a cathode electrode and an anode electrode at both ends, an insulating oil in which the X-ray tube is immersed, and a metal made of the X-ray tube and the insulating oil. An X-ray generator comprising an enclosure, wherein the X-ray tube includes a hollow cylindrical insulator and shield that surround a side surface, a cup-shaped insulator that covers the cathode electrode, and a first insulator A cup-shaped shield,
A heat exchanger made of aluminum nitride provided in close contact with the anode electrode and the enclosure, and a second cup-shaped shield covering the anode electrode and the heat exchanger, and the enclosure Is an X-ray generator provided with a heat sink on the outer surface.

  According to the invention configured as described above, it is possible to greatly improve the cooling performance and efficiently prevent leakage of scattered X-rays from the X-ray tube.

  In the X-ray generator according to the present invention, a heat transfer device is disposed between the anode electrode from which most of the heat generated in the X-ray tube is released and the enclosed container, so that heat from the X-ray tube can be obtained. Therefore, the cooling performance of the X-ray generator is greatly improved, and it can be used continuously for a long time.

Embodiments of the present invention will be described with reference to the drawings.
An X-ray generator according to the present invention is shown in FIG. FIG. 1 is a cross-sectional view from the side showing the structure of the X-ray generator.

  This X-ray generator irradiates a subject or the like (not shown) placed above with X-rays, and is a metal enclosure containing an X-ray tube 1, an insulating oil 2 and a heat transfer device 3. 4 is mainly configured, and a high voltage generator 5 is installed in the lower part thereof.

  The X-ray tube 1 is installed immersed in the insulating oil 2 so that the X-ray emission port 6 for emitting X-rays faces the upper surface of the enclosure 4.

  The side surface of the X-ray tube 1 excluding the X-ray emission port 6 has a hollow cylindrical insulating sleeve 7 on the inside for preventing discharge, and a hollow cylindrical shielding body 8 for shielding scattered X-rays on the outside. And is covered twice.

  The X-ray tube 1 has a cathode electrode 9 and an anode electrode 10 at both ends, and is electrically connected to a high voltage generator 5 at the lower part thereof.

  Like the side surface of the X-ray tube 1, the periphery of the cathode electrode 9 is double-covered by a cup-shaped insulator cup 11 and a cathode shielding cup 12, but the anode electrode 10 has a heat transfer device. 3 is directly attached by a set screw 14, and a cup-shaped anode shielding cup 13 covers the periphery thereof.

  The structure of the heat transfer device will be described with reference to FIGS. FIG. 2 shows a heat transfer device, where (a) is a top view, (b) is a side view, and (c) is a bottom view.

  The heat transfer device 3 has a thick cup-like shape having a recess 32 at the center, and a set screw inserted from the recess 32 side through a funnel-shaped through hole 31 provided at the center of the recess 32. 14, the end of the anode electrode 10 is fixed so as to contact the lower surface side (FIG. 2C).

  A plurality of fixing screw holes 33 are provided in the convex portion 32 on the outer periphery of the heat transfer device 3, and the heat transfer device 3 is inserted through the anode shielding cup 13 from the outside of the enclosure 4 for fixing. The screw 15 and the fixing screw hole 33 are screwed together to be fixed to the enclosure 4.

  In addition, the fixing method of the heat exchanger 3 and the anode electrode 10 or the enclosure 4 is not limited to the mechanical fixing method using the above screws, and may be a heat-resistant adhesive.

  Since this heat exchanger 3 needs to be excellent in heat conductivity and insulation resistance, it is preferable to form it using aluminum nitride or its inclusion.

  The insulating oil 2 serves to prevent slow heat from the X-ray tube 1 and discharge due to a high voltage, and is filled in a gap in the enclosure 4.

In addition, a heat sink 15 made of aluminum is installed outside the enclosure 4.
The effect | action regarding cooling in the X-ray generator which concerns on this invention is demonstrated below.

  When a high voltage is applied between the cathode electrode 9 and the anode electrode 10 by the high voltage generator 5, X-rays are generated by the thermal electrons emitted from the cathode electrode 9 colliding with the target. At this time, 90% or more of the generated heat is generated from the anode electrode 10 connected to the target.

  The heat generated from the anode electrode 10 is transferred to the enclosing container 4 through the heat transfer device 3 through the anode shielding cup 13. Since this heat transfer is due to direct contact between the solids, much larger heat can be transferred in a shorter time than conventional heat transfer only by convection of insulating oil.

  Heat generated from portions other than the anode electrode 10 is transferred to the enclosure 4 via the insulating oil 2 as in the conventional case.

  The heat transmitted to these enclosing containers 4 is radiated to the outside through the heat sink 15 made of aluminum.

  In this way, the cooling performance can be improved without greatly changing the size of the X-ray generator.

  In this X-ray generator, scattered X-rays generated from the X-ray tube 1 are effectively shielded by using a cup-shaped shielding cup (11, 13). It is not necessary to cover the entire outer surface of the container with a shielding plate, and the weight of the X-ray generator can be reduced.

It is sectional drawing of the X-ray generator which concerns on this invention. It is drawing which shows the structure of a heat exchanger, (a) is a top view, (b) is a side view, (c) is a bottom view. It is sectional drawing of the conventional X-ray generator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X-ray tube 2 Insulating oil 3 Heat exchanger 4 Enclosed container 5 High voltage generator 6 X-ray emission port 7 Insulating sleeve 8 Shielding body 9 Cathode electrode 10 Anode electrode 11 Insulating cup 12 Cathode side shielding cup 13 Anode side shielding cup 14 Set screw 15 Fixing screw 30 Concave portion 31 Through hole 32 Convex portion 33 Fixing screw hole 40 X-ray tube 41 Insulating oil 42 Enclosed container 43 X-ray emission port 44 Insulating sleeve 45 Shielding body 46 Insulating plate 47 Shielding plate 48 High voltage generation Device 49 Anode electrode

Claims (3)

An X-ray tube having an anode electrode at the end is housed in a metal enclosure,
In the X-ray generator filled with insulating oil in the enclosure,
An X-ray generator, wherein a heat transfer device for transferring heat generated in the anode electrode is provided in close contact with the anode electrode and an inner surface of the enclosure. The X-ray generator according to claim 1, wherein the heat exchanger is made of aluminum nitride. An X-ray tube having a cathode electrode and an anode electrode at both ends;
Insulating oil in which the X-ray tube is immersed;
An X-ray generator comprising a metal enclosure for storing the X-ray tube and the insulating oil,
The X-ray tube is
A hollow cylindrical insulator and shielding body surrounding the side surface;
A cup-shaped insulator and a first cup-shaped shield covering the cathode electrode;
A heat exchanger made of aluminum nitride provided in close contact with the anode electrode and the enclosure;
A second cup-shaped shielding body covering the anode electrode and the heat exchanger,
The enclosure is an X-ray generator having a heat sink on an outer surface.

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