JP4559377B2 - X-ray generator - Google Patents

Description

  The present invention relates to an X-ray generation device, and more particularly to an X-ray generation device used for nondestructive inspection for detecting foreign matter in an object to be inspected such as food and medicine.

  In a production line for foodstuffs and pharmaceuticals, continuous inspection of all products is performed for the presence or absence of foreign substances in the product, and non-destructive inspection using X-rays is performed as the means. In this inspection, X-rays radiated from the X-ray generator are irradiated onto an object to be inspected, and foreign matter is detected by image processing the amount of transmission.

  As shown in FIG. 5, the X-ray generator mainly includes an X-ray tube 20 and an insulating oil 21, and is mainly composed of a sealed container 24 having a fin-like heat transfer device 22 and a heat radiator 23 on the upper surface. In addition, a metal casing 25 that houses the entire enclosure 24 is provided.

  In the above X-ray generator, X-rays 28 are radiated to the outside by applying a high voltage between the fixed anode electrode 26 and the cathode electrode 27 of the X-ray tube 20. More than 99% of the supplied energy is converted into heat. Therefore, a cooling method is adopted in which the heat generated in the X-ray tube 20 is transmitted to the radiator 23 via the insulating oil 21 and the heat transfer device 22 and is radiated to the outside by the air cooling fan 29 attached to the housing 25. It has been.

  Here, in recent food and pharmaceutical production lines, it has been demanded to adopt an X-ray generator having a sealed structure without a cooling fan 29 mainly from the viewpoint of dust-proof measures.

  However, in the conventional X-ray generator, since the heat transfer is performed mainly by the convection phenomenon of the insulating oil 21 as described above, the cooling efficiency is limited, and the installation of the cooling fan 29 is indispensable.

Regarding the improvement of the cooling efficiency, Patent Document 1 discloses an invention in which the cooling efficiency is improved by connecting the fixed anode electrode to the inner surface of the enclosure via an electrically insulating heat conducting member. However, since the heat transferred to the sealed container is also transferred to the insulating oil and raises its temperature, the effect of improving the cooling efficiency is small, and a cooling fan is still required and a sealed X-ray generator is provided. There was a problem that it was difficult.
Japanese Patent No. 3168760

  The present invention has been made in view of such problems, and an object of the present invention is to provide an X-ray generator having a sealed structure that has high cooling efficiency and does not require a cooling fan.

  In order to achieve the above object, the present invention according to claim 1 includes an X-ray tube in which a cathode electrode and a fixed anode electrode are arranged to face each other, an insulating oil in which the X-ray tube is immersed, An X-ray generator comprising a metal enclosure containing the X-ray tube and the insulating oil, wherein the first anode protrudes outside through the sealed container at an end of the fixed anode electrode. The X-ray generator is characterized in that a heat insulator is connected and a thermal insulator is provided between the enclosure and the first heat conductive member.

  According to a second aspect of the present invention, in the X-ray generator according to the first aspect, the first heat conducting member is any one of aluminum nitride, beryllia, silicon carbide, or alumina. It is.

  According to a third aspect of the present invention, the surface of the first heat conducting member that contacts the insulating oil is covered with a heat insulating material. It is a line generator.

  According to a fourth aspect of the present invention, the X-ray generator includes a housing that houses the enclosure, and the first heat conducting member is connected to an inner surface of the housing via a second heat conducting member. The X-ray generator according to any one of claims 1 to 3, wherein the X-ray generator is connected.

  The present invention according to claim 5 is the X-ray generator according to claim 4, wherein the second heat conducting member is any one of copper, aluminum, and a heat pipe.

  According to the present invention, the first heat conducting member that protrudes outside through the enclosure is connected to the fixed anode electrode of the X-ray tube, and the thermal insulator is provided between the through portion. The cooling efficiency of the heat generated in the X-ray tube can be improved, and an X-ray generator having a sealed structure that does not require a cooling fan can be provided.

  In addition, the cooling efficiency can be further improved by connecting the first heat conducting member to the housing that houses the entire sealed container via the second heat conducting member.

  The X-ray generator according to the present invention will be described below with reference to the drawings.

  An X-ray generator according to the first embodiment of the present invention is shown in FIG. FIG. 1 is a cross-sectional view of the structure of the X-ray generator.

  This X-ray generator mainly includes an X-ray tube 1 and an insulating oil 2 and a metal enclosure 5 having a fin-like heat transfer device 3 and a heat radiator 4 on the upper surface.

  The X-ray tube 1 is provided with a fixed anode electrode 7 and a cathode electrode 8 which are enclosed in a vacuum glass and arranged opposite to each other, and a high voltage is applied between them by a high voltage generator (not shown) to X-rays 9 are radiated to the outside by causing the thermoelectrons from the electrode 8 to collide with the fixed anode electrode 7.

  The insulating oil 2 is filled in a sealed container 5, cools the X-ray tube 1 that generates heat due to the radiation of the X-ray 9, encloses between the fixed anode electrode 7 and the cathode electrode 8, and both the electrodes. It serves to insulate between the containers 5.

  The fixed anode electrode 7 of the X-ray tube 1 is connected to a first heat conducting member 10 that penetrates the enclosure 5 and protrudes to the outside, and a thermal insulator 11 is interposed between them. Is provided. For this thermal insulator 11, for example, polybutylene terephthalate, which is a plastic material, or a ceramic material can be used.

  The first heat conducting member 10 needs to have high electrical insulation properties in order to be connected to the fixed anode electrode 7. For example, aluminum nitride, beryllia, silicon carbide, or alumina can be used. It is preferable to use aluminum nitride because of its high thermal conductivity.

  Further, from the viewpoint of increasing the cooling efficiency, the shape of the first heat conducting member 10 has a T-shaped longitudinal section as shown in FIG. 1 so that the surface area of the portion protruding to the outside is increased. It is desirable to do so.

  In such a configuration, the heat generated in the fixed anode electrode 7 with the generation of X-rays 9 from the X-ray tube 1 is directly guided to the outside of the enclosure 5 through the first heat conducting member 10. To dissipate heat. At this time, since the thermal insulator 11 is provided between the first heat conducting member 10 and the enclosure 5, the leakage of the insulating oil 2 from the through portion and the heat from the fixed anode electrode 7 are generated. Transmission to the insulating oil 2 through the enclosure 5 can be prevented.

  Therefore, since the heat of the fixed anode electrode 7 can be efficiently radiated to the outside of the enclosure 5, the cooling efficiency can be greatly improved and the temperature rise of the insulating oil can be suppressed.

  Further, in order to prevent the heat of the fixed anode electrode 7 from being locally transmitted to the insulating oil 2 from the portion where the first heat conducting member 10 and the insulating oil 2 are in direct contact, the temperature of the insulating oil 2 is prevented from rising. As shown in FIG. 2, it is preferable to cover the contact portion with a heat insulating member 12.

  The material of the thermal insulating member 12 may be the same as that of the thermal insulator 11, and it is desirable to increase the creepage distance by making the corrugated cross-sectional shape as shown in FIG.

  With such a configuration, the cooling efficiency can be further improved. Moreover, since the local temperature rise of the insulating oil 2 can be suppressed, its durability can be enhanced, and it is also possible to ensure the stable generation of the X-ray 9 by making the thermal equilibrium in the enclosure 5 uniform. It is.

  An X-ray generator according to the second embodiment of the present invention is shown in FIG. FIG. 3 is a cross-sectional view of the structure of the X-ray generator, and the same reference numerals are given to portions common to FIG. 1 and description thereof is omitted.

  The X-ray generator includes a metal housing 6 that houses the entire enclosure 5, and a portion that protrudes outside the first heat conducting member 10 in the first embodiment is a second heat conducting member. 13 is connected to the inner surface of the housing 6 via 13.

  Since the second heat conducting member 13 does not require electrical insulation, a material having an extremely high thermal conductivity such as copper or aluminum can be used. The second heat conducting member 13, the first heat conducting member 10 and the inner surface of the housing 6 may be joined by welding or mechanical fixing.

  In such a configuration, the heat generated in the fixed anode electrode 7 is transferred to the casing 6 having a large surface area through the first heat conducting member 10 and the second heat conducting member 13 to dissipate heat to the outside. Is done.

  Therefore, the cooling efficiency can be further improved as compared with the case of the first embodiment.

  Moreover, as the 2nd heat conductive member 13, the heat pipe 14 can also be used as shown in FIG. Here, the heat pipe 14 means a device that performs heat transfer using latent heat of liquid evaporation and condensation. The joining of the heat pipe 14 to the first heat conducting member 10 and the inner surface of the housing 6 may be directly fixed by mechanical means or may be fixed through a heat block or the like.

  With such a configuration, the cooling efficiency can be further improved, and the heat pipe 14 itself is small in size, does not take up equipment space, and is inexpensive, so that the entire X-ray generator can be reduced in size and cost. It becomes possible.

  In addition, about the shape of the 1st and 2nd heat conductive member in the above embodiment, a magnitude | size, arrangement | positioning, etc., it changes suitably according to the performance and use environment of an X-ray generator, and the example shown in drawing It is not limited to.

It is sectional drawing of the X-ray generator which concerns on 1st Embodiment of this invention. It is sectional drawing of the X-ray generator which installed the heat insulating member in 1st Embodiment. It is sectional drawing of the X-ray generator which concerns on 2nd Embodiment of this invention. It is sectional drawing of the X-ray generator which used the heat pipe in 2nd Embodiment. 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 Radiator 5 Enclosed container 6 Case 7 Fixed anode electrode 8 Cathode electrode 9 X-ray 10 First heat conduction member 11 Thermal insulator 12 Thermal insulation member
13 Second heat conduction member 14 Heat pipe

Claims (5)

An X-ray tube in which a cathode electrode and a fixed anode electrode are arranged to face each other, an insulating oil in which the X-ray tube is immersed, and a metal enclosure containing the X-ray tube and the insulating oil A first heat conduction member that penetrates the enclosure and protrudes to the outside at an end of the fixed anode electrode, and the enclosure and the first heat conduction An X-ray generator characterized in that a thermal insulator is provided between the members. The X-ray generator according to claim 1, wherein the first heat conducting member is any one of aluminum nitride, beryllia, silicon carbide, or alumina. The X-ray generator according to claim 1, wherein a surface of the first heat conducting member that contacts the insulating oil is covered with a heat insulating material. 2. The X-ray generator includes a housing that houses the enclosure, and the first heat conducting member is connected to an inner surface of the housing through a second heat conducting member. 2. The X-ray generator according to 2 or 3. The X-ray generator according to claim 4, wherein the second heat conducting member is any one of copper, aluminum, and a heat pipe.

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