JP2007026800A - X-ray generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact, lightweight X-ray generator capable of shielding leaked X rays and cooling itself. <P>SOLUTION: The X-ray generator 1 comprises a sealing case 2 for storing an X-ray bulb 3 and an insulating oil 4; a heat conductor 6 and a radiator 7 provided on the upper surface of the sealing case 2. In the X-ray generator 1, an X-ray shielding material 8 is arranged between the heat conductor 6 and the radiator 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an X-ray generator, and more particularly, non-destructive inspection that emits X-rays to an object to be inspected, such as food products and industrial products, and detects foreign matter in the object to be inspected from the amount of X-ray transmission The present invention relates to an X-ray generator used in the above.

  Conventionally, non-destructive inspection using X-rays has been performed as means for continuously detecting foreign matters in an inspection object such as food and industrial products. This inspection is to detect foreign matter by irradiating the inspection object with X-rays emitted from the X-ray generator and image processing the amount of transmission.

  An X-ray generator used for inspection usually has a structure in which an X-ray tube immersed in insulating oil is sealed in a metal enclosure, but the X-ray tube generates heat as X-rays are emitted. Therefore, it is necessary to cool by releasing the heat conducted from the X-ray tube to the insulating oil to the outside of the apparatus. As this cooling means, a method of providing a heat exchanger outside the X-ray generator has been used, but recently, cooling fins respectively provided on the inside and outside of the wall surface of the enclosure for miniaturization and cost reduction. An air cooling method is employed in which the heat of the insulating oil is released into the outside air through a cooler having

  As the material of the cooler, aluminum having good thermal conductivity is usually used. However, since aluminum has a high X-ray transmittance, X-rays scattered in the enclosure (scattered X-rays) are part of the cooler. May leak outside.

  For this reason, conventionally, a method for preventing leakage of scattered X-rays by storing the entire X-ray generator in a lead shielding hood has been taken. However, the shielding hood does not dissipate heat from the cooler. This hinders cooling performance from deteriorating.

  For this reason, a structure has been proposed in which the shielding hood is removable, and a structure capable of shielding leakage X-rays while improving the cooling performance. (See Patent Documents 1 and 2).

For example, in the latter case, as shown in FIG. 6, a substantially U-shaped shielding member 52 is installed outside the cooling fin 51 of the X-ray generator 50, and a straight air passage 54 is formed by a rectangular tube 53 on both sides thereof. The cooling fins 51 are cooled by the air passages 54 and are attenuated by absorbing and scattering the X-rays leaked from the cooling fins 51 on the inner surfaces of the air passages 54.
JP-A-11-183405 JP 2001-318062 A

  In continuous X-ray inspections for mass-produced products such as food and industrial products, X-ray generators are generally installed on those production lines, so miniaturization and weight reduction are desired. Has been.

  However, in the conventional structure described above, a member that shields scattered X-rays, such as a shielding hood and a rectangular tube forming a ventilation path, must be provided outside the X-ray generating apparatus. There is a problem that the weight increases as the size increases.

  The present invention has been made in view of such problems, and provides a small and lightweight X-ray generator capable of shielding leakage X-rays and cooling the X-ray generator. .

  An X-ray generator according to the present invention includes a bottom plate and a side wall, and an X-ray tube that generates X-rays is disposed in the vicinity of the bottom plate of a container having an opening at the top, and the opening is provided with a heat transfer fin. Closed with a heat transfer plate that protrudes from the bottom and protrudes, and further has a heat dissipation plate that protrudes from the heat transfer plate and stands above the heat transfer plate. While cooling the X-ray tube, the heat of the insulating oil is collected on the heat transfer fins, and a metal X-ray shielding material is interposed between the heat transfer plate and the heat radiating plate with good heat conduction and integrated. X-ray generator.

  Thus, a small and lightweight X-ray generator capable of shielding a leaky X-ray and cooling the X-ray generator by incorporating a leaky X-ray shielding material between the heat transfer plate and the heat radiating plate is provided. be able to.

  Moreover, the shielding performance and the cooling performance can be improved by using a lead plate excellent in shielding performance and adhesion to a heat transfer device or the like as the shielding material for the leaked X-rays.

  Furthermore, the cooling performance of the X-ray generator can be further improved by providing a suction port which is an intake port for outside air in the longitudinal direction of the heat radiating plate and providing an air fan above the heat radiating fins.

  According to the present invention, it is possible to provide a small and lightweight X-ray generator capable of shielding leakage X-rays and cooling the X-ray generator.

  Embodiments according to the present invention will be described with reference to FIGS.

  FIG. 1 is a cross-sectional view showing the structure of an X-ray generator according to the present invention.

  An X-ray generator 1 according to the present invention is composed of a metal enclosure 2 having an upper surface that accommodates an X-ray tube 3 and an insulating oil 4, and a heat transfer device 6 and a radiator 7 have openings on the upper surface. It is attached to close.

  In general, the X-ray tube 3 applies a high voltage between the anode 10 and the cathode 11 sealed in the vacuum glass, and collides thermal electrons from the cathode 11 with the anode 10, thereby causing the X-ray emission port 13. X-rays 12 are generated.

  The X-ray tube 3 is installed such that the X-ray emission port 13 faces the bottom surface of the enclosure 2, and the X-ray 12 is applied to an inspection object (not shown) placed below the X-ray generator 1. Can be irradiated.

  In order to prevent X-ray emission from other than the X-ray emission port 13, the surface of the X-ray tube 3 is covered with a cylindrical lead shielding cover 14 except for the X-ray emission port 13.

  Since the X-ray tube 3 generates heat when emitting the X-rays 12, it is immersed in the insulating oil 4 to serve both as slow heating and prevention of discharge due to a high voltage. A bellows 9 is provided on the side surface of the enclosure 2 in order to absorb the expansion of the insulating oil 4 whose temperature has risen due to the slow heating of the X-ray tube 3.

  An aluminum heat exchanger 6 and a radiator 7 are attached to the upper surface of the enclosure 2.

  A perspective view of the heat transfer device 6 is shown in FIG.

  The heat transfer device 6 gradually heats the insulating oil 4 and has heat transfer fins 21 made up of a plurality of substantially rectangular parallelepiped protrusions arranged in a grid pattern on a flat base 20.

  By using the heat transfer fins 21 having such a shape, the contact area with the insulating oil 4 that convects in the sealed container 2 is increased, and the efficiency of heat dissipation can be increased.

  The heat radiator 7 radiates heat transferred from the heat transfer device 6 into the outside air, and has a shape and a structure in which the heat transfer device 6 is turned upside down.

  FIG. 3 shows a perspective view of a structure in which the heat transfer device 6 and the heat radiator 7 are combined.

  The heat transfer device 6 and the heat radiator 7 are arranged so that the pedestal portions 20 and 22 correspond to each other with the X-ray shielding material 8 interposed therebetween, and fixed bolts 24 through through holes provided at a plurality of locations. It is fixed by tightening.

  The X-ray shielding material 8 generally includes iron, lead, etc. Here, from the viewpoint of adhesion to the heat transfer device 6 and the heat radiator 7 and shielding performance, lead that is relatively soft and has a high specific gravity is used. Use.

  As shown in FIG. 1, in the heat transfer device 6 and the heat radiator 7 fixed to each other in this way, the heat transfer fins 21 are immersed in the insulating oil 4 and the opposite heat radiation fins 23 are exposed to the outside air. Thus, it attaches to the opening part of the upper part of the enclosure 2.

  And since the shielding material 8 for shielding scattered X-rays is attached as a part of the heat exchanger 6 and the radiator 7, the X-ray generator 1 can be made small and light.

  The operation in the embodiment described above will be described.

  The heat generated by the generation of X-rays in the X-ray tube 3 is conducted to the insulating oil 4 in contact with the X-ray tube 3, so that the heated and heated insulating oil 4 is convected in the enclosure 2. Move to the top. Then, heat is transferred from the insulating oil 4 moved to the upper portion to the heat transfer fins 21, and is transferred to the pedestal 20 and the shielding material 8 to be radiated from the heat dissipation fins 23 to the outside air. Here, the convection of the insulating oil 4 occurs in a random direction. However, since the heat transfer fins 21 have a shape as shown in FIG. 2, heat can be efficiently collected from the insulating oil 4.

  A thin plate-like shielding material 5 is interposed between the heat transfer device 6 and the radiator 7 and these are integrally formed by tightening them with bolts. The heat of the insulating oil 4 causes the heat radiation fins 23 to be formed. Since the heat is radiated by air cooling, the heat of the insulating oil 4 can be efficiently released by the exhaust action of a cooling fan or the like to maintain the X-ray tube 3 at a low temperature and increase the X-ray radiation efficiency.

  Moreover, since the scattered X-rays generated from the X-ray generator 1 are shielded by the thin plate-shaped shielding material 5 disposed between the heat transfer device 6 and the heat radiator 7, the X-rays are transmitted through the upper surface of the enclosure 2. There is no leakage outside the generator 1.

  An example of the configuration when the X-ray generator 1 according to the present invention is actually used is shown in FIGS. 4 is a front sectional view of the configuration example, and FIG. 5 is a sectional view taken along the AA plane in FIG.

  In this configuration example, the X-ray generator 1 is housed in a storage case 30, and as shown in FIG. 4, one intake port 31 is provided on the upper side surface.

  As shown in FIG. 5, a clearance 35 serving as an air inlet is provided at the lower end of the storage case 30 along the longitudinal direction of the X-ray generator 1.

  A plurality of air fans 32 are installed on the upper surface of the storage case 30 so that air heated in the storage case 30 can be discharged to the outside.

  The air 33 sucked from outside through the air inlet 31 is heated while flowing between the heat radiation fins 23 and is exhausted from above the storage case 30 to the outside through the air fan 32.

  Further, the wall surface of the X-ray generator 1 can be simultaneously cooled by the air 33 flowing in from the gap 35 at the lower end of the storage case 30 and flowing in the vertical direction.

  Thus, by performing forced cooling using the air fan 32, the heat radiation efficiency from the radiation fin 23 can be improved, and the cooling performance of the X-ray generator 1 can be improved.

  Here, the scattered X-rays 34 generated in the X-ray generator 1 and directed toward the upper surface are shielded by the shielding material 8 provided between the heat transfer device 6 and the heat radiator 7, so that X-ray generation occurs. There is no leakage outside the apparatus 1. Note that scattered X-rays directed in the horizontal direction can be easily shielded by the enclosure 2 or the storage case 30.

It is sectional drawing which shows the X-ray generator which concerns on this invention. It is a perspective view which shows the shape of a heat exchanger. It is a perspective view which shows the structure which combined the heat exchanger and the heat radiator. It is sectional drawing in the structural example of the X-ray generator shown in FIG. It is sectional drawing of the AA arrow shown in FIG. It is a perspective view which shows the structure of the conventional X-ray generator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X-ray generator 2 Enclosed container 3 X-ray tube 4 Insulating oil 6 Heat exchanger 7 Radiator 8 Shielding material 9 Bellows 10 Anode 11 Cathode 12 X-ray 13 X-ray radiation port 14 Shielding cover 20 Heat-transfer base part 21 Heat transfer fin 22 Radiator base 23 Radiation fin 24 Fixing bolt 30 Storage case 31 Air inlet 32 Air fan 33 Air flow 34 Scattered X-ray 35 Clearance 50 X-ray generator 51 Cooling fan 52 Shielding member 53 Square cylinder 54 Ventilation Road 55 mounting table

Claims (3)

An X-ray tube that generates X-rays is disposed in the vicinity of the bottom plate of the container having a bottom plate and a side wall and having an opening at the top,
The opening is closed with a heat transfer plate that protrudes from the bottom of the heat transfer fin,
Furthermore, a heat radiating plate having a radiating fin projecting upward on the heat transfer plate is projected,
Insulating oil in the container to cool the X-ray tube,
An X-ray generator that collects heat of insulating oil on heat transfer fins and integrates a metal X-ray shielding material between the heat transfer plate and the heat radiating plate with good heat conduction. The X-ray generator according to claim 1, wherein the X-ray shielding material is a lead plate. Having a suction port in the longitudinal direction of the heat sink;
An air fan is provided above the radiating fin,
The X-ray generator according to claim 1, wherein cooling air is introduced between the heat radiating fins and air is discharged in a direction away from the radiating fins.

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