JP2017134984A - X-ray generator and X-ray imaging system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray generator including a lid and a body, capable of being opened and closed, capable of being maintained, and capable of increasing withstand pressure of an insulating container while minimizing the size of the apparatus and increasing the material cost.SOLUTION: A lid 11b of an insulating container 11 includes: a protruding portion 12 protruding along an inner surface of a side wall of the insulating container 11; and a protruding source joining portion 15 where the protruding portion 12 is joined to an inner surface of the lid 11b. In the protruding portion 12, a plurality of insulating plates 21 is laminated via a plate-to-plate joining portion 16 joining adjacent insulating plates 21 along a transverse direction of the protruding source joining portion 15.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an X-ray imaging system applicable to a medical device, a nondestructive inspection apparatus, and the like, and an X-ray generator used in the system.

  The X-ray generator tube is a vacuum tube composed of a cathode, an anode and a tubular insulating tube, which accelerates electrons emitted from an electron emission source connected to the cathode at a high voltage and irradiates a target provided on the anode. Thus, X-rays are generated. In an X-ray generator in which such an X-ray generation tube is enclosed in a storage container, there is a risk of discharge failure between the X-ray generation tube and the storage container defined by the ground potential, resulting in poor pressure resistance. As a measure for improving the pressure resistance, an insulating container may be provided inside the storage container. In particular, when maintenance is required, an insulating container having an engaging portion that can be opened and closed may be used. In Patent Document 1, the engaging portion has a bent portion or a curved portion in the cross section in the thickness direction of the insulating member constituting the insulating container, and thus occurs between the X-ray generating tube and the storage container. An X-ray generator that suppresses discharge is disclosed. Specifically, it is disclosed that a protruding portion is provided on the lid of the insulating container, and the bent portion of the engaging portion is formed by the protruding portion.

Japanese Patent Laid-Open No. 2015-028909

  In the X-ray generator, in order to perform maintenance such as replacement of the internal X-ray generator tube, the insulating container having the engaging portion may be used as described above. In the container, a sufficient pressure resistance may not be obtained at the engaging portion. In order to improve the pressure resistance performance, it is only necessary to enlarge the protruding part and enlarge the bent part or curved part of the engaging part. However, the enlargement of the protruding part goes against the downsizing and weight reduction of the X-ray generator. Unnecessarily increasing the protruding portion is not preferable. In addition, the formation of the projecting portion increases the material cost.

  An object of the present invention is to provide an X-ray generator that can be opened and closed with an insulating container that can be opened and closed by a lid and a main body, and minimizes the increase in the size of the apparatus and the increase in material costs. The purpose is to increase the pressure resistance of the container. The present invention also provides an X-ray imaging system using such an X-ray generator.

The first of the present invention comprises an X-ray generator tube, an insulating container that stores the X-ray generator tube, and a conductive container that stores the insulating container,
The insulating container has a main body having a side wall that defines an opening, and a lid that is removable and closes the opening,
One of the lid and the side wall is a protrusion that protrudes along the inner surface of the other of the lid and the side wall, and the protrusion that is joined to the inner surface of either one of the lid and the side wall. An X-ray generator comprising a former joint,
The projecting portion is adjacent to a plurality of insulating plates having electrical insulation properties along a direction that is not longer between a length in the projecting direction of the projecting portion and a length in the short direction of the projecting joint portion. It is an X-ray generator characterized by being laminated | stacked via the board | plate junction part which joins the said insulating board to perform.

A second aspect of the present invention is an X-ray generator,
An X-ray detector that detects X-rays emitted from the X-ray generator and transmitted through the subject;
An X-ray imaging system comprising a control device that controls the X-ray generation device and the X-ray detection device in a coordinated manner.

  In the present invention, by providing a protrusion formed by laminating a plurality of insulating plates on either the lid or the main body of the insulating container, an insulating structure in which the withstand voltage in the laminating direction is secured is obtained. . Further, by specifying the stacking direction of the insulating plates in the projecting portion, it is possible to reliably obtain a higher withstand voltage, and to suppress an increase in the size of the device. Therefore, according to the present invention, it is possible to provide an X-ray generator that can withstand a higher voltage than before and that is small and can be maintained. Furthermore, in the present invention, a highly reliable X-ray imaging system can be provided using such an X-ray generator.

It is a cross-sectional schematic diagram of one Embodiment of the X-ray generator of this invention. It is the elements on larger scale of the cross section around the engaging part of the storage container of the X-ray generator of FIG. It is the perspective view which showed typically the engaging part periphery of an insulating container. It is a cross-sectional schematic diagram of the periphery of the protrusion part of the insulating container from which this invention differs in the structure of a protrusion part. It is the electric circuit diagram which showed the withstand voltage of the engaging part shown in FIG. 2 (a) and FIG. 4 (a), (b), the protrusion origin junction part, and the board-to-plate junction part by an electrical resistance. It is a figure which shows the synthetic | combination resistance ratio at the time of changing the electrical resistance ratio and aspect ratio of a protrusion origin junction part and an engaging part in the protrusion part which concerns on this invention. It is a cross-sectional schematic diagram which shows the protrusion part periphery of the insulating container of other embodiment of the X-ray generator of this invention. 1 is a block diagram of an embodiment of an X-ray imaging system of the present invention.

  Hereinafter, with reference to the drawings, the X-ray generator of the present invention will be described with reference to preferred embodiments. However, the present invention is not limited to the embodiment. In addition, conventional techniques are preferably applied to matters not described in the embodiment.

  FIG. 1 is a schematic cross-sectional view of a preferred embodiment of the X-ray generator of the present invention, FIG. 1 (a) is a schematic cross-sectional view along the tube axis of the X-ray generator tube, and FIG. FIG. 2 is a schematic cross-sectional view corresponding to AA ′ in FIG.

  In the X-ray generator 1 of the present invention, an X-ray generation tube 2 is accommodated in a storage container 3, and an extra space in the storage container 3 is filled with an insulating fluid 4. As the X-ray generation tube 2, either a reflection type or a transmission type can be used, and X-rays that transmit X-rays to the storage container 3 corresponding to the X-ray emission position (target 9) of the X-ray generation tube 2. A discharge window 14 is provided. In this example, a configuration example using a transmission X-ray generator tube is shown. The present invention is preferably applied to an X-ray generator in which a tube voltage circuit (not shown) for applying a tube voltage to the X-ray generator tube 2 is accommodated in the storage container 3 and mounted in a mono tank.

  In the transmission type X-ray generation tube 2, a cathode 5 is joined to one opening of a tubular insulating tube 7, and an anode 6 is joined to the other opening. The insulating tube 7 is preferably cylindrical in consideration of miniaturization and ease of manufacture, and in this example, a cylindrical configuration example is shown, but the present invention is not limited to this, and is a rectangular tube. Also good. Further, the cathode 5 and the anode 6 have a shape corresponding to the opening of the insulating tube 7, that is, a circular shape in this example.

  An X-ray generator tube 2 has an electron gun 8 whose potential is regulated with respect to the potential of the cathode 5, and a target 9 is joined to the anode 6. The electron gun 8 may include a grid electrode and a focusing electrode. In such an X-ray generating tube 2, a potential difference of about 40 kV to 150 kV is applied between the cathode 5 and the anode 6, and electrons emitted from the electron gun 8 are irradiated toward the target 9 on the anode 6. The target 9 irradiated with electrons generates X-rays, and the transmissive target 9 extracts X-rays from the side opposite to the electron irradiation surface to the outside of the X-ray generation tube 2.

  In the present invention, the storage container 3 has a double structure of a conductive container 10 such as a metal container on the outside and an insulating container 11 on the inside. Further, the conductive container 10 includes a main body 10a having a side wall that defines an opening and a lid 10b that is removable and closes the opening, and the insulating container 11 is also removable from the main body 11a having a side wall that defines the opening and blocks the opening. It consists of a lid 11b. Therefore, the X-ray generator 1 is configured to be maintainable.

  In the present invention, the main body 10a and the lid body 10b of the conductive container 10 are engaged via the engaging portion. In the present invention, “engagement” means a state that can be easily separated without performing bonding such as adhesion. In this example, the lid 10b of the conductive container 10 covers the opening of the main body 10a, and contacts with the side wall of the main body 10a to form an engaging portion. Therefore, when assembling the X-ray generator 1, the storage container 3 is sealed by fastening the side wall of the main body 10a and the peripheral portion of the lid 10b with a screw fastening structure or the like via an O-ring (not shown). As a material for the conductive container 10, metals such as iron, stainless steel, lead, brass, and copper can be used.

  Further, the main body 11a and the lid body 11b of the insulating container 11 are also engaged through the engaging portion. FIG. 2 shows the periphery of the engaging portion in detail. 2A and 2B show the region indicated by B in FIG. 1A and the region indicated by C in FIG. 1B in an enlarged and exaggerated manner, respectively.

  In the present invention, either one of the lid 11b of the insulating container 11 or the side wall of the main body 11a includes the protruding portion 12 and the protruding source joint portion 15 in the vicinity of the opening of the main body 11a. The projecting portion 12 projects along the inner surface of either the lid body 11b or the side wall of the main body 11a, and is joined to either the inner surface of the lid body 11b or the side wall of the main body 11a by the projecting joint 15. ing. The protruding portion 12 has an engaging portion 13 that contacts either the side wall of the main body 11a or the lid body 11b. In the embodiment of FIGS. 1 and 2, the lid body 11b includes a protruding portion 12 that protrudes along the inner surface of the side wall of the main body 11a, and a protruding source joint in which the protruding portion 12 is bonded to the inner surface of the lid body 11b. The protrusion part 12 has the engaging part 13 which contact | connects the side wall of the main body 11a.

  In the engaging portion 13 between the projecting portion 12 and the main body 11a of the insulating container 11, both surfaces are in contact with each other, but a minute gap is generated between both surfaces due to the unevenness caused by processing, and the gap has a dimensional accuracy. Even if it is raised, it cannot be reduced. This minute gap can be a discharge path that connects between the conductive container 10 and the high-voltage portion housed in the insulating container 11. Therefore, when the voltage is increased as the X-ray output increases, it is necessary to increase the size of the projecting portion 12 and lengthen the shortest path of the gap of the engaging portion 13. The enlargement of the protrusion 12 makes it difficult to obtain a member depending on the material. Moreover, the enlargement of the protrusion 12 becomes a barrier to the miniaturization of the X-ray generator 1.

  In the present invention, the protruding portion 12 is formed by laminating a plurality of insulating plates 21 having electrical insulation properties through inter-plate joining portions 16 that join adjacent insulating plates 21. Therefore, an insulating structure in which the withstand voltage in the stacking direction is ensured is obtained. In particular, the use of a plate having the same thickness as the insulating plate material used for the insulating container 11 makes it easy to obtain materials, and since the plate thickness is thin, processing such as cutting is facilitated. It is less expensive than the case where it is cut into a thickness and used as an insulating plate. In addition, a higher withstand voltage is ensured than when a block-shaped insulating material is joined in the plate surface direction.

  In the present invention, the pressure resistance of the engaging portion 13 can be obtained at a higher level by specifying the stacking direction of the protruding portions 12. Specifically, the stacking direction of the projecting portions 12 is set along the longer direction of the length of the projecting portion 12 in the projecting direction and the length of the projecting original joint portion 15 in the short direction. In addition, the protrusion direction of the protrusion part 12 corresponds with the Z direction shown by Fig.3 (a). Further, the short direction of the projecting joint 15 corresponds to the X direction shown in FIG. 3A, and corresponds to the direction separating the inside and the outside of the insulating container 11 through the engaging portion 13. Here, “not long” of the length of the protruding portion 12 in the protruding direction and the length of the protruding original joint portion 15 in the short direction includes cases of “equal” and “short”.

  In the example shown in FIG. 2A, the length L <b> 2 in the short direction of the protruding joint 15 is shorter than the length L <b> 1 in the protruding direction of the protruding portion 12. Therefore, the stacking direction of the projecting portions 12 indicated by the arrow F is along the short direction of the projecting joint portion 15. In other words, the inter-plate joint 16 is arranged in parallel with the protruding direction of the protruding portion 12. When the length L1 of the protruding portion 12 in the protruding direction is equal to the length L2 of the protruding original joint portion 15 in the short direction, as shown in FIGS. 3B and 3C, the protruding direction of the protruding portion 12 and the protruding direction What is necessary is just to set the lamination direction F of the protrusion part 12 so that any one of the transversal directions of the former junction part 15 may be followed.

  In the present invention, the reason why a higher breakdown voltage can be obtained by specifying the stacking direction F of the protrusions 12 will be described with reference to FIGS.

  4 (a) and 4 (b) show the protrusions 12 having the same size as that of FIG. 2 (a) so that the stacking direction F is different, that is, the stacking direction F is along the protrusion direction of the protrusions 12. is there. 4A is the same as FIG. 2A in the number of layers and the thickness of the insulating plate 21 is different, and FIG. 4B is the same as FIG. Is different. FIGS. 5A, 5B, and 5C are electric circuit diagrams in the configurations of FIGS. 2A, 4A, and 4B, respectively.

  When the insulating container 11 has the protruding portion 12, when the insulating fluid 4 is locally microdischarged in the insulating container 11, the portion D exposed to the internal space of the insulating container 11 of the protruding portion 12 is substantially reduced. There is a possibility of high voltage. Therefore, it is necessary to suppress the discharge from D to the conductive container 10. Usually, the insulating plate constituting the insulating container 11 and the protruding portion 12 has a higher pressure resistance per unit volume than the insulating fluid 4 and the bonding material, and therefore the pressure resistance around the protruding portion 12 is substantially the insulating fluid 4. Are affected by the pressure resistance of the engaging portion 13 filled with the above and the pressure resistance of the protruding joint 15 due to the bonding material. In the cross section parallel to the protruding direction 12 of the protruding portion, there is only one path from the point E where the engaging portion 13 and the protruding source joint 15 intersect to the conductive container 10. Therefore, from D to E, the length in the protruding direction of the protruding portion 12 and the length in the short direction of the protruding original joint portion 15 are determined in each pressure resistance capability.

  The form of the present invention shown in FIG. 2 (a) is compared with the form of FIGS. 4 (a) and 4 (b). Note that, in any case, a case where the pressure resistance of the bonding material constituting the protruding source joint 15 and the inter-plate joint 16 is higher than that of the insulating fluid 4 is taken as an example. Further, the length L1 of the protruding portion 12 in the protruding direction is longer than the length L2 of the protruding original joint portion 15 in the short direction. 2A, the length L1 of the protruding portion 12 in the protruding direction and the length L2 of the protruding source joint 15 in the short direction are compared, and the shorter direction of the shorter protruding source connecting portion 15 is compared. When the stacking direction F is along, the inter-plate joint 16 is longer than the protruding joint 15. Therefore, the pressure resistance of the inter-plate joint 16 is higher than that of the protruding joint 15. On the other hand, in the case of FIG. 4A in which the number of stacks is the same and the stacking direction F is changed, the inter-plate joint 16 is parallel to the projecting joint 15 and has the same length. This is the same as the protruding joint 15.

  2A, FIG. 4A, and FIG. 4B, the respective pressure resistances of the protruding joint portion 15, the inter-plate joint portion 16, and the engaging portion 13 will be quantitatively described. Generally, the withstand voltage depends on the area, and the withstand voltage decreases as the area increases. The breakdown voltage depends on the length of the medium, and the breakdown voltage increases as the length of the medium increases. Therefore, although the degree of dependence differs for each medium, the withstand voltage can be considered the same as the electrical resistance, and when replaced with the electrical resistance, the level of the electrical resistance can be read as the level of the withstand voltage.

  Therefore, when the withstand voltage of the protruding joint 15, the inter-plate joint 16, and the engaging portion 13 in each configuration of FIG. 2A, FIG. 4A and FIG. This path can be replaced by the electrical circuit diagrams of FIGS. 5 (a), 5 (b), and 5 (c). This will be described in detail with reference to FIG.

  The electrical resistance of the engaging portion 13 is R1, the electrical resistance of the protruding joint 15 is R2, and the aspect ratio α (= the length L1 of the protruding portion 12 in the protruding direction 1 / the length L2 of the protruding source connecting portion 15 in the short direction). ), The combined resistance of the path from D to E in FIGS. 2 (a), 4 (a) and 4 (b) is as follows.

The combined resistance Ra in FIG. 2A = ((1 + 4α) · R1 · R2) / (2 · (1 + 2α) · R1 + (1 + 4α) · R2)
The combined resistance Rb = ((R1 + 4R2) · R1 · R2) / (R1 ² + 6 · R1 · R2 + 4R2 ² ) in FIG.
The combined resistance Rc = ((R1 ³ + 24R1 ² · R2 + 160 · R1 · R2 ² + 256R2 ³ ) · R1 · R2) / (R1 ⁴ + 28R1 ³ · R2 + 240R1 ² · R2 ² + 640R1 · R2 ³ + 256R2 ⁴ )

  Here, the combined resistance ratios (Ra / Rb) and (Ra / Rc) when the electrical resistance ratio (R2 / R1) and the aspect ratio α between the protruding joint 15 and the engaging portion 13 are changed are shown in FIG. Shown in (a), (b). As shown in FIGS. 6A and 6B, when the aspect ratio α is 1 or more, the combined resistance ratios (Ra / Rb) and (Ra / Rc) are 1 or more in most regions. Therefore, it was found that a higher withstand voltage can be obtained when the stacking direction F is along the shorter direction of the length of the protruding portion 12 in the protruding direction and the length of the protruding original joint portion 15 in the short direction. In particular, when the electric resistance R2 of the protruding joint 15 is equal to or higher than the electric resistance R1 of the engaging portion 13 ((R2 / R1) ≧ 1), a high withstand voltage can be surely obtained, which is preferable.

  Even if a discharge occurs, the insulating fluid 4 is replaced by convection in the engaging portion 13, so that no great damage remains and the possibility of causing a discharge again is low. Damage to the bonding material will remain. For this reason, there is a possibility that the discharge will occur again at the protruding joint 15 where the damage remains. Also in this respect, the withstand pressure of the protruding joint 15 is preferably higher than the withstand of the engaging portion 13. When the pressure resistance capability of the insulating fluid 4 is higher than that of the bonding material, the length L1 in the protruding direction of the protruding portion 12 is set to the length in the short direction of the protruding original bonding portion 15 as shown in FIG. It is preferable that the protruding portion 12 is provided so that the stacking direction F is along the protruding direction of the protruding portion 12 with a length shorter than the length L2 ((R2 / R1) ≧ 1).

  Further, the number of stacked layers of the protrusions 12 may be changed depending on the size, and the number of stacked layers can be three or more as shown in FIG.

  The insulating plate 21 forming the protruding portion 12 has the same thickness as the insulating plate forming the insulating container 11 from the viewpoint of availability. Therefore, it is desirable that the thickness of the insulating plate 21 that forms the protruding portion 12 is equal to or less than the thickest portion of the insulating plate that forms the insulating container 11.

  In general, the withstand voltage is limited to the place with the weakest withstand voltage. Therefore, it is preferable that the projecting joint 15 has the shortest path through the joint between D and E. In other words, the length of the path passing through the inter-plate joint 16 (for example, L1 in FIG. 7B) is equal to or longer than the length in the short direction (for example, L2 in FIG. 7B) of the protruding joint 15 (L1 ≧ L2) is preferred.

  In the present invention, as shown in FIG. 7C, the insulating plate 21 forming the protruding portion 12 has a length in the protruding direction of the protruding portion 12 from the inner surface of the side wall of the main body 11a to the inside of the insulating container 11. On the other hand, gradually decreasing is preferable from the viewpoint of miniaturization. On the other hand, if the length of the protruding portion 12 of the inner insulating plate 21 in the protruding direction becomes too short, the path passing through the inter-plate bonding portion 16 becomes shorter than the length of the protruding original bonding portion 15 in the short direction. It becomes impossible to express the pressure resistance. Therefore, the length of the protruding portion 12 of the arbitrary insulating plate 21 in the protruding direction is equal to or greater than the total thickness of the insulating plate 21 and the insulating plate 21 positioned on the inner side. In other words, the length of the insulating plate 21 is set so that the path passing through the inter-plate joint 16 and the projecting joint 15 is longer than the path passing through only the projecting joint 15. For example, in FIG.7 (c), it is the thickness of L4> = L3-plate junction part 16. In FIG.

  The engaging part 13 by the protrusion part 12 should just be arrange | positioned suitably in a required place. Therefore, when providing corresponding to two sides orthogonal to each other on the outer periphery of the lid 11b, as shown in FIG.2 (b), at the corners where the projecting parts abut, the ends of the projecting parts 12 are It is preferable from the standpoint of pressure resistance that the bumps are stepped through the joint. Reference numeral 17 in FIG. 2 (b) denotes a protruding portion combination portion formed of a bonding material that bonds the ends of the protruding portions 12 and 12 on the two sides. When combined in a staircase shape in this way, the length of the protrusion combination part 17 that connects the inside and outside of the insulating container 11 can be made longer than when combined linearly at right angles or diagonally, and the pressure resistance is improved. The protrusion combination part 17 may be engaged, but it is more preferable to join the protrusion part 17 in terms of pressure resistance.

  In the present invention, as the bonding material used for the protruding joint 15, the inter-plate bonding 16, and the protruding portion combination 17, an instantaneous adhesive or an epoxy adhesive that is compatible with the insulating fluid 4 is preferably used. In particular, when an epoxy-based adhesive is used, since pressure resistance is higher than that of the insulating fluid 4 unless bubbles enter the adhesive, the length L1 of the protruding portion 12 in the protruding direction is the length of the protruding joint 15. It is preferably applied to a form longer than L2.

  As a material for the insulating container 11 and the insulating plate 21 of the protruding portion 12 according to the present invention, a resin having both oil resistance and pressure resistance is preferably used. Specifically, acrylic resin, ABS resin, epoxy resin, fluororesin, polyimide resin, polyetherimide resin, polycarbonate resin, polypropylene resin, glass epoxy containing glass fiber, and the like can be used.

  In the present invention, the protruding portion 12 may be provided on the side wall of the main body 11a of the insulating container 11, and in this case, the engaging portion 13 is formed on the protruding portion 12 and the lid body 11b. Further, there may be a plurality of lids 11b, and the present invention is appropriately applied.

The insulating fluid 4 used in the present invention fills the extra space in the insulating container 11 and is responsible for cooling and preventing discharge of the members stored in the container, so that the electrical insulation is high and the cooling capacity is high. Those that are less likely to be altered by heat are preferred. In particular, an insulating liquid is preferably used. For example, mineral oil, PFPE oil (perfluoropolyether), silicone oil, etc. can be used as the electrical insulating oil. As the non-liquid insulating fluid 4, SF ₆ (sulfur hexafluoride gas) is preferably used. The insulating fluid 4 is filled from an oil filling port (not shown) provided in the storage container 3.

  Next, an embodiment of the X-ray imaging system according to the present invention will be described with reference to FIG. The X-ray imaging system can be used for nondestructive inspection of industrial products and pathological diagnosis of human bodies and animals.

  As shown in FIG. 8, the X-ray generator 1 of the present invention has an X-ray generator tube 2 and a tube voltage circuit 32, and a movable aperture unit provided in the X-ray emission window 14 portion as necessary. 18 is provided. The movable aperture unit 18 has a function of adjusting the width of the irradiation field of the X-ray 19 irradiated from the X-ray generator 1. Further, as the movable aperture unit 18, a unit to which a function capable of simulating and displaying the irradiation field of the X-rays 19 with visible light can be used.

  The system control device 30 controls the X-ray generation device 1 and the X-ray detection device 31 in a coordinated manner. The tube voltage circuit 32 outputs various control signals to the X-ray generation tube 2 under the control of the system control device 30. The emission state of the X-rays 19 emitted from the X-ray generator 1 is controlled by this control signal. X-rays 19 emitted from the X-ray generator 1 pass through the subject 33 and are detected by the detector 34. The detector 34 converts the detected X-rays into image signals and outputs them to the signal processing unit 35. The signal processing unit 35 performs predetermined signal processing on the image signal under the control of the system control device 30, and outputs the processed image signal to the system control device 30. The system control device 30 outputs a display signal for displaying an image on the display device 36 to the display device 36 based on the processed image signal. The display device 36 displays an image based on the display signal on the screen as a captured image of the subject 33.

<Example 1, comparative example 1>
An X-ray generator 1 having the structure shown in FIG. 1 was produced. FeNiCo alloy was used for the cathode 5 and the anode 6, alumina was used for the insulating tube 7, and they were joined by brazing. The electron gun 8 includes an impregnated cathode electron emission source, a gate electrode, and a focusing electrode. The target 9 was a diamond substrate on which a tungsten film was formed.

  The conductive container 10 is a rectangular parallelepiped made of brass, the main body 10a is a five-faced container joined by brazing after bending, and a plate-like lid 10b is attached to the main body 10a with an O-ring made of nitrile rubber (not shown). ) And screwed (not shown) and sealed. The insulating container 11 is a rectangular parallelepiped made of glass epoxy, and the main body 11a is a five-faced container in which a glass epoxy plate is bonded with an epoxy adhesive, and is sealed by engaging the lid 11b. The glass epoxy plate had a thickness of 2 mm, and the junction portion of the main body 11a secured a withstand voltage by separating the distance from the high voltage portion or providing an insulating baffle plate.

  Protruding portions 12 as shown in FIG. 2A are provided on the periphery of the lid 11b of the insulating container 11. The length L2 in the short direction of the protruding joint 15 is 4.2 mm, and the length L1 in the protruding direction of the protruding portion 12 is 8 mm. Then, two glass epoxy plates (insulating plate 21) having a thickness of 2 mm were laminated so as to divide the protruding joint 15 into two, and the laminated surfaces were joined via the inter-plate joint 16. An epoxy adhesive was used for the protruding joint 15 and the inter-plate joint 16 and dried while applying a weight. The thickness of the joint was about 0.2 mm.

  The thickness of the gap of the engaging portion 13 is not actually measured, but is estimated to be about 0.3 mm from the processing accuracy.

  An X-ray generator tube 2 and a tube voltage circuit (not shown) are accommodated inside the insulating container 11, and after the conductive container 10 is sealed, the high-pressure insulating oil A (JX Nippon Oil & Gas Company) is used as the insulating fluid 4. Energy) was filled from an oil filling port (not shown) provided in the storage container 3.

  The voltage applied between the cathode 5 and the anode 6 is defined as Va, the conductive container 10 and the anode 6 are defined as the ground potential, the cathode 5 is defined as −Va, and the withstand voltage effect is evaluated without driving the electron gun 8. . Va was boosted by 10 kV by a tube voltage circuit and held at each voltage for 30 minutes, but no discharge was made to 60 kV.

  As Comparative Example 1, as shown in FIG. 4B, the same configuration as in this example except that the stacking direction F and the number of stacks of the protrusions 12 were changed, and the breakdown voltage was evaluated. It was.

  Next, when X-rays were generated by driving the electron gun 8 in the X-ray generator 1 of this example, desired X-rays could be generated at 60 kV.

<Example 2, comparative example 2>
As shown in FIG. 7B, the number of laminated insulating plates 21 is increased to three in the protruding portion 12, the length L2 in the short direction of the protruding joint 15 is 6.4 mm, and the protruding portion 12 protrudes. An X-ray generator 1 was produced in the same manner as in Example 1 except that the length L1 in the direction was 12 mm. When the withstand voltage effect was evaluated in the same manner as in Example 1 in the obtained X-ray generator, there was no discharge up to 90 kV.

  As Comparative Example 2, when the withstand voltage was evaluated with the same configuration as in this example except that 6 glass epoxy plates having a thickness of 2 mm were laminated so that the lamination direction F was along the protruding direction of the protruding portion 12, the breakdown voltage was 80 kV. There was a case of discharge.

  Next, when X-rays were generated by driving the electron gun 8 in the X-ray generator 1 of this example, desired X-rays could be generated at 90 kV.

<Example 3, Comparative Example 3>
As shown in FIG. 7C, the protruding portion is the same as in Example 2 except that three insulating plates 21 are stacked so that the length is sequentially reduced toward the inside of the insulating container 10. 12 was formed, and the X-ray generator 1 was produced. The length of the insulating plate 21 was 12 mm, 4 mm, and 2 mm in order from the side closer to the engaging portion 13. In this case, the length in the protruding direction of the protruding portion 12 of each inter-plate bonding portion 16 is equal to or greater than the total thickness of the insulating plate 21 inside the inter-plate bonding portion 16. Therefore, as the path from the inside of the insulating container 11 to the conductive container 10 through the joint portion, the path passing only the protruding source joint portion 15 is the shortest, while reducing the breakdown voltage degradation due to the inter-plate joint portion 16. The storage container 3 can be downsized. In this example, the periphery of the insulating container 11 could be reduced by about 5 mm toward the inside.

  In the obtained X-ray generator 1, when the withstand voltage effect was evaluated in the same manner as in Example 1, it was not discharged to 80 kV.

  As Comparative Example 3, the pressure resistance is the same as in this example except that six glass epoxy plates having a thickness of 2 mm are stacked in a three-step shape so that the stacking direction F is along the protruding direction of the protruding portion 12. As a result of evaluation, there was a case of discharging at 80 kV.

  Next, when the X-ray was generated by driving the electron gun 8 in the X-ray generator 1 of this example, it was possible to generate a desired X-ray at 80 kV.

1: X-ray generator, 2: X-ray generator tube, 3: storage container, 4: insulating fluid, 10: conductive container, 11: insulating container, 11a: main body, 11b: lid, 12: protrusion , 13: engaging portion, 15: protruding joint portion, 16: inter-plate joining portion, 19: X-ray, 21: insulating plate, 30: control device, 31: X-ray detection device, 33: subject

Claims (12)

An X-ray generation tube, an insulating container for storing the X-ray generation tube, and a conductive container for storing the insulating container,
The insulating container has a main body having a side wall that defines an opening, and a lid that is removable and closes the opening,
One of the lid and the side wall is a protrusion that protrudes along the inner surface of the other of the lid and the side wall, and the protrusion that is joined to the inner surface of either one of the lid and the side wall. An X-ray generator comprising a former joint,
The projecting portion is adjacent to a plurality of insulating plates having electrical insulation properties along a direction that is not longer between a length in the projecting direction of the projecting portion and a length in the short direction of the projecting joint portion. An X-ray generator characterized in that the X-ray generator is laminated via an inter-plate joint for joining the insulating plates.   The X-ray generator according to claim 1, wherein the protrusion is provided on the lid.   The X-ray generator according to claim 1 or 2, wherein a length of the protruding portion in a protruding direction is longer than a length in a short direction of the protruding source joint portion.   The length of the protrusion direction of the protrusions of the plurality of insulating plates forming the protrusions gradually decreases toward the inside of the insulating container. X-ray generator.   The length in the protruding direction of the protruding portion of the arbitrary insulating plate forming the protruding portion is equal to or greater than the total plate thickness of the arbitrary insulating plate and the insulating plate positioned on the inner side thereof. The X-ray generator according to claim 4.   In a cross section parallel to the projecting direction of the projecting portion, a path from the inner side to the outer side of the insulating container through the inter-plate joint portion and the projecting source joint portion passes through only the projecting source joint portion and the insulation. The X-ray generator according to claim 4, wherein the X-ray generator is longer than a path from the inner side to the outer side of the conductive container.   The X-ray generator according to claim 1, wherein a thickness of the insulating plate is equal to a thickness of the insulating container.   The X-ray generator according to any one of claims 1 to 7, wherein an extra space in the insulating container is filled with an insulating fluid.   9. The X according to claim 8, wherein the insulating plate has a pressure resistance per unit volume higher than that of the bonding material and the insulating fluid included in the protruding joint portion and the inter-plate bonding portion. Line generator.   The X-ray generator according to any one of claims 1 to 9, wherein a pressure resistance of the projecting joint portion is higher than a pressure resistance of the engaging portion.   The X-ray generator according to any one of claims 1 to 10, further comprising a tube voltage circuit that applies a tube voltage to the X-ray generator tube inside the insulating container. An X-ray generator according to any one of claims 1 to 11,
An X-ray detector that detects X-rays emitted from the X-ray generator and transmitted through the subject;
An X-ray imaging system comprising: a control device that controls the X-ray generation device and the X-ray detection device in a coordinated manner.

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