JP2009176462A - X-ray generating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting technology for aiming at downsizing of a mono-tank type X-ray generating device which seals in and mounts a high-voltage generating part and an X-ray tube in a high-voltage tank filled with the same insulation oil. <P>SOLUTION: The mono-tank type high-voltage generating part and X-ray generating part are structured of a high-voltage transformer 3, a Cockcroft-Walton circuit 4 converting into direct-current high voltage by boosting the voltage multiple times, an X-ray tube 5 generating X rays through grounding of a cathode 5b, and a grounded high-voltage tank 7 sealing and mounting these above in insulating oil. The Cockcroft-Walton circuit 4 is divided into units 4A, 4B, 4C each resin-molded, and the molded units 4A, 4B, 4C are superposed one on another. The unit 4A, with a lowest potential among them, is arranged to be mounted in the vicinity of an inner wall of the high-voltage tank 7, and the unit 4C, with a highest potential, is arranged to be mounted in the vicinity of an anode 5a of the X-ray tube 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an X-ray generator suitable for an industrial or medical X-ray imaging apparatus, in particular, a mono tank type in which a high voltage generator and an X-ray tube are enclosed and mounted in the same insulating oil tank. The present invention relates to miniaturization technology of X-ray generators.

X-ray devices that measure the dose of X-rays that have passed through the subject, create an image based on the dose, and inspect or diagnose the subject are used as industrial products for various foreign substance inspection devices and defects. It is widely used for inspection devices and for medical use, such as X-ray fluoroscopy devices and X-ray imaging devices.
In such an X-ray apparatus, there is known an X-ray generation apparatus having a mono-tank type high-voltage tank in which a high-voltage generator and an X-ray tube are housed in the same insulating oil tank in order to move and rotate the apparatus. It has been. For example, a monotank type X-ray generator disclosed in Patent Document 1 is known for industrial use, and a monotank X-ray generator disclosed in Patent Document 2 is known for medical use.

  In these mono-tank type X-ray generators, in order to reduce the high-voltage transformer housed in the high-voltage tank, the voltage supplied from the DC power source is converted into a high-frequency AC voltage using an inverter circuit, and this high-frequency AC voltage is converted. The voltage is input to a relatively small high-voltage transformer and boosted to an intermediate voltage. The output voltage of this high-voltage transformer is converted to a DC high voltage by the Cockcroft-Walton circuit and further boosted to the final voltage to obtain an X-ray tube. In many cases, a configuration in which the voltage is applied to is adopted.

Japanese Patent Laid-Open No. 2003-317996 JP-A-6-76982

  There is a demand for further miniaturization of an X-ray apparatus using the monotank type X-ray generation apparatus, and for this purpose, the monotank type X-ray generation apparatus also needs to be miniaturized. In other words, it is essential to reduce the size of the high-voltage tank that houses the high-voltage generator and the X-ray tube. To this end, mounting technology is used to shorten the insulation distance between the high-voltage generator and the high-voltage tank. Is required.

  However, Patent Documents 1 and 2 and the like do not consider anything about the downsizing and mounting of the tank, and do not raise any problems.

  Accordingly, the present invention has been made in view of the above problems, and is a monotank type X-ray generator that encloses and mounts a high-voltage generator and an X-ray tube in a high-voltage tank filled with the same insulating oil. An object of the present invention is to provide a mounting technique for reducing the size of the device.

  In order to solve the above-described problems, the present invention provides a DC power supply, DC / AC conversion means for converting the output voltage of the DC power supply into an AC voltage having a predetermined frequency, and boosting the output voltage of the DC / AC conversion means. A Cockcroft-Walton circuit which boosts the output voltage of the high-voltage transformer and converts it into a DC voltage, and a cockcroft-Walton An X-ray comprising: an X-ray tube that generates X-rays when an output voltage of the circuit is applied; and a high-voltage tank that encloses and mounts the high-voltage transformer, the Cockcroft-Walton circuit, and the X-ray tube in insulating oil In the generator, the multiplication circuit of the predetermined number of stages of the Cockcroft-Walton circuit is divided into a plurality of units for each arbitrary number of stages, and each unit is divided into the high voltage tank. A unit having a minimum maximum potential among the plurality of units is disposed closest to the inner wall of the high-voltage tank.

  The unit having the maximum potential among the plurality of units is preferably arranged in the vicinity of the anode or cathode of the X-ray tube.

The plurality of units are preferably stacked on a plurality of surfaces along one inner wall surface of the high-voltage tank facing the anode or cathode of the X-ray tube. In this case, it is desirable that the plurality of units be connected so that the potential of each stage increases in a zigzag manner.
The plurality of units may be divided and arranged along a plurality of surfaces of one inner wall surface and the other inner wall surface of the high-voltage tank facing the anode or cathode of the X-ray tube.
The plurality of units are preferably resin-molded for each unit.
Preferably, the plurality of units are integrally formed with a gap between the units using a resin mold.

  According to the present invention, the Cockcroft-Walton circuit is divided into a plurality of units, and the plurality of units are arranged at positions where the insulation distance between the high-voltage tank and the insulation distance according to the potential of each unit is maintained. Alternatively, each unit is arranged along a plurality of surfaces in the high voltage tank and a unit having the maximum output voltage is arranged close to the anode or cathode of the X-ray tube. The insulation distance between voltage tanks can be shortened. As a result, miniaturization of the monotank type X-ray generator is achieved, and the X-ray generator using the monotank X-ray generator is also miniaturized.

Hereinafter, preferred embodiments of the X-ray generator of the present invention will be described in detail with reference to the accompanying drawings.
Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment of the present invention, and the repetitive description thereof will be omitted.

  FIG. 1 is an overall configuration diagram of an X-ray generator according to the present invention. In FIG. 1, an X-ray generator of the present invention includes a DC power source 1, an inverter circuit (DC / AC converting means) 2 that converts the voltage of the DC power source 1 into an AC voltage having a predetermined frequency, and the inverter circuit 2 The high voltage transformer 3 that boosts the AC voltage of the current, the Cockcroft-Walton circuit 4 that boosts the output voltage of the high-voltage transformer 3 multiple times to convert it to a DC high voltage, and the Cockcroft-Walton circuit 4 A high voltage that encloses and mounts the X-ray tube 5 that generates the X-rays when the DC high voltage converted in step 1 is applied, and the high-voltage transformer 3, the Cockcroft-Forton circuit 4 and the X-ray tube 5 in insulating oil. And a tank 7.

  The DC power source 1 may be any DC power source such as a DC power source obtained by converting a commercial AC power source voltage (not shown) into a DC voltage, or a DC power source using a battery. The circuit form for converting the commercial AC power supply voltage into a DC voltage is also a form in which the commercial AC power supply voltage is full-wave rectified by a full-wave rectifier circuit, or a DC voltage obtained by the full-wave rectification is a chopper circuit. It is not limited to the conversion form, such as a form to be adjusted or a form in which the full-wave rectifier circuit has a voltage variable function.

  In the X-ray generator configured as described above, the high-voltage generator 3 including the primary winding 3a and the secondary winding 3b and the Cockcroft-Walton circuit 4 constitute a high-voltage generation circuit 6. The output voltage of the high voltage generation circuit 6 is applied between the anode 5a and the cathode 5b of the X-ray tube 5 to generate X-rays.

  Since the cathode 5b of the X-ray tube 5 and the high-voltage tank 7 are grounded, between the inner wall surface of the high-voltage tank 7 and the high-voltage transformer 3, the Cockcroft-Walton circuit 4 and the X-ray tube 5 Causes a potential difference.

  In the present invention, the Cockcroft-Walton circuit 4 is divided into a plurality of parts, and the divided circuits are arranged corresponding to the potential difference, whereby the insulation distance between the inner wall of the high-voltage tank 7 and the electric parts and the electric The size is reduced by shortening the insulation distance between components. Here, the microfocus X-ray tube disclosed in Patent Document 1 is used for the X-ray tube 5, and the full-wave multiple-type Cockcroft Walton disclosed in the International Publication No. WO2004 / 103033 is used for the Cockcroft-Walton circuit 4. An example using a circuit will be described.

  Figure 2 shows a full-wave multiple-type Cockcroft-Walton circuit. In this circuit, the secondary winding 3b of the high voltage transformer 3 is provided with a neutral point tap, and the output voltage of the secondary winding 3b is converted into a DC high voltage M times using a capacitor and a diode. FIG. 2 shows a case where the number of boosting stages is 16.

  This 16-stage full-wave 16 × type Cockcroft-Walton circuit includes a first-stage first full-wave rectification booster circuit 41 including capacitors 411a, 411b, 412 and diodes 413a, 413b, 414a, 414b, and a capacitor 421a. , 421b, 422 and second stage full-wave rectification booster circuit 42 consisting of diodes 423a, 423b, 424a, 424b, as well as capacitors 4161a, 4161b, 4162 and diodes 4163a, 4163b, 4164a, 4164b. And a 16th full wave rectification booster circuit 416 in the 16th stage.

  Here, if the rated voltage between the anode and cathode of the microfocus X-ray tube is 100 kV, the number of boosting stages of the full-wave multiple type Cockcroft-Walton circuit is 16, so the full-wave rectified voltage per stage is 100kV / 16 stages = 6.25kV. When the positive DC output terminal A of the 16th stage is connected to the anode 5a of the X-ray tube and the negative DC output terminal K of the first stage is connected to the cathode 5b of the X-ray tube, A voltage of 100 kV is applied between the anode 5a and the cathode 5b of the ray tube.

  FIG. 3 shows a first division form of the full-wave multiple type Cockcroft-Walton circuit. As shown in FIG. 3 (a), conventionally, the Cockcroft-Walton circuit is formed in a series connection state from the first stage to the (n + m) stage on one substrate. In this case, the insulation distance between the high voltage tanks at each stage is the minimum dmin at the first stage and the maximum dmax at the (n + m) stage. For this reason, conventionally, the Cockcroft-Walton circuit has been arranged in the high-voltage tank using dmax as a guide.

  The present invention divides the Cockcroft-Walton circuit consisting of a plurality of stages from the first stage shown in FIG. 3 (a) to the (n + m) stage into a plurality of units as shown in FIG. An input terminal and an output terminal are provided on the printed circuit board, and the input and output terminals of each unit are connected by a conductive wire. The division of the Cockcroft-Walton circuit is, for example, 1 to n stages U1, U (n + 1) to (n + i) U2,..., (N + k) to (n The Cockcroft-Walton circuit is divided so that each unit is composed of a plurality of arbitrary stages, such as + m) stage Um. By dividing the Cockcroft-Walton circuit in this way, the difference between the maximum dmax and the minimum dmin of the insulation distance of each unit can be reduced. Therefore, it becomes possible to arrange the plurality of units at positions such that the insulation distance between the high-voltage tanks keeps the insulation distance corresponding to the potential of each unit. An example of mounting the Cockcroft-Walton circuit adopting the first division form on a high-voltage tank will be briefly described later.

  FIG. 4 shows a second division form of the full-wave multiple-type Cockcroft-Walton circuit. The second embodiment of the division mode of the full-wave multiple-type cockcroft-Walton circuit is a cockcroft-Walton circuit composed of a plurality of stages from the first stage to the (n + m) stage as in the example shown in FIG. 4 (a)), 1 to n stages are unit U1, (n + 1) to (n + i) stages are U2, ..., (n + k) stages to (n + m) ) Divide each unit into multiple stages, such as Um (see Fig. 4 (b)), and then isolate each unit U1, U2, ..., Um in a high-voltage tank Molding is performed with a resin having higher insulation strength than oil, for example, epoxy resin, input / output terminals are provided in each molded unit, and each unit is connected by a conductive wire. According to this embodiment, as compared with the divided form shown in FIG. 3, even when each unit is mounted, the electrical component is covered with the epoxy resin, so that the insulation distance is further shortened. An example of mounting the Cockcroft-Walton circuit adopting the second division form on a high voltage tank will be described in detail later.

  FIG. 5 shows an example in which the second division form of the full-wave multiple type Cockcroft-Walton circuit shown in FIG. 4 is mounted on a monotank type X-ray generator. As disclosed in Patent Document 1, the microfocus X-ray tube of this example is a three-pole X-ray including an anode 5a, a cathode 5b, three grid electrodes (not shown), and an anode rotating winding 5c. In the tube, the X-ray generator of the present embodiment includes a high-voltage transformer 3 to which an output voltage of an inverter circuit that converts a DC voltage supplied from a DC power source into a high-frequency AC voltage is supplied, and a Cockcroft-Walton circuit 4 The X-ray tube 5, the tube voltage / tube current detection circuit 8, and the grid power supply 9 (9a to 9c) for supplying the grid voltage to the grid electrode are integrated in the high voltage tank 7 in which the insulating oil 10 is enclosed. It has a mono tank type X-ray generator. The X-ray tube 5 is fixed to the X-ray tube mounting portion 7a of the high voltage tank 7 at the fixing portion 5d.

  The high voltage tank 7 is a rectangular parallelepiped housing made of, for example, a metal plate, and an X-ray shield such as a lead plate is attached to a necessary portion of the inner wall surface for X-ray protection. A cathode 5b including a grid electrode of the X-ray tube 5 is disposed in the vicinity of the upper wall of the high voltage tank 7, and a tube between the anode 5a of the X-ray tube 5 and the vicinity of the lower inner wall of the high voltage tank 7 is disposed. In the axial direction, Cockcroft-Walton circuits 4 divided into a plurality of units 4A, 4B, 4C are arranged in three layers along different planes, preferably along a plane. In addition, a grid electrode power source 9 is arranged in the empty space portion between the left inner wall surface of the high voltage tank 7 and the anode 5a of the X-ray tube 5, and the vicinity of the left inner wall surface below the high voltage tank 7 and the cockcroft A high-voltage transformer 3 is disposed between the Walton circuit 4 and a tube voltage / tube current detection circuit 8 is disposed between the vicinity of the right inner wall below the high-voltage tank 7 and the Cockcroft-Walton circuit 4.

  FIG. 6 is a diagram for explaining the details of the Cockcroft-Walton circuit 4 in FIG. In FIG. 6, the Cockcroft-Walton circuit 4 adopts the second division form shown in FIG. 4, that is, each divided unit is molded with resin. In mounting, each unit is stacked and disposed along a plurality of different surfaces, and each unit is disposed with a predetermined gap between each unit, and is integrally formed with a resin mold at an input / output end.

FIG. 6 shows an example in which the rated voltage of the anode 5a and the cathode 5b of the microfocus X-ray tube 5 is 100 kV, and the number of boosting stages of the full-wave multiple type Cockcroft-Walton circuit 4 is 16. In FIG. 6, the Cockcroft-Walton circuit 4 composed of all 16 stages includes the first unit 4A, the first stage to the sixth stage from the first stage to the sixth stage arranged from left to right in the figure. Reversely (in a zigzag shape) From the right to the left, the 7th to 12th steps are arranged in the second unit 4B, and the 7th to 12th steps are reversed (in a zigzag shape) from the left The remaining 13th to 16th rows arranged to the right are divided into three units as third units 4C. The divided connection terminals of the first unit 4A and the second unit 4B are provided at both end resin portions, and the connection terminals of the third unit 4C are provided at the left end and the upper surface. The high voltage transformer 3 is connected to the input terminal of the first unit 4A, the anode of the X-ray tube 5 is connected to the output terminal of the third unit 4C, and each unit is shown in FIGS. 6 (a) and 6 (c). As shown in (), both ends are connected by a conductive wire at the resin portion.
The maximum potential of the first unit 4A divided in this way is (100 kV ÷ 16 stages) x 6 stages = 37.5 kV, the maximum potential of the second unit 4B is 37.5 kV + 6.25 kV x 6 stages = 75 kV, the third unit The maximum potential of 4C is 75kV + 6.25kV x 4 stages = 100kV.

  The electric potentials between the electric components housed in the high voltage tank 7 are different, and the insulation distance between the electric components having different electric potentials and the inner wall surface of the high voltage tank 7 that is grounded also differs depending on the location in the high voltage tank 7. For example, if the rated voltage between the anode 5a and the cathode 5b of the X-ray tube 5 is 100 kV and the dielectric breakdown strength of the medium surrounding the Cockcroft-Walton circuit is 10 kV / mm as described above, for example, Since the maximum potential of the body-type Cockcroft-Walton circuit is 100 kV, the insulation distance between the Cockcroft-Walton circuit and the inner wall surface of the high voltage tank needs to be 100 kV / (10 kV / mm) = 10 mm.

  In this way, when the Cockcroft-Walton circuit, which requires different insulation distances for each stage, is integrally mounted as in the conventional case, the insulation distance from the inner wall of the high-voltage tank with respect to the maximum potential of the final stage of the Cockcroft-Walton circuit is reduced. It must be set, and the insulation distance must be increased more than necessary. However, according to the present embodiment, the insulation distance between the inner wall of the high voltage tank and the Cockcroft-Walton circuit can be set by the maximum potential in the first stage.

  That is, in the present embodiment, the maximum potential of the first unit 4A is 37.5 KV, so the insulation distance is 37.5 kV / (10 kV / mm) = 3.75 mm. Therefore, in the present embodiment, the Cockcroft-Walton circuit can be disposed closer to the inner wall of the high voltage tank than the conventional technology by 6.25 mm. In addition, since the Cockcroft-Walton circuit is stacked in three, it is particularly advantageous when the projection area in the plan view direction of the high-voltage tank is reduced (downsizing).

  In the X-ray generator in which electrical parts are arranged and stored in this way, the divided cockcroft-Walton circuit 4 is configured such that the first unit 4A to the third unit 4C are stacked in a zigzag manner and the units are connected in series. Therefore, the first unit 4A has a potential of 37.5kV at the maximum, and the insulation distance from the high voltage tank 7 is higher than the second unit 4B to which the maximum 75kV is applied and the third unit 4C to which 100kV is applied Is short, and can be arranged and mounted near the inner wall surface of the grounded high-voltage tank 7.

  Since the third unit 4C has a high potential from 81.25 kV to 100 kV, the third unit 4C is disposed near the anode 5a of the X-ray tube 5 having a potential of 100 kV, and the second unit 4B is connected to the first unit 4A and the third unit 4C. In order to become a potential between the units 4C, they are arranged between the units 4A and 4B.

  Between the first stage of the first unit 4A and the 12th stage of the second unit 4B stacked as described above, a potential difference of 75 kV-6.25 kV = 68.75 kV occurs, and the 12th stage of the second unit 4B Since a potential difference of 100 kV−56.25 kV = 43.75 kV is generated between the 16th stage of the third unit 4C, it is necessary to take the corresponding insulation distance, but in the embodiment of the present invention, the divided units The insulation distance is minimized by resin molding. As a result, each of the divided units can be arranged at an appropriate location, so that the degree of freedom of mounting is improved and the entire high voltage tank 7 can be made small.

  In addition, since the divided and resin-molded units are integrated with a predetermined gap, the gap (space) serves as a path for the convection of the insulating oil, and the insulating oil flows. Cooling is also efficiently performed against heat generation due to dielectric loss.

  If heat generation due to dielectric loss does not become a problem, the first unit 4A and the second unit 4B may be molded integrally, and the third unit 4C may be divided. By dividing the Cockcroft-Walton circuit 4 in this way, it is possible to increase the portion of the resin mold that has a higher dielectric breakdown strength than that of the insulating oil. The insulation distance becomes shorter and further miniaturization becomes possible.

  Further, since the divided units are molded, the molding material is likely to penetrate the entire Cockcroft-Walton circuit, and the insulation reliability is improved.

  Furthermore, since the divided units are provided with input and output terminals, the number of units may be changed in accordance with the specifications even if the specifications of the X-ray generator are different. For example, if the rating of the voltage applied between the anode and cathode of the X-ray tube (hereinafter referred to as tube voltage) is 70 kV, the third unit 4C is eliminated in FIG. 4 or 6 and the two units 4A and 4B are used. Constitute. On the contrary, when the rated voltage is 130 kV, the unit 4A or the unit 4B may be added. Thus, the present embodiment can easily cope with the specifications of the apparatus.

  In the present embodiment, the Cockcroft-Walton circuit 4 is divided into three units 4A, 4B, and 4C. However, the cockcroft-Walton circuit 4 may be divided into two or four or more units. Is not limited to the number of divisions.

The embodiment in FIG. 5 is an example in which the cathode of the X-ray tube is grounded, but it can also be applied to an X-ray generator having the anode grounded as shown in FIG.
In this case, the units 4A, 4B, 4C are disposed in a space surrounded by the side surface and the bottom surface of the anode 5a and cathode 5b of the X-ray tube 5 supported by the X-ray tube support portion 72a of the high-voltage tank 72 and the high-voltage tank 7. The first unit 4A of the Cockcroft-Walton circuit 4 divided into two is arranged so as to face the side wall of the high voltage tank 72. In addition, a grid electrode power source 9 (9a to 9c) is disposed in an empty space portion between the Cockcroft-Walton circuit 4 and the anode 5a of the X-ray tube 5, and the left inner wall surface above the high voltage tank 72 A high voltage transformer 3 and a tube voltage / tube current detection circuit 8 are disposed between the cathode 5 b of the X-ray tube 5.

  Thus, the embodiment of FIG. 7 arranges the plurality of molded units along a plurality of different surfaces in the vertical direction into a space surrounded by the inner wall of the high voltage tank and the anode and cathode of the X-ray tube. It is a thing. According to this embodiment, there is a merit when the height of the high voltage tank is shortened (downsized).

  FIG. 8 shows an example in which the present invention is applied to a monotank type X-ray generator in which the X-ray tube is a bipolar X-ray tube. The X-ray generator shown in FIG. 8 includes a high-voltage transformer 3 to which an output voltage of an inverter circuit that converts a DC voltage supplied from a DC power source into a high-frequency AC voltage is supplied, a Cockcroft-Walton circuit 40, and two poles An X-ray tube 50, a tube voltage / tube current detection circuit 8, and a mono-tank type X-ray generation device housed in a high voltage tank 74 in which an insulating oil 10 is enclosed are provided. The X-ray tube 50 is fixed to the X-ray tube mounting portion of the high voltage tank 74 at a fixing portion (not shown).

  As in the embodiment shown in FIG. 5, the high voltage tank 74 is a rectangular parallelepiped housing made of, for example, a metal plate, and a lead plate for X-ray protection is affixed to a necessary portion of the inner wall surface. Yes. Above the high voltage tank 74, a bipolar X-ray tube 50 that is elongated in the horizontal direction in the figure is disposed. A space 11 is provided between the X-ray tube 50 and the lower inner wall surface of the high voltage tank 74, and a space 12 is provided between the anode 50a of the X-ray tube 50 and the right inner wall surface of the high voltage tank 74. . These spaces 11 and 12 take into account the insulation that isolates the anode 50a and the cathode 50b of the X-ray tube 50, and the divided Cockcroft-Walton circuit 40, the high-voltage transformer 3, the tube voltage / tube It is set so that the current detection circuit 8 can be accommodated.

  The space 11 includes a high voltage transformer 3 and a molded unit 40D of a divided Cockcroft-Walton circuit 40. The space 12 includes a tube voltage / tube current detection circuit 8 and a Cockcroft-Walton circuit. Forty molded units 40E are mounted and arranged. The unit 40D of the Cockcroft-Walton circuit 40 is disposed on the surface along the lower inner wall surface of the high voltage tank 74, while the unit 40E is disposed along the side inner wall surface of the high voltage tank 74 facing the anode of the X-ray tube 50. Placed on the surface. The input terminal of the unit 40D is connected to the output terminal of the high voltage transformer, the output terminal of the unit 40E is connected to the anode 50a of the X-ray tube 50, and the unit 40D and the unit 40E are connected in series.

  The Cockcroft-Walton circuit 40 shown in FIG. 8 is an implementation example in which the number of boosting stages is eleven. If the rated voltage of the X-ray tube 50 is 100 KV, the maximum potential of the unit 40D consisting of the first to seventh stages is (100 KV ÷ 11 stages) x 7 stages ≒ 63.7 KV, and the maximum potential of the unit 40E is 63.7KV + 9.09KV x 4 stages = 100KV.

  Therefore, assuming that the dielectric breakdown strength of the medium surrounding the Cockcroft-Walton circuit is 10 KV / mm as described in FIG. 5, the unit 40D is 6.37 mm from the inner wall surface of the high voltage tank 74, and the unit 40E is the high voltage tank 74. The distance from the inner wall surface should be 10 mm, and the width of the high voltage tank and the size in the height direction can be reduced as compared with the case where the Cockcroft-Walton circuit is configured as a single unit connected in series.

  As described above, the unit 40D up to a relatively low potential, which requires a short insulation distance from the inner wall surface of the high-voltage tank 74, is arranged in the space 11, and the unit 40E including the maximum potential is arranged in the space 12. Since the space in the voltage tank 74 is not wasted and can be mounted with an appropriate insulation distance, the monotank type X-ray generator can be miniaturized.

The embodiment in FIG. 8 is an example in which the cathode of the bipolar X-ray tube is grounded, but can be modified when the anode is grounded.
Although illustration in this case is omitted, the positions of the anode 50a and the cathode 50b of the X-ray tube 50 in FIG. 8 are switched by rotating 180 °, the output terminal of the unit 40E is switched to the cathode 50b, and the anode 50a is switched to a high voltage. What is necessary is just to earth | ground through the tank 74.

  As mentioned above, although embodiment of this invention was described based on drawing, this invention is not limited to the said embodiment, A various deformation | transformation is possible in the range which does not deviate from the meaning of this invention.

  For example, in the embodiment shown in FIG. 5, FIG. 7, and FIG. 8 described above, an example in which each unit of the divided Cockcroft-Walton circuit is molded with an epoxy resin has been described. However, as shown in FIG. You may apply each unit to said each embodiment with a board | substrate.

In the above embodiment, a full-wave multiple type cockcroft-Walton circuit is used for the cockcroft-Walton circuit. good.
Further, the grounding method of the X-ray tube is not limited to the anode grounding and the cathode grounding, and may be a neutral point grounding method.

1 is a block diagram showing an overall schematic configuration of an X-ray generator according to the present invention. The figure which shows the circuit structure of a full wave multiple type | mold cockcroft-Walton circuit. The figure which shows the example which divides | segments a Cockcroft-Walton circuit and makes it a plurality of units. The figure which shows the example which molds, after dividing a Cockcroft-Walton circuit and making it into several units. The figure which shows the internal structure of 1st Embodiment of the mono tank type X-ray generator applied to the X-ray generator of this invention. FIG. 6 is a diagram showing a configuration of a Cockcroft-Walton circuit in FIG. The figure which shows the internal structure of 2nd Embodiment of the mono tank type X-ray generator applied to the X-ray generator of this invention. The figure which shows the internal structure of 3rd Embodiment of the mono tank type X-ray generator applied to the X-ray generator of this invention.

Explanation of symbols

  1 DC power supply, 2 Inverter circuit, 3 High voltage transformer, 4, 40 Cockcroft-Walton circuit, 5, 50 X-ray tube, 7, 70 High voltage tank, 8 tube voltage / tube current detection circuit, 9 Power supply for grid electrode , 10 Insulating oil

Claims (7)

DC power supply, DC / AC conversion means for converting the output voltage of the DC power supply into AC voltage of a predetermined frequency, a high voltage transformer for boosting the output voltage of the DC / AC conversion means, and a capacitor and a diode The circuit is made up of a predetermined number of stages connected in series, boosts the output voltage of the high-voltage transformer and converts it into a DC voltage, and the X-ray is generated by applying the output voltage of the cockcroft-Walton circuit. An X-ray generator comprising: an X-ray tube, and a high-voltage tank that encloses and mounts the high-voltage transformer, the Cockcroft-Walton circuit, and the X-ray tube in insulating oil.
The multiplier circuit of the predetermined number of stages of the Cockcroft-Walton circuit is divided into a plurality of units for each arbitrary number of stages, each unit is arranged along a plurality of surfaces in the high voltage tank, and among the plurality of units An X-ray generation apparatus characterized in that the unit having the smallest maximum potential is disposed closest to the inner wall of the high voltage tank.   2. The X-ray generator according to claim 1, wherein a unit having the maximum output potential among the plurality of units is arranged in the vicinity of an anode or a cathode of the X-ray tube.   2. The X-ray according to claim 1, wherein the plurality of units are stacked on a plurality of surfaces along one inner wall surface of the high voltage tank facing an anode or a cathode of the X-ray tube. Generator.   The X-ray generator according to claim 3, wherein the plurality of stacked units are connected so that the potential of each stage increases in a zigzag manner.   The plurality of units are divided and arranged along a plurality of surfaces of one inner wall surface and another inner wall surface of the high voltage tank facing the anode or cathode of the X-ray tube. 2. The X-ray generator according to 1.   6. The X-ray generator according to claim 2, wherein the plurality of units are resin-molded for each unit.   The X-ray generator according to any one of claims 2 to 4, wherein the plurality of units are integrally formed with a gap between the units using a resin mold.

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