X-ray generating device

Abstract

An X-ray generating apparatus includes an X-ray tube, an X-ray tube housing, and a power supply section configured by sealing an internal circuit board for supplying a voltage to the X-ray tube in an insulating inner portion. An insulating oil is enclosed in a space delimited by an upper surface of the insulating block and an inner surface of the X-ray tube housing. A high-voltage feed section connected to a target support section is disposed on the upper surface. At least one protruding portion protruding to a position further to the insulating valve side than a boundary portion of the high-voltage feed section, the upper surface, and the insulating oil and surrounding the high-voltage feed section when viewed in a tube axis direction is provided on the upper surface. A top of the protruding portion is separated by a gap from a virtual plane including an end portion of the insulating valve and extending in a direction orthogonal to the tube axis.

Description

[0001] This application was filed on [date]. February 18, 2019 Application number is 201980024620.X The invention is named X-rays Generating device A divisional application of the patent application. Technical Field

[0002] One aspect of the present invention relates to an X-ray generating apparatus. Background Technology

[0003] In the prior art, there is a known structure in which a metal container (X-ray tube housing) for housing the X-ray tube and insulating oil is placed on the upper surface of an insulating block (see, for example, Patent Documents 1 and 2). A high-voltage generating circuit for supplying voltage to the X-ray tube is molded in the insulating block.

[0004] Patent Document 1 describes a structure in which an annular wall portion 2E is provided on the upper surface of the insulating block, surrounding a high-voltage application portion protruding from the valve portion of the X-ray tube, thereby shielding the high-voltage application portion from the metal cylindrical component (X-ray tube housing). Patent Document 2 describes a structure in which an annular wall portion 13h is provided on the upper surface of the insulating block, such as surrounding the base end of the rod-shaped anode (high-voltage application portion). The wall portion described above serves to suppress discharge from the high-voltage application portion to the X-ray tube housing, and suppresses surface discharge by increasing the surface distance on the upper surface of the insulating block.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 4231288.

[0008] Patent Document 2: Japanese Patent No. 4889979. Summary of the Invention

[0009] The technical problem that the invention aims to solve

[0010] However, if the wall portion, as described in Patent Documents 1 and 2, is formed in a manner that surrounds the area between the valve portion of the X-ray tube and the upper surface of the insulating block, this wall portion may obstruct the circulation of insulating oil within the X-ray tube housing. Specifically, insulating oil that is heated in contact with the high-voltage application portion of the X-ray tube may easily become trapped in the aforementioned area. As a result, there is a possibility of reduced cooling efficiency of the X-ray tube.

[0011] Therefore, one objective of the present invention is to provide an X-ray generating apparatus capable of suppressing surface discharge on the surface of an insulating block and suppressing the reduction in cooling efficiency of the X-ray tube.

[0012] Technical means for solving problems

[0013] An X-ray generating apparatus according to one aspect of the present invention includes: an X-ray tube having a valve portion and a high-voltage application portion protruding from the valve portion; an X-ray tube housing portion that houses the valve portion in a manner that at least surrounds the valve portion when viewed from the tube axis direction along the tube axis of the X-ray tube; and a power supply portion consisting of a high-voltage generating circuit for supplying voltage to the X-ray tube sealed within an insulating block made of an insulating material, wherein an insulating liquid is sealed in a space defined by the surface of the insulating block facing the X-ray tube and the inner surface of the X-ray tube housing portion, a conductive feed portion electrically connected to the high-voltage application portion is disposed on the surface of the insulating block, and at least one protrusion is provided on the surface of the insulating block, the at least one protrusion protruding to a position closer to the valve portion than the boundary between the feed portion, the surface of the insulating block, and the insulating liquid, and surrounding the feed portion when viewed from the tube axis direction, the top of the at least one protrusion being spaced apart from a virtual plane extending in a direction orthogonal to the tube axis, including the end of the valve portion on the surface side.

[0014] In one aspect of the X-ray generating apparatus of the present invention, the boundary between the conductive feed section and two different insulating materials (the surface of the insulating block and the insulating liquid) becomes a region where the electric field is easily concentrated and discharged. Therefore, in the aforementioned X-ray generating apparatus, a protrusion is provided on the surface of the insulating block opposite the valve section of the X-ray tube, protruding to a position closer to the valve section than the boundary and surrounding the feed section. This protrusion allows the boundary section to be hidden from the X-ray tube housing section surrounding the X-ray tube. This suppresses discharge between the boundary section and the X-ray tube housing section. Furthermore, by providing the protrusion on the surface of the insulating block, the surface distance of the insulating block can be increased compared to making the surface of the insulating block flat. This suppresses surface discharge of the insulating block. On the other hand, the top of the protrusion is spaced apart from the end of the valve section, which includes the surface side, and a virtual plane extending in a direction orthogonal to the tube axis. This prevents obstruction of the circulation of the insulating liquid in the region between the valve section of the X-ray tube and the surface of the insulating block, and suppresses a decrease in the cooling efficiency of the X-ray tube. Therefore, according to the above-mentioned X-ray generating device, surface discharge on the surface of the insulating block can be suppressed, and the reduction in cooling efficiency of the X-ray tube can be suppressed.

[0015] The surface of the insulating block can also have a continuously varying surface shape. Thus, by not providing discontinuous corners (i.e., areas where the electric field easily concentrates and discharges) on the surface of the insulating block, it is possible to suppress the concentration of the electric field in specific areas (corners) on the surface of the insulating block, and to more effectively suppress the generation of discharge.

[0016] At least one protrusion may also be included in the annular first protrusion surrounding the feed section. According to this structure, since the X-ray tube housing section can be properly shielded by the first protrusion, the discharge between the boundary section X and the X-ray tube housing section can be more effectively suppressed.

[0017] At least one protrusion may also include a second annular protrusion with a groove formed between it and the inner surface of the X-ray tube housing. According to this structure, the surface distance of the insulating block can be effectively extended through the second protrusion.

[0018] Alternatively, the surface of the insulating block may have: an annular recess surrounding the power supply section; and an inclined section connected to the recess and inclined along the tube axis in a manner that approaches the recess as it moves away from the virtual plane. According to this structure, foreign matter or the like generated in the insulating oil can be guided into the recess by moving along the inclined section. This suppresses discharge caused by foreign matter or the like in the insulating oil.

[0019] The effects of the invention

[0020] According to one aspect of the present invention, an X-ray generating apparatus capable of suppressing surface discharge on the surface of an insulating block and suppressing the reduction in cooling efficiency of the X-ray tube can be provided. Attached Figure Description

[0021] Figure 1 This is a perspective view showing the appearance of an X-ray generating apparatus according to one embodiment.

[0022] Figure 2 It is along Figure 1 A sectional view along line II-II.

[0023] Figure 3 This is a cross-sectional view showing the structure of an X-ray tube.

[0024] Figure 4 It is a cross-sectional view showing the structure of the upper surface of the insulating block.

[0025] Figure 5 This is a diagram illustrating an example of changes in the insulating block. Detailed Implementation

[0026] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the same or equivalent parts in each drawing will be labeled with the same symbols, and repeated descriptions will be omitted. In addition, terms indicating specific directions such as "up" and "down" are used for convenience based on the states shown in the accompanying drawings.

[0027] Figure 1 This is a perspective view showing the appearance of an X-ray generating apparatus according to one embodiment of the present invention. Figure 2 It is along Figure 1 A cross-sectional view of line II-II. Figure 1 and Figure 2 The X-ray generating apparatus 1 shown is, for example, a microfocus X-ray source used for non-destructive X-ray examination to observe the internal structure of a subject. The X-ray generating apparatus 1 has a housing 2. Inside the housing 2 are mainly housed an X-ray tube 3 that generates X-rays and a power supply unit 5 that supplies electrical power to the X-ray tube 3. The housing 2 has an X-ray tube housing 4 and a housing 21 that house a portion of the X-ray tube 3.

[0028] The storage section 21 is the main part for storing the power supply section 5. The storage section 21 has a bottom wall 211, an upper wall 212, and side walls 213. The bottom wall 211 and the upper wall 212 are each approximately square. The edges of the bottom wall 211 and the upper wall 212 are connected via four side walls 213. Thus, the storage section 21 is formed into a generally cuboid shape. Furthermore, in this embodiment, for convenience, the direction in which the bottom wall 211 and the upper wall 212 face each other is defined as the Z direction, the bottom wall 211 side is defined as the bottom, and the upper wall 212 side is defined as the top. In addition, the directions in which the side walls 213, which are orthogonal to the Z direction and facing each other, face each other are defined as the X direction and the Y direction. A circular through hole, i.e., an opening 212a, is provided in the center of the upper wall 212 when viewed from the Z direction.

[0029] The X-ray tube housing 4 is formed of a metal with high thermal conductivity (high heat dissipation). Examples of materials for the X-ray tube housing 4 include aluminum, iron, copper, and alloys containing them. In this embodiment, the material of the X-ray tube housing 4 is aluminum (or its alloy). The X-ray tube housing 4 is a cylindrical part with openings at both ends in the axial direction (Z direction) of the X-ray tube 3. The axial direction of the X-ray tube housing 4 is aligned with the axial direction AX of the X-ray tube 3. The X-ray tube housing 4 has a holding part 41, a cylindrical part 42, a conical part 43, and a flange part 44. The holding part 41 is the part that holds the X-ray tube 3 at the flange part 311 using a fixing member (not shown), and hermetically seals the upper opening of the X-ray tube housing 4 together with the X-ray tube 3. The cylindrical part 42 is connected to the lower end of the holding part 41 and is formed as a cylindrical part with a wall extending in the Z direction. The conical portion 43 is connected to the end of the cylindrical portion 42, including a portion of the wall surface that gradually and continuously expands in diameter as it moves away from the cylindrical portion 42 along the Z direction from this end. The cylindrical portion 42 and the conical portion 43 are connected to each other in cross-sections along the ZX and ZY planes such that the angle between the planar walls of the cylindrical portion 42 and the conical portion 43 is an obtuse angle. The flange portion 44 is connected to the end of the conical portion 43 and extends outward when viewed from the Z direction. The flange portion 44 is configured as an annular member with a thicker wall than the cylindrical portion 42 and the conical portion 43. This increases the heat capacity and improves heat dissipation. When viewed from the Z direction, the flange portion 44 is hermetically fixed to the upper surface 212e of the upper wall portion 212 at the location surrounding the opening 212a of the upper wall portion 212. In this embodiment, the flange portion 44 is thermally connected (thermally conductive contact) to the upper surface 212e of the upper wall portion 212. An electrically insulating liquid, namely insulating oil 45, is airtightly sealed (filled) inside the X-ray tube housing 4.

[0030] The power supply unit 5 supplies electrical power of several kV to several hundred kV to the X-ray tube 3. The power supply unit 5 has an electrically insulating block 51 made of solid epoxy resin and an internal circuit board 52 containing a high-voltage generating circuit molded within the insulating block 51. The insulating block 51 is generally cuboid in shape. The center of the upper surface of the insulating block 51 protrudes through the opening 212a of the upper wall portion 212. On the other hand, the edge 51a of the upper surface of the insulating block 51 is hermetically fixed to the lower surface 212f of the upper wall portion 212. A high-voltage feeder 54, containing a cylindrical socket electrically connected to the internal circuit board 52, is disposed at the center of the upper surface of the insulating block 51. The power supply unit 5 is electrically connected to the X-ray tube 3 via the high-voltage feeder 54.

[0031] The outer diameter of the portion of the insulating block 51 inserted into the opening 212a (i.e., the central portion of the upper surface) is the same as or slightly smaller than the inner diameter of the opening 212a.

[0032] Next, the structure of X-ray tube 3 will be explained. For example... Figure 3As shown, the X-ray tube 3 is a so-called reflection-type X-ray tube. The X-ray tube 3 includes a vacuum housing 10, which serves as a vacuum perimeter to maintain an internal vacuum; an electron gun 11, which serves as an electron generating unit; and a target material T. The electron gun 11 has, for example, a cathode C formed by impregnating a substance that readily emits electrons with a substrate containing a high-melting-point metal material. Furthermore, the target material T is, for example, a plate-shaped component containing a high-melting-point metal material such as tungsten. The center of the target material T is located on the tube axis AX of the X-ray tube 3. The electron gun 11 and the target material T are housed inside the vacuum housing 10. When electrons emitted from the electron gun 11 strike the target material T, X-rays are generated. The X-rays are generated radially with the target material T as the focal point. Of the X-ray components facing the X-ray exit window 33a, the X-rays extracted to the outside through the X-ray exit window 33a are used as the desired X-rays.

[0033] The vacuum housing 10 is mainly composed of an insulating valve 12 (valve section) formed by an insulating material (e.g., glass) and a metal section 13 having an X-ray exit window 33a. The metal section 13 has a main body section 31 that houses the target material T, which serves as the anode, and an electron gun housing section 32 that houses the electron gun 11, which serves as the cathode.

[0034] The main body 31 is cylindrical and has an internal space S. A cover plate 33 with an X-ray exit window 33a is fixed to one end (outer end) of the main body 31. The X-ray exit window 33a is made of an X-ray permeable material, such as beryllium or aluminum. The cover plate 33 closes one end of the internal space S. The main body 31 has a flange portion 311 and a cylindrical portion 312. The flange portion 311 is provided on the outer periphery of the main body 31. The flange portion 311 is the portion fixed to the holding portion 41 of the X-ray tube housing 4. The cylindrical portion 312 is the portion formed into a cylindrical shape at one end of the main body 31.

[0035] The electron gun housing 32 is cylindrical and fixed to one end of the main body 31. The central axis of the main body 31 (i.e., the tube axis AX of the X-ray tube 3) is approximately orthogonal to the central axis of the electron gun housing 32. The interior of the electron gun housing 32 communicates with the interior space S of the main body 31 through an opening 32a provided at the end of the electron gun housing 32 on the side of the main body 31.

[0036] The electron gun 11 includes a cathode C, a heater 111, a first gate electrode 112, and a second gate electrode 113. Through the cooperation of these components, the diameter of the generated electron beam can be reduced (microfocusing). The cathode C, heater 111, first gate electrode 112, and second gate electrode 113 are mounted on a substrate 115 via a plurality of parallel-extending feed pins 114. The cathode C, heater 111, first gate electrode 112, and second gate electrode 113 are fed from the outside via their respective feed pins 114.

[0037] The insulating valve 12 is generally cylindrical. One end of the insulating valve 12 is connected to the main body 31. The other end of the insulating valve 12 holds the target material T fixed to the front end of the target support 60. The target support 60 is formed into a cylindrical shape using, for example, copper, and extends in the Z direction. An inclined surface 60a is formed on the front end of the target support 60, tilting away from the electron gun 11 as it moves from the insulating valve 12 side toward the main body 31 side. The target material T is embedded in the end of the target support 60 such that it is flush with the inclined surface 60a.

[0038] The base end 60b of the target support 60 protrudes further outward than the lower end of the insulating valve 12, and is connected to the high-voltage feed section 54 of the power supply section 5 (see reference). Figure 2 That is, a high-voltage application part (base end 60b in this embodiment) that applies voltage through the high-voltage feed section 54 protrudes from the insulating valve 12. In this embodiment, the vacuum housing 10 (metal part 13) is set to ground potential, and a positive high voltage is supplied to the target support part 60 in the high-voltage feed section 54. However, the voltage application method is not limited to the above example.

[0039] Next, refer to Figure 4 The shape of the upper surface of the insulating block 51 is described in detail below. As described above, insulating oil 45 is sealed in the space defined by the upper surface 51e (surface) of the insulating block 51 facing the X-ray tube 3 and the inner surface 4a of the X-ray tube housing 4. The upper surface 51e is the surface that includes the central portion and the edge portion 51a of the upper surface. However, in this embodiment, the portion that mainly defines the space sealed with insulating oil 45 is the portion of the upper surface 51e that protrudes into the inside of the X-ray tube housing 4, especially the through opening 212a.

[0040] At least one annular protrusion 55 surrounding the high-voltage feed section 54 is provided on the upper surface 51e of the insulating block 51. The protrusion 55 is a portion that protrudes further toward the insulating valve 12 than the boundary portion B of the high-voltage feed section 54, the upper surface 51e of the insulating block 51, and the insulating oil 45. The protrusion 55 is arranged in an annular shape centered on the tube axis AX. When viewed from a direction orthogonal to the tube axis direction (Z direction), the protrusion 55 has an arc-shaped top. The boundary portion B exists annularly along the lower edge of the high-voltage feed section 54. In this embodiment, the protrusion 55 includes a protrusion 55A (first protrusion) that covers the boundary portion B, and a protrusion 55B (second protrusion) that is provided further outward than the protrusion 55A.

[0041] The protrusion 55A is an annular protrusion provided near the high-voltage feed section 54, directly surrounding it. The protrusion 55A is provided to directly surround the boundary section B, thus covering it from all sides. The high-voltage feed section 54 is housed within a recess (recess) formed in the central region inside the protrusion 55A. By providing this protrusion 55A near the high-voltage feed section 54, the boundary section B is shielded from the inner surface 4a of the X-ray tube housing 4. More specifically, the boundary section B is shielded in a manner that prevents direct penetration from the inner surface 4a of the X-ray tube housing 4 when the X-ray tube 3 is connected to the high-voltage feed section 54.

[0042] The protrusion 55B is an annular protrusion located near the inner surface 4a of the X-ray tube housing 4, forming an annular groove 56 between it and the inner surface 4a (the groove 56 separates the inner surface 4a from the inner surface 4a). When viewed from the tube axis direction (Z direction), the protrusion 55B is not opposite to the insulating valve 12. More specifically, the protrusion 55B is positioned at a distance from the insulating valve 12 in a direction orthogonal to the tube axis AX, such that when viewed from the tube axis direction, it is not opposite to the end 12b of the insulating valve 12 on the upper surface 51e side (power supply 5 side) or the corner R of its outer edge. At the bottom of the groove 56, the inner surface 4a of the X-ray tube housing 4 (and the upper surface 212e of the upper wall 212), the upper surface 51e of the insulating block 51, and the boundary B2 of the insulating oil 45 are annularly located. That is, the boundary portion B2 is shielded from the surrounding area by the protrusion 55B, in particular, it is shielded in a way that it is not directly visible from the high-voltage feed section 54, the high-voltage application section (base end 60b) of the X-ray tube 3, and the boundary portion B. In this embodiment, the top of the protrusion 55B is located at a higher position than the top of the protrusion 55A. In other words, the top of the protrusion 55B is located closer to the end 12b containing the insulating valve 12 and extending in a direction orthogonal to the tube axis AX than the top of the protrusion 55A. However, the top of the protrusion 55A may also be located at a higher position than the top of the protrusion 55B (closer to the virtual plane P). In this embodiment, the groove 56 is surrounded by the inner surface 4a of the protrusion 55B and the flange 44, and is formed in an annular shape around the protrusion 55B (spaced apart from the inner surface 4a throughout the entire circumference).

[0043] On the other hand, when viewed from a direction orthogonal to the tube axis (Z direction), the tops of protrusions 55A and 55B are spaced apart from the virtual plane P. In other words, when viewed from a direction orthogonal to the tube axis (Z direction), the tops of protrusions 55A and 55B are located on the upper surface 51e side (power supply 5 side) of the end 12b of the insulating valve 12. Furthermore, there is no upper surface 51e of the insulating block 51 between the end 12b of the insulating valve 12 and the top of the protrusion 55B (i.e., the top of the highest protrusion among the protrusions 55). That is, any part of the upper surface 51e is located below the end 12b of the insulating valve 12 in the direction along the tube axis (Z direction) more than the end 12b (virtual plane P) of the insulating valve 12. That is, no wall portion that would obstruct the circulation of insulating oil 45 is provided on the upper surface 51e. The so-called wall portion that obstructs the circulation of insulating oil 45 is, for example, an annular wall portion (shielding plate) that protrudes to the same height as or above the end 12b of the insulating valve 12, in a manner that shields the high voltage application portion from the X-ray tube housing portion 4.

[0044] Furthermore, a recess 57 and an inclined portion 58 are provided on the upper surface 51e of the insulating block 51. The recess 57 is arranged in a ring shape, having an arc-shaped cross-section when viewed from a direction orthogonal to the tube axis (Z direction), so as to surround the high-voltage feed section 54. In this embodiment, as Figure 4 As shown, the recess 57 is provided in a manner that is continuous with the protrusion 55A on the outside. That is, the outer surface of the protrusion 55A and the inner surface of the recess 57 are continuous. When viewed from a direction orthogonal to the tube axis (Z direction), the recess 57 extends further into the insulating block 51 (internal circuit board 52) than the boundary portion B. Figure 2 )) Depression.

[0045] The inclined portion 58 occupies most of the central portion of the upper surface of the insulating block 51, connecting the recess 57 and the protrusion 55B. The inclined portion 58 is formed by a continuous plane extending from the protrusion 55B to the recess 57. The inclined portion 58 is inclined relative to a plane (XY plane) orthogonal to the tube axis direction (Z direction). Specifically, the inclined portion 58 is inclined along the tube axis AX as it moves away from the virtual plane P (i.e., Figure 4 The inclined surface 58 is a continuously inclined surface that slopes downwards along the tube axis (Z direction) from the protrusion 55B towards the recess 57. In other words, the inclined surface 58 is an inclined surface that slopes downwards along the tube axis (AX) from the insulating valve 12 side towards the insulating block 51 side, towards the recess 57. Furthermore, the corner R of the insulating valve 12 is opposite to the flat surface, i.e., the inclined surface 58, and not opposite to the protrusion 55.

[0046] The upper surface 51e, which is provided with the aforementioned protrusion 55, recess 57, and inclined portion 58, has a surface shape that continuously changes from the boundary portion B to the inner surface 4a of the X-ray tube receiving portion 4. That is, on the upper surface 51e, there are no discontinuous corner portions from the protrusion 55A to the protrusion 55B. In addition, the aforementioned protrusion 55, recess 57, and inclined portion 58 are all about the tube axis AX of the X-ray tube 3 (refer to...). Figure 2 The upper surface 51e is arranged symmetrically with respect to any angle from 0 to 360 degrees. Thus, the entire upper surface 51e has a circularly symmetrical shape with respect to the tube axis AX of the X-ray tube 3. More specifically, the upper surface 51e of the insulating block 51 has: a central annular portion (protrusion 55A) with a recess formed at the center of a generally frustum-shaped protrusion surrounded by a recess 57; and an outer peripheral annular portion including a plane (inclined portion 58) that is held by the groove 56 and the recess 57 and slopes downwards from the protrusion 55B to the tube axis AX. Both the central annular portion and the outer peripheral annular portion have a circularly symmetrical shape with respect to the tube axis AX, and their end edges have rounded chamfers.

[0047] [Effects]

[0048] Next, the effects of one aspect of this embodiment will be explained. In the X-ray generating apparatus 1, the boundary B between the conductive high-voltage feed section 54 and the two different insulating materials (the upper surface 51e of the solid insulating block 51 and the insulating oil 45) becomes a part where the electric field is easily concentrated and discharged. Therefore, in the X-ray generating apparatus 1, a protrusion 55 is provided on the upper surface 51e of the insulating block 51 opposite to the insulating valve 12 of the X-ray tube 3, protruding further towards the insulating valve 12 than the boundary B and surrounding the high-voltage feed section 54. Through this protrusion 55, the boundary B can be hidden from the X-ray tube housing 4 surrounding the X-ray tube 3. As a result, the discharge between the high-potential boundary B and the ground potential (0V) X-ray tube housing 4 can be suppressed.

[0049] Furthermore, by providing a protrusion 55 on the upper surface 51e of the insulating block 51, the surface distance of the upper surface 51e of the insulating block 51 can be increased compared to the case where the upper surface 51e of the insulating block 51 is a flat surface. This helps to suppress surface discharge on the surface of the insulating block 51. On the other hand, when viewed from a direction orthogonal to the tube axis (Z direction), the top of the protrusion 55 is spaced apart from the virtual plane P, which includes the end 12b of the insulating valve 12 and extends in a direction orthogonal to the tube axis AX. That is, no portion protruding further than the end 12b (virtual plane P) of the insulating valve 12 on the upper surface 51e of the insulating block 51 is provided. Specifically, as described above, no wall portion (shielding plate) that would obstruct the circulation of insulating oil 45 is provided on the upper surface 51e. This prevents obstruction of the circulation of insulating oil 45 in the area between the insulating valve 12 of the X-ray tube 3 and the upper surface 51e of the insulating block 51. That is, the insulating oil 45 can circulate smoothly in the area between the insulating valve 12 and the protrusion 55 of the X-ray tube 3. As a result, the reduction in the cooling efficiency of the X-ray tube 3 can be suppressed. Thus, according to the X-ray generating apparatus 1, surface discharge on the surface of the insulating block 51 can be suppressed, and the reduction in the cooling efficiency of the X-ray tube 3 can be suppressed.

[0050] Furthermore, the upper surface 51e of the insulating block 51 has a continuously varying surface shape. Thus, by eliminating discontinuous corners (i.e., areas where the electric field easily concentrates and discharges) on the upper surface 51e of the insulating block 51, the concentration of the electric field in specific areas (corners) of the surface of the insulating block 51 can be suppressed, and discharge can be more effectively suppressed. In addition, in this embodiment, the region of the upper surface 51e in contact with the insulating oil 45 is formed with a surface (curved or inclined) that has a longer distance along the surface compared to a flat surface. Thus, by continuously forming a surface shape with a longer distance along the surface compared to a flat surface throughout the region of the upper surface 51e in contact with the insulating oil 45, surface discharge can be effectively suppressed.

[0051] Furthermore, the protrusion 55 includes an annular protrusion 55A surrounding the high-voltage feed section 54. The protrusion 55A allows for appropriate shielding of the boundary section B of the X-ray tube housing 4. This, in turn, more effectively suppresses discharge between the boundary section B and the inner surface 4a of the X-ray tube housing 4.

[0052] Furthermore, the protrusion 55 includes an annular protrusion 55B that forms a groove 56 between itself and the inner surface 4a of the X-ray tube housing 4. The protrusion 55B effectively extends the surface distance of the insulating block 51. Additionally, the protrusion 55B covers the boundary portion B2 at the bottom of the groove 56 from all sides. Specifically, the protrusion 55B shields the boundary portion B2 in a manner that prevents direct penetration from the high-voltage feed section 54, the high-voltage application section (base end 60b) of the X-ray tube 3, and the boundary portion B. Since the boundary portion B2 is also a region prone to discharge between high-potential areas such as the high-voltage feed section 54, the high-voltage application section (base end 60b) of the X-ray tube 3, and the boundary portion B, shielding the discharge path with the protrusion 55B effectively suppresses discharge. Furthermore, the corner R of the insulating valve 12 is also a part with a strong electric field, making it a high-probability area for discharge. However, the protrusion 55B is positioned at a distance from the insulating valve 12 in a direction orthogonal to the tube axis AX, so as not to be opposite the corner R when viewed from the tube axis (Z direction). This effectively suppresses discharge. Additionally, in the X-ray tube housing 4, the area opposite the corner R is also separated from the corner R by forming a cone 43. That is, by cooperating with the cone 54, the space around the corner R can be expanded (by expanding the distance between the corner R and other components), thus more effectively suppressing discharge. Alternatively, the corner R could be separated from other components simply by enlarging the X-ray tube housing 4. However, in this case, since the capacity of the insulating oil 45 also becomes excessively large, there is a possibility that the insulating oil 45 itself may act as an insulating material or become easily trapped. As a result, the cooling efficiency of the X-ray tube 3 may decrease.

[0053] Furthermore, an annular recess 57 surrounding the high-voltage feed section 54 is provided on the upper surface 51e of the insulating block 51, and an inclined portion 58 is connected to the recess 57 and inclined in a manner that approaches the recess 57 along the tube axis direction (Z direction) as it moves away from the virtual plane P. For example, the X-ray generating device 1 uses... Figure 4 When used in the orientation shown (with the upper surface 51e of the insulating block 51 facing upwards), foreign matter generated in the insulating oil 45 can be guided to the recess 57 by tilting it along the inclined portion 58. This allows foreign matter that could potentially cause insulation failure to be hidden from the boundary portion B. As a result, discharge caused by foreign matter in the insulating oil 45 can be suppressed. Furthermore, the X-ray generating device 1 is connected to... Figure 4When used in the opposite orientation (with the upper surface 51e of the insulating block 51 facing downwards), even if a few bubbles are generated in the insulating oil 45, they can be guided to the recess 57 by rising along the inclined portion 58. This allows bubbles that could potentially cause insulation failure to be hidden from the boundary portion B. As a result, discharge caused by bubbles in the insulating oil 45 can be suppressed. Furthermore, by positioning the corner R of the insulating valve 12 opposite the protrusion 55 to the flat surface, i.e., the inclined portion 58, discharge caused by the corner R can be suppressed.

[0054] While embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various changes can be made to the present invention without departing from its spirit. That is, the shape and material of each part of the X-ray generating apparatus are not limited to the specific shapes and materials shown in the above embodiments.

[0055] Figure 5 This is a cross-sectional view of the upper surface of insulating blocks 151, 251, 351, and 451, showing variations. Additionally, Figure 5 In this example, the open end of the cylindrical X-ray tube housing 4A without the cone portion 43 is joined to the upper surface edge 51a of the insulating blocks 151, 251, 351, and 451. Thus, the X-ray tube housing and the insulating blocks can be directly connected, or they can be connected via other components (upper wall portion 212 in the above embodiment) as described above.

[0056] Figure 5 The upper surface 151a of the insulating block 151 shown in (A) is formed into a conical shape (sloping upwards from the inside to the outside) by means of a protrusion 152 and an inclined portion 153. The protrusion 152 is the same as the protrusion 55B in the above embodiment. That is, the protrusion 152 is an annular protrusion provided near the inner surface 4a of the X-ray tube housing 4A, forming an annular groove between it and the inner surface 4a. The top of the protrusion 152 is located below the end 12b of the insulating valve 12. The inclined portion 153 is the part connecting the boundary portion B and the protrusion 152. The inclined portion 153 slopes along the tube axis AX towards the X-ray tube 3 side ( Figure 5The inclined surface 151a is inclined away from the tube axis AX (above the tube axis). In the above-described upper surface 151a, compared to the case where the upper surface is a flat surface (e.g., a plane orthogonal to the tube axis direction (Z direction) via the boundary portion B), the surface distance is extended by the protrusion 152 and the inclined portion 153. Furthermore, similar to the upper surface 51e of the above embodiment, any portion of the upper surface 151a is located below the end 12b (virtual plane P) of the insulating valve 12. Therefore, with the insulating block 151 having the upper surface 151a, similar to the insulating block 51 having the upper surface 51e of the above embodiment, surface discharge on the surface of the insulating block 151 can be suppressed, and the reduction in cooling efficiency of the X-ray tube 3 can be suppressed.

[0057] Figure 5 The upper surface 251a of the insulating block 251 shown in (B) is formed into an inverted cone shape (sloping downwards from the inside to the outside) by means of a protrusion 252 and an inclined portion 253. The protrusion 252 is the same as the protrusion 55A in the above embodiment. That is, the protrusion 252 is an annular protrusion provided in a manner that surrounds the high-voltage feed section 54 near the high-voltage feed section 54. The top of the protrusion 252 is located below the end 12b (virtual plane P) of the insulating valve 12. The inclined portion 253 is the part that connects the protrusion 252 and the upper surface edge 51a. The inclined portion 253 slopes downwards along the tube axis AX towards the X-ray tube 3 side ( Figure 5 The upper surface 251a is inclined towards the tube axis AX, while the upper surface 251a is inclined at the top. Compared to the case where the upper surface is flat, the surface distance is extended by the protrusion 252 and the inclined portion 253. In addition, similar to the upper surface 51e in the above embodiment, any part of the upper surface 251a is located below the end 12b (virtual plane P) of the insulating valve 12. Therefore, the insulating block 251 with the upper surface 251a, similar to the insulating block 51 with the upper surface 51e in the above embodiment, can suppress surface discharge on the surface of the insulating block 251 and suppress the reduction of cooling efficiency of the X-ray tube 3. In addition, the discharge suppression effect of the boundary portion B is very high, and foreign objects can easily reach the X-ray tube receiving portion 4 at the ground potential (0V) through the inclined surface. Therefore, discharge caused by foreign objects is less likely to occur, and foreign objects are also easy to remove.

[0058] Figure 5The upper surface 351a of the insulating block 351 shown in (C) is formed into a wave shape by a plurality of annular protrusions 352 periodically arranged from the inside to the outside. Each protrusion 352, when viewed from the Z direction, is arranged as a concentric circle centered on the tube axis AX. The protrusion 352 connected to the boundary portion B (the innermost protrusion 352) is arranged to surround the boundary portion B. The top of each protrusion 352 is located below the end 12b (virtual plane P) of the insulating valve 21. In the upper surface 351a described above, compared to the case where the upper surface is flat, the surface distance is further extended by the plurality of protrusions 352. Furthermore, similar to the upper surface 51e of the above embodiment, any part of the upper surface 351a is located below the end 12b (virtual plane P) of the insulating valve 12. Therefore, the insulating block 351 with an upper surface 351a, similar to the insulating block 51 with an upper surface 51e in the above embodiment, can suppress surface discharge on the surface of the insulating block 351 and suppress the reduction of cooling efficiency of the X-ray tube 3.

[0059] Figure 5 The upper surface 451a of the insulating block 451 shown in (D) is stepped by a cylindrical protrusion 452 surrounding the high-voltage feed section 54. The protrusion 452 protrudes through the boundary portion B into a plane (XY plane) orthogonal to the tube axis direction (Z-direction). As a result, an annular groove 453 is provided between the protrusion 452 and the high-voltage feed section 54, and an annular groove 454 is also provided between the protrusion 452 and the inner surface 4a of the X-ray tube housing 4A. The top of the protrusion 452 is located below the end 12b (virtual plane P) of the insulating valve 12. In the upper surface 451a described above, the surface distance is extended by the protrusion 452 compared to the case where the upper surface is a flat surface. Specifically, the surface distance increases the extent to which the side surface of the protrusion 452 (the inner surface forming the groove 453 and the outer surface forming the groove 454) increases compared to a flat surface. Furthermore, similar to the upper surface 51e in the above embodiment, any portion of the upper surface 451a is located below the end 12b (virtual plane P) of the insulating valve 12. Therefore, with the insulating block 451 having the upper surface 451a, similar to the insulating block 51 having the upper surface 51e in the above embodiment, surface discharge on the surface of the insulating block 451 can also be suppressed, and the reduction in cooling efficiency of the X-ray tube 3 can be suppressed. In addition, protrusions can be easily formed.

[0060] Furthermore, the shape of the upper surface of the insulating block is not limited to the specific upper surface shape (upper surface 51e, 151a, 251a, 351a, 451a) mentioned above, but can also be any combination of the shapes of the above parts.

[0061] Furthermore, the X-ray tube 3 of the above embodiment is a reflective X-ray tube that extracts X-rays from a direction different from the electron incident direction toward the target. However, it can also be a permeable X-ray tube that extracts X-rays along the electron incident direction toward the target (the X-rays generated by the target pass through the target itself and are extracted from the X-ray exit window). In addition, in the X-ray tube 3 of the above embodiment, an X-ray exit window 33a is formed above the target T, and an electron gun 11 is arranged on the side of the target T. However, the X-ray extraction method can also be a so-called side-window method (i.e., the X-ray exit window is arranged on the side of the target T). Specifically, an electron gun that emits electrons toward the target T along the tube axis can be arranged at the position where the X-ray exit window 33a is provided (i.e., above the target T), and an X-ray exit window can be arranged at the position where the electron gun 11 is provided (i.e., on the side of the target T).

[0062] Symbol Explanation

[0063] 1…X-ray generating device, 3…X-ray tube, 4…X-ray tube housing, 4a…inner surface, 5…power supply, 12…insulating valve (valve part), 45…insulating oil (insulating liquid), 60b…base end (high voltage application part), 51, 151, 251, 351, 451…insulating block, 51e, 151a, 251a, 351a, 451a…upper surface (surface), 52…internal circuit board (high voltage generating circuit), 54…high voltage feed part (feed part), 55…protrusion, 55A…protrusion (first protrusion), 55B…protrusion (second protrusion), 56…groove, 57…recess, 58…inclined part, AX…tube shaft, B, B2…boundary part.

Claims

1. An X-ray generating device, characterized in that, include: An X-ray tube having a valve section and a high-voltage application section protruding from the valve section; The X-ray tube housing includes a valve portion that, when viewed along the tube axis of the X-ray tube, at least surrounds the valve portion. and The power supply unit is constructed by sealing a high-voltage generating circuit for supplying voltage to the X-ray tube within a solid insulating block made of insulating material. An insulating liquid is sealed in the space defined by the surface of the insulating block facing the X-ray tube and the inner surface of the X-ray tube housing. A conductive feed portion electrically connected to the high-voltage application portion is disposed on the surface of the insulating block. At least one protrusion is provided on the surface of the insulating block, the protrusion extending further towards the valve section than the boundary between the power supply section, the surface of the insulating block, and the insulating liquid, and surrounding the power supply section when viewed from the tube axis. The at least one protrusion includes a first annular protrusion surrounding the power supply portion in the vicinity of the power supply portion. The inner side of the recess surrounding the first protrusion and continuous with the outer side of the first protrusion is inclined along the tube axis in a manner that moves away from the tube axis from the valve side toward the insulating block side.

2. The X-ray generating apparatus as described in claim 1, characterized in that: The end edge of the first protrusion has a rounded chamfer shape.

3. The X-ray generating apparatus as described in claim 1 or 2, characterized in that: The outer surface of the recess is inclined along the tube axis as it approaches the tube axis from the valve side toward the insulating block side.

4. The X-ray generating apparatus according to any one of claims 1 to 3, characterized in that: The at least one protrusion includes a second annular protrusion with a groove formed between it and the inner surface of the X-ray tube receiving portion. The outer surface of the second protrusion is inclined along the tube axis as it moves away from the tube axis from the valve side toward the insulating block side.

5. The X-ray generating apparatus according to any one of claims 1 to 4, characterized in that: The area on the surface of the insulating block that comes into contact with the insulating liquid is not provided with discontinuous corners throughout its entirety.

6. The X-ray generating apparatus as described in claim 5, characterized in that: The area of ​​the surface of the insulating block that is in contact with the insulating liquid is formed with a curved or inclined surface throughout the entire surface.

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