Energy ray tube

Abstract

The present invention provides an energy ray tube capable of suppressing the destruction of the sealing state of the internal space. The energy ray tube (3) includes a frame portion (40), a window portion (50), and a sealing portion (70). An opening (40a) is formed in the frame portion (40). The window portion (50) covers the opening (40a) when viewed from the opening direction and includes a window (53) through which energy rays are transmitted. The sealing portion (70) fixes the window portion (50) relative to the frame portion (40) and seals the internal space (R) surrounded by the frame portion (40) and the window portion (50). The sealing portion (70) is disposed in a frame-shaped region (α) in the window portion (50) along the edge of the opening (40a). When the thickness of the window portion (50) in region (α) is set to t, the width of region (α) is set to w, and the thickness of the frame portion (40) from the inside to the outside of the interior space (R) is set to d, the relationship w / d≥1 and t / d≥0.3 is satisfied.

Description

Technical Field

[0001] This invention relates to an energy ray tube. Background Technology

[0002] Energy ray tubes that irradiate or incident energy rays are known (e.g., Patent Document 1). Patent Document 1 describes a transmission-type energy ray tube that emits energy rays. This energy ray tube includes a frame portion and a window portion provided in the frame portion. The window portion allows energy rays to pass through.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2002-042705 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] The energy ray tube contains a sealed internal space within a frame. This internal space is maintained in a vacuum state. However, the seal of the internal space is susceptible to damage due to stress caused by various factors. For example, a heating process is often performed during vacuum sealing. In this heating process, the energy ray tube is heated to a high temperature and then cooled to room temperature. At this time, thermal stress may occur in the fixing part that secures the window to the frame due to the difference in the coefficients of thermal expansion between the window and the frame. In this case, there is a risk that the fixing part may warp due to thermal stress. If the fixing part warps, it may break, compromising the seal of the internal space. For example, if the seal is compromised during manufacturing, it may lead to a decrease in production efficiency.

[0008] One aspect of the present invention is to provide an energy ray tube capable of preventing the sealing of the internal space from being compromised.

[0009] Technical means for solving technical problems

[0010] In one embodiment of the present invention, an energy ray tube includes a frame portion, a window portion, and a sealing portion. The frame portion has an opening and includes an edge portion dividing the opening. The window portion covers the opening when viewed from its opening direction and includes a window through which energy rays can be transmitted. The sealing portion fixes the window portion to the frame portion and seals the internal space enclosed by the frame portion and the window portion. The sealing portion is disposed in a frame-shaped region along the edge of the opening in the window portion. When the thickness of the window portion in the region is t, the width of the region is w, and the thickness of the frame portion in the edge portion is d, the relationships w / d≥1 and t / d≥0.3 are satisfied.

[0011] In one of the above embodiments, the energy ray tube includes the aforementioned sealing portion that secures the window to the frame. When the energy ray tube satisfies the above relationship, the sealing of the internal space is not easily compromised.

[0012] In one of the above methods, the sealing part can also be formed by brazing. In this case, the internal space can be sealed in a structure that is easy to manufacture.

[0013] In one of the above embodiments, a frame portion may also be included, which is disposed along the edge of the opening and fixed to the frame portion by welding. Alternatively, a sealing portion may be used to fix the window portion and the frame portion. In this case, the internal space can be easily sealed.

[0014] In one of the above methods, the frame portion can be fixed to the frame body portion at a position closer to the outside than the window portion when viewed from the opening direction. In this case, the frame portion and the frame body portion can be easily fused together.

[0015] In one of the above embodiments, the window portion may be located at the end opposite the edge in the opening direction of the opening. In this case, displacement between the window portion and the frame portion can be suppressed. Therefore, the sealing of the interior space is less likely to be compromised.

[0016] In one of the above methods, it can also be at least one of the following: 0.5mm≤d≤20mm, 0.5mm≤t≤10mm, and 1.0mm≤w≤20mm.

[0017] Invention Effects

[0018] One aspect of the present invention provides an energy ray tube capable of preventing the sealing of the internal space from being compromised. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view showing the energy ray generating device in this embodiment.

[0020] Figure 2 This is a cross-sectional view of an energy ray tube.

[0021] Figure 3 This is a diagram showing a portion of an energy ray tube.

[0022] Figure 4 This is a magnified view of a section of an energy ray tube.

[0023] Figure 5 This is a diagram showing the manufacturing process of an energy ray tube.

[0024] Figure 6 This is a diagram showing the manufacturing process of an energy ray tube.

[0025] Figure 7 This is a diagram used to illustrate the stress applied to an energy ray tube.

[0026] Figure 8 Figures (a) to (c) are used to illustrate the cracks that occur in the window section of the energy ray tube in the comparative example. Detailed Implementation

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, in the description, the same reference numerals are used to denote the same elements or elements having the same function, and repeated descriptions are omitted.

[0028] First, refer to Figure 1 and Figure 2 The structure of the energy ray tube in this embodiment will be described. Figure 1 This is a schematic diagram showing the structure of the energy ray generating device in this embodiment. Figure 2 This is a longitudinal cross-sectional view of the energy ray tube in this embodiment. (As shown...) Figure 1 and Figure 2 As shown, the energy ray generating device 100 is, for example, an X-ray generating device that irradiates X-rays. The X-axis, Y-axis, and Z-axis directions are orthogonal to each other. In this embodiment, X-rays are irradiated in the Z-axis direction. The energy ray generating device 100 includes a device housing 1, a power supply unit 2, and an energy ray tube 3.

[0029] The device housing 1 includes a cylindrical member 10 and a power supply housing 20. The cylindrical member 10 is made of metal. The cylindrical member 10 is cylindrical with an opening 10a at one end and an opening 10b at the other end. A portion of an energy ray tube 3 is inserted into the cylindrical member 10 through the opening 10a.

[0030] At one end of the cylindrical member 10, a mounting flange 3a of the energy ray tube 3 is abutted against and fixed by a threaded fitting or the like. The energy ray tube 3 is fixed to the opening 10a of the cylindrical member 10, sealing the opening 10a. Inside the cylindrical member 10, insulating oil 11, which is a liquid electrical insulating material, is sealed.

[0031] The power supply unit 2 supplies power to the energy ray tube 3. In addition to the power supply unit housing 20 described above, the power supply unit 2 also includes an insulating block 21, a boost circuit 22, and a control board 23. The power supply unit housing 20 houses the insulating block 21, the boost circuit 22, and the control board 23. The insulating block 21 is made of a solid insulating material obtained by molding, such as epoxy resin as an insulating resin. The boost circuit 22 is molded within the insulating block 21. The boost circuit 22 generates a high voltage V. The insulating block 21 seals the boost circuit 22 with insulating material. The control board 23 controls the operation of the energy ray generating device 100. The control board 23 performs controls related to the generation of energy rays. For example, the control board 23 controls the voltage or current supplied to the energy ray tube 3 and controls the driving of the boost circuit 22. The control board 23 has an inner substrate 23a molded within the insulating block 21 and an outer substrate 23b disposed outside the insulating block 21.

[0032] The other end of the cylindrical member 10 is fixed to the power supply section 2. Thus, the opening 10b of the cylindrical member 10 is sealed, and the insulating oil 11 is hermetically sealed into the interior of the cylindrical member 10. The opening 10b is located on the opposite side of the opening 10a.

[0033] The energy beam generating device 100 also includes a high-voltage power supply unit 4. The high-voltage power supply unit 4 is disposed on the insulating block 21. The high-voltage power supply unit 4 includes a cylindrical socket electrically connected to the boost circuit 22 and the control board 23. The energy beam tube 3 is electrically connected to the power supply unit 2 via the high-voltage power supply unit 4. Furthermore, the high-voltage power supply unit 4 is fixed to the insulating block 21 while electrically connected to the boost circuit 22 and the control board 23.

[0034] The energy ray tube 3 is an X-ray tube that irradiates the outside with X-rays generated in the internal space R (described later). The energy ray tube 3 has an insulating tube 6 and a head 7. The insulating tube 6 is formed of an insulating material. Examples of insulating materials include glass and ceramic. The insulating tube 6 is made of glass or ceramic, for example. The insulating tube 6 is inserted into the cylindrical member 10. The head 7 is made of metal. Examples of metal materials include stainless steel and Kovar alloy. The head 7 is made of stainless steel or Kovar alloy, for example. The insulating tube 6 and the head 7 form the internal space R. The internal space R is sealed to form a vacuum space. The energy ray tube 3 also has an electron gun 110 within the internal space R. The electron gun 110 is equivalent to the cathode of the energy ray tube 3 in terms of potential, generating and emitting an electron beam B.

[0035] The electron gun 110 is fixed to the insulating tube 6. The insulating tube 6 is cylindrical, extending along the axis of the energy ray tube 3. The insulating tube 6 has a bottom 6a opposite to the head 7. A stempin S for powering the electron gun 110 is provided at the bottom 6a. The stempin S passes through the bottom 6a and supports the electron gun 110 at a predetermined position in the internal space R. The stempin S protrudes from the bottom 6a of the insulating tube 6 of the energy ray tube 3 to the outside of the internal space R and is electrically connected to the high-voltage power supply unit 4.

[0036] The electron gun 110 has a heater 111, a negative electrode 112, a first grid electrode 113, and a second grid electrode 114. The heater 111 is formed by a filament that heats up when energized. The negative electrode 112 releases electrons through heating by the heater 111. The first grid electrode 113 controls the amount of electrons released from the negative electrode 112. The second grid electrode 114 causes electrons that have passed through the first grid electrode 113 to converge toward the target T. The second grid electrode 114 is cylindrical. The first grid electrode 113 is disposed between the negative electrode 112 and the second grid electrode 114. An energy ray tube 3 is fixed to one end of the cylindrical member 10.

[0037] The head 7 is equivalent to the anode of the energy ray tube 3 in terms of potential. The head 7 is cylindrical and coaxial with the X-ray emission direction axis. The X-ray emission direction axis corresponds to the Z-axis. A hollow portion 7a is formed in the head 7, which constitutes part of the internal space R. The head 7 is connected to the insulating tube 6, which is coaxial with the emission direction axis, on the electron gun 110 side of the hollow portion 7a. In this embodiment, the head 7 is grounded, and a negative high voltage is supplied from the power supply unit 2 to the electron gun 110 of the energy ray tube 3 via the high voltage power supply unit 4. The voltage applied to the energy ray tube 3 by the power supply unit 2 is, for example, -10kV to -500kV.

[0038] Below, refer to Figures 2 to 4 The structure of the energy ray tube will be explained in more detail. Figure 3 This refers to the head 7 of the energy ray tube 3. Figure 4 This is a magnified view of part 7 of the head. (See image below.) Figure 3 and Figure 4 As shown, the head 7 includes a frame portion 40, a window portion 50, and a frame portion 60. The interior space R is surrounded by the frame portion 40 and the window portion 50. The frame portion 40, the window portion 50, and the frame portion 60 form part of the interior space R.

[0039] The frame portion 40 is cylindrical. For example, the frame portion 40 is cylindrical. The frame portion 40 extends in the Z-axis direction. An opening 40a is formed at one end of the frame portion 40, and an opening 40b is formed at the other end. The frame portion 40 includes an edge portion 41 that divides the opening 40a. The edge portion 41 is an annular planar portion formed by countersinking a hole to a depth h along the entire circumference of one end face of the frame portion 40. The edge portion 41 includes a planar bottom surface 45 extending in a direction intersecting the tube axis direction of the energy ray tube 3 and a side surface 46 extending in the tube axis direction of the energy ray tube 3. In this embodiment, the tube axis direction of the energy ray tube 3 corresponds to the Z-axis direction. The openings 40a and 40b open in the Z-axis direction. In other words, the opening directions of the openings 40a and 40b are in the Z-axis direction. The openings 40a and 40b of the frame portion 40 are continuous with the internal space R. The opening 40a is located at the edge of the internal space R. The frame portion 40 contains metal. The frame portion 40 is mainly formed of a metallic material. Examples of metallic materials include stainless steel. The frame portion 40 is, for example, made of stainless steel.

[0040] Window 50 constitutes a window through which energy rays are transmitted. Window 50 covers opening 40a when viewed from the Z-axis direction. Window 50 includes an end portion 51 and a central portion 52. End portion 51 is an edge region. Central portion 52 is a central region surrounding end portion 51, where window 53 (described later) is disposed. In window 50, a through hole H is formed approximately at the center of central portion 52. Through hole H is a passage hole for electron beam B. Central portion 52 is continuous with end portion 51. End portion 51 is a frame-shaped region opposite edge portion 41 in the Z-axis direction. For example, end portion 51 is annular. Central portion 52 covers opening 40a when viewed from the Z-axis direction. In this embodiment, end portion 51 and central portion 52 are integral components, not components with strict boundaries, but components that define a general area in window 50. Central portion 52 does not face edge portion 41 in the Z-axis direction. Window 50 includes target T, window 53, and window holding member 54. Figure 2 As shown, the target T is disposed on the surface of the interior space R side of the window 53, and generates X-rays by irradiation from the electron beam B from the electron gun 110. Examples of targets T include tungsten. The target T is, for example, made of tungsten.

[0041] Window 53 allows energy rays to pass through. Window 53 is disposed in the central portion 52. Window 53 closes and seals the through hole H. In other words, window 53 forms part of the central portion 52. Window 53 is in the shape of a circular plate. Window 53 holds the target T on the internal space R side. In this embodiment, the energy ray tube 3 is a transmission-type X-ray tube, and the X-rays generated at the target T pass through window 53 and irradiate the outside. Window 53 is formed, for example, of a material with high transmittance to energy rays. Examples of materials for window 53 include beryllium and diamond. Window 53 is made of, for example, beryllium or diamond.

[0042] The window retaining member 54 constitutes the main body of the window portion 50 and retains the window 53. The window 53 is positioned by the window retaining member 54. The window retaining member 54 is in the shape of a circular plate. In this embodiment, the window retaining member 54 consists of an end portion 51 and a central portion 52. That is, in the Z-axis direction, the end portion 51 of the window retaining member 54 faces the edge portion 41, and the central portion 52 covers the opening 40a. The window retaining member 54 is made of, for example, a metallic material. Examples of metallic materials include molybdenum. The window retaining member 54 is made of, for example, molybdenum.

[0043] The frame portion 60 fixes the window portion 50 to the frame portion 40. The frame portion 60 is continuously provided along the edge portion 41, forming a frame shape. The frame portion 60 is continuously formed into a frame shape without being divided. For example, the frame portion 60 is annular. Figure 4 As shown, the frame portion 60 is fixed to the window retaining member 54 of the window portion 50 and the edge portion 41 of the frame portion 40. As a result, the internal space R is airtightly sealed. The frame portion 60 is made of a metallic material, for example. Examples of metallic materials include Kovar alloy. The coefficient of thermal expansion of the frame portion 40 is greater than that of the window portion 50. The coefficient of thermal expansion of the frame portion 40 is greater than that of the window retaining member 54. In this embodiment, the coefficient of thermal expansion of the edge portion 41 of the frame portion 40 is greater than that of the window 53, the window retaining member 54, and the frame portion 60. The coefficient of thermal expansion of the frame portion 60 is substantially equal to that of the window retaining member 54. The coefficient of thermal expansion of the window 53 is smaller than that of any of the frame portion 40, the window retaining member 54, and the frame portion 60. The coefficient of thermal expansion of the frame portion 60 is substantially equal to that of the window retaining member 54. The coefficient of thermal expansion of window 53 is smaller than that of any of the frame 40, window retaining member 54 and frame 60.

[0044] The frame portion 60 includes a first frame portion 61 and a second frame portion 62. In this embodiment, the first frame portion 61 and the second frame portion 62 are each frame-shaped and formed integrally. The first frame portion 61 and the second frame portion 62 are located on the same plane in the X-axis direction and the Y-axis direction, which are orthogonal to the Z-axis direction.

[0045] The first frame portion 61 is fixed to the edge portion 41 of the frame portion 40. The end of the first frame portion 61 on the side separating from the tube axis of the energy ray tube 3 forms the outer edge 61a of the frame portion 60. The edge portion 41 has a bottom surface 45 opposite to the other side of the first frame portion 61 and a side surface 46 opposite to the outer edge 61a. The first frame portion 61 is joined to the frame portion 40, for example, by welding. The end region of the first frame portion 61 on the outer edge 61a side is joined to the frame portion 40, for example, by laser welding. At least a portion of the first frame portion 61 is located further outward than the window portion 50 when viewed from the Z-axis direction. The end region on the outer edge 61a side is located further outward than the window portion 50 when viewed from the Z-axis direction. At least a portion of the first frame portion 61 is exposed when viewed from the Z-axis direction, not covered by the window portion 50. Therefore, in laser welding, the laser is irradiated onto the weld portion not obstructed by the window portion 50.

[0046] The second frame portion 62 is arranged overlapping the central portion 52 when viewed from the Z-axis direction. In other words, the second frame portion 62 is positioned within the area overlapping the opening 40a when viewed from the Z-axis direction. The second frame portion 62 does not overlap with the edge portion 41 when viewed from the Z-axis direction. The second frame portion 62 is fixed to the window portion 50. The second frame portion 62 is engaged with the portion of the surface 50a of the window portion 50 on the interior space R side, corresponding to the central portion 52. The surface 50a is the surface of the window portion 50 opposite to the opening 40a.

[0047] In this embodiment, the head 7 also includes a sealing portion 70. The sealing portion 70 includes a fixing member 71, which seals the internal space R and is sealed by fixing members 71 to the frame portion 62 and the window portion 50. The fixing member 71 of the sealing portion 70 is disposed between the second frame portion 62 and the window portion 50. The fixing member 71 of the sealing portion 70 engages one side of the second frame portion 62 with the surface 50a of the window portion 50. The fixing member 71 of the sealing portion 70 is disposed in a frame-shaped region α along the edge of the opening 40a in the surface 50a. The frame-shaped region α is continuous. Region α is located in the central portion 52. In other words, the fixing member 71 of the sealing portion 70 continuously surrounds the tube axis of the energy ray tube 3 without being divided. The fixing member 71 of the sealing portion 70 is, for example, in an annular shape. The sealing portion 70 is formed, for example, by brazing. In other words, the frame portion 60 is joined to the window portion 50, for example, by brazing. In this case, the fixing member 71 is made of brazing filler metal. Examples of brazing filler metal include alloys. For example, silver brazing alloy can be cited as an example.

[0048] In the energy ray tube 3, when the thickness of the frame portion 40 in the edge portion 41 is set as d, the thickness of the window portion 50 in the region α is set as t, and the width of the region α is set as w, the relationships w / d≥1 and t / d≥0.3 are satisfied. The thickness d of the frame portion 40 is the thickness of the frame portion 40 from the inside to the outside of the internal space R. For example, the thickness d of the frame portion 40 is the thickness of the portion of the frame portion 40 that surrounds the internal space R in the X-axis or Y-axis direction orthogonal to the opening direction. The thickness t of the window portion 50 is, for example, the thickness of the window holding member 54 in the Z-axis direction. The width w of the region α is the length of a continuous portion in the direction orthogonal to the Z-axis direction. For example, the width w of the region α is the same as the width of the fixing member 71 of the sealing portion 70 in the direction orthogonal to the Z-axis direction. The width of the fixing member 71 of the sealing portion 70 is the length in the cross-sectional direction of a continuous portion in the cross-section in the direction orthogonal to the Z-axis direction. The width w of region α is, for example, the same as the frame width of the fixing member 71 of the frame-shaped sealing part 70.

[0049] The greater the thickness d of the frame portion 40, the higher its strength. The smaller the thickness d of the frame portion 40, the lower its weight and material cost. For example, the thickness d of the frame portion 40 satisfies the relationship 0.5mm ≤ d ≤ 20mm. In other words, the thickness d of the frame portion 40 is, for example, 0.5mm or more and 20mm or less. In this case, a balance can be achieved between the strength, weight, and material cost of the frame portion 40. Thickness d is more preferably 10mm or less. When the thickness d of the frame portion 40 is 0.5mm or more and 10mm or less, the strength of the frame portion 40 can be ensured, and the weight and material cost can be further reduced.

[0050] The thickness d of the frame portion 40 satisfies, for example, the relationship 0.5mm ≤ d ≤ 20mm. More preferably, the thickness d is 10mm or less. The thickness t of the window portion 50 satisfies, for example, the relationship 0.5mm ≤ t ≤ 10mm. More preferably, the thickness t is 7mm or less. The width w of the region α satisfies, for example, the relationship 1.0mm ≤ w ≤ 20mm. More preferably, the width w is 15mm or less. More preferably, the width w is 3mm or more.

[0051] Below, refer to Figure 5 and Figure 6 This section describes a part of the manufacturing method for energy ray tubes. Figure 5 and Figure 6 A diagram showing the manufacturing process of an energy ray tube.

[0052] First, such as Figure 5As shown, a window 53 with a target T, a window retaining member 54, and a frame portion 60 are connected to each other. Arrow A1 indicates the direction in which the window 53 is mounted on the window retaining member 54. Arrow A2 indicates the direction in which the window retaining member 54 is mounted on the frame portion 60. The window 53 is fixed to the center of the central portion 52 of the window retaining member 54. The frame portion 60 is fixed to the window retaining member 54 by brazing. Specifically, it is fixed to one side of the second frame portion 62 of the window retaining member 54 by brazing. At this time, in a direction orthogonal to the window 53, the window retaining member 54 overlaps with the second frame portion 62. The brazing is performed, for example, at 600 to 1000°C.

[0053] Next, the unit 80, which is formed by connecting the window 53, the window retaining member 54, and the frame 60 to each other, is subjected to vacuum heating treatment. The vacuum heating treatment is performed, for example, at 200 to 1000°C.

[0054] Next, as Figure 6 As shown, unit 80 is fixed to frame portion 40. Arrow A3 indicates the direction in which unit 80 is mounted on frame portion 40. Thus, unit 80 is embedded in edge portion 41 of frame portion 40. With unit 80 embedded in edge portion 41 of frame portion 40, frame portion 60 and frame portion 40 are fixed by welding. Specifically, the first frame portion 61 of frame portion 60 and frame portion 40 are welded by laser. The joining of unit 80 to frame portion 40 is performed at room temperature.

[0055] Next, after assembling the insulating tube 6 into the insulating tube of unit 90, which connects unit 80 and frame 40, the internal space R is evacuated. The heating process at this time is performed, for example, at 200–650°C. The energy ray tube 3 is sealed after the internal space R is evacuated through the heating process and then cooled to room temperature. By performing the above processes, the energy ray tube 3 is manufactured.

[0056] The effects of the energy ray tube 3 will be explained below. Figure 7 This represents the force applied to the sealing portion 70 of the energy ray tube 3. For example, when the energy ray tube 3 is placed in a high-temperature environment, the frame portion 40 thermally expands in a direction orthogonal to the Z-axis. The frame portion 60 is fixed to the frame portion 40 at the bottom surface 45. The frame portion 60 is fixed to the window portion 50 in region α by a fixing member 71. When the coefficient of thermal expansion of the frame portion 40 is greater than that of the window portion 50 and the frame portion 60, under the same heating conditions, the frame portion 40 expands relatively more than the window portion 50 and the frame portion 60. In other words, the frame portion 40 deforms relatively more than the window portion 50 and the frame portion 60. In other words, the window portion 50 and the frame portion 60 are relatively less prone to deformation under heat than the frame portion 40. Therefore, forces A4 and A5 caused by the difference in the coefficients of thermal expansion between the frame portion 40 and the window portion 50 and the frame portion 60 are applied to the sealing portion 70.

[0057] Forces A4 and A5 are forces generated in opposite directions orthogonal to the Z-axis. Therefore, the stress caused by forces A4 and A5 acts on the sealing portion 70. This stress is shear stress. When the magnitude of this stress exceeds the mechanical strength of the sealing portion 70, there is a risk of damage such as cracking occurring in the sealing portion 70, and the sealing state of the internal space R being compromised.

[0058] The shear stress in region α is the value obtained by dividing the force applied to the sealing portion 70 in a direction orthogonal to the Z-axis by the area of ​​region α. ​​Therefore, it is assumed that a larger area of ​​region α results in lower shear stress, thus resolving the problem of seal failure. However, the investigation revealed that a larger area of ​​region α leads to a higher frequency of window breakage due to crack formation. This crack formation poses a risk of compromise to the seal of the internal space R.

[0059] The inventors of this application evacuated the internal space R in an energy ray tube under various conditions through a heating process. For example, when the thickness of the window portion 50 in region α was set as t, the width of region α as w, and the thickness of the frame portion from the inner side to the outer side of the internal space as d, multiple samples were fabricated using t, d, and w as parameters, and experiments based on the evacuation process were conducted on each sample. Multiple samples were also fabricated using the same parameters. In these samples, the window holding member 54 of the window portion 50 was formed of molybdenum, and the sealing portion 70 was formed of silver solder.

[0060] As a result, in an energy ray tube with t = 1 mm, d = 4.5 mm, and w = 3.5 mm, the seal 70 was damaged. In an energy ray tube with t = 1 mm, d = 4.5 mm, and w = 6 mm, the window 50 was damaged. In an energy ray tube with t = 1 mm, d = 4.5 mm, and w = 9 mm, the window 50 was damaged. In an energy ray tube with t = 2 mm, d = 4.5 mm, and w = 6 mm, neither the seal 70 nor the window 50 was damaged.

[0061] from Figure 8 (a) to Figure 8 Figure (c) illustrates a crack generated in the window portion of the energy ray tube in the comparative example. When the joint strength between the frame portion 40 and the window portion 50 is too high, a crack may occur in the window portion 50. In the structure of this comparative example, a sealing portion 200 is provided in place of the sealing portion 70 in the energy ray tube. The sealing portion 200 differs from the sealing portion 70 in that it has a width greater than that of the sealing portion 70 in a direction orthogonal to the Z-axis direction. In other words, the width w of region α in this comparative example is greater than the width w of region α in the energy ray tube 3. With this sealing portion 200, multiple energy ray tubes are manufactured using the manufacturing method described above. In this case, in a large number of energy ray tubes, such as... Figure 8 (a) and Figure 8 As shown in (b), a crack C1 was formed along the inner periphery 200a of the sealing portion 200. In several energy ray tubes, such as... Figure 8 As shown in (c), when viewed from the Z-axis direction, a crack C2 is generated on the inner side of the inner perimeter 200a, in the window portion 50.

[0062] Based on the aforementioned experiments, the inventors of this application modified the parameters t, d, and w, and simulated the stress applied to the sealing portion 70 after applying stress to the window portion 50. The results showed that, satisfying the relationships R / d≥1 and t / d≥0.3, it was determined that cracks were unlikely to occur in the window portion 50. In other words, the energy ray tube 3, satisfying these relationships, can suppress the formation of cracks in the window portion 50, thus preventing damage to the seal of the internal space R.

[0063] The greater the thickness d of the frame portion 40, the higher its strength. The smaller the thickness d of the frame portion 40, the lower its weight and material cost. For example, the thickness d of the frame portion 40 satisfies the relationship 0.5mm ≤ d ≤ 20mm. In other words, the thickness d of the frame portion 40 is, for example, 0.5mm or more and 20mm or less. In this case, a balance can be achieved between the strength, weight, and material cost of the frame portion 40. Thickness d is more preferably 10mm or less. When the thickness d of the frame portion 40 is 0.5mm or more and 10mm or less, the strength of the frame portion 40 can be ensured, and the weight and material cost can be further reduced.

[0064] The greater the thickness t of the window portion 50, the higher its strength and the better its thermal conductivity. The smaller the thickness t of the window portion 50, the lower the material cost and the smaller the focal diameter of the energy rays passing through the window 53. The thickness t of the window portion 50 satisfies, for example, the relationship 0.5 mm ≤ t ≤ 10 mm. In other words, the thickness t of the window portion 50 is, for example, 0.5 mm or more and 10 mm or less. In this case, a balance can be achieved between the strength and thermal conductivity of the window portion 50 and the material cost and focal diameter. A thickness t is more preferably 1 mm or more. A thickness t is more preferably 7 mm or less. When the thickness t of the window portion 50 is 1 mm or more and 7 mm or less, a higher balance can be achieved between the strength and thermal conductivity of the window portion 50 and the material cost and focal diameter.

[0065] The larger the width w of region α, the stronger the seal of the internal space R. The smaller the width w of region α, the lower the material cost and the better the resistance to breakage of the joint between the window portion 50 and the frame portion 40. The width w of region α satisfies, for example, the relationship 1.0 mm ≤ w ≤ 20 mm. In other words, the width w of region α is, for example, 1.0 mm or more and 20 mm or less. In this case, a sealed state can be easily formed, and a balance can be achieved between material cost, the joint strength between the window portion 50 and the frame portion 40, and the seal strength. Width w is more preferably 15 mm or less. Width w is more preferably 3 mm or more. When the width w is 3 mm or more, a more stable seal can be ensured by brazing. When the width w of region α is 3 mm or more and 15 mm or less, a sealed state can be formed more easily, and a higher balance can be achieved between material cost, the joint strength between the window portion 50 and the frame portion 40, and the seal strength.

[0066] In the energy ray tube 3, the sealing part 70 is formed by brazing. In this case, the internal space R can be sealed in a structure that is easy to manufacture.

[0067] The frame portion 60 is provided along the edge of the opening 40a and is fixed to the frame portion 40 by welding. The sealing portion 70 fixes the window portion 50 and the frame portion 60. In this case, the internal space R can be easily sealed.

[0068] When viewed from the Z-axis direction, the frame portion 60 is fixed to the frame body portion 40 at a position closer to the outer side than the window portion 50. In this case, the frame portion 60 and the frame body portion 40 can be easily welded together.

[0069] The window portion 50 includes an end portion 51 opposite to the edge portion 41 in the Z-axis direction. In this case, even if an external stress β is applied to the window portion 50, such as pushing it towards the frame portion 40, the window portion 50 is supported by the edge portion 41, thus suppressing displacement between the window portion 50 and the frame portion 40. Therefore, the sealing state of the internal space R is not easily compromised. Moreover, changes in the emission conditions of energy rays transmitted through the window portion 50 can also be suppressed.

[0070] The embodiments and variations of the present invention have been described above. However, the present invention is not necessarily limited to the embodiments described above, and various changes can be made without departing from its spirit.

[0071] For example, the energy ray tube is not limited to the energy ray tube 3 installed in the energy ray generating device. For example, it may also be an energy ray detection tube that detects energy rays irradiating the energy ray tube from the outside. In this case, the energy rays enter the internal space R of the energy ray tube from the window 50.

[0072] In this embodiment, the window retaining member 54 is fixed to the frame portion 40 via the frame portion 60. However, the window retaining member 54 may also be directly fixed to the frame portion 40.

[0073] Symbol Explanation

[0074] 3……Energy ray tube, 40a……Opening, 40……Frame part, 41……Edge part, 50……Window part, 50a……Surface, 51……End, 53……Window, 60……Frame part, 70……Sealing part, R……Internal space, t, d……Thickness, w……Width, α……Area.

Claims

1. An energy ray tube, wherein, have: The frame portion has an opening and includes an edge portion that divides the opening; A window portion that covers the opening when viewed from the opening direction of the opening, and includes a window that allows energy rays to pass through; as well as A sealing part that fixes the window portion to the frame portion fixed to the frame portion, and seals the internal space surrounded by the frame portion and the window portion. The sealing portion is disposed in a frame-shaped area along the edge of the opening on the surface of the window. When the thickness of the frame portion in the edge is set to d, the thickness of the window portion in the region is set to t, and the width of the region is set to w, The relationship satisfies w / d≥1 and t / d≥0.

3.

2. The energy ray tube as described in claim 1, wherein, The sealing part is formed by brazing.

3. The energy ray tube as described in claim 1, wherein, The frame portion is disposed along the edge of the opening and is fixed to the frame body portion by welding. The sealing part secures the window part and the frame part.

4. The energy ray tube as described in claim 2, wherein, The frame portion is disposed along the edge of the opening and is fixed to the frame body portion by welding. The sealing part secures the window part and the frame part.

5. The energy ray tube as described in claim 3, wherein, When viewed from the opening direction of the opening, the frame is fixed to the frame body at a position closer to the outside than the window.

6. The energy ray tube as claimed in claim 4, wherein, When viewed from the opening direction of the opening, the frame is fixed to the frame body at a position closer to the outside than the window.

7. The energy ray tube as claimed in any one of claims 1 to 6, wherein, The window portion is included at the end opposite the edge portion in the opening direction of the opening.

8. The energy ray tube as claimed in any one of claims 1 to 6, wherein, The relationship that satisfies 0.5mm≤d≤20mm The relationship between 0.5mm≤t≤10mm and At least one of the relationships 1.0mm≤w≤20mm.

9. The energy ray tube as claimed in claim 7, wherein, The relationship that satisfies 0.5mm≤d≤20mm The relationship between 0.5mm≤t≤10mm and At least one of the relationships 1.0mm≤w≤20mm.

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