X-ray tube and method for manufacturing X-ray tube

Abstract

Provided are an X-ray tube and a method for manufacturing the X-ray tube, which are capable of increasing the amount of heat dissipated to the outside of a housing and of facilitating heating of elements inside the housing in a manufacturing process. An X-ray tube according to an embodiment includes: a housing capable of maintaining a reduced air pressure to an atmosphere lower than atmospheric pressure; the cathode is arranged in the shell and is sealed at the end part of one side of the shell; the anode is arranged in the shell and is sealed at the end part of the other side of the shell; and a heat dissipation part, which is provided on the outside of the housing, and which is joined to the anode. The anode has a rod, an end portion of one side of the rod is disposed inside the housing, and an end portion of the other side of the rod is exposed to the outside of the housing. The heat dissipation portion is fitted or screwed to the end portion of the rod exposed to the outside of the housing.

Description

Technical Field

[0001] Embodiments of the present invention relate to an X-ray tube and a method for manufacturing the X-ray tube. Background Art

[0002] There is an X-ray tube including a housing and a cathode and an anode disposed inside the housing. The anode faces the cathode and has a target at the end on the cathode side. In addition, the end of the anode on the side opposite to the cathode side is exposed from the housing.

[0003] Here, the thermal electrons generated at the filament provided at the cathode are pulled toward the anode side and collide with the target. When the thermal electrons collide with the target, heat is generated while generating X-rays. The generated heat is transferred through the anode and released to the outside of the housing. At this time, if the amount of heat dissipated to the outside is small, there is a possibility that the temperature of the target becomes too high, the target melts, or the amount of X-rays generated is reduced.

[0004] In this case, if a heat dissipation member is provided at the end of the anode exposed from the housing, the heat dissipation to the outside of the housing can be increased. However, if only a heat dissipation member is provided, there is a possibility that a gap is generated between the anode and the heat dissipation member, thereby reducing the heat dissipation or causing a deviation in the heat dissipation.

[0005] In addition, when manufacturing an X-ray tube, it is necessary to discharge the gas adsorbed or absorbed on the surface of the element inside the housing. Therefore, when the inside of the housing is exhausted, the element inside the housing is heated. At this time, if a heat dissipation member is provided at the end of the anode, the heat of the heated element is released to the outside through the heat dissipation member. Therefore, there is a possibility that the temperature of the element becomes difficult to rise or the heating time of the element becomes longer.

[0006] Therefore, it is desired to develop a technology that can increase the amount of heat dissipated to the outside of the housing and facilitate heating of elements inside the housing during the manufacturing process. Prior art literature Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2009-176654 Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide an X-ray tube and a method for manufacturing the X-ray tube, wherein the X-ray tube can increase the amount of heat dissipated to the outside of the housing and can facilitate heating of elements inside the housing during the manufacturing process.

[0009] An X-ray tube of an embodiment includes: a housing capable of maintaining an atmosphere in which the gas pressure is reduced to a pressure lower than the atmospheric pressure; a cathode disposed inside the housing and sealed at an end portion on one side of the housing; an anode disposed inside the housing and sealed at an end portion on the other side of the housing; and a heat sink disposed outside the housing and joined to the anode. The anode has a rod, an end portion on one side of the rod is disposed inside the housing, and an end portion on the other side is exposed to the outside of the housing. The heat sink is fitted or screwed to the end portion of the rod exposed to the outside of the housing.

[0010] According to the embodiments of the present invention, an X-ray tube capable of increasing the amount of heat dissipated to the outside of a housing and facilitating heating of elements inside the housing during a manufacturing process and a method for manufacturing the X-ray tube can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic cross-sectional view for illustrating the X-ray tube according to the present embodiment. Figure 2 It is a schematic cross-sectional view for illustrating a heat dissipation portion of a comparative example. Figure 3 This is a schematic cross-sectional view for illustrating a rod according to another embodiment. Figure 4 This is a schematic cross-sectional view for illustrating a heat dissipation portion according to another embodiment. Figure 5 (a) and (b) are schematic cross-sectional views for illustrating a heat dissipation portion according to another embodiment. Figure 6 This is a schematic cross-sectional view for illustrating the screw connection between the rod and the heat dissipation portion. Explanation of symbols 1X-ray tube; 1a central axis; 10 housing; 20 cathode; 30 anode; 31 rod; 31c rod; 31ca male thread; 32 target; 40 heat sink; 40a hole; 40b heat sink; 40ba hole; 40b1 recess; 41 heat sink; 41b fin; 42 heat sink; 43 heat sink; 43a female thread; 44 layer; 45 layer. DETAILED DESCRIPTION

[0012] Hereinafter, the embodiments will be described with reference to the accompanying drawings. In addition, in each of the drawings, the same components are denoted by the same reference numerals, and detailed descriptions thereof will be appropriately omitted. (X-ray tube) The X-ray tube 1 of the present embodiment can be provided in, for example, an X-ray inspection device for nondestructive inspection, an X-ray imaging diagnostic device for medical diagnosis, etc. However, the application of the X-ray tube 1 is not limited thereto.

[0013] Figure 1 It is a schematic cross-sectional view for illustrating the X-ray tube 1 according to the present embodiment. like Figure 1 As shown, the X-ray tube 1 may be a fixed anode type X-ray tube. The X-ray tube 1 includes, for example, a housing 10 , a cathode 20 , an anode 30 , and a heat dissipation unit 40 .

[0014] The housing 10 can maintain an atmosphere (also referred to as a vacuum state) in which the air pressure is reduced to a pressure lower than the atmospheric pressure. The housing 10 is tubular (e.g., cylindrical). The housing 10 extends along the central axis 1a of the X-ray tube 1. The end of one side of the housing 10 is closed, and the end of the other side is open. The exhaust pipe 11 can be integrally provided at the closed end of the housing 10. The exhaust pipe 11 is used when exhausting the interior of the housing 10. After exhausting the interior of the housing 10, the exhaust pipe 11 is burned off, so that the interior of the housing 10 is sealed in an airtight manner. In addition, the exhaust pipe 11 can also be provided on the side of the housing 10, etc. The housing 10 is formed using a glass material such as borosilicate glass, for example.

[0015] The cathode 20 is provided inside the housing 10 and is sealed at one end of the housing 10 (the closed end of the housing 10 ). The cathode 20 includes, for example, a filament 21, a filament terminal 22, a connection pin 23, a cover 24, and a bracket 25. The filament 21, the filament terminal 22, and the cover 24 are provided inside the housing 10.

[0016] The filament 21 is heated by energizing and generates thermal electrons 26. The filament 21 includes, for example, a coiled portion 21a and a pair of conductive wires 21b. The coiled portion 21a and the pair of conductive wires 21b are integrally formed. The coiled portion 21a extends in a direction orthogonal to the central axis 1a of the X-ray tube 1. The pair of conductive wires 21b are respectively provided at the ends of the coiled portion 21a. The pair of conductive wires 21b extend in a direction along the central axis 1a of the X-ray tube 1.

[0017] A pair of filament terminals 22 is provided. The pair of filament terminals 22 is, for example, pin-shaped and extends in a direction along the central axis 1a of the X-ray tube 1. The ends of the filament terminals 22 on the anode 30 side hold the lead wire 21b of the filament 21 and are electrically connected to the lead wire 21b.

[0018] A pair of connecting pins 23 are provided. For example, the pair of connecting pins 23b extend in a direction along the central axis 1a of the X-ray tube 1. The pair of connecting pins 23 are hermetically fused to the closed end of the housing 10. The end of the connecting pin 23 on the anode 30 side is provided inside the housing 10 and is electrically connected to the filament terminal 22. The end of the connecting pin 23 on the side opposite to the anode 30 side is exposed to the outside of the housing 10.

[0019] The cover 24 is, for example, cylindrical and extends in the direction along the central axis 1a of the X-ray tube 1. The filament 21 and the target 32 ​​of the anode 30 are arranged inside the cover 24. That is, the cover 24 surrounds the filament 21 and the target 32 ​​of the anode 30. In the direction along the central axis 1a of the X-ray tube 1, the filament 21 and the target 32 ​​are opposite to each other. The side of the cover 24 is provided with an X-ray emission port 24a.

[0020] The cover 24 is formed of metal such as stainless steel. The cover 24 has, for example, a disc-shaped portion having the function of a focusing electrode (Wenelt electrode); and a cylindrical portion having the function of suppressing the generated X-rays from entering an undesired area of ​​the housing 10. In addition, depending on the purpose of the X-ray tube 1, etc., the cover 24 may surround the filament 21, and the target 32 ​​may be exposed from the cover 24. That is, there is also a case where the cylindrical portion is not provided. In this case, the cover 24 has the function of a focusing electrode. However, as long as the cover 24 also surrounds the target 32, the generated X-rays can be suppressed from entering an undesired area of ​​the housing 10. Therefore, it is possible to suppress the housing 10 from deteriorating over time.

[0021] For example, a pair of brackets 25 can be provided. The pair of brackets 25 is, for example, pin-shaped and extends in the direction along the central axis 1a of the X-ray tube 1. The pair of brackets 25 are airtightly fused to the closed end of the housing 10. In addition, the number of brackets 25 can be appropriately changed. It is sufficient to provide at least one bracket 25. The end of the bracket 25 on the anode 30 side is provided inside the housing 10 and connected to the cover 24. The end of the bracket 25 on the opposite side to the anode 30 side is exposed to the outside of the housing 10.

[0022] The anode 30 is provided inside the housing 10 and is sealed at the other end of the housing 10 (the end of the opening of the housing 10 ). The anode 30 has, for example, a rod 31 and a target 32 ​​.

[0023] The rod 31 is, for example, columnar and extends in the direction along the central axis 1a of the X-ray tube 1. One end of the rod 31 (the end on the cathode 20 side) is disposed inside the housing 10, and the other end (the end on the side opposite to the cathode 20 side) is exposed to the outside of the housing 10. The rod 31 is disposed at the end of the opening of the housing 10 via, for example, a cylindrical connecting member 33. One end of the connecting member 33 is airtightly connected to the rod 31. The other end of the connecting member 33 is airtightly fused to the end of the opening of the housing 10. Therefore, the atmosphere inside the housing 10 can be maintained in a state where the air pressure is reduced to be lower than the atmospheric pressure.

[0024] The cathode 20 side end of the rod 31 is inclined relative to the central axis 1a of the X-ray tube 1. The cathode 20 side end of the rod 31 is spaced a predetermined distance from the filament 21 and faces the filament 21 in the direction along the central axis 1a of the X-ray tube 1.

[0025] A female thread 31a is provided on the end surface of the rod 31 on the side opposite to the cathode 20 side. The female thread 31a may be provided on the heat dissipation portion 40 described later, or may be provided on both the rod 31 and the heat dissipation portion 40.

[0026] The female thread 31a can be used when installing the X-ray tube 1. For example, the X-ray tube 1 is installed inside a container containing insulating oil or the like. Therefore, if the female thread 31a is provided, the X-ray tube 1 can be installed inside the container by attaching the female thread 31a to the male thread provided inside the container. Alternatively, the X-ray tube 1 may be provided with a male thread, and the container may be provided with a female thread. In addition, depending on the method of installing the X-ray tube 1, the female thread 31a or the male thread may be omitted.

[0027] The rod 31 is formed of, for example, a material having high electrical conductivity and high thermal conductivity. The rod 31 can be formed of, for example, a metal such as copper or a copper alloy.

[0028] The target 32 ​​has a disk shape, for example, and is provided inside the housing 10. The target 32 ​​is provided at the end of the rod 31 on the cathode 20 side. Therefore, the target 32 ​​is inclined with respect to the central axis 1a of the X-ray tube 1.

[0029] The target 32 ​​contains a material that generates X-rays when the thermal electrons 26 collide with the target 32. The target 32 ​​contains, for example, at least one of Rh (rhodium), W (tungsten), molybdenum (Mo), and chromium (Cr).

[0030] Here, if Figure 1As shown, when a power source provided outside the X-ray tube 1 applies a negative voltage to the filament 21 via the connection pin 23 of the cathode 20, the filament 21 is heated and generates thermal electrons 26. In addition, when a power source provided outside the X-ray tube 1 applies a positive voltage (tube voltage) to the target 32 ​​via the rod 31 of the anode 30, the thermal electrons 26 are accelerated by the potential difference between the filament 21 and the target 32, and the accelerated thermal electrons 26 (electron beam) collide with the target 32. The thermal electrons 26 collide with the target 32 ​​to generate X-rays. The target 32 ​​is inclined with respect to the central axis 1a of the X-ray tube 1, and therefore, the generated X-rays are directed in a direction intersecting with the direction in which the central axis 1a of the X-ray tube 1 extends, and are radiated to the outside through the side of the housing 10.

[0031] When thermal electrons 26 collide with target 32 ​​, most of the energy is converted into heat. The converted heat is transferred through rod 31 and released from the vicinity of the end of rod 31 exposed outside housing 10 to insulating oil or the like outside housing 10 .

[0032] In this case, if the amount of heat dissipated from the portion exposed to the outside of the housing 10 is small, the temperature of the target 32 ​​becomes too high, and there is a possibility that the target 32 ​​melts or the amount of generated X-rays decreases.

[0033] For example, if a heat dissipation portion is provided at the end portion of the rod 31 exposed to the outside of the housing 10 , the amount of heat dissipated to the outside of the housing 10 can be increased. Figure 2 It is a schematic cross-sectional view for illustrating the heat dissipation unit 140 of the comparative example. like Figure 2 As shown, the heat dissipation portion 140 is columnar and is disposed at the end of the rod 31 exposed to the outside of the housing 10. The heat dissipation portion 140 has a hole 140a opened to the end surface on one side. The rod 31 is disposed inside the hole 140a. A gap 140b is provided between the inner wall of the hole 140a and the rod 31.

[0034] In this case, if there is a gas such as air or a liquid such as insulating oil inside the gap 140b, it is difficult for heat to be transferred from the rod 31 to the heat dissipation portion 140. Therefore, a layer 140c containing a low melting point alloy such as solder or silver solder is provided inside the gap 140b. If the layer 140c containing a low melting point alloy is provided inside the gap 140b, heat can be easily transferred from the rod 31 to the heat dissipation portion 140.

[0035] However, if Figure 2As shown in FIG. 1 , it is difficult to provide the layer 140c in the entire area of ​​the gap 140b. In addition, it is difficult to suppress the size of the area where the layer 140c is provided. Therefore, there is a possibility that the amount of heat dissipated to the outside of the housing 10 may be different in each of the plurality of X-ray tubes. When the amount of heat dissipated to the outside of the housing 10 is different, it may be impossible to suppress the melting of the target 32 ​​or the reduction in the amount of X-rays generated.

[0036] For this purpose, the heat dissipation portion 40 of the present embodiment is fitted or screwed to the end portion of the rod 31 exposed to the outside of the housing 10 . For example, the heat dissipation portion 40 is columnar and has a hole 40a that opens to one end face. The rod 31 is fitted into the inside of the hole 40a. For example, the heat dissipation portion 40 may be pressed into the end of the rod 31, or may be heat-pressed to the end of the rod 31, or may be shrink-fitted to the end of the rod 31. In this case, it is preferred that the heat dissipation portion 40 is heat-pressed to the end of the rod 31. If the heat dissipation portion 40 is heat-pressed to the end of the rod 31, the inner wall of the hole 40a can be more reliably made to fit tightly to the side of the rod 31. Therefore, heat is easily transferred from the rod 31 to the heat dissipation portion 40, and therefore, the amount of heat dissipated to the outside of the housing 10 can be increased, and the deviation of the heat dissipation can be suppressed. In addition, the interference can be increased, and therefore, the joining force between the heat dissipation portion 40 and the rod 31 can be increased.

[0037] The heat dissipation portion 40 is formed of a material having high thermal conductivity. For example, the heat dissipation portion 40 can be formed of aluminum or an aluminum alloy.

[0038] Here, as described above, the heat generated when the thermal electrons 26 collide with the target 32 ​​is released to the outside of the housing 10 via the rod 31 and the heat sink 40. Therefore, when the X-ray tube 1 is operated, the heat sink 40 is heated, and there is a possibility that the bonding force between the rod 31 and the heat sink 40 becomes excessively weak. If the bonding force between the rod 31 and the heat sink 40 becomes excessively weak, it is difficult for the heat to be transferred from the rod 31 to the heat sink 40, and the position of the heat sink 40 may be shifted.

[0039] Figure 3 This is a schematic cross-sectional view for illustrating a rod 31b according to another embodiment. like Figure 3 As shown, the recess 31b1 can be provided on the side of the rod 31b. At least one recess 31b1 can be provided. The recess 31b1 can be provided near the end of the rod 31b exposed to the outside of the housing 10. For example, the recess 31b1 can be provided in the area of ​​the side of the rod 31b where the heat dissipation portion 40 is fitted.

[0040] The recessed portion 31b1 may be, for example, a groove formed by cutting. For example, the recessed portion 31b1 may be a threaded groove or the like. In addition, the recessed portion 31b1 may be a depression formed at a random position by sandblasting or the like.

[0041] If the recessed portion 31b1 is provided on the side of the rod 31b, the inner wall of the hole 40a of the heat dissipating portion 40 can be inserted into the recessed portion 31b1 when the heat dissipating portion 40 is fitted to the rod 31b. In this case, if the heat dissipating portion 40 is formed of a soft material such as an aluminum alloy, the inner wall of the hole 40a of the heat dissipating portion 40 can be easily inserted into the recessed portion 31b1.

[0042] When the inner wall of the hole 40a of the heat sink 40 bites into the inside of the recess 31b1, an anchoring effect can be generated, so that the joining force between the heat sink 40 and the rod 31b can be increased. When the joining force between the heat sink 40 and the rod 31b is increased, it is difficult for heat to be transferred from the rod 31b to the heat sink 40 when the X-ray tube 1 is operated, and the positional deviation of the heat sink 40 can be suppressed.

[0043] In this case, the joining force between the heat sink 40 and the rod 31b can be adjusted by the opening size, depth, and number of the recesses 31b1. Therefore, the opening size, depth, and number of the recesses 31b1 can be appropriately changed according to the temperature of the heat sink 40, the interference fit, the material of the heat sink 40, and the material of the rod 31b.

[0044] Figure 4 It is a schematic cross-sectional view for illustrating a heat dissipation portion 40 b according to another embodiment. like Figure 4 As shown in FIG. 1 , the recess 40b1 can be provided on the inner wall of the hole 40ba of the heat dissipating portion 40b into which the rod 31 is fitted. At least one recess 40b1 can be provided.

[0045] The recessed portion 40b1 may be, for example, a groove formed by cutting. For example, the recessed portion 40b1 may be a threaded groove or the like. In addition, the recessed portion 40b1 may be a depression formed at a random position by sandblasting or the like.

[0046] If the recessed portion 40b1 is provided on the inner wall of the hole 40ba, the side of the rod 31 can be bitten into the recessed portion 40b1 when the heat dissipating portion 40b is fitted to the rod 31. Therefore, an anchoring effect can be generated, thereby increasing the joining force between the heat dissipating portion 40b and the rod 31. As a result, as in the case of the rod 31b described above, when the X-ray tube 1 is operated, it is possible to suppress the positional deviation of the heat dissipating portion 40, which makes it difficult for heat to be transferred from the rod 31 to the heat dissipating portion 40b.

[0047] In this case, the joining force between the heat dissipation portion 40b and the rod 31 can be adjusted by the opening size, depth, and number of the recessed portions 40b1. Therefore, the opening size, depth, and number of the recessed portions 40b1 can be appropriately changed according to the temperature of the heat dissipation portion 40b, the interference fit, the material of the heat dissipation portion 40b, and the material of the rod 31.

[0048] In addition, the above description has been given of the case where the recess is provided on the side surface of the rod or inside the hole of the heat dissipation part, but the recess can also be provided on the side surface of the rod and the inner wall of the hole of the heat dissipation part. That is, the recess can be provided on at least one of the side surface of the rod and the inner wall of the hole of the heat dissipation part.

[0049] In addition, the above description is about the case where the concave portion is provided on at least one of the side surface of the rod and the inner wall of the hole of the heat dissipation portion, but the convex portion can also be provided on at least one of the side surface of the rod and the inner wall of the hole of the heat dissipation portion. In this case, the convex portion bites into the surface of the mating partner. This can also produce an anchoring effect, so that the bonding force between the heat dissipation portion and the rod can be increased.

[0050] In this case, if the protruding dimension (height) of the convex portion is excessively increased, there is a possibility that a gap will be generated between the side surface of the rod and the inner wall of the hole of the heat dissipation portion. Therefore, the protruding dimension of the convex portion is preferably 0.1 mm or less.

[0051] As described above, when the heat dissipation portion and the end portion of the rod are fitted together, a part of one can be bitten into the other at the contact portion between the heat dissipation portion and the rod.

[0052] Figure 5 (a) and (b) are schematic cross-sectional views for illustrating heat dissipation parts 41 and 42 according to another embodiment. like Figure 5 As shown in (a) and (b) of FIG. 1 , the heat dissipation parts 41 and 42 include a main body 41a and fins 41b. The main body 41a may be the same as the heat dissipation part 40 having the above-mentioned recessed part 40a. That is, the heat dissipation parts 41 and 42 can be obtained by further providing the fins 41b on the heat dissipation part 40. In addition, the recessed part 40b1 can be provided on the inner wall of the hole 40ba in the same manner as the above-mentioned heat dissipation part 40b.

[0053] The fin 41b is plate-shaped and is provided on the side of the main body 41a. The fin 41b extends in a direction intersecting the side of the main body 41a. At least one fin 41b can be provided. When a plurality of fins 41b are provided, the plurality of fins 41b can be arranged in a row along the direction in which the main body 41a extends.

[0054] In this case, the amount of heat dissipated to the outside of the housing 10 can be adjusted by at least one of the size (surface area) and the number of the fins 41b. Therefore, the size (surface area) and the number of the fins 41b can be appropriately changed according to the purpose (heat generation) of the X-ray tube 1. The size (surface area) and the number of the fins 41b can be appropriately determined by performing experiments and simulations.

[0055] Furthermore, if the fins 41b are provided, the amount of heat dissipated to the outside of the housing 10 can be increased, but the manufacturing cost increases. Therefore, depending on the use (heat generation) of the X-ray tube 1, the fins 41b may be omitted.

[0056] Furthermore, the heat dissipation portion can be screwed to the end portion of the rod exposed to the outside of the housing 10 . Figure 6 4 is a schematic cross-sectional view for illustrating the threaded connection between the rod 31c and the heat dissipation portion 43. Figure 6 As shown, the male thread 31ca can be set on the side of the rod 31c, and the female thread 43a can be set on the inner wall of the hole of the heat dissipation part 43. That is, the heat dissipation part 43 can be screwed into the end of the rod 31c exposed to the outside of the housing 10. In this case, a gap sometimes occurs between the male thread 31ca and the female thread 43a. Therefore, it is preferred that at least one of the layer 44 containing thermally conductive grease and the layer (a layer formed by curing the thermally conductive adhesive) 45 containing a component of a thermally conductive adhesive is set between the male thread 31ca and the female thread 43a. For example, it is sufficient to apply at least one of the thermally conductive grease and the thermally conductive adhesive to at least one of the male thread 31ca and the female thread 43a, and then screw the heat dissipation part 43 into the rod 31c.

[0057] In this way, the rod 31c and the heat sink 43 are easily joined compared to the above-mentioned joining by fitting. Therefore, it is possible to reduce the manufacturing cost. However, the transfer of heat from the rod to the heat sink is easier in the case of the above-mentioned joining by fitting. Therefore, the joining method can be appropriately selected according to the purpose (heat generation) of the X-ray tube 1. For example, when the temperature of the heat sink is below 100°C, a joining method using a male thread, a female thread, and a thermally conductive grease (or a thermally conductive adhesive) can be selected.

[0058] (Manufacturing method of X-ray tube) Next, a method for manufacturing the X-ray tube 1 according to the present embodiment will be described. In addition, as an example, the following Figure 1 A method for manufacturing the X-ray tube 1 having the structure exemplified in FIG. 1 is described.

[0059] The method for manufacturing the X-ray tube 1 of the present embodiment may include, for example, the following steps: A step of manufacturing the cathode 20 including the filament 21 , the filament terminal 22 , the connecting pin 23 , the cover 24 , and the holder 25 . A process of manufacturing the anode 30 including the rod 31 and the target 32 ​​. A step of sealing the cathode 20 at one end of the casing 10 . A step of sealing anode 30 via connecting member 33 at the other end of casing 10 . The exhaust process is to exhaust the inside of the housing 10 through the exhaust pipe 11 connected to the housing 10, and to heat the elements inside the housing 10 to exhaust the gas. This is a step of burning off the exhaust pipe 11 to seal the interior of the housing 10 in an airtight manner. In addition, since known techniques can be applied to the above steps, detailed descriptions thereof will be omitted.

[0060] Here, in the above-mentioned exhaust process, in order to exhaust the gas adsorbed or stored on the surface of the element located inside the housing 10, the anode 30 and the like are heated to, for example, about 500° C. Therefore, when the heat dissipation portion 40 is joined to the anode 30, there is a possibility that the temperature of the anode 30 and the like is difficult to rise due to the heat dissipation from the heat dissipation portion 40, and the heating time of the anode 30 and the like may be prolonged.

[0061] To this end, the manufacturing method of the X-ray tube 1 of the present embodiment includes a step of fitting or screwing the heat sink 40 to the rod 31 of the anode 30 exposed from the end of the sealed housing 10. That is, in the manufacturing method of the X-ray tube 1 of the present embodiment, the heat sink 40 is fitted or screwed to the rod 31 of the anode 30 exposed from the end of the housing 10 after the exhaust step.

[0062] As described above, when the rod 31 and the heat dissipating portion 40 are joined by fitting, the fitting can be performed by any one of press fitting, shrink fitting, and shrink fitting, for example. However, as described above, it is preferable to fit the heat dissipation portion 40 and the rod 31 by shrink fit. In this way, the rod 31 and the heat dissipation portion 40 can be more reliably attached. Therefore, heat is easily transferred from the rod 31 to the heat dissipation portion 40, so that the amount of heat dissipated to the outside of the housing 10 can be increased, and the amount of heat dissipation can be suppressed from being uneven. In addition, the interference can be increased, so the joining force between the heat dissipation portion 40 and the rod 31 can be increased. The same also applies to the above-mentioned heat dissipation portions 40 b , 41 , and 42 .

[0063] In addition, if Figure 3As illustrated in FIG. 1 , when the recess 31 b 1 is provided on the side surface of the rod 31 b of the anode 30 , the inner wall of the hole 40 a of the heat dissipating portion 40 can be made to bite into the recess 31 b 1 . In addition, if Figure 4 As illustrated in FIG. 1 , when the recess 40 b 1 is provided on the inner wall of the hole 40 ba of the heat dissipating portion 40 b , the side surface of the rod 31 of the anode 30 can be inserted into the recess 40 b 1 . Therefore, the joining force between the heat dissipating part and the rod can be increased, so that it is possible to prevent heat from being difficultly transferred from the rod to the heat dissipating part or positional displacement of the heat dissipating part when the X-ray tube 1 is operated.

[0064] In addition, if Figure 6 As shown in the example, the heat dissipation part 43 can also be threadedly connected to the rod 31c exposed from the end of the housing 10. In this case, at least one of thermal conductive grease and thermal conductive adhesive can be applied to at least one of the male thread 31ca of the rod 31c and the female thread 43a of the heat dissipation part 43, and then the heat dissipation part 43 can be screwed into the rod 31c.

[0065] Several embodiments of the present invention are described above, but these embodiments are only examples and do not limit the scope of the invention. Even if a person skilled in the art makes appropriate design changes to the above specific examples, as long as they include the features of the present disclosure, they are also included in the scope of the present disclosure.

[0066] For example, the shape, size, material, arrangement, etc. of each element included in the X-ray tube 1 are not limited to the exemplified contents, and can be changed as appropriate. Furthermore, the elements included in the above-described embodiments can be combined as much as possible, and any combination thereof is included in the scope of the present invention as long as it includes the features of the present invention.

[0067] Hereinafter, additional notes related to the above-mentioned embodiment are shown.

[0068] (Supplementary Note 1) An X-ray tube, characterized in that it comprises: an enclosure capable of maintaining an atmosphere reduced in pressure to less than atmospheric pressure; a cathode, the cathode being disposed inside the housing and sealed at an end portion of one side of the housing; an anode disposed inside the housing and sealed at an end portion of the other side of the housing; and a heat dissipation portion, the heat dissipation portion being disposed outside the housing and being bonded to the anode, The anode has a rod, one end of which is disposed inside the housing, and the other end of which is exposed outside the housing. The heat dissipation portion is fitted or screwed to the end portion of the rod exposed to the outside of the housing.

[0069] (Note 2) The X-ray tube according to Supplementary Note 1, characterized in that The heat dissipation portion is engaged with the end portion of the rod, At a contact portion between the heat dissipating portion and the rod, a portion of one bites into the other.

[0070] (Note 3) The X-ray tube according to Supplement 1 or 2, characterized in that The heat dissipation portion is shrink fit to the end portion of the rod.

[0071] (Note 4) The X-ray tube according to Supplementary Note 1, characterized in that The heat dissipation portion is threadedly connected to the end portion of the rod, At least one of a layer containing thermally conductive grease and a layer containing a component of a thermally conductive adhesive is provided between the male thread and the female thread.

[0072] (Note 5) An X-ray tube according to any one of Supplementary Notes 1 to 4, characterized in that The heat dissipation portion further has plate-shaped fins.

[0073] (Note 6) A method for manufacturing an X-ray tube is the method for manufacturing an X-ray tube according to any one of Appendix 1 to 5, characterized in that it comprises: an exhaust step, in which the interior of the housing is exhausted through an exhaust pipe connected to the housing, and elements in the housing are heated to exhaust the gas; a step of sealing the interior of the housing in an airtight manner by burning off the exhaust pipe; and A step of fitting or screwing a heat dissipation portion to a rod of the anode exposed from an end portion of the sealed housing.

[0074] (Note 7) The method for manufacturing an X-ray tube according to Supplementary Note 6 is characterized in that: In the step of fitting the heat dissipating portion, the heat dissipating portion is fitted to the rod by shrink fitting.

[0075] (Note 8) The method for manufacturing an X-ray tube according to Supplementary Note 6 is characterized in that: In the step of threading the heat dissipation part, at least one of thermally conductive grease and thermally conductive adhesive is applied to at least one of the male thread and the female thread, and the heat dissipation part is screwed into the rod.

Claims

1. An X-ray tube, characterized in that: include: an enclosure capable of maintaining an atmosphere reduced in pressure to less than atmospheric pressure; a cathode, the cathode being disposed inside the housing and sealed at an end portion of one side of the housing; an anode disposed inside the housing and sealed at an end portion of the other side of the housing; and a heat dissipation portion, the heat dissipation portion being disposed outside the housing and being bonded to the anode, The anode has a rod, one end of which is disposed inside the housing, and the other end of which is exposed outside the housing. The heat dissipation portion is fitted or screwed to the end portion of the rod exposed to the outside of the housing.

2. The X-ray tube according to claim 1, characterized in that The heat dissipation portion is engaged with the end portion of the rod, At a contact portion between the heat dissipating portion and the rod, a portion of one bites into the other.

3. The X-ray tube according to claim 1 or 2, characterized in that The heat dissipation portion is shrink fit to the end portion of the rod.

4. The X-ray tube according to claim 1, characterized in that The heat dissipation portion is threadedly connected to the end portion of the rod, At least one of a layer containing thermally conductive grease and a layer containing a component of a thermally conductive adhesive is provided between the male thread and the female thread.

5. The X-ray tube according to claim 1 or 2, characterized in that: The heat dissipation portion further has plate-shaped fins.

6. A method for manufacturing an X-ray tube, the method for manufacturing an X-ray tube according to claim 1, characterized in that: include: an exhaust step, in which the interior of the housing is exhausted through an exhaust pipe connected to the housing, and elements in the housing are heated to exhaust the gas; a step of sealing the interior of the housing in an airtight manner by burning off the exhaust pipe; and A step of fitting or screwing a heat dissipation portion to a rod of the anode exposed from an end portion of the sealed housing.

7. The method for manufacturing an X-ray tube according to claim 6, characterized in that: In the step of fitting the heat dissipating portion, the heat dissipating portion is fitted to the rod by shrink fitting.

8. The method for manufacturing an X-ray tube according to claim 6, characterized in that: In the step of threading the heat dissipation part, at least one of thermally conductive grease and thermally conductive adhesive is applied to at least one of the male thread and the female thread, and the heat dissipation part is screwed into the rod.

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