JP2014154423A - X-ray generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix an outside insulation cylinder of a fixed-anode X-ray tube with high reliability.SOLUTION: An X-ray generator includes: a fixed-anode X-ray tube having a cylindrical-shaped vacuum envelope; an insulation cylinder 121 having a step part 127 formed on the inner surface while surrounding the vacuum envelope in the circumferential direction; and a potting material which fixes the insulation cylinder 121 to a fixing surface 125 on a fixing surface 125 at least partially containing the step part 127. The insulation cylinder 121 is, for example, made of thermosetting resin. The potting material is, for example, an ultraviolet curing resin adhesive.

Description

  Embodiments relate to an X-ray generator.

  The fixed anode X-ray tube is an electron tube that emits X-rays from an anode target by colliding an electron beam emitted and accelerated from the cathode side under high vacuum with an anode target disposed on the anode side. This fixed anode X-ray tube is used as an X-ray generation means in various applications such as medical diagnosis, nondestructive inspection, and analysis evaluation.

  As an integrated X-ray generator using a fixed anode X-ray tube, for example, there is an integrated X-ray generator called a mono-tank type compacted for medical use. In the monotank type integrated X-ray generator, a fixed anode X-ray tube and a high voltage generator as main parts are housed in one housing filled with insulating oil. X-rays radiated from the fixed anode X-ray tube are extracted from a radiation window provided in a part of the housing. Usually, the housing is formed of a conductive material, and an X-ray shielding material is attached to the inner wall thereof.

  The fixed anode X-ray tube includes a cathode filament and a focusing electrode arranged on the cathode side in a glass vacuum envelope, an anode target arranged on the anode side, a vacuum envelope, an anode, and a cooling fin. And have. On the outside of the fixed anode X-ray tube, an insulating cylinder made of resin for fixing the X-ray tube and insulating from the surroundings is fixed by a potting material. Further, a lead cylinder made of lead for X-ray shielding is fixed outside the resin cylinder. This potting material is, for example, an adhesive that is cured by ultraviolet rays, and adheres between the X-ray tube and the insulating cylinder.

  The high voltage generator includes, for example, a high voltage transformer and a filament transformer, and generates a high voltage from a low voltage AC input supplied through a low voltage cable. Further, a desired high voltage is supplied to the anode through the high-voltage cable, and a required voltage is supplied to the cathode side through the filament cable.

  In a fixed anode X-ray tube to which a required voltage is supplied, an electron beam emitted from a cathode filament and focused by a focusing electrode collides with an anode target to which a high voltage is applied to generate X-rays.

  An insulating resin cylinder is disposed around the fixed anode X-ray tube.

JP-A-10-214582 JP 2009-164038 A

  For example, fixed anode X-ray tubes and integrated X-ray generators used for surgical or dental use are currently strongly required to reduce costs, and it is necessary to use resin-made insulating cylinders as low-cost materials. . Engineering plastics such as phenol and polybutylene terephthalate (PBT) are thermoplastic resins that are easily recyclable and therefore have excellent environmental performance. In addition, material costs are low, and molding is possible by injection molding. Suitable for cost reduction of cylinders. However, the adhesive strength with the potting material for fixing the X-ray tube is weak, and it is easy to come off.

  Therefore, an object of the present invention is to fix the insulating cylinder outside the fixed anode X-ray tube with high reliability.

  In order to achieve the above-described object, according to the embodiment, an X-ray generator includes a fixed anode X-ray tube having a cylindrical vacuum envelope and an inner surface that surrounds the vacuum envelope in a circumferential direction. An insulating cylinder having a stepped portion, and a potting material for fixing the insulating cylinder to the vacuum envelope at the stepped portion.

It is sectional drawing of the integrated X-ray generator by one Embodiment. It is a top view of a fixed anode X-ray tube, an insulating cylinder, and a lead cylinder according to an embodiment. It is a side view of a fixed anode X-ray tube, an insulating cylinder, and a lead cylinder according to an embodiment. It is a bottom view of a fixed anode X-ray tube, an insulating cylinder, and a lead cylinder according to one embodiment. 1 is a perspective view of an insulating cylinder and a lead cylinder according to one embodiment. FIG. 1 is a side view of an insulating cylinder and a lead cylinder according to one embodiment. FIG. FIG. 7 is a sectional view taken along arrow VII-VII in FIG. 6. It is VIII-VIII arrow sectional drawing of FIG. It is IX-IX arrow sectional drawing of FIG. It is a perspective view of the insulation cylinder and lead cylinder by the modification of one Embodiment. It is a side view of the insulation cylinder and lead cylinder by the modification of one Embodiment. It is XII-XII arrow sectional drawing of FIG. It is XIII-XIII arrow sectional drawing of FIG. It is XIV-XIV arrow sectional drawing of FIG.

  Hereinafter, an integrated X-ray generator according to an embodiment will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or similar structure, and the overlapping description is abbreviate | omitted. This embodiment is merely an example, and the present invention is not limited to this.

  FIG. 1 is a cross-sectional view of an integrated X-ray generator according to an embodiment. FIG. 2 is a top view of the fixed anode X-ray tube, the insulating cylinder, and the lead cylinder according to the present embodiment. FIG. 3 is a side view of the fixed anode X-ray tube, insulating cylinder, and lead cylinder according to the present embodiment. FIG. 4 is a bottom view of the fixed anode X-ray tube, the insulating cylinder, and the lead cylinder according to the present embodiment.

  The integrated X-ray generator of this embodiment is an integrated X-ray generator called a mono tank type that is compact for medical use, for example. This integrated X-ray generator has a fixed anode X-ray tube 101. The fixed anode X-ray tube 101 and the high voltage generator 102 are housed inside the housing 104. The interior of the housing 104 is filled with an insulating oil 103. A radiation window 105 is formed in the housing 104. X-rays 116 generated from the fixed anode X-ray tube 101 are taken out through the radiation window 105. The housing 104 is made of, for example, a conductor material and is fixed to the ground potential. An X-ray shielding material may be attached to a portion of the inner wall of the housing 104 other than the radiation window 105.

  The fixed anode X-ray tube 101 includes a vacuum envelope 106, a cathode filament 107, a focusing electrode 108, an anode target 109, an anode 110, and a cooling fin 111. The vacuum envelope 106 is made of glass and has a substantially cylindrical shape with both ends closed. The cathode filament 107, the focusing electrode 108, and the anode target 109 are housed inside a vacuum envelope 106 such as a glass tube.

  The cathode filament 107 is disposed in the vicinity of one end of the vacuum envelope 106. The anode target 109 is disposed inside the vacuum envelope 106 so as to face the cathode filament 107. The side opposite to the cathode filament 107 of the anode target 109 is in close contact with the anode 110. The anode 110 extends through the other end of the vacuum envelope 106 in a vacuum-tight manner. The anode target 109 is made of a refractory metal such as tungsten (W) or molybdenum (Mo). The anode 110 is made of, for example, copper (Cu). A cooling fin 111 is attached in the vicinity of the end of the anode 110 opposite to the anode target 109. The focusing electrode 108 is disposed on the cathode side.

  A cylindrical insulating cylinder 121 that surrounds the vacuum envelope 106 in the circumferential direction is disposed outside the fixed anode X-ray tube 101. The insulating cylinder 121 is made of a resin such as thermosetting acmelite, phenol, polybutylene terephthalate (PBT). The insulating cylinder 121 is fixed to the outer surface of the vacuum envelope 106 by a potting material 122. The potting material is, for example, an adhesive that is cured by ultraviolet rays, and fixes the fixed anode X-ray tube 101 and the insulating cylinder 121 to each other.

  The insulating cylinder 121 fixes the fixed anode X-ray tube 101 and insulates it from the surroundings. A lead cylinder 123 made of lead for X-ray shielding is fixed to the outer peripheral surface of the insulating cylinder 121. The lead cylinder 123 is formed by winding a lead plate around the insulating cylinder 121 and soldering or welding the butted portions of the lead plate. Even if a lead plate is wound around the outer periphery of the insulating cylinder 121 and bonded with an adhesive, or a lead cylinder is fitted to the outer periphery of the insulating cylinder 121 and bonded with an adhesive, the lead cylinder 123 is formed. Good. A through hole through which the X-ray 116 passes is formed on the side surfaces of the insulating cylinder 121 and the lead cylinder 123.

  The high voltage generator 102 includes, for example, a high voltage transformer and a filament transformer, and generates a high voltage from a low voltage AC power source input through the low voltage cable 112. The predetermined high voltage generated by the high voltage generator 102 is applied to the anode 110 through the high voltage cable 113. A predetermined voltage is also applied to the focusing electrode 108. A predetermined voltage is applied from the high voltage generator 102 to the cathode filament 107 through the filament cable 114.

  When a predetermined voltage is supplied to the fixed anode X-ray tube 101, the electron beam 115 emitted from the cathode filament 107 and focused by the focusing electrode 108 collides with the anode target 109 to which a high voltage is applied and the X-ray 116. Is generated.

  FIG. 5 is a perspective view of an insulating cylinder and a lead cylinder according to the present embodiment. FIG. 6 is a side view of the insulating cylinder and the lead cylinder according to the present embodiment. 7 is a cross-sectional view taken along arrow VII-VII in FIG. 8 is a cross-sectional view taken along arrow VIII-VIII in FIG. 9 is a cross-sectional view taken along arrow IX-IX in FIG.

  The insulating cylinder 121 is made of, for example, polybutylene terephthalate (PBT) and is formed by injection molding. Stepped portions 126 and 127 are formed on the inner surface of the insulating cylinder 121. The step portions 126 and 127 protrude from the inner surface of the insulating cylinder 121 toward the central axis, for example. The stepped portions 126 and 127 may have a groove shape that is recessed outward from the inner surface of the insulating cylinder 121. The height of the stepped portions 126 and 127 is, for example, about 0.1 to 2 mm. As the stepped portions 126 and 127, there are formed an inner cylindrical inner surface extending in the circumferential direction (first stepped portion 127) and an axially extending portion (second stepped portion 126).

  FIG. 10 is a perspective view of an insulating cylinder and a lead cylinder according to a modification of the present embodiment. FIG. 11 is a side view of an insulating cylinder and a lead cylinder according to this modification. 12 is a cross-sectional view taken along arrow XII-XII in FIG. 13 is a cross-sectional view taken along arrow XIII-XIII in FIG. 14 is a cross-sectional view taken along arrow XIV-XIV in FIG.

  5 to 9 show a stepped portion 126 extending as a part of the insulating cylinder 106 in the axial direction as the second stepped portion. In this example, the second stepped portion 126 is an insulating cylinder. 106 extends in the entire axial direction. Such a stepped portion 126 may be formed.

  After an organic solvent such as xylene is applied to the fixing surface 125 that is a part of the inner surface of the insulating cylinder 121 and includes at least part of the step portions 126 and 127, the fixing surface 125 is heated to about 150 to 200 ° C. 125 is activated. Thereafter, the insulating cylinder 121 is fixed to the fixed anode X-ray tube 101 (see FIG. 1 and the like) by the potting material 122 (see FIG. 1 and the like) disposed on the fixing surface 125.

  The bonding surface 125 between the insulating cylinder 106 and the potting material 122 tends to come off in the axial direction and the rotational direction of the cylinder. However, according to the present embodiment, even if the potting material 122 is peeled off from the inner surface of the insulating cylinder 121, the surface of the potting material 122 has a shape corresponding to the surface shape of the fixing surface 125. A step is formed in the material 122, and the step is caught by the step portions 126 and 127 of the insulating cylinder 121. For this reason, possibility that the insulation cylinder 121 and the potting material 122 will remove | deviate becomes small.

  In addition, if the stepped portions 126 and 127 are formed to extend in the circumferential direction and those that extend in the axial direction, the stepped portions 126 and 127 and the potting material 122 are caught, so that either the circumferential direction or the axial direction can be obtained. Will hardly move. Moreover, since the step portions 126 and 127 are formed at the time of injection molding, there is almost no increase in the manufacturing cost of the step.

  Thus, according to this embodiment, the insulating cylinder outside the fixed anode X-ray tube can be fixed with high reliability.

DESCRIPTION OF SYMBOLS 101 ... Fixed anode X-ray tube, 102 ... High voltage generator, 104 ... Housing, 103 ... Insulating oil, 105 ... Radiation window, 106 ... Vacuum envelope, 107 ... Cathode filament, 108 ... Focusing electrode, 109 ... Anode target 110 ... anode, 111 ... cooling fin, 112 ... cable for low pressure, 113 ... cable for high pressure, 114 ... cable for filament, 115 ... electron beam, 116 ... X-ray, 121 ... insulating cylinder, 122 ... potting material, 123 ... Lead cylinder, 125 ... fixing surface, 126 ... stepped portion, 127 ... stepped portion

Claims (3)

A fixed anode X-ray tube having a cylindrical vacuum envelope;
An insulating cylinder that surrounds the vacuum envelope in the circumferential direction and has a stepped portion formed on the inner surface;
A potting material for fixing the insulating cylinder to the vacuum envelope at the stepped portion;
An X-ray generation apparatus comprising:   The X-ray generator according to claim 1, wherein the stepped portion includes a first stepped portion extending in a circumferential direction of the insulating cylinder and a second stepped portion extending in an axial direction of the insulating cylinder. A high voltage generator for applying a high voltage to the X-ray generator;
A housing for housing the X-ray generator and the high voltage generator;
The X-ray generator according to claim 1, further comprising:

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