JPH0231976Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention is a rotating anode X-ray tube in which rotating anode and cathode structures are arranged at both ends of a metal envelope via an insulating envelope. In particular, it relates to a rotating anode X-ray tube with improved cooling efficiency.

(B) Prior art The envelope of a rotating anode X-ray tube is generally made of glass, and the anode structure has a cathode structure and a rotating target at both ends thereof, and the cathode and the rotating target are connected to the focal plane of the former cathode and the latter rotating target. are arranged so that they are facing each other. In operation, the rotating target is heated to high temperatures by thermal shock from the cathode and radiates infrared radiation, heating the glass envelope surrounding the rotating target.

The glass envelope has relatively good infrared transmittance at the beginning of use, but as time passes, the glass envelope becomes discolored due to exposure to X-rays.
This type of X-ray tube is usually housed in a tube container filled with high-voltage insulating oil to reduce the transmittance of infrared rays and to prevent electric shock, so it is cooled by radiant heat from the glass envelope and rotating target. The insulating oil, which is a heat transfer medium, is heated and sludge is generated and adheres to the glass envelope. In these areas of the glass envelope that are colored or have sludge attached, local infrared rays are absorbed more, making it more likely that the glass envelope will be destroyed due to a sudden change in the thermal stress distribution. Therefore, in order to avoid such defects, metal has come to be used as part or all of the envelope instead of glass.

However, if a metal envelope is used, although damage to the envelope can be prevented, the inner surface of the metal envelope acts as an infrared reflector, and most of the infrared rays radiated from the rotating target are absorbed by the metal and conducted. By reflection, the temperature of the rotating target and anode structure is increased without being emitted outside the envelope, reducing the load capacity of the X-ray tube and shortening the life of the X-ray tube. Become.

(C) Purpose In view of the above-mentioned problems, this invention has been developed to develop a rotating anode in which the metal envelope absorbs infrared rays radiated from the target without reflecting it, and effectively dissipates heat from the outer surface of the metal envelope. An object of the present invention is to provide a rotating anode X-ray tube with improved cooling efficiency.

(d) Structure In order to achieve the above objective, part or all of the inner surface of the metal envelope facing the high-temperature anode is formed into a rough surface with fine irregularities, so that the metal envelope can absorb infrared rays. It is designed to function effectively as an absorber.

(E) Example Next, an example of this invention will be described. 1st
The figure is a cross-sectional view showing the structure of the present invention. 1 is a metal envelope, and various materials can be used such as copper, titanium, or iron-based alloys, but copper is the easiest to process. It also has many advantages such as high heat conduction. Reference numeral 2 denotes an uneven surface (rough surface) formed on the inner surface of the metal envelope 1. This rough surface can be easily formed by surface treatment such as honing, polishing, and bombardment with heavy metal ions. The rough surface is formed using the metal envelope 1 facing the rotating target.
For example, when liquid honing is performed using glass beads with a diameter of 5 to 25 mm, the surface area increases by approximately 1.5 to 1.8 times compared to the ideal mirror state. Therefore, the heat or infrared ray absorption effect also increases in proportion to the rate of increase in surface area. Reference numeral 3 denotes a glass insulating cylinder sealed to one end of the metal envelope 1, and this insulating cylinder holds the rotating target 5, the rotor 7 that supports it, and the rotor 7.
An anode structure consisting of an axle box 9 that rotatably supports the anode is fixed. A glass insulating cylinder 4 is sealed to the other end of the metal envelope 1 facing the insulating cylinder 3, and a cathode structure 8 having a cathode 6 is fixed to this insulating cylinder.

(F) Effect This invention has a rough inner surface of the metal envelope, so when the rotating anode X-ray tube is in operation, the infrared rays radiated from the rotating target are effectively absorbed, and the radiant heat from the rotating target is absorbed. Since the heat is effectively transmitted to the metal envelope, the cooling efficiency of the rotating anode X-ray tube is significantly improved.

As a result, the load capacity and life of the rotating anode X-ray tube can be increased.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of the rotating anode X-ray tube of this invention. DESCRIPTION OF SYMBOLS 1... Metal envelope, 2... Rough surface (uneven surface), 3... Glass insulating tube, 4... Glass insulating tube, 5... Rotating target, 6... Cathode, 7... Rotor, 8... Cathode structure, 9 ...Axle box.

Claims (1)

[Scope of utility model registration request] In an X-ray tube in which an anode structure and a cathode structure having a rotating target are arranged at both ends of a metal envelope via an insulator, at least the inner surface of the metal envelope facing the rotation target is formed to have a rough surface. A rotating anode X-ray tube featuring: