JPH06251735A - Fixed anode x-ray tube device - Google Patents

Abstract

PURPOSE:To provide a fixed anode X-ray tube device having a cooling structure which can let heat generated in an anode escape outside efficiently. CONSTITUTION:An X-ray tube 2 where a cathode 4 and a fixed anode 5 are arranged oppositely in a bulb 3 from which air is exhausted under high vacuum, is housed in a housing 10 in which insulating oil 9 is filled. In this fixed anode X-ray tube device 20, the end part of the fixed anode derived outside the bulb 3 is connected to an inner wall surface of the housing 10 through an electrically insulating heat conductive member 21, and the end part of a support arm 23 is connected to a position opposed to the heat conductive member 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed anode X-ray tube device, and more particularly to a fixed anode heat radiation structure.

[0002]

2. Description of the Related Art X-ray tube apparatuses are roughly classified into rotating anode X-ray tube apparatuses and fixed anode X-ray tube apparatuses. Rotating anode X-ray tube devices are widely used mainly in devices involving X-ray imaging because they can withstand a momentary heavy load. On the other hand, fixed anode X
The X-ray tube device has a relatively small instantaneous load, but is used for a relatively long period of time, and is used, for example, in a fluoroscopic apparatus for surgery.

A schematic structure of a conventional fixed anode X-ray tube device of this type will be described with reference to FIG. Fixed anode X shown
The wire tube device 1 is a so-called monotank type device that is made compact for surgery, and is provided with a cathode (filament) 4 and a fixed anode (target) 5 that are oppositely arranged in a glass bulb 3 evacuated to a high vacuum. Fixed anode X-ray tube 2,
A high-voltage transformer 6 for applying a high voltage between the cathode 4 and the fixed anode 5, a filament transformer 7 for feeding filament, and the like are housed in one housing 10 filled with insulating oil 9. Has been done.

The thermoelectrons generated when the cathode 4 is energized are accelerated by the high voltage applied between the cathode 4 and the fixed anode 5 and collide with the fixed anode 5 to generate X-rays. At this time, 99% or more of the energy supplied to the X-ray tube is converted into heat. In order to release this heat to the outside, the conventional fixed anode X-ray tube device 1 has a cooling fin 8 attached to one end of the fixed anode 5 led out of the glass bulb 3. The heat generated in the fixed anode 5 is transferred to the insulating oil 9 through the cooling fins 8 and further transferred to the housing 10 by the convection of the insulating oil 9. The heat transferred to the housing 10 is released from the housing 10 to the outside air,
The X-ray tube 2 is cooled by being transmitted to the C-shaped support arm 11 of the fluoroscope which supports the housing 10 in a linked manner. The reason why the housing 10 is naturally cooled as described above is that dust is scattered when a cooling fan or the like is used, which is inconvenient in a surgical operating room or the like that requires a clean environment.

Further, in the fixed anode X-ray tube device 1 of this type, when the temperature of the insulating oil 9 rises excessively due to the heat generation of the X-ray tube 2, the insulating oil 9 expands and transiently raises the internal pressure of the housing 10. Therefore, in consideration of safety, a bellows (not shown) which is displaced in accordance with the thermal expansion of the insulating oil 9 is attached to the housing 10, and when the bellows is displaced more than a predetermined amount, the micro switch is operated to operate the X-ray. A safety mechanism is provided to prevent the X-ray tube 2 from rising above a predetermined temperature (for example, 55 ° C. or more at the outer surface temperature of the housing 10) by stopping the application of the high voltage to the tube 2.

[0006]

However, the conventional example having such a structure has the following problems. That is, in medical X-ray fluoroscopy, the X-ray intensity may be increased (the load on the X-ray tube is increased) in order to improve the image quality of the fluoroscopic image depending on the size of the fluoroscopic target region, etc. In the X-ray device 1, the heat generated by the convection of the insulating oil 9 is transferred to the housing 10, so that the heat generated during the heavy load cannot be quickly released. for that reason,
The temperature of the insulating oil 9 in the housing 10 suddenly rises, the safety mechanism operates, and the X-ray tube device 1 stops, which may hinder diagnosis and treatment.

The present invention has been made in view of such circumstances, and provides a fixed anode X-ray tube device having a cooling structure capable of efficiently dissipating heat generated in the anode to the outside. It is an object.

[0008]

The present invention has the following constitution in order to achieve such an object. That is, the present invention relates to a fixed anode X-ray tube device in which an X-ray tube in which a cathode and a fixed anode are arranged to face each other in a valve evacuated to a high vacuum is housed in a housing filled with insulating oil. The end portion of the fixed anode led out of the bulb is connected to the inner wall surface of the housing via an electrically insulating heat conducting member.

[0009]

The operation of the present invention is as follows. That is, the heat generated in the fixed anode due to the collision of the thermoelectrons emitted from the cathode with the fixed anode is efficiently transmitted to the housing via the heat conducting member connected to the end of the fixed anode.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an embodiment of a fixed anode X-ray tube device according to the present invention.

This fixed anode X-ray tube device 20 has a cathode 4 inside a high vacuum glass bulb 3 as in the conventional device described above.
And a fixed anode X-ray tube 2 in which the fixed anode 5 and the fixed anode 5 are arranged to face each other,
A high voltage transformer 6 for applying a high voltage, a transformer 7 for feeding a filament, and the like are housed in one housing 10 filled with insulating oil 9.

Further, the fixed anode X-ray tube device 20 is
As a characteristic configuration, the following cooling structure for the X-ray tube 2 is provided. That is, the end of the fixed anode 5 led out from the glass bulb 3 is electrically insulated by the heat conducting member 21.
Is connected to the inner wall surface of the housing 10 via. Since it is necessary to electrically insulate the fixed anode 5 to which a high voltage is applied from the housing 10 and to efficiently conduct the heat generated in the fixed anode 5, a material for the heat conducting member 21 is an insulating material. Materials with relatively high thermal conductivity,
For example, AlN, SiC, BeO or the like is used.

The heat conducting member 21 is preferably attached to the fixed anode 5 and the housing 10 so that the thermal resistance becomes small. FIG. 2 shows an example of a mounting structure of the heat conducting member 21. In this embodiment, the heat conducting member 21 is
Flange-shaped connecting members 22a, 2 made of Cu or the like
It is connected to the end surface of the fixed anode 5 and the inner wall surface of the housing 10 by screwing via 2b.

Further, in this embodiment, in order to further improve the heat dissipation efficiency, one end of the support arm 23 is connected to the portion of the housing 10 to which the heat conducting member 21 is connected to support the housing 10. is doing.

According to the fixed anode X-ray tube device 20 having the above-mentioned structure, the heat generated in the fixed anode 5 is transferred to the heat conducting member 21 connected to the end face of the anode, and the heat conducting member 21 promptly transfers the heat. Is transmitted to the housing 10. Then, the heat transferred to the housing 10 is applied to the housing 1
It is transmitted to the support arm 23 having a large heat capacity, which is connected to the heat conducting member 21 so as to face it via the wall surface of 0.

Incidentally, according to the conventional device shown in FIG.
As shown in FIG. 4 (a), the fixed anode X-ray tube device 1 has an image integrator 12 for detecting transmitted X-rays.
When the support arm 11 is set such that the upper surface of the housing 10 becomes higher than the other surfaces due to the convection of the insulating oil 9, the support arm 11 is relatively efficiently heated. Is conducted, but in FIG. 4 (b)
As described above, when the fixed anode X-ray tube device 1 is set up, the heat transfer to the wall surface of the housing 10 to which the support arm 11 is attached becomes poor, so that the support arm 11 does not release much heat. I can not expect it.

As described above, according to the conventional apparatus, the temperature distribution of the housing 10 changes depending on the posture of the fixed anode X-ray tube apparatus 1 and the heat radiation effect by the support arm 11 varies, but according to this embodiment. For example, fixed anode X-ray tube device 20
Regardless of the posture, it is possible to obtain a certain high heat dissipation effect.

The present invention can be modified as follows. (1) The outer peripheral portion of the heat conducting member 21 may be formed in a pleated shape so that the heat conducting efficiency from the heat conducting member 21 to the insulating oil 9 can be improved.

(2) The X-ray device 2 and the transformers 6 and 7 may be housed in separate housings.

[0020]

As is apparent from the above description, according to the present invention, since the end portion of the fixed anode is connected to the inner wall surface of the housing through the electrically insulating heat conducting member, the fixed anode can be used. The generated heat can be quickly transmitted to the housing via the heat conducting member. Therefore, even if the load of the X-ray apparatus becomes large, the temperature rise of the anode can be suppressed, so that the X-ray apparatus can be used for a long time under a high load state, and the X-ray apparatus can be operated by the operation of the safety mechanism during treatment and diagnosis. It is possible to prevent an unexpected situation of stopping.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a fixed anode X-ray tube device according to an example.

FIG. 2 is a sectional view showing an example of a mounting structure of a heat conducting member.

FIG. 3 is a diagram showing a schematic configuration of a conventional fixed anode X-ray tube device.

FIG. 4 is a diagram for explaining a problem of a conventional device.

[Explanation of symbols]

 2 ... Fixed anode X-ray tube 3 ... Glass bulb 4 ... Cathode 5 ... Fixed anode 6 ... High voltage transformer 7 ... Filament transformer 9 ... Insulating oil 10 ... Housing 20 ... Fixed anode X-ray tube device 21 ... Heat conduction member 23 ... Support arm

Claims (1)

[Claims] 1. A fixed anode X-ray tube device comprising an X-ray tube in which a cathode and a fixed anode are arranged opposite to each other in a valve evacuated to high vacuum in a housing filled with insulating oil. The end of the fixed anode led out of the bulb,
A fixed anode X-ray tube device, which is connected to an inner wall surface of the housing via an electrically insulating heat conducting member.