JP5257607B2 - Envelope rotating X-ray tube device - Google Patents

Description

  The present invention relates to an X-ray tube apparatus for medical diagnosis, and more particularly to an envelope rotating X-ray tube apparatus.

  As a conventional envelope rotation type X-ray tube device, for example, a metal vacuum vessel (hereinafter referred to as an envelope) is rotatably supported in an X-ray irradiator housing (hereinafter referred to as a tube vessel), 2. Description of the Related Art An envelope rotating X-ray tube apparatus having a structure in which an anode plate (hereinafter referred to as an anode) on an outer surface of an envelope is cooled by a liquid coolant such as cooling oil is known. In this apparatus, an open storage tank for storing the cooling oil and a transport pump for transporting the cooling oil are provided below the envelope, and the cooling oil is transferred from the open storage tank to the anode by the transport pump. The anode is cooled by being forcibly supplied and circulated in the tube container. (For example, see Patent Document 1)

Special table 2003-515877

However, in this prior art, since the envelope is rotated at a high speed in the cooling oil, a load is applied to the rotating motor due to a large viscous resistance generated between the cooling oil and the envelope. The increase in size, weight, and cost associated with the increase in torque of the motor that rotates the motor have been problems. Further, since an open storage tank and a transfer pump are required to forcibly circulate the cooling oil in the tube container, it has been difficult to reduce the size and weight of the envelope rotating X-ray tube device.
Therefore, the subject of this invention is providing the envelope rotation type | mold X-ray tube apparatus which can be reduced in size and weight.

  In order to solve the above-described problems, the present invention provides a tube container, an envelope accommodated in the tube container, a cathode and an anode disposed opposite to each other in the envelope, and a straight line connecting the cathode and the anode. A rotating shaft extending to both outer sides of the envelope along the outer periphery, a bearing provided on the tube container to support the rotating shaft, a driving device for rotating the rotating shaft, and the enclosure in the tube container In an envelope rotating X-ray tube device comprising an insulating gas filled in the outer space of the vessel, the surface of the anode opposite to the cathode is exposed in the tube container, and the exposed surface of the anode or The first inner surface provided on the inner surface of the tube container or both of them, and radially outward from the rotation center of the exposed surface along the exposed surface in the tube container as the envelope rotates. From the flow and away from the exposed surface. An envelope rotating type comprising an insulating gas forced circulation means for forcibly forming a circulating flow of the insulating gas including a second flow toward the rotation center of the exposed surface along the axial direction. An x-ray tube apparatus is provided.

  In the above configuration, preferably, the insulating gas forced circulation means has at least one or more blades protruding from the exposed surface and extending in the radial direction from the rotation center of the exposed surface. More preferably, the insulating gas forced circulation means is disposed at a predetermined interval from the exposed surface so as to face the exposed surface, and has a partition plate having an opening through which the rotating shaft passes, and the tube Partition plate supporting means provided on the inner surface of the container and supporting the partition plate, and when the envelope rotates, the first flow comes out of a gap between the partition plate and the exposed surface. On the other hand, the second flow is configured to enter the gap from the opening.

  In the above-described configuration, preferably, the bypass channel is provided outside the tube container, takes a part of the circulation flow and discharges it into the tube container, and the bypass channel is provided in the middle of the bypass channel. An insulating gas cooling device is further provided.

  According to the present invention, since the viscous resistance between the insulating gas and the envelope is reduced by using an insulating gas having a low viscosity instead of the cooling oil, it is not necessary to increase the torque of the motor, and the motor can be downsized. Weight reduction and cost reduction are possible. In addition, while the envelope is rotated by the insulating gas forced circulation means, a first flow radially outward from the rotation center of the exposed surface along the exposed surface of the anode in the tube container, Since the second flow is formed from the place away from the exposed surface along the rotation axis toward the rotation center of the exposed surface to circulate the insulating gas forcibly, the anode can be efficiently cooled. It becomes possible.

  Here, as the insulating gas forced circulation means, preferably, by providing a blade, the rotational force of the envelope can be more efficiently transmitted to the circulating flow of the insulating gas, and is further fixed in the tube container. Since the first flow and the second flow of the insulating gas are rectified by the partition plate, the anode can be cooled more efficiently.

  In addition, since the bypass passage and the insulating gas cooling device are provided outside the tube container, a part of the circulation flow is taken into the bypass flow path, cooled by the insulating gas cooling device, and discharged again into the tube container. The insulating gas in the tube container can be efficiently circulated and cooled.

1 is a side sectional view showing a schematic configuration of an envelope rotating X-ray tube device according to one embodiment of the present invention. FIG. 2 is a cross-sectional view taken along an arrow line X-X ′ in FIG. 1.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

(Example)
FIG. 1 is a side sectional view showing a schematic configuration of an envelope rotating X-ray tube apparatus according to one embodiment of the present invention, and FIG. 2 is a sectional view taken along an arrow line XX ′ in FIG. is there.

As shown in FIGS. 1 and 2, the envelope rotary X-ray tube apparatus 1 includes a tube container 2 and an envelope 3 accommodated in the tube container 2.
The envelope 3 has a cathode 4 and an anode 5 which are disposed so as to face each other. The surface 6 of the anode 5 opposite to the cathode 4 is exposed in the tube container 2. The envelope 3 is made of a known material made of metal or ceramic, and the surface of the envelope 3 on the cathode 4 side is preferably made of an insulating material such as ceramic. The anode 5 is made of a high melting point metal such as tungsten or molybdenum because it becomes high temperature due to electron collision described later.
On both outer sides of the envelope 3, rotating shafts 7 a and 7 b extend along a straight line connecting the cathode 4 and the anode 5. The rotary shafts 7a and 7b are provided in the tube container 2 and support the bearings 8a and 8b. The bearings 8 a and 8 b are attached to partition walls 9 a and 9 b provided in the tube container 2. A motor (driving device) 10 that rotates the rotating shaft 7b is provided at an end of the rotating shaft 7b that protrudes outward from the tube container 2.
Here, flanges 11a and 11b are provided in the vicinity of the outer bearings 8a and 8b of the partition walls 9a and 9b, respectively. Stop rings 14a and 14b, which are electrically connected via high voltage wires 13a and 13b from sockets 12a and 12b that are partially inserted and fixed in the tube container 2, are fixed to the upper surfaces of the flanges 11a and 11b. Has been. The stop rings 14a and 14b apply a high voltage to the cathode 4 and the anode 5 through the rotation shafts 7a and 7b, respectively. The flanges 11a and 11b, the sockets 12a and 12b, the high voltage lines 13a and 13b, and the stop rings 14a and 14b are separated from the envelope 3 by the partition walls 9a and 9b.
A deflection coil 15 is disposed in the tube container 2 so as to face the concave portion of the envelope 3. The tube container 2 is provided with an X-ray window 16.
In addition, an insulating gas 17 made of, for example, sulfur hexafluoride (SF ₆ ) is filled in the outer space of the envelope 3 in the tube container 2.

The envelope rotary X-ray tube apparatus 1 includes blades 18, a partition plate 19, and a partition plate support unit 20 as an insulating gas forced circulation unit to be described later.
The blade 18 projects from the exposed surface 6 of the anode 5 and extends from the center of rotation of the exposed surface 6 in the radial direction. The partition plate 19 is disposed at a predetermined interval from the exposed surface 6 so as to face the exposed surface 6. An opening 21 is formed at the center of the partition plate 19, and the rotating shaft 7 b is passed through the opening 21. The partition plate support means 20 has a substantially cylindrical shape and is provided on the inner surface of the tube container 2. One end side 20 a is fixed to the partition wall 9 b and the other end opening 20 b faces the exposed surface 6 side. doing. In the partition plate support means 20, the partition plate 19 is fitted into the partition plate support means 20, and the outer peripheral surface of the partition plate 19 is joined to the inner peripheral surface of the partition plate support means 20. Further, the partition plate support means 20 has a notch-shaped opening 20c at a part of the edge of the other end opening 20b, and the notch-shaped opening 20c faces an inlet 22a of a bypass channel 22 described later. Yes. Here, the depth of the notch-shaped opening 20 c is preferably shorter than the distance between the edge of the other end opening 20 b and the partition plate 19.

  The envelope rotary X-ray tube apparatus 1 includes a bypass channel 22 provided outside the tube container 2, a radiator 23 serving as an insulating gas cooling device provided in the middle of the bypass channel 22, and cooling. A fan 24 is provided. Both ends of the bypass channel 22 are connected to the tube container 2, and a part 25 of the insulating gas 17 is taken into the bypass channel 20 through the notch-shaped opening 20 c and the inlet 22 a and passes through the outlet 22 b. Then, it is returned to the tube container 2 again. The cooling fan 24 is installed in the vicinity of the radiator 23 and cools the radiator 23.

  Next, the operation of the envelope rotating X-ray tube apparatus 1 will be briefly described.

While driving the motor 10 to rotate the envelope 3 at a high speed, the filament (not shown) of the cathode 4 is heated and a DC high voltage is applied between the cathode 4 and the anode 5. As a result, electrons generated by the filament of the cathode 4 are accelerated by a high voltage, changed in path by the deflection coil 15 and collide with the anode 5. Due to the electron collision with the anode 5, X-rays are emitted from the anode 5 and irradiated to the outside of the tube container 2 through the X-ray window 16. The reason why the envelope 3 is rotated is to prevent the electron collision from concentrating only on a specific portion of the anode 5 and heating the specific portion.
Along with the rotation of the envelope 3, the first flow 26 radially outward from the rotation center of the exposed surface 6 along the exposed surface 6 along the exposed surface 6, and a place away from the exposed surface 6. A second flow 27 is formed along the direction of the rotation axis 7b toward the rotation center of the exposed surface 6, and a circulation flow of the insulating gas 17 is forcibly formed. The first flow 26 exits from the gap between the partition plate 19 and the exposed surface 6 by the rotation of the blades 18, while the second flow 27 enters the gap from the opening 21. Thereby, the heated anode 5 is cooled.
Further, a part 25 of the circulating flow of the insulating gas 17 is taken into the bypass passage 22 through the notch-shaped opening 20c and the inlet 22a, cooled by the radiator 23 and the cooling fan 24, and passed through the outlet 22b. Then, it is discharged again into the tube container 2. As a result, the insulating gas 17 in the tube container 2 is circulated and cooled.

  According to the envelope rotating type X-ray tube device of the present invention, since the viscous resistance between the insulating gas and the envelope is reduced by using a low viscosity insulating gas instead of the cooling oil, the load on the motor is reduced. It is greatly reduced compared to the prior art, and the motor can be reduced in size, weight and cost. Further, the insulating gas forced circulation means forms a first flow and a second flow while the envelope rotates, forcibly circulating the insulating gas, and bypassing a part of the circulation flow. Since it is configured to take in the passage, cool with the insulating gas cooling device, and discharge again into the tube container, the insulating gas in the tube container can be efficiently circulated and cooled.

  The configuration of the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the insulating gas forced circulation means is composed of the blades, the partition plate and the partition plate support means, but circulates the insulating gas in the tube container in accordance with the rotational force of the envelope. If so, these may be omitted or other new structures may be provided. Various modifications and improvements can be made in the structure of the claims of the present application.

DESCRIPTION OF SYMBOLS 1 Envelope rotation type X-ray tube apparatus 2 Tube container 3 Envelope 4 Cathode 5 Anode 6 Exposed surface 7a, 7b Rotating shaft 8a, 8b Bearing 9a, 9b Partition wall 10 Motor (driving device)
11a, 11b Flange 12a, 12b Sockets 13a, 13b High voltage wires 14a, 14b Stop ring 15 Deflection coil 16 X-ray window 17 Insulating gas 18 Blade 19 Partition plate 20 Partition plate support means 20a One end side 20b Other end opening 20c Notch shape Opening 21 Opening 22 Bypass flow path 22a Inlet 22b Outlet 23 Radiator (insulating gas cooling device)
24 Cooling fan 25 Part of circulating flow 26 First flow 27 Second flow

Claims (4)

A tube container, an envelope housed in the tube container, a cathode and an anode disposed opposite to each other in the envelope, and on both outer sides of the envelope along a straight line connecting the cathode and the anode A rotating shaft that extends, a bearing that is provided in the tube container and supports the rotating shaft, a drive device that rotates the rotating shaft, and an insulating gas that fills an outer space of the envelope in the tube container In an envelope rotation type X-ray tube device comprising:
A surface of the anode opposite to the cathode is exposed in the tube container;
Provided on the exposed surface of the anode and / or the inner surface of the tube container, and in the radial direction from the rotation center of the exposed surface along the exposed surface in the tube container as the envelope rotates. A circulating flow of the insulating gas is forcibly formed including an outward first flow and a second flow from the location away from the exposed surface toward the rotation center of the exposed surface along the rotation axis direction. An envelope rotating type X-ray tube device comprising an insulating gas forced circulation means for performing the operation.   2. The enclosure according to claim 1, wherein the insulating gas forced circulation means has at least one blade that protrudes from the exposed surface and extends in a radial direction from a rotation center of the exposed surface. Rotating X-ray tube device. The insulating gas forced circulation means is further disposed at a predetermined interval from the exposed surface so as to face the exposed surface, and a partition plate having an opening through which the rotating shaft passes, and the tube container. Partition plate support means provided on the inner surface and supporting the partition plate;
When the envelope rotates, the first flow exits from the gap between the partition plate and the exposed surface, while the second flow enters the gap from the opening. The envelope rotating X-ray tube apparatus according to claim 2.   A bypass passage provided outside the tube vessel for taking a part of the circulation flow and discharging it into the tube vessel; and the insulating gas cooling device provided in the middle of the bypass passage. The envelope rotation type X-ray tube device according to any one of claims 1 to 3.

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