JP2005016581A - Seal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal device which does not apply large loads to a helium vessel, and is not affected by the installation accuracy and the working accuracy of the helium vessel. <P>SOLUTION: The seal device comprises an expansion means 13 which is provided on a tip of a flange 28 of a neutron target 27, a supporting frame 16 provided on a tip of the expansion means 13, a seal means 18 provided on a tip of the supporting frame 16, a moving means 21 which moves the neutron target 27 to a predetermined position in the axial direction and forms a predetermined gap g between the seal means 18 and a flange 26 of the helium vessel 25, and a drive means 20 which expands the expansion means 13 in the axial direction so as to seal the gap g and presses the seal means 18 against the flange 26 of the helium vessel 25. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device for sealing between a helium vessel and a neutron target used in a neutron scattering facility.
[0002]
[Prior art]
Research on neutron chemistry based on high-intensity proton accelerators is promising for research and development such as basic science of life and materials, and transmutation of long-lived nuclides, and one of the means is a neutron scattering facility.
[0003]
FIG. 3 shows a schematic diagram of the neutron scattering facility. As shown in FIG. 3, the neutron scattering facility directs a high-intensity proton beam b accelerated to near the speed of light by a high-intensity proton accelerator to the inside e of the helium vessel d, and the nuclei accommodated inside the neutron target a. In order to generate and take out secondary particles such as neutrons.
[0004]
The neutron target a is provided in the target carriage c, and is moved in the axial direction (left-right direction in the drawing) by the target carriage c. When the neutron target a is inserted into the helium vessel d, the space between the helium vessel d and the neutron target a is sealed by a sealing device, and the helium vessel d is sealed.
[0005]
Thereafter, helium gas is sealed in the inside e of the helium vessel d. The sealing device plays an important role in dividing the atmosphere inside the helium vessel d and the atmosphere f outside the helium vessel d.
[0006]
Conventionally, a sealing member (sealing device) is provided in the neutron target a, and sealing has been performed by sandwiching the sealing member between the neutron target a and the helium vessel d. Such a sealing device is also described in Patent Document 1 and the like.
[0007]
[Patent Document 1]
JP 2002-228002 A
[Problems to be solved by the invention]
However, conventionally, in order to sandwich the seal member between the neutron target a and the helium vessel d, the seal member provided in the neutron target a is pressed against the helium vessel d by the target carriage c. Since the weight of the target carriage c is relatively heavy (about 1 t), a large force proportional to the weight becomes the pressing force. Therefore, a great load (mainly impact force) due to the pressing force of the target carriage c is applied to the helium vessel d, and a part of the helium vessel d may be deformed.
[0009]
Further, when the installation accuracy (for example, the perpendicularity to the axis of the neutron target a) and the processing accuracy (for example, the flatness of the surface in contact with the seal member) of the flange serving as a connection portion with the helium vessel d, particularly the neutron target a, are low. The seal member may not adhere to the flange. In such a case, it becomes difficult to seal the helium vessel d.
[0010]
Accordingly, an object of the present invention is to provide a sealing device that solves the above-described problems, does not apply a great load to the helium vessel, and is not affected by the installation accuracy and processing accuracy of the helium vessel. .
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a sealing device that seals between a flange when a neutron target is inserted into a helium vessel from its axial direction, and is provided at the tip of the flange of the neutron target. , An extending means capable of extending in the axial direction, a support frame provided at the tip of the extending means, a sealing means provided at the tip of the support frame, and moving the neutron target to a predetermined position in the axial direction. And a moving means for forming a predetermined gap between the sealing means and the flange of the helium vessel, and in order to seal the gap, the extending means is extended in the axial direction, and the sealing means is moved to the helium vessel. And a drive unit that presses against the flange.
[0012]
According to a second aspect of the present invention, the extension means is inclined with respect to the flange of the neutron target so as to absorb the inclination when the flange of the helium vessel and the flange of the neutron target are not completely parallel. The sealing device according to claim 1, which is possible.
[0013]
According to a third aspect of the present invention, the extension means includes a bellows doubled in the radial direction of the neutron target, and the driving means applies a gas pressure between the bellows. It is a sealing device of Claim 1 or 2.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0015]
1A and 1B are enlarged views of a portion I in FIG. FIG. 2 is a schematic view of the sealing device of the present embodiment.
[0016]
As shown in FIG. 2, the sealing device 10 includes a sealing device main body 11 and a target carriage (moving means) 21 for moving the neutron target 27 in the axial direction. The target carriage 21 is provided with a neutron target 27.
[0017]
The sealing device main body 11 is arranged in a form sandwiched between the flange 26 of the helium vessel 25 and the flange 28 of the neutron target 27 in the axial direction. The flange 26 of the helium vessel 25 is assumed to have a diameter of about 1 m.
[0018]
The seal device main body 11 will be described with reference to FIG. At the tip of the flange 28 of the neutron target 27, two bellows rings (extension means) 13 that can extend in the axial direction are provided at a predetermined interval in the radial direction. The two bellows rings 13 have different outer diameters, and a bellows ring 13 having an outer diameter smaller than the former is provided inside one bellows ring 13. The bellows ring 13 includes a bellows 15 and two support rings 14 provided so as to sandwich the bellows 15 in the axial direction. The bellows 15 can be inclined and extended in the radial direction.
[0019]
A ring-shaped support frame 16 is provided at the tips of the bellows rings 13. Connection portions of the support frame 16, the two bellows rings 13, and the flange 28 of the neutron target 27 are sealed, and a filling space 19 for filling a gas is formed between them. Yes. The filling space 19 is formed so as to communicate with the inflow passage 12 provided in the flange 28 of the neutron target 27.
[0020]
Drive means (for example, a cylinder) 20 is connected to the inflow passage 12. When gas (for example, helium gas) is sent into the filling space 19 via the inflow passage 12 by the driving means 20, the bellows ring 13 is extended in the axial direction. That is, the support frame 16 is pushed in the direction of the helium vessel 25 (in the axial direction of the neutron target 27) by the gas pressure inside the filling space 19, and the bellows 15 expands following this. In the present embodiment, the extension stroke is about 10 mm.
[0021]
A seal member (seal means) 18 is provided at the tip of the support frame 16. The seal member 18 is formed by forming a metal with a W-shaped cross section, and is attached to the support frame 16 by a fixture 17.
[0022]
Here, the seal member 18 has a small seal line load (for example, about 4 kg / cm), and can follow the processing accuracy (flatness, etc.) of the flange 26 of the opposing helium vessel 25. That is, the seal member 18 is capable of obtaining a sufficient sealing effect even with a small pressing force and relatively allowing deformation. In addition, a plating process is performed on the seal member 18 as necessary. Thereby, there is an effect that the plating is familiar with the surface of the flange 26 and the sealing performance is improved.
[0023]
The seal device body 11 is moved in the axial direction by the target carriage 21 integrally with the neutron target 27. The seal member 18 is moved in the axial direction by the bellows ring 13.
[0024]
Operation | movement of the sealing apparatus 10 of this Embodiment is demonstrated.
[0025]
First, the target carriage 21 moves the neutron target 27 to a predetermined position in the axial direction to form a predetermined gap g between the seal member 18 and the flange 26 of the helium vessel 25. At this time, the tip of the neutron target 27 is inserted into the helium vessel 25 from the axial direction (see FIG. 2).
[0026]
Next, gas is filled into the filling space 19 by the driving means 20, the bellows ring 13 is extended in the axial direction of the neutron target 27, and the gap g is sealed. At this time, the bellows ring 13 is extended in the direction of the flange 26 of the helium vessel 25 as shown in FIG. As a result, the support frame 16 is moved forward in the axial direction (left direction in the figure), and the seal member 18 is pressed against the flange 26 of the helium vessel 25. At this time, the sealed state of the helium vessel 25 is ensured by the elasticity of the seal member 18.
[0027]
As described above, the sealing device 10 of the present embodiment presses the sealing member 18 against the flange 26 of the helium vessel 25 by the gas pressure. Since the pressing force at this time does not involve a large impact force, a great load is not applied to the flange 26. The pressing force can be adjusted by adjusting the amount of gas fed into the filling space 19.
[0028]
Further, since the bellows ring 13 can be inclined with respect to the flange 28 of the neutron target 27, the sealing member 18 can be reliably brought into close contact with the flange 26 of the helium vessel 25. For example, even if the flange 26 is inclined with respect to the flange 28 of the neutron target 27 (not perpendicular to the axis of the neutron target 27), the bellows ring 13 and the support frame 16 are inclined to follow the inclination. The seal member 18 is in close contact with the flange 26. That is, even if the flange 26 of the helium vessel 25 and the flange 28 of the neutron target 27 are not completely parallel, the bellows 15 extends with an inclination with respect to the flange 28 of the neutron target 27, thereby providing both flanges. 26 and 28 can be absorbed. Therefore, the sealing device 10 according to the present embodiment is less likely to be affected by the installation accuracy of the flange 26.
[0029]
Since the seal member 18 is formed of a material that can relatively follow the processing accuracy of the flange 26 of the helium vessel 25, the seal member 18 can be securely attached to the flange 26. For example, even if the flatness of the flange 26 is poor, the seal member 18 is deformed so that the flange 26 adheres closely. Therefore, the sealing device 10 according to the present embodiment is less likely to be affected by the processing accuracy of the flange 26.
[0030]
In addition, although the sealing member 18 of this Embodiment shall be attached to the support frame 16 with the fixing tool 17, you may attach to the support frame 16 by welding.
[0031]
Further, the seal member 18 is formed of a metal film in order to enhance a deformation following function corresponding to a low tightening load, a distortion of the flange, and the like. Shall be inflated by pressurizing, or have high spring characteristics.
[0032]
【The invention's effect】
In short, according to the present invention, an excellent effect is achieved in that a great load is not applied to the helium vessel and airtightness can be maintained without being affected by the installation accuracy and processing accuracy of the flange of the helium vessel.
[Brief description of the drawings]
FIG. 1 (a) is an enlarged view of a portion I in FIG. (B) is the I section enlarged view of FIG.
FIG. 2 is a schematic view of a sealing device showing a preferred embodiment of the present invention.
FIG. 3 is a schematic view of a neutron scattering facility.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Sealing device 11 Sealing device main body 21 Target cart (moving means)
13 Bellows ring (stretching means)
16 Support frame 18 Seal member (sealing means)
20 Driving means 25 Helium vessel 27 Neutron target

Claims (3)

A sealing device that seals between the flanges when a neutron target is inserted into the helium vessel from the axial direction, and is provided at the tip of the flange of the neutron target, and can be extended in the axial direction. A support frame provided at the tip of the extension means, a seal means provided at the tip of the support frame, the neutron target is moved to a predetermined position in the axial direction, and the seal means and the flange of the helium vessel Moving means for forming a predetermined gap therebetween, and driving means for extending the extension means in the axial direction and pressing the seal means against the flange of the helium vessel to seal the gap. A sealing device characterized by the above. 2. The extending means can be inclined with respect to the flange of the neutron target so that the inclination of the flange of the helium vessel and the flange of the neutron target can be absorbed when the flange of the neutron target is not completely parallel. Sealing device. The said extending | stretching means is provided with the bellows provided double in the radial direction of the said neutron target, The said drive means adds a gas pressure between the said bellows. Sealing device.

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