阅读说明：本技术 一种大型托卡马克真空室非圆通道超高真空密封法兰结构 (Ultrahigh vacuum sealing flange structure for non-circular channel of large tokamak vacuum chamber ) 是由 侯吉来 冉红 宋斌斌 曹曾 蔡立君 黄运聪 唐乐 李瑞鋆 张炜 蔡潇 李勇 于 2021-01-22 设计创作，主要内容包括：本发明属于磁约束核聚变技术,具体为一种大型托卡马克真空室非圆通道超高真空密封法兰结构,包括的凹法兰、凸法兰和接管；凹法兰和凸法兰相对端面内侧加工配合的两级90°密封台阶,两者之间放置铜丝圈,使得凹法兰和凸法兰沿轴向保留间隙；通过双头螺纹销或双头螺柱将凹法兰和凸法兰连接。通过90°密封台阶压缩无氧铜丝的结构方式,可以满足不同形状的非圆通道窗口法兰的超高真空密封需求,减少了非圆窗口的密封面的加工和维护难度。(The invention belongs to a magnetic confinement nuclear fusion technology, in particular to a large-scale tokamak vacuum chamber non-circular channel ultrahigh vacuum sealing flange structure, which comprises a concave flange, a convex flange and a connecting pipe; two-stage 90-degree sealing steps matched with each other are processed on the inner sides of the opposite end surfaces of the concave flange and the convex flange, and a copper wire ring is placed between the concave flange and the convex flange, so that a gap is reserved between the concave flange and the convex flange along the axial direction; the female and male flanges are connected by a double-threaded pin or stud. Through the structural mode that 90 sealed steps compress the anaerobic copper wire, can satisfy the sealed demand of the super high vacuum of the non-circular passageway window flange of different shapes, reduced the sealed face's of non-circular window processing and the maintenance degree of difficulty.)

1. The utility model provides a real empty room non-circular passageway super high vacuum seal flange structure of large-scale tokamak which characterized in that: comprises a concave flange (1) fixedly welded with a vacuum chamber, a convex flange (2) positioned at one end of the concave flange (1), and a connecting pipe (7) connected with the convex flange (2); the sealing structure is characterized in that a concave two-stage 90-degree sealing step (101) is machined on the inner side of the end face, facing the convex flange (2), of the concave flange (1), a convex two-stage 90-degree sealing step (201) is machined on the inner side of the end face, facing the concave flange (1), of the convex flange (2), the concave two-stage 90-degree sealing step (101) is matched with the convex two-stage 90-degree sealing step (201), and a copper wire ring (3) is placed between the concave sealing step (101) and the convex sealing step (201) so that a gap is reserved between the concave flange (1) and the convex; concave flange (1) and convex flange (2) on be equipped with and connect the mounting hole, place double-end screw pin (4) or stud in the connection mounting hole, connect concave flange (1) and convex flange (2).

2. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 1, wherein: threaded blind holes are uniformly distributed on the end face of the concave flange (1) along the circumferential direction, the threaded blind holes correspondingly provided with the double-headed threaded pins (4) are double-headed threaded pin mounting holes (103), and the threaded blind holes correspondingly provided with the double-headed studs are double-headed stud mounting holes (104); bolt through holes (202) are uniformly distributed on the corresponding end surface of the convex flange (2) along the circumferential direction; the threaded blind holes and the bolt through holes (202) are the same in number.

3. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 2, wherein: the two double-threaded pin mounting holes (103) are respectively positioned on the upper side and the lower side of the vertical center line of the concave flange (1); the stud mounting hole (104) is a threaded blind hole outside the vertical center line of the concave flange (1).

4. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 2, wherein: the cross section shapes of the concave flange (1) and the convex flange (2) are the same.

5. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 2, wherein: stud bolt (4) or stud bolt pass bolt through hole (202) on protruding flange (2), one end gets into stud bolt mounting hole (103) or stud bolt mounting hole (104) respectively, the other end is located outside protruding flange (2), compresses tightly through belleville spring (6) and nut (5) fixed.

6. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 5, wherein: the inner side of the double-head threaded pin mounting hole (103) is provided with threads, and the outer side of the double-head threaded pin mounting hole is provided with a unthreaded hole; the double-threaded pin (4) comprises a middle polished rod (401) positioned in the middle and head threads (402) at two ends, and the polished rod (401) at the middle and the outer side polished holes of the double-threaded pin mounting hole (102) and the bolt through holes (202) of the convex flange (2) form a pin hole fit.

7. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 2, wherein: the tip (102) of the concave two-stage 90-degree step sealing surface (101) is processed into a round angle with the radius of R0.05mm-R0.1mm.

8. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 7, wherein: the surface roughness of the concave two-stage 90-degree step sealing surface (101) and the convex two-stage 90-degree step sealing surface (201) is Ra0.8 mu m.

9. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 8, wherein: the copper wire ring (3) is made of oxygen-free copper TU2, and the diameter of the copper wire is phi 1.5 mm-phi 2.0 mm; the compression amount of the copper wire ring (3) is 30-50% of the diameter of the copper wire.

10. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 8, wherein: the female flange (1), the male flange (2) and the nut (5) are made of austenitic stainless steel S31603, and the disc spring (6), the double-end threaded pin (4) and the double-end stud are made of GH 2132.

11. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 2, wherein: the nut (5) is matched with one or 2-4 disc springs (6) for installation, and the flange is further pressed.

12. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 2, wherein: the distance between the threaded blind holes on the concave flange (1) and the adjacent threaded holes is 40-50 mm.

13. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 2, wherein: the connecting pipe (7) is connected with the inner side of the convex flange (2) in a sealing way.

14. The large tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure of claim 13, wherein: the connecting pipe (7) is provided with 3-6 connecting pipes which are respectively connected with one end of the convex flange (2) in a sealing manner, so that the connecting pipe (7) is communicated with the inner side of the convex flange (2) in a sealing manner.

Technical Field

The invention belongs to the technical field of magnetic confinement nuclear fusion, and particularly relates to a sealed flange structure of a tokamak vacuum chamber.

Background

With the continuous improvement of plasma experiment parameters, the tokamak experiment device develops towards large-scale and precise directions. The outer diameter of a vacuum chamber container body of a new generation of tokamak experimental device is larger than 5.2 meters and the height is larger than 3.2 meters, and one of the main functions of the vacuum chamber container body is to provide an ultrahigh vacuum environment for the operation of a plasma experiment. In order to provide channels for heating, diagnosis, vacuum pumping, lead wire, material inlet and outlet, windows with different positions and sizes are arranged on the vacuum chamber, the windows are in a metal sealing flange structure type, and the leakage rate of the flange during operation is less than 1 multiplied by 10^-9Pa·m³And s. In order to increase the through hole area of the vacuum chamber window, the cross sections of the windows are designed into non-circular section channels, and the cross sections of the windows are mainly square and trapezoidal. Because the window shape is not standard round, the existing sealing effect is comparatively goodThe metal sealing flange structure is not suitable.

The vacuum chamber of the tokamak device is less than or equal to 10 in the initial operation stage^-6Pa of ultrahigh vacuum, the window flange needs to be baked and degassed at 200-300 ℃, and at the moment, the air leakage of the window flange due to the expansion and contraction effect during baking and heating and cooling is one of the common problems of the metal flange with the non-circular section. Meanwhile, in the operation stage of a plasma discharge experiment, serious electromagnetic force impact is generated on the vacuum chamber, and the size and the weight of the flange are large, so that the risk of leakage caused by the fact that the flange sealing structure bears impact forces in different directions is greatly increased. In addition, the flange structure for the tokamak vacuum chamber also needs to meet the requirement that the relative magnetic permeability of the material is less than 1.05.

The existing non-circular channel ultrahigh vacuum flange sealing technology has great defects in the aspects of vacuum sealing reliability, sealing performance under vibration impact, structural maintainability and the like when being baked at high temperature of 300 ℃.

Disclosure of Invention

The invention aims to provide a large-scale tokamak vacuum chamber non-circular channel ultrahigh vacuum sealing flange structure.

The technical scheme of the invention is as follows:

a large-scale tokamak vacuum chamber non-circular channel ultra-high vacuum sealing flange structure comprises a concave flange fixedly welded with a vacuum chamber, a convex flange positioned at one end of the concave flange, and a connecting pipe connected with the convex flange; the concave flange is provided with two concave 90-degree sealing steps facing the inner side of the end face of the convex flange, the convex flange is provided with two convex 90-degree sealing steps facing the inner side of the end face of the concave flange, the two concave 90-degree sealing steps are matched with the two convex 90-degree sealing steps, and a copper wire ring is arranged between the two steps, so that a gap is reserved between the concave flange and the convex flange along the axial direction; the female flange and the male flange are provided with connecting mounting holes, and double-end threaded pins or double-end studs are placed in the connecting mounting holes to connect the female flange and the male flange.

Threaded blind holes are uniformly distributed on the end face of the concave flange along the circumferential direction, the threaded blind holes correspondingly provided with the double-headed threaded pins are double-headed threaded pin mounting holes, and the threaded blind holes correspondingly provided with the double-headed studs are double-headed stud mounting holes; bolt through holes are uniformly distributed on the corresponding end face of the convex flange along the circumferential direction; the threaded blind holes and the bolt through holes are the same in number.

The two double-threaded pin mounting holes are respectively positioned on the upper side and the lower side of the vertical center line of the concave flange; the stud mounting hole is a threaded blind hole outside the vertical center line of the concave flange.

The cross section shapes of the concave flange and the convex flange are the same.

The double-end thread pin or the double-end stud penetrates through the bolt through hole in the convex flange, one end of the double-end thread pin or the double-end stud respectively enters the double-end thread pin mounting hole or the double-end stud mounting hole, and the other end of the double-end thread pin or the double-end stud is located outside the convex flange and is fixedly pressed through the disc spring and the nut.

The inner side of the double-threaded pin mounting hole is provided with threads, and the outer side of the double-threaded pin mounting hole is provided with a unthreaded hole; the double-threaded pin comprises a middle polished rod in the middle and head threads at two ends, and the polished rod in the middle and the outer polished hole of the mounting hole of the double-threaded pin are matched with the bolt through hole of the convex flange to form a pin hole.

The tip of the concave two-stage 90-degree step sealing surface 101 is processed into a round angle with the radius of R0.05mm-R0.1mm.

The surface roughness of the concave two-stage 90-degree step sealing surface 101 and the convex two-stage 90-degree step sealing surface is Ra0.8 mu m.

The copper wire ring is made of oxygen-free copper TU2, and the diameter of the copper wire is phi 1.5 mm-phi 2.0 mm; the compression amount of the copper wire ring is 30-50% of the diameter of the copper wire.

The female flange, the male flange and the nut are made of austenitic stainless steel S31603, and the disc spring, the double-end threaded pin and the double-end stud are made of GH 2132.

The nut is matched with one or 2-4 disc springs for installation, and the flange is further pressed.

The distance between the threaded blind holes on the concave flange and the adjacent threaded holes is 40-50 mm.

The connecting pipe is connected with the inner side of the convex flange in a sealing way.

The takeover have 3 ~ 6, respectively with protruding flange one end sealing connection for the takeover all communicates with protruding flange inboard sealing.

The invention has the following remarkable effects: through the structural mode that 90 sealed steps compress the anaerobic copper wire, can satisfy the sealed demand of the super high vacuum of the non-circular passageway window flange of different shapes, reduced the sealed face's of non-circular window processing and the maintenance degree of difficulty. Through reasonable combination of materials of all parts, the thermal expansion difference of various materials in the baking temperature rise and temperature drop stages is reduced, and the vacuum tightness of the flange under the baking working condition is ensured. The characteristic that the disc spring has larger elastic performance is utilized, so that the sealing copper wire has more stable pressing force under the working conditions of baking and vibration impact, and particularly the vacuum sealing performance of the flange under the baking working condition is improved. The design of the double-threaded pin can enable the concave flange and the convex flange to be quickly and accurately positioned during assembly, and the pin holes are matched to improve the vibration and impact resistance of the flange and improve the vacuum sealing reliability of the flange when the flange bears electromagnetic force impact. The relative magnetic permeability of the whole flange sealing structure is less than 1.05, the structure is simple, and the flange sealing structure is easy to process and maintain.

Drawings

FIG. 1 is a schematic view of a flange assembly;

FIG. 2 is a cross-sectional view of the vertical center of the female flange;

FIG. 3 is a cross-sectional view of the vertical center of the male flange;

FIG. 4 is a schematic view of a double-start threaded pin;

FIG. 5 is a schematic external view of a female flange;

in the figure: v-vacuum chamber shell, 1-concave flange, 2-convex flange, 3-copper wire ring, 4-double thread pin, 5-nut, 6-disc spring, 7-connecting pipe, 101-concave two-stage 90-degree step sealing surface, 102-tip; 103-stud pin mounting hole, 104-stud mounting hole, 201-convex two-stage 90-degree step sealing surface, 202-bolt through hole, 401-middle polish rod and 402-head thread.

Detailed Description

The invention is further illustrated by the accompanying drawings and the detailed description.

As shown in fig. 1, a female flange 1 is welded to the housing of the vacuum chamber V, and a male flange 2 is welded to the end of a nozzle 7. The entire flange structure may be located in the upper, middle, and lower regions of the outer housing of the vacuum chamber. The flange structure can also be arranged at the coil position if the connecting pipe of the flange can be led out from the neutral position of the coil.

The connecting pipe 7 has the function of forming an ultrahigh vacuum boundary together with the vacuum chamber shell and the flange and is connected with plasma diagnosis, heating, vacuum pumping and other equipment positioned outside the vacuum chamber of the Tokamak device. A flange structure is designed between the vacuum chamber V and the connecting pipe 7 to form an ultrahigh vacuum channel.

The connecting pipe 7 is a channel for connecting equipment such as diagnosis, heating, vacuum pumping, lead penetration and the like, when the device runs, the inside of the vacuum chamber is kept in ultrahigh vacuum, so that the equipment such as diagnosis, heating and the like is communicated with the vacuum chamber, and the physical quantity measuring lead can be input and output.

In practical use, the connecting pipe 7 can be hermetically connected with the inner side of the convex flange 2, and a plurality of pipeline residual connecting pipes 7 can be arranged on the convex flange 2 for connection.

In this embodiment, the cross sections of the designed concave flange 1 and the designed convex flange 2 can be designed to be the same shape. Concave two-stage 90-degree sealing steps 101 are machined on the inner side of the end face of the concave flange 1 facing the convex flange 2, convex two-stage 90-degree sealing steps 201 are machined on the inner side of the end face of the convex flange 2 facing the concave flange 1, the concave two-stage 90-degree sealing steps 101 are matched with the convex two-stage 90-degree sealing steps 201, and a copper wire ring 3 is placed between the concave two-stage 90-degree sealing steps 101 and the convex two-stage 90-degree sealing steps 201, so that a gap is reserved between the concave flange 1 and.

As shown in fig. 2 and 3, the end face of the female flange 1 is uniformly distributed with blind threaded holes along the circumferential direction of the ring, the corresponding end face of the male flange 2 is uniformly distributed with the same number of bolt through holes 202 along the circumferential direction of the ring, and the mounting hole structure is used for mounting the stud bolt 4 or stud bolt (not shown). The double-end threaded pin 4 or the double-end stud penetrates through the bolt through hole 202 on the convex flange 2, one end of the double-end threaded pin enters the threaded blind hole of the concave flange 1 for threaded fixation, and the other end of the double-end threaded pin is connected with the nut 5 through the disc spring 6 in an assembling mode, so that the two flanges are further pressed tightly, and pressing force is provided for the copper coil 3. The threaded blind holes corresponding to the installation of the stud bolts are stud bolt installation holes 103, and the threaded blind holes corresponding to the installation of the stud bolts are stud bolt installation holes 104, which are not shown in fig. 2, but shown in fig. 5.

The tip 102 of the concave two-stage 90-degree step sealing surface 101 is processed into a round angle with the radius of R0.05mm-R0.1mm, the surface roughness of the concave two-stage 90-degree step sealing surface 101 and the convex two-stage 90-degree step sealing surface 201 is Ra0.8 mu m, when the flange works, the concave two-stage 90-degree step sealing surface 101, the tool nose of the concave two-stage 90-degree step sealing surface and the convex two-stage 90-degree step sealing surface 201 directly participate in compressing the copper wire coil 3, the air leakage rate of the sealing position can be reduced through the precision setting, and the vacuum sealing performance of the flange is improved.

The function of processing the tip 102 into a fillet is different from the edge chamfer (generally 0.5mm to 2mm) of a general machined product, and the sharp corner of the tip of the flange sealing surface is also called a knife edge and is used for cutting into a sealing material. However, in practical processing, the fillet of the tip 102 cannot be infinitely small, so there is a limitation that the fillet of the tip r0.05mm to r0.1mm can meet the above requirement in consideration of both the processing capability and the practical sealing effect.

The copper wire ring 3 is made of oxygen-free copper TU2, and the diameter of the copper wire is phi 1.5 mm-phi 2.0 mm; when the flange works, the optimal compression amount of the copper wire ring 3 is 30-50% of the diameter of the copper wire.

The female flange 1, the male flange 2 and the nut 5 are made of austenitic stainless steel S31603, the double-threaded pin 4 and the double-threaded stud are made of GH2132, and the combination of the materials makes use of the characteristic that the GH2132 has higher material strength and similar material thermal expansion coefficients compared with the material strength of S31603, so that the double-threaded pin and the double-threaded stud have higher material strength, and meanwhile, the thermal expansion difference of each part in the baking stage is small. In addition, the relative permeability of the materials of GH2132 and S31603 is less than 1.05, so that the relative permeability of the whole flange structure is ensured to be less than 1.05.

The material of the disc spring 6 is GH2132, and the structural type and the size are selected according to the national standard GB/T1972-2005. When the flange works, one nut can be matched with one or more disc springs for use. Through the arrangement of the disc spring, the pressure fluctuation of the copper wire coil in the baking temperature rise and temperature reduction stages can be reduced, and the ultrahigh vacuum sealing reliability of the flange under the baking working condition is improved.

As shown in fig. 2 and 5, the thread specification of the threaded blind hole formed on the end face of the concave flange is M12, and the distance between two adjacent threaded holes is 40 mm-50 mm; the threaded blind hole positioned on the vertical center line of the concave flange is used as a double-threaded pin mounting hole 103, the inner side of the hole is provided with M12 threads, and the outer side of the hole is provided with a unthreaded hole; a threaded blind hole located outside the vertical centerline of the female flange 1 serves as the stud mounting hole 104.

As shown in fig. 4, the double-threaded pin 4 comprises a middle polished rod 401 in the middle and head threads 402 of M12 at two ends, the polished rod 401 at the outer side of the double-threaded pin mounting hole 103 and the bolt through hole 202 of the male flange 2 form a pin-hole fit, and the fit clearance is 0.02 mm-0.05 mm. The arrangement improves the assembly precision and the shock and vibration resistance of the flange by utilizing the pin hole positioning and shearing resisting principles of the double-threaded pin, and improves the vacuum sealing reliability of the flange when the flange is subjected to vibration and impact.