Decompression sealing tool

Abstract

To provide a decompression sealing tool with excellent workability, easily assembled and disassembled, and capable of reliably decompressing and sealing a decompression object by work under atmospheric pressure in a simple procedure.SOLUTION: A decompression sealing tool 10 for use in decompression and sealing of a decompression object 11 whose exhaust port 16 is hermetically sealed by fixing a sealing lid 18 to an exhaust port flange 17 formed around an outer periphery of the exhaust port 16 on a longitudinal tip side of an exhaust pipe 15, includes a decompression chamber 20 detachably attached to the exhaust pipe 15, and connected to a vacuum pump, with it hermetically covering the exhaust port flange 17 and the sealing lid 18, and a pressing tool 21 slidably held in the decompression chamber 20 and moving the sealing lid 18 toward the exhaust port flange 17. The decompression chamber 20 can be opened / closed in a state where the sealing lid 18 is pressed by the pressing tool 21, the exhaust port 16 is hermetically sealed and the decompression object 11 is decompressed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vacuum sealing tool used for decompressing and sealing an object to be decompressed, and particularly to a vacuum sealing tool suitable for evacuation and sealing of vacuum structures such as vacuum double containers (thermo flasks), vacuum containers, and vacuum double tubes. [Background technology]

[0002] Conventional general vacuum drawing work processes require large-scale equipment, and sealing methods for exhaust holes with brazing material or glass have the problem of complicated processes and lack of productivity. In response to this, for example, Patent Document 1 discloses a sealing method for a vacuum structure in which a metal plate is resistance-welded or vacuum-diffusion-bonded to a structural member around the exhaust hole with a metal foil interposed therebetween to seal the exhaust hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2004-57675 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the sealing process is simplified compared to conventional methods, and post-processing of the vacuum structure after sealing is also easy, but resistance welding and vacuum diffusion bonding must be performed in a vacuum, as in conventional sealing using brazing material or glass. In addition, the metal foil and metal plate must be continuously heated and pressurized during resistance welding and vacuum diffusion bonding. Therefore, there has been a demand for the development of a vacuum sealing tool that has a simpler structure and process and can easily and reliably decompress and seal an object to be decompressed. The present invention has been made in consideration of the above circumstances, and aims to provide a vacuum sealing tool with excellent workability that is easy to assemble and disassemble, and can reliably depressurize and seal an object to be depressurized under atmospheric pressure in a simple procedure. [Means for solving the problem]

[0005] A vacuum sealing tool according to the present invention that meets the above-mentioned objective is a vacuum sealing tool used for decompressing and sealing an object to be decompressed, the object being an exhaust port of which is sealed by fixing a sealing lid to an exhaust port flange formed on the outer periphery of the exhaust port at the end of the longitudinal direction of an exhaust pipe, the vacuum sealing tool comprising: The device includes a pressure reduction chamber that is detachably attached to the exhaust pipe, sealably covers the exhaust port flange and the sealing lid, and is connected to a vacuum pump, and a pressing tool that is slidably held in the pressure reduction chamber and moves the sealing lid toward the exhaust port flange, and the pressure reduction chamber can be opened and closed when the sealing lid is pressed by the pressing tool to seal the exhaust port and reduce the pressure of the object to be depressurized.

[0006] In the reduced pressure sealing jig of the present invention, it is preferable that the reduced pressure chamber has a base flange arranged on the base side of a joint plate provided midway along the longitudinal direction of the exhaust pipe, a cover flange arranged opposite the base flange across the joint plate and screwed to the base flange, a transparent pipe section held inside the cover flange and surrounding the outer periphery of the exhaust port flange and the sealing lid, and a pressing tool holding means connected to the tip side of the transparent pipe section and holding the pressing tool slidably in an airtight state.

[0007] In the reduced pressure sealing tool according to the present invention, it is preferable that the pressing tool holding means comprises a cylindrical outer case, a bellows inserted into the outer case, a bellows fixing device having a through hole formed in the center and fixing a front end of the bellows to the outer case to seal the front end of the outer case, and a bellows cover closing a base side of the bellows, and the pressing tool comprises a shaft arranged between the sealing lid and the bellows cover, and a pressing shaft inserted into the bellows with its base side abutting the bellows cover and its front side protruding from the through hole to the outside of the reduced pressure chamber, and capable of pressing the sealing lid via the shaft.

[0008] In the reduced pressure sealing jig of the present invention, the pressing tool holding means has a pipe clamp that is connected to the base side of the outer case and detachably connected to the cover flange to hold the tip side of the transparent pipe portion, and the pipe clamp can have a shaft insertion portion that slidably holds the shaft, and an air hole that connects the transparent pipe portion and the outer case.

[0009] In the reduced pressure sealing jig according to the present invention, a connecting portion that is detachably connected to the sealing lid is formed at the base end of the shaft, and a fitting portion that fixes and holds the tip end of the shaft is formed at the base side of the bellows cover.

[0010] In the reduced pressure sealing jig according to the present invention, it is preferable that a pressing shaft holding portion for rotatably holding the base end of the pressing shaft is formed at the base end of the bellows, a male screw portion is formed at the tip side of the pressing shaft, the pressing tool has a pressing flange that is detachably connected to the base flange via a plurality of tie rods, and a female screw hole that screws into the male screw portion of the pressing shaft is formed in the center of the pressing flange.

[0011] The reduced pressure sealing jig according to the present invention may further comprise a spacer that is fitted onto the pressing shaft at the tip side of the bellows fixing device when the reduced pressure is applied to the reduced pressure chamber, and that sets an initial gap between the exhaust port flange and the sealing lid.

[0012] In the reduced pressure sealing tool of the present invention, it is preferable that, while the reduced pressure chamber and the object to be reduced pressure are in a reduced pressure state, the sealing lid is pressed by the pressing tool, and a reusable metal gasket is sandwiched between the exhaust port flange and the sealing lid, thereby sealing the exhaust port. Effect of the Invention

[0013] With the vacuum sealing tool of the present invention, the exhaust port flange and the sealing lid are covered with a vacuum chamber that is detachably attached to the exhaust pipe of the object to be depressurized, and after the object to be depressurized and the inside of the vacuum chamber are depressurized, the sealing lid can be pressed with a pressing tool to seal the exhaust port, and the vacuum chamber can be opened with the exhaust port sealed with the sealing lid, and the sealing lid can be fixed to the exhaust port flange to reliably seal the exhaust port, eliminating the need to use a vacuum valve and simplifying the work of depressurizing and sealing the object to be depressurized.

[0014] In the vacuum sealing jig of the present invention, when the vacuum chamber has a base flange arranged on the base side of a joint plate provided midway along the longitudinal direction of the exhaust pipe, a cover flange arranged opposite the base flange across the joint plate and screwed to the base flange, a transparent pipe section held inside the cover flange and surrounding the outer periphery of the exhaust port flange and the sealing lid, and a pressing tool holding means connected to the tip of the transparent pipe section and holding the pressing tool in an airtight and slidable manner, it is easy to attach and detach the jig to the exhaust pipe, the worker can visually confirm the tight contact between the exhaust port flange and the sealing lid through the transparent pipe section, and with the exhaust port sealed by the sealing lid, the cover flange, the transparent pipe section and the pressing tool holding means can be slid over the pressing tool to open the vacuum chamber.

[0015] In the reduced pressure sealing tool according to the present invention, when the pressing tool holding means has a cylindrical outer case, a bellows inserted into the outer case, a bellows fixing tool having a through hole formed in the center and fixing the tip side of the bellows to the outer case to seal the tip side of the outer case, and a bellows cover that closes the base side of the bellows, and the pressing tool has a shaft arranged between the sealing lid and the bellows cover, and a pressing shaft that is inserted into the bellows with its base side abutting the bellows cover and its tip side protruding from the through hole to the outside of the reduced pressure chamber and can press the sealing lid via the shaft, the sealing lid can be reliably pressed to seal the exhaust port while the sliding pressing shaft is covered with the bellows to maintain a sealed state inside the reduced pressure chamber.

[0016] In the reduced pressure sealing jig of the present invention, the pressing tool holding means has a pipe clamp that is connected to the base side of the outer case and detachably connected to the cover flange to hold the tip side of the transparent pipe section, and when the pipe clamp has a shaft insertion portion that slidably holds the shaft and an air hole that connects the transparent pipe section to the outer case, the transparent pipe section can be clamped between the cover flange and the pipe clamp, the transparent pipe section and the pressing tool holding means can be integrated, the sliding shaft can be supported by the pipe clamp, and the inside of the reduced pressure chamber can be uniformly reduced pressure.

[0017] In the vacuum sealing jig of the present invention, when a connecting portion that is detachably connected to the sealing lid is formed at the base end of the shaft, and a fitting portion that fixedly holds the tip end of the shaft is formed at the base side of the bellows cover, axial misalignment of the shaft is prevented, and the shaft pressed by the pressing shaft can be slid smoothly and reliably, allowing the sealing lid to be tightly attached to the exhaust port flange.

[0018] In the reduced pressure sealing jig according to the present invention, a pressing shaft holding portion that rotatably holds the base end of the pressing shaft is formed at the base end of the bellows, a male screw portion is formed at the tip side of the pressing shaft, the pressing tool has a pressing flange that is detachably connected to the base flange via a plurality of tie rods, and a female screw hole that screws into the male screw portion of the pressing shaft is formed in the center of the pressing flange, then by rotating the pressing shaft, the bellows expands and contracts in conjunction with the sliding of the pressing shaft, the position of the pressing shaft that presses the sealing lid towards the exhaust port flange via the shaft is fixed, and a tight contact state between the sealing lid and the exhaust port flange can be maintained.

[0019] In the vacuum sealing jig according to the present invention, when the vacuum chamber is depressurized, if a spacer is provided which is fitted onto the pressing shaft at the tip side of the bellows fixing device and sets the initial distance between the exhaust port flange and the sealing lid, the amount of movement of the pressing shaft can be managed to reliably bring the sealing lid and the exhaust port flange into close contact with each other.

[0020] In the vacuum sealing tool of the present invention, when the vacuum chamber and the object to be decompressed are decompressed, the sealing lid is pressed by the pressing tool and a reusable metal gasket is sandwiched between the exhaust port flange and the sealing lid to seal the exhaust port. Unlike conventional sealing using rubber or resin O-rings, which are prone to air leakage, not only is the reduced pressure state (high vacuum) of the object to be decompressed maintained for a long period of time, but costs can also be reduced. [Brief description of the drawings]

[0021] [Figure 1] 1 is a partial cross-sectional front view showing a state in which a vacuum sealing jig according to an embodiment of the present invention is attached to an exhaust pipe of an object to be decompressed. [Diagram 2] 13 is a partial cross-sectional front view showing a state in which the inside of the decompression object and the decompression chamber are decompressed by the decompression sealing jig and the exhaust port is sealed with a sealing lid. FIG. [Diagram 3] 13 is a partial cross-sectional front view showing a state in which the decompression chamber is opened after the decompression object is decompressed by the decompression sealing jig and the exhaust port is sealed with a sealing lid. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Next, with reference to the attached drawings, an embodiment of the present invention will be described for understanding the present invention. A decompression sealing jig 10 according to an embodiment of the present invention shown in Figs. 1 to 3 is used to decompress and seal an object 11 to be decompressed. The object 11 to be decompressed is composed of an inner container wall 12 and an outer container wall 13, and a hollow portion 14 formed between the inner container wall 12 and the outer container wall 13 is decompressed to a vacuum, thereby being used as a vacuum double container. The object 11 to be decompressed has an exhaust pipe 15 communicating with the hollow portion 14, and an exhaust port flange 17 is formed on the outer periphery of an exhaust port 16 on the longitudinal tip side of the exhaust pipe 15. A sealing lid 18 is fixed to the exhaust port flange 17 with screws, thereby sealing the exhaust port 16.

[0023] The reduced pressure sealing jig 10 will now be described in detail. The vacuum sealing jig 10 is removably attached to the exhaust pipe 15, and has a vacuum chamber 20 that hermetically covers the exhaust port flange 17 and the sealing lid 18 and has a vacuum pump connection port 19 that is connected to a vacuum pump (not shown), and a pressing tool 21 that is slidably held in the vacuum chamber 20 and moves the sealing lid 18 toward the exhaust port flange 17. The reduced pressure chamber 20 has a base flange 23 that is arranged on the base side of a joint plate 22 that is provided midway along the longitudinal direction of the exhaust pipe 15 (between the outer surface of the outer container wall 13 and the exhaust port flange 17), and a cover flange 24 that is arranged opposite the base flange 23 across the joint plate 22 and is screwed to the base flange 23.

[0024] In this embodiment, the base flange 23 is formed in two pieces (halves), so that it can be disposed on the base side of the joint plate 22. In plan view, a plurality of (for example, four) female screw holes 23a are formed on the circumference of the base flange 23, and male screw insertion holes 24a are formed on the circumference of the cover flange 24 in correspondence with the positions of the female screw holes 23a. Therefore, the cover flange fixing male screws 25 inserted from the male screw insertion holes 24a are screwed into the female screw holes 23a, and the base flange 23 and the cover flange 24 are connected, so that the joint plate 22 is sandwiched between the base flange 23 and the cover flange 24, and the decompression chamber 20 is attached (fixed) to the exhaust pipe 15.

[0025] Furthermore, the decompression chamber 20 has a transparent pipe section 26 that is held inside the cover flange 24 and surrounds the outer periphery of the exhaust port flange 17 and the sealing lid 18, and a pressing tool holding means 27 that is connected to the tip of the transparent pipe section 26 and slidably holds the pressing tool 21 in an airtight state (while maintaining the decompression state (sealed state) including the vacuum of the decompression chamber 20). The pressing tool holding means 27 has a cylindrical outer case 28, a bellows 29 inserted into the outer case 28, a bellows fixing device 31 having a through hole 30 formed in the center and fixing the tip end of the bellows 29 to the outer case 28 to seal the tip end of the outer case 28, and a bellows cover 32 that closes the base side of the bellows 29. The pressing tool 21 has a shaft 34 arranged between the sealing lid 18 and the bellows cover 32, and a pressing shaft 35 that is inserted into the bellows 29 so that its base side abuts the bellows cover 32 and its tip side protrudes from the through hole 30 of the bellows fixing tool 31 to the outside of the reduced pressure chamber 20 (the outer case 28 of the pressing tool holding means 26) and can press the sealing lid 18 via the shaft 34.

[0026] Here, a connecting portion 36 that is detachably connected to the sealing lid 18 is formed at the base end of the shaft 34, and a fitting portion 38 that holds the tip end 37 of the shaft 34 to prevent axial misalignment is formed at the base side of the bellows cover 32. This ensures that the force of the pressing shaft 35 can be transmitted to the shaft 34, and the sealing lid 18 can be pressed from outside the decompression chamber 20 to make it adhere tightly to the exhaust port flange 17. In this embodiment, the shaft 34 is connected to the sealing lid 18 by inserting the connecting portion 36 of the shaft 34, to which an O-ring 40 is attached, into a recess 39 formed in the center of the front surface of the sealing lid 18, but the two may be connected by forming a convex portion on the sealing lid side and a recess on the shaft side. In addition, in this embodiment, the fitting portion 38 of the bellows cover 32 is formed concavely and the tip end 37 of the shaft 34 is formed convexly, but the fitting portion of the bellows cover may be formed convexly and the tip end of the shaft may be formed concavely. The tip end may be formed integrally with the shaft, or may be formed of a separate member and integrated with the shaft by welding.

[0027] The pressing tool holding means 27 has a pipe holder 42 which is connected to the base side of the outer case 28 and detachably connected to the cover flange 24 to hold the tip side of the transparent pipe part 26. In this embodiment, in a plan view, a plurality of (for example, two) female screw holes 24b are formed on the circumference of the cover flange 24, and a male screw insertion hole 42a is formed on the circumference of the pipe holder 42 in correspondence with the positions of the female screw holes 24b. Therefore, the cover flange 24 and the pipe holder 42 are connected by inserting a connecting male screw 43 through the male screw insertion hole 42a and screwing it into the female screw hole 24b, and the transparent pipe part 26 is held (clamped) by the cover flange 24 and the pipe holder 42. The pipe holder 42 also has a shaft insertion part 45 which slidably holds the shaft 34, and an air hole 46 which communicates between the transparent pipe part 26 and the outer case 28. In this embodiment, six circular air vents 46 are arranged at equal angular intervals around the outer periphery of the shaft insertion portion 45 when viewed in a plan view. This is for exhaust when pressure is reduced, and the shape, size, number and arrangement of the air vents can be selected appropriately.

[0028] The contact surface between the joint plate 22 and the cover flange 24 (the base surface of the cover flange 24), the contact surface between the cover flange 24 and the transparent pipe section 26 (the inner peripheral surface of the cover flange 24), and the contact surface between the transparent pipe section 26 and the pipe holder 42 (the inner peripheral surface of the pipe holder 42) are each kept airtight by an O-ring 47. Heat-resistant glass is preferably used as the material for the transparent pipe section 26, but the material is not limited to this and any material having durability that will not be damaged by reduced pressure can be appropriately selected. Since the outer periphery of the exhaust port flange 17 and the sealing lid 18 are surrounded by the transparent pipe section 26, the worker can visually check the adhesion between the exhaust port flange 17 and the sealing lid 18 during work. However, since the pressing tool 21 (pressing shaft 35) will not move once the exhaust port flange 17 and the sealing lid 18 are in close contact, visual confirmation is not essential, and an opaque pipe made of metal or the like may be used instead of the transparent pipe section. Additionally, the outer case 28, the bellows fixing device 31 and the pipe holder 42 are formed from a metal such as stainless steel, and are integrated together by welding.

[0029] With the above configuration, the airtightness of the entire decompression chamber 20 is maintained, and deformation during decompression is prevented. In this embodiment, the outer case 28 is formed by connecting (welding) two cylindrical bodies 28a, 28b with different diameters, but the shape of the outer case is not limited to this and can be selected appropriately. In this embodiment, the vacuum pump connection port 19 is formed on the front side (cylindrical body 28a) of the outer case 28, but the position of the vacuum pump connection port can be selected appropriately. A pressing shaft holding portion 48 that rotatably holds the base end portion 35a of the pressing shaft 35 is formed at the base end portion of the bellows 29. Also, a male screw portion 50a is formed on the outer periphery of a male screw forming body 50 connected to the tip side of the pressing shaft 35. In this embodiment, a fitting portion 50b having a larger diameter than the pressing shaft 35 is formed at the base side of the male screw forming body 50, so that the pressing shaft 35 and the male screw forming body 50 are connected (fitted) and integrated, but the method of attaching the male screw forming body 50 to the pressing shaft 35 can be selected appropriately. Also, a male screw portion may be formed directly on the outer periphery of the tip side of the pressing shaft.

[0030] The pressing tool 21 has a pressing flange 53 that is detachably connected to the base flange 23 via a plurality of (for example, four) tie rods 52. Here, male screw portions 52a, 52b are formed at both ends of the tie rod 52. In plan view, a plurality of (for example, four) connecting female screw holes 23b are formed on the circumference of the base flange 23, and a tie rod insertion hole 53a is formed on the circumference of the pressing flange 53 in correspondence with the positions of the connecting female screw holes 23b. Therefore, the base flange 23 and the pressing flange 53 are connected and held at a constant distance by screwing the male screw portion 52a on the base side of the tie rod 52 into the connecting female screw hole 23b of the base flange 23 and screwing a fixing nut 54 into the male screw portion 52b on the tip side of the tie rod 52 inserted into the tie rod insertion hole 53a. Further, a female screw portion 55 is formed in the center of the pressure flange 53 to be screwed with the male screw portion 50a at the tip side of the pressure shaft 35. Then, when the pressure reduction chamber 20 is reduced, a spacer 56, which is U-shaped or C-shaped in plan view, is fitted to the tip side of the bellows fixing device 31 (here, between the fitting portion 50b and the bellows fixing device 31). This makes it possible to set an initial distance (e.g., 10 mm) between the exhaust port flange 17 and the sealing cover 18, and ensure exhaust from the exhaust port 16 to reduce the pressure of the hollow portion 14. The pressure inside the pressure reduction chamber 20 can be monitored by a pressure gauge (not shown), and the pressure of the object 11 (hollow portion 14) to be reduced to a desired pressure (e.g., vacuum).

[0031] In Fig. 1, when the hollow portion 14 of the object 11 to be decompressed and the decompression chamber 20 are decompressed, the spacer 56 is removed, and the worker simply rotates the pressing shaft 35, so that the pressing shaft 35 can be moved along the female screw hole 55 toward the object 11 to be decompressed, as shown in Fig. 2. The tip end of the male screw forming body 50 is formed with a tool mounting portion 50c having a polygonal shape (square or hexagonal) in a plan view, so that the worker can easily rotate the pressing shaft 35 using a tool such as a wrench. As the pressing shaft 35 moves, the bellows 29 expands, the shaft 34 is pressed by the pressing shaft 35, and the sealing lid 18 approaches the exhaust port flange 17, and eventually the sealing lid 18 and the exhaust port flange 17 come into close contact with each other to seal the exhaust port 16.

[0032] 2, the operator removes the cover flange fixing male screw 25, and moves the handle 57 attached to the cover flange 24 toward the tip side (here, upward) of the exhaust port 16. At this time, the base flange 23 and the pressing flange 53 are connected by the tie rod 52, and the male screw portion 50a is screwed into the female screw hole 54 formed in the pressing flange 53, so that the sealing lid 18, the shaft 34, the bellows cover 32, and the pressing shaft 35 remain fixed and do not move, and only the cover flange 24, the transparent pipe portion 26, the outer case 28, and the bellows fixing tool 31 move along the pressing shaft 35, and the bellows 29 extends, as shown in FIG. 3. In other words, the decompression chamber 20 can be opened and closed in a state in which the sealing lid 18 is pressed by the pressing tool 21, the exhaust port 16 is sealed, and the decompression target 11 is decompressed.

[0033] 3, after the decompression chamber 20 is opened to the atmosphere, an operator holds a support tool 58 between the base flange 23 and the handle 57, thereby maintaining a gap 59 formed between the joint plate 22 and the cover flange 24. Here, in a plan view, a plurality of (for example, four) female screw holes 18a are formed on the circumference of the sealing cover 18, into which male sealing screws 60 are screwed in advance, and male screw insertion holes 17a are formed on the circumference of the exhaust port flange 17 in correspondence with the positions of the female screw holes 18a. Therefore, when the exhaust port flange 17 and the sealing cover 18 are in close contact with each other, the tip of the sealing male screw 60 protrudes from the male screw insertion hole 17a toward the base side of the exhaust port flange 17, so that an operator can screw a sealing female screw (not shown) (for example, a U-nut) into the sealing male screw 60 through the gap 59 to seal and fix the exhaust port 16. After sealing the exhaust port 16, an operator can loosen the screws of each part of the reduced pressure sealing jig 10, disassemble the reduced pressure sealing jig 10, and remove it from the exhaust pipe 15. In addition, the reduced pressure state of the object 11 to be decompressed after sealing is stably maintained for a long period of time by sandwiching the metal gasket 61 between the exhaust port flange 17 and the sealing lid 18. In addition, the metal gasket 61 can be used repeatedly, and when the reduced pressure state of the object 11 to be decompressed decreases, the operator can decompress and seal the object 11 to be decompressed in the same manner as described above.

[0034] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and includes other embodiments and modifications conceivable within the scope of the claims, and all changes in conditions that do not deviate from the gist of the invention are within the scope of application of the present invention. In the above embodiment, the case where the object to be depressurized is a vacuum double vessel has been described, but the depressurization sealing jig is used for depressurization (evacuation) and sealing of other objects to be depressurized, including vacuum structures such as vacuum vessels and vacuum double tubes. In addition, in the above embodiment, a flange joint in which the exhaust port flange and the flange portions on the outer periphery of the sealing lid are fixed with screws is used as a means for fixing the exhaust port flange and the sealing lid, but a ferrule joint in which the exhaust port flange and the flange portions on the outer periphery of the sealing lid are fixed with a clamp band may also be used. [Explanation of symbols]

[0035] 10: decompression sealing jig, 11: object to be decompressed (vacuum double vessel), 12: inner vessel wall, 13: outer vessel wall, 14: hollow portion, 15: exhaust pipe, 16: exhaust port, 17: exhaust port flange, 17a: male screw insertion hole, 18: sealing cover, 18a: female screw hole, 19: vacuum pump connection port, 20: decompression chamber, 21: pressing tool, 22: joint plate, 23: base flange, 23a: female screw hole, 23b: female screw hole for connection, 24: cover flange, 24a: male screw insertion hole, 24b: female screw hole, 25: male screw for fixing cover flange, 26: transparent pipe portion, 27: pressing tool holding means, 28: outer case, 28a, 28b: cylinder, 29: bellows, 30: through hole, 31: bellows fixing tool, 32: bellows cover, 34: shaft, 35 pressing shaft, 35a: base end, 36: connecting portion, 37: tip end, 38: fitting portion, 39: recess, 40: O-ring, 42: pipe holder, 42a: male screw insertion hole, 43: connecting male screw, 45: shaft insertion portion, 46: vent hole, 47: O-ring, 48: pressing shaft holding portion, 50: male screw forming body, 50a: male screw portion, 50b: fitting portion, 50c: tool mounting portion, 52: tie rod, 52a, 52b: male screw portion, 53: pressing flange, 53a: tie rod insertion hole, 54: fixing nut, 55: female screw portion, 56: spacer, 57: handle, 58: support tool, 59: gap, 60: sealing male screw, 61: metal gasket

Claims

1. A decompression sealing jig used for decompressing and sealing an object to be decompressed, in which a sealing lid is fixed to an exhaust port flange formed on an outer periphery of an exhaust port at a longitudinal end of an exhaust pipe, and the exhaust port is sealed, a pressure reduction chamber that is detachably attached to the exhaust pipe, sealably covers the exhaust port flange and the sealing lid, and is connected to a vacuum pump; and a pressing tool that is slidably held in the pressure reduction chamber and moves the sealing lid toward the exhaust port flange, wherein the pressure reduction chamber can be opened and closed when the sealing lid is pressed by the pressing tool to seal the exhaust port and the object to be depressurized is depressurized.

2. 2. The vacuum sealing jig according to claim 1, wherein the vacuum chamber comprises: a base flange disposed on the base side of a joint plate provided midway along the longitudinal direction of the exhaust pipe; a cover flange disposed opposite the base flange across the joint plate and screwed to the base flange; a transparent pipe portion held inside the cover flange and surrounding the outer periphery of the exhaust port flange and the sealing lid; and a pressing tool holding means connected to the tip of the transparent pipe portion and for slidably holding the pressing tool in an airtight state.

3. In the vacuum sealing jig according to claim 2, the pressing tool holding means comprises a cylindrical outer case, a bellows inserted into the outer case, a bellows fixing device having a through hole formed in the center thereof for fixing a front end of the bellows to the outer case to seal the front end of the outer case, a bellows cover for closing a base end of the bellows, and a pipe presser provided adjacent to the base end of the outer case and detachably connected to the cover flange to hold the front end of the transparent pipe part, and the pressing tool comprises a shaft disposed between the sealing lid and the bellows cover, a pressing shaft inserted into the bellows, the base end of which abuts against the bellows cover and the front end of which protrudes from the through hole to the outside of the vacuum chamber, and which can press the sealing lid via the shaft, and a pressing flange detachably connected to the base flange via a plurality of tie rods, the pipe presser has a shaft insertion portion that slidably holds the shaft, and an air vent that connects the transparent pipe portion and the outer case; a pressing shaft holding portion that rotatably holds the base end of the pressing shaft is formed at the base end of the bellows; a male screw portion is formed at the tip end of the pressing shaft; a female screw hole that screws onto the male screw portion of the pressing shaft is formed in the center of the pressing flange; and a spacer is provided that is fitted onto the pressing shaft at the tip end of the bellows fixing device and sets an initial gap between the exhaust port flange and the sealing lid when the decompression chamber is decompressed; and when the decompression chamber and the object to be decompressed are decompressed, the sealing lid is pressed by the pressing tool, and a reusable metal gasket is sandwiched between the exhaust port flange and the sealing lid, thereby sealing the exhaust port.

4. A vacuum structure with a reduced pressure sealing jig, characterized by comprising: a vacuum structure in which a sealing lid is fixed to an exhaust port flange formed on the outer periphery of the exhaust port at the longitudinal end of the exhaust pipe, thereby sealing the exhaust port; and a reduced pressure sealing jig described in any one of claims 1 to 3 that is detachably attached to the exhaust pipe.

5. A vacuum structure with a reduced pressure sealing jig as described in claim 4, characterized in that the vacuum structure is a vacuum double vessel, a vacuum vessel, or a vacuum double tube.

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