Holding device for closing interior of container

Abstract

The utility model provides a tight supporting device for sealing the interior of a container, which comprises a plurality of telescopic rods arranged along the peripheral side of a rotating central shaft, one end part of each telescopic rod is detachably connected with the rotating central shaft, and the other end part of each telescopic rod is detachably connected with a square pipe joint; an outer ring square tube is arranged between every two adjacent square tube joints; the side, away from the rotating center shaft, of any outer ring square pipe is provided with a supporting claw, the adjusting device is used for adjusting the supporting claw to be close to or away from the outer ring square pipe connected with the supporting claw, the side, away from the outer ring square pipe, of any supporting claw is provided with a main base plate or a compensation base plate, and the main base plate and the compensation base plate are matched to form a circular ring. The center supporting shaft and equipment connecting structure provides a center supporting point, can be disassembled from outside to inside in an arbitrary symmetry mode, does not have the problems of falling apart and toppling, meets the requirement that a tool and a workpiece are effectively attached without gaps, guarantees the stability of the welding process, and avoids the problem of material leakage caused by too large gaps between base plates.

Description

Technical Field

[0001] The utility model relates to the field of detachable internal support devices, and specifically, to a tightening device for the interior of a closed container. Background Art

[0002] Large aluminum alloy fuel tanks of spacecraft such as launch vehicles and space shuttles are welded by several cylinder segments, a front bottom, and a rear bottom. Cylinder segments belong to thin-walled parts of plate and shell types, and are severely deformed without internal support and cannot be docked.

[0003] With the in-depth development and application of friction stir welding technology, this technology will gradually replace fusion welding for the docking of aluminum alloy fuel tanks. Friction stir welding belongs to solid-phase connection technology, and during the welding process, upsetting force needs to be applied to the outer surfaces of the workpieces on both sides of the weld. These characteristics result in the need for high-rigidity support inside the workpieces during the friction stir welding docking process. In addition, the fuel tank has a closed structure. After the last circumferential weld is completed, the internal support is located inside the tank and is difficult to remove. It is necessary to disassemble the internal support and output it from the small holes in the tank.

[0004] The existing Chinese patent application document with the publication number CN113798761B discloses a serpentine internal support device for circumferential welds of large-diameter tank cylinder segments, which relates to the field of internal support devices for circumferential welds of large thin-walled cylindrical components. It includes an intermediate unit, a first section unit, a tail section unit, an intermediate connection module, and a head and tail self-locking module. The intermediate connection module connects each unit in sequence, and the head and tail self-locking module is located between the first section unit and the tail section unit. When the intermediate connection module and the head and tail self-locking module are in the self-locking state, each unit is arranged circumferentially along the inner wall of the tank cylinder segment to provide high-rigidity internal support and realize the function of internal support during the circumferential weld of the tank cylinder segment. When the intermediate connection module and the head and tail self-locking module are in the moving or disconnected state, the device is in a super-redundant free state and can withdraw from the manhole of the tank by itself.

[0005] When the support device in the prior art is removed or installed inside the workpiece, there are problems of tipping or falling apart, which are likely to cause damage to the workpiece. In addition, there are certain gaps between the connections of each unit of the support device, which are likely to cause material leakage and there is room for improvement. Summary of the Utility Model

[0006] Aiming at the defects in the prior art, the purpose of the present utility model is to provide a tightening device for the interior of a closed container.

[0007] A tightening device for closing the interior of a container according to the present utility model includes a central support shaft, a rotation central shaft, telescopic rods, outer ring square tubes, square tube connectors, support claws, an adjustment device, a main backing plate, and a compensation backing plate; a plurality of telescopic rods are arranged on the circumferential side of the rotation central shaft, one end of any one of the telescopic rods is detachably connected to the rotation central shaft, and the other end of any one of the telescopic rods is detachably connected to the square tube connector; an outer ring square tube is arranged between any two adjacent square tube connectors; a support claw is arranged on one side of any one of the outer ring square tubes away from the rotation central shaft, the adjustment device is used to adjust the support claw to approach or move away from the outer ring square tube connected thereto, a main backing plate or a compensation backing plate is arranged on one side of any one of the support claws facing away from the outer ring square tube, and the main backing plate and the compensation backing plate are arranged in sequence along the circumferential side of the rotation central shaft; in the support state, the central support shaft is coaxially connected to the rotation central shaft, the axis of the central support shaft coincides with the central axis of the closed container, and the main backing plate and the compensation backing plate cooperate to form a ring.

[0008] Preferably, the adjustment device includes an adjustment screw, one end of the adjustment screw is screwed into the outer ring square tube and is threadedly connected thereto, and the other end of the adjustment screw is rotatably connected to the support claw.

[0009] Preferably, a guide rod is arranged between the outer ring square tube and the support claw, one or more groups of adjustment screws are arranged on both sides of the guide rod, and one end of any one of the guide rods close to the rotation central shaft and one end of any one of the adjustment screws close to the rotation central shaft both point to the rotation central shaft.

[0010] Preferably, the outer ring square tube and the two square tube connectors connected thereto are both connected by press-fitting with a wedge-shaped inclined surface.

[0011] Preferably, the detachable connection structures of the telescopic rod and the rotation central shaft and the detachable connection structure of the telescopic rod and the square tube connector both include a T-shaped groove and a block arranged at the end of the telescopic rod; the T-shaped groove forms an opening on the side surface and the outer peripheral surface of the rotation central shaft respectively, the opening of the T-shaped groove on the side surface of the rotation central shaft allows the block to pass through, the opening of the T-shaped groove on the outer peripheral surface of the rotation central shaft does not allow the block to pass through, and the opening of the T-shaped groove on the outer peripheral surface of the rotation central shaft allows the telescopic rod to pass through; or, the T-shaped groove forms an opening on the side surface of the square tube connector and the side surface of the square tube connector close to the rotation central shaft respectively, the opening of the T-shaped groove on the side surface of the square tube connector allows the block to pass through, the opening of the T-shaped groove on the side surface of the square tube connector close to the rotation central shaft does not allow the block to pass through, and the opening of the T-shaped groove on the side surface of the square tube connector close to the rotation central shaft allows the telescopic rod to pass through.

[0012] Preferably, the square pipe joint includes a long square pipe joint and a short square pipe joint, and the long square pipe joint and the short square pipe joint are respectively located at both ends of the same outer ring square pipe; two telescopic rods are respectively connected to both ends of the long square pipe joint along the axial direction of the rotation center axis, and the other ends of the two telescopic rods connected to the same long square pipe joint are respectively connected to both ends of the rotation center axis along the axial direction; one telescopic rod is connected to the short square pipe joint, and the other end of the telescopic rod connected to the short square pipe joint is connected to the middle part of the rotation center axis along the axial direction.

[0013] Preferably, the two telescopic rods connected to the same long square pipe joint are fixedly connected by a clamp.

[0014] Preferably, the telescopic rod includes a screw rod assembly, and the screw rod assembly includes a plurality of hollow pipes connected in sequence by threads.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] 1. By adopting the connection structure of the central support shaft and the equipment, the utility model provides a central support point for the tooling, solves the problem that the tooling is prone to tipping and falling apart and damaging the workpiece during the disassembly and installation inside the workpiece due to the lack of a support point, and the tooling can be symmetrically disassembled from the outside to the inside without the problems of falling apart and tipping.

[0017] 2. By adjusting the screw rod to adjust the position of the support claw and the cooperation of the compensation pad and the main pad, the utility model solves the problem that the inner diameter of the workpiece has an error due to the error in the manufacturing process of the workpiece, achieves the internal tightening of workpieces with different diameters, meets the effective fitting of the tooling and the workpiece without gaps, ensures the stability of the welding process, and avoids the problem of material leakage caused by too large a gap between the pads.

[0018] 3. By adopting the structure of connecting the telescopic rod and the rotation center axis to provide support for the support claw, and the two ends of the telescopic rod are in a card slot structure, the connection points are reduced, the problem of cumbersome disassembly and assembly of the tooling is solved, the tooling can be quickly tightened, and when disassembling, it only needs to be directly taken out from the T-shaped groove without disassembling the threads, and can be quickly disassembled.

[0019] 4. By connecting the rotation center axis with the central support shaft and connecting the central support shaft with the equipment, the utility model solves the problems of difficult to ensure the coaxiality between the inner support tooling and the workpiece and difficult to adjust, achieves the effective fitting of the tooling and the workpiece, and can make the tooling and the workpiece rotate synchronously through the rotation center axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] By reading the detailed description of the non-restrictive embodiments with reference to the following drawings, other features, purposes and advantages of the utility model will become more obvious:

[0021] Figure 1 This is a schematic diagram showing the overall structure of the tightening device mainly embodied in the present utility model;

[0022] Figure 2 This is a schematic diagram showing the detachable connection structure of the telescopic rod mainly embodied in the present utility model;

[0023] Figure 3 This is a schematic diagram showing the working state of the tightening device mainly embodied in the present utility model;

[0024] Figure 4 This is a flowchart showing the installation method mainly embodied in the present utility model;

[0025] Figure 5 This is a flowchart showing the disassembly method mainly embodied in the present utility model.

[0026] Reference numerals:

[0027] Central support shaft 1 Clamp 9

[0028] Support claw 2 Rectangular pipe joint 10

[0029] Outer ring square pipe 3 Telescopic rod 11

[0030] Main backing plate 4 Rotation center shaft 12

[0031] Compensation backing plate 5 Cylindrical section workpiece 13

[0032] Guide rod 6 Bottom plate workpiece 14

[0033] Adjusting screw 7 Workpiece hole 15

[0034] Short rectangular pipe joint 8 Detailed implementation manners

[0035] The present utility model will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present utility model, but do not limit the present utility model in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several changes and improvements can still be made. These all belong to the protection scope of the present utility model.

[0036] As Figure 1 shown, a tightening device for closing the interior of a container according to the present utility model includes a central support shaft 1, a rotation center shaft 12, a telescopic rod 11, an outer ring square pipe 3, a pipe joint, a support claw 2, an adjusting device, a main backing plate 4, and a compensation backing plate 5.

[0037] Specifically, a plurality of telescopic rods 11 are arranged on the circumferential side of the rotation center axis 12. One end of any telescopic rod 11 is detachably connected to the rotation center axis 12, and the other end of any telescopic rod 11 is detachably connected to the square pipe joint. An outer ring square pipe 3 is arranged between any two adjacent square pipe joints.

[0038] Further, a support claw 2 is arranged on the side of any outer ring square pipe 3 away from the rotation center axis 12. The adjusting device is used to adjust the support claw 2 to be close to or away from the outer ring square pipe 3 connected thereto. A main backing plate 4 or a compensation backing plate 5 is arranged on the side of any support claw 2 facing away from the outer ring square pipe 3, and the main backing plate 4 and the compensation backing plate 5 are arranged in sequence along the circumferential side of the rotation center axis 12.

[0039] In the support state, the central support shaft 1 is coaxially connected to the rotation center axis 12. The axis of the central support shaft 1 is collinear with the central axis of the closed container, and the main backing plate 4 and the compensation backing plate 5 cooperate to form a ring.

[0040] More specifically, the main backing plate 4 and the compensation backing plate 5 are arranged at intervals in sequence on a plurality of support claws 2 arranged along the circumferential side of the rotation center axis 12. The main backing plate 4 is of an arc structure, and both ends of the arc direction of the main backing plate 4 extend above two adjacent support claws 2. The upper part of the support claw 2 equipped with the compensation backing plate 5 can be completely covered by the main backing plates 4 on the two adjacent support claws 2 or there is a gap. If the two adjacent support claws 2 to the support claw 2 equipped with the compensation backing plate 5 move in place, and there is a gap above the support claw 2 equipped with the compensation backing plate 5 between the two main backing plates 4, the support claw 2 equipped with the compensation backing plate 5 can be moved away from the rotation center axis 12 by the adjusting device until the compensation backing plate 5 completely closes the gap formed by the two main backing plates 4. Thus, seamless tightening inside workpieces with different diameters can be achieved.

[0041] Furthermore, the adjusting device includes an adjusting screw 7. One end of the adjusting screw 7 is screwed into the outer ring square pipe 3 and is threadedly connected thereto. The other end of the adjusting screw 7 is rotatably connected to the support claw 2. When the adjusting screw 7 is screwed into the outer ring square pipe 3 clockwise, the support claw 2 moves towards the outer ring square pipe 3. When the adjusting screw 7 is unscrewed out of the outer ring square pipe 3 counterclockwise, the support claw 2 moves away from the outer ring square pipe 3.

[0042] To improve the stability of the relative movement between the supporting claw 2 and the outer ring square tube 3, a guide rod 6 is provided between the outer ring square tube 3 and the supporting claw 2. One or more groups of adjusting screws 7 are respectively arranged on both sides of the guide rod 6. One end of any guide rod 6 close to the rotation center axis 12 and one end of any adjusting screw 7 close to the rotation center axis 12 both point to the rotation center axis 12. Regarding the guide rod 6, a feasible implementation manner is proposed in this application: one end of the guide rod 6 is fixedly connected to the middle part of the supporting claw 2, and the other end of the guide rod 6 penetrates into the outer ring square tube 3 from the middle part of the outer ring square tube 3 and is in sliding fit with it. One adjusting screw 7 is symmetrically arranged on each side of the guide rod 6. Thus, when the distance between the supporting claw 2 and the outer ring square tube 3 is adjusted by the forward or reverse rotation of the two adjusting screws 7, the guide rod 6 plays a guiding role.

[0043] Specifically, the outer ring square tube 3 and the two square tube connectors connected thereto are both connected by press-fitting with a wedge-shaped inclined surface. The square tube connectors include a long square tube connector 10 and a short square tube connector 8. The long square tube connector 10 and the short square tube connector 8 are respectively located at both ends of the same outer ring square tube 3. The outer ring square tube 3, the long square tube connector 10, and the short square tube connector 8 form a regular polygon, and they are all connected by wedge-shaped inclined surfaces and support each other tightly to form a regular polygon frame that is tightly pressed against each other.

[0044] One telescopic rod 11 is respectively connected to both ends of the long square tube connector 10 along the axial direction of the rotation center axis 12. The other ends of the two telescopic rods 11 connected to the same long square tube connector 10 are respectively connected to both ends of the rotation center axis 12 along the axial direction. One telescopic rod 11 is connected to the short square tube connector 8. The other end of the telescopic rod 11 connected to the short square tube connector 8 is connected to the middle part of the rotation center axis 12 along the axial direction. It should be noted that the outer ring square tube 3, the long square tube connectors 10 and the short square tube connector 8 on both sides of the outer ring square tube 3, and the telescopic rods 11 connected to the long square tube connector 10 or the short square tube connector 8 form several stable triangular structures. Due to the limited position around the rotation center axis 12, in order to improve the overall stability and concentration of the tightening device, the other end of the telescopic rod 11 connected to the short square tube connector 8 is connected to the middle part of the rotation center axis 12.

[0045] As Figure 1 and Figure 2 shown, a feasible detachable connection structure is proposed in this application. Specifically, the detachable connection structures of the telescopic rod 11 and the rotation center axis 12, and the telescopic rod 11 and the square tube connector both include a T-shaped groove and a block provided at the end of the telescopic rod 11.

[0046] The T-shaped groove is formed with an opening on the side surface and the outer peripheral surface of the rotation center axis 12 respectively. The opening of the T-shaped groove on the side surface of the rotation center axis 12 allows the insert block to pass through, the opening of the T-shaped groove on the outer peripheral surface of the rotation center axis 12 does not allow the insert block to pass through, and the opening of the T-shaped groove on the outer peripheral surface of the rotation center axis 12 allows the telescopic rod 11 to pass through.

[0047] Or, the T-shaped groove is formed with an opening on the side surface of the square pipe joint and the side surface of the square pipe joint close to the rotation center axis 12 respectively. The opening of the T-shaped groove on the side surface of the square pipe joint allows the insert block to pass through, the opening of the T-shaped groove on the side surface of the square pipe joint close to the rotation center axis 12 does not allow the insert block to pass through, and the opening of the T-shaped groove on the side surface of the square pipe joint close to the rotation center axis 12 allows the telescopic rod 11 to pass through.

[0048] It should be further noted that the two telescopic rods 11 connected to the same rectangular pipe joint 10 are fixedly connected by a clamp 9, thereby preventing the telescopic rod 11 from falling off. The telescopic rod 11 of the present application includes a screw rod assembly, and the screw rod assembly includes a plurality of hollow pipes that are sequentially thread-connected.

[0049] Such as Figure 1 、 Figure 2 And Figure 3 As shown, the tightening device of the present application adopts a structure in which the telescopic rod 11 is connected to the rotation center axis 12 to provide support for the support claw 2, and both ends of the telescopic rod 11 are of a card slot structure, reducing the connection points and solving the problem of cumbersome disassembly and assembly of the tooling. It can realize the rapid tightening of the tooling. When disassembling, it only needs to be directly taken out from the T-shaped groove, without disassembling the thread, and can be quickly disassembled.

[0050] Adopting the connection structure of the central support shaft 1 and the equipment to provide a central support point for the tooling, solving the problem that the tooling is prone to tipping and falling apart and damaging the workpiece during the disassembly and installation inside the workpiece due to the lack of a support point. The tooling can be symmetrically disassembled from the outside to the inside arbitrarily without the problems of falling apart and tipping.

[0051] Adopting the connection mode of the rotation center axis 12 and the central support shaft 1, and the central support shaft 1 and the equipment, solves the problems that it is difficult to ensure the coaxiality between the internal support tooling and the workpiece and the adjustment is difficult, achieving effective fitting between the tooling and the workpiece, and the tooling and the workpiece can be rotated synchronously through the rotation center axis 12.

[0052] By adopting the structure that the support claw 2 can move along the radial direction and the structure that the compensation pad 5 can move along the axis of the workpiece, the problem that the inner diameter of the workpiece has an error due to the error in the manufacturing process of the workpiece is solved, achieving the internal tightening of workpieces with different diameters, meeting the effective fitting between the tooling and the workpiece without gaps, ensuring the stability of the welding process, and avoiding the problem of material leakage caused by too large gaps between the pads.

[0053] Such asFigure 1 , Figure 3 and Figure 4 As shown in Figure 4 , the present application also provides a disassembly and assembly method for a tightening device used to enclose the interior of a container. The installation method includes the following steps:

[0054] Step S1.1: Install the central support shaft 1 on a fixed device, hoist the cylindrical workpiece 13 and / or the bottom workpiece 14 of the box over the central support shaft 1, and fixedly connect the rotating central shaft 12 to the central support shaft 1. Specifically, install the central support shaft 1 on other parts of the fixed device, hoist the cylindrical workpiece 13 or the bottom workpiece 14 of the box over the central support shaft 1, and fix the device on the central support shaft 1 on the device through the rotating central shaft 12.

[0055] Step S1.2: Assemble the other components of the tightening device. After assembly, place the tightening device at the target position. Specifically,

[0056] Step S1.3: Move the support claws 2 away from the rotating central shaft 12 through the adjusting device to tighten the workpiece. Specifically, adjust the screw rod 7 to move the support claws 2 away from the axis center to tighten the workpiece, and the compensation pad 5 moves along the axial direction to compensate for the gap between the compensation pads 5, realizing seamless tightening inside workpieces with different diameters.

[0057] If it is necessary to install the tightening device of the present application inside a complete workpiece, first install the rotating central shaft 12 on the central support shaft 1, extend it into the workpiece from the central hole of the workpiece, and then install a circle of telescopic rods 11 and clamps 9. Then, install the rectangular pipe joint 10, the outer ring square pipe 3, and the short pipe joint 8 in sequence to form a polygon, and then install the guide rod 6, the adjusting screw rod 7, the support claws 2, the pads, and the compensation pads 5. After assembly, adjust the positions of the adjusting screw rod 7 and the compensation pads 5 to complete the tightening of the workpiece.

[0058] As Figure 1 , Figure 3 and Figure 5 shown, after machining such as milling or welding of the workpiece is completed, the present application also provides a disassembly and assembly method for a tightening device used to enclose the interior of a container. The disassembly method includes the following steps:

[0059] Step S2.1: Move the support claws 2 towards the rotating central shaft 12 through the adjusting device to a specified position, so that the tightening device is disengaged from the workpiece. Specifically, guide through the guide rod 6, rotate the adjusting screw rods 7 on both sides, and retract the support claws 2 along the radial direction to a specified position to disengage the tooling from the workpiece.

[0060] Step S2.2: Remove the support claws 2, the pads, and the compensation pads 5 according to the rule of diagonal disassembly.

[0061] Step S2.3: Remove the outer ring square tube 3 according to the rule of diagonal removal.

[0062] Step S2.4: Then, symmetrically remove the square tube joint, the clamp 9, and the telescopic rod 11 in sequence.

[0063] Step S2.5: Withdraw the central support shaft 1 and the rotation center shaft 12 from the central hole of the workpiece.

[0064] Step S2.6: Then, transport the other components of the tightening device out of the central hole or the workpiece hole 15.

[0065] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application.

[0066] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined arbitrarily with each other.

Claims

1. A tightening device for closing the interior of a container, characterized in that: It comprises a central support shaft (1), a rotating central shaft (12), a telescopic rod (11), an outer ring square tube (3), a square tube joint, a support claw (2), an adjustment device, a main pad (4) and a compensation pad (5); A plurality of telescopic rods (11) are arranged along the circumference of the central axis of rotation (12); one end of any telescopic rod (11) is detachably connected to the central axis of rotation (12); the other end of any telescopic rod (11) is detachably connected to a square pipe joint; and an outer ring square pipe (3) is arranged between any two adjacent square pipe joints; A support claw (2) is provided on the side of any of the outer ring square tubes (3) away from the rotation center axis (12); the adjustment device is used to adjust the support claw (2) to be close to or away from the outer ring square tube (3) connected thereto; a main pad (4) or a compensation pad (5) is provided on the side of any of the support claws (2) away from the outer ring square tube (3); and the main pad (4) and the compensation pad (5) are arranged in sequence along the circumference of the rotation center axis (12); In the supporting state, the central support shaft (1) is connected to the rotating central shaft (12), the axis of the central support shaft (1) is colinear with the central axis of the closed container, and the main pad (4) and the compensation pad (5) cooperate to form a circular ring.

2. The tightening device for closing the interior of a container according to claim 1, characterized in that: The adjusting device comprises an adjusting screw (7), one end of which is screwed into the outer ring square tube (3) and threadedly connected thereto, and the other end of which is rotatably connected to the supporting claw (2).

3. The tightening device for closing the interior of a container according to claim 2, characterized in that: A guide rod (6) is arranged between the outer ring square tube (3) and the supporting claw (2), and one or more groups of adjusting screws (7) are arranged on both sides of the guide rod (6), and one end of any guide rod (6) close to the rotation center axis (12) and one end of any adjusting screw (7) close to the rotation center axis (12) both point to the rotation center axis (12).

4. The tightening device for closing the interior of a container according to claim 1, characterized in that: The outer ring square tube (3) and the two square tube joints connected thereto are connected by press-fitting with wedge-shaped inclined surfaces.

5. The tightening device for closing the interior of a container according to claim 1, characterized in that: The detachable connection structure between the telescopic rod (11) and the rotating central shaft (12), and the detachable connection structure between the telescopic rod (11) and the square pipe joint both comprise a T-shaped groove and an insert block arranged at the end of the telescopic rod (11); The T-slot has an opening formed on the side and outer peripheral surface of the rotating central shaft (12), respectively; the opening of the T-slot on the side of the rotating central shaft (12) allows the insert to pass through, the opening of the T-slot on the outer peripheral surface of the rotating central shaft (12) does not allow the insert to pass through, and the opening of the T-slot on the outer peripheral surface of the rotating central shaft (12) allows the telescopic rod (11) to pass through; Alternatively, the T-slot has an opening formed on the side of the square tube joint and on the side of the square tube joint close to the rotation center axis (12), respectively; the opening of the T-slot on the side of the square tube joint allows the insert to pass through, the opening of the T-slot on the side of the square tube joint close to the rotation center axis (12) does not allow the insert to pass through, and the opening of the T-slot on the side of the square tube joint close to the rotation center axis (12) allows the telescopic rod (11) to pass through.

6. The tightening device for closing the interior of a container according to claim 1, characterized in that: The square pipe joint comprises a rectangular pipe joint (10) and a short square pipe joint (8), wherein the rectangular pipe joint (10) and the short square pipe joint (8) are respectively located at two ends of the same outer ring square pipe (3); The two ends of the rectangular pipe joint (10) along the axial direction of the central axis of rotation (12) are respectively connected to a telescopic rod (11), and the other ends of the two telescopic rods (11) connected to the same rectangular pipe joint (10) are respectively connected to the two ends of the axial direction of the central axis of rotation (12); A telescopic rod (11) is connected to the short square pipe joint (8), and the other end of the telescopic rod (11) connected to the short square pipe joint (8) is connected to the middle part of the axial direction of the rotation center axis (12).

7. The tightening device for closing the interior of a container according to claim 6, characterized in that: Two telescopic rods (11) connected to the same rectangular pipe joint (10) are fixedly connected via a clamp (9).

8. The tightening device for closing the interior of a container according to claim 1, characterized in that: The telescopic rod (11) comprises a screw assembly, and the screw assembly comprises a plurality of hollow tubes which are threadedly connected in sequence.

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