Sealing device for vacuum tube of bolt tightening equipment

Abstract

The utility model relates to the technical field of automatic assembly equipment, in particular to a sealing device for a vacuum tube of bolt tightening equipment, which comprises a sealing base detachably connected with an air exhaust base and a sealing mechanism used for sealing a tightening rod and the vacuum tube. The sealing mechanism comprises a first sealing piece and a second sealing piece, the first sealing piece is installed in the installation hole and arranged on the tightening rod in a sleeving mode, and the second sealing piece is installed on the surface of the sealing base and used for abutting against the end face of the vacuum pipe. On the premise that the structure of the vacuum tube does not need to be improved, the stability of the sealing structure of the vacuum tube is effectively improved, and sealing failure caused by friction of the tightening rod is avoided.

Description

Technical Field

[0001] This utility model relates to the field of automated assembly equipment technology, and more specifically, to a sealing device for a vacuum tube of a bolt tightening device. Background Technology

[0002] In automotive manufacturing, machinery assembly, and other fields, bolt feeding and tightening equipment is a key component for automating bolt assembly. Current technologies typically employ a coaxial design integrating a bolt-feeding vacuum tube and a tightening rod. The bolt is gripped by vacuum and positioned in the target hole. Once the vacuum tube releases its negative pressure, the bolt is lowered, and the tightening rod slides downwards within the tube until it contacts the bolt, completing the tightening operation. The sealing structure at the end of the vacuum tube often uses a nylon sealing ring, utilizing the material's elasticity to form a sealing interface with the outer wall of the tightening rod to maintain the vacuum negative pressure. However, because the tightening rod undergoes a combined axial movement and high-speed rotation during operation, existing sealing structures have significant shortcomings: nylon has poor wear resistance, leading to gaps at the sealing interface after prolonged use, resulting in vacuum leakage; simultaneously, the heat generated by continuous friction can soften and deform the nylon, further reducing sealing reliability; additionally, dust or foreign matter from the external environment can easily penetrate the sealing interface, accelerating seal failure. These problems force frequent equipment downtime for maintenance, severely impacting assembly efficiency and costs.

[0003] While existing solutions attempt to alleviate these problems by replacing sealing materials or adding sealing layers, they often have limitations: simply replacing the sealing material doesn't prevent potential failures, while replacing the sealing structure requires modifying the vacuum tube, which is too costly. Therefore, designing a simple sealing structure within a limited space that balances dynamic adaptability, long-term sealing stability, and overall functionality has become a critical technical challenge. Utility Model Content

[0004] The purpose of this invention is to overcome the problem that the sealing structure between the tightening rod and the vacuum tube in the prior art is prone to failure, and to provide a sealing device for the vacuum tube of a bolt tightening device.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] A sealing device for a vacuum tube of a bolt tightening device is provided, comprising a sealing base for detachable connection with a vacuum base and a sealing mechanism for sealing a tightening rod and a vacuum tube. The sealing base is provided with a mounting hole for inserting the tightening rod. The sealing mechanism includes a first sealing element and a second sealing element. The first sealing element is installed in the mounting hole and fitted onto the tightening rod. The second sealing element is installed on the surface of the sealing base and abuts against the end face of the vacuum tube.

[0007] During the operation of the above scheme, when the external vacuum equipment is started, the vacuum tube is evacuated through the vacuum base, so that a negative pressure is formed inside the vacuum tube. At this time, the first and second sealing elements of the sealing mechanism are respectively arranged on both sides of the mounting hole (that is, the two outer ends of the connection between the vacuum tube and the tightening rod), forming a two-way isolation barrier on the outside. When the negative pressure area generated inside the vacuum tube is confined within the cavity between two seals, the first seal (the end furthest from the suction port of the pumping equipment) is lubricated with a small amount of oil before operation to prevent air and dust from entering during operation. The second seal (the end closest to the suction port of the pumping equipment) focuses on maintaining the airtightness of the negative pressure cavity, allowing the vacuum tube to stably adsorb the bolt. After the bolt is positioned, the negative pressure in the vacuum tube is released, and the tightening rod slides axially inside the vacuum tube until it aligns with the bolt and is tightened. When the entire sealing mechanism seals the tightening rod and the vacuum tube from the outside, an oil film is formed between the first seal and the tightening rod to reduce wear and achieve a seal. The second seal abuts against the end face of the vacuum tube and does not rotate with the tightening rod, significantly reducing the wear of the tightening rod during axial sliding and circumferential rotation of the vacuum tube. The entire sealing mechanism takes into account both dynamic motion adaptability and long-term sealing stability. At the same time, the sealing base is installed on the pumping base, eliminating the need for complex modifications to the vacuum tube structure of the tightening equipment. The structure is simple, and the maintenance and manufacturing costs are low.

[0008] Furthermore, the first sealing element is a skeleton oil seal, the second sealing element is a sealing ring, and an annular groove is provided on the sealing base outside the mounting hole. The second sealing element is installed in the annular groove, and the first sealing element is interference-fitted with the mounting hole. The first sealing element needs to perform rotary sealing, and the rotary sealing forms include oil seal, mechanical seal and magnetohydrodynamic seal. The low-cost oil seal is preferred as the first sealing element. The second sealing element only needs to maintain the airtightness of the vacuum tube, so only an annular groove is provided to install the sealing ring.

[0009] Furthermore, it also includes a locking mechanism. The sealing base includes an A-side rod and B-side rods located on both sides of the A-side rod. The A-side rod and the B-side rods form a mounting cavity for accommodating the vacuum base. The mounting hole is located on the A-side rod, and the locking mechanism is disposed on the two B-side rods. The vacuum base and the sealing base need to be easy to disassemble while also having a tight fixed connection during installation. The locking mechanism is provided to fix the vacuum base and the sealing base to achieve the purpose of preventing loosening.

[0010] Furthermore, the locking mechanism includes a clamping part and a driving part. The clamping part abuts against the surface of the vacuum base, and the driving part is connected to the clamping part. The driving part drives the clamping part to approach the vacuum base and press against the vacuum base. The driving part can be electric or manual.

[0011] Furthermore, the clamping part includes a clamping block and a buffer pad, the clamping block and the buffer pad are fixedly connected, and the buffer pad abuts against the vacuum base; the buffer pad can prevent the clamping force between the clamping block and the vacuum base from being too large and crushing the contact surface between them.

[0012] Furthermore, the drive unit includes a screw and a handle. One end of the screw is connected to the handle, and the other end is connected to the clamping part. The screw is threadedly connected to the B-side rod. Since the operation of the drive unit in the workshop is not complicated and the manual operation is easy, a manual operation is adopted to reduce costs. The screw is rotated by manually operating the handle to make the clamping block press against the vacuum base. The handle can be a nut-shaped cylinder or a butterfly handle.

[0013] Furthermore, the locking mechanism also includes a locking part, which is connected to the driving part; during use, vibration may cause the screw to rotate in the threaded hole of the B-side rod, resulting in the failure of the fixation between the vacuum base and the sealing base. Therefore, a locking part is provided to prevent the screw from loosening.

[0014] Furthermore, the locking part includes a nut component, which is threadedly connected to the screw rod. The locking part is in the form of a nut component, which is directly threadedly installed on the screw rod. When locking is required, it can be rotated until the nut component abuts and presses against the surface of the B-side rod to complete the locking. The structure is simple and easy to install.

[0015] Furthermore, it also includes a telescopic adjustment mechanism. The A-side rod is slidably connected to the B-side rod through the telescopic adjustment mechanism. The telescopic adjustment mechanism includes a sliding rod and a sliding hole that are slidably connected to each other. The sliding hole is located at one end of the B-side rod, and the sliding rod is located at one end of the A-side rod. The sliding hole and the sliding rod are slidably connected. The telescopic adjustment mechanism can slide to adjust the distance between the two B-side rods to change the size of the mounting cavity to adapt to different sizes of vacuum bases and improve the versatility of the device.

[0016] Furthermore, the sliding hole is provided with several grooves, and the sliding rod is provided with several elastic protrusions. The elastic protrusions are engaged with the grooves, and both the grooves and the elastic protrusions are arc-shaped. After the sliding rod and the sliding hole are adjusted, there needs to be a suitable and stable limiting structure to maintain the stability of the distance between the two B-side rods. The engagement of multiple elastic protrusions and multiple grooves can limit the sliding rod under different adjustment length conditions to maintain the stability of the outer frame length. The contours of the grooves and elastic protrusions are arc-shaped, which can provide a certain limiting resistance. At the same time, only a large external force needs to be applied to achieve sliding during sliding adjustment, thus taking into account the dual functions of limiting and sliding.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] 1. The first sealing element is installed in the mounting hole, and the second sealing element is installed on the surface of the sealing base on one side of the mounting hole. The first sealing element is fitted over the tightening rod and connected to the tightening rod. The second sealing element abuts against the end face of the vacuum tube and is installed on the outside of the vacuum base through the sealing base. The entire sealing mechanism seals the tightening rod and the vacuum tube from the outside. It can achieve the effect of not causing wear to the first and second sealing elements when the tightening rod slides and rotates without complicated modifications to the structure of the vacuum tube. It takes into account both dynamic motion adaptability and long-term sealing stability. At the same time, the structure is simple and the maintenance and manufacturing costs are low.

[0019] 2. The locking mechanism includes a clamping part, a driving part, and a locking part. The clamping part includes a clamping block and a buffer pad, the driving part includes a screw and a handle, and the locking part includes a nut. By setting the locking mechanism, the vacuum base and the sealing base are fixed to achieve the purpose of preventing loosening. At the same time, the fixing can be released by simply rotating the nut and the handle, making disassembly convenient. Attached Figure Description

[0020] Figure 1 A perspective view of a sealing device for a vacuum tube in a bolt tightening device;

[0021] Figure 2 Another perspective view of the sealing device of the vacuum tube of a bolt tightening device;

[0022] Figure 3 This is a schematic diagram of the internal structure of a sealing device for a vacuum tube in a bolt tightening device.

[0023] Figure 4 for Figure 3 A magnified view of a section at point A in the middle;

[0024] Figure 5 This is a schematic diagram of the structure of a sealing base of a sealing device for a vacuum tube of a bolt tightening equipment, mounted on a vacuum pump base.

[0025] In the attached diagram: 100, sealing base; 110, side rod A; 111, mounting hole; 112, annular groove; 120, side rod B; 200, sealing mechanism; 210, first seal; 220, second seal; 300, locking mechanism; 310, clamping part; 311, clamping block; 312, buffer pad; 320, driving part; 321, screw; 322, handle; 330, locking part; 331, nut; 400, telescopic adjustment mechanism; 410, slide rod; 411, elastic protrusion; 420, sliding hole; 421, groove; 500, vacuum base; 600, tightening rod; 700, vacuum tube. Detailed Implementation

[0026] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0027] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0028] Example 1

[0029] This embodiment is a first embodiment of a sealing device for a vacuum tube in a bolt tightening device, such as... Figures 1 to 2 and Figure 5 As shown, the device includes a sealing base 100 for detachable connection with the vacuum base 500 and a sealing mechanism 200 for sealing the tightening rod 600 and the vacuum tube 700. The sealing base 100 is provided with a mounting hole 111 for the tightening rod 600 to pass through. The sealing mechanism 200 includes a first sealing element 210 and a second sealing element 220, both for sealing the connection between the vacuum tube 700 and the tightening rod 600. The first sealing element 210 is installed in the mounting hole 111, and the second sealing element 220 is installed on the surface of the sealing base 100 on one side of the mounting hole 111. The first sealing element 210 is fitted over the tightening rod 600 and connected to the tightening rod 600. The second sealing element 220 abuts against the end face of the vacuum tube 700.

[0030] The mounting hole 111 is a stepped hole, with an annular cylinder of appropriate height protruding on the sealing base 100 to increase the mounting space of the first seal 210.

[0031] Specifically, the first seal 210 is a skeleton oil seal, and the second seal 220 is a sealing ring. An annular groove 112 is provided on the sealing base 100 outside the mounting hole 111. The second seal 220 is installed in the annular groove 112, and the first seal 210 is interference-fitted with the mounting hole 111. The first seal 210 needs to perform rotary sealing. The rotary sealing can be in the form of oil seal, mechanical seal, or magnetohydrodynamic seal. The low-cost oil seal is preferred as the first seal 210. The second seal 220 only needs to maintain the airtightness of the vacuum tube 700, so only the annular groove 112 needs to be provided to install the sealing ring.

[0032] The working principle of the sealing device for the vacuum tube of a bolt tightening device in this embodiment is as follows:

[0033] When the vacuum tube 700 adsorbs the bolt, most of the shaft section of the tightening rod 600 is outside the vacuum tube 700. The vacuum tube 700 moves onto the bolt, and the external vacuum pump 500 extracts gas from the vacuum tube 700, creating a negative pressure or vacuum inside the tube. At this time, the bolt is adsorbed onto the vacuum tube 700 under the action of external atmospheric pressure. The first sealing element 210 of the oil seal structure forms an isolation barrier against the tightening rod 600 within the mounting hole 111. The second sealing element 220 of the sealing ring structure presses against the vacuum tube 700 at its end face, maintaining... The airtightness of the negative pressure chamber inside the vacuum tube 700 is ensured. Subsequently, the vacuum tube 700 is moved so that the bolt is moved to the designated installation position. The negative pressure in the vacuum tube 700 is released, and the bolt is released. At the same time, the tightening rod 600 slides into the vacuum tube 700 until the bolt contacts it. Then, it is rotated to tighten. During the sliding and rotation process, lubricating oil is added between the tightening rod 600 and the first seal 210 to generate an oil film, which avoids dry friction and wear. The second seal 220 is on the end face of the vacuum tube 700, and its sealing surface does not contact the tightening rod 600, so it will not rub against the tightening rod 600.

[0034] The beneficial effects of this embodiment are: the oil seal and sealing ring seal the tightening rod 600 and the vacuum tube 700 from the outside, and the tightening rod 600 is less likely to cause wear to the oil seal and sealing ring when sliding and rotating, taking into account both dynamic motion adaptability and long-term sealing stability. At the same time, the structure is simple and does not require complex structural modifications to the vacuum tube 700, resulting in low maintenance and manufacturing costs.

[0035] Example 2

[0036] This embodiment is a second embodiment of a sealing device for a vacuum tube in a bolt tightening device, such as... Figures 2 to 3 as well as Figure 5As shown, it also includes a locking mechanism 300. The sealing base 100 includes an A-side rod 110 and B-side rods 120 located on both sides of the A-side rod 110. The A-side rod 110 and the B-side rods 120 form a mounting cavity for accommodating the vacuum base 500. The mounting hole 111 is located on the A-side rod 110. The locking mechanism 300 is provided on the two B-side rods 120. The vacuum base 500 and the sealing base 100 need to be easy to disassemble and also have a tight fixed connection during installation. The locking mechanism 300 fixes the vacuum base 500 and the sealing base 100 to achieve the purpose of preventing loosening.

[0037] Specifically, the locking mechanism 300 includes a clamping part 310 and a driving part 320. The clamping part 310 abuts against the surface of the vacuum base 500, and the driving part 320 is connected to the clamping part 310. The driving part 320 drives the clamping part 310 to approach the vacuum base 500 and press the vacuum base 500. The driving part 320 can be electric or manual.

[0038] Specifically, the clamping part 310 includes a clamping block 311 and a buffer pad 312. The clamping block 311 and the buffer pad 312 are fixedly connected, and the buffer pad 312 abuts against the vacuum base 500. The buffer pad 312 can prevent the clamping force between the clamping block 311 and the vacuum base 500 from being too large and crushing the contact surface between them.

[0039] Specifically, the drive unit 320 includes a screw 321 and a handle 322. One end of the screw 321 is connected to the handle 322, and the other end is connected to the clamping part 310. The screw 321 is threadedly connected to the B-side rod 120. Since the operation of the drive unit 320 in the workshop is not complicated and the manual operation is easy, a manual operation is adopted to reduce costs. By manually operating the handle 322 to rotate the screw 321, the clamping block 311 presses against the vacuum base 500. The handle 322 can be a nut-shaped cylinder or a butterfly handle 322.

[0040] The clamping block 311 of the clamping part 310 can be rotatably connected to the screw 321 of the driving part 320 to prevent the clamping part 310 from rotating along with the driving part 320 when the screw 321 rotates.

[0041] Specifically, the locking mechanism 300 also includes a locking part 330, which is connected to the driving part 320. During use, vibration may cause the screw 321 to rotate in the threaded hole of the B-side rod 120, resulting in the failure of the fixation between the vacuum base 500 and the sealing base 100. Therefore, a locking part 330 is provided to prevent the screw 321 from loosening.

[0042] Specifically, the locking part 330 includes a nut 331, which is threadedly connected to the screw 321. The locking part 330 adopts the form of a nut 331, which is directly threadedly installed on the screw 321. When locking is required, it can be completed by rotating the nut 331 until it abuts and presses against the surface of the B-side rod 120. The structure is simple and easy to install.

[0043] The working principle of the sealing device for the vacuum tube of a bolt tightening device in this embodiment is as follows:

[0044] The vacuum base 500 is installed in the mounting cavity of the sealing base 100. The handle 322 is turned manually with a tool, and the screw 321 is screwed into the mounting cavity. The buffer pad 312 on the clamping block 311 contacts the surface of the vacuum base 500. The screw 321 is screwed in to deform the buffer pad 312 and press it against the vacuum base 500. Finally, the nut 331 is rotated to make the end face of the nut 331 contact the surface of the B side rod 120 to complete the locking.

[0045] The beneficial effects of this embodiment are: the series of locking structures of screw 321, clamping block 311, and nut 331 can press the entire sealing base 100 onto the vacuum base 500 to achieve the purpose of preventing loosening.

[0046] Example 3

[0047] This embodiment is a third embodiment of a sealing device for a vacuum tube in a bolt tightening device, such as... Figure 3 and 4 As shown, it also includes a telescopic adjustment mechanism 400. The A-side rod 110 is slidably connected to the B-side rod 120 through the telescopic adjustment mechanism 400. The telescopic adjustment mechanism 400 includes a sliding rod 410 and a sliding hole 420 that are slidably connected to each other. The sliding hole 420 is located at one end of the B-side rod 120, and the sliding rod 410 is located at one end of the A-side rod 110. The sliding hole 420 and the sliding rod 410 are slidably connected. The telescopic adjustment mechanism 400 can slide to adjust the distance between the two B-side rods 120 to change the size of the mounting cavity to adapt to different sizes of vacuum bases 500 and improve the versatility of the device.

[0048] Specifically, the sliding hole 420 has several grooves 421, and the sliding rod 410 has several elastic protrusions 411. The elastic protrusions 411 engage with the grooves 421, and both the grooves 421 and the elastic protrusions 411 are arc-shaped. After the sliding rod 410 and the sliding hole 420 are adjusted, there needs to be a suitable and stable limiting structure to maintain the stability of the distance between the two B-side rods 120. The engagement of multiple elastic protrusions 411 and multiple grooves 421 can limit the sliding rod 410 under different adjustment length conditions to maintain the stability of the length of the outer frame. The contours of the grooves 421 and the elastic protrusions 411 are arc-shaped, which can provide a certain limiting resistance. At the same time, only a large external force needs to be applied during sliding adjustment to achieve sliding, thus taking into account the dual functions of limiting and sliding.

[0049] The working principle of the sealing device for the vacuum tube of a bolt tightening device in this embodiment is as follows:

[0050] When the slide rod 410 of side rod 110 slides away from the sliding hole 420 of side rod 120, the arc-shaped elastic protrusion 411 on the slide rod 410 is compressed under the action of external force and gradually disengages from the arc-shaped groove 421. The slide rod 410 can then slide relative to the sliding hole 420. When the distance between the two side rods 120 of side rod 120 is adjusted to an appropriate size, part of the elastic protrusion 411 enters the groove 421. The elastic protrusion 411 restores its deformation and engages with the groove 421, forming a locking limit.

[0051] The beneficial effects of this embodiment are: the sliding telescopic adjustment setting of the slide rod 410 and the slide hole 420 can slide and adjust the distance between the two B side rods 120 to adapt to different sizes of vacuum base 500, effectively improving the versatility of the device.

[0052] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0053] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A sealing device for a vacuum tube of a bolt tightening device, characterized in that, The device includes a sealing base (100) for detachable connection with a vacuum base (500) and a sealing mechanism (200) for sealing a tightening rod (600) and a vacuum tube (700). The sealing base (100) is provided with a mounting hole (111) for inserting the tightening rod (600). The sealing mechanism (200) includes a first sealing element (210) and a second sealing element (220). The first sealing element (210) is installed in the mounting hole (111) and fitted onto the tightening rod (600). The second sealing element (220) is installed on the surface of the sealing base (100) and abuts against the end face of the vacuum tube (700).

2. The sealing device for the vacuum tube of a bolt tightening device according to claim 1, characterized in that, The first seal (210) is an oil seal, the second seal (220) is a sealing ring, and an annular groove (112) is provided on the sealing base (100) outside the mounting hole (111). The second seal (220) is installed in the annular groove (112), and the first seal (210) is interference-fitted with the mounting hole (111).

3. The sealing device for the vacuum tube of a bolt tightening device according to claim 1, characterized in that, It also includes a locking mechanism (300). The sealing base (100) includes an A-side rod (110) and B-side rods (120) located on both sides of the A-side rod (110). The A-side rod (110) and the B-side rods (120) form a mounting cavity for accommodating the vacuum base (500). The mounting hole (111) is located on the A-side rod (110). The locking mechanism (300) is disposed on the two B-side rods (120).

4. The sealing device for the vacuum tube of a bolt tightening device according to claim 3, characterized in that, The locking mechanism (300) includes a clamping part (310) and a driving part (320). The clamping part (310) abuts against the surface of the vacuum base (500), and the driving part (320) is connected to the clamping part (310).

5. The sealing device for the vacuum tube of a bolt tightening device according to claim 4, characterized in that, The clamping part (310) includes a clamping block (311) and a buffer pad (312), the clamping block (311) and the buffer pad (312) are fixedly connected, and the buffer pad (312) abuts against the vacuum base (500).

6. The sealing device for the vacuum tube of a bolt tightening device according to claim 4, characterized in that, The drive unit (320) includes a screw (321) and a handle (322). One end of the screw (321) is connected to the handle (322), and the other end is connected to the clamping part (310). The screw (321) is threadedly connected to the B-side rod (120).

7. A sealing device for a vacuum tube of a bolt tightening device according to claim 6, characterized in that, The locking mechanism (300) further includes a locking part (330), which is connected to the driving part (320).

8. The sealing device for the vacuum tube of a bolt tightening device according to claim 7, characterized in that, The locking part (330) includes a nut (331) which is threadedly connected to the screw (321).

9. A sealing device for a vacuum tube of a bolt tightening device according to any one of claims 3-8, characterized in that, It also includes a telescopic adjustment mechanism (400), wherein the A side rod (110) is slidably connected to the B side rod (120) through the telescopic adjustment mechanism (400). The telescopic adjustment mechanism (400) includes a slide rod (410) and a slide hole (420) that are slidably connected to each other. The slide hole (420) is located at one end of the B side rod (120), and the slide rod (410) is located at one end of the A side rod (110). The slide hole (420) is slidably connected to the slide rod (410).

10. A sealing device for a vacuum tube of a bolt tightening device according to claim 9, characterized in that, The sliding hole (420) is provided with a plurality of grooves (421), and the sliding rod (410) is provided with a plurality of elastic protrusions (411). The elastic protrusions (411) are engaged with the grooves (421), and both the grooves (421) and the elastic protrusions (411) are arc-shaped.

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