A thin-walled circular tube inner wall clamping device

Abstract

The present invention discloses a thin-walled circular tube inner wall clamping device, comprising a clamping body shell for extending into the thin-walled circular tube, a spiral jacking mechanism arranged in the clamping body shell, a jacking drive mechanism, and a double-helix supporting mechanism; the spiral jacking mechanism comprises a plurality of clamping top plates, the double-helix supporting mechanism comprises a plurality of clamping struts, the outer surface of the clamping struts is provided with supporting protrusions, the jacking drive mechanism drives the clamping top plates and the clamping struts to move away from or towards the clamping body shell, the clamping body shell is provided with notches corresponding to the shapes of the clamping top plates and the clamping struts, the clamping top plates and the clamping struts are conformal to the clamping body shell, and when the clamping top plates and the clamping struts are away from the clamping body shell, the supporting protrusions on the outer surface of the clamping top plates and the clamping struts contact the inner wall of the thin-walled circular tube. Through a small-area multi-point contact clamping and fixing method, the contact area of ​​a single contact point is minimized while ensuring a secure fastening condition, thereby reducing scratches and abrasions on the inner wall of the thin-walled circular tube and reducing the defective rate.

Description

Technical Field

[0001] The invention relates to a fixture, in particular to a thin-walled circular tube inner wall clamping device. Background Art

[0002] Cylindrical batteries have been widely used in electric vehicles, portable electronic devices, energy storage devices and other fields in recent years due to a series of advantages such as mature production technology, low packaging cost, high product yield and good heat dissipation performance. Cylindrical batteries are usually packaged with metal materials such as stainless steel or aluminum. Their cylindrical metal shells are characterized by light weight, thin thickness and compact structure, but their strength and rigidity are low. They are prone to deformation and distortion during processing and transportation. Damage to the built-in battery cells in this process can cause serious accidents such as short circuits and fires.

[0003] To improve the yield rate of lithium battery casings and enhance the safety of lithium batteries in the early stages of battery production, the battery casings need to be inspected for axial straightness, radial cylindricity, surface damage, and other items. Traditional inspection methods rely primarily on manual visual identification, which requires a significant amount of manpower and time for batch inspection. These methods suffer from low inspection efficiency, reliance on experience, and a high rate of defective products. Using machine vision to inspect the outer wall of thin-walled circular tubes for defects is a mature and feasible solution. A clamping device secures the battery casing and rotates it circumferentially. A camera identifies defects in the casing, and an automatic control mechanism sorts out defective casings, improving inspection speed and quality, thereby enhancing battery quality. Existing clamping devices mostly use external robotic grippers, which cannot fully identify casing defects. Summary of the Invention

[0004] Purpose of the invention: In order to solve the above problems, the present invention provides a thin-walled circular tube inner wall clamping device that reduces the clamping contact area.

[0005] Technical solution: In order to solve the above problems, the present invention adopts a thin-walled circular tube inner wall clamping device, including a clamping body shell for extending into the thin-walled circular tube, a spiral tightening mechanism arranged in the clamping body shell, a tightening drive mechanism, and a double-helix supporting mechanism; the spiral tightening mechanism includes a plurality of clamping top plates, and the double-helix supporting mechanism includes a plurality of clamping struts, and the outer surface of the clamping struts is provided with a supporting protrusion, and the supporting protrusion is made of flexible material, and the tightening drive mechanism drives the clamping top plate and the clamping strut away from or close to the clamping body shell, and the clamping body shell is provided with a notch corresponding to the shape of the clamping top plate and the clamping strut, when the clamping top plate and the clamping strut are close to the clamping body shell, the clamping top plate and the clamping strut are conformal with the clamping body shell, and when the clamping top plate and the clamping strut are away from the clamping body shell, the outer surface of the clamping top plate and the support protrusion on the clamping strut are in contact with the inner wall of the thin-walled circular tube.

[0006] Furthermore, the device also includes a shell driving mechanism for driving the outer shell of the clamping body to rotate, the shell driving mechanism includes a shell driving motor and a reducer fixed to the output shaft of the shell driving motor, the output shaft of the reducer is fixedly connected to the outer shell of the clamping body, and the shell driving motor drives the outer shell of the clamping body to rotate, thereby driving the corresponding clamped thin-walled circular tube to rotate.

[0007] Furthermore, the tightening drive mechanism includes a tightening drive motor, a tightening transmission mechanism, a supporting transmission mechanism and a coaxial reversing mechanism. The tightening drive motor drives the clamping top plate away from or close to the clamping body shell through the tightening transmission mechanism. The coaxial reversing mechanism is arranged between the tightening transmission mechanism and the supporting transmission mechanism. The coaxial reversing mechanism transmits the driving force of the tightening drive motor to the supporting transmission mechanism, driving the clamping strut away from or close to the clamping body shell. The tightening transmission mechanism includes a tightening transmission shaft, the supporting transmission mechanism includes a supporting transmission shaft, and the coaxial reversing mechanism includes a first reversing bevel gear fixedly connected to the tightening transmission shaft, and a second reversing bevel gear fixedly connected to the supporting transmission shaft. The small ends of the first reversing bevel gear and the second reversing bevel gear are arranged face to face, and a number of third reversing bevel gears are circumferentially arranged between the first reversing bevel gear and the second reversing bevel gear, and the third reversing bevel gear is meshed with the first reversing bevel gear and the second reversing bevel gear.

[0008] Furthermore, the tightening transmission mechanism also includes a spiral track slider, a plurality of first tightening hinged rods and a plurality of second tightening hinged rods. The spiral track slider is sleeved on the outside of the tightening transmission shaft, and the spiral track slider is threadedly connected to the tightening transmission shaft. One end of the first tightening hinged rod is hinged to the spiral track slider, and the other end of the first tightening hinged rod is hinged to the inner side surface of the clamping top plate. One end of the second tightening hinged rod is hinged to the inner side surface of the clamping top plate, and the other end of the second tightening hinged rod is hinged to the outer shell of the clamping body.

[0009] Furthermore, the clamping body shell is provided with a hinge seat extending toward the tightening transmission shaft, the other end of the second tightening hinge rod is hinged to the clamping body shell through the hinge seat, and a dumbbell-shaped notch is provided at the position of the tightening transmission shaft corresponding to the hinge seat.

[0010] Furthermore, the support transmission mechanism includes a hinged disk, a double-helix guide rail slider and a plurality of support hinged rods that are sleeved on the outside of the support transmission shaft. One end of the clamping strut is hinged on the outer periphery of the hinged disk, one end of the support hinged rod is hinged to the inner wall of the clamping strut, and the other end is hinged to the double-helix guide rail slider. A double-helix slide rail is arranged on the outside of the support transmission shaft, and the two slide rails of the double-helix slide rail have a common end face. Two relative sliding rollers are arranged on the inner wall of the double-helix guide rail slider, and the sliding rollers slide along the double-helix guide rail to drive the double-helix guide rail slider to move axially along the support transmission shaft. The support protrusion on the outer surface of the clamping strut is located at the end away from the hinged disk.

[0011] Furthermore, the first tightening hinged rod, the second tightening hinged rod and the supporting hinged rod are telescopic rods.

[0012] Furthermore, the clamping strut is twisted 180 degrees around the supporting transmission shaft from the hinged end with the hinged disk, and the hinge points of the clamping strut and the hinged disk, the clamping strut and the supporting hinged rod, and the hinge points of the supporting hinged rod and the double helical guide rail slider are never on the same straight line.

[0013] Beneficial effects: Compared with the prior art, the significant advantage of the present invention is that the clamping top plate and the clamping support rod are conformal to the outer shell of the clamping device, and the overall structure is compact. Through the small-area multi-point contact clamping and fixing method, the contact area of ​​a single contact point is minimized while ensuring a firm fastening condition, reducing scratches and abrasions on the inner wall of the thin-walled circular tube, and reducing the defective rate. The hinge connecting rod used in the spiral tightening mechanism and the double-helix support mechanism is an adjustable-length telescopic rod. By adjusting the length of the hinge connecting rod, the clamping and fastening of circular tubes with various inner diameter specifications can be achieved, thereby improving the scope of application. Under limited space conditions, the axial rotation is converted into radial clamping movement through the spiral track and the double-helix guide rail, and the space utilization rate is high. The spiral structure can accurately control the opening angle and displacement of the clamping mechanism. The clamping and release of the circular tube are achieved by controlling the forward and reverse rotation of the motor. The control method is simple and the clamping efficiency is improved. The coaxial reversing mechanism allows a drive motor to drive axes with different rotation frequencies at the same time, thereby improving the applicability of the clamping device. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the clamping device of the present invention when it is contracted.

[0015] Figure 2 It is a schematic diagram of the axial structure of the clamping device of the present invention when it is contracted.

[0016] Figure 3 It is a schematic diagram of the overall structure of the clamping device of the present invention when it is unfolded.

[0017] Figure 4 It is a schematic diagram of the axial structure of the clamping device of the present invention when it is unfolded.

[0018] Figure 5 It is a schematic diagram of the structural decomposition of the clamping device in the present invention.

[0019] Figure 6 It is a schematic cross-sectional view of the structure of the clamping device in the present invention.

[0020] Figure 7 It is a structural schematic diagram of the screw tightening mechanism in the present invention.

[0021] Figure 8 It is a structural schematic diagram of the coaxial reversal mechanism in the present invention.

[0022] Figure 9 It is a schematic diagram of the structure of the double-helix supporting mechanism in the present invention.

[0023] Figure 10 It is a structural schematic diagram of the outer shell of the clamping body in the present invention.

[0024] Figure 11 It is a schematic cross-sectional view of the outer shell of the clamping body in the present invention.

[0025] Figure 12 It is a structural schematic diagram of the tightening transmission shaft in the present invention.

[0026] Figure 13 It is a structural schematic diagram of the spiral track slider in the present invention.

[0027] Figure 14 It is a structural schematic diagram of the clamping top plate in the present invention.

[0028] Figure 15 It is a structural schematic diagram of the hinge plate in the present invention.

[0029] Figure 16 It is a structural schematic diagram of the supporting transmission shaft in the present invention.

[0030] Figure 17 It is a structural schematic diagram of the double-helix guide rail slider in the present invention.

[0031] Figure 18 It is a structural schematic diagram of the clamping support rod in the present invention.

[0032] Figure 19 It is a schematic diagram of the plane projection of the clamping rod in the present invention. DETAILED DESCRIPTION

[0033] like Figures 1 to 6 As shown, in this embodiment, a thin-walled circular tube inner wall clamping device includes a clamping body device for clamping the thin-walled circular tube, a shell driving mechanism for driving the clamping body device to rotate circumferentially, a tightening driving mechanism for driving the tightening transmission shaft 4 and the supporting transmission shaft 14 to rotate circumferentially, a spiral tightening mechanism for driving the clamping top plate 6 to tighten against the inner wall of the thin-walled circular tube, a coaxial reversing mechanism for driving the supporting transmission shaft 14 to rotate circumferentially in the opposite direction, and a double spiral supporting mechanism for driving the clamping support rod 15 to clamp the inner wall of the thin-walled circular tube. Figure 10 、 11 As shown, the outer shell of the clamping body is provided with a notch corresponding to the shape of the clamping top plate and the clamping support rod.

[0034] The shell drive mechanism includes a shell drive motor 1 and a servo motor reducer 2 fixedly connected to the shell drive motor 1. The shell drive motor 1 is fixed to the detection assembly line by bolts. The servo motor reducer 2 is fixed to the output shaft end of the shell drive motor 1 through a limiting step and bolts. The shell drive motor 1 outputs power through the servo motor reducer 2. The servo motor reducer 2 is connected to the clamping body shell 17 through a flange. After the clamping device clamps the thin-walled circular tube, it is rotated circumferentially as a whole, so that the camera can completely capture the image of the outer wall of the circular tube.

[0035] The tightening drive mechanism includes a tightening drive motor 3, which is a reduction motor. The tightening drive motor 3 is arranged inside the clamping body shell 17 near the flange end and is fixed by a limiting groove inside the clamping body shell 17. The tightening drive motor 3 transmits the rotation to the tightening transmission shaft 4 and the supporting transmission shaft 14 through the shaft end flange, driving the spiral track slider 8 on the tightening transmission shaft 4 and the double spiral guide rail slider 12 on the supporting transmission shaft 14 to move axially, completing the opening and closing action of the clamping device.

[0036] like Figure 7 、 12 As shown in Figure 14, the spiral tightening mechanism includes a tightening transmission shaft 4, several second tightening hinge rods 5, a clamping top plate 6, a first tightening hinge rod 7, and a spiral track slider 8. The tightening transmission shaft 4 is placed at the internal axial center position of the clamping body shell 17, and the tightening transmission shaft 4 is connected to the shaft end flange of the tightening drive motor 3 through the shaft end flange. The spiral track slider 8 is screwed with the spiral on the tightening transmission shaft 4 through the internal thread surface to realize axial movement along the tightening transmission shaft 4. The front of the clamping top plate 6 is made of small curvature flexible material and thin-walled circular tube, and a coaxial hinge interface is designed on the back to simultaneously hinge the second tightening hinge rod 5 and the first tightening hinge rod 7. The other end of the second tightening hinge rod 5 is hinged to the internal hinge interface of the clamping body shell 17, and a dumbbell-shaped notch is designed on the axis of the tightening transmission shaft 4 below this hinge interface to prevent interference with the rotation of the hinge joint. The other end of the first tightening hinge rod 7 is hinged to the hinge joint around the spiral track slider 8. The clamping top plate 6 is co-shaped with the clamping body shell 17 in the initial position. After the tightening drive motor 3 drives the tightening transmission shaft 4 to rotate clockwise through the flange, the spiral track slider 8 moves axially along the tightening transmission shaft 4 toward the tail of the clamping device. The clamping top plate 6 is subjected to the combined torque of the second tightening hinge rod 5 and the first tightening hinge rod 7 and moves radially along the anti-center direction of the clamping body shell 17 to complete the opening of the mechanism and press and fix the inner wall of the thin-walled circular tube. Conversely, when the tightening drive motor 3 rotates counterclockwise, the clamping top plate 6 will move radially along the center direction of the clamping body shell 17 to release the contact with the inner wall of the thin-walled circular tube.

[0037] like Figure 8As shown, the coaxial reversing mechanism includes a third reversing bevel gear 9 and two large reversing bevel gears 10. The two large reversing bevel gears 10 are the first reversing bevel gear and the second reversing bevel gear respectively. The first reversing bevel gear and the second reversing bevel gear are fixed to the ends of the tightening transmission shaft 4 and the supporting transmission shaft 14 respectively through key connections. The small ends of the first reversing bevel gear and the second reversing bevel gear are arranged face to face. Three fixed shafts are arranged at equal intervals in the circumferential direction on the inner wall of the clamping body shell 17 between the first reversing bevel gear and the second reversing bevel gear. A third reversing bevel gear 9 is arranged on each fixed shaft. The third reversing bevel gear 9 is meshed with the first reversing bevel gear and the second reversing bevel gear. When the tightening transmission shaft 4 rotates clockwise, the large reversing bevel gear 10 fixed at the end of the shaft of the tightening transmission shaft 4 converts the clockwise rotation into the counterclockwise rotation of the supporting transmission shaft 14 through the three third reversing bevel gears 9 meshing with the two large reversing bevel gears 10, thereby completing the conversion of the rotation direction. The first reversing bevel gear and the second reversing bevel gear can adopt different gear ratios to adapt to the different rotation frequencies required by the tightening transmission shaft 4 and the supporting transmission shaft 14. Through the coaxial reversing mechanism, one drive motor can simultaneously drive shafts with different rotation frequencies to work, thereby improving the applicability of the clamping device.

[0038] like Figure 9 、 15 As shown in Figure 19, the double-helix support mechanism includes a bearing 11, a double-helix guide slider 12, a support hinge rod 13, a support transmission shaft 14, a clamping support rod 15, and a hinge plate 16. The support transmission shaft 14 is placed at the internal axis center position of the clamping body shell 17. The shaft end of the support transmission shaft 14 close to the top drive motor 3 is connected to the large reversing bevel gear 10, and the end close to the double-helix track is fixed to the center of the inner wall of the clamping body shell 17 through the shaft shoulder. The bearing 11 is nested on the support transmission shaft 14 through a groove. The hinge plate 16 is tightly connected to the bearing 11. The three clamping support rods 15 are hinged to the hinge interfaces equidistantly spaced around the hinge plate 16. Figure 18 、 19 As shown, the clamping strut 15 is twisted 180 degrees as a whole to avoid the supporting hinge rod 13 to prevent the clamping strut 15 from interfering with the clamping body shell 17 when it is in a common position. A hemispherical flexible material is fixed to the end of the clamping strut 15. The double-helix guide rail slider 12 is sleeved on the outside of the supporting transmission shaft 14. Two sliding rollers are arranged opposite to each other on the inner wall of the double-helix guide rail slider 12. The sliding rollers slide along the supporting transmission shaft 14. When the main axis of the supporting transmission shaft 14 rotates, the sliding rollers on the inner wall of the double-helix guide rail slider 12 are subjected to the component force perpendicular to the direction of the track along the axial direction of the supporting transmission shaft 14 and will move axially along the supporting transmission shaft 14. Three hinge joints are arranged at equal intervals around the outer wall of the double-helix guide rail slider 12, and each hinge joint is hinged to a supporting hinge rod 13.

[0039] The other end of the support hinge rod 13 is hinged to the spherical hinge joint on the clamping support rod 15 at a position 60 degrees offset from the root hinge joint through a spherical hinge joint. The clamping support rod 15 is co-shaped with the clamping body shell 17 in the initial position. When the tightening drive motor 3 rotates clockwise, it drives the tightening transmission shaft 4 and the large reversing bevel gear 10 at its end to rotate clockwise. The clockwise rotation is converted into the counterclockwise rotation of the support transmission shaft 14 through the coaxial reversing mechanism. The double-helix guide rail slider 12 is acted upon by the force of the support transmission shaft 14 through the sliding roller on the inner wall and moves axially along the clamping body shell 17 toward the head of the clamping device. The clamping support rod 15 is constrained by the hinge plate 16 and the axial torque transmitted by the support hinge rod 13 and rotates around the tail hinge joint to complete the opening of the mechanism. The clamping support rod 15 mainly assists the thin-walled round tube to maintain balance during the clamping process to prevent the clamping point from slipping due to the gravity of the round tube itself during rotation, causing the clamping to fail. On the contrary, when the tightening drive motor 3 rotates counterclockwise, the double-helix supporting mechanism will release the contact with the inner wall of the thin-walled circular tube.

[0040] The second tightening hinge rod 5, the first tightening hinge rod 7 and the supporting hinge rod 13 all adopt a two-section connecting rod structure, with the small diameter rod body nested in the large diameter sleeve, so that the length of the connecting rod can be changed. By adjusting its length and adjusting the positions of the spiral track slider 8 and the double spiral guide slider 12 on the tightening transmission shaft 4 and the supporting transmission shaft 14 respectively, it can adapt to clamping actions of various inner diameter sizes and improve the scope of application.

[0041] The working process of the above-mentioned clamping device is as follows: the clamping device is placed on a movable workbench, the position of the clamping device is adjusted so that the clamping body extends into the interior of the thin-walled circular tube, the tightening drive motor 3 works, driving the tightening transmission shaft 4 and the supporting transmission shaft 14 to rotate, and the clamping structure of the spiral tightening mechanism and the double-spiral supporting mechanism opens to clamp and fix the inner wall of the thin-walled circular tube, then the outer shell drive motor 1 works to make the clamping device rotate circumferentially as a whole for one circle, after the system inspection is completed, the tightening drive motor 3 reverses and works, the clamping structure gradually closes and returns to its position, and the thin-walled circular tube is released. The mobile workbench adjusts the clamping device to extend from the inside of the thin-walled circular tube, and the automatic control mechanism performs the next step of processing on the thin-walled circular tube.

Claims

1. A thin-walled tube inner wall clamping device, characterized in that: The invention comprises a clamping body shell (17) for extending into a thin-walled circular tube, a screw tightening mechanism, a tightening driving mechanism, and a double-screw supporting mechanism arranged in the clamping body shell (17); the screw tightening mechanism comprises a plurality of clamping top plates (6), the double-screw supporting mechanism comprises a plurality of clamping support rods (15), the outer surface of the clamping support rods (15) is provided with a supporting protrusion, the supporting protrusion is made of a flexible material, the tightening driving mechanism drives the clamping top plates (6) and the clamping support rods (15) to move away from or close to the clamping body shell (17); A holding body shell (17), wherein the holding body shell (17) is provided with a notch corresponding to the shape of the clamping top plate (6) and the clamping support rod (15); when the clamping top plate (6) and the clamping support rod (15) are close to the holding body shell, the clamping top plate (6) and the clamping support rod (15) are conformal to the holding body shell (17); when the clamping top plate (6) and the clamping support rod (15) are away from the holding body shell, the outer surface of the clamping top plate (6) and the supporting protrusions on the clamping support rod (15) contact the inner wall of the thin-walled circular tube; The tightening drive mechanism includes a tightening drive motor (3), a tightening transmission mechanism, a supporting transmission mechanism and a coaxial reversing mechanism. The tightening drive motor (3) drives the clamping top plate (6) away from or close to the clamping body shell (17) through the tightening transmission mechanism. The coaxial reversing mechanism is arranged between the tightening transmission mechanism and the supporting transmission mechanism. The coaxial reversing mechanism transmits the driving force of the tightening drive motor (3) to the supporting transmission mechanism, drives the clamping support rod (15) away from or close to the clamping body shell (17). The tightening transmission mechanism It includes a tightening transmission shaft (4), the supporting transmission mechanism includes a supporting transmission shaft (14), the coaxial reversing mechanism includes a first reversing bevel gear fixedly connected to the tightening transmission shaft (4), and a second reversing bevel gear fixedly connected to the supporting transmission shaft (14), the small ends of the first reversing bevel gear and the second reversing bevel gear are arranged face to face, and a plurality of third reversing bevel gears (9) are circumferentially arranged between the first reversing bevel gear and the second reversing bevel gear, and the third reversing bevel gear (9) is meshed with the first reversing bevel gear and the second reversing bevel gear; The tightening transmission mechanism further comprises a spiral track slider (8), a plurality of first tightening hinged rods (7) and a plurality of second tightening hinged rods (5), wherein the spiral track slider (8) is sleeved on the outside of the tightening transmission shaft (4), and the spiral track slider (8) is threadedly connected to the tightening transmission shaft (4), one end of the first tightening hinged rod (7) is hinged to the spiral track slider (8), the other end of the first tightening hinged rod (7) is hinged to the inner side surface of the clamping top plate (6), one end of the second tightening hinged rod (5) is hinged to the inner side surface of the clamping top plate (6), and the other end of the second tightening hinged rod (5) is hinged to the outer shell of the clamping body; The supporting transmission mechanism includes a hinge plate (16) sleeved on the outside of the supporting transmission shaft (14), a double-helix guide rail slider (12) and a plurality of supporting hinged rods (13), one end of the clamping support rod (15) is hinged on the outer periphery of the hinge plate (16), one end of the supporting hinged rod (13) is hinged to the inner wall of the clamping support rod (15), and the other end is hinged to the double-helix guide rail slider (12), a double-helix slide rail is provided on the outside of the supporting transmission shaft (14), the two slide rails of the double-helix slide rail have a common end face, two opposite sliding rollers are provided on the inner wall of the double-helix guide rail slider (12), the sliding rollers slide along the double-helix guide rail, driving the double-helix guide rail slider (12) to move axially along the supporting transmission shaft (14), and the supporting protrusion on the outer surface of the clamping support rod (15) is located at the end away from the hinge plate (16); The clamping strut (15) is twisted 180 degrees around the support transmission shaft (14) from the hinge end with the hinge plate (16), and the hinge point between the clamping strut (15) and the hinge plate (16), the hinge point between the clamping strut (15) and the support hinge rod (13), and the hinge point between the support hinge rod (13) and the double helical guide rail slider (12) are never located on the same straight line.

2. The thin-walled circular tube inner wall clamping device according to claim 1, characterized in that: The outer surface of the clamping top plate (6) is made of a flexible material with a small curvature.

3. The thin-walled circular tube inner wall clamping device according to claim 1, characterized in that: The invention also includes a housing drive mechanism for driving the clamping body housing (17) to rotate, wherein the housing drive mechanism includes a housing drive motor (1) and a reducer (2) fixed to the output shaft of the housing drive motor (1), wherein the output shaft of the reducer (2) is fixedly connected to the clamping body housing, and the housing drive motor (1) drives the clamping body housing to rotate, thereby driving the corresponding clamped thin-walled circular tube to rotate.

4. The thin-walled circular tube inner wall clamping device according to claim 1, characterized in that: The clamping body shell is provided with a hinge seat extending toward the tightening transmission shaft (4); the other end of the second tightening hinge rod (5) is hinged to the clamping body shell through the hinge seat; and a dumbbell-shaped notch is provided on the tightening transmission shaft (4) at a position corresponding to the hinge seat.

5. The thin-walled circular tube inner wall clamping device according to claim 4, characterized in that: The first tightening hinged rod (7), the second tightening hinged rod (5) and the supporting hinged rod (13) are telescopic rods.

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