A clamping device for pipe cutting

Abstract

The present application provides a clamping device for pipe cutting, which belongs to the technical field of pipe processing, and comprises a frame and two bearing seats symmetrically arranged at the middle part thereof, and the two bearing seats are connected to the frame by sliding rails transversely; sleeves are rotatably connected inside the bearing seats, and clamping components for clamping metal pipes are arranged inside the sleeves, and driving components for driving the sleeves to rotate are arranged on the bearing seats; a first elastic member capable of prompting the two bearing seats to move away from each other is arranged between the two bearing seats, two first spring pins corresponding to the bearing seats are arranged on the upper surface of the frame, limiting holes for inserting the first spring pins are opened on the two bearing seats, and trigger components capable of withdrawing the first spring pins from the limiting holes after the sleeves rotate one circle are arranged inside the two bearing seats; the present application can reduce the possibility of the tool being stuck during the return stroke and the possibility of the metal pipe colliding with the tool.

Description

Technical Field

[0001] The present application relates to the technical field of pipeline processing, and in particular to a clamping device for pipeline cutting. Background Art

[0002] Metal pipes are equipment used to transport and deliver fluids. They are usually made of a variety of metal materials, such as carbon steel, stainless steel, etc., and have excellent corrosion resistance and pressure resistance. According to the material and purpose, they can be divided into many types, including welded steel pipes, galvanized pipes, etc. Metal pipes are widely used in industries, construction, water supply, etc., and are an indispensable infrastructure in modern construction and production.

[0003] During the installation and construction of the pipeline system, in order to meet the specific layout and design requirements, metal pipes are often cut to ensure that the metal pipes can be correctly connected and adapt to the space. At the same time, in order to improve the stability of the metal pipes during the cutting process, it is also necessary to use a clamping device to clamp the metal pipes to prevent the metal pipes from shifting in position.

[0004] Referring to the Chinese patent document with announcement number CN215468427U and announcement date January 11, 2022, entitled "A clamping device for metal pipe cutting", through the cooperation between the lower support assembly and the clamping assembly, metal pipe parts of different lengths can be clamped, effectively increasing the scope of application of the device, and at the same time, the pipe can be clamped stably, reducing the probability of the pipe moving during the cutting process and affecting the cutting quality.

[0005] Referring to the above technical solution, the existing metal pipe cutting method is usually to directly feed the tool to cut the metal pipe, but since the metal pipe has a large cutting depth and the metal pipe is in a clamped and fixed state, the tool may have a large friction with the cut end face of the metal pipe during the return stroke, resulting in a tool jam; and at the moment of cutting, the metal pipe may have a certain degree of jitter displacement due to its own stress and the cutting pressure during the cutting process, which may easily cause the cut end face of the metal pipe to collide with the tool and be damaged. Summary of the invention

[0006] In view of this, the present application provides a clamping device for pipe cutting, which is mainly used to solve the problem that the tool is prone to getting stuck during the return stroke and the metal pipe may collide with the tool.

[0007] In order to solve the above technical problems, the present application provides a clamping device for pipe cutting, including a frame and two bearing seats symmetrically arranged in the middle thereof, and the two bearing seats are connected to the frame by sliding rails transversely; sleeves are rotatably connected inside the bearing seats, and clamping components for clamping metal pipes are arranged inside the sleeves, and driving components for driving the sleeves to rotate are arranged on the bearing seats; a first elastic member capable of prompting the two bearing seats to move away from each other is arranged between the two bearing seats, two first spring pins corresponding to the bearing seats are arranged on the upper surface of the frame, limiting holes for inserting the first spring pins are opened on the two bearing seats, and trigger components capable of withdrawing the first spring pins from the limiting holes after the sleeve rotates one circle are arranged inside the two bearing seats.

[0008] By adopting the above technical solution, during the cutting process of the metal pipe, the sleeve is rotated by cooperating with the driving component, so that the tool can feed along the circumferential position of the metal pipe. Compared with the direct cutting method, the cutting amount of the metal pipe can be reduced, the friction between the metal pipe and the tool can be reduced, and the risk of tool jamming can be reduced. Under the action of the trigger member, when the cutting work is completed, the elastic potential energy of the first elastic member can be used to make the two supporting seats move away from each other. At this time, the metal pipe clamped by the clamping assembly inside the supporting seat will also move away from the tool to prevent the metal pipe from colliding with the tool after shaking and displacement.

[0009] Optionally, the trigger member includes a second spring pin arranged on the inner walls of two bearing seats, and the sliding hole where the second spring pin is located is connected to the limiting hole, and the opposing surfaces of the two sleeves are provided with conical blocks. When the sleeve rotates one circle, the second spring pin is abutted by the cone and can push the first spring pin out of the limiting hole.

[0010] By adopting the above technical solution, after the sleeve rotates one circle, the conical block is used as a trigger reference, and with the cooperation of the second spring pin, the second spring pin can be pulled out from the limiting hole, thereby releasing the position lock of the second spring pin on the bearing seat.

[0011] Optionally, a lifting platform is provided at the opening in the middle of the frame, and a circular saw for cutting metal pipes is provided on the lifting platform.

[0012] Optionally, a gas support is provided on the lifting platform, and the circular saw is located at the telescopic end of the gas support. A limiting ring is provided on the periphery of the blade of the circular saw, which is coaxial with itself and can be abutted by a metal pipe, and the diameter of the limiting ring is smaller than the diameter of the blade of the circular saw.

[0013] By adopting the above technical solution, due to the presence of the air support, the circular saw can participate in the cutting of the metal pipe in an adaptive floating manner. When cutting the square pipe or the rectangular pipe, after the square pipe or the rectangular pipe abuts against the limit ring, the circular saw can be appropriately displaced based on the outer contour surface of the square pipe or the rectangular pipe, so that the cutting amount of the circumferential points of the square pipe or the rectangular pipe remains consistent.

[0014] Optionally, the clamping assembly includes three transition rings arranged inside the sleeve, and the transition ring close to the lifting platform side is fixedly connected to the inside of the sleeve, and the other two transition rings are axially slidingly connected to the inside of the sleeve, and a second elastic member and two clamping plates that are rotationally symmetrical one hundred and eighty degrees with their own center as a reference are arranged between every two adjacent transition rings, and the clamping plates are hinged between two adjacent transition rings by hinges, and the angle between two clamping plates that are located in the same sleeve and adjacent in the circumferential direction is ninety degrees, and a cylinder is arranged on the sleeve, and a pressure ring is arranged at the execution end of the cylinder, and a pressure rod that can abut the pressure ring is arranged on the transition ring away from the lifting platform side.

[0015] By adopting the above technical solution, with the cooperation of the second elastic member and the three transition rings, the four clamping plates located in the same sleeve can be adaptively tensioned according to the shape of the metal pipe to meet the centering clamping requirements of circular pipes, square pipes and rectangular pipes.

[0016] Optionally, a ball is provided on one end of the pressure rod close to the pressure ring, and the ball is used to replace the pressure rod to contact the pressure ring.

[0017] By adopting the above technical solution, when the ball replaces the pressure rod and contacts the pressure ring, the possibility of friction damage to the pressure rod and the pressure ring can be reduced.

[0018] Optionally, the driving assembly includes a driving motor arranged on a bearing seat and a transmission shaft axially slidably connected between the two bearing seats. Large diameter gear rings are arranged on both sleeves. The driving motor can drive the large diameter gear rings to rotate through gear transmission. Two transmission gears corresponding to and meshing with the large diameter gear rings are arranged on the transmission shaft.

[0019] Optionally, a reset assembly is provided between the transmission shaft and the two bearing seats, for resetting the two bearing seats after the cutting and blanking of the metal pipe is completed.

[0020] Optionally, the reset assembly includes an axial sliding cavity opened on two bearing seats, and the interior of the axial sliding cavity is axially slidably connected with an internal threaded ring, and both ends of the transmission shaft are provided with a screw that can extend into the interior of the axial sliding cavity and match the internal threaded ring, and the thread directions of the two screws are opposite.

[0021] By adopting the above technical solution, when the two bearing seats pop open, the internal thread ring can limit the movement of the bearing seats, reducing the risk of the bearing seats detaching from the slide rail, and when the personnel take out the cut metal pipe from the inside of the sleeve, the screw and the internal thread ring can cooperate to quickly reset the two bearing seats, so that the subsequent cutting of the metal pipe can be carried out quickly.

[0022] Optionally, flexible gaskets are provided on the opposite inner side surfaces of the two internal threaded rings.

[0023] By adopting the above technical solution, the flexible gasket can serve as a buffer component between the internal thread ring and the bearing seat when the two bearing seats pop open, thereby reducing the possibility of damage to the internal thread ring due to excessive impact force generated by the bearing seat.

[0024] In summary, compared with the prior art, the present application includes at least one of the following beneficial technical effects: 1. During the cutting process of the metal pipe, the metal pipe is rotated so that the circular saw can cut along the outer surface of the metal pipe, so that the cutting amount of each circumferential point of the metal pipe is kept consistent, thereby reducing the possibility of the circular saw getting stuck; and after the metal pipe is cut, the metal pipe and its supporting parts can be bounced away from the circular saw together, reducing the risk of collision between the metal pipe and the circular saw.

[0025] 2. Use floating adaptive clamping components to meet the centering clamping requirements of circular pipes, square pipes and rectangular pipes, increase the application range of the device, and at the same time, perform floating optimization on the circular saw so that the cutting amount at each circumferential point of the metal pipe remains consistent when cutting square or rectangular pipes.

[0026] 3. After completing the cutting and blanking of the metal pipe, the various components can be quickly reset by driving the motor in reverse, which is conducive to the subsequent metal pipe cutting work. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic structural diagram of a clamping device for pipe cutting in the present application; Figure 2 A cross-sectional view of the bearing seat of this application; Figure 3 A plan cross-sectional view of the bearing seat of this application; Figure 4 For this application Figure 3 A partial enlarged view of the middle area A; Figure 5 This is a cross-sectional view of the axial sliding cavity of the present application; Figure 6 This is a schematic diagram of the structure of the transmission shaft of this application.

[0028] Explanation of the reference numerals in the accompanying drawings: 1. frame; 2. bearing seat; 21. sleeve; 22. clamping assembly; 221. transition ring; 222. second elastic member; 223. clamping plate; 224. cylinder; 225. pressure ring; 226. pressure rod; 227. ball; 23. driving assembly; 231. driving motor; 232. transmission shaft; 233. large diameter gear ring; 234. transmission gear; 3. first elastic member; 4. first spring pin; 41. limiting hole; 42. trigger member; 421. second spring pin; 422. conical block; 5. lifting platform; 51. circular saw; 52. gas support; 53. limiting ring; 6. reset assembly; 61. axial sliding cavity; 62. internal thread ring; 63. screw; 64. flexible gasket. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the embodiments of the present application. Figure 1-Figure 6 , the technical solutions of the embodiments of the present application are clearly and completely described. Based on the described embodiments of the present application, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of this application.

[0030] Reference Figure 1 and Figure 2 The present embodiment provides a clamping device for pipe cutting, comprising a frame 1, two bearing seats 2, two sleeves 21, a clamping assembly 22, a cutting mechanism, a driving assembly 23 and a spring mechanism. The two bearing seats 2 are symmetrically arranged on the frame 1 in a transverse sliding connection through a slide rail, and the two sleeves 21 are rotatably connected inside the two bearing seats 2 respectively.

[0031] Among them, refer to Figure 1 , Figure 2 and Figure 3 The clamping assembly 22 includes three transition rings 221 , a second elastic member 222 , four clamping plates 223 , a cylinder 224 , a pressure ring 225 and a pressure rod 226 . The transition ring 221 near the lifting platform 5 is fixedly connected to the inside of the sleeve 21, and the other two transition rings 221 are axially slidably connected to the inside of the sleeve 21. A second elastic member 222 and two clamping plates 223 that are rotationally symmetrical one hundred and eighty degrees with their own center as a reference are provided between every two adjacent transition rings 221. The clamping plates 223 are hinged between two adjacent transition rings 221 through hinges, and the angle between two clamping plates 223 adjacent to each other in the circumferential direction and located in the same sleeve 21 is ninety degrees; the cylinder 224 is provided on the sleeve 21, the pressure ring 225 is provided at the execution end of the cylinder 224, the pressure rod 226 is provided on the transition ring 221 near the side of the pressure ring 225, and the end of the pressure rod 226 near the pressure ring 225 is provided with a ball 227 that can abut the pressure ring 225.

[0032] When the metal pipe is placed inside the two sleeves 21, the cylinder 224 runs to drive the pressure ring 225 to move, and the pressure rod 226 will cause the three transition ring 221 components to move closer due to the pressure of the pressure ring 225. At this time, the second elastic member 222 is compressed, and the hinge connected by the four clamping plates 223 will gradually tend from an inclined state to a state of coincidence with the radius of the transition ring 221, so that the four clamping plates 223 move toward the center of the transition ring 221, and the centering clamping of the metal pipe is achieved through the adaptive tensioning of the four clamping plates 223, and the four clamping plates 223 can cooperate to simultaneously meet the clamping and positioning requirements of circular pipes, square pipes and rectangular pipes.

[0033] Among them, refer to Figure 1 and Figure 2 The cutting mechanism includes a lifting platform 5 and a circular saw 51. The lifting platform 5 is arranged at an opening in the middle of the frame 1, and the circular saw 51 is arranged on the lifting platform 5. When the metal pipe is clamped and fixed, the lifting platform 5 drives the circular saw 51 to move upward, so that the circular saw 51 in the high-speed rotating process contacts the metal pipe, and the metal pipe can be cut.

[0034] Among them, refer to Figure 1 and Figure 2 The driving assembly 23 includes a driving motor 231, a transmission shaft 232, two large-diameter gear rings 233 and two transmission gears 234. The driving motor 231 is arranged on the bearing seat 2, the transmission shaft 232 is axially slidably connected between the two bearing seats 2, the two large-diameter gear rings 233 are respectively arranged on the two sleeves 21, and the driving motor 231 can drive the large-diameter gear rings 233 to rotate by gear transmission. The two transmission gears 234 are both arranged on the transmission shaft 232 and mesh with the corresponding large-diameter gear rings 233. When the driving motor 231 is running, the two sleeves 21 can rotate synchronously through the transmission of the transmission gear 234, the large-diameter gear ring 233 and the transmission shaft 232.

[0035] During the cutting process of the metal pipe, the driving motor 231 is operated to rotate the large diameter gear ring 233 on one side, and then the two sleeves 21 can be rotated synchronously with the cooperation of the transmission shaft 232 and the transmission gear 234 in the external axial spline groove. Under the premise that the position of the tool remains unchanged, the metal pipe in a fixed state can rotate circumferentially, so that the cutting amount at each circumferential point of the metal pipe remains consistent.

[0036] Among them, refer to Figure 2 , Figure 3 and Figure 4The pop-up mechanism includes a first elastic member 3, two first spring pins 4, two limiting holes 41 and a trigger member 42. The first elastic member 3 is arranged between the two bearing seats 2 and can cause the two bearing seats 2 to move away from each other. The two first spring pins 4 are arranged on the upper surface of the frame 1 and correspond to the two bearing seats 2 one by one. The two limiting holes 41 are respectively provided on the two bearing seats 2, and when the first spring pins 4 are inserted into the limiting holes 41, the position of the bearing seats 2 can be locked; the trigger member 42 includes two second spring pins 421 and two conical blocks 422. The two second spring pins 421 are respectively arranged on the inner walls of the two bearing seats 2, and the sliding holes where the second spring pins 421 are located are connected with the limiting holes 41. The two conical blocks 422 are respectively arranged on the opposite surfaces of the two sleeves 21. When the sleeve 21 rotates one circle, the second spring pin 421 is abutted by the cone and can push the first spring pin 4 out of the limiting hole 41.

[0037] When the sleeve 21 rotates one circle, the circular saw 51 completes the cutting of the metal pipe. At this time, the second spring pin 421 is abutted by the cone and moves toward a position away from the center of the sleeve 21, thereby pushing the first spring pin 4 out of the limiting hole 41 to release the position lock of the supporting seat 2. Under the action of the first elastic member 3, the two supporting seats 2 will move away from each other, reducing the possibility of collision between the metal pipe and the circular saw 51.

[0038] In addition, refer to Figure 2 A gas support 52 is provided on the lifting platform 5, and the circular saw 51 is located at the telescopic end of the gas support 52. The outer periphery of the blade of the circular saw 51 is provided with a limiting ring 53 which is coaxial with itself and can be abutted by the metal pipe, and the diameter of the limiting ring 53 is smaller than the blade diameter of the circular saw 51.

[0039] When cutting a square or rectangular metal pipe, due to the presence of the gas support 52, the circular saw 51 will be in a floating state, and with the rotation of the sleeve 21, when the outer contour surface of the square or rectangular metal pipe abuts against the limiting ring 53, the limiting ring 53 will cause the gas support 52 to contract, thereby causing the circular saw 51 to perform corresponding compensatory displacement, so that the cutting amount at each circumferential point of the square or rectangular metal pipe remains consistent.

[0040] Reference Figure 5 and Figure 6A reset assembly 6 is provided between the transmission shaft 232 and the two bearing seats 2, and is used to reset the two bearing seats 2 after the cutting and blanking of the metal pipe is completed. The reset assembly 6 includes two axial sliding cavities 61, two internal threaded rings 62 and two screws 63. The two axial sliding cavities 61 are respectively provided on the two bearing seats 2, and the two internal threaded rings 62 are respectively provided inside the axial sliding cavities 61 in an axial sliding connection manner. The two screws 63 are respectively provided at both ends of the transmission shaft 232 and have opposite thread directions to each other. The screws 63 can extend into the axial sliding cavities 61 and match with the internal threaded rings 62.

[0041] During the cutting process of the metal pipe, the transmission shaft 232 drives the two screws 63 to rotate together, so that the two internal threaded rings 62 can be displaced in the axial sliding cavity 61 in a back-to-back manner. When the two bearing seats 2 pop open, the internal threaded ring 62 can provide a certain movement limiting effect for the bearing seats 2 to prevent the two bearing seats 2 from moving too far away and detaching from the slide rail. At this time, the internal threaded ring 62 will abut against the inner wall of the axial sliding cavity 61 on the side close to the circular saw 51. When the personnel takes the cut metal pipe out of the sleeve 21, the drive motor 231 is reversed. At this time, the transmission shaft 232 drives the two screws 63 to reverse together, and can apply a thrust to the two bearing seats 2 to move toward each other through the internal threaded ring 62, thereby completing the resetting of the two bearing seats 2 to facilitate the subsequent metal pipe cutting work.

[0042] In addition, refer to Figure 6 Flexible gaskets 64 are provided on the opposite inner sides of the two internal threaded rings 62 .

[0043] When the two bearing seats 2 pop open, the flexible gasket 64 can replace the internal thread ring 62 to abut against the bearing seat 2, thereby reducing the impact force when the bearing seat 2 pops open to a certain extent, so as to prevent the internal thread ring 62 from being damaged by the impact force generated by the bearing seat 2.

[0044] The implementation principle of a clamping device for pipe cutting in the embodiment of the present application is as follows: First, place the metal pipe inside the two sleeves 21, and then the cylinder 224 runs to drive the pressure ring 225 to move. The pressure of the pressure ring 225 will cause the pressure rod 226 to force the three transition ring 221 components to move closer. At this time, the second elastic member 222 is compressed, and the hinge connected by the four clamping plates 223 will gradually tend from an inclined state to a state that coincides with the radius of the transition ring 221, so that the four clamping plates 223 move toward the center of the transition ring 221. The centering clamping of the metal pipe is achieved through the adaptive tensioning of the four clamping plates 223, and the four clamping plates 223 can cooperate to simultaneously meet the clamping and positioning requirements of circular pipes, square pipes and rectangular pipes.

[0045] When the metal pipe is clamped and fixed, the lifting platform 5 drives the circular saw 51 to move upward, so that the circular saw 51 in the high-speed rotating process contacts the metal pipe and the cutting work of the metal pipe can be carried out.

[0046] During the cutting process of the metal pipe, the driving motor 231 is operated to rotate the large diameter gear ring 233 on one side, and then the two sleeves 21 can be rotated synchronously with the cooperation of the transmission shaft 232 and the transmission gear 234 in the external axial spline groove, so that the metal pipe in a fixed state rotates circumferentially under the premise that the position of the tool remains unchanged, so that the cutting amount of each circumferential point of the metal pipe remains consistent. In addition, when cutting a square or rectangular metal pipe, due to the presence of the gas support 52, the circular saw 51 will be in a floating state, and as the sleeve 21 rotates, when the outer contour surface of the square or rectangular metal pipe abuts against the limit ring 53, the limit ring 53 will cause the gas support 52 to contract, so that the circular saw 51 performs corresponding compensation displacement, so that the cutting amount of each circumferential point of the square or rectangular metal pipe remains consistent.

[0047] When the sleeve 21 rotates one circle, the circular saw 51 completes the cutting of the metal pipe. At this time, the second spring pin 421 is abutted by the cone and moves toward a position away from the center of the sleeve 21, thereby pushing the first spring pin 4 out of the limiting hole 41 to release the position lock of the supporting seat 2. Under the action of the first elastic member 3, the two supporting seats 2 will move away from each other, reducing the possibility of collision between the metal pipe and the circular saw 51.

[0048] In addition, during the cutting process of the metal pipe, the transmission shaft 232 drives the two screw rods 63 to rotate together, so that the two internal threaded rings 62 can be displaced in the axial sliding cavity 61 in a back-to-back manner. When the two bearing seats 2 pop open, the internal threaded ring 62 can provide a certain movement limiting effect for the bearing seats 2 to prevent the two bearing seats 2 from moving too far away and detaching from the slide rail. At this time, the internal threaded ring 62 will abut against the inner wall of the axial sliding cavity 61 on the side close to the circular saw 51. When the personnel takes the cut metal pipe out of the sleeve 21, the drive motor 231 is reversed. At this time, the transmission shaft 232 drives the two screw rods 63 to reverse together, and can apply a thrust towards the two bearing seats 2 through the internal threaded ring 62, thereby completing the resetting of the two bearing seats 2 to facilitate the subsequent metal pipe cutting work.

[0049] The above is a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles described in the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A clamping device for pipe cutting, comprising a frame (1) and two bearing seats (2) symmetrically arranged in the middle thereof, wherein the two bearing seats (2) are both connected to the frame (1) by sliding rails in a transverse manner, characterized in that: The bearing seat (2) is rotatably connected to a sleeve (21), and a clamping assembly (22) for clamping a metal pipe is provided inside the sleeve (21). A driving assembly (23) for driving the sleeve (21) to rotate is provided on the bearing seat (2); A first elastic member (3) capable of urging the two bearing seats (2) to move away from each other is arranged between the two bearing seats (2); two first spring pins (4) corresponding one to each of the bearing seats (2) are arranged on the upper surface of the frame (1); limiting holes (41) for inserting the first spring pins (4) are provided on the two bearing seats (2); and trigger members (42) capable of pulling the first spring pins (4) out of the limiting holes (41) after the sleeve (21) rotates one circle are arranged inside the two bearing seats (2).

2. A clamping device for pipe cutting according to claim 1, characterized in that: The trigger member (42) comprises a second spring pin (421) arranged on the inner walls of two bearing seats (2), and the sliding hole where the second spring pin (421) is located is connected to the limiting hole (41), and the opposing surfaces of the two sleeves (21) are both provided with a conical block (422), and when the sleeve (21) rotates one circle, the second spring pin (421) is abutted by the cone and can push the first spring pin (4) out of the limiting hole (41).

3. A clamping device for pipe cutting according to claim 1, characterized in that: A lifting platform (5) is provided at an opening in the middle of the frame (1), and a circular saw (51) for cutting metal pipes is provided on the lifting platform (5).

4. A clamping device for pipe cutting according to claim 3, characterized in that: The lifting platform (5) is provided with a gas support (52), the circular saw (51) is located at the telescopic end of the gas support (52), and the outer periphery of the blade of the circular saw (51) is provided with a limiting ring (53) which is coaxial with the circular saw (51) and can be abutted by the metal pipe, and the diameter of the limiting ring (53) is smaller than the diameter of the blade of the circular saw (51).

5. The clamping device for pipe cutting according to claim 1, characterized in that: The clamping assembly (22) comprises three transition rings (221) arranged inside the sleeve (21), wherein the transition ring (221) close to the lifting platform (5) is fixedly connected inside the sleeve (21), and the other two transition rings (221) are axially slidably connected inside the sleeve (21), and a second elastic member (222) and two clamping plates (223) which are rotationally symmetrical at 180 degrees with respect to their own center of circle are arranged between every two adjacent transition rings (221). The clamping plates (223) are hinged between two adjacent transition rings (221) via hinges. The angle between the two clamping plates (223) located in the same sleeve (21) and adjacent in the circumferential direction is ninety degrees. The sleeve (21) is provided with a cylinder (224). The execution end of the cylinder (224) is provided with a pressure ring (225). The transition ring (221) on the side away from the lifting platform (5) is provided with a pressure rod (226) capable of abutting against the pressure ring (225).

6. A clamping device for pipe cutting according to claim 5, characterized in that: A ball (227) is provided on one end of the pressure rod (226) close to the pressure ring (225), and the ball (227) is used to replace the pressure rod (226) to contact the pressure ring (225).

7. The clamping device for pipe cutting according to claim 1, characterized in that: The driving assembly (23) comprises a driving motor (231) arranged on the bearing seat (2) and a transmission shaft (232) axially slidably connected between the two bearing seats (2); large-diameter toothed rings (233) are arranged on the two sleeves (21); the driving motor (231) can drive the large-diameter toothed rings (233) to rotate by means of gear transmission; and the transmission shaft (232) is provided with two transmission gears (234) corresponding to and meshing with the large-diameter toothed rings (233).

8. A clamping device for pipe cutting according to claim 7, characterized in that: A reset assembly (6) is provided between the transmission shaft (232) and the two bearing seats (2), and is used to reset the two bearing seats (2) after the cutting and blanking of the metal pipe is completed.

9. A clamping device for pipe cutting according to claim 8, characterized in that: The reset assembly (6) comprises an axial sliding cavity (61) opened on two bearing seats (2), and an internal threaded ring (62) is axially slidably connected inside the axial sliding cavity (61), and screw rods (63) that can extend into the axial sliding cavity (61) and match the internal threaded ring (62) are provided at both ends of the transmission shaft (232), and the thread directions of the two screw rods (63) are opposite.

10. A clamping device for pipe cutting according to claim 9, characterized in that: Flexible gaskets (64) are provided on the opposite inner side surfaces of the two internal threaded rings (62).

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