Heat exchanger tube number control cutting equipment and high-precision cutting method thereof

Abstract

This invention relates to the field of cutting equipment technology, and proposes a CNC cutting device for heat exchanger tubes and its high-precision cutting method. The device includes a base, on which a first support plate, a second support plate, and a third support plate are arranged along its length. The first support plate is slidably connected to the base, while the second and third support plates are fixed to the base. In this invention, a third driving mechanism precisely controls the rotation of a second turntable. The rotation of the second turntable drives a stop bar to move within a limiting groove, pushing a support to rotate around a third hinge axis. This causes the plasma spray direction of the plasma gun to be tangential to the tube wall. In traditional vertical cutting, after the plasma penetrates one side of the tube wall, a reflecting surface forms on the other side, causing plasma collision. This invention, however, uses tangential angle cutting, causing the plasma beam to spray along the tangential direction, avoiding collision and thus controlling the cutting gap. Compared to traditional methods, this improves cutting accuracy.

Description

Technical Field

[0001] This invention relates to the field of cutting equipment technology, specifically to CNC cutting equipment for heat exchanger tubes and its high-precision cutting method. Background Technology

[0002] Heat exchanger tubes are the core heat transfer elements in a heat exchanger, typically composed of multiple parallel metal tubes (such as stainless steel, copper, titanium, etc.) used for heat exchange between two fluids. The production of heat exchanger tubes involves cutting long tubes into multiple sections using cutting equipment to meet specific application requirements.

[0003] A search revealed that CN104526139A discloses a cutting device for heat exchanger tubes, comprising a servo motor, belt, support shaft, pulley, magnet, transmission belt, tube to be processed, right pulley, plasma cutting device, bracket, cutting fluid pipe, cutting fluid tank, and machine body. The servo motor is located at the left end of the machine body and is connected to the left pulley via a belt. The left pulley is fixed to the left end of the machine body via the support shaft. The left pulley is connected to the right pulley via the transmission belt. Magnets are provided on the surface of the transmission belt. A bracket is located on the right side of the right pulley and is welded to the machine body. The plasma cutting device is mounted on the machine frame. This cutting device uses plasma cutting to cut the tube to be processed, avoiding deformation of the tube due to the cutting force and ensuring the quality of the tube.

[0004] However, the aforementioned heat exchanger tube cutting device still has the following problem: the plasma spray gun structure of the aforementioned heat exchanger tube cutting device is directly facing the center of the tubes, such as... Figure 9 As shown, when the side of the tube closest to the jet direction is pierced, the inner wall of the other side of the tube forms a reflective surface against the jet direction, which in turn deflects the plasma ejected by the spray gun in the opposite direction, thereby widening the cutting gap of the tube, reducing the cutting accuracy and affecting the cutting quality.

[0005] This invention adjusts the spray direction of the spray gun so that the spray direction is tangential to the tube. Figure 10 As shown in the figure, the tube is then centered and clamped by the clamping mechanism, which drives the tube to rotate circumferentially to complete the cutting. This avoids the inner wall of the tube from forming a reflective surface on the direction of the jet after penetration, thereby reducing the tube cutting gap and improving the cutting accuracy. Summary of the Invention

[0006] This invention proposes a CNC cutting device for heat exchanger tubes and its high-precision cutting method, which solves the problem in the prior art where the inner wall of the tube forms a reflective surface against the jet direction after penetration, causing the tube cutting gap to widen and resulting in reduced cutting accuracy.

[0007] The technical solution of the present invention is as follows: a CNC cutting equipment for heat exchanger tubes, including a base, on which a first support plate, a second support plate and a third support plate are provided along its length direction. The first support plate is slidably connected to the base, and the second support plate and the third support plate are both fixed to the base. A first driving mechanism is provided between the first support plate and the second support plate for driving the first support plate to slide horizontally relative to the second support plate. The first support plate has several annularly distributed stepped holes on the side facing the second support plate; The second support plate is provided with a first turntable, a number of clamping mechanisms arranged in a ring around the first turntable, and a second drive mechanism that drives the clamping mechanisms to clamp the passing tubes by driving the first turntable to rotate. The third support plate is provided with a second turntable, several cutting mechanisms arranged in a ring around the second turntable, and a third drive mechanism that adjusts the cutting direction of the cutting mechanism by driving the second turntable to be tangent to the tube. The third support plate has several through holes that are alternately arranged with the third drive mechanism. The through holes coincide with the stepped holes, the clamping mechanism and the shaft. After the clamping mechanism centers and clamps the tube, it can drive the tube to rotate circumferentially under the drive of the second drive mechanism.

[0008] Preferably, the first drive mechanism includes a first servo motor, which is fixed to a second support plate, and the output shaft end of the first servo motor is fixed with a lead screw that is threadedly engaged with the first support plate.

[0009] Preferably, the first turntable is rotatably connected to the second support plate, and the circumferential surface of the first turntable is provided with a first tooth segment corresponding to the clamping mechanism and a second tooth segment corresponding to the second driving mechanism. The second turntable is rotatably connected to the third support plate, and the circumferential surface of the second turntable is provided with a fourth tooth segment corresponding to the third drive mechanism.

[0010] Preferably, the second drive mechanism includes a second servo motor, the second servo motor is fixed to the second support plate, and the output shaft end of the second servo motor is fixed with a first drive gear that meshes with the second tooth segment; The third drive mechanism includes a third servo motor, which is fixed to a third support plate. The output shaft of the third servo motor is fixed with a second drive gear that meshes with the fourth tooth segment.

[0011] Preferably, the clamping mechanism includes an outer rotating ring, an inner rotating ring located within the outer rotating ring, a centering clamping assembly of a triangular array, and an elastic traction member that elastically connects the inner rotating ring to the outer rotating ring. The inner rotating ring drives the centering clamping assembly of the triangular array to center and clamp the tube under the transmission of the first turntable.

[0012] Preferably, the outer rotating ring is rotatably connected to the second support plate, and the outer rotating ring has a first opening facing the first turntable and a second opening for accommodating the elastic traction member, and a friction sleeve is fitted on the outer circumferential surface of the outer rotating ring; The outer circumferential surface of the inner rotating ring is provided with a third tooth segment, and the first tooth segment meshes with the third tooth segment through a first through-hole. The inner circumferential surface of the inner rotating ring is provided with movable grooves that correspond to the centering clamping components.

[0013] Preferably, the centering clamping assembly includes two curved arms, with a first hinge shaft, a second hinge shaft, and a pressure roller fixed between the two curved arms. The first hinge shaft is hinged to an outer rotating ring, and the hinge hole between the outer rotating ring and the first hinge shaft is an oblong hole. The second hinge shaft is hinged to an inner rotating ring. The pressure roller can move within a movable groove, and a number of evenly distributed protrusions are provided on the circumferential surface of the pressure roller.

[0014] Preferably, the elastic traction component includes a first hanging rod, a second hanging rod, and a tension spring. The first hanging rod is fixed inside the second opening of the outer rotating ring, the second hanging rod is fixed on the outer circumferential surface of the inner rotating ring, and the two ends of the tension spring are hooked onto the first hanging rod and the second hanging rod, respectively.

[0015] Preferably, the cutting mechanism includes a support, a plasma spray gun, a third hinge shaft, and a stop bar. The support is rotatably connected to a third support plate via the third hinge shaft. The plasma spray gun is fixed to the outer side of the support. The stop bar is fixed to a second turntable. The support has a limiting groove for limiting the stop bar.

[0016] Based on the aforementioned CNC cutting equipment for heat exchanger tubes, this invention also proposes a high-precision cutting method for heat exchanger tubes, comprising the following steps: Step 1: Pass one end of the multiple tubes to be cut through the through hole into the clamping mechanism and place them in the stepped hole; Step two: The first turntable is driven to rotate by the second drive mechanism, and the first turntable drives the clamping mechanism to center and clamp the passing tubes. Step 3: The first support plate is driven to slide horizontally towards the second support plate by the first drive mechanism. The first support plate pushes multiple tubes to extend beyond the third support plate and maintains a fixed length. Step four: The second turntable is driven to rotate by the third drive mechanism, and the second turntable drives each cutting mechanism to rotate synchronously, thereby adjusting the cutting direction of the cutting mechanism to be tangent to the tube. The cutting mechanism, together with the clamping mechanism, performs plasma cutting by rotating and clamping the tube. Step 5: After the section of tubes located outside the third support plate is cut, the first drive mechanism drives the first support plate to continue sliding horizontally towards the second support plate. The first support plate pushes multiple tubes simultaneously to extend beyond the third support plate and maintains a fixed length. Then, the cutting mechanism, in conjunction with the clamping mechanism, rotates and clamps the tubes to perform the next stage of plasma cutting. Step six: Repeat step five until the segmented cutting process of the entire tube is completed.

[0017] The beneficial effects of this invention are as follows: In this invention, the rotation of the second turntable is precisely controlled by the third drive mechanism (third servo motor + second drive gear). The rotation of the second turntable drives the stop bar to move in the limiting groove, which in turn drives the support to rotate around the third hinge axis. This makes the spray direction of the plasma spray gun tangential to the tube wall. In traditional vertical cutting, after the plasma penetrates one side of the tube wall, the inner wall on the other side will form a reflective surface, causing plasma collision. However, this invention cuts at a tangential angle, so that the plasma beam is sprayed along the tangential direction, avoiding the collision phenomenon, thereby controlling the cutting gap and improving the cutting accuracy compared to the traditional method. In this invention, stepped holes are arranged in a ring on the first support plate, clamping mechanisms are arranged in a ring on the second support plate, and cutting mechanisms are arranged in a ring on the third support plate. The first drive mechanism drives the first support plate to push all tubes synchronously through the lead screw, the second drive mechanism controls all clamping mechanisms synchronously through the first turntable, and the third drive mechanism adjusts the angle of all cutting mechanisms synchronously through the second turntable. This enables the simultaneous positioning, clamping, and cutting of multiple tubes. This invention employs a triangular array centering clamping assembly. The circumferential surface of the pressure rollers is provided with protrusions to increase friction. Automatic centering is achieved by the inner rotating ring driving the three pressure rollers to move synchronously towards the center. Initially, the outer rotating ring remains stationary due to the friction sleeve, while the inner rotating ring rotates to clamp the tubes. After clamping, the outer rotating ring overcomes friction and rotates synchronously with the inner rotating ring, causing the tubes to rotate. An elastic traction element (tension spring) provides a constant clamping force, preventing excessive tightness that could lead to deformation. Attached Figure Description

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] Figure 1 This is a schematic diagram of the structure of the CNC cutting equipment for heat exchanger tubes proposed in this invention; Figure 2This is a front view schematic diagram of the CNC cutting equipment for heat exchanger tubes proposed in this invention; Figure 3 This is a schematic diagram of the structure of the first turntable, clamping mechanism and the second driving mechanism proposed in this invention; Figure 4 This is a schematic diagram of the first turntable and the second drive mechanism proposed in this invention; Figure 5 This is a schematic diagram of the clamping mechanism structure proposed in this invention; Figure 6 This is an exploded view of the clamping mechanism proposed in this invention; Figure 7 This is a schematic diagram of the second turntable, cutting mechanism, and third drive mechanism proposed in this invention; Figure 8 This is a schematic diagram of the cutting mechanism structure proposed in this invention; Figure 9 This is a schematic diagram of the cutting direction of a plasma spray gun on a tube in the existing technology. Figure 10 This is a schematic diagram of the cutting direction of the plasma spray gun on the tube in this invention; Figure 11 This is a schematic diagram of a high-precision cutting method proposed in this invention; In the diagram: 1. First support plate; 11. Stepped hole; 2. Second support plate; 3. Third support plate; 31. Through hole; 4. First drive mechanism; 41. First servo motor; 42. Lead screw; 5. First turntable; 51. First tooth segment; 52. Second tooth segment; 6. Clamping mechanism; 61. Outer rotating ring; 611. First through port; 612. Second through port; 613. Friction sleeve; 62. Inner rotating ring; 621. Third tooth segment; 622. Movable groove; 63. Centering clamping assembly; 631. Bent arm; 632. First hinge shaft 633, Second hinge shaft; 634, Pressure roller; 635, Protrusion; 64, Elastic traction component; 641, First hanging rod; 642, Second hanging rod; 643, Tension spring; 7, Second drive mechanism; 71, Second servo motor; 72, First drive gear; 8, Second turntable; 81, Fourth tooth segment; 9, Cutting mechanism; 91, Support; 92, Plasma spray gun; 93, Third hinge shaft; 94, Stop bar; 95, Limiting groove; 10, Third drive mechanism; 101, Third servo motor; 102, Second drive gear. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1 and Figure 2 This invention provides a technical solution: a CNC cutting device for heat exchanger tubes, including a base. A first support plate 1, a second support plate 2, and a third support plate 3 are arranged on the base along its length. The first support plate 1 is slidably connected to the base, while the second support plate 2 and the third support plate 3 are both fixed to the base. A first driving mechanism 4 is provided between the first support plate 1 and the second support plate 2 to drive the first support plate 1 to slide horizontally relative to the second support plate 2. The side of the first support plate 1 facing the second support plate 2 has several annularly distributed stepped holes 11. The second support plate 2 is provided with a first turntable 5, several clamping mechanisms 6 arranged annularly around the first turntable 5, and a second driving mechanism 7 that drives the clamping mechanisms 6 to clamp the passing tubes by driving the first turntable 5 to rotate. The third support plate 3 is provided with a second turntable 8, several cutting mechanisms 9 arranged annularly around the second turntable 8, and a... The third drive mechanism 10, which drives the second turntable 8 to rotate and adjusts the cutting direction of the cutting mechanism 9 to be tangent to the tubes, has several through holes 31 on the third support plate 3 that are alternately arranged with the third drive mechanism 10. The through holes 31, the stepped holes 11, the clamping mechanism 6 and the axis are coincident. After the clamping mechanism 6 centers and clamps the tubes, it can drive the tubes to rotate circumferentially under the drive of the second drive mechanism 7. By opening the stepped holes 11 in a ring on the first support plate 1, setting the clamping mechanism 6 in a ring on the second support plate 2, and setting the cutting mechanism 9 in a ring on the third support plate 3, the first drive mechanism 4 drives the first support plate 1 to push all the tubes synchronously through the lead screw 42, the second drive mechanism 7 controls all the clamping mechanisms 6 synchronously through the first turntable 5, and the third drive mechanism 10 adjusts the angle of all the cutting mechanisms 9 synchronously through the second turntable 8. This enables the simultaneous positioning, clamping and cutting of multiple tubes.

[0022] Please see Figure 1 The first drive mechanism 4 includes a first servo motor 41, which is fixed on the second support plate 2. The output shaft end of the first servo motor 41 is fixed with a lead screw 42 that is threadedly engaged with the first support plate 1. The first servo motor 41 controls the tube advance length.

[0023] Please see Figure 3 and Figure 4 The first turntable 5 is rotatably connected to the second support plate 2. The circumferential surface of the first turntable 5 is provided with a first tooth segment 51 corresponding to the clamping mechanism 6 and a second tooth segment 52 corresponding to the second drive mechanism 7. Please see Figure 1 and Figure 7The second turntable 8 is rotatably connected to the third support plate 3, and the circumferential surface of the second turntable 8 is provided with a fourth tooth segment 81 corresponding to the third drive mechanism 10.

[0024] Please see Figure 3 and Figure 4 The second drive mechanism 7 includes a second servo motor 71, which is fixed to the second support plate 2. The output shaft end of the second servo motor 71 is fixed with a first drive gear 72 that meshes with the second tooth segment 52. The second servo motor 71 controls the clamping and rotation speed.

[0025] Please see Figure 7 The third drive mechanism 10 includes a third servo motor 101, which is fixed to the third support plate 3. The output shaft end of the third servo motor 101 is fixed with a second drive gear 102 that meshes with the fourth tooth segment 81. The third servo motor 101 controls the cutting angle.

[0026] Please see Figure 5 and Figure 6The clamping mechanism 6 includes an outer rotating ring 61, an inner rotating ring 62 located within the outer rotating ring 61, a centering clamping assembly 63 of a triangular array, and an elastic traction member 64 that elastically connects the inner rotating ring 62 to the outer rotating ring 61. Under the transmission of the first turntable 5, the inner rotating ring 62 drives the centering clamping assembly 63 of the triangular array to center and clamp the tubes. The outer rotating ring 61 is rotatably connected to the second support plate 2. The outer rotating ring 61 has a first opening 611 facing the first turntable 5 and a second opening 612 for accommodating the elastic traction member 64. A friction sleeve 613 is fitted on the outer circumferential surface of the outer rotating ring 61. The outer circumferential surface of the inner rotating ring 62 is provided with a third tooth segment 621. The first tooth segment 51 meshes with the third tooth segment 621 through the first through-hole 611. The inner circumferential surface of the inner rotating ring 62 is provided with movable grooves 622 corresponding to the centering clamping assembly 63. The centering clamping assembly 63 includes two bent arms 631. A first hinge shaft 632, a second hinge shaft 633, and a pressure roller 634 are fixed between the two bent arms 631. The first hinge shaft 632 is hinged to the outer rotating ring 61, and the hinge hole between the outer rotating ring 61 and the first hinge shaft 632 is an oblong hole. The first hinge shaft 632 adopts an oblong hole design. The design allows for a certain degree of floating. The second hinge pin 633 is hinged to the inner rotating ring 62. The pressure roller 634 can move within the movable groove 622, which provides space for the pressure roller 634 to accommodate the clamping requirements of tubes of different diameters. The circumferential surface of the pressure roller 634 has several evenly distributed protrusions 635. The elastic traction member 64 includes a first hanging rod 641, a second hanging rod 642, and a tension spring 643. The first hanging rod 641 is fixed within the second opening 612 of the outer rotating ring 61, and the second hanging rod 642 is fixed to the outer circumferential surface of the inner rotating ring 62. The tension spring 643... The two ends are hooked onto the first hanging rod 641 and the second hanging rod 642 respectively. A centering clamping assembly 63 with a triangular array is used. The circumferential surface of the pressure roller 634 is provided with protrusions 635 to increase friction. Automatic centering is achieved by driving the three pressure rollers to move synchronously towards the center through the inner rotating ring 62. In the initial stage: the outer rotating ring 61 is kept stationary by the friction sleeve 613, and the inner rotating ring 62 rotates to make the pressure roller 634 clamp the tube. After clamping: the outer rotating ring 61 overcomes the friction and rotates synchronously with the inner rotating ring 62, driving the tube to rotate. The elastic traction member 64 (tension spring 643) provides a constant clamping force to avoid deformation caused by excessive tightness.

[0027] Please see Figure 7 and Figure 8The cutting mechanism 9 includes a support 91, a plasma spray gun 92, a third hinge shaft 93, and a stop bar 94. The support 91 is rotatably connected to the third support plate 3 via the third hinge shaft 93. The plasma spray gun 92 is fixed to the outer side of the support 91. The stop bar 94 is fixed to the second turntable 8. The support 91 is provided with a limiting groove 95 for limiting the stop bar 94. The second turntable 8 is precisely controlled to rotate by the third drive mechanism (third servo motor 101 + second drive gear 102). The rotation of the second turntable 8 drives the stop bar 94 to move in the limiting groove 95, pushing the support 91 to rotate around the third hinge shaft 93, so that the spray direction of the plasma spray gun 92 is tangential to the tube wall.

[0028] like Figure 11 As shown, based on the above-mentioned CNC cutting equipment for heat exchanger tubes, this invention also proposes a high-precision cutting method for heat exchanger tubes, comprising the following steps: Step 1: Pass one end of the multiple tubes to be cut through the through hole 31 through the clamping mechanism 6 and place them in the stepped hole 11; Step 2: The first turntable 5 is driven to rotate by the second drive mechanism 7, and the first turntable 5 drives the clamping mechanism 6 to center and clamp the passing tubes. Step 3: The first support plate 1 is driven by the first drive mechanism 4 to slide horizontally towards the second support plate 2, and the first support plate 1 pushes multiple tubes to extend out of the third support plate 3 at the same time and maintains a fixed length. Step four: The second turntable 8 is driven to rotate by the third drive mechanism 10, and the second turntable 8 drives each cutting mechanism 9 to rotate synchronously, thereby adjusting the cutting direction of the cutting mechanism 9 to be tangent to the tube column. The cutting mechanism 9, together with the clamping mechanism 6, performs plasma cutting by rotating and clamping the tube column. Step 5: After the section of tubes located outside the third support plate 3 is cut, the first drive mechanism 4 drives the first support plate 1 to continue sliding horizontally towards the second support plate 2. The first support plate 1 pushes multiple tubes simultaneously to extend beyond the third support plate 3 and maintains a fixed length. Then, the cutting mechanism 9, in conjunction with the clamping mechanism 6, rotates and clamps the tubes to perform the next stage of plasma cutting. Step six: Repeat step five until the segmented cutting process of the entire tube is completed.

[0029] The working principle of this invention is as follows: After one end of the tube to be cut is passed through the through hole 31 through the clamping mechanism 6 and placed in the stepped hole 11, the second servo motor 71 works. Under the meshing of the first drive gear 72 and the second tooth segment 52, the first turntable 5 rotates. Under the meshing of the first tooth segment 51 and the third tooth segment 621 of each clamping mechanism 6, the inner rotating ring 62 is driven to overcome the elastic force of the elastic traction member 64 and rotate. In the initial stage, due to the friction of the friction sleeve 613, the outer rotating ring 61 is subjected to frictional resistance much greater than the elastic pulling force of the elastic traction member 64 on the outer rotating ring 61. That is, the outer rotating ring 61 remains stationary relative to the second support plate 2. Then, the hinge action of the first hinge shaft 632 and the second hinge shaft 633 with the outer rotating ring 61 and the inner rotating ring 62 respectively can drive the three sets of bent arms 631 to swing synchronously until the three pressure rollers 634 center and clamp the tube. After clamping, the first servo motor 41 drives the lead screw 42. With the threaded engagement between the lead screw 42 and the first support plate 1, and the sliding guide of the slide rail on the base on the first support plate 1, the first support plate 1 can be driven to move towards the second support plate 2. Then, the first support plate 1 pushes multiple tubes through the through hole 31 to extend out of the third support plate 3 and maintains a fixed length. Then, the third servo motor 101 drives the second drive gear 102. The second drive gear 102 meshes with the fourth tooth segment 81, driving the second turntable 8 to rotate on the third support plate 3. Through the movement of the stop bar 94 in the limiting groove 95, it can push each support 91 to rotate synchronously around the third hinge shaft 93 until the spray direction of the plasma spray gun 92 is tangent to the tube wall. Then, the second servo motor 71 continues to work to drive the first turntable 5 to rotate. Since the pressure roller 634 is in contact with the tube, the bent arm 631 can no longer swing relative to the outer rotating ring 61. At this time, the outer rotating ring 61 can overcome the friction between the friction sleeve 613 and the hole of the second support plate 2 and rotate synchronously with the inner rotating ring 62. In turn, it carries the tube held by the three pressure rollers 634 to rotate circumferentially, thereby cooperating with the plasma spray gun 92 to complete the plasma cutting of the tube.

[0030] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A heat exchanger tube numerical control cutting device, comprising a base, characterized in that, The base is provided with a first support plate (1), a second support plate (2), and a third support plate (3) along its length. The first support plate (1) is slidably connected to the base, and the second support plate (2) and the third support plate (3) are both fixed to the base. A first driving mechanism (4) is provided between the first support plate (1) and the second support plate (2) for driving the first support plate (1) to slide horizontally relative to the second support plate (2); a plurality of annularly distributed stepped holes (11) are provided on the side of the first support plate (1) facing the second support plate (2). The second support plate (2) is provided with a first turntable (5), a number of clamping mechanisms (6) arranged in a ring around the first turntable (5), and a second drive mechanism (7) that drives the clamping mechanisms (6) to clamp the passing tubes by driving the first turntable (5) to rotate. The third support plate (3) is provided with a second turntable (8), several cutting mechanisms (9) arranged in a ring around the second turntable (8), and a third drive mechanism (10) that adjusts the cutting direction of the cutting mechanism (9) by driving the second turntable (8) to be tangent to the tube. The first turntable (5) is rotatably connected to the second support plate (2). The circumferential surface of the first turntable (5) is provided with a first tooth segment (51) corresponding to the clamping mechanism (6) and a second tooth segment (52) corresponding to the second driving mechanism (7). The second turntable (8) is rotatably connected to the third support plate (3). The circumferential surface of the second turntable (8) is provided with a fourth tooth segment (81) corresponding to the third driving mechanism (10). The clamping mechanism (6) includes an outer rotating ring (61), an inner rotating ring (62) located inside the outer rotating ring (61), a centering clamping assembly (63) of a triangular array, and an elastic traction member (64) that elastically connects the inner rotating ring (62) to the outer rotating ring (61). The inner rotating ring (62) drives the centering clamping assembly (63) of the triangular array to center and clamp the tube under the transmission of the first turntable (5). The outer rotating ring (61) is rotatably connected to the second support plate (2), and the outer rotating ring (61) has an opening facing the first turntable. (5) has a first opening (611) and a second opening (612) for accommodating the elastic traction member (64). A friction sleeve (613) is fitted on the outer circumferential surface of the outer rotating ring (61). A third tooth segment (621) is provided on the outer circumferential surface of the inner rotating ring (62). The first tooth segment (51) meshes with the third tooth segment (621) through the first opening (611). An active groove (622) corresponding to the centering clamping assembly (63) is opened on the inner circumferential surface of the inner rotating ring (62). The second drive mechanism (7) includes a second servo motor (71), which is fixed to the second support plate (2). The output shaft end of the second servo motor (71) is fixed with a first drive gear (72) that meshes with the second tooth segment (52). The third drive mechanism (10) includes a third servo motor (101), which is fixed to the third support plate (3). The output shaft end of the third servo motor (101) is fixed with a second drive gear (102) that meshes with the fourth tooth segment (81). The third support plate (3) has several through holes (31) that are alternately arranged with the third drive mechanism (10). The through holes (31) coincide with the axis of the stepped hole (11) and the clamping mechanism (6). After the clamping mechanism (6) centers and clamps the tube, it can drive the tube to rotate circumferentially under the drive of the second drive mechanism (7).

2. The heat exchanger tube numerical control cutting device according to claim 1, characterized in that, The first drive mechanism (4) includes a first servo motor (41), which is fixed on the second support plate (2). The output shaft end of the first servo motor (41) is fixed with a lead screw (42) that is threadedly engaged with the first support plate (1).

3. The CNC cutting equipment for heat exchanger tubes according to claim 1, characterized in that, The centering clamping assembly (63) includes two curved arms (631), and a first hinge shaft (632), a second hinge shaft (633), and a pressure roller (634) are fixed between the two curved arms (631). The first hinge shaft (632) is hinged to the outer rotating ring (61), and the hinge hole between the outer rotating ring (61) and the first hinge shaft (632) is an oblong hole. The second hinge shaft (633) is hinged to the inner rotating ring (62). The pressure roller (634) can move in the movable groove (622). The circumferential surface of the pressure roller (634) is provided with a number of evenly distributed protrusions (635).

4. The CNC cutting equipment for heat exchanger tubes according to claim 1, characterized in that, The elastic traction member (64) includes a first hanging rod (641), a second hanging rod (642), and a tension spring (643). The first hanging rod (641) is fixed inside the second opening (612) of the outer rotating ring (61), and the second hanging rod (642) is fixed on the outer circumferential surface of the inner rotating ring (62). The two ends of the tension spring (643) are hooked onto the first hanging rod (641) and the second hanging rod (642) respectively.

5. The CNC cutting equipment for heat exchanger tubes according to claim 1, characterized in that, The cutting mechanism (9) includes a support (91), a plasma spray gun (92), a third hinge (93), and a stop rod (94). The support (91) is rotatably connected to the third support plate (3) through the third hinge (93). The plasma spray gun (92) is fixed to the outer side of the support (91). The stop rod (94) is fixed on the second turntable (8). The support (91) is provided with a limiting groove (95) for limiting the stop rod (94).

6. A high-precision cutting method for heat exchanger tubes, using the CNC cutting equipment for heat exchanger tubes as described in claim 5, characterized in that, Includes the following steps: Step 1: Pass one end of the multiple tubes to be cut through the through hole (31) through the clamping mechanism (6) and place it in the stepped hole (11); Step 2: The first turntable (5) is driven to rotate by the second drive mechanism (7), and the clamping mechanism (6) drives the passing tube to center and clamp it. Step 3: The first support plate (1) is driven to slide horizontally towards the second support plate (2) by the first drive mechanism (4), and the first support plate (1) pushes multiple tubes to extend out of the third support plate (3) at the same time and maintains a fixed length. Step 4: The second turntable (8) is driven to rotate by the third drive mechanism (10), and the second turntable (8) drives each cutting mechanism (9) to rotate synchronously, thereby adjusting the cutting direction of the cutting mechanism (9) to be tangent to the tube. The cutting mechanism (9) cooperates with the clamping mechanism (6) to perform plasma cutting by rotating and clamping the tube. Step 5: After the section of tubes located outside the third support plate (3) is cut, the first drive mechanism (4) drives the first support plate (1) to continue sliding horizontally towards the second support plate (2). The first support plate (1) pushes multiple tubes to extend beyond the third support plate (3) and maintains a fixed length. Then, the cutting mechanism (9) cooperates with the clamping mechanism (6) to rotate and clamp the tubes for the next stage of plasma cutting. Step six: Repeat step five until the segmented cutting process of the entire tube is completed.

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