A pipe laser cutting machine and cutting method

Abstract

This invention relates to the field of laser cutting technology, and provides a tube laser cutting machine and cutting method, including a frame, a clamping mechanism mounted on the frame for clamping the tube, and a laser cutting head located on one side of the clamping mechanism; a lifting platform mounted on the frame and located below the clamping mechanism; a support cam rotatably mounted on the lifting platform, which can move closer to or further away from the clamping mechanism under the lifting action of the lifting platform; a support groove extending circumferentially on the outer peripheral surface of the support cam, the projection of the support groove in the vertical section where the rotation axis is located is an arc-shaped groove; the inner diameter of the support groove gradually decreases along the extension direction, so that the inner diameter of the support groove at the top of the support cam gradually decreases when the support cam rotates. The tube laser cutting machine provided by this invention utilizes the continuous arc surface of the support groove to form a covering support under the tube and adapt to different tube diameters, realizing continuous and uniform load-bearing on the middle section of the tube and reducing the deflection deformation of the tube.

Description

Technical Field

[0001] This invention relates to the field of laser cutting technology, specifically to a tube laser cutting machine and cutting method. Background Technology

[0002] In laser cutting of long tubes, in order to reduce the bending deformation of the tube under its own weight, the tube is usually clamped by chucks at both ends, and several intermediate support devices are arranged between the two chucks.

[0003] Currently, common intermediate support devices mostly adopt structures such as opposing rollers, idlers, and V-blocks. Their support method for pipes is essentially to form multiple discrete point contacts in the circumferential direction in a certain area of ​​the middle section of the pipe. They can only form multiple point contacts in the circumferential direction to constrain the pipe, and cannot provide uniform and continuous circumferential load in a certain area of ​​the pipe.

[0004] Under these multi-point contact support conditions, the pipe is also prone to flexural deformation and vibration within the support span due to the combined effects of the bending moment caused by its own weight, the centrifugal force generated by the rotation of the chuck, and the impact reaction force of the auxiliary cutting gas on the pipe wall. Deformation and vibration can cause a dynamic shift in the relative position between the laser focus and the surface of the pipe to be cut, directly reducing the accuracy of the cutting trajectory, resulting in a rough cut surface, slag buildup, or even dimensional deviations, thus affecting the quality of the cut surface. Summary of the Invention

[0005] To overcome the above-mentioned defects, embodiments of the present invention provide a tube laser cutting machine and cutting method, which solves the technical problem in the prior art where, when long tubes are clamped by chucks at both ends, the intermediate support device can only provide multiple point contact support for the middle section of the tube in the circumferential direction, and cannot form a uniform circumferential load in a certain area. This causes the tube to bend and deform under its own weight, rotational centrifugal force and auxiliary airflow, thereby affecting the cutting accuracy and cross-sectional quality.

[0006] At least one embodiment of the present invention provides a tube laser cutting machine, comprising: The machine frame has a movable clamping mechanism for holding both ends of a tube and a laser cutting head located at one end of the clamping mechanism. The clamping mechanism can move one end of the tube closer to the laser cutting head. A lifting platform is mounted on the frame and positioned below the clamping mechanism. A support cam is rotatably mounted on the lifting platform to support the pipe below, and a locking mechanism is provided between the support cam and the lifting platform; The outer circumferential surface of the support cam is provided with an arc-shaped support groove, and the inner diameter of the support groove gradually decreases along the circumference of the support cam so that the support groove can be adapted to pipes of different sizes.

[0007] According to one embodiment provided in this application, the depth of the support groove gradually decreases along the direction in which the inner diameter of the support groove gradually decreases, so that when any region of the support groove is located in the longitudinal section of the support cam axis, its center is at the same height, thereby making the axes of pipes with different diameters located at the same height.

[0008] According to one embodiment of this application, the outer peripheral surface of the support cam is further provided with an initial overlapping groove, which is connected to the large diameter end of the support groove. The initial overlapping groove is configured to be located at the top of the support cam in the initial state for initially supporting the pipe material.

[0009] According to one embodiment of this application, the lifting platform is further provided with a centering mechanism located on one side of the supporting cam, the centering mechanism comprising: Two swing arms are symmetrically arranged on the lifting platform and rotate in coordination with the lifting platform; Two abutting rollers are rotatably mounted on the free ends of the two swing arms, and are used to synchronously abut against both sides of the pipe to center the pipe.

[0010] According to one embodiment of this application, the outer periphery of the hinged ends of the two swing arms is provided with first teeth. A horizontally extending sliding rod is slidably disposed on the lifting platform to drive the swing arms. The sliding rod is located between the two swing arms. The two sides of the sliding rod are respectively provided with second teeth that mesh with the first teeth. The sliding rod can slide axially to drive the swing arms on both sides to swing synchronously.

[0011] According to one embodiment of this application, the clamping mechanism includes: A clamping chuck is located at one end of the frame and is used to slide and engage with the outer periphery of one end of the pipe. A feed chuck is slidably mounted on the frame to hold the other end of the tube. The feed chuck can slide towards the side of the clamping chuck to drive the tube to feed towards the side of the laser cutting head. The feed chuck can slide through the inner cavity of the clamping chuck to bring the pipe tail material closer to the laser cutting head.

[0012] According to one embodiment of this application, the clamping chuck is slidably disposed on the frame so that the laser cutting head is slidable to the side away from the feed chuck, so that the laser cutting head can cut the tail material clamped between the clamping chuck and the feed chuck.

[0013] According to one embodiment provided in this application, the rack is further provided with: The support frame is raised and lowered on the frame. The support frame can rise to receive the pipes delivered from the outside and fall to unload the pipes into the support groove of the support cam for clamping by the clamping mechanism. A lifting drive component is mounted on the frame and is driven to connect with the support frame, used to drive the support frame to lift.

[0014] According to one embodiment of this application, the support bracket has a support surface for contacting the pipe; a feeding detection rod is hinged to the support bracket, and the middle part of the feeding detection rod is oscillatingly connected to one end of the support bracket; The feeding detection rod has a detection end extending towards the center of the support surface and an extension end extending towards the lower outer side of the support frame. The extension end is provided with a counterweight. The detection end is configured to swing upward under the action of the counterweight until it protrudes from the support surface, and swing to be flush with the support surface under the downward pressure of the pipe. The support frame is provided with a detection sensor located below the detection end. The detection sensor is used to detect the swing position signal of the detection end and send it to the controller.

[0015] According to another aspect, at least one embodiment of the present invention also provides a method for laser cutting of pipes, using a pipe laser cutting machine, comprising the following steps: S1. Place the pipe to be cut into the support groove from top to bottom; S2. Rotate the support cam so that the inner diameter of the support groove matches the outer diameter of the pipe to support the lower outer periphery of the pipe. S3. The pipe is clamped by the clamping mechanism and fed along its axial direction to one side of the laser cutting head; S4. The pipe is laser-cut using the laser cutting head.

[0016] The present invention provides a tube laser cutting machine and cutting method. Compared with the prior art, the support groove extending in the circumferential direction is opened on the outer peripheral surface of the support cam. The support groove is projected as an arc-shaped groove in the vertical section. This structure makes the lower outer periphery of the tube form a continuous arc surface contact with the inner wall of the support groove.

[0017] This continuous contact method replaces the discrete point contact formed by V-blocks or rollers in existing technologies, eliminating the unsupported suspended arc segment of the pipe circumferentially. The pipe wall is constrained by the groove wall at all points within the contact arc segment. During cutting, when the pipe is subjected to its own weight, the centrifugal force of the chuck rotation, and the impact force of the auxiliary cutting gas, the supporting force of the support groove is evenly distributed along the contact arc segment. The flexural deformation of the pipe within the support span is continuously limited by the groove wall. The inner diameter of the support groove gradually decreases along the extension direction. When the support cam rotates, the inner diameter of the support groove at the top changes accordingly. Pipes of different outer diameters can form an arc surface fit with the corresponding inner diameter groove segment. A single support cam can cover multiple pipe diameter specifications without the need to replace the support element. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a tube laser cutting machine provided in an embodiment of the present invention; Figure 2 This is an embodiment of the present invention. Figure 1 Schematic diagram of the middle lifting platform; Figure 3 This is an embodiment of the present invention. Figure 1 A cross-sectional structural diagram of the central lifting platform; Figure 4 This is an embodiment of the present invention. Figure 1 Another structural diagram of a laser cutting machine; Figure 5 for Figure 4 Enlarged view of point A in the middle; Figure 6 for Figure 1 Enlarged view of section B in the middle.

[0020] In the diagram: 1. Frame, 2. Clamping mechanism, 3. Laser cutting head, 4. Lifting platform, 5. Support cam, 51. Support groove, 52. Initial overlap groove, 6. Centering mechanism, 61. Swing arm, 62. Abutting roller, 611. First tooth, 63. Sliding rod, 631. Second tooth, 21. Clamping chuck, 22. Feeding chuck, 7. Support bracket, 71. Supporting surface, 8. Feeding detection rod, 81. Counterweight, 9. Detection sensor. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0024] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those illustrated or described herein.

[0025] To make the drawings concise and easy to understand, some drawings only show one of the components with the same structure or function, or only one of them is marked. In this article, "one" not only means "only one", but can also mean "more than one", and "several" includes "two" and "more than two".

[0026] Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. The embodiments of this application are described in detail below with reference to the accompanying drawings.

[0027] This application relates to the field of laser cutting technology, specifically to a tube laser cutting machine and a tube laser cutting method. In the laser cutting of long tubes, the tube is usually held horizontally between chucks at both ends, and the laser cutting head cuts the tube wall along the radial direction. Under the combined action of its own weight, the centrifugal force generated by the rotation of the chucks, and the impact reaction force of the auxiliary cutting gas on the tube wall, the tube will undergo flexural deformation and vibration in the suspended section between the two chucks. Flexural deformation causes a dynamic shift in the relative position between the laser focus and the surface of the tube to be cut. The focal depth of laser cutting is usually only on the order of millimeters (e.g., 0.5mm to 2mm). If the downward deflection of the middle section of the tube exceeds half of the focal depth, the laser power density at the top and bottom of the cut will differ, resulting in uneven surface roughness, slag buildup at the bottom, or even incomplete cutting in some areas. Vibration causes the laser focus to generate high-frequency micro-oscillations on the tube surface, resulting in wavy undulations at the cut edge, affecting the perpendicularity and dimensional accuracy of the cut surface.

[0028] In laser cutting of long tubes, the role of the intermediate support device is to provide additional support for the middle section of the tube between the two end chucks, reducing the suspended span of the tube and thus reducing deflection and vibration amplitude. Currently, common intermediate support devices often employ structures such as opposing rollers, idlers, or V-blocks. Their support method involves creating discrete two- or three-point contacts along the circumferential direction of the tube's middle section. For example, a pair of rollers obliquely support the tube wall from both sides below, or the two inclined surfaces of a V-block form two lines of contact with the tube wall. In this multi-point discrete contact support method, the tube wall is in an unsupported suspended state in the area between two contact points (along the circumferential arc). When the high-pressure gas flow from the cutting nozzle impacts the tube wall in this suspended area, the tube wall experiences localized micro-vibrations. As the chuck rotates the tube, different arc segments along the circumferential direction of the tube wall alternately enter and leave the contact support state, causing the support stiffness to fluctuate periodically along the circumference, further exacerbating the vibration of the tube.

[0029] This design replaces discrete contact support elements with a support cam. A circumferentially extending arc-shaped support groove is created on the outer periphery of the support cam. The projection of the support groove into the cam's cross-section is a continuous arc-shaped groove. When the pipe is placed in the support groove, the arc-shaped inner wall of the support groove forms a continuous arc-shaped contact with the pipe wall circumferentially below the outer periphery. This is no longer one or two discrete contact points (lines), but rather an arc-shaped bearing surface that continuously covers a certain central angle range (e.g., 60 to 180 degrees) of the lower part of the pipe circumferentially. The support stiffness of the continuous arc-shaped contact is uniform within the contact arc segment. There is no unsupported free surface on the pipe wall within the contact arc segment, making it less likely for the impact of auxiliary airflow to induce local vibrations. When the pipe rotates, different arc segments of the pipe wall continuously slide over the arc-shaped inner wall of the support groove, resulting in a smooth transition of the support state circumferentially without abrupt changes in stiffness. Meanwhile, the inner diameter of the support groove gradually decreases along the circumferential extension direction of the support cam. That is, the support groove has different inner diameters (radii of the cross-sectional arc) at different circumferential positions of the cam. By rotating the support cam, the positions of different inner diameters on the support groove can be switched to the top of the cam (the pipe support position), thus adapting to pipes of different outer diameters. A single support cam can cover multiple pipe specifications within a certain range of outer diameters, eliminating the need to replace the support element separately for each pipe diameter.

[0030] Reference Figure 1 An embodiment of this application provides a tube laser cutting machine, including a frame 1, a clamping mechanism 2, a laser cutting head 3, a lifting platform 4, and a support cam 5.

[0031] The frame 1 serves as the support and mounting base for the cutting machine, employing a welded steel frame structure or a cast bed. The clamping mechanism 2, mounted on the frame 1, clamps the end of the pipe to be cut. The clamping direction of the clamping mechanism 2 extends horizontally (the axial direction of the pipe is along this direction). The clamping mechanism 2 can drive the clamped pipe to feed along its axial direction towards one side of the laser cutting head 3, achieving axial feeding motion of the pipe during the cutting process. The laser cutting head 3 is mounted on the frame 1, located to one side of the clamping mechanism 2. The laser cutting head 3 is connected to an external laser generator via an optical path system (such as optical fiber or a mirror assembly), focusing a high-power laser beam onto the area to be cut on the outer wall of the pipe. It then uses an auxiliary cutting gas (such as oxygen, nitrogen, or compressed air) to perform melting or oxidative melting cutting of the pipe wall.

[0032] The support cam 5 is rotatably mounted on the lifting platform 4. The support cam 5 supports the lower part of the pipe, providing support for the middle section of the pipe. The rotation axis of the support cam 5 is horizontal and perpendicular to the clamping direction of the clamping mechanism 2. A locking mechanism (not shown separately in the figure) is provided between the support cam 5 and the lifting platform 4. The locking mechanism is used to lock the support cam 5 at the angle position that matches the outer diameter of the pipe after it rotates, preventing the support cam 5 from shifting due to pipe rotation or vibration during the cutting process. The locking mechanism can adopt a structure with a pin and indexing hole, an eccentric locking handle, or a worm gear self-locking structure.

[0033] An arc-shaped support groove 51 is formed on the outer peripheral surface of the support cam 5. The support groove 51 is an arc-shaped groove recessed inward from the outer peripheral surface of the support cam 5. In the vertical section where the rotation axis of the support cam 5 is located, the projection of the support groove 51 is a circular arc-shaped groove. The arc-shaped inner wall of the support groove 51 is used to support the lower outer periphery of the pipe. The inner diameter of the support groove 51 gradually decreases along the circumferential direction of the support cam 5. At different circumferential positions of the support cam 5, the support groove 51 has different inner diameters—the larger diameter end is adapted to pipes with larger outer diameters, and the smaller diameter end is adapted to pipes with smaller outer diameters. By rotating the support cam 5, the different inner diameter positions of the support groove 51 can be switched to the top of the cam, thereby adapting to pipes with different outer diameters.

[0034] The inner diameter of the support groove 51 (i.e., the radius of curvature of the arc surface of the support groove 51) gradually decreases along the extension direction of the support groove 51 (i.e., the circumferential direction of the support cam 5). That is, at different circumferential positions of the support cam 5, the support groove 51 has different inner diameters. At a certain position (large diameter end) of the support cam 5, the inner diameter of the support groove 51 is larger, suitable for pipes with larger outer diameters; gradually transitioning circumferentially to another position (small diameter end), the inner diameter of the support groove 51 is smaller, suitable for pipes with smaller outer diameters. When the support cam 5 is rotated, the circumferential sections with different inner diameters on the support groove 51 pass sequentially through the top position of the support cam 5, and the inner diameter of the support groove 51 at the top position changes accordingly, thus enabling it to support pipes with different outer diameters. The rotation drive of the support cam 5 can be manually adjusted by a handwheel (suitable for small-batch, multi-specification production) or driven by a servo motor (suitable for automatically switching the cam angle according to pipe specifications in automated production lines).

[0035] Reference Figure 2 and Figure 3Along the direction where the inner diameter of the support groove 51 gradually decreases, the depth of the support groove 51 also gradually decreases. The projection of the support groove 51 onto the vertical section where the rotation axis of the support cam 5 is located is an arc. Since the depth of the support groove 51 decreases circumferentially, the center of this arc is at the same horizontal height at any position on the support groove 51. The technical significance of this geometric feature is that no matter what angle the support cam 5 rotates to, the vertical height of the axis of the pipe supported in the support groove 51 remains constant. The lifting platform 4 only needs to rise to the same fixed height each time to raise the axis of pipes with different outer diameters to a position coaxial with the clamping direction of the clamping mechanism 2. With the cooperation of the centering mechanism 6, the pipes are horizontally aligned from both sides, thus completing the centering of the pipes and the clamping mechanism 2. If the centers of the arcs of each section of the support groove 51 are not at the same horizontal height, the rising stroke of the lifting platform 4 needs to be reset after changing the pipe specifications to compensate for the height difference, increasing the changeover time and parameter setting workload.

[0036] If traditional V-blocks or opposing rollers are used as intermediate support devices, the contact between the pipe and the support element is either two oblique lines (V-blocks) or two point contacts (rollers), leaving the pipe wall arc segment between the two contact areas unsupported. When the auxiliary cutting gas is ejected at high speed from the nozzle of the laser cutting head 3 and impacts the pipe, the pipe wall experiences bending vibration in this arc segment. The continuous arc-shaped inner wall of the support groove 51 eliminates the aforementioned unsupported arc segment, ensuring that the lower part of the pipe remains in contact with the groove wall throughout the entire central angle covered by the support groove 51. The vibration caused by the auxiliary airflow impacting the pipe wall is suppressed by the continuous rigid constraint of the support groove 51.

[0037] The outer peripheral surface of the support cam 5 is also provided with an initial overlap groove 52. The initial overlap groove 52 is connected to the end of the large-diameter end of the support groove 51 (i.e., the end with the largest inner diameter of the support groove 51). The cross-sectional width of the initial overlap groove 52 (the opening width in the direction perpendicular to the cam rotation axis) is greater than the width of the large-diameter end of the support groove 51, and its groove wall is an outwardly expanding inclined surface or flared shape. The initial overlap groove 52 is configured to be located at the top of the support cam 5 in the initial state (i.e., the default state when the cam angle is not precisely adjusted according to the pipe diameter), and is used to initially receive the pipe put in from the feeding mechanism or the operator's hand. The pipe first falls into the wide opening of the initial overlap groove 52, and then, as the support cam 5 rotates, the pipe slides from the initial overlap groove 52 into the large-diameter end of the support groove 51, and gradually enters the inner diameter section that matches the outer diameter of the pipe as the support cam 5 continues to rotate. The flared design of the initial overlap groove 52 reduces the alignment accuracy requirements when the pipe is placed into the support cam 5. The operator or the feeding mechanism only needs to roughly align the pipe with the opening range of the initial overlap groove 52, and the pipe can automatically slide into the groove under the action of gravity.

[0038] Reference Figure 1 and Figure 2The lifting platform 4 is also equipped with a centering mechanism 6, which is used to center and fix the pipe from both sides before it is clamped by the clamping mechanism 2, ensuring that the axis of the pipe coincides with the clamping direction of the clamping mechanism 2. The centering mechanism 6 includes two swing arms 61 and two abutment rollers 62.

[0039] Two swing arms 61 are symmetrically arranged on both sides of the lifting platform 4 along the clamping direction of the clamping mechanism 2 (i.e., the pipe axis), with one swing arm 61 located on the left side of the pipe and the other on the right side. The hinged end (lower or inner end) of each swing arm 61 is rotatably connected to the lifting platform 4 via a vertical pivot, allowing the swing arm 61 to swing around this pivot in the horizontal plane. The free end (upper or outer end) of the swing arm 61 can move closer to or away from the pipe. Two abutting rollers 62 are rotatably arranged at the free ends of the two swing arms 61, with the rotation axis of each abutting roller 62 along the vertical direction and the outer circumferential surface of the abutting roller 62 being cylindrical. When the two swing arms 61 swing synchronously towards each other, the two abutting rollers 62 approach the pipe from the left and right sides, and the cylindrical outer circumferential surface of the abutting rollers 62 contacts and abuts against the outer circumferential wall of the pipe, applying a symmetrical horizontal thrust to the pipe from both sides, pushing the pipe to the center position of the clamping mechanism 2, thus completing the centering.

[0040] To achieve synchronous swinging of the two swing arms 61, a first tooth 611 is provided on the outer periphery of the connecting end (hinged end) of the two swing arms 61. The first tooth 611 is an arc tooth machined along the outer edge of the hinged end of the swing arm 61. The centering mechanism 6 also includes a sliding rod 63, which is slidably mounted on the lifting platform 4 in the horizontal direction and located between the two swing arms 61. The sliding direction of the sliding rod 63 is perpendicular to the axial direction of the pipe (i.e., the sliding rod 63 slides in the left-right direction). Second teeth 631 are machined on both sides (left side and right side) of the sliding rod 63. The second tooth 631 on the left side meshes with the first tooth 611 of the left swing arm 61, and the second tooth 631 on the right side meshes with the first tooth 611 of the right swing arm 61. When the sliding rod 63 slides horizontally under external force (such as cylinder or motor drive), the sliding rod 63 simultaneously drives the two swing arms 61 to rotate around their respective pivots via the second teeth 631 on both sides. When the sliding rod 63 slides in one direction, the two swing arms 61 swing synchronously towards each other (approaching the pipe) to center the pipe; when the sliding rod 63 slides in the opposite direction, the two swing arms 61 swing synchronously away from each other (moving away from the pipe) to release the pipe. The synchronous transmission of the gear and rack ensures that the swing angles of the two swing arms 61 are always symmetrical, and the pushing force of the two abutting rollers 62 on the pipe is equal in magnitude and opposite in direction, so the pipe will not be pushed to one side due to uneven pushing force on both sides. If the two swing arms 61 are driven by their own independent cylinders (instead of being linked by the sliding rod 63), the slight difference in the response time and pushing force of the cylinders on both sides will cause the timing and force of the abutting rollers 62 reaching the pipe wall on both sides to be different, and the pipe may be pushed off-center by the side that arrives first during the centering process.

[0041] In one specific embodiment, the clamping mechanism 2 includes a clamping chuck 21 and a feed chuck 22. The clamping chuck 21 is disposed on the frame 1, located on the side near the laser cutting head 3, and is used to slide and grip the outer periphery of the end of the tube near the laser cutting head 3, i.e., to grip the tube from the outer periphery in a radially converging manner. The feed chuck 22 is disposed on the frame 1 in a manner that allows it to slide along the axial direction of the tube, located on the side of the clamping chuck 21 away from the laser cutting head 3, and is used to clamp the other end of the tube. The feed chuck 22 can slide towards the clamping chuck 21 along the axial direction of the tube, pushing the clamped tube towards the side of the laser cutting head 3.

[0042] As the pipe is cut to its end, the length of the tail section held by the feed chuck 22 gradually shortens. To further shorten the length of the uncut tail section, the outer dimensions of the feed chuck 22 are designed to slide through the inner cavity of the clamping chuck 21. That is, as the feed chuck 22 continues to slide forward, the clamping end (front end) of the feed chuck 22 can pass through the central through hole of the clamping chuck 21, pushing the short tail section of the pipe to the front of the clamping chuck 21 (i.e., below the laser cutting head 3). This allows the short tail section that could not be cut because the feed chuck 22 could not pass through the clamping chuck 21 to be cut by the laser cutting head 3, reducing the length of waste material in the pipe. If the feed chuck 22 cannot penetrate the inner cavity of the clamping chuck 21, the extreme position of the front end of the feed chuck 22 is blocked by the rear end face of the clamping chuck 21. There will always be a distance between the clamping point of the feed chuck 22 and the clamping chuck 21 (at least the length from the jaws of the feed chuck 22 to the front end face). The length of the pipe corresponding to this distance is the shortest tail material that cannot be cut.

[0043] When the tail material is long, the clamping chuck 21 and the feed chuck 22 simultaneously clamp both ends of the tail material and slide synchronously along the axial direction towards the laser cutting head 3. The feed chuck 22 slides forward to the original position of the clamping chuck 21 before the slide (i.e., the position of the clamping chuck 21 near the laser cutting head 3 before the slide). At this time, the clamping chuck 21 has moved synchronously to the side of the laser cutting head 3 away from the feed chuck 22 (i.e., in front of the laser cutting head 3). The feed chuck 22 is located on the side of the laser cutting head 3 closer to the material feeding direction (i.e., behind the laser cutting head 3). The clamping chuck 21 and the feed chuck 22 are located on both sides of the laser cutting head 3. The laser cutting head 3 performs laser cutting on the long tail material segment clamped between the two chucks. Since the two chucks always clamp both ends of the tail material synchronously and slide synchronously, both ends of the tail material are constrained during the sliding process, and there will be no cantilevered drooping or swaying due to single-end clamping.

[0044] To facilitate automatic pipe feeding, the frame 1 is also equipped with a support frame 7 and a lifting drive. The support frame 7 is mounted on the frame 1 in a liftable manner and is positioned on one side of the lifting platform 4 along the clamping direction of the clamping mechanism 2. The support frame 7 is driven by the lifting drive to rise to a receiving height higher than the top of the support cam 5. An external conveying mechanism (such as a conveyor roller, chain conveyor, or robot) conveys the pipe onto the support surface 71 of the support frame 7. After the pipe is received by the support frame 7, the support frame 7 descends, unloading the pipe into the initial overlapping groove 52 at the top of the support cam 5. The lifting of the support frame 7 is driven by the lifting drive, which can be a cylinder.

[0045] The support frame 7 has a support surface 71 for contacting the pipe. The support surface 71 is horizontal or a plane or arc surface with a slight inclination angle. A loading detection rod 8 is provided at one end of the support frame 7, and the middle part of the loading detection rod 8 is oscillatingly connected to the support frame 7 via a horizontal pivot. The loading detection rod 8 has a detection end extending towards the middle of the support surface 71 and an extension end extending outward and downward from the support frame 7. The extension end is provided with a counterweight 81. In the natural state (when not subjected to external force), the weight of the counterweight 81 drives the extension end to sink downward, and lifts the detection end upward through leverage, so that the detection end protrudes above the support surface 71. When the external conveying mechanism conveys the pipe above the support frame 7 and lowers it, the lower surface of the pipe first contacts the detection end of the loading detection rod 8. The weight of the pipe presses the detection end downward, and the loading detection rod 8 oscillates around its middle pivot. The detection end descends until it is flush with the support surface 71, and the lower surface of the pipe is completely against the support surface 71. The support frame 7 is also equipped with a detection sensor 9, which is located below the detection end. The detection sensor 9 is used to detect whether the detection end has swung to a position flush with the support surface 71. After the detection is in place, it sends a position signal to the controller. After receiving the position signal, the controller controls the lifting drive to drive the support frame 7 to descend and unload the pipe onto the support cam 5.

[0046] When the external conveying mechanism transports the pipe to the support frame 7 and lowers it, the lower surface of the pipe first contacts the detection end of the loading detection rod 8 (because it is tilted upwards, it contacts the pipe first). The weight of the pipe presses the detection end downwards, and the loading detection rod 8 swings around its central pivot. The detection end descends until its top surface is flush with the support surface 71 of the support frame 7, and the lower surface of the pipe is completely against the support surface 71. The support frame 7 is also equipped with a detection sensor 9 (such as a proximity switch, photoelectric sensor, or micro switch). The detection sensor 9 is aligned with the detection end of the loading detection rod 8 or its connecting rod to detect whether the detection end has swung to a position flush with the support surface 71 (i.e., the pipe has fallen onto the support surface 71). After detecting the position, the sensor sends a position signal to the controller. After receiving the position signal, the controller controls the lifting drive to drive the support frame 7 to descend, unloading the pipe onto the support cam 5.

[0047] If the support frame 7 is not equipped with a feeding detection rod 8 and a detection sensor 9, the controller cannot accurately determine whether the pipe has been placed on the support frame 7 by the external conveying mechanism. It can only trigger the descent of the support frame 7 through a preset time delay. If the preset time is too short, the pipe will not be placed in place before the support frame 7 begins to descend, causing the pipe to fall or become misaligned; if the preset time is too long, it will waste production time. The mechanical detection method of the feeding detection rod 8 does not rely on the electrical feedback signal of the external conveying mechanism, and the detection result is not affected by the status of the conveying mechanism control system.

[0048] One embodiment of this application also provides a method for laser cutting pipes, using the pipe laser cutting machine in any of the above embodiments, including the following steps: Step S1: Place the pipe to be cut into the support groove 51 from top to bottom. The placement can be achieved by lifting and conveying the support frame 7, or by the operator placing it directly. During placement, the initial overlap groove 52 of the support cam 5 is at the top position, and the pipe first falls into the initial overlap groove 52.

[0049] Step S2: Rotate the support cam 5 so that the inner diameter of the support groove 51 located at the top of the support cam 5 matches the outer diameter of the pipe, and the arc-shaped inner wall of the support groove 51 covers the lower outer periphery of the pipe. If the outer diameter of the pipe corresponds to a certain inner diameter segment in the middle of the support groove 51, then the support cam 5 is rotated to an angle that positions that inner diameter segment at the top; the amount of rotation angle can be pre-calibrated according to the correspondence between the outer diameter of the pipe and the inner diameter of the support groove 51.

[0050] Step S3: The pipe is clamped by the clamping mechanism 2, and the clamping mechanism 2 drives the pipe to feed along its axis toward one side of the laser cutting head 3. The feed chuck 22 in the clamping mechanism 2 clamps the tail end of the pipe and pushes it forward, while the clamping chuck 21 provides auxiliary clamping after the pipe passes through or near the cutting area.

[0051] Step S4: Laser cutting of the pipe is performed using the laser cutting head 3. The laser cutting head 3 focuses a high-power laser beam onto the area to be cut on the outer wall of the pipe, while the cutting gas helps to blow away the molten metal, thus forming the cut. During the cutting process, the support cam 5 always supports the bottom of the pipe, providing continuous arc support for the middle section of the pipe. When the pipe is cut to the end, it can be fed into the chuck 22 through the inner cavity of the clamping chuck 21 (for short tail material processing) or the clamping chuck 21 can be slid in front of the laser cutting head 3 (for long tail material processing).

[0052] The specific structure and method of this application have been described above. The following describes various implementations of the technical features involving dimensions and parameters.

[0053] Regarding the circumferential wrapping angle of the support groove 51 on the pipe (i.e., the central angle of the arc-shaped inner wall of the support groove 51 covering the pipe cross-section), it can be selected between 60 degrees and 180 degrees. When the wrapping angle is between 60 degrees and 90 degrees, the circumferential constraint of the support groove 51 on the pipe is relatively weak, but the operating space for inserting and removing the pipe is larger, making it suitable for occasions where pipe specifications are frequently changed. When the wrapping angle is between 90 degrees and 180 degrees, the coverage area of ​​the support groove 51 on the pipe is larger, and the constraint is stronger, making it suitable for occasions where the outer diameter of the pipe is larger or the cutting precision requirement is higher. The wrapping angle should not exceed 180 degrees; otherwise, the groove opening will be too narrow when the pipe is inserted into the support groove 51 from above, making insertion inconvenient.

[0054] The above describes the core implementation method of this application. Based on the above technical concept, those skilled in the art can make various lateral extensions to the above implementation method without departing from the technical principles of this application.

[0055] In terms of structural variations, the support cam 5 can be configured as multiple independent cam segments arranged along the pipe axis. Each cam segment is provided with a support groove 51, and the cross-sectional dimensions of the support groove 51 of each segment can be different. The cam segment located in the middle section of the pipe provides the main support force, while the cam segment near the end of the pipe can be set with a smaller wrapping angle to facilitate the entry and exit of the pipe. In addition to using gear and rack linkage, the centering mechanism 6 can also use a linkage mechanism or synchronous belt linkage to realize the synchronous swing of the two swing arms 61. In addition to using lifting conveyor, the feeding method of the support frame 7 can also use a flipping arm structure. One end of the support frame 7 is hinged to the frame 1, and the pipe is flipped from the conveyor roller to the support groove 51 of the support cam 5 by flipping.

[0056] In terms of alternative driving methods, in addition to manual or servo motor drive, the rotation of the support cam 5 can also be driven by a scale and locking pin on the rotating shaft of the support cam 5. The operator can manually rotate it to the corresponding scale according to the pipe specifications and then insert the locking pin to fix it. This is suitable for simple cutting machines without electrical control systems.

[0057] In terms of material substitution, the support cam 5 itself can be made of nylon, and the arc-shaped inner wall surface of the support groove 51 can be inlaid or coated with friction-reducing and wear-resistant materials (such as polytetrafluoroethylene pads or diamond-like coatings) to reduce the frictional resistance of the tube when rotating in the groove and extend the service life of the support groove 51.

[0058] Regarding the basic manufacturing, assembly, and optical path debugging technologies involved in this application, those skilled in the art can implement them using conventional technologies according to actual production conditions. For example, the support cam 5 can be formed by CNC milling or wire cutting, and the arc-shaped cross-section of the support groove 51 can be machined by forming milling cutter or CNC programming; the clamping chuck 21 and the feed chuck 22 can be pneumatic chucks or hydraulic chucks; the optical path collimation and focal position calibration of the laser cutting head 3 can be performed using a coaxial red light indicator in conjunction with a focal test plate.

[0059] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A tube laser cutting machine, characterized in that, include: A frame (1) is provided with a clamping mechanism (2) for clamping both ends of a pipe and a laser cutting head (3) located at one end of the clamping mechanism (2). The clamping mechanism (2) can drive one end of the pipe to approach the laser cutting head (3). The lifting platform (4) is mounted on the frame (1) and is located below the clamping mechanism (2); A support cam (5) is rotatably mounted on the lifting platform (4) for supporting the pipe below. A locking mechanism is provided between the support cam (5) and the lifting platform (4). The outer peripheral surface of the support cam (5) is provided with an arc-shaped support groove (51), and the inner diameter of the support groove (51) gradually decreases along the circumference of the support cam (5) so that the support groove (51) can be adapted to pipes of different sizes.

2. The tube laser cutting machine according to claim 1, characterized in that, Along the direction where the inner diameter of the support groove (51) gradually decreases, the depth of the support groove (51) gradually decreases, so that when any area of ​​the support groove (51) is in the longitudinal section of the axis of the support cam (5), its center is at the same height, thereby making the axes of pipes of different diameters at the same height.

3. The tube laser cutting machine according to claim 1, characterized in that, The outer peripheral surface of the support cam (5) is also provided with an initial overlapping groove (52), which is connected to the large diameter end of the support groove (51). The initial overlapping groove (52) is configured to be located at the top of the support cam (5) in the initial state for initially supporting the pipe material.

4. A tube laser cutting machine according to claim 1, characterized in that, The lifting platform (4) is also provided with a centering mechanism (6) located on one side of the supporting cam (5), the centering mechanism (6) including: Two swing arms (61) are symmetrically arranged on the lifting platform (4) and rotate in coordination with the lifting platform (4); Two abutting rollers (62) are rotatably mounted on the free ends of the two swing arms (61) respectively, for synchronously abutting against both sides of the pipe to center the pipe.

5. A tube laser cutting machine according to claim 4, characterized in that, The outer periphery of the hinge ends of the two swing arms (61) is provided with a first tooth (611). A sliding rod (63) extending in the horizontal direction to drive the swing arms (61) is slidably provided on the lifting platform (4). The sliding rod (63) is located between the two swing arms (61). The two sides of the sliding rod (63) are respectively provided with a second tooth (631) that meshes with the first tooth (611). The sliding rod (63) can slide axially to drive the swing arms (61) on both sides to swing synchronously.

6. A tube laser cutting machine according to claim 1, characterized in that, The clamping mechanism (2) includes: A clamping chuck (21) is provided at one end of the frame (1) for sliding and engaging with the outer periphery of one end of the pipe; The feed chuck (22) is slidably mounted on the frame (1) for clamping the other end of the tube. The feed chuck (22) can slide towards the clamping chuck (21) to drive the tube to feed towards the side of the laser cutting head (3). The feed chuck (22) can slide through the inner cavity of the clamping chuck (21) to bring the pipe tail material closer to the laser cutting head (3).

7. A tube laser cutting machine according to claim 6, characterized in that, The clamping chuck (21) is slidably disposed on the frame (1) so that the laser cutting head (3) is on the side away from the feed chuck (22) so that the laser cutting head (3) can cut the tail material clamped between the clamping chuck (21) and the feed chuck (22).

8. A tube laser cutting machine according to claim 1, characterized in that, The frame (1) is also equipped with: The support frame (7) is raised and lowered on the frame (1). The support frame (7) can rise to receive the pipes delivered from the outside and fall to unload the pipes into the support groove (51) of the support cam (5) for clamping by the clamping mechanism (2). A lifting drive component is provided on the frame (1) and is driven to connect with the support frame (7) to drive the support frame (7) to lift.

9. A tube laser cutting machine according to claim 8, characterized in that, The support frame (7) has a support surface (71) for contacting the pipe; a feeding detection rod (8) is hinged to the support frame (7), and the middle part of the feeding detection rod (8) is swayed and connected to one end of the support frame (7); The feeding detection rod (8) has a detection end extending to the middle of the support surface (71) and an extension end extending to the lower outside of the support frame. The extension end is provided with a counterweight (81). The detection end is configured to swing upward under the action of the counterweight (81) until it protrudes from the support surface (71) and swing to be flush with the support surface (71) under the downward pressure of the pipe. The support frame is provided with a detection sensor (9) located below the detection end. The detection sensor (9) is used to detect the swing position signal of the detection end and send the position signal to the controller.

10. A method for laser cutting pipes, using a pipe laser cutting machine as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Place the pipe to be cut into the support groove (51) from top to bottom; S2. Rotate the support cam (5), and the inner diameter of the support groove (51) is adapted to the outer diameter of the pipe to support the lower outer periphery of the pipe. S3. The pipe is clamped by the clamping mechanism (2) and fed along its axial direction to one side of the laser cutting head (3); S4. The pipe is laser-cut using the laser cutting head (3).

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