Multi-degree-of-freedom heating device and method for hot gas expansion tube type parts

Abstract

This invention discloses a multi-degree-of-freedom heating device and method for hot-expanding tube parts, including a worktable and symmetrically distributed clamping robots. The worktable supports and laterally limits the tube parts via freely matching and positioning ceramic bodies. The clamping robot's end is equipped with electrically heated copper electrode grippers for adaptively clamping both ends of the tube. The multi-degree-of-freedom heating method for hot-expanding tube parts utilizes the ceramic bodies to restrict the radial expansion of the tube, causing it to elongate only axially. Simultaneously, the copper electrode grippers adaptively displace with the axial elongation of the tube to release thermal elongation, avoiding bending caused by rigid constraints. Cooling water channels are provided inside the copper electrode grippers to prevent overheating. This invention achieves rapid and uniform heating of the tube with no radial deformation through a synergistic mechanism of radial constraint, axial release, self-heating by electricity, and electrode cooling, resulting in automated operation.

Description

Technical Field

[0001] This invention relates to a heating device for hot gas expansion tube parts, and more particularly to a multi-degree-of-freedom heating device and method for hot gas expansion tube parts. Background Technology

[0002] The hot gas expansion forming process involves preheating tubular parts to a target temperature (typically 930–950°C), then rapidly transferring the heated tubing into a mold cavity. High-pressure gas is then introduced into the tubing to cause it to expand and form the desired cross-sectional shape. After placing a steel pipe on the mold, resistance current is used to heat the metal, raising the pipe to approximately 900°C within 10 seconds. Subsequently, two high-pressure air injections are used to achieve flange forming and mold quenching, ultimately yielding parts with a strength exceeding 1500 MPa. However, the preheating stage of the tubing remains a key bottleneck restricting production efficiency and product quality throughout the entire hot gas expansion forming process.

[0003] Long-term practice has revealed the following prominent problems in the preheating stage of pipe fittings in existing hot air expansion processes: Pipe fittings are prone to radial bulging deformation when heated. When pipe parts are heated to a high temperature of 930-950℃, the material undergoes significant thermal expansion. Because traditional heating methods lack effective constraints on the radial thermal expansion of pipe fittings, the pipe fittings are very prone to radial bulging or bending deformation (i.e., arching towards the middle) after being heated. This makes it impossible for the heated pipe fittings to be smoothly placed into the fixed mold cavity, which seriously affects the normal progress of subsequent forming processes.

[0004] Existing heating methods are inefficient and have poor temperature uniformity. Traditional heating methods mainly include resistance furnace heating and induction heating. Resistance furnace heating relies on thermal radiation and thermal conduction to transfer heat from the surface of the pipe to the interior. The heating speed is slow, and a large temperature difference easily forms between the surface and the core of the pipe, making it difficult to ensure temperature uniformity. Although induction heating has a faster heating speed, it requires specially designed induction coils for pipes with different cross-sectional shapes, resulting in poor equipment versatility. Furthermore, it is difficult to precisely control the heating uniformity of different parts of the pipe during induction heating.

[0005] In addition, the electrode clamps of existing resistance heating devices are mostly rigid clamping structures. When the pipe is heated and elongates axially, it cannot adaptively release the elongation, causing the pipe to bend under axial rigid constraint. Summary of the Invention

[0006] To address the shortcomings of the aforementioned technologies, this invention provides a multi-degree-of-freedom heating device and method for hot gas expansion tube components.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is: a multi-degree-of-freedom heating device for hot gas expansion tube parts, including a worktable and at least one set of clamping robots symmetrically distributed on both sides of the worktable. The worktable supports and laterally limits the tube parts by ceramic bodies that can be freely matched and positioned. The clamping ends of the clamping robots are set as electrically heated copper electrode grippers. Each set of symmetrically distributed clamping robots adaptively clamps both ends of the same tube part through copper electrode grippers matching.

[0008] Furthermore, the ceramic body includes a bottom support roller and a lateral limiting ceramic roller. The ceramic body can be freely matched and positioned on the worktable by the bottom support roller fixed in a fixed position and the lateral limiting ceramic roller movable in a movable position on the worktable.

[0009] Furthermore, the lateral limiting ceramic rollers installed on the movable position of the worktable include: Adjustment slides are spaced along the length of the tubular parts on the worktable. Each adjustment slide is equipped with at least one lateral limiting ceramic roller. Several lateral limiting ceramic rollers abut against the sides or outer sides, limited by the bending path of the same tubular part.

[0010] Furthermore, there are at least two bottom support rollers on the fixed position of the worktable, and they are located below the same tubular part.

[0011] Furthermore, the copper electrode gripper includes copper electrode blocks that are symmetrically clamped vertically. Each of the symmetrically clamped copper electrode blocks is connected to a sliding module arranged opposite to each other via a conductive connecting block. At least one connecting block of each copper electrode gripper is provided with a current terminal. The sliding module is connected to the manipulator of the gripping robot via an elastic body.

[0012] Furthermore, each connecting block is equipped with a cooling water inlet and a hot water outlet, which are connected by a cooling water channel located inside the connecting block.

[0013] Furthermore, the adjustment slide is set on the retraction support plate on the worktable. The retraction support plate is slidably set on the retraction slide on the worktable by a slider. The retraction slide is parallel to the adjustment slide. The retraction support plate is connected to the retraction cylinder, which is installed on the worktable.

[0014] A multi-degree-of-freedom heating device for hot gas expansion tube parts and a multi-degree-of-freedom heating method for hot gas expansion tube parts are disclosed. The method utilizes a ceramic body that can be freely matched and positioned on a worktable to provide lateral limiting support for the tube parts. The copper electrode jaws at both ends of the tube parts are used to clamp and pass heating current, causing the tube parts to heat up as resistance. During the heating process, the ceramic body restricts the radial expansion of the tube parts, causing them to elongate only along the axial direction. The copper electrode jaws adaptively displace as the axial elongation of the tube parts is achieved to release the axial thermal elongation.

[0015] Furthermore, the ceramic body includes a bottom support roller and a lateral limiting ceramic roller. The lateral limiting ceramic roller abuts against the side of the tubular part and maintains rolling contact with the tubular part during the heating process to balance the radial expansion force of the tubular part.

[0016] Furthermore, the adaptive displacement is achieved by the active retraction of the copper electrode gripper driven by the gripping robot, and / or by passive compensation by the floating elastomer between the copper electrode gripper and the gripping robot.

[0017] This invention discloses a multi-degree-of-freedom heating device and method for hot-expansion tube-type parts. The invention features a freely matching and positioning ceramic body on a worktable, including a fixed bottom support roller and a movable lateral limiting ceramic roller. During heating, the lateral limiting ceramic roller maintains rolling contact with the sidewall of the tube, applying a reverse constraint force radially to limit the radial thermal expansion of the tube to a minimal range, fundamentally eliminating radial bulging deformation and ensuring that the heated tube can be smoothly placed into the mold cavity. A high-current resistance heating method is employed, with both ends of the tube held by copper electrode claws and a heating current flowing through it. The current flows axially through the entire tube, utilizing its own resistance to generate Joule heating, causing the entire tube to simultaneously heat to the target temperature within seconds. This method offers rapid heating and excellent temperature uniformity, eliminating the temperature difference between the surface and the core. The invention incorporates an adaptive clamping design with copper electrode grippers. The clamping force of the copper electrode grippers on the pipe meets the requirements for conductive contact. When the pipe expands axially due to heat, the copper electrode grippers can adaptively displace through active retraction by the clamping robot and / or passive compensation by an elastic body, allowing the axial thermal expansion of the pipe to be released freely and avoiding bending deformation caused by rigid constraints. To address the issue of overheating of the copper electrode under high current operation, this invention incorporates a cooling water channel inside the connecting block. During operation, circulating cooling water flows through the area near the interface between the connecting block and the copper electrode block, dissipating the Joule heat generated by the copper electrode block and the connecting block. This effectively reduces electrode temperature rise, prevents electrode oxidation, softening, or melting, and ensures the stability and service life of the electrode under long-term high-current operating conditions. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0019] Figure 2 for Figure 1 A magnified schematic diagram of the structure of A in the middle circle.

[0020] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0021] Figure 4 This is a schematic diagram of the structure of Embodiment 3 of the present invention.

[0022] Figure 5 for Figure 4 A magnified schematic diagram of the structure of B in the middle circle.

[0023] In the diagram, 1. Workbench; 2. Clamping robot; 3. Copper electrode gripper; 41. Copper electrode block; 42. Connecting block; 43. Current terminal; 44. Cooling water inlet; 45. Hot water outlet; 5. Sliding module; 6. Elastomer; 7. Bottom support roller; 8. Lateral limiting ceramic roller; 9. Adjustment slide; 10. Retraction support plate; 11. Retraction slide; 12. Retraction cylinder; 13. Slider; 14. Tubular parts. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] Example 1;

[0026] like Figure 1 and 2 As shown, the multi-degree-of-freedom heating device for hot gas expansion tube parts in this embodiment includes a worktable 1 and two sets of clamping robots 2 symmetrically distributed on both sides of the worktable 1. The worktable 1 is the basic support component for the hot gas expansion tube parts, and the clamping robots 2 are commercially available six-axis industrial robots whose arms are fixedly mounted on bases on both sides of the worktable 1, allowing for flexible adjustment of their end-effector positions and postures in three-dimensional space. A ceramic body is provided on the worktable 1 to support and laterally limit the tube parts 14.

[0027] Specifically, the ceramic body includes a bottom support roller 7 and a lateral limiting ceramic roller 8. The ceramic body can be freely matched and positioned, that is, the bottom support roller 7 is fixedly set in the fixed position on the worktable 1, while the lateral limiting ceramic roller 8 is movably set in the movable position on the worktable 1.

[0028] The bottom support roller 7 is fixedly installed at a fixed position on the worktable 1. There are two bottom support rollers 7 located below the same tubular part 14 and distributed along the length of the tubular part 14. The roller body of the bottom support roller 7 is made of high-temperature resistant ceramic material, utilizing its high-temperature strength and wear resistance. The bottom support roller 7 is installed on the worktable 1 through a bearing seat, rotates freely, and makes rolling contact with the tubular part, providing vertical load support. The rolling contact prevents damage to the surface of the tubular part due to friction.

[0029] Lateral limiting ceramic rollers 8 are movably mounted on the worktable 1. Multiple adjusting slides 9 are spaced apart along the length of the tubular part 14 on the worktable 1. Each adjusting slide 9 contains a lateral limiting ceramic roller 8. "Movable" means that the lateral limiting ceramic roller 8 is mounted in the adjusting slide 9 via a roller bracket. The roller bracket can slide freely within the adjusting slide 9 and is fixed by locking bolts after sliding to the target position. The operator can move each lateral limiting ceramic roller 8 to its appropriate position according to the actual bending path of the tubular part 14, so that several lateral limiting ceramic rollers 8 abut against the sides or outer side of the tubular part 14, limited by the bending path of the same tubular part 14. For straight pipes, the lateral limiting ceramic rollers 8 are arranged along a straight line; for bent pipes, the lateral limiting ceramic rollers 8 are arranged along the bending curve.

[0030] The main body of the lateral limiting ceramic roller 8 is also made of high-temperature resistant ceramic material. During the heating process, the lateral limiting ceramic roller 8 always maintains rolling contact with the side wall of the pipe part 14, which effectively limits the radial expansion of the pipe and the rolling contact method will not damage the surface of the pipe due to friction.

[0031] The gripping end of the gripping robot 2 is configured as a copper electrode gripper 3 that can be electrically heated. The copper electrode gripper 3 includes two copper electrode blocks 41 that are symmetrically gripped from top to bottom. The two copper electrode blocks 41 are respectively connected to two sliding modules 5 arranged opposite each other through conductive connecting blocks 42. The two sliding modules 5 are respectively installed at the end of the manipulator of the gripping robot 2 and can move closer or further away from each other under the control of the gripping robot 2 to achieve clamping or loosening of the end of the tubular part 14.

[0032] Each symmetrically distributed clamping robot 2 uses its respective copper electrode grippers 3 to adaptively clamp the two ends of the same tubular part 14. It should be noted that adaptive clamping means that while clamping the end of the tubular part, the copper electrode grippers 3 can adapt to the displacement changes caused by axial thermal expansion during heating, maintaining good electrical contact with the end face of the tubular part without constituting a rigid obstacle to axial expansion. In this embodiment, adaptive clamping is achieved by connecting the sliding module 5 and the manipulator of the clamping robot 2 via an elastic body 6. This elastic body 6 can be a compression spring, disc spring, gas spring, or elastic rubber block, or other components with elastic deformation capabilities. In this embodiment, the back plate of the sliding module is connected to the front plate of the manipulator using four sets of compression springs. When the tubular part 14 undergoes axial thermal expansion during heating, the elongated end of the tubular part pushes against the copper electrode block 41, causing the sliding module 5 to slide relative to the manipulator, while simultaneously compressing the elastic body 6.

[0033] At least one connecting block 42 of each copper electrode jaw 3 is provided with a current terminal 43 for connecting a high-current cable to introduce a high current (8000~10000A) from the heating power supply into the copper electrode jaw 3.

[0034] Example 2;

[0035] like Figure 3 As shown, this embodiment adds a cooling method for the copper electrode grippers based on embodiment one. During the high current flow process, the copper electrode block 41 generates a large amount of Joule heat. The copper electrode block 41 is attached to the connecting block 42, and the two are tightly connected. The connecting block 42 is made of a conductive material (preferably iron, copper, or an iron-copper alloy). Therefore, current and heat are conducted between the two. In this embodiment, a cooling water channel is set inside the connecting block 42. During operation, circulating cooling water is introduced. The cooling water enters the cooling water channel inside the connecting block 42 from the cooling water inlet 44. The cooling water channel removes the Joule heat generated by the copper electrode block 41 through the cooling connecting block 42.

[0036] The cooling water temperature can be room temperature (approximately 20-25°C). The cross-sectional dimensions and layout of the cooling water channels should ensure smooth cooling water flow, and the channels should cross the connecting block 42 as much as possible to achieve uniform cooling.

[0037] The copper electrode block 41 is made of copper, which has excellent electrical and thermal conductivity. The clamping surface of the copper electrode block 41 is machined with an arc-shaped groove that matches the shape of the end of the tubular part 14. The current terminal 43 is set on a connecting block 42 of the copper electrode jaw 3 for connecting a high-current cable. The heating power supply output current can reach 8000~10000A, and the high-current design allows the tubular part to heat up rapidly within seconds.

[0038] Two copper electrode blocks 41, symmetrically clamped from top to bottom, are connected to two opposing sliding modules 5 via their respective connecting blocks 42. When the sliding modules 5 are brought closer together under the control of the clamping robot 2, the two copper electrode blocks 41 clamp the ends of the tubular parts from both top and bottom directions; when they are moved away from each other, the clamping on the ends of the tubular parts is released.

[0039] Example 3;

[0040] like Figure 4 and Figure 5 As shown, in Embodiment 3, based on Embodiment 2, the structure of the retraction support plate, the retraction slide, and the retraction cylinder is further added, so that the lateral limiting ceramic roller can retract and make way as a whole after heating is completed.

[0041] The overall structure of the device in this embodiment is the same as that in Embodiment 2, including a worktable 1, a clamping robot 2, copper electrode grippers 3, bottom support rollers 7, lateral limiting ceramic rollers 8, and adjustment slides 9. The freely matching positioning method of the ceramic body and the cooling structure of the copper electrode grippers are the same as in Embodiment 2, and will not be described again here.

[0042] like Figure 1 As shown, the adjustment slide 9 is provided on the retraction support plate 10. The retraction support plate 10 is an integral flat plate structure. Multiple adjustment slides 9 are provided on its upper surface, which are spaced apart along the length of the pipe part 14. Each lateral limiting ceramic roller 8 is installed in each adjustment slide 9 and can move freely along the adjustment slide 9 to adapt to the bending path of different pipe parts.

[0043] The bottom of the retraction support plate 10 is fixedly connected to a slider 13, which is slidably disposed in the retraction slide 11 on the worktable 1. The retraction slide 11 is parallel to the adjustment slide 9. One end of the retraction support plate 10 is connected to the piston rod of the retraction cylinder 12, and the cylinder body of the retraction cylinder 12 is fixedly installed on the worktable 1.

[0044] The extension and retraction of the piston rod of the retraction cylinder 12 aims to drive the retraction support plate 10 to retract and make way for the material. After the tubular part 14 has been heated, it is gripped and lifted by the grippers or unloading robot in subsequent processes. The heating power supply stops outputting, the retraction cylinder 12 actuates, the piston rod retracts, and the retraction support plate 10 slides along the retraction slide 11 away from the tubular part 14. The retraction support plate 10 drives all the lateral limiting ceramic rollers 8 to simultaneously retract from the side of the tubular part 14, and the lateral space of the tubular part 14 is completely released. At this time, the heated tubular part 14 can be removed without obstruction.

[0045] Example 4;

[0046] Combination Figures 1-5 As shown, Embodiment 4 discloses a method for heating a hot-expansion tube-like part using a device. A freely matching and positioning ceramic body on a worktable 1 provides limiting support for the tube-like part 14. Copper electrode grippers 3 at both ends of the tube-like part 14 hold it and pass a heating current through it, causing the tube-like part 14 to heat up as a resistance. During heating, the ceramic body restricts the radial expansion of the tube-like part 14, causing it to elongate only axially. Furthermore, the copper electrode grippers 3 adaptively displace as the axial elongation of the tube-like part 14 occurs, releasing the axial thermal elongation.

[0047] Among them, radial constraint ensures that the pipe fitting does not bulge or deform after heating and can be smoothly placed into the mold; axial adaptive release ensures that the pipe fitting's thermal expansion is not rigidly hindered and does not cause bending instability. Together, they ensure that the pipe fitting maintains good shape accuracy after heating.

[0048] In this embodiment, the ceramic body includes a bottom support roller 7 and a lateral limiting ceramic roller 8. The bottom support roller 7 is fixedly disposed at a fixed position on the worktable 1, and at least two bottom support rollers 7 are located below the tubular part 14, distributed along the length direction of the tubular part 14, and bear the weight of the tubular part 14 vertically. The lateral limiting ceramic roller 8 is movably disposed at a movable position on the worktable 1, abutting against the side of the tubular part 14.

[0049] During the heating process, the lateral limiting ceramic roller 8 maintains rolling contact with the tubular part 14. Specifically, the outer circumferential surface of the lateral limiting ceramic roller 8 is in tangential contact with the outer wall of the tubular part 14. When the tubular part 14 tends to expand radially due to heat, its radial expansion force acts on the roller surface of the lateral limiting ceramic roller 8, driving the roller to rotate; simultaneously, the roller applies a reverse supporting force to the tubular part 14, balancing the radial expansion force of the tubular part 14. Since the position of the lateral limiting ceramic roller 8 is fixed after adjustment, the radial dimension of the tubular part 14 is constrained within the limiting space enclosed by the lateral limiting ceramic roller 8. The lateral limiting ceramic roller 8 and the tubular part 14 are in rolling contact rather than sliding contact, resulting in minimal frictional resistance and preventing damage to the surface of the tubular part due to friction. Ceramic materials possess excellent high-temperature strength and wear resistance, maintaining sufficient mechanical strength even at high temperatures of 930–950℃, without softening or deforming due to high temperatures.

[0050] In the method of this embodiment, the adaptive displacement is achieved by the gripping robot 2 driving the copper electrode gripper 3 to actively retract, and / or by the floating elastic body 6 between the copper electrode gripper 3 and the gripping robot 2 for passive compensation.

[0051] The first implementation method involves the gripping robot 2 actively retracting. Based on a preset program or real-time signals from an external temperature sensor (which can be synchronously installed at the gripping end of the robot 2), the robot 2 drives the robotic arm to actively retract during the heating process of the tubular part 14, following its axial elongation. The key is to ensure that the retraction speed of the gripping robot 2 matches the thermal elongation rate of the tubular part 14.

[0052] The second implementation method is passive compensation by the elastic body 6. The sliding module 5 is connected to the manipulator of the gripping robot 2 through the elastic body 6. When the tubular part 14 is axially elongated, its end pushes against the copper electrode block 41, causing the sliding module 5 to elastically displace relative to the manipulator.

[0053] The third approach is a combination of active yielding and passive compensation. The passive compensation of the elastomer 6 is the primary method to absorb most of the axial thermal elongation of the pipe fitting. The active yielding of the clamping robot 2 is the auxiliary method, which is activated when the compression of the elastomer 6 reaches a predetermined threshold to further release the axial thermal elongation. The two methods can work together to achieve the tracking of the axial thermal elongation of the pipe fitting.

[0054] It should be understood that, due to the special structure of the copper electrode gripper 3, the clamping force applied by the copper electrode gripper 3 to the tubular part 14 only needs to meet the requirements of conductive contact, and does not constitute a rigid obstacle when the tubular part 14 elongates axially. This clamping force can be controlled by the force control function of the gripping robot 2, or by setting a force sensor and a force limiting device in the drive mechanism of the sliding module 5.

[0055] The complete workflow of the method in this embodiment is as follows; The loading robot places the tubular parts 14 to be heated onto the bottom support rollers 7 of the worktable 1, so that the bottom support rollers 7 bear the weight of the tubular parts 14. According to the actual length and bending path of the tubular parts 14, the lateral limiting ceramic rollers 8 are moved to the appropriate positions along the adjustment slides 9 (or can be pre-adjusted according to the tubular material), so that the lateral limiting ceramic rollers 8 abut against the sides or outer sides of the tubular parts 14, forming lateral limiting constraints on the tubular parts 14.

[0056] The clamping robots 2 on both sides of the worktable 1 move, driving the copper electrode grippers 3 to clamp the tubular parts 14 from both ends. The clamping force of the copper electrode grippers 3 meets the adhesion force required for conductive contact.

[0057] When the heating power supply is turned on, a large current (8000-10000A) is introduced into the tubular part 14 through the copper electrode clamps 3. The current flows along the axial direction of the tubular part 14, generating Joule heat through its own resistance, raising its temperature to 930-950℃. The basic principle of resistance heating is: connecting both ends of the tubing to electrodes, and then applying a large current, the current flows along the axial direction of the tubing, generating Joule heat (Q=I²Rt) through its own resistance, thus raising its temperature. Compared to traditional heating methods, resistance heating has extremely high heating efficiency, heating the tubing to 950℃ within seconds, allowing the entire tubing to heat up simultaneously, and resulting in high energy utilization. During the heating process, the lateral limiting ceramic rollers 8 maintain constant rolling contact with the tubular part 14, constraining its radial expansion and causing it to elongate only axially. When the tubular part 14 is heated and elongated axially, the copper electrode gripper 3 adapts to the displacement through active yielding and / or passive compensation by the elastic body 6, releasing the amount of axial thermal elongation.

[0058] After heating is completed, the retraction cylinder 12 drives the retraction support plate 10 to slide along the retraction slide 11, causing the lateral limiting ceramic roller 8 to retract from the side of the tubular part 14.

[0059] The clamping robot 2 releases the copper electrode gripper 3 and removes the heated tubular part 14.

[0060] The method in this embodiment further monitors the temperature of the tubular component 14 in real time using a temperature sensor, and the temperature controller controls the on / off state of the heating power supply based on the feedback signal from the temperature sensor. When the temperature of the tubular component 14 reaches a preset upper limit (e.g., 950°C), the temperature controller sends a power-off signal, and the heating power supply stops outputting power; when the temperature of the tubular component 14 falls below a preset lower limit (e.g., 945°C), the temperature controller sends a power-on signal, and the heating power supply resumes outputting power. Through this closed-loop control, the temperature of the tubular component 14 is maintained within a constant temperature range of 945°C to 950°C (±5°C) until the component is removed. The specific temperature control method depends on the response speed and accuracy of the temperature sensor and the algorithm of the temperature controller. In this embodiment, an infrared temperature sensor with a response speed of less than 10ms and a PID control algorithm are preferably used.

[0061] The above embodiments are not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the technical solution of the present invention are also within the protection scope of the present invention.

Claims

1. A multi-degree-of-freedom heating device for hot gas expansion tube parts, comprising a worktable and at least one set of clamping robots symmetrically distributed on both sides of the worktable, characterized in that: The workbench is supported and laterally limited by a ceramic body that can be freely matched and positioned. The gripping end of the clamping robot is set with electrically heated copper electrode grippers. Each group of symmetrically distributed clamping robots adaptively clamps the two ends of the same tubular part through matching copper electrode grippers.

2. The multi-degree-of-freedom heating device for hot gas expansion tube parts according to claim 1, characterized in that: The ceramic body includes a bottom support roller and a lateral limiting ceramic roller. The ceramic body can be freely matched and positioned on the worktable. The bottom support roller is fixed in one position, and the lateral limiting ceramic roller is movable in another position on the worktable.

3. The multi-degree-of-freedom heating device for hot gas expansion tube parts according to claim 2, characterized in that: The lateral limiting ceramic rollers installed on the movable part of the worktable include: Adjustment slides are spaced along the length of the tubular parts on the worktable. Each adjustment slide is equipped with at least one lateral limiting ceramic roller. Several lateral limiting ceramic rollers abut against the sides or outer sides, limited by the bending path of the same tubular part.

4. The multi-degree-of-freedom heating device for hot gas expansion tube parts according to claim 3, characterized in that: At least two bottom support rollers are fixed at the workbench and are located below the same tubular part.

5. The multi-degree-of-freedom heating device for hot gas expansion tube parts according to any one of claims 1-4, characterized in that: The copper electrode gripper includes copper electrode blocks that are symmetrically clamped vertically. Each of the symmetrically clamped copper electrode blocks is connected to a sliding module arranged opposite to each other via a conductive connecting block. At least one connecting block of each copper electrode gripper is provided with a current terminal. The sliding module is connected to the manipulator of the gripping robot via an elastic body.

6. The multi-degree-of-freedom heating device for hot gas expansion tube parts according to claim 5, characterized in that: Each of the connecting blocks is provided with a cooling water inlet and a hot water outlet, which are connected by a cooling water channel located inside the connecting block.

7. The multi-degree-of-freedom heating device for hot gas expansion tube parts according to claim 5, characterized in that: The adjusting slide is provided on the retraction support plate on the workbench. The retraction support plate is slidably mounted on the retraction slide of the workbench via a slider. The retraction slide is parallel to the adjusting slide. The retraction support plate is connected to the retraction cylinder, which is mounted on the workbench.

8. A method for heating multi-degree-of-freedom components of a multi-degree-of-freedom heating device for hot gas expansion tube components according to any one of claims 1-7, characterized in that: The tube-shaped parts are laterally limited and supported by a ceramic body that can be freely matched and positioned on the worktable. The copper electrode jaws at both ends of the tube-shaped parts are used to clamp them and pass heating current through them, so that the tube-shaped parts themselves are heated by resistance. During the heating process, the ceramic body restricts the radial expansion of the tube-shaped parts so that they only elongate along the axial direction. The copper electrode jaws adapt to the displacement as the tube-shaped parts elongate axially to release the axial thermal elongation.

9. The method for heating multi-degree-of-freedom components of a multi-degree-of-freedom heating device for hot gas expansion tube components according to claim 8, characterized in that: The ceramic body includes a bottom support roller and a lateral limiting ceramic roller. The lateral limiting ceramic roller abuts against the side of the tubular part and maintains rolling contact with the tubular part during the heating process to balance the radial expansion force of the tubular part.

10. The method for heating multi-degree-of-freedom components of a multi-degree-of-freedom heating device for hot gas expansion tube components according to claim 8 or 9, characterized in that: The adaptive displacement is achieved by the active retraction of the copper electrode gripper driven by the gripping robot, and / or by passive compensation by the floating elastomer between the copper electrode gripper and the gripping robot.

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