A hot gas expansion tube material self-resistance heating device

Abstract

The application relates to a heating device, in particular to a hot gas expansion pipe self-resistance heating device; the device comprises a sealing part, a power supply and a heating part electrically connected with the power supply; the sealing part comprises a sealing cover and a sealing seat, and the sealing cover and the sealing seat are connected through a support guide part; the heating part comprises multiple groups of heating electrodes and moving pairs, the heating electrode comprises a profiled electrode clamp and an electrode, the profiled electrode clamp comprises an upper clamp block and a lower clamp block, the upper clamp block is arranged on the sealing cover through a moving pair, and the lower clamp block is arranged on the sealing seat through a moving pair; the power supply, the electrode and the profiled electrode clamp are electrically connected; the hot gas expansion pipe self-resistance heating device has the advantages that the product can be punched after the hot gas expansion is completed, the scale is less, and the deformation amounts of the power-on ends are basically consistent.

Description

Technical Field

[0001] This invention relates to a heating device, specifically a self-resistance heating device for hot gas expansion pipes. Background Technology

[0002] Hot gas expansion is a process in which tubing is heated to an austenitizing temperature, rapidly transferred to a sealed mold, and filled with high-pressure inert gas to cause the tubing to expand and adhere to the mold. While maintaining pressure, the tubing is rapidly quenched within the mold, transforming the material into martensite. Finally, the finished product is obtained through trimming, drilling, and surface treatment. It is commonly used in the processing of automotive A / B pillars, door rings, and crash beams.

[0003] Existing multi-layer box furnace heating schemes suffer from complex structures, low efficiency, high energy consumption, and the formation of a large amount of oxide scale on the product surface. Using box furnace units requires significant investment and has very high energy requirements. After forming, the product transforms into martensite, making drilling for positioning impossible. To ensure accurate cutting and positioning, drilling is necessary at the cut end of the tube. However, due to the hardness and brittleness of martensite, its extremely poor plasticity, and high residual stress, drilling is impossible on the tube after thermal expansion. Therefore, using existing technologies for tube positioning is difficult. Summary of the Invention

[0004] The present invention aims to provide a self-resistance heating device for hot-expanding pipes, which solves the problems of the inability to punch holes and inconsistent deformation at the energized end after hot expansion.

[0005] This solution discloses a self-resistance heating device for hot-expanding pipes, comprising a sealing part, a power supply, and a heating part electrically connected thereto. The sealing part includes a sealing cover and a sealing seat, which are connected by a support guide part for controlling the opening or closing of the sealing cover. The heating part includes multiple sets of heating electrodes, a sliding pair, and a driving device. The heating electrodes include conformal electrode clamps and electrodes, with the electrode clamps made of a material with high conductivity. The conformal electrode clamps include an upper clamp and a lower clamp. The upper clamp is mounted on the sealing cover via a sliding pair, and the lower clamp is mounted on the sealing seat via a sliding pair. The driving device enables the upper and lower clamps to reciprocate under the action of the sliding pair. Because the pipe will deform to a certain extent after heating, the contact position between the conformal electrode clamps and the pipe needs to be adjusted during the heating process. The power supply, electrodes, and conformal electrode clamps are electrically connected.

[0006] Furthermore, the sealing seat is also provided with a workpiece support block, so that the workpiece can only move in the horizontal direction, preventing the conformal electrode clamp from getting stuck during movement.

[0007] Furthermore, a limiting block is provided at one end of the sliding pair to set the starting position of the sliding pair. Since the energized positions at both ends of different workpieces are different, the limiting block can be used for rapid positioning.

[0008] Furthermore, the conformal electrode clamp is provided with a workpiece hole that adapts to the shape of the workpiece, allowing it to move according to the shape of the workpiece.

[0009] Furthermore, the upper clamping block is provided with an upper slot, and the lower clamping block is provided with a lower slot. The upper slot and the lower slot are combined to form a workpiece hole. The lower slot can hold the workpiece in place and prevent the workpiece from moving or shifting.

[0010] Furthermore, both the upper and lower clamping blocks are provided with cooling through holes, which are connected to cooling pipes. Non-conductive coolant is introduced through these holes, resulting in a significant cooling effect, preventing the electrodes at both ends from overheating and reducing unnecessary power consumption.

[0011] Furthermore, both the sealing cover and the sealing seat are equipped with an insulating plate.

[0012] Furthermore, the power supply includes multiple sets of DC power generators connected in parallel, which are connected in parallel via hollow copper tubes; the hollow copper tubes are connected to cooling pipes. The increased outer wall area of ​​the hollow copper tubes results in heat dissipation efficiency far exceeding that of ordinary copper wires. The hollow copper tubes also contain non-conductive coolant, ensuring they do not overheat even under prolonged high current.

[0013] Furthermore, the hollow copper tube is provided with multiple insulating support blocks at its lower part; the hollow copper tube includes a positive copper tube and a negative copper tube, and an insulating spacer is provided between the positive copper tube and the negative copper tube.

[0014] Furthermore, a heat dissipation channel is provided on one side of the power supply to prevent the power supply from overheating.

[0015] The advantages of this invention are: 1) After heating, there is no need to transfer it to an insulated box; it can be heated directly when the wall thickness is thin, and kept warm directly in the heating chamber for a period of time when the wall thickness is thick. 2) Heating after sealing reduces the oxygen inside, further reducing oxide scale after forming. 3) It solves the problem that the product cannot be punched after thermal expansion. Attached Figure Description

[0016] Figure 1 This is a perspective view of a self-resistance heating device for hot gas expansion pipes according to the present invention; Figure 2 This is a schematic diagram of the structure of a self-resistance heating device for hot gas expansion pipes according to the present invention; Figure 3 This is a schematic diagram of the sealing cover in a self-resistance heating device for hot gas expansion pipes according to the present invention; Figure 4 This is a schematic diagram of the sealing seat and power supply in a self-resistance heating device for hot gas expansion pipes according to the present invention.

[0017] Figure 5 for Figure 4 Enlarged view of A in the middle; Figure 6This is a schematic diagram illustrating the use of the conformal electrode clamp in the self-resistance heating device for hot gas expansion tubes according to the present invention. Figure 7 This is a schematic diagram of the arrangement of hollow copper tubes in a self-resistance heating device for hot gas expansion tubes according to the present invention.

[0018] In the diagram, 1 is the heating element, 1-1 is the conformal electrode clamp, 1-11 is the upper clamping block, 1-12 is the upper slot, 1-13 is the lower clamping block, 1-14 is the lower slot, 1-2 is the electrode, 1-3 is the moving pair, 1-4 is the limiting block, 1-5 is the workpiece support block, 1-6 is the cylinder, 1-7 is the solenoid valve, 2 is the sealing element, 2-1 is the sealing cover, 2-2 is the sealing seat, 2-3 is the insulating plate, 2-4 is the guide post, 2-5 is the lifting cylinder, 2-6 is the sealing strip, 3 is the power supply, 3-1 is the DC power generator, 3-2 is the insulating support block, 3-3 is the insulating spacer, 3-4 is the heat dissipation channel, 3-5 is the wire, 3-6 is the positive copper tube, 3-7 is the negative copper tube, 4 is the cooling device, 4-1 is the cooling pipe, and 5 is the workpiece. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: according to Figures 1 to 7 As shown, this solution provides a self-resistance heating device for hot gas expansion pipes. The sealed heating section 1 and the power supply 3 are both mounted on a support frame. Specifically, the interior of the sealed section 2 is a cavity structure, the heating section 1 is located inside the sealed section 2, and the power supply 3 is located below the sealed section 2 and electrically connected to the heating section 1. To ensure safety, a baffle is provided on the support frame to protect and shield the power supply 3. Specifically, as... Figure 1 and Figure 2 As shown, the sealing part 2 includes a sealing cover 2-1 and a sealing seat 2-2. The sealing cover 2-1 and the sealing seat 2-2 are connected by a supporting guide. A sealing ring, sealing groove, or other components to increase airtightness can be provided between the sealing cover 2-1 and the sealing seat 2-2. In this embodiment, a sealing strip 2-6 is preferably provided at the port of the sealing cover 2-1. An insulating plate 2-3 is provided inside both the sealing cover 2-1 and the sealing seat 2-2. The supporting guide includes two symmetrically arranged guide pillars 2-4. The sealing cover 2-1 slides up and down along the guide pillars 2-4 under the action of the lifting cylinder 2-5. Preferably, there are two lifting cylinders 2-5 arranged symmetrically, and the guide pillars 2-4 are spaced apart from the lifting cylinder to ensure smooth operation of the sealing cover 2-1 and airtightness when the sealing cover 2-1 is closed.

[0020] The heating unit 1 includes heating electrodes 1-2 and a sliding pair 1-3. In this embodiment, the sliding pair 1-3 is preferably a slider and a slide rail. Specifically, as shown... Figure 6As shown, the conformal electrode clamp 1-1 includes an upper clamping block 1-11 and a lower clamping block 1-13. The upper clamping block 1-11 is mounted on the insulating plate 2-3 inside the sealing cover 2-1 via a set of slide rails and sliders. The lower clamping block 1-13 is mounted on the insulating plate 2-3 inside the sealing seat 2-2 via a set of slide rails and sliders. Figure 3 , 4 As shown. One end of the slide rail is also equipped with limit blocks 1-4, as... Figure 5 As shown, the limiting block 1-4 is used to set the starting position of the slider. Since the energized positions at both ends of different workpieces 5 are different, the limiting block 1-4 can quickly position them. Preferably, the slider can be driven by the cylinder 1-6, and the solenoid valve 1-7 controls the cylinder 1-6 to reset.

[0021] In this embodiment, the heating electrode 1-2 includes an electrode 1-2 and two pairs of conformal electrode clamps 1-1. The electrode 1-2 is disposed on the insulating plate 2-3 inside the sealing seat 2-2 and electrically connected to the lower clamping block 1-13, so that both the upper clamping block 1-11 and the lower clamping block 1-13 are electrically connected to the electrode 1-2 during use. Preferably, an insulating ring is also provided between the electrode 1-2 and the insulating plate 2-3. The conformal electrode clamps 1-1 are provided with workpiece 5 holes adapted to the shape of the energized end of the workpiece 5. For example, when the pipe is only bent in the middle, the workpiece 5 holes on the conformal electrode clamps 1-1 at both ends of the workpiece 5 are oblique holes; when both ends of the pipe are arc-shaped pipes, the workpiece 5 holes on the conformal electrode clamps 1-1 are arc-shaped holes, ensuring that the conformal electrode clamps 1-1 can move with the shape of the pipe. Preferably, after the sealing cover 2-1 moves down and seals, a closed workpiece 5 hole is formed between the upper clamping block 1-11 and the lower clamping block 1-13. Specifically, the upper clamping block 1-11 is provided with an upper slot 1-12, and the lower clamping block 1-13 is provided with a lower slot 1-14. When the upper slot 1-12 and the lower slot 1-14 are combined, they form the 5 holes of the workpiece. Preferably, the arc of the lower slot 1-14 is larger than the arc of the upper slot 1-12, such as... Figure 6 As shown, the workpiece 5 is inserted into the lower slot 1-14 to prevent the workpiece 5 from shifting, ensure that the upper and lower slots 1-14 close smoothly, and avoid scratching the workpiece 5 during the closing process.

[0022] As a further improvement to this embodiment, each pair of conformal electrode clips 1-1 is connected to the positive and negative poles of electrode 1-2 respectively, enabling simultaneous heating of two workpieces 5. Furthermore, for irregularly shaped tubular components, the arrangement of the components saves space; for example, when simultaneously heating two bent tubes, the bends are staggered, making full use of space and achieving heating in a smaller area, resulting in rapid heating and good heat retention. The conformal electrode clips 1-1 are preferably made of copper.

[0023] As a further improvement to this embodiment, the sealing seat 2-2 is also provided with a workpiece 5 support block 1-5, so that the workpiece 5 can only move in the horizontal direction, such as Figure 4As shown, when the workpiece 5 being heated is a tube with a bend in the middle, the holes for workpiece 5 in the upper clamping block 1-11 and the lower clamping block 1-13 are oblique holes. When the upper clamping block 1-11 and the lower clamping block 1-13 move to both sides with the slider, the tube also moves. At this time, the bend in the tube needs to be on the same horizontal plane as both ends of the tube to ensure that the energized end of the tube is on the same horizontal plane, preventing the conformal electrode clamp 1-1 from getting stuck during movement.

[0024] To prevent the electrodes 1-2 from overheating, both the upper clamping block 1-11 and the lower clamping block 1-13 are equipped with cooling through holes, which are connected to the cooling device 4 via cooling pipes 4-1. The coolant flows into the cooling through holes through the cooling pipes 4-1 to directly cool the electrodes 1-2, resulting in a significant cooling effect.

[0025] As a further improvement to this embodiment, the power supply 3 includes multiple sets of parallel DC power generators 3-1. The DC power generators 3-1 are connected in parallel via hollow copper tubes, which are connected to cooling pipes 4-1. Non-conductive coolant flows into the hollow copper tubes for cooling. The hollow copper tubes include a positive electrode copper tube 3-6 and a negative electrode copper tube 3-7, specifically, as shown... Figure 4 and Figure 7 As shown, the positive terminal of each DC power generator 3-1 is connected to the positive copper tube 3-6 via a wire 3-5, and the negative terminal of each DC power generator 3-1 is connected to the negative copper tube 3-7 via a wire 3-5. The lower parts of both the positive and negative copper tubes 3-6 and 3-7 are fixed by multiple insulating support blocks 3-2, and an insulating spacer 3-3 is provided between the positive and negative copper tubes 3-6 and 3-7. To ensure heating efficiency and reduce unnecessary power consumption, a heat dissipation channel 3-4 is provided at the bottom of the power supply 3.

[0026] The workflow is as follows: Step 1: The robot places the tube on the sealing seat 2-2, with both ends of the tube positioned at the lower clamping blocks 1-13. The sealing cap 2-1, driven by the lifting cylinder 2-5, descends along the guide post 2-4 until it closes with the sealing seat 2-2, forming a sealed space inside. Simultaneously, the upper clamping block 1-11 engages with the lower clamping block 1-13, positioning the tube within the workpiece hole 5, forming a closed loop.

[0027] Step 2: The DC power generator 3-1 starts working, providing a low-voltage, high-current power supply 3 to both ends of the tube. Since the tube will deform after heating, the upper clamping block 1-11 and the lower clamping block 1-13 move synchronously under the action of the slider and the guide rail during deformation, thereby adjusting the contact position between the conformal electrode clamp 1-1 and the tube.

[0028] Step 3: When the heated workpiece 5 (pipe) reaches the expected temperature, the sealing cover 2-1 moves upward along the guide column 2-4 under the drive of the lifting cylinder 2-5. After it rises to the designated position, the robot takes out the heated pipe.

[0029] Step 4: Under the control of solenoid valve 1-7, cylinder 1-6 moves upper clamping block 1-11 and lower clamping block 1-13 to limit block 1-4 and abuts against limit block 1-4.

[0030] Repeat the above steps again.

[0031] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics in the solutions is not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A self-resistance heating device for hot gas expansion pipes, characterized in that: Includes a sealing part, a power supply, and a heating part electrically connected to it; The sealing part includes a sealing cover and a sealing seat, and the sealing cover and the sealing seat are connected by a support guide part; The heating unit includes multiple sets of heating electrodes, a sliding pair, and a driving device. The heating electrode includes a conformal electrode clamp and an electrode. The conformal electrode clamp includes an upper clamping block and a lower clamping block. The upper clamping block is mounted on the sealing cover via a sliding pair, and the lower clamping block is mounted on the sealing seat via a sliding pair. The driving device can cause the upper and lower clamping blocks to reciprocate. The power supply, electrodes, and conformal electrode clamps are electrically connected.

2. The self-resistance heating device for hot gas expansion pipes according to claim 1, characterized in that: The sealing seat is also provided with a workpiece support block, which allows the two ends of the workpiece to be located on a horizontal plane and to move only in the horizontal direction.

3. The self-resistance heating device for hot gas expansion pipes according to claim 1, characterized in that: One end of the sliding pair is also provided with a limit block, which is used to set the starting position of the sliding pair.

4. A self-resistance heating device for hot gas expansion pipes according to any one of claims 1 to 3, characterized in that: The conformal electrode clamp is provided with a workpiece hole adapted to the shape of the workpiece.

5. The self-resistance heating device for hot gas expansion pipes according to claim 4, characterized in that: The upper clamping block shown has an upper slot, and the lower clamping block has a lower slot. The upper slot and the lower slot together form a workpiece hole; the lower slot can be used to clamp the workpiece.

6. A self-resistance heating device for hot gas expansion pipes according to claim 1 or 2, characterized in that: Both the upper and lower clamping blocks are provided with cooling through holes, which are connected to cooling pipes.

7. The self-resistance heating device for hot gas expansion pipes according to claim 1, characterized in that: Both the sealing cap and the sealing seat are equipped with insulating plates.

8. The self-resistance heating device for hot gas expansion pipes according to claim 1, characterized in that: The power supply includes multiple sets of DC power generators connected in parallel, which are connected in parallel via hollow copper tubes; the hollow copper tubes are connected to cooling pipes.

9. The self-resistance heating device for hot gas expansion pipes according to claim 8, characterized in that: The hollow copper tube is provided with multiple insulating support blocks at its lower part; the hollow copper tube includes a positive copper tube and a negative copper tube, and an insulating spacer is provided between the positive copper tube and the negative copper tube.

10. A self-resistance heating device for hot gas expansion pipes according to claim 1 or 8, characterized in that: A heat dissipation channel is provided on one side of the power supply.

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