An electric heating machine for ultra-high strength steel profile
Patent Information
- Application Number
- CN202610936536.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-26
- Publication Date
- 2026-10-23
AI Technical Summary
[0004]本发明的目的是解决现有通电加热设备在加热管材时，由于管材的两端被支座所刚性固定，管材的热膨胀迫使管材产生挤压、弯曲甚至屈曲等塑性变形，严重影响最终产品的质量的问题
[0006]与现有技术相比，上述方案构建了对管材的两级装夹机制：在初步定位阶段，通过第二动力缸推动前支座靠近后支座，使得管材的两端分别插入前插槽和后插槽，从而不仅能实现对管材的轴向约束，而且能实现对管材在径向上的位置的初步定位；而在二次定位阶段，通过第三动力缸推动后限位块向前靠近前限位块，使得前限位块和后限位块分别从管材内孔的前端和后端插入，实现对管材的径向约束，确保管材被稳定、准确地定位在前支座和后支座之间；同时，前限位块和后限位块将管材和线缆连接成回路，当供电组件供电时，管材通过自身电阻的热效应实现迅速加热，加热效率高且均匀性好，且由于此时第一动力缸的输出杆为随动状态，当管材受热膨胀伸长时，前支座可随之向前移动，有效释放了管材的热应力，从根本上避免了现有技术中管材加热时因刚性约束而产生挤压、弯曲甚至屈曲等塑性变形，保证了管材的直线度与端部结构稳定性，显著提升了热加工质量。
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Figure CN122970723A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of pipe heating equipment, and more specifically to an electric heating machine for ultra-high strength steel profiles. Background Technology
[0002] Electric heating is a technology that utilizes the workpiece's own resistance for heating. Due to its rapid heating and high thermal efficiency, it has been widely used in the heat treatment of tubular profiles. Its basic principle is to connect the tube to be heated as a conductor in series with a low-voltage, high-current circuit. When the high current flows, the Joule heat generated by the tube's own resistance causes its temperature to rise rapidly, thus achieving the heating purpose.
[0003] In existing electrically heated devices of this type, a pair of supports are typically installed to fix both ends of the pipe. These supports serve as both the fixing carrier for the pipe and the connection carrier between the pipe and the circuit. However, in practical applications, a significant drawback of existing devices has been found: due to the relatively long axial length of the pipe, as the pipe temperature rises during heating, the material expands due to heat, resulting in significant elongation deformation in the axial direction. Because the two ends of the pipe are rigidly fixed by the supports, this expansion deformation cannot be effectively absorbed, forcing the pipe to undergo plastic deformation such as compression, bending, or even buckling. When the heating process ends and the pipe cools and shrinks, these deformations remain permanently, directly causing a decline in key quality indicators such as the straightness and end shape accuracy of the pipe, seriously affecting the quality of the final product. Summary of the Invention
[0004] The purpose of this invention is to solve the problem that when existing electrically heated pipes are heated, the pipes are rigidly fixed at both ends by supports, and the thermal expansion of the pipes forces them to undergo plastic deformations such as compression, bending, or even buckling, which seriously affects the quality of the final product.
[0005] To address the aforementioned problems, this invention provides an electric heating machine for ultra-high strength steel profiles, comprising a base, a front support slidably connected to the front of the base in a front-to-back direction, and a rear support fixed to the rear of the base. The front of the base is further provided with a fixed first power cylinder and a second power cylinder movable back-to-back. The output rod of the first power cylinder acts on the second power cylinder to drive it to move back and forth, and the output rod of the second power cylinder acts on the front support to drive it to move back and forth. The front and rear supports are respectively provided with a front slot and a rear slot for inserting pipes. A front limiting block is fixed inside the front slot, and a rear limiting block is provided inside the rear slot. The rear support is provided with a third power cylinder for driving the rear limiting block to move back and forth. Both the front and rear limiting blocks are made of conductive material and are electrically connected via cables. At least one of the front and rear supports is provided with a power supply module. The output rod of the first power cylinder has a fixed state and a follow-up state: when the pipe is moved between the front support and the rear support, the output rod of the first power cylinder is in a fixed state. The second power cylinder drives the front support to move backward so that the front end and the rear end of the pipe are inserted into the front slot and the rear slot respectively. At this time, the third power cylinder drives the rear limit block to move forward so that the front limit block and the rear limit block are inserted into the front end and the rear end of the inner hole of the pipe respectively. The pipe and the cable form a circuit and are powered by the power supply module. When the power supply module supplies power, the output rod of the first power cylinder switches to the follow-up state.
[0006] Compared with existing technologies, the above solution constructs a two-stage clamping mechanism for the pipe: In the initial positioning stage, the second power cylinder pushes the front support closer to the rear support, causing both ends of the pipe to be inserted into the front and rear slots respectively. This not only achieves axial constraint on the pipe but also provides initial radial positioning. In the secondary positioning stage, the third power cylinder pushes the rear limiting block forward closer to the front limiting block, causing the front and rear limiting blocks to be inserted from the front and rear ends of the pipe's inner hole respectively. This achieves radial constraint on the pipe, ensuring that the pipe is stably and accurately positioned on the front support. Between the seat and the rear support; at the same time, the front limit block and the rear limit block connect the pipe and the cable into a circuit. When the power supply component supplies power, the pipe is rapidly heated through the thermal effect of its own resistance. The heating efficiency is high and the uniformity is good. Since the output rod of the first power cylinder is in a follow-up state at this time, when the pipe expands and elongates due to heat, the front support can move forward accordingly, effectively releasing the thermal stress of the pipe. This fundamentally avoids the plastic deformation such as squeezing, bending or even buckling caused by rigid constraints when the pipe is heated in the existing technology, ensuring the straightness of the pipe and the stability of the end structure, and significantly improving the quality of hot processing.
[0007] In an improved embodiment, the distance between the outer peripheral wall of the front limiting block and the side peripheral wall of the front slot is greater than the thickness of the tube, and the distance between the outer peripheral wall of the rear limiting block and the side peripheral wall of the rear slot is greater than the thickness of the tube. This ensures that when the front and rear limiting blocks are inserted into the front and rear ends of the inner hole of the tube, respectively, the outer wall of the front end of the tube is in a non-contact state with the side peripheral wall of the front slot, and the outer wall of the rear end of the tube is in a non-contact state with the side peripheral wall of the rear slot. This not only avoids the problem of the outer wall of the tube abutting or getting stuck with the side slot walls of the front and rear slots when heated and expanded, but also reduces the requirements for the dimensional tolerance of the tube and improves the adaptability of the tube.
[0008] In an improved embodiment, both the front and rear supports are equipped with side-push cylinders. Each of the front and rear slots has an opening on either side in the left or right direction. The side-push cylinder is oriented towards the corresponding opening, and its output rod has a pusher for pushing the tube. By driving the pusher, the side-push cylinder pushes the tube, ensuring the accurate positioning of the tube end within the front or rear slot. This creates more precise alignment conditions for the subsequent insertion of the front and rear limit blocks into the tube's inner hole.
[0009] In an improved embodiment, the base is provided with a heat insulation cover extending in the front-rear direction. The heat insulation cover is located between the front support and the rear support, and the heat insulation cover has an inner hole in the front-rear direction for the pipe to pass through. Thus, the heat insulation cover covers the pipe, reduces heat loss from the pipe during heating, and improves the heating rate and energy utilization.
[0010] In an improved embodiment, the heat insulation cover includes a side plate fixedly connected to the base and a housing slidably connected to the base in a left-right direction. The side plate and the housing are located on the left and right sides of the pipe, respectively. The housing has a C-shaped cross-section with the C-shaped opening facing the side plate. The inner hole is formed when the housing and the side plate are closed. When the housing and the side plate are closed, an inner hole is formed, providing good insulation for the pipe; when separated, it opens up the operating space, facilitating the loading and unloading of the pipe.
[0011] In an improved embodiment, the base is provided with a push-and-close power cylinder arranged in the left-right direction. The output rod of the push-and-close power cylinder acts on the cover to drive the cover to close or separate from the side plate, thereby realizing automatic pushing of the cover through the push-and-close power cylinder, which is convenient for operation.
[0012] In an improved embodiment, the lower side wall of the inner hole is provided with a support for the pipe to abut against, thereby supporting the middle part of the pipe and preventing the middle part of the pipe from being suspended and deformed during heating. Attached Figure Description
[0013] Figure 1 A schematic diagram of an electric heating machine for ultra-high strength steel profiles; Figure 2 A top view schematic diagram of an electric heating machine for ultra-high strength steel profiles; Figure 3 For along Figure 2 Cross-sectional view of section AA in the middle; Figure 4 For along Figure 2 Cross-sectional view of the BB section line; Figure 5 For along Figure 2 A cross-sectional view of the CC section line; Figure 6 For along Figure 2 Schematic diagram of the DD section line in the middle.
[0014] Explanation of reference numerals in the attached figures. 1. Base; 11. Push-opening power cylinder; 2. Front support; 21. Front limit block; 22. Front slot; 23. Power supply module; 24. Cable; 3. Rear support; 31. Rear limit block; 32. Rear slot; 33. Third power cylinder; 4. First power cylinder; 5. Second power cylinder; 6. Side push-opening power cylinder; 61. Push plate; 7. Heat insulation cover; 7a. Inner hole; 71. Side plate; 72. Cover; 721. Support platform. Detailed Implementation
[0015] It should be understood by those skilled in the art that the following embodiments are merely illustrative of the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.
[0016] In the following description of the embodiments, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.
[0017] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0018] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0019] Please see Figures 1-6An embodiment of the present invention provides an electric heating machine for ultra-high strength steel profiles, comprising a base 1, a front support 2 slidably connected to the front of the base 1 in a front-rear direction, and a rear support 3 fixed to the rear of the base 1. The front of the base 1 is also provided with a fixed first power cylinder 4 and a second power cylinder 5 that can move back and forth. The output rod of the first power cylinder 4 acts on the second power cylinder 5 to drive the second power cylinder 5 to move back and forth, and the output rod of the second power cylinder 5 acts on the front support 2 to drive the front support 2 to move back and forth. The front support 2 and the rear support 3 are respectively provided with a front slot 22 and a rear slot 32 for pipe insertion on opposite sides. A front limit block 21 is fixed in the front slot 22, and a rear limit block 31 is provided in the rear slot 32. The rear support 3 is provided with a third power cylinder 33 for driving the rear limit block 31 to move back and forth. The front limit block 21 and the rear limit block 31 are both made of conductive material and are electrically connected by a cable 24. At least one of the front support 2 and the rear support 3 is provided with a power supply module 23. The output rod of the first power cylinder 4 has a fixed state and a follow-up state: when the pipe is moved between the front support 2 and the rear support 3, the output rod of the first power cylinder 4 is in a fixed state. The second power cylinder 5 drives the front support 2 to move backward so that the front end and the rear end of the pipe are inserted into the front slot 22 and the rear slot 32 respectively. At this time, the third power cylinder 33 drives the rear limit block 31 to move forward so that the front limit block 21 and the rear limit block 31 are inserted into the front end and the rear end of the inner hole 7a of the pipe respectively. The pipe and the cable 24 form a circuit and are powered by the power supply module 23. When the power supply module 23 supplies power, the output rod of the first power cylinder 4 switches to the follow-up state.
[0020] Compared with existing technologies, the above solution constructs a two-stage clamping mechanism for the pipe: In the initial positioning stage, the second power cylinder 5 pushes the front support 2 closer to the rear support 3, so that both ends of the pipe are inserted into the front slot 22 and the rear slot 32 respectively, thereby achieving not only axial constraint of the pipe, but also initial positioning of the pipe in the radial direction; In the secondary positioning stage, the third power cylinder 33 pushes the rear limiting block 31 forward closer to the front limiting block 21, so that the front limiting block 21 and the rear limiting block 31 are inserted from the front end and the rear end of the inner hole 7a of the pipe respectively, achieving radial constraint of the pipe and ensuring that the pipe is stably and accurately positioned. Located between the front support 2 and the rear support 3; at the same time, the front limit block 21 and the rear limit block 31 connect the pipe and the cable 24 into a circuit. When the power supply component supplies power, the pipe is rapidly heated through the thermal effect of its own resistance. The heating efficiency is high and the uniformity is good. Since the output rod of the first power cylinder 4 is in a follow-up state at this time, when the pipe expands and elongates due to heat, the front support 2 can move forward accordingly, effectively releasing the thermal stress of the pipe. This fundamentally avoids the plastic deformation such as squeezing, bending or even buckling caused by rigid constraints when the pipe is heated in the prior art, ensuring the straightness of the pipe and the stability of the end structure, and significantly improving the quality of hot processing.
[0021] In this embodiment, the front of the base 1 is provided with a slide rail arranged in the front-to-back direction. The cylinder bodies of the front support 2 and the second power cylinder 5 are slidably connected to the slide rail to achieve a movable effect in the front-to-back direction. The first power cylinder 4, the second power cylinder 5, and the third power cylinder 33 are preferably pneumatic cylinders, but they can also be hydraulic cylinders, etc. The cylinder body of the first power cylinder 4 is installed on the base 1. The output rod of the first power cylinder 4 is set rearward and connected to the cylinder body of the second power cylinder 5. The output rod of the second power cylinder 5 is set rearward and connected to the front support 2. Pneumatic cylinders have the advantages of compact structure and simple control. Only the charging / discharging of the medium in the first power cylinder 4 needs to be controlled to switch the fixed state and the follow-up state of the output rod of the first power cylinder 4. The cable 24 is located on the side of the base 1. The front end of the cable 24 is connected to the front limit block 21 and the rear end is connected to the rear limit block 31. The power supply module 23 is installed on the front support 2 and connected in series to the cable 24.
[0022] In practical use, before the power supply module 23 supplies power, the first power cylinder 4 is inflated, causing the output rod to extend and remain in a fixed state, so that the cylinder body of the second power cylinder 5 remains stationary relative to the base 1. When the tube is moved between the front support 2 and the rear support 3, the second power cylinder 5 pushes the front support 2 closer to the rear support 3, so that both ends of the tube are inserted into the front slot 22 and the rear slot 32 respectively. Then, the third power cylinder 33 pushes the rear limit block 31 forward to approach the front limit block 21, so that the front limit block 21 and the rear limit block 31 are inserted from the front end and the rear end of the inner hole 7a of the tube respectively. At this time, the tube is positioned between the front support 2 and the rear support 3, and the front limit block 21 and the rear limit block 31 connect the tube and the cable 24 into a circuit. Then, when the power supply component supplies power, the first power cylinder 4 switches to deflating, so that the output rod is in a follow-up state. When the tube expands and elongates due to the thermal effect of its own resistance, the front support 2 can move forward accordingly, thereby effectively releasing the thermal stress of the tube.
[0023] In this embodiment, the distance between the outer peripheral wall of the front limiting block 21 and the side peripheral wall of the front slot 22 is greater than the thickness of the pipe, and the distance between the outer peripheral wall of the rear limiting block 31 and the side peripheral wall of the rear slot 32 is greater than the thickness of the pipe. This ensures that when the front limiting block 21 and the rear limiting block 31 are respectively inserted into the front end and the rear end of the inner hole 7a of the pipe, the outer wall of the front end of the pipe is in a non-contact state with the side peripheral wall of the front slot 22, and the outer wall of the rear end of the pipe is in a non-contact state with the side peripheral wall of the rear slot 32. This not only avoids the problem of the outer wall of the pipe abutting or getting stuck with the side slot walls of the front slot 22 and the rear slot 32 when the pipe expands due to heating, but also reduces the requirements for pipe size tolerance and improves the adaptability of the pipe.
[0024] Furthermore, both the front support 2 and the rear support 3 are equipped with side-push cylinders 6. Openings are provided on either the left or right side of the front slot 22 and the rear slot 32, with the side-push cylinder 6 facing the corresponding opening. The output rod of the side-push cylinder 6 is equipped with a pusher plate 61 for pushing the pipe. By driving the pusher plate 61, the side-push cylinder 6 pushes the pipe, ensuring the accurate positioning of the pipe end within the front slot 22 or the rear slot 32. This creates more accurate alignment conditions for the subsequent smooth insertion of the front limit block 21 and the rear limit block 31 into the inner hole 7a of the pipe. Of course, the side-push cylinder 6 will only push the push plate 61 to push the front and rear ends of the pipe when the end of the pipe is just inserted into the front slot 22 and the rear slot 32. After the front limit block 21 and the rear limit block 31 are inserted into the front and rear ends of the inner hole 7a of the pipe to achieve radial constraint on the pipe, the side-push cylinder 6 can drive the push plate 61 to detach from the outer wall of the pipe and re-form a non-contact state, so as to avoid the outer wall of the pipe being squeezed by the push plate 61 when it is heated and expanded.
[0025] As an improvement to this embodiment, the base 1 is provided with a heat insulation cover 7 extending in the front-rear direction. The heat insulation cover 7 is located between the front support 2 and the rear support 3, and the heat insulation cover 7 has an inner hole 7a for the pipe to pass through in the front-rear direction. Thus, the heat insulation cover 7 covers the pipe, reduces the heat loss of the pipe during heating, and improves the heating rate and energy utilization.
[0026] Furthermore, the heat insulation cover 7 includes a side plate 71 fixedly connected to the base 1 and a cover 72 slidably connected to the base 1 in the left-right direction. The side plate 71 and the cover 72 are located on the left and right sides of the pipe, respectively. The cover 72 has a C-shaped cross-section with the C-shaped opening facing the side plate 71. The inner hole 7a is formed when the cover 72 and the side plate 71 are closed. When the cover 72 and the side plate 71 are closed, the inner hole 7a is formed, which provides good heat insulation for the pipe. When separated, it opens the operating space, facilitating the loading and unloading of the pipe. Furthermore, the base 1 is provided with a push-and-close power cylinder 11 arranged in the left-right direction. The output rod of the push-and-close power cylinder 11 acts on the cover 72 to drive the cover 72 to close or separate from the side plate 71, thereby realizing the automatic pushing of the cover 72 through the push-and-close power cylinder 11, which is convenient for operation.
[0027] In this embodiment, the lower side wall of the inner hole 7a is provided with a support 721 for the pipe to abut against, thereby supporting the middle part of the pipe and preventing the pipe from being suspended in the air and deforming during heating. Of course, the heat insulation cover 7 should preferably be made of insulating material to prevent leakage.
[0028] It should be noted that in the description of this application, the terms "inner" and "outer," etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application. All directional indications (such as up, down, left, right, front, back, inner, and outer) are only used to explain the relative positional relationships and movement between components in a specific posture. If the specific posture changes, the directional indication will also change accordingly.
[0029] In the description of this application, the references to terms such as "an embodiment," "some embodiments," "in this embodiment," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0030] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. An electric heating machine for ultra-high strength steel profiles, characterized in that, The system includes a base (1), a front support (2) slidably connected to the front of the base (1) in a front-rear direction, and a rear support (3) fixed to the rear of the base (1). The front of the base (1) is also provided with a fixed first power cylinder (4) and a second power cylinder (5) that can move back and forth. The output rod of the first power cylinder (4) acts on the second power cylinder (5) to drive the second power cylinder (5) to move back and forth. The output rod of the second power cylinder (5) acts on the front support (2) to drive the front support (2) to move back and forth. The front support (2) and the rear support (3) On opposite sides, there are front slots (22) and rear slots (32) for inserting pipes. A front limiting block (21) is fixed in the front slot (22), and a rear limiting block (31) is provided in the rear slot (32). The rear support (3) is provided with a third power cylinder (33) for driving the rear limiting block (31) to move back and forth. The front limiting block (21) and the rear limiting block (31) are both made of conductive material and are electrically connected by a cable (24). At least one of the front support (2) and the rear support (3) is provided with a power supply module (23). The output rod of the first power cylinder (4) has a fixed state and a follow-up state: when the pipe is moved between the front support (2) and the rear support (3), the output rod of the first power cylinder (4) is in a fixed state. The second power cylinder (5) drives the front support (2) to move backward so that the front end and the rear end of the pipe are inserted into the front slot (22) and the rear slot (32) respectively. At this time, the third power cylinder (33) drives the rear limit block (31) to move forward so that the front limit block (21) and the rear limit block (31) are inserted into the front end and the rear end of the inner hole (7a) of the pipe respectively. The pipe and the cable (24) form a circuit and are powered by the power supply module (23). When the power supply module (23) supplies power, the output rod of the first power cylinder (4) switches to the follow-up state.
2. The electric heating machine for ultra-high strength steel profiles according to claim 1, characterized in that, The distance between the outer peripheral wall of the front limiting block (21) and the side peripheral wall of the front slot (22) is greater than the thickness of the pipe, and the distance between the outer peripheral wall of the rear limiting block (31) and the side peripheral wall of the rear slot (32) is greater than the thickness of the pipe, so that when the front limiting block (21) and the rear limiting block (31) are respectively inserted into the front end and the rear end of the inner hole (7a) of the pipe, the outer peripheral wall of the front end of the pipe and the side peripheral wall of the front slot (22) and the outer peripheral wall of the rear end of the pipe and the side peripheral wall of the rear slot (32) are in a non-contact state.
3. The electric heating machine for ultra-high strength steel profiles according to claim 1 or 2, characterized in that, Both the front support (2) and the rear support (3) are provided with a side thrust cylinder (6). The front slot (22) and the rear slot (32) are provided with an opening on either side in the left or right direction. The side thrust cylinder (6) is set facing the corresponding opening, and the output rod of the side thrust cylinder (6) is provided with a pusher (61) for pushing the tube.
4. The electric heating machine for ultra-high strength steel profiles according to claim 1, characterized in that, The base (1) is provided with a heat insulation cover (7) extending in the front-rear direction. The heat insulation cover (7) is located between the front support (2) and the rear support (3), and the heat insulation cover (7) has an inner hole (7a) for the pipe to pass through in the front-rear direction.
5. The electric heating machine for ultra-high strength steel profiles according to claim 4, characterized in that, The heat insulation cover (7) includes a side plate (71) fixedly connected to the base (1) and a cover (72) slidably connected to the base (1) in the left and right direction. The side plate (71) and the cover (72) are located on the left and right sides of the pipe, respectively. The cover (72) has a C-shaped cross section and the C-shaped opening faces the side plate (71). The inner hole (7a) is formed by the cover (72) and the side plate (71) closing together.
6. The electric heating machine for ultra-high strength steel profiles according to claim 5, characterized in that, The base (1) is provided with a push-and-close power cylinder (11) arranged in the left and right direction. The output rod of the push-and-close power cylinder (11) acts on the cover (72) to drive the cover (72) to close or separate from the side plate (71).
7. The electric heating machine for ultra-high strength steel profiles according to claim 5, characterized in that, The lower side wall of the inner hole (7a) is provided with a support (721) for the pipe to abut against.