Aluminum flat tube profile extrusion on-line correction and cutting process

Abstract

This invention relates to an online straightening and precision cutting process for extruded aluminum flat tube profiles. After cleaning, the aluminum rod is fed into a mold for constant-temperature extrusion, followed by surface zinc spraying, then forced-air cooling quenching, and finally eddy current testing, tension checking, straightening and traction, precision cutting to length, conveying, and packaging. In the forced-air cooling quenching process, an online forced-air cooling device is used to cool the aluminum flat tube profiles. This device includes an upper air box, a lower air box, and an eddy current tube, which is driven by compressed air and supplied with a cold air source. This invention utilizes forced-air cooling quenching to replace conventional air-cooling or water-cooling quenching processes. By using a forced-air cooling device for online air cooling of the aluminum flat tube profiles, it overcomes the low cooling rate and low quenching strength defects caused by conventional air-cooling quenching processes, improves the uniformity of cooling of the aluminum flat tube profiles, and reduces the defect rate.

Description

Technical Field

[0001] This invention relates to an online straightening and precision cutting process for extruding aluminum flat tube profiles, belonging to the field of new energy component manufacturing technology. Background Technology

[0002] Aluminum flat tube profiles are short for porous microchannel flat tube profiles of aluminum and aluminum alloys. The process involves placing aluminum or aluminum alloy into an extrusion cylinder and applying pressure, causing it to flow out through specific die holes to obtain the desired cross-sectional shape and dimensions. Subsequent dimensional adjustments include width correction, thickness correction, leveling, straightening, and tensile testing. Currently, this production method is inefficient, costly, and cumbersome.

[0003] Its main process flow is as follows:

[0004] The process begins with cleaning the aluminum rods, followed by gradient heating of the aluminum rods and preparation of the mold. Then, constant temperature extrusion is performed, followed by zinc spraying on the surface, water quenching, cooling annealing, drying, eddy current testing, tension checking, straightening and traction, length cutting, conveying, and packaging.

[0005] Online quenching can play a role in controlling the shape and properties of extruded aluminum flat tube profiles. Currently, online air-cooled quenching of aluminum flat tube profiles mostly adopts the method of overall top and bottom air blowing cooling. That is, the lower air nozzle of the quenching device is supplied with air by a fan to cool the extruded aluminum flat tube profile, while the upper air nozzle and the air nozzles on both sides of the quenching device are supplied with air by a single fan to cool the extruded aluminum flat tube profile. This method can achieve a good cooling effect for extruded profiles with symmetrical structures by adjusting the air volume output of the fan. However, for extruded aluminum materials with asymmetrical structures, since it is not possible to adjust the left and right air nozzles individually, it will cause uneven cooling, resulting in a higher defect rate of aluminum flat tube profiles.

[0006] In addition, compared with water-cooled quenching, the temperature of the compressed air output by the air compressor is usually 25~30℃, which has low cooling efficiency and makes it difficult to meet the quenching strength requirements. If you want to improve the cooling efficiency of air-cooled quenching, lowering the temperature of the compressed air can significantly improve the quenching strength. However, if you want to cool down the air compressor, conventional heat exchangers cannot achieve this. You can only use ice water or low-temperature refrigerant for cooling, which has limited heat exchange efficiency, large heat loss, and is very energy-intensive.

[0007] While water immersion quenching (water cooling quenching) has a high cooling rate, it cannot accurately control the cooling rate of aluminum profiles with different materials and wall thicknesses. Due to the fast cooling rate, a large amount of stress is generated, and defects such as twisting and straightness of the aluminum flat tube profiles after they come out of the water tank cannot be controlled. The quenching of aluminum flat tube profiles often results in severe deformation, which brings difficulties to subsequent online straightening and precision cutting processes.

[0008] Based on this, the present invention is proposed. Summary of the Invention

[0009] This invention addresses the shortcomings of existing technologies by providing an online straightening and precision cutting process for extruding aluminum flat tube profiles. The specific technical solution is as follows:

[0010] An online straightening and precision cutting process for extruding aluminum flat tube profiles includes the following steps:

[0011] After cleaning, the aluminum bars are fed into the mold for constant temperature extrusion, followed by surface zinc spraying, strong air quenching, eddy current testing, tension inspection, straightening and traction, precision cutting to length, conveying, and pipe packaging.

[0012] As an improvement to the above technical solution, in the high-pressure air cooling quenching operation, a high-pressure air cooling quenching device is used to cool aluminum flat tube profiles online. The high-pressure air cooling quenching device includes an upper air box, a lower air box, and a vortex tube for supplying cold air to the upper and lower air boxes. The vortex tube is driven by compressed air and provides a cold air source. An upper air nozzle is provided at the lower center of the upper air box, and side air pipes are provided on both sides of the upper air box. A side air nozzle is provided on the inner side of the lower end of the side air pipe. A lower air nozzle is provided at the upper center of the lower air box. The upper and lower air nozzles are arranged opposite each other, and the two side air nozzles are arranged opposite each other. An air inlet pipe is provided at the upper part of the upper air box.

[0013] As an improvement to the above technical solution, the side duct includes an elastic pipe section and a rigid pipe section. The lower end of the rigid pipe section is closed, and the side wall of the elastic pipe section is provided with a pleated structure. The outer side of the side duct is a planar structure. A first magnetic block is embedded at the lower end of the outer side of the side duct, and a side duct magnetic drive mechanism for driving the side duct to swing is provided on the outer side of the side duct.

[0014] As an improvement to the above technical solution, the side duct magnetic drive mechanism includes a vertical plate fixedly connected to the lower end of the upper air box. A first electromagnet matching the first magnetic block is embedded in the lower end of the vertical plate. An oval hole is also provided in the middle of the vertical plate. A side plate is fixedly installed on the outer side of the vertical plate. A tension spring is provided between the side plate and the outer side of the rigid pipe section. One end of the tension spring is fixedly connected to the side plate, and the other end of the tension spring passes through the oval hole and is fixedly connected to the outer side of the rigid pipe section.

[0015] As an improvement to the above technical solution, the lower air box includes a box body, an air inlet is provided at the center of the lower part of the box body, and a rectangular tube is embedded at the center of the upper end of the lower air box. The inner cavity of the rectangular tube is connected to the inner cavity of the box body. A partition is fixedly installed inside the rectangular tube. The partition is provided with multiple air holes. A magnetic gate plate for controlling the opening degree of the air holes is provided inside the air holes. The magnetic gate plate is rotatably connected to the partition. A first magnetic drive mesh plate located above the partition is fixedly installed at the upper end of the rectangular tube. A first electromagnetic plate for driving the magnetic gate plate to rotate is provided on the first magnetic drive mesh plate. A second magnetic drive mesh plate located below the partition is also provided inside the rectangular tube. The surfaces of the second magnetic drive mesh plate and the first magnetic drive mesh plate are provided with mesh holes. A second electromagnetic plate for driving the magnetic gate plate to rotate is provided on the second magnetic drive mesh plate.

[0016] As an improvement to the above technical solution, an annular third electromagnetic plate located above the second magnetic drive mesh plate is also fixedly installed inside the rectangular tube. A permanent magnet ring adapted to the third electromagnetic plate is fixedly installed on the edge of the second magnetic drive mesh plate. An electromagnetic ring matching the permanent magnet ring is fixedly installed at the lower end of the rectangular tube. Multiple compression springs are provided between the permanent magnet ring and the electromagnetic ring.

[0017] As an improvement to the above technical solution, a collar is fixedly installed inside the box body. The collar is sleeved on the outside of the rectangular tube, and the lower part of the collar is provided with an inclined surface structure.

[0018] As an improvement to the above technical solution, the magnetic gate plate and the air hole are fitted with a clearance, and the permanent magnet ring and the rectangular tube are fitted with a clearance.

[0019] As an improvement to the above technical solution, the magnetic gate includes a square shaft made of aluminum alloy. The two ends of the square shaft are coaxially connected to a circular rotating shaft. The wall of the air hole is provided with a mounting hole that is clearance-fitted with the rotating shaft. The two ends of the square shaft are respectively fixedly connected to permanent magnet plates. The ends of the permanent magnet plates and the ends of the air holes are both arc-shaped structures.

[0020] As an improvement to the above technical solution, the oscillation frequency of the rigid pipe section is 1~2Hz, the angle between the width direction of the magnetic gate and the length direction of the air hole is λ, the variation range of λ is -27°~27°, and the rate of change of the value of λ is 2° / s.

[0021] The beneficial effects of this invention are:

[0022] The online straightening and precision cutting process for aluminum flat tube profile extrusion has been improved by optimizing the existing conventional air-cooling quenching operation into a high-intensity air-cooling quenching operation, providing a foundation for subsequent online straightening and precision cutting. The high-intensity air-cooling quenching equipment overcomes the low quenching strength caused by the low cooling rate of conventional air-cooling quenching operations. Regardless of whether the aluminum flat tube profile structure is symmetrical, the cooling air can be controlled at the bottom, left, and right sides of the aluminum flat tube profile according to its material and structure, improving the uniformity of cooling and reducing the defect rate of the aluminum flat tube profile to below 6.8%. Furthermore, the high-intensity air-cooling quenching equipment provides rapid, efficient, and energy-saving cooling. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the high-pressure air cooling and quenching equipment described in this invention;

[0024] Figure 2 This is a schematic diagram of the upper wind box described in this invention;

[0025] Figure 3 This is a schematic diagram of the upper air box of the present invention without the side air duct installed;

[0026] Figure 4 This is a schematic diagram of the upper air box without the side air duct magnetic drive mechanism installed according to the present invention;

[0027] Figure 5 This is a schematic diagram of the structure of the lower air box described in this invention;

[0028] Figure 6 A schematic diagram showing the distribution of the magnetic gate and air holes when the value of λ is negative;

[0029] Figure 7 A schematic diagram showing the distribution of the magnetic gate and air holes when λ is a positive value. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0031] In the description of this invention, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention 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, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Example 1

[0033] An online straightening and precision cutting process for extruding aluminum flat tube profiles includes the following steps:

[0034] After cleaning, the aluminum bars are fed into the mold for constant temperature extrusion, followed by surface zinc spraying, strong air quenching, eddy current testing, tension inspection, straightening and traction, precision cutting to length, conveying, and pipe packaging.

[0035] First, compared to the water immersion quenching method, the process in this embodiment uses a strong air cooling quenching operation. Compared to the water immersion quenching method, the defects such as twist and straightness of the aluminum flat tube profile can be effectively controlled after quenching, the defect rate is significantly reduced, and it is convenient for subsequent online correction and precision cutting.

[0036] As for the problem that ordinary air-cooled quenching has low cooling efficiency and is not easy to meet the quenching strength requirements, the present invention can significantly improve this through strong air-cooled quenching operation. Example 2

[0037] In high-pressure air cooling quenching operations, high-pressure air cooling quenching equipment is used for online air cooling of aluminum flat tube profiles, such as... Figure 1As shown, the high-pressure air cooling quenching equipment includes an upper air box 10, a lower air box 20, and a vortex tube 40 for supplying cold air to the upper air box 10 and the lower air box 20. The vortex tube 40 is driven by compressed air and provides a cold air source. An upper air nozzle 12 is provided at the lower center of the upper air box 10. Side air pipes 30 are provided on both sides of the upper air box 10. A side air nozzle 32 is provided on the inner side of the lower end of the side air pipe 30. A lower air nozzle is provided at the upper center of the lower air box 20. The upper air nozzle 12 and the lower air nozzle are arranged opposite each other, and the two side air nozzles 32 are arranged opposite each other. An air inlet pipe 11 is provided at the upper part of the upper air box 10.

[0038] First, the vortex tube 40 can be a vortex tube from Nanjing Jinbeide Technology Development Co., Ltd., which can achieve an instantaneous temperature drop of up to 35℃. For example, the inlet temperature of compressed air entering the vortex tube 40 is 27℃, the inlet pressure is 0.7MPa, its cold end temperature can reach as low as 4℃, and its hot end temperature exceeds 42℃. The vortex tube 40 is a purely mechanical component, requiring no additional electric drive. It has high cooling efficiency and can cool high-pressure compressed air to low-temperature compressed air (such as 4℃) in a short time. The low-temperature compressed air will be used to provide cooling air to the upper air box 10 and the lower air box 20. Compared with air cooling using room temperature compressed air, the readily available and energy-efficient low-temperature compressed air performs strong air cooling quenching operations on aluminum flat tube profiles, with high cooling efficiency and maximizing the satisfaction of quenching strength requirements.

[0039] Finally, the lower air nozzle, the two side air nozzles 32, and the upper air nozzle 12 are located around the aluminum flat tube profile, providing all-round air cooling for the aluminum flat tube profile. Example 3

[0040] like Figures 2-4 As shown, the side duct 30 includes an elastic pipe section 33 and a rigid pipe section 31. The lower end of the rigid pipe section 31 is closed, and the side wall of the elastic pipe section 33 is provided with a pleated structure. The outer side of the side duct 30 is a planar structure. A first magnetic block 34 is embedded at the lower end of the outer side of the side duct 30, and a side duct magnetic drive mechanism 50 for driving the side duct 30 to swing is provided on the outer side of the side duct 30.

[0041] The side air duct magnetic drive mechanism 50 can drive the side air duct 30 to swing, mainly to adjust the direction of the cold air blown out of the side air nozzle 32. By changing the air direction, the wind force of the cold air facing the aluminum flat tube profile is changed, thereby dynamically adjusting the cooling effect of the side of the aluminum flat tube profile. Example 4

[0042] The side duct magnetic drive mechanism 50 includes a vertical plate 51 fixedly connected to the lower end of the upper air box 10. The lower end of the vertical plate 51 is fitted with a first electromagnet 52 that matches the first magnetic block 34. The middle part of the vertical plate 51 is also provided with an oval hole 511. A side plate 54 is fixedly installed on the outer side of the vertical plate 51. A tension spring 53 is provided between the side plate 54 and the outer side of the rigid pipe section 31. One end of the tension spring 53 is fixedly connected to the side plate 54, and the other end of the tension spring 53 passes through the oval hole 511 and is fixedly connected to the outer side of the rigid pipe section 31.

[0043] Based on Embodiment 3, when the first electromagnet 52 is energized, it generates a magnetic force that repels the first magnetic block 34 (permanent magnet), causing the rigid tube segment 31 to swing. The pleated structure on the elastic tube segment 33 facilitates the swinging of the rigid tube segment 31. When the first electromagnet 52 is de-energized, the elastic force of the stretched tension spring 53 can pull the swinging rigid tube segment 31 back to its original position.

[0044] In this way, the magnitude and frequency of the magnetic force generated by energizing the first electromagnet 52 can be used to control the direction and oscillation frequency of the cold air blown out from the side air nozzle 32. Example 5

[0045] like Figure 5 As shown, the lower air box 20 includes a box body 21. An air inlet 211 is located at the center of the lower part of the box body 21. A rectangular tube 22 is embedded at the center of the upper end of the lower air box 20, and the inner cavity of the rectangular tube 22 communicates with the inner cavity of the box body 21. A partition 25 is fixedly installed inside the rectangular tube 22. Multiple air holes 251 are provided on the partition 25. A magnetic gate 26 for controlling the opening degree of the air holes 251 is installed inside each air hole 251. The magnetic gate 26 is rotatably connected to the partition 25. The rectangular tube... A first magnetic drive mesh plate 23 is fixedly installed on the upper end of the 22 above the partition 25. The first magnetic drive mesh plate 23 is provided with a first electromagnetic plate 231 for driving the magnetic gate 26 to rotate. The inside of the rectangular tube 22 is also provided with a second magnetic drive mesh plate 27 located below the partition 25. The surfaces of the second magnetic drive mesh plate 27 and the first magnetic drive mesh plate 23 are provided with mesh holes. The second magnetic drive mesh plate 27 is provided with a second electromagnetic plate 271 for driving the magnetic gate 26 to rotate.

[0046] The lower air nozzle is located at the upper end of the rectangular tube 22. Inside the rectangular tube 22, an annular third electromagnetic plate 210 is fixedly installed above the second magnetic drive mesh plate 27. A permanent magnet ring 272, compatible with the third electromagnetic plate 210, is fixedly installed along the edge of the second magnetic drive mesh plate 27. An electromagnetic ring 29, matching the permanent magnet ring 272, is fixedly installed at the lower end of the rectangular tube 22. Multiple compression springs 28 are provided between the permanent magnet ring 272 and the electromagnetic ring 29.

[0047] A collar 24 is fixedly installed inside the housing 21. The collar 24 is sleeved on the outside of the rectangular tube 22, and the lower part of the collar 24 is provided with an inclined surface structure. The magnetic gate 26 and the air hole 251 are in clearance fit, and the permanent magnet ring 272 and the rectangular tube 22 are in clearance fit.

[0048] like Figure 6 As shown, the magnetic gate 26 includes a square shaft 262 made of aluminum alloy. Both ends of the square shaft 262 are coaxially connected to a circular rotating shaft 261. The hole wall of the air hole 251 is provided with a mounting hole that is clearance-fitted with the rotating shaft 261. Both ends of the square shaft 262 are respectively fixedly connected to a permanent magnet plate 263. The ends of the permanent magnet plate 263 and the ends of the air hole 251 are both arc-shaped structures.

[0049] Since the upper air nozzle 12 is directly facing the upper surface of the aluminum flat tube profile, it plays a major role in cooling. Therefore, its air volume and air speed do not need to be adjusted. However, the air cooling corresponding to the lower air nozzle must be adjusted, especially for cooling aluminum flat tube profiles (whether internally symmetrical or not); otherwise, it is easy to cause excessive stress, which will eventually lead to excessive deformation.

[0050] If used for aluminum rods (round or rectangular), the air-cooling efficiency corresponding to the upper nozzle 12 and the lower nozzle must be the same.

[0051] When the first electromagnetic plate 231 is energized and generates magnetic force, it can generate an attractive or repulsive magnetic force on one of the permanent magnet plates 263. In addition, when the second electromagnetic plate 271 is energized and generates magnetic force, it can generate an attractive or repulsive magnetic force on the other permanent magnet plate 263. The first electromagnetic plate 231 and the second electromagnetic plate 271 are staggered. Therefore, the magnetic gate plate 26 can be rotated by magnetic force to control the opening degree between the magnetic gate plate 26 and the air hole 251, thereby controlling the different flow directions and flow rates from the upper end of the rectangular tube 22.

[0052] For aluminum flat tube profiles made of 7A04 aluminum alloy, if the lower surface of the aluminum flat tube profile is directly exposed to excessively cold air (such as 4°C), micro-cracks are easily generated on the lower surface, thus affecting the service life of the aluminum flat tube profile. Under direct exposure to 4°C cold air, the probability of micro-cracks occurring is 11.7%.

[0053] In this invention, the third electromagnetic plate 210 is energized to generate a magnetic force that repels the permanent magnet ring 272, pushing the second magnetic drive mesh plate 27 downward. Then, through the changes in the magnetic forces of the first electromagnetic plate 231 and the second electromagnetic plate 271, the magnetic gate plate 26 rotates continuously at a speed controlled at 10~12 r / min. This disrupts the airflow through the vent 251, preventing cold air from directly blowing onto the lower surface of the aluminum flat tube profile, thereby reducing the probability of microcrack formation to below 3.9%. It should be noted that the magnetic force between the electromagnetic ring 29 and the permanent magnet ring 272, or the elastic force of the compression spring 28, allows the second magnetic drive mesh plate 27 to move up and down to prevent fogging, ultimately ensuring that the magnetic gate plate 26 rotates at a speed of 10~12 r / min.

[0054] For aluminum flat tube profiles made of aluminum alloys such as 5A06, 6063, and 5A06, the rotation speed of the magnetic gate 26 is 12 r / min or 0 r / min. These types of aluminum flat tube profiles will not produce micro-cracks on their lower surface.

[0055] If the second magnetic drive mesh plate 27 remains stationary, even if the second magnetic drive mesh plate 27 is far away from the magnetic gate plate 26, it is difficult to control the magnetic gate plate 26 to complete and continuously rotate 360°. Example 6

[0056] For aluminum flat tube profiles made of 6A02 aluminum alloy, the oscillation frequency of the rigid tube section 31 is 1~2Hz. Simultaneously, the angle between the width direction of the magnetic gate plate 26 and the length direction of the vent 251 is λ, with λ varying from -27° to 27° and a rate of change of λ of 2° / s. At this point, the probability of cracking in the corresponding aluminum flat tube profile at bending angles exceeding 60° (usually corners) is 2.8%.

[0057] Definition: When the end of the permanent magnet plate 263 on the right is located below the air hole 251, the value of λ is negative, such as... Figure 6 As shown; when the end of the permanent magnet plate 263 on the right is above the air hole 251, the value of λ is positive, as shown. Figure 7 As shown.

[0058] The rate of change of λ is 2° / s, which means that the value of λ changes by 2° per second. For example, in the 1st second, the value of λ is -27°; in the 2nd second, the value of λ is -25°, and so on.

[0059] For aluminum flat tube profiles made of aluminum alloys such as 3A21, 6063, and 5A06, even with direct exposure to 4°C cold air, the probability of cracking in areas with a bending angle exceeding 60° is less than 2.3%. However, for aluminum flat tube profiles made of 6A02 aluminum alloy, if direct exposure to 4°C cold air occurs in areas with a bending angle exceeding 60°, the probability of cracking exceeds 32.5%.

[0060] Comparative Example 1

[0061] In this example, for the aluminum flat tube profile made of 6a02 aluminum alloy, the oscillation frequency of the rigid tube section 31 is 1~2Hz, and λ is always 27°. At this time, the probability of cracking in the corresponding aluminum flat tube profile where the bending angle exceeds 60° is 32.9%.

[0062] Comparative Example 2

[0063] In this example, for the aluminum flat tube profile made of 6a02 aluminum alloy, the oscillation frequency of the rigid tube section 31 is 0Hz, the variation range of λ is -27° to 27°, and the rate of change of λ value is 2° / s; at this time, the probability of cracking in the corresponding aluminum flat tube profile where the bending angle exceeds 60° is 36.1%.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An online straightening and precision cutting process for extruding aluminum flat tube profiles, characterized in that... Includes the following steps: After cleaning, the aluminum bars are fed into the mold for constant temperature extrusion, followed by surface zinc spraying, strong air quenching, eddy current testing, tension inspection, straightening and traction, precision cutting to length, conveying, and pipe packaging. In the high-pressure air cooling quenching operation, a high-pressure air cooling quenching device is used to cool aluminum flat tube profiles online. The high-pressure air cooling quenching device includes an upper air box (10), a lower air box (20), and a vortex tube (40) for providing cold air to the upper air box (10) and the lower air box (20). The vortex tube (40) is driven by compressed air and provides a cold air source. An upper air nozzle (12) is provided at the lower center of the upper air box (10). Side air pipes (30) are provided on both sides of the upper air box (10). A side air nozzle (32) is provided on the inner side of the lower end of the side air pipe (30). A lower air nozzle is provided at the upper center of the lower air box (20). The upper air nozzle (12) and the lower air nozzle are arranged opposite each other, and the two side air nozzles (32) are arranged opposite each other. An air inlet pipe (11) is provided at the upper part of the upper air box (10). The side duct (30) includes an elastic pipe section (33) and a rigid pipe section (31). The lower end of the rigid pipe section (31) is closed, and the side wall of the elastic pipe section (33) is provided with a pleated structure. The outer side of the side duct (30) is a planar structure. A first magnetic block (34) is embedded at the lower end of the outer side of the side duct (30), and a side duct magnetic drive mechanism (50) for driving the side duct (30) to swing is provided on the outer side of the side duct (30). The side air duct magnetic drive mechanism (50) includes a vertical plate (51) fixedly connected to the lower end of the upper air box (10). The lower end of the vertical plate (51) is fitted with a first electromagnet (52) that matches the first magnetic block (34). The middle part of the vertical plate (51) is also provided with an oval hole (511). A side plate (54) is fixedly installed on the outside of the vertical plate (51). A tension spring (53) is provided between the side plate (54) and the outside of the rigid pipe section (31). One end of the tension spring (53) is fixedly connected to the side plate (54), and the other end of the tension spring (53) passes through the oval hole (511) and is fixedly connected to the outside of the rigid pipe section (31).

2. The online straightening and precision cutting process for extruding aluminum flat tube profiles according to claim 1, characterized in that: The lower air box (20) includes a box body (21), an air inlet (211) is provided at the center of the lower part of the box body (21), and a rectangular tube (22) is embedded at the center of the upper end of the lower air box (20). The inner cavity of the rectangular tube (22) is connected to the inner cavity of the box body (21). A partition (25) is fixedly installed inside the rectangular tube (22). A plurality of air holes (251) are provided on the partition (25). A magnetic gate (26) for controlling the opening degree of the air hole (251) is provided inside the air hole (251). The magnetic gate (26) is rotatably connected to the partition (25). The upper end of the tube (22) is fixedly installed with a first magnetic drive mesh plate (23) located above the partition plate (25). The first magnetic drive mesh plate (23) is provided with a first electromagnetic plate (231) for driving the magnetic gate plate (26) to rotate. The inside of the rectangular tube (22) is also provided with a second magnetic drive mesh plate (27) located below the partition plate (25). The surfaces of the second magnetic drive mesh plate (27) and the first magnetic drive mesh plate (23) are provided with mesh holes. The second magnetic drive mesh plate (27) is provided with a second electromagnetic plate (271) for driving the magnetic gate plate (26) to rotate.

3. The online straightening and precision cutting process for extruding aluminum flat tube profiles according to claim 2, characterized in that: The rectangular tube (22) is also fixedly installed inside, with an annular third electromagnetic plate (210) located above the second magnetic drive mesh plate (27). The edge of the second magnetic drive mesh plate (27) is fixedly installed with a permanent magnet ring (272) that is compatible with the third electromagnetic plate (210). The lower end of the rectangular tube (22) is fixedly installed with an electromagnetic ring (29) that matches the permanent magnet ring (272). Multiple compression springs (28) are provided between the permanent magnet ring (272) and the electromagnetic ring (29).

4. The online straightening and precision cutting process for extruding aluminum flat tube profiles according to claim 2, characterized in that: A collar (24) is fixedly installed inside the box (21). The collar (24) is sleeved on the outside of the rectangular tube (22). The lower part of the collar (24) is provided with an inclined surface structure.

5. The online straightening and precision cutting process for extruding aluminum flat tube profiles according to claim 3, characterized in that: The magnetic gate (26) and the air hole (251) are fitted with a clearance, and the permanent magnet ring (272) and the rectangular tube (22) are fitted with a clearance.

6. The online straightening and precision cutting process for extruding aluminum flat tube profiles according to claim 2, characterized in that: The magnetic gate (26) includes a square shaft (262) made of aluminum alloy. Both ends of the square shaft (262) are coaxially connected to a circular rotating shaft (261). The hole wall of the air hole (251) is provided with a mounting hole that is clearance-fitted with the rotating shaft (261). Both ends of the square shaft (262) are respectively fixedly connected to permanent magnet plates (263). The ends of the permanent magnet plates (263) and the ends of the air holes (251) are both arc-shaped structures.

7. The online straightening and precision cutting process for extruding aluminum flat tube profiles according to claim 2, characterized in that: The oscillation frequency of the rigid tube section is 1~2Hz, the angle between the width direction of the magnetic gate and the length direction of the air hole is λ, the range of λ is -27°~27°, and the rate of change of λ value is 2° / s.

Images