A sheet metal bending machine for reducing springback and its usage method

Abstract

The present invention relates to the technical field of metal processing, and discloses a metal sheet bending machine for reducing springback, which includes a processing table. A pressing component is arranged on the upper part of the processing table, a heating component is arranged on the lower side of the middle part of the processing table, a guiding component is arranged directly above the heating component, and side pressing components are arranged on both the left and right sides of the guiding component. During the process of the connecting plate moving downward along the inner wall of the slot, when the uppermost tooth of each set of tooth portions engages and then disengages from the gear, the bottom end of the connecting plate abuts against the side of the pressing switch away from the heat insulation cover and squeezes the pressing switch to move towards the heat insulation cover, so that the circuit where the heating wire is located is connected, and then the heating wire generates heat to heat the whole base, thereby heating both sides of the bottom of the bent part of the metal sheet, so as to reduce the compressive stress and tensile stress at the metal sheet, and achieve the effect of reducing the springback of the metal sheet during bending.

Description

Technical Field

[0001] The present invention relates to the technical field of metal processing, and particularly to a metal sheet bending machine for reducing springback and a using method thereof. Background Art

[0002] In industrial production, a large number of metal fittings are required. For example, the metal shell of some devices needs to be bent and formed from a metal sheet, so that the metal sheet is processed into a required shape, and then through welding, multiple metal sheets are enclosed into the shape of a shell to protect the components inside the device.

[0003] When a metal sheet is bent, compressive stress and tensile stress will be generated on the inner and outer sides of the bent part. When the pressure that causes the metal sheet to bend is removed, the metal sheet often rebounds under the combined action of the compressive stress and the tensile stress, resulting in a poor bending effect of the metal sheet, and it needs to be processed again to achieve the required bending effect.

[0004] We apply a downward pressure from above the metal sheet to cause the metal sheet to bend twice, apply auxiliary lateral forces from both sides to ensure the bending effect of the metal sheet, and heat the bent part of the metal sheet to enhance the plasticity of the bent part of the metal sheet, and then propose a metal sheet bending machine for reducing springback and a using method thereof. Summary of the Invention

[0005] (I) Technical Problems to be Solved

[0006] Aiming at the deficiencies of the prior art, the present invention provides a metal sheet bending machine for reducing springback and a using method thereof, which have the advantages of suppressing the springback of the bent metal sheet and the like, and solve the problem that the metal sheet is prone to springback after bending.

[0007] (II) Technical Solutions

[0008] To achieve the above object of suppressing the springback of the bent metal sheet, the present invention provides the following technical solutions: A metal sheet bending machine for reducing springback, including a processing table, on the upper part of the processing table is provided a pressing component, on the lower side of the middle part of the processing table is provided a heating component, directly above the heating component is provided a guiding component, and on both the left and right sides of the guiding component are provided side pressing components. The processing table includes a supporting table, in the middle of the supporting table is provided a forming groove, on the left and right sides of the top of the supporting table are arranged a first row of rotating rollers, on the left side of the supporting table is fixedly installed an L-shaped bracket, and the horizontal part of the L-shaped bracket extends to the right. The heating component includes a base welded to the bottom of the groove of the supporting table, the base is in a "concave" shape, the side walls of the base are flush with the side walls of the forming groove, the inner walls at the corners of the base are arc-shaped, inside the base are arranged electric heating wires in an array, on the left, right and top of the base are fixedly installed heat insulation covers, and further includes installation grooves opened on the surface of the supporting table and on the side walls of the forming groove, on the inner walls of the installation grooves are fixedly installed pressing switches, and the pressing switches are connected in series with the electric heating wires through wires passing through the base and the heat insulation covers.

[0009] Preferably, the pressing component includes a hydraulic telescopic rod fixedly installed at the bottom of the horizontal part of the L-shaped bracket, at the bottom end of the hydraulic telescopic rod is fixedly installed a fixing plate, in the middle of the bottom of the fixing plate is welded a pressing plate, and on both the left and right sides of the bottom of the fixing plate are arranged a second row of rotating rollers, and the second row of rotating rollers is directly above the first row of rotating rollers.

[0010] Preferably, the guiding component includes a U-shaped plate slidably connected up and down in the forming groove, on the top of the U-shaped plate is integrally formed a supporting plate extending outward, on the bottom of the supporting plate are fixedly installed a number of connecting plates in an array, on the surface of the connecting plates are arranged a number of groups of tooth engaging parts, and the tooth engaging parts include a number of teeth.

[0011] Preferably, the side pressing component includes square grooves opened on the surface of the supporting table and at the side walls of the forming groove, in the square grooves are slidably connected left and right with clamping plates, the clamping plates are flush with the side walls of the forming groove under normal conditions, on the end faces of the square grooves are arranged through holes, in the through holes are slidably connected left and right with magnets I, the magnets I are welded to the clamping plates, at the end of the magnets I away from the clamping plates is fixedly installed a partition plate, at the end face of the through hole is provided an installation cavity, the installation cavity is perpendicular to the through hole, the cross-section of the installation cavity is circular, and a transmission component is arranged in the installation cavity.

[0012] Preferably, the transmission component includes a second magnet disposed at the center of the installation cavity. A gear is fixedly installed at the rear side of the second magnet, and a rotating shaft is fixedly installed at the rear side of the gear. The other end of the rotating shaft is rotatably connected to the inner wall of the installation cavity. A disc spring is fixedly installed between the end of the rotating shaft away from the gear and the inner wall of the installation cavity. A slot is also opened at the top of the support table.

[0013] Preferably, the second magnet is in a horizontal state under normal conditions, and the polarities of the opposite ends of the second magnet and the first magnet are opposite.

[0014] Preferably, the slot penetrates the installation cavity and is located on one side of the central axis of the installation cavity. The connecting plate is slidably connected up and down in the slot. Each set of tooth engaging portions meshes with a gear. The number of teeth in each set of tooth engaging portions is half of the number of teeth on the surface of the gear.

[0015] Preferably, the bottom of the slot extends to the top wall of the installation groove, and the slot communicates with the installation groove. The side of the push switch away from the heat insulation cover is designed to be arc-shaped. When the bottom end of the connecting plate moves downward, it abuts against the side of the push switch away from the heat insulation cover.

[0016] Preferably, the bending method of this bending machine is as follows:

[0017] S1. Place the metal thin plate to be bent on the top of the U-shaped plate and support plate assembly, and the middle part of the metal thin plate is directly above the middle part of the U-shaped plate. At this time, the support plate holds the metal thin plate from the left and right sides.

[0018] S2. Then, extend the hydraulic telescopic rod to drive the assembly of the fixed plate and the pressing plate to move downward, so that the bottom of the pressing plate abuts against the top of the metal thin plate, and push the metal thin plate, the U-shaped plate and the support plate to move downward simultaneously until the support plate abuts against the top of the support table. After that, the pressing plate continues to move downward to press the metal thin plate into the U-shaped plate. The inner wall shape of the U-shaped plate is used to bend the metal thin plate. During the process of pressing the metal thin plate into the U-shaped plate, the metal thin plates on the left and right sides abut between the first roller and the second roller and move towards the middle. The first roller and the second roller rotate to make the movement of the metal thin plates on both sides smoother.

[0019] S3. During the downward movement of the U-shaped plate and support plate assembly, the connecting plate moves downward simultaneously with the U-shaped plate and support plate assembly. When the lowermost tooth of each set of tooth engaging portions contacts the gear and slides along its surface, it drives the gear to rotate 180 degrees, drives the gear to rotate, the second magnet and the rotating shaft rotate simultaneously, and elastic potential energy is accumulated by torsion in the disc spring. At this time, the polarities of the opposite ends of the second magnet and the first magnet are the same.

[0020] S4. Since the polarities of the opposite ends of Magnet 2 and Magnet 1 are the same, under the repulsive force, the assembly of Magnet 1 and the partition is driven to move along the inner wall of the through hole towards the square groove, pushing the clamping plate to move inwards, squeezing on the left and right sides of the U-shaped plate, applying pressure to the U-shaped plate from the left and right sides, and then transmitting the force to the metal thin plate through the U-shaped plate, applying an auxiliary lateral force to the upper side of the bent part of the metal thin plate;

[0021] S5. During the process of the connecting plate moving downwards along the inner wall of the slot, when the uppermost tooth of each set of tooth portions engages and then disengages from the gear, the bottom end of the connecting plate abuts against the side of the push switch away from the heat insulation cover, and squeezes the push switch to move towards the heat insulation cover, making the circuit where the heating wire is located connected, and then heating the whole base through the heating of the heating wire, so as to heat the two sides of the bottom of the bent part of the metal thin plate.

[0022] (III) Beneficial effects

[0023] Compared with the prior art, the present invention provides a metal thin plate bending machine for reducing springback and its use method, which has the following beneficial effects:

[0024] 1. For the metal thin plate bending machine for reducing springback and its use method, the metal thin plate to be bent is placed on the top of the assembly of the U-shaped plate and the support plate. Then, the hydraulic telescopic rod extends, so that the bottom of the pressing plate abuts against the top of the metal thin plate, and pushes the metal thin plate, the U-shaped plate and the support plate to move downwards at the same time. After that, the pressing plate continues to move downwards, pressing the metal thin plate into the U-shaped plate. Through the inner wall shape of the U-shaped plate, the metal thin plate is bent. The connecting plate moves downwards at the same time as the assembly of the U-shaped plate and the support plate. When the lowermost tooth of each set of tooth portions contacts the gear and slides along its surface, the gear is driven to rotate 180 degrees. The polarities of the opposite ends of Magnet 2 and Magnet 1 are the same, driving the assembly of Magnet 1 and the partition to move along the inner wall of the through hole towards the square groove, pushing the clamping plate to move inwards, squeezing on the left and right sides of the U-shaped plate, applying pressure to the U-shaped plate from the left and right sides, and then transmitting the force to the metal thin plate through the U-shaped plate, applying an auxiliary lateral force to the upper side of the bent part of the metal thin plate, and suppressing the springback of the metal thin plate after bending through the lateral force;

[0025] 2. For the metal thin plate bending machine for reducing springback and its use method, during the process of the connecting plate moving downwards along the inner wall of the slot, when the uppermost tooth of each set of tooth portions engages and then disengages from the gear, the bottom end of the connecting plate abuts against the side of the push switch away from the heat insulation cover, and squeezes the push switch to move towards the heat insulation cover, making the circuit where the heating wire is located connected, and then heating the whole base through the heating of the heating wire, so as to heat the two sides of the bottom of the bent part of the metal thin plate, thereby achieving the effect of reducing the compressive stress and tensile stress at the metal thin plate and reducing the springback of the metal thin plate bending. Description of the drawings

[0026] Figure 1 Schematic three-dimensional structure diagram of a sheet metal bending machine for reducing springback and its usage method proposed by the present invention;

[0027] Figure 2 Front view sectional structure diagram of a sheet metal bending machine for reducing springback and its usage method proposed by the present invention;

[0028] Figure 3 Front view sectional structure diagram at the processing table of a sheet metal bending machine for reducing springback and its usage method proposed by the present invention;

[0029] Figure 4 Rear view sectional three-dimensional structure diagram at the installation cavity of a sheet metal bending machine for reducing springback and its usage method proposed by the present invention;

[0030] Figure 5 For a sheet metal bending machine for reducing springback and its usage method proposed by the present invention Figure 2 Enlarged detailed structure diagram at position A;

[0031] Figure 6 For a sheet metal bending machine for reducing springback and its usage method proposed by the present invention Figure 2 Enlarged detailed structure diagram at position B.

[0032] In the figure: 1. Processing table; 2. Pressing component; 3. Guiding component; 4. Heating component; 5. Side pressing component; 11. Support table; 12. Forming groove; 13. First roller; 14. L-shaped bracket; 21. Hydraulic telescopic rod; 22. Fixed plate; 23. Pressing plate; 24. Second roller; 31. U-shaped plate; 32. Support plate; 33. Connecting plate; 34. Tooth engaging part; 41. Base; 42. Electric heating wire; 43. Heat insulation cover; 44. Installation groove; 45. Pressing switch; 51. Square groove; 52. Clamping plate; 53. Through hole; 54. First magnet; 55. Partition board; 56. Installation cavity; 57. Transmission component; 571. Second magnet; 572. Gear; 573. Rotating shaft; 574. Disc spring; 575. Slot. Detailed implementation manners

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] Please refer to Figures 1-6, A sheet metal bending machine for reducing springback, comprising a processing table 1, a pressing component 2 is arranged on the upper part of the processing table 1, a heating component 4 is arranged on the lower side of the middle part of the processing table 1, a guiding component 3 is arranged directly above the heating component 4, and side pressing components 5 are arranged on both the left and right sides of the guiding component 3.

[0035] Please refer to Figures 2-3 , The processing table 1 includes a supporting table 11, a forming groove 12 is opened in the middle of the supporting table 11, a first set of rotating rollers 13 are arranged in an array on both the left and right sides of the top of the supporting table 11. A part of the first set of rotating rollers 13 is located inside the supporting table 11, and the other part is exposed above the supporting table 11. An L-shaped bracket 14 is fixedly installed on the left side of the supporting table 11, and the horizontal part of the L-shaped bracket 14 extends to the right.

[0036] Please refer to Figure 2 , The pressing component 2 includes a hydraulic telescopic rod 21 fixedly installed at the bottom of the horizontal part of the L-shaped bracket 14. The bottom end of the hydraulic telescopic rod 21 is fixedly installed with a fixing plate 22. A pressing plate 23 is welded to the middle of the bottom of the fixing plate 22. A second set of rotating rollers 24 are arranged in an array on both the left and right sides of the bottom of the fixing plate 22. The second set of rotating rollers 24 are located directly above the first set of rotating rollers 13.

[0037] Please refer to Figure 2 , The guiding component 3 includes a U-shaped plate 31 slidably connected up and down in the forming groove 12. A supporting plate 32 extending outward is integrally formed at the top of the U-shaped plate 31. The height of the part of the first set of rotating rollers 13 exposed above the supporting table 11 is equal to the thickness of the supporting plate 32. When the pressing plate 23 is completely inserted into the U-shaped plate 31, the distance between the second set of rotating rollers 24 and the first set of rotating rollers 13 is equal to the thickness of the sheet metal. A number of connecting plates 33 are fixedly installed in an array at the bottom of the supporting plate 32. A number of groups of tooth engaging parts 34 are arranged in an array on the surface of the connecting plates 33. The tooth engaging parts 34 include a number of teeth.

[0038] Please refer to Figures 2-3 and Figure 6, the heating component 4 includes a base 41 welded to the bottom of the groove of the support table 11. The base 41 is in a "concave" shape. The two side walls of the base 41 are flush with the side walls of the forming groove 12. The inner walls at the corners of the base 41 are arc-shaped. Electric heating wires 42 are arranged in an array inside the base 41. Heat insulation covers 43 are fixedly installed on the left and right sides and the top of the base 41. It also includes mounting grooves 44 opened on the surface of the support table 11 and located on the two side walls of the forming groove 12. A pressing switch 45 is fixedly installed on the inner wall of the mounting groove 44. The pressing switch 45 is connected in series with the electric heating wires 42 through wires passing through the base 41 and the heat insulation covers 43. There are two non-contact metal sheets inside the pressing switch 45, and these two metal sheets are connected in series with the electric heating wires 42 in the same circuit. An arc-shaped pressing part is arranged on the side of the pressing switch 45 away from the heat insulation cover 43. The arc-shaped pressing part is perpendicular to one of the metal plates and is connected to it. When the arc-shaped pressing part is squeezed, the two metal plates come into contact, making the circuit where these two metal plates and the electric heating wires 42 are located conductive.

[0039] Please refer to Figures 2-6 , the side pressing component 5 includes square grooves 51 opened on the surface of the support table 11 and located at the two side walls of the forming groove 12. A clamping plate 52 is slidably connected left and right in the square groove 51. The clamping plate 52 is flush with the side wall of the forming groove 12 under normal conditions. Notches adapted to the clamping plate 52 are opened on the left and right sides of the U-shaped plate 31, facilitating the clamping plate 52 to move inward and pass through the U-shaped plate 31 to squeeze against the side of the metal thin plate. Additionally, notches may not be opened on the two sides of the U-shaped plate 31. At this time, the U-shaped plate 31 is processed with shape memory metal, and the thickness of the U-shaped plate 31 is small and easy to deform. When the clamping plate 52 moves inward, it can squeeze against the two sides of the U-shaped plate 31, and through the transmission of force, the metal thin plate inside the U-shaped plate 31 is subjected to lateral forces from the left and right sides.

[0040] Please refer to Figures 2-6 , through holes 53 are arranged in an array on the end surface of the square groove 51. A magnet 54 is slidably connected left and right in the through hole 53. The magnet 54 is welded to the clamping plate 52. A partition plate 55 is fixedly installed at the end of the magnet 54 away from the clamping plate 52 to prevent the magnet 54 from detaching from the inner opening of the through hole 53. An installation cavity 56 is arranged at the end surface of the through hole 53. The installation cavity 56 is perpendicular to the through hole 53. The cross-section of the installation cavity 56 is circular. A transmission component 57 is arranged in the installation cavity 56. The transmission component 57 includes a magnet 571 arranged at the center of the installation cavity 56. The magnet 571 is in a horizontal state under normal conditions. The opposite end of the magnet 571 to the magnet 54 has the opposite polarity. Under the attraction of the magnet 571 and the magnet 54, the assembly of the clamping plate 52, the magnet 54, and the partition plate 55 approaches the magnet 571, ensuring that the clamping plate 52 is flush with the side wall of the forming groove 12 under normal conditions.

[0041] Please refer to Figures 2-6, a gear 572 is fixedly installed at the rear side of the magnet two 571, a rotating shaft 573 is fixedly installed at the rear side of the gear 572, the other end of the rotating shaft 573 is rotatably connected to the inner wall of the installation cavity 56, a disc spring 574 is fixedly installed between the end of the rotating shaft 573 far from the gear 572 and the inner wall of the installation cavity 56. It also includes a slot 575 opened at the top of the support table 11, the slot 575 penetrates through the installation cavity 56 and is located on one side of the central axis of the installation cavity 56. The connecting plate 33 is slidably connected up and down in the slot 575. Each group of tooth engaging parts 34 meshes with a gear 572. The number of teeth in each group of tooth engaging parts 34 is half of the number of teeth on the surface of the gear 572. The bottom of the slot 575 extends to the top wall of the installation groove 44, and the slot 575 communicates with the installation groove 44. The side of the pressing switch 45 far from the heat insulation cover 43 is designed to be arc-shaped. When the bottom end of the connecting plate 33 moves downward, it abuts against the side of the pressing switch 45 far from the heat insulation cover 43.

[0042] Working principle: The bending method of this bending machine is as follows in specific steps.

[0043] S1. Place the metal thin plate to be bent on the top of the assembly of the U-shaped plate 31 and the support plate 32, and the middle part of this metal thin plate is directly above the middle part of the U-shaped plate 31. At this time, the support plate 32 holds the metal thin plate from the left and right sides.

[0044] S2. Then, extend the hydraulic telescopic rod 21 to drive the assembly of the fixed plate 22 and the pressing plate 23 to move downward, so that the bottom of the pressing plate 23 abuts against the top of the metal thin plate, and push the metal thin plate, the U-shaped plate 31 and the support plate 32 to move downward simultaneously until the support plate 32 abuts against the top of the support table 11. After that, the pressing plate 23 continues to move downward to press the metal thin plate into the U-shaped plate 31. Through the inner wall shape of the U-shaped plate 31, the metal thin plate is bent. During the process of pressing the metal thin plate into the U-shaped plate 31, the metal thin plates on the left and right sides abut between the roller one 13 and the roller two 24 and move towards the middle. The roller one 13 and the roller two 24 rotate to make the movement of the metal thin plates on both sides smoother.

[0045] S3. During the downward movement of the assembly of the U-shaped plate 31 and the support plate 32, the connecting plate 33 moves downward simultaneously with the assembly of the U-shaped plate 31 and the support plate 32. When the lowermost tooth of each group of tooth engaging parts 34 contacts the gear 572 and slides along its surface, it drives the gear 572 to rotate 180 degrees, drives the gear 572 to rotate, and the magnet two 571 and the rotating shaft 573 rotate simultaneously. Elastic potential energy is torsionally stored in the disc spring 574. At this time, the opposite ends of the magnet two 571 and the magnet one 54 have the same polarity.

[0046] S4. Since the polarities of the opposite ends of the second magnet 571 and the first magnet 54 are the same, under the repulsive force, the assembly of the first magnet 54 and the partition 55 moves along the inner wall of the through hole 53 towards the square groove 51, pushing the clamping plate 52 to move inwards and squeezing the left and right sides of the U-shaped plate 31, applying pressure to the U-shaped plate 31 from the left and right sides, and then transmitting the force to the metal thin plate through the U-shaped plate 31 to apply an auxiliary lateral force to the upper side of the bent part of the metal thin plate;

[0047] S5. During the process of the connecting plate 33 moving downwards along the inner wall of the slot 575, when the uppermost tooth of each set of tooth portions 34 meshes with and then separates from the gear 572, the bottom end of the connecting plate 33 abuts against the side of the push switch 45 away from the heat shield 43 and squeezes the push switch 45 to move towards the heat shield 43, so that the circuit where the heating wire 42 is located is connected, and then the heating wire 42 generates heat to heat the whole base 41, thereby heating both sides of the bottom of the bent part of the metal thin plate.

[0048] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A sheet metal bending machine for reducing springback, comprising a processing table (1), characterized in that: The upper part of the processing table (1) is provided with a pressing component (2), the lower side of the middle part of the processing table (1) is provided with a heating component (4), a guiding component (3) is arranged directly above the heating component (4), and side pressing components (5) are arranged on both the left and right sides of the guiding component (3); The processing table (1) includes a supporting table (11), a forming groove (12) is formed in the middle of the supporting table (11), the first rotating rollers (13) are arranged in an array on both the left and right sides of the top of the supporting table (11), an L-shaped bracket (14) is fixedly installed on the left side of the supporting table (11), and the horizontal part of the L-shaped bracket (14) extends to the right; The heating component (4) includes a base (41) welded to the bottom of the groove of the supporting table (11), the base (41) is in a "concave" shape, the side walls of the base (41) are flush with the side walls of the forming groove (12), the inner walls of the corners of the base (41) are arc-shaped, electric heating wires (42) are arranged in an array inside the base (41), heat insulation covers (43) are fixedly installed on both the left and right sides and the top of the base (41), and mounting grooves (44) are further formed in the surface of the supporting table (11) and on both side walls of the forming groove (12), a pressing switch (45) is fixedly installed on the inner wall of the mounting groove (44), and the pressing switch (45) is connected in series with the electric heating wires (42) through a wire passing through the base (41) and the heat insulation cover (43); The pressing component (2) includes a hydraulic telescopic rod (21) fixedly installed at the bottom of the horizontal part of the L-shaped bracket (14), a fixing plate (22) is fixedly installed at the bottom end of the hydraulic telescopic rod (21), a pressing plate (23) is welded to the middle of the bottom of the fixing plate (22), and the second rotating rollers (24) are arranged in an array on both the left and right sides of the bottom of the fixing plate (22), and the second rotating rollers (24) are located directly above the first rotating rollers (13); The guiding component (3) includes a U-shaped plate (31) slidably connected up and down in the forming groove (12), a supporting plate (32) extending outward is integrally formed at the top of the U-shaped plate (31), a plurality of connecting plates (33) are fixedly installed in an array at the bottom of the supporting plate (32), a plurality of groups of tooth engaging parts (34) are arranged in an array on the surface of the connecting plates (33), and the tooth engaging parts (34) include a plurality of teeth; The side pressing member (5) includes a square groove (51) formed on the surface of the supporting table (11) and located at both side walls of the forming groove (12). A clamping plate (52) is slidably connected left and right in the square groove (51). The clamping plate (52) is flush with the side wall of the forming groove (12) under normal conditions. Through holes (53) are arranged in an array on the end face of the square groove (51). A first magnet (54) is slidably connected left and right in the through hole (53). The first magnet (54) is welded to the clamping plate (52). A partition plate (55) is fixedly installed at one end of the first magnet (54) away from the clamping plate (52). An installation cavity (56) is arranged at the end face of the through hole (53). The installation cavity (56) is perpendicular to the through hole (53). The cross section of the installation cavity (56) is circular. A transmission member (57) is arranged in the installation cavity (56).

2. The sheet metal bending machine for reducing springback according to claim 1, characterized in that: The transmission member (57) includes a second magnet (571) arranged at the center of the installation cavity (56). A gear (572) is fixedly installed at the rear side of the second magnet (571). A rotating shaft (573) is fixedly installed at the rear side of the gear (572). The other end of the rotating shaft (573) is rotatably connected to the inner wall of the installation cavity (56). A disc spring (574) is fixedly installed between the end of the rotating shaft (573) away from the gear (572) and the inner wall of the installation cavity (56). A slot (575) is also formed at the top of the supporting table (11).

3. The sheet metal bending machine for reducing springback according to claim 2, characterized in that: The second magnet (571) is in a horizontal state under normal conditions, and the polarities of the opposite ends of the second magnet (571) and the first magnet (54) are opposite.

4. The sheet metal bending machine for reducing springback according to claim 2, characterized in that: The slot (575) penetrates the installation cavity (56) and is located on one side of the central axis of the installation cavity (56). The connecting plate (33) is slidably connected up and down in the slot (575). Each set of tooth engaging parts (34) meshes with a gear (572). The number of teeth in each set of tooth engaging parts (34) is half of the number of teeth on the surface of the gear (572).

5. The sheet metal bending machine for reducing springback according to claim 2, characterized in that: The bottom of the slot (575) extends to the top wall of the installation groove (44). The slot (575) communicates with the installation groove (44). The side of the pressing switch (45) away from the heat insulation cover (43) is designed to be arc-shaped. When the bottom end of the connecting plate (33) moves downward, it abuts against the side of the pressing switch (45) away from the heat insulation cover (43).

6. The sheet metal bending machine for reducing springback according to claim 1, characterized in that, The bending method of this bending machine is as follows: S1. Place the metal thin plate to be bent on the top of the assembly of the U-shaped plate (31) and the support plate (32), and the middle part of the metal thin plate is directly above the middle part of the U-shaped plate (31). At this time, the support plate (32) lifts the metal thin plate from both left and right sides. S2. Then, the hydraulic telescopic rod (21) extends, driving the assembly of the fixed plate (22) and the pressing plate (23) to move downward, so that the bottom of the pressing plate (23) abuts against the top of the metal thin plate, and the metal thin plate, the U-shaped plate (31), and the support plate (32) are simultaneously pushed downward until the support plate (32) abuts against the top of the support table (11). After that, the pressing plate (23) continues to move downward, pressing the metal thin plate into the U-shaped plate (31). Through the inner wall shape of the U-shaped plate (31), the metal thin plate is bent. During the process of pressing the metal thin plate into the U-shaped plate (31), the metal thin plates on the left and right sides abut between the first roller (13) and the second roller (24) and move toward the middle. The first roller (13) and the second roller (24) rotate, making the movement of the metal thin plates on both sides smoother; S3. During the downward movement of the assembly of the U-shaped plate (31) and the support plate (32), the connecting plate (33) moves downward simultaneously with the assembly of the U-shaped plate (31) and the support plate (32). When the lowest tooth of each set of tooth portions (34) contacts and slides along the surface of the gear (572), the gear (572) is driven to rotate 180 degrees. Driving the gear (572) to rotate, the second magnet (571) and the rotating shaft (573) rotate simultaneously, and elastic potential energy is stored by torsion in the disc spring (574). At this time, the opposite ends of the second magnet (571) and the first magnet (54) have the same polarity; S4. Since the opposite ends of the second magnet (571) and the first magnet (54) have the same polarity, under the repulsive force, the assembly of the first magnet (54) and the partition plate (55) is driven to move along the inner wall of the through hole (53) toward the square groove (51), pushing the clamping plate (52) to move inward and squeezing the left and right sides of the U-shaped plate (31), applying pressure to the U-shaped plate (31) from the left and right sides, and then transmitting the force to the metal thin plate through the U-shaped plate (31), applying an auxiliary lateral force to the upper side of the bent portion of the metal thin plate; S5. During the downward movement of the connecting plate (33) along the inner wall of the slot (575), when the uppermost tooth of each set of tooth portions (34) meshes with and then separates from the gear (572), the bottom end of the connecting plate (33) abuts against the side of the push button switch (45) away from the heat insulation cover (43) and squeezes the push button switch (45) to move toward the heat insulation cover (43), making the circuit where the heating wire (42) is located connected. Then, the heating wire (42) generates heat to heat the whole base (41), thereby heating both sides of the bottom of the bent portion of the metal thin plate.

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