A forming device for horizontal bending of corrugated board

Abstract

This application relates to the field of corrugated sheet forming and processing technology, and discloses a forming and processing device for horizontally bent corrugated sheets. The device includes a base mounted on one side of a worktable surface. A lower mold is fixedly connected to the upper surface of the base for horizontally supporting the corrugated sheet. A lifting mechanism is provided on the other side of the worktable surface. An upper mold is fixedly connected to the lifting end of the lifting mechanism. The upper mold matches the lower mold and is used to press the corrugated sheet. A rotary mechanism is provided inside the lower mold. A bending unit is provided on the rotary table surface of the rotary mechanism. Driven by the rotary mechanism, the bending unit applies horizontal bending to the bent section of the corrugated sheet. By using the rotary table surface of the rotary mechanism to support the bending unit, the bent section of the corrugated sheet held by the bending unit rotates and forms in the horizontal plane around the bending line. This rotary bending method replaces the cavity extrusion of the stamping die, avoiding the phenomenon of the outer curved material being forcibly stretched and lost along the thickness direction during stamping.

Description

Technical Field

[0001] This invention relates to the field of corrugated sheet forming and processing technology, specifically to a forming and processing device for horizontally bent corrugated sheets. Background Technology

[0002] The inner wall of liquefied natural gas (LNG) storage tanks uses a thin-film corrugated plate as a sealing layer. This corrugated plate consists of flat sections and raised corrugated sections. The corrugations are divided into longitudinal corrugations and transverse corrugations according to their direction of extension. The inner wall of the storage tank is made up of multiple corrugated plates spliced ​​together. At the splicing point of two adjacent corrugated plates, each corrugation must be completely overlapped along the edge of the assembly to form a reliable sealing structure.

[0003] The inner wall of a storage tank is not entirely flat. To accommodate structures with specific geometric shapes, such as the cylindrical bottom wall of the tank, continuous corrugated plates need to be extended and spliced ​​along the circumference. This requires that the corrugation direction of some of the corrugated plates can be changed or bent, that is, to form a horizontal bend in the plane of the corrugated plate, so that several corrugated plates with horizontal bends can be spliced ​​together in sequence to form a circular tank wall.

[0004] Currently, the production of corrugated sheets with horizontal bends typically involves a single-stage forming process using a stamping die. Stamping relies on the die cavity to compress the sheet metal, forcing the metal to flow along the predetermined cavity to achieve the bent shape. The problem is that the material on the outer side of the bent area is forcibly stretched during the extrusion process, causing metal to leak along the thickness direction, resulting in significant thinning of the sheet metal in that area. Since the corrugated sheet itself has a relatively thin wall, localized thinning significantly reduces the strength of that area. Under the long-term conditions of storage tanks subjected to cryogenic media and pressure loads, the thinned section becomes a weak point, affecting the reliability and service life of the entire sealing layer.

[0005] Even more inconvenient is the variety of splicing methods for corrugated sheets, with different tank wall structures placing varying requirements on the bending length and angle of the horizontally bent corrugated sheets. The die cavities for stamping are specifically designed for a particular bending length and angle, meaning one set of dies can only produce one specification of horizontally bent corrugated sheet. When the tank wall structure changes, requiring corrugated sheets with different bending lengths or angles, the corresponding dies must be redesigned and manufactured. This necessitates a large number of specialized dies for producing corrugated sheets of various specifications, incurring considerable costs for die design, manufacturing, and storage. Frequent die changes during production also complicate the process and hinder efficiency. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a forming and processing device for horizontally bent corrugated sheets. It solves the problems of excessive thinning and reduced strength of the sheet material in the bending area due to forced extrusion and stretching when forming horizontally bent corrugated sheets using stamping dies, and the high investment cost and cumbersome production process caused by the need for separate special dies for corrugated sheets with different bending lengths and bending angles. This invention enables the forming and processing of horizontally bent corrugated sheets with various bending lengths and bending angles using the same set of equipment while ensuring the strength of the corrugated sheets.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A forming and processing device for horizontally bent corrugated sheets includes a base, which is installed on one side of the upper surface of a workbench. A lower mold is fixedly connected to the upper surface of the base for horizontally supporting the corrugated sheet. A lifting mechanism is provided on the other side of the upper surface of the workbench. An upper mold is fixedly connected to the lifting end of the lifting mechanism. The upper mold matches the lower mold and is used to press the corrugated sheet. A rotary mechanism is provided inside the lower mold. A bending unit is provided on the rotary disk surface of the rotary mechanism. The bending unit applies horizontal bending to the bending section of the corrugated sheet under the drive of the rotary mechanism. A positioning mechanism is provided on the outside of the lower mold for adjusting the positioning of the corrugated sheet according to the length of the bending section of the corrugated sheet.

[0009] The bending unit is supported by a rotary mechanism's turntable, causing it to rotate horizontally around its center. This center coincides with the bending line of the corrugated plate, which is the vertical boundary line extending along the thickness of the plate between the flat area and the bending section. The rotary mechanism drives the bending unit to rotate around this center, achieving horizontal bending of the corrugated plate's bending section. Unlike traditional stamping methods that force metal flow, this invention uses a rotary bending method, resulting in more uniform and controllable material flow during bending. This reduces localized overstretching that leads to thinning of the plate, improving the strength and service life of the formed corrugated plate. Furthermore, by adjusting the rotation angles of the positioning and rotary mechanisms, the same device can adapt to different bending section lengths and angles, eliminating the need for dedicated molds for each specification, significantly reducing mold investment costs and simplifying the production process.

[0010] Preferably, the lower mold is also provided with an arc-shaped limiting component, which is concentrically arranged with the rotary table surface, and the arc-shaped limiting component and the rotary table surface are a capture-type mating section that clamps vertically.

[0011] When the bending unit applies a bend in the horizontal plane, the bending reaction force generated by the bending segment on the bending unit is offset in the vertical direction, thus creating an overturning moment on the turntable surface. This overturning moment causes the turntable surface to tend to tilt or sway. This invention utilizes a capture-type mating section between the arc-shaped limiting component and the turntable surface to create support reactions on both the upper and lower sides in the vertical direction. These two support reactions form a couple with the radius of the arc-shaped limiting component as the lever arm, bearing the overturning moment. Because the radius of the arc-shaped limiting component is much larger than that of a traditional single-point support, the lever arm is significantly increased, and the anti-overturning capability is correspondingly enhanced, ensuring the stability of the turntable surface during bending, improving the accuracy and repeatability of the bending angle, and ensuring that the corrugations can be precisely aligned and overlapped when adjacent corrugated plates are spliced.

[0012] Preferably, the bending unit includes a base, which is fixedly connected to the outer edge of the upper surface of the rotary table. A bending section bottom support is fixedly connected between the base and the center of the rotary table. The bending section bottom support is used to provide support for the bottom surface of the bending section of the corrugated plate. Two sliding columns are symmetrically arranged on the upper wall of the base. A pressure plate is sleeved on and slidably connected to the outer wall of the sliding column. A first lower groove matching the bending section bottom support is opened at the bottom of the pressure plate to press the upper surface of the bending section of the corrugated plate. A return spring is provided between the lower wall of the pressure plate and the upper wall of the base to provide an upward lifting force to the pressure plate.

[0013] The bottom support of the bending section provides support from the bottom surface of the bending section, and the pressure plate presses against the upper surface of the bending section from above through the first lower groove. The two work together to form an upper and lower clamping of the bending section. The first lower groove matches the bottom support of the bending section and can adapt to the undulating shape of the corrugated plate's protruding corrugated part, avoiding flattening or deformation of the corrugations. The return spring keeps the pressure plate raised when not in operation, facilitating the placement and removal of the sheet metal. During operation, the pressure plate presses down to clamp the bending section, ensuring that the bending section does not shift or detach during the rotation of the turntable, guaranteeing the accuracy and stability of the bending position, and ensuring that the bent corrugated plate meets the precision requirement of complete corrugation overlap when spliced ​​with other corrugated plates.

[0014] Preferably, two upper rollers are symmetrically arranged on both sides of the upper part of the bottom support of the bending section, and the mounting seats of the two upper rollers are fixedly connected to the lower wall of the pressure plate. Two lower rollers are symmetrically arranged on both sides of the lower part of the bottom support of the bending section, and the mounting seats of the two lower rollers are fixedly connected to the upper surface of the turntable. The upper rollers and lower rollers correspond one-to-one.

[0015] This design addresses the need for corrugated plates on the inner wall of liquefied natural gas (LNG) storage tanks to extend and splice around the circumference of a circular structure to form the bottom wall of a cylindrical tank. Therefore, both ends of the corrugated sections of a single plate require horizontal bending, adapting to both clockwise and counterclockwise bending conditions. Upper and lower rollers are located on either side of the bottom support of the bending section, clamping the area adjacent to the bending line from the plate thickness direction. During the rotation of the bending section on the rotary table, the upper and lower rollers continuously apply pressure in the plate thickness direction to the narrow strips adjacent to the bending line on both sides of the bending section. This causes the area to bear bending stress in the horizontal plane while simultaneously experiencing compressive stress in the plate thickness direction, altering the stress state and prompting more material in this area to cross the yield point and enter plastic deformation. This reduces the elastically recoverable strain reserve, thereby suppressing angular rebound in the horizontal plane when the bending force is removed after bending, ensuring the accuracy of the bending angle. Simultaneously, the clamping action of the upper and lower rollers concentrates and fixes the bending deformation within this narrow area, forming a clear plastic hinge. This prevents deformation from spreading into the bending section, reduces excessive thinning of the sheet material in certain areas due to uneven deformation, and improves forming quality. The two symmetrically arranged sets of rollers are suitable for bidirectional bending conditions: one set of rollers provides clamping during clockwise bending, while the other set provides clamping during counterclockwise bending. This ensures that regardless of the bending direction, the areas adjacent to the bending line on both sides of the bending section are effectively constrained, meeting the process requirements for splicing the two ends of the corrugated sheet together to form a sealing assembly.

[0016] Preferably, two lower pressure roller assemblies are slidably connected in the vertical direction inside the lower mold. An inclined block is provided below the lower pressure roller assembly. One end of the inclined block is located inside the lower mold and is slidably connected to the lower mold in the horizontal direction. The other end is located outside the lower mold and is provided with a locking component. The locking component keeps the inclined block and the lower mold relatively stationary. An inclined surface cooperation structure is provided between the inclined block and the lower pressure roller assembly. The inclined block drives the lower pressure roller assembly to rise and fall through the inclined surface cooperation structure. A clearance opening is symmetrically opened on the rotary table. When the inclined block is pushed to move into the lower mold, it drives the lower pressure roller assembly to rise and pass through the clearance opening until it contacts the lower surface of the corrugated plate. When the inclined block is pulled to move out of the lower mold, the lower pressure roller assembly descends until its height is lower than the rotary table surface.

[0017] When the corrugated plate is bent horizontally, the flat area serves as the reaction force reference for bending and needs to be reliably fixed to ensure the accuracy of the bending angle and bending line position. The lower pressure roller assembly provides support from the lower surface of the corrugated plate, cooperating with the upper clamping to enhance the fixation of the flat area. Since the turntable needs to rotate, if the lower pressure roller assembly is fixedly protruding from the turntable surface, it will interfere with the rotational movement; if it is fixed below the turntable surface, it cannot contact the lower surface of the corrugated plate. This invention converts the horizontal movement of the inclined block into the vertical lifting and lowering of the lower pressure roller assembly through the inclined surface cooperation structure, realizing the controllable extension and retraction of the lower pressure roller assembly: when needed, it extends through the clearance opening to press against the corrugated plate; when not needed, it retracts to allow rotation. The two symmetrically arranged lower pressure roller assemblies are adapted to bidirectional bending conditions. One of them can be selectively extended to work according to the bending direction, and cooperate with the corresponding upper pressure roller assembly above to form a clamping and fixing on the corresponding side of the flat area, providing a stable reaction force reference, ensuring the straightness of the edge of the corrugated plate and the accuracy of the corrugation position after bending, and meeting the splicing requirement that each corrugation between the two corrugated plates must be completely overlapped along the edge of the assembly.

[0018] Preferably, two upper pressure roller assemblies are detachably installed in the upper mold, and the upper pressure roller assembly corresponds one-to-one with the lower pressure roller assembly. When the upper mold descends and docks with the lower mold, the upper pressure roller assembly contacts the upper surface of the corrugated plate and provides downward pressure. In each bending process, only one upper pressure roller assembly is installed, and its installation position is opposite to the deflection direction of the bending unit. At the same time, only the lower pressure roller assembly corresponding to this upper pressure roller assembly passes through the clearance opening and contacts the lower surface of the corrugated plate.

[0019] The collaborative working method of the upper and lower pressure roller assemblies during bidirectional bending was clarified. Since the bending reaction force is opposite to the bending direction, the flat area bears a greater reaction force on the side opposite to the bending direction, requiring stronger fixation on that side. This invention addresses this by installing only the upper pressure roller assembly on the side opposite to the bending direction, and having it cooperate with the corresponding lower pressure roller assembly. This concentrates the force on the stressed side, forming an upper and lower clamping structure, specifically strengthening the fixation of the flat area on that side and ensuring a stable reaction force reference. The detachable installation design allows the same device to adapt to both clockwise and counterclockwise bending directions by simply changing the installation position of the upper pressure roller assembly. This meets the process requirements for bending in different directions when splicing corrugated plates around the circular perimeter of liquefied natural gas storage tank inner walls, improving the flexibility and versatility of the device and avoiding the need to create multiple sets of molds for different bending directions.

[0020] Preferably, the bottom of the lower mold is also fixedly connected to a fixed section bottom support, which corresponds to the bending section bottom support and is used to provide support for the bottom surface of the non-bending section of the corrugated plate. The bottom of the upper mold is provided with a second lower groove corresponding to the fixed section bottom support, which is used to press the upper surface of the non-bending section of the corrugated plate. A guide column is also provided between the lower mold and the upper mold.

[0021] The fixed section bottom support supports the bottom surface of the flat area. The upper mold presses the flat area from above through the second lower groove, forming a reliable fixation of the flat area and keeping its position stable during bending, serving as a bending reference. The guide post is used for centering guidance when the upper mold is closed relative to the lower mold, ensuring the alignment accuracy of the upper and lower molds. Furthermore, the center of the arc-shaped limiting component is aligned and fixed to the mold closing reference determined by the guide post, so that the rotation center of the rotary table and the mold closing alignment reference of the upper and lower molds refer to the same reference system. Structurally, this eliminates the cumulative error caused by the separate calibration and reassembly of two sets of references, improves the positional accuracy of the bending line and the repeatability of the bending angle, ensures the dimensional consistency of each corrugated plate after bending, and ensures that the corrugations can be completely overlapped and aligned when multiple corrugated plates are spliced.

[0022] Preferably, the positioning mechanism includes a guide rail, one end of which is fixedly connected to the base, and the other end is fixedly connected to a support frame. The sliding end of the guide rail is fixedly connected to a base plate, and a positioning section bottom support is fixedly connected to the base plate. A lead screw is threaded through and connected to the bottom of the base plate. One end of the lead screw is rotatably connected to the side wall of the lower mold, and the other end is fixedly connected to a servo motor. The outer wall of the servo motor is fixedly connected to the support frame.

[0023] This solution addresses the issue of varying horizontal bending lengths of corrugated plates due to different tank wall structures, and the need for custom molds for each length in traditional stamping methods. The positioning section bottom support supports the corrugated plate to be positioned. A servo motor drives a lead screw to rotate, which converts the rotational motion into linear movement of the base plate along the guide rail via a threaded joint. This causes the positioning section bottom support to adjust its position horizontally, determining the bending line's location on the corrugated plate according to the bending length. The advantages of servo motor control include high positioning accuracy, programmability, and remote control, adapting to the needs of digital production. The guide rail and lead screw structure ensures smooth movement and reliable positioning of the positioning section bottom support. No tooling changes are needed for each bending length; a single device can cover bending angles from 3° to 15° and various bending lengths, significantly reducing mold investment costs, simplifying the production process, improving production efficiency, and meeting the diverse bending length and angle requirements of corrugated plates for liquefied natural gas storage tanks due to different tank wall structures.

[0024] This invention provides a forming and processing apparatus for horizontally bent corrugated sheets. It has the following beneficial effects:

[0025] 1. This invention utilizes a rotary mechanism with a rotating disc supporting a bending unit. The bending unit holds the bent section of the corrugated sheet and rotates it around the bending line in a horizontal plane to form the bent section. This rotary bending method replaces the extrusion of the stamping die cavity. During rotation, the material gradually undergoes plastic bending, resulting in a smooth and uniform flow. This avoids the phenomenon of material loss along the thickness direction due to forced stretching on the outer side of the bend during stamping, thus preserving the original wall thickness of the corrugated sheet and improving its strength and service life after forming. Simultaneously, a servo motor-driven lead screw in the positioning mechanism moves the bottom support of the positioning section along the guide rail. Combined with precise control of the rotation angle by the rotary mechanism, the position of the bending line and the bending angle of the corrugated sheet are adjustable. The same device can process corrugated sheets with different bending lengths and angles without changing the mold, fundamentally reducing the number of dedicated molds, lowering mold investment costs, and simplifying production preparation and specification switching processes.

[0026] 2. This invention symmetrically arranges upper and lower rollers on both sides of the bottom support of the bending section in the bending unit. During the rotation of the bending section with the turntable, the upper and lower rollers clamp the area adjacent to the bending line from the thickness direction of the plate, so that the area is superimposed with the compressive stress in the thickness direction of the plate in addition to the bending stress. This causes more material to enter the plastic deformation state, reduces the angle rebound after the bending force is removed, and constrains the bending deformation into a stable plastic hinge, thereby improving the accuracy of the bending angle and the dimensional consistency between different corrugated plates.

[0027] 3. This invention utilizes the capture-type mating section between the arc-shaped limiting guide rail and the turntable surface to allow the overturning moment generated by the bending reaction force to be borne by the support reaction forces on both sides of the arc-shaped limiting guide rail with its radius as the lever arm. Compared with single-point support at the center, the bearing lever arm is significantly increased. The turntable surface does not warp or wobble during the bending process, ensuring the stability of the bending process and the accuracy of the bending angle, so that the corrugations of adjacent corrugated plates can be precisely aligned and overlapped during splicing.

[0028] 4. This invention sets the lower pressure roller assembly to be controllable in height by means of a combination of inclined blocks and inclined surfaces, and sets the upper pressure roller assembly to be detachable and installable. The two are selectively matched according to the bending direction. Concentrated upper and lower clamping is applied to the flat area on the side with greater bending reaction force. This not only stabilizes the bending reaction force benchmark, but also allows the same set of devices to adapt to both clockwise and counterclockwise bidirectional bending by simple adjustment of component positions. This meets the process requirements of splicing the corrugated plate around the circular tank wall after bending at both ends. Attached Figure Description

[0029] Figure 1 This is a perspective view of the present invention;

[0030] Figure 2 This is a three-dimensional schematic diagram of the positioning mechanism in this invention;

[0031] Figure 3This is a top view of the lower mold in this invention;

[0032] Figure 4 This is a three-dimensional schematic diagram of the lower mold in this invention;

[0033] Figure 5 for Figure 4 Enlarged view of point A in the middle;

[0034] Figure 6 This is a schematic diagram showing the position of the inclined block in this invention.

[0035] The components include: 1. Base; 2. Workbench; 3. Lower mold; 4. Lifting mechanism; 5. Upper mold; 501. Second lower groove; 6. Rotation mechanism; 7. Positioning mechanism; 701. Guide rail; 702. Support frame; 703. Base plate; 704. Positioning section bottom support; 705. Lead screw; 706. Servo motor; 8. Arc-shaped limit assembly; 9. Base; 10. Bending section bottom support; 11. Sliding column; 12. Pressure plate; 1201. First lower groove; 13. Return spring; 14. Upper roller; 15. Lower roller; 16. Lower pressure roller assembly; 17. Inclined block; 18. Clearance opening; 19. Upper pressure roller assembly; 20. Fixed section bottom support; 21. Guide column. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] In this invention, corrugated plate refers to a thin-film corrugated plate used for the inner wall of liquefied natural gas storage tanks, mainly composed of a flat portion and a protruding corrugated portion. Corrugations are divided into longitudinal corrugations and transverse corrugations. Longitudinal corrugations are those whose extension direction is parallel to the length direction of the corrugated plate, while transverse corrugations are those whose extension direction is perpendicular to the length direction of the corrugated plate. The bending line of the corrugated plate is the boundary line between the flat area and the bending section of the corrugated plate, and this bending line extends as a vertical straight line along the plate thickness direction. The bending section refers to the area of ​​the corrugated plate that needs to be horizontally bent, while the flat area refers to the area of ​​the corrugated plate that remains flat and is pressed and fixed as a reference during the bending process.

[0038] In this invention, horizontal bending refers to the bending and shaping of the corrugated plate within its horizontal plane while it is placed horizontally. The bent section rotates within the horizontal plane around a vertical axis (the projection of this axis onto the plate surface is the bending line), thereby forming a certain angle between the bent section and the flat area. The bending angle range described in this invention is 3° to 15°, which refers to the range of angles within the horizontal plane in which the bent section rotates relative to the flat area.

[0039] In this invention, the virtual center refers to the geometric center point around which the turntable moves in a circular motion. This center point coincides with the bending line of the corrugated plate, and no physical rotation axis or supporting hardware is set at this center point, keeping it in an empty state. The bending unit rotates around this virtual center, and the rotation effect around the virtual center is achieved by the turntable moving along the arc of the arc-shaped limiting component 8.

[0040] In this invention, the capture-type mating section refers to the mating form in which the arc-shaped limiting component 8 and the turntable surface are mutually constrained in the vertical direction. When the turntable surface moves in a circle along the arc-shaped limiting component 8, it is not only constrained in the radial direction, but also clamped and constrained in the vertical direction, preventing the turntable surface from tilting upward or falling off when subjected to overturning moment.

[0041] In this invention, bidirectional bending refers to the device's ability to achieve horizontal bending in both clockwise and counterclockwise directions to meet the application requirement that both ends of the corrugated plate need to be bent in order to be spliced ​​into a circular tank wall. Symmetrically arranged components refer to components arranged at equal distances and angles on both sides with the bending line or the center of the rotary table as a reference, to adapt to bidirectional bending conditions.

[0042] Please refer to the accompanying drawings*-Figures*. This invention provides a forming and processing apparatus for horizontally bending corrugated sheets, used for horizontally bending corrugated sheets for the inner wall of liquefied natural gas storage tanks. This solves the problems of thinner sheet material, reduced strength, and the need for multiple sets of molds for different bending specifications caused by traditional stamping forming. The forming and processing apparatus for horizontally bending corrugated sheets includes a base 1, a worktable 2, a lower mold 3, a lifting mechanism 4, an upper mold 5, a rotating mechanism 6, and a positioning mechanism 7. The base 1 is fixedly mounted on one side of the upper surface of the worktable 2, providing a stable support foundation for the entire apparatus. The lower mold 3 is bolted to the upper surface of the base 1. The lower mold 3 has a cuboid frame structure, and its top plane is used to horizontally support the corrugated sheet to be bent.

[0043] A lifting mechanism 4 is provided on the other side of the upper surface of the workbench 2. The lifting mechanism 4 is driven by a hydraulic cylinder or a pneumatic cylinder, and its lifting end is fixedly connected to an upper mold 5 via a connecting plate. The outer dimensions of the upper mold 5 match those of the lower mold 3, and it can move up and down vertically under the drive of the lifting mechanism 4 to achieve engagement and disengagement with the lower mold 3. The upper mold 5 is used to press the flat area of ​​the corrugated plate from above during the bending process, so that the flat area remains in a fixed position during bending, serving as a reference for bending.

[0044] A rotary mechanism 6 is installed inside the lower mold 3. The rotary mechanism 6 is mounted on a support platform at the bottom of the lower mold 3. The rotary mechanism 6 includes a drive motor and a reducer. The drive motor drives the rotary disc surface to perform circular motion through the reducer. The rotary disc surface is a circular flat plate structure, with its center coinciding vertically with the bending line of the corrugated plate. Bending units are provided on the outer edge of the upper surface of the rotary disc surface, and these bending units rotate around the center in the horizontal plane along with the rotary disc surface.

[0045] The bending unit is used to support and clamp the bent section of the corrugated plate. Driven by the rotary mechanism 6, the bending unit causes the bent section to move in an arc around the bending line in the horizontal plane, applying a horizontal bend to the bent section. The bending line is the boundary line between the flat area and the bent section on the corrugated plate. This boundary line extends along the thickness direction of the plate, forming a vertical line in space. The center of the rotary table coincides with this vertical line, and the bent section rotates around this vertical line, thereby achieving a horizontal bend in the relatively flat area.

[0046] A positioning mechanism 7 is provided on the outer side of the lower mold 3. The positioning mechanism 7 is arranged along the length of the corrugated plate and is used to adjust the positioning position of the corrugated plate on the lower mold 3 according to the bending section length of different corrugated plates. By moving the position of the positioning section bottom support 704, the positioning mechanism 7 ensures that the bending line of the corrugated plate falls precisely above the center of the rotary table surface, ensuring that the bending section can bend around the correct bending line.

[0047] The corrugated plate is placed horizontally on the top plane of the lower mold 3 and the upper surface of the rotary table. The corrugated plate includes a flat portion and a corrugated portion, with the corrugations undulating periodically along the plate surface. The flat area of ​​the corrugated plate is clamped and fixed by the mating surfaces of the upper mold 5 and the lower mold 3, and the bending section is supported and clamped by the bending unit.

[0048] During the bending process, the lifting mechanism 4 drives the upper mold 5 to descend, and the upper mold 5 aligns with the lower mold 3, firmly clamping the flat area of ​​the corrugated plate. Subsequently, the rotary mechanism 6 is activated, driving the turntable to rotate around its center in the horizontal plane. The bending unit on the turntable rotates accordingly, causing the clamped bending segment to rotate through a set angle in the horizontal plane. As the bending segment rotates around the bending line, the material near the bending line undergoes plastic bending deformation, forming a bend in the horizontal plane.

[0049] The rotation angle is determined based on the geometric requirements when the corrugated plates are finally assembled into a circular tank wall. The device of this invention can achieve adjustable angle bending within the range of 3° to 15°. By controlling the rotation angle of the rotation mechanism 6, the bent section forms a corresponding angle relative to the non-bent section. After bending is completed, the upper mold 5 rises, the corrugated plate is removed from the device, the rotation mechanism 6 rotates in the opposite direction, and the bending unit returns to its initial position, completing one bending process.

[0050] Because the center of the rotary table coincides with the bending line, and no physical rotation axis or support structure is set at this center, the position of the bending line remains empty. Therefore, the corrugated sheet can be completely laid flat on the lower mold 3 and the rotary table, eliminating the problem of the corrugated sheet being unable to be placed due to the space occupied by a physical rotation axis. The bending unit achieves the rotation effect around the virtual center by moving along the circumference of the arc-shaped limiting component 8. This structure ensures the bending accuracy and solves the geometric contradiction of the rotation center overlapping with the sheet material position.

[0051] The positioning mechanism 7 is designed to accommodate bending sections of varying lengths. For corrugated sheets of different specifications, the lengths of the bending sections differ, and the positions of the bending lines on the corrugated sheets also vary accordingly. By adjusting the position of the positioning section base support 704, the positioning mechanism 7 ensures that the bending lines of corrugated sheets of different lengths are precisely aligned with the center of the turntable surface during placement. This guarantees that the bending sections rotate around the correct centerline, ensuring that the bent corrugated sheets meet the precision requirement of complete corrugation overlap during splicing.

[0052] The device of this invention uses a back-bending forming method, which differs from the traditional stamping die method that forcibly extrudes metal. The back-bending allows the material in the bending area to undergo gradual plastic deformation under relatively gentle stress, resulting in a more uniform deformation process and reducing excessive stretching and thinning caused by localized stress concentration. This forming method preserves more of the original wall thickness of the corrugated plate, improving the strength and pressure-bearing capacity of the formed corrugated plate and extending the service life of the liquefied natural gas storage tank.

[0053] Meanwhile, through the length adjustment of the positioning mechanism 7 and the angle control of the rotation mechanism 6, the same set of equipment can process corrugated plates with different bending lengths and different bending angles, without the need to design and manufacture special molds for each specification. This flexible production method significantly reduces mold investment costs, shortens product changeover time, simplifies the production process, improves production efficiency, and meets the diverse bending requirements of corrugated plates for the inner wall of liquefied natural gas storage tanks due to different tank wall structures.

[0054] In this embodiment, a rotary mechanism 6 is provided on the inner bottom surface of the lower mold 3. The rotary mechanism 6 includes a mounting base plate, a drive motor, a reducer, and a rotary table. The mounting base plate is fixed to the inner bottom surface of the lower mold 3 with bolts. The drive motor is mounted on the mounting base plate, and the output shaft of the drive motor is connected to the input shaft of the reducer via a coupling. The reducer is a planetary gear reducer or a worm gear reducer, and the reduction ratio is determined according to the required bending torque and rotation speed. The output shaft of the reducer extends vertically upward and is fixedly connected to the center of the rotary table.

[0055] The rotary table is disc-shaped, and its diameter is determined based on the maximum length of the bending section and the range of bending angles. The rotary table surface is made of high-strength alloy steel and undergoes heat treatment to ensure sufficient rigidity and wear resistance. The upper surface of the rotary table is precision ground, with a flatness controlled within 0.05mm to ensure uniform stress on the bending section during rotation.

[0056] An arc-shaped limiting component 8 is fixedly connected to the inner wall of the lower mold 3. The center of the arc-shaped limiting component 8 coincides with the center of the rotary table surface, forming a concentric configuration. The arc-shaped limiting component 8 is arranged along the circumference of the outer edge of the rotary table surface, and its arc segment covers the working stroke range of the rotary table surface.

[0057] The arc-shaped limiting component 8 is made of steel with a rectangular or I-shaped cross-section, providing sufficient bending stiffness. The arc-shaped limiting component 8 is fixed to the lower mold 3 by multiple mounting seats, which are evenly distributed and each seat is connected to the lower mold 3 by bolts. The inner surface of the arc-shaped limiting component 8 maintains a uniform clearance with the outer edge of the rotary table surface, ensuring smooth rotation of the rotary table surface while limiting its radial displacement.

[0058] The key technical feature of this invention is that the arc-shaped limiting component 8 and the rotary table surface adopt a capture-type mating section. The capture-type mating section refers to a mating structure that forms an upper and lower clamping constraint in the vertical direction, so that the rotary table surface is not only constrained by the arc-shaped limiting component 8 in the radial direction, but also restricted in the vertical direction, preventing the rotary table surface from tilting upward or detaching downward when subjected to overturning moment.

[0059] The specific implementation of the capture-type mating section is as follows: an outwardly extending annular flange is provided on the outer edge of the rotary table surface, and an upper roller group and a lower roller group are respectively provided on the upper and lower surfaces of the annular flange. The upper roller group is installed on the upper side of the arc-shaped limiting component 8, and the lower roller group is installed on the lower side of the arc-shaped limiting component 8. The rollers of the upper roller group press against the upper surface of the annular flange from above, and the rollers of the lower roller group support the lower surface of the annular flange from below, forming a capture structure with upper and lower clamping.

[0060] The upper roller assembly comprises multiple upper rollers, each mounted on the upper bracket of the arc-shaped limiting assembly 8 via a mounting seat. The upper rollers are horizontally aligned radially, with their outer surfaces in line or surface contact with the upper surface of the annular flange. The upper rollers are made of bearing steel and have undergone surface hardening treatment, resulting in high hardness and wear resistance. The upper rollers are evenly distributed along the arc direction of the arc-shaped limiting assembly 8.

[0061] The lower roller assembly is symmetrical to the upper roller assembly. The lower roller is also mounted on the lower bracket of the arc-shaped limiting component 8 via a mounting base, and the lower roller supports the lower surface of the annular flange from below. The lower roller and the upper roller correspond one-to-one in the vertical direction, forming a pair of clamping rollers.

[0062] When the bending unit applies a horizontal bending force to the bending section, the bending reaction force generated by the bending section is transmitted to the bending unit and then to the rotary table surface. Since the bending section is located on the outer edge of the upper surface of the rotary table, the point of application of the bending reaction force is horizontally distanced from the center of the rotary table surface. This horizontal reaction force, along with the distance from its point of application to the center, forms a torque, exerting an overturning moment on the rotary table surface. This overturning moment causes the rotary table surface to tend to flip around a certain horizontal axis, manifesting as one side of the rotary table surface tilting upwards and the other side pressing downwards.

[0063] In traditional single-point support structures, the rotary table is supported only by the central output shaft, and its anti-overturning capability depends on the bending stiffness of the output shaft and the radial load-bearing capacity of the bearings. When the overturning moment is large, the output shaft bends and deforms, the rotary table wobbles, causing the bending section to shift, the bending angle accuracy to decrease, and even causing the device to jam or be damaged.

[0064] This invention changes the bearing method of overturning moment from single-point support to large-radius couple support by using a capture-type mating section between the arc-shaped limiting component 8 and the turntable surface. When the turntable surface tilts upward under the action of overturning moment, the upper surface of the annular flange immediately abuts against the upper roller, and the upper roller applies a downward support reaction force to the annular flange. At the same time, the turntable surface tends to press downward, and the lower surface of the annular flange on that side immediately presses against the lower roller, and the lower roller applies an upward support reaction force to the annular flange.

[0065] These two opposing support reactions form a couple, the lever arm of which is the radius of the arc-shaped limiting component 8. Since the radius of the arc-shaped limiting component 8 is much larger than the radius of the central output shaft, the lever arm of the couple increases significantly. Under the same support reaction force value, the balancing torque generated by the couple increases significantly. This balancing torque is opposite in direction to the overturning torque; when the two are equal, the rotary table reaches a state of torque balance, and no more tilting or swaying occurs.

[0066] The materials and heat treatment processes used for the upper and lower rollers ensure sufficient strength and hardness to withstand repeated contact stresses over long periods without indentation or wear. The roller bearings are deep groove ball bearings or tapered roller bearings, providing high radial and axial load capacity. The roller mounting positions are precisely adjusted to ensure uniform clearance between the upper and lower rollers and the annular flange, preventing overloading of some rollers due to uneven clearance.

[0067] The arc-shaped limiting component 8 of the present invention also serves to limit the rotation angle of the turntable surface. Limiting blocks are provided at both ends of the arc-shaped limiting component 8, and these blocks are fixed to the ends of the arc-shaped limiting component 8 and protrude inwards. A limiting boss is provided on the annular flange of the turntable surface, extending radially outwards. When the turntable surface rotates clockwise or counterclockwise to its maximum angle, the limiting boss contacts the limiting block on the corresponding side, preventing the turntable surface from continuing to rotate, thus achieving mechanical limiting protection.

[0068] The position of the limiting block is determined based on the bending angle range. In this embodiment, the bending angle range is 3° to 15°. Considering the requirement for bidirectional bending, the limiting block is configured such that the rotary table can rotate 15° to each side from the center, with a total stroke of 30°. The limiting block adopts an elastic buffer structure. When the limiting boss contacts the limiting block, it is buffered by a rubber pad or spring to avoid rigid impact damage to the components.

[0069] The drive motor is equipped with precise position and speed control capabilities. An encoder provides real-time feedback on the angular position of the turntable, and the control system controls the motor's rotation angle according to the set bending angle, achieving precise positioning. During bending, the motor drives the turntable to rotate at a constant, low speed, controlled between 1° / s and 3° / s. This ensures sufficient time for the material in the bending section to undergo plastic deformation, preventing cracking or uneven deformation due to excessively high rotation speed.

[0070] The selection of the reducer is determined based on the maximum torque required for bending. During bending, the resistance torque exerted by the bending section on the rotary table surface is related to the length of the bending section, the thickness of the corrugated plate, the yield strength of the material, and the bending angle. Through mechanical calculations, the maximum resistance torque is determined, and then the specifications of the reducer and drive motor are selected according to the reduction ratio and safety factor to ensure that the drive system has sufficient torque reserve and can stably and reliably complete the bending action under various working conditions.

[0071] In this embodiment, a bending unit is fixedly connected to the upper surface of the rotary table. The bending unit includes a base 9, a bending section bottom support 10, a sliding column 11, a pressure plate 12, and a return spring 13. The bottom plane of the base 9 is fixedly connected to the outer edge of the upper surface of the rotary table by bolts, and the base 9 rotates around the center in the horizontal plane along with the rotary table.

[0072] A bending section bottom support 10 is fixedly connected between the base 9 and the center of the rotary table surface. The bending section bottom support 10 is in the shape of a long strip plate, extending radially along the rotary table surface, and its length is determined according to the maximum length of the bending section. The upper surface of the bending section bottom support 10 is used to support the bottom surface of the corrugated plate bending section, providing stable support for the bending section.

[0073] Two sliding columns 11 are symmetrically arranged on both sides of the upper wall of the base 9. The sliding columns 11 extend vertically upward, with their lower ends fixed to the upper wall surface of the base 9 and their upper ends being free. A pressure plate 12 is fitted onto the outer wall of the sliding column 11, and the pressure plate 12 and the sliding column 11 are in sliding fit. A first lower groove 1201 is formed at the bottom of the pressure plate 12. The shape of the first lower groove 1201 corresponds to the shape of the upper surface of the bending section bottom support 10, and the two fit together in the vertical direction to clamp the bending section of the corrugated plate from top to bottom. The inner surface of the first lower groove 1201 also matches the corrugation of the upper surface of the corrugated plate.

[0074] A return spring 13 is provided between the lower wall of the pressure plate 12 and the upper wall of the base 9. In this embodiment, a return spring 13 is provided around each sliding column 11, and two return springs 13 are provided for the two sliding columns 11. The return spring 13 is a cylindrical helical compression spring, with its lower end seated in a spring seat on the upper wall of the base 9 and its upper end pressing against the lower wall surface of the pressure plate 12. The free length of the return spring 13 is greater than the distance between the pressure plate 12 and the upper wall of the base 9, so that the return spring 13 is in a compressed state in the free state, applying an upward lifting force to the pressure plate 12.

[0075] When the corrugated plate is placed on the bending section bottom support 10, the pressure plate 12 is in an upward state. The opening of the first lower groove 1201 is downward and spacious, which facilitates the bending section of the corrugated plate to extend into the space between the first lower groove 1201 and the bending section bottom support 10. After the corrugated plate is in place, the pressure plate 12 is pressed down by the downward pressure applied externally or by the descent of the upper mold 5, so that the pressure plate 12 moves downward against the elastic force of the return spring 13. The inner surface of the first lower groove 1201 gradually approaches the upper surface of the corrugated plate, and finally clamps the bending section of the corrugated plate tightly from top to bottom.

[0076] During the bending process, the rotary table drives the bending unit to rotate, and the bending segment experiences bending resistance during rotation. If the clamping force of the pressure plate 12 on the bending segment is insufficient, the bending segment will slip between the first lower groove 1201 and the bottom support 10 of the bending segment under the action of bending resistance, resulting in a deviation in the bending position and an inaccurate bending angle. Therefore, the clamping force of the pressure plate 12 needs to be large enough to ensure that the position of the bending segment relative to the bending unit remains fixed throughout the entire rotation process.

[0077] In this embodiment, the clamping force of the pressure plate 12 is obtained through the clamping force of the upper mold 5. When the upper mold 5 descends to clamp the flat area of ​​the corrugated plate, the bottom of the upper mold 5 simultaneously presses against the upper surface of the pressure plate 12, pressing the pressure plate 12 downwards, so that the pressure plate 12 overcomes the elastic force of the return spring 13 and clamps the bent section. The clamping force applied by the upper mold 5 is provided by the hydraulic cylinder or pneumatic cylinder of the lifting mechanism 4, and the magnitude of the clamping force is achieved by adjusting the pressure of the hydraulic system or the pneumatic system.

[0078] After bending, the upper mold 5 rises, the downward pressure on the pressure plate 12 disappears, and the elastic force of the return spring 13 causes the pressure plate 12 to rise automatically. The first lower groove 1201 separates from the upper surface of the corrugated plate, and the bent section of the corrugated plate is released from the bending unit, making it easy to remove the formed corrugated plate. The return speed of the return spring 13 is controlled by the spring stiffness and damping device to prevent the pressure plate 12 from rising too quickly and causing impact.

[0079] In this embodiment, two upper rollers 14 are symmetrically arranged on both sides of the upper part of the bottom support 10 of the bending section. The mounting base of the upper roller 14 is fixedly connected to the lower wall of the pressure plate 12. Each upper roller 14 includes a roller body, a rotating shaft and a mounting base. The two ends of the rotating shaft are supported in the mounting base by bearings, and the roller body is fixedly fitted in the middle of the rotating shaft and can rotate freely around the rotating shaft.

[0080] The mounting base of the upper roller 14 is fixed to the lower wall of the pressure plate 12, and the position of the mounting base is such that the upper roller 14 is located on both sides of the bottom support 10 of the bending section. The two upper rollers 14 are arranged symmetrically about the bending line.

[0081] Two lower rollers 15 are symmetrically arranged on both sides of the lower part of the bottom support 10 of the bending section. The mounting base of the lower rollers 15 is fixedly connected to the upper surface of the rotary table by bolts. The structure of the lower rollers 15 is the same as that of the upper rollers 14.

[0082] The lower roller 15 is positioned one-to-one with the upper roller 14 in the vertical direction. When the pressure plate 12 is in the downward pressing state and the first lower groove 1201 clamps the bent section of the corrugated plate, there is a lower roller 15 directly below each upper roller 14. The vertical distance between the upper roller 14 and the lower roller 15 is equal to the thickness of the bent section of the corrugated plate plus the amount of pressure applied to the corrugated plate by the upper and lower rollers.

[0083] The upper roller 14 and the lower roller 15 act on the area near the bending line of the corrugated plate's bending section. During the bending process, the material near the bending line undergoes plastic bending deformation; this area is a concentration point of bending stress and the main source of springback. The upper roller 14 applies downward pressure to this area from the upper surface of the corrugated plate, while the lower roller 15 applies upward support force to the area from the lower surface of the corrugated plate. Together, they form an upper and lower clamping force on the bending section of the corrugated plate.

[0084] As the rotary table drives the bending unit to rotate around the center, the bending section rotates along with the bending unit, and the material near the bending line gradually bends and deforms during the rotation. The upper roller 14 and the lower roller 15 are always positioned on both sides of the bending section near the bending line, moving horizontally with the bending section and continuously applying pressure in the thickness direction to the area near the bending line. This continuous clamping action continues throughout the entire bending process, from the start of bending until the bending angle reaches the set value.

[0085] The pressure applied to the corrugated plate by the upper roller 14 and the lower roller 15 alters the stress state of the bending area. In a conventional bending process, the material near the bending line mainly bears bending stress in the horizontal plane, with the material on the outer side of the bend being stretched and the material on the inner side being compressed. This unidirectional tensile and compressive stress causes the material to store strain energy within its elastic range. When the bending force is removed, the stored elastic strain energy is released, resulting in a springback of the bending angle.

[0086] This invention applies compressive stress along the thickness direction of the plate using upper roller 14 and lower roller 15, changing the stress state of the bending region from uniaxial bending stress to a triaxial stress state consisting of bending stress superimposed with compressive stress along the thickness direction. Under this triaxial stress state, the yield criterion of the material changes, and the material is more likely to enter a state of plastic deformation under the same bending stress. Material that has entered plastic deformation no longer possesses elastic recovery capability; when the bending force is removed, the plastically deformed portion remains deformed and does not spring back.

[0087] Applying compressive stress along the thickness of the plate causes more material in the bending region to cross the yield point, increasing the proportion of the plastic deformation region and decreasing the proportion of the elastic deformation region. After bending, the strain energy stored in the elastic region decreases, and the springback decreases accordingly. This method of suppressing springback by changing the stress state differs from traditional over-bending compensation or post-springback correction methods, reducing the source of springback from the essence of material deformation.

[0088] The clamping action of the upper roller 14 and the lower roller 15 also concentrates the bending deformation within the clamped narrow band area. After the area adjacent to the bending line is clamped by the upper and lower rollers, the material in this area is constrained in the thickness direction, and the deformation is mainly manifested as bending along the surface direction of the plate.

[0089] In this embodiment, the pressure exerted on the corrugated plate by the upper roller 14 and the lower roller 15 is transmitted through the downward pressure of the pressure plate 12. Under the clamping force of the upper mold 5, the pressure plate 12 moves downward, and the upper roller 14, fixed to the lower wall of the pressure plate 12, moves downward along with it, with the roller body of the upper roller 14 pressing against the upper surface of the corrugated plate. The corrugated plate deforms downward under the pressure of the upper roller 14, and the lower surface of the corrugated plate presses against the lower roller 15, which applies an upward counterforce to the corrugated plate. The downward pressure applied by the upper roller 14 and the upward counterforce applied by the lower roller 15 are equal in magnitude and opposite in direction, forming a clamping effect on the corrugated plate.

[0090] The roller bodies of the upper roller 14 and lower roller 15 can rotate freely around the pivot axis, making the contact between the rollers and the corrugated plate a rolling contact rather than a sliding contact. During the bending process, the bending section undergoes a slight relative movement with respect to the rollers, and the roller bodies rotate accordingly. This relative movement does not generate sliding friction, thus avoiding scratches on the surface of the corrugated plate caused by sliding friction. The coefficient of friction for rolling contact is much lower than that for sliding contact, reducing the resistance during the bending process and lowering the power requirements of the drive motor.

[0091] In this embodiment, two downward pressure roller assemblies 16 are slidably connected in the lower mold 3 along the vertical direction. Each downward pressure roller assembly 16 includes a sliding bracket, a downward pressure roller, and a guide rod. The sliding bracket has a rectangular frame structure, with the downward pressure roller fixedly connected to its upper part and the guide rod fixedly connected to its lower part. The guide rod extends vertically downward, passes through a guide hole at the bottom of the lower mold 3, and forms a vertical sliding fit with the lower mold 3.

[0092] The two lower pressure roller assemblies 16 are positioned within the lower die 3 corresponding to the two sides of the flat area near the bending line. When the corrugated plate is placed on the lower die 3, the two lower pressure roller assemblies 16 are located on both sides of the bending line, below the bottom surface of the flat area. In the initial state, the lower pressure roller assemblies 16 are in a descending position, with the top of the lower pressure rollers below the upper surface of the turntable and not in contact with the lower surface of the corrugated plate, providing space for the placement of the corrugated plate and the rotation of the turntable.

[0093] A wedge block 17 is provided below the lower pressure roller assembly 16. One end of the wedge block 17 is located inside the lower mold 3, and this end forms a horizontal sliding connection with the inner bottom surface of the lower mold 3. The other end of the wedge block 17 protrudes from the side wall of the lower mold 3 and is located outside the lower mold 3. This end is provided with a handle or operating rod to facilitate the operator to push and pull the wedge block 17 for horizontal movement.

[0094] A locking component is provided at the exposed end of the inclined block 17. The locking component adopts a quick clamping device or a locking bolt. When the inclined block 17 moves to the set position, the locking component is operated to keep the inclined block 17 relatively stationary with respect to the lower mold 3, so as to prevent the inclined block 17 from being displaced due to vibration or force during the bending process.

[0095] An inclined surface engagement structure is provided between the inclined block 17 and the guide rod of the lower pressure roller assembly 16. The inclined surface of the inclined block 17 contacts the inclined surface of the inclined push block, forming an inclined surface engagement. When the inclined block 17 moves horizontally into the lower mold 3, the inclined surface of the inclined block 17 pushes the inclined surface of the inclined push block, and the inclined surface engagement converts the horizontal movement of the inclined block 17 into the vertical upward movement of the guide rod.

[0096] Two clearance openings 18 are symmetrically formed on the rotary table surface. The positions of the clearance openings 18 correspond to the positions of the lower pressure roller assembly 16. The two clearance openings 18 are symmetrically arranged about the center of the rotary table surface, located on both sides of the bending line. The distance between the clearance opening 18 and the center of the rotary table surface is determined according to the length of the flat area and the position of the bending line, so that the clearance opening 18 is located exactly below the area of ​​the flat area near the bending line. This symmetrical arrangement is suitable for bidirectional bending. When bending clockwise, the clearance opening 18 and the lower pressure roller assembly 16 on one side are used, and when bending counterclockwise, the clearance opening 18 and the lower pressure roller assembly 16 on the other side are used.

[0097] Before the bending process begins, the operator determines the lower pressure roller assembly 16 to be used based on the bending direction. If the bending direction is clockwise, the inclined block 17 located on the opposite side of the clockwise bending direction is pushed to move into the lower mold 3. The inclined surface of the inclined block 17 pushes the inclined push block of the corresponding lower pressure roller assembly 16, driving the lower pressure roller assembly 16 to rise vertically.

[0098] During the ascent of the lower pressure roller assembly 16, the lower pressure roller gradually rises from inside the lower mold 3, passing through the clearance opening 18 on the rotary table surface. The lower pressure roller continues to rise until its top contacts the lower surface of the corrugated plate. At this point, the inclined block 17 reaches the set horizontal position, and the operator operates the locking component to lock the inclined block 17 in this position, keeping the lower pressure roller assembly 16 in the ascending state.

[0099] The lower surface of the corrugated plate contacts the top of the pressing assembly 16 under the action of gravity, and the pressing assembly 16 provides an upward supporting force to the corrugated plate. When the upper mold 5 descends to press the corrugated plate, the corrugated plate is clamped by the fixed section bottom support 20 of the upper mold 5 and the lower mold 3. At the same time, near the bending line, the lower surface of the corrugated plate is pressed from below by the pressing roller, and the upper surface of the corrugated plate is pressed from above by the upper pressure roller assembly 19, forming an upper and lower clamping at this position.

[0100] After bending, the upper mold 5 rises, and the clamping force on the corrugated plate disappears. At this time, the operator releases the lock of the inclined block 17 and pulls the inclined block 17 to move it outside the lower mold 3. The inclined surface of the inclined block 17 slides relative to the inclined surface of the inclined push block, and the inclined push block moves downward under the action of gravity, driving the lower pressure roller assembly 16 to descend vertically.

[0101] During the descent of the lower pressure roller assembly 16, the lower pressure roller gradually detaches from the lower surface of the corrugated plate, passes through the clearance opening 18, and returns to the interior of the lower mold 3, eventually descending to its initial position, with the top of the lower pressure roller lower than the upper surface of the rotary table. After the lower pressure roller assembly 16 is reset, there are no obstructions above the rotary table, allowing it to rotate freely in preparation for the next bending process.

[0102] The rising height of the lower pressure roller assembly 16 is limited by the horizontal stroke of the inclined block 17. A limit block is provided inside the side wall of the lower mold 3. The position of the limit block causes the end of the inclined block 17 to contact the limit block when it moves horizontally to a set distance, preventing the inclined block 17 from moving further. At this time, the lower pressure roller assembly 16 rises to the set height, and the contact pressure between the lower pressure roller and the lower surface of the corrugated plate reaches a predetermined value.

[0103] In this embodiment, two upper pressure roller assemblies 19 are detachably mounted on the bottom of the upper mold 5. The upper pressure roller assembly 19 includes a mounting base, an upper pressure roller, and fixing bolts. The mounting base has an L-shaped structure, with its horizontal section connected to the mounting groove at the bottom of the upper mold 5 by fixing bolts, and its vertical section extending downward, with the upper pressure roller mounted at the lower end of the vertical section.

[0104] The bottom of the upper mold 5 has two mounting slots, which are symmetrically arranged about the center line of the upper mold 5. The bottom of the mounting slot has threaded holes, and the fixing bolts pass through the through holes of the mounting base and are screwed into the threaded holes to fix the mounting base in the mounting slot.

[0105] The upper pressure roller assembly 19 is detachable; it can be removed from the mounting slot by loosening the fixing bolts. This detachable installation design allows the same device to adapt to both clockwise and counterclockwise bending conditions through simple component position adjustments.

[0106] The upper pressure roller assembly 19 and the lower pressure roller assembly 16 are horizontally aligned. The two mounting slots at the bottom of the upper mold 5 are vertically aligned with the two lower pressure roller assemblies 16 inside the lower mold 3. When the upper mold 5 descends and docks with the lower mold 3, the upper pressure roller is positioned directly above the corresponding lower pressure roller, forming a pair of mating pressure rollers in the vertical direction.

[0107] In each bending process, only one upper pressure roller assembly 19 is installed according to the bending direction. The bending direction is determined based on the geometric requirements and process flow arrangement when splicing corrugated plates. The bending direction mentioned in this invention refers to the rotation direction of the relatively flat area of ​​the bent section in the horizontal plane, which is divided into clockwise and counterclockwise.

[0108] When the bending direction is clockwise, the bent section rotates clockwise relative to the flat area. At this point, one side of the bend is the outer side, where the material is stretched, while the other side is the inner side, where the material is compressed. During the bending process, the reaction force exerted by the bent section on the flat area is opposite to the bending direction; that is, the bending reaction force points counterclockwise. Under the action of the bending reaction force, the counterclockwise side of the flat area experiences greater stress and a greater tendency to deform, requiring stronger fixation and support.

[0109] Based on the direction of the bending reaction force, the upper pressure roller assembly 19 is installed on the side opposite to the deflection direction of the bending unit. During clockwise bending, the upper pressure roller assembly 19 is installed in the mounting groove on the counter-clockwise side. This position is precisely on the side where the bending reaction force is greater. The upper pressure roller presses against the upper surface of the flat area of ​​the corrugated plate from above, forming a clamping effect with the corresponding lower pressure roller below, providing direct support and constraint at the position of maximum bending reaction force.

[0110] Simultaneously, the operator pushes the inclined block 17 on the corresponding side according to the bending direction, causing the lower pressure roller assembly 16 on that side to rise, and the lower pressure roller passes through the clearance opening 18 and contacts the lower surface of the corrugated plate. When bending clockwise, the inclined block 17 on the counterclockwise side is pushed, causing the lower pressure roller assembly 16 on the counterclockwise side to rise. This lower pressure roller assembly 16 cooperates with the upper pressure roller assembly 19 installed on the same side to form a complete upper and lower clamping unit.

[0111] As the upper mold 5 descends, the upper pressure roller first contacts the upper surface of the flat area of ​​the corrugated plate, applying downward pressure to the corrugated plate. Under the pressure of the upper pressure roller, the corrugated plate deforms downward, and the lower surface of the corrugated plate presses against the lower pressure roller, which in turn applies an upward reaction force to the corrugated plate. The downward pressure applied by the upper pressure roller and the upward reaction force applied by the lower pressure roller are equal in magnitude and opposite in direction, forming an upper and lower clamping effect on that position of the flat area of ​​the corrugated plate.

[0112] The upper and lower pressure roller assemblies work precisely in the area where the bending reaction force is greatest and the flat area is most prone to warping or displacement. By applying concentrated upper and lower clamping forces to this area, the fixation of this area is specifically strengthened to prevent deformation or displacement of the flat area under the action of bending reaction force, ensuring the stability of the bending line position and guaranteeing the bending angle and dimensional accuracy.

[0113] Simultaneously, the inclined block 17 on the counterclockwise side is pulled out, causing the lower pressure roller assembly 16 on that side to descend and reset. Then, the inclined block 17 on the clockwise side is pushed, causing the lower pressure roller assembly 16 on the clockwise side to rise. During counterclockwise bending, the upper and lower pressure roller assemblies on the clockwise side work together to provide upper and lower clamping at the position where the bending reaction force is applied, ensuring the fixation effect in the flat area.

[0114] This design, which adjusts the working position of the upper and lower pressure roller assemblies according to the bending direction, enables the device to adapt to bidirectional bending requirements while ensuring consistent process conditions and fixing effects during bending in both directions. The corrugated plates on the inner wall of liquefied natural gas storage tanks need to be spliced ​​around the perimeter of a circle, and both ends of each corrugated plate need to be bent, with the bending directions at both ends being opposite. The device of this invention can complete the bidirectional bending process at both ends of the same corrugated plate through simple component position adjustments, eliminating the need for two different configurations of equipment or frequent tooling changes.

[0115] This invention achieves targeted reinforcement of the fixing force in the flat area through the selective use of upper and lower pressure roller assemblies. Compared to applying uniform clamping force over the entire length of the flat area, concentrating the greater clamping force at the bending reaction point saves on the clamping force requirement, reduces the load on the lifting mechanism 4, and provides more effective constraint at key locations, thereby improving bending accuracy and stability.

[0116] In this embodiment, a fixed section bottom support 20 is fixedly connected to the top of the lower mold 3. The fixed section bottom support 20 corresponds to the bending section bottom support 10, and the two together form a complete bottom support for the corrugated plate. The fixed section bottom support 20 supports the non-bending section near the bending section, and the bending section bottom support 10 supports the bending section.

[0117] The bottom of the upper mold 5 is provided with a second lower groove 501. The planar shape of the second lower groove 501 corresponds to the planar shape of the fixed section bottom support 20, so that when the upper mold 5 is lowered into place, it applies a clamping force to the flat area of ​​the corrugated plate.

[0118] A guide post 21 is provided between the lower mold 3 and the upper mold 5. The function of the guide post 21 is to provide guidance for the upper mold 5 during its lifting and lowering process, ensuring that the upper mold 5 moves vertically relative to the lower mold 3 without horizontal deviation or rotation around the vertical axis. The guide post 21 also serves to center the upper and lower molds. When the upper mold 5 descends along the guide post 21, the center of the upper mold 5 automatically aligns with the center of the lower mold 3, achieving precise centering of the upper and lower molds.

[0119] In this embodiment, a positioning mechanism 7 is provided on the outer side of the lower mold 3. The positioning mechanism 7 includes a guide rail 701, a support frame 702, a base plate 703, a positioning section bottom support 704, a lead screw 705, and a servo motor 706. The positioning mechanism 7 can position corrugated plates with different bending section lengths by adjusting the horizontal position of the positioning section bottom support 704.

[0120] The guide rail 701 is arranged horizontally, with one end fixedly connected to the base 1 and the other end fixedly connected to the support frame 702. The sliding end of the guide rail 701 is fixedly connected to the base plate 703. The base plate 703 and the guide rail 701 form a horizontal sliding fit. The base plate 703 can reciprocate along the guide rail 701 in the horizontal direction.

[0121] A positioning section bottom support 704 is fixedly connected to the base plate 703. It is used to support the bottom surface of the corrugated plate to be positioned. The shape of the upper surface of the positioning section bottom support 704 matches the corrugation of the corrugated plate, so that the corrugated plate to be positioned is stably supported on the positioning section bottom support 704.

[0122] The upper surface height of the positioning section bottom support 704 is consistent with the upper surface height of the fixed section bottom support 20 and the bending section bottom support 10, and the three form the same horizontal plane, jointly supporting the corrugated plate. This keeps the corrugated plate in a horizontal state.

[0123] A lead screw 705 is threaded through and connected to the bottom of the base plate 703. The lead screw 705 is arranged horizontally, and its axis is parallel to the direction of the guide rail 701. The lead screw 705 passes through a nut seat at the bottom of the base plate 703, and the external thread of the lead screw 705 and the internal thread of the nut seat form a threaded engagement. When the lead screw 705 rotates, it drives the nut seat to move axially along the lead screw 705 through the threaded engagement. The nut seat is fixed on the base plate 703, thereby driving the base plate 703 to move horizontally along the guide rail 701.

[0124] One end of the lead screw 705 is rotatably connected to the side wall of the lower mold 3 and supported by a bearing, allowing the lead screw 705 to rotate around its own axis without axial movement. The other end of the lead screw 705 is fixedly connected to a servo motor 706. The output shaft of the servo motor 706 is connected to the end of the lead screw 705 via a coupling, and the servo motor 706 drives the lead screw 705 to rotate. The outer wall of the servo motor 706 is fixedly connected to a support frame 702, providing mounting support for the servo motor 706.

[0125] The servo motor 706 has precise position control capabilities. The encoder provides real-time feedback on the rotation angle of the lead screw 705, and the control system controls the rotation angle of the servo motor 706 according to the set positioning position, achieving precise positioning of the positioning section base support 704. The positioning accuracy and repeatability of the servo motor 706 are guaranteed by the encoder resolution and the accuracy of the control system.

[0126] The positioning mechanism 7 of this invention solves the problem of requiring different molds for different bending lengths in traditional stamping methods. The horizontal bending length of the corrugated plates on the inner wall of liquefied natural gas storage tanks varies due to differences in tank wall structure. Traditionally, each bending length requires the design and manufacture of a corresponding dedicated mold, resulting in a large number of molds, high investment costs, and complex production changeovers. This invention, through an adjustable positioning mechanism 7 driven by a servo motor 706, achieves continuous adjustment of the bending length. One device covers multiple bending lengths, significantly reducing mold investment costs and simplifying the production process.

[0127] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A forming and processing device for a horizontally curved corrugated plate, comprising a base (1), characterized in that, The base (1) is installed on one side of the upper surface of the workbench (2). A lower mold (3) is fixedly connected to the upper surface of the base (1) for horizontally supporting the corrugated plate. A lifting mechanism (4) is provided on the other side of the upper surface of the workbench (2). An upper mold (5) is fixedly connected to the lifting end of the lifting mechanism (4). The upper mold (5) matches the lower mold (3) and is used to press the corrugated plate. A rotary mechanism (6) is provided inside the lower mold (3). A bending unit is provided on the rotary disk surface of the rotary mechanism (6). The bending unit applies horizontal bending to the bending section of the corrugated plate under the drive of the rotary mechanism (6). A positioning mechanism (7) is provided on the outside of the lower mold (3) for adjusting the positioning of the corrugated plate according to the bending section length of the corrugated plate.

2. The forming and processing device for a horizontally bent corrugated plate according to claim 1, characterized in that, The lower mold (3) is also provided with an arc-shaped limiting component (8). The arc-shaped limiting component (8) is concentrically set with the rotary table surface, and the arc-shaped limiting component (8) and the rotary table surface are a capture-type mating section that clamps vertically. When the bending unit applies bending in the horizontal plane, the bending reaction force generated forms an overturning moment on the rotary table surface. This overturning moment is borne by the radius of the arc-shaped limiting component (8) as the lever arm.

3. The forming and processing device for a horizontally bent corrugated plate according to claim 1, characterized in that, The bending unit includes a base (9), which is fixedly connected to the outer edge of the upper surface of the rotary table. A bending section bottom support (10) is fixedly connected between the base (9) and the circular surface of the rotary table. The bending section bottom support (10) is used to provide support for the bottom surface of the bending section of the corrugated plate. Two sliding columns (11) are symmetrically arranged on the upper wall of the base (9). A pressure plate (12) is sleeved and slidably connected to the outer wall of the sliding column (11). A first lower groove (1201) matching the bending section bottom support (10) is opened at the bottom of the pressure plate (12) to press the upper surface of the bending section of the corrugated plate. A return spring (13) is provided between the lower wall of the pressure plate (12) and the upper wall of the base (9) to provide an upward lifting force to the pressure plate (12).

4. The forming and processing apparatus for a horizontally bent corrugated plate according to claim 3, characterized in that, Two upper rollers (14) are symmetrically arranged on both sides of the upper part of the bending section bottom support (10). The mounting seats of the two upper rollers (14) are fixedly connected to the lower wall of the pressure plate (12). Two lower rollers (15) are symmetrically arranged on both sides of the lower part of the bending section bottom support (10). The mounting seats of the two lower rollers (15) are fixedly connected to the upper surface of the turntable. The upper rollers (14) and the lower rollers (15) correspond one-to-one.

5. The forming and processing apparatus for a horizontally bent corrugated plate according to claim 1, characterized in that, Two lower pressure roller assemblies (16) are slidably connected vertically inside the lower mold (3). An inclined block (17) is provided below each lower pressure roller assembly (16). One end of the inclined block (17) is located inside the lower mold (3) and slidably connected to it horizontally. The other end is located outside the lower mold (3) and is equipped with a locking component. The locking component keeps the inclined block (17) relatively stationary with respect to the lower mold (3). The inclined block (17) and the lower pressure roller assembly (16)... An inclined plane is provided between the two parts. The inclined block (17) drives the lower pressure roller assembly (16) to rise and fall through the inclined plane. A clearance opening (18) is symmetrically opened on the rotary table. When the inclined block (17) is pushed to move into the lower mold (3), it drives the lower pressure roller assembly (16) to rise and pass through the clearance opening (18) until it contacts the lower surface of the corrugated plate. When the inclined block (17) is pulled to move out of the lower mold (3), the lower pressure roller assembly (16) falls until its height is lower than the rotary table surface.

6. The forming and processing apparatus for a horizontally bent corrugated plate according to claim 5, characterized in that, The upper mold (5) is detachably equipped with two upper pressure roller assemblies (19), which correspond one-to-one with the lower pressure roller assembly (16). When the upper mold (5) descends and docks with the lower mold (3), the upper pressure roller assembly (19) contacts the upper surface of the corrugated plate and provides downward pressure. In each bending process, only one upper pressure roller assembly (19) is installed, and its installation position is opposite to the deflection direction of the bending unit. At the same time, only the lower pressure roller assembly (16) corresponding to this upper pressure roller assembly (19) passes through the clearance opening (18) and contacts the lower surface of the corrugated plate.

7. The forming and processing apparatus for a horizontally bent corrugated plate according to claim 2, characterized in that, The lower mold (3) is also fixedly connected to a fixed section bottom support (20), which corresponds to the bending section bottom support (10) and is used to provide support for the bottom surface of the non-bending section of the corrugated plate. The upper mold (5) has a second lower groove (501) at the bottom corresponding to the fixed section bottom support (20) for pressing the upper surface of the non-bending section of the corrugated plate. A guide column (21) is also provided between the lower mold (3) and the upper mold (5).

8. The forming and processing apparatus for a horizontally bent corrugated plate according to claim 1, characterized in that, The positioning mechanism (7) includes a guide rail (701), one end of which is fixedly connected to the base (1), and the other end is fixedly connected to a support frame (702). The sliding end of the guide rail (701) is fixedly connected to a base plate (703). A positioning section bottom support (704) is fixedly connected to the base plate (703). A lead screw (705) is threaded through and threaded to the bottom of the base plate (703). One end of the lead screw (705) is rotatably connected to the side wall of the lower mold (3), and the other end is fixedly connected to a servo motor (706). The outer wall of the servo motor (706) is fixedly connected to the support frame (702).

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