A creep aging forming device and forming method for large thin-walled components

Abstract

The present invention provides a creep aging forming device and forming method for large thin-walled components. The forming device includes a mechanical loading device, a mold and an autoclave. The mechanical loading device includes a frame and a loading assembly. The frame includes two side beams and a cross beam located between the two side beams. The lower ends of the two side beams are provided with two through holes. The loading assembly includes a fixing box fixed in the middle of the cross beam and multiple rows of parallel screws vertically penetrating the fixing box. The lower end of each screw is provided with a directional wheel. Two through holes are provided on the mounting plates at the corresponding positions on the two side surfaces of one end of the mold. The connecting line of the two through holes on each mounting plate is perpendicular to the mold surface. The present invention uses a directional wheel to press against the part of the workpiece to be formed that is prone to buckling instability, so that during the continuous loading process in the autoclave, the part that is prone to buckling instability is always subject to the pressure applied by the directional wheel, thereby effectively avoiding the buckling instability.

Description

Technical Field

[0001] The invention relates to a creep aging forming device and a forming method for a large thin-walled component, belonging to the technical field of aerospace manufacturing engineering. Background Art

[0002] Creep aging forming is a new type of sheet metal forming technology that can simultaneously form and improve the strength of components. It is widely used in the manufacture of aerospace components. The process of creep aging forming technology is divided into three stages. First, the sheet is elastically deformed by a certain loading method at room temperature and fixed on the mold; then the combination of the sheet and the mold is placed in an autoclave, and the sheet is kept at a certain temperature for a period of time, so that the sheet is subjected to creep and stress relaxation, and the internal organization and structure are changed; finally, the sheet and the mold are taken out and unloaded to obtain the required components. In the field of aviation manufacturing engineering technology, vacuum molds are generally used, that is, the sheet is fixed on a mold with a concave surface and the airtightness between the sheet and the mold is ensured, and then the concave cavity between the sheet and the mold is evacuated, so that the sheet is tightly attached to the mold under the action of atmospheric pressure.

[0003] When manufacturing aerospace components, sheet metal is very prone to buckling instability during creep aging forming. Patents CN 111575615 B, CN 111195677 A and CN 111195678 A all suppress the occurrence of buckling instability by increasing the stiffness of sheet metal by adding metal strips or metal plates. However, the above methods are limited to the production of small components, such as small melon-shaped components with a tank diameter of 3.35 meters or less. For large thin-walled components, the occurrence of buckling instability cannot be suppressed by continuously adding metal plates to increase the stiffness of sheet metal. In fact, due to the excessive number of metal plates, it is difficult to fit the mold during the loading process, and the production cost is greatly increased. The devices of patents CN 110899481 A and CN 112338052A are complex in structure and expensive in cost, and are not suitable for the production of large thin-walled components. In creep aging forming technology, 95% of the load is completed inside the autoclave, and the buckling instability of the sheet metal generally occurs during the loading stage after entering the autoclave. The inventors found in practical research that the above methods still have their drawbacks for the production of large thin-walled components. In the production process of large melon slices with a tank diameter greater than 3.35 meters, the workpiece to be formed is an isosceles trapezoidal sheet metal. Experiments show that the middle part of the long side of the bottom side of the isosceles trapezoidal sheet metal is prone to serious buckling instability during the loading stage in the autoclave, and the existing technology cannot solve this problem well. Summary of the invention

[0004] In view of the above problems to be solved, the present invention provides a creep aging forming device and forming method for large thin-walled components. When the workpiece to be formed is in the loading stage of an autoclave, a mechanical loading device is used to support the part of the workpiece to be formed that is prone to buckling and instability, thereby effectively avoiding buckling and instability of the workpiece to be formed during the loading stage of the autoclave.

[0005] In order to solve the above technical problems, the present invention provides a large thin-walled component creep aging forming device, including a mechanical loading device, a mold and an autoclave, wherein the mechanical loading device includes a frame and a loading assembly;

[0006] The frame includes two side beams and a cross beam located between the two side beams, and the lower ends of the two side beams are each provided with two through holes;

[0007] The loading assembly includes a fixing box fixed in the middle of the crossbeam and multiple rows of parallel screws that vertically penetrate the fixing box, each row of screws is provided with at least one screw, each screw is provided with two nuts, the two nuts are respectively located above and below the fixing box, and a directional wheel is provided at the lower end of each screw;

[0008] Mounting plates matching the side beams are arranged at corresponding positions on both sides of one end of the mold, and each mounting plate is provided with two through holes, and the connecting line of the two through holes on each mounting plate is perpendicular to the mold profile, and the two through holes on each mounting plate correspond one to one with the two through holes on the corresponding side beam;

[0009] The workpiece to be formed wrapped in the breathable felt is placed on the mold. The workpiece to be formed is an isosceles trapezoidal sheet. The long side of the bottom side of the workpiece to be formed is placed at one end of the mold where a mounting plate matching the side beam is provided. High-temperature glue and a vacuum bag are used to seal the workpiece to be formed in the closed space formed by the vacuum bag and the mold. The vacuum bag is evacuated. Bolts are connected to two through holes on each side beam and two through holes corresponding to them on the mounting plate to fix the frame to one end of the mold. When the frame is fixed to one end of the mold, each screw is perpendicular to the mold surface. The direction of the axis of the corresponding directional wheel can be adjusted by rotating each screw. The position of each screw can be adjusted and each screw can be fixed by adjusting the nut on each screw. When each screw is fixed, the corresponding directional wheel is against the middle of the long side of the bottom side of the workpiece to be formed. The axis of the corresponding directional wheel is parallel to the bolts connecting the through holes on the mounting plate and the through holes on the side beam. The assembled mechanical loading device, mold and the combination of the workpiece to be formed are placed in the autoclave as a whole.

[0010] Preferably, a cushion block is arranged between the vacuum bag and all the directional wheels so that the vacuum bag does not contact with all the directional wheels, and the cushion block is silica gel wrapped with air-permeable felt.

[0011] Preferably, the screws are arranged in three rows, and the three rows of screws are arranged in sequence with one screw, three screws, and one screw, and the five screws are arranged in a "+" shape.

[0012] Preferably, the thickness of the silica gel is 3 mm.

[0013] Accordingly, the present invention also provides a creep aging forming method for large thin-walled components, comprising the following steps:

[0014] Step 1, using a sheet material that meets the requirements to cut out an isosceles trapezoidal sheet material for creep aging forming, using the isosceles trapezoidal sheet material as a workpiece to be formed, placing the workpiece to be formed wrapped in a breathable felt on a mold, placing the long side of the bottom edge of the workpiece to be formed on one end of the mold provided with a mounting plate that matches the side beam, using high-temperature glue and a vacuum bag to seal the workpiece to be formed in a closed space formed by the vacuum bag and the mold, and then evacuating the vacuum bag;

[0015] Step 2, after vacuum treatment, bolt the two through holes on each side beam to the two corresponding through holes on the mounting plate to fix the frame to one end of the mold. When the frame is fixed to one end of the mold, each screw is perpendicular to the mold surface;

[0016] Step 3, rotate each screw rod to make the axis of the corresponding directional wheel parallel to the bolts connecting the through hole on the mounting plate and the through hole on the side beam, then place the cushion block between the vacuum bag and all the directional wheels, and then adjust the nut on each screw rod to adjust the position of each screw rod and fix each screw rod. When adjusting the nut on the screw rod, clamp the corresponding screw rod with a clamp to keep the axis of the directional wheel at its lower end parallel to the bolts connecting the through hole on the mounting plate and the through hole on the side beam. When each screw rod is fixed, the corresponding directional wheel is against the middle of the long side of the bottom side of the workpiece to be formed;

[0017] Step 4, placing the mechanical loading device, the mold and the workpiece to be formed into a hot press for vacuum creep aging forming. After the vacuum creep aging forming is completed, the mechanical loading device, the mold and the workpiece to be formed are separated, and the excess area of ​​the workpiece to be formed is cut off, thus completing the production of the large thin-walled component.

[0018] Preferably, before the workpiece to be formed is wrapped in the air-permeable felt, both ends of the long side of the bottom edge of the workpiece to be formed are cut off by the same length to eliminate the sharp angle of the workpiece to be formed.

[0019] Preferably, the upper base of the workpiece to be formed is 610 mm, the lower base is 2100 mm, the height is 2650 mm, the thickness of the workpiece to be formed is 3-6 mm, and both ends of the lower base of the workpiece to be formed are cut off by 50 mm to eliminate the sharp angles of the workpiece to be formed.

[0020] Preferably, the sheet material that meets the requirements is an aluminum-lithium alloy sheet.

[0021] Preferably, during the vacuum creep aging forming, a positive pressure of 1.9 MPa is continuously loaded in the autoclave.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention uses multiple directional wheels of a mechanical loading device to support the parts of the workpiece to be formed that are prone to buckling and instability. During the continuous loading of the workpiece to be formed in the autoclave, the directional wheels can roll on the workpiece to be formed, and multiple screws are perpendicular to the mold surface. The axis of each directional wheel is parallel to the bolts connecting the through hole on the mounting plate and the through hole on the side beam. The direction of each directional wheel is consistent with the loaded moving direction of the workpiece to be formed. The middle part of the long side of the bottom side of the workpiece to be formed is always subject to the pressure applied by the directional wheels, thereby effectively avoiding the buckling and instability of the workpiece to be formed, successfully producing stable large thin-walled components, and avoiding scratches on the surface of large thin-walled components.

[0024] 2. The mechanical loading device of the present invention effectively restrains the movement of the workpiece to be formed, avoids the movement of the workpiece to be formed due to hot air and vibration of the autoclave, ensures that it is in the effective area of ​​the mold surface, and greatly improves the forming accuracy of large thin-walled components.

[0025] 3. The present invention has simple structure, simple operation and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of the mechanical loading device of the present invention.

[0027] Figure 2 It is a side view of the mold of the present invention.

[0028] Figure 3 It is a schematic structural diagram of the loading assembly, the workpiece to be formed and the mold matching of the present invention.

[0029] Figure 4 It is a schematic diagram of a workpiece to be formed according to the present invention.

[0030] Figure 5 Schematic diagram of a large thin-walled component obtained by the method of the present invention (the remaining area is not cut off).

[0031] Reference numerals: side beam 1, directional wheel 2, cross beam 3, nut 4, screw 5, mold 6, mounting plate 7, workpiece to be formed 8, fixing box 9. DETAILED DESCRIPTION

[0032] The present invention will be described in detail below in conjunction with the embodiments and drawings. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0033] like Figures 1 to 3 As shown, a creep aging forming device for large thin-walled components includes a mechanical loading device, a mold 6 and an autoclave, wherein the mechanical loading device includes a frame and a loading assembly;

[0034] The frame includes two side beams 1 and a cross beam 3 located between the two side beams 1, and the lower ends of the two side beams 1 are each provided with two through holes;

[0035] The loading assembly includes a fixing box 9 fixed in the middle of the cross beam 3 and a plurality of rows of parallel screws 5 vertically penetrating the fixing box 9, each row of screws 5 is provided with at least one screw 5, each screw 5 is provided with two nuts 4, the two nuts 4 are respectively located above and below the fixing box 9, a directional wheel 2 is provided at the lower end of each screw 5, and each screw 5 is parallel to the side beam 1;

[0036] Mounting plates 7 matching the side beam 1 are provided at corresponding positions on both sides of one end of the mold 6, and each mounting plate 7 is provided with two through holes, and the connecting line of the two through holes on each mounting plate 7 is perpendicular to the mold profile, and the two through holes on each mounting plate 7 correspond one to one with the two through holes on the corresponding side beam 1;

[0037] The workpiece 8 to be formed wrapped in the breathable felt is placed on the mold 6. The workpiece 8 to be formed is an isosceles trapezoidal sheet. The long side of the bottom side of the workpiece 8 to be formed is placed at one end of the mold 6 provided with a mounting plate 7 matched with the side beam 1. The workpiece 8 to be formed is sealed in the closed space formed by the vacuum bag and the mold 6 using high-temperature glue and a vacuum bag, and the vacuum bag is evacuated.

[0038] The two through holes on each side beam 1 are connected with the two corresponding through holes on the mounting plate 7 by bolts to fix the frame to one end of the mold 6. When the frame is fixed to one end of the mold 6, each screw 5 is perpendicular to the mold surface, and the direction of the axis of the corresponding directional wheel 2 can be adjusted by rotating each screw 5. The position of each screw 5 can be adjusted and each screw 5 can be fixed by adjusting the nut 4 on each screw 5. When each screw 5 is fixed, the corresponding directional wheel 2 is against the middle of the long side of the bottom edge of the workpiece 8 to be formed, and the axis of the corresponding directional wheel 2 is parallel to the bolts connecting the through holes on the mounting plate 7 and the through holes on the side beam 1. The direction of the corresponding directional wheel 2 is consistent with the load-bearing moving direction of the workpiece 8 to be formed. Preferably, a pad is arranged between the vacuum bag and all the directional wheels 2 so that the vacuum bag does not contact all the directional wheels 2 to prevent the directional wheels from scratching the vacuum bag. The pad is silicone wrapped with breathable felt. Preferably, the thickness of the silicone is 3 mm.

[0039] The assembled mechanical loading device, the mold 6 and the combination of the workpiece 8 to be formed are placed in the autoclave as a whole. During the continuous loading of the workpiece 8 to be formed in the autoclave, the directional wheels 2 can roll on the workpiece 8 to be formed. The direction of each directional wheel 2 is consistent with the loaded moving direction of the workpiece 8 to be formed. The middle part of the long side of the bottom side of the workpiece 8 to be formed is always subject to the pressure applied by the directional wheels 2, thereby effectively avoiding the buckling and instability phenomenon of the workpiece 8 to be formed.

[0040] Preferably, there are three rows of screws 5, and the three rows of screws 5 are arranged with one screw, three screws, and one screw in sequence, and the five screws are arranged in a "+" shape. When the workpiece 8 to be formed is loaded and moved, the directional wheel 6 applies pressure to it, effectively preventing it from buckling and becoming unstable.

[0041] A creep aging forming method for large thin-walled components comprises the following steps:

[0042] Step 1: Use the sheet material that meets the requirements to cut out an isosceles trapezoidal sheet material for creep aging forming, and use the isosceles trapezoidal sheet material as the workpiece 8 to be formed. Preferably, before the workpiece 8 to be formed is wrapped in the breathable felt, the two ends of the long side of the bottom edge of the workpiece 8 to be formed are cut off to the same length to eliminate the sharp angle of the workpiece to be formed, so as to effectively avoid scratching the mold 6. Figure 4 As shown, after the workpiece 8 to be formed is cleaned with kerosene and alcohol, the workpiece 8 to be formed is wrapped in a breathable felt, and then the workpiece 8 to be formed is placed on the mold, and the long side of the bottom side of the workpiece 8 to be formed is placed on one end of the mold 6 provided with a mounting plate 7 that matches the side beam 1, and the workpiece 8 to be formed is sealed in the closed space formed by the vacuum bag and the mold 6 using high-temperature glue and a vacuum bag, and then the vacuum bag is vacuumized. After the vacuumization treatment is completed, the workpiece 8 to be formed is subjected to an atmospheric pressure load of 0.1MPa;

[0043] Step 2, after the vacuum treatment is completed, bolts are used to connect the two through holes on each side beam 1 with the two corresponding through holes on the mounting plate 7 to fix the frame to one end of the mold 6. When the frame is fixed to one end of the mold 6, each screw 5 is perpendicular to the mold surface;

[0044] Step 3, rotate each screw rod 5 to make the axis of the corresponding directional wheel 2 parallel to the bolts connecting the through hole on the mounting plate 7 and the through hole on the side beam 1, then place the pad between the vacuum bag and all the directional wheels 2 to prevent the directional wheels from scratching the vacuum bag, and then adjust the nut 4 on each screw rod 5 to adjust the position of each screw rod 5 and fix each screw rod 5. When adjusting the nut on the screw rod 5, clamp the corresponding screw rod 5 with a clamp so that the axis of the directional wheel 2 at its lower end is parallel to the bolts connecting the through hole on the mounting plate 7 and the through hole on the side beam 1. The orientation of the directional wheel 2 at the lower end of the screw rod 5 is consistent with the loaded moving direction of the workpiece 8 to be formed. When each screw rod 5 is fixed, the corresponding directional wheel 2 is against the middle of the long side of the bottom side of the workpiece 8 to be formed. When adjusting the nut 8, it is necessary to adjust it multiple times in a diagonal, cross, and alternating manner to prevent the loading component from being unevenly stressed, thereby causing its deformation. After the screw rod 8 is fixed, the value of each bolt when monitored with a fixed torque wrench is not less than 100N·m;

[0045] During the continuous loading process of the workpiece 8 to be formed in the autoclave, the directional wheels 2 can roll on the workpiece 8 to be formed, and the direction of each directional wheel 2 is consistent with the loaded moving direction of the workpiece 8 to be formed. The middle part of the long side of the bottom side of the workpiece 8 to be formed is always under the pressure applied by the directional wheels 2, thereby effectively avoiding the buckling instability of the workpiece 8 to be formed;

[0046] Step 4, the combination of the mechanical loading device, the mold 6 and the workpiece 8 to be formed is placed in the autoclave for vacuum creep aging forming. After the vacuum creep aging forming is completed, the mechanical loading device, the mold 6 and the workpiece 8 to be formed are separated, and the excess area of ​​the workpiece 8 to be formed is cut off, thus completing the production of the large thin-walled component.

[0047] Preferably, the upper bottom of the workpiece 8 to be formed is 610mm, the lower bottom is 2100mm, the height is 2650mm, and the thickness of the workpiece to be formed is 3-6mm. In order to produce melon slices with a tank diameter of 5 meters, both ends of the lower bottom of the workpiece 8 to be formed are cut off by 50mm to eliminate the sharp corners of the workpiece to be formed, effectively avoiding scratching the mold.

[0048] Preferably, the material of the workpiece 8 to be formed is an aluminum-lithium alloy plate, which has the characteristics of low density, high specific strength and high specific modulus, and has good application prospects in the aerospace field (such as rocket tanks).

[0049] Preferably, a positive pressure of 1.9 MPa is continuously loaded in the autoclave during vacuum creep aging forming.

[0050] The workpiece 8 to be formed is subjected to a load of 2MPa during vacuum creep aging forming. The middle of the long side of the bottom side of the workpiece 8 to be formed is always subjected to the pressure exerted by the directional wheel 2, thereby effectively avoiding the buckling instability of the workpiece 8 to be formed. At the same time, the directional wheel 2 supports the workpiece 8 to be formed so that it does not move due to hot air and the vibration of the autoclave, thereby generating a large thin-walled component with good stability and high precision, such as Figure 5 shown.

[0051] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions and substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A creep aging forming device for large thin-walled components, characterized in that: It comprises a mechanical loading device, a mold (6) and an autoclave, wherein the mechanical loading device comprises a frame and a loading assembly; The frame comprises two side beams (1) and a cross beam (3) located between the two side beams (1), and the lower ends of the two side beams (1) are each provided with two through holes; The loading assembly comprises a fixing box (9) fixed at the middle of the crossbeam (3) and a plurality of rows of parallel screw rods (5) vertically penetrating the fixing box (9), each row of screw rods (5) being provided with at least one screw rod (5), each screw rod (5) being provided with two nuts (4), the two nuts (4) being respectively located above and below the fixing box (9), and a directional wheel (2) being provided at the lower end of each screw rod (5); Mounting plates (7) matching the side beams (1) are provided at corresponding positions on both side surfaces of one end of the mold (6), each mounting plate (7) being provided with two through holes, the connecting line of the two through holes on each mounting plate (7) being perpendicular to the mold profile, and the two through holes on each mounting plate (7) corresponding one to one with the two through holes on the corresponding side beam (1); The workpiece (8) to be formed wrapped in the air-permeable felt is placed on the mold (6). The workpiece (8) to be formed is an isosceles trapezoidal sheet. The long side of the bottom side of the workpiece (8) to be formed is placed at one end of the mold (6) provided with a mounting plate that matches the side beam (1). The workpiece (8) to be formed is sealed in a closed space formed by the vacuum bag and the mold (6) using high-temperature glue and a vacuum bag. The vacuum bag is evacuated. The two through holes on each side beam (1) are connected to the two through holes on the mounting plate (7) corresponding thereto by bolts to fix the frame to one end of the mold (6). When the frame is fixed to one end of the mold (6), each screw rod (5) is The screw rod (5) is perpendicular to the mold surface, and the direction of the axis of the corresponding directional wheel (2) can be adjusted by rotating each screw rod (5). The position of each screw rod (5) can be adjusted and each screw rod (5) can be fixed by adjusting the nut (4) on each screw rod (5). When each screw rod (5) is fixed, the corresponding directional wheel (2) abuts against the middle of the long side of the bottom side of the workpiece (8) to be formed, and the axis of the corresponding directional wheel (2) is parallel to the bolt connecting the through hole on the mounting plate (7) and the through hole on the side beam (1). The assembled mechanical loading device, the mold (6) and the workpiece (8) to be formed are placed in the autoclave as a whole.

2. The creep aging forming device for large thin-walled components according to claim 1, characterized in that: A cushion block is arranged between the vacuum bag and all the directional wheels (2) so that the vacuum bag does not contact with all the directional wheels, and the cushion block is silica gel wrapped with air-permeable felt.

3. The creep aging forming device for large thin-walled components according to claim 2, characterized in that: The screw rods (5) are arranged in three rows, with one screw rod, three screw rods, and one screw rod being arranged in sequence in the three rows, and the five screw rods are arranged in a "+" shape.

4. The creep aging forming device for large thin-walled components according to claim 3, characterized in that: The thickness of the silica gel is 3 mm.

5. A creep aging forming method for large thin-walled components, using the creep aging forming device for large thin-walled components according to any one of claims 1 to 4, characterized in that: The steps include: Step 1, using a sheet material that meets the requirements to cut out an isosceles trapezoidal sheet material for creep aging forming, using the isosceles trapezoidal sheet material as a workpiece to be formed (8), placing the workpiece to be formed (8) wrapped in a breathable felt on a mold (6), placing the long side of the bottom side of the workpiece to be formed (8) at one end of the mold (6) provided with a mounting plate (7) that cooperates with the side beam (1), using high-temperature glue and a vacuum bag to seal the workpiece to be formed (8) in a closed space formed by the vacuum bag and the mold (6), and then performing a vacuum treatment on the vacuum bag; Step 2, after vacuum treatment, bolts are connected between two through holes on each side beam (1) and two corresponding through holes on the mounting plate (7) to fix the frame to one end of the mold (6). When the frame is fixed to one end of the mold (6), each screw rod (5) is perpendicular to the mold surface; Step 3, after rotating each screw rod (5) so that the axis of the corresponding directional wheel (2) is parallel to the bolt connecting the through hole on the mounting plate (7) and the through hole on the side beam (1), a cushion block is placed between the vacuum bag and all the directional wheels (2), and then the nut (4) on each screw rod (5) is adjusted to adjust the position of each screw rod (5) and fix each screw rod (5). When adjusting the nut (4) on the screw rod (5), the corresponding screw rod (5) is clamped with a clamp so that the axis of the directional wheel (2) at its lower end is parallel to the bolt connecting the through hole on the mounting plate (7) and the through hole on the side beam (1). When each screw rod (5) is fixed, the corresponding directional wheel (2) abuts against the middle of the long side of the bottom side of the workpiece (8) to be formed; Step 4, placing the mechanical loading device, the mold (6) and the workpiece to be formed (8) in a hot autoclave for vacuum creep aging forming. After the vacuum creep aging forming is completed, the mechanical loading device, the mold (6) and the workpiece to be formed (8) are separated, and the excess area of ​​the workpiece to be formed (8) is cut off, thereby completing the production of the large thin-walled component.

6. The creep aging forming method for large thin-walled components according to claim 5, characterized in that: Before the workpiece to be formed (8) is wrapped in the air-permeable felt, both ends of the long side of the bottom edge of the workpiece to be formed (8) are cut off to the same length to eliminate the sharp angle of the workpiece to be formed.

7. The creep aging forming method for large thin-walled components according to claim 6, characterized in that: The upper base of the workpiece (8) to be formed is 610 mm, the lower base is 2100 mm, the height is 2650 mm, the thickness of the workpiece (8) to be formed is 3-6 mm, and both ends of the lower base of the workpiece (8) to be formed are cut off by 50 mm to eliminate the sharp angles of the workpiece (8) to be formed.

8. The creep aging forming method for large thin-walled components according to claim 7, characterized in that: The sheet material that meets the requirements is an aluminum-lithium alloy sheet.

9. The creep aging forming method for large thin-walled components according to claim 8, characterized in that: During the vacuum creep aging forming, a positive pressure of 1.9 MPa is continuously loaded in the autoclave.

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