Creep aging forming method for variable thickness high-rib components

Abstract

The present invention provides a creep aging forming method for a variable thickness high rib component. The forming method comprises the following steps: placing a blank corresponding to the variable thickness high rib component on a mold forming space in a forming mold; the forming mold has two support baffles at both ends in its length direction; a first flexible pad is arranged in a first gap between the thick end of the blank and the corresponding support baffle; a clearance fit is formed between the thick end and the corresponding support baffle; covering the blank with a vacuum bag film, sealing the mold forming space, and evacuating to obtain a blank mold seal; placing the blank mold seal in an autoclave for creep aging treatment to obtain a variable thickness high rib component. The above forming method can prevent the buckling instability of ribs and cracking of ribs or skins caused by the limited movement of the blank in the mold, and helps to improve the forming integrity of the blank.

Description

Technical Field

[0001] The invention relates to the field of plastic forming processing of metal components, in particular to a creep aging forming method of variable thickness high-rib components. Background Art

[0002] Creep aging forming technology is a form-integrated manufacturing technology that utilizes the characteristics of metal creep and precipitation phase transformation to combine component plastic forming with artificial aging to achieve the purpose of improving both forming and properties. It has high forming accuracy, good performance stability, and high repeatability. It has been widely used in the overall manufacturing of key aerospace components.

[0003] The creep aging forming process usually places the blank (also called sheet) on the mold, uses a vacuum bag to wrap the mold surface and the blank, and evacuates to form a vacuum pressure environment, forcing the blank to gradually approach the mold surface, and then pushes it into the autoclave to provide thermal pressure to ensure the blank is film-bonded and the required heat treatment temperature. However, for variable thickness external grid high-rib siding, due to the uneven skin thickness and rib height, in production practice, the components often deviate after leaving the tank, resulting in manufacturing defects such as rib bending, rib cracking, skin buckling, and poor surface accuracy, which brings great hidden dangers to production.

[0004] At present, there are related technologies that attempt to solve such problems, such as the "Method for Suppressing Skin Concavity During Creep Aging Forming of External Grid Wall Panels" applied by Central South University, with announcement number: CN 118371594 B. The method disclosed in this patent is to add fillers to the grid area corresponding to the thin skin area, and at the same time, the auxiliary plate is closely fitted with the external grid wall panel to achieve the purpose of fixing the wall panel. However, in the subsequent practical application process, it was found that there were still buckling damage and even cracking of the ribs on the edge of the wall panel, and there was also a risk of overall failure of the component.

[0005] The "Creep aging forming method and application of deformation coordination between reinforcement area and thin skin area" applied by China Aviation Manufacturing Technology Research Institute, publication number: CN 116099934 A, discloses that the problem of inconsistent deformation of different thicknesses is solved by placing a fixed pad of a certain thickness on the surface of the thin skin area. However, there is a risk that the pad will lose its fixing function or even restrict the movement of the component, resulting in local instability.

[0006] Therefore, it is urgent to propose a new process for precise creep aging forming of variable thickness high-rib wall panel components. Summary of the invention

[0007] The main purpose of the present invention is to provide a creep aging forming method for variable thickness high rib components to solve the technical problem of overall failure or local instability of variable thickness high rib components using conventional creep aging forming methods.

[0008] To achieve the above object, the present invention provides a creep aging forming method for a variable thickness high rib component, comprising the following steps:

[0009] The blank corresponding to the variable thickness high rib component is placed on the mold forming space in the forming mold. The bottom surface of the mold forming space is a mold profile area that matches the target profile of the variable thickness high rib component. The length direction of the mold profile area corresponds to the thickness change direction of the blank. The forming mold has two support baffles at both ends of its length direction for forming the mold forming space.

[0010] A first flexible pad is arranged in the first gap between the thick end of the blank and the corresponding support baffle, wherein the heat-resistant temperature of the first flexible pad is greater than or equal to the temperature of the creep aging treatment. There is a clearance fit between the thick end and the corresponding support baffle. The length of the first flexible pad extending into the first gap is 0.5-3 times the thickness of the thick end.

[0011] The blank is covered with a vacuum bag film to seal the mold forming space, and vacuum is drawn to obtain a blank mold seal.

[0012] The blank mold seal is placed in an autoclave for creep aging treatment to obtain a variable thickness high rib component.

[0013] According to an embodiment of the present application, the first flexible pad includes a first flexible portion extending into the first gap and a second flexible portion placed on the upper surface of the thick end, and the first flexible portion and the second flexible portion are connected to each other.

[0014] According to an embodiment of the present application, there are multiple first flexible pads, and the multiple first flexible pads are evenly distributed along the width direction of the blank.

[0015] According to an embodiment of the present application, the number of the first flexible pad is one, and the first flexible pad covers the side edge of the blank in the width direction.

[0016] According to an embodiment of the present application, before the step of covering the blank with a vacuum bag film and sealing the mold forming space, the step further includes:

[0017] A second flexible pad is disposed above at least one of the thick end and the thin end of the blank and between the corresponding support baffle, and the second flexible pad covers the first slit in the width direction of the blank.

[0018] The second flexible pad includes a first contact portion, a second contact portion and a third contact portion connected in sequence. The first contact portion is placed on the top of the support baffle, the second contact portion is attached to the inner side of the support baffle, and the third contact portion contacts the upper surface of the blank.

[0019] According to an embodiment of the present application, the length of the first contact portion is 0.2-1 times the thickness of the support baffle. The length of the third contact portion is 0.1-0.5 times the width of the blank.

[0020] According to an embodiment of the present application, a second flexible pad is provided between the upper portion of the thick end of the blank and the corresponding support baffle, and between the upper portion of the thin end of the blank and the corresponding support baffle.

[0021] The thickness of the second flexible pad is 0.1-1 times the thickness of the blank.

[0022] According to an embodiment of the present application, the material of the first flexible pad is silicone or rubber.

[0023] According to the implementation mode of the present application, it also includes:

[0024] The surface structure of the blank is scanned to obtain the structural characteristics of the skin and ribs in different areas, and the material constitutive equation of the blank is fitted to obtain the fitted constitutive equation.

[0025] The creep aging forming of the blank is simulated based on the fitted constitutive equation to obtain simulated creep aging process parameters.

[0026] In the step of subjecting the blank mold seal to creep aging treatment in an autoclave, the creep aging treatment is performed using simulated creep aging process parameters.

[0027] According to the implementation mode of the present application, it also includes:

[0028] Collecting three-dimensional profile data of the variable thickness high-rib component, comparing it with target profile data, and judging whether the variable thickness high-rib component meets the standard;

[0029] If the standard is not met, the process parameters of the creep aging treatment are adjusted and the steps in the creep aging forming method of variable thickness high-rib components are repeated.

[0030] In the above-mentioned creep aging forming method of variable thickness high-rib components, the first flexible pad is inserted into the gap between the support baffle and the outside of the blank, which plays a buffering role between the blank and the support baffle, effectively preventing the blank from being damaged by lateral movement during the film pasting process, and significantly reducing the manufacturing cost. At the same time, the first flexible pad is clearance-fitted in the gap, giving the component space for lateral movement, preventing the buckling and instability of the ribs and cracking of the ribs or the skin caused by the limited movement of the blank in the mold, which helps to improve the forming integrity of the blank. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0032] Figure 1 It is a schematic flow chart of a creep aging forming method for a variable thickness high rib component according to an embodiment of the present application;

[0033] Figure 2 It is a schematic flow chart of a creep aging forming method for a variable thickness high rib component according to another embodiment of the present application;

[0034] Figure 3 It is a partial structural schematic diagram of a creep aging forming device for a variable thickness high rib component according to an embodiment of the present application;

[0035] Figure 4 It is a structural schematic diagram of a creep aging forming device for a variable thickness high-rib component according to an embodiment of the present application.

[0036] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings.

[0037] Explanation of the reference numerals: 10, forming die; 20, blank; 30, first flexible pad; 40, second flexible pad; 11, die body; 12, support baffle. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that all directional indications (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0040] In addition, in the present invention, the descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0041] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0042] The applicant has studied the relevant technologies, especially the two related patent applications in the background technology. The "method for inhibiting the skin depression during the creep aging forming process of the outer grid wall panel" applied by Central South University is mainly that the wall panel will move in a direction perpendicular to the auxiliary plate on the mold, and the fixing between the auxiliary plate and the wall panel can easily cause the wall panel to contact and scratch the auxiliary plate during the film forming, causing the ribs on the edge of the wall panel to bend, damage or even crack, and there is also a risk of overall failure of the component.

[0043] The "Creep aging forming method and application for coordinated deformation of reinforcement zone and thin skin zone" applied by the China Aviation Manufacturing Technology Research Institute ignores the fact that the movement process of the component gradually fitting toward the mold surface during creep aging forming will drive the pad, causing the pad to lose its fixing function or even restrict the movement of the component, resulting in the risk of local instability.

[0044] Based on this, the present invention provides a creep aging forming method for variable thickness high rib components, see Figure 1~Figure 4 , including the following steps:

[0045] S100: placing a blank 20 corresponding to a variable thickness high rib component on a mold forming space in a forming mold 10. The bottom surface of the mold forming space is a mold profile area that matches the target profile of the variable thickness high rib component. The length direction of the mold profile area corresponds to the thickness change direction of the blank 20. The forming mold 10 has two support baffles 12 at both ends of its length direction for forming the mold forming space.

[0046] In this step, the blank 20 is not limited to a flat plate, but also includes a blank 20 with a rib height and a bent plate with a certain curvature. Meanwhile, the curvature of the blank 20 is not limited to a single curve.

[0047] In order to facilitate the shape correction, the influence of impurities or oxides on the surface of the blank 20 may be reduced. In some embodiments, the blank 20 is also pre-treated, such as polishing the surface of the blank 20, wiping it with alcohol, and drying it for standby use. The blank 20 that has not been pre-treated can be called the original blank 20. If the blank 20 itself is relatively clean, the pre-treatment process does not need to be performed.

[0048] Among them, the surface polishing treatment includes, but is not limited to, manual polishing with sandpaper, local polishing with an angle grinder, and local electrolytic polishing.

[0049] The forming mold 10 has a space for mold forming, namely, a mold forming space. For example, the forming mold 10 includes a mold body 11 and two support baffles 12. The shape of the mold body 11 corresponds to the variable thickness high-rib component. Taking the variable thickness high-rib component as a single-curved surface component as an example, the variable thickness high-rib component has a curved groove. The two support baffles 12 are located at both ends of the groove to form a mold forming space. Correspondingly, the bottom surface of the mold forming space (i.e., a partial area of ​​the upper surface of the mold body 11) is a mold profile area that matches the target profile of the variable thickness high-rib component. Moreover, the length direction of the mold profile area corresponds to the thickness change direction of the blank 20. The thick end and the thin end of the component to be subsequently formed are both located in the length direction of the mold profile.

[0050] The blank 20 includes a skin and ribs connected to the skin. The overall thickness of the blank 20 is variable, corresponding to a variable thickness high rib component. The blank 20 can be placed in a mold forming space. Before placement, the forming mold 10 is cleaned as needed, such as the mold surface area.

[0051] In some embodiments, the bottom of the support baffle 12 fits the working surface, and there is no gap or cavity between the bottom of the support baffle 12 and the working surface.

[0052] S200: a first flexible pad 30 is arranged in the first gap between the thick end of the blank 20 and the corresponding support baffle 12, wherein the heat-resistant temperature of the first flexible pad 30 is greater than or equal to the temperature of the creep aging treatment. There is a clearance fit between the thick end and the corresponding support baffle 12. The length of the first flexible pad 30 extending into the first gap is 0.5-3 times the thickness of the thick end.

[0053] The thick end of the blank 20 is the end with high rigidity, and the thin end of the blank 20 is the end with low rigidity. In the autoclave, under the action of air pressure loading, the thin and weak end of the blank 20 is easy to bend, while the thick and strong end is difficult to bend, and the blank 20 presents an inclined bending state. The thick end of the blank 20 shows a tendency to deflect toward the side of the support baffle 12 (i.e., move sideways).

[0054] See also Figure 3 and Figure 4 The length of the first flexible pad 30 extending into the first gap is 0.5-3 times the thickness of the thick end.

[0055] Under this condition, the extension length of the first flexible pad 30 satisfies the space for the thick end to deflect in the length direction, that is, the thick end does not contact the support baffle 12. In some specific embodiments, the extension length of the first flexible pad 30 into the first gap is 1-3 times the thickness of the thick end. In this way, the end surface of the thick end is completely wrapped by the extension portion of the first flexible pad 30, which is more conducive to the thick end contacting the support baffle 12.

[0056] Therefore, the first flexible pad 30 is inserted into the gap between the support baffle 12 and the outside of the blank 20, playing a buffering role between the blank 20 and the support baffle 12, effectively preventing the blank 20 or the support baffle 12 from being damaged due to lateral movement of the blank 20 during the film lamination process, and significantly reducing the manufacturing cost.

[0057] At the same time, the pad is a clearance fit in the gap, which allows the component to move in the direction of the corresponding support baffle. The pad itself is a flexible structure with a certain elastic deformation space, and can also provide a certain movement space in the direction of the corresponding support baffle. In this way, the buckling instability of the ribs and the cracking of the ribs or skin caused by the limited movement of the blank 20 in the mold can be prevented, which helps to improve the forming integrity of the blank 20.

[0058] The heat-resistant temperature of the first flexible pad 30 is greater than or equal to the temperature of the creep aging treatment, which ensures that the first flexible pad 30 does not fail during the creep aging treatment and maintains a good elastic state.

[0059] S300: Covering the blank 20 with a vacuum bag film, sealing the mold forming space, and evacuating the space to obtain a blank 20 mold seal.

[0060] In this step, a high temperature adhesive may be attached to the vacuum bag film around the mold forming space to seal the blank 20 and the mold forming space therein. Then, vacuum is drawn, for example, by using a vacuum nozzle, so that the blank 20, the support baffle 12, and the mold surface area form a vacuum environment in the vacuum bag, and the sheet material gradually moves toward the mold surface area.

[0061] In some embodiments, the high temperature glue is applied around the mold forming space in 3-5 circles around the mold, and the outer circle of each adjacent circle needs to press the inner circle 0.1-0.5 times the width of the high temperature glue, and the outer circle is pressed on the inner circle.

[0062] S400: placing the blank 20 mold seal in an autoclave for creep aging treatment to obtain a variable thickness high rib component.

[0063] The process parameters of the specific processing steps of the creep aging treatment of the present application are not specifically limited. For example, the blank 20 is treated accordingly according to the conventional creep aging treatment process, or the conventional creep aging treatment process is adjusted, such as adjusting the specific process parameters. Therefore, accordingly, the preset creep aging process parameters can be conventional creep aging process parameters, or can be adjusted creep aging process parameters.

[0064] In some embodiments, the creep aging process parameters include parameters specifically including creep temperature, creep holding time, gas pressure loading amount, gas pressure loading rate, heating rate, gas pressure unloading rate, and cooling rate.

[0065] In the above-mentioned creep aging forming method of variable thickness high-rib components, the first flexible pad 30 is inserted into the gap between the support baffle 12 and the outside of the blank 20, playing a buffering role between the blank 20 and the support baffle 12, effectively preventing the blank 20 from moving lateral to avoid damage to the blank 20 or the support baffle 12 during the film pasting process, significantly reducing the manufacturing cost. At the same time, the first flexible pad 30 is a clearance fit in the gap, providing the component with space for lateral movement, preventing the blank 20 from being restricted in movement in the mold, resulting in rib buckling and instability, rib cracking or skin cracking, and helping to improve the forming integrity of the blank 20.

[0066] In some embodiments, see Figure 1 and Figure 3 The first flexible pad 30 includes a first flexible portion extending into the first gap and a second flexible portion placed on the upper surface of the thick end, and the first flexible portion and the second flexible portion are connected to each other.

[0067] The first flexible portion and the second flexible portion are connected to each other, such as the two are vertically formed into an inverted L shape. The second flexible portion is placed on the upper surface of the thick end to provide an upward supporting force. The first flexible pad 30 is not easy to slide down from the gap between the blank 20 and the support baffle 12 and fall below the blank 20.

[0068] In some embodiments, see Figure 3 and Figure 4 There are multiple first flexible pads 30 , and the multiple first flexible pads 30 are evenly distributed along the width direction of the blank 20 .

[0069] In this embodiment, the width of the first flexible pad 30 is relatively narrow. A plurality of first flexible pads 30 are arranged along the width direction of the blank 20, such as two adjacent first flexible pads 30 are in contact, or there is a certain distance between two adjacent first flexible pads 30. The plurality of first flexible pads 30 cooperate to prevent the support baffle 12 from contacting the pad due to deflection in a local area in the width.

[0070] At the same time, the coordination of the plurality of first flexible pads 30 is more flexible to use and can be adapted to the creep aging forming method of variable thickness high-rib components of different widths.

[0071] In some embodiments, see Figure 3 and Figure 4 The number of the first flexible pad 30 is 1, and the first flexible pad 30 covers the side of the blank 20 in the width direction.

[0072] In this embodiment, the width of the first flexible pad 30 is relatively large, matching the width of the blank 20. This can also prevent the support baffle 12 from contacting the pad due to deflection in a local area of ​​the width.

[0073] During creep aging forming, some areas of the blank 20 may have some irregular movement. For example, after the movement of some areas, the gap between the support baffle 12 increases, which may cause the first flexible pad 30 with a narrower width corresponding to the area to slide down to the bottom of the blank 20. Since the first flexible pad 30 of this embodiment is an integrated structure with a wider width, this situation will not occur. Therefore, the reliability is higher.

[0074] In addition, the first flexible pad 30 of this embodiment can also reduce the probability of the vacuum bag entering into the gap between the supporting baffle 12 and the blank 20 .

[0075] Since the stiffness of the thick end is too large, the blank 20 cannot be completely bent to fit the mold surface (especially the thick end of the blank 20) ​​by vacuuming and loading the sealed vacuum bag. If the conventional creep aging forming mold 10 structure is used, a cavity will be formed between the side of the blank 20 and the mold, causing the vacuum film bag to be sucked into the cavity. If the vacuum bag is broken under the continuous vacuuming, the bent blank 20 will rebound instantly, which may injure the operator. If the vacuuming is stopped, the vacuum degree of the vacuum film bag will be insufficient, and the blank 20 will not fit the mold surface well.

[0076] Alternatively, a conventional creep aging forming die 10 structure is used. During the creep aging forming process in the autoclave, the vacuum bag is pressed into the gap between the component and the molding surface due to the excessive air pressure in the autoclave, which eventually causes the vacuum bag to rupture, the creep aging forming process ends prematurely, and the component cannot be formed.

[0077] The first flexible pad 30 of the above-mentioned embodiment of the present application can basically close the gap between the pad and the support baffle 12, thereby reducing the probability of the vacuum bag entering the gap between the support baffle 12 and the blank 20, and further reducing the probability of the vacuum bag entering the cavity formed between the side of the blank 20 and the mold.

[0078] Therefore, during vacuum loading, the vacuum bag film is adsorbed on the outer surface of the support baffle 12 during the bending process of the blank 20, which can increase the vacuum pressure so that it will not break, improve safety, and achieve a more ideal vacuum degree, which is beneficial to subsequent creep aging treatment.

[0079] In some embodiments, see Figure 3 and Figure 4 Before the step of covering the blank 20 with a vacuum bag film to seal the mold forming space, the method further includes:

[0080] A second flexible pad 40 is disposed above at least one of the thick end and the thin end of the blank 20 and between the corresponding support baffle 12. The second flexible pad 40 covers the first slit in the width direction of the blank 20.

[0081] The second flexible pad 40 includes a first contact portion, a second contact portion and a third contact portion connected in sequence. The first contact portion is placed on the top of the support baffle 12, the second contact portion is attached to the inner side of the support baffle 12, and the third contact portion contacts the upper surface of the blank 20.

[0082] The second flexible pad 40 is in a Z-shaped structure. The first contact portion, the second contact portion and the third contact portion cooperate with the top of the support baffle 12, the inner side of the support baffle 12 and the upper surface of the blank 20 respectively, forming a relatively strict seal on the gap between the support baffle 12 and the blank 20 on the side where the second flexible pad 40 is arranged, which can prevent the vacuum bag from entering the cavity between the side of the blank 20 and the mold.

[0083] In particular, when the first flexible pad 30 includes the first flexible portion and the second flexible portion, and the first flexible pad 30 matches the width of the blank 20, the third contact portion fits with the second flexible portion, further improving the sealing performance of the gap between the support baffle 12 and the blank 20, and providing higher reliability.

[0084] Specifically, the width setting of the second flexible pad 40 and its arrangement on the blank 20 can refer to the width setting of the first flexible pad 30 and its arrangement on the blank 20, which will not be repeated. The specific effects can also refer to the part of the first flexible pad 30, which will not be repeated.

[0085] Exemplarily, there are a plurality of the second flexible pads 40 , and the plurality of the first flexible pads 30 are evenly distributed along the width direction of the blank 20 . Parts of each first flexible pad 30 are in contact with the support baffle 12 and the blank 20 .

[0086] For example, in some embodiments, the number of the first flexible pad 30 is one, and the first flexible pad 30 covers the side edge of the blank 20 in the width direction. Each part of the first flexible pad 30 contacts the support baffle 12 and the blank 20.

[0087] In some embodiments, see Figure 3 and Figure 4 The length of the first contact portion is 0.2-1 times the thickness of the support baffle 12 . The length of the third contact portion is 0.1-0.5 times the width of the blank 20 .

[0088] Under this condition, the second flexible pad 40 is more conducive to improving the sealing performance of the gap between the support baffle 12 and the blank 20, and has higher reliability.

[0089] In some embodiments, see Figure 3 and Figure 4 A second flexible pad 40 is provided between the thick end of the blank 20 and the corresponding support baffle 12, and between the thin end of the blank 20 and the corresponding support baffle 12. The thickness of the second flexible pad 40 is 0.1-1 times the thickness of the blank 20. This design can simultaneously improve the sealing performance of the gaps between the thick end and the thin end and the corresponding support baffle 12, and has higher reliability.

[0090] In some embodiments, the material of the first flexible pad 30 is silicone or rubber. The temperature of creep aging treatment is generally 120° C.-220° C. Silicone or rubber has good heat resistance and will not change in this temperature range.

[0091] It is understandable that the heat-resistant temperature of the second flexible pad 40 is also greater than or equal to the temperature of the creep aging treatment, and a flexible material with better heat-resistant temperature, such as silicone or rubber, may also be selected.

[0092] In some embodiments, see Figure 1 , also includes:

[0093] The surface structure of the blank 20 is scanned to obtain the structural characteristics of the skin and ribs in different regions, and the material constitutive equation of the blank 20 is fitted to obtain the fitted constitutive equation.

[0094] In this step, the material constitutive equation of the blank 20 can be constructed by conducting basic experimental tests on the same material of the sheet material. For example, the basic experimental tests include creep performance tests and mechanical performance tests, and the test parameters include creep temperature, creep stress, loading speed, creep time, yield strength, tensile strength, hardness, and elongation.

[0095] The creep aging forming of the blank 20 is simulated based on the fitted constitutive equation to obtain simulated creep aging process parameters.

[0096] In this step, the fitted constitutive equation can be imported into the simulation software to simulate the creep aging forming process of the sheet metal and obtain the best process to achieve the target profile.

[0097] In the step of subjecting the blank 20 mold seal to creep aging treatment in an autoclave, the creep aging treatment is performed using simulated creep aging process parameters.

[0098] In this embodiment, the creep aging process parameters are better and the forming effect of the component is good.

[0099] In some embodiments, see Figure 1 , also includes:

[0100] Collecting three-dimensional profile data of the variable thickness high-rib component, comparing it with target profile data, and judging whether the variable thickness high-rib component meets the standard;

[0101] If the standard is not met, the process parameters of the creep aging treatment are adjusted and the steps in the creep aging forming method of variable thickness high-rib components are repeated.

[0102] In this embodiment, the mold is unloaded and cooled, and the mold is taken out of the autoclave. The surface of the formed blank 20 is scanned by a three-dimensional optical measurement system, and the surface information is recorded and compared with the target surface to determine whether the surface meets the standards. If not, the process parameters need to be adjusted and steps S100-S400 are repeated.

[0103] For example, the 3D optical measurement system mainly includes a handheld 3D scanner, scanning software, a calibration board, a scanning point sheet, a transmission data cable, and a power cable. The measurement content of the 3D optical measurement system is 3D point cloud information, and the measurement features include holes, feature points, edge lines, waist lines, section lines, R angles and other feature information.

[0104] In some embodiments, the support baffle 12 is made of high temperature resistant alloys such as steel and titanium alloy.

[0105] In some embodiments, the support baffle 12 is fixed by pins. For example, through holes are set inside the support baffle 12, and the positions of the through holes are 100-500 mm apart and evenly distributed on the support baffle 12. Positioning holes are set on the mold surface to cooperate with the through holes to ensure that the pins fix the support baffle 12 on the mold surface.

[0106] In some embodiments, the method further includes: completely wrapping the first flexible pad with air-permeable felt. The air-permeable felt may be cut to a size that can completely wrap the pad, for example, the air-permeable felt may be cut to a length greater than 2 times the pad length and a width greater than 1 times the pad width, and the air-permeable felt may be wrapped around the pad with high temperature glue.

[0107] In some embodiments, the method further includes: completely wrapping the blank with air-permeable felt.

[0108] The technical solution of the present application is described below in conjunction with a specific embodiment.

[0109] Example 1

[0110] The variable thickness outer grid high-rib siding material is made of 7xxx series high-strength aluminum alloy plate with a thickness of 80mm, the heat treatment state is over-aging state, and the plate size is The surface of the sheet is milled to produce vertical cross ribs with heights of 12mm, 16mm, 18mm, and 20mm, and the rib thickness is 8mm.

[0111] The overall dimensions of the mold are The mold base and mold surface area are made of Q345 steel, the surface roughness is Ra1.5, the maximum working pressure is 2.4MPa, and the maximum working temperature is 320℃.

[0112] The supporting baffle 12 is arc-shaped, 150 mm thick, made of Q235 steel, with a maximum working pressure of 2.2 MPa and a maximum working temperature of 300°C.

[0113] The first flexible pad 30 and the second flexible pad 40 are made of silicone with a heat resistance temperature of 200° C. The thickness of the second flexible pad 40 corresponding to the thick end and the second flexible pad 40 corresponding to the thin end is 30 mm, and the thickness of the first flexible pad 30 is 8 mm.

[0114] The effective space inside the autoclave is The creep aging forming temperature is 180°C, the temperature fluctuation is ±2°C, the heating rate is 3°C / min, the creep aging high temperature holding time is 2h, and the vacuum loading rate is 0.2bar / min.

[0115] The above technical solutions of the present invention are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereto. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the protection scope of the present invention.

Claims

1. A creep aging forming method for variable thickness high rib components, characterized in that: The following steps are involved: Placing a blank corresponding to a variable thickness high-rib component on a mold forming space in a forming mold; wherein the bottom surface of the mold forming space is a mold profile area that matches a target profile of the variable thickness high-rib component; the length direction of the mold profile area corresponds to the thickness variation direction of the blank; and the forming mold has two support baffles at both ends in its length direction for forming the mold forming space; A first flexible pad is arranged in the first gap between the thick end of the blank and the corresponding support baffle, wherein the heat resistance temperature of the first flexible pad is greater than or equal to the temperature of the creep aging treatment; there is a clearance fit between the thick end and the corresponding support baffle, and the length of the first flexible pad extending into the first gap is 0.5-3 times the thickness of the thick end; Covering the blank with a vacuum bag film, sealing the mold forming space, and evacuating the blank to obtain a blank mold seal; The blank mold seal is placed in an autoclave for creep aging treatment to obtain a variable thickness high rib component; The first flexible pad includes a first flexible portion extending into the first slit and a second flexible portion placed on the upper surface of the thick end, the first flexible portion and the second flexible portion being connected to each other; Before the step of covering the blank with a vacuum bag film to seal the mold forming space, the method further comprises: A second flexible pad is arranged above at least one of the thick end and the thin end of the blank and between the corresponding support baffle; the second flexible pad covers the first gap in the width direction of the blank; The second flexible pad includes a first contact portion, a second contact portion and a third contact portion connected in sequence; the first contact portion is placed on the top of the support baffle, the second contact portion is attached to the inner side of the support baffle, and the third contact portion is attached to the second flexible portion.

2. The creep aging forming method of variable thickness high rib component according to claim 1, characterized in that: There are multiple first flexible pads, and the multiple first flexible pads are evenly distributed along the width direction of the blank.

3. The creep aging forming method of variable thickness high rib component according to claim 1, characterized in that: The number of the first flexible pad is one, and the first flexible pad covers the side edge of the blank in the width direction.

4. The creep aging forming method of variable thickness high rib component according to claim 1, characterized in that: The length of the first contact portion is 0.2-1 times the thickness of the support baffle; the length of the third contact portion is 0.1-0.5 times the width of the blank.

5. The creep aging forming method of variable thickness high rib component according to claim 1, characterized in that: A second flexible pad is provided between the upper portion of the thick end of the blank and the corresponding support baffle, and between the upper portion of the thin end of the blank and the corresponding support baffle; The thickness of the second flexible pad is 0.1-1 times the thickness of the blank.

6. The creep aging forming method of variable thickness high rib component according to claim 1, characterized in that: The material of the first flexible pad is silicone or rubber.

7. The creep aging forming method of a variable thickness high rib component according to any one of claims 1 to 6, characterized in that: Also includes: Scan the surface structure of the blank to obtain the structural characteristics of the skin and ribs in different regions, fit the material constitutive equation of the blank, and obtain the fitted constitutive equation; Based on the fitted constitutive equation, a creep aging forming simulation is performed on the blank to obtain simulated creep aging process parameters; In the step of subjecting the blank mold seal to creep aging treatment in an autoclave, the creep aging treatment is performed using simulated creep aging process parameters.

8. The creep aging forming method of variable thickness high rib component according to claim 7, characterized in that: Also includes: Collecting three-dimensional profile data of the variable thickness high-rib component, comparing it with target profile data, and judging whether the variable thickness high-rib component meets the standard; If the standard is not met, the process parameters of the creep aging treatment are adjusted and the steps in the creep aging forming method of variable thickness high-rib components are repeated.

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