Bulging aging die for aluminum-lithium alloy thin-wall grid rib barrel and using method of bulging aging die

Abstract

The invention relates to the technical field of aluminum lithium alloy, and discloses a bulging aging mold for an aluminum lithium alloy thin-wall grid rib barrel and a using method thereof.The bulging aging mold comprises a base, and an inner supporting mold is placed on the inner side of a first outer side rigid mold and the inner side of a second outer side rigid mold; locking blocks are fixed to the exteriors of the first outer side rigid mold and the second outer side rigid mold, a mold pressing block is fixed to the bottom of the upper mold, and an inner mold base is fixed to the top of the base. Compared with the prior art, according to the bulging aging mold, the first outer side rigid mold body and the second outer side rigid mold body are designed to restrain the outer surface of the barrel, the eight equally-divided inner supporting mold bodies are attached to the inner wall of the barrel, and the sand-resin mixture is used for filling rib gaps to form a composite supporting structure, so that the surface of the barrel is free of obvious pits after bulging; whole-process rigid constraint is formed through the locking blocks and the upper die, the technical structure of bulging, locking and die aging is achieved, and it is ensured that the bulging amount is maintained in the whole aging process.

Description

Technical Field

[0001] This invention relates to the field of aluminum-lithium alloy technology, specifically to an expansion aging mold for a thin-walled mesh-ribbed aluminum-lithium alloy cylinder and its application method. Background Technology

[0002] Aluminum-lithium alloys, due to their low density, high specific strength, and excellent low-temperature toughness, have become the core material for thin-walled cylindrical structures such as fuel tanks for next-generation aerospace launch vehicles and spacecraft modules. These components often employ a grid-reinforced design, using ribs to enhance buckling resistance and achieve a balance between lightweight and high load-bearing capacity. However, this structure faces two technical bottlenecks during heat treatment strengthening (i.e., ribbed area depression and creep relaxation during aging): To achieve peak strength, aluminum-lithium alloys require the synergistic effect of solution quenching, pre-deformation, and artificial aging. Applying pre-deformation and aging after quenching can significantly increase dislocation density and promote the nucleation and precipitation of strengthening phases T1 (Al-CuLi) and θ' (Al-Cu). However, the release of residual stress during free aging leads to uncontrollable deformation (large roundness error), and the amount of pre-deformation is lost due to creep relaxation at the high aging temperature (150-190℃), resulting in the strength failing to reach peak strength.

[0003] There is a height difference between the inner wall of the cylinder and the ribs. Traditional rigid internal support molds can only contact the top of the ribs, and the non-rib areas become unstable and dented under the expansion pressure due to lack of support. Although existing groove molds can match the ribs, the increased gap between the cylinder ribs after expansion leads to a mismatch in the geometric dimensions of the grooves and the expanded cylinder, causing local voids and stress concentration.

[0004] Aluminum-lithium alloys typically require pre-deformation and aging after solution quenching to improve strength. However, existing technologies cannot rigidly lock the pre-deformation amount throughout the aging process of the cylinder, leading to creep relaxation at high temperatures and insufficient strength improvement. Therefore, based on the above problems, an expansion aging mold for aluminum-lithium alloy thin-walled mesh-ribbed cylinders is proposed. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art by providing a bulging aging mold for thin-walled aluminum-lithium alloy mesh-ribbed cylinders and its method of use. This mold eliminates inward concavity during bulging and maintains the bulging amount throughout the aging process, solving the problem of inward collapse in non-ribbed areas under bulging pressure in traditional rigid internal support molds. The mold of this invention can be locked at both ends, maintaining the bulging amount during aging without continuous pressure from a press, thus preventing loosening.

[0006] This invention can be achieved through the following technical solutions: The first objective of this invention is to provide an bulging and aging mold for a thin-walled aluminum-lithium alloy mesh-reinforced cylindrical body, used for bulging the mesh-reinforced cylindrical body. The bulging and aging mold includes a base and a mold assembly structure.

[0007] Furthermore, the mold assembly structure includes a first outer rigid mold and a second outer rigid mold located on the top of the base. An inner support mold is placed inside the first outer rigid mold and the second outer rigid mold. Locking blocks are fixed to the outside of both the first outer rigid mold and the second outer rigid mold. An upper mold is provided on the top of the locking blocks. A locking bolt is inserted into the inside of the locking blocks. A pressure module is fixed to the bottom of the upper mold. An inner mold base is fixed to the top of the base.

[0008] Furthermore, the inner mold base is located inside the first outer rigid mold and the second outer rigid mold (i.e., between the first outer rigid mold and the second outer rigid mold), and the inner support mold is above the inner mold base.

[0009] Furthermore, both the first outer rigid mold and the second outer rigid mold have mold grooves; the inner support mold is located in the mold grooves; guide rods are fixedly connected to the top of both the first outer rigid mold and the second outer rigid mold; the mesh reinforcement cylinder is placed on the outside of the inner support mold.

[0010] Furthermore, the base has several positioning holes on its inner side; a first positioning bolt is inserted into the inner side of the first outer rigid mold, and the bottom of the first positioning bolt extends into the positioning hole to fix the first outer rigid mold; a second positioning bolt is inserted into the inner side of the second outer rigid mold, and the bottom of the second positioning bolt extends into the positioning hole to fix the second outer rigid mold.

[0011] Furthermore, the first outer rigid mold and the second outer rigid mold are symmetrically distributed, and each has a mold groove with a semi-cylindrical surface structure.

[0012] Furthermore, the mold groove of the first outer rigid mold and the mold groove of the second outer rigid mold are arranged opposite to each other. When the first outer rigid mold and the second outer rigid mold are in close contact, the mold groove of the first outer rigid mold and the mold groove of the second outer rigid mold combine to form a groove with a cylindrical surface structure.

[0013] Furthermore, the number of inner support molds is an even number, and the even number of inner support molds are evenly divided and respectively fitted to two mold slots, and the even number of inner support molds are fitted to the top of the inner mold base.

[0014] Furthermore, the number of inner support molds is eight, and the eight inner support molds are evenly divided and respectively fitted to two mold slots, and the eight inner support molds are set to fit the top of the inner mold base.

[0015] Furthermore, each of the two outer rigid molds is fixed with a locking block. Each locking block has a locking hole inside. The locking bolt is threaded into the inner side of the locking hole. The top of the locking bolt passes through the interior of the upper mold and is rotatably connected to the upper mold.

[0016] Furthermore, the upper mold has a vertical groove inside, and is slidably connected to the outside of the guide rod through the vertical groove.

[0017] Furthermore, the upper mold has an internal mounting hole, and a third positioning bolt is threaded into the internal mounting hole. The bottom of the third positioning bolt is inserted and fixed to the pressure module, which has a frustum structure.

[0018] Furthermore, the inner mold base is threaded with bolts on its inner side, and the inner mold base is fixed to the top of the base by the bolts. A mesh rib cylinder is placed on the inner side of the inner support mold.

[0019] Furthermore, the locking block, locking bolt, and upper mold together constitute a rigid mold locking mechanism.

[0020] Furthermore, the first outer rigid mold, the second outer rigid mold, and the inner support mold are made of Cr12MoV heat-resistant steel, and the locking bolts are made of No. 45 steel, which can withstand the high temperature of aging of 150-190℃. After the inner support mold is driven by the upper mold to achieve the pre-deformation of the cylinder, tightening the locking bolts can form a rigid constraint with the upper mold through the locking block, which avoids the loss of bulging amount due to creep relaxation under the high temperature of aging, and ensures that the pre-deformation amount is maintained throughout the process. This promotes the full nucleation and precipitation of the strengthening phase in the aluminum-lithium alloy, so that the cylinder reaches the peak strength and achieves the technical effect of maintaining the bulging amount throughout the aging process.

[0021] The second objective of this invention is to provide a method for using a bulging and aging mold for an aluminum-lithium alloy thin-walled mesh-reinforced cylindrical body, the method comprising the following steps: S1. The first outer rigid mold and the second outer rigid mold are tightly closed to constrain the deformation of the outer surface of the mesh tube. The inner support mold, which is divided into eight equal parts, is placed into the mold groove of the first outer rigid mold and the second outer rigid mold. S2. Then insert the mesh reinforcement cylinder body, ensuring that the outer surface of the inner support mold fits the inner wall of the mesh reinforcement cylinder body; S3. Under the guidance of the guide rod, the upper mold and the pressing module are pressed down to push the inner support mold to move horizontally on the inner mold base, pushing the grid rib cylinder to expand. The first outer rigid mold and the second outer rigid mold limit the expansion amount. S4. After expansion, the mold is closed by locking the locking bolts and locking blocks, which can achieve the effect of locking the upper and lower parts of the mold and suppress the shrinkage of the grid rib cylinder during the aging process.

[0022] Furthermore, step S2 also includes the following process: The filling medium for the mesh reinforcement cylinder (11) is quartz sand + high temperature resistant epoxy resin. After solution quenching, the quartz sand (sand) and epoxy resin are mixed and then filled into the gaps between the mesh reinforcements of the mesh reinforcement cylinder. After curing at room temperature, an adaptive inner support is formed.

[0023] Compared with the prior art, the present invention has the following beneficial effects: 1) The bulging and aging mold for a thin-walled aluminum-lithium alloy mesh-ribbed cylinder provided by the present invention constrains the outer surface of the cylinder by designing a first outer rigid mold and a second outer rigid mold. An inner support mold (preferably 8 equally divided inner support molds) fits against the inner wall of the cylinder and fills the gaps between the ribs with a sand-resin mixture. After the sand-resin mixture is cured, it fully fits against the inner wall of the cylinder, forming uniform support for the non-rib areas. With the auxiliary support of the inner support mold, the surface of the cylinder after bulging is free of obvious depressions, and the roundness error and wall thickness uniformity error are greatly reduced. It can achieve the technical effect of eliminating the inward concavity of the bulging, thereby solving the problem that the traditional rigid inner support mold only supports the ribs and the non-rib areas collapse inward under the bulging pressure.

[0024] 2) The bulging aging mold for a thin-walled mesh-reinforced aluminum-lithium alloy cylinder provided by the present invention is designed with a rigid mold locking mechanism consisting of a locking block, a locking bolt, and an upper mold. After the cylinder is pre-deformed by pressing down on the inner support mold through the upper mold, tightening the locking bolt can form a rigid constraint between the locking block and the upper mold throughout the process. This avoids the loss of bulging amount due to creep relaxation at the high temperature of aging, ensures that the pre-deformation amount is maintained throughout the process, and promotes the full nucleation and precipitation of the strengthening phase in the aluminum-lithium alloy, so that the cylinder reaches the peak strength and achieves the technical effect of maintaining the bulging amount throughout the aging process.

[0025] 3) The expansion aging mold for a thin-walled mesh ribbed aluminum-lithium alloy cylinder provided by the present invention has an outer rigid mold and an inner support mold made of Cr12MoV heat-resistant steel, and a locking bolt made of No. 45 steel, which can withstand the high temperature of aging of 150-190℃.

[0026] 4) The aluminum-lithium alloy thin-walled mesh ribbed cylinder bulging and aging mold provided by the present invention integrates the entire process of sand filling, bulging, locking and aging with mold through a modular mold assembly structure. Unlike traditional processes, it does not require transferring the cylinder to the aging equipment after bulging. Instead, it uses the mold as a carrier to achieve the technical effect of integrating bulging, locking and aging with mold, which greatly shortens the processing cycle, reduces the risk of defects during cylinder transfer and improves product yield. Attached Figure Description

[0027] In this invention, all figures are schematic and not drawn to scale.

[0028] Figure 1 This is a schematic diagram of the structure of the bulging aging mold of the present invention; Figure 2 This is a front view of the bulging aging mold of the present invention; Figure 3 This is a cross-sectional view of the bulging aging mold of the present invention; Figure 4 This is a top view of the structure of the first outer rigid mold and the second outer rigid mold of the present invention; Figure 5 This is a schematic diagram of the mesh-reinforced cylindrical body structure of the present invention.

[0029] Figure label: 1. Base; 2. Mold assembly structure; 201. First outer rigid mold; 202. Second outer rigid mold; 203. Inner support mold; 204. Locking block; 205. Upper mold; 206. Locking bolt; 207. Pressing module; 208. Inner mold base; 3. Positioning hole; 4. First positioning bolt; 5. Second positioning bolt; 6. Mold groove; 7. Locking hole; 8. Guide rod; 9. Mounting hole; 10. Third positioning bolt; 11. Mesh rib cylinder. Detailed Implementation

[0030] The present invention will now be described in detail with reference to specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0031] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection achieved by screw fastening, welding, or cooperation with a seal; they can also refer to a direct or indirect connection between components, or an interaction relationship achieved through other elements; they can be a fixed connection, a detachable connection, or an integral part; they can be a mechanical connection or an electrical connection; they can be a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction relationship between two components; "upper," "lower," "left," "right," etc., are only used to indicate relative positional relationships, and the relative positional relationship may change when the absolute position of the described object changes. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0033] This invention relates to the field of aluminum-lithium alloy technology and discloses a forming and aging mold for a thin-walled mesh-ribbed aluminum-lithium alloy cylinder. The mold includes a base, an inner support mold placed inside the first and second outer rigid molds, and locking blocks fixed to the exterior of both the first and second outer rigid molds. A pressure module is fixed to the bottom of the upper mold, and an inner mold base is fixed to the top of the base. This forming and aging mold for the thin-walled mesh-ribbed aluminum-lithium alloy cylinder features a design where the first and second outer rigid molds constrain the outer surface of the cylinder, and eight equally spaced inner support molds adhere to the inner wall of the cylinder, with a sand-resin mixture filling the gaps between the ribs. This composite support structure ensures no obvious depressions on the cylinder surface after forming. The locking blocks and the upper mold form a rigid constraint throughout the entire process, achieving a technical structure of forming + locking + mold-based aging, ensuring that the forming amount is maintained throughout the aging process.

[0034] In this invention, any component models, material names, connection structures, control methods, etc., not explicitly stated are considered common technical features disclosed in the prior art.

[0035] Example 1 like Figures 1-5 As shown, this embodiment provides an expansion aging mold for a thin-walled mesh ribbed aluminum-lithium alloy cylinder. The expansion aging mold includes a base 1 and a mold assembly structure 2.

[0036] The mold assembly structure 2 includes a first outer rigid mold 201 and a second outer rigid mold 202 located on the top of the base 1. An inner support mold 203 is placed inside the first outer rigid mold 201 and the second outer rigid mold 202. Locking blocks 204 are fixed to the outside of the first outer rigid mold 201 and the second outer rigid mold 202. An upper mold 205 is provided on the top of the locking blocks 204. Locking bolts 206 are inserted into the inside of the locking blocks 204. A pressure module 207 is fixed to the bottom of the upper mold 205. An inner mold base 208 is fixed to the top of the base 1.

[0037] The inner mold base 208 is located inside the first outer rigid mold 201 and the second outer rigid mold 202 (i.e., between the first outer rigid mold 201 and the second outer rigid mold 202), and the inner support mold 203 is above the inner mold base 208.

[0038] Both the first outer rigid mold 201 and the second outer rigid mold 202 are provided with mold grooves 6; the inner support mold 203 is provided in the mold grooves 6; guide rods 8 are fixedly connected to the top of both the first outer rigid mold 201 and the second outer rigid mold 202; the mesh rib cylinder 11 is placed on the outside of the inner support mold 203.

[0039] The base 1 has several positioning holes 3 on its inner side; a first positioning bolt 4 is inserted into the inner side of the first outer rigid mold 201, and the bottom of the first positioning bolt 4 extends into the positioning hole 3 to fix the first outer rigid mold 201; a second positioning bolt 5 is inserted into the inner side of the second outer rigid mold 202, and the bottom of the second positioning bolt 5 extends into the positioning hole 3 to fix the second outer rigid mold 202.

[0040] The first outer rigid mold 201 and the second outer rigid mold 202 are symmetrically distributed, and each has a mold groove 6 with a semi-cylindrical surface structure.

[0041] The mold groove 6 of the first outer rigid mold 201 and the mold groove 6 of the second outer rigid mold 202 are arranged opposite to each other. When the first outer rigid mold 201 and the second outer rigid mold 202 are in close contact, the mold groove 6 of the first outer rigid mold 201 and the mold groove 6 of the second outer rigid mold 202 are combined to form a groove with a cylindrical surface structure.

[0042] The number of inner support molds 203 is eight. The eight inner support molds 203 are evenly divided and respectively fitted to the two mold slots 6. The eight inner support molds 203 are set to fit the top of the inner mold base 208.

[0043] Two locking blocks 204 are fixed to the outside of the first outer rigid mold 201 and the second outer rigid mold 202. The locking blocks 204 are provided with locking holes 7 inside. The locking bolts 206 are threaded to the inside of the locking holes 7. The top of the locking bolts 206 is provided through the inside of the upper mold 205 and is rotatably connected to the upper mold 205.

[0044] The upper mold 205 has a vertical groove inside, and is slidably connected to the guide rod 8 outside through the vertical groove.

[0045] The upper mold 205 has an installation hole 9 inside, and a third positioning bolt 10 is threadedly connected inside the installation hole 9. The bottom of the third positioning bolt 10 is inserted and fixed to the pressure module 207 (through threaded connection). The pressure module 207 has a frustum structure (specifically an inverted frustum, with the upper surface diameter larger than the lower surface).

[0046] The inner mold base 208 is threaded with bolts on its inner side, and the inner mold base 208 is fixed to the top of the base 1 by the bolts. A grid-ribbed cylinder 11 is placed on the inner side of the inner support mold 203.

[0047] In this embodiment, eight positioning holes 3 are evenly opened along the length direction on the inner side of the base 1 (for the eight positioning holes 3, four holes are evenly opened along the length direction in a group, and two groups of positioning holes 3 are symmetrically arranged in the base 1, one group corresponds to the first positioning bolt 4, and the other group corresponds to the second positioning bolt 5), to meet the outer mold fixing requirements of the mesh reinforcement cylinder body 11 to be processed. The first positioning bolt 4 of No. 45 steel (galvanized for rust prevention) is selected to fix the first outer rigid mold 201. It is inserted through the pre-set through hole at the top of the first outer rigid mold 201 so that the bottom of the first positioning bolt 4 is completely inserted into the positioning hole 3 and the top of the first positioning bolt 4 is lower than the top surface of the first outer rigid mold 201, so as to achieve precise mold positioning. The second outer rigid mold 202 is fixed by a second positioning bolt 5 with the same specifications as the first positioning bolt 4. The second outer rigid mold 202 is fixed in the above manner to ensure that the first outer rigid mold 201 and the second outer rigid mold 202 are symmetrically distributed and the spacing is 6mm larger than the outer diameter of the mesh tube 11 to reserve space for expansion. Both the first outer rigid mold 201 and the second outer rigid mold 202 are made of Cr12MoV steel. The inner side of each mold has a semi-cylindrical mold groove 6 with a radius of curvature designed according to the radius of the grid-ribbed cylinder 11 + 3mm. The length (i.e. the height of the mold groove 6) is consistent with the grid-ribbed cylinder 11. There are a total of 8 inner support molds 203 (Cr12MoV steel). The outer arc curvature is adapted to the mold groove 6, and the outer arc fits the inner wall of the grid-ribbed cylinder 11. The 8 inner support molds 203 are evenly divided along the circumference (adjacent included angle 45°). The bottom fits the inner mold base 208 (Cr12MoV steel) to reduce movement friction.

[0048] The locking block 204 is welded to both ends of the first outer rigid mold 201 and the second outer rigid mold 202. It has an M22 internal thread locking hole 7. A 45 steel locking bolt 206 is screwed into the bottom of the locking hole 7 and passes through the pre-set through hole of the upper mold 205 at the top. It is rotatably connected to the upper mold 205 through the bearing. After the press presses down on the upper mold 205 to make the mesh rib cylinder 11 expand by 1-3%, the locking bolt 206 is tightened with a wrench to achieve rigid locking and no loosening during the aging process.

[0049] Example 2 like Figures 1-5 As shown, this embodiment provides an bulging and aging mold for an aluminum-lithium alloy thin-walled mesh-ribbed cylinder. Based on Embodiment 1, this embodiment further includes the following settings: In this embodiment, No. 45 steel guide rods 8 are welded to the top ends of the first outer rigid mold 201 and the second outer rigid mold 202. A vertical groove is opened at the bottom of the upper mold 205 corresponding to the guide rod 8, and the depth is adapted to the length of the guide rod. When the upper mold 205 is pressed down, the vertical groove slides vertically along the guide rod 8 and restricts the horizontal displacement of the upper mold, ensuring that the pressing module 207 accurately acts on the inner support mold 203. Four M18 mounting holes 9 are opened along the circumference of the top of the upper mold 205. The third positioning bolt 10 of No. 45 steel is selected and screwed into the mounting holes 9. The bottom protrudes about 10mm from the upper mold 205. The pressing module 207 is a frustum structure (side slope 1:5). Four through holes matching the third positioning bolt 10 are opened on the top. After insertion, tightening is achieved to fix the pressing module 207. When pressing down, the side of the frustum (pressing module 207) converts the vertical pressure into a horizontal thrust, which is evenly transmitted to the 8 inner support molds 203 to ensure that the circumferential expansion of the grid-ribbed cylinder 11 is consistent. The bottom of the inner mold base 208 (Cr12MoV steel) has four φ14 bolt holes. M14×50mm bolts are screwed into the threaded holes of the base 1 to achieve rigid fixation. The 2195 aluminum-lithium alloy thin-walled mesh cylinder 11, which has been filled and cured, is placed into the cavity of the inner support mold 203. The position is adjusted so that the axis of the mesh cylinder 11 coincides with the axis of the pressing module 207, and the top of the mesh cylinder 11 is completely in contact with the bottom of the pressing module 207 to avoid uneven expansion caused by eccentricity. After the mold is locked, the expansion aging mold and the mesh cylinder 11 are put into the aging furnace together and processed according to the process of 190℃ / 4h+160℃ / 24h. The inner mold base 208 stably supports the inner support mold 203 to prevent the mesh cylinder 11 from creeping and loosening.

[0050] Example 3 This embodiment provides a method for using the bulging and aging mold of the aluminum-lithium alloy thin-walled mesh ribbed cylinder of Embodiment 1 or Embodiment 2.

[0051] In this embodiment, the process of using the bulging and aging mold for the aluminum-lithium alloy thin-walled mesh ribbed cylinder includes: 1. The first outer rigid mold 201 and the second outer rigid mold 202 are tightly closed on the left and right sides and fixed on the base 1 to constrain the deformation of the outer surface of the mesh rib cylinder 11. The inner support mold 203, which is divided into eight equal parts, is placed into the mold groove 6 of the first outer rigid mold 201 and the mold groove 6 of the second outer rigid mold 202 to form a cylindrical structure. 2. Then, place the mesh reinforcement cylinder 11, ensuring that the outer surface of the inner support mold 203 fits the inner wall of the mesh reinforcement cylinder 11. The filling medium for the mesh reinforcement cylinder 11 is quartz sand + high temperature resistant epoxy resin. After solution quenching, the quartz sand and epoxy resin raw materials are mixed and filled into the mesh gaps of the mesh reinforcement cylinder 11. After curing at room temperature, an adaptive inner support is formed. 3. Under the guidance of the guide rod 8, the upper mold 205 and the pressing module 207 are pressed down. At this time, the inner support mold 203 moves horizontally on the inner mold base 208, pushing the mesh rib cylinder 11 to expand. The first outer rigid mold 201 and the second outer rigid mold 202 limit the expansion amount. 4. After the mesh reinforcement cylinder 11 is expanded, the locking bolt 206 and the locking block 204 are used to lock the connection for mold closing, which can achieve the upper and lower locking effect of the mold and suppress the shrinkage of the mesh reinforcement cylinder 11 during the aging process.

[0052] The gaps between the mesh ribs are filled by a mixture of quartz sand and epoxy resin. After curing, it forms a support that is fully attached to the inner wall, eliminating the problem of depression. It provides rigid constraint throughout the aging process of the aluminum-lithium alloy thin-walled mesh rib cylinder 11, preventing pre-deformation springback. At the same time, the pre-deformation and aging of the aluminum-lithium alloy thin-walled mesh rib cylinder 11 are completed continuously in the locked state, realizing the process flow of sand filling + expansion + locking + molded aging.

[0053] Example 4 This embodiment provides a method for using the bulging and aging mold of the aluminum-lithium alloy thin-walled mesh-ribbed cylinder of Embodiment 1 or Embodiment 2. Based on Embodiment 3, this embodiment also includes the following settings: In this embodiment, Figure 5 The 2195 aluminum-lithium alloy thin-walled mesh rib cylinder 11 shown is first solution-treated at 520℃ for 30 minutes, followed by water quenching. Quartz sand (sand) is mixed with epoxy resin to obtain sand filler to fill the mesh rib gaps of the mesh rib cylinder 11, and then cured at room temperature. Considering that the gaps between the ribs will become larger after expansion, the height of the sand filling can be slightly higher than the ribs. The mesh reinforcement cylinder 11 is placed into the bulging aging mold. The upper mold 205 is pressed down by a press, causing the inner support mold 203 to move horizontally on the inner mold base 208, pushing the mesh reinforcement cylinder 11 to bulge. The first outer rigid mold 201 and the second outer rigid mold 202 limit the bulging amount. The bulging amount of the mesh reinforcement cylinder 11 can be controlled between 1-3% depending on the pressing amount. After closing the bulging aging mold, the locking bolt 206 is tightened to lock the entire bulging aging mold. The bulging aging mold was placed in an aging furnace and aged at 190℃ / 4h and 160℃ / 24h. After cooling in the furnace, the mold was disassembled after cooling to room temperature, and the mesh reinforcement cylinder 11 was taken out. The sand filler was hammered to break it, and the residue was cleaned with a shovel. The surface of the bulging mesh reinforcement cylinder 11 had no obvious depressions, and the bulging effect was good.

[0054] In summary, the bulging and aging mold for the aluminum-lithium alloy thin-walled mesh cylinder 11, through the design of a first outer rigid mold 201 and a second outer rigid mold 202 constraining the outer surface of the mesh cylinder 11, and a composite support structure consisting of eight equally divided inner support molds 203 attached to the inner wall of the mesh cylinder 11 and a sand-resin mixture filling the gaps between the ribs, utilizes the sand-resin mixture to fully adhere to the inner wall of the mesh cylinder 11 after curing, forming uniform support for the non-rib areas. With the auxiliary support of the inner support molds 203, the surface of the mesh cylinder 11 after bulging is free of obvious depressions, and the roundness error and wall thickness uniformity error are significantly reduced. This achieves the technical effect of eliminating bulging concavity, thereby solving the problem that traditional rigid inner support molds only support the ribs, and the non-rib areas collapse inward under bulging pressure. By designing a rigid mold locking mechanism consisting of locking block 204, locking bolt 206 and upper mold 205, with the outer rigid mold and inner support mold 203 made of Cr12MoV heat-resistant steel and locking bolt 206 made of No. 45 steel, it can withstand the high temperature of aging of 150-190℃. When the upper mold 205 drives the inner support mold 203 to achieve the pre-deformation of the grid-ribbed cylinder 11, tightening the locking bolt 206 can form a rigid constraint throughout the process through the locking block 204 and the upper mold 205, avoiding the loss of bulging amount due to creep relaxation under the high temperature of aging, ensuring that the pre-deformation amount is maintained throughout the process, thereby promoting the full nucleation and precipitation of the strengthening phase in the aluminum-lithium alloy, so that the cylinder reaches the peak strength, and achieving the technical effect of maintaining the bulging amount throughout the aging process; Through the modular mold assembly structure 2, the sand-resin mixture (filling pretreatment), bulging (upper mold 205 pressing down drive), locking (locking bolt 206 locking the mold), and mold aging (bulging aging mold and grid-ribbed cylinder 11) are put into the furnace together for the whole process integration. Unlike the traditional process, the cylinder does not need to be transferred to the aging equipment after bulging. Instead, the mold is used as a carrier to achieve the technical effect of integrated bulging, locking and mold aging, which greatly shortens the processing cycle, reduces the risk of defects during cylinder transfer, and improves product yield.

[0055] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles and methods described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A forming and aging mold for a thin-walled aluminum-lithium alloy mesh-reinforced cylindrical body (11), the forming and aging mold comprising a base (1), characterized in that, The bulging aging mold also includes a mold assembly structure (2). The mold assembly structure (2) includes a first outer rigid mold (201) and a second outer rigid mold (202) located on the top of the base (1). An inner support mold (203) is placed inside the first outer rigid mold (201) and the second outer rigid mold (202). Locking blocks (204) are fixed on the outside of the first outer rigid mold (201) and the second outer rigid mold (202). An upper mold (205) is provided on the top of the locking block (204). A locking bolt (206) is inserted into the inside of the locking block (204). A pressure module (207) is fixed at the bottom of the upper mold (205). An inner mold base (208) is fixed on the top of the base (1). Both the first outer rigid mold (201) and the second outer rigid mold (202) are provided with mold grooves (6); The inner support mold (203) is located inside the mold groove (6); Guide rods (8) are fixedly connected to the top of both the first outer rigid mold (201) and the second outer rigid mold (202); The mesh-reinforced cylinder (11) is placed on the outside of the inner support mold (203).

2. The bulging and aging mold for a thin-walled, mesh-reinforced aluminum-lithium alloy cylinder according to claim 1, characterized in that, The base (1) has several positioning holes (3) on its inner side; A first positioning bolt (4) is inserted into the inner side of the first outer rigid mold (201), and the bottom of the first positioning bolt (4) extends into the positioning hole (3) to fix the first outer rigid mold (201); A second positioning bolt (5) is inserted into the inner side of the second outer rigid mold (202), and the bottom of the second positioning bolt (5) extends into the positioning hole (3) to fix the second outer rigid mold (202).

3. The bulging and aging mold for a thin-walled, mesh-reinforced aluminum-lithium alloy cylinder according to claim 1, characterized in that, The first outer rigid mold (201) and the second outer rigid mold (202) are symmetrically distributed, and both have mold grooves (6) with a semi-cylindrical surface structure. The mold groove (6) of the first outer rigid mold (201) and the mold groove (6) of the second outer rigid mold (202) are arranged opposite to each other. When the first outer rigid mold (201) and the second outer rigid mold (202) are in close contact, the mold groove (6) of the first outer rigid mold (201) and the mold groove (6) of the second outer rigid mold (202) are combined to form a groove with a cylindrical surface structure. The number of inner support molds (203) is an even number. The even number of inner support molds (203) are evenly divided and respectively fitted to two mold slots (6). The even number of inner support molds (203) are fitted to the top of the inner mold base (208).

4. The bulging and aging mold for a thin-walled mesh-reinforced aluminum-lithium alloy cylinder according to claim 3, characterized in that, The number of inner support molds (203) is eight. The eight inner support molds (203) are evenly divided and respectively fitted to two mold slots (6). The eight inner support molds (203) are fitted to the top of the inner mold base (208).

5. The bulging and aging mold for a thin-walled mesh-reinforced aluminum-lithium alloy cylinder according to claim 1, characterized in that, The locking block (204) has a locking hole (7) inside. The locking bolt (206) is threaded to the inside of the locking hole (7). The top of the locking bolt (206) is inserted through the inside of the upper mold (205) and is rotatably connected to the upper mold (205).

6. The bulging and aging mold for a thin-walled, mesh-reinforced aluminum-lithium alloy cylinder according to claim 1, characterized in that, The upper mold (205) has a vertical groove inside, and is slidably connected to the guide rod (8) outside through the vertical groove.

7. The bulging and aging mold for a thin-walled, mesh-reinforced aluminum-lithium alloy cylinder according to claim 1, characterized in that, The upper mold (205) has an installation hole (9) inside, and a third positioning bolt (10) is threaded inside the installation hole (9). The bottom of the third positioning bolt (10) is inserted and fixed to the pressure module (207). The pressure module (207) has a frustum structure.

8. The bulging and aging mold for a thin-walled mesh-reinforced aluminum-lithium alloy cylinder according to claim 1, characterized in that, The inner mold base (208) is threaded with bolts on its inner side, and the inner mold base (208) is fixed to the top of the base (1) by means of the bolts.

9. A method of using a bulging and aging mold for an aluminum-lithium alloy thin-walled mesh-ribbed cylinder as described in any one of claims 1-8, characterized in that, The method of use includes the following steps: S1. The first outer rigid mold (201) and the second outer rigid mold (202) are closed together to constrain the deformation of the outer surface of the mesh tube (11). The inner support mold (203) is placed in the mold groove (6) of the first outer rigid mold (201) and the second outer rigid mold (202). S2. Place the mesh reinforcement cylinder (11) in, ensuring that the inner support mold (203) fits the inner wall of the mesh reinforcement cylinder (11); S3. Under the guidance of the guide rod (8), the upper mold (205) and the pressing module (207) are pressed down to push the inner support mold (203) to move horizontally on the inner mold base (208) and push the grid rib cylinder (11) to expand. The first outer rigid mold (201) and the second outer rigid mold (202) limit the expansion amount. S4. After expansion, the locking bolt (206) and locking block (204) are used to lock the mold together, which can achieve the upper and lower locking effect of the mold and suppress the shrinkage of the grid rib cylinder (11) during the aging process.

10. The method of using the bulging and aging mold for an aluminum-lithium alloy thin-walled mesh-ribbed cylinder according to claim 9, characterized in that, Step S2 also includes the following process: Quartz sand and epoxy resin are used as the filling medium for the mesh reinforcement cylinder (11). After solution quenching, the quartz sand and epoxy resin are mixed and then filled into the mesh reinforcement gaps of the mesh reinforcement cylinder (11). After curing at room temperature, an adaptive inner support is formed.

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