A method, apparatus, and system for lip forming an aeroengine

Abstract

The application relates to the technical field of aircraft manufacturing, in particular to an aero-engine lip forming method, device and system. The first forming die comprises a first male die, a first female die, a first outer pressure part and a first inner pressure part; the second forming die comprises a second male die, a second female die, a second outer pressure part and a second inner pressure part. The forming device of the application forms a straight-cylinder annular groove in steps through the first forming die and the second forming die, instead of directly forming a lip curve, and overcomes defects such as wrinkling and uneven sheet flow in the lip curve forming process. In the process of forming the straight-cylinder positive deep drawing part and the annular groove, full clamping is realized through the first forming die and the second forming die, the die profile dynamically adapts to the straight-cylinder positive deep drawing part and the annular groove throughout the process, the forming precision of the lip part is guaranteed, and the forming indexes are ensured to meet the design requirements.

Description

Technical Field

[0001] This invention relates to the field of aircraft manufacturing technology, and more specifically, to a method, apparatus, and system for forming the lip of an aero-engine. Background Technology

[0002] The engine lip, located at the foremost part of the engine nacelle, is a crucial component of the engine intake, and its aerodynamic performance directly impacts the engine's intake efficiency and operational reliability. The lip is a ring-shaped curved skin structure with a deep U-shaped cross-section. Both sides of the cross-section are variable curvature curves. For high-bypass engines, the lip diameter can reach over 3 meters, and the ratio of cross-sectional depth to opening is greater than 1. To meet the hydrodynamic requirements and impact energy absorption requirements of high-speed flight, engine lips are typically made of 2-series high-strength aluminum alloy sheet. Furthermore, to meet lightweight requirements, the thinnest part of the lip is less than 2 mm thick. Because the lip operates under harsh conditions such as high-speed airflow and resonance, extremely high requirements are placed on its drawing depth, shape accuracy, and other forming parameters.

[0003] To achieve integral shaping of engine lip parts, existing technologies typically employ one or two-stage deep drawing processes. This means the overall curved surface of the lip part must be formed through a single or two-stage deep drawing operation. During this process, wrinkling and uneven sheet material flow are easily induced. Furthermore, it is difficult to achieve dynamic adaptation between the die surface and the continuously changing curved surface throughout the deep drawing process. Consequently, some areas of the lip surface are not supported and constrained by the die surface, leading to wrinkling and uneven sheet material flow. Summary of the Invention

[0004] This invention provides a method, apparatus, and system for forming the lip of an aero-engine, to solve the problems of wrinkling of the lip parts and uneven sheet metal that are easily generated by the forming process and molds in the prior art.

[0005] To solve the above problems, the present invention provides the following technical solution: a method for forming the lip of an aero-engine, comprising: Forward deep drawing involves forming a ring-shaped slab into a forward deep-drawn part using a first forming die. Reverse drawing forming: the forward drawing part is formed into a reverse drawing part by a second forming die, and a straight cylindrical annular groove is formed on the reverse drawing part. Liquid-filled bulging: The annular groove is bulged into a shape consistent with the forming cavity of the liquid-filled bulging mold using a liquid-filled bulging mold.

[0006] Preferably, during forward deep drawing, the inner pressure edge constraint between the first punch and the first inner pressure member, the outer pressure edge constraint between the first outer pressure member and the first die, and the liquid chamber pressure in the filling chamber are adjusted simultaneously. During reverse deep drawing, the inner pressure edge constraint between the second punch and the second inner pressure member, the outer pressure edge constraint between the second outer pressure member and the second die, and the liquid chamber pressure in the filling chamber are adjusted simultaneously.

[0007] A lip forming device includes: a first forming mold and a second forming mold; The first forming die includes: a first punch, a first die, a first outer pressure member, and a first inner pressure member; the first punch and the first inner pressure member are arranged vertically opposite each other, and the first outer pressure member and the first die are arranged vertically opposite each other; the first punch is cylindrical and its outer diameter is adapted to the inner diameter of the first die; during forward deep drawing, the first die and the first outer pressure member clamp the outer edge of the annular blank, and the first punch and the first inner pressure member clamp the inner edge of the annular blank and move downward to form the annular blank into a basin-shaped forward deep-drawn part; The second forming die includes: a second punch, a second die, a second outer pressure member, and a second inner pressure member. The second punch and the second inner pressure member are arranged vertically opposite each other, and the second outer pressure member and the second die are arranged vertically opposite each other. The second punch is cylindrical and its outer diameter is adapted to the inner diameter of the second die. A cavity is provided on the side of the second punch facing the second inner pressure member. The cavity is used to accommodate the basin-shaped portion of the forward drawn part. The radial dimensions of the first punch and the second inner pressure member are consistent and adapted to the inner diameter of the cavity. During reverse drawing, the second die and the second outer pressure member clamp the flange edge of the forward drawing part, the second inner pressure member extends into the basin-shaped part and fits against the inner wall, the second punch and the second inner pressure member clamp the basin-shaped part and move downward to form the forward drawing part into a reverse drawing part, and a straight cylindrical annular groove is formed on the reverse drawing part.

[0008] Preferably, the device includes a liquid chamber assembly, which is provided with a filling chamber. During forward deep drawing, the liquid chamber assembly is used in conjunction with the first forming die, the first die cavity is connected to the liquid chamber assembly, and the first punch and the first inner pressure member move downwards into the filling chamber. During reverse deep drawing, the liquid chamber assembly is used in conjunction with the second forming die, the second die cavity is connected to the liquid chamber assembly, and the second punch and the second inner pressure member move downwards into the filling chamber.

[0009] Preferably, the liquid chamber assembly includes: an outer liquid chamber, the filling chamber being the inner cavity of the outer liquid chamber, the first die or the second die being disposed above the outer liquid chamber and connected to the end face of the outer liquid chamber; the port size of the outer liquid chamber is larger than the radial size of the first punch, the first inner pressure member, the second punch, and the second inner pressure member.

[0010] Preferably, the liquid chamber assembly further includes a guide assembly disposed in the liquid filling chamber, the guide assembly being connected to the first internal pressure member and driving the first internal pressure member to move toward the first punch, or the guide assembly being connected to the second internal pressure member and driving the second internal pressure member to move toward the second punch.

[0011] Preferably, the guiding assembly includes: a guide cylinder, an inner pressure component cylinder, and a liquid chamber cylinder arranged coaxially and with their radial dimensions increasing sequentially. The liquid chamber cylinder is sleeved outside the guide cylinder, the inner pressure component cylinder is connected to the first inner pressure component or the second inner pressure component, and the inner pressure component cylinder moves between the guide cylinder and the liquid chamber cylinder.

[0012] A lip forming device includes a liquid-filled bulging mold, the liquid-filled bulging mold having an annular forming cavity that matches the shape of an engine lip, the liquid-filled bulging mold clamping the reverse drawing part, and the annular groove being smaller than the forming cavity.

[0013] Preferably, the liquid-filled bulging mold includes: an upper mold, a lower mold, and a bulging seal. The forming cavity is disposed on the lower mold. The upper mold is provided with a liquid filling hole that communicates with the outside and the forming cavity respectively. The upper mold and the lower mold are closed to clamp the reverse drawing part, and the bulging seal is disposed between the upper mold and the upper surface of the reverse drawing part.

[0014] A lip forming system for implementing the aero-engine lip forming method described above or in section 2, comprising: First forming die for forward deep drawing; A second forming die for reverse deep drawing; Liquid-filled bulging molds for use in liquid-filled bulging.

[0015] The beneficial effects of this invention are as follows: At the initial stage of forward deep drawing, the first punch and the first inner pressure member are arranged vertically opposite each other to clamp the inner edge of the annular blank, and the first outer pressure member and the first die are arranged vertically opposite each other to clamp the outer edge of the annular blank. Both the outer and inner edges of the annular blank are supported and constrained by the upper and lower sides. During the forward deep drawing process, the first punch and the first inner pressure member clamp the inner edge of the annular blank and move downwards. During the deep drawing process, a portion of the annular blank enters between the first punch and the first die. Since the first punch is cylindrical and matches the inner diameter of the first die, the portion of the annular blank entering between the first punch and the first die is also supported and constrained, forming a straight wall surface rather than a curved surface. In other words, the basin-shaped portion of the forward deep-drawn part is cylindrical.

[0016] At the initial stage of reverse deep drawing, the second punch and the second inner pressure member are arranged vertically opposite each other to clamp the basin-shaped portion of the forward deep drawing part, and the second outer pressure member and the second die are arranged vertically opposite each other to clamp the flange edge of the forward deep drawing part. In order to fully clamp the basin-shaped portion, the second punch has a cavity on the side facing the second inner pressure member, which can accommodate the basin-shaped portion. Since the radial dimension of the cavity is adapted to the first punch, the cavity can adapt to the outer wall of the basin-shaped portion formed during forward deep drawing. Therefore, during reverse deep drawing, the basin-shaped portion can extend into the cavity and its outer wall adapts to the inner wall of the cavity. Since the radial dimension of the cavity is adapted to the second inner pressure member, the second inner pressure member can extend into the basin-shaped portion and adapt to the inner wall of the basin-shaped portion. That is, the basin-shaped portion can be fully supported and constrained on both the inner and outer sides. During the reverse drawing process, the second punch and the second inner pressure member clamp the basin-shaped part and move downward. During the drawing process, the forward drawing part partially enters between the second punch and the second die. Since the inner diameter of the second die is adapted to the second punch, the forward drawing part between the second punch and the second die is always supported and constrained during the drawing process, forming a straight wall surface rather than a curved surface. Finally, the forward drawing part is formed into a reverse drawing part, and a straight cylindrical annular groove is formed on the reverse drawing part.

[0017] Compared to existing lip forming devices, the forming device of this invention, firstly, uses a first forming die and a second forming die to sequentially form a cylindrical basin-shaped part (forward deep-drawn part) and a reverse deep-drawn part with a cylindrical annular groove from the blank, rather than directly forming the lip surface. This avoids the defects such as wrinkling and uneven sheet flow that are easily caused during the direct deep-drawing process of forming the lip surface. This advantage is particularly significant for the lips of high-bypass ratio engines. More importantly, during the formation of the cylindrical forward deep-drawn part and the reverse deep-drawn part with the annular groove, the first forming die and the second forming die achieve sufficient clamping. The sheet is formed under a supported and constrained state. The die surface dynamically adapts to the cylindrical forward deep-drawn part and the annular groove throughout the process, ensuring the forming accuracy of the lip part and ensuring that its forming indicators meet the design requirements. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the annular slab in this invention; Figure 2 This is a schematic diagram of the forward deep-drawn part in this invention; Figure 3 This is a schematic diagram of the reverse drawing part in this invention; Figure 4 This is a schematic diagram of the liquid-filled bulging component in this invention; Figure 5 This is a schematic diagram of the first forming mold in its initial state; Figure 6 for Figure 5 The diagram shown is a schematic of the first forming die after forward drawing; Figure 7 This is a schematic diagram of the second forming mold in its initial state; Figure 8 for Figure 7 The diagram shown is a schematic of the second forming die after reverse drawing; Figure 9 This is a schematic diagram of the liquid-filled bulging mold of the present invention; Figure 10 for Figure 9 The diagram shown is a schematic of the structure after it has been filled with liquid and expanded.

[0019] Explanation of reference numerals in the attached figures: 1. Annular slab; 2. Pre-drilled hole; 3. Forward deep-drawn part; 4. Flange edge; 5. Basin-shaped part; 6. Annular groove; 7. First punch; 8. First die; 9. First external pressure component; 10. First internal pressure component; 11. Second punch; 12. Second die; 13. Second internal pressure component; 14. Second external pressure component; 15. Filling chamber; 16. Guide assembly; 17. Outer cylinder of the liquid chamber; 18. Guide cylinder; 19. Inner pressure component cylinder; 20. Inner cylinder of the liquid chamber; 21. First seal; 22. Second seal; 23. Third seal; 24. Cylinder piston; 25. Upper die; 26. Lower die; 27. Expansion seal; 28. Filling hole. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0021] In the attached diagram, the Z-axis represents the vertical direction, i.e., up and down, with the positive direction of the Z-axis representing upward and the negative direction representing downward. The X-axis represents the horizontal direction and is designated as front and back, with the positive direction of the X-axis representing the front and the negative direction representing the back. The Y-axis represents the left and right position, with the positive direction of the Y-axis representing the left and the negative direction representing the right. It should be noted that the aforementioned representations of the Z, Y, and X axes are merely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0022] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0023] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0024] Example 1 This embodiment provides a lip-forming device, such as... Figures 1-10 As shown, it includes: a first forming mold and a second forming mold. During the engine lip forming process, the first forming mold and the second forming mold work together to process the annular blank 1 sequentially. The annular blank 1 has an inner edge and an outer edge, with a pre-drilled hole 2 in the middle. The edge of the pre-drilled hole 2 is the inner edge of the annular blank 1. Figure 1 , Figure 2 As shown, the annular slab 1 is formed into a forward-drawn part 3 by forward drawing using a first forming die. The forward-drawn part includes a basin-shaped portion 5 and a flange edge 4, and its cross-section is cylindrical. Figure 3 , Figure 4 As shown, the forward-drawn part is formed into a reverse-drawn part by reverse drawing through the second forming die. The reverse-drawn part has an annular groove 6, and the cross-section of the annular groove 6 is cylindrical.

[0025] The first forming mold includes: a first punch 7, a first die 8, a first outer pressure member 9, and a first inner pressure member 10; the first punch 7 and the first inner pressure member 10 are arranged vertically opposite each other, and the first die 8 and the first inner pressure member 10 are arranged vertically opposite each other. The first punch 7 is cylindrical and its outer diameter is adapted to the inner diameter of the first die 8. It should be explained that the relative arrangement here means that the functional areas of the two components on the annular blank 1 overlap and their functional directions are opposite.

[0026] At the initial stage of forward deep drawing, such as Figure 1 , Figure 5As shown, the first punch 7 and the first outer pressure member 9 are located above the annular blank 1, and the first die 8 and the first inner pressure member 10 are located below the annular blank 1. The first punch 7 and the first inner pressure member 9 clamp the inner edge of the annular blank 1, forming an inner pressure edge constraint on the annular blank. The first outer pressure member 9 and the first die 7 clamp the outer edge of the annular blank 1, forming an outer pressure edge constraint on the annular blank 1. This ensures that both the outer and inner edges of the annular blank 1 are supported and constrained by the upper and lower sides, and the size of the inner and outer pressure edge constraints can be dynamically adjusted.

[0027] In the forward deep drawing process, such as Figure 2 , Figure 6 As shown, the first punch 7 and the first inner pressure member 9 clamp the inner edge of the annular blank 1 and move downwards. A portion of the annular blank 1 flows between the first punch 7 and the first die 8. Since the first punch is cylindrical and matches the inner diameter of the first die, the annular blank portion entering between the first punch and the first die is also supported and constrained, forming a straight wall surface rather than a curved surface. In other words, the basin-shaped portion of the forward drawn part formed by deep drawing is cylindrical.

[0028] The second forming die includes a second punch 11, a second die 12, a second outer pressure member 14, and a second inner pressure member 13. The second punch 11 and the second inner pressure member 13 are arranged vertically opposite each other, and the second die 12 and the first inner pressure member 10 are arranged vertically opposite each other. The second punch 11 is cylindrical, and its outer diameter is adapted to the inner diameter of the second die 12 so that the second punch 11 can pass downward through the second die 12. In order to fully clamp the basin-shaped portion 5, the second punch 11 has a cavity on the side facing the second inner pressure member 13, which can accommodate the basin-shaped portion 5. The radial dimensions of the first punch 7 and the second inner pressure member 13 are consistent and adapted to the inner diameter of the cavity. Therefore, the cavity can adapt to the outer wall of the basin-shaped portion 5 formed during forward deep drawing, and the second inner pressure member 13 can adapt to the inner wall of the basin-shaped portion 5.

[0029] At the initial stage of reverse deep drawing, such as Figure 3 , Figure 6 As shown, the second punch 11 and the second inner pressure member 13 clamp the basin-shaped portion 5 of the forward drawing member 3 to apply inner pressure edge constraint. The second outer pressure member 14 and the second die 12 are arranged vertically opposite to clamp the flange edge 4 of the forward drawing member 3 to apply outer pressure edge constraint. The basin-shaped portion 5 extends into the cavity and its outer wall is adapted to the inner wall of the cavity. The second inner pressure member 13 can extend into the basin-shaped portion 5 and adapt to the inner wall of the basin-shaped portion 5. That is, the basin-shaped portion 5 can be supported and constrained in the entire area on both the inner and outer sides.

[0030] In the reverse deep drawing process, such as Figure 4 , Figure 7As shown, the second punch 11 and the second inner pressure member 13 clamp the basin-shaped part 5 and move downward. During the drawing process, part of the forward drawing member 3 enters between the second punch 11 and the second die 12. The part of the forward drawing member 3 that enters between the second punch 11 and the second die 12 is always supported and constrained during the drawing process, forming a straight wall surface rather than a curved surface. Finally, the forward drawing member 3 is formed into a reverse drawing member, and a straight cylindrical annular groove 6 is formed on the reverse drawing member.

[0031] Instead of directly forming the lip surface, the cylindrical annular groove 6 is formed step-by-step using the first and second forming dies. This overcomes the defects of wrinkling and uneven sheet metal flow during the forming process of the lip surface, especially for the lip of a high-bypass engine, where this advantage is even more significant. More importantly, during the formation of the cylindrical forward-drawn part 3 and the annular groove 6, the first and second forming dies achieve full clamping, forming the sheet metal under supported constraints. The die surfaces dynamically adapt to the cylindrical forward-drawn part 3 and the annular groove 6 throughout the process, ensuring the forming accuracy of the lip part and guaranteeing that its forming indicators meet the design requirements.

[0032] It should be further noted that, in this embodiment, the power source driving the first punch 7, the first external pressure member 9, the second punch 11, and the second external pressure member 14 is a press, and the power source driving the first internal pressure member 10 and the second internal pressure member 13 is an ejector cylinder. The press and the ejector cylinder are not part of this invention and will not be described in detail here. The power source here refers to the driving force provided directly or indirectly.

[0033] Furthermore, such as Figures 5-8 As shown, the lip forming apparatus of this embodiment includes a liquid chamber assembly, which is provided with a liquid filling chamber 15. After the liquid chamber assembly is provided, both the first forming mold and the second forming mold are used in conjunction with the liquid chamber assembly during the forming process. It should be noted that the first forming mold and the second forming mold do not necessarily share only one liquid chamber assembly; in actual use, the first forming mold and the second forming mold are provided with separate liquid chamber assemblies. Specifically: During forward drawing, the liquid chamber assembly is used in conjunction with the first forming die, and the first die cavity 8 is connected to the liquid chamber assembly. For example... Figure 6 As shown, the first punch 7 and the first inner pressure member 10 move downward into the filling chamber 15. The part of the annular blank that is not supported and constrained is subjected to the action of the high pressure liquid in the filling chamber, so that the annular blank 1 always fits the first punch 7 during the deep drawing process, ensuring that the sheet is supported and constrained during the forward deep drawing process.

[0034] During reverse deep drawing, the liquid chamber assembly is used in conjunction with the second forming die, and the second die 12 is connected to the liquid chamber assembly. For example... Figure 8As shown, the second punch 11 and the second inner pressure member 13 move downward into the filling chamber 15. The high-pressure liquid in the filling chamber 15 ensures that the reverse drawing member is always in contact with the second punch 11, thus ensuring that the sheet metal is supported and constrained during the reverse drawing process.

[0035] By setting up the liquid chamber assembly, forces are applied to areas that cannot be supported and constrained by the first punch 7 and the first inner pressure member 10, and the second punch 11 and the second inner pressure member 13 during the deep drawing process, thereby ensuring forming accuracy.

[0036] Furthermore, by using the liquid chamber assembly in conjunction with the first forming die and the second forming die, the contact area between the high-pressure liquid in the filling chamber and the sheet metal is small, the force exerted by the high-pressure liquid on the sheet metal is small, and the friction between the sheet metal and the first punch 7 and the second punch 11 will not hinder the pressure between the first punch 7 and the first inner pressure member 10, or the pressure adjustment between the first outer pressure member 9 and the first die 8. It should be noted that if the force exerted by the high-pressure liquid on the sheet metal is too large, it will cause excessive resistance to the sheet metal during deep drawing, making it difficult to flow and replenish material, thus affecting the accuracy of the final product; in addition, excessive force exerted by the high-pressure liquid on the sheet metal will also result in a high tonnage of the liquid chamber pressure equipment providing high pressure, thereby increasing the production and manufacturing costs.

[0037] Specifically, the liquid chamber assembly includes: an outer liquid chamber 17, a filling chamber 15 which is the inner cavity of the outer liquid chamber 17, a first die 8 or a second die 12 disposed above the outer liquid chamber 17 and connected to the end face of the outer liquid chamber 17; the port size of the outer liquid chamber 17 is larger than the radial size of the first punch 7, the first inner pressure member 10, the second die 12 and the second inner pressure member 13. Specifically, during forward drawing, the first die 8 is disposed below the outer liquid chamber 17 and connected to the end face of the outer liquid chamber 17. Since the port size of the outer liquid chamber 17 is larger than the radial size of the first punch 7 and the first inner pressure member 10, during forward drawing, the first punch 7 and the first inner pressure member 10 can clamp the inner edge of the annular slab 1 and enter the outer liquid chamber 17, and the high-pressure liquid in the outer liquid chamber 17 acts on the annular slab 1. Similarly, during reverse drawing, the second punch 11 and the second inner pressure component 13 enter the outer cylinder 17 of the liquid chamber, and the high-pressure liquid in the outer cylinder 17 acts on the annular slab 1.

[0038] Furthermore, the liquid chamber assembly also includes a guide assembly 16, which is disposed within the liquid filling chamber 15. During forward deep drawing, the guide assembly 16 connects to the first inner pressure member 10 and drives the first inner pressure member 10 to move towards the first punch 7. During reverse deep drawing, the guide assembly 16 connects to the second inner pressure member 13 and drives the second inner pressure member 13 to move towards the second punch 11. The guide assembly 16 serves to guide and support the first inner pressure member 10 or the second inner pressure member 13. More importantly, the guide assembly 16 is disposed within the liquid filling chamber 15, thereby reducing the volume of the liquid chamber that can be filled with liquid and further reducing the tonnage of the liquid chamber pressure equipment required for high-pressure liquid.

[0039] Specifically, the guide assembly 16 includes a guide cylinder 18, an inner pressure cylinder 19, and a liquid chamber cylinder 20, which are coaxially arranged and whose radial dimensions increase sequentially. The liquid chamber cylinder 20 is sleeved outside the guide cylinder 18. When used in conjunction with the first forming mold, the inner pressure cylinder 19 is connected to the first inner pressure component 10. When used in conjunction with the second forming mold, the inner pressure cylinder 19 is connected to the second inner pressure component 13. The inner pressure cylinder 19 moves between the guide cylinder 18 and the liquid chamber cylinder 20. The guide cylinder 18 and the liquid chamber cylinder 20 provide radial restraint to the inner pressure cylinder 19, so that the inner pressure cylinder 19 can only move axially.

[0040] This embodiment also includes a hydraulic cylinder piston 24. One end of the hydraulic cylinder piston 24 extends into the space between the guide cylinder 18 and the liquid chamber cylinder 20 and is connected to the inner pressure cylinder 19. The other end extends out of the liquid chamber cylinder 17 and is connected to the lifting cylinder. The lifting cylinder drives the inner pressure cylinder 19 to rise and fall.

[0041] To ensure the sealing of the filling chamber 15, this embodiment also includes a first sealing element 21, a second sealing element 22, and a third sealing element 23. The first sealing element 21 is disposed between the inner wall of the inner cylinder 20 and the outer cylinder 17; the second sealing element 22 is disposed on the inner pressure cylinder 19 and / or the inner cylinder 20, and is located between the inner pressure cylinder 19 and / or the inner cylinder 20; the third sealing element 23 is disposed between the first die 8 and the first outer pressure element 9, and between the second die 12 and the second outer pressure element 14.

[0042] Example 2 The lip forming device in this embodiment further includes: a liquid-filled bulging mold, such as... Figure 9 , Figure 10 As shown, the liquid-filled bulging mold has an annular forming cavity that matches the shape of the engine lip. The liquid-filled bulging mold clamps the reverse-drawn part, and the annular groove 6 is located in the forming cavity. After liquid filling, the annular groove 6 expands and deforms towards the inner wall of the forming cavity, ultimately forming a liquid-filled bulging part that matches the cross-sectional line of the forming cavity. After liquid filling, the liquid can exert forces on the annular groove 6 in all directions, ensuring the forming accuracy.

[0043] Specifically, the liquid-filled bulging mold includes an upper mold 25, a lower mold 26, and a bulging seal 27. The forming cavity is located on the lower mold 26. The upper mold 25 is provided with a liquid filling hole 28 that communicates with the outside and the forming cavity respectively for injecting bulging liquid. The upper mold 25 and the lower mold 26 are closed to support and constrain the outer edge of the reverse drawing part. The bulging seal 27 is located between the upper mold 25 and the upper surface of the reverse drawing part to prevent liquid leakage.

[0044] Example 3 This embodiment provides a method for forming a lip. For example... Figures 1-10 As shown, the lip forming apparatus based on Embodiment 1 and Embodiment 2 includes: S1. A pre-drilled hole 2 is made in the center of the sheet material to form an annular slab; S2, forward drawing forming, the slab 1 is formed into a basin-shaped forward drawing part 3 through the first forming die; S3. Reverse drawing forming: The forward drawing part 3 is formed into a reverse drawing part by the second forming die, and a straight cylindrical annular groove 6 is formed on the reverse drawing part. S4. Fluid-filled bulging: The annular groove 6 is bulged into a shape consistent with the forming cavity of the fluid-filled bulging mold using a fluid-filled bulging mold.

[0045] In step S1 of this embodiment, the pre-drilled holes 2 are used to form the slab into an annular shape. During deep drawing, the sheet material from both the inner and outer edges of the annular slab can be fed into the deep drawing deformation area, reducing the probability of wrinkling and uneven sheet material flow, and ensuring forming accuracy.

[0046] In this embodiment, the overall forming of the lip part is achieved through steps S2 to S4. Specifically, steps S2 and S3 first form the annular blank into a cylindrical annular groove, thus avoiding the wrinkling and uneven material flow problems induced when directly machining the sheet metal into a curved surface in existing forming processes. Secondly, during the forming process, by adjusting the size of the inner and outer pressure edge constraints of the first forming die, material is simultaneously fed into the deep drawing deformation area from the inner and outer edges of the annular blank under support constraints. By adjusting the size of the inner and outer pressure edge constraints of the second forming die, material is simultaneously fed into the deep drawing deformation area from the inner and outer edges of the forward deep drawing part when forming the annular groove. Furthermore, the forming method of this embodiment uses the first and second forming dies for deep drawing, which ensures sufficient support and constraint for the annular blank and the forward deep drawing part during the forming process, further improving the deep drawing accuracy.

[0047] Further, step S2 includes S21: synchronously adjusting the inner pressure edge constraint between the first punch 7 and the first inner pressure member 10, the outer pressure edge constraint between the first outer pressure member 9 and the first die 8, and the magnitude of the liquid chamber pressure in the filling chamber 15. Specifically, at the initial stage of forward deep drawing, the inner and outer pressure edge constraints are adjusted to 0.5~2.0 MPa per unit area, and the initial liquid chamber pressure in the filling chamber 15 is adjusted to 0.2~2.0 MPa. During the forward deep drawing process, the inner and outer pressure edge constraints are adjusted to 2.0~5.0 MPa per unit area, and the liquid chamber pressure in the filling chamber 15 varies between 2.0~30.0 MPa. It should be noted that the inner pressure edge constraint, the outer pressure edge constraint, and the liquid chamber pressure in the filling chamber 15 are dynamically adjusted according to a preset pressurization curve. The pressurization curve is obtained through repeated optimization via process simulation or experimentation, and will not be elaborated here.

[0048] Further, step S3 includes S31, synchronously adjusting the inner pressure edge constraint between the second punch 11 and the second inner pressure member 13, the outer pressure edge constraint between the second outer pressure member 14 and the second die 12, and the liquid chamber pressure in the filling chamber 15. The adjustment range and method for the inner pressure edge constraint, outer pressure edge constraint, and liquid chamber pressure are the same as in forward deep drawing, i.e., dynamic adjustment is also achieved through a preset pressure curve.

[0049] The forming process in this embodiment achieves dynamic closed-loop control through multiple independently controllable pressure systems, while ensuring sufficient support and constraint. The internal pressure edge constraint, external pressure edge constraint, and liquid chamber pressure work together to adjust synchronously in real time according to the preset pressure curve during the forming process, further improving the forming accuracy.

[0050] like Figure 5 , Figure 6 As shown, step S2 specifically includes: 1b. In the initial state, the upper surface of the first inner pressure member 10 and the first die 8 are on the same plane. The annular blank 1 with pre-made holes 2 is placed on the first die 8 and the first inner pressure member 10. 2b. The first punch 7 and the first external pressure member 9 move downwards to contact the annular blank, and the lower surfaces of the first punch 7 and the first external pressure member 9 are in the same plane; 3b. The first punch 7 and the first inner pressure member 10 clamp the inner edge of the annular blank, and the first outer pressure member 9 and the first die 8 clamp the outer edge of the annular blank. 4b. The first punch 7 and the first external pressure piece 9 descend to the end of their stroke, and the forward drawing process ends; 5b. The first punch 7 and the first inner pressure member 10 move upward to the initial state.

[0051] It should be noted that step S21 is set between steps 2a and 3a.

[0052] Among them, such as Figure 7 , Figure 8 As shown, step S3 specifically includes: 1c. In the initial state, the forward drawing part 3 is flipped over and placed on the second die 12 in an "inverted" position, and the second inner pressing part 13 extends into the basin-shaped part 5 and fits against its inner wall. 2c. The second punch 11 and the second external pressure member 14 move downwards until they contact the flange edge, and the lower surfaces of the second punch 11 and the second external pressure member 14 are in the same plane. 3c. The second punch 11 and the second inner pressure member 13 clamp the basin-shaped part 5, and the second die 12 and the second outer pressure member 14 clamp the flange edge 4. 4c. The second punch 11 and the second inner pressure member 13 descend to the forming endpoint, and the reverse drawing process ends; 5c. The second punch 11 and the second inner pressure member 13 move upward to the initial state.

[0053] It should be noted that step S31 is set between steps 2b and 3b.

[0054] Furthermore, step S5, performed between step S3 and step S4, involves solution treatment and quenching, where the reverse deep-drawn part is heat-treated using a heat treatment fixture. At this time, the liquid filling and bulging process in step S4 not only bulges the annular groove 6 but also avoids the problem of distortion and deformation caused by high-temperature heat treatment after forming. This improves the forming accuracy of the lip part while also enhancing its mechanical properties.

[0055] Specifically, step S5 includes: 1f. Heat the forward drawn part 3 after step S3 to the solution temperature and hold it at that temperature; 2f. Transfer to cold water for quenching.

[0056] Specifically, the solution treatment temperature is usually between 480 and 550°C, ensuring that the temperature difference throughout the furnace is within ±3°C. During quenching, the forward-drawn part 3 is rapidly transferred to water at a temperature not exceeding 30°C within 10 seconds, and the quenching cooling time is not less than 180 seconds, during which the water temperature does not exceed 35°C.

[0057] Specifically, after the heat treatment in step S5, step S4 includes: 1d. Initial state: Place the reverse drawn part on the lower die 26; 2d. The upper mold 25 moves downwards until it contacts the flange edge 4; 3d. Fill the forming cavity with liquid and maintain pressure; the liquid filling and expansion process is complete. 4d, the upper mold 25 moves upward to restore to the initial state.

[0058] Among them, such as Figures 1-4 As shown, step S1 specifically includes: 1a. Based on the geometric model of the lip part, construct a process part that includes a deep drawing method fillet and inner and outer flanges, wherein the method fillet radius r is 6 to 10 times the plate thickness t, the flange area width B is 2 to 4 times the method fillet r, and its center hole diameter is d1. 2a. The surface area S of the liquid-filled bulging part was measured using 3D CAD software; 3a. Calculate the minimum diameter D and d range of the annular slab 1 according to Formula 1 and Formula 2. Cut the slab and open the pre-drilled holes 2 according to the range of D and d. Correct the values ​​of D and d according to the simulation results and experimental results.

[0059] (1) (2) Where D is the initial diameter of the annular slab 1, d0 is the diameter of the pre-made hole 2, S is the surface area of ​​the liquid-filled bulging part, d1 is the diameter of the center hole, and δ is the elongation of the sheet metal. Specifically, the elongation of 2219 aluminum alloy is δ≈24%.

[0060] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for forming the lip of an aero-engine, characterized in that, include: Forward deep drawing: The annular slab (1) is formed into a forward deep drawing part (3) through the first forming die. Reverse drawing forming: the forward drawing part (3) is formed into a reverse drawing part by a second forming die, and a straight cylindrical annular groove (6) is formed on the reverse drawing part. Liquid-filled bulging: The annular groove (6) is bulged into a shape consistent with the forming cavity of the liquid-filled bulging mold using a liquid-filled bulging mold. During forward deep drawing, the inner pressure edge constraint between the first punch (7) and the first inner pressure member (10), the outer pressure edge constraint between the first outer pressure member (9) and the first die (8), and the liquid chamber pressure in the filling chamber (15) are adjusted simultaneously. During reverse deep drawing, the inner pressure edge constraint between the second punch (11) and the second inner pressure member (13), the outer pressure edge constraint between the second outer pressure member (14) and the second die (12), and the liquid chamber pressure in the filling chamber (15) are adjusted simultaneously.

2. A lip forming apparatus, employing the aero-engine lip forming method of claim 1, characterized in that, include: First forming mold and second forming mold; The first forming die includes: a first punch (7), a first die (8), a first outer pressure member (9), and a first inner pressure member (10); the first punch (7) and the first inner pressure member (10) are arranged vertically opposite each other, the first outer pressure member (9) and the first die (8) are arranged vertically opposite each other, the first punch (7) is cylindrical and its outer diameter is adapted to the inner diameter of the first die (8); during forward deep drawing, the first die (8) and the first outer pressure member (9) clamp the outer edge of the annular blank (1), the first punch (7) and the first inner pressure member (10) clamp the inner edge of the annular blank (1) and move downward to form the annular blank (1) into a basin-shaped forward deep drawing part (3). The second forming die includes: a second punch (11), a second die (12), a second outer pressure member (14), and a second inner pressure member (13). The second punch (11) and the second inner pressure member (13) are arranged vertically opposite each other, and the second outer pressure member (14) and the second die (12) are arranged vertically opposite each other. The second punch (11) is cylindrical and its outer diameter is adapted to the inner diameter of the second die (12). The second punch (11) has a cavity on the side facing the second inner pressure member (13). The cavity is used to accommodate the basin-shaped part (5) of the forward drawing part (3). The radial dimensions of the first punch (7) and the second inner pressure member (13) are consistent and adapted to the inner diameter of the cavity. During reverse drawing, the second die (12) and the second outer pressure member (14) clamp the flange edge (4) of the forward drawing member (3), the second inner pressure member (13) extends into the basin-shaped part (5) and fits against the inner wall, the second punch (11) and the second inner pressure member (13) clamp the basin-shaped part (5) and move downward to form the forward drawing member (3) into a reverse drawing member, and a straight cylindrical annular groove (6) is formed on the reverse drawing member.

3. The lip-forming device according to claim 2, characterized in that, The device includes a liquid chamber assembly, which is provided with a filling chamber (15). When the device is used for forward deep drawing, the liquid chamber assembly is used in conjunction with the first forming die, the first die (8) is connected to the liquid chamber assembly, and the first punch (7) and the first inner pressure member (10) move downward into the filling chamber (15). When the device is used for reverse deep drawing, the liquid chamber assembly is used in conjunction with the second forming die, the second die (12) is connected to the liquid chamber assembly, and the second punch (11) and the second inner pressure member (13) move downward into the filling chamber (15).

4. The lip-forming device according to claim 3, characterized in that, The liquid chamber assembly includes: an outer liquid chamber (17), the filling chamber (15) being the inner cavity of the outer liquid chamber (17), the first die (8) or the second die (12) being disposed above the outer liquid chamber (17) and connected to the end face of the outer liquid chamber (17); the port size of the outer liquid chamber (17) is greater than the radial size of the first punch (7), the first inner pressure member (10), the second punch (11) and the second inner pressure member (13).

5. The lip-forming device according to claim 4, characterized in that, The liquid chamber assembly further includes a guide assembly (16), which is disposed in the filling chamber (15). The guide assembly (16) is connected to the first internal pressure member (10) and drives the first internal pressure member (10) to move toward the first punch (7), or the guide assembly (16) is connected to the second internal pressure member (13) and drives the second internal pressure member (13) to move toward the second punch (11).

6. The lip-forming apparatus according to claim 5, characterized in that, The guide assembly (16) includes a guide cylinder (18), an inner pressure cylinder (19), and a liquid chamber cylinder (20) arranged coaxially and whose radial dimensions increase sequentially. The liquid chamber cylinder (20) is sleeved outside the guide cylinder (18). The inner pressure cylinder (19) is connected to the first inner pressure component (10) or the second inner pressure component (13), and the inner pressure cylinder (19) moves between the guide cylinder (18) and the liquid chamber cylinder (20).

7. A lip forming apparatus, employing the aero-engine lip forming method of claim 1, characterized in that, It includes a liquid-filled bulging mold, which has an annular forming cavity that matches the shape of the engine lip. The liquid-filled bulging mold holds the reverse drawing part, and the annular groove (6) is smaller than the forming cavity.

8. The lip-forming apparatus according to claim 7, characterized in that, The liquid-filled bulging mold includes an upper mold (25), a lower mold (26), and a bulging seal (27). The forming cavity is located on the lower mold (26). The upper mold (25) is provided with a liquid filling hole (28) that communicates with the outside and the forming cavity respectively. The upper mold (25) and the lower mold (26) clamp the reverse drawing part together, and the bulging seal (27) is located between the upper mold (25) and the upper surface of the reverse drawing part.

9. A lip-forming system, characterized in that, The method for forming the lip of an aero-engine as described in claim 1 includes: First forming die for forward deep drawing; A second forming die for reverse deep drawing; Liquid-filled bulging molds for use in liquid-filled bulging.

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