A bending die for processing aerospace parts

Abstract

This invention discloses a bending die for aerospace component processing, belonging to the field of parts processing technology. It achieves tube bending by driving the movable half-wheel of the bending mandrel assembly around a fixed wheel using a moving mold. Its core innovation lies in: utilizing a steel rope penetrating the tube body, combined with tension components and nitrogen spring components at both ends, to replace the traditional end thrust seal with a tension seal, significantly improving the flexibility and sealing stability of long tube processing. During bending, the inner lining ring on the steel rope gathers inward to form dense support, inhibiting material accumulation and thickening; simultaneously, the tension of the steel rope, linked to the compression of the nitrogen spring, drives the mandrel into the tube to adjust the internal oil pressure, achieving proportional control of internal pressure support and end extrusion pressure. Combined with radial pressure compensation from the external shaping mold core, this invention can effectively compensate for thinning of the outer wall thickness, solving the problems of cross-sectional instability and uneven wall thickness distribution, achieving high-precision forming of aerospace tubes.

Description

Technical Field

[0001] This invention relates to the field of parts processing technology, and in particular to bending dies for processing aerospace parts. Background Technology

[0002] In the field of precision forming of aerospace piping, metal tubes undergoing small-radius, multi-angle bending are typically formed using a rolling bending structure with fixed and movable wheels, supplemented by internal support structures or internal media to enhance resistance to instability. In practical applications, such as the fabrication of airborne hydraulic delivery lines or fuel distribution lines, the tubes not only need to complete complex bending paths within a limited space but also must ensure the cross-sectional integrity and wall thickness uniformity of the bending area to meet sealing and pressure-bearing requirements. While existing technologies can achieve basic bending forming, their precision control capabilities remain insufficient.

[0003] In traditional bending processes, the pipe wall is thickened during pipe manufacturing to ensure that the thickness of the thinned bending zone is sufficient for working strength. However, in the aerospace industry, the thickness of pipes and other workpieces is strictly controlled. Excessive thickness of components will increase weight and affect the overall thrust-to-weight ratio calculation.

[0004] In existing bending structures, the outer region of the tube is under tension and continuously thins during bending, while the inner region accumulates material and forms a thickened area due to compression. This thickened area is further amplified during subsequent bending, altering the local curvature and causing deviations in the bending trajectory and cross-section roundness. Current technology lacks a structural means to synchronously suppress the thickening trend of the inner side as the bending angle changes, resulting in uncontrolled material flow. Simultaneously, axial elongation is inevitable during tube bending. In existing solutions, this elongation is mostly left uncontrolled or only rigidly constrained, failing to effectively couple and regulate the inner thickening. This results in insufficient material compensation for the outer thinning, leading to localized excessive thinning or even structural failure during small-radius bending. Summary of the Invention

[0005] The purpose of this invention is to provide a bending die for aerospace parts processing, in order to solve the problem that traditional bending methods are not applicable to high-precision production requirements.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a bending die for processing aerospace parts, comprising a bending assembly and a bending auxiliary tool, wherein the bending assembly includes two symmetrically fixed fixed dies, and a bending mandrel assembly is installed between the two fixed dies, and a moving die that pushes the bending mandrel assembly to operate is limited and slidably mounted on one side of the fixed die; Two symmetrical fixed molds clamp and limit the sliding of the moving mold within them. The moving mold includes a hydraulic frame that slides on the inner wall of the fixed mold. A shaping hydraulic rod is fixed on the hydraulic frame, and a telescopic frame that slides on the end of the hydraulic frame is fixed at the end of the shaping hydraulic rod. A mounting base is fixed on the telescopic frame, and a shaping mold core is quickly installed on the mounting base. Guide posts are fixed on both sides of the hydraulic frame, and the guide posts pass through and rotate at the end of the deflection plate. When the movable half-wheel cooperates with the fixed wheel to bend the tube to a predetermined angle, the shaping mold core conforms to the outer bending area of ​​the tube under the pressure of the shaping hydraulic rod.

[0007] Specifically, the fixed mold includes a positioning mold body, which has a groove and an arc-shaped guide hole for reinforcing the sliding of the shaft. A straight guide hole for the sliding of the guide post is provided on one side of the groove, and a slide rail for the sliding of the hydraulic frame is provided on the positioning mold body.

[0008] One side of the positioning module is fixed with a clamping slide for mounting a hydraulic frame by bolts. The clamping slide is used to maintain stable guidance for the hydraulic movement of the hydraulic frame.

[0009] Furthermore, the bending mandrel assembly includes a fixed wheel and two movable half-wheels that move around the arcuate trajectory of the fixed wheel, as well as a deflection plate that connects to the moving mold; Furthermore, the bending mandrel assembly includes a circumferential frame movably connected to both ends of the fixed wheel, and one end of the circumferential frame is rotatably connected to the end of the corresponding movable half wheel. The movable half wheel meshes with the fixed wheel, and a deflection plate that is initially inclined is rotatably installed at the end of the movable half wheel. When the deflection plate is pressed, it moves the movable half wheel along the arc-shaped trajectory of meshing with the fixed wheel, and deflects synchronously with the displacement of the arc-shaped trajectory.

[0010] Preferably, the movable half-wheel includes a semi-circular wheel body, and the arc-shaped sidewall of the semi-circular wheel body is provided with a forming groove that conforms to the roundness of the tube body. Both sides of the semi-circular wheel body are provided with meshing parts. One end of the semi-circular wheel body is provided with a reinforcing shaft that slides on the circumferential frame and the deflection plate, and the two reinforcing shafts are located on the same axis.

[0011] As a further description of the bending aid in the above scheme, the bending aid includes a steel rope passing through the tube body and a tension assembly and a nitrogen spring assembly installed at both ends of the steel rope. The nitrogen spring assembly is sealed at one end of the tube body, and the tension assembly pulls the nitrogen spring assembly through the steel rope to press the quick-release cap at the other end of the tube body. Preferably, the nitrogen spring assembly includes a first sealing seat that is pressure-sealed and fitted to one end of the tube, and a housing is fixed on the first sealing seat. The inner wall of the first sealing seat is sealed through a core, and a piston is fixed at the top of the core. A rope seat is threaded onto the inner wall of the core. The top of the steel rope passes through the rope seat and is fixed by a clamp. A pressure regulating interface and a pressure gauge are respectively provided on both sides of the housing. In this process, the tension of the steel rope acts directly on the core and piston to slide. The piston compresses the nitrogen gas and moves, causing the core to extend into the tube at different lengths, which increases the internal pressure as the pressure increases. At the same time, the tension is transmitted to the first sealing seat through the piston and nitrogen compression, which is converted into pressure to hold one end of the tube. This results in the tube end pressure being proportionally adjusted to the internal oil pressure. The amount of nitrogen is controlled through the pressure regulating interface to adjust the specific ratio between the tube end pressure and the internal oil pressure.

[0012] Based on the above scheme, the tension component further includes a tightening structure that uses leverage to mechanically wind up the steel rope, and a reaction frame that presses against the quick-release end cap slides on the tightening structure to form a clamping force between the two ends of the steel rope on the nitrogen spring assembly and the quick-release end cap, thereby sealing the oil in the pipe. It also includes an internal pressure adjusting rod that lifts the reaction frame and slides relative to the tightening structure to adjust the internal pressure and the extrusion pressure at both ends of the pipe. For easy disassembly and assembly, a quick-release end cap is designed at one end, which includes a second sealing seat that is sealed and fitted to one end of the tube body. A conical sealing core block slides on the inner wall of the second sealing seat. The inner wall of the second sealing seat is conical, and control interfaces for draining or replenishing liquid are provided on both sides of the second sealing seat.

[0013] The reaction frame includes a support frame body fitted into the end of the quick-release end cap, and the support frame body has a second sliding hole. Two sliders are symmetrically fixed at both ends of the support frame body, and the end of the internal pressure adjusting rod is fixed through the support frame body.

[0014] The tightening structure includes an outer slide that slides on the outside of the support frame. The outer slide has first sliding holes on both sides for sliding with the slider. A take-up shaft is rotatably mounted at the end of the outer slide, and a one-way ratchet is mounted at one end of the take-up shaft. A buckle that engages with the one-way ratchet is rotatably mounted on the outer slide. The take-up shaft slides through the second sliding hole. The telescopic end of the inner pressure adjusting rod is fixed on the outer slide.

[0015] The steel rope has multiple inner lining rings distributed in the bending area of ​​the tube body for limiting sliding; When the moving mold pushes the bending mandrel assembly to bend the tube, the distance between the edges of the inner lining ring towards the inner bending area of ​​the tube continuously decreases, forming dense support with the fixed wheel, and keeping the steel rope on the axis of the tube. Based on the tension of the steel rope, the length of both ends of the tube remains constant, and based on the internal pressure support of the tube, the change in the length of the tube is squeezed to compensate for the bending of the outer area of ​​the tube.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: This solution utilizes the hydraulic frame of the moving mold to synchronously press two movable half-wheels onto the side of the fixed wheel, causing them to deflect. This allows the pipe body clamped between the two movable half-wheels and the fixed wheel to be bent. During the bending process, the two movable half-wheels move synchronously and roll against the pipe body. Combined with the immovable fixed wheel, this allows for a non-destructive bending operation at any angle on the pipe surface. After bending to the predetermined angle, the shaping hydraulic rod, through the telescopic frame, carries the shaping mold core to shape the outer area of ​​the pipe body in conjunction with the clamping of the fixed wheel. Overall, this achieves non-destructive bending of the pipe to shape and reinforce weak areas, and combined with internal pressure within the pipe body, it achieves the shaping of the weak areas. During the bending process, the tube's length is maintained by the tension of the steel rope at both ends. During bending, the tube's bending elongation is compressed by the steel rope through the nitrogen spring assembly and quick-release end cap. Combined with the dense support and fit of the inner lining ring on the thickened inner side of the tube, the bent, taut steel rope applies pressure. This pressure, combined with the fixed wheel, holds the thickened inner side of the tube in place. As the bending angle increases, the pressure on the thickened area increases proportionally to the thickness increase, preventing further thickness buildup. Combined with the compression at both ends, the collapsed length compensates for the thinned outer side of the tube, ensuring the thinned area... When the moving mold pushes the bending core mold assembly to bend the tube, the distance between the edges of the inner lining ring towards the inner bending area of ​​the tube continuously decreases, forming dense support with the fixed wheel and keeping the steel rope on the tube axis. Based on the tension of the steel rope, the length of both ends of the tube is kept constant. Based on the internal pressure support of the tube, the change in tube length is squeezed to compensate for the bending of the outer area of ​​the tube. With the support of the shaping core outside the thinning area, the thickness of the tube is compensated during bending under the internal pressure, external pressure and the compression of both ends, and the shape is stabilized. This solution also tightens the steel rope using a tightening structure. The internal pressure adjusting rod extends and retracts, causing the tightening structure to slide and displace on the reaction frame. This tension acts on the nitrogen spring assembly, compressing one end of the tube. Meanwhile, the reaction force of the shaping hydraulic rod acts on the quick-release end cap, applying pressure to the other end of the tube. This creates a compressive force at both ends of the tube. The core of the nitrogen spring assembly, carrying a piston, compresses nitrogen. This compression force acts directly on one end of the tube. The sliding amount of the core, besides being related to the pressure at the tube end, also directly compresses the oil inside the tube, achieving synchronous control of the tube end pressure and internal pressure. Based on changes in tube thickness and material, the initial nitrogen pressure can be adjusted via a pressure regulating interface combined with a pressure gauge, thereby adjusting the ratio of internal pressure to end pressure. This method simultaneously achieves proportional increases and decreases in end pressure and internal pressure while also adjusting their ratio, enabling precise control of the processing. Furthermore, the combined internal and end pressures shape a well-formed tube, preventing deformation.

[0017] In summary, this solution addresses the problems of easy deformation during pipe bending, changes in pipe length, large thickness differences between the inner and outer bending areas, and easy damage during bending. Attached Figure Description

[0018] Figure 1 A front view schematic diagram according to the present invention is shown; Figure 2 A three-dimensional schematic diagram according to the present invention is shown; Figure 3 An explosion diagram according to the present invention is shown; Figure 4 A three-dimensional schematic diagram of the moving mold according to the present invention is shown; Figure 5 A three-dimensional schematic diagram of the movable half-wheel according to the present invention is shown; Figure 6 A schematic diagram of the bending state of the bending mandrel assembly according to the present invention is shown; Figure 7 A schematic diagram showing the before and after bending according to the present invention is provided; Figure 8 A cross-sectional schematic diagram of the bending aid according to the present invention is shown; Figure 9 A cross-sectional schematic diagram of a nitrogen spring assembly according to the present invention is shown; Figure 10 A three-dimensional schematic diagram of the tension assembly according to the present invention is shown; Figure 11 A three-dimensional cross-sectional schematic diagram of the quick-release end cap according to the present invention is shown; Figure 12 An explosion schematic diagram of a nitrogen spring assembly according to the present invention is shown.

[0019] Legend: 1. Bending components; 11. Fixed mold; 111. Positioning mold body; 112. Groove; 113. Arc-shaped guide hole; 114. Straight guide hole; 115. Slide rail; 12. Moving mold; 121. Hydraulic frame; 122. Guide pillar; 123. Telescopic frame; 124. Shaping hydraulic rod; 125. Mounting base; 126. Shaping mold core; 13. Bending mandrel assembly; 131. Fixed wheel; 132. Movable half-wheel; 1321. Semi-circular wheel body; 1322. Engaging part; 1323. Forming groove; 1324. Reinforcing shaft; 133. Circumferential frame; 134. Deflection plate; 2. Bending aids; 21. Tension assembly; 211. Tightening structure; 2111. Outer slide; 2112. Rewind shaft; 2113. One-way ratchet; 2114. Buckle; 2115. First sliding hole; 212. Reaction frame; 2121. Support frame; 2122. Slider; 2123. Second sliding hole; 213. Internal pressure adjusting rod; 22. Steel rope; 23. Nitrogen spring assembly; 231. Core; 232. Piston; 233. Rope seat; 234. Housing; 235. First sealing seat; 236. Pressure regulating port; 237. Pressure gauge; 24. Quick-release end cap; 241. Second sealing seat; 242. Sealing core block; 3. Clamping slide; 4. Tube body; 5. Inner liner ring. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] During the bending process of the existing tube body 4, the inner material is compressed and thickens, which accumulates and amplifies with the bending angle. The outer material is continuously stretched and undergoes irreversible thinning. At the same time, the axial elongation is in an ineffective or rigidly limited state. There is a lack of linkage and control among the three, which leads to material flow imbalance and the inability to achieve directional compensation to the outer thinning area. In addition, the internal pressure and the force at the end of the tube body 4 are independent of each other and cannot be matched and adjusted with the bending process. This results in the support strength being inconsistent with the actual deformation stage, ultimately causing instability of the cross section in the bending area, uneven wall thickness distribution, and difficulty in controlling the shape accuracy.

[0022] Traditional end pressurization and end sealing using thrust require the bending direction of the pipe body 4 to change accordingly, which demands extremely high precision. In order to achieve the change of thrust direction along the bending direction, it often requires a great deal of cost to achieve the required precision, and it is difficult to apply to the end sealing of longer pipe bodies 4.

[0023] The tensile method adopted in this solution is applicable to both ends of the pipe when bent in any section of the pipe body. Compared with the traditional thrust sealing at both ends, it has extremely high flexibility and greatly reduces the structural complexity.

[0024] like Figures 1-12As shown, the present invention provides a bending die for processing aerospace parts, which consists of a bending assembly 1 and a bending auxiliary tool 2. The bending assembly 1 includes two symmetrically fixed fixed dies 11, and a bending mandrel assembly 13 is installed between the two fixed dies 11. A moving die 12 that pushes the bending mandrel assembly 13 to operate is limited and slidably mounted on one side of the fixed die 11. The two fixed dies 11 form a double-sided limiting guide for the moving die 12, so that the moving die 12 moves stably only along a predetermined straight trajectory, avoiding the deviation of the bending trajectory caused by off-center operation.

[0025] Two symmetrical fixed molds 11 clamp and limit the sliding of the moving mold 12 within them. The moving mold 12 includes a hydraulic frame 121 that slides on the inner wall of the fixed mold 11. A shaping hydraulic rod 124 is fixed on the hydraulic frame 121, and a telescopic frame 123 that slides on the end of the hydraulic frame 121 is fixed at the end of the shaping hydraulic rod 124. A mounting base 125 is fixed on the telescopic frame 123, and a shaping mold core 126 is quickly installed on the mounting base 125. Through the axial extension and retraction of the telescopic frame 123, the shaping mold core 126 can be radially fitted to the outer region of the tube body 4 after bending, thereby achieving directional pressing and contour correction of the thinned area. Guide posts 122 are fixed on both sides of the hydraulic frame 121. The guide posts 122 rotate through the end of the deflection plate 134. The movable half wheel 132 cooperates with the fixed wheel 131 to bend the tube body 4 to a predetermined angle. The shaping mold core 126 fits the outer bending area of ​​the tube body 4 under the pressure of the shaping hydraulic rod 124.

[0026] Its guide post 122 rotates through the end of the deflection plate 134, so that the linear motion of the hydraulic frame 121 is converted into the pressure drive of the deflection plate 134. After the movable half wheel 132 cooperates with the fixed wheel 131 to bend the tube body 4 to a predetermined angle, the shaping mold core 126 fits the outer bending area of ​​the tube body 4 under the pressure of the shaping hydraulic rod 124, realizing the continuous connection between bending and shaping.

[0027] Specifically, in combination Figure 3 As shown, the fixed mold 11 includes a positioning mold body 111, a groove 112 is provided on the positioning mold body 111, and an arc-shaped guide hole 113 for reinforcing the sliding of the shaft 1324 is provided in the groove 112 so that the movable half wheel 132 runs stably along a preset arc trajectory during the bending process.

[0028] A linear guide hole 114 for sliding of the guide post 122 is provided on one side of the groove 112, so that the guide post 122 maintains guiding constraint during the rotation of the deflection plate 134. The positioning mold 111 is provided with a slide rail 115 for the hydraulic frame 121 to slide, so as to ensure the precise linear feed of the hydraulic frame 121 under hydraulic pressure.

[0029] One side of the positioning module 111 is fixed with a clamping slide 3 for mounting the hydraulic frame 121 by bolts. The clamping slide 3 is used to maintain the stable guidance of the hydraulic movement of the hydraulic frame 121.

[0030] The clamping slide 3 forms a wrapping support guide with the hydraulic frame 121, so that it can maintain a stable posture when subjected to large hydraulic pressure, and avoid lateral swaying that affects the bending accuracy.

[0031] Furthermore, combined Figure 6 As shown, the bending mandrel assembly 13 includes a fixed wheel 131 and two movable half-wheels 132 that move around the arc trajectory of the fixed wheel 131, as well as a deflection plate 134 that connects to the moving mold 12. The two movable half-wheels 132 are symmetrically distributed and form a three-point clamp with the fixed wheel 131, so that the tube 4 is subjected to uniform force during the bending process. Furthermore, the bending mandrel assembly 13 includes a circumferential frame 133 movably connected to both ends of the fixed wheel 131, and one end of the circumferential frame 133 is rotatably connected to the end of the corresponding movable half wheel 132. The movable half wheel 132 meshes with the fixed wheel 131, and a deflection plate 134 initially inclined is rotatably installed at the end of the movable half wheel 132. When the deflection plate 134 is pressed, it moves the movable half wheel 132 along the arc trajectory of meshing with the fixed wheel 131, and deflects synchronously with the displacement of the arc trajectory.

[0032] When the deflector plate 134 is pressed, it moves along an arc-shaped trajectory with the movable half-wheel 132 engaging the fixed wheel 131, and deflects synchronously with the displacement of the arc-shaped trajectory, so that the linear drive is transformed into a stable arc-shaped enveloping motion, thereby ensuring the consistency of the trajectory during the continuous change of the bending angle.

[0033] The preferred movable half-wheel 132 includes a semi-circular wheel body 1321, and the arc-shaped sidewall of the semi-circular wheel body 1321 is provided with a forming groove 1323 that conforms to the roundness of the tube body 4. The forming groove 1323 covers and supports the outer wall of the tube body 4. Both sides of the semi-circular wheel body 1321 on the forming groove 1323 are provided with a meshing part 1322 for forming a stable meshing transmission with the fixed wheel 131. One end of the semi-circular wheel body 1321 is provided with a reinforcing shaft 1324 that slides on the circumferential frame 133 and the deflection plate 134, and the two reinforcing shafts 1324 are located on the same axis, so that the movable half-wheel 132 maintains axial stability under force and avoids swaying.

[0034] As a further description of the bending auxiliary tool 2 in the above scheme, the bending auxiliary tool 2 includes a steel rope 22 that passes through the tube body 4 and a tension assembly 21 and a nitrogen spring assembly 23 installed at both ends of the steel rope 22. The nitrogen spring assembly 23 is sealed at one end of the tube body 4, and the tension assembly 21 pulls the nitrogen spring assembly 23 through the steel rope 22 to press the quick-release end cap 24 at the other end of the tube body 4 with the reaction force. The tension assembly 21 pulls the nitrogen spring assembly 23 through the steel rope 22, and the reaction force presses the quick-release end cap 24 at the other end of the tube body 4, so that the two ends of the tube body 4 form an axial opposing compressive force and establish an internal pressure sealing environment.

[0035] Preferably, the nitrogen spring assembly 23 includes a first sealing seat 235 that is pressure-sealed and fitted to one end of the tube body 4, and a housing 234 is fixed on the first sealing seat 235. The inner wall of the first sealing seat 235 is sealed through a core 231, and a piston 232 is fixed to the top of the core 231. A rope seat 233 is threaded onto the inner wall of the core 231. The top of the steel rope 22 passes through the rope seat 233 and is fixed by a clamp. A pressure regulating interface 236 and a pressure gauge 237 are respectively provided on both sides of the housing 234. The axial linkage between the core 231 and the piston 232 converts the tension of the steel rope 22 into nitrogen compression force and forms elastic feedback. At the same time, the pressure regulating interface 236 can control the initial pressure of nitrogen inside the housing 234 according to the value of the pressure gauge 237. Meanwhile, the clamp is fixed to the top of the steel rope 22 to limit the rope seat 233 to seal the surface of the steel rope 22. The threaded engagement between the rope seat 233 and the core 231 achieves sealing while maintaining good synchronization. This structure is easy to disassemble and replace, which is beneficial for the replacement of the steel rope 22.

[0036] The tension of the steel rope 22 first acts directly on the sliding of the core 231 and the piston 232. The piston 232 compresses the nitrogen gas and moves, and the length of the core 231 extending into the tube 4 changes, causing its internal pressure to increase with the increase of pressure. At the same time, the tension is transmitted to the first sealing seat 235 through the piston 232 and the nitrogen gas compression, which is converted into pressure to hold one end of the tube 4, forming a proportional adjustment between the pressure at the end of the tube 4 and the internal pressure of the oil. The amount of nitrogen is controlled through the pressure regulating interface 236 to adjust the specific ratio between the pressure at the end of the tube 4 and the internal pressure of the oil.

[0037] The structure of the piston 232 compressing nitrogen gas forms the support of a traditional nitrogen spring, allowing the tension to be supported by nitrogen gas, creating an elastic holding force. Utilizing the compressibility of the gas, it provides a nearly constant tension within a certain stroke range. This ensures that regardless of changes in the bending angle, the axial locking force of the steel cable 22 on the tube 4 remains within a preset scientific range.

[0038] At the same time, it provides a flexible range. When the force exceeds the support of the steel rope 22 or the tube 4, it can provide a buffer through elastic support to avoid the steel rope 22 breaking or the tube 4 twisting, thus achieving a self-protection effect against misoperation.

[0039] Based on the above scheme, the tension component 21 further includes a tightening structure 211 that uses leverage to mechanically wind up the steel rope 22, and a reaction frame 212 that presses against the quick-release end cap 24 slides on the tightening structure 211, forming a clamping force between the two ends of the steel rope 22 on the nitrogen spring assembly 23 and the quick-release end cap 24, sealing the oil in the tube body 4. It also includes an internal pressure adjusting rod 213 that lifts the reaction frame 212 and slides relative to the tightening structure 211 to adjust the internal pressure and the pressure at both ends of the tube body 4. By using leverage-force mechanical winding, a large initial tension of the steel rope 22 can be generated with a small driving force. At the same time, the tension generated by the steel rope 22 is directly converted into positive pressure on the quick-release end cap 24 through the reaction frame 212, forming a closed loop where the higher the tension, the tighter the seal.

[0040] For easy disassembly and assembly, a quick-release end cap 24 is designed at one end, which includes a second sealing seat 241 that is sealed and fitted to one end of the tube body 4. A conical sealing core block 242 slides on the inner wall of the second sealing seat 241. The inner wall of the second sealing seat 241 is conical, and control interfaces for draining or replenishing liquid are provided on both sides of the second sealing seat 241.

[0041] The reaction frame 212 includes a support frame 2121 fitted into the end of the quick-release end cap 24, and the support frame 2121 is provided with a second sliding hole 2123. Two sliders 2122 are symmetrically fixed at both ends of the support frame 2121, and the end of the internal pressure adjusting rod 213 is fixed through the support frame 2121.

[0042] The tightening structure 211 includes an outer slide 2111 that slides on the outside of the support frame 2121. The outer slide 2111 has first sliding holes 2115 on both sides for sliding with the slider 2122. A winding shaft 2112 is rotatably mounted at the end of the outer slide 2111. A one-way ratchet 2113 is mounted at one end of the winding shaft 2112. A buckle 2114 that engages with the one-way ratchet 2113 is rotatably mounted on the outer slide 2111. The winding shaft 2112 slides through the second sliding hole 2123. The telescopic end of the inner pressure adjusting rod 213 is fixed on the outer slide 2111.

[0043] In addition to winding the steel rope 22, the rotating take-up shaft 2112 on the outer slide 2111 also slides in the second slide hole 2123. At the same time, the slider 2122 on the support frame 2121 slides in the first slide hole 2115, realizing the sliding of the slider 2122 and the take-up shaft 2112 towards each other, forming a stable telescopic mechanism controlled by the internal pressure adjusting rod 213.

[0044] The steel rope 22 has multiple inner lining rings 5 ​​distributed in the bending area of ​​the tube body 4. The inner lining rings 5 ​​are sleeved on the surface of the steel rope 22 and gradually gather inward as the bending occurs. The spacing between them decreases as the bending angle increases, and finally a continuous and dense support belt is formed on the inner side of the bend. Under the synergistic pressing action of the support belt and the fixed wheel 131, a stable constraint force is applied to the thickened area caused by the inner pressure, which suppresses the tendency of material to accumulate in the local area.

[0045] The steel rope 22 in the bending section is axially held by the inner lining ring 5. Combined with the supports at both ends, the steel rope 22 is in an axial position, which can meet the application of pipes 4 of different lengths.

[0046] The inner lining ring 5 forms radial support for the inner area when the steel rope 22 is taut, so that the cross section of the tube body 4 remains round and stable under pressure, avoiding wrinkling or collapse. At the same time, the inner lining ring 5 limits the steel rope 22 to always be located on the axis of the tube body 4, so that the axial tension can be evenly transmitted to the entire bending area, thereby ensuring the stability of the length constraint.

[0047] Combination Figure 8 It can be seen that when the moving mold 12 pushes the bending core mold assembly 13 to bend the tube 4, the distance between the inner lining ring 5 and the edge of the inner bending area of ​​the tube 4 continuously decreases, forming a dense support clamped by the fixed wheel 131, and keeping the steel rope 22 on the axis of the tube 4. Based on the tension of the steel rope 22, the length of both ends of the tube 4 is kept constant. Based on the internal pressure support of the tube 4, the change in the length of the tube 4 is squeezed to compensate for the bending of the outer area of ​​the tube 4.

[0048] Working principle: In this scheme, the tube body 4 passes through the fixed mold 11 and the bending core mold assembly 13, and then the steel rope 22 passes through the tube body 4. The nitrogen spring assembly 23 is attached to the tube body 4 at one end of the steel rope 22 through its first sealing assembly. After the steel rope 22 passes through the tube body 4, it is wound around the winding shaft 2112 of the tightening structure 211. Then, a wrench is inserted into one end of the winding shaft 2112 to make it rotate. The other end of the winding shaft 2112 rotates with the ratchet. Combined with the buckle 2114 on one side of the ratchet, it is limited to prevent rotation and achieves unidirectional winding to keep the steel rope 22 taut. The force of the taut steel rope 22 is applied to the support frame 2121 of the reaction frame 212 through the tightening structure 211, so that the support frame 2121 presses the sealing core block 242 of the quick-release sealing head 24. Under the pressure, the sealing core block 242 is squeezed into the second sealing seat 241 to keep the steel rope 22 in a sliding state of sealing. After sealing, connect the pressure regulating port 236 on one side of the nitrogen spring assembly 23 housing 234 to the pressure regulating machine. The pressure regulating machine has an air compressor for replenishing air, as well as a check valve and a pressure relief valve, which can control the increase, decrease and stabilize the internal air pressure of the nitrogen spring assembly 23. Then, by connecting the two control ports on the second sealing seat 241, one for exhaust and one for liquid inlet, the interior can be kept full of oil. After the above installation, the moving mold 12 is moved by hydraulic pressure. The hydraulic frame 121 of the moving mold 12 slides in the slide rail 115 of the positioning mold body 111 and is supported and guided by the two clamping slides 3. The hydraulic frame 121 pushes the deflection plates 134 at both ends to move. The deflection plates 134 are inclined. When moving, they press the corresponding movable half wheel 132 to engage the fixed wheel 131 to deflect and move. The deflection process relies on the deflection of the circumferential frame 133 held by the deflection plate 134 to maintain the stable engagement between the fixed wheel 131 and the movable half wheel 132 under the arc trajectory. During the bending process described above, the steel rope 22 remains taut. After reaching the predetermined bending angle, the shaping mold core 126, under the action of the telescopic frame 123 pushed by the shaping hydraulic rod 124, conforms to the weak area on the outer side of the tube body 4. At the same time, the relative sliding of the reaction frame 212 and the tightening structure 211 is controlled by the internal pressure adjusting rod 213 to adjust the tension of the steel rope 22. When the tension of the steel rope 22 changes, the rope seat 233, which is sealed and limited by the end clamp, moves. The core 231, which is threaded on the surface of the rope seat 233, can slide with the piston 232 inside the shell 234 and compress nitrogen. The pressure of the compressed nitrogen acts on the tube body 4 with elastic force, causing the tube body 4 to be subjected to a flexible compression. At the same time, the sliding core 231 enters the tube body 4, compressing the internal space of the tube body 4 and increasing the internal pressure. Under the support of the internal pressure of the oil, the two ends of the tube body 4 are squeezed and retracted to compensate for the extension of the bend. The internal pressure adjusting rod 213 is used for fine-tuning during the bending deformation stage, such as when stretching and thinning are about to occur, thereby achieving active control of the directional flow of material from the inner thickening area to the outer thinning area.

[0049] At the same time, as the steel rope 22 bends along with the pipe body 4, it combines... Figure 8 Multiple inner lining rings 5 ​​are limited by clamps on the steel rope 22. The inner lining rings 5 ​​overlap each other and have a fixed gap L2 on their outer edges. The fixed gap L2 is determined by the width L1 of the outer edge. In use, different specifications of inner lining rings 5 ​​are selected for the tube body 4 with different bending angles. The outer edge width L1 of the inner lining rings 5 ​​of different specifications is different. When the tube body 4 is bent, a dense fit is formed in the thickened area K2 of the tube body 4. Combined with the tension of the steel rope 22, a pressure is provided to tightly press the thickened area K2 onto the fixed wheel 131 to maintain the stability of the arc and avoid the continuous accumulation of thickness, thus maintaining a stable thickness. During the extrusion and retraction process of the extended amount of the above-mentioned tube body 4 bend, the thickened area K2 is held, and the retraction amount is compensated to the weak area K1, so that the K1 area is shaped and thickness compensated under the clamping of the fixed wheel 131 and the shaping mold core 126.

[0050] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A bending die for processing aerospace parts, comprising a bending assembly (1) for bending a tube body (4) and a bending fixture (2), characterized in that, The bending component (1) includes two symmetrically fixed fixed molds (11), and a bending core mold component (13) is installed between the two fixed molds (11). A moving mold (12) that pushes the bending core mold component (13) to operate is limited and slidable on one side of the fixed mold (11). The bending core mold assembly (13) includes a fixed wheel (131) and two movable half-wheels (132) that move around the arc trajectory of the fixed wheel (131), as well as a deflection plate (134) that connects to the moving mold (12). The bending aid (2) includes a steel rope (22) that passes through the tube (4) and a tension assembly (21) and a nitrogen spring assembly (23) installed at both ends of the steel rope (22). The nitrogen spring assembly (23) is sealed at one end of the tube (4), and the tension assembly (21) pulls the nitrogen spring assembly (23) through the steel rope (22) to press the quick-release cap (24) at the other end of the tube (4) with the reaction force. The steel rope (22) has multiple inner lining rings (5) distributed in the bending area of ​​the tube body (4) for limiting sliding. When the moving mold (12) pushes the bending core mold assembly (13) to bend the tube (4), the spacing of the inner lining ring (5) bending towards the inner area of ​​the tube (4) continuously decreases, forming a dense support that is clamped towards the fixed wheel (131), and keeping the steel rope (22) at the axis of the tube (4) to pull the two ends of the tube (4), and compensating the deformation length of the tube (4) towards the outer area of ​​the tube (4) under the internal pressure support environment.

2. The bending die for processing aerospace parts according to claim 1, characterized in that, The nitrogen spring assembly (23) includes a first sealing seat (235) that is pressure-sealed and fitted to one end of the tube body (4), and a housing (234) is fixed on the first sealing seat (235). The inner wall of the first sealing seat (235) is sealed through a core (231), and a piston (232) is fixed at the top of the core (231). A rope seat (233) is threaded onto the inner wall of the core (231), and the top of the steel rope (22) passes through the rope seat (233) and is fixed by a clamp. The housing (234) is provided with a pressure regulating port (236) and a pressure gauge (237) on both sides respectively. The tension of the steel rope (22) first acts directly on the core (231) and the piston (232) to slide. The piston (232) compresses the nitrogen gas and moves. The length of the core (231) extending into the tube (4) changes, so that its internal pressure increases with the increase of pressure. At the same time, the tension is transmitted to the first sealing seat (235) through the piston (232) and the nitrogen gas compression, so that it is converted into pressure to hold one end of the tube (4), forming a proportional adjustment between the pressure at the end of the tube (4) and the internal pressure of the oil. The amount of nitrogen gas is controlled through the pressure regulating interface (236) to adjust the specific ratio between the pressure at the end of the tube (4) and the internal pressure of the oil.

3. The bending die for processing aerospace parts according to claim 1, characterized in that, The tension assembly (21) includes a tightening structure (211) that uses leverage to mechanically wind up the steel rope (22), and a reaction frame (212) that presses against the quick-release end cap (24) slides on the tightening structure (211), forming a clamping force between the two ends of the steel rope (22) on the nitrogen spring assembly (23) and the quick-release end cap (24), sealing the oil inside the tube (4), and also includes an internal pressure adjusting rod (213) that slides relative to the lifting reaction frame (212) and the tightening structure (211) to adjust the internal pressure and the pressure at both ends of the tube (4).

4. The bending die for processing aerospace parts according to claim 3, characterized in that, The reaction frame (212) includes a support frame body (2121) fitted into the end of the quick-release end cap (24), and a second sliding hole (2123) is provided on the support frame body (2121). Two sliders (2122) are symmetrically fixed at both ends of the support frame body (2121), and the end of the internal pressure adjusting rod (213) is fixed through the support frame body (2121). The tightening structure (211) includes an outer slide (2111) that slides on the outside of the support frame (2121). The outer slide (2111) has first sliding holes (2115) on both sides for sliding with the slider (2122). A winding shaft (2112) is rotatably mounted on the end of the outer slide (2111), and a one-way ratchet (2113) is mounted on one end of the winding shaft (2112). A buckle (2114) that engages with the one-way ratchet (2113) is rotatably mounted on the outer slide (2111). The winding shaft (2112) slides through the second sliding hole (2123). The telescopic end of the inner pressure adjusting rod (213) is fixed on the outer slide (2111).

5. The bending die for processing aerospace parts according to claim 1, characterized in that, The bending core mold assembly (13) includes a circumferential frame (133) movably connected to both ends of the fixed wheel (131), and one end of the circumferential frame (133) is rotatably connected to the end of the corresponding movable half wheel (132). The movable half wheel (132) meshes with the fixed wheel (131). The end of the movable half wheel (132) is rotatably mounted with a deflection plate (134) that is initially inclined. When the deflection plate (134) is pressed, it moves the movable half wheel (132) along the arc trajectory of meshing with the fixed wheel (131), and deflects synchronously with the displacement of the arc trajectory.

6. The bending die for processing aerospace parts according to claim 5, characterized in that, The moving mold (12) includes a hydraulic frame (121) that slides on the inner wall of the fixed mold (11). A shaping hydraulic rod (124) is fixed on the hydraulic frame (121), and a telescopic frame (123) that slides on the end of the hydraulic frame (121) is fixed at the end of the shaping hydraulic rod (124). A mounting seat (125) is fixed on the telescopic frame (123), and a shaping mold core (126) is quickly installed on the mounting seat (125). Guide posts (122) are fixed on both sides of the hydraulic frame (121). The guide posts (122) pass through and rotate at the end of the deflection plate (134). The movable half wheel (132) cooperates with the fixed wheel (131) to bend the tube body (4) to a predetermined angle. The shaping mold core (126) fits the outer bending area of ​​the tube body (4) under the pressure of the shaping hydraulic rod (124).

7. The bending die for processing aerospace parts according to claim 6, characterized in that, The movable half-wheel (132) includes a semi-circular wheel body (1321), and the arc-shaped sidewall of the semi-circular wheel body (1321) is provided with a forming groove (1323) that fits the roundness of the tube body (4). The semi-circular wheel body (1321) on both sides of the forming groove (1323) is provided with a meshing part (1322). One end of the semi-circular wheel body (1321) is provided with a reinforcing shaft (1324) that slides on the circumferential frame (133) and the deflection plate (134), and the two reinforcing shafts (1324) are located on the same axis.

8. The bending die for processing aerospace parts according to claim 7, characterized in that, The fixed mold (11) includes a positioning mold body (111), a groove (112) is provided on the positioning mold body (111), and an arc-shaped guide hole (113) for sliding of the reinforcing shaft (1324) is provided in the groove (112). A straight guide hole (114) for sliding of the guide post (122) is provided on one side of the groove (112). A slide rail (115) for sliding of the hydraulic frame (121) is provided on the positioning mold body (111).

9. The bending die for processing aerospace parts according to claim 8, characterized in that, One side of the positioning module (111) is fixed with a clamping slide (3) for mounting the hydraulic frame (121) by bolts. The clamping slide (3) is used to maintain the stable guidance of the hydraulic movement of the hydraulic frame (121).

10. The bending die for processing aerospace parts according to claim 1, characterized in that, The quick-release cap (24) includes a second sealing seat (241) that is sealed and fitted to one end of the tube body (4), and a conical sealing core block (242) slides on the inner wall of the second sealing seat (241). The inner wall of the second sealing seat (241) is conical, and control interfaces for draining or replenishing liquid are provided on both sides of the second sealing seat (241).

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