Device for forming corrugated pipe through high-pressure water expansion
Through the modular design of the high-pressure water expansion forming device, the full-process automated forming of large-size bellows is achieved, which solves the problems of insufficient forming capacity and low precision in the existing technology, improves production efficiency and forming accuracy, and is suitable for the manufacture of high-precision bellows in fields such as aerospace.
Patent Information
- Application Number
- CN202521990864.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-16
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2035-09-16
AI Technical Summary
The existing technology in the manufacture of large-size bellows has problems such as insufficient forming capacity, low level of process automation, sealing system reliability defects and mold structure limitations, resulting in low production efficiency and low forming accuracy, which makes it difficult to meet the high-precision requirements of aerospace and other fields.
The modular high-pressure water expansion forming device, including a workbench, an adjustment platform, upper and lower plugging cover assemblies, an expansion die assembly and an insert die assembly, realizes the full-process automated forming of pipe fittings. The synchronous opening and closing of the mold is achieved through electric push rods and hydraulic control, and the flexible chain and support ring are used for collaborative forming to ensure the high precision and stability of the corrugated pipe.
The full-process automated production of bellows has been achieved, which significantly improves processing efficiency and forming accuracy. It is capable of processing complex and special-shaped structures, meeting the high-precision requirements of large-size bellows, reducing labor costs and improving the fatigue life and compressive strength of products.
Smart Images
Figure CN223476030U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of corrugated pipe forming equipment, specifically relating to a device for high-pressure water expansion forming of corrugated pipes. Background Technology
[0002] A metal bellows is a tubular component with a continuous corrugated cross-section. Its unique corrugated structure endows the pipe with excellent axial compensation, sealing performance, and vibration damping effect—characteristics that straight-walled pipes and traditional metal hoses cannot achieve. Due to its high reliability requirements, metal bellows have been widely used in cutting-edge fields such as aerospace, deep space exploration equipment, and marine engineering.
[0003] In the manufacturing of small and medium-sized thin-walled corrugated pipes, hydraulic expansion forming technology dominates due to its advantages such as simplified process chain, high efficiency and stability, and convenient operation. However, with the increasing market demand for larger, higher-precision corrugated pipes, the core technological bottlenecks facing this process are becoming increasingly prominent:
[0004] (1) The forming capacity of large-size components is insufficient. The traditional hydraulic expansion process can only achieve single-wave sequential forming, which is difficult to meet the one-time integral forming requirement of large-size bellows.
[0005] (2) The level of process automation is low. Mold positioning / disassembly depends on manual operation, and the dimensions need to be measured manually frequently after forming, which significantly restricts production efficiency and increases labor costs.
[0006] (3) Defects in the reliability of the sealing system: The three-lobe locking structure has insufficient sealing performance, which can easily cause pressure fluctuations and liquid leakage during processing, resulting in inaccurate bellows dimensions.
[0007] (4) The inherent limitations of the mold structure and the semi-cylindrical opening and closing outer cover design make it difficult to suppress the coaxiality deviation of the molded parts.
[0008] The aforementioned bottlenecks severely hinder the large-scale and stable mass production of high-precision, large-size corrugated pipes, especially in fields such as aerospace, where they directly restrict the reliability of core performance indicators such as fatigue life and pressure resistance. Therefore, there is an urgent need to develop a corrugated pipe forming equipment with a combination of high-pressure water expansion and axial compression forming, and an innovative billet sealing structure, to achieve full automation of the corrugated pipe (diameter ≤ 800mm, length ≤ 1000mm) manufacturing process, thereby improving production efficiency and forming accuracy. Utility Model Content
[0009] The main purpose of this invention is to overcome the shortcomings of the prior art and provide a device for high-pressure water expansion forming of corrugated pipes.
[0010] This utility model is achieved through the following technical solution: a device for high-pressure water expansion forming of corrugated pipe, including a worktable, an adjustment platform, an upper plug, a lower plug assembly, an expansion mold assembly, and an insert mold assembly, wherein the adjustment platform is fixedly arranged above the middle of the worktable, the expansion mold assembly is movably installed between the adjustment platform and the worktable, and the insert mold assemblies are movably installed on the left and right sides of the worktable respectively, and the expansion mold assembly and the insert mold assembly open or close synchronously relative to the center of the worktable;
[0011] The workbench is provided with an expansion hole in the center and a blind hole coaxial with the expansion hole on the upper surface of the workbench. The lower plug assembly includes a hoop and an expansion plug. The expansion plug is inserted into the expansion hole from bottom to top, and the hoop is locked in the blind hole. The pipe wall at the lower end of the pipe to be formed is pressed between the expansion plug and the hoop. The water pipe passes through the expansion plug and communicates with the inner cavity of the pipe to be formed. The upper plug is provided at the upper end of the pipe to be formed, and a pressure head is provided above the upper plug.
[0012] The insert mold assembly includes a movable column and insert modules. The free end of the insert module is set in a wedge shape, and the end of the free end of the insert module is provided with a cylindrical relief groove. The insert modules are installed at equal intervals on the side wall of the movable column near the expansion mold assembly, and an insert groove is set between adjacent insert modules.
[0013] The adjustment platform has a through hole in its center. The upper part of the tube to be formed is inserted into the through hole. Four guide slots are symmetrically arranged around the through hole about the center. Electric push rods are respectively arranged on the adjustment platform outside the four guide slots. The end of the electric push rod is connected to the base of the electric telescopic rod. The electric telescopic rod passes vertically downward through the corresponding guide slot.
[0014] The expansion mold assembly includes forming mold pieces, flexible chains, and support rings. Each forming mold piece consists of a set of symmetrically arranged forming mold piece units, with the core of each set of forming mold piece units forming a forming hole. Each support ring consists of two symmetrically arranged semi-circular support rings, which are fixedly mounted on the upper surface of the corresponding forming mold piece unit. In the initial state, several forming mold pieces are stacked sequentially, and the edges of adjacent forming mold pieces are movably connected by flexible chains of equal length. The lower end of the electric telescopic rod is fixedly connected to the uppermost forming mold piece. When the electric telescopic rod retracts upward to a predetermined height, the forming mold pieces unfold sequentially from top to bottom in the vertical direction, with each section of the flexible chain in a naturally drooping state. At the same time, the electric push rod drives the electric telescopic rod to close the forming mold piece units to form the forming mold piece. The outer wall of the tube to be formed contacts the inner wall of the forming hole, the insert mold assembly closes, and the outer edge of the forming mold piece unit is inserted into the corresponding insert slot.
[0015] Furthermore, the height of the support ring is set according to the spacing of the troughs of the pipe to be formed.
[0016] Furthermore, the outer diameter of the upper plug is smaller than the inner diameter of the support ring when the mold is closed.
[0017] The beneficial effects of this utility model are as follows:
[0018] 1) This utility model realizes fully automated production from clamping, forming to demolding, and its processing efficiency is significantly better than that of traditional hydraulic expansion forming equipment. The equipment adopts a modular design and can customize expansion mold components and insert mold components according to the specifications of the corrugated pipe, realizing efficient one-time forming and significantly saving labor and time costs.
[0019] 2) The formed bellows exhibit excellent dimensional accuracy, with both bellows height tolerance and cumulative pitch error controlled at a high level. The surface quality is good, free from mechanical damage, and easy to polish. The equipment has the capability to form complex irregular structures, processing asymmetrical waveforms and variable pitch structures. It automatically sets the system and pressing position through the forming procedure, and uses closed-loop control to optimize hydraulic parameters and water pressure curves in real time, ensuring forming stability. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the initial state front view sectional structure of this utility model;
[0021] Figure 2 This is a schematic diagram of the main sectional view of the expansion mold assembly;
[0022] Figure 3 This is a side view of the insert module structure.
[0023] Figure 4 This is a schematic diagram of the main cross-sectional view of the hydraulic expansion forming process of this utility model;
[0024] Figure 5 This is a schematic diagram of the main cross-sectional structure of the hydraulic compression forming process of this utility model.
[0025] In the diagram, 1 is the workbench, 2 is the movable column, 3 is the insert module, 4 is the adjustment platform, 5 is the electric push rod, 6 is the electric telescopic rod, 7 is the pipe to be formed, 8 is the guide groove, 9 is the insert groove, 10 is the forming mold, 11 is the flexible chain, 12 is the support ring, 13 is the hoop ring, 14 is the expansion plug, 15 is the water pipe, and 16 is the upper plug. Detailed Implementation
[0026] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.
[0027] like Figures 1 to 3The device shown is for high-pressure water expansion forming of corrugated pipes, including a worktable 1, an adjustment platform 4, an upper plug 16, a lower plug assembly, an expansion mold assembly, and an insert mold assembly. The adjustment platform 4 is fixedly arranged above the middle of the worktable 1. For example, the adjustment platform 4 can be fixedly installed above the worktable 1 by means of a column (not shown in the figure). The expansion mold assembly is movably installed between the adjustment platform 4 and the worktable 1. The insert mold assemblies are movably installed on the left and right sides of the worktable 1, respectively. The expansion mold assembly and the insert mold assembly open or close synchronously with respect to the center of the worktable 1.
[0028] The workbench 1 is provided with an expansion hole in the center and a blind hole coaxial with the expansion hole is provided on the upper surface of the workbench 1. The lower plug assembly includes a hoop 13 and an expansion plug 14. The expansion plug 14 is inserted into the expansion hole from bottom to top, and the hoop 13 is locked in the blind hole. The pipe wall at the lower end of the pipe to be formed 7 is pressed between the expansion plug 14 and the hoop 13. The water pipe 15 passes through the expansion plug and communicates with the inner cavity of the pipe to be formed 7. The upper plug 16 is provided at the upper end of the pipe to be formed 7, and a pressure head is provided above the upper plug 16.
[0029] The insert mold assembly includes a movable column 2 and insert modules 3. The free end of the insert module 3 is wedge-shaped, and the end of the free end of the insert module 3 is provided with a cylindrical relief groove. The insert modules 3 are installed at equal intervals on the side wall of the movable column 2 near the expansion mold assembly. An insert groove 9 is provided between adjacent insert modules 3. In this specific embodiment, the movable column 2 is synchronously driven by a motor, hydraulic cylinder or electric cylinder (not shown in the figure) to drive the insert modules 3 to synchronously open or close the mold along the worktable 1.
[0030] The adjustment platform 4 has a through hole in its center. The upper part of the tube to be formed 7 is inserted into the through hole. Four guide slots 8 are symmetrically arranged around the through hole about the center. Electric push rods 5 are respectively arranged on the adjustment platform 4 on the outside of the four guide slots 8. The end of the electric push rod 5 is connected to the base of the electric telescopic rod 6. The electric telescopic rod 6 penetrates vertically downward through the corresponding guide slot 8.
[0031] The expansion mold assembly includes forming mold pieces 10, flexible chains 11, and support rings 12. Each forming mold piece 10 is composed of a set of symmetrically arranged forming mold pieces, and the core of each set of forming mold pieces forms a forming hole. Each support ring 12 is composed of two symmetrically arranged semi-circular support rings, which are fixedly set on the upper surface of the corresponding forming mold pieces. In the initial state, several forming mold pieces 10 are stacked sequentially, and the edges of adjacent forming mold pieces 10 are movably connected by flexible chains 11 of equal length. The lower end of the electric telescopic rod 6 is fixedly connected to the uppermost forming mold piece 10. When the electric telescopic rod 6 retracts upward to a predetermined height, the forming mold pieces 10 unfold sequentially from top to bottom in the vertical direction. Each section of the flexible chain 11 is in a naturally drooping state. At the same time, the electric push rod 5 drives the electric telescopic rod 6 to close the forming mold pieces to form the forming mold pieces. The outer wall of the tube to be formed 7 contacts the inner wall of the forming hole, the insert mold assembly closes, and the outer edge of the forming mold piece is inserted into the corresponding insert slot 9.
[0032] Furthermore, the height of the support ring 12 is set according to the spacing of the troughs of the tube to be formed 7.
[0033] Furthermore, the outer diameter of the upper cover 16 is smaller than the inner diameter of the support ring 12 when the mold is closed.
[0034] The usage process of this utility model is as follows:
[0035] S1, Pre-assembled tubular fittings to be formed 7: Initial state as follows Figure 1 As shown, both the insert mold assembly and the expansion mold assembly are in the open state, that is, the forming mold unit and the semi-circular support ring are in the open state, and the forming mold units are stacked on the workbench 1 from bottom to top. The flexible chain 11 is in a naturally curled state because it is not under force. At this time, the tube to be formed 7 is inserted into the blind hole of the workbench 1 from top to bottom through the through hole. The expansion plug 14 with water pipe 15 is inserted into the expansion hole from bottom to top, so that the top of the expansion plug 14 extends into the inner cavity of the tube to be formed 7, and the water pipe 15 is connected to the inner cavity of the tube to be formed 7. Finally, the clamping ring 13 is installed in the blind hole from top to bottom. The inner wall of the clamping ring 13 presses the lower end of the tube to be formed 7 against the outer wall of the expansion plug 14. The upper plug 16 is installed on the upper end of the tube to be formed 7.
[0036] S2, Compression mold assembly closing: such as Figure 4As shown, on the one hand, the four electric telescopic rods 6 synchronously retract upward to a predetermined height, and the forming mold 10 unfolds from top to bottom in the vertical direction, with each section of the flexible chain 11 in a natural drooping state; on the other hand, the four electric push rods 5 synchronously push the electric telescopic rods 6 along the guide groove toward the tube to be formed 7, so that the forming mold 10 is assembled into the forming mold 10 (used to form the trough of the corrugated pipe during the expansion forming process), and the inner circular surface of the forming mold 10 contacts the outer wall of the tube to be formed 7, completing the mold closing of the expansion mold assembly;
[0037] S3, Mold closing of insert mold assembly: such as Figure 4 As shown, the two insert mold assemblies simultaneously close inward until the outer edge of the forming mold piece 10 is inserted into the corresponding insert slot 9, thus completing the mold closing of the insert mold assembly;
[0038] S4. Radial hydraulic expansion forming and axial compression forming: Water is filled into the inner cavity of the pipe to be formed 7 through water pipe 15. Then, the upper plug 16 is installed on the upper end of the pipe to be formed 7. Finally, high-pressure water is continuously filled and pressure is maintained for a period of time. The pipe to be formed 7 at the position of forming mold 10 forms a trough, and the diameter of the pipe to be formed 7 between forming mold 10s becomes thicker, completing the radial hydraulic expansion forming and obtaining the corrugated pipe blank; Next, as Figure 5 As shown, in the reverse operation steps S2 and S3, after the expansion mold assembly and the insert mold assembly are opened, the pressure head applies downward force until the forming mold 10 is pressed tightly. In this state, the support ring 12 plays a supporting and limiting role. The height of the support ring 12 is the spacing between the troughs of the corrugated pipe 7 to be formed. After holding the pressure for a period of time, the pressure head releases the force upward, and the axial compression forming of the corrugated pipe blank is completed, and the corrugated pipe is obtained.
[0039] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.
Claims
1. An apparatus for high-pressure water-expanding corrugated pipe forming, comprising a worktable (1), an adjustment platform (4), an upper plug (16), a lower plug assembly, an expansion mold assembly, and an insert mold assembly, characterized in that, The adjustment platform (4) is fixedly set above the middle part of the workbench (1). The expansion mold assembly is movably installed between the adjustment platform (4) and the workbench (1). The insert mold assembly is movably installed on the left and right sides of the workbench (1). The expansion mold assembly and the insert mold assembly open or close the mold synchronously relative to the center of the workbench (1). The workbench (1) is provided with an expansion hole in the center and a blind hole coaxial with the expansion hole is provided on the upper surface of the workbench (1). The lower plug assembly includes a hoop (13) and an expansion plug (14). The expansion plug (14) is inserted into the expansion hole from bottom to top, and the hoop (13) is clamped in the blind hole. The pipe wall at the lower end of the pipe to be formed (7) is pressed between the expansion plug (14) and the hoop (13). The water pipe (15) passes through the expansion plug and communicates with the inner cavity of the pipe to be formed (7). The upper plug (16) is provided at the upper end of the pipe to be formed (7), and a pressure head is provided above the upper plug (16). The insert mold assembly includes a movable column (2) and insert modules (3). The free end of the insert module (3) is set in a wedge shape. The end of the free end of the insert module (3) is provided with a cylindrical relief groove. The insert modules (3) are installed at equal intervals on the side wall of the movable column (2) near the expansion mold assembly. The insert slots (9) are set between adjacent insert modules (3). The adjustment platform (4) has a through hole in its center. The upper part of the tube to be formed (7) is inserted into the through hole. Four guide slots (8) are symmetrically arranged around the through hole about the center. Electric push rods (5) are respectively arranged on the adjustment platform (4) on the outside of the four guide slots (8). The end of the electric push rod (5) is connected to the base of the electric telescopic rod (6). The electric telescopic rod (6) passes vertically downward through the corresponding guide slot (8). The expansion mold assembly includes forming mold pieces (10), flexible chains (11), and support rings (12). Each forming mold piece (10) is composed of a set of symmetrically arranged forming mold pieces, and the core of each set of forming mold pieces forms a forming hole. Each support ring (12) is composed of two symmetrically arranged semi-circular support rings, which are respectively fixedly disposed on the upper surface of the corresponding forming mold piece. In the initial state, several forming mold pieces (10) are stacked sequentially, and the edges of adjacent forming mold pieces (10) are connected by flexible chains (11) of equal length. The lower end of the electric telescopic rod (6) is fixedly connected to the uppermost forming mold (10). When the electric telescopic rod (6) retracts upward to a predetermined height, the forming mold (10) unfolds from top to bottom in the vertical direction. Each section of the flexible chain (11) is in a natural drooping state. At the same time, the electric push rod (5) drives the electric telescopic rod (6) to drive the forming mold unit to close the mold to form the forming mold. The outer wall of the tube to be formed (7) contacts the inner wall of the forming hole. The insert mold assembly closes the mold, and the outer edge of the forming mold unit is inserted into the corresponding insert slot (9).
2. The apparatus for high-pressure water-expanded corrugated pipe forming according to claim 1, characterized in that, The height of the support ring (12) is set according to the spacing of the troughs of the pipe fitting (7) to be formed.
3. The apparatus for high-pressure water-expanded corrugated pipe forming according to claim 1, characterized in that, The outer diameter of the upper plug (16) is smaller than the inner diameter of the support ring (12) when the mold is closed.