An inner high pressure forming device for a profiled tube and a method thereof

Abstract

This invention discloses an internal high-pressure forming apparatus and method for irregularly shaped tubes. The apparatus includes a mold body, a pusher assembly, and a radial compensation assembly. The mold body includes an upper mold and a lower mold. The upper mold has a first cavity, and the lower mold has a second cavity. The first cavity and the second cavity enclose each other to form a forming cavity. The pusher assembly is disposed at both ends of the forming cavity. The radial compensation assembly includes a protective cover and a support base. The support base and the protective cover are detachably connected. There are at least two radial compensation assemblies, which are located on opposite sides of the tube blank. The two protective covers are connected to each other to form a support cavity. By introducing radial compensation assemblies during the sealing stage, this application provides buckling-resistant support for the tube blank, preventing axial bending deformation of the tube blank caused by pressure support lag, improving the mold adhesion rate, and reducing flash generation.

Description

Technical Field

[0001] This invention relates to the technical field of pipe forming, and in particular to an internal high-pressure forming apparatus for irregularly shaped pipes. Background Technology

[0002] Internal high-pressure forming technology is increasingly being applied to the forming process of aerospace tubing due to its unique advantages in manufacturing lightweight, high-performance structures. Using this technology to manufacture irregularly shaped air intakes not only ensures aerodynamic performance while achieving uniform wall thickness distribution, high strength and stiffness, and high dimensional accuracy, but also meets the design requirements for lightweight structures. In the internal high-pressure forming process, when processing long tubing exceeding 1.5 meters in length (such as automotive longitudinal beams and aerospace hydraulic lines), the recessed middle section of the irregularly shaped forming cavity causes the middle part of the tubing blank to be suspended when placed in the forming cavity. During the sealing stage between the tubing blank and the pusher assembly, when the tubing blank is replenished with fluid and axially fed, the axial feeding force easily induces buckling deformation of the tubing blank due to the delayed establishment of internal pressure support during the fluid replenishment stage. This results in a gap deviation between the axis of the tubing blank and the axis of the forming cavity, affecting the mold closing effect, leading to poor mold adhesion and easy flash formation. Summary of the Invention

[0003] Therefore, it is necessary to provide an internal high-pressure forming apparatus and method for irregularly shaped tubes to solve the above-mentioned technical problems.

[0004] An internal high-pressure forming apparatus for irregularly shaped tubes, comprising: The mold body includes an upper mold and a lower mold. The upper mold has a first cavity and the lower mold has a second cavity. When the upper mold and the lower mold are closed, the first cavity and the second cavity surround each other to form a forming cavity. The forming cavity is used to accommodate the tube blank to be processed. A pusher assembly is disposed at both ends of the forming cavity, the interior of the tube blank is used to contain the pressure medium, and the pusher assembly is configured to be sealed to both ends of the tube blank; A radial compensation assembly includes a protective cover and a support base, the support base being detachably connected to the protective cover. The number of radial compensation assemblies is at least two, the two radial compensation assemblies being located on opposite sides of the tube blank, the two protective covers being connected to form a support cavity, the inner wall surface of the support cavity being adapted to the outer peripheral surface of the tube blank, and the support cavity being configured to accommodate the tube blank.

[0005] Optionally, the radial compensation assembly includes a connecting rod, one end of which is connected to the protective cover, and the other end of which is detachably connected to the support base.

[0006] Optionally, the top of the support base is provided with a receiving hole, and the other end of the connecting rod is inserted into the receiving hole.

[0007] Optionally, the number of the support base and the connecting rod is at least two, with the two connecting rods spaced apart on the same side of the protective cover, and the two connecting rods being detachably connected to the two support bases respectively.

[0008] Optionally, it also includes a pressing block assembly, which includes a first pressing block and a second pressing block. The first pressing block and the second pressing block are detachably disposed at both ends of the upper mold, and the first pressing block and the second pressing block are respectively located at both ends of the tube blank.

[0009] Optionally, the upper mold has mounting grooves at both ends, and the first pressure block and the second pressure block are respectively disposed in the two mounting grooves.

[0010] Optionally, the pusher assembly includes a first pusher and a second pusher, the first pusher being disposed at one end of the tube blank and the second pusher being disposed at the other end of the tube blank, the first pusher and the second pusher cooperating to seal the pressure medium inside the tube blank.

[0011] Optionally, the second pusher head is further provided with a liquid inlet hole, which is used to supply pressure medium to the interior of the tube blank.

[0012] A method for internal high-pressure forming of an irregularly shaped tube, the method using the aforementioned internal high-pressure forming apparatus for irregularly shaped tubes, the method comprising the following steps: Sealing of the tube blank: Place the tube blank in the second cavity of the lower mold, and make the first pusher and the second pusher contact the two ends of the tube blank respectively. Install two radial compensation components on both sides of the tube blank so that the tube blank is placed in the support cavity. Then drive the first pusher and the second pusher to feed along the tube blank axial direction and seal the tube blank. After sealing, remove the two radial compensation components. Pre-bending of the tube blank: After sealing, the pressure medium is jogged to make the pressure in the liquid chamber of the tube blank reach the first preset value, and the upper die is driven to move down to perform the tube blank pre-bending test until the upper and lower dies are closed. Then the upper die is driven up and the mold is opened to check the pre-bending quality. High-pressure bulging inside the tube blank: After the pre-bending forming quality is qualified, the upper die is driven to move downward, the die closing pressure is set to the second preset value, the first pusher and the second pusher feed to seal again, after sealing, the die closing pressure is set to the third preset value, the internal high-pressure bulging test is carried out, and the liquid chamber pressure inside the tube blank is increased until the liquid chamber pressure is the fourth preset value, until the shaped tube is formed.

[0013] Optionally, the process may further include the following steps prior to sealing the tube blank: Preparation before the experiment: Deburr both ends of the tube blank, and then apply multiple layers of plastic film to both ends of the tube blank; lubricate the first cavity of the upper mold, the second cavity of the lower mold, and the pusher assembly.

[0014] The internal high-pressure forming apparatus for irregularly shaped tubes provided in this application features two radial compensation components. Two protective covers enclose a support cavity, which houses and supports the tube blank. When the tube blank is placed in the second cavity, and the upper and lower molds are not closed, the radial compensation components provide containment support. When the pusher assembly seals the end of the tube blank and feeds it axially, the support cavity prevents bending deformation. After sealing, the two protective covers are removed, the upper and lower molds are closed, and finally, an internal high-pressure forming experiment is performed. Therefore, compared to traditional internal high-pressure forming methods where the tube blank is prone to bending deformation during the sealing stage, this application introduces radial compensation components during the sealing stage, providing buckling-resistant support for the tube blank, preventing axial bending deformation due to pressure support lag, improving the die-fitting rate, and reducing flash. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the internal high-pressure forming device for a shaped tube in one embodiment; Figure 2 This is a schematic diagram of the radial compensation component in one embodiment; Figure 3 This is a schematic diagram of the upper mold in one embodiment; Figure 4 This is a schematic diagram of the lower mold structure in one embodiment; Figure 5 This is a schematic diagram of the irregularly shaped tube in one embodiment.

[0017] 1. Mold body; 11. Upper mold; 111. Mounting groove; 12. Lower mold; 13. First cavity; 14. Second cavity; 15. Positioning hole; 2. Pusher assembly; 21. First pusher; 22. Second pusher; 23. Liquid inlet hole; 3. Radial compensation assembly; 31. Protective cover; 32. Support base; 33. Support cavity; 34. Connecting rod; 35. Support rod; 36. Accommodation hole; 4. Pressing block assembly; 41. First pressing block; 42. Second pressing block; 5. Tube blank.

[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0021] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the term "and / or" throughout the text includes three solutions; taking A and / or B as an example, it includes technical solution A, technical solution B, and a technical solution that simultaneously satisfies A and B. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0022] refer to Figures 1 to 4This application provides an internal high-pressure forming apparatus for irregularly shaped tubes. The apparatus includes a mold body 1, a pusher assembly 2, and a radial compensation assembly 3. The mold body 1 includes an upper mold 11 and a lower mold 12. The upper mold 11 has a downwardly convex first cavity 13, and the lower mold 12 has a downwardly concave second cavity 14. When the upper mold 11 and lower mold 12 are closed, the first cavity 13 and the second cavity 14 surround each other to form a forming cavity, which is used to accommodate the tube blank 5 to be processed. The pusher assembly 2 is disposed at both ends of the forming cavity, and the interior of the tube blank 5 is used to contain the pressure medium. The pusher assembly 2 is used to extrude the pressure medium inside the tube blank 5 so that the tube blank 5 expands to form a shaped tube; the radial compensation assembly 3 includes a protective cover 31 and a support base 32, the support base 32 and the protective cover 31 are detachably connected, the number of radial compensation assemblies 3 is at least two, the radial compensation assemblies 3 are spaced apart from the lower die 12, the two radial compensation assemblies 3 are configured to be located on opposite sides of the tube blank 5 respectively, the two protective covers 31 are connected to form a support cavity 33, the inner wall surface of the support cavity 33 is adapted to the outer peripheral surface of the tube blank 5, and the support cavity 33 is configured to accommodate the tube blank 5.

[0023] The internal high-pressure forming apparatus for irregularly shaped tubes provided in this application includes two radial compensation components 3 and two protective covers 31 forming a support cavity 33. The support cavity 33 is used to accommodate and support the tube blank 5. When the tube blank 5 is placed in the second cavity 14 and the upper mold 11 and lower mold 12 are not closed, the radial compensation components 3 can provide containment support for the tube blank 5. Then, when the pusher assembly 2 seals the end of the tube blank 5 and feeds it along the axial direction of the tube blank 5, the support cavity 33 can prevent the tube blank 5 from bending and deforming. After sealing, the two protective covers 31 are removed, and then the upper mold 11 and lower mold 12 are closed. Finally, an internal high-pressure forming experiment is performed. Therefore, compared with the traditional internal high-pressure forming method where the tube blank 5 is prone to bending deformation during the sealing stage, this application provides buckling-resistant support for the tube blank 5 by introducing radial compensation components 3 during the sealing stage, preventing the tube blank 5 from axial bending deformation caused by pressure support lag, improving the die-fitting rate, and reducing the generation of flash.

[0024] This application is applicable to the forming of large-section irregular tubes, and is suitable for precision tube processing scenarios such as automobile exhaust pipes and aviation hydraulic pipelines. It greatly improves the efficiency in the production and manufacturing process, and creates a safer working environment for internal high-pressure forming, reducing the probability of accidents and risks.

[0025] Specifically, when the radial compensation component 3 supports the tube blank 5, the tube blank 5 is in a suspended state, that is, the tube blank 5 does not contact the second cavity 14 of the lower mold 12.

[0026] Specifically, the cross-sectional shape of the protective cover 31 is semi-circular.

[0027] Specifically, the radial compensation component 3 is located in the middle of the tube blank 5. The sum of the outer diameter of the tube blank 5 and the thickness of the protective cover 31 is less than the minimum diameter of the forming cavity, so that the protective cover 31 can enter the second cavity 14 and support the tube blank 5.

[0028] Specifically, the lower mold 12 is fixedly mounted on the machine tool by a pad, and the upper mold 11 is fixedly connected to the main cylinder. The upper mold 11 can move up and down in the vertical direction under the drive of the main cylinder so that the upper mold 11 and the lower mold 12 can be closed or separated from the lower mold 12.

[0029] Furthermore, the mold body 1 also includes a positioning pin and a positioning hole 15. The positioning hole 15 is set through the upper mold 11 and the lower mold 12 along the thickness direction. The positioning pin is inserted into the positioning hole 15. When the upper mold 11 and the lower mold 12 are closed, the positioning pin is used to fix the upper mold 11 and the lower mold 12.

[0030] In this embodiment, the pressure medium is water.

[0031] refer to Figure 2 The compensation component includes a connecting rod 34, one end of which is fixedly connected to the protective cover 31, and the other end of which is detachably connected to the support base 32. This arrangement allows the protective cover 31 to be angled, facilitating its passage through the lower mold 12 and fit against the tube blank 5. The detachable connection also facilitates the replacement of the protective cover 31 to accommodate tube blanks of various specifications. Specifically, the distance between the connecting rod 34 and the support base 32 is greater than the maximum thickness of the lower mold 12, ensuring that the lower mold 12 does not obstruct the installation of the radial compensation component 3, and the bottom surface of the lower mold 12 is positioned higher than the bottom surface of the support base 32.

[0032] Specifically, the radial compensation component 3 also includes a silicone damping pad and a diaphragm. The silicone damping pad is disposed between the protective cover 31 and the support 32 to absorb instantaneous impact force, and the diaphragm is disposed on the inner side of the protective cover 31 to ensure the surface quality of the product.

[0033] refer to Figure 2 The top of the support base 32 is provided with a receiving hole 36, and the other end of the connecting rod 34 is inserted into the receiving hole 36. The top of the receiving hole 36 is open.

[0034] Furthermore, the radial compensation assembly 3 also includes multiple fasteners. The connecting rod 34 has external threads, and two fasteners are threaded to the two sides of the connecting rod 34 located in the receiving hole 36, thereby clamping and fixing the connecting rod 34 to the support base 32.

[0035] In this embodiment, the fastener is a nut, and the protective cover 31, connecting rod 34 and base are all made of metal.

[0036] Specifically, the support base 32 has an L-shaped structure, and the end of the support base 32 away from the connecting rod 34 is fixed to the machine tool by bolts.

[0037] Furthermore, the radial compensation component 3 also includes a support rod 35, one end of which is connected to the vertical section of the support base 32, and the other end of which is connected to the horizontal section of the support base 32, thereby improving the overall stability.

[0038] When the tube blank 5 is not bent or deformed, the addition of the protective cover 31 can prevent the tube blank 5 from bending or deforming. If the tube blank 5 is bent or deformed before the cover is installed, the radial compensation component 3 of this application can also be used for compensation. Specifically, the radial compensation component 3 is adjusted by moving along the extension direction of the horizontal section of the L-shaped support 32 according to the amount of longitudinal bending deformation of the tube blank 5, thereby adjusting the clamping force and tightness of the radial compensation component 3 to achieve the compensation effect.

[0039] Furthermore, there are at least two support bases 32 and connecting rods 34. The two connecting rods 34 are spaced apart on the same side of the protective cover 31. The two connecting rods 34 are detachably connected to the two support bases 32 respectively, which can improve the stability of the radial compensation assembly 3.

[0040] refer to Figure 1 and Figure 3 The apparatus of this application further includes a pressing block assembly 4, which includes a first pressing block 41 and a second pressing block 42. The first pressing block 41 and the second pressing block 42 are detachably disposed at both ends of the upper mold 11, and the first pressing block 41 and the second pressing block 42 are respectively disposed at both ends of the tube blank 5. By disposing the first pressing block 41 and the second pressing block 42 at both ends of the tube blank 5, it is possible to prevent the ends of the tube blank 5 from warping and deforming, thereby improving the yield of the shaped tube. In addition, by separating the first pressing block 41 and the second pressing block 42 from the upper mold 11, when the upper mold 11 and the lower mold 12 are not closed, the first pressing block 41 and the second pressing block 42 can also fix the ends of the tube blank 5 located in the second cavity 14.

[0041] refer to Figure 1 and Figure 2 The upper mold 11 has mounting grooves 111 at both ends, and the first pressing block 41 and the second pressing block 42 are respectively embedded in the two mounting grooves 111. Furthermore, the first pressing block 41 and the second pressing block 42 are fixed to the upper mold 11 or the lower mold 12 by screws.

[0042] refer to Figure 1 The pusher assembly 2 includes a first pusher 21 and a second pusher 22. The first pusher 21 is disposed at one end of the tube blank 5, and the second pusher 22 is disposed at the other end of the tube blank 5. The first pusher 21 and the second pusher 22 cooperate to seal the pressure medium inside the tube blank 5.

[0043] refer to Figure 1 The second pusher 22 also has a liquid inlet hole, which is used to supply pressure medium to the interior of the tube blank 5.

[0044] This application also provides a method for internal high-pressure forming of irregularly shaped tubes, which uses the aforementioned internal high-pressure forming apparatus for irregularly shaped tubes, and includes the following steps: S1. Install the main body of the mold 1 The first pressure block 41 and the second pressure block 42 are installed on the upper mold 11, which is then installed on the main cylinder. The position of the lower mold 12 is determined by the position of the locating pin of the upper mold 11. A pad is placed on the machine tool, and the lower mold 12 is fixedly installed on the pad. After the upper mold 11 and the lower mold 12 are closed, a mold body 1 is formed. A first piston cylinder and a second piston cylinder are respectively installed at both ends of the mold body 1, with their axes coinciding. The mold body 1 is adjusted so that its axis coincides with the axis of the first piston rod. Then, the first push head 21 is fixedly connected to the first piston cylinder, and the second push head 22 is fixedly connected to the second piston cylinder. Finally, a high-pressure water pipe is installed in the inlet hole of the second push head 22. After the mold body 1 is installed, it is checked whether the mold body 1 is offset, whether the first push head 21 and the second push head 22 move smoothly, and whether the high-pressure water pipe inlets are stable.

[0045] Specifically, the first pressing block 41 and the second pressing block 42 are always installed and connected to the upper mold 11, and the first pressing block 41 and the second pressing block 42 can move up and down along the mounting groove 111 of the upper mold 11. During the mold closing stage, the first pressing block 41 and the second pressing block 42 first contact the two ends of the tube blank 5. As the upper mold 11 and the lower mold 12 gradually close, the first pressing block 41 and the second pressing block 42 are also completely fitted into the mounting groove 111 and become one with the upper mold 11.

[0046] Specifically, by reducing the thickness of the lower mold 12, the overall weight of the mold can be reduced, thus lowering the cost. The lower mold 12 is not in direct contact with the machine tool. In order to achieve the center height of the first piston cylinder, a pad needs to be added between the lower mold 12 and the machine tool.

[0047] S2. Preparations before the experiment Remove the tube blank 5, deburr both ends of the tube blank 5, and then apply 25 layers of PTFE film to both ends of the tube blank 5 to fill the gap between the first pusher head 21, the second pusher head 22 and the tube blank 5. Spray a small amount of oily molybdenum disulfide or aviation grease onto the upper mold 11, the lower mold 12, the first pusher head 21 and the second pusher head, and lubricate the forming cavity to ensure that the first pusher head 21 and the second pusher head 22 can smoothly enter the two ends of the tube blank 5 and to ensure sufficient material flow inside the tube blank 5.

[0048] S3, sealing of tube blank 5 Lubricant is applied to both ends of the tube blank 5 and the sealing positions of the first pusher 21 and the second pusher 22. Then, the tube blank 5 covered with a PTFE film is placed in the second cavity 14 of the lower mold 12. After the tube blank 5 is placed, the first piston cylinder and the second piston cylinder are jogged to drive the first pusher 21 and the second pusher 22 to move towards each other along the axis of the tube blank 5. The water injection position is when the front ends of the first pusher 21 and the second pusher 22 contact the tube blank 5. Two radial compensation components 3 are installed, and two protective covers 31 surround the tube blank 5 to restrict the degree of freedom of the tube blank 5 and prevent the tube blank 5 from bending and deforming during sealing. Then, water is jogged into the tube blank 5 until water overflows from both ends of the tube blank 5. The first pusher 21 and the second pusher 22 advance to seal the tube blank 5. After sealing, the radial compensation components 3 are removed.

[0049] S4, pre-bending of tube blank 5 After sealing, the liquid is added in jogs to bring the pressure in the liquid chamber of the tube blank 5 to the first preset value. After slowing down the movement speed of the main cylinder, the main cylinder drives the upper mold 11 to move down to perform a pre-bending test on the tube blank 5. If pressure is released in the later stage of the pre-bending test, the liquid is added in jogs to keep the pressure in the liquid chamber at the first preset value until the upper mold 11 and the lower mold 12 are closed. Then, the upper mold 11 is driven to move up and the mold is opened to check the pre-bending forming quality.

[0050] Specifically, the first preset value is 5 MPa.

[0051] S5, high-pressure bulging of tube blank 5 After the pre-bending forming quality is qualified, the upper mold 11 is driven to move down to close the mold. The mold closing pressure is set to the second preset value. The first pusher 21 and the second pusher 22 are fed again to seal until no water flows out from both ends of the mold body 1 after mold closing. The mold closing pressure is set to the third preset value, and an internal high-pressure expansion test is carried out. The pressure booster cylinder is operated to increase the liquid chamber pressure until the liquid chamber pressure is the fourth preset value. If water overflows or the pressure cannot be increased during the pressure boosting process, the first pusher 21 and the second pusher 22 are fed again to seal until the shaped tube is formed.

[0052] Specifically, the booster cylinder is connected to the high-pressure water pipe.

[0053] Specifically, the second preset value is 150 MPa, the third preset value is 210 MPa, and the fourth preset value is 15 MPa.

[0054] refer to Figure 5 In this embodiment, the axis of the irregular tube obtained by the above method is a two-dimensional curve, the cross-sectional shape of the left end is circular, and the cross-sectional shape of the right end is similar to a concave ellipse. The geometry of the irregular tube is a transition from a circular left end to a concave ellipse on the right end. The axis length is 812.86 mm, the diameter of the cross-section at the left end is 170 mm, the perimeter of the cross-section at the right end is 516.2 mm, and the radius of the rounded corner at the right end is 30.32 mm.

[0055] Specifically, the tube blank 5 undergoes plastic deformation along the forming cavity under the interaction of internal pressure and the feeding force of the first pusher 21 and the second pusher 22. As the internal pressure increases, axial feeding is carried out to continuously form the shaped tube and fit into the forming cavity. The tube blank 5 completes the initial expansion. The first pusher 21 and the second pusher 22 stop feeding and hold the pressure for a period of time until the high-pressure forming inside the shaped tube is completed, which improves the forming efficiency and quality.

[0056] This application also achieves internal high-pressure forming of the shaped tube by adding radial compensation devices 3 at both ends of the shaped tube before mold closing, using the pusher assembly 2 for rigid sealing, and then injecting pressure medium through the liquid inlet 23 to provide internal support for the shaped tube. After the internal pressure of the shaped tube rises and stabilizes, the radial compensation devices 3 are removed. After mold closing, the shaped tube is expanded to fully adhere to the mold by replenishing liquid, thereby achieving internal high-pressure forming of the shaped tube.

[0057] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A high-pressure forming device for irregularly shaped tubes, characterized in that, include: The mold body includes an upper mold and a lower mold. The upper mold has a first cavity and the lower mold has a second cavity. When the upper mold and the lower mold are closed, the first cavity and the second cavity surround each other to form a forming cavity. The forming cavity is used to accommodate the tube blank to be processed. A pusher assembly is disposed at both ends of the forming cavity, the interior of the tube blank is used to contain the pressure medium, and the pusher assembly is configured to be sealed to both ends of the tube blank; A radial compensation assembly includes a protective cover and a support base, the support base being detachably connected to the protective cover. The number of radial compensation assemblies is at least two, the two radial compensation assemblies being located on opposite sides of the tube blank, the two protective covers being connected to form a support cavity, the inner wall surface of the support cavity being adapted to the outer peripheral surface of the tube blank, and the support cavity being configured to accommodate the tube blank.

2. The internal high-pressure forming device for irregularly shaped tubes according to claim 1, characterized in that, The radial compensation assembly includes a connecting rod, one end of which is connected to the protective cover, and the other end of which is detachably connected to the support base.

3. The internal high-pressure forming device for irregularly shaped tubes according to claim 2, characterized in that, The top of the support base has a receiving hole, and the other end of the connecting rod is inserted into the receiving hole.

4. The internal high-pressure forming device for irregularly shaped tubes according to claim 2, characterized in that, The number of the support base and the connecting rod is at least two, and the two connecting rods are spaced apart on the same side of the protective cover. The two connecting rods are detachably connected to the two support bases respectively.

5. The internal high-pressure forming device for irregularly shaped tubes according to claim 1, characterized in that, It also includes a pressing block assembly, which includes a first pressing block and a second pressing block. The first pressing block and the second pressing block are detachably disposed at both ends of the upper mold, and the first pressing block and the second pressing block are respectively located at both ends of the tube blank.

6. The internal high-pressure forming device for irregularly shaped tubes according to claim 5, characterized in that, The upper mold has mounting slots at both ends, and the first pressure block and the second pressure block are respectively disposed in the two mounting slots.

7. The internal high-pressure forming device for irregularly shaped tubes according to claim 1, characterized in that, The pusher assembly includes a first pusher and a second pusher. The first pusher is disposed at one end of the tube blank, and the second pusher is disposed at the other end of the tube blank. The first pusher and the second pusher cooperate to seal the pressure medium inside the tube blank.

8. The internal high-pressure forming apparatus for irregularly shaped tubes according to claim 7, characterized in that, The second pusher head is also provided with a liquid inlet hole, which is used to input pressure medium into the interior of the tube blank.

9. A method for internal high-pressure forming of an irregularly shaped tube, the method using the internal high-pressure forming apparatus for an irregularly shaped tube as described in any one of claims 1-8, characterized in that, The method includes: Sealing of the tube blank: Place the tube blank in the second cavity of the lower mold, and make the first pusher and the second pusher contact the two ends of the tube blank respectively. Install two radial compensation components on both sides of the tube blank so that the tube blank is placed in the support cavity. Then drive the first pusher and the second pusher to feed along the tube blank axial direction and seal the tube blank. After sealing, remove the two radial compensation components. Pre-bending of the tube blank: After sealing, the pressure medium is jogged to make the pressure in the liquid chamber of the tube blank reach the first preset value, and the upper die is driven to move down to perform the tube blank pre-bending test until the upper and lower dies are closed. Then the upper die is driven up and the mold is opened to check the pre-bending quality. High-pressure bulging inside the tube blank: After the pre-bending forming quality is qualified, the upper die is driven to move downward, the die closing pressure is set to the second preset value, the first pusher and the second pusher feed to seal again, after sealing, the die closing pressure is set to the third preset value, the internal high-pressure bulging test is carried out, and the liquid chamber pressure inside the tube blank is increased until the liquid chamber pressure is the fourth preset value, until the shaped tube is formed.

10. The method for internal high-pressure forming of an irregularly shaped tube according to claim 9, characterized in that, The sealing step of the tube blank is preceded by: Preparation before the experiment: Deburr both ends of the tube blank, and then apply multiple layers of plastic film to both ends of the tube blank; lubricate the first cavity of the upper mold, the second cavity of the lower mold, and the pusher assembly.

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