Water expansion machine for metal pipe body

Abstract

The invention relates to the technical field of water expansion machines, and particularly discloses a water expansion machine for a metal pipe body, the water expansion machine comprises a base and a workbench, the workbench is arranged on the base, a module is arranged on the workbench and is used for placing and shaping a metal pipe, and a water expansion unit is further arranged on the base and is used for performing water expansion treatment on the metal pipe in the module; the die set comprises a pedestal, a lower die cylinder and an upper die cylinder, the pedestal is arranged at the top of the workbench, the lower die cylinder is formed by splicing two half cylinders, and the two half cylinders can rotate relative to the pedestal; according to the water expansion machine for the metal pipe body, through mutual cooperation of the first traction rope and the torsion component, the lower mold barrel can be automatically opened when the upper mold barrel is lifted and can be automatically closed when the upper mold barrel is descended, so that mold opening and mold closing of the lower mold barrel are controlled by the upper mold barrel, and mold opening and mold closing are controlled by the lower mold barrel; die opening and closing of the lower die cylinder can be automatically conducted without additionally arranging a die opening and closing unit, the equipment cost is reduced, and the trouble of manual die opening and closing of workers is omitted.

Description

Technical Field

[0001] The present invention relates to the technical field of hydroforming machines, and particularly relates to a hydroforming machine for metal pipe bodies. Background Art

[0002] A hydroforming machine uses a liquid (usually water) as a medium to apply uniform pressure within a specific mold, causing plastic deformation of metal or other materials under the action of pressure, thereby achieving the purpose of forming. In the processing of metal pipe bodies, it can be produced through a hydroforming process, and the pipe is hydroformed into the required shape within the mold using a hydroforming machine.

[0003] When the existing hydroforming machine processes metal pipes, after the hydroforming of the metal pipe is completed, after waiting for the upper die cylinder to lift and separate from the lower die cylinder, the staff opens the lower die cylinder to replace the metal pipe fitting, which is rather troublesome, inconvenient, and has low efficiency, and the working intensity is relatively high. Although some hydroforming machine equipment is equipped with mechanisms such as cylinders to enable the lower die cylinder to open and close automatically, in order to ensure that the lower die cylinder can open in the shortest time after the upper die cylinder lifts, saving the time for replacing the metal pipe fitting, a numerical control system needs to be added to coordinate the cylinder and the die cylinder, and the coordination and debugging process is relatively complex and the usage cost is relatively high. Summary of the Invention

[0004] The present invention provides a hydroforming machine for metal pipe bodies, aiming to solve the problems in the related art that it is rather troublesome, inconvenient, and has low efficiency for the staff to manually open the lower die cylinder, the working intensity is relatively high, and the cost of using a numerical control system to control the opening of the lower die cylinder is relatively high.

[0005] The hydroforming machine for metal pipe bodies of the present invention includes a base and a workbench. The workbench is arranged on the base, and a module is arranged on the workbench for placing and shaping the metal pipe. A hydroforming unit is also arranged on the base for hydroforming the metal pipe in the module. The module includes a pedestal, a lower die cylinder, and an upper die cylinder. The pedestal is arranged on the top of the workbench. The lower die cylinder is composed of two half cylinders spliced together, and both half cylinders can rotate relative to the pedestal. The upper die cylinder is located directly above the lower die cylinder and can move up and down relative to the lower die cylinder. A first towing rope is fixedly connected to each of the two half cylinders, and the top end of the first towing rope is fixedly connected to the upper die cylinder, which can pull the half cylinder to rotate and open the die after the upper die cylinder lifts and disengages from the lower die cylinder. A connecting shaft that rotates within the pedestal is fixedly installed on the half cylinder, and a torsion member is arranged between the connecting shaft and the pedestal, which can drive the connecting shaft to rotate and reset after the half cylinder loses the pulling force of the first towing rope.

[0006] Preferably, an arc-shaped guiding groove is formed on the outer side of the half cylinder, and a guiding ring is arranged on the top of the workbench. The first towing rope passes through the guiding ring and is carried inside the guiding groove.

[0007] Preferably, a protective box is fixedly installed on the top of the base. A support platform is arranged in the middle of the protective box. A plurality of upright columns are fixedly arranged on the top of the support platform in a rectangular array. A water storage tank is arranged on the base and is located below the protective box.

[0008] Preferably, a hydro-expansion tube is vertically fixed in the middle of the pedestal, and the bottom end of the hydro-expansion tube is communicated with the water outlet hole. A plug adapted to the top pipe orifice of the lower die barrel is fixedly installed inside the upper die barrel.

[0009] Preferably, a hydraulic cylinder is fixedly installed at the top end of the upright column. A lifting platform is arranged at the telescopic end of the hydraulic cylinder. The upper die barrel is arranged at the bottom of the lifting platform.

[0010] Preferably, the workbench is arranged on the top of the support platform and is located between a plurality of upright columns. A water injection hole is formed in the side wall of the workbench. A water outlet hole is formed in the top of the workbench, and the water outlet hole is communicated with the water injection hole.

[0011] Preferably, the hydro-expansion unit includes a water cylinder, a piston, an oil cylinder and a water pump. The water cylinder is fixedly installed on the base and is communicated with the workbench. The oil cylinder is fixedly installed directly above the water cylinder. The piston is fixedly installed at the output end of the oil cylinder, and the bottom end of the piston extends into the water cylinder.

[0012] Preferably, an inner cavity is formed inside the water cylinder. A connection hole communicated with the inner cavity is formed in the side wall of the water cylinder. The connection hole and the water injection hole are connected through a first water pipe. The piston is slidably assembled inside the inner cavity. An L-shaped water replenishing groove is formed inside the piston. The bottom end of the water replenishing groove is communicated with the inner cavity. The top end of the water replenishing groove is connected with the output end of the water pump through a second water pipe. The input end of the water pump is connected with the water storage tank through a third water pipe.

[0013] Preferably, a storage cylinder is fixedly installed on one side of the workbench close to the feed inlet. A mounting shaft is coaxially fixed inside the storage cylinder. A water blocking cloth is wound around the outside of the mounting shaft. The end of the water blocking cloth extends outside the storage cylinder and is fixed to the upper die barrel.

[0014] Preferably, a connecting rod slidably assembled on the upright column is fixedly installed at the end of the water blocking cloth. A second traction rope is fixedly installed at the bottom of the upper die barrel. A ring sleeve is fixedly installed on the upright column, and the height of the ring sleeve is higher than the top end of the lower die barrel. The bottom end of the second traction rope passes through the ring sleeve and is fixed to the connecting rod.

[0015] Beneficial effects: 1. When the present invention is in use, through the mutual cooperation of the first towing rope and the torsion member, the lower die cylinder can be automatically opened when the upper die cylinder is lifted, and the lower die cylinder can be automatically closed when the upper die cylinder descends. The opening and closing of the lower die cylinder are both controlled by the upper die cylinder, and the opening and closing of the lower die cylinder can be automatically carried out without separately adding an opening and closing die unit, reducing the equipment cost, saving the trouble of manual opening and closing die by the staff, making the replacement and placement of the metal pipe more convenient and fast, and improving the processing efficiency of the metal pipe.

[0016] 2. When the present invention is in use, through the winding and stretching of the water-blocking cloth when the upper die cylinder moves up and down, the upper die cylinder and the lower die cylinder can be shielded during water pressure inflation, and then the water column sprayed during water pressure inflation can be blocked, preventing the water inflation solution from spraying to the outside of the equipment. The shielding of the upper die cylinder and the lower die cylinder can be released during die opening to facilitate the replacement of the metal pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a three-dimensional view of the present invention.

[0018] Figure 2 is a three-dimensional view of the present invention from another angle.

[0019] Figure 3 is the present invention Figure 2 is an enlarged schematic structural view of part A in the present invention.

[0020] Figure 4 is the present invention Figure 2 is an enlarged schematic structural view of part B in the present invention.

[0021] Figure 5 is the present invention Figure 2 is a front view of the present invention.

[0022] Figure 6 is a schematic structural view of the inside of the protective box of the present invention.

[0023] Figure 7 is the present invention Figure 6 is an enlarged schematic structural view of part C in the present invention.

[0024] Figure 8 is a sectional view of the water tank of the present invention.

[0025] Figure 9 is a sectional view of the upper die cylinder and the lower die cylinder of the present invention.

[0026] Figure 10 is the present invention Figure 9 is an enlarged schematic structural view of part D in the present invention.

[0027] Figure 11 is a schematic structural view of the inside of the lower die cylinder and the installation cylinder of the present invention.

[0028] Reference numerals: 10. Base; 11. Protection box; 12. Support table; 13. Column; 131. Ring sleeve; 14. Water storage tank; 20. Workbench; 21. Water injection hole; 22. Water outlet hole; 30. Module; 31. Base; 311. Hydro-expansion tube; 32. Lower die cylinder; 321. Guide groove; 33. Upper die cylinder; 331. Plug; 332. Second traction rope; 40. Lifting mechanism; 41. Hydraulic cylinder; 42. Lifting table; 50. Die opening mechanism; 51. First traction rope; 52. Guide ring; 60. Die closing mechanism; 61. Installation cylinder; 62. Connecting shaft; 63. Torsion component; 70. Hydro-expansion unit; 71. Water cylinder; 711. Inner cavity; 712. Connecting hole; 72. Piston; 721. Water replenishing tank; 73. Oil cylinder; 74. Water pump; 80. Splash-proof mechanism; 81. Storage cylinder; 82. Installation shaft; 83. Splash-proof cloth; 831. Connecting rod. Detailed implementation manners

[0029] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention, but should not be construed as a limitation to the present invention.

[0030] As Figures 1 to 11 shown, the hydro-expansion machine for metal pipe bodies of the present invention includes a base 10, a workbench 20, a module 30, a lifting mechanism 40, a die opening mechanism 50, a die closing mechanism 60, a hydro-expansion unit 70, and a splash-proof mechanism 80. The workbench 20 is arranged inside the base 10 and is used for supporting the module 30 and injecting water, so as to facilitate the placement and hydro-expansion processing of metal pipes. The lifting mechanism 40 is arranged above the module 30. The die opening mechanism 50 and the die closing mechanism 60 are arranged on one side of the module 30 and can cooperate with the lifting mechanism 40 to open and close the module 30. The hydro-expansion unit 70 is located on one side of the workbench 20 and is used for conveying hydro-expansion solution into the workbench 20. The splash-proof mechanism 80 is located on one side of the module 30 and can prevent the hydro-expansion solution from being sprayed outside the equipment under high pressure during hydro-expansion.

[0031] Refer to Figure 1 , Figure 2 and Figure 6 , a protection box 11 is fixedly installed at the top of the base 10. A feeding port is arranged on one side of the protection box 11 to facilitate the taking and placing of metal pipes. A support table 12 is arranged in the middle of the protection box 11. A plurality of columns 13 are fixedly arranged on the top of the support table 12 in a rectangular array for supporting the lifting mechanism 40. A water storage tank 14 is arranged on the base 10 below the protection box 11 for storing the hydro-expansion solution. The water storage tank 14 is communicated with the protection box 11 and can recover the hydro-expansion solution in the protection box 11.

[0032] Refer to Figure 1 WithFigure 2 , the workbench 20 is arranged on the top of the support table 12 and is located between multiple columns 13. A water injection hole 21 is formed on the side wall of the workbench 20, and a water outlet hole 22 is formed on the top of the workbench 20. The water outlet hole 22 is communicated with the water injection hole 21, so that water can be injected into the workbench 20 from the water injection hole 21, and then the water is discharged from the water outlet hole 22 to perform hydroforming treatment on the metal pipe.

[0033] Reference Figure 2 And Figure 5 , the module 30 includes a pedestal 31, a lower die cylinder 32 and an upper die cylinder 33. The pedestal 31 is arranged on the top of the workbench 20. The lower die cylinder 32 is composed of two half cylinders spliced together, and both half cylinders can rotate relative to the pedestal 31. The upper die cylinder 33 is located directly above the lower die cylinder 32 and can lift and lower relative to the lower die cylinder 32. When the upper die cylinder 33 descends, it can be sleeved outside the lower die cylinder 32 to press the two half cylinders to prevent them from separating during the hydroforming process of the metal pipe. When the upper die cylinder 33 is lifted, it can be separated from the outside of the lower die cylinder 32, so that the two half cylinders can be separated, and the lower die cylinder 32 can be opened to take, place and replace the metal pipe.

[0034] Reference Figure 9 , a hydroforming pipe 311 is vertically fixed in the middle of the pedestal 31, and the bottom end of the hydroforming pipe 311 is communicated with the water outlet hole 22, which is used to support the bottom end of the metal pipe, so that the hydroforming solution can be injected into the lower die cylinder 32 from the hydroforming pipe 311. A plug 331 adapted to the top pipe orifice of the lower die cylinder 32 is fixedly installed inside the upper die cylinder 33. After the upper die cylinder 33 is sleeved outside the lower die cylinder 32, the plug 331 can be inserted into the lower die cylinder 32 to block the upper pipe orifice of the metal pipe and ensure the sealing inside the metal pipe during the hydroforming operation.

[0035] Reference Figure 2 , the lifting mechanism 40 includes a hydraulic cylinder 41 and a lifting platform 42. The hydraulic cylinder 41 is fixedly installed at the top of the column 13. The lifting platform 42 is arranged at the telescopic end of the hydraulic cylinder 41, and the lifting platform 42 is slidably assembled on the column 13. The upper die cylinder 33 is fixedly installed at the bottom of the lifting platform 42, and can follow the lifting platform 42 to lift and lower when the hydraulic cylinder 41 drives the lifting platform 42 to lift and lower.

[0036] Reference Figure 6 And Figure 7, There are two sets of mold opening mechanisms 50 respectively arranged on two half cylinders. After the upper mold cylinder 33 is lifted to a certain height, it can drive the half cylinders to rotate on the pedestal 31, separate the two half cylinders from each other, and perform mold opening of the lower mold cylinder 32. The two sets of mold opening mechanisms 50 both include a first traction rope 51 and a guide ring 52. The top end of the first traction rope 51 is fixedly connected to the upper mold cylinder 33, the bottom end of the first traction rope 51 is fixed to the half cylinder, the guide ring 52 is fixedly installed on the pedestal 31, an arc-shaped guide groove 321 is formed on the outer wall of the half cylinder, and the first traction rope 51 passes out of the guide ring 52 and is carried inside the guide groove 321. The guide rings 52 in the two sets of mold opening mechanisms 50 are arranged oppositely, and the first traction ropes 51 in the two sets of mold opening mechanisms 50 are respectively fixed to the two half cylinders. After the upper mold cylinder 33 is lifted and separated from the lower mold cylinder 32, the first traction rope 51 pulls the half cylinder to rotate, separating the two half cylinders by rotation, realizing automatic mold opening of the lower mold cylinder 32 so as to facilitate the picking, placing and replacement of the metal pipe.

[0037] Reference Figure 7 And Figure 11 , The two sets of mold closing mechanisms 60 both include an installation cylinder 61, a connecting shaft 62 and a torsion member 63. The installation cylinder 61 is fixedly installed inside the pedestal 31, the connecting shaft 62 is vertically rotatably assembled inside the installation cylinder 61, the two half cylinders are respectively fixedly installed at the top ends of the connecting shafts 62 in the two sets of mold closing mechanisms 60, the torsion member 63 is arranged outside the connecting shaft 62, and can drive the connecting shaft 62 to rotate and reset after the half cylinder loses the tension of the first traction rope 51. In this solution, the torsion member 63 is specifically a torsion spring. The torsion spring is sleeved outside the connecting shaft 62, and its two ends are respectively fixed to the installation cylinder 61 and the connecting shaft 62. When the two half cylinders are rotated to open the mold, the torsion spring can apply a torsional force to the connecting shaft 62, and then drive the two half cylinders to rotate and reset on the top of the pedestal 31 after losing the tension of the first traction rope 51, realizing mold closing of the lower mold cylinder 32 so as to facilitate the hydroforming operation of the metal pipe.

[0038] Reference Figure 1 And Figure 6 , The hydroforming unit 70 includes a water cylinder 71, a piston 72, an oil cylinder 73 and a water pump 74. The water cylinder 71 is fixedly installed on the base 10 and communicates with the workbench 20. The oil cylinder 73 is fixedly installed directly above the water cylinder 71. The piston 72 is fixedly installed at the output end of the oil cylinder 73, and the bottom end of the piston 72 extends into the water cylinder 71 and can lift and lower in the water cylinder 71 under the drive of the oil cylinder 73. The water pump 74 is arranged between the water storage tank 14 and the water cylinder 71 and can transport the hydroforming solution in the water storage tank 14 into the water cylinder 71, so that the hydroforming solution is transported into the workbench 20 through the water cylinder 71 and enters the metal pipe through the water outlet hole 22. The piston 72 descends to pressurize the transported hydroforming solution, and then performs hydroforming processing on the metal pipe.

[0039] Reference Figure 6 AndFigure 8 , an inner cavity 711 is formed inside the water tank 71, and a connection hole 712 communicating with the inner cavity 711 is formed on the side wall of the water tank 71. The connection hole 712 and the water injection hole 21 are connected by a first water pipe (not shown in the figure), so that the water swelling solution in the inner cavity 711 can be transported into the inside of the workbench 20. The piston 72 is slidably assembled inside the inner cavity 711. An L-shaped water replenishing groove 721 is formed inside the piston 72. The bottom end of the water replenishing groove 721 communicates with the inner cavity 711, and the top end of the water replenishing groove 721 is connected to the output end of the water pump 74 by a second water pipe (not shown in the figure). The input end of the water pump 74 is connected to the water storage tank 14 by a third water pipe (not shown in the figure). So that the water pump 74 can pump out the water swelling solution in the water storage tank 14, inject it into the inner cavity 711 of the water tank 71 through the water replenishing groove 721 in the piston 72, and then the water swelling solution in the inner cavity 711 is injected into the inside of the workbench 20 through the water injection hole 21. As the piston 72 descends to compress the space of the inner cavity 711, the water swelling solution being transported can be pressurized, thereby realizing the water swelling operation of the metal tube.

[0040] Reference Figure 10 The splash-proof mechanism 80 includes a storage cylinder 81, a mounting shaft 82 and a water blocking cloth 83. The storage cylinder 81 is fixedly installed on one side of the workbench 20 close to the feed port. The mounting shaft 82 is coaxially fixed inside the storage cylinder 81. The water blocking cloth 83 is wound around the outside of the mounting shaft 82, and a torsion spring is provided between the water blocking cloth 83 and the mounting shaft 82. An access slot is formed on the side wall of the storage cylinder 81. The top end of the water blocking cloth 83 passes through the access slot and extends to the outside of the storage cylinder 81 to be connected to the upper die cylinder 33. When the upper die cylinder 33 descends, the water blocking cloth 83 can be pulled out of the storage cylinder 81 to block between the lower die cylinder 32 and the upper die cylinder 33, thereby preventing the water swelling solution from being sprayed outside the protective box 11 under high pressure during the water swelling process. When the upper die cylinder 33 rises, the water blocking cloth 83 can be wound into the storage cylinder 81 by the torsion spring to avoid blocking and affecting the replacement of the metal tube.

[0041] Reference Figures 2 to 4 , a connecting rod 831 slidably assembled on the column 13 is installed at the end of the water blocking cloth 83. A second towing rope 332 is fixedly installed at the bottom of the upper die cylinder 33. A collar 131 is fixedly installed on the column 13, and the height of the collar 131 is higher than the top height of the lower die cylinder 32. The bottom end of the second towing rope 332 passes through the collar 131 and is fixed to the connecting rod 831, so that the water blocking cloth 83 can be pulled out when the upper die cylinder 33 descends and wound when the upper die cylinder 33 rises.

[0042] Working principle: The hydraulic cylinder 41 drives the lifting platform 42 to rise, so that the upper die cylinder 33 rises and separates from the lower die cylinder 32. The first traction rope 51 pulls the half cylinder to rotate, so that the two half cylinders move away from each other to open the lower die cylinder 32. Then, the metal tube is inserted outside the hydroforming tube 311 in the pedestal 31. The lifting platform 42 drives the upper die cylinder 33 to descend. The half cylinder gradually loses the pulling force of the first traction rope 51 and rotates and resets under the action of the torsion member 63, so that the two half cylinders approach each other to complete the closing of the lower die cylinder 32. Then, the upper die cylinder 33 sleeves outside the lower die cylinder 32 during the descent to fix it, and the plug 331 enters the lower die cylinder 32 to block the top end of the metal tube. The water pump 74 pumps out the hydroforming solution in the water storage tank 14 and injects it into the inner cavity 711 of the water cylinder 71 through the water replenishing groove 721 in the piston 72. Then, the hydroforming solution is injected into the workbench 20 through the injection hole 21 and input into the metal tube through the hydroforming tube 311. As the piston 72 descends to compress the space of the inner cavity 711, the hydroforming solution in the pipeline can be pressurized, and then the hydroforming operation of the metal tube is realized. Then, the upper die cylinder 33 is lifted to open the lower die cylinder 32 and take out the formed metal tube. As the upper die cylinder 33 descends into the outside of the lower die cylinder 32, the water blocking cloth 83 can be pulled out of the storage cylinder 81 through the second traction rope 332 to block the upper die cylinder 33 and the lower die cylinder 32, and block the hydroforming solution splashed during hydroforming for easy recovery.

[0043] In the present invention, through the mutual cooperation of the first traction rope 51 and the torsion member 63, the lower die cylinder 32 can be automatically opened when the upper die cylinder 33 is lifted, and the lower die cylinder 32 can be automatically closed when the upper die cylinder 33 descends, so that the opening and closing of the lower die cylinder 32 are both controlled by the upper die cylinder 33. The opening and closing of the lower die cylinder 32 can be automatically carried out without separately adding an opening and closing die unit, reducing the equipment cost, saving the trouble of manual opening and closing by the staff, making the replacement and placement of the metal tube more convenient and fast, and improving the processing efficiency of the metal tube; through the winding and stretching of the water blocking cloth 83 when the upper die cylinder 33 rises and falls, the upper die cylinder 33 and the lower die cylinder 32 can be shielded during pressurized hydroforming, and then the water column sprayed during hydroforming pressurization can be blocked, avoiding the hydroforming solution from spraying outside the equipment, and the shielding of the upper die cylinder 33 and the lower die cylinder 32 can be released during die opening for easy replacement of the metal tube.

[0044] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A hydroforming machine for metal pipe bodies, comprising a base (10) and a workbench (20), the workbench (20) is arranged on the base (10), and is characterized in that, A module (30) is arranged on the workbench (20) for placing and shaping metal pipes. A hydroforming unit (70) is also arranged on the base (10) for hydroforming the metal pipes in the module (30). The module (30) includes a pedestal (31), a lower die cylinder (32) and an upper die cylinder (33). The pedestal (31) is arranged on the top of the workbench (20). The lower die cylinder (32) is composed of two half cylinders spliced together, and both half cylinders can rotate relative to the pedestal (31). The upper die cylinder (33) is located directly above the lower die cylinder (32) and can move up and down relative to the lower die cylinder (32). First traction ropes (51) are fixedly connected to both half cylinders. The top ends of the first traction ropes (51) are fixedly connected to the upper die cylinder (33), which can pull the half cylinders to rotate and open the die after the upper die cylinder (33) is lifted away from the lower die cylinder (32). A connecting shaft (62) that rotates in the pedestal (31) is fixedly installed on the half cylinder, and a torsion member (63) is arranged between the connecting shaft (62) and the pedestal (31), which can drive the connecting shaft (62) to rotate back to its original position after the half cylinder loses the tension of the first traction rope (51).

2. The hydroforming machine for metal tubes according to claim 1, characterized in that, An arc-shaped guide groove (321) is formed on the outer side of the half cylinder. A guide ring (52) is arranged on the top of the workbench (20). The first traction rope (51) passes through the guide ring (52) and is carried inside the guide groove (321).

3. The hydroforming machine for metal tubes according to claim 2, characterized in that, A protective box (11) is fixedly installed on the top of the base (10). A support platform (12) is arranged in the middle of the protective box (11). A plurality of columns (13) are fixedly arranged on the top of the support platform (12) in a rectangular array. A water storage tank (14) is arranged on the base (10) below the protective box (11).

4. The hydroforming machine for a metal tube body according to claim 3, characterized in that, A hydroforming pipe (311) is vertically fixed in the middle of the pedestal (31), and the bottom end of the hydroforming pipe (311) is communicated with a water outlet hole (22). A plug (331) adapted to the top pipe orifice of the lower die cylinder (32) is fixedly installed inside the upper die cylinder (33).

5. The hydroforming machine for a metal tube body according to claim 3, wherein, The top ends of the columns (13) are fixedly installed with hydraulic cylinders (41). The telescopic ends of the hydraulic cylinders (41) are provided with lifting platforms (42). The upper die cylinder (33) is arranged at the bottom of the lifting platform (42).

6. The hydroforming machine for metal tubes according to claim 5, wherein, The workbench (20) is arranged on the top of the support platform (12) and located between a plurality of columns (13). A water injection hole (21) is formed on the side wall of the workbench (20). A water outlet hole (22) is formed on the top of the workbench (20), and the water outlet hole (22) is communicated with the water injection hole (21).

7. The hydroforming machine for metal tube bodies according to claim 6, characterized in that, The hydroforming unit (70) includes a water cylinder (71), a piston (72), an oil cylinder (73) and a water pump (74). The water cylinder (71) is fixedly installed on the base (10) and communicated with the workbench (20). The oil cylinder (73) is fixedly installed directly above the water cylinder (71). The piston (72) is fixedly installed at the output end of the oil cylinder (73), and the bottom end of the piston (72) extends into the water cylinder (71).

8. The hydroforming machine for a metal tube body according to claim 7, characterized in that, The water tank (71) is internally provided with an inner cavity (711). A connection hole (712) communicating with the inner cavity (711) is provided on the side wall of the water tank (71). The connection hole (712) and the water injection hole (21) are connected by a first water pipe. The piston (72) is slidably assembled inside the inner cavity (711). An L-shaped water replenishing groove (721) is provided inside the piston (72). The bottom end of the water replenishing groove (721) communicates with the inner cavity (711). The top end of the water replenishing groove (721) is connected to the output end of the water pump (74) by a second water pipe. The input end of the water pump (74) is connected to the water storage tank (14) by a third water pipe.

9. The hydroforming machine for a metal tube body according to claim 3, characterized in that, A storage cylinder (81) is fixedly installed on one side of the workbench (20) close to the feed inlet. A mounting shaft (82) is coaxially fixed inside the storage cylinder (81). A water blocking cloth (83) is wound around the outside of the mounting shaft (82). The end of the water blocking cloth (83) extends outside the storage cylinder (81) and is fixed to the upper die cylinder (33).

10. The hydroforming machine for metal tube bodies according to claim 9, characterized in that, A connecting rod (831) slidably assembled on the column (13) is fixedly installed at the end of the water blocking cloth (83). A second towing rope (332) is fixedly installed at the bottom of the upper die cylinder (33). A ring sleeve (131) is fixedly installed on the column (13), and the height of the ring sleeve (131) is higher than the top end of the lower die cylinder (32). The bottom end of the second towing rope (332) passes out of the ring sleeve (131) and is fixed to the connecting rod (831).

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