Mould, closing device and process for closing pressure vessel

Abstract

The present invention provides a mold and a closing device and a process for closing a pressure vessel, the mold comprising a male mold and a female mold matched with the male mold; the male mold is a detachable combined male mold, the upper end and the lower end of the male mold are respectively provided with an upper fixing ring and a lower fixing ring, the closing device comprises a mold, a heating device, a heating device moving mechanism, a hydraulic support platform, and a quick-release pull rod assembly; the closing process completes the closing and molding operation of the workpiece through multiple steps of preparation work, hole opening, and closing operation; the male mold of the mold for closing a pressure vessel of the present invention is a detachable combined male mold, which can meet various needs of actual production, and the design of the combined male mold reduces the specifications of the mold when the pressure vessel is closed and molded, and can achieve multiple uses of one mold; the closing device for closing a pressure vessel has significant advantages such as simple structure, easy assembly, stable operation, good molding quality, and high efficiency, and can meet the closing and molding requirements of various multi-cavity pressure vessels.

Description

Technical Field

[0001] The invention belongs to the technical field of pressure vessel closing, and more specifically, relates to a mold and a closing device and a process for closing the pressure vessel. Background Art

[0002] In the chemical production industry, pressure vessels are the most widely used chemical equipment. With the development of chemical production technology, the requirements for various chemical equipment, especially pressure vessel equipment, are getting higher and higher. The design of various reaction vessels, mixing vessels, and towers is increasingly tending towards high temperature, high pressure, large size, and more complex structure. Among them, the multi-chamber container has two internal and external pressure chambers: the inner cylinder and the jacket body. The inner and outer chambers work separately. This structure requires strict separation of the inner and outer chambers and no cross-chamber is allowed in the design. At the same time, the various opening pipes of the inner cylinder must pass through the jacket body, which produces a transition design of the inner and outer chambers, that is, the jacket body closing structure.

[0003] The traditional processing of the jacket body closing structure requires flame heating and manual hammer hammering. This method of processing the closing structure is extremely inefficient, labor-intensive and has poor molding quality. When the plate thickness δ of the jacket body is ≥18mm, manual work cannot be completed at all; in addition, this method of processing the closing structure requires the construction of scaffolding for high-altitude work in the closing operation of large equipment, which has great safety hazards.

[0004] With the development of society, my country has higher and higher requirements for safety and environmental protection in the chemical industry, and the corresponding control of chemical equipment has become more and more stringent. In the current design of pressure vessels, especially fatigue vessels designed by analysis, the stress environment requirements of the details of the vessel are very high, and irregular dents, creases and other defects are no longer allowed. Since the quality of the closing structure formed by the traditional processing method of the jacket body is poor, the traditional manual forming of the pressure vessel closing structure can no longer meet the current design requirements of pressure vessels. Summary of the invention

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: to provide a mold for closing the mouth of a pressure vessel, including a punch and a die matching the punch; the punch is a detachable combined punch, and the upper and lower ends of the punch are respectively provided with an upper fixing ring and a lower fixing ring, and the upper fixing ring and the lower fixing ring are used to connect the split punch into one.

[0006] Preferably, the punch is punch A, which includes several arc-shaped split segments; the upper fixing ring is the upper fixing ring A, and the lower fixing ring is the lower fixing ring A; several arc-shaped split segments are combined into the punch A, and the upper fixing ring A and the lower fixing ring A are respectively arranged at the upper end and the lower end of the punch A to connect the punch A into one.

[0007] Preferably, the punch is punch B, which includes several arc-shaped split segments and several expansion segments; the upper fixing ring is the upper fixing ring B, and the lower fixing ring is the lower fixing ring B; several arc-shaped split segments and several expansion segments are combined into the punch B, and the upper fixing ring B and the lower fixing ring B are respectively arranged at the upper end and the lower end of the punch B to connect the punch B into one.

[0008] Furthermore, the upper fixing ring A is circular; the lower fixing ring A is circular.

[0009] Furthermore, the upper fixing ring B is elliptical; and the lower fixing ring B is elliptical.

[0010] A closing device for closing a pressure vessel, comprising a mold, a heating device, a heating device moving mechanism, a hydraulic support platform, and a quick-install pull rod assembly; the heating device moving mechanism comprises a guide rail, the heating device is slidably arranged on the guide rail, the heating device is located inside a workpiece to be closed, and the heating device slides along the guide rail to the workpiece to be closed and then heats the workpiece;

[0011] A hydraulic device is arranged on the hydraulic support platform, and the punch is arranged on the top of the hydraulic device. The lifting and lowering of the hydraulic support platform drives the lifting and lowering of the hydraulic device and the punch; the quick-loading pull rod assembly includes a pull rod, an upper quick-loading structure, and a lower quick-loading structure. The upper end of the pull rod is connected to the die located inside the workpiece through the upper quick-loading structure, and the lower end of the pull rod is connected to the hydraulic device through the lower quick-loading structure. The setting of the upper and lower quick-loading structures can realize the rapid installation and disassembly of the pull rod, the die and the hydraulic device.

[0012] Furthermore, the hydraulic device includes a hollow hydraulic cylinder, which includes a cylinder body and a hollow piston rod. The cylinder body is fixedly arranged on the hydraulic support platform, and the hollow piston rod is arranged on the inner side of the cylinder body; the punch is fixedly arranged on the output end of the hollow piston rod.

[0013] Furthermore, the pull rod is arranged to penetrate the interior of the hollow piston rod;

[0014] The upper quick-install structure comprises a clamp assembly and an upper fixing sleeve, and the upper fixing sleeve is placed on the outside of the clamp assembly; the lower quick-install structure comprises a clamp assembly and a lower fixing sleeve, and the lower fixing sleeve is placed on the outside of the clamp assembly and fixedly connected to the cylinder body of the hollow hydraulic cylinder.

[0015] Furthermore, the clamp assembly is composed of two matching clamp parts, the inner side of the clamp parts is provided with an inner step; the upper end and the lower end of the pull rod are both provided with an outer step matching with the inner step.

[0016] A closing process for closing a pressure vessel comprises the following steps:

[0017] a. Preparation: Place the workpiece on the cylinder support mechanism; the guide rail of the heating device moving mechanism passes through the inside of the workpiece, and the heating device is arranged on the guide rail and can slide axially along the guide rail; the hydraulic support platform and the hollow hydraulic cylinder are installed as a whole and placed under the workpiece; the punch of the mold is fixedly installed on the output end of the hollow piston rod of the hollow hydraulic cylinder;

[0018] b. Opening holes: cutting and opening holes at the pre-opening positions on the workpiece;

[0019] c. Closing operation: Start the cylinder support mechanism, which drives the workpiece to rotate until the opening of the workpiece is directly below the workpiece; the heating device slides along the guide rail to directly above the opening of the workpiece; the hydraulic support platform is moved to drive the hydraulic device to directly below the opening of the workpiece, and the hydraulic support platform is raised to drive the hollow hydraulic cylinder located on it to move upward, thereby driving the punch located at the output end of the hollow piston rod to move upward to the opening of the workpiece; the die of the mold is placed inside the workpiece;

[0020] The opening of the workpiece is heated by a heating device. When the temperature of the opening of the workpiece reaches the set closing temperature, the heating device stops heating and moves away from the opening of the workpiece along the guide rail.

[0021] Move the die to just above the opening of the workpiece and make the position of the die correspond to that of the punch; insert the pull rod on the inner side of the hollow piston rod, the lower end of the pull rod is fixedly connected to the cylinder body of the hollow hydraulic cylinder through the lower quick-fit structure, and the upper end of the pull rod is fixedly connected to the die through the upper quick-fit structure, and the position of the die relative to the hollow hydraulic cylinder is determined; start the hollow hydraulic cylinder, the hollow piston rod of the hollow hydraulic cylinder extends to drive the punch to rise and press upward against the opening of the workpiece, the punch and the die cooperate to realize the inward flanging of the opening of the workpiece, and complete the closing forming operation of the opening of the workpiece.

[0022] The punch of the mold for closing the pressure vessel of the present invention is a detachable combined punch, which can meet various needs of actual production. The design of the combined punch reduces the specifications of the mold during the closing molding of the pressure vessel, and can achieve multiple uses of one mold; the closing device for closing the pressure vessel has significant advantages such as simple structure, easy assembly, stable operation, good molding quality, high efficiency, etc., and can meet the closing molding requirements in various multi-cavity pressure vessels. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 It is a schematic diagram of the positional relationship between the mold, the closing device and the workpiece of the present invention.

[0025] Figure 2 It is a schematic diagram of the working state of the closing device of the present invention.

[0026] Figure 3 It is a schematic diagram of the structure of the punch A in Example 1.

[0027] Figure 4 It is a schematic diagram of the structure of the punch B in the second embodiment.

[0028] Figure 5 This is the main view of punch B.

[0029] Figure 6 for Figure 5 Top view of the .

[0030] Figure 7 Schematic diagram of the positional relationship between the punch, quick-release tie rod assembly and hydraulic device.

[0031] Figure 8 It is a structural schematic diagram of the quick-release tie rod assembly.

[0032] Fig. 9 It is a structural schematic diagram of the quick-release tie rod assembly.

[0033] Fig.10 A cross-sectional view of the quick-release tie rod assembly.

[0034] Fig.11 It is a schematic diagram of the structure of the pull rod.

[0035] Explanation of symbols in the figure:

[0036] 1. Punch; 2. Die; 3. Arc-shaped split section; 4. Upper fixing ring A; 5. Lower fixing ring A; 6. Expansion section; 7. Upper fixing ring B; 8. Lower fixing ring B; 9. Heating device; 10. Hydraulic support platform; 11. Hollow hydraulic cylinder; 12. Quick-release tie rod assembly; 13. Workpiece; 14. Guide rail; 15. Hollow piston rod; 16. Tie rod; 17. Upper quick-release structure; 18. Lower quick-release structure; 19. Clamp assembly; 20. Upper fixing sleeve; 21. Clamp; 22. Lower fixing sleeve; 23. Roller frame support; 24. Inner step; 25. Outer step. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0038] A mold for closing a pressure vessel is used to realize the closing molding operation at an opening on a workpiece; the mold comprises a punch 1 and a die 2 matched with the punch, and the die is a cylinder of a corresponding diameter rolled according to the closing shape; in actual production, the closing shape on the pressure vessel is not only a circular closing, but also a large number of elliptical closings. The punch 1 of the present invention is a detachable combined punch, which can meet various needs of actual production. The design of the combined punch reduces the specifications of the mold when the pressure vessel is closed and molded, and can realize multiple uses of one mold.

[0039] The combined punch 1 of the present invention comprises a basic punch and an extended punch. The basic punch is used for performing circular closing molding on the opening of a workpiece, and the extended punch is used for performing elliptical closing molding on the opening of the workpiece.

[0040] The basic punch is composed of a plurality of equally divided split punch segments. The top and bottom of the basic punch are respectively provided with an upper fixing ring and a lower fixing ring. Both the upper and lower fixing rings are circular and adapted to the shape and size of the basic punch. The split punch segments are connected and fixed into one body through the setting of the upper and lower fixing rings to form the basic punch.

[0041] The expansion type punch is a basic punch with a punch expansion section added, and is composed of a plurality of split punch sections and a plurality of punch expansion sections; the top and bottom of the expansion type punch are respectively provided with an upper fixing ring and a lower fixing ring, and the upper and lower fixing rings are both elliptical and adapted to the shape and size of the expansion type punch; the split punch sections and the punch expansion sections are connected and fixed into one body through the setting of the upper and lower fixing rings to form the expansion type punch.

[0042] Embodiment 1

[0043] like Figure 3 As shown, the punch 1 of the mold for closing the pressure vessel in this embodiment is the punch A, and the punch A is a basic punch; the punch A includes four equally divided arc-shaped split segments, and the four arc-shaped split segments are combined to form the punch A; the upper fixing ring is the upper fixing ring A4, and the lower fixing ring is the lower fixing ring A5. The upper fixing ring A4 and the lower fixing ring A5 are both circular and have sizes corresponding to the top and bottom of the punch A, respectively. The upper fixing ring A and the lower fixing ring A are respectively placed on the upper end and the lower end of the punch A to connect the punch A as a whole.

[0044] Embodiment 2

[0045] like Figure 4-6As shown, the punch 1 of the mold for closing the pressure vessel in this embodiment is a punch B, and the punch B is an expansion type mold; the punch B includes four equally divided arc-shaped split segments and two expansion segments, and the four equally divided arc-shaped split segments and the two expansion segments together constitute the punch B; the upper fixing ring is an upper fixing ring B7, and the lower fixing ring is a lower fixing ring B8. The upper fixing ring B and the lower fixing ring B are both elliptical and their sizes are respectively adapted to the top and bottom of the punch B. The upper fixing ring B and the lower fixing ring B are respectively placed on the upper end and the lower end of the punch B to connect the punch B as a whole.

[0046] like Figure 1 , Figure 2 As shown, the closing device for closing a pressure vessel of the present invention includes a mold, and also includes a barrel support mechanism, a heating device 9, a heating device moving mechanism, a hydraulic support platform 10, and a quick-release pull rod assembly 12. The barrel support mechanism is used to support the workpiece. The barrel support mechanism adopts the roller frame support in the prior art. The roller frame support 23 can drive the workpiece to perform flexible circular rotation to realize closing operations at different positions of the workpiece.

[0047] In the process of closing, in order to reduce the closing force and prevent cracks from occurring during metal deformation, the closing part needs to be heated. In view of the working characteristics of the closing, the heating device of the present invention uses a high-frequency electromagnetic heating device to heat the opening of the workpiece, abandoning the flame heating method in the prior art, and has the advantages of fast heating speed, uniform heating area and temperature.

[0048] The moving mechanism of the heating device includes a guide rail 14, which passes through the interior of the workpiece. The heating device 9 is slidably arranged on the guide rail 14, and the heating device 9 is located inside the workpiece to be closed. When the opening of the workpiece needs to be heated, the heating device 9 slides along the guide rail 14 to the opening on the workpiece for heating.

[0049] like Figure 7 As shown, the bottom of the hydraulic support platform 10 is provided with universal wheels to facilitate the movement of the hydraulic support platform 10; a hydraulic device is provided on the hydraulic support platform 10, and the hydraulic device includes a hollow hydraulic cylinder 11; the hollow hydraulic cylinder includes a cylinder body and a hollow piston rod 15, and the hollow piston rod 15 is arranged inside the cylinder body, and the cylinder body is fixedly arranged on the hydraulic support platform 10, and the punch 1 is fixedly arranged on the output end of the hollow piston rod 15; the lifting and lowering of the hydraulic support platform drives the hollow hydraulic cylinder and the punch thereon to lift and lower, so as to drive the punch to rise and press against the opening of the workpiece or drive the punch to descend and move away from the workpiece.

[0050] like Figure 8-Figure 11As shown, the quick-install rod assembly 12 includes a rod 16, an upper quick-install structure 17, and a lower quick-install structure 18. The rod 16 is arranged inside the hollow piston rod 15; the upper quick-install structure 17 includes a clamp assembly 19 and an upper fixing sleeve 20, and the upper fixing sleeve 20 is sleeved on the outside of the clamp assembly 19; the clamp assembly 19 is composed of two separate matching clamp parts, and the inner side of the clamp part 21 is provided with an inner step 24; the upper end of the rod 16 is provided with an outer step 25 matching with the inner step 24; When assembling the pull rod and the die, first pass the upper end of the pull rod through the die, then install the clamp assembly on the upper end of the pull rod, and determine the relative position of the clamp assembly and the pull rod in the vertical direction through the cooperation of the inner step and the outer step. Then place the upper fixing sleeve on the outside of the clamp assembly, connect the two separate clamp parts into one, and fix the clamp assembly on the pull rod to further fix the die below the clamp assembly. The setting of the upper quick-release structure determines the position of the die relative to the pull rod.

[0051] The lower quick-release structure 18 includes a clamp assembly 19 and a lower fixed sleeve 22, and the lower fixed sleeve 22 is placed on the outside of the clamp assembly 19; the clamp assembly 19 is composed of two matching clamp parts, and the inner side of the clamp part 21 is provided with an inner step 24; the lower end of the pull rod 16 is provided with an outer step matching with the inner step 24; when assembling the pull rod and the hollow hydraulic cylinder, the lower end of the pull rod passes through the cylinder body, and the clamp assembly is installed on the lower end of the pull rod. The relative position of the clamp assembly and the pull rod in the vertical direction is determined by the cooperation of the inner step and the outer step, and then the lower fixed sleeve is placed on the outside of the clamp assembly, the two separate clamp parts are connected as one, and then the lower fixed sleeve 22 is fixedly connected to the cylinder body of the hollow hydraulic cylinder to determine the position of the pull rod relative to the hollow hydraulic cylinder.

[0052] The upper end of the tie rod of the closing device of the present invention determines the position of the die 2 inside the workpiece through the upper quick-install structure 17, and the lower end of the tie rod 16 passes through the cylinder body of the hollow hydraulic cylinder and is fixedly connected to the cylinder body through the lower quick-install structure 18. The arrangement of the upper and lower quick-install structures can realize the rapid installation and disassembly of the tie rod, the die and the hydraulic device, so that the tie rod can be quickly assembled with the die, which is very convenient and saves time and effort.

[0053] The upper quick-release structure is installed on the pull rod 16 to determine the position of the die relative to the cylinder body. When the closing forming operation is performed at the opening of the workpiece, the die is in a stationary state, the hollow hydraulic cylinder is started, and the hollow piston rod 15 is extended to drive the punch 1 fixed on the top thereof to rise and push up the opening of the workpiece. The pushed-up punch 1 cooperates with the stationary die 2 to realize the inward flanging forming of the opening of the workpiece, thereby completing the closing forming operation at the opening of the workpiece.

[0054] The steps of the closing process for closing the pressure vessel of the present invention are as follows:

[0055] a. Preparation: Place the workpiece 13 on the cylinder support mechanism and adjust the height of the workpiece through the cylinder support mechanism; the guide rail 14 of the heating device moving mechanism passes through the inside of the workpiece, and the heating device 9 is arranged on the guide rail 14 and can slide axially along the guide rail; the hydraulic support platform 10 and the hollow hydraulic cylinder 11 are installed as a whole and placed under the workpiece 13; the punch 1 of the mold is fixedly installed on the output end of the hollow piston rod 15 of the hollow hydraulic cylinder;

[0056] b. Drilling: Cut and drill holes at the pre-drilled positions on the workpiece, and grind the cut surfaces of the holes to make them smooth;

[0057] c. Closing operation: Start the cylinder support mechanism, which drives the workpiece 13 to rotate to the workpiece opening and is located directly below the workpiece; the heating device 9 slides along the guide rail 14 to the top of the workpiece opening; the mobile hydraulic support platform 10 drives the hydraulic device 11 to move to the bottom of the workpiece opening, the hydraulic support platform 10 rises and drives the hollow hydraulic cylinder 11 located thereon to move upward, thereby driving the punch 1 located at the output end of the hollow piston rod of the hollow hydraulic cylinder to move upward to the opening of the workpiece to press against the workpiece, and the die 2 of the mold is placed inside the workpiece; the workpiece opening is heated by the heating device; when the temperature of the workpiece opening reaches the set closing temperature, the heating device Stop heating, and move the heating device along the guide rail 14 away from the opening of the workpiece; move the die 2 to a position directly above the opening of the workpiece and corresponding to the position of the punch 1; insert the pull rod 16 on the inner side of the hollow piston rod 15, and the lower end of the pull rod is fixedly connected to the cylinder body of the hollow hydraulic cylinder through the lower quick-release structure 18, and the upper end of the pull rod is fixedly connected to the die 2 through the upper quick-release structure, and the position of the die relative to the hollow hydraulic cylinder is determined; start the hollow hydraulic cylinder 11, and the hollow piston rod 15 of the hollow hydraulic cylinder extends to drive the punch 1 to rise and press upward against the opening of the workpiece, and the punch 1 cooperates with the die 2 to realize the inward flanging of the workpiece opening, thereby completing the closing forming operation of the workpiece opening.

[0058] The punch of the mold for closing the pressure vessel of the present invention is a detachable combined punch, which can meet various needs of actual production. The design of the combined punch reduces the specifications of the mold during the closing molding of the pressure vessel, and can achieve multiple uses of one mold; the closing device for closing the pressure vessel has significant advantages such as simple structure, easy assembly, stable operation, good molding quality, high efficiency, etc., and can meet the closing molding requirements in various multi-cavity pressure vessels.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A closing device for closing a pressure vessel, characterized in that: The invention comprises a mould, a hydraulic support platform (10), and a quick-release pull rod assembly (12); the mould comprises a punch (1) and a die (2) matching the punch; the punch (1) is a detachable combined punch, and an upper fixing ring and a lower fixing ring are respectively provided at the upper end and the lower end of the punch (1), and the upper fixing ring and the lower fixing ring are used to connect the split punches into one; The punch (1) is a punch A, and the punch A comprises a plurality of arc-shaped split segments; the upper fixing ring is an upper fixing ring A (4), and the lower fixing ring is a lower fixing ring A (5); the plurality of arc-shaped split segments are combined into the punch A, and the upper fixing ring A and the lower fixing ring A are respectively arranged at the upper end and the lower end of the punch A to connect the punch A into one body; Or the punch (1) is a punch B, and the punch B includes a plurality of arc-shaped split segments and a plurality of expansion segments; the upper fixing ring is an upper fixing ring B (7), and the lower fixing ring is a lower fixing ring B (8); the plurality of arc-shaped split segments and the plurality of expansion segments are combined to form the punch B, and the upper fixing ring B and the lower fixing ring B are respectively arranged at the upper end and the lower end of the punch B to connect the punch B into one body; The upper fixing ring A (4) is circular; the lower fixing ring A (5) is circular; The upper fixing ring B (7) is elliptical; the lower fixing ring B (8) is elliptical; The hydraulic support platform (10) is provided with a hydraulic device, the punch (1) is provided on the top of the hydraulic device, and the hydraulic support platform is raised and lowered to drive the hydraulic device and the punch to rise and fall; the quick-installation tie rod assembly (12) comprises a tie rod (16), an upper quick-installation structure (17), and a lower quick-installation structure (18); the upper end of the tie rod is connected to the die (2) located inside the workpiece via the upper quick-installation structure (17), and the lower end of the tie rod (16) is connected to the hydraulic device via the lower quick-installation structure (18); the arrangement of the upper and lower quick-installation structures enables the tie rod, the die, and the hydraulic device to be quickly installed and removed; The hydraulic device comprises a hollow hydraulic cylinder (11), the hollow hydraulic cylinder comprising a cylinder body and a hollow piston rod (15), the cylinder body being fixedly arranged on the hydraulic support platform (10), and the hollow piston rod being arranged on the inner side of the cylinder body; the punch (1) being fixedly arranged on the output end of the hollow piston rod (15); The pull rod (16) is arranged to penetrate the interior of the hollow piston rod (15); The upper quick-install structure (17) comprises a clamp assembly and an upper fixing sleeve (20), wherein the upper fixing sleeve (20) is sleeved on the outside of the clamp assembly; the lower quick-install structure (18) comprises a clamp assembly and a lower fixing sleeve (22), wherein the lower fixing sleeve (22) is sleeved on the outside of the clamp assembly and is fixedly connected to the cylinder body of the hollow hydraulic cylinder; The clamp assembly is composed of two matching clamp parts, the inner side of which is provided with an inner step; the upper end and the lower end of the pull rod (16) are both provided with an outer step matching with the inner step.

2. The closing device for closing a pressure vessel according to claim 1, characterized in that: The closing device also includes a heating device (9) and a heating device moving mechanism; the heating device moving mechanism includes a guide rail (14), the heating device (9) is slidably arranged on the guide rail (14), the heating device (9) is located inside the workpiece to be closed, and the heating device slides along the guide rail to the position of the workpiece to be closed and then performs heating.

3. The closing process of the closing device for closing the pressure vessel according to any one of claims 1 to 2, characterized in that: The steps of the closing process are: a. Preparation: Place the workpiece (13) on the cylinder support mechanism; the guide rail (14) of the heating device moving mechanism passes through the inside of the workpiece, and the heating device (9) is arranged on the guide rail (14) and can slide axially along the guide rail; the hydraulic support platform (10) and the hollow hydraulic cylinder (11) are installed as a whole and placed under the workpiece (13); the punch (1) of the mold is fixedly installed on the output end of the hollow piston rod (15) of the hollow hydraulic cylinder; b. Opening holes: cutting and opening holes at the pre-opening positions on the workpiece; c. Closing operation: start the cylinder support mechanism, which drives the workpiece (13) to rotate until the opening of the workpiece is located directly below the workpiece; the heating device (9) slides along the guide rail (14) to directly above the opening of the workpiece; the hydraulic support platform (10) is moved to drive the hydraulic device to move directly below the opening of the workpiece, the hydraulic support platform (10) is lifted and drives the hollow hydraulic cylinder (11) located thereon to move upward, thereby driving the punch (1) located at the output end of the hollow piston rod to move upward to the opening of the workpiece; the die (2) of the mold is placed inside the workpiece; The opening of the workpiece is heated by a heating device, and when the temperature of the opening of the workpiece reaches a set closing temperature, the heating device stops heating, and the heating device moves away from the opening of the workpiece along a guide rail (14); The die (2) is moved to the position directly above the opening of the workpiece and the position of the die (2) corresponds to the position of the punch (1); a pull rod (16) is inserted into the inner side of the hollow piston rod (15); the lower end of the pull rod is fixedly connected to the cylinder body of the hollow hydraulic cylinder via a lower quick-install structure (18); the upper end of the pull rod is fixedly connected to the die (2) via an upper quick-install structure, and the position of the die relative to the hollow hydraulic cylinder is determined; the hollow hydraulic cylinder (11) is started, the hollow piston rod (15) of the hollow hydraulic cylinder extends to drive the punch (1) to rise and press upward against the opening of the workpiece, and the punch (1) cooperates with the die (2) to realize inward flanging of the opening of the workpiece, thereby completing the closing forming operation of the opening of the workpiece.

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