Thin-walled small-bore cylindrical metal shell ribbing die and demolding process

Abstract

A kind of thin-walled small-bore cylindrical metal shell ribbing mould and demoulding process, comprising: upper die, lower die, hydraulic press workbench, upper die is fixed below hydraulic press upper pillow, lower die is installed above hydraulic press workbench, male model frame movable body is equipped with male die inner slide block, male die inner slide block passes through male die inner slide block fixed pin and is installed in the inner slide block groove of male model frame movable body by passing through male model frame movable body, male model frame movable body is sleeved on multistage stepped die core, and its bottom is abutted with ejector rod.The process steps are as follows: A. put in metal shell;B. male die inner slide block extrusion ribbing;C. upper die returns, male model frame movable body rises in position;D. manually complete demoulding.The advantages of the present application are that, for small-bore thin shell under the premise of space limitation, the design of hidden slide block in male movable body realizes multiple ribs once forming by stamping, so as to improve the quality and performance of mould, improve product quality and production efficiency, and reduce production cost.

Description

Technical Field

[0001] This invention relates to the manufacture and manufacturing process of a metal container, and particularly to a die for punching and demolding a thin-walled, small-diameter cylindrical metal shell for a stainless steel insulated container. Background Technology

[0002] Currently, the industry standard for stamping ribs and strong demolding processes in the stretching of thin-walled, small-diameter cylindrical metal shells for insulated containers typically employs a single-stroke, multi-stage method. This involves horizontally sizing the cylinder body, rotating it, and then stamping a second or third time, and so on. This method results in deformation and dimensional errors of approximately 1mm in the thin-walled, small-diameter cylindrical metal shell, causing looseness or excessive tightness during installation and fitting, thus affecting production efficiency and product quality stability. If an inverted die structure is used to stamp the ribs in one go, the limited internal space of the sliding block of the convex mold frame leads to insufficient mold strength, making it prone to cracking. Furthermore, there is simply no space to install a stripping device, making the inverted die solution difficult to implement. Therefore, it is necessary to overcome the shortcomings and stamping efficiency of the existing molds and seek new die stamping structures and stripping methods. Summary of the Invention

[0003] The purpose of this invention is to address the deficiencies in the existing technology by providing a thin-walled, small-diameter cylindrical metal shell punching mold and demolding process.

[0004] This invention comprises: an upper mold, a lower mold, and a hydraulic press worktable, characterized in that the upper mold is fixed below the upper support of the hydraulic press. The upper mold includes an upper mold base, a concave mold frame fixing plate, a concave mold pad, and a concave mold frame slider. The concave mold frame slider has a stop groove, and the slider is fixed to the concave mold frame fixing plate by hanging screws around the concave mold frame fixing plate. The upper mold base, the concave mold pad, and the concave mold frame fixing plate are fixed to the upper mold base by fixing screws. The lower mold is installed above the hydraulic press worktable and includes a lower mold base, a convex mold frame movable body, a convex inner slider, a convex inner slider fixing pin, a multi-stage stepped mold core, and an ejector rod. The lower mold base is fixed to the pads on the hydraulic press worktable. The lower mold base has several independent guide pillars, which are fixed to the lower mold base by fixing screws. The top ends of the independent guide pillars are embedded in corresponding positions on the upper mold base. The upper part of the movable part of the punch mold frame has several inner slider grooves for installing the inner slider of the punch. The inner slider of the punch is installed in the inner slider groove of the movable part of the punch mold frame through the inner slider fixing pin. A foolproof vertical plane is provided on the circumference of the central hole of the movable part of the punch mold frame. Similarly, a foolproof guide vertical plane is also provided on the circumferential side of the multi-stage stepped mold core. The two planes cooperate with each other to prevent the movable part of the punch mold frame from rotating left and right during the punching process, which would cause misalignment of the inner slider of the punch and the slider of the concave mold frame and lead to mold damage. The movable part of the punch mold frame is fitted on the multi-stage stepped mold core. The multi-stage stepped mold core has multiple different diameters. Each step has a slope transition. The multi-stage stepped mold core is fixed on the lower mold base. The hydraulic press ejector rod abuts against the ejector rod through the ejector plate. The ejector rod passes through the multi-stage stepped mold core and abuts against the bottom of the movable part of the punch mold frame. An upper dead center stroke sensor switch 24 and a lower dead center stroke sensor switch 25 are provided on the upper mold and lower mold respectively.

[0005] During mold operation, the upper mold descends, the slider of the concave mold frame is pressed down by the upper support of the hydraulic press, and the movable body of the convex mold frame is pushed up by the ejector plate and ejector rod. The upper mold continues to descend, causing the slider inside the convex mold to pass through the diameter changes on the multi-stage stepped mold core until it moves to the second step of the multi-stage stepped mold, completely ejecting the slider inside the convex mold and completing the punching process. When the upper support of the hydraulic press moves down to the lower stop of the stroke sensor switch, the upper support of the hydraulic press begins to return until it returns to the upper stop. The movable body of the convex mold frame rises through the rise of the ejector rod of the hydraulic press, causing the ejector rod to rise synchronously. The movable body of the convex mold frame moves up to the first step of the multi-stage stepped mold core. At this time, the thin-walled, small-diameter cylindrical metal shell tightly wraps around the movable body of the convex mold frame. By manually rotating the small-diameter cylindrical metal shell, it is made to intersect with the R-angle on the slider inside the convex mold frame, completing the demolding action.

[0006] The multi-stage stepped mold core has a first-stage inclined transition of 18-28 degrees, with a distance of 10-20mm from the top to the bottom of the first-stage step. The diameter of the bottom of the first-stage step is 20-30mm. The distance from the bottom of the first-stage step to the bottom of the second-stage step is 10-20mm, and the diameter of the bottom of the second-stage step is 30-50mm. The inclined surfaces have rounded corners at both ends. The second-stage step features a guide and anti-misalignment structure. This ensures smooth, unobstructed downward movement of the slider within the punch. The reasonable design of the inclined surface and rounded corners minimizes the reaction force during the downward movement of the slider. The guide and anti-misalignment structure in the second-stage step improves the guiding accuracy and installation uniqueness of the mold. The guide and anti-misalignment structure guides the movable body of the punch frame to move up and down under the guidance of the anti-misalignment position, and also prevents the movable body of the punch frame from rotating left and right, which could cause misalignment between the slider within the punch and the slider of the concave mold frame, leading to mold damage.

[0007] Both ends of the movable body of the convex mold frame and both ends of the inner slider of the convex mold are provided with rounded corners with a radius of ≥1mm. The purpose is to eliminate the internal stress generated during mold processing and improve the mold strength.

[0008] The movable body of the convex mold frame adopts an inverted structure, and the thickness of the inner slider groove on the movable body from the top plane is ≥2mm. This thickness does not affect the mass production life of the mold, and the design of the large and small steps of the movable body of the convex mold frame also enhances the strength of the mold.

[0009] The process of this invention includes the following steps:

[0010] A. Place the thin-walled, small-diameter cylindrical metal shell onto the movable body of the convex mold frame, start the hydraulic press operation switch, and the slider of the concave mold frame begins to descend, gradually pressing against the movable body of the convex mold frame.

[0011] The upper and lower dies move vertically along the central axis, with independent guide pillars ensuring their smooth operation.

[0012] B. As the upper die continues to descend, the bottom end of the inner slider of the punch in the lower die is subjected to pressure from the changing diameter of the multi-step die core. The top end of the inner slider extends from several inner slider slots on the upper part of the moving part of the punch mold frame, extruding the thin-walled, small-diameter cylindrical metal shell to achieve punching. The inner slider of the concave die frame and the moving part of the convex die frame move in a corresponding manner during this process. After the upper die moves down to the second step of the multi-step die core where the moving part of the convex die frame is squeezed, it continues to move down to the lower stop point, causing the thin-walled, small-diameter cylindrical shell to...

[0013] The ribs of the metal shell are now complete;

[0014] C. When the concave mold frame slider moves down to the lower stop point of the upper pillow of the hydraulic press, the inner slider of the punch and the thin-walled, small-diameter cylindrical metal shell are tightly bound together. The upper pillow of the hydraulic press begins to return. After the concave mold frame slider returns to the upper stop point, the moving body of the punch frame is pushed upward by the hydraulic press ejector rod to eject the plate and the ejector plate.

[0015] The rod pushes the movable body of the convex model frame onto the first step of the multi-level stepped mold core;

[0016] D. When the thin-walled, small-diameter cylindrical metal shell is tightly clamped onto the moving part of the punch, it is located at the first step of the multi-step mold core. Gently rotate the thin-walled, small-diameter cylindrical metal shell to the left or right by 5°-10°. The force of the rotation acts on the inner slider of the punch. Since both ends are rounded, the inner slider of the punch retracts inward and returns to the inner slider groove at the top of the moving part of the punch mold frame, thus completing the demolding.

[0017] The hydraulic press has a main cylinder servo pressure of 15 MPa and a servo flow rate of 80%. The lower cylinder pressure is divided into segments: segment 1 is 0.1 MPa, and segments 2, 3, and 4 are 0.2 MPa.

[0018] The advantages of this invention are that, under space constraints, the design of a sliding block hidden within the movable body of the convex mold frame enables multi-ribbed, one-time stamping forming of small-diameter, thin-shell components. This improves mold quality and performance, thereby enhancing product quality and production efficiency. The inverted design of the movable convex mold frame also facilitates mold maintenance and quick product handling, effectively ensuring the mold's strength. In particular, its use in conjunction with a hydraulic press ensures that the mold quality meets normal mass production requirements. It solves the problems of punching ribs and demolding in small-diameter cylindrical metal shell stretching parts. It also overcomes the difficulty of demolding small-diameter cylindrical metal shells. The cylindrical metal casing between the sections allows for more precise and efficient punching, reducing production costs. Attached Figure Description

[0019] Figure 1 A schematic diagram of the structure of this invention;

[0020] Figure 2 A magnified schematic diagram of the local structure at the starting position of the upper and lower dies during the stamping process;

[0021] Figure 3 A magnified schematic diagram of the local structure of the concave mold frame slider descending to the lower stop point during the stamping process;

[0022] Figure 4 A three-dimensional structural diagram of stamping and demolding;

[0023] Figure 5 A schematic diagram of a thin-walled, small-diameter cylindrical metal shell;

[0024] Figure 6 A schematic diagram of the structure of the movable body of the convex model frame;

[0025] Figure 7 A schematic diagram of the structure of a multi-stage stepped mold core.

[0026] In the diagram: 1 Upper mold base, 2 Die mold pad, 3 Die mold frame fixing plate, 4 Die mold frame slider, 5 Convex mold frame moving body, 6 Convex mold inner slider, 7 Convex mold inner slider fixing pin, 8 Fixing screw, 9 Hanging screw, 10 Independent guide pillar, 11 Lower mold base, 12 Ejector plate, 13 Hydraulic press ejector rod, 14 Hydraulic press worktable, 15 Ejector rod, 16 Multi-stage stepped mold core, 17 Thin-walled small-diameter cylindrical metal shell, 18 Guide pillar fixing screw, 19 Guide pillar fixing screw, 20 Hydraulic press upper pillow, 21 Foot pad, 22 Anti-foolproof vertical plane, 23 Anti-foolproof guide vertical plane, 24 Upper dead center travel sensor switch, 25 Lower dead center travel sensor switch. Detailed Implementation

[0027] The embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0028] See Figures 1 to 7 This embodiment consists of an upper mold, a lower mold, and a hydraulic press worktable 14. The upper mold is fixed below the upper support 20 of the hydraulic press. The upper mold includes an upper mold base 1, a concave mold frame fixing plate 3, a concave mold pad 2, and a concave mold frame slider 4. The concave mold frame slider 4 has a stop groove, and the concave mold frame slider 4 is fixed to the concave mold frame fixing plate 3 by hanging screws 9 around the concave mold frame fixing plate 3. The upper mold base 1, the concave mold pad 2, and the concave mold frame fixing plate 3 are fixed to the upper mold base 1 by fixing screws 19.

[0029] The lower mold is installed above the hydraulic press worktable 14. The lower mold consists of a lower mold base 11, a movable punch frame 5, an inner punch slider 6, an inner punch slider fixing pin 7, a multi-stage stepped mold core 16, and an ejector pin 15. The lower mold base 11 is fixed to the pads 21 on the hydraulic press worktable 14. Several independent guide pillars 10 are provided on the lower mold base 11, and the independent guide pillars 10 are fixed to the lower mold base 11 by fixing screws 18. In this embodiment, there are two independent guide pillars 10. The top of each independent guide pillar 10 is embedded in the corresponding position of the upper mold base 1.

[0030] The upper part of the movable body 5 of the punch frame is provided with several inner slider grooves for mounting the inner slider 6 of the punch; in this embodiment, there are six inner slider grooves. The inner slider 6 of the punch is mounted inside the movable body 5 of the punch frame 5 via the inner slider fixing pin 7. The movable body 5 of the punch frame 5 is mounted on the top of the ejector pin 15 using an inverted structure. The thickness of the inner slider groove of the punch on the movable body 5 from the top plane is ≥2mm. This thickness does not affect the mass production life of the mold, and the large and small step design of the movable body 5 of the punch frame 5 also enhances the strength of the mold.

[0031] The movable body 5 of the convex mold frame has a foolproof inner hole that mates with a foolproof position on the multi-stage stepped mold core 16. A foolproof vertical plane 22 is provided on the circumference of the central hole of the movable body 5, and similarly, a foolproof guide vertical plane 23 is provided on the circumferential side of the multi-stage stepped mold core 16. The two planes cooperate with each other. During the punching process of the movable body 5, this prevents the movable body 5 from rotating left and right, causing misalignment between the slider 6 inside the punch and the slider 4 of the concave mold frame, which could lead to mold damage. The movable body 5 of the convex mold frame is fitted onto the multi-stage stepped mold core 16, which has multiple different diameters, and each step has a sloped transition. The multi-stage stepped mold core 16 has a first-stage slope transition of 18-28 degrees, with a distance of 10-20mm from the top to the bottom of the first-stage step, a diameter of 20-30mm at the bottom of the first-stage step, a distance of 10-20mm from the bottom of the first-stage step to the bottom of the second-stage step, and a diameter of 30-50mm at the bottom of the second-stage step. In this embodiment, the distance from the top to the bottom of the first-stage step is 10mm, the diameter of the bottom of the first-stage step is 20mm, the distance from the bottom of the first-stage step to the bottom of the second-stage step is 10mm, and the diameter of the bottom of the second-stage step is 30mm. The slope has rounded corners at both ends, and both ends of the movable body 5 of the punch mold frame and both ends of the inner slider 6 of the punch have rounded corners with a radius ≥1mm. This is to eliminate internal stress generated during mold processing and improve mold strength. The second-stage step is equipped with a guide and anti-foolproof structure. The slide block 6 inside the punch moves smoothly without obstruction, and the reaction force during the downward movement of the slide block 6 inside the punch is reduced as much as possible through a reasonable structure of inclined surface and rounded corner transition. The second step is equipped with a foolproof structure, which allows the movable body 5 of the punch mold frame to move up and down under the guidance of the foolproof structure. It also prevents the movable body 5 of the punch mold frame from rotating left and right, causing misalignment between the slide block 6 inside the punch and the slide block 4 of the concave mold frame, which would lead to mold damage.

[0032] The multi-stage stepped mold core 16 is fixed on the lower mold base 11. The hydraulic press ejector rod 13 abuts against the ejector rod 15 via the ejector plate 12. The ejector rod 15 passes through the multi-stage stepped mold core 16 and abuts against the bottom of the convex mold frame movable body 5. An upper dead center travel sensor switch 24 and a lower dead center travel sensor switch 25 are respectively provided on the upper mold and the lower mold.

[0033] During mold operation, the upper mold descends, the concave mold frame slider 4 is pressed down by the upper bolster 20 of the hydraulic press, and the convex mold frame movable body 5 is pushed up by the ejector plate 12 and ejector rod 15. The upper mold continues to descend, causing the inner slider 5 of the convex mold to change diameter along the multi-stage stepped mold core 16 until it reaches the second step of the multi-stage stepped mold 16, completely ejecting the inner slider 6 of the convex mold to complete the punching process. When the upper bolster 20 of the hydraulic press moves down to the lower stop of the stroke sensor switch, the upper bolster 20 of the hydraulic press begins to return until it returns to the upper stop. The convex mold frame movable body 5 rises through the ejector rod 13 of the hydraulic press, causing the ejector rod 15 to rise synchronously. The convex mold frame movable body 5 moves up to the first step of the multi-stage stepped mold core 16. At this time, the thin-walled small-diameter cylindrical metal shell tightly wraps around the convex mold frame movable body 5. By manually rotating the small-diameter cylindrical metal shell, it is made to intersect with the R-angle on the inner slider 6 of the convex mold frame movable body 5, completing the demolding action.

[0034] Thin-walled, small-diameter cylindrical metal shell refers to a shell with a diameter of Cold-rolled steel sheet wall thickness ≤ 1mm. Stainless steel wall thickness ≤ 0.6mm.

[0035] In this embodiment, the concave mold frame slider 4, the convex mold frame movable body 5, the inner slider 6 of the convex mold, and the multi-stage stepped mold core 16 adopt a quenching heat treatment + surface hard nitriding process. The quenching hardness is controlled between HRC45 and 58 according to different part requirements, seeking hardness without reducing the original toughness of the material. DC53 steel or materials with equivalent properties are selected, with the advantage that the hardness after heat treatment is higher than SKD11, and the toughness is twice that of SKD11. Combined with the flexible pressure of a hydraulic press, the mold can achieve mass production performance.

[0036] Fixing screws 18 and 19. The upper mold base 1 is fixed to the upper support 20 of the hydraulic press. The upper mold base 1, the die pad 2, and the die frame fixing plate 3 are fixed to the upper mold base 1 by fixing screws 8. The die frame slider 4 is fixed to the die frame fixing plate 3 by hanging screws 9. The convex mold frame movable body 5 includes an inner convex slider 6 and an inner convex slider fixing pin 7. The inner convex slider fixing pin 7 passes through the inner convex slider 6 to fix the slider to the convex mold frame movable body, preventing the inner slider from falling off. The ejector rod 15 passes through the multi-stage stepped mold core 16 and directly abuts against the convex mold frame movable body. The ejector rod 15 rests on the ejector plate 12. The ejector plate 12 contacts the hydraulic press ejector rod and is subjected to the ejection force F2 of the hydraulic press. The multi-stage stepped mold core is fixed to the lower mold base. The anti-foolproof inner hole in the convex mold frame movable body 5 and the anti-foolproof position on the multi-stage stepped mold core are matched. The shape-based anti-misalignment structure effectively prevents the moving part of the punch from rotating and misaligning with the slider of the die frame, thus preventing mold damage. The pad 21 is fixed to the lower die base. An ejector plate 12 is hollowly provided. The ejector plate contacts the hydraulic press ejector rod and receives the ejection force. The upper die base 1 and lower die base 11 are connected and fixed on the centerline by independent guide pillars 10.

[0037] This embodiment includes the following process steps:

[0038] A. Place the thin-walled, small-diameter cylindrical metal shell 17 onto the convex mold frame movable body 5, start the hydraulic press working button switch, the concave mold frame slider 4 begins to descend, and after it comes into contact with the convex mold frame movable body 5, it gradually presses and descends. The upper mold and the lower mold rely on the independent guide pillars 10 to ensure that they move up and down along the central axis.

[0039] B. The upper die continues to descend, and the bottom end of the inner slider 6 of the punch in the lower die is subjected to pressure from the changing diameter of the multi-stage stepped die core 16. The top end of the inner slider 6 of the punch extends from several inner slider grooves on the upper part of the moving body 5 of the punch model frame, and squeezes the thin-walled small-diameter cylindrical metal shell 17 until the punching is completed. The inner slider 4 of the concave die model frame and the moving body 5 of the punch model frame move in a corresponding manner during this process. After the upper die moves down to the second step of the multi-stage stepped die core 16, the moving body 5 of the punch model frame is squeezed down to the lower stop point, and the punching of the thin-walled small-diameter cylindrical metal shell 17 is completed.

[0040] C. When the concave mold frame slider 4 moves down to the lower stop point of the hydraulic press upper pillow 20, the inner slider 6 of the punch and the cylindrical body of the thin-walled small-diameter cylindrical metal shell 17 are tightly bound together. The hydraulic press upper pillow 20 begins to return. After the concave mold frame slider 4 returns to the upper stop point, the movable body 5 of the punch mold frame pushes the ejector plate 12 and the ejector rod 15 through the hydraulic press ejector rod 13, pushing the movable body 5 of the punch mold frame to the first step of the multi-stage stepped mold core 16.

[0041] D. When the thin-walled, small-diameter cylindrical metal shell 17 is tightly clamped onto the moving punch 5, it is located at the first step of the multi-step mold core 16. Gently rotate the thin-walled, small-diameter cylindrical metal shell 17 to the left or right by 5°-10°. Through the rotation of the thin-walled, small-diameter cylindrical metal shell 17, the force of rotation acts on the inner slider 5 of the punch, causing the inner slider 6 of the punch to rotate accordingly. Since both ends of the inner slider 6 of the punch are provided with rounded corners, the inner slider 6 of the punch retracts inward and returns to the inner slider groove at the top of the moving punch frame 5, thus completing the demolding.

[0042] The hydraulic press has a main cylinder servo pressure of 15 MPa and a servo flow rate of 80%. The lower cylinder pressure is divided into segments: segment 1 is 0.1 MPa, and segments 2, 3, and 4 are 0.2 MPa.

Claims

1. A thin-walled small-bore cylindrical metal shell bead line mold, comprising: The upper die, the lower die and the hydraulic machine workbench are characterized in that the upper die is fixed below the upper pillow of the hydraulic machine, the upper die is provided with an upper die seat, a concave die frame fixing plate and a concave die pad, and a concave die frame slider is arranged on the upper die, the concave die frame slider is fixed in the concave die frame fixing plate through hanging screws around the concave die frame fixing plate, the upper die seat and the concave die pad and the concave die frame fixing plate are fixed on the upper die seat through fixing screws, the lower die is installed above the hydraulic machine workbench, the lower die is provided with a lower die seat, a convex die frame movable body, a convex die inner slider, a convex die inner slider fixing pin, a multi-stage stepped die core and a top rod, the lower die seat is fixed on the pad foot on the hydraulic machine workbench, a plurality of independent guide columns are arranged on the lower die seat, the top ends of the independent guide columns are embedded in the corresponding positions of the upper die seat, the independent guide columns are fixed on the lower die seat through fixing screws, the convex die frame movable body is provided with a plurality of inner slider grooves for installing the convex die inner slider on the upper part of the convex die frame movable body, the convex die inner slider is installed in the inner slider groove of the convex die frame movable body through the convex die inner slider fixing pin, a foolproof vertical plane is arranged on the circumference of the central hole of the convex die frame movable body, a foolproof guide vertical plane is also arranged on the circumference side of the multi-stage stepped die core, the two planes cooperate with each other, the convex die frame movable body is sleeved on the multi-stage stepped die core, the top of the multi-stage stepped die core is provided with a plurality of different diameters, a slope transition is arranged on each stage, the lower end of the multi-stage stepped die core is fixed on the lower die seat, the top rod of the hydraulic machine abuts against the ejection plate, the top rod passes through the multi-stage stepped die core and abuts against the bottom of the convex die frame movable body, an upper stop point stroke sensing switch and a lower stop point stroke sensing switch are arranged on the upper die and the lower die.

2. The thin-walled small-bore cylindrical metal shell bead line mold according to claim 1, characterized in that The first stage of the multi-stage stepped die core is provided with a slope transition of 18-28 degrees, the distance from the top end to the bottom of the first stage is 10-20 mm, the diameter of the bottom of the first stage is 20-30 mm, the distance from the bottom of the first stage to the bottom of the second stage is 10-20 mm, the diameter of the bottom of the second stage is 30-50 mm, and round corners are arranged at both ends of the slope, and the first stage and the second stage are provided with a guide parallel foolproof structure.

3. The thin-walled small-bore cylindrical metal shell bead line mold according to claim 1, characterized in that The both ends of the convex die frame movable body and the both ends of the convex die inner slider are provided with round corners with a radius of ≥1 mm.

4. The thin-walled small-bore cylindrical metal shell bead line mold according to claim 1, characterized in that The convex die frame movable body adopts an inverted structure, and the thickness of the inner slider groove on the convex die frame movable body from the top plane is ≥2 mm.

5. A ribbing and demolding process for a thin-walled small-bore cylindrical metal shell, which process comprises the following steps: A. placing the thin-walled small-bore cylindrical metal shell on the convex die frame movable body, starting the hydraulic machine work button switch, and the concave die frame slider starts to descend and abuts against the convex die frame movable body and gradually presses and descends; B. the upper die continues to descend, the bottom end of the convex die inner slider in the lower die is subjected to the pressure of the diameter change of the multi-stage stepped die core, the top end of the convex die inner slider extends out of the plurality of inner slider grooves on the upper part of the convex die frame movable body, the thin-walled small-bore cylindrical metal shell is extruded to realize ribbing, the upper die descends to the second stage of the multi-stage stepped die core after the convex die frame movable body is extruded, continues to descend to the lower stop point, and the ribbing of the thin-walled small-bore cylindrical metal shell is completed. C. When the concave mold frame slider is lowered to the lower stop point of the upper pillow of the hydraulic machine, the convex mold frame slider and the thin-walled small-diameter cylindrical metal shell body are tightly clamped together, the upper pillow of the hydraulic machine starts to return, and after the concave mold frame slider returns to the upper stop point, the convex mold frame movable body pushes the convex mold frame movable body to the first step of the multi-step ladder through the hydraulic machine top rod, the top rod and the top rod. D. Hand turn the thin-walled small-diameter cylindrical metal shell to make the round corners on the convex mold frame movable body slider intersect, and complete demolding.

6. The process as claimed in claim 5, wherein the process is characterized by The hydraulic machine main cylinder servo pressure value is 15Mpa, the servo flow value is 80%, the lower cylinder pressure is segmented, and the first segment value is 0.1Mpa, and the second, third and fourth segments are 0.2Mpa.

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