Blank holder capable of preventing instability and fracture and blanking and drawing die

Abstract

The utility model relates to the technical field of stamping dies, in particular to a blank holder capable of preventing instability and fracture and a blanking and stretching die, which are used for blanking and stretching material sheets, and the top of the blank holder is provided with a first contact part used for counteracting excessive blank holding force and a second contact part used for bearing the material sheets. The height of the first contact part is larger than that of the second contact part, and the problem of wrinkling and cracking caused by inconstant blank holder force is solved by improving the structure of the blank holder; the blanking drawing die comprises an upper die base, a lower die base and a blank holder, the upper die base comprises a punch-die, an upper material returning block and an upper die plate, the punch-die is fixedly connected to the upper die plate, and the upper material returning block is movably connected to the interior of the punch-die; the lower die base comprises a female die plate, a stretching male die and a lower die plate, the female die plate is fixedly connected to the lower die plate, the stretching male die is arranged in the center of the female die plate, the blank holder is arranged on the stretching male die in a sleeving mode and movably connected with the female die plate, and the production efficiency and the finished product percent of pass in the blanking and stretching process can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of stamping dies, and more specifically to a blank holder ring and a blanking and stretching die capable of preventing instability and rupture. Background Art

[0002] Blanking and stretching is a common production technology. Common metal products on the market, such as cups, bowl lids, and alarm bells, are all manufactured using this type of blanking and stretching die. The blanking and stretching process uses a blanking-then-stretching process. During the stretching process, when the material in the blank is not flowing smoothly, it can cause material accumulation in certain areas, forming irregular, wavy wrinkles on the surface. These wrinkles can be distributed along the edges, corners, or even across the entire surface of the part, creating a noticeable undulation and wrinkling. This can even cause the part to become unstable and rupture. In the prior art, for example, Chinese patent CN204685826U discloses a composite die for blanking and stretching of metal sheets, comprising a lower die plate, a stretching punch being arranged at the center of the lower die plate, a concave-convex die being added to the upper half of the stretching punch, and blank holders being connected at both ends of the bottom of the concave-convex die; a blanking die being fixedly installed at the periphery of the junction of the blank holder and the concave-convex die; a punching rod being fixedly installed on both sides of the concave-convex die by two bolts respectively; one side of the periphery of the junction surface between the lower die plate and the blank holder is fixed by an adjustable bolt, and a vacant structure is arranged on the lower die plate on the other side opposite to the adjustable bolt position. The die can simultaneously complete the blanking and stretching processing, but cannot avoid the problem of instability and rupture of the product during the processing, which affects the qualified rate of the finished product. Utility Model Content

[0003] In response to the problem that products in the prior art are prone to instability and rupture, the utility model provides a pressure ring and a blanking and stretching die that can prevent instability and rupture, so that the plastic deformation of the sheet is more stable, the material is prevented from instability and rupture, and the qualified rate of the finished product is higher.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] A blank holder ring that can prevent instability and rupture is used to assist a sheet in blanking and stretching. The top of the blank holder ring is provided with a first contact portion for offsetting excessive blank holder force and a second contact portion for supporting the sheet. The height of the first contact portion is greater than that of the second contact portion.

[0006] The utility model provides a blank holding ring that can prevent instability and rupture. First, a sheet is placed on the blank holding ring. During the mold closing process, the first contact part cuts the sheet off to complete the blanking process. During the stretching process, the blank holding ring provides a blank holding force for the sheet. Since the height of the first contact part is greater than that of the second contact part, the protruding first contact part offsets the excessive blank holding force, thereby avoiding instability and rupture caused by unsmooth sliding and feeding of the sheet. The sheet slides smoothly on the second contact part whose height is lower than the first contact part, and the blank holding force and friction force it receives are stable, thereby avoiding instability and rupture caused by rapid thinning of some areas, and can further improve the qualified rate of finished products.

[0007] Furthermore, the height difference between the first contact portion and the second contact portion is 0.02mm to 0.1mm greater than the thickness of the sheet, leaving a slight gap to ensure that the sheet can slide smoothly on the second contact portion, keep the clamping force and the friction force on the sheet stable, and improve the qualified rate of finished products and the stretching speed.

[0008] Furthermore, a connecting portion is provided between the first contact portion and the second contact portion. The connecting portion, at its junction with both the first and second contact portions, has rounded corners, and the angle between the connecting portion and the horizontal plane is 40° to 50°. The rounded corners and controlled inclination angle between the connecting portion and the horizontal plane ensure smoother sliding of the sheet from the first contact portion to the second contact portion, preventing significant vibration on the sheet and wrinkling of the product surface.

[0009] Furthermore, the blank holder is provided with a third contact portion on its outer side that provides a clearance fit with the die plate, and a fourth contact portion on its inner side that provides a clearance fit with the punch. The small clearance between the die plate and the third contact portion on the blank holder prevents metal chips generated by cutting the blank during blanking from affecting the stretching process. The small clearance between the punch and the fourth contact portion on the blank holder facilitates control of the relative position between the punch and the blank holder, minimizing vibration during the stretching process and improving product quality.

[0010] Furthermore, a limiting boss is provided on the outer side of the blank holder for limiting the reset position of the blank holder. The limiting boss ensures that the blank holder can stably move to a specified position during the reset process, thereby limiting the reset position of the blank holder.

[0011] The utility model also provides a blanking and stretching die that can prevent instability and rupture, which is used for blanking and stretching a sheet. The upper die base includes a male and female die, an upper stripping block and an upper die plate, and the lower die base includes a female die plate, a stretching punch and a lower die plate; the male and female dies are fixedly connected to the upper die plate and movably connected to the female die plate, the upper stripping block is movably connected to the inside of the male and female dies, the female die plate is fixedly connected to the lower die plate, the stretching punch is arranged at the center of the female die plate and movably connected to the male and female dies, and the pressure ring is sleeved on the stretching punch and movably connected to the female die plate.

[0012] The utility model provides a blanking and stretching die that can prevent instability and rupture. During the working process, the material sheet is first placed on the concave plate and the pressure ring, and then the lower die seat is fixed, and the upper die seat descends to cooperate with the first contact portion protruding from the pressure ring to cut off the material sheet, and complete the blanking process; the concave plate and the stretching punch remain fixed, and the male and female dies continue to descend, driving the pressure ring to separate from the concave plate. At this time, the first contact portion abuts against the male and female dies to ensure that excessive pressure force can be offset, and avoid instability and rupture caused by unsmooth sliding and feeding of the material sheet, and the material sheet slides on the second contact portion whose height is lower than the first contact portion, and the pressure force and friction force it is subjected to are stable, and the material sheet is clamped between the stretching punch, the male and female dies and the upper stripping block to complete the stretching process; after the product is formed, the male and female dies ascend and separate from the concave plate and the pressure ring, and at the same time, the upper stripping block moves downward relative to the male and female dies to remove the product from the mold, and complete the unloading operation. By abutting the protruding first contact portion with the male and female dies, the blanking force and friction force on the sheet are controlled to be stable, and the sheet can slide smoothly on the second contact portion to avoid unstable rupture, thereby improving the processing speed and product qualification rate during the blanking and stretching process.

[0013] Furthermore, the upper die holder also includes an upper pad and an upper fixed plate. The upper pad is fixedly connected to the upper die plate, and the upper fixed plate is connected to the upper pad and the male and female dies. The upper die plate is equipped with an upper inner withdrawal spring connected to the upper stripper. The upper pad improves the overall rigidity of the die and extends its service life. The fixed plate strengthens the position of the male and female dies, ensuring that they do not shift during mold closing and are always aligned with the blank holder. The upper inner withdrawal spring connects the upper stripper to the upper die holder, controlling the stable movement of the upper stripper within the male and female dies to complete product stripping.

[0014] The upper die holder further includes a stripper plate surrounding the male and female dies. The female die plate is provided with a guide sleeve hole. One end of the stripper plate is provided with a stripper spring connected to the upper die plate, and the other end is provided with a guide post that engages with the guide sleeve hole. When the mold is closed, the guide post and the guide sleeve hole initially engage to provide guidance. The stripper plate compresses the blank, keeping it in close contact with the female die plate. After blanking and stretching are completed, the stripper spring controls the remaining blank to separate from the mold.

[0015] Furthermore, the lower die base also includes a lower fixing plate and a lower lining plate. The concave die plate is fixedly connected to the lower lining plate, which is fixedly connected to the lower fixing plate. The lower fixing plate is connected to the lower die plate and the drawing punch. The lower fixing plate limits the position of the drawing punch, improving the fixing effect and product processing accuracy. The lower lining plate can reduce wear, protect the mold surface structure, and extend the mold life.

[0016] Furthermore, an exhaust duct is provided within the punch, with one end of the exhaust duct's air inlet located on the top surface of the punch and the exhaust duct's air outlet communicating with the outside air. The exhaust duct exhausts air from the mold, reducing the effect of internal air pressure on the mold forming process and improving product dimensional accuracy and surface finish.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The blank holder of the present invention effectively controls the blank holding force exerted on the sheet by cooperating with the protruding first contact portion and the second contact portion, thereby solving the problem of material instability and rupture caused by uncontrollable blank holding force;

[0018] 2. The blanking and stretching die of the present invention improves the processing speed and product qualification rate during the blanking and stretching process through the cooperation between the upper die base, the lower die base and the pressure ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0020] Figure 1 This is a schematic diagram of the blank holder structure of the utility model;

[0021] Figure 2 This is a schematic diagram of the blanking state in Example 1;

[0022] Figure 3 for Figure 2 A partial enlarged view of position A in the middle;

[0023] Figure 4 This is a schematic diagram of the initial stretching state in Example 1;

[0024] Figure 5 for Figure 4 A partial enlarged view of position B in the middle;

[0025] Figure 6 This is a schematic diagram of the late stretching state in Example 1;

[0026] Figure 7This is a schematic diagram of the overall structure of the blanking and stretching die of the present utility model;

[0027] Figure 8 This is a schematic diagram of the blanking and stretching die of the present invention in the open die state;

[0028] Figure 9 This is a schematic diagram of the working state of the blanking and stretching die of the present utility model;

[0029] Figure 10 This is an exploded view of the blanking and stretching die of the present invention;

[0030] Explanation of the accompanying reference numerals: 1. Punch and concave molds; 2. Upper material return block; 21. Upper inner return spring; 3. Concave mold plate; 4. Stretching punch; 41. Exhaust duct; 5. Pressure ring; 51. First contact portion; 52. Second contact portion; 53. Connecting portion; 54. Third contact portion; 55. Fourth contact portion; 56. Limiting boss; 6. Lower support plate; 7. Push rod; 8. Upper mold plate; 9. Upper pad; 10. Upper fixed plate; 11. Unloading plate; 12. Unloading spring; 13. Guide column; 14. Lower mold plate; 15. Lower fixed plate; 16. Lower lining plate; 17. Pressure spring; 18. Connecting plate; 19. Connecting rod; 20. Sheet. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present utility model, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.

[0034] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] Example 1

[0036] like Figure 1 As shown, this embodiment is an embodiment of a blank holder ring that can prevent unstable rupture. The top of the blank holder ring 5 is provided with a first contact portion 51 for offsetting excessive blank holder force and a second contact portion 52 for supporting the sheet 20. The height of the first contact portion 51 is greater than that of the second contact portion 52.

[0037] The blank holder 5 in this embodiment is sleeved on the stretching punch 4 during use, and cooperates with the punch and die 1 to complete the blanking and stretching process of the sheet 20. Figure 2 、 Figure 3 As shown, during the blanking process, the blank is clamped between the first contact portion 51 and the male and female molds 1. The first contact portion 51 abuts against the blank 20, continuously increasing the pressure, thereby cutting the product from the blank 20. During the processing, the blank holding force can be controlled to be slightly greater than the blank holding force in a conventional mold. Since the first contact portion 51 on the blank holder ring 5 is higher than the second contact portion 52, the first contact portion 51 abuts against the male and female molds 1 during the stretching process, which offsets the excessive blank holding force. This can prevent the outer ring of the product from becoming unstable and wrinkling due to too little blank holding force, and can also prevent the product from not flowing smoothly due to too much blank holding force, resulting in a sudden thinning of some areas and unstable rupture caused by the poor stretching process.

[0038] In this embodiment, the height difference between the first contact portion 51 and the second contact portion 52 is 0.02mm to 0.1mm greater than the material thickness. If the thickness of the sheet 20 is T, the height difference between the first contact portion 51 and the second contact portion 52 is controlled to be The gap between the second contact portion 52 and the male and female molds 1 is slightly larger than the material thickness. Figure 4 、 Figure 5 As shown, in the initial stage of the stretching state, the first contact portion 51 abuts against the male and female molds 1, which can offset the excessive clamping force, and the sheet 20 slides on the second contact portion 52 with a lower height. The sliding friction between the sheet 20 and the second contact portion 52 and the male and female molds 1 is constant. The slight gap of 0.02 to 0.10 mm above and below the sheet 20 makes the material flow here smoother, avoiding unstable rupture.

[0039] like Figures 4 to 6 As shown, during the stretching process, the sheet 20 slides from the first contact portion 51 to the second contact portion 52. A connecting portion 53 is provided between the first contact portion 51 and the second contact portion 52. The connecting portion 53 has rounded corners at its junctions with both the first and second contact portions 51, 52. The angle between the connecting portion 53 and the horizontal plane is 40° to 50°. In this embodiment, the connecting portion 53 has a 45° angle with the horizontal plane and is smoothly connected to the first and second contact portions 51, 52 by rounded corners, ensuring smooth flow of the sheet 20 from the first contact portion 51 to the second contact portion 52.

[0040] like Figure 1 、 Figure 7 As shown, a third contact portion 54 is provided on the outside of the blank holder 5, and a clearance fit is formed between the third contact portion 54 and the concave plate 3. The clearance fit between the third contact portion 54 and the concave plate 3 ensures that the surface structures of the blank holder 5 and the concave plate 3 are not damaged during the stretching process, while also preventing metal debris generated when cutting the sheet 20 from entering the mold and affecting the product molding quality. A fourth contact portion 55 is provided on the inside of the blank holder 5, and a clearance fit is formed between the fourth contact portion 55 and the stretching punch 4. This prevents significant shaking of the blank holder 5, which is mounted on the outside of the stretching punch 4, during movement, thereby improving processing accuracy.

[0041] A limiting boss 56 is provided on the outside of the blank holder 5 for limiting the reset position of the blank holder 5. After the processing is completed, the limiting boss 56 cooperates with other limiting structures on the mold to control the correct reset of the blank holder 5.

[0042] Example 2

[0043] This embodiment is the first embodiment of a blanking and stretching die that can prevent instability and rupture, and is used for blanking and stretching a sheet, and includes an upper die base, a lower die base, and a pressure ring 5. The upper die base includes a male and female die 1, an upper stripping block 2, and an upper die plate 8. The lower die base includes a female die plate 3, a stretching punch 4, and a lower die plate 14. The male and female die 1 is fixedly connected to the upper die plate 8 and movably connected to the female die plate 3. The upper stripping block 2 is movably connected to the inside of the male and female die 1. The female die plate 3 is fixedly connected to the lower die plate 14. The stretching punch 4 is arranged at the center of the female die plate 3 and movably connected to the male and female die 1. The pressure ring 5 is sleeved on the stretching punch 4 and movably connected to the female die plate 3.

[0044] like Figure 8 、 Figure 9 、 Figure 10 As shown, during the processing, the blanking and stretching processes are carried out sequentially, and the product is formed by a blanking and stretching composite die. During the blanking process, the blanking sheet 20 is first placed and fixed on the die plate 3. The male and female dies 1 are controlled to continue to descend until the male and female dies 1 contact the blank holder 5. Then, the pressure is increased to cut the product from the blanking sheet 20, completing the blanking process. During the stretching process, the male and female dies 1, the product, and the blank holder 5 continue to descend. The blank holder 5 separates from the die plate 3, and the stretching punch 4 is fixed in position with the die plate 3. After the stretching is completed, the male and female dies 1 are controlled to ascend, separating from the blank holder 5 and the die plate 3. The blank holder 5 ascends until it contacts the die plate 3. At the same time, the upper stripper 2 moves downward relative to the male and female dies 1 to eject the product from the die, facilitating unloading and removing the formed product, saving processing time. The upper stripper 2 is provided with a limiting protrusion, and the male and female dies 1 are provided with a limiting step that cooperates with the limiting protrusion to ensure that the upper stripper can reach the appropriate ejection position and eject the completed product from the die. The blanking and stretching die in this embodiment effectively controls the blanking force exerted on the sheet 20 during the blanking and stretching process, solves the problem of material instability and fracture caused by uncontrollable blanking force, and improves processing speed and product qualification rate.

[0045] like Figure 7 As shown, the upper die holder in this embodiment also includes an upper pad 9 and an upper fixed plate 10. The upper pad 9 is fixedly connected to the upper template 8. The upper fixed plate 10 is connected to the upper pad 9 and the male and female molds 1. The upper template 8 is provided with an upper inner withdrawal spring 21 connected to the upper stripping block 2. The upper pad 9 is installed on the upper template 8 to improve the overall rigidity of the mold and protect the structure of the male and female molds 1. The upper fixed plate 10 is installed on the upper pad 9 and fixedly connected to the male and female molds 1 to ensure that the position of the male and female molds 1 is always aligned with the pressure ring 5, thereby improving the processing accuracy of the product. One end of the upper inner withdrawal spring 21 is connected to the upper template 8, and the other end is connected to the upper stripping block 2 to control the movement of the upper stripping block 2 inside the male and female molds 1 to complete the stripping process after the product is formed.

[0046] The blanking and stretching die in this embodiment also includes a stripper plate 11 arranged around the male and female molds 1. The female mold plate 3 is provided with a guide sleeve hole. A stripper spring 12 is attached to one end of the stripper plate 11, connected to the upper mold plate 8, and a guide post 13 is provided at the other end, which engages with the guide sleeve hole. The guide post 13 can also be provided on the female mold plate 3 and engages with the guide sleeve hole provided on the stripper plate 11, providing guidance during the mold closing process and ensuring accurate mold closing position. During the mold closing process, the stripper plate 11 can press the blank 20 against the female mold plate 3 to reduce shaking. After the blanking and stretching process is completed, the stripper plate 11, under the control of the stripper spring 12, separates the blank 20 from the mold, facilitating the removal of the blank 20 or its transport to the next processing location.

[0047] The blanking and drawing die in this embodiment also includes a lower die plate 14, a lower fixing plate 15, and a lower backing plate 16. The die plate 3 is fixedly connected to the lower backing plate 16, which is fixedly connected to the lower fixing plate 15. The lower fixing plate 15 is connected to the lower die plate 14 and the drawing punch 4. The lower die plate 14 provides support for the entire die. The lower fixing plate 15 limits the position of the drawing punch 4, improving the fixation effect and product processing accuracy. The lower backing plate 16 reduces wear, protects the die surface structure, and extends the die life. The lower die base also includes a lower support plate 6. One end of the lower support plate 6 is connected to the blank holder 5 via a push rod 7. The other end is mounted on a connecting rod 19. The other end of the connecting rod 19 is fixedly connected to the connecting plate 18. The outer side of the connecting rod 19 is mounted with a blanking spring 17 fixedly connected to the lower support plate 6 and the connecting plate 18. During the drawing process, the lower support plate 6 moves downward along the connecting rod 19, compressing the blanking spring 17. The blanking spring 17 provides a blanking force to the blank holder 5, ensuring smooth product formation.

[0048] Example 3

[0049] like Figure 7 As shown, this embodiment is a second embodiment of a blanking and drawing die that prevents instability and fracture. Similar to the second embodiment, this embodiment differs in that an exhaust duct 41 is provided within the drawing punch 4. The air inlet of the exhaust duct 41 is located on the top surface of the drawing punch 4, and the air outlet is connected to the outside air. The air inside the mold can affect the shape and size of the product, and as the air volume decreases, it may even cause product deformation. The provision of the exhaust duct 41 effectively exhausts this air, reducing product deformation and improving product consistency.

[0050] In the specific contents of the above-mentioned specific implementation methods, the various technical features can be combined in any non-contradictory manner. In order to make the description concise, not all possible combinations of the above-mentioned technical features are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0051] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. A person skilled in the art will be able to make other variations or modifications based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A blank holder capable of preventing instability and rupture, used for assisting a sheet (20) in blanking and stretching, characterized in that: The top of the blank holder ring (5) is provided with a first contact portion (51) for offsetting excess blank holder force and a second contact portion (52) for supporting the sheet (20), and the height of the first contact portion (51) is greater than that of the second contact portion (52).

2. The blank holder capable of preventing instability and rupture according to claim 1, characterized in that: The height difference between the first contact portion (51) and the second contact portion (52) is 0.02 mm to 0.1 mm greater than the thickness of the material sheet (20).

3. The blank holder capable of preventing instability and rupture according to claim 1, characterized in that: A connecting portion (53) is provided between the first contact portion (51) and the second contact portion (52); the connection portions between the connecting portion (53), the first contact portion (51), and the second contact portion (52) are all rounded structures; and the angle between the connecting portion (53) and the horizontal plane is 40° to 50°.

4. The blank holder capable of preventing instability and rupture according to claim 1, characterized in that: A limiting boss (56) for limiting the reset position of the blank pressing ring (5) is provided on the outer side of the blank pressing ring (5).

5. A blanking and stretching die capable of preventing instability and rupture, used for blanking and stretching a sheet (20), characterized in that: It comprises an upper die base, a lower die base and a pressure ring as described in any one of claims 1 to 4, wherein the upper die base comprises a male and female die (1), an upper stripping block (2) and an upper die plate (8), and the lower die base comprises a female die plate (3), a stretching die (4) and a lower die plate (14); the male and female die (1) are fixedly connected to the upper die plate (8) and are movably connected to the female die plate (3), the upper stripping block (2) is movably connected to the inside of the male and female die (1), the female die plate (3) is fixedly connected to the lower die plate (14), the stretching die (4) is arranged at the center of the female die plate (3) and is movably connected to the male and female die (1), and the pressure ring (5) is sleeved on the stretching die (4) and is movably connected to the female die plate (3).

6. A blanking and stretching die capable of preventing instability and cracking according to claim 5, characterized in that: The upper die base further comprises an upper pad (9) and an upper fixed plate (10), wherein the upper pad (9) is fixedly connected to the upper die plate (8), and the upper fixed plate (10) is connected to the upper pad (9) and the male and female dies (1), and the upper die plate (8) is provided with an upper inner withdrawal spring (21) connected to the upper withdrawal block (2).

7. The blanking and stretching die capable of preventing instability and cracking according to claim 5, characterized in that: The upper die base also includes a stripper plate (11) arranged around the male and female dies (1), the female die plate (3) is provided with a guide sleeve hole, one end of the stripper plate (11) is provided with a stripper spring (12) connected to the upper die plate (8), and the other end is provided with a guide column (13) that cooperates with the guide sleeve hole.

8. The blanking and stretching die capable of preventing instability and cracking according to claim 5, characterized in that: The lower die base further comprises a lower fixed plate (15) and a lower lining plate (16); the concave die plate (3) is fixedly connected to the lower lining plate (16); the lower lining plate (16) is fixedly connected to the lower fixed plate (15); and the lower fixed plate (15) is connected to the lower die plate (14) and the stretching punch (4).

9. A blanking and stretching die capable of preventing instability and cracking according to any one of claims 5 to 8, characterized in that: An exhaust duct (41) is provided in the stretching punch (4), an air inlet of the exhaust duct (41) is provided on the top surface of the stretching punch (4), and an air outlet of the exhaust duct (41) is communicated with external air.

10. The blanking and stretching die capable of preventing instability and cracking according to claim 5, characterized in that: The outer side of the pressure ring (5) is provided with a third contact portion (54) that is clearance-matched with the concave template (3), and the inner side is provided with a fourth contact portion (55) that is clearance-matched with the stretching punch (4).

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