A punch die for a non-wrinkled container of a raw foil

Abstract

A kind of punch die for plain foil wrinkle-free container, it includes upper die plate, lower die plate, upper die assembly and lower die assembly.The second lower inner circle of the lower die assembly is arranged with multiple top blocks outside, and the gap is formed with the edge part of the upper inner circle, to provide local pressure release channel for plain aluminum foil material shrinkage, effectively eliminate the wrinkles of mouth plane.The lower inner circle is split into first lower inner circle and the second lower inner circle, the height of the first lower inner circle is different from the height of the second lower inner circle, to form a step structure between the adjacent side walls of the two, cooperate with the matching height difference of upper die and upper inner circle, realize gradient pressure control, make plain aluminum foil material keep controlled tension in flow and pre-stretching flatten, ensure that the mouth plane is smooth and smooth, without relying on coating or film to achieve wrinkle-free forming requirements, significantly improve the yield and product surface quality, while ensuring the purity of material and food safety, meet the requirements of green manufacturing.

Description

Technical Field

[0001] This invention relates to the field of stamping die technology, and in particular to a stamping die for a wrinkle-free container made of plain foil. Background Technology

[0002] Aluminum foil containers are widely used in food packaging, pharmaceutical packaging, airline meal boxes, and home baking due to their excellent barrier properties, good thermal conductivity, lightweight portability, and environmental recyclability. In the disposable aluminum foil container industry, wrinkle-free aluminum foil containers refer to containers with a smooth, flat opening. This flat surface ensures a complete seal between the container and the lid. If wrinkles appear on this surface, air leakage will occur after sealing, resulting in poor sealing performance and severely impacting the sealing effect.

[0003] In existing technologies, aluminum foil containers are mainly manufactured using cold stamping processes. Traditional stamping dies typically include basic structures such as upper and lower mold plates, upper mold components, and lower mold components. The aluminum foil material is cut, stretched, and shaped through the cooperation of the upper and lower molds. However, because plain aluminum foil, i.e., pure aluminum alloy, does not have any coating or film added to improve its properties, it is soft and has limited ductility. In most cases, the container is relatively easy to form, but the opening surface of the container may wrinkle slightly, which can lead to poor sealing or even failure.

[0004] To address the aforementioned issues, existing technologies often involve coating the surface of plain aluminum foil with a lubricating coating or a composite plastic film. This increases the lubricity and strength of the material surface, reducing wrinkling. However, this approach requires significant investment in production equipment, increasing material costs and process complexity. Furthermore, aluminum foil containers manufactured using coating or film processes generate additional emissions during production and recycling compared to pure aluminum alloys, such as organic waste gases and plastic film decomposition products, which do not meet environmental protection requirements. Summary of the Invention

[0005] In view of this, the present invention provides a stamping die for a plain foil wrinkle-free container to solve the above problems.

[0006] A stamping die for a wrinkle-free container made of plain foil includes an upper die plate, a lower die plate disposed on one side of the upper die plate, an upper die assembly disposed on the upper die plate, and a lower die assembly disposed on the lower die plate. The upper die assembly includes an upper pressure plate seat disposed on the upper die plate, an upper pressure plate seat disposed on the upper pressure plate seat, an upper inner ring seat disposed on the upper die plate, an upper inner ring seat disposed on the upper inner ring seat, a first piston disposed on the upper die plate and connected to the upper inner ring seat, and an upper die disposed on the upper die plate. The upper inner ring seat and the upper inner ring are located between the upper pressure edge seat and the upper mold. The outer side wall of the upper inner ring is in contact with the inner side wall of the upper pressure edge, and the inner side wall of the upper inner ring is in contact with the outer side wall of the upper mold. The lower mold assembly includes a second piston disposed on the lower template, a base disposed on the output end of the second piston, a third piston disposed on the lower template, a lower mold disposed on the output end of the third piston, a first lower inner ring disposed on the base, a second lower inner ring disposed on the base, a top block disposed on the base, a lower pressure edge disposed on the base, and a limiting block disposed on the lower template. The first lower inner ring is located between the lower mold and the second lower inner ring, and its outer side is in contact with the inner side wall of the second lower inner ring. The top of the first lower inner ring corresponds to the bottom edge of the upper mold. The second lower inner ring is located between the upper mold and the lower mold. Between the first lower inner ring and the lower pressing edge, its inner side is in contact with the outer side wall of the first lower inner ring, and its outer side is in contact with the inner side wall of the lower pressing edge. The top of the second lower inner ring corresponds to the upper inner ring. A plurality of top blocks are respectively located on the outer side of the second lower inner ring. The top blocks are located between the second lower inner ring and the lower pressing edge. The outer side of the upper inner ring is respectively provided with pressing edge portions. The top blocks are provided corresponding to the pressing edge portions. The limiting block is located below the second lower inner ring and the top blocks. When the base descends, the top surface of the limiting block abuts against and supports the bottom surface of the second lower inner ring and the top blocks. The height of the top block is less than the height of the second inner ring, so that a gap is formed between the top of the top block and the pressing edge portion. The height of the first lower inner ring is different from the height of the second lower inner ring, so that a stepped structure is formed between the adjacent side walls of the two.

[0007] Furthermore, the upper template is movably mounted on at least four guide posts, one end of which is fixedly mounted on the lower template, and the other end is movably mounted on the upper template.

[0008] Furthermore, at least four limiting posts are movably inserted on the end face of the upper template facing the lower template, and a waste pressure plate is fixedly installed at the bottom end of the limiting posts.

[0009] Furthermore, the upper mold assembly also includes an upper cylinder seat disposed on the upper mold plate, an upper cylinder disposed on the upper cylinder seat, and a stripper plate disposed on the upper cylinder. The upper cylinder seat is used to house the first piston and the upper cylinder. The output end of the upper cylinder is connected to the stripper plate and is used to drive the stripper plate to move vertically. The stripper plate is located at the center of the upper mold.

[0010] Furthermore, a rolled edge groove is provided on the inner sidewall of the upper inner ring, the rolled edge groove is located at the end of the upper inner ring facing the lower mold assembly, and the cross-section of the rolled edge groove has an arc-shaped structure.

[0011] Furthermore, the second piston is fixedly disposed on the side of the lower template facing away from the upper template, and the output end of the second piston movably passes through the lower template and connects to the bottom of the base. The third piston is fixedly disposed on the side of the lower template facing away from the upper template, and the output end of the third piston movably passes through the lower template and connects to the bottom surface of the lower mold.

[0012] Furthermore, the base has a plate-like structure, and a through hole is provided in the center of the base to allow the lower mold to move. The base is provided with a clearance hole corresponding to the position of the limiting block, and the shape of the through hole is adapted to the outer contour of the lower mold.

[0013] Furthermore, the height difference between the first lower inner ring and the second lower inner ring is set to be 0.01mm~0.1mm.

[0014] Compared with existing technologies, the stamping die for wrinkle-free containers made of plain aluminum foil provided by this invention addresses the characteristics of soft texture and limited ductility of plain aluminum foil by splitting the lower inner ring into a first lower inner ring and a second lower inner ring. The heights of the first and second lower inner rings differ, creating a stepped structure between their adjacent sidewalls, with a height difference of 0.01mm to 0.1mm between their top surfaces. During die-cutting, a larger pressure is applied to the bottom surface of the upper die edge and the top surface of the first lower inner ring, while a relatively smaller pressure is applied to the bottom surface of the upper inner ring and the top surface of the second lower inner ring. This allows the pressure to gradually increase during material flow, maintaining a controlled tension. Simultaneously, when the aluminum foil flows through the stepped structure between the first and second lower inner rings, the material is forced to bend multiple times, achieving a pre-stretching and leveling effect through repeated stretching. This effectively eliminates micro-wrinkles in the material, ensuring that the material is flat before entering the area between the bottom surface of the upper die edge and the top surface of the first lower inner ring, thus solving the wrinkling problem during the stamping process of plain aluminum foil containers. In addition, multiple top blocks are spaced apart around the outer perimeter of the second lower inner ring, so that a gap is formed between the top of the top block and the pressing edge of the upper inner ring. This gap provides a local pressure release channel when the aluminum foil material shrinks into the mold cavity, effectively avoiding the problem of excessive tightness or looseness of the material caused by continuous pressing of the entire ring, and significantly reducing the phenomenon of wrinkling at the edge of the material. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the stamping die for a wrinkle-free container made of plain foil provided by the present invention.

[0016] Figure 2 for Figure 1 A schematic diagram of the upper template and upper mold assembly of a stamping die for a plain foil wrinkle-free container.

[0017] Figure 3 for Figure 1 An exploded view of the upper die plate and upper die assembly of a stamping die for a plain foil wrinkle-free container.

[0018] Figure 4 for Figure 1 A schematic diagram of the structure of the lower die plate and lower die assembly of the stamping die used for the plain foil wrinkle-free container.

[0019] Figure 5 for Figure 1 An exploded view of the lower die plate and lower die assembly of a stamping die for a plain foil wrinkle-free container.

[0020] Figure 6 for Figure 1 A schematic diagram of the cross-section of a stamping die used for wrinkle-free foil containers during die parting.

[0021] Figure 7 for Figure 1 A schematic diagram of the cross-section of a stamping die used for a wrinkle-free foil container during stamping.

[0022] Figure 8 for Figure 1 A cross-sectional schematic diagram of a stamping die used for edge curling of plain foil wrinkle-free containers. Detailed Implementation

[0023] The following provides a more detailed description of specific embodiments of the present invention. It should be understood that the description of the embodiments of the present invention herein is not intended to limit the scope of protection of the present invention.

[0024] like Figure 1 The diagram shows a structural schematic of a stamping die for a wrinkle-free container made of plain foil provided by the present invention. The stamping die includes an upper die plate 10, a lower die plate 20 disposed on one side of the upper die plate 10, an upper die assembly 30 disposed on the upper die plate 10, and a lower die assembly 40 disposed on the lower die plate 20. It is conceivable that the stamping die for the wrinkle-free container also includes other functional modules, such as a drive module, an air blowing module, etc., which are technologies known to those skilled in the art and will not be described in detail here.

[0025] The upper template 10 is used to set the upper mold assembly 30. The upper template 10 is movably fitted on at least four guide posts 11. One end of each guide post 11 is fixedly mounted on the lower template 20, and the other end is movably mounted on the upper template 10. The upper template 10 is controlled by a drive module so that it can reciprocate along the length direction of the guide post 11, thereby driving the upper mold assembly 30 to perform stamping work.

[0026] At least four limiting posts 12 are movably inserted through the end face of the upper template 10 facing the lower template 20. A waste material pressure plate 13 is fixedly installed at the bottom end of each limiting post 12. During die closing and stamping, the waste material pressure plate 13 is used to press and fix the aluminum foil paper to ensure the stability of the cutting operation. It is conceivable that the aluminum foil paper is transported by a paper feeding mechanism, the method of which is existing technology and will not be described in detail here.

[0027] A shearing seat 21 and a shearing plate 22 are fixedly provided on the end face of the lower template 20 facing the upper template 10. The shearing plate 22 has a lower shearing opening, which can cooperate with the upper mold assembly 30 to cut aluminum foil.

[0028] The upper mold assembly 30 includes an upper pressure seat 31 disposed on the upper template 10, an upper pressure edge 32 disposed on the upper pressure seat 31, an upper inner ring seat 33 disposed on the upper template 10, an upper inner ring 34 disposed on the upper inner ring seat 33, a first piston 35 disposed on the upper template 10 and connected to the upper inner ring seat 33, an upper mold 36 disposed on the upper template 10, an upper cylinder seat 37 disposed on the upper template 10, an upper cylinder 38 disposed on the upper cylinder seat 37, and a discharge plate 39 disposed on the upper cylinder 38.

[0029] The end face of the upper template 10 facing the lower mold assembly 40 is used to set the upper pressure seat 31, the upper inner ring seat 33, and the upper mold 36, and the other end face is used to set the upper cylinder seat 37 and the first piston 35.

[0030] The upper pressure seat 31 and the upper pressure edge 32 form an annular frame structure with a central through hole, so that the upper inner ring seat 33 and the upper mold 36 can be accommodated in the center. The top end of the upper pressure seat 31 is connected to the upper template 10, and the bottom end of the upper pressure seat 31 is provided with the upper pressure edge 32. The outer side wall of the upper pressure edge 32 corresponds to the inner side wall of the shearing plate 22, so that when the mold is closed, the outer side wall of the upper pressure edge 32 and the inner side wall of the shearing plate 22 move alternately to cut the aluminum foil.

[0031] The upper inner ring seat 33 and the upper inner ring 34 also have an annular frame structure and a central through hole, so that the upper mold 36 can be accommodated in the center. The top end of the upper inner ring seat 33 is connected to the upper inner ring 34, and the bottom end of the upper inner ring seat 33 is provided with the upper inner ring 34. The upper inner ring seat 33 and the upper inner ring 34 are located between the upper pressure edge seat 31 and the upper mold 36. The outer side wall of the upper inner ring 34 is in contact with the inner side wall of the upper pressure edge 32, and the inner side wall of the upper inner ring 34 is in contact with the outer side wall of the upper mold 36. A curling groove 341 is provided on the inner side wall of the upper inner ring 34. The curling groove 341 is located at the end of the upper inner ring 34 facing the lower mold assembly 40, and the cross-section of the curling groove 341 is arc-shaped. The curling groove 341 is used to curl the aluminum foil during stamping, and a detailed description will be given below in conjunction with the lower mold assembly 40.

[0032] The output end of the first piston 35 is connected to the upper inner ring seat 33, and is used to drive the upper inner ring seat 33 and the upper inner ring 34 to move vertically independently.

[0033] The upper die 36 is located at the center of the upper inner ring seat 33 and is used to form a stamping component. The upper die 36 is a concave die with the same shape as the aluminum foil container to be stamped, and its shape can be set according to actual needs.

[0034] The upper cylinder seat 37 is used to house the first piston 35 and the upper cylinder 38. The output end of the upper cylinder 38 is connected to the stripper plate 39 and is used to drive the stripper plate 39 to move vertically. The stripper plate 39 is located at the center of the upper mold 36. After stamping is completed, the stripper plate 39 ejects the product from the upper mold 36, ensuring that the product can smoothly leave the mold after stamping.

[0035] The lower mold assembly 40 includes a second piston 41 disposed on the lower template 20, a base 42 disposed on the output end of the second piston 41, a third piston 43 disposed on the lower template 20, a lower mold 44 disposed on the output end of the third piston 43, a first lower inner ring 45 disposed on the base 42, a second lower inner ring 46 disposed on the base 42, a top block 47 disposed on the base 42, a lower pressing edge 48 disposed on the base 42, and a limiting block 49 disposed on the lower template 20.

[0036] The second piston 41 is fixedly disposed on the side of the lower template 20 facing away from the upper template 10. The output end of the second piston 41 is movably passed through the lower template 20 and connected to the bottom of the base 42, thereby driving the base 42 to reciprocate in the vertical direction.

[0037] The base 42 has a plate-like structure and is used to support the first lower inner ring 45, the second lower inner ring 46, the top block 47, and the lower pressing edge 48. The center of the base 42 is provided with a through hole 421 to avoid the movement of the lower mold 44. The shape of the through hole 421 is adapted to the outer contour of the lower mold 44, so that the lower mold 44 can independently reciprocate vertically within the through hole 421.

[0038] The third piston 43 is fixedly disposed on the side of the lower template 20 facing away from the upper template 10. The output end of the third piston 43 is movably passed through the lower template 20 and connected to the bottom surface of the lower mold 44, thereby independently driving the lower mold 44 to reciprocate in the vertical direction.

[0039] The lower mold 44 is a punch structure, and its shape is adapted to the shape of the upper mold 36. The shapes of the upper mold 36 and the lower mold 44 can be designed into different shapes according to actual product requirements, such as circles, squares, ovals, etc.

[0040] The first lower inner ring 45 and the second lower inner ring 46 form a ring-shaped frame structure. The first lower inner ring 45 is located between the lower mold 44 and the second lower inner ring 46, and its outer side surface is in contact with the inner sidewall of the second lower inner ring 46. The top end of the first lower inner ring 45 corresponds to the edge of the upper mold 36. During die closing and stamping, the upper mold 36 mates with the top end surface of the first lower inner ring 45 to clamp the aluminum foil.

[0041] The second lower inner ring 46 is located between the first lower inner ring 45 and the lower pressing edge 48. Its inner side is in contact with the outer side wall of the first lower inner ring 45, and its outer side is in contact with the inner side wall of the lower pressing edge 48. The top of the second lower inner ring 46 corresponds to the upper inner ring 34.

[0042] In this embodiment, four top blocks 47 are provided. The multiple top blocks 47 are located on the outer side of the second lower inner ring 46, and the top blocks 47 are located between the second lower inner ring 46 and the lower pressing edge 48. The outer side of the upper inner ring 34 is provided with pressing edge portions 342, and the top blocks 47 are provided corresponding to the pressing edge portions 342.

[0043] The limiting block 49 is disposed on the end face of the lower template 20 facing the upper template 10 and extends vertically. The base 42 has a clearance hole 422 corresponding to the position of the limiting block 49. The limiting block 49 is located below the second lower inner ring 46 and the top block 47. When the base 42 descends to a predetermined stroke, the top surface of the limiting block 49 can directly abut and support the bottom surface of the second lower inner ring 46 and the top block 47, while other components such as the first lower inner ring 45, the lower pressing edge 48, and the lower mold 44 are not blocked by the limiting block 49.

[0044] The height of the top block 47 is less than the height of the second inner ring 46, thus forming a gap between the top of the top block 47 and the pressing edge 342. During stamping, the aluminum foil material needs to shrink into the mold cavity, and this gap helps to locally relax the pressure when the material shrinks into the cavity. By changing the size of this gap, i.e., the height of the top block 47, the flow rate and pressing force at the edge of the material can be precisely controlled, ensuring that the material shrinks smoothly and naturally, preventing wrinkling at the edges. In addition, during the drawing and stamping process of aluminum foil, the resistance and wrinkling of the material flowing into the mold cavity vary significantly in different areas, such as the straight edge area and the corner area of ​​the product. Therefore, the top block 47 is not continuously set as a whole circle along the circumference of the second lower inner ring 46, but is distributed at intervals. The spaced and dispersed top blocks 47 provide local pressure relief channels, allowing the material to flow smoothly and naturally as it contracts into the inner cavity. This avoids excessive tightness or looseness of the material as a whole due to continuous full-circle pressing. Moreover, the multiple independently distributed top blocks 47 allow technicians to independently fine-tune the height of a single or specific top block 47 according to the specific shape and material characteristics of the stamped product, thereby precisely controlling the flow rate and pressing force of the material edge in all directions.

[0045] The heights of the first lower inner ring 45 and the second lower inner ring 46 are different, creating a stepped structure between their adjacent sidewalls. Furthermore, there is a height difference of 0.01mm to 0.1mm between their top surfaces. Preferably, the height of the first lower inner ring 45 is higher than the height of the second lower inner ring 46. Correspondingly, there is a matching height difference between the bottom edge of the upper mold 36 and the bottom surface of the upper inner ring 34. During die-cutting, the bottom edge of the upper mold 36 is in contact with the top surface of the first lower inner ring 45, applying greater pressure to the aluminum foil near the edge of the product forming area. The bottom surface of the upper inner ring 34 is in contact with the top surface of the second lower inner ring 46, applying relatively less pressure to the outer material. The lower pressure at the second lower inner ring 46 allows the material to initially stretch and eliminate local wrinkles. As the material flows inward, the pressure gradually increases, forcing the stretched material to remain flat under higher pressure as it enters the stepped structure between the first lower inner ring 45 and the second lower inner ring 46. This ensures that the material remains under controlled tension throughout the flow path, achieving natural flattening. When the aluminum foil is fed into the mold cavity and flows through the stepped structure, the material is forced to bend multiple times. This forced bending repeatedly stretches the material, causing any potential micro-wrinkles to be pre-stretched and flattened before entering the area between the bottom surface of the upper mold 36 edge and the top surface of the first lower inner ring 45, thereby eliminating wrinkles.

[0046] During stamping, the aluminum foil is fed between the upper and lower die assemblies by the paper feeding mechanism, such as... Figure 6As shown in the diagram, the red line represents aluminum foil. When the upper template 10 descends, the waste pressure plate 13 and the shearing plate 22 first contact and press down on the outer waste area of ​​the aluminum foil, ensuring the material is fixed in position. As the upper template 10 continues to press down, the outer wall of the upper pressing edge 32 and the inner wall of the shearing plate 22 move in an alternating motion, precisely cutting the aluminum foil to produce a blank of the required shape. At the same time, the upper pressing edge 32 and the lower pressing edge 48 clamp the outermost part of the blank, the upper inner ring 34 and the second lower inner ring 46 clamp the middle section of the blank, and the edge of the upper mold 36 and the first lower inner ring 45 clamp the inner area of ​​the blank, so that the upper and lower mold assemblies jointly apply pressure to the aluminum foil blank and move downward synchronously. During this process, the lower die 44 acts as the blank material at the center of the punch, forcing the aluminum foil material to shrink and flow into the inner cavity of the die. As the material flows inward, the gap formed between the spaced-out top blocks 47 and the pressing edge 342 provides a channel for the material to partially relax the pressure as it shrinks into the die cavity, avoiding excessive tension caused by continuous pressing of the entire circle. At the same time, the material undergoes multiple bends and pre-stretches when passing through the step between the first lower inner ring 45 and the second lower inner ring 46, eliminating micro-wrinkles, thereby ensuring the flatness of the product edge at the bottom edge of the upper die 36 and the top surface of the first lower inner ring 45.

[0047] When the object descends to its predetermined travel distance, the top of the limiting block 49 abuts against and supports the bottom surfaces of the second lower inner ring 46 and the top block 47, forcibly preventing them from moving downwards. Figure 7 As shown. Simultaneously, the first piston 35 retracts synchronously, causing the upper inner ring seat 33 and the upper inner ring 34 to move upwards, while the base 42, the first lower inner ring 45, the lower pressing edge 48, and the lower mold 44, and other components, are not obstructed by the limiting block 49 and continue to move downwards with the downward pressure of the upper mold assembly 30. At this time, as... Figure 8 As shown, the edge of the blank is positioned between the inner wall of the second lower inner ring 46 and the outer wall of the upper mold 36, thereby aligning with the crimping groove 341 provided on the upper inner ring 3.

[0048] After completion, the mold enters the rising reset phase, and the upper mold plate 10 begins its return stroke. Simultaneously, the second piston 41 and the third piston 43 drive the base 42 and the lower mold 44 to rise. Since the base 42 is still spaced from the second lower inner ring 46 and the top block 47, the second lower inner ring 46, the top block 47, and the upper inner ring 34 remain stationary. During this relative motion, the edge of the blank between the inner wall of the second lower inner ring 46 and the outer wall of the upper mold 36 rises upward and enters the crimping groove 341, which has not yet moved. Utilizing the arc-shaped cross-sectional structure of the crimping groove 341, the edge of the blank bends and deforms within the groove, completing the stamping and crimping of the aluminum foil container.

[0049] Compared with existing technologies, the stamping die for wrinkle-free containers made of plain aluminum foil provided by this invention addresses the characteristics of the soft texture and limited ductility of plain aluminum foil by dividing the lower inner ring into a first lower inner ring 45 and a second lower inner ring 46. The heights of the first lower inner ring 45 and the second lower inner ring 46 are different, creating a stepped structure between their adjacent sidewalls, and a height difference of 0.01mm to 0.1mm is provided between their top surfaces. During die closing and stamping, the bottom edge of the upper die 36 applies greater pressure to the top surface of the first lower inner ring 45, while the bottom surface of the upper inner ring 34 applies relatively less pressure to the top surface of the second lower inner ring 46, allowing the pressure to gradually increase during material flow and maintaining a controlled tension state. Meanwhile, when the aluminum foil material flows through the stepped structure between the first lower inner ring 45 and the second lower inner ring 46, the material is forced to bend multiple times. Through repeated stretching, a pre-stretching and flattening effect is achieved, effectively eliminating micro-wrinkles in the material. This ensures that the material is in a flat state before entering the area between the bottom edge of the upper mold 36 and the top surface of the first lower inner ring 45, solving the wrinkling problem in the stamping process of plain aluminum foil containers and effectively eliminating wrinkles on the opening plane. In addition, multiple top blocks 47 are spaced apart around the outer perimeter of the second lower inner ring 46, forming a gap between the top of the top block 47 and the pressing edge portion 342 of the upper inner ring 34. This gap provides a local pressure release channel when the aluminum foil material shrinks into the mold cavity, effectively avoiding the problem of excessive tightness or looseness of the material caused by continuous full-circle pressing, and significantly reducing the phenomenon of wrinkling at the material edge.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions or improvements within the spirit of the present invention are covered within the scope of the claims of the present invention.

Claims

1. A stamping die for a wrinkle-free foil container, characterized in that: The stamping die for a wrinkle-free container made of plain foil includes an upper die plate, a lower die plate disposed on one side of the upper die plate, an upper die assembly disposed on the upper die plate, and a lower die assembly disposed on the lower die plate. The upper die assembly includes an upper pressure plate seat disposed on the upper die plate, an upper pressure plate seat disposed on the upper pressure plate seat, an upper inner ring seat disposed on the upper die plate, an upper inner ring seat disposed on the upper inner ring seat, a first piston disposed on the upper die plate and connected to the upper inner ring seat, and an upper die disposed on the upper die plate. The upper inner ring seat and the upper inner ring are located between the upper pressure edge seat and the upper mold. The outer side wall of the upper inner ring is in contact with the inner side wall of the upper pressure edge, and the inner side wall of the upper inner ring is in contact with the outer side wall of the upper mold. The lower mold assembly includes a second piston disposed on the lower template, a base disposed on the output end of the second piston, a third piston disposed on the lower template, a lower mold disposed on the output end of the third piston, a first lower inner ring disposed on the base, a second lower inner ring disposed on the base, a top block disposed on the base, a lower pressure edge disposed on the base, and a limiting block disposed on the lower template. The first lower inner ring is located between the lower mold and the second lower inner ring, and its outer side is in contact with the inner side wall of the second lower inner ring. The top of the first lower inner ring corresponds to the bottom edge of the upper mold. The second lower inner ring is located between the upper mold and the lower mold. Between the first lower inner ring and the lower pressing edge, its inner side is in contact with the outer side wall of the first lower inner ring, and its outer side is in contact with the inner side wall of the lower pressing edge. The top of the second lower inner ring corresponds to the upper inner ring. A plurality of top blocks are respectively located on the outer side of the second lower inner ring. The top blocks are located between the second lower inner ring and the lower pressing edge. The outer side of the upper inner ring is respectively provided with pressing edge portions. The top blocks are provided corresponding to the pressing edge portions. The limiting block is located below the second lower inner ring and the top blocks. When the base descends, the top surface of the limiting block abuts against and supports the bottom surface of the second lower inner ring and the top blocks. The height of the top block is less than the height of the second inner ring, so that a gap is formed between the top of the top block and the pressing edge portion. The height of the first lower inner ring is different from the height of the second lower inner ring, so that a stepped structure is formed between the adjacent side walls of the two.

2. The stamping die for a wrinkle-free container made of plain foil according to claim 1, characterized in that: The upper template is movably fitted onto at least four guide posts, one end of which is fixedly mounted on the lower template, and the other end is movably mounted on the upper template.

3. The stamping die for a wrinkle-free container made of plain foil according to claim 1, characterized in that: At least four limiting posts are movably inserted on the end face of the upper template facing the lower template, and a waste pressure plate is fixedly installed at the bottom end of the limiting posts.

4. The stamping die for a wrinkle-free container made of plain foil according to claim 1, characterized in that: The upper mold assembly further includes an upper cylinder seat disposed on the upper mold plate, an upper cylinder disposed on the upper cylinder seat, and a stripper plate disposed on the upper cylinder. The upper cylinder seat is used to house the first piston and the upper cylinder. The output end of the upper cylinder is connected to the stripper plate and is used to drive the stripper plate to move vertically. The stripper plate is located at the center of the upper mold.

5. The stamping die for a wrinkle-free container made of plain foil according to claim 1, characterized in that: A rolled edge groove is provided on the inner sidewall of the upper inner ring. The rolled edge groove is located at the end of the upper inner ring facing the lower mold assembly, and the cross-section of the rolled edge groove has an arc-shaped structure.

6. The stamping die for a wrinkle-free container made of plain foil according to claim 1, characterized in that: The second piston is fixedly disposed on the side of the lower template facing away from the upper template. The output end of the second piston movably passes through the lower template and connects to the bottom of the base. The third piston is fixedly disposed on the side of the lower template facing away from the upper template. The output end of the third piston movably passes through the lower template and connects to the bottom surface of the lower mold.

7. The stamping die for a wrinkle-free container made of plain foil according to claim 1, characterized in that: The base has a plate-like structure, and a through hole is provided in the center of the base to allow the lower mold to move. The base also has a clearance hole corresponding to the position of the limiting block, and the shape of the through hole is adapted to the outer contour of the lower mold.

8. The stamping die for a wrinkle-free container made of plain foil according to claim 1, characterized in that: The height difference between the first lower inner ring and the second lower inner ring is set to be 0.01mm~0.1mm.

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