One-piece concave tank forming preparation mold

Abstract

The utility model relates to a one-piece concave tank forming preparation die, which is characterized in that a first sequence die for punching and shearing a blank, a second sequence die for stretching a tank body, a third sequence die for deep concave forming and a fourth sequence die for forming and trimming are arranged according to a punching sequence, and the third sequence die is a core innovation part. The third sequence die comprises a concave bottom lower forming die and a concave bottom upper pressing die; the concave bottom lower forming die comprises a lower forming seat and a lower forming die with a surrounding edge; the concave bottom upper pressing die comprises an upper forming seat, an upper core die and an upper blank pressing die; the upper forming base synchronously drives the upper core mold and the upper blank pressing mold through a first driving device, and the upper cover mold is provided with a limiting edge for preventing deviation. The number of the second-sequence dies can be adjusted as required, and the lower forming base and the stretching upper forming die are matched with an automatic stripping structure. According to the utility model, the deep concave forming is independent as an exclusive process, the upper blank pressing die is matched to effectively disperse the material stress and limit the excessive extension of the material, the synchronous driving and guiding structure further ensures the forming stability, and finally, the yield is obviously improved.

Description

Technical Field

[0001] This utility model relates to the field of mold technology, and in particular to a one-piece concave can molding preparation mold. Background Technology

[0002] Metal cans are mainly divided into two-piece cans and three-piece cans. Three-piece cans are assembled from a top lid, a can body, and a bottom lid. The can body needs to be assembled through multiple processes such as rounding and welding, making the manufacturing process complicated. Two-piece cans, on the other hand, adopt a one-piece can body design. The can body is formed by stamping and stretching a single piece of metal material in one piece, without splicing seams. It only needs to be matched with the top lid to form a complete can body. Its manufacturing process is simpler. Specifically, it requires steps such as cupping, one / multiple stretching, bottom forming, can wall pressing, diameter expansion, and edge trimming.

[0003] The stamping process for the concave bottom structure of a one-piece two-piece can is a core technological challenge, especially for processing deep concave structures. Traditional processes rely on the material's own extensibility to create the concave bottom. However, this method only achieves shallow concavities and cannot meet the requirements for deep concavities. When the concavity depth reaches a certain standard, the material's extensibility exceeds its limit, leading to tearing or breakage. This significantly increases the scrap rate and severely limits the application of two-piece cans in scenarios involving deep concave bottom structures. Therefore, it is necessary to optimize the stamping die for deep concavity two-piece cans to improve the yield rate. Utility Model Content

[0004] The purpose of this utility model is to provide a one-piece concave can molding mold, which specifically solves the technical problems of "material breakage, low yield and poor mold versatility" in the traditional one-piece two-piece deep concave can molding. Through sequential molding and structural optimization, stable production of deep concave cans can be achieved.

[0005] To achieve the above objectives, this utility model provides a one-piece concave can forming mold, which includes, in the stamping sequence, a first mold for punching and shearing the stamped material into a blank, a second mold for stretching the stamped material into a can, a third mold for deep concave forming of the bottom of the stamped material, and a fourth mold for forming and trimming the stamped material.

[0006] The second sequence module has multiple configurations based on the required tank height.

[0007] The third die includes a concave bottom forming die and a concave bottom upper pressing die. The concave bottom forming die includes a lower forming seat and a lower forming die. The concave bottom upper pressing die includes an upper forming seat, an upper core die, and an upper pressing edge die.

[0008] The lower forming seat is disposed opposite to the upper forming seat and the upper forming seat reciprocates and moves up and down relative to the lower forming seat. The lower forming mold is fixedly connected to the lower forming seat. The lower forming mold is provided with a surrounding edge, the inside of which is a hollow structure and corresponds to the upper core mold. The upper pressing mold is connected to the upper forming seat and is sleeved on the outer periphery of the upper core mold and reciprocates and moves up and down along the axial direction of the upper core mold.

[0009] When the mold is closed, the upper forming seat descends and drives the upper core mold to extend into the perimeter of the lower forming mold. The bottom of the stamped object is located between the upper core mold and the lower forming mold and forms a recess. At the same time, the upper pressing die abuts against the bottom of the stamped object.

[0010] Preferably, the upper forming seat includes a first driving device and an upper cover mold. The first driving device is fixedly connected to the upper core mold and to the upper pressing edge mold. One end of the upper cover mold is fixedly connected to the first driving device and sleeved on the outer periphery of the upper pressing edge mold. The first driving device drives the upper pressing edge mold to reciprocate up and down within the upper cover mold.

[0011] Preferably, the upper cover mold is provided with a limiting edge at the other end away from the first driving device, and the limiting edge is used to prevent the upper pressing edge mold from leaving the range of the upper cover mold during the lifting and lowering movement.

[0012] Preferably, the upper pressing die is in the shape of a "7", the long side of the outer corner of the upper pressing die is fixedly connected to the first driving device, the short side of the outer corner abuts against the outer periphery of the upper core die, the end face corresponding to the long side of the upper pressing die abuts against the upper cover die, and the end face corresponding to the short side abuts against the bottom of the stamped object.

[0013] Preferably, the upper pressing die is in the shape of a "7", the short side of the outer corner of the upper pressing die is fixedly connected to the first driving device, the long side of the outer corner abuts against the upper cover die, the short side of the inner corner of the upper pressing die abuts against the bottom of the stamped object, the long side of the inner corner abuts against the outer periphery of the bottom of the stamped object, and the end face corresponding to the short side abuts against the upper core die.

[0014] Preferably, the lower forming base includes a first driving device, a lower stripping mold, and a lower cover mold. The first driving device is fixedly connected to the lower cover mold and the lower forming mold respectively. The lower stripping mold is located between the lower cover mold and the lower forming mold and is connected to the first driving device. The first driving device drives the lower stripping mold to perform reciprocating lifting and lowering motion.

[0015] Preferably, the first driving device includes a mold base, a piston cylinder, and a guide post. The piston cylinder is fixedly connected to the mold base and its output end is connected to the guide post. The guide post passes through the mold base and is connected to the upper pressing mold or the lower stripping mold.

[0016] Preferably, the second die includes an upper stretching die and a lower stretching die. The upper stretching die includes an upper stretching die base, an upper shaping die, and an upper clamping die. The upper clamping die is fixedly connected to the upper stretching die base, and the upper shaping die passes through the upper stretching die base and is disposed within the upper clamping die.

[0017] The lower stretching die includes a lower stretching die base and a lower stretching core die fixedly connected to the lower stretching die base. The upper clamping die has an inner groove corresponding to the lower stretching core die.

[0018] When the mold is closed, the upper clamping mold is sleeved on the outer periphery of the lower stretching core mold, the side of the stamped object is located between the upper clamping mold and the lower stretching core mold, and the bottom of the stamped object is located between the upper shaping mold and the lower stretching core mold.

[0019] The beneficial effects of this utility model are:

[0020] By employing a four-step forming design of "punching-shearing-stretching-deep concave forming-trimming," deep concave forming is separated into the third step. This avoids the concentrated stress problem caused by the material having to simultaneously bear stretching and local concavity when stretching and deep concave forming are performed simultaneously in traditional processes. In the third-step die, the cooperation between the upper core die and the lower forming die directly forms the deep concave shape, while the upper pressing die abuts and presses against the bottom of the stamped material in real time, effectively limiting excessive elongation of the material during the stretching process and effectively dispersing local stress. This fundamentally solves the technical pain point of materials being prone to tearing or fracture during traditional deep concave stamping, enabling the stable forming of deep concave structures that were previously impossible, and significantly improving the product yield. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0022] Figure 1 This is a process flow diagram of this utility model.

[0023] Figure 2 This is a flowchart of the integral stamping process of this utility model.

[0024] Figure 3 This is a schematic diagram of the mold closing state of the third mold of this utility model.

[0025] Figure 4 This is a schematic diagram of the mold splitting state of the third sequence mold of this utility model.

[0026] Figure 5 This is a schematic diagram of the connection of the upper pressing die of this utility model. Figure 1 .

[0027] Figure 6 This is a schematic diagram of the connection of the upper pressing die of this utility model. Figure 2 .

[0028] Figure 7 This is a schematic diagram of the mold closing state of the second mold of this utility model.

[0029] In the figure: First mold 1; Second mold 2; Upper stretching forming mold 20; Upper stretching mold base 201, Upper shaping mold 202, Upper clamping mold 203, Drive rod 204; Lower stretching forming mold 21; Lower stretching mold base 211, Lower stretching core mold 212; Third mold 3; Lower concave bottom forming mold 30; Lower forming base 301, Lower forming mold 302, Edge band 3021, Lower stripping mold 303, Lower cover mold 304; Upper concave bottom pressing mold 31; Upper forming base 311, First driving device 3111; Mold base 3111a; Piston cylinder 3111b; Guide post 3111c; Upper cover mold 3112; Limiting edge 3112a; Upper core mold 312; Upper pressing edge mold 313; Fourth mold 4. Detailed Implementation

[0030] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0031] In the traditional one-piece and two-piece deep concave forming process, there is a prominent core problem: the stamped material is prone to cracking after undergoing "bottom deep concavity" and "can body stretching". This is because the metal material has to withstand the dual stress of overall stretching and local concavity, and it is very easy to tear and break due to the local elongation exceeding the material limit.

[0032] Based on the above, this utility model proposes a one-piece concave can molding and manufacturing mold, such as... Figures 1-2 As shown, the first to fourth sequence dies are set in the order of "punching-shearing-stretching-deep concave forming-trimming". Through sequence optimization and structural innovation, the pain points of traditional processes are systematically solved.

[0033] Among them, the first die 1 is responsible for punching and cutting the metal sheet into blanks of a preset shape (i.e., Figure 1 The middle and lower die forming process provides the basic blank for subsequent molding; the second die 2 is responsible for stretching the blank into the preliminary can body shape (i.e., Figure 1 The number of intermediate stretching dies can be flexibly adjusted according to the tank height requirements. When producing taller tanks, the number of second-order dies is increased to achieve multiple progressive stretching operations, avoiding uneven tank wall thickness caused by excessive single stretching. The third-order die 3 is responsible for forming the deep concave structure at the bottom (i.e., Figure 1In the concave bottom forming process, the upper forming seat synchronously drives the upper core mold and the upper pressing mold, and the upper core mold and the lower forming mold cooperate to form a deep concave shape; the fourth mold 4 then performs edge trimming on the formed tank body (i.e., Figure 1 (Edge trimming process) to ensure the product meets design requirements.

[0034] In one embodiment, the number of molds for the second sequence mold can be set according to a preset ratio based on product requirements. For example, when the target can diameter is 65mm and the height is 116mm, the subsequent stretching process can be set to 0.7 times that of the previous one, that is, the can diameter of the previous stretching process is 65mm / 0.7≈92.9mm, and so on, and the preliminary can body is formed after four stretching processes.

[0035] Specifically, such as Figure 3 As shown, the third mold 3 of this utility model includes a concave bottom forming mold 30 and a concave bottom upper pressing mold 3. Through the dual-mold collaborative structure of "lower support + upper pressure", stress dispersion and precise shape control are achieved during deep concave forming. The concave bottom forming mold 30 includes a lower forming seat 301 and a lower forming mold 302; the concave bottom upper pressing mold 31 includes an upper forming seat 311, an upper core mold 312, and an upper pressing edge mold 313. The lower forming seat 301 and the upper forming seat 311 are arranged opposite to each other. The upper forming seat 311 can reciprocate up and down in the vertical direction to provide stamping power for forming. The lower forming mold 302 is fixed on the lower forming seat 301. Its upper rim 3021 forms an "inner cavity" for deep concave forming. The hollow structure inside the rim 3021 corresponds precisely to the upper core mold 312 to ensure the consistency of the deep concave dimensions. The upper pressing edge mold 313 is sleeved on the outer periphery of the upper core mold 312 and can be independently raised and lowered along the axis of the upper core mold 312.

[0036] When the mold is closed, the upper forming seat 311 drives the upper core mold 312 to descend synchronously and extend into the perimeter 3021 of the lower forming mold 302. At this time, the bottom of the stamped material (the can body blank stretched by the second mold) is clamped between the upper core mold 312 and the lower forming mold 302. Under the downward pressure of the upper core mold 312 and the limiting action of the perimeter 3021, a deep concave shape is initially formed. At the same time, the upper pressing edge mold 313 descends and abuts against the bottom of the stamped material, applying a uniform clamping force to the bottom material. Unlike the traditional deep concave forming process of first forming the bottom concavity and then stretching the can body, this utility model first stamps the stamped material into a can in multiple stages (exceeding the required height to provide material deformation space for the concave bottom in the next process), and then restricts the flow range of the bottom material during the concavity process through the "active clamping" of the upper pressing edge mold 313, controlling the material elongation within its limit, and at the same time dispersing the local pressure applied by the upper core mold 312 to avoid stress concentration and breakage.

[0037] For further details, please refer to [link / reference]. Figure 2The upper forming base 311 includes a first driving device 3111 and an upper cover mold 3112. The first driving device 3111 is simultaneously associated with the upper core mold 312 (fixed connection) and the upper pressing edge mold 313 (driven connection). The upper cover mold 3112 is sleeved on the outer periphery of the upper pressing edge mold 313, forming a guide and protection. When the first driving device 3111 is activated, the downward pressing of the upper core mold 312 and the clamping action of the upper pressing edge mold 313 can be controlled synchronously to ensure that "deep concave forming" and "stress dispersion" are completely synchronized, and to prevent the bottom material from being excessively stretched instantaneously due to lack of restraint. At the same time, the upper cover mold 3112 provides an outer peripheral guide for the upper pressing edge mold 313 to prevent it from radially deviating during the lifting and lowering process, ensuring that the clamping force is evenly applied to the bottom of the stamped material, and avoiding stress concentration caused by insufficient local clamping force.

[0038] Furthermore, a limiting edge 3112a is provided at the end of the upper cover die 3112 away from the first drive device 3111 to limit the maximum descent stroke of the upper pressing die 313. The limiting edge 3112a can effectively prevent the upper pressing die 313 from detaching from the upper cover die 3112 due to excessive descent, thus avoiding mechanism failure; at the same time, it can prevent the upper pressing die 313 from rigidly colliding with the lower forming die 302, protecting the die components from damage and extending their service life; more importantly, by limiting the stroke of the upper pressing die 313, it ensures that its clamping force always acts on the preset area at the bottom of the stamped object, avoiding stress dispersion failure caused by clamping position deviation.

[0039] The targeted design of the “7”-shaped upper pressure die and the structure of the upper pressure die 313 directly determine the pressing effect.

[0040] In one embodiment, such as Figure 5 As shown, the long outer corner of the upper pressing die 313 is fixed to the first driving device 3111, and the short outer corner is positioned against the outer periphery of the upper core die 312. The end face corresponding to the short side abuts against the center area of ​​the bottom of the stamped object. Technical effect: This structure is designed for "medium-depth concave" shapes. By precisely pressing the bottom center (the area of ​​maximum stress) with the short end face, the pressure applied by the upper core die 312 is specifically dispersed, avoiding breakage in the center area. The structure is simple and has high pressing efficiency.

[0041] In another embodiment, such as Figure 6 As shown, the short outer corner of the upper pressing die 313 is fixed to the first driving device 3111, the short inner corner presses against the center of the bottom of the stamped object, the long inner corner presses against the outer periphery of the bottom, and the short end face abuts against the upper core die 312. This structure, through the double pressing of "center + periphery", comprehensively restricts the flow of bottom material, disperses overall stress, avoids tearing caused by excessive stress gradient at the junction of the center and periphery, and breaks through the deep concave depth limit of traditional processes.

[0042] After deep-recessed molding, the can body and the mold have a high degree of fit, and traditional manual stripping can easily lead to deformation of the deep-recessed structure. This invention adds a stripping structure to the lower molding base 301, such as... Figure 4 As shown, the lower forming base 301 includes a first driving device 3111, a lower stripping mold 303, and a lower cover mold 304. The lower stripping mold 303 is located between the lower cover mold 304 and the lower forming mold 302, and is driven to rise and fall by the first driving device 3111. When the mold is separated, the first driving device 3111 drives the lower stripping mold 303 to rise, smoothly ejecting the formed can from the perimeter 3021 of the lower forming mold 302, thus achieving automated stripping. Compared with traditional stripping methods, this structure avoids deformation or scratches caused by manual intervention, improves production efficiency, and ensures the integrity of the deep concave structure.

[0043] like Figure 7 As shown, the second die 2 includes an upper stretching die 20 and a lower stretching die 21: the upper clamping die 203 of the upper stretching die 20 cooperates with the lower stretching core die 212 of the lower stretching die 21 to clamp the sides of the stamped material; the upper shaping die 202 cooperates with the lower stretching core die 212 to position the bottom of the stamped material. Working process and technical effects: When the die is closed, the upper clamping die 203 is fitted around the outer periphery of the lower stretching core die 212, clamping the sides of the stamped material to prevent material shifting or wrinkling during stretching; the upper shaping die 202 presses down, cooperating with the lower stretching core die 212 to stretch the blank into a can shape. The side clamping design ensures uniform can wall thickness, and the bottom positioning design ensures the accuracy of the can diameter and height—if the blank wall thickness is uneven, the thinner parts are prone to cracking due to stress concentration during deep forming; if there is a dimensional deviation, it will lead to unstable clamping by the third die, increasing the risk of cracking. Therefore, the precise stretching of the second mold 2 provides a "qualified foundation" for subsequent deep concave forming, reducing the defect rate from the source.

[0044] In addition, the drive rod 204 added to the upper forming die 20 is connected to the upper shaping die 202 (e.g., Figure 5 As shown in the figure, when the mold is separated, the drive rod 204 drives the upper shaping mold 202 to descend, and smoothly pushes the molded blank out of the upper clamping mold 203, avoiding surface damage caused by the blank sticking together, and further improving the quality of the blank.

[0045] This utility model employs a first driving device 3111 with a unified structure for multiple components, such as... Figure 2As shown, the mold includes a mold base 3111a, a piston cylinder 3111b, and a guide post 3111c. The piston cylinder 3111b provides stable power, and the guide post 3111c passes through the mold base 3111a and connects to the actuator (upper pressing die 313 or lower stripping die 303) to achieve precise guidance. The driving force of the piston cylinder 3111b can be precisely controlled by adjusting hydraulic (or pneumatic) pressure to adapt to the ductility characteristics and depth requirements of different metal materials (such as aluminum and iron). The guiding function of the guide post 3111c ensures the stability of the actuator's movement trajectory and avoids uneven force caused by deviation. The universal structure reduces mold design and maintenance costs and improves the consistency of mass production.

[0046] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art will understand that all or part of the processes for implementing the above embodiments and equivalent variations made in accordance with the claims of this application are still within the scope of this application.

Claims

1. A one-piece draw-and-iron mold for forming a one-piece, internally recessed can, characterized by, The first sequence die is used for cutting and blanking the punched material, the second sequence die is used for drawing the punched material into a can body, the third sequence die is used for deep drawing the bottom of the punched material, and the fourth sequence die is used for forming and trimming the punched material; The second sequence die is provided with a plurality of, The third sequence die comprises a concave bottom lower forming die and a concave bottom upper pressing die, the concave bottom lower forming die comprises a lower forming seat and a lower forming die, and the concave bottom upper pressing die comprises an upper forming seat, an upper core die and an upper trimming die, The lower forming seat is arranged opposite to the upper forming seat, the upper forming seat reciprocatingly moves up and down relative to the lower forming seat, the lower forming die is fixedly connected with the lower forming seat, the lower forming die is provided with a surrounding edge, the surrounding edge is hollow inside and corresponds to the upper core die, the upper trimming die is connected with the upper forming seat, the upper trimming die is sleeved on the outer periphery of the upper core die and reciprocatingly moves up and down along the axis direction of the upper core die. When the dies are closed, the upper forming seat descends, the upper core die is driven to extend into the surrounding edge inside the lower forming die, the bottom of the punched material is located between the upper core die and the lower forming die and forms a concave bottom, and the upper trimming die abuts against the bottom of the punched material.

2. A one-piece draw-and-iron mold for making a one-piece concave can, as defined in claim 1, wherein, The upper forming seat comprises a first driving device and an upper cover die, the first driving device is fixedly connected with the upper core die and connected with the upper trimming die, one end of the upper cover die is fixedly connected with the first driving device and sleeved on the outer periphery of the upper trimming die, and the first driving device drives the upper trimming die to reciprocatingly move up and down in the upper cover die.

3. A one-piece draw-and-iron mold for making a one-piece concave can, according to claim 2, wherein The other end of the upper cover die away from the first driving device is provided with a limiting edge, the limiting edge is used to prevent the upper trimming die from moving out of the range of the upper cover die during the up and down movement.

4. A one-piece draw-and-iron mold for making a one-piece concave can, according to claim 3, wherein The upper trimming die is in the shape of "7", the outer corner long side of the upper trimming die is fixedly connected with the first driving device, the outer corner short side abuts against the outer periphery of the upper core die, the corresponding end surface of the long side of the upper trimming die abuts against the upper cover die, and the corresponding end surface of the short side abuts against the bottom of the punched material.

5. A one-piece draw-and-iron mold for making a one-piece concave can, as defined in claim 3, wherein, The upper trimming die is in the shape of "7", the outer corner short side of the upper trimming die is fixedly connected with the first driving device, the outer corner long side abuts against the upper cover die, the inner corner short side of the upper trimming die abuts against the bottom of the punched material, the inner corner long side abuts against the outer periphery of the bottom of the punched material, and the corresponding end surface of the short side abuts against the upper core die.

6. A one-piece draw-and-iron mold for making a one-piece concave can, as defined in claim 2, wherein, The lower forming seat comprises a first driving device, a lower stripper die and a lower cover die, the first driving device is fixedly connected with the lower cover die and the lower forming die, the lower stripper die is located between the lower cover die and the lower forming die and connected with the first driving device, and the first driving device drives the lower stripper die to reciprocatingly move up and down.

7. A one-piece draw-and-iron mold for making a one-piece concave can, according to claim 6, wherein The first driving device comprises a die seat, a piston cylinder and a guide column, the piston cylinder is fixedly connected with the die seat and connected with the guide column at the output end, and the guide column is connected with the upper trimming die or the lower stripper die through the die seat.

8. A one-piece draw-and-iron mold for making a one-piece concave can, as defined in claim 1, wherein, The second sequence die comprises a stretch upper forming die and a stretch lower forming die, the stretch upper forming die comprises a stretch upper die seat, an upper setting die and an upper clamping die, the upper clamping die is fixedly connected with the stretch upper die seat, the upper setting die passes through the stretch upper die seat and is arranged in the upper clamping die, The stretch lower forming die comprises a stretch lower die seat and a stretch lower core die fixedly connected with the stretch lower die seat, the upper clamping die is provided with an inner groove corresponding to the stretch lower core die, When the die is closed, the upper clamping die is sleeved on the outer periphery of the stretch lower core die, the side of the stamping object is between the upper clamping die and the stretch lower core die, and the bottom of the stamping object is between the upper setting die and the stretch lower core die.

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