An adjustable trolley case shell continuous punch forming die

Abstract

The application discloses a continuously stamping forming die of an adjustable trolley case shell, and relates to the technical field of stamping dies.The continuously stamping forming die of the adjustable trolley case shell comprises an upper die assembly, a lower die assembly, a servo feeding unit and stamping stations arranged in sequence along a feeding direction, the stamping stations comprise a deep-drawing main forming station; the deep-drawing main forming station is provided with an adjustable male die assembly below and a female die assembly corresponding to the male die assembly above; the male die assembly comprises a base assembly, an insert male die, a jacking die group, a wedge locking mechanism and a hydraulic support group; the insert male die comprises a jacking base plate at a lower portion and a male die main piece at an upper portion; the jacking die group is assembled on the jacking base plate; the jacking die group comprises four groups of servo motors which are uniformly embedded in the jacking base plate, and the end of each group of servo motors is fixedly connected with a ball screw penetrating through the jacking base plate; the universal adaptation capability of the die is improved, and the flexible production requirement of the trolley case shell of multiple specifications is adapted.

Description

Technical Field

[0001] This invention relates to the field of stamping die technology, specifically to an adjustable continuous stamping die for a trolley case shell. Background Technology

[0002] With the continuous development of the luggage manufacturing industry, trolley case shells made of metal materials such as aluminum-magnesium alloy and cold-rolled steel have been widely used in mid-to-high-end luggage products due to their excellent structural strength and appearance. Currently, the industrial production of this type of metal shell generally adopts a split production mode of single-stage drawing dies followed by multiple subsequent punching processes. However, the matching forming dies have gradually revealed many technical defects in actual production applications, making it difficult to adapt to the current industrial upgrading requirements of flexibility, high quality, and high efficiency.

[0003] First, the molds lack universal adaptability and have low resource reuse rates. Existing trolley case shell molding molds are mostly customized structures corresponding to single product specifications, with each mold only suitable for shell products of a specific size. When companies develop new product models, they need to completely redesign, manufacture, and install the entire mold set. This not only results in high mold investment costs but also a lengthy product development cycle. It also fails to adequately meet the flexible production needs of multiple varieties and small batches, making it difficult to efficiently reuse mold resources and indirectly increasing the overall manufacturing cost of the product.

[0004] Secondly, the core forming parameters are fixed, resulting in poor process adaptability. Existing conventional molds have fixed core process parameters such as drawing depth, blank holder force, and forming gap, which cannot be flexibly adjusted according to differences in sheet thickness and material properties. In actual drawing processes, mismatch between process parameters and processed materials easily leads to various forming defects such as sidewall wrinkling, corner tearing, and excessive springback, resulting in significant fluctuations in product yield and making it difficult to consistently guarantee the dimensional consistency and appearance quality of shells within the same batch.

[0005] Secondly, adjustable structures have limitations in load-bearing capacity and precision, restricting their practical performance. Some existing adjustable depth dies use a lead screw to directly lift the punch to expand their adaptability. However, in this type of structure, the transmission lead screw must directly bear the large load impacts during the stamping process for extended periods. This generally results in inherent problems such as insufficient overall load-bearing rigidity, susceptibility to tilting under off-center load conditions, rapid attenuation of transmission precision, and short impact resistance lifespan. Furthermore, after the punch height is adjusted, the corresponding blank holder system cannot synchronously match the corresponding process parameters, further exacerbating forming defects and severely restricting the practical application and promotion of adjustable dies.

[0006] Therefore, developing a continuous stamping die for a suitcase shell that combines a wide range of flexible adjustability, high rigidity load-bearing capacity, stable forming accuracy, and high operational reliability is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] The purpose of this invention is to provide an adjustable continuous stamping die for a suitcase shell, in order to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: an adjustable continuous stamping forming die for a trolley case shell, comprising an upper die assembly, a lower die assembly, a servo feeding unit, and stamping stations arranged sequentially along the feeding direction, wherein the stamping stations include a deep drawing main forming station; The deep drawing main forming station is equipped with an adjustable punch assembly below and a die assembly corresponding to the punch assembly above; The punch assembly includes a base assembly, an insert punch, a lifting module, a wedge locking mechanism, and a hydraulic support assembly. The insert punch adopts a segmented structure, including a lower lifting base plate and an upper punch main component; The lifting module is assembled on the lifting base plate; the lifting module includes four sets of servo motors that are evenly embedded in the lifting base plate, and each set of servo motors has a ball screw that extends out of the lifting base plate fixedly connected to its end. The lower surface of the main punch has screw holes for corresponding ball screws at its four corners; the main punch is driven to move vertically by the ball screws to adjust the forming depth; the bottom of the main punch has locking slopes for corresponding wedge locking mechanisms on its four sides. The wedge locking mechanism is arranged around the outer periphery of the insert punch. Each wedge locking mechanism includes a wedge block corresponding to the locking slope and a push cylinder assembled at the bottom of the lifting base plate. After the wedge block is pushed along the upper surface of the lifting base plate by the push cylinder, it forms a surface contact with the locking slope and is rigidly locked, thus forming the main load bearing path for stamping. The hydraulic support assembly is mounted on the main punch component; the hydraulic support assembly includes four sets of telescopic cylinders embedded in the top of the screw holes. The telescopic cylinders adopt a three-stage sleeve structure and are used to fill the gap between the screw holes and the ball screw after the height of the main punch component is adjusted to the correct position, forming auxiliary support and pre-tightening.

[0009] As a preferred technical solution of the present invention, the base assembly includes a base fixed on the lower mold assembly, a mold groove for inserting a punch is opened in the middle of the upper surface of the base, positioning holes opened on the base are provided on the four outer corners of the mold groove, and positioning seats embedded in the base are provided on the outer side of the long side of the mold groove. A pressure platform is provided above the base, facing the mold groove. Lower positioning posts that fit the insertion positioning holes are fixedly connected to the four corners of the lower surface of the pressure platform. Upper positioning posts are fixedly connected to the four corners of the upper surface of the pressure platform. A seat groove for docking positioning seat is opened on the long side of the lower surface of the pressure platform. A spring for support is fixedly connected between the pressure platform and the base. The bottom of the mold groove has four corresponding space slots for assembling the wedge locking mechanism.

[0010] In a preferred embodiment of the present invention, the lifting base plate is inserted and fixed at the bottom of the mold groove; the main punch slides along the mold groove; and the upper end of the main punch is adapted to the insertion pressing table. The upper surface of the lifting base plate is fixedly connected to the four corners of the plate, and the lower surface of the punch main component is provided with guide holes adapted to insert the guide posts at the four corners of the plate.

[0011] As a preferred embodiment of the present invention, a disc spring assembly is connected in series between the wedge block and the propulsion cylinder. After the propulsion cylinder drives the wedge block to advance into place, the disc spring assembly maintains the locking thrust.

[0012] As a preferred embodiment of the present invention, the hydraulic support assembly includes a control embedded in the lifting base plate. The control and the telescopic cylinder are connected by an oil supply circuit. The oil supply circuit is provided with a spring-type accumulator embedded in the main punch and a constant pressure relief valve. When the oil expands due to heat, the excess oil enters the accumulator through the constant pressure relief valve to maintain a constant support pressure.

[0013] As a preferred embodiment of the present invention, the die assembly includes a base block fixed on the upper die assembly, and the lower surface of the base block has positioning grooves at the four corners for fitting and inserting the upper positioning pins. The lower surface of the base block is embedded in the middle of the die main component, which is adapted to the punch main component. The upper end of the die main component is fitted with an elastic component embedded in the top of the base block. The die assembly is equipped with a pressing system, which includes a rectangular pressing ring embedded in the bottom of the base block. The upper end face of the rectangular pressing ring is fixedly connected with elastic rods embedded in the top of the base block at equal intervals. The main die component is inserted into the rectangular pressing ring. The upper surface of the rectangular pressing ring is uniformly and equidistantly provided with nitrogen spring units that intersect with the elastic rod. Each group of nitrogen spring units can be independently connected or disconnected, and the total pressing force and the distribution of the pressing force in different zones can be adjusted by increasing or decreasing the number of connected units.

[0014] As a preferred embodiment of the present invention, each nitrogen spring unit is disposed in the lower space within the base block; the nitrogen spring unit includes a nitrogen spring body, a force transmission pin, and a switching pin; when the switching pin is activated, the force transmission pin and the nitrogen spring body work together to output a pressing force; when the switching pin is disabled, a free stroke is formed between the force transmission pin and the nitrogen spring body.

[0015] As a preferred embodiment of the present invention, the end of the nitrogen spring body is fixed to the top of the base block; the force transmission top column is fixed to the rectangular pressure ring. The switching pin is located between the nitrogen spring body and the force transmission top column, and includes a spherical pin body. The end of the nitrogen spring body is adapted to fit the pin body. The pin is horizontally and laterally inserted with a flexible bladder adapted to the end of the nitrogen spring body. The pin is fixed to a rotating shaft in both horizontal and vertical directions. The pin is fitted with a regulator via the rotating shaft. A connecting post is fixed between the regulator and the end of the nitrogen spring body.

[0016] Compared with the prior art, the beneficial effects of the present invention are: (1) An adjustable continuous stamping die for trolley case housing, which allows the main punch to move vertically along the die groove through the screw hole and ball screw connection, can achieve precise adjustment of forming depth within the range, and can directly adapt to the housing cavity of different depth specifications. This not only effectively improves the universal adaptability of the die and reduces the die development cost for multi-variety production, but also ensures the dimensional accuracy of forming depth and batch consistency, and adapts to the flexible production needs of multi-specification trolley case housing.

[0017] (2) An adjustable continuous stamping die for a trolley case housing, wherein the inclined wedge locking mechanism can be pushed along the upper surface of the lifting plate by the push cylinder after the main punch is adjusted to the position, thereby forming a surface contact rigid lock with the locking inclined surface of the main punch, so that the stamping load is transmitted through the rigid support surface, avoiding the ball screw and the main punch from flexing and deforming under the working load, effectively delaying the attenuation of the transmission component accuracy, and greatly improving the overall bearing rigidity and structural stability of the die.

[0018] (3) An adjustable continuous stamping die for a trolley case housing, after the main punch is adjusted to the position, the distance between the ball screw and the top of the screw hole is determined. The control is activated to supply hydraulic oil through the oil supply circuit. The telescopic cylinder presses the end of the ball screw with a set pressure. It can automatically compensate for the machining error and assembly gap of the parts, realize zero gap contact of the support surface, avoid impact noise and small displacement caused by gap during stamping, greatly improve the batch consistency of the forming depth, and eliminate the fit error.

[0019] (4) An adjustable continuous stamping die for a trolley case shell, by assembling a hydraulic support group, the damping characteristics of the telescopic cylinder can absorb the impact peak, disperse the instantaneous load of the wedge block, greatly reduce impact wear and die noise, at the same time reduce the vibration of the insert punch, improve the joint stability of the insert punch, and extend the die life.

[0020] (5) An adjustable trolley case shell continuous stamping forming die, which optimizes and upgrades the idea of ​​separate design adjustment structure and load-bearing structure by assembling a hydraulic support group. The wedge locking mechanism is used as the main load-bearing path to ensure high rigidity load-bearing capacity and long-term dimensional stability. At the same time, the hydraulic support group is used to achieve stepless gap filling pre-tightening and impact buffering vibration absorption. The two have clear functional division and complementary performance advantages. It can stably adapt to the drawing forming condition of trolley case shell within the adjustment range and has better comprehensive performance.

[0021] (6) An adjustable continuous stamping die for a trolley case housing, wherein a disc spring assembly is connected in series between the wedge block and the push cylinder. Relying on the passive adaptive constant force characteristics of the disc spring assembly, the thermal expansion caused by the temperature rise of the die can be automatically offset. It can effectively avoid the problem of the wedge block seizing at high temperature and loosening after cooling, improve the impact resistance and oil stain resistance, and significantly improve the reliability of the die for long-term continuous operation.

[0022] (7) An adjustable continuous stamping die for a trolley case shell, wherein the rotating shaft is controlled by a controller to change the working state of the switching pin. When the flexible bladder is facing the end, the switching pin is in a disabled state, and a free stroke is formed between the force transmission pin and the nitrogen spring body, thereby reducing the support force of the rectangular pressure ring; conversely, the support force can be increased. By increasing or decreasing the number of nitrogen spring unit groups connected, the total pressure force range is dynamically matched to avoid the problem of pressure force imbalance and insufficient stroke after the main punch is raised or lowered, effectively suppressing sidewall wrinkling and corner tearing defects, and ensuring process stability under different forming depths. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the deep drawing main forming station of the present invention; Figure 3 This is a schematic diagram of the base assembly of the present invention; Figure 4 This is a schematic diagram of the base of the present invention; Figure 5 This is a schematic diagram of the pressure table of the present invention; Figure 6 This is a schematic diagram of the insert punch of the present invention; Figure 7 This is a schematic diagram of the lifting module of the present invention; Figure 8 This is a schematic diagram of the main punch component of the present invention; Figure 9 This is a schematic diagram showing the position of the wedge locking mechanism of the present invention; Figure 10 This is a schematic diagram of the wedge locking mechanism of the present invention; Figure 11 This is a schematic diagram of the hydraulic support assembly of the present invention; Figure 12 This is a schematic diagram showing the position of the telescopic cylinder of the present invention; Figure 13 This is a schematic diagram of the die assembly of the present invention; Figure 14 This is a schematic diagram of the elastic element of the present invention; Figure 15 This is a schematic diagram of the nitrogen spring unit of the present invention.

[0024] In the picture: 101. Upper die assembly; 102. Lower die assembly; 103. Servo feeding unit; 104. Deep drawing main forming station; 2. Die assembly; 201. Base block; 202. Positioning groove; 203. Main die component; 204. Elastic component; 205. Rectangular pressure ring; 206. Elastic rod; 207. Nitrogen spring body; 208. Force transmission top column; 209. Pin; 210. Flexible bladder; 211. Rotating shaft; 212. Regulator; 213. Connecting column; 3. Base assembly; 301. Base; 302. Mold groove; 303. Positioning hole; 304. Positioning seat; 305. Pressing table; 306. Lower positioning post; 307. Upper positioning post; 308. Seat groove; 309. Spring; 310. Spatial groove; 4. Insert punch; 401. Lifting base plate; 402. Main punch component; 403. Guide post; 404. Guide hole; 405. Screw hole; 406. Locking bevel; 5. Lifting module; 501. Servo motor; 502. Ball screw; 6. Wedge locking mechanism; 601. Wedge block; 602. Push cylinder; 603. Disc spring assembly; 7. Hydraulic support assembly; 701. Telescopic cylinder; 702. Oil supply circuit; 703. Controls; 704. Accumulator; 705. Constant pressure relief valve. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example: Please refer to Figures 1-15An adjustable continuous stamping die for a suitcase shell includes an upper die assembly 101, a lower die assembly 102, a servo feeding unit 103, and stamping stations arranged sequentially along the feeding direction. The stamping stations include a guide hole punching station, a pre-stretching forming station, a deep drawing main forming station 104, a shaping springback compensation station, a functional hole punching station, a trimming station, and a finished product blanking station. The deep drawing main forming station 104 is equipped with an adjustable punch assembly below and a die assembly 2 corresponding to the punch assembly above; The punch assembly includes a base assembly 3, an insert punch 4, a lifting module 5, a wedge locking mechanism 6, and a hydraulic support assembly 7; The insert punch 4 adopts a segmented structure, including a lower lifting base plate 401 and an upper punch main component 402; The lifting module 5 is mounted on the lifting base plate 401. The lifting module 5 includes four sets of servo motors 501 that are evenly embedded in the lifting base plate 401. Each set of servo motors 501 has a ball screw 502 that extends out of the lifting base plate 401. The lower surface of the main punch 402 is provided with screw holes 405 corresponding to the screwed ball screw 502 at the four corners; the main punch 402 is driven to move in the vertical direction by the ball screw 502 to realize the forming depth adjustment; the bottom of the main punch 402 is provided with locking inclined surfaces 406 corresponding to the inclined wedge locking mechanism 6 on the four sides. The wedge locking mechanism 6 is arranged around the outer periphery of the insert punch 4. Each wedge locking mechanism 6 includes a wedge block 601 corresponding to the locking slope 406 and a push cylinder 602 assembled at the bottom of the lifting base plate 401. After the wedge block 601 is pushed along the upper surface of the lifting base plate 401 by the push cylinder 602, it forms a surface contact with the locking slope 406 and is rigidly locked, thus forming the main load bearing path for stamping. The hydraulic support assembly 7 is mounted on the main punch 402. The hydraulic support assembly 7 includes four sets of telescopic cylinders 701 embedded in the top of the screw hole 405. The telescopic cylinders 701 adopt a three-stage sleeve structure and are used to fill the gap between the screw hole 405 and the ball screw 502 after the height of the main punch 402 is adjusted to the position, forming auxiliary support and pre-tightening.

[0027] The base assembly 3 includes a base 301 fixed on the lower mold assembly 102. A mold groove 302 for inserting the punch 4 is opened in the middle of the upper surface of the base 301. Positioning holes 303 opened on the base 301 are provided on the outer side of the four corners of the mold groove 302. Positioning seats 304 embedded in the base 301 are provided on the outer side of the long side of the mold groove 302. A pressure table 305 is provided above the base 301, facing the mold groove 302. Lower positioning posts 306 that are adapted to the insertion positioning holes 303 are fixedly connected to the four corners of the lower surface of the pressure table 305. Upper positioning posts 307 are fixedly connected to the four corners of the upper surface of the pressure table 305. A seat groove 308 for docking with the positioning seat 304 is opened on the long side of the lower surface of the pressure table 305. A spring 309 for support is fixedly connected between the pressure table 305 and the base 301. The bottom of the mold groove 302 has four space slots 310 on the four sides, which are corresponding to the mounting of the inclined wedge locking mechanism 6.

[0028] The lifting base plate 401 is inserted and fixed at the bottom of the mold groove 302; the punch main component 402 slides along the mold groove 302; the upper end of the punch main component 402 is adapted to the insertion pressing table 305; Guide posts 403 are fixedly connected to the four corners of the upper surface of the lifting base plate 401, and guide holes 404 adapted to insert the guide posts 403 are opened at the four corners of the lower surface of the punch main component 402.

[0029] A disc spring assembly 603 is connected in series between the wedge block 601 and the push cylinder 602. After the push cylinder 602 drives the wedge block 601 to advance into place, the disc spring assembly 603 maintains the locking thrust. When the temperature change causes the locking surface to expand thermally, the disc spring assembly 604 adaptively compresses to absorb the thermal expansion and maintain a stable locking force.

[0030] The hydraulic support assembly 7 includes a control 703 embedded in the lifting base plate 401. The control 703 and the telescopic cylinder 701 are connected by an oil supply circuit 702. The oil supply circuit 702 is equipped with a spring-type accumulator 704 embedded in the punch main component 402 and a constant pressure relief valve 705. When the oil expands due to heat, the excess oil enters the accumulator 704 through the constant pressure relief valve 705 to maintain a constant support pressure.

[0031] The die assembly 2 includes a base block 201 fixed on the upper die assembly 101. The lower surface of the base block 201 has positioning grooves 202 at the four corners that are adapted to be inserted into the positioning pins 307. The lower surface of the base block 201 is inlaid with a die main component 203 that is adapted to the punch main component 402, and the upper end of the die main component 203 is fitted with an elastic component 204 embedded in the top of the base block 201. The die assembly 2 is equipped with a pressing system, which includes a rectangular pressing ring 205 embedded in the bottom of the base block 201. The upper end face of the rectangular pressing ring 205 is fixedly connected with elastic rods 206 embedded in the top of the base block 201 at equal intervals. The die main component 203 is inserted into the rectangular pressing ring 205. Nitrogen spring units, which are interspersed with elastic rods 206, are evenly and equidistantly arranged on the upper end face of the rectangular pressing ring 205. Each set of nitrogen spring units can be independently connected or disconnected, and the total pressing force and the distribution of the pressing force in different zones can be adjusted by increasing or decreasing the number of connected units.

[0032] Each nitrogen spring unit is located in the lower space within the base block 201, matching the operation of the lifting module 5 to maintain a predetermined stroke difference between the rectangular pressure ring 205 and the punch forming surface. The nitrogen spring unit includes a nitrogen spring body 207, a force transmission pin 208, and a switching pin. When the switching pin is activated, the force transmission pin 208 and the nitrogen spring body 207 work together to output pressure force. When the switching pin is disabled, a free stroke is formed between the force transmission pin 208 and the nitrogen spring body 207.

[0033] The end of the nitrogen spring body 207 is fixed to the top of the base block 201; the force transmission top column 208 is fixed to the rectangular pressure ring 205; The switching pin is located between the nitrogen spring body 207 and the force transmission pin 208, including a spherical pin 209, and the end of the nitrogen spring body 207 is adapted to fit the pin 209. The pin 209 is horizontally inserted into a flexible bladder 210 that is adapted to the end of the nitrogen spring body 207. The pin 209 is horizontally and vertically fixed to the rotating shaft 211. The pin 209 is equipped with the regulator 212 through the rotating shaft 211. The regulator 212 and the end of the nitrogen spring body 207 are fixedly connected to the connecting post 213.

[0034] The working principle of this invention is as follows: A lifting module 5 is assembled on the lifting base plate 401. The ball screw 502 is rotated by the servo motor 501. The main punch 402 moves vertically along the mold groove 302 through the screw hole 405 and the screw connection of the ball screw 502. The forming depth can be precisely adjusted within the range. It can directly adapt to shell cavities of different depth specifications, which not only effectively improves the universal adaptability of the mold and reduces the mold development cost of multi-variety production, but also ensures the dimensional accuracy of the forming depth and batch consistency, and adapts to the flexible production needs of multi-specification trolley case shells.

[0035] A wedge locking mechanism 6 is arranged around the outer periphery of the insert punch 4, thus forming a design structure that separates load bearing and adjustment. After the punch main component 402 is adjusted into place, the wedge locking mechanism 6 can be pushed along the upper surface of the lifting plate 401 by the push cylinder 602, thereby forming a surface contact rigid lock with the locking inclined surface 406 of the punch main component 402. This allows the stamping load to be transmitted through the rigid support surface, preventing the ball screw 502 and the punch main component 402 from flexing and deforming under the working load, effectively delaying the attenuation of the transmission component's accuracy, and greatly improving the overall load bearing rigidity and structural stability of the mold.

[0036] A hydraulic support assembly 7 is assembled on the main punch 402. The hydraulic support assembly 7 includes four telescopic cylinders 701 embedded in the top of the screw hole 405. After the main punch 402 is adjusted to the correct position, the distance between the ball screw 502 and the top of the screw hole 405 is determined. The control 703 is activated to supply hydraulic oil through the oil supply circuit 702. The telescopic cylinders 701 press against the end of the ball screw 502 with a set pressure. This can automatically compensate for part machining errors and assembly gaps, achieve zero-gap contact of the support surface, avoid impact noise and slight displacement caused by gaps during stamping, greatly improve the batch consistency of forming depth, and eliminate fit errors.

[0037] After the height of the punch main component 402 is adjusted to the correct position by the telescopic cylinder 701, the gap between the screw hole 405 and the ball screw 502 is filled to form auxiliary support and preload. The transient impact of stamping will directly act on the locking surface of the wedge block 601. Long-term high-frequency impact can easily lead to wear and roughening of the inclined surface and a decrease in locking accuracy. By assembling the hydraulic support group 7, the damping characteristics of the telescopic cylinder 701 can absorb the impact peak, disperse the instantaneous load of the wedge block 601, greatly reduce impact wear and mold noise, reduce the vibration of the insert punch 4, improve the joint stability of the insert punch 4, and extend the mold life.

[0038] By assembling the hydraulic support group 7, the design of the separate adjustment structure and load-bearing structure is optimized and upgraded. The wedge locking mechanism 6 is used as the main load-bearing path to ensure high rigidity load-bearing capacity and long-term dimensional stability. At the same time, the hydraulic support group 7 is used to achieve stepless gap filling pre-tightening and impact buffering vibration absorption. The two have clear functional division and complementary performance advantages. They can stably adapt to the drawing and forming conditions of the trolley case shell within the adjustment range, and have better comprehensive performance.

[0039] A disc spring assembly 603 is connected in series between the wedge block 601 and the propulsion cylinder 602. Relying on the passive adaptive constant force characteristics of the disc spring assembly 603, the thermal expansion caused by the temperature rise of the mold can be automatically offset. This can effectively avoid the problems of the wedge block 601 seizing at high temperature and loosening after cooling, improve its impact resistance and oil resistance, and significantly improve the reliability of the mold for long-term continuous operation.

[0040] Nitrogen spring units, interspersed with elastic rods 206, are evenly spaced on the upper surface of the rectangular blank holder ring 205 to match the height adjustment range of the punch main component 402. The support force of the rectangular blank holder ring 205 is adjusted synchronously by the adjustment operation of the matching lifting module 5 to maintain a reasonable blank holder prestroke. The controller 212 controls the rotation of the rotating shaft 211 to change the working state of the switching pin. When the flexible bladder 210 is facing the end of 207, the switching pin is in the disabled state, and a free stroke is formed between the force transmission pin 208 and the nitrogen spring body 207, thereby reducing the support force of the rectangular blank holder ring 205; conversely, the support force can be increased. By increasing or decreasing the number of nitrogen spring unit groups, the total blank holder force range is dynamically matched to avoid the blank holder force imbalance and insufficient stroke problems that occur after the punch main component 402 is adjusted up or down. This effectively suppresses sidewall wrinkling and corner tearing defects and ensures process stability at different forming depths.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An adjustable continuous stamping die for a suitcase shell, comprising an upper die assembly (101), a lower die assembly (102), a servo feeding unit (103), and stamping stations arranged sequentially along the feeding direction, wherein the stamping stations include a deep drawing main forming station (104). Its features are: The deep drawing main forming station (104) is equipped with an adjustable punch assembly below and a die assembly (2) corresponding to the punch assembly above. The punch assembly includes a base assembly (3), an insert punch (4), a lifting module (5), a wedge locking mechanism (6), and a hydraulic support assembly (7). The insert punch (4) adopts a segmented structure, including a lower lifting base plate (401) and an upper punch main component (402). The lifting module (5) is mounted on the lifting base plate (401); the lifting module (5) includes four sets of servo motors (501) evenly embedded in the lifting base plate (401), and each set of servo motors (501) has a ball screw (502) that passes through the lifting base plate (401) fixedly connected to its end. The lower surface of the main punch (402) is provided with screw holes (405) for corresponding screwed ball screws (502) at the four corners; the main punch (402) is driven to move vertically by the ball screws (502) to achieve the adjustment of forming depth; the bottom of the main punch (402) is provided with locking inclined surfaces (406) for corresponding wedge locking mechanisms (6) on the four sides. The wedge locking mechanism (6) is arranged around the outer periphery of the insert punch (4). Each wedge locking mechanism (6) includes a wedge block (601) corresponding to the locking slope (406) and a push cylinder (602) assembled at the bottom of the lifting base plate (401). After the wedge block (601) is pushed along the upper surface of the lifting base plate (401) by the push cylinder (602), it forms a surface contact with the locking slope (406) and is rigidly locked, thus forming the main load bearing path for stamping. The hydraulic support assembly (7) is mounted on the main punch (402); the hydraulic support assembly (7) includes four telescopic cylinders (701) embedded in the top of the screw hole (405). The telescopic cylinder (701) adopts a three-stage sleeve structure and is used to fill the gap between the screw hole (405) and the ball screw (502) after the height of the main punch (402) is adjusted to the position, so as to form auxiliary support and pre-tightening.

2. The adjustable trolley case shell continuous stamping die according to claim 1, characterized in that: The base assembly (3) includes a base (301) fixed on the lower mold assembly (102). The upper surface of the base (301) is provided with a mold groove (302) for inserting a punch (4). The four corners of the mold groove (302) are provided with positioning holes (303) opened on the base (301). The long side of the mold groove (302) is provided with a positioning seat (304) embedded in the base (301). A pressure platform (305) is provided above the base (301) facing the mold groove (302). Lower positioning posts (306) that are adapted to the insertion positioning holes (303) are fixedly connected to the four corners of the lower surface of the pressure platform (305). Upper positioning posts (307) are fixedly connected to the four corners of the upper surface of the pressure platform (305). A seat groove (308) for docking positioning seat (304) is opened on the long side of the lower surface of the pressure platform (305). A spring (309) for support is fixedly connected between the pressure platform (305) and the base (301). The bottom of the mold groove (302) has four sides with corresponding space grooves (310) for mounting the inclined wedge locking mechanism (6).

3. The adjustable trolley case shell continuous stamping die according to claim 2, characterized in that: The lifting base plate (401) is inserted into the bottom of the mold groove (302); the punch main component (402) slides along the mold groove (302); the upper end of the punch main component (402) is adapted to the insertion pressure table (305). The upper surface of the lifting base plate (401) is fixedly connected with guide posts (403) at the four corners, and the lower surface of the punch main component (402) is provided with guide holes (404) adapted to insert the guide posts (403) at the four corners.

4. The adjustable trolley case shell continuous stamping die according to claim 1, characterized in that: A disc spring assembly (603) is connected in series between the wedge block (601) and the propulsion cylinder (602). After the propulsion cylinder (602) drives the wedge block (601) to advance into place, the disc spring assembly (603) maintains the locking thrust.

5. The adjustable trolley case shell continuous stamping die according to claim 1, characterized in that: The hydraulic support assembly (7) includes a control (703) embedded in the lifting base plate (401). The control (703) and the telescopic cylinder (701) are connected to an oil supply circuit (702). The oil supply circuit (702) is equipped with a spring accumulator (704) embedded in the punch main component (402) and a constant pressure relief valve (705). When the oil expands due to heat, the excess oil enters the accumulator (704) through the constant pressure relief valve (705) to maintain a constant support pressure.

6. The adjustable trolley case shell continuous stamping die according to claim 2, characterized in that: The die assembly (2) includes a base block (201) fixed on the upper die assembly (101), and the lower surface of the base block (201) has positioning grooves (202) at the four corners for fitting and inserting the upper positioning post (307). The lower surface of the base block (201) is inlaid with a die main component (203) adapted to the punch main component (402), and the upper end of the die main component (203) is fitted with an elastic component (204) embedded in the top of the base block (201). The die assembly (2) is equipped with a pressing system, which includes a rectangular pressing ring (205) embedded in the bottom of the base block (201). The upper end face of the rectangular pressing ring (205) is fixedly connected with elastic rods (206) embedded in the top of the base block (201) at equal intervals. The die main component (203) is inserted into the rectangular pressing ring (205). The upper end face of the rectangular pressing ring (205) is uniformly and equidistantly provided with nitrogen spring units that intersect with the elastic rod (206). Each group of nitrogen spring units can be independently connected or disconnected, and the total pressing force and the distribution of the pressing force in different areas can be adjusted by increasing or decreasing the number of connected units.

7. The adjustable trolley case shell continuous stamping die according to claim 6, characterized in that: Each nitrogen spring unit is located in the lower space of the base block (201); the nitrogen spring unit includes a nitrogen spring body (207), a force transmission pin (208) and a switching pin; when the switching pin is activated, the force transmission pin (208) and the nitrogen spring body (207) work together to output a pressing force; when the switching pin is disabled, a free stroke is formed between the force transmission pin (208) and the nitrogen spring body (207).

8. The adjustable trolley case shell continuous stamping die according to claim 7, characterized in that: The top of the end of the nitrogen spring body (207) is fixed to the base block (201); the force transmission top column (208) is fixed to the rectangular pressure ring (205). The switching pin is located between the nitrogen spring body (207) and the force transmission pin (208), and includes a spherical pin (209). The end of the nitrogen spring body (207) is adapted to fit the pin (209). The pin (209) is horizontally inserted into a flexible bladder (210) adapted to the end of the nitrogen spring body (207). The pin (209) is fixed to a rotating shaft (211) in both horizontal and vertical directions. The pin (209) is equipped with a regulator (212) through the rotating shaft (211). A connecting post (213) is fixed between the regulator (212) and the end of the nitrogen spring body (207).

Images