Shape correcting punching die of power battery box cover

Abstract

The invention relates to the field of automobile part manufacturing, and discloses a power battery box cover shape correcting stamping die which comprises a bottom frame, a lower shape correcting die, a lifting frame, an upper shape correcting die and an upper water gap stamping knife. The lower shape correcting die comprises a lower plate, a lower shape correcting sub-block and a lower gasket; the upper shape correcting die comprises an upper plate, an upper shape correcting sub-block and an upper gasket. According to the shape correcting stamping die, the water gap punching process and the shape correcting process are integrated in the same die and are synchronously completed through one-time die closing operation, the upper shape correcting die and the lower shape correcting die are both designed in a partitioned modular mode through combination of the shape correcting sub-blocks and the gaskets, and each shape correcting sub-block independently corresponds to an easy-to-deform area of a workpiece. By adjusting the thickness of the upper gasket or the lower gasket in the corresponding area, the material springback amount of the area can be compensated in a targeted mode, the problem of residual deformation caused by the fact that springback is not considered in a traditional integrated mold is solved, the size precision of the box cover is remarkably improved, and the requirement for manual secondary adjustment is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobile parts manufacturing, in particular to a shaping die for a power battery box cover. BACKGROUND

[0002] In the new energy vehicle industry, the safety and reliability of the power battery as a core component are of great importance. The power battery box cover, as a key protective structure of the battery pack, is usually manufactured by aluminum alloy die casting process to meet the requirements of lightweight and structural strength. However, there are two technical problems to be solved for the power battery box cover casting after die casting: on the one hand, a large number of sprues (i.e. the redundant part connecting the casting system and the casting) will be left on the surface of the casting, which needs to be quickly removed by punching to improve production efficiency; on the other hand, due to the extrusion and traction effect during demolding and the manufacturing error of the mold, the shaped box cover is prone to elastic deformation, especially for the box cover structure with two wide planes. Even if the inner surface is provided with reinforcing ribs to enhance the structural strength, there is still a high risk of deformation due to the low elastic modulus of aluminum alloy material, which leads to the size precision of the box cover being unable to meet the requirements of qualified products, seriously affecting the subsequent use requirements.

[0003] In the prior art, the shaping process for the power battery box cover usually adopts an integrated shaping upper die and a shaping lower die with the same size as the qualified product for mold closing shaping. The upper and lower shaping bodies of such shaping dies are integrally formed structures, and the shaping principle is to forcibly shape the box cover by fitting the outer surface and the inner surface of the mold. However, it is found in practice that such shaping method has the following defects:

[0004] Firstly, the influence of material springback characteristics on the shaping effect is not considered. For the parts with severe deformation, especially the wide plane area, it is impossible to achieve ideal size precision by one-time shaping, resulting in residual deformation after shaping; that is, there is still a size deviation after shaping, which needs to be adjusted manually for the second time

[0005] Secondly, when different degrees of deformation need to be adjusted, the integrated shaping upper die and lower die need to be repeatedly modified or re-manufactured, which not only prolongs the adjustment period, but also results in high mold manufacturing cost;

[0006] Thirdly, if new deformation problems occur in subsequent production, it is difficult to quickly adjust the shaping parameters due to the fixed structure of the mold, which seriously restricts the production efficiency and product quality stability.

[0007] In addition, the existing shaping equipment is usually independent of the sprue punching process, and the shaping and sprue punching operations need to be performed separately, resulting in complicated process and low production efficiency.

[0008] It can be seen that the prior art still needs to be improved and improved. SUMMARY

[0009] In view of the shortcomings of the prior art, the purpose of this invention is to provide a shaping die for a power battery box cover, which can efficiently cut the gate and achieve precise shaping through flexible adjustment.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A shaping die for a power battery box cover includes a base frame, a lower shaping die mounted on the base frame, a lifting frame mounted above the base frame, an upper shaping die mounted at the bottom of the lifting frame, and an upper sprue punch. The upper sprue punch is used to cut sprues on the workpiece and is arranged around the upper shaping die. The lower shaping die includes a lower plate divided into multiple lower shaping sections, lower shaping sub-blocks detachably mounted on the lower shaping sections, and a lower shim disposed between the lower plate and the lower shaping sub-blocks. All the lower shaping sub-blocks form a lower shaping model adapted to the inner surface of the workpiece. The upper shaping die includes an upper plate, upper shaping sub-blocks mounted on the upper plate and corresponding one-to-one with the lower shaping sub-blocks, and an upper shim disposed between the upper plate and the upper shaping sub-blocks. All the upper shaping sub-blocks form an upper shaping model adapted to the outer surface of the workpiece.

[0012] As a further improvement to the above technical solution, each lower shaping sub-block is provided with a positioning protrusion at its bottom, and a positioning groove adapted to the positioning protrusion is provided on the lower plate.

[0013] As a further improvement to the above technical solution, each lower shaped sub-block is provided with a countersunk hole that passes through the positioning protrusion. The lower plate is provided with a threaded hole corresponding to the countersunk hole in the positioning groove. The lower washer is provided with a relief opening in the middle. The screw passes through the countersunk hole and the relief opening from top to bottom and then connects to the threaded hole.

[0014] As a further improvement to the above technical solution, the positioning protrusion is a square protrusion, the clearance opening is a square through hole, and the positioning groove is a square groove with each corner of the square groove being a rounded corner transition.

[0015] As a further improvement to the above technical solution, the lower plate is provided with several positioning pins that can move vertically. The positioning pins extend upward through the corresponding lower pads and lower shaping blocks. The bottom of the lower plate is provided with a support leg, and the support leg is provided with a spring that acts on the bottom of the positioning pin.

[0016] As a further improvement to the above technical solution, each lower-shaped sub-block has a blind hole on its top surface to avoid the connecting rib position.

[0017] As a further improvement to the above technical solution, the lower correction partition is set in a grid, the lower correction sub-block is square, and a gap is formed between two adjacent lower correction sub-blocks.

[0018] As a further improvement to the above technical solution, the sprue punch includes a knife holder and a cutting blade mounted on the knife holder. The knife holder has a lubrication channel for guiding lubricating oil to flow and lubricate the cutting blade. A distributor is provided at the bottom of the lifting frame. The distributor is connected to the lubrication channel on the knife holder through a connector and a conduit.

[0019] As a further improvement to the above technical solution, the base frame is provided with a cleaning component for blowing air onto the lower shaping phantom.

[0020] As a further improvement to the above technical solution, the base frame is provided with a discharge port to prevent the water outlet from falling down, and the base frame is provided with a guardrail around the discharge port.

[0021] The beneficial effects of this invention are as follows: The forming die provided by this invention integrates the sprue punching and forming processes into the same mold, which are completed simultaneously in a single mold closing operation. Both the upper and lower forming dies adopt a modular design with forming sub-blocks and shims, with each forming sub-block independently corresponding to a deformable area of ​​the workpiece. By adjusting the thickness of the upper or lower shim in the corresponding area, the material springback in that area can be specifically compensated, solving the problem of residual deformation caused by the lack of consideration for springback in traditional one-piece molds. This significantly improves the dimensional accuracy of the lid and reduces the need for manual secondary adjustments.

[0022] Because the lower alignment block and the lower plate, as well as the upper alignment block and the upper plate, are detachably connected, when adjustments are needed for different degrees of deformation, only the corresponding alignment blocks or shims in the relevant areas need to be replaced or adjusted individually, without modifying or remanufacturing the entire mold. Compared to the overall mold repair or remaking of traditional one-piece molds, the adjustment cycle is shortened and the mold manufacturing cost is significantly reduced. Furthermore, the modular alignment block structure makes the mold scalable. If new deformation problems arise during subsequent production due to process adjustments or mold wear, only targeted adjustments or replacements of the corresponding alignment blocks and shims are needed to quickly optimize the alignment parameters, ensuring stable production efficiency and product quality. Attached Figure Description

[0023] Figure 1 This is a perspective view of the forming die provided by the present invention.

[0024] Figure 2 This is a schematic diagram showing the lower calibration mold set on the base frame.

[0025] Figure 3 This is a schematic diagram of the lower calibration mold.

[0026] Figure 4 This is a 3D diagram of the lower-order sub-block.

[0027] Figure 5 This is a schematic diagram showing the colonel's mold set on the lifting frame.

[0028] Figure 6 This is a schematic diagram of the structure of the inner surface of the power battery box cover.

[0029] Key component symbols: 1-Base frame, 11-Discharge port, 13-Guardrail, 14-Sprue punch, 2-Lower shaping mold, 21-Lower plate, 211-Positioning groove, 212-Threaded hole, 213-Rounded corner hole, 22-Lower shaping sub-block, 221-Positioning protrusion, 222-Counterhead hole, 223-Blind hole, 23-Lower gasket, 231-Allowing opening, 24-Lower shaping phantom, 25-Leg, 31-Lifting frame, 32-Floating plate, 33-Buffer assembly, 34-Guide Components, 4-Upper collimator mold, 42-Upper collimator sub-block, 44-Upper collimator phantom, 5-Upper sprue punch, 51-Knife holder, 52-Cutter, 53-Diverter, 54-Connector, 55-Conduit, 61-Positioning pin, 62-Spring, 63-Limiting block, 7-Cleaning component, 81-Guide post, 82-Guide sleeve, 83-Lower limit post, 84-Upper limit post, 85-Sensor, 9-Power battery box cover, 91-Connecting rib, 92-Rib hole, 93-Sprue. Detailed Implementation

[0030] This invention provides a forming die for a power battery box cover 9. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining this invention and are not intended to limit the scope of protection of this invention.

[0031] Please see Figures 1 to 5 This invention provides a forming die for a power battery box cover 9, including a base frame 1, a lower forming die 2 disposed on the base frame 1, a lifting frame 31 disposed above the base frame 1, an upper forming die 4 disposed at the bottom of the lifting frame 31, and an upper sprue punch 5. The upper sprue punch 5 is used to punch the sprue 93 on the workpiece and is disposed around the upper forming die 4. The lower forming die 2 includes a lower plate 21 divided into multiple lower forming sections, and lower forming elements correspondingly and detachably installed on the lower forming sections. The upper calibration mold 4 includes an upper plate, upper calibration sub-blocks 42 disposed on the upper plate and corresponding to the lower calibration sub-blocks 22, and upper shims disposed between the upper plate and the upper calibration sub-blocks 42. All the upper calibration sub-blocks 22 form an upper calibration mold 44 that is adapted to the inner surface of the workpiece.

[0032] The power battery box cover 9 to be processed is placed on the lower shaping model 24 of the lower shaping mold 2, and the inner surface of the workpiece is fitted and positioned with the lower shaping sub-block 22; the lifting frame 31 (usually driven by a hydraulic press) drives the upper shaping mold 4 and the upper gate punch 5 to move downwards, entering the mold closing stage.

[0033] Since the upper gate punch 5 is arranged around the upper calibration mold 4, during the descent of the lifting frame 31, the upper gate punch 5 will contact the gate 93 (casting residue) on the workpiece surface before the upper calibration mold 4. As the mold closing force increases, the upper gate punch 5 generates a shearing force on the gate 93, quickly cutting and separating the gate 93 from the power battery box cover 9, completing the gate 93 removal process.

[0034] Simultaneously or slightly after the sprue 93 is punched (depending on the mold stroke design), the upper aligning sub-block 42 of the upper aligning mold 4 and the lower aligning sub-block 22 of the lower aligning mold 2 press against the outer and inner surfaces of the power battery box cover 9, respectively. Since both the upper and lower aligning molds 2 employ a zoned, flexible adjustment structure, each upper aligning sub-block 42 and its corresponding lower aligning sub-block 22 constitute an independent alignment unit, allowing for precise pressure application to different areas of the power battery box cover 9 (especially easily deformable areas such as wide flat surfaces). By adjusting the thickness of the upper or lower shim 23, the springback caused by the low elastic modulus of the aluminum alloy material can be actively compensated. For example, if the power battery box cover 9 bulges upwards with significant deformation, the thickness of the upper shim in the alignment unit should be increased, and the thickness of the lower shim 23 decreased; if the power battery box cover 9 bulges downwards with significant deformation, the thickness of the upper shim in the alignment unit should be decreased, and the thickness of the lower shim 23 increased. The thickness adjustment range for the shims is 0.1mm-1mm. This ensures that the final dimensions of the workpiece after being subjected to pressure are close to the requirements for qualified products, thus avoiding residual deformation.

[0035] After the shaping and punching are completed, the lifting frame 31 rises and resets, takes out the workpiece that has completed the removal of the sprue 93 and the shaping, and enters the next round of processing.

[0036] The sprue-forming die provided by this invention integrates the sprue 93 punching and sprue-forming processes into a single mold, which are completed synchronously in a single mold-closing operation. Both the upper and lower sprue 2 adopt a modular design with sprue sub-blocks and shims, with each sprue sub-block independently corresponding to a deformable area of ​​the workpiece. By adjusting the thickness of the upper or lower shim 23 in the corresponding area, the material springback in that area can be specifically compensated, solving the problem of residual deformation caused by the lack of consideration for springback in traditional one-piece molds. This significantly improves the dimensional accuracy of the lid and reduces the need for manual secondary adjustments.

[0037] Since the lower calibration sub-block 22 and the lower plate 21, and the upper calibration sub-block 42 and the upper plate are all detachably connected, when adjustments are needed for different degrees of deformation, only the calibration sub-blocks or shims in the corresponding areas need to be replaced or adjusted individually, without modifying or remanufacturing the entire mold. Compared with the overall mold repair or remanufacturing of traditional one-piece molds, the debugging cycle is shortened and the mold manufacturing cost is significantly reduced.

[0038] The modular alignment sub-block structure makes the mold scalable. If new deformation problems occur during subsequent production due to process adjustments or mold wear (such as new deformation in a certain local area), the alignment sub-blocks and shims at the corresponding positions can be adjusted or replaced to quickly optimize the alignment parameters and ensure the stability of production efficiency and product quality.

[0039] To position the lower alignment sub-block 22, each lower alignment sub-block 22 is provided with a positioning protrusion 221 at its bottom, and the lower plate 21 is provided with a positioning groove 211 that matches the positioning protrusion 221. Through the cooperation of the positioning protrusion 221 and the positioning groove 211, the lower alignment sub-block 22 can quickly and accurately determine its installation position on the lower plate 21, avoiding the offset or misalignment of the lower alignment sub-block 22 due to manual assembly errors.

[0040] Furthermore, each lower shaping sub-block 22 has a countersunk hole 222 that penetrates the positioning protrusion 221. The lower plate 21 has a threaded hole 212 corresponding to the countersunk hole 222 in the positioning groove 211. The lower washer 23 has a relief opening 231 in the middle. The screw passes through the countersunk hole 222 and the relief opening 231 from top to bottom and then connects with the threaded hole 212, forming a three-layer tightly fitting structure of lower shaping sub-block 22, lower washer 23 and lower plate 21. The design of the countersunk hole 222 allows the screw head to be completely recessed into the lower shaping sub-block 22, avoiding the screw head protruding and interfering with the fit between the sub-block and the workpiece. The setting of the relief opening 231 ensures that the lower washer 23 will not be squeezed and deformed by the screw and the positioning protrusion 221 passing through it. The three work together to ensure the connection strength and avoid local stress concentration, significantly improving the structural stability of the mold during the shaping process.

[0041] The core function of the lower shim 23 is to compensate for the springback of the corresponding area of ​​the workpiece by adjusting its thickness (e.g., increasing the shim thickness can increase the shaping and pressing amount in that area). Because the lower shim 23 has a clearance opening 231 in the middle, when it is necessary to replace the lower shim 23 with one of different thicknesses, only the screws need to be removed, the original lower shim 23 taken out, and the new lower shim 23 replaced before tightening again. There is no need to disassemble the entire lower shaping sub-block 22 or disrupt the positioning relationships of other areas. Compared to the traditional method of requiring overall mold repair for integrated molds, this structure significantly shortens the debugging cycle and reduces the difficulty of debugging.

[0042] In this embodiment, the positioning protrusion 221 is a square protrusion, the positioning groove 211 is a square groove, and the clearance opening 231 is a square through hole. The square positioning protrusion 221 and the positioning groove 211 have regular structures and can be quickly completed by conventional processes such as CNC milling. Compared with irregular structures (such as polygons or curves), its processing accuracy is easier to control and the processing cost is lower.

[0043] Understandably, the clearance 231 is slightly larger than the square groove. Since the lower pad 23 needs frequent replacement to adjust the pressing amount, when it needs to be lifted for replacement, the traditional right-angled square groove lacks space to assist in gripping it. Therefore, workers can only lift the lower pad 23 by rubbing the edge of its square through-hole. However, the sharp edges of the square through-hole pose a significant risk of hand injury. To address this, each corner of the square groove is rounded with a hole 213. This rounded hole 213 design eliminates the sharp corners of the square groove, creating an auxiliary gripping space. Workers can easily lift the lower pad 23 by inserting their fingers into the square groove and using the rounded hole 213, thus preventing hand injuries during replacement and adjustment. This fundamentally solves the risk of cuts during operation and significantly improves the safety of mold maintenance.

[0044] After the shaping is completed, due to the elastic properties of the aluminum alloy material and the tight fit between the mold and the power battery box cover 9 during the shaping process (especially in the wide flat area), the power battery box cover 9 is prone to sticking to the lower shaping model 24. Traditionally, it needs to be pried off manually or with tools, which can easily lead to workpiece deformation or surface scratches. To address this, the lower plate 21 is provided with several vertically movable positioning pins 61. The lower plate 21 is also provided with limiting blocks 63 to restrict the positioning pins 61 from disengaging and to guide their vertical movement. The positioning pins 61 extend upward through the corresponding lower pads 23 and the lower shaping sub-blocks 22. The bottom of the lower plate 21 is provided with support legs 25, and springs 62 acting on the bottom of the positioning pins 61 are hidden in the support legs 25. The positioning pin 61 is automatically lifted by the elastic force of the spring 62: when the mold is closed, the power battery box cover 9 presses down on the positioning pin 61 to compress the spring 62; when the mold is separated, the spring 62 rebounds and pushes the positioning pin 61 upward, smoothly lifting the power battery box cover 9 off the lower shaping model 24. In addition, the rib holes 92 (such as the connecting holes between reinforcing ribs) on the inner surface of the power battery box cover 9 are its inherent structure. The positioning pin 61 is aligned with the rib holes 92, which can achieve pre-positioning during the placement stage of the power battery box cover 9. This can quickly complete the initial alignment of the power battery box cover 9 with the lower shaping model 24, avoiding the positional deviation caused by manual visual inspection or multiple adjustments in the traditional method. This ensures the fitting accuracy of the subsequent workpiece with the lower shaping model 24 (especially the easily deformable large flat area), so that the shaping pressure of each area is evenly applied to the target position during the shaping process, improving the dimensional consistency and pass rate after shaping.

[0045] See Figure 6 As shown, since the connecting rib 91 on the inner surface of the power battery box cover 9 will protrude downward, in order to avoid the connecting rib 91 interfering with the fitting effect between the lower shaping sub-block 22 and the power battery box, a blind hole 223 is provided on the top surface of each lower shaping sub-block 22 to avoid the connecting rib 91.

[0046] The lower correction partition is set up in a grid pattern, and the lower correction sub-blocks 22 are square-shaped, with gaps between adjacent lower correction sub-blocks 22. The grid partition divides the lower correction mold 2 into regular row and column grids (such as 6×3), and each square lower correction sub-block 22 corresponds to an independent grid unit, covering a local area of ​​the inner surface of the workpiece (such as a specific location on a wide plane). This design refines the correction area from the traditional monolithic design to grid units, allowing each lower correction sub-block 22 to be independently adjusted according to the degree of deformation of its covered area, by replacing the lower correction sub-block 22 or increasing or decreasing the thickness of the lower shim 23. For example, if the deformation of a planar area in a corner of the workpiece is large, only the thickness of the sub-block shim at the corresponding grid position needs to be adjusted to accurately compensate, avoiding the problem of uneven correction caused by the inability to make local adjustments in monolithic molds, and significantly improving the accuracy and targeting of the correction.

[0047] It should be noted that the connection and positioning structure of the upper plate, the upper collimating sub-block 42 and the upper pad can be specifically set with reference to the connection and positioning structure of the lower plate 21, the lower collimating sub-block 22 and the lower pad 23, and will not be described in detail here.

[0048] During the shaping process, the mold may experience thermal expansion due to the residual heat of the casting (due to incomplete cooling after die casting) or frictional heat generated during shaping. If the lower shaping sub-block 22 is a seamless integral or tightly spliced ​​structure, the thermal expansion between the lower shaping sub-blocks 22 will cause mutual compression, leading to local deformation of the mold (such as bulging or warping), affecting the contour accuracy of the lower shaping phantom 24. The gap between adjacent lower shaping sub-blocks 22 provides a buffer space for thermal expansion, absorbing the dimensional changes of the lower shaping sub-blocks 22 caused by temperature variations, avoiding mold deformation or cracking caused by stress concentration, and extending the service life of the mold.

[0049] Aluminum alloy castings retain a certain residual temperature (approximately 100-200℃) after die casting, resulting in high surface viscosity. During the punching of the sprue 93, the cutter 52 is prone to aluminum adhesion (aluminum shavings adhere to the cutting edge of the cutter 52) when in contact with the high-temperature aluminum, leading to blunting of the cutting edge, incomplete punching (such as burr residue), or aluminum shavings accumulating and pressing against the casting surface. Therefore, in this embodiment, the upper sprue punch 5 includes a cutter holder 51 and a cutter 52 mounted on the cutter holder 51. The cutter holder 51 has a lubrication channel for guiding lubricating oil to lubricate the cutter 52. A distributor 53 is located at the bottom of the lifting frame 31, and the distributor 53 is connected to the lubrication channel on the cutter holder 51 via a connector 54 and a conduit 55. The lubrication channel guides the lubricating oil to the cutting edge of the cutter 52, forming a continuous oil film at the contact interface between the cutter and aluminum. The oil film reduces the direct contact area between the cutter 52 and the aluminum through its isolation effect. At the same time, the polar molecules of the lubricating oil can be adsorbed on the metal surface to form a chemical adsorption film, further inhibiting the adhesion of aluminum.

[0050] If aluminum chips adhere to the cutting edge of the cutter 52 due to aluminum sticking, these chips may drag across the casting surface (especially the thin-walled area near the sprue 93) during the retraction after punching, causing scratches or pits. This severely affects the appearance quality of the casting and subsequent assembly. The lubrication system keeps the cutting edge of the cutter 52 clean and free of aluminum sticking, preventing additional friction or dragging between the cutter 52 and the casting surface during retraction. This fundamentally avoids scratches and ensures the integrity and aesthetics of the casting surface.

[0051] In practice, because the sprue 93 on the casting forms a large sprue head at the aluminum inlet and aluminum flow channel, if only one-sided punching is used (only the upper sprue punch 5 is pressed down), the connection area between the large sprue head 93 and the casting body (usually thick and large in area) will experience stress concentration due to unilateral force: when the shearing force of the upper sprue punch 5 is transmitted downwards, the lower shaping mold 2 only acts as a passive support and cannot counteract the reaction force, which may cause the casting body to be pulled or locally dented. To ensure that the sprue 93 at this position is completely removed without damaging the casting body, a lower sprue punch 14 that cooperates with the upper sprue punch 5 is also provided next to the lower shaping mold 2.

[0052] Preferably, the base frame 1 is equipped with a cleaning component 7 (such as an air blowing pipe) for blowing air onto the lower shaping phantom 24. During the shaping process, aluminum shavings generated by the sprue 93 punching, residual mold release agent particles from die casting, or dust from the environment can easily adhere to the top surface or gaps of the lower shaping sub-block 22 of the lower shaping phantom 24. If not cleaned in time, these impurities will accumulate between the inner surface of the workpiece and the phantom, causing the workpiece to be unable to fit tightly with the phantom (such as local lifting or tilting), resulting in uneven pressure distribution during shaping, and ultimately causing dimensional deviations in the workpiece (such as excessive flatness or abnormal local springback). The cleaning component 7 blows impurities away from the surface of the phantom by blowing air, ensuring a tight fit between the phantom and the inner surface of the workpiece, and allowing the shaping pressure to be precisely applied to the target area, significantly improving the dimensional accuracy and pass rate after shaping.

[0053] In a preferred embodiment, the base frame 1 is provided with guide posts 81, and the bottom of the lifting frame 31 is provided with guide sleeves 82 that cooperate with the guide posts 81. The cooperation between the guide posts 81 and the guide sleeves 82 provides precise guiding constraints for the vertical movement of the lifting frame 31: when the lifting frame 31 descends, the guide sleeves 82 slide along the outer circular surface of the guide posts 81, ensuring that the lateral positional deviation between the upper forming mold 4 and the lower forming mold 2 is controlled within a very small range. This design avoids misalignment of the forming sub-blocks or misalignment of the sprue 93 due to tilting or offset of the lifting frame 31, ensuring uniform stress on all areas of the workpiece during forming and clean removal of the sprue 93 during punching, significantly improving the dimensional accuracy and appearance quality of the product.

[0054] In a preferred embodiment, the base frame 1 is provided with a lower limit post 83, and the bottom of the lifting frame 31 is provided with an upper limit post 84 corresponding to the lower limit post 83. The setting of the lower limit post 83 and the upper limit post 84 provides a rigid limit on the descent distance of the lifting frame 31: when the lifting frame 31 descends to the rated position required for shaping and punching, the upper limit post 84 contacts the lower limit post 83 (usually by adjusting the height of the limit post to set the stroke), preventing the lifting frame 31 from continuing to press down. This design avoids excessive pressing caused by equipment misoperation (such as hydraulic press overtravel) or incorrect adjustment of shaping parameters (such as deformation of the shaping sub-block due to overpressure, or chipping of the 93-type punch due to overcutting), while also preventing the workpiece from breaking due to excessive pressure.

[0055] When manually placing castings, carelessness, fatigue, or obstructed vision may cause the castings to become misaligned. If this is not detected in time, the pressing of the upper and lower forming molds 4 and 2 during the straightening process will cause localized stress concentration due to the casting's positional deviation, leading to deformation of the casting or damage to the mold. Therefore, the base frame 1 is equipped with a sensor 85 to detect whether the casting on the lower forming mold 2 is misaligned. The sensor 85 can quickly determine whether the casting is misaligned through real-time detection (such as photoelectric sensing) and trigger an alarm or stop signal to prevent mold closing, thus avoiding damage to the casting and equipment at the source.

[0056] Preferably, the base frame 1 is equipped with a discharge port 11 to prevent the sprue 93 from falling downwards. The sprue 93 after punching can fall directly through the discharge port 11 to the bottom of the mold (such as a receiving trough or recycling bin), avoiding accumulation in the working area and ensuring the continuity of the shaping process. The base frame 1 is equipped with a guardrail 13 surrounding the discharge port 11. When punching the sprue 93, the violent shearing action between the cutter 52 and the sprue 93 may cause fragments of the sprue 93 (especially thin-walled or burr-shaped sprue 93) to fly in all directions, posing a risk of scratches to nearby operators. If the splashed sprue 93 falls into the moving parts of the mold (such as guide pillars 81 or limit pillars), it may also cause jamming, leading to equipment shutdown or even damage. The outer guardrail 13 physically limits the splash range of the sprue 93, allowing it to fall only through the discharge port 11, preventing fragments from splashing out and causing injury to personnel or equipment, complying with industrial safety regulations, and improving the safety of the production site.

[0057] If the impact force generated during the start-up or mold closing of the hydraulic press is directly transmitted to the lifting frame 31, it may cause a rigid collision between the upper forming mold 4 and the lower forming mold 2, or deformation of the workpiece due to instantaneous overpressure. The lifting frame 31 is equipped with a floating plate 32, and the output end of the hydraulic press is driven by the floating plate 32. A buffer assembly 33 and a guide assembly 34 are provided between the floating plate 32 and the lifting frame 31. When the floating plate 32 is pressed down, the buffer assembly 33 is compressed first, absorbing some energy and gradually transmitting the driving force of the hydraulic press to the lifting frame 31, thus avoiding rigid impact. The guide assembly 34 provides linear guidance for the movement of the floating plate 32.

[0058] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0059] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0060] It is understood that those skilled in the art can make equivalent substitutions or changes to the technical solution and inventive concept of the present invention, and all such changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A forming die for a power battery box cover, characterized in that, The device includes a base frame, a lower sizing mold mounted on the base frame, a lifting frame mounted above the base frame, an upper sizing mold mounted at the bottom of the lifting frame, and an upper sprue punch. The upper sprue punch is used to cut sprues on the workpiece and is arranged around the upper sizing mold. The lower sizing mold includes a lower plate divided into multiple lower sizing sections, lower sizing sub-blocks detachably mounted on the lower sizing sections, and a lower shim between the lower plate and the lower sizing sub-blocks. All the lower sizing sub-blocks form a lower sizing model adapted to the inner surface of the workpiece. The upper sizing mold includes an upper plate, upper sizing sub-blocks mounted on the upper plate and corresponding one-to-one with the lower sizing sub-blocks, and an upper shim between the upper plate and the upper sizing sub-blocks. All the upper sizing sub-blocks form an upper sizing model adapted to the outer surface of the workpiece.

2. The forming die for the power battery box cover according to claim 1, characterized in that, Each lower sub-block has a positioning protrusion at its bottom, and the lower plate has a positioning groove that matches the positioning protrusion.

3. The forming die for the power battery box cover according to claim 2, characterized in that, Each lower shaped sub-block has a countersunk hole that passes through the positioning protrusion. The lower plate has a threaded hole in the positioning groove that corresponds to the countersunk hole. The lower washer has a relief opening in the middle. The screw passes through the countersunk hole and the relief opening from top to bottom and then connects to the threaded hole.

4. The forming die for the power battery box cover according to claim 3, characterized in that, The positioning protrusion is a square protrusion, the clearance opening is a square through hole, and the positioning groove is a square groove with each corner of the square groove being a rounded corner transition.

5. The forming die for the power battery box cover according to claim 1, characterized in that, The lower plate is provided with several vertically movable positioning pins. The positioning pins extend upward through the corresponding lower pads and lower shaping blocks. The bottom of the lower plate is provided with a support leg, and the support leg is provided with a spring that acts on the bottom of the positioning pin.

6. The forming die for the power battery box cover according to claim 1, characterized in that, Each lower-shaped sub-block has a blind hole on its top surface to avoid the connecting rib position.

7. The forming die for the power battery box cover according to any one of claims 1-6, characterized in that, The lower correction partition is set in a grid, and the lower correction sub-blocks are square-shaped with gaps between adjacent lower correction sub-blocks.

8. The forming die for the power battery box cover according to claim 1, characterized in that, The upper water inlet punch includes a knife holder and a cutting blade mounted on the knife holder. The knife holder has a lubrication channel for guiding lubricating oil to flow and lubricate the cutting blade. The bottom of the lifting frame is equipped with a distributor, which is connected to the lubrication channel on the knife holder through a connector and a conduit.

9. The forming die for the power battery box cover according to claim 1, characterized in that, The base frame is equipped with a cleaning component for blowing air onto the lower-shaped phantom.

10. The forming die for the power battery box cover according to claim 1, characterized in that, The base frame is equipped with a discharge port to prevent water from falling downwards, and the base frame is equipped with a guardrail around the discharge port.

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