Quick changeover die and processing method for electroplating bent parts

Abstract

The present application relates to a kind of electroplating bending piece quick line change mould and processing method, it includes the cutting section and bending section of sequentially arranged along first direction;Cutting section is used to form semi-finished product strip, semi-finished product strip is formed with semi-finished product in plane structure;Bending section is used to bend semi-finished product into finished product in three-dimensional structure;The forming sequence of bending section is sequentially arranged along second direction, first direction and second direction are opposite;Bending section is configured to switch between working state and non-working state.This mould does not change the state of cutting section, only changes the state of bending section, significantly reduces the length of time when changing type debugging, significantly improves effective production ratio, indirectly improves overall stamping production efficiency.Processing method steps include processing preparation, first continuous stamping, electroplating, mould change type and second continuous stamping.Processing method reduces the risk of falling of plating layer of electroplating bending piece due to contact and scratching, effectively protects the surface plating layer integrity of product.

Description

Technical Field

[0001] This invention relates to the field of metal stamping technology, and in particular to a quick-change die and processing method for electroplated bending parts. Background Technology

[0002] In recent years, with the development of intelligent and customized automotive industries, the company's automotive connector business has continued to expand, and the product iteration speed has accelerated. The connector category has shown characteristics of a surge in variety, small order volume per batch, and significant specification differences. In particular, for precision L-shaped connector parts that are bent after electroplating, a step-by-step processing technology of "first stamping → electroplating protection → second stamping and bending" is required to meet the dual quality requirements of product structural precision and surface anti-rust coating. This process is also the mainstream production path for such precision connectors in the industry.

[0003] Currently, the company's workshop uses a traditional progressive die structure for these products, where the first and second punches share the same die. This means the first planar punching and the second bending and blanking process both use the same progressive die, with process switching achieved only by changing internal die parts. However, this model has revealed significant production drawbacks in actual mass production: after the first-punch planar semi-finished product is processed, it cannot be directly transferred to the second-punch bending process. The relevant parts used for the first-punch blanking must be completely dismantled, replaced one by one with dedicated bending parts, and then the die must be re-erected, dimensions repeatedly adjusted, and step distance and positioning accuracy calibrated until the product dimensions meet the standards before formal production can begin.

[0004] According to actual production data from the workshop, this traditional changeover mode is extremely inefficient. Each batch of products requires two complete in-mold changeover operations, with each changeover taking up to 2.5 hours. The total time spent on changeover alone reaches 5 hours, and this time does not include the additional time spent on adjusting the machine, repairing damaged parts, and recalibrating positioning during mold part replacement. Due to the lengthy changeover time, the actual effective production time for a single batch of products is only 8-16 hours. The downtime for changeovers accounts for a proportion close to or even exceeding the effective production time. Human resources and equipment capacity are heavily tied up, resulting in a production dilemma of "consuming manpower, time, and effort." This mode is completely unsuitable for the production needs of multi-variety, small-batch, and rapid changeover, leading to continuously extended order delivery cycles and a significantly low overall workshop capacity utilization rate.

[0005] Regarding the existing technologies for rapid mold changeover in the industry, taking the rapid mold changeover mechanism for production lines disclosed in Chinese patent CN222919482U as an example, although this technology proposes the idea of ​​rapid changeover in the bending area and adopts a combination structure of replaceable punch and clamping plate to achieve changeover, its core solution still relies on the overall disassembly and replacement of sub-molds and inserts inside the mold. During changeover, heavy bending punches, forming inserts and other components need to be completely disassembled from the mold base. After replacing the matching parts, they are then locked and fixed one by one with screws and pressure plates.

[0006] In practical applications, this existing technology has obvious drawbacks: On the one hand, the mold parts involved in the changeover are quite heavy, and the disassembly and assembly process requires the cooperation of a specialist, which is not only time-consuming and labor-intensive, but also carries the risk of damage to the mold cutting edge and forming surface by collision of parts, which increases the cost of parts rework and mold maintenance; on the other hand, after disassembly and assembly, the tool needs to be re-aligned, and the clearance and stamping depth need to be adjusted, so the changeover cycle cannot be effectively compressed. The time spent on trial stamping and fine-tuning after the changeover is still long, resulting in a very low proportion of effective processing time for the equipment within a single changeover cycle, which limits the improvement of production efficiency. It cannot fundamentally solve the pain point of rapid changeover of multi-variety, small-batch products, and it cannot meet the dual requirements of plating protection and high dimensional accuracy of bent parts after electroplating.

[0007] In summary, the traditional disassembly-and-assemble line changeover mode of common molds, as well as the inherent defects of existing technology changeover mechanisms, have severely restricted the production efficiency and order delivery capabilities of the company's automotive connector business, significantly increasing production manpower and time costs. Therefore, in combination with the actual production needs of the workshop, developing a new type of rapid line changeover mold that is compatible with the "one-stroke electroplating two-stroke" process, requires no disassembly of core parts, and can quickly switch process states, has become a core technology requirement that urgently needs to be broken through in the current production process to solve the problems of long line changeover time, high labor intensity, easy mold damage, and low effective production ratio. Summary of the Invention

[0008] A primary objective of this invention is to provide a quick-change die for electroplated bending parts, which can not only simultaneously meet the stamping processing requirements of electroplated bending parts before and after electroplating, but also significantly reduce the time required for line changeover. Within the same line changeover production cycle, the effective production ratio is significantly increased, indirectly improving the overall stamping production efficiency.

[0009] The present invention achieves the above-mentioned objective through the following technical solution: a quick-change mold for electroplated bending parts, comprising a punching section and a bending section arranged sequentially along a first direction; the punching section is used to form a semi-finished strip, on which a semi-finished product with a planar structure is formed; the bending section is used to bend the semi-finished product into a finished product with a three-dimensional structure; the forming sequence of the bending section is arranged sequentially along a second direction, the first direction being opposite to the second direction; the bending section is configured to switch between a working state and a non-working state.

[0010] Specifically, the bending section includes a pre-bending die, a full-bending die, and a blanking die arranged sequentially along the second direction. The pre-bending die is used to pre-form a bend in the middle of the semi-finished product. The full-bending die is used to further bend the bend to turn the semi-finished product into a finished product. The blanking die is used to punch and cut off the connection point between the finished product and the connection area. The pre-bending die, the full-bending die, and the blanking die all include a punch and a line-changing insert.

[0011] Furthermore, the pre-bending angle of the pre-bending die is designed to be 45°, and the full bending angle of the full bending die is designed to be 90°.

[0012] Furthermore, a forming die is provided between the full bending die and the blanking die. The forming die adopts a side-punch structure, including a side punch, a side punch push block, and a side punch bending block. The side punch push block and the side punch bending block are arranged on the same die side, and the side punch is arranged on the opposite die side of the side punch push block. The die-closing movement path of the side punch is located outside the material feeding width of the strip. When the die is closed, the side punch strikes the side punch push block vertically downward, thereby driving the side punch push block to move closer to the side punch bending block to complete the angle forming compensation.

[0013] Furthermore, the upper part of the side punch is provided with a first contact slope, and the forming die is also provided with a stroke fine-tuning rod arranged on the same side of the side punch. The rod section of the stroke fine-tuning rod extending into the die is provided with a second contact slope that is adapted to fit the first contact slope.

[0014] Specifically, the punching section includes a hole-cutting die and an edge-cutting combination die arranged sequentially along a first direction. The hole-cutting die is used to cut out positioning holes on the strip. The processing unit area of ​​the strip includes a semi-finished product and a connecting area surrounding the semi-finished product. The positioning holes are located within the connecting area. The edge-cutting combination die is used to cut out the outer contour of the semi-finished product in steps.

[0015] Furthermore, the edge trimming assembly mold includes an end waste removal mold, an end chamfering mold, a plurality of contour forming molds, and a waste removal mold arranged sequentially along a first direction. The end waste removal mold is used to remove end waste near the two tips of the semi-finished product. The end chamfering mold is used to extrude the two tips of the semi-finished product into a chamfered structure. The contour forming mold removes the outer peripheral waste in multiple stations and blocks. The waste removal mold is used to remove the T-shaped waste on one half of the connecting area during the first continuous stamping and to remove the T-shaped waste on the other half of the connecting area during the second continuous stamping.

[0016] Another major objective of this invention is to provide a processing method for electroplated bent parts, which allows the finished product to automatically detach from the blanking station after only passing through the bending, shaping, and blanking stations during the second continuous stamping process. This reduces the risk of the plating layer falling off due to contact or scratching, and effectively protects the integrity of the plating layer on the product surface.

[0017] This invention achieves the above objective through the following technical solution: a processing method for electroplated bent parts, which utilizes a quick-change die for electroplated bent parts, comprising the following steps: S1. Pre-processing preparation: Switch the bending section to a non-working state; S2, First continuous stamping: The strip is fed into the die from one end of the punching section along the first direction. The punching die punches out positioning holes on the strip as positioning references for subsequent processing. The edge cutting combination die cuts out the outer contour of the semi-finished product step by step. The length direction of the semi-finished product is perpendicular to the direction of the strip. The two long sides of the semi-finished product are connected to the connection area to obtain the semi-finished strip. S3. Electroplating: The semi-finished material strip is passed through the electroplating bath, and a coating is applied to the surface. The coating is then dried and cured. S4. Die changing: Switch the bending section to the working state; S5. Second continuous stamping: The electroplated semi-finished strip is rotated 180° and fed into the mold from one side of the bending section along the second direction. The middle of the flat semi-finished product is pre-folded by the pre-bending mold to form a folded corner. Then, it is further bent by the full bending mold. Finally, the remaining connection points between the finished product and the connecting area are cut off by the blanking mold, so that the finished product can be directly dropped from the station.

[0018] Specifically, the process of the first continuous stamping is as follows: S21. Hole cutting: Using the hole cutting die, a positioning hole is cut in the connecting area, and at the same time, the side waste of the strip is cut off at a fixed width. S22, Edge trimming: The waste material around the tip of the semi-finished product is removed by the end waste removal die. Then, the two tips of the semi-finished product are extruded and formed into a chamfered structure by the end chamfering die. Then, the outer peripheral waste material of the semi-finished product is removed by the contour forming die in sections and waste removal in steps. Finally, the waste removal die removes half of the T-shaped waste material in the connecting area, leaving the other half of the T-shaped connecting structure.

[0019] Specifically, in the mold changing step, the forming angle of the bend is controlled by adjusting the insertion amount of the stroke fine-tuning rod. When the forming angle reaches 90°, the mold changing and debugging are completed.

[0020] The beneficial effects of the technical solution of this invention are: 1. This mold changes only the bending section without altering the punching section. A single line-changing operation can be completed within 10 seconds, and the overall debugging time is controlled within 5 minutes. Compared to the traditional method of disassembling and reassembling the entire mold for line changeover, the debugging time is significantly reduced. Within the same line changeover production cycle, the effective production ratio is significantly increased, indirectly improving the overall stamping production efficiency.

[0021] 2. The two stamping processes adopt a reverse feeding layout. The second continuous stamping does not require refeeding from the punching section. During the second continuous stamping process, the semi-finished product can be automatically removed from the blanking station after passing through the bending, shaping and blanking stations. Only the overall waste material in the connecting area continues to pass through the punching section. Even if the waste material causes slight friction when passing through the station, it will not come into contact with or scratch the already formed coated finished product, effectively protecting the integrity of the coating on the product surface.

[0022] 3. The stroke fine-tuning rod in the forming die relies on the inclined surface to adjust its own extension and retraction, thereby changing the stroke distance of the side punch protruding from the template. This allows for precise control of the minimum distance between the side punch push block and the side punch bending block, enabling fine-tuning of the forming R angle and precise control of the corner forming angle. The mold closing action will not cause bending deformation to the flat strip passing through the station, so the forming die does not need to switch between locking and unlocking states.

[0023] 4. At the end of the first continuous stamping, the scrap removal die cuts off half of the T-shaped scrap in the connecting area, while the remaining half of the T-shaped structure in the connecting area maintains the connection relationship between each processing unit. The semi-finished product is still attached to the remaining half of the T-shaped structure. During the second continuous stamping, the scrap removal die cuts and separates the remaining half of the T-shaped structure in the connecting area and discharges the scrap. This prevents the scrap in the connecting area from flowing through the remaining stations between the hole cutting die and the contour forming die, avoiding friction and collision of the scrap, which would increase the wear and tear on the parts of these single-station dies. Attached Figure Description

[0024] Figure 1 Left view of the electroplated bent part; Figure 2 This is a top view of the semi-finished material strip; Figure 3 Schematic diagram of the stamping principle for a quick-change die for electroplated bending parts; Figure 4 This is a diagram showing the closed state of the pre-bending die; Figure 5 This is a diagram showing the closed state of a full bending die; Figure 6 This is a diagram showing the mold closing state of the forming mold; Figure 7 This is a diagram showing the closed state of the blanking die.

[0025] The numbers in the image represent: 1-Electroplated bending parts quick-change die, 11-Punching section, 111-Drilling die, 112-Edge trimming combination die, 1121-End scrap removal die, 1122-End chamfering die, 1123-Contour forming die, 1124-Scrap removal die, 12-Bending section, 121-Pre-bending die, 1211-First punch, 1212-First line-changing insert, 122-Full bending die, 1221-Second punch, 1222-Second line-changing insert, 123-Shaping die, 1231-Side punch, 12311-First contact slope, 1232-Side punch push block, 1233-Shaping block, 1234-Stroke fine-tuning insert, 12341-Second contact slope, 124-Blanking die, 1241-Third punch, 1242-Third line-changing insert; 2-Material strip, 21-Semi-finished product, 22-Connecting area, 221-Positioning hole, 23-End waste, 24-Outer peripheral waste, 25-Side waste; 3-Finished product, 31-Folded corner, 32-Sharp point. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to specific embodiments.

[0027] Example: I. Structure and Production Process of Electroplated Bending Parts like Figure 1 As shown, the finished product 3 to be processed in this embodiment has a bend 31 in the middle and two tips 32. The angle of the bend 31 is 90°, so the finished product 3 has an L-shaped structure. The two tips 32 have chamfers on both sides, so they have a shape that is thinner towards the ends. In addition to the material itself, the finished product 3 also has a plating (such as tin, nickel, zinc, etc.) on its surface to prevent rusting.

[0028] like Figure 2 As shown, the core structure of finished product 3 is formed by stamping a complete strip 2. The strip 2 is initially a complete strip structure with a certain rigidity, and it undergoes two processing steps to obtain the independent finished product 3. The production process for this finished product 3 generally involves first processing a planar semi-finished product 21 onto the strip 2. These semi-finished products 21 are then connected side-by-side to a connecting area 22, where several positioning holes 221 are first machined. Then, the strip 2 is continuously conveyed through an electroplating bath to complete electroplating. After the plating layer is dried, it is continuously stamped to first form an L-shaped structure, and then cut into independent products, i.e., finished product 3. In short, the processing of finished product 3 can be summarized as: first continuous stamping, electroplating, and second continuous stamping.

[0029] II. Structure of the Quick Change-off Die 1 for Electroplated Bending Parts In the production of finished product 3, the process involves a series of steps: "first continuous stamping to form a flat semi-finished product → electroplating protection → second continuous stamping and bending." Traditionally, the first and second continuous stampings are completed using the same continuous die. Because the position of the positioning hole 221 on the strip 2 remains unchanged throughout the two processes, the processing step distance does not need to be altered, and the positioning pins on the die can be uniformly arranged according to the fixed processing step distance, ensuring consistent positioning accuracy in both processes. This new die structure, while retaining this positioning design and ensuring processing accuracy, focuses on optimizing the switching method between the two stamping working states. It addresses the industry pain points of traditional die line changeovers being time-consuming, labor-intensive, and prone to damaging the die and product plating, achieving efficient, precise, and low-cost rapid line changeover production.

[0030] like Figure 3As shown, the electroplating bending part quick-change mold 1 adopts a segmented structure design, including a punching section 11 and a bending section 12 arranged sequentially. Only the bending section 12 is configured to switch between working and non-working states. The two sections work independently and cooperate with each other, achieving efficient connection between the two stamping processes through bidirectional feeding, and the process switching can be completed without disassembling the core components of the mold. In the first continuous stamping process, each step is completed independently by the punching section 11. The strip 2 smoothly passes through the entire mold along the first direction (forward). During this process, each single mold in the bending section 12 switches to a non-working state, and its internal punch does not participate in any stamping action, thus avoiding interference with the forming of the flat semi-finished product 21. In the second continuous stamping process, each step is completed independently by the bending section 12. The strip 2 passes through the entire mold along the second direction (reverse, 180° opposite to the first direction). During this process, each single mold in the bending section 12 switches to a working state, and the punch normally outputs bending and punching loads. The single molds in the punching section 11 maintain their original structural state without any modification, only playing the role of auxiliary feeding and waste discharge, without the need for additional debugging.

[0031] 2.1 Structure and function of punching section 11 The punching section 11, as the core working unit of the first continuous punching, is mainly responsible for completing the positioning hole processing of the strip 2, the outer contour forming of the semi-finished product 21, and the step-by-step discharge of various waste materials. It provides precise positioning and qualified flat semi-finished products for subsequent electroplating processes and the second bending punching. Its structural design directly determines the forming accuracy of the semi-finished product 21 and the stability of subsequent processing. For example... Figure 3 As shown, the punching section 11 includes a hole-cutting die 111 and an edge-cutting combination die 112 arranged sequentially along the first direction. The two dies work together to complete the punching process of the strip 2 step by step according to the preset process steps, ensuring that each processing step meets the requirements of the subsequent process.

[0032] Among them, the hole-cutting die 111, as the first station of the punching section 11, undertakes the dual functions of positioning reference processing and auxiliary process hole processing. Specifically, it is used to cut out the positioning hole 221 of the connecting area 22 on the material strip 2. The positioning hole 221 runs through the entire processing process and is the core positioning reference in the first punching, the second punching and the material strip 2 conveying process, ensuring that the material strip 2 has accurate step distance and no deviation during continuous feeding. At the same time, the hole-cutting die 111 can also process the product's own structural holes (functional holes for product assembly) and process holes (auxiliary process holes other than positioning holes 221 and product structural holes, used for positioning, waste removal or assembly assistance in subsequent processes) according to the product structure requirements, realizing multi-functionality of one die and improving processing efficiency.

[0033] The trimming die 112 is located downstream of the hole-cutting die 111 and is mainly used to punch and form most of the shape of the semi-finished product 21. The semi-finished product 21 is the core material of the electroplated bending part. Before it is fully formed into the L-shaped product 3, it is collectively referred to as the semi-finished product 21. During the punching process, the trimming die 112 retains only a few evenly distributed connection points to keep the semi-finished product 21 connected to the remaining part of the strip 2 (i.e., the connection area 22). This ensures that the semi-finished product 21 can be accurately positioned by relying on the positioning holes 221 on the connection area 22, and successfully complete the subsequent electroplating process and the second continuous punching, avoiding processing defects caused by the semi-finished product 21 falling off or being misaligned. In addition, under some production conditions, the strip 2 itself has an overall width control requirement to adapt to the feeding requirements of the subsequent electroplating equipment and mold. This width control can be completed simultaneously at the hole-cutting die 111 station. By accurately punching the side of the connection area 22, excess side waste 25 is removed, ensuring that the width of the strip 2 meets the preset standard.

[0034] like Figure 3 As shown, the edge trimming combination mold 112 is not a single mold, but a combination mold composed of an end waste removal mold 1121, an end chamfering mold 1122, several contour forming molds 1123 and waste removal molds 1124 arranged sequentially along the first direction. Each single mold has a clear division of labor and works together to gradually complete the shape forming and waste removal of the semi-finished product 21 according to the structural characteristics and processing requirements of the semi-finished product 21. The specific structure of each step of the trimming die 112 can be flexibly adapted to the finished product 3 of different specifications and structures. Its core functions can be clearly defined according to the processing purpose as follows: The end waste removal die 1121 is mainly used to remove the end waste 23 near the two tips of the semi-finished product 21. This waste is a redundant part that does not need to be retained during the forming process of the semi-finished product 21. Timely removal can avoid problems such as jamming and scratching in subsequent processing; The end chamfering die 1122 is used to extrude the two tips of the semi-finished product 21 into a smooth chamfer structure, which not only meets the appearance requirements of the product, but also avoids the hidden dangers of plating damage and assembly scratches caused by sharp tips; The contour forming die 1123 and the waste removal die 1124 work together to remove the peripheral waste 24 around the semi-finished product 21. At the same time, the waste removal die 1124 also undertakes the function of removing the half T-shaped waste of the connecting area 22, laying the foundation for the waste treatment of the second stamping.

[0035] In actual production, the structural complexity of the peripheral waste 24 directly determines the choice of waste removal method: if the peripheral waste 24 has a simple structure and no complex surrounding structure, it is not easy to encounter material jamming problems, and single-station one-time punching can be used to remove waste, improving processing efficiency; however, in most working conditions, the peripheral waste 24 has a three-sided surrounding structure. If punched in one go, the waste is easy to get stuck between the die cutting edge and the strip 2, causing the strip 2 to be stuck, the die cutting edge to wear, and even damaging the semi-finished product 21. Therefore, a segmented punching method is usually adopted. Through the contour forming die 1123 of each single station, the peripheral waste 24 is divided into regular structures such as blocks without concave corners, L-shapes, and T-shapes, and then cut off step by step to completely avoid material jamming failures, ensure the continuous and stable conveying of the strip 2, and extend the service life of the die cutting edge.

[0036] In the final step of the first continuous stamping, the waste removal die 1124 will precisely cut off the T-shaped waste on one half of the connecting area 22. At this time, the connecting area 22 will retain the remaining half of the T-shaped structure. The core function of this structure is to maintain the connection relationship of each processing unit on the strip 2, and ensure that the semi-finished product 21 can be stably attached to the remaining half of the T-shaped structure, so as to prevent the semi-finished product 21 from falling off before electroplating. When entering the second continuous stamping, the material strip 2 is reversed 180° and fed in the opposite direction. At this time, the waste discharge die 1124 will be activated again to punch and separate the T-shaped structure on the remaining half of the connecting area 22 and discharge the waste. The core advantage of this design is that the waste in the connecting area 22 only passes through the waste discharge die 1124 during the second stamping and does not flow through the other stations between the hole cutting die 111 and the contour forming die 1123. This avoids the waste from rubbing and bumping against the mold parts of these stations during the conveying process, reduces the wear of mold parts, lowers mold maintenance costs, and at the same time avoids the waste from scratching the coating on the surface of the semi-finished product 21.

[0037] 2.2 Structure and function of bending section 12 Bending section 12 is the core working unit of the second continuous stamping process. It is mainly responsible for pre-bending, full bending, shaping compensation, and blanking of the electroplated flat semi-finished product 21. Its structural design directly determines the corner accuracy, shape quality, and plating integrity of the finished product 3. Simultaneously, it achieves efficient switching with the first stamping process through a quick-change line structure. For example... Figures 3 to 7 As shown, the bending section 12 includes a pre-bending die 121, a full bending die 122, a shaping die 123 and a blanking die 124 arranged sequentially along the second direction. The first direction and the second direction are opposite to each other. The dies cooperate in the processing sequence to gradually shape the flat semi-finished product 21 into an L-shaped product 3 that meets the requirements.

[0038] Each mold has a clearly defined core function and is closely integrated: the pre-bending mold 121 is mainly used to pre-form the bend angle 31 in the middle of the semi-finished product 21, laying the foundation for the subsequent full bending process. Its pre-bending angle is designed at 45°, which has been repeatedly tested and verified. This angle can avoid material stress concentration and bend angle cracking caused by direct full bending, and can also ensure the accuracy of the subsequent full bending process and reduce the impact of material springback. The full bending mold 122 is used to further bend the pre-bent bend angle 31. Its full bending angle is designed at 90°, initially forming the semi-finished product 21 into an L shape. The bending structure is designed to compensate for the springback of metal materials during bending. Without shaping compensation, the final angle of the bending angle 31 will deviate from the 90° standard, affecting the product assembly accuracy. Therefore, a shaping die 123 is set to perform overpressure shaping compensation on the bending angle 31, so that the final forming angle of the bending angle 31 is stable at 90°, ensuring that the structural accuracy of the finished product 3 meets the design requirements and a qualified finished product structure is obtained. The blanking die 124 is used to punch and cut off the two connection points between the finished product 3 and the connecting area 22, so that the formed finished product 3 is separated from the strip 2 and falls off, completing the unloading of the finished product.

[0039] To achieve rapid switching between the two stamping processes, the pre-bending die 121, the full-bending die 122, and the blanking die 124 all adopt a combination structure of "punch + line-changing rod". Through the extension and retraction of the line-changing rod, the punch's working state and standby state can be quickly switched without disassembling the die components, significantly shortening the line changeover time. Figure 4 , Figure 5 and Figure 7 As shown, the specific structures of each mold are as follows: The pre-bending mold 121 is provided with a first punch 1211 and a first wire-changing rod 1212. The first punch 1211 is used to realize the pre-bending action of the semi-finished product 21, and the first wire-changing rod 1212 is used to control the working state of the first punch 1211; The full bending mold 122 is provided with a second punch 1221 and a second wire-changing rod 1222. The second punch 1221 is used to realize the full bending action of the semi-finished product 21, and the second wire-changing rod 1222 is used to control the working state of the second punch 1221; The blanking mold 124 is provided with a third punch 1241 and a third wire-changing rod 1242. The third punch 1241 is used to realize the punching separation of the finished product 3 and the connecting area 22, and the third wire-changing rod 1242 is used to control the working state of the third punch 1241.

[0040] The core working principle of the line-changing insert is: by controlling the fixed state of the punch and the upper die, the punch can be controlled to apply bending or cutting force to the strip 2. During the first continuous stamping operation, all three sets of line-changing pins (first line-changing pin 1212, second line-changing pin 1222, and third line-changing pin 1242) are pulled out to their maximum unlocked positions. At this time, each punch (first punch 1211, second punch 1221, and third punch 1241) is in an unlocked, movable state, without rigid connection to the upper die. When the die is closed, it cannot output effective bending and cutting loads. Therefore, the semi-finished product 21 can remain flat and flush with the connecting area 22, smoothly passing through the bending section 12 without being subjected to any bending action. Before switching to the second continuous stamping operation, all three sets of line-changing pins are pushed into their maximum locked positions, rigidly fixing each punch to the upper die. When the die is closed, it can stably output bending and cutting loads, driving the semi-finished product 21 to further deform and separate, ultimately forming the finished product 3. This line-changing method is simple and quick to operate; a single switching operation can be completed within 10 seconds, requiring no professional technicians and significantly reducing labor intensity.

[0041] As a key component ensuring the accuracy of the bend angle 31, the forming die 123 adopts a side-punch structure design, which differs from the forward punching method of the pre-bending die 121 and the full-bending die 122. This design better adapts to the forming compensation requirements of the bend angle 31 and avoids scratching the coating on the surface of the semi-finished product 21. Figure 6 As shown, the forming die 123 includes a side punch 1231, a side punch pusher 1232, and a side punch bending block 1233. Its structural layout is precisely designed: the side punch pusher 1232 and the side punch bending block 1233 are arranged on the same die side, and the side punch 1231 is arranged on the opposite die side of the side punch pusher 1232. Furthermore, the die-closing movement path of the side punch 1231 is located outside the feeding width of the strip 2, ensuring that the side punch 1231 will not directly contact the strip 2 and the semi-finished product 21 during die closing, thus avoiding scratching the coating. Its working process is as follows: during die closing, the side punch 1231 descends vertically and precisely impacts the side punch pusher 1232. Under the impact force, the side punch pusher 1232 moves closer to the side punch bending block 1233, performing over-pressure forming on the bend angle 31 of the semi-finished product 21, completing the springback compensation of the bend angle 31, and ensuring the stability of the bend angle 31.

[0042] To achieve precise fine-tuning of the 31-degree bend angle and meet the processing requirements of products with different specifications, the forming die 123 is also equipped with a stroke fine-tuning rod 1234, such as... Figure 6 As shown, the upper part of the side punch 1231 is provided with a first contact slope 12311, and the stroke fine adjustment rod 1234 is arranged on the same mold side of the side punch 1231. The rod section extending into the mold is provided with a second contact slope 12341 that is adapted to fit the first contact slope 12311. Through the fit and cooperation of the two slopes, stepless fine adjustment of the stroke is realized.

[0043] The core structural difference between the stroke fine-tuning rod 1234 and the line-changing rod lies in the following: the mating surface between the line-changing rod and the punch is a planar structure without any bevel design. Therefore, the punch can only stop at two specific positions, locked and unlocked, and cannot achieve stepless adjustment. In contrast, the stroke fine-tuning rod 1234, relying on the cooperation of two contact bevels, can change the stroke distance of the side punch 1231 extending from the template by adjusting its own extension and retraction. This allows for precise control of the minimum distance between the side punch push block 1232 and the side punch bending block 1233, ultimately achieving fine-tuning of the forming R-angle and precisely controlling the forming angle of the bend 31, ensuring that the accuracy of the bend 31 meets design requirements. It should be noted that the tilt direction of the two contact bevels (left or right) does not affect the fine-tuning function. Its core function is to convert the extension and retraction of the stroke fine-tuning rod 1234 into the extension of the side punch 1231 through bevel transmission. In this embodiment, the slope of the contact ramp is designed to be 1:10, that is, for every 1mm inserted into the stroke fine-tuning rod 1234, the side punch head 1231 can be driven to extend by 0.1mm. This slope design can achieve precise fine-tuning and avoid deformation of the bend angle 31 caused by excessive adjustment, thus balancing fine-tuning accuracy and ease of operation.

[0044] Furthermore, the forming die 123 does not require switching between locking and unlocking states because: during the first continuous stamping process, the strip 2 remains flat and straight. Even if the side punch 1232 moves during die closing, it will not cause any bending or deformation to the flat strip 2 passing through the forming station, and will not affect the flat state of the semi-finished product 21. Therefore, unlike the pre-bending die 121 and the full bending die 122, it does not require switching the working state through the line-changing plug, further simplifying the line-changing operation process.

[0045] 2.3 Key Design Considerations for Molds The core originality of this quick-change die for electroplated bending parts lies in its quick-change structure and reasonable workstation layout, which effectively solves industry pain points such as long changeover time, easy scratching of plating, and difficulty in controlling precision in traditional dies. The specific design points are as follows: 1) Rapid line changeover design significantly improves production efficiency. This mold changes only the bending section without altering the punching section. Through a combination of a "line changeover lever + punch," it achieves rapid switching between the working states of the 12 molds in the bending section. A single line changeover operation can be completed within 10 seconds, offering convenient operation without disassembling core mold components. Only during parameter debugging of the forming mold 123 does a small number of trial punches need to be performed, with the overall debugging time controlled within 5 minutes. Compared to traditional mold-based whole-machine disassembly and line changeovers (which typically take over 2.5 hours per changeover), the changeover debugging time is significantly reduced. Within the same production cycle, the effective production time of the equipment is significantly increased, indirectly improving overall stamping production efficiency. This is particularly suitable for the multi-variety, small-batch production needs of automotive connectors, enabling rapid response to changeover requirements for different product specifications and shortening order delivery cycles.

[0046] 2) A reasonable workstation layout effectively protects the integrity of the product's plating. This mold breaks away from the traditional design of placing the blanking station at the end of the bending section 12. Instead, the blanking station is located between the punching section 11 and the bending section 12. This layout is compatible with the bidirectional feeding method and fully considers the plating protection requirements of the semi-finished product 21 after electroplating. Because the two stamping processes use a reverse feeding layout, the second continuous stamping does not require refeeding from the punching section 11. During processing, the semi-finished product 21 only passes through three workstations: bending, shaping, and blanking, and can automatically detach from the blanking station without passing through the punching section 11. Only the overall scrap from the connecting area 22 continues to pass through the punching section 11. Even if the scrap slightly rubs against the mold parts of the punching section 11 during the conveying process, it will not contact or scratch the already formed plating finished product 3, effectively protecting the integrity of the product's surface plating and avoiding problems such as rust and poor appearance caused by plating damage, thus improving the product qualification rate.

[0047] 3) The segmented waste removal and step-by-step waste cutting design avoids material jamming and extends mold life. The edge cutting combination mold 112 adopts a segmented punching method for the outer peripheral waste 24. For waste structures that are prone to jamming, such as those with three-sided encirclement, it is divided into regular structures and cut off step by step to completely avoid material jamming failure. The waste removal mold 1124 adopts a design to cut off the T-shaped waste in the connecting area 22 in two stages, so that the waste no longer flows through the previous station of the punching section 11, reducing the friction and collision between the waste and the mold parts, reducing the wear of mold parts, extending the mold life, and reducing mold maintenance costs and downtime for cleaning.

[0048] 4) Precise micro-adjustment structural design ensures product processing accuracy. The stroke micro-adjustment rod 1234 set in the forming die 123 achieves stepless micro-adjustment of the extension amount of the side punch 1231 through the cooperation of the inclined surface. It can precisely control the forming angle of the forming R angle and the forming angle 31, effectively compensate for the accuracy deviation caused by material springback, and ensure that the forming angle 31 is finally stable at 90°, which meets the product assembly accuracy requirements. At the same time, the angle design of the pre-bending die 121 (45° pre-bending) and the full-bending die 122 (90° full bending) further improves the forming accuracy and consistency of the forming angle 31 and reduces the product defect rate.

[0049] III. Stamping process of strip 2 S1. Preparation before processing: Pull out the first wire changing plug 1212, the second wire changing plug 1222 and the third wire changing plug 1242 to the unlock position, so that the first punch 1211, the second punch 1221 and the third punch 1241 are all in a non-cutting state. At this time, the bending section 12 is in a non-working state.

[0050] S2, First continuous stamping: The strip 2 is fed into the electroplating bending part quick-change die 1 from one end of the punching section 11 along the first direction. The processing unit area of ​​the strip 2 includes the semi-finished product 21 and the connecting area 22 surrounding the semi-finished product 21. The positioning hole 221 is located within the connecting area 22. The hole cutting die 111 punches out the positioning hole 221 on the strip 2 as the positioning reference for subsequent processing. The edge cutting combination die 112 cuts out the outer contour of the semi-finished product 21 in steps. The length direction of the semi-finished product 21 is perpendicular to the direction of the strip 2. The two long sides of the semi-finished product 21 are connected to the connecting area 22.

[0051] S21. Cutting holes: Using the cutting die 111, a positioning hole 221 is cut out on the connecting area 22, and at the same time, the side waste material 25 of the strip 2 is cut off at a fixed width. S22, Edge trimming: The waste material 23 around the tip of the semi-finished product 21 is removed by the end waste removal die 1121. Then, the two tips of the semi-finished product 21 are extruded and formed into a chamfer structure by the end chamfering die 1122. Then, the outer peripheral waste material 24 of the semi-finished product 21 is removed by the contour forming die 1123 in sections and in steps to avoid material jamming. Finally, the waste removal die 1124 removes half of the T-shaped waste material of the connecting area 22, leaving the other half of the T-shaped connecting structure. When the strip 2 passes through the die completely for the first time, a positioning hole 221 is left on the remaining connecting area 22, and the strip 2 is wound up.

[0052] S3. Electroplating: The semi-finished strip is continuously passed through the electroplating bath and a tin / nickel / zinc protective coating is plated on the surface; then the coating is dried and cured, and the semi-finished product 21 remains in a flat, continuous state with the coating intact and undamaged.

[0053] S4. Die Change: Push the first line change rod 1212, the second line change rod 1222, and the third line change rod 1242 into the locked position, so that the first punch 1211, the second punch 1221, and the third punch 1241 are all in the punching state. At this time, the bending section 12 is in the working state. Then, perform a test punch on the strip sample. Then, control the forming angle of the folding angle 31 by adjusting the insertion amount of the stroke fine adjustment rod 1234, and control the forming R angle. When the actual forming angle reaches the target angle of the folding angle 31 (i.e., 90°), the die change and debugging are completed.

[0054] S5. Second continuous stamping: The electroplated strip 2 is rotated 180° and fed into the mold from one side of the bending section 12 along the second direction. The pre-bending mold 121 pre-bends the middle of the flat semi-finished product 21 by 45° to form a bend 31; then it is further bent by the full bending mold 122 to form the bend 31 to 90°, initially forming an L-shaped structure; then it is formed by the side punching and overpressure shaping of the forming mold 123 to compensate for material springback, so that the bend 31 is finally stabilized into a standard 90° L-shape, forming the finished product 3; then the blanking mold 124 punches and cuts off the remaining connection points between the finished product 3 and the connecting area 22, and the finished product 3 is directly removed from the station; after the product is separated, only the waste material of the connecting area 22 continues to enter the punching section 11 along the second direction, and the waste removal mold 1124 punches and removes the remaining half of the T-shaped structure of the connecting area 22.

[0055] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A quick-change die for electroplated bending parts, comprising a punching section and a bending section arranged sequentially along a first direction; the punching section is used to form a semi-finished strip, on which a semi-finished product with a planar structure is formed; the bending section is used to bend the semi-finished product into a finished product with a three-dimensional structure; characterized in that: The bending sections are arranged sequentially along the second direction, which is opposite to the first direction; the bending sections are configured to switch between working and non-working states.

2. The quick-change die for electroplated bending parts according to claim 1, characterized in that: The bending section includes a pre-bending die, a full-bending die, and a blanking die arranged sequentially along the second direction. The pre-bending die is used to pre-form a bend in the middle of the semi-finished product. The full-bending die is used to further bend the bend to turn the semi-finished product into a finished product. The blanking die is used to punch and cut off the connection point between the finished product and the connection area. The pre-bending die, the full-bending die, and the blanking die all include a punch and a line-changing insert.

3. The quick-change die for electroplated bending parts according to claim 2, characterized in that: The pre-bending angle of the pre-bending die is designed to be 45°, and the full bending angle of the full bending die is designed to be 90°.

4. The quick-change die for electroplated bending parts according to claim 3, characterized in that: A forming die is provided between the full bending die and the blanking die. The forming die adopts a side-punch structure, including a side punch, a side punch push block, and a side punch bending block. The side punch push block and the side punch bending block are arranged on the same die side. The side punch is arranged on the opposite die side of the side punch push block. The die-closing movement path of the side punch is located outside the material feeding width of the strip. When the die is closed, the side punch strikes the side punch push block vertically downward, thereby driving the side punch push block to move closer to the side punch bending block to complete the angle forming compensation.

5. The quick-change die for electroplated bending parts according to claim 4, characterized in that: The side punch has a first contact slope at its upper part, and the forming die also has a stroke fine-tuning rod arranged on the same side of the side punch. The rod section of the stroke fine-tuning rod that extends into the die has a second contact slope that is adapted to fit the first contact slope.

6. The quick-change die for electroplated bending parts according to claim 1, characterized in that: The punching section includes a hole-cutting die and an edge-cutting combination die arranged sequentially along a first direction. The hole-cutting die is used to cut out positioning holes on the strip. The processing unit area of ​​the strip includes a semi-finished product and a connecting area surrounding the semi-finished product. The positioning holes are located within the connecting area. The edge-cutting combination die is used to cut out the outer contour of the semi-finished product in steps.

7. The quick-change die for electroplated bending parts according to claim 6, characterized in that: The edge trimming assembly includes an end waste removal die, an end chamfering die, several contour forming dies, and a waste removal die arranged sequentially along a first direction. The end waste removal die is used to remove end waste near the two tips of the semi-finished product. The end chamfering die is used to extrude the two tips of the semi-finished product into a chamfered structure. The contour forming die removes the outer peripheral waste in multiple stations and blocks. The waste removal die is used to remove the T-shaped waste on one half of the connecting area during the first continuous stamping and to remove the T-shaped waste on the other half of the connecting area during the second continuous stamping.

8. A method for processing electroplated bent parts, using a quick-change die for electroplated bent parts as described in any one of claims 1-7, characterized in that the steps are as follows: include: S1. Pre-processing preparation: Switch the bending section to a non-working state; S2, First continuous stamping: The strip is fed into the die from one end of the punching section along the first direction. The punching die punches out positioning holes on the strip as positioning references for subsequent processing. The edge cutting combination die cuts out the outer contour of the semi-finished product step by step. The length direction of the semi-finished product is perpendicular to the direction of the strip. The two long sides of the semi-finished product are connected to the connection area to obtain the semi-finished strip. S3. Electroplating: The semi-finished material strip is passed through the electroplating bath, and a coating is applied to the surface. The coating is then dried and cured. S4. Die changing: Switch the bending section to the working state; S5. Second continuous stamping: The electroplated semi-finished strip is rotated 180° and fed into the mold from one side of the bending section along the second direction. The middle of the flat semi-finished product is pre-folded by the pre-bending mold to form a folded corner. Then, it is further bent by the full bending mold. Finally, the remaining connection points between the finished product and the connecting area are cut off by the blanking mold, so that the finished product can be directly dropped from the station.

9. The processing method according to claim 8, characterized in that: The specific process of the first continuous stamping is as follows: S21. Hole cutting: Using the hole cutting die, a positioning hole is cut in the connecting area, and at the same time, the side waste of the strip is cut off at a fixed width. S22, Edge trimming: The waste material around the tip of the semi-finished product is removed by the end waste removal die. Then, the two tips of the semi-finished product are extruded and formed into a chamfered structure by the end chamfering die. Then, the outer peripheral waste material of the semi-finished product is removed by the contour forming die in sections and waste removal in steps. Finally, the waste removal die removes half of the T-shaped waste material in the connecting area, leaving the other half of the T-shaped connecting structure.

10. The processing method according to claim 8, characterized in that: In the mold changing step, the forming angle of the bend is controlled by adjusting the insertion amount of the stroke fine-tuning rod. When the forming angle reaches 90°, the mold changing and debugging are completed.

Images