Stretching die for cylinder with special-shaped flange face

Abstract

The utility model discloses a drawing die for a cylinder with a special-shaped flange face, which comprises an upper die holder and a lower die holder which are vertically opposite to each other, and a drawing female die is arranged on the lower wall of the upper die holder. By means of closed-loop control of the split type blank holder and the pressure sensors, dynamic adaptation of blank holder force of all areas of the special-shaped flange face is achieved, each split block is independently provided with the pressure sensor, pressure data are monitored in real time and fed back to a hydraulic driving system for controlling the hydraulic cylinder, pressure closed-loop adjustment is formed, and therefore the pressure of the special-shaped flange face can be adjusted in real time. Areas with different contact areas of the special-shaped flange face all obtain adaptive blank holder force, local over-constraint or insufficient pressure is avoided, the forming precision of a complex contour is guaranteed, the movement tracks of the split blocks are restrained through the guide rods, dislocation or deflection of the split blocks is restrained, and surface damage of the flange face caused by discontinuous connection of the split blocks is avoided by arranging the gasket layer. And the production quality of products is ensured.

Description

Technical Field

[0001] This utility model relates to the field of stretching die technology, and in particular to a stretching die for a cylinder with an irregularly shaped flange. Background Technology

[0002] In recent years, the use of precision cylindrical drawing products with irregular flange faces has been increasing in the machinery and electrical industries. However, the manufacturing process for these products is complex, especially high-speed continuous stamping, which makes drawing even more difficult. This often results in the use of combined riveting or welding processes, leading to low-grade products, high costs, and unstable quality, thus hindering further improvement. Precision cylindrical drawing products with irregular flange faces have excellent overall appearance, high strength, and wide application, and have a promising future in the machinery and electrical industries.

[0003] In existing technologies, the main production challenge of precision cylindrical drawing parts with irregular flange faces lies in the uneven distribution of tangential compressive stress. Due to the varying distances from the edges to the center of the irregular flange, the contact area between the blank holder of the drawing die and the flange face differs significantly. Areas with larger contact areas experience excessive constraint, hindering material flow and leading to tensile cracking defects; areas with smaller contact areas suffer from insufficient compressive stress, resulting in localized material accumulation and thickening. The traditional spring-assisted blank holder pressing method used in symmetrical flange face cylindrical drawing dies is insufficient to effectively address this non-uniform stress distribution problem. Therefore, targeted improvements and optimizations to the structure of cylindrical drawing dies for irregular flange faces are necessary. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a stretching die for a cylinder with an irregularly shaped flange.

[0005] To achieve the above objectives, this utility model adopts the following technical solution: a cylindrical stretching die with an irregularly shaped flange, comprising an upper die base and a lower die base positioned opposite each other. A stretching die is disposed on the lower wall of the upper die base. A lower pad and a lower template are fixedly connected sequentially from bottom to top on the upper wall of the lower die base. A punch for stretching material in conjunction with the stretching die is disposed on the upper wall of the lower template. A lifting plate is sleeved on the outer wall of the punch. The lifting plate is movably connected to the lower template via springs and screws. A pressure cavity extending vertically through the inner wall of the lifting plate is disposed, and the punch is located within the pressure cavity. A pressure ring is slidably connected inside the pressure chamber and on the outer wall of the punch. A gasket layer is provided on the upper wall of the pressure ring. The pressure ring is composed of multiple sets of split blocks. A fixed seat is provided on the lower wall of each set of split blocks at the center of gravity. A connector is slidably connected inside the fixed seat. A pressure sensor is provided between the connector and the split block. A fixed plate is fixedly connected to the lower wall of the lifting plate through four sets of equal height blocks. A pressure driving structure for applying pressure to the connector is provided on the lower wall of the fixed plate. A guide structure for keeping the split blocks stable when the pressure driving structure is in operation is also provided on the lower wall of the fixed plate.

[0006] As a further description of the above technical solution:

[0007] Multiple sets of the aforementioned separate blocks are connected together to the lower wall of the gasket layer.

[0008] As a further description of the above technical solution:

[0009] A gap is provided between adjacent groups of the multiple sets of split blocks. The width of the gap is 1 / 10 of the material thickness and does not exceed 0.5 mm.

[0010] As a further description of the above technical solution:

[0011] The gasket layer is either a polytetrafluoroethylene-coated gasket or a metal spiral wound gasket.

[0012] As a further description of the above technical solution:

[0013] The material pressing drive structure includes multiple sets of hydraulic cylinders, all of which are fixedly connected to the lower wall of the fixed plate. Each set of hydraulic cylinders is vertically opposite to a set of connectors. The extension shaft of the hydraulic cylinder passes through the inner wall of the fixed plate and is fixedly connected to the lower wall of the connector. The lower template, the lower pad, and the lower mold base are all provided with clearance holes for the hydraulic cylinders to pass through.

[0014] As a further description of the above technical solution:

[0015] The guide structure includes multiple sets of guide rods, which are fixedly connected in pairs to the lower wall of a group of modular blocks. The ends of the guide rods away from the modular blocks all pass through a fixed plate and are slidably connected to the fixed plate.

[0016] As a further description of the above technical solution:

[0017] The pressure sensor is a thin-film force sensor.

[0018] As a further description of the above technical solution:

[0019] The lower end of the fixed base is threaded with an anti-detachment cap to prevent the connector from coming off.

[0020] This utility model has the following beneficial effects:

[0021] 1. Compared with the existing technology, this cylindrical stretching die with irregular flange surface achieves dynamic adaptation of the blank holder force in each area of ​​the irregular flange surface through closed-loop control of the split blank holder ring and pressure sensor. Each split block is independently equipped with a pressure sensor, which monitors and feeds back the pressure data to the hydraulic drive system that controls the hydraulic cylinder in real time, forming a closed-loop pressure regulation. This ensures that areas with different contact areas of the irregular flange surface receive the appropriate blank holder force, avoiding local over-constraint or insufficient pressure, and ensuring the forming accuracy of complex contours.

[0022] 2. Compared with the existing technology, the cylindrical stretching die with irregular flange surface uses guide rods to constrain the movement trajectory of the split blocks, suppressing misalignment or skew of the split blocks, and sets gasket layers to avoid damage to the flange surface caused by discontinuous connection of each split block, thus ensuring the production quality of the product. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of a cylindrical stretching die with an irregularly shaped flange surface proposed in this utility model.

[0024] Figure 2 A partial sectional view from above of the connection structure of the lifting plate, punch, and fixing plate of a cylindrical stretching die with an irregularly shaped flange surface proposed in this utility model.

[0025] Figure 3 A partial sectional view from above of the lifting plate, punch, and split block connection structure of a cylindrical stretching die with an irregularly shaped flange surface proposed in this utility model.

[0026] Figure 4 This utility model presents a partial sectional view of the gasket layer, split blocks, fixing seat, connector, hydraulic cylinder, and guide rod connection structure of a cylindrical stretching die with an irregular flange surface.

[0027] Legend:

[0028] 1. Lower mold base; 2. Lower backing plate; 3. Lower template; 4. Lifting plate; 5. Punch; 6. Gasket layer; 7. Fixing plate; 8. Hydraulic cylinder; 9. Guide rod; 10. Separate block; 11. Anti-detachment cover; 12. Fixing base; 13. Connector; 14. Pressure sensor. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] Reference Figures 1 to 4 This utility model provides a cylindrical stretching die with an irregular flange surface: it includes an upper die base and a lower die base 1 that are positioned opposite each other. The lower wall of the upper die base is provided with a stretching die. The upper wall of the lower die base 1 is fixedly connected with a lower pad plate 2 and a lower template plate 3 from bottom to top. The upper wall of the lower template plate 3 is provided with a punch 5 for stretching the material in conjunction with the stretching die. The outer wall of the punch 5 is fitted with a lifting plate 4. The lifting plate 4 is movably connected to the lower template plate 3 by springs and screws. The inner wall of the lifting plate 4 is provided with a pressing cavity that runs vertically through the material. The punch 5 is located in the pressing cavity.

[0031] In order to achieve dynamic adaptation of the blank holder force in different areas of the irregular flange surface and avoid uneven material flow resistance, a blank holder ring is slidably connected inside the blank holder cavity and on the outer wall of the punch 5. The blank holder ring is composed of multiple sub-blocks 10. A gap is provided between two adjacent sub-blocks 10. The gap width is 1 / 10 of the material thickness and does not exceed 0.5mm.

[0032] Through the above-mentioned gap design, the area with a larger contact area of ​​the irregular flange surface allows for slight deformation when the material flows, releasing the tangential compressive stress in the over-constrained area. At the same time, the area with a smaller contact area compensates for insufficient compressive stress through the independent movement of the split block 10, thereby avoiding the tearing or material accumulation problems caused by the traditional integral pressure ring.

[0033] To avoid scratches or indentations on the flange surface caused by the gaps between the modular blocks 10, a gasket layer 6 is provided on the upper wall of the pressure ring. The multiple modular blocks 10 are connected to the lower wall of the gasket layer 6. The gasket layer 6 is either a polytetrafluoroethylene-coated gasket or a metal spiral wound gasket. In this embodiment, a metal spiral wound gasket is used.

[0034] When the split block 10 is dynamically adjusted with the blank holder force, the gasket layer 6 covers the gap between the split blocks 10 and adheres to the flange surface. Through its flexible deformation capability, it compensates for the small height difference at the joint of the split blocks 10, prevents the flange surface from being scratched due to hard contact friction, and avoids surface wrinkling defects caused by obstruction of material flow.

[0035] In order to apply appropriate pressing force to different areas of the flange surface and form a pressure closed-loop adjustment, each set of sub-blocks 10 is provided with a fixed seat 12 on the lower wall and at the center of gravity. The fixed seat 12 is slidably connected to a connector 13. A pressure sensor 14 is provided between the connector 13 and the sub-block 10. The pressure sensor 14 is a thin film force sensor. The lower wall of the lifting plate 4 is fixedly connected to a fixed plate 7 through four sets of equal height blocks. The lower wall of the fixed plate 7 is provided with a pressing drive structure for applying pressure to the connector 13. The pressing drive structure includes multiple sets of hydraulic cylinders 8. The multiple sets of hydraulic cylinders 8 are fixedly connected to the lower wall of the fixed plate 7. The multiple sets of hydraulic cylinders 8 are respectively vertically opposite to a set of connectors 13. The extension shaft of the hydraulic cylinder 8 passes through the inner wall of the fixed plate 7 and is fixedly connected to the lower wall of the connector 13. The lower template 3, the lower pad 2 and the lower mold base 1 are all provided with clearance holes for the hydraulic cylinders 8 to pass through. The lower end of the fixed seat 12 is threadedly connected with an anti-detachment cover 11 to prevent the connector 13 from coming off.

[0036] Through the above structure, the pressure sensor 14 monitors the blanking force data of the split block 10 in real time and feeds it back to the hydraulic drive system of the hydraulic cylinder 8. The hydraulic cylinder 8 dynamically adjusts the pressure applied by each split block 10 according to the feedback, so that the areas with large differences in the contact area of ​​the irregular flange surface can all obtain the appropriate blanking force, forming a closed-loop control, eliminating the problem of uneven stress distribution caused by the inability of the traditional spring blanking ring to be dynamically adjusted.

[0037] To ensure that the hydraulic cylinder 8 drives the split block 10 to move and maintain a stable trajectory, the lower wall of the fixed plate 7 is also provided with a guide structure for maintaining the stability of the split block 10 when the pressing drive structure is in motion. The guide structure includes multiple sets of guide rods 9, which are fixedly connected in pairs to the lower wall of a set of split blocks 10. The ends of the multiple sets of guide rods 9 away from the split block 10 all pass through the fixed plate 7 and are slidably connected to the fixed plate 7.

[0038] When the split block 10 is driven up and down by the hydraulic cylinder 8, the guide rod 9 restricts the lateral offset or rotation of the split block 10 through rigid constraint, ensuring that the multi-part split block 10 always maintains perpendicular contact with the flange surface during dynamic pressure adjustment, and avoiding local over-constraint or pressure failure caused by the skewness of the split block 10.

[0039] Working principle: Through gap design, the larger contact area of ​​the irregular flange surface allows for slight deformation during material flow, releasing the tangential compressive stress in the over-constrained area. Simultaneously, the smaller contact area compensates for insufficient compressive stress through the independent movement of the split blocks 10, thus avoiding the tearing or material accumulation problems caused by traditional integral pressure rings. When the split blocks 10 dynamically adjust with the pressure force, the gasket layer 6 covers the gap between the split blocks 10 and adheres to the flange surface. Its flexible deformation capability compensates for the slight height difference at the joint of the split blocks 10, preventing flange surface scratches caused by hard contact friction, and avoiding surface wrinkling defects caused by obstructed material flow. Pressure sensor 1 4. The pressure force data of the split block 10 is monitored in real time and fed back to the hydraulic drive system of the hydraulic cylinder 8. The hydraulic cylinder 8 dynamically adjusts the pressure of each split block 10 according to the feedback, so that the areas with large differences in the contact area of ​​the irregular flange surface can all obtain the appropriate pressure force, forming a closed-loop control, eliminating the problem of uneven stress distribution caused by the inability of traditional spring pressure rings to be dynamically adjusted; when the split block 10 is driven up and down by the hydraulic cylinder 8, the guide rod 9 restricts the lateral offset or rotation of the split block 10 through rigid constraint, ensuring that the multiple split blocks 10 always maintain perpendicular contact with the flange surface during the dynamic pressure adjustment process, avoiding local over-constraint or pressure failure caused by the skew of the split block 10.

[0040] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A drawing die for a cylinder with a profiled flange, characterized in that: The assembly includes an upper die base and a lower die base (1) positioned vertically opposite each other. The lower wall of the upper die base is provided with a stretching die. The upper wall of the lower die base (1) is fixedly connected with a lower pad plate (2) and a lower template plate (3) from bottom to top. The upper wall of the lower template plate (3) is provided with a punch (5) for stretching the material in conjunction with the stretching die. A lifting plate (4) is sleeved on the outer wall of the punch (5). The lifting plate (4) is movably connected to the lower template plate (3) by a spring and screws. The inner wall of the lifting plate (4) is provided with a pressure cavity that runs vertically through the material. The punch (5) is located in the pressure cavity. A pressure ring is slidably connected inside the pressure cavity and on the outer wall of the punch (5). The upper wall of the pressure ring is provided with... A gasket layer (6) is provided. The pressure ring is composed of multiple sub-blocks (10). Each sub-block (10) has a fixed seat (12) on its lower wall and located at the center of gravity. A connector (13) is slidably connected inside the fixed seat (12). A pressure sensor (14) is provided between the connector (13) and the sub-block (10). The lower wall of the lifting plate (4) is fixedly connected to a fixed plate (7) by four sets of equal height blocks. The lower wall of the fixed plate (7) is provided with a pressure driving structure for applying pressure to the connector (13). The lower wall of the fixed plate (7) is also provided with a guide structure for keeping the sub-block (10) stable when the pressure driving structure is in operation.

2. The drawing die for a cylinder with a profiled flange according to claim 1, characterized in that: Multiple sets of the aforementioned split blocks (10) are connected together to the lower wall of the gasket layer (6).

3. The drawing die for a cylinder with a profiled flange according to claim 2, characterized in that: The multiple sets of the split blocks (10) are provided with a gap between adjacent sets, the gap width is 1 / 10 of the material thickness, and the maximum is no more than 0.5mm.

4. The drawing die for a cylinder with a profiled flange according to claim 3, characterized in that: The gasket layer (6) is either a polytetrafluoroethylene-coated gasket or a metal spiral wound gasket.

5. The drawing die for a cylinder with a profiled flange according to claim 4, characterized in that: The pressing drive structure includes multiple sets of hydraulic cylinders (8), all of which are fixedly connected to the lower wall of the fixed plate (7). The multiple sets of hydraulic cylinders (8) are respectively opposite to a set of connectors (13). The extension shaft of the hydraulic cylinder (8) passes through the inner wall of the fixed plate (7) and is fixedly connected to the lower wall of the connector (13). The lower template (3), the lower pad (2), and the lower mold base (1) are all provided with clearance holes for the hydraulic cylinders (8) to pass through.

6. The drawing die for a cylinder with a profiled flange according to claim 5, characterized in that: The guide structure includes multiple sets of guide rods (9), which are fixedly connected in pairs to the lower wall of a set of sub-blocks (10). The ends of the multiple sets of guide rods (9) away from the sub-blocks (10) all pass through the fixing plate (7) and are slidably connected to the fixing plate (7).

7. The drawing die for a cylinder with a profiled flange according to claim 6, characterized in that: The pressure sensor (14) is a thin-film force sensor.

8. The drawing die for a cylinder with a profiled flange according to claim 7, characterized in that: The lower end of the fixing seat (12) is threaded with an anti-detachment cover (11) to prevent the connector (13) from coming off.

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