A high-throughput multi-pass sheet metal stamping process simulation device and method

Abstract

This invention discloses a simulation device and method for high-throughput multi-pass stamping forming process of sheet metal, relating to the field of material plastic processing control. It includes a multi-head upper stamping die, a multi-hole lower stamping die, a stamping die, and a pressure-displacement acquisition system. The multi-head upper stamping die has multiple stamping die heads of different heights and diameters. The multi-hole lower stamping die has stamping die grooves corresponding to the stamping die heads. The stamping die has through holes for the stamping die heads to pass through and is connected to the upper die via a compression spring connecting rod. The pressure-displacement acquisition system is used to collect pressure and displacement data during the stamping process. By acquiring high-throughput experimental data under multiple working conditions and multiple passes, the system can not only build a comprehensive and reliable basic database for sheet metal stamping forming processes but also verify multi-pass stamping forming results under different process parameters in batches, thereby quickly selecting the optimal stamping forming process parameters.

Description

Technical Field

[0001] This invention relates to the field of material plastic processing control, and in particular to a device and method for simulating high-throughput multi-pass stamping forming process of sheet metal. Background Technology

[0002] With the increasing demands for lightweighting and high performance in fields such as automotive manufacturing and aerospace, the forming quality and production efficiency of complex thin-walled components have become key bottlenecks. Multi-pass stamping processes have emerged to address this need. These processes sequentially form the blank into the final component through multiple stations within the same mold system. The core idea is to replace the concentrated deformation in traditional single-process operations with step-by-step loading to reduce the risk of local instability and fracture. Building upon this, high-throughput multi-pass stamping of sheet metal further breaks through the traditional single-path, single-condition testing model. It enables parallel or rapid switching of different process parameters and pass paths in the same platform or series of tests, achieving efficient forming testing and data accumulation under multiple working conditions and parameter spaces. This systematically improves the breadth and speed of forming process development.

[0003] High-throughput multi-pass processes not only provide richer and more accurate combinations of boundary conditions and process parameters for numerical simulation of the forming process, enabling the predictive capabilities of simulation models to be fully verified and improved under multiple operating conditions, but also provide a large volume of comparable experimental data for mold design and process optimization, supporting the rapid optimization and system improvement of forming paths. More importantly, high-throughput multi-pass stamping can systematically reveal the evolution of material flow and stress distribution in a multi-parameter space, significantly improving the forming limits and dimensional stability of complex parts. Therefore, in the process of transitioning from experience-based trial and error to digital precision forming, sheet metal high-throughput multi-pass stamping plays a crucial role in moving from "single-point optimization" to "global optimization."

[0004] While traditional multi-pass stamping is a core process for manufacturing complex thin-walled components, traditional stamping equipment lacks real-time control capabilities between passes. Parameters such as deformation, blank holder force, and lubrication conditions must be manually adjusted one by one, making operation cumbersome and difficult to guarantee continuity and consistency. Furthermore, traditional stamping tests, such as the fixed metal sheet stamping stiffness testing device disclosed in patent document CN101706401A, can only complete one pass of loading at a time, resulting in low efficiency and an inability to monitor the formability and quality of the sheet metal in real time. These shortcomings are particularly pronounced in high-throughput testing—high-throughput testing requires rapid switching or parallel execution of multiple pass sequences and parameter combinations, which traditional equipment struggles to meet in terms of automated control, process stability, and synchronous data acquisition.

[0005] In terms of experimental verification, although finite element simulation can be used for multi-pass forming analysis, the simulation results lack high-throughput and highly repeatable experimental verification methods. Boundary conditions between passes are difficult to obtain accurately, and poor repeatability due to manual operation further hinders the establishment of a reliable process database. The texture evolution caused by material anisotropy is complex, making it difficult to systematically compare and model forming behaviors under different process paths. In summary, existing equipment and methods have significant shortcomings in forming quality control, high-throughput control of process parameters, equipment capability adaptation, and system-level experimental verification. Summary of the Invention

[0006] To address the technical problems of traditional single-condition, low-efficiency testing methods, this invention provides a simulation device and method for high-throughput multi-pass stamping forming processes of sheet metal. It can efficiently simulate the stamping forming process of sheet metal under high-throughput multi-pass conditions, supporting rapid switching or parallel testing of various process paths and parameter combinations. It can monitor in real time key characteristics of the sheet metal under different pass sequences, such as forming limits, thinning rate, springback, wrinkling, cracking, thickness distribution, and stress-strain. By acquiring high-throughput test data under multiple working conditions and multiple passes, the system can not only build a comprehensive and reliable basic database for sheet metal stamping forming processes but also batch verify multi-pass stamping forming results under different process parameters. This allows for rapid selection of optimal stamping forming process parameters, significantly improving process development efficiency and forming quality control.

[0007] The technical solution adopted by the present invention to solve its technical problem is: a high-throughput multi-pass stamping forming process simulation device for sheet metal, including a multi-head stamping upper die, a multi-hole stamping lower die, a stamping die and a pressure displacement acquisition system;

[0008] The multi-head stamping upper die is provided with multiple stamping die heads of different heights and diameters;

[0009] The multi-hole stamping lower die is provided with stamping die grooves that correspond one-to-one with the stamping die pressure head;

[0010] The stamping die is provided with a through hole for the stamping die head to pass through, and is connected to the upper die through a compression spring connecting rod;

[0011] The pressure and displacement acquisition system is used to collect pressure and displacement data during the stamping process.

[0012] Preferably, the stamping die head is cylindrical with a hemispherical end; the height of the central stamping die head is h, and the diameter is 2R; the remaining stamping die heads are arranged in layers according to their distance from the center, with 4 heads in each layer, and the diameters are 2R, 2(R+1), 2(R+2), and 2(R+3) respectively, and the heights are h-2, h-4, h-6, and h-8 respectively.

[0013] Preferably, the upper end face of the multi-hole stamping die is provided with a blank material groove, and the stamping die groove is located in the blank material groove; the stamping die groove is cylindrical with a diameter of 2.5R and a depth of h.

[0014] Preferably, the stamping die is a cuboid with a square cross-section and a thickness of x; the through hole has a square cross-section with a side length of 4R.

[0015] Preferably, the compression spring connecting rod includes an external spring and a guide rod disposed inside the spring, the height of which is 1 / 3 of the free height of the compression spring.

[0016] Preferably, a stroke guide rod assembly is provided between the multi-head stamping upper die and the multi-hole stamping lower die.

[0017] Preferably, a pressure sensor is provided between each stamping die head and the multi-head stamping upper die to measure the stamping pressure of each stamping die head;

[0018] The multi-head stamping die is equipped with a displacement sensor to measure the overall displacement of the multi-head stamping die.

[0019] Preferably, the pressure-displacement acquisition system is used to generate stress-strain curves corresponding to each pressure head based on the acquired data from the pressure sensor and displacement sensor.

[0020] The present invention also provides a method for simulating a high-throughput multi-pass stamping process of sheet metal using the above-mentioned device, comprising the following steps:

[0021] Step 1: Place the sheet material into the slab blank groove;

[0022] Step 2: Perform the first stamping pass, with the upper die pressing down by y for the multi-head stamping.

[0023] Step 3: Rotate the sheet metal counterclockwise by 90° and perform the second stamping. The upper die of the multi-head stamping press has a pressing amount of y-4.

[0024] Step 4: Rotate the sheet metal counterclockwise by 90° again for the third stamping pass. The upper die of the multi-head stamping press has a pressing amount of y-8.

[0025] Step 5: Remove the sheet metal and analyze the formed parts and their stress-strain curves under different passes.

[0026] Preferably, the amount of reduction y of the upper die in the multi-head stamping process satisfies: y>x+8, and y<2 / 3(hx).

[0027] Advantages of this invention:

[0028] 1. By setting multiple pressure heads of different heights and diameters in the upper die of a multi-pressure stamping process and setting corresponding grooves in the lower die, high-throughput parallel simulation of multiple deformation conditions in a single forming process is achieved, significantly improving experimental efficiency;

[0029] 2. By combining multi-pass rotating billet with decreasing pressure, the cumulative deformation behavior of sheet metal can be realistically simulated, supporting flexible switching of process paths;

[0030] 3. Relying on the pressure displacement data acquisition system, it is possible to acquire forming force and stress-strain curves under different parameters in batches, and quickly screen the optimal process;

[0031] 4. This method eliminates the influence of external variables between batches, providing an efficient and reliable platform for constructing a basic database of multi-pass stamping of sheet metal and improving the level of forming quality control. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only five of the drawings in this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the overall structure of the high-throughput multi-pass stamping process simulation device for sheet metal of the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of the multi-hole stamping die of the present invention;

[0035] Figure 3 This is a schematic diagram of the structure of the multi-head stamping upper die of the present invention;

[0036] Figure 4 This is a schematic diagram of the stamping die of the present invention;

[0037] Figure 5 This is a flowchart of the method of the present invention.

[0038] In the diagram: 1. Multi-head stamping upper die; 2. Stamping die; 3. Multi-hole stamping lower die; 4. Pressure displacement acquisition system; 5. Stamping die groove; 6. Slab material groove; 7. Stroke guide rod; 8. Stamping die pressure head; 9. Pressure sensor; 10. Displacement sensor; 11. Through hole; 12. Compression spring connecting rod; 121. Spring; 122. Navigation rod. Detailed Implementation

[0039] To enhance understanding of the present invention, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. These embodiments are only used to explain the invention and do not limit the scope of protection of the invention.

[0040] In this solution, all formulas, parameters, or values ​​involving length are in millimeters.

[0041] like Figure 1 As shown, a high-throughput multi-pass stamping process simulation device for sheet metal includes a multi-head upper stamping die 1, a multi-hole lower stamping die 3, a stamping die 2, and a pressure displacement acquisition system 4.

[0042] The multi-head stamping upper die 1 is fixed on the upper slide of a large hydraulic press, and the multi-hole stamping lower die 3 is fixed on the base of the hydraulic press and moves under the guidance of the stroke guide rod 7.

[0043] Combination Figure 3 As shown, the multi-head stamping upper die 1 has multiple stamping die heads 8 of different heights and diameters. Each stamping die head 8 is cylindrical with a hemispherical stamping end. The central stamping die head 8 has a height of h and a diameter of 2R. The remaining stamping die heads 8 are arranged in layers according to their distance from the center, with a distance a from the center... ,2a, …There are 4 per layer, with diameters of 2R, 2(R+1), 2(R+2), and 2(R+3) respectively, and heights of h-2, h-4, h-6, and h-8 respectively;

[0044] Combination Figure 2 As shown, the multi-hole stamping lower die 3 is provided with stamping die grooves 5 corresponding one-to-one with the stamping die pressure head 8, and the central axis of each stamping die groove 5 coincides with the central axis of the stamping die pressure head 8 of the multi-pressure head stamping upper die 1; the upper end face of the multi-hole stamping lower die 3 is provided with a blank material groove 6, the size of which is d×d and the depth is L, and the stamping die groove 5 is located in the blank material groove 6; the stamping die groove 5 is cylindrical, with a diameter of 2.5R and a depth of h;

[0045] Combination Figure 4 As shown, the stamping die 2 is provided with a through hole 11 for the stamping die head 8 to pass through, and is connected to the upper die through a compression spring connecting rod 12; the stamping die 2 is a cuboid with a square cross-section, a side length of c, and a thickness of x; the through hole 11 has a square cross-section with a side length of 4R, and the central axis of each through hole 11 coincides with the central axis of the stamping die head 8 and the stamping die groove 5, respectively.

[0046] The square through hole 11 on the stamping die 2 divides the sheet metal into multiple independent stamping areas. The stamping die 2 is used to press down the edge of the sheet metal during the stamping process to prevent the sheet metal from wrinkling or moving.

[0047] n equally spaced compression spring connecting rods 12 are arranged around the periphery of the stamping die 2. Each compression spring connecting rod 12 includes an outer spring 121 and a guide rod 122 disposed inside the spring 121. The inner diameter of each spring 121 is b, and its free height is (hx). The outer diameter of the guide rod 122 is smaller than the inner diameter of the compression spring 121, and the height of the guide rod 122 is 1 / 3 of the free height of the compression spring 121. These rods are used to guide the upper die for precise positioning and vertical movement.

[0048] The pressure and displacement acquisition system 4 is used to acquire pressure and displacement data during the stamping process.

[0049] Between the multi-head stamping upper die 1 and the multi-hole stamping lower die 3, stroke guide rod assemblies are respectively provided on the multi-head stamping upper die 1 and the stamping die 2. The stroke guide rod assembly includes a sliding cylinder and a sliding rod. The sliding cylinders are all disposed on the multi-head stamping upper die 1, and the sliding rods are respectively disposed on the multi-hole stamping lower die 3 and the stamping die 2 corresponding to the sliding cylinders. The sliding cylinders and the sliding rods are slidably fitted together. The stroke guide rod assembly guides the multi-head stamping upper die 1 on one hand and the stamping die 2 on the other, ensuring that the stamping die 2 is aligned with the blank material groove.

[0050] Each stamping die head 8 is equipped with a pressure sensor 9 between it and the multi-head stamping upper die 1, which is used to measure the stamping pressure of each stamping die head 8;

[0051] The multi-head stamping upper die 1 is equipped with a displacement sensor 10, which is used to measure the overall displacement of the multi-head stamping upper die 1.

[0052] The pressure-displacement acquisition system 4 is used to generate stress-strain curves corresponding to each pressure head based on the acquired data from the pressure sensor 9 and displacement sensor 10, where stress is the pressure data obtained by the pressure sensor and displacement data obtained by the strain gauge displacement sensor.

[0053] Combination Figure 5 As shown, the present invention also provides a method for simulating a high-throughput multi-pass stamping process of sheet metal using the above-mentioned device, comprising the following steps:

[0054] Step 1: Place a sheet material with dimensions d×d (e.g., 1000×1000mm) and a thickness of s (2mm) into the sheet material groove 6;

[0055] Step 2: Set the stamping rate of the multi-head stamping upper die 1, start the pressure displacement acquisition system 4, and perform the first stamping pass. The pressing amount of the multi-head stamping upper die 1 is y, where y>x+8. This ensures that all stamping die heads 8 can press into the sheet metal, and y<2 / 3(hx). This is because the spring 121 compression rod has a connecting rod inside to ensure that all heads can press into the sheet metal without damaging the navigation rod 122.

[0056] Step 3: Rotate the sheet metal counterclockwise by 90° and perform the second stamping. The upper die 1 of the multi-head stamping press reduces the amount by y-4.

[0057] Step 4: Rotate the sheet metal counterclockwise by 90° again for the third stamping pass. The upper die 1 of the multi-head stamping press reduces the amount by y-8.

[0058] Step 5: After the experiment, the sheet metal is removed, and stamped parts with different deformation amounts and different passes and their stress-strain curves can be obtained. These can be used for subsequent analysis of key characteristics of the sheet metal under different deformation amounts, such as multi-pass formability, thinning rate, springback, wrinkling, cracking, thickness distribution, stress and strain, and for screening and optimization of multi-pass stamping process parameters.

[0059] The plate is a square thin plate with dimensions d×d and a thickness of s; the dimensions of the plate blank groove 6 (6) are slightly larger than the dimensions of the plate.

[0060] By setting multiple pressure heads of different heights and diameters in the upper die of a multi-head stamping process and corresponding grooves in the lower die, high-throughput parallel simulation of various deformation conditions during a single forming process is achieved, significantly improving experimental efficiency. Combined with inter-pass billet rotation and progressive pressure reduction, the cumulative deformation behavior of sheet metal can be realistically simulated, supporting flexible switching of process paths. Relying on a pressure-displacement data acquisition system, forming force and stress-strain curves under different parameters can be acquired in batches, enabling rapid selection of the optimal process. This method eliminates the influence of external variables between batches, providing an efficient and reliable platform for constructing a basic database for multi-pass sheet metal stamping and improving the level of forming quality control.

[0061] Example

[0062] This embodiment uses TC4 titanium alloy sheet as an example to illustrate the simulation method and apparatus for high-throughput multi-pass stamping forming process of sheet metal. The specific steps of this embodiment are as follows:

[0063] Step 1: Fix the multi-head stamping upper die 1 on the hydraulic press slide block, and fix the multi-hole stamping lower die 3 on the hydraulic press worktable. Position the multi-hole stamping upper and lower dies so that the multi-head stamping upper die 1 can move up and down under the guidance of the stroke guide rod 7.

[0064] Step 2: Place a TC4 sheet with dimensions of 1000×1000mm and a thickness of 2mm into the blank material groove 6 on the multi-hole stamping lower die 3. The material groove on the multi-hole stamping lower die 3 has dimensions of 1001×1001×2mm.

[0065] Step 3: Set the stamping rate of the multi-head stamping upper die 1 to 10 mm / s, start the pressure displacement acquisition system 4, and conduct the first sheet metal stamping experiment. The upper die pressing amount is 210 mm.

[0066] Step 4: After the first sheet metal stamping test is completed, rotate the blank 90° counterclockwise and perform the second sheet metal stamping test. The upper die pressing amount is 206mm.

[0067] Step 5: After the second sheet metal stamping test is completed, rotate the blank counterclockwise by 90° to conduct the third sheet metal stamping test, with the upper die pressing down by 202mm.

[0068] Step 6: After the experiment, the TC4 sheet is taken out for analysis. Stamped parts with different deformation amounts and different passes and their stress-strain curves can be obtained. These curves can be used for subsequent analysis of key characteristics of the TC4 sheet under different deformation amounts, such as multi-pass formability, thinning rate, springback, wrinkling, cracking, thickness distribution, stress and strain.

[0069] The central stamping die head 8 has a maximum height of 400mm and a diameter of 80mm.

[0070] The stamping die 2 has dimensions of 1000×1000×50mm, the inner diameter of the compression spring 121 is 60mm, and the height of the spring 121 is 350mm.

[0071] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A device for simulating a high-throughput, multi-pass stamping process for sheet metal, characterized in that: It includes a multi-head stamping upper die (1), a multi-hole stamping lower die (3), a stamping die (2), and a pressure displacement acquisition system (4); The multi-head stamping upper die (1) is provided with multiple stamping die heads (8) of different heights and diameters; The multi-hole stamping lower die (3) is provided with stamping die grooves (5) that correspond one-to-one with the stamping die pressure head (8); The stamping die (2) is provided with a through hole (11) for the stamping die head (8) to pass through, and is connected to the upper die through a compression spring connecting rod (12); The pressure and displacement acquisition system (4) is used to acquire pressure and displacement data during the stamping process.

2. The high-throughput multi-pass stamping process simulation device for sheet metal according to claim 1, characterized in that, The stamping die head (8) is cylindrical with a hemispherical end; the height of the central stamping die head (8) is h and the diameter is 2R; the remaining stamping die heads (8) are arranged in layers according to their distance from the center stamping die head (8), with 4 heads in each layer, and the diameters are 2R, 2(R+1), 2(R+2), 2(R+3) respectively, and the heights are h-2, h-4, h-6, h-8 respectively.

3. The high-throughput multi-pass stamping process simulation device for sheet metal according to claim 1, characterized in that, The upper end face of the multi-hole stamping die (3) is provided with a blank material groove (6), and the stamping die groove (5) is located in the blank material groove (6); the stamping die groove (5) is cylindrical with a diameter of 2.5R and a depth of h.

4. The high-throughput multi-pass stamping process simulation device for sheet metal according to claim 1, characterized in that, The stamping die (2) is a cuboid with a square cross-section and a thickness of x; the through hole (11) has a square cross-section with a side length of 4R.

5. The high-throughput multi-pass stamping process simulation device for sheet metal according to claim 1, characterized in that, The compression spring connecting rod (12) includes an external spring (121) and a navigation rod (122) disposed inside the spring (121). The height of the navigation rod (122) is 1 / 3 of the free height of the compression spring (121).

6. The high-throughput multi-pass stamping process simulation device for sheet metal according to claim 1, characterized in that, Between the multi-head stamping upper die (1) and the multi-hole stamping lower die (3), the multi-head stamping upper die (1) and the stamping die (2) are respectively provided with stroke guide rod assemblies.

7. The high-throughput multi-pass stamping process simulation device for sheet metal according to claim 1, characterized in that, Each stamping die head (8) is equipped with a pressure sensor (9) between it and the multi-head stamping upper die (1) to measure the stamping pressure of each stamping die head (8); The multi-head stamping upper die (1) is equipped with a displacement sensor (10) for measuring the overall displacement of the multi-head stamping upper die (1).

8. The high-throughput multi-pass stamping process simulation device for sheet metal according to claim 7, characterized in that, The pressure displacement acquisition system (4) is used to generate stress-strain curves corresponding to each pressure head based on the acquired data from the pressure sensor (9) and displacement sensor (10).

9. A method for simulating a high-throughput multi-pass stamping process of sheet metal using the apparatus described in any one of claims 1-8, characterized in that: Includes the following steps: Step 1: Place the sheet material in the slab blank groove (6); Step 2, perform the first stamping pass, the upper die (1) of the multi-head stamping press has a pressing amount of y; Step 3: Rotate the sheet metal counterclockwise by 90° and perform the second stamping. The upper die (1) of the multi-head stamping press has a pressing amount of y-4. Step 4, rotate the sheet metal counterclockwise by 90° again for the third stamping, and press down the upper die (1) of the multi-head stamping with a pressing amount of y-8; Step 5: Remove the sheet metal and analyze the formed parts and their stress-strain curves under different passes.

10. The method for simulating high-throughput multi-pass stamping forming process of sheet metal according to claim 9, characterized in that: The pressing amount y of the multi-head stamping upper die (1) satisfies: y>x+8, and y<2 / 3(hx).

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