Method and system for generating blank holder type multiple curved surfaces of stamping grinding tool

Abstract

The invention belongs to the technical field of curved surface blank pressing manufacturing, and provides a stamping grinding tool blank pressing ring type multi-curved-surface generation method and system, in the historical blank pressing process of a concave-convex transition area in a ring type multi-curved-surface, blank pressing analysis is carried out on a concave surface sub-area and a convex surface sub-area divided in the concave-convex transition area, and a blank pressing result is obtained. Identifying the speed change type of the concave-convex material, if the speed change type of the concave-convex material is slow in convex and fast in concave, extracting the blank pressing pressure when blank pressing is performed on the concave-convex transition area in the ring-shaped multi-curved surface in a plurality of historical blank pressing periods and the corresponding material flow speed, and performing correlation analysis to finish static adjustment of blank pressing pressure parameters; by means of the technical scheme, the flow direction and speed of the materials can be accurately controlled, the situation that the materials flow excessively or insufficiently is avoided, the problem caused by blank pressing pressure in the material flow process is found and determined in time by monitoring the material pressing speed difference value in real time, and the batch quality problem is avoided.

Description

Technical Field

[0001] This invention belongs to the field of curved surface edge pressing technology, specifically a method and system for generating multi-curved surfaces of stamping die edge pressing rings. Background Technology

[0002] When pressing the edge of the concave-convex transition zone of the circular multi-curved surface, the lack of detailed analysis of the concave and convex sub-regions in the concave-convex transition zone makes it difficult to accurately identify the type of material velocity change. This results in the inability to accurately control the material flow direction and speed according to the actual material velocity change, which can easily lead to problems of excessive or insufficient material flow, affecting the product shape accuracy and reducing the efficiency of mass production.

[0003] In existing technologies, there is a lack of effective assessment and monitoring of sudden changes in material flow velocity during the edge pressing process. Sudden changes in material flow velocity can cause uneven material flow, leading to surface defects in the product. It can also generate significant impact and friction on the mold, accelerating mold wear and shortening its lifespan. Furthermore, without a properly defined smoothing range for sudden changes, the amplitude of material flow velocity variations cannot be limited, making it difficult to effectively reduce internal stress concentration in the material. This makes it difficult to avoid defects caused by localized flow anomalies, ultimately affecting the overall product quality and the stability of the production process.

[0004] Therefore, the present invention provides a method and system for generating multi-curved surfaces of stamping die blank holders. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] In a first aspect, a method for generating a multi-curved surface of a stamping die blank holder includes the following steps:

[0008] During the historical edge pressing process of the concave-convex transition zone in the circular multi-curved surface, edge pressing analysis was performed on the concave and convex sub-regions within the concave-convex transition zone to identify the types of material velocity changes.

[0009] If the material flow rate change type is convex slow and concave fast, then extract the edge pressing pressure and the corresponding material flow rate when pressing the concave-convex transition zone in the circular multi-curved surface within multiple historical edge pressing cycles, and perform correlation analysis to complete the static adjustment of the edge pressing pressure parameters.

[0010] After making historical static adjustments, when pressing the edge again in the concave-convex transition area of ​​the circular multi-curved surface, the material flow velocity is analyzed to assess whether a sudden change in material velocity will occur.

[0011] Extract the static adjustment parameters for sudden changes in material speed during each pressing cycle, as well as for non-corresponding sudden changes, to determine the range of sudden changes and the range of non-sudden changes after static adjustment, and set the smoothing range for sudden change adjustment.

[0012] As a preferred approach, the process for identifying the velocity change type of uneven materials is as follows:

[0013] The concave-convex transition area is divided into multiple concave and convex sub-regions according to the grid. Visual recognition technology is used to extract the contours of adjacent concave and convex sub-regions and input them into a two-dimensional coordinate system to obtain concave and convex sub-contour curves respectively. The peaks and valleys on the convex sub-contour curves and the coordinates of the peaks and valleys on the convex contour curves are obtained respectively, resulting in multiple convex and concave contour curves.

[0014] Input the coordinates of the peaks and valleys on each convex and concave profile peak-valley curve into the slope formula, and then perform mean-averaging calculations to obtain the slope of the concave sub-profile and the slope of the convex sub-profile.

[0015] If the slope of the convex surface profile is greater than the threshold for the slope of the convex surface profile, and the slope of the concave surface profile is greater than the threshold for the slope of the concave surface profile, then the material velocity change type is convex fast and concave slow.

[0016] If the slope of the convex sub-profile is less than or equal to the convex sub-profile slope threshold, and the slope of the concave sub-profile is less than or equal to the concave sub-profile slope threshold, then the material velocity change type is convex slow and concave fast.

[0017] The preferred approach is as follows: The correlation analysis process is as follows:

[0018] Extract the blanking pressure and the corresponding material flow rate within each historical blanking cycle, and construct the blanking pressure set and the material flow rate set according to the time sequence within the historical blanking cycle where the corresponding operation time node is located;

[0019] Based on the same operation time node, adjacent elements are extracted from the edge pressure set and the material flow rate set respectively, and the difference is calculated to obtain the edge pressure difference and the material flow rate difference. The edge pressure difference and the material flow rate difference at the same time dimension are combined to obtain multiple pressure and material flow rate analysis combinations, which are then sorted and integrated to obtain a combined correlation sequence.

[0020] The velocity analysis of adjacent pressure materials is combined and input into the improved Euclidean distance formula to output the velocity difference value of the pressure materials.

[0021] The preferred solution is as follows: the static adjustment process of the blank holder pressure parameter is as follows:

[0022] If the pressure material speed difference value is less than or equal to the pressure material speed difference threshold, it is displayed as a pressure speed tight signal. Then, the ratio of the pressure edge pressure difference and the material flow rate difference in each pressure material flow rate analysis combination is summed and averaged to output the pressure speed tightness coefficient.

[0023] Based on the preset material flow rate and the pressing speed compaction coefficient, a ratio calculation is performed to obtain the static adjustment parameter of the pressing pressure, and the difference between this parameter and the current static adjustment parameter of the pressing pressure is used to obtain the static adjustment amount of the pressing pressure.

[0024] The preferred approach is as follows: After historical static adjustments, when re-pressing the concave-convex transition zone of the circular multi-curved surface, the material flow velocity analysis process is as follows:

[0025] After the historical static adjustment, the adjusted historical period is reset, and the adjusted historical period is divided into several adjusted historical periods. The material flow rate in each adjusted historical period is obtained, and the adjusted material flow rate change curve is constructed with the X-axis as the force and the Y-axis as the material flow rate.

[0026] Input two adjacent coordinate points on the material flow velocity variation curve into the slope calculation formula to get the unit variation value. Input all the unit variation values ​​into the root mean square formula of slope variation to get the root mean square of unit variation.

[0027] The change values ​​of adjacent units are combined to obtain multiple combinations of changes of adjacent units, and then input into the Euclidean distance formula to output the difference value between adjacent units.

[0028] The root mean square of the element change is summed with the difference between adjacent elements to obtain the material velocity change assessment value.

[0029] The preferred approach is to assess whether a sudden change in material velocity will occur, as follows:

[0030] If the material rate change assessment value is greater than the material rate change assessment threshold, it is a material rate change signal.

[0031] If the material rate change assessment value is less than or equal to the material rate change assessment threshold, it is a non-material rate change signal.

[0032] The preferred approach is as follows: the process for determining the range of sudden change and the range of non-sudden change after static adjustment is as follows:

[0033] When the material speed change signal is displayed, the corresponding static adjustment parameter is extracted, marked as a high-risk sudden change adjustment parameter, and the corresponding historical edge pressing cycle is marked as a high-risk historical edge pressing cycle.

[0034] The high-risk sudden change adjustment parameters corresponding to each high-risk historical pressing cycle are compared, and the largest and smallest high-risk sudden change adjustment parameters are selected to form the sudden change range after static adjustment.

[0035] When the material speed does not change abruptly, extract the corresponding static adjustment parameters, mark them as low-risk abrupt change adjustment parameters, and mark the corresponding historical edge pressing cycle as a low-risk historical edge pressing cycle.

[0036] The high-risk sudden change adjustment parameters corresponding to each low-risk historical pressure cycle are compared, and the largest and smallest low-risk sudden change adjustment parameters are selected to form the non-sudden change range after static adjustment.

[0037] A preferred approach is to set the smoothing range for sudden changes:

[0038] If the range of sudden change after static adjustment does not overlap with the range of non-sudden change after static adjustment, a non-overlapping range signal is displayed. If the smallest high-risk sudden change adjustment parameter within the range of sudden change after static adjustment is greater than the largest high-risk sudden change adjustment parameter within the range of non-sudden change after static adjustment, then the sudden change adjustment smoothing range S is... t =[N max N max +K t ×N max ];

[0039] If the highest high-risk sudden change adjustment parameter within the sudden change range after static adjustment is less than the lowest high-risk sudden change adjustment parameter within the non-sudden change range after static adjustment, then the sudden change adjustment smoothing range S t =[N min -K t ×N min N min ];

[0040] Where, N max N represents the maximum high-risk sudden change adjustment parameter within the non-sudden change range after static adjustment. min K represents the minimum high-risk sudden change adjustment parameter within the non-sudden change range after static adjustment. t It is represented as the abrupt change equilibrium coefficient.

[0041] The preferred approach is to obtain the abrupt change equilibrium coefficient as follows:

[0042] The high-risk sudden change adjustment parameters corresponding to each high-risk historical edge pressing cycle and the high-risk sudden change adjustment parameters corresponding to each low-risk historical edge pressing cycle are summed and averaged to obtain the high-risk sudden change adjustment mean and the low-risk sudden change adjustment mean. The difference is calculated and then the ratio is calculated with the low-risk sudden change adjustment mean to output the sudden change balance coefficient.

[0043] Secondly, a multi-curved surface generation system for stamping die blank holders includes the following modules:

[0044] Type identification module: During the historical edge pressing process of the concave-convex transition zone in the circular multi-curved surface, edge pressing analysis is performed on the concave and convex sub-regions divided in the concave-convex transition zone to identify the type of material velocity change of concave and convex surfaces.

[0045] Static adjustment module: If the material flow rate change type is convex slow and concave fast, then extract the pressing pressure and corresponding material flow rate when pressing the concave-convex transition area in the circular multi-curved surface within multiple historical pressing cycles, and perform correlation analysis to complete the static adjustment of the pressing pressure parameters.

[0046] Sudden Change Analysis Module: After performing historical static adjustments, when pressing the edge again in the concave-convex transition zone of the circular multi-curved surface, the material flow velocity is analyzed to assess whether a sudden change in material velocity will occur.

[0047] Smoothing setting module: Extracts the static adjustment parameters for sudden changes in material speed and non-corresponding sudden changes in each pressing cycle, determines the sudden change range and non-sudden change range after static adjustment, and sets the smoothing range for sudden change adjustment.

[0048] The beneficial effects of this invention are as follows:

[0049] 1. In the historical edge pressing process of the concave-convex transition zone within a circular multi-curved surface, this invention performs edge pressing analysis on the concave and convex sub-regions within the transition zone to identify the type of material velocity change. If the material velocity change type is slow on the convex side and fast on the concave side, the edge pressing pressure and corresponding material flow velocity during edge pressing of the concave-convex transition zone within the circular multi-curved surface in multiple historical edge pressing cycles are extracted and correlation analysis is performed to complete the static adjustment of the edge pressing pressure parameters. This not only accurately controls the material flow direction and speed, avoiding excessive or insufficient material flow, but also, by monitoring the material velocity difference value in real time, it can promptly detect and determine that problems in the material flow process are caused by the edge pressing pressure, avoiding batch quality problems and improving the efficiency of batch production.

[0050] 2. After historical static adjustments, this invention re-analyzes the material flow velocity during the pressing of the concave-convex transition zone of the circular multi-curved surface. It assesses whether sudden changes in material velocity will occur, thus helping to predict such changes in advance through the assessment value. Static adjustment parameters are extracted for both sudden and non-sudden changes within each pressing cycle. The range of sudden and non-sudden changes after static adjustment is determined, and a smoothing range for sudden changes is set. This limits the amplitude of material flow velocity variation, making the material flow more stable and uniform during the pressing process. This not only helps reduce stress concentration within the material and avoid defects caused by excessively fast or slow local flow, but also prevents drastic changes in material velocity, reducing the impact and friction forces on the mold, thereby slowing down the mold's wear rate and extending its service life. Attached Figure Description

[0051] The invention will now be further described with reference to the accompanying drawings.

[0052] Figure 1 This is a flowchart of the steps in the method for generating a multi-curved surface of a stamping die blank holder according to the present invention;

[0053] Figure 2 This is a flowchart illustrating the judgment process of a method for generating a multi-curved surface of a stamping die blank holder according to the present invention.

[0054] Figure 3 This is a schematic diagram of a multi-curved surface generation system for stamping die blank holders according to the present invention. Detailed Implementation

[0055] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0056] Example 1

[0057] Please see Figure 1 As shown in the embodiment of the present invention, a method for generating a multi-curved surface of a stamping die blank holder includes the following steps:

[0058] Step 1: During the historical edge pressing process of the concave-convex transition zone in the circular multi-curved surface, edge pressing analysis is performed on the concave and convex sub-regions divided within the concave-convex transition zone to identify the type of material velocity change between the concave and convex surfaces.

[0059] Among them, the types of changes in the material speed of concave and convex materials include slow convex and fast concave or fast convex and slow concave.

[0060] In a preferred embodiment, the concave-convex transition region is divided into multiple concave sub-regions and convex sub-regions according to a mesh pattern.

[0061] Visual recognition technology is used to extract the contours of adjacent concave and convex sub-regions, and both are input into a two-dimensional coordinate system to obtain concave and convex sub-contour curves respectively.

[0062] For example, take the convex surface profile curve as an example;

[0063] By taking the local contour curve between adjacent peaks and valleys on the convex surface sub-contour curve as a convex surface contour peak-valley curve, multiple convex surface contour peak-valley curves are obtained.

[0064] Extract the coordinates of the peak and trough points on the peak and trough curve of the convex profile, input them into the slope formula, and output the convex peak and trough slope. Then, sum and average the convex peak and trough slopes corresponding to each convex profile peak and trough curve to output the convex sub-profile slope.

[0065] Similarly, take the concave surface contour curve as an example;

[0066] By taking the local contour curve between adjacent peaks and valleys on the concave surface contour curve as a concave surface contour peak-valley curve, multiple concave surface contour peak-valley curves can be obtained.

[0067] Extract the coordinates of the peaks and valleys on the concave profile peak-valley curves and input them into the slope formula. Output the concave profile peak-valley slope. Then, sum and average the concave profile peak-valley slopes corresponding to each concave profile peak-valley curve to output the concave sub-profile slope.

[0068] If the slope of the convex surface profile is greater than the threshold of the convex surface profile slope, and the slope of the concave surface profile is greater than the threshold of the concave surface profile slope, it indicates that the convex surface area is more convex and the concave surface area is more concave, resulting in a lower fit with the stamping die edge. In this case, the material speed change type is convex fast and concave slow.

[0069] If the slope of the convex surface profile is less than or equal to the threshold of the convex surface profile, and the slope of the concave surface profile is less than or equal to the threshold of the concave surface profile, it indicates that the convex surface area has a smaller degree of protrusion and the concave surface area has a smaller degree of concavity, and the fit with the pressing edge of the stamping mold is higher. In this case, the material speed change type is convex slow and concave fast.

[0070] It should be noted that the slope thresholds for both convex and concave sub-contours are set by those skilled in the art.

[0071] Specifically, for convex sub-regions where the slope of the convex sub-profile is less than or equal to the threshold of the convex sub-profile slope, and for concave sub-regions where the slope of the concave sub-profile is less than or equal to the threshold of the concave sub-profile slope, the contact area between the pressure ring and the sheet metal is larger and the contact pressure is more concentrated, resulting in greater friction and resistance during material flow. Consequently, the flow velocity in the convex sub-region tends to be slower, hence the term "convex fast, concave slow".

[0072] For convex regions where the slope of the convex sub-profile is greater than the threshold of the convex sub-profile slope, and for concave regions where the slope of the concave sub-profile is greater than the threshold of the concave sub-profile slope, since the contact area between the pressure ring and the sheet is small and the contact pressure is more dispersed, the friction and resistance during material flow are smaller → the flow velocity in the concave sub-region tends to be faster, which is called convex slow and concave fast.

[0073] Step 2: If the material flow rate change type is slow on the convex side and fast on the concave side, extract the pressing pressure and corresponding material flow rate when pressing the concave-convex transition zone in the circular multi-curved surface within multiple historical pressing cycles, and perform correlation analysis to complete the static adjustment of the pressing pressure parameters.

[0074] It should be noted that there is only one operation to press the ring-shaped multi-curved surface with a stamping die within each historical pressing cycle. Therefore, the time of each pressing operation of the stamping die on the ring-shaped multi-curved surface corresponds to one historical pressing cycle.

[0075] In a preferred embodiment, the edge pressing pressure and the corresponding material flow rate are extracted in each historical edge pressing cycle, and the edge pressing pressure set and the material flow rate set are constructed according to the time sequence in the historical edge pressing cycle where the corresponding operation time node is located.

[0076] It should be noted that the operation time node corresponding to each element at each sorting position within the edge pressure set and the material flow velocity set is the same operation time node.

[0077] For example, the elements in the set of edge pressure are F1, F2, F3 and F4, and the elements in the set of material flow rate are V1, V2, v3 and V4.

[0078] The corresponding operation time node for F1 is T1, the corresponding operation time node for F2 is T2, the corresponding operation time node for F3 is T3, and the corresponding operation time node for F4 is T4;

[0079] The corresponding operation time node for V1 is T1, the corresponding operation time node for V2 is T2, the corresponding operation time node for V3 is T3, and the corresponding operation time node for V4 is T4;

[0080] Based on the same operation time point, adjacent elements are extracted from the edge pressure set and the material flow rate set respectively, and the difference is calculated to obtain the edge pressure difference and the material flow rate difference.

[0081] For example, extract adjacent elements F1 and F2 from the set of edge pressure, and calculate their difference to obtain the edge pressure difference;

[0082] Extract adjacent elements V1 and V2 from the material flow velocity set, and calculate their difference to obtain the material flow velocity difference;

[0083] It should be noted that since adjacent elements are extracted from the set of edge pressure and the set of material flow rate respectively, they correspond one-to-one in the time dimension. Therefore, the edge pressure difference and the material flow rate difference also correspond in the time dimension.

[0084] By combining the edge pressure difference and material flow rate difference at the same time dimension, multiple pressure material flow rate analysis combinations are obtained;

[0085] Multiple pressure material flow velocity analysis combinations are sorted and integrated according to the time sequence corresponding to the pressure difference of the inner pressure edge and the flow velocity difference of the material to obtain a combined correlation sequence;

[0086] The velocity analysis of adjacent pressure materials is combined and input into the improved Euclidean distance formula, and the velocity difference value C of the pressure materials is output. fv ;

[0087] Specifically: in, This represents the ratio of the pressure difference at the pressure edge to the velocity difference at the material flow rate within the (i-1)th pressure material flow rate analysis combination in the combined correlation sequence. It represents the ratio of the pressure difference at the pressure edge to the velocity difference within the i-th pressure material velocity analysis combination in the combined correlation sequence;

[0088] It is understandable that the difference in pressing speed represents the changes in pressing pressure and material flow velocity at adjacent moments within different historical pressing cycles. Specifically, its main purpose is:

[0089] Objective 1: Since the material flow directly affects the shape and quality of the final product during the generation of the multi-curved surface of the blank holder ring, mapping the dynamic relationship between the change of blank holder pressure and the change of material flow velocity based on the difference in blank holder speed allows for the indirect control of material flow velocity by adjusting the blank holder pressure parameters. This enables precise control of the material flow direction and speed, avoiding excessive or insufficient material flow, and improving the dimensional and shape accuracy of the product.

[0090] Objective 2: When the difference in pressing speed changes abnormally, it may indicate a problem in the material flow process, such as mold wear or changes in material properties. By monitoring the difference in pressing speed in real time, these potential problems can be detected in time, and corresponding measures can be taken to prevent and solve them, avoiding batch quality problems, reducing production costs, and ensuring that the difference in pressing speed is within a reasonable range in different production batches. This will ensure that the relationship between the pressing pressure and the material flow rate is basically consistent, thereby producing products with stable quality.

[0091] The process of comparing the difference in pressing speed with the threshold for difference in pressing speed is as follows:

[0092] If the difference in pressing speed is greater than the threshold value, it indicates that the correlation between the pressing pressure and the change in material flow rate at adjacent moments is low, which is a signal of non-close pressing speed.

[0093] If the difference in pressing speed is less than or equal to the threshold of pressing speed, it indicates that the change in pressing pressure and material flow velocity at adjacent moments is highly correlated, which is displayed as a pressing speed tight signal. Then, the ratio of pressing pressure difference to material flow velocity difference in each pressure material flow velocity analysis combination is summed and averaged to calculate the pressing speed tight coefficient.

[0094] Based on the preset material flow rate and the pressure density coefficient, the ratio is calculated to obtain the static adjustment parameters of the edge pressure;

[0095] The static adjustment amount of the blank holder pressure is obtained by subtracting the static adjustment parameter of the blank holder pressure from the current static adjustment parameter of the blank holder pressure.

[0096] The specific solution in this embodiment is as follows: During the historical edge pressing process of the concave-convex transition zone within the circular multi-curved surface, edge pressing analysis is performed on the concave and convex sub-regions within the transition zone to identify the type of material velocity change. If the material velocity change type is slow on the convex side and fast on the concave side, the edge pressing pressure and corresponding material flow velocity during edge pressing of the concave-convex transition zone within the circular multi-curved surface in multiple historical edge pressing cycles are extracted, and correlation analysis is performed to complete the static adjustment of the edge pressing pressure parameters. This not only accurately controls the material flow direction and speed, avoiding excessive or insufficient material flow, but also, by monitoring the material velocity difference value in real time, it can promptly detect and determine that problems in the material flow process are caused by the edge pressing pressure, avoiding batch quality problems and improving the efficiency of batch production.

[0097] Example 2

[0098] Please see Figure 1 - Figure 2 As shown in the embodiment of the present invention, a method for generating multiple curves of a stamping die blank holder ring further includes the following steps:

[0099] Step 3: After performing historical static adjustments, when pressing the edge of the concave-convex transition zone of the circular multi-curved surface again, analyze the material flow velocity and assess whether a sudden change in material velocity will occur.

[0100] In a preferred embodiment, after the historical static adjustment, the adjusted historical period is reset, and the adjusted historical period is equally divided into several adjusted historical time periods, wherein the duration of each adjusted historical time period is equal.

[0101] Obtain the material flow rate for each adjusted historical period, and construct a material flow rate change curve with the X-axis as the force and the Y-axis as the material flow rate;

[0102] Input the coordinates of two adjacent points on the material flow velocity variation curve into the slope calculation formula, and the output will be the unit variation value.

[0103] Input all the unit change values ​​into the root mean square formula for slope change, and output the root mean square (RMS) of unit change.

[0104] Specifically, in, It is represented by the square of the change value of the j-th unit, and n represents the total number of unit changes;

[0105] The variation values ​​of adjacent cells are combined to obtain multiple combinations of adjacent cell variations. These combinations are then input into the Euclidean distance formula to output the adjacent cell difference value C. db ;

[0106] Specifically, Among them, K e-1 Represented as the change value of the (e-1)th unit, K e Let represent the change value of the e-th unit, and r represent the total number of combinations of changes between adjacent units;

[0107] The root mean square (RMS) of the cell variation is compared with the difference between adjacent cells, C. db Perform a summation calculation and output the material velocity change assessment value;

[0108] It is understandable that the material velocity change assessment value represents a comprehensive index calculated by combining the root mean square of unit changes and the difference between adjacent units. Specifically, the root mean square of unit changes reflects the overall fluctuation of material flow velocity changes over the entire adjusted historical period. On the other hand, the difference between adjacent units reflects the degree of difference in the rate of change of material flow velocity between adjacent time periods, thereby identifying the changes in material flow velocity after historical static adjustments. Its purpose is to:

[0109] Objective 1: When the stamping die is used to press the edge of the circular multi-curved surface, the sudden change in material flow rate can lead to uneven material flow, which in turn affects the shape accuracy and surface quality of the product. Therefore, the material flow rate change assessment value can be used to predict in advance whether a sudden change in material flow rate will occur.

[0110] Objective 2: By analyzing the evaluation values ​​of sudden changes in material flow rate under different combinations of process parameters, we can find the process parameter combination that minimizes the evaluation value, i.e., the parameter settings that are most conducive to maintaining a stable material flow rate. Based on this, we can further fine-tune the parameters, such as the magnitude and distribution of blank holder force and the speed of stamping, to achieve the best blank holder effect and improve production efficiency and product quality.

[0111] The material rate change assessment value is compared with the material rate change assessment threshold, as follows:

[0112] If the material velocity change assessment value is greater than the material velocity change assessment threshold, it indicates that the probability of a sudden change in material flow velocity is high, and it is displayed as a material velocity change signal.

[0113] If the material velocity change assessment value is less than or equal to the material velocity change assessment threshold, it indicates that the probability of a sudden change in material flow velocity is low, and it is displayed as a non-material velocity change signal.

[0114] Step 4: Extract the static adjustment parameters for sudden changes in material speed and non-corresponding sudden changes in each pressing cycle, determine the sudden change range and non-sudden change range after static adjustment, and set the sudden change adjustment smoothing range.

[0115] In a preferred embodiment, when the material speed change signal is displayed, the corresponding static adjustment parameter is extracted, marked as a high-risk sudden change adjustment parameter, and the corresponding historical edge pressing cycle is marked as a high-risk historical edge pressing cycle.

[0116] The high-risk sudden change adjustment parameters corresponding to each high-risk historical pressing cycle are compared, and the largest and smallest high-risk sudden change adjustment parameters are selected to form the sudden change range after static adjustment.

[0117] When the material speed does not change abruptly, extract the corresponding static adjustment parameters, mark them as low-risk abrupt change adjustment parameters, and mark the corresponding historical edge pressing cycle as a low-risk historical edge pressing cycle.

[0118] The high-risk sudden change adjustment parameters corresponding to each low-risk historical pressure cycle are compared, and the largest and smallest low-risk sudden change adjustment parameters are selected to form the non-sudden change range after static adjustment.

[0119] The process of comparing the range of sudden change after static adjustment with the range of non-sudden change after static adjustment is as follows:

[0120] If the range of sudden change after static adjustment and the range of non-sudden change after static adjustment do not overlap, then a range non-overlap signal will be displayed.

[0121] If the range of sudden change after static adjustment overlaps with the range of non-sudden change after static adjustment, it will be displayed as a range overlap signal.

[0122] Based on non-overlapping range signals, if the minimum high-risk sudden change adjustment parameter within the sudden change range after static adjustment is greater than the maximum high-risk sudden change adjustment parameter within the non-sudden change range after static adjustment, then the sudden change adjustment smoothing range S... t =[N max N max +K t ×N max ];

[0123] If the highest high-risk sudden change adjustment parameter within the sudden change range after static adjustment is less than the lowest high-risk sudden change adjustment parameter within the non-sudden change range after static adjustment, then the sudden change adjustment smoothing range S t =[N min -K t ×N min N min ];

[0124] Where, N max N represents the maximum high-risk sudden change adjustment parameter within the non-sudden change range after static adjustment. min K represents the minimum high-risk sudden change adjustment parameter within the non-sudden change range after static adjustment. t Represented as the abrupt change equilibrium coefficient;

[0125] The method for obtaining the abrupt change equilibrium coefficient is as follows:

[0126] For example, the high-risk sudden change adjustment parameters corresponding to each high-risk historical edge pressing cycle are summed and averaged to output the high-risk sudden change adjustment mean.

[0127] The high-risk sudden change adjustment parameters corresponding to each low-risk historical edge pressing cycle are summed and averaged to output the low-risk sudden change adjustment mean.

[0128] The difference between the high-risk sudden change adjusted mean and the low-risk sudden change adjusted mean is calculated, and the ratio of the difference to the low-risk sudden change adjusted mean is calculated to output the sudden change balance coefficient.

[0129] It should be noted that the purpose of setting the smoothing range for sudden changes is:

[0130] Objective 1: The smoothing range of sudden changes limits the variation in material flow velocity, making the material flow more stable and uniform during the edge pressing process. This not only helps to reduce stress concentration inside the material and avoid defects caused by excessively fast or slow local flow, but also ensures that the material flows in the predetermined direction and reduces deviation in the flow direction.

[0131] Objective 2: Since sudden changes in material velocity can generate significant impact and friction on the mold surface, accelerating mold wear, setting a smooth adjustment range for sudden changes can avoid drastic changes in material velocity, reduce the impact and friction on the mold, thereby slowing down the mold wear rate and extending the mold's service life.

[0132] The specific solution in this embodiment is as follows: After historical static adjustment, when pressing the concave-convex transition area of ​​the circular multi-curved surface again, the material flow velocity is analyzed to assess whether a sudden change in material velocity will occur. This helps to predict in advance whether a sudden change in material velocity will occur through the material velocity change assessment value. Static adjustment parameters are extracted for sudden changes in material velocity and non-corresponding sudden changes in each pressing cycle. The range of sudden changes and the range of non-sudden changes after static adjustment are determined. A smoothing range for sudden change adjustment is set to limit the variation of material flow velocity, making the material flow more stable and uniform during the pressing process. This not only helps to reduce stress concentration inside the material and avoid defects caused by excessively fast or slow local flow, but also avoids drastic changes in material velocity, reduces the impact and friction forces on the mold, thereby slowing down the wear rate of the mold and extending its service life.

[0133] Example 3

[0134] Please see Figure 3 As shown in the embodiment of the present invention, a multi-curve generation system for stamping die blank holders further includes the following modules:

[0135] Type identification module: During the historical edge pressing process of the concave-convex transition zone in the circular multi-curved surface, edge pressing analysis is performed on the concave and convex sub-regions divided in the concave-convex transition zone to identify the type of material velocity change of concave and convex surfaces.

[0136] Static adjustment module: If the material flow rate change type is convex slow and concave fast, then extract the pressing pressure and corresponding material flow rate when pressing the concave-convex transition area in the circular multi-curved surface within multiple historical pressing cycles, and perform correlation analysis to complete the static adjustment of the pressing pressure parameters.

[0137] Sudden Change Analysis Module: After performing historical static adjustments, when pressing the edge again in the concave-convex transition zone of the circular multi-curved surface, the material flow velocity is analyzed to assess whether a sudden change in material velocity will occur.

[0138] Smoothing setting module: Extracts the static adjustment parameters for sudden changes in material speed and non-corresponding sudden changes in each pressing cycle, determines the sudden change range and non-sudden change range after static adjustment, and sets the smoothing range for sudden change adjustment.

[0139] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for generating a multi-curved surface of a stamping die blank holder, characterized in that: include: During the historical edge pressing process of the concave-convex transition zone in the circular multi-curved surface, edge pressing analysis was performed on the concave and convex sub-regions within the concave-convex transition zone to identify the types of material velocity changes. If the material flow rate change type is convex slow and concave fast, then extract the edge pressing pressure and the corresponding material flow rate when pressing the concave-convex transition zone in the circular multi-curved surface within multiple historical edge pressing cycles, and perform correlation analysis to complete the static adjustment of the edge pressing pressure parameters. After making historical static adjustments, when pressing the edge again in the concave-convex transition area of ​​the circular multi-curved surface, the material flow velocity is analyzed to assess whether a sudden change in material velocity will occur. Extract the static adjustment parameters for sudden changes in material speed during each pressing cycle, as well as for non-corresponding sudden changes, to determine the range of sudden changes and the range of non-sudden changes after static adjustment, and set the smoothing range for sudden change adjustment.

2. The method for generating a multi-curved surface of a stamping die blank holder according to claim 1, characterized in that: The process for identifying the velocity change type of uneven materials is as follows: The concave-convex transition area is divided into multiple concave and convex sub-regions according to the grid. Visual recognition technology is used to extract the contours of adjacent concave and convex sub-regions and input them into a two-dimensional coordinate system to obtain concave and convex sub-contour curves respectively. The peaks and valleys on the convex sub-contour curves and the coordinates of the peaks and valleys on the convex contour curves are obtained respectively, resulting in multiple convex and concave contour curves. Input the coordinates of the peaks and valleys on each convex and concave profile peak-valley curve into the slope formula, and then perform mean-averaging calculations to obtain the slope of the concave sub-profile and the slope of the convex sub-profile. If the slope of the convex surface profile is greater than the threshold for the slope of the convex surface profile, and the slope of the concave surface profile is greater than the threshold for the slope of the concave surface profile, then the material velocity change type is convex fast and concave slow. If the slope of the convex sub-profile is less than or equal to the convex sub-profile slope threshold, and the slope of the concave sub-profile is less than or equal to the concave sub-profile slope threshold, then the material velocity change type is convex slow and concave fast.

3. The method for generating a multi-curved surface of a stamping die blank holder according to claim 1, characterized in that: The process of correlation analysis is as follows: Extract the blanking pressure and the corresponding material flow rate within each historical blanking cycle, and construct the blanking pressure set and the material flow rate set according to the time sequence within the historical blanking cycle where the corresponding operation time node is located; Based on the same operation time node, adjacent elements are extracted from the edge pressure set and the material flow rate set respectively, and the difference is calculated to obtain the edge pressure difference and the material flow rate difference. The edge pressure difference and the material flow rate difference at the same time dimension are combined to obtain multiple pressure and material flow rate analysis combinations, which are then sorted and integrated to obtain a combined correlation sequence. The velocity analysis of adjacent pressure materials is combined and input into the improved Euclidean distance formula to output the velocity difference value of the pressure materials.

4. The method for generating a multi-curved surface of a stamping die blank holder according to claim 3, characterized in that: The process of statically adjusting the blank holder pressure parameters is as follows: If the pressure material speed difference value is less than or equal to the pressure material speed difference threshold, it is displayed as a pressure speed tight signal. Then, the ratio of the pressure edge pressure difference and the material flow rate difference in each pressure material flow rate analysis combination is summed and averaged to output the pressure speed tightness coefficient. Based on the preset material flow rate and the pressing speed compaction coefficient, a ratio calculation is performed to obtain the static adjustment parameter of the pressing pressure, and the difference between this parameter and the current static adjustment parameter of the pressing pressure is used to obtain the static adjustment amount of the pressing pressure.

5. The method for generating a multi-curved surface of a stamping die blank holder according to claim 1, characterized in that: After performing historical static adjustments, the material flow velocity was analyzed when re-pressing the concave-convex transition zone of the circular multi-curved surface. The process is as follows: After the historical static adjustment, the adjusted historical period is reset, and the adjusted historical period is divided into several adjusted historical periods. The material flow rate in each adjusted historical period is obtained, and the adjusted material flow rate change curve is constructed with the X-axis as the force and the Y-axis as the material flow rate. Input two adjacent coordinate points on the material flow velocity variation curve into the slope calculation formula to get the unit variation value. Input all the unit variation values ​​into the root mean square formula of slope variation to get the root mean square of unit variation. The change values ​​of adjacent units are combined to obtain multiple combinations of changes of adjacent units, and then input into the Euclidean distance formula to output the difference value between adjacent units. The root mean square of the element change is summed with the difference between adjacent elements to obtain the material velocity change assessment value.

6. The method for generating a multi-curved surface of a stamping die blank holder according to claim 1, characterized in that: The process for assessing whether a sudden change in material velocity will occur is as follows: If the material rate change assessment value is greater than the material rate change assessment threshold, it is a material rate change signal. If the material rate change assessment value is less than or equal to the material rate change assessment threshold, it is a non-material rate change signal.

7. The method for generating a multi-curved surface of a stamping die blank holder according to claim 1, characterized in that: The process for determining the range of sudden change and the range of non-sudden change after static adjustment is as follows: When the material speed change signal is displayed, the corresponding static adjustment parameter is extracted, marked as a high-risk sudden change adjustment parameter, and the corresponding historical edge pressing cycle is marked as a high-risk historical edge pressing cycle. The high-risk sudden change adjustment parameters corresponding to each high-risk historical pressing cycle are compared, and the largest and smallest high-risk sudden change adjustment parameters are selected to form the sudden change range after static adjustment. When the material speed does not change abruptly, extract the corresponding static adjustment parameters, mark them as low-risk abrupt change adjustment parameters, and mark the corresponding historical edge pressing cycle as a low-risk historical edge pressing cycle. The high-risk sudden change adjustment parameters corresponding to each low-risk historical pressure cycle are compared, and the largest and smallest low-risk sudden change adjustment parameters are selected to form the non-sudden change range after static adjustment.

8. The method for generating a multi-curved surface of a stamping die blank holder according to claim 7, characterized in that: Setting the smoothing range for sudden changes: If the sudden change range after static adjustment does not overlap with the non-sudden change range after static adjustment, a non-overlapping range signal is displayed. If the smallest high-risk sudden change adjustment parameter within the sudden change range after static adjustment is greater than the largest high-risk sudden change adjustment parameter within the non-sudden change range after static adjustment, then the sudden change adjustment smoothing range S is... t =[N max N max +K t ×N max ]; If the highest high-risk sudden change adjustment parameter within the sudden change range after static adjustment is less than the lowest high-risk sudden change adjustment parameter within the non-sudden change range after static adjustment, then the sudden change adjustment smoothing range S t =[N min -K t ×N min N min ]; Where, N max N represents the maximum high-risk sudden change adjustment parameter within the non-sudden change range after static adjustment. min K represents the minimum high-risk sudden change adjustment parameter within the non-sudden change range after static adjustment. t It is represented as the abrupt change equilibrium coefficient.

9. The method for generating a multi-curved surface of a stamping die blank holder according to claim 8, characterized in that: The method for obtaining the abrupt change equilibrium coefficient is as follows: The high-risk sudden change adjustment parameters corresponding to each high-risk historical edge pressing cycle and the high-risk sudden change adjustment parameters corresponding to each low-risk historical edge pressing cycle are summed and averaged to obtain the high-risk sudden change adjustment mean and the low-risk sudden change adjustment mean. The difference is calculated and then the ratio is calculated with the low-risk sudden change adjustment mean to output the sudden change balance coefficient.

10. A multi-curved surface generation system for stamping die blank holders, characterized in that: Includes the following modules: Type identification module: During the historical edge pressing process of the concave-convex transition zone in the circular multi-curved surface, edge pressing analysis is performed on the concave and convex sub-regions divided in the concave-convex transition zone to identify the type of material velocity change of concave and convex surfaces. Static adjustment module: If the material flow rate change type is convex slow and concave fast, then extract the pressing pressure and corresponding material flow rate when pressing the concave-convex transition area in the circular multi-curved surface within multiple historical pressing cycles, and perform correlation analysis to complete the static adjustment of the pressing pressure parameters. Sudden Change Analysis Module: After performing historical static adjustments, when pressing the edge again in the concave-convex transition zone of the circular multi-curved surface, the material flow velocity is analyzed to assess whether a sudden change in material velocity will occur. Smoothing setting module: Extracts the static adjustment parameters for sudden changes in material speed and non-corresponding sudden changes in each pressing cycle, determines the sudden change range and non-sudden change range after static adjustment, and sets the smoothing range for sudden change adjustment.

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