Flow channel overturning design method and device, electronic equipment and storage medium

Abstract

The application belongs to the technical field of runner design methods, and provides a runner flip design method and device, an electronic device and a storage medium, which comprise the following steps: performing mold flow analysis on an initial runner without a flip to obtain melt temperature distribution data and shear rate history data of a runner cross section upstream of each flow splitting node; calculating a thermal asymmetry index of each flow splitting node based on the melt temperature distribution data and the shear rate history data; determining whether the flow splitting node needs a runner flip based on the thermal asymmetry index; for the flow splitting node that needs the runner flip, taking the minimum melt temperature difference between the inside cavity and the outside cavity after the flip as the target, calculating an optimal flip angle of the flow splitting node; and setting a runner flip structure at the corresponding flow splitting node according to the optimal flip angle. The application provides quantifiable numerical indicators, is reproducible, matches the actual temperature profile of the upstream of the flow splitting node, realizes flow balance, is not limited by the number of cavities and the layout of the runner, and has high universality.

Description

Technical Field

[0001] This application belongs to the technical field of flow channel design methods, and more specifically, relates to a flow channel flipping design method, apparatus, electronic device and storage medium. Background Technology

[0002] In the field of injection molding, flow balance in multi-cavity molds is crucial for ensuring consistent product quality across all cavities. Traditionally, designers have primarily employed geometrically balanced runners, aiming to simultaneously fill each cavity by ensuring that the melt flows from the main runner to the gates of each cavity with equal path lengths. However, in actual production, it has been found that even with perfectly symmetrical runner geometry, asynchronous filling of each cavity can still occur, leading to defects such as dimensional discrepancies and warping in the finished product.

[0003] To alleviate this problem, existing technologies have developed channel flipping techniques. Before or after the branching node, the channel is rotated around its axis by a certain angle, thereby changing the orientation of the melt temperature in the cross-sectional space. This redistributes the high-temperature or low-temperature regions that originally flowed into the inner side of the branch channel to the outer side, aiming to achieve heat rebalancing in subsequent branching. This method improves, to some extent, the filling imbalance caused by uneven shear heat distribution.

[0004] However, existing flow channel flipping techniques have rigid flipping strategies that rely heavily on experience or fixed rules, resulting in limited balancing effects and low design efficiency. Moreover, this method mainly focuses on post-hoc corrections for temperature asymmetry, failing to consider the pressure distribution throughout the flow channel and the synchronicity of the flow front. Summary of the Invention

[0005] The purpose of this application is to provide a flow channel reversal design method, apparatus, electronic device and storage medium to solve the technical problems in the prior art that the reversal strategy is rigid, relies on experience and does not consider the flow channel pressure distribution and the synchronization of the flow front.

[0006] To achieve the above objectives, firstly, the technical solution adopted in this application is: to provide a flow channel flipping design method, comprising: Mold flow analysis was performed on the initial flow channel without inversion to obtain melt temperature distribution data and historical shear rate data of the upstream flow channel cross section of each flow split node; Based on the melt temperature distribution data and the shear rate history data, the thermal asymmetry index of each of the flow splitting nodes is calculated. Based on the thermal asymmetry index, determine whether the flow channel of the flow splitter node needs to be flipped; For the flow divider node that needs to be flipped, the optimal flipping angle of the flow divider node is calculated with the goal of minimizing the melt temperature difference between the inner cavity and the outer cavity after flipping. At the corresponding flow branching node, a flow channel flipping structure is set according to the optimal flipping angle.

[0007] Optionally, calculating the thermal asymmetry index of each of the flow splitters based on the melt temperature distribution data and the historical shear rate data includes: The degree of asymmetry in the temperature distribution of the splitting node is determined based on the melt temperature distribution data at the cross-section of the upstream flow channel of the splitting node. The thermal asymmetry index of the shunt node is determined based on the degree of asymmetry and the historical shear rate data.

[0008] Optionally, the thermal asymmetry index is calculated according to the following formula:

[0009] in, The thermal asymmetry index, The weighted average temperature of the melt flowing into the inner cavity on the upstream flow channel cross-section of the diversion node. The weighted average temperature of the melt flowing towards the outer cavity on the upstream flow channel cross-section of the diversion node; Used to quantify the degree of asymmetry in the temperature distribution of the shunt nodes; This represents the maximum temperature difference across the cross section. The volume-average shear rate before the flow passes through this branching node; This is the reference shear rate.

[0010] Optionally, determining whether the flow channel of the splitter node needs to be flipped based on the thermal asymmetry index includes: The thermal asymmetry index is compared with a preset threshold. If the thermal asymmetry index is less than a preset threshold, then the shunt node is determined not to need to be flipped. If the thermal asymmetry index is greater than or equal to a preset threshold, then the shunt node needs to be flipped.

[0011] Optionally, for the flow divider node that needs to be flipped, the calculation of the optimal flipping angle of the flow divider node, with the goal of minimizing the melt temperature difference between the inner and outer cavities after flipping, includes: The candidate angle for the flow diversion node to flip around the channel axis Based on the melt temperature distribution data of the upstream flow channel cross-section of the diversion node Candidate angles are determined through spatial coordinate transformation. New melt temperature distribution data ; Based on new melt temperature distribution data Based on the flow channel topology downstream of the diversion node, the weighted average temperature of the melt expected to flow towards the outer cavity on the flow channel cross-section upstream of the diversion node is obtained. and the weighted average temperature of the melt expected to flow into the inner cavity ; Set multiple different candidate angles Select to make and Candidate angle with the smallest absolute value of the difference As the optimal flip angle.

[0012] Optionally, the setting of multiple different candidate angles This includes setting the candidate angle within a preset step size interval in the range of 0° to 180°. .

[0013] Optionally, if multiple consecutive candidate angles All make and When the absolute value of the difference is less than the preset value, the candidate angle with the smallest angle is selected as the optimal flip angle.

[0014] Secondly, embodiments of this application provide a flow channel flipping design apparatus, which includes: The simulation module is used to perform mold flow analysis on the initial flow channel without inversion settings, and to obtain melt temperature distribution data of the upstream flow channel cross-section at each flow split node. and historical shear rate data; The calculation module is used to calculate the thermal asymmetry index of each of the flow splitting nodes based on the melt temperature distribution data and the shear rate history data. The flip decision module is used to determine whether the flow channel of the diversion node needs to be flipped based on the thermal asymmetry index. An angle optimization module is used to calculate the optimal flip angle of the flow branch node for the flow channel that needs to be flipped, with the goal of minimizing the melt temperature difference between the inner cavity and the outer cavity after flipping. The output module is used to set the flow channel flipping structure at the corresponding flow branching node according to the optimal flipping angle.

[0015] Thirdly, embodiments of this application also provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the steps of the flow channel flip design method as described in the first aspect.

[0016] Fourthly, embodiments of this application also provide a computer-readable storage medium having a computer program stored thereon, characterized in that the computer program, when executed by a processor, implements the flow channel flipping design method as described in the first aspect.

[0017] The beneficial effects of the flow channel reversal design method, apparatus, electronic device, and storage medium provided in this application are as follows: Compared with the prior art, this application transforms the problem of uneven temperature distribution, which originally relied on empirical judgment, into a quantifiable numerical index by calculating the thermal asymmetry index. This avoids the arbitrariness of subjective judgment and provides an objective and reproducible decision-making basis for whether to implement reversal. Furthermore, with the goal of minimizing the temperature difference between the inner and outer melts after reversal, the optimal reversal angle is calculated independently for each branch node, rather than applying a fixed angle to all branch nodes. This allows the reversal strategy to accurately match the actual temperature profile upstream of the branch node, thereby reducing the temperature difference between the inner and outer sides after reversal to the theoretical minimum. Since each branch node is calculated independently, it is not limited by the number of cavities or the flow channel layout. Therefore, the same framework can be adapted to various complex flow channel networks without modification, exhibiting high versatility. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A comparison of the filling-flow front temperature color scale diagrams of the elongated flow channels before and after flipping.

[0020] Figure 2 A comparison of the filling-flow front temperature color scale diagrams of the I-shaped flow channels before and after flipping.

[0021] Figure 3 The image shows a comparison of the filling-flow front temperature color scale diagrams for a circular flow channel under the following conditions: no flipping, one downward flipping, one upward flipping, and half-flipping.

[0022] Figure 4 The image shows a comparison of the filling-flow wavefront temperature color scale diagrams for a U-shaped flow channel under the following conditions: no flipping, simple flipping, flipping down twice, and flipping down twice with a disk.

[0023] Figure 5 A comparison of the filling-flow front time-color scale diagrams of the elongated flow channels before and after flipping.

[0024] Figure 6A comparison of the filling-flow front time-scale diagrams of the I-shaped flow channels before and after flipping.

[0025] Figure 7 The images show a comparison of the filling-flow wavefront time-color scale diagrams of a circular flow channel under the following conditions: no flipping, one downward flipping, one upward flipping, and the upper half flipping.

[0026] Figure 8 Comparison of filling-flow wavefront time-color scale diagrams for U-shaped flow channels under the following conditions: no flipping, simple flipping, flipping down twice, and flipping down twice with a disk.

[0027] Figure 9 A flowchart illustrating the flow channel inversion design method provided in this application embodiment. Figure 1 .

[0028] Figure 10 This is a graph showing the temperature change when heat is diverted in the flow channel.

[0029] Figure 11 A flowchart illustrating the flow channel inversion design method provided in this application embodiment. Figure 2 .

[0030] Figure 12 A flowchart illustrating the flow channel inversion design method provided in this application embodiment. Figure 3 .

[0031] Figure 13 This is a schematic diagram of the flow channel flipping design device provided in the embodiments of this application.

[0032] Figure 14 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0033] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0034] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0035] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0037] Different flow channel layouts include H-type and radial layouts. The H-type layout features a multi-stage flow branching structure, with primary branching from the main flow channel to both sides, followed by secondary branching on each side, each branching extending outwards in an H-shape. In the radial layout, the main flow channel is located in the center, and each stage of the flow channel radiates outwards like wheel spokes. The H-type layout includes multi-cavity flow channel structures arranged in long strips or I-shapes. Figure 1 A comparison of the filling-flow wavefront temperature color scale diagrams of the elongated flow channels before and after flipping. Figure 1 (a) is a color scale diagram of the filling-flow front temperature of the elongated flow channels before overturning. Figure 1 (b) A colorimetric diagram of the filling-flow front temperature after the U-shaped flow channels arranged in a long strip are flipped. (Comparison) Figure 1 (a) and Figure 1 (b) It can be seen that the melt temperature of the elongated channel is 315.04℃~323.47℃, with a melt temperature deviation of 8.43℃; after inversion, the melt temperature is 318.11℃~320.75℃, with a melt temperature deviation of 2.64℃, which is close to equilibrium. Figure 2 A comparison of the filling-flow front temperature color scale diagrams of the I-shaped flow channels before and after flipping. Figure 2 (a) is a color scale diagram of the filling-flow front temperature of the U-shaped flow channel arranged in an I-shape before it flips. Figure 2 (b) is the color scale diagram of the filling-flow front temperature of the I-shaped flow channel after inversion. (Comparison) Figure 2 (a) and Figure 2(b) It can be seen that the melt temperature of the I-shaped flow channel is 315.91℃~322.13℃ before inversion, with a melt temperature deviation of 6.22℃; after inversion, the melt temperature is 316.36℃~321.38℃, with a melt temperature deviation of 5.02℃. This shows that the inverted flow channel can achieve heat rebalancing in subsequent flow splitting.

[0038] Figure 3 The image shows a comparison of the filling-flow front temperature color scale diagrams for a circular flow channel with the same layout, under the following conditions: no flipping, one downward flip (90° downward), one upward flip (90° upward), and half-flipping (45° upward). Figure 3 (a) is a color scale diagram of the filling-flow front temperature when the circular flow channel is not overturned, where the melt temperature of the two cavities is 318.66℃ and 314.92℃, with a melt temperature deviation of 3.74℃; Figure 3 (b) is the color scale diagram of the filling-flow front temperature after the circular flow channel is flipped down once. The melt temperatures of the two cavities at the same position are 317.5℃ and 320.09℃, with a melt temperature difference of 2.59℃. Figure 3 (c) is a simulation diagram of the melt temperature after the outer side of the circular flow channel is flipped up once. The melt temperatures of the two cavities at the same position are 320.42℃ and 317.58℃, with a melt temperature deviation of 2.84℃. Figure 3 (d) shows the simulated melt temperature of the circular flow channel after the upper half is flipped up. The melt temperatures of the two cavities at the same location are 320.51℃ and 314.71℃, with a melt temperature difference of 5.80℃. Figure 3 (a), 3 (b) and Figure 3 (c) It can be seen that proper flipping can reduce the temperature difference between the two types of cavity melts; from Figure 3 As can be seen in (a) and 3(d), improper flipping can exacerbate thermal imbalance.

[0039] Figure 4 The filling-flow wavefront temperature gradation diagrams of the U-shaped flow channel are compared under the following conditions: no flipping, simple flipping (flipping 90°), flipping down twice (flipping 180°), and flipping down twice with a disk. Figure 4 (a) is the filling-flow front temperature color scale diagram when the U-shaped flow channel is not overturned, where the melt temperature of the two cavities is 318.51℃ and 314.12℃, with a melt temperature deviation of 4.39℃; Figure 4 (b) is the filling-flow front temperature color scale diagram after a simple flip (single 180° flip) of the U-shaped flow channel. The melt temperatures of the two cavities at the same position are 316.63℃ and 318.10℃, with a melt temperature difference of 1.47℃. Figure 4 (c) is a simulation diagram of the melt temperature after the outer side of the U-shaped flow channel is flipped down twice. The melt temperatures of the two cavities at the same position are 318.3℃ and 320.59℃, with a melt temperature deviation of 2.29℃. Figure 4 (d) shows the simulated melt temperature of the U-shaped flow channel after two downward inversions and the addition of a disc. The melt temperatures of the two cavities at the same location are 320.57℃ and 322.19℃, with a temperature difference of 1.62℃. Figure 4 (b) and Figure 4 (c) It is evident that increasing the number of flips did not reduce the thermal imbalance. Figure 4 (c) and Figure 4 (d) It can be seen that the additional disk did not reduce the thermal imbalance.

[0040] Depend on Figures 1 to 4 It is known that the traditional rigid flipping strategy, such as using a fixed 180° flipping mode, may not be able to adapt to the diverse needs of different numbers of cavities (such as 4, 8, 16, and 32 cavities), different flow channel layouts, and different material rheological properties, resulting in poor improvement of thermal imbalance in some flow channels.

[0041] Figure 5 A comparison of the filling-flow wavefront time-scale diagrams of the elongated flow channels before and after flipping. Figure 5 (a) is a time-color scale diagram of the filling-flow front of the elongated flow channels before overturning. Figure 5 (b) A time-scale diagram of the filling-flow wavefront after the U-shaped channels arranged in a long strip are flipped. (Comparison) Figure 5 (a) and Figure 5 (b) It can be seen that the inner side of the elongated channel fills quickly, while the outer side fills slowly; after flipping, the filling is close to equilibrium. Figure 6 A comparison of the filling-flow wavefront time-scale diagrams of the I-shaped flow channels before and after flipping. Figure 6 (a) is a color scale diagram of the filling-flow wavefront time before the overturning of the U-shaped flow channel with an I-shaped arrangement. Figure 6 (b) is the time-color scale diagram of the filling-flow wavefront after the I-shaped flow channels are flipped. (Comparison) Figure 6 (a) and Figure 6 (b) It can be seen that the inner side of the I-shaped flow channel fills quickly and the outer side fills slowly when it is not flipped; after flipping, the filling of the inner and outer sides is basically balanced. It can be seen that flipping the flow channel can achieve filling balance in the subsequent flow splitting, thus making the mechanical properties of the product closer to isotropic, but the density distribution may be uneven due to insufficient filling pressure.

[0042] Figure 7 The image shows a comparison of the filling-flow wavefront time-color scale diagrams for the same flow channel layout, under the following conditions: no flipping, one downward flip (90° downward), one upward flip (90° upward), and half-flipping (45° upward). Figure 7(a) is the filling-flow front time color scale diagram when the circular flow channel is not overturned. The inner side fills faster than the outer side, and the filling difference between the inner and outer sides is large. Figure 7 (b) is the filling-flow front time color scale diagram after the circular flow channel flips down once. The outer side fills faster than the inner side, and the filling difference between the inner and outer sides is large. Figure 7 (c) is the filling-flow front time color scale diagram after the outer side of the circular flow channel flips up once. The inner side fills faster than the outer side, and the filling difference between the inner and outer sides is large. Figure 7 (d) is the filling-flow front time-color scale diagram of the circular channel after the upper half is flipped. The inner side fills faster than the outer side, and the difference in filling speed between the inner and outer sides is significant. Figure 7 (a), 7 (b), Figure 7 As can be seen in (c) and 7(d), flipping improves the filling speed on both the inside and outside.

[0043] Figure 8 The image shows a comparison of the filling-flow wavefront time-color scale diagrams of the U-shaped flow channel under the following conditions: no flipping, simple flipping, flipping down twice, and flipping down twice with a disk. Figure 8 (a) is the filling-flow front time color scale diagram when the U-shaped flow channel is not overturned. The filling speed on the inner side is faster than that on the outer side, and the filling difference between the inner and outer sides is large. Figure 8 (b) is the filling-flow wavefront time color scale diagram after a simple flip (single 180° flip) of the U-shaped flow channel. The filling speed on the outside is faster than that on the inside, and there is a large difference in filling speed between the inside and outside. Figure 8 (c) is a simulation diagram of the melt temperature after the outer side of the U-shaped flow channel is flipped down twice. The filling speed on the outer side is faster than that on the inner side, and there is a large difference in filling speed between the inner and outer sides. Figure 8 (d) is a simulation diagram of the melt temperature after the U-shaped flow channel is folded down twice and a disc is added. The filling speed on the outer side is faster than that on the inner side, and the filling speed difference between the inner and outer sides is significant. Figure 8 As can be seen from (a), 8 (b), 8 (c) and 8 (d), the number of flips can adjust the longest filling time. Increasing the number of flips does not optimize the filling difference, that is, the synchronization of the flow front is poor.

[0044] Combination Figure 3 , Figure 4 , Figure 7 and Figure 8 It is evident that while the flipped flow channel alleviates the asymmetry of temperature distribution, it does not fundamentally optimize the pressure distribution of the flow channel or the synchronicity of the flow front. Therefore, the product may still experience problems such as deformation and dimensional differences due to uneven pressure holding.

[0045] To address this, this application provides a flow channel reversal design method that no longer uses a fixed 180° reversal mode for all flow splitting points. Instead, based on the prediction of the melt temperature field and shear rate field by the previous mold flow analysis, it judges the necessity of reversal for each flow splitting point and calculates an optimal reversal angle, thereby achieving flow balance.

[0046] like Figure 9 As shown in the figure, this application provides a flow channel flipping design method, including: Step S100: Perform mold flow analysis on the initial flow channel without setting the flip to obtain melt temperature distribution data and shear rate history data of the upstream flow channel cross section of each flow split node; Step S200: Calculate the thermal asymmetry index of each flow splitting node based on melt temperature distribution data and historical shear rate data. Step S300: Determine whether the flow channel needs to be flipped at the splitting node based on the thermal asymmetry index; Step S400: For the flow branch node that needs to be flipped, the optimal flipping angle of the flow branch node is calculated with the goal of minimizing the melt temperature difference between the inner cavity and the outer cavity after flipping. Step S500: Set the flow channel flipping structure at the corresponding flow branch node according to the optimal flipping angle.

[0047] The initial flow channel is a geometrically balanced flow channel, suitable for different cavity configurations or different flow channel layouts. Different cavity configurations include 4, 8, 16, 32, or 64 cavities, and different flow channel layouts include H-type or radial layouts. It should be noted that when designing the flow channel, different flow channel layouts can be compared and the optimal solution can be selected.

[0048] like Figure 10 As shown, when the melt flows through the runner, the region near the runner wall experiences viscous heat dissipation due to shearing action, i.e., shear heat; simultaneously, the relative motion between the melt and the cavity wall also generates frictional heat. The combined effect of shear heat and frictional heat results in an asymmetrical heat distribution across the runner cross-section. Influenced by the flow patterns during runner branching and turning, heat tends to flow inwards (i.e.,... Figure 10 (As shown in the red area) accumulation causes the inner melt temperature to be significantly higher than the outer temperature, thus forming a temperature gradient across the cross-section. Based on modulus-flow analysis, a melt temperature distribution profile and shear rate history can be obtained at each flow splitting node. The melt temperature distribution profile is obtained by extracting melt temperature distribution data at the center cross-section of the upstream main channel of each flow splitting node at the V / P switching moment. Typically, the cross-section is discretized into N points perpendicular to the flow direction, and the temperature at each point is recorded. Because the cross-section is a two-dimensional plane, the obtained melt temperature distribution data is a two-dimensional matrix. Shear rate history is the curve showing the change of the average shear rate per unit volume of melt before it passes through the splitting node over time. The melt temperature distribution data is the set of temperature values ​​at discrete points in the melt temperature distribution profile, and the shear rate history data is a numerical sequence of the shear rate at a specific location over time.

[0049] Runner nodes are categorized into main runners, secondary runners, tertiary runners, and so on, up to the cavity gate. Due to the different locations of these nodes, the shear and thermal histories experienced by the upstream melt will vary. For example, in a 16-cavity or 32-cavity mold, the primary runner nodes near the main runner have a longer melt shear history and more severe accumulated thermal asymmetry, potentially requiring more reversal to reset the temperature distribution. Conversely, the final runner nodes near the cavity gate have a shorter melt shear history and a relatively simpler thermal history, possibly requiring only minor angle adjustments. Therefore, selecting an appropriate reversal strategy for each runner node allows for precise heat redistribution. Shear history refers to the cumulative effect of the entire shearing process experienced by the melt from its entry into the mold (or from the previous runner node) to the current runner node.

[0050] The flow channel reversal design method provided in this application transforms the problem of uneven temperature distribution, which originally relied on empirical judgment, into a quantifiable numerical index by calculating the thermal asymmetry index. This avoids the arbitrariness of subjective judgment and provides an objective and reproducible basis for deciding whether to implement reversal. Furthermore, aiming to minimize the temperature difference between the inner and outer melt sides after reversal, the optimal reversal angle is calculated independently for each flow branch node, rather than applying a fixed angle (such as 180°) to all flow branch nodes. This allows the reversal strategy to accurately match the actual temperature profile upstream of the flow branch node, thereby reducing the temperature difference between the inner and outer sides after reversal to the theoretical minimum. Because each flow branch node is calculated independently, it is not limited by the number of cavities (4 / 8 / 16 / 32 / 64 cavities) or the flow channel layout (H-type, radial type). Therefore, the same framework can be adapted to various complex flow channel networks without modification, exhibiting high versatility.

[0051] In some specific embodiments of this application, the thermal asymmetry index of each shunt node is calculated based on melt temperature distribution data and historical shear rate data, including: The degree of temperature asymmetry at the split-node is determined based on the melt temperature distribution data at the upstream flow channel cross-section. The thermal asymmetry index of the shunt node is determined based on historical data of asymmetry degree and shear rate.

[0052] Specifically, thermal asymmetry index Calculate using the following formula:

[0053] in, The weighted average temperature of the melt flowing into the inner cavity on the upstream flow channel cross-section of the split node. The weighted average temperature of the melt flowing outward into the cavity on the upstream flow channel cross-section of the splitting node; Used to quantify the degree of asymmetry in the temperature distribution at the shunt nodes; This represents the maximum temperature difference across the cross section. The volume-average shear rate before the flow passes through this branching node; This is the reference shear rate.

[0054] in, Used to quantify the degree of temperature distribution asymmetry at the shunt node. The closer the value is to 1, the more dominant the temperature difference between the inner and outer sides is, and the stronger the asymmetry. The influence of shear history is introduced. Higher shear rates generate more shear heat, the temperature distribution is more significantly affected by the flow history, and the necessity for overturning may be higher. Thermal asymmetry index. The larger the value, the higher the risk of downstream filling imbalance due to differences in thermal history at the branch node.

[0055] In this embodiment, the thermal asymmetry index Introduced in and , It can be adjusted based on the shear sensitivity characteristic value of the material. Therefore, for shear-sensitive materials (such as PC, PMMA) or shear-insensitive materials (such as PP, PE), the thermal asymmetry index can automatically reflect the influence of material differences on the necessity of flipping, without the need for manual adjustment of the rules.

[0056] In addition, thermal asymmetry index It includes When process parameters such as injection speed and mold temperature change, recalculation is required. The system automatically outputs a flipping strategy that adapts to new processes, based on the optimal flipping angle, thus making the flipping design of the same mold transferable under different production conditions.

[0057] In some specific embodiments of this application, such as Figure 11 As shown, determining whether a flow channel needs to be flipped at a splitter node based on the thermal asymmetry index includes: Compare the thermal asymmetry index with a preset threshold; Step S210: If the thermal asymmetry index is less than the preset threshold, it is determined that the shunt node does not need to be flipped. Step S220: If the thermal asymmetry index is greater than or equal to a preset threshold, it is determined that the shunt node needs to be flipped.

[0058] Among them, the preset threshold Pre-determined through a database of historical success stories or benchmark injection molding tests for specific materials and products. If the thermal asymmetry of the shunt node is considered acceptable, the benefits of flipping it (improved balance) may outweigh its costs (increased pressure loss, manufacturing complexity). Therefore, flipping is not implemented for this shunt node. If the thermal asymmetry is significant, it is considered that it may adversely affect the downstream filling balance. Therefore, this branch node needs to be flipped.

[0059] The flow channel flipping design method provided in this application embodiment, compared with the traditional fixed flipping mode, can determine whether to flip based on the quantitative comparison result of the thermal asymmetry index and the preset threshold. When the degree of thermal asymmetry is slight ( Actively abandoning the flipping process reduces unnecessary pressure loss and manufacturing costs, and when the degree of thermal asymmetry is significant ( This forces a flip to prevent downstream filling imbalance caused by failure to flip, enabling precise decision-making at each diversion node, eliminating reliance on traditional experience, and improving design consistency and reproducibility.

[0060] like Figure 12 As shown, for a flow branch node that requires flow channel reversal, with the goal of minimizing the melt temperature difference between the inner and outer cavities after reversal, the optimal reversal angle for the flow branch node is calculated as follows: Step S310: The candidate angle of the split node is flipped around the flow channel axis. Melt temperature distribution data based on the upstream flow channel cross-section of the splitting node Candidate angles are determined through spatial coordinate transformation. New melt temperature distribution data ; Step S320, based on the new melt temperature distribution data Based on the flow channel topology downstream of the splitting node, the expected melt weighted average temperature flowing outward to the outer cavity is obtained on the flow channel cross-section upstream of the splitting node. and the weighted average temperature of the melt expected to flow into the inner cavity ; Step S330: Set multiple different candidate angles Select to make and Candidate angle with the smallest absolute value of the difference As the optimal flip angle.

[0061] For nodes that need to be flipped, the optimal flip angle is... The computational goal is to predict that the melt temperature flowing into the inner and outer cavities will be as consistent as possible after flipping.

[0062] Specifically, the melt temperature distribution data upstream of the splitting node is considered as a two-dimensional distribution. Assume the splitter node rotates around the channel axis at candidate angles. That is, to implement a flip angle New melt temperature distribution data were calculated based on the rotation matrix. .

[0063] Step S320: Predict the temperature after the flow split. Based on the flow channel topology downstream of the flow split node, the new melt temperature distribution data is... The flow path is divided into an inner cavity flow path region and an outer cavity flow path region according to the future flow direction of the melt. The temperature values ​​in the two regions are then weighted by volumetric flow rate to obtain the weighted average temperature of the melt expected to flow into the inner cavity. and the weighted average temperature of the melt expected to flow to the outer cavity .

[0064] Step S330: Define the optimization objective function, which aims to minimize the temperature difference between the inner and outer sides. Therefore, for each candidate angle φ, calculate the objective function value:

[0065] Searching from multiple candidate perspectives smallest The value is the optimal flip angle for that branch node. . That is,

[0066] The flow channel flipping design method provided in this application accurately redistributes the melt temperature distribution data of arbitrary upstream shapes to the two downstream branches through rotation, making the weighted average temperature of the inner and outer sides more consistent. Taking minimizing the temperature difference between the inner and outer sides as the objective function, the optimal flipping angle is automatically determined by scanning the entire range of 0° to 180°, replacing the traditional empirical mode of fixed flipping angle and avoiding getting trapped in local optima. By making the difference between the weighted average temperature of the inner and outer sides after flipping approach the minimum value, the melt filling of each cavity is synchronized in the end.

[0067] Traverse the range from 0° to 180° in a specific step size, such as 1°, or use an optimization algorithm to find the optimal solution. The minimum angle value is the optimal flip angle.

[0068] In an optional embodiment, multiple different candidate angles are set. This includes: setting candidate angles within a preset step size interval in the range of 0° to 180°. .

[0069] The preset step size can be 15°, 10°, 1°, etc. For example, calculating every 1° within the range of 0° to 180° to achieve high-precision search would require 181 CAE data remappings and objective function calculations. Discretizing the continuous interval between 0° and 180° into 13 candidate angles (0°, 15°, 30°...165°, 180°) at 15° intervals within the range of 0° to 180° allows for discrete rotation sampling of the melt temperature distribution data in each calculation, rather than continuous rotation integration, thus reducing computational resource consumption and increasing calculation speed. Furthermore, in practical engineering, flow channel inversion is achieved through mold processing, and the actual manufacturing accuracy is typically only ±5° to ±10°. The 15° angle interval is compatible with the conventional mold manufacturing accuracy, ensuring that the calculated optimal angle can be reliably achieved in actual processing. In addition, candidate angles can also be set at 5° and 10° intervals within the range of 0° to 180°. .

[0070] In some optional embodiments, an optimization algorithm is used to set multiple different candidate angles within the range of 0° to 180°. For example, a reference candidate angle is obtained by referring to historical data, and multiple candidate angles are determined at set intervals, centered on the reference candidate angle. Therefore, by referencing historical data to obtain candidate angles and combining them with empirical analysis, the computational load can be reduced and the computational speed can be improved.

[0071] If multiple consecutive candidate angles All make and When the absolute value of the difference is less than the preset value, the candidate angle with the smallest angle is selected as the optimal flip angle.

[0072] The preset value is 0.3~0.5, consistent with the temperature detection error in injection molding. For example, the preset value can be 0.3, 0.35, 0.4, 0.5°C, or any other value between 0.3 and 0.5. Candidate angles are set in 15° intervals within the range of 0° to 180°. Calculate the results for each candidate angle In some optional embodiments, if the three consecutive angles of 60°, 75°, and 90° (intervals of 15°) all satisfy... If the temperature is less than 0.5℃, then the smallest of the three angles, 60°, is selected as the optimal flip angle.

[0073] The smaller the flip angle, the less the geometric twist of the runner, and the less the additional inlet effect and wall friction loss caused by the change in flow direction when the melt flows through. This reduces the injection pressure requirement, which is beneficial for low-pressure molding and mold protection. Small-angle flips result in a gentler curvature of the runner centerline, which can be achieved using a conventional three-axis machining center with a simple rotary table. This avoids the need for five-axis simultaneous machining or complex EDM strategies required for large-angle flips (such as 150°~180°), helping to reduce manufacturing costs. Furthermore, excessively large flip angles may induce secondary circulation or localized stagnation zones at high injection speeds, affecting melt flow stability. Small-angle flips result in smoother streamlines and flow behavior closer to straight-pipe flow, which is beneficial for maintaining the stability of the filling process.

[0074] The flow channel flipping design method provided in this application can reduce the additional resistance to melt flow caused by abrupt changes in flow channel geometry by selecting a smaller flipping angle; moreover, the flow channel twisting degree corresponding to a small-angle flipping is light, and the processing difficulty and cost are lower; and it avoids melt turbulence or stagnation zones that may be introduced by large-angle flipping, which is beneficial to maintaining the stability of the filling process.

[0075] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0076] The flow channel reversal design apparatus provided in this application is described below. The flow channel reversal design apparatus described below can be referred to in correspondence with the flow channel reversal design method described above.

[0077] Figure 13 This is a schematic diagram of the flow channel overturning design device provided in an embodiment of this application. Figure 13 As shown, the flow channel flipping design device includes: Simulation module 1610 is used to perform mold flow analysis on an initial flow channel without inversion settings, and to obtain melt temperature distribution data of the upstream flow channel cross-section at each flow split node. and historical shear rate data; Calculation module 1620 is used to calculate the thermal asymmetry index of each split node based on melt temperature distribution data and shear rate history data; The flip decision module 1630 is used to determine whether the flow channel of the split node needs to be flipped based on the thermal asymmetry index. The angle optimization module 1640 is used to calculate the optimal flip angle of the flow branch node for flow branch nodes that need to be flipped, with the goal of minimizing the melt temperature difference between the inner cavity and the outer cavity after flipping. The output module 1650 is used to set the flow channel flipping structure at the corresponding flow branch node according to the optimal flipping angle.

[0078] The flow channel reversal design device provided in this application embodiment uses a reversal decision module 1630 based on the thermal asymmetry index to make reversal decisions. This transforms the problem of uneven temperature distribution, which originally relied on experience-based judgment, into a quantifiable numerical indicator, avoiding the arbitrariness of subjective judgment and providing an objective and reproducible basis for deciding whether to implement reversal. Furthermore, the angle optimization module 1640 aims to minimize the temperature difference between the inner and outer melt sides after reversal. It independently calculates the optimal reversal angle for each branch node, rather than applying a fixed angle (such as 180°) to all branch nodes. This allows the reversal strategy to accurately match the actual temperature profile upstream of the branch node, thereby reducing the temperature difference between the inner and outer sides after reversal to the theoretical minimum. Because each branch node is calculated independently, it is not limited by the number of cavities (4 / 8 / 16 / 32 / 64 cavities) or the flow channel layout (H-type, radial type). Therefore, the same framework can be adapted to various complex flow channel networks without modification, exhibiting high versatility.

[0079] like Figure 14 As shown, this application embodiment also provides an electronic device 1700, including: at least one processor 1701 ( Figure 11 The diagram shows only one processor, memory 1702, and computer program 1703 stored in memory 1702 and executable on at least one processor 1701. When processor 1701 executes computer program 1703, it implements the steps in any of the above method embodiments.

[0080] In applications, electronic devices may include, but are not limited to, processors and memory. Those skilled in the art will understand that... Figure 14 The examples shown are merely examples of electronic devices and do not constitute a limitation on electronic devices. They may include more or fewer components than shown, or combinations of certain components, or different components. For example, they may also include face capture devices, input / output devices, network access devices, etc.

[0081] In applications, the processor can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0082] In applications, memory can be an internal storage unit of an electronic device in some embodiments, such as a hard drive or RAM. In other embodiments, memory can be an external storage device of the electronic device, such as a plug-in hard drive, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, memory can include both internal and external storage units of the electronic device. Memory is used to store operating systems, applications, bootloaders, data, and other programs, such as program code for computer programs. Memory can also be used to temporarily store data that has been output or will be output.

[0083] It should be noted that the information interaction and execution process between the above-mentioned devices / modules are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0084] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The functional modules in the embodiments can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules can be implemented in hardware or as software functional modules. Furthermore, the specific names of the functional modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the modules in the above-described device can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0085] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the above-described flow channel flip design method embodiments.

[0086] This application provides a computer program product that, when run on an electronic device, enables the electronic device to implement the steps described in the above-described flow channel flipping design method embodiments.

[0087] If an integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. A computer-readable medium can include at least: any entity or device capable of carrying computer program code to a device / electronic device, a recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0088] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0089] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0090] In the embodiments provided in this application, it should be understood that the disclosed apparatus / device and method can be implemented in other ways. For example, the apparatus / device embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or modules may be electrical, mechanical, or other forms.

[0091] The modules described as separate components may or may not be physically separate. Similarly, the components shown as modules may or may not be physical modules; they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0092] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A flow channel flipping design method, characterized in that, include: Mold flow analysis was performed on the initial flow channel without inversion to obtain melt temperature distribution data and historical shear rate data of the upstream flow channel cross section of each flow split node; Based on the melt temperature distribution data and the shear rate history data, the thermal asymmetry index of each of the flow splitting nodes is calculated. Based on the thermal asymmetry index, determine whether the flow channel of the flow splitter node needs to be flipped; For the flow divider node that needs to be flipped, the optimal flipping angle of the flow divider node is calculated with the goal of minimizing the melt temperature difference between the inner cavity and the outer cavity after flipping. At the corresponding flow branching node, a flow channel flipping structure is set according to the optimal flipping angle.

2. The flow channel flipping design method as described in claim 1, characterized in that, The calculation of the thermal asymmetry index for each of the flow splitters based on the melt temperature distribution data and the historical shear rate data includes: The degree of asymmetry in the temperature distribution of the splitting node is determined based on the melt temperature distribution data at the cross-section of the upstream flow channel of the splitting node. The thermal asymmetry index of the shunt node is determined based on the degree of asymmetry and the historical shear rate data.

3. The flow channel flipping design method as described in claim 2, characterized in that, The thermal asymmetry index is calculated according to the following formula: in, The thermal asymmetry index, The weighted average temperature of the melt flowing into the inner cavity on the upstream flow channel cross-section of the diversion node. The weighted average temperature of the melt flowing towards the outer cavity on the upstream flow channel cross-section of the diversion node; Used to quantify the degree of asymmetry in the temperature distribution of the shunt nodes; This represents the maximum temperature difference across the cross section. The volume-average shear rate before the flow passes through this branching node; This is the reference shear rate.

4. The flow channel flipping design method as described in claim 1, characterized in that, The step of determining whether the flow splitter node needs to be flipped based on the thermal asymmetry index includes: The thermal asymmetry index is compared with a preset threshold. If the thermal asymmetry index is less than a preset threshold, then the shunt node is determined not to need to be flipped. If the thermal asymmetry index is greater than or equal to a preset threshold, then the shunt node needs to be flipped.

5. The flow channel flipping design method as described in claim 1, characterized in that, For the flow divider node that needs to be flipped, the optimal flipping angle of the flow divider node is calculated with the goal of minimizing the melt temperature difference between the inner and outer cavities after flipping. Flip the candidate angle of the diversion node around the channel axis Based on the melt temperature distribution data of the upstream flow channel cross-section of the diversion node Candidate angles are determined through spatial coordinate transformation. New melt temperature distribution data ; Based on new melt temperature distribution data Based on the flow channel topology downstream of the diversion node, the weighted average temperature of the melt expected to flow towards the outer cavity on the flow channel cross-section upstream of the diversion node is obtained. and the weighted average temperature of the melt expected to flow into the inner cavity ; Set multiple different candidate angles Select to make and Candidate angle with the smallest absolute value of the difference As the optimal flip angle.

6. The flow channel flipping design method as described in claim 5, characterized in that, The setting of multiple different candidate angles This includes setting the candidate angle within a preset step size interval in the range of 0° to 180°. .

7. The flow channel flipping design method as described in claim 5, characterized in that, If multiple consecutive candidate angles All make and When the absolute value of the difference is less than the preset value, the candidate angle with the smallest angle is selected as the optimal flip angle.

8. A flow channel flipping design device, characterized in that, include: The simulation module is used to perform mold flow analysis on the initial flow channel without inversion settings, and to obtain melt temperature distribution data of the upstream flow channel cross-section at each flow split node. and historical shear rate data; The calculation module is used to calculate the thermal asymmetry index of each of the flow splitting nodes based on the melt temperature distribution data and the shear rate history data. The flip decision module is used to determine whether the flow channel of the diversion node needs to be flipped based on the thermal asymmetry index. An angle optimization module is used to calculate the optimal flip angle of the flow branch node for the flow channel that needs to be flipped, with the goal of minimizing the melt temperature difference between the inner cavity and the outer cavity after flipping. The output module is used to set the flow channel flipping structure at the corresponding flow branching node according to the optimal flipping angle.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the flow channel flipping design method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the flow channel flipping design method as described in any one of claims 1 to 7.

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