A method and system for optimizing the design of an internal cavity runner of a cast sand mold

Abstract

The application provides a method and system for optimizing the design of an inner cavity runner of a casting sand mold, and relates to the technical field of sand mold design. A three-dimensional structure model of a target casting sand mold is obtained, an initial structure of an inner cavity runner is constructed, and initial runner data is generated. An entrance flow guide area, a stable conveying area, and a sensitive scouring area are divided along a preset metal liquid flow path, local flow velocities and wall impact intensities of each subarea are calculated, the maximum actual flow velocity value and the maximum wall impact intensity value of the sensitive scouring area are extracted, the maximum flow velocity value is determined according to the maximum wall impact intensity value and a preset sand mold damage threshold, and flow velocity control constraint data is generated. A gradually expanding buffer section is constructed upstream of the sensitive scouring area, the cross-sectional area variation rate, the expansion angle, and the length of the buffer section are limited, the curvature at the connection position is continuously adjusted, and the final inner cavity runner optimization structure parameters are generated after review. The method can reduce the impact of the metal liquid on the sand mold wall of the sensitive scouring area.

Description

Technical Field

[0001] This invention relates to the field of sand mold design technology, and in particular to a method and system for optimizing the internal flow channel design of a casting sand mold. Background Technology

[0002] In existing technologies, the design of internal flow channels in casting sand molds is typically optimized using a combination of empirical formulas and simulation analysis. Designers first determine the dimensional proportions of the gating system, runner, and ingate based on experience, and then use numerical simulation software to analyze the molten metal filling process, such as observing flow velocity distribution, temperature field changes, and possible turbulent regions, thereby iteratively adjusting the flow channel structure. This method can improve filling quality and increase casting density to a certain extent and has been widely used in the sand mold design of complex castings.

[0003] However, in the specific scenario of automotive engine block casting, due to the complex internal structure and drastic changes in wall thickness, the above method is prone to problems such as excessively high local flow velocities. For example, although the simulation results show smooth overall filling, in actual production, the flow velocity of molten metal in some narrow channels can exceed 1.5 m / s, causing sand inclusion defects due to erosion of the molding sand, which in turn forms pores or inclusions in the water jacket area of ​​the cylinder block. These defects are exposed during subsequent machining, causing leakage in the cooling water channels and directly affecting the engine's sealing performance. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for optimizing the internal flow channel design of casting sand molds, aiming to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] In a first aspect, a method for optimizing the internal flow channel design of a casting sand mold, the method comprising:

[0007] Obtain the three-dimensional structural model of the target casting sand mold, and construct the corresponding initial structure of the internal cavity flow channel based on it, generating initial flow channel data;

[0008] Based on the initial flow channel data, the internal flow channel is divided into segments along the preset flow path of the molten metal to form an inlet guiding zone, a stable conveying zone, and a sensitive scouring zone, and flow channel partition data is generated.

[0009] Based on the flow channel partition data, the local flow velocity and wall impact intensity of the molten metal during the filling process are calculated for each flow channel partition, generating partition flow parameter data, and extracting the maximum actual flow velocity value and maximum wall impact intensity value of the sensitive scouring zone from the partition flow parameter data.

[0010] The maximum allowable flow velocity is determined by comparing the maximum wall impact strength in the sensitive scour zone with the preset molding sand failure threshold. When the maximum wall impact strength exceeds the preset molding sand failure threshold, the maximum actual flow velocity is reduced to a value where the wall impact strength is not greater than the preset molding sand failure threshold, and the reduced flow velocity is used as the maximum allowable flow velocity. When the maximum wall impact strength is not greater than the preset molding sand failure threshold, the maximum actual flow velocity is used as the maximum allowable flow velocity. Flow velocity control constraint data is generated based on the maximum allowable flow velocity.

[0011] Based on the flow velocity control constraint data, a gradually expanding buffer section is constructed upstream of the sensitive scour zone, and the cross-sectional area of ​​the gradually expanding buffer section is controlled to change monotonically along the flow direction, and the area change rate between adjacent sections is not greater than a preset proportional threshold, thereby generating preliminary buffer structure data.

[0012] Based on the preliminary buffer structure data, the expansion angle and length of the gradually expanding buffer section are limited to satisfy the functional relationship with the maximum allowable flow velocity value, thereby generating the target buffer structure data;

[0013] Based on the target buffer structure data, the curvature of the connection position between the stable conveying zone and the gradually expanding buffer section is continuously adjusted so that the rate of change of flow direction is less than the preset flow direction change rate threshold, thereby generating continuous transition channel data.

[0014] The filling process is verified and calculated based on the continuous transition channel data to obtain updated flow parameter data. When the impact intensity of the inner wall of the sensitive scour zone is lower than the preset molding sand failure threshold, the final optimized structural parameters of the inner cavity channel are generated.

[0015] Secondly, a system for optimizing the internal flow channel design of a casting sand mold, the system comprising:

[0016] The initial flow channel data generation module is used to obtain the three-dimensional structural model of the target casting sand mold and construct the corresponding initial internal cavity flow channel structure accordingly, thereby generating initial flow channel data.

[0017] The flow channel partition data generation module is used to divide the inner cavity flow channel into segments along the preset flow path of the molten metal based on the initial flow channel data, forming an inlet guiding zone, a stable conveying zone, and a sensitive scouring zone, and generating flow channel partition data.

[0018] The partition flow parameter generation module is used to calculate the local flow velocity and wall impact intensity of the molten metal during the filling process for each partition based on the flow channel partition data, generate partition flow parameter data, and extract the maximum actual flow velocity value and maximum wall impact intensity value of the sensitive scouring zone from the partition flow parameter data.

[0019] The flow velocity control constraint data generation module is used to determine the maximum allowable flow velocity value based on the comparison between the maximum wall impact intensity value of the sensitive scour zone and the preset molding sand failure threshold. When the maximum wall impact intensity value is greater than the preset molding sand failure threshold, the maximum actual flow velocity value is reduced to a value where the corresponding wall impact intensity is not greater than the preset molding sand failure threshold, and the reduced flow velocity value is used as the maximum allowable flow velocity value. When the maximum wall impact intensity value is not greater than the preset molding sand failure threshold, the maximum actual flow velocity value is used as the maximum allowable flow velocity value. Flow velocity control constraint data is generated based on the maximum allowable flow velocity value.

[0020] The preliminary buffer structure data generation module is used to construct a gradually expanding buffer section upstream of the sensitive scour zone based on the flow velocity control constraint data, and control the cross-sectional area of ​​the gradually expanding buffer section to change monotonically along the flow direction, and the area change rate between adjacent sections is not greater than a preset proportional threshold, thereby generating preliminary buffer structure data.

[0021] The target buffer structure data generation module is used to determine the expansion angle and length of the gradually expanding buffer section based on the preliminary buffer structure data, so that it satisfies the functional relationship corresponding to the maximum allowable flow velocity value, and generate the target buffer structure data.

[0022] The continuous transition channel data generation module is used to continuously adjust the curvature of the connection position between the stable conveying zone and the gradually expanding buffer section based on the target buffer structure data, so that the rate of change of flow direction is less than the preset rate of change of flow direction threshold, and generate continuous transition channel data.

[0023] The final structural parameter generation module is used to perform verification calculations on the filling process based on the continuous transition channel data to obtain updated flow parameter data. When the impact intensity of the inner wall of the sensitive scour zone is lower than the preset molding sand failure threshold, the final optimized structural parameters of the inner cavity channel are generated.

[0024] The above-described solution of the present invention has at least the following beneficial effects:

[0025] First, by obtaining a three-dimensional structural model of the target casting sand mold and constructing the initial structure of the internal cavity flow channel, the inlet guiding zone, stable conveying zone and sensitive scour zone are divided along the preset flow path of the molten metal. This allows the internal cavity flow channel design to no longer rely solely on whether the overall filling is smooth, but to identify narrow flow channels, turning flow channels and other easily scoured locations as independent objects, providing a clear area for subsequent constraints on local scour risks.

[0026] After the sensitive scour zone is determined, the local flow velocity and wall impact intensity of each flow channel section are calculated, and the maximum actual flow velocity and maximum wall impact intensity of the sensitive scour zone are extracted. This transforms the basis for flow channel optimization from empirical size ratios to flow parameters directly related to the impact state of the molding sand, enabling the identification of locations with excessively high local flow velocities in complex internal cavities such as the water jacket of an automobile engine cylinder block.

[0027] When the maximum wall impact strength value exceeds the preset molding sand failure threshold, the maximum actual flow velocity value is reduced and the maximum allowable flow velocity value is determined so that the wall impact strength corresponding to the maximum allowable flow velocity value is not greater than the preset molding sand failure threshold. This transforms the molding sand's erosion resistance into a flow velocity control constraint, reducing the situation where molten metal exceeds the molding sand's tolerance range and erodes the sand mold wall in narrow flow channels.

[0028] A gradually expanding buffer section is constructed upstream of the sensitive scour zone, and the cross-sectional area of ​​the gradually expanding buffer section is limited to monotonically increasing along the flow direction, and the area change rate between adjacent sections is not greater than a preset proportional threshold, so that the molten metal forms a continuous deceleration process before entering the sensitive scour zone, reducing the velocity concentration and wall impact concentration caused by abrupt changes in local cross sections.

[0029] Furthermore, by limiting the expansion angle and length of the gradually expanding buffer section and continuously adjusting the curvature of the connection position between the stable conveying zone and the gradually expanding buffer section, the flow direction change of the molten metal from the stable conveying zone into the gradually expanding buffer section is constrained, reducing turbulence and scouring concentration phenomena generated at the transition position.

[0030] Finally, by verifying and calculating the filling process of the continuous transition channel data, and generating the final internal cavity channel optimization structural parameters when the impact strength of the inner wall surface in the sensitive scouring zone is lower than the preset molding sand damage threshold, the output channel structure can provide a structural design basis for addressing issues such as sand inclusions, porosity, inclusions, and leakage of cooling water channels exposed by subsequent machining in the cylinder water jacket area. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating an optimized design method for the internal flow channel of a casting sand mold, provided by an embodiment of the present invention. Detailed Implementation

[0032] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0033] like Figure 1As shown, an embodiment of the present invention proposes a method for optimizing the internal flow channel design of a casting sand mold, the method comprising:

[0034] Obtain the three-dimensional structural model of the target casting sand mold, and construct the corresponding initial structure of the internal cavity flow channel based on it, generating initial flow channel data;

[0035] Based on the initial flow channel data, the inner cavity flow channel is divided into segments along the preset flow path of the molten metal to form an inlet guiding zone, a stable conveying zone, and a sensitive scouring zone, and flow channel partition data is generated. The preset flow path is determined based on the three-dimensional structural model of the target casting sand mold.

[0036] Based on the flow channel partition data, the local flow velocity and wall impact intensity of the molten metal during the filling process are calculated for each flow channel partition, generating partition flow parameter data, and extracting the maximum actual flow velocity value and maximum wall impact intensity value of the sensitive scouring zone from the partition flow parameter data.

[0037] The maximum allowable flow velocity is determined by comparing the maximum wall impact strength in the sensitive scour zone with the preset molding sand failure threshold. When the maximum wall impact strength exceeds the preset molding sand failure threshold, the maximum actual flow velocity is reduced to a value where the wall impact strength is not greater than the preset molding sand failure threshold, and the reduced flow velocity is used as the maximum allowable flow velocity. When the maximum wall impact strength is not greater than the preset molding sand failure threshold, the maximum actual flow velocity is used as the maximum allowable flow velocity. Flow velocity control constraint data is generated based on the maximum allowable flow velocity.

[0038] Based on the flow velocity control constraint data, a gradually expanding buffer section is constructed upstream of the sensitive scour zone, and the cross-sectional area of ​​the gradually expanding buffer section is controlled to change monotonically along the flow direction, and the area change rate between adjacent sections is not greater than a preset proportional threshold, thereby generating preliminary buffer structure data.

[0039] Based on the preliminary buffer structure data, the expansion angle and length of the gradually expanding buffer section are limited to satisfy the functional relationship with the maximum allowable flow velocity value, thereby generating the target buffer structure data;

[0040] Based on the target buffer structure data, the curvature of the connection position between the stable conveying zone and the gradually expanding buffer section is continuously adjusted so that the rate of change of flow direction is less than the preset flow direction change rate threshold, thereby generating continuous transition channel data.

[0041] The filling process is verified and calculated based on the continuous transition channel data to obtain updated flow parameter data. When the impact intensity of the inner wall of the sensitive scour zone is lower than the preset molding sand failure threshold, the final optimized structural parameters of the inner cavity channel are generated.

[0042] In this embodiment of the invention, the inner cavity flow channel is divided into an inlet guiding zone, a stable conveying zone and a sensitive scouring zone by following a preset flow path of the molten metal. This allows subsequent flow parameter calculations to focus on the locations where molding sand scouring is likely to occur, avoiding the neglect of local scouring areas caused by uniform adjustments based solely on the overall flow channel state.

[0043] The maximum actual flow velocity and the maximum wall impact strength in the sensitive scour zone are used as constraints. When the maximum wall impact strength exceeds the preset molding sand damage threshold, the maximum actual flow velocity is reduced. The maximum allowable flow velocity is determined by the wall impact strength not being greater than the preset molding sand damage threshold. This directly links the flow velocity control target with the impact state of the molding sand, thereby reducing the scour damage of the molding sand wall in the sensitive scour zone by the molten metal.

[0044] A gradually expanding buffer section is constructed upstream of the sensitive scour zone, and the cross-sectional area of ​​the gradually expanding buffer section is limited to increase monotonically along the flow direction. At the same time, the area change rate between adjacent sections is restricted, so that the molten metal forms a continuous deceleration process before entering the sensitive scour zone, reducing local acceleration, backflow and concentrated wall impact caused by abrupt changes in cross-section.

[0045] The expansion angle and length of the gradually expanding buffer section are limited according to the maximum allowable flow velocity value, and the curvature of the connection position between the stable conveying zone and the gradually expanding buffer section is continuously adjusted so that the rate of change of flow direction is less than the preset flow direction change rate threshold, thereby reducing the impact load on the inner wall of the molding sand caused by the sudden change of the flow direction of the molten metal at the connection position.

[0046] By verifying the continuous transition channel data through the filling process, the impact strength of the inner wall of the sensitive scour zone is lower than the preset molding sand damage threshold before the final internal cavity channel optimization structural parameters are generated. This reduces the probability of sand inclusion, impurities, and leakage defects caused by molding sand scour.

[0047] In a preferred embodiment of the present invention, the basis for setting the preset molding sand failure threshold includes:

[0048] Obtain the material parameters of the molding sand used for the target casting sand mold, including the type of molding sand, type of binder, moisture content, compactness, compressive strength, tensile strength and hot strength, and generate basic data of molding sand material;

[0049] Based on the basic data of molding sand materials, molding sand samples with the same mix ratio and the same compaction conditions as the target casting sand mold were prepared, and the molding sand samples were subjected to erosion resistance tests under thermal conditions corresponding to the pouring temperature of molten metal to generate hot erosion resistance data of molding sand.

[0050] Based on the hot erosion resistance data of molding sand, record the wall impact strength corresponding to the time when sand grains begin to peel off, surface damage or erosion grooves appear on the molding sand sample, and generate critical impact strength data.

[0051] Based on the critical impact strength data, discrete data caused by sample molding defects, local looseness, or test abnormalities are eliminated to generate effective critical impact strength data.

[0052] Based on the effective critical impact strength data, a value lower than the critical impact strength corresponding to the start of erosion failure of the molding sand is selected as the preset molding sand failure threshold.

[0053] In a preferred embodiment of the present invention, the basis for setting the preset ratio threshold includes:

[0054] The arrangable length, inlet section position, and outlet section position of the gradually expanding buffer section are determined based on the three-dimensional structural model of the target casting sand mold.

[0055] Multiple candidate cross-sectional area change rates are set within the arrangeable length, and candidate cross-sectional area change rates that ensure the wall impact strength is not greater than the preset molding sand failure threshold are selected based on the molten metal flow conditions and the preset molding sand failure threshold. The maximum value in the selection results is determined as the preset ratio threshold.

[0056] In a preferred embodiment of the present invention, the basis for setting the preset flow direction change rate threshold includes:

[0057] Based on the three-dimensional structural model of the target casting sand mold, determine the adjustable path length, inlet flow direction, and outlet flow direction of the connection position between the stable conveying zone and the gradually expanding buffer section;

[0058] Within the adjustable path length, multiple candidate flow direction change rates are set, and candidate flow direction change rates that ensure the wall impact intensity is not greater than the preset molding sand damage threshold are selected based on the molten metal flow conditions and the preset molding sand damage threshold. The maximum value in the selection results is determined as the preset flow direction change rate threshold.

[0059] In a preferred embodiment of the present invention, a three-dimensional structural model of the target casting sand mold is obtained, and a corresponding initial structure of the internal cavity flow channel is constructed based on this model to generate initial flow channel data, including:

[0060] Obtain the three-dimensional model of the casting and the three-dimensional model of the sand mold corresponding to the target casting sand mold, and perform coordinate unification processing on the three-dimensional model of the casting and the three-dimensional model of the sand mold cavity to generate unified spatial model data;

[0061] Based on the unified spatial model data, extract the cavity boundary, inner cavity contour, pouring port position and target forming area related to the molten metal filling in the target casting sand mold, and generate sand mold inner cavity boundary data;

[0062] Based on the boundary data of the sand mold cavity, the initial flow path of the molten metal from the pouring inlet into the target forming area is determined, and the center path of the cavity flow channel is constructed along the initial flow path to generate flow channel path data;

[0063] Based on the flow path data and the sand mold inner cavity boundary data, the initial cross-sectional shape, initial cross-sectional area and connection position of the inner cavity flow channel are set to form the initial structure of the inner cavity flow channel;

[0064] Based on the initial structure of the internal flow channel, the center path, cross-sectional area, cross-sectional shape, flow direction, connection boundary, and spatial coordinates of each flow channel location are extracted to generate initial flow channel data.

[0065] In a preferred embodiment of the present invention, based on the flow channel partition data, the local flow velocity and wall impact intensity of the molten metal during the filling process are calculated for each flow channel partition to generate partition flow parameter data, including:

[0066] Based on the flow channel partition data, the spatial boundaries and flow paths corresponding to the inlet guide zone, stable transport zone and sensitive scour zone are extracted respectively to generate partition calculation area data;

[0067] Based on the partition calculation area data, each flow channel partition is discretized into a grid, and the corresponding cross-sectional area, wall position and flow direction are associated with each discrete position to generate partition discrete data.

[0068] Based on the discrete data of each zone, the pouring temperature, density, viscosity, pouring inlet speed and filling time conditions of the molten metal are input, and the flow of the molten metal in each flow channel zone is solved time by time to generate the filling state data of each zone.

[0069] Based on the partitioned filling status data, the velocity magnitude and velocity direction of each discrete location during the filling process are extracted to generate local flow velocity data;

[0070] Based on local flow velocity data, wall location, and the flow direction of the molten metal acting on the wall, the intensity of the impact of the molten metal on each wall location is determined, and wall impact intensity data is generated.

[0071] Among them, the wall impact strength I satisfies: ; The density of the molten metal, This represents the local flow velocity of the molten metal near the wall. The angle between the local flow direction and the normal direction of the wall;

[0072] Based on local velocity data and wall impact intensity data, the data is collected according to the corresponding flow channel zones to generate zoned flow parameter data.

[0073] In a preferred embodiment of the present invention, based on the target buffer structure data, the curvature of the connection position between the stable delivery zone and the gradually expanding buffer section is continuously adjusted so that the rate of change of flow direction is less than a preset threshold for the rate of change of flow direction, thereby generating continuous transition channel data, including:

[0074] Based on the target buffer structure data, extract the stable transport zone outlet boundary, the gradually expanding buffer section inlet boundary, and the connection position between the two to generate connection boundary data.

[0075] Based on the connection boundary data, the flow direction at the outlet of the stable conveying zone and the flow direction at the inlet of the gradually expanding buffer section are determined respectively, and connection direction data is generated.

[0076] Based on the connection direction data, a transition center path is set between the outlet boundary of the stable conveying zone and the inlet boundary of the gradually expanding buffer section. The starting direction of the transition center path is consistent with the flow direction at the outlet of the stable conveying zone, and the ending direction of the transition center path is consistent with the flow direction at the inlet of the gradually expanding buffer section, thereby generating initial transition path data.

[0077] Based on the initial transition path data, the curvature of the transition center path is continuously adjusted, and the cross-sectional profile of the transition position is adjusted synchronously to make the rate of change of flow direction between adjacent path positions less than the preset flow direction change rate threshold, thereby generating transition path correction data.

[0078] Based on the transition path correction data, the stable transport zone, transition position, and gradually expanding buffer section are continuously connected to generate continuous transition channel data.

[0079] In a preferred embodiment of the present invention, the filling process is recalculated based on continuous transition channel data to obtain updated flow parameter data, including:

[0080] Based on the continuous transition channel data, the spatial structure of the adjusted inlet guide zone, stable conveying zone, gradually expanding buffer section, sensitive scouring zone, and each connection position is extracted to generate the verification channel model data.

[0081] Based on the verification flow channel model data, the adjusted inner cavity flow channel is discretized, and the metal liquid material parameters, pouring inlet conditions and filling time conditions are set to be consistent with the initial filling calculation to generate verification calculation condition data.

[0082] Based on the verification calculation data, the flow solution of the molten metal filling process in the adjusted inner cavity flow channel is performed to generate verification filling state data.

[0083] Based on the verification filling state data, the local flow velocity, flow direction, pressure state, and wall impact intensity at each flow channel location are extracted to generate verification flow parameter data;

[0084] Based on the verified flow parameter data, the wall impact intensity, maximum flow velocity, and flow direction change rate at the connection point in the sensitive scour zone are extracted to generate updated flow parameter data.

[0085] In a preferred embodiment of the present invention, based on flow velocity control constraint data, a gradually expanding buffer section is constructed upstream of the sensitive scour zone, and the cross-sectional area of ​​the gradually expanding buffer section is controlled to change monotonically along the flow direction, with the area change rate between adjacent sections not exceeding a preset proportional threshold, thereby generating preliminary buffer structure data, including:

[0086] Based on the flow rate control constraint data, the target flow rate reduction range before the molten metal enters the sensitive scouring zone is determined, and the target flow rate reduction range is discretized along the flow direction to generate target flow rate interval data.

[0087] Based on the target flow velocity range data, the range of cross-sectional area values ​​for each flow velocity range is determined, and cross-sectional area range data is generated.

[0088] Based on the cross-sectional area range data, the gradually expanding buffer section is divided into sub-segments along the flow direction, and multiple control sections are set in each sub-segment to generate control section position data.

[0089] Based on the control section location data and section area range data, each control section is assigned a corresponding section area value to generate an initial section area sequence;

[0090] The initial cross-sectional area sequence is adjusted incrementally one by one to make the area of ​​the subsequent control cross-section larger than the area of ​​the previous control cross-section, thus generating an incremental cross-sectional area sequence.

[0091] Based on the increasing cross-sectional area sequence, determine the area increment between any adjacent control sections, and calculate the ratio of the area increment to the cross-sectional area of ​​the previous control section to generate the area change rate between adjacent control sections.

[0092] The area change rate between adjacent control sections is compared with a preset ratio threshold. When the area change rate is greater than the preset ratio threshold, a callback correction process is performed on the cross-sectional area of ​​the next control section to make the corrected cross-sectional area fall within the corresponding cross-sectional area value range, until the area change rate is no greater than the preset ratio threshold, and a constrained cross-sectional area sequence is generated.

[0093] Based on the constrained cross-sectional area sequence, a continuous geometric profile of the gradually expanding buffer segment is constructed, generating preliminary buffer structure data.

[0094] In this embodiment of the invention, the target velocity reduction range before entering the sensitive scouring zone is converted into multiple target velocity intervals. The cross-sectional area range is then determined by these target velocity intervals, ensuring that the velocity control target is implemented within the specific cross-sectional area distribution of the gradually expanding buffer section. By setting control sections within each sub-segment and incrementally adjusting the area of ​​these control sections, a flow space that gradually expands along the direction of molten metal flow is formed. After the rate of change of area between adjacent control sections is limited by a preset proportional threshold, the velocity reduction process of the molten metal within the gradually expanding buffer section remains continuous, reducing local impacts and flow separation caused by abrupt changes in cross-sectional area. The corrected cross-sectional area remains within the corresponding value range, ensuring that the buffer section meets the velocity reduction requirements while avoiding disruption of the overall gradually expanding profile due to local cross-sectional adjustments.

[0095] In a preferred embodiment of the present invention, the target velocity reduction range before the molten metal enters the sensitive scouring zone is determined based on velocity control constraint data, and the target velocity reduction range is discretized along the flow direction to generate target velocity interval data, including:

[0096] Based on the flow velocity control constraint data, extract the maximum allowable flow velocity value corresponding to the sensitive scour zone and the inlet flow velocity value upstream of the sensitive scour zone;

[0097] The target velocity reduction range is generated by using the inlet velocity value as the starting value of the target velocity reduction range and the maximum allowable velocity value as the ending value of the target velocity reduction range.

[0098] Based on the preset flow path of the molten metal, the flow direction of the gradually expanding buffer section is determined, and the target flow velocity reduction range is segmented along the flow direction to generate multiple continuous target flow velocity intervals.

[0099] The target flow velocity intervals are sorted according to the direction of molten metal flow, and the starting flow velocity value, ending flow velocity value and interval order corresponding to each target flow velocity interval are recorded to generate target flow velocity interval data.

[0100] The number of segments in the target flow velocity range is determined based on the design length of the gradually expanding buffer section, the maximum allowable flow velocity value corresponding to the sensitive scouring zone, and the velocity range of the molten metal inlet.

[0101] In a preferred embodiment of the present invention, based on the target flow velocity range data, the cross-sectional area range for each flow velocity range is determined accordingly, and cross-sectional area range data is generated, including:

[0102] Based on the target velocity range data, extract the starting velocity value and the ending velocity value corresponding to each target velocity range in sequence;

[0103] Based on the starting and ending flow rates corresponding to each target flow rate range, determine the required flow area range for the molten metal to pass through the gradually expanding buffer section within that target flow rate range.

[0104] Based on the aforementioned flow area range, and in conjunction with the inlet and outlet cross-sectional shapes of the gradually expanding buffer section, the range of cross-sectional area values ​​corresponding to each target flow velocity interval is determined.

[0105] The range of cross-sectional area values ​​adjacent to each other along the direction of molten metal flow is continuously corrected so that the range of cross-sectional area values ​​corresponding to the next flow velocity interval is not less than the range of cross-sectional area values ​​corresponding to the previous flow velocity interval.

[0106] Based on the range of cross-sectional area values ​​after continuity correction and their corresponding target velocity ranges, cross-sectional area range data is generated.

[0107] In a preferred embodiment of the present invention, the gradually expanding buffer section is divided into sub-segments along the flow direction based on cross-sectional area range data, and multiple control sections are set in each sub-segment to generate control section position data, including:

[0108] Based on the cross-sectional area range data, determine the range of the gradually expanding buffer section position corresponding to each cross-sectional area value range;

[0109] Along the direction of molten metal flow, the gradually expanding buffer section is divided into multiple continuous sub-segments corresponding to the range of area values ​​for each cross-section;

[0110] Set control sections at the start and end positions of each sub-segment, as well as between the start and end positions, so that adjacent sub-segments can share the boundary control sections.

[0111] Based on the axial position of each control section in the gradually expanding buffer section, the sub-segment to which it belongs, and the corresponding range of cross-sectional area values, control section position data is generated.

[0112] The number of control sections in each sub-segment is determined based on the variation range of the axial length and cross-sectional area of ​​the corresponding sub-segment, as well as the machining accuracy requirements of the gradually expanding buffer section.

[0113] In a preferred embodiment of the present invention, based on the control section location data and the section area interval data, a corresponding section area value is assigned to each control section to generate an initial section area sequence, including:

[0114] Based on the control section location data, determine the arrangement order of each control section along the direction of molten metal flow and the sub-segment to which each control section belongs;

[0115] Based on the sub-segment to which each control section belongs, extract the corresponding range of cross-sectional area values ​​from the cross-sectional area interval data;

[0116] For control sections located within the same sub-segment, assign cross-sectional area values ​​within the range of corresponding cross-sectional area values ​​according to their positional order along the direction of molten metal flow.

[0117] For control sections located at the boundary of adjacent sub-segments, the overlapping value or continuous connection value of the area range of two adjacent sections is used as the cross-sectional area value of the control section.

[0118] The cross-sectional area values ​​corresponding to each control section are arranged sequentially according to the direction of molten metal flow to generate an initial cross-sectional area sequence.

[0119] In a preferred embodiment of the present invention, a continuous geometric profile of a gradually expanding buffer segment is constructed based on a constrained cross-sectional area sequence to generate preliminary buffer structure data, including:

[0120] Based on the constrained cross-sectional area sequence, the arrangement order, cross-sectional area value and corresponding axial position of each control section along the direction of molten metal flow are extracted to generate cross-sectional profile control data;

[0121] Based on the cross-sectional profile control data, determine the cross-sectional shape parameters of each control section, and ensure that the cross-sectional area of ​​each control section is consistent with the corresponding cross-sectional area value in the constrained cross-sectional area sequence.

[0122] Based on the cross-sectional shape parameters of adjacent control sections, the contour boundaries between adjacent control sections are continuously connected to generate segmented progressive contour data;

[0123] Based on the segmented gradually expanding contour data, the contour boundary at the connection of adjacent segments is smoothed to make the outer contour of the gradually expanding buffer section transition continuously along the direction of molten metal flow.

[0124] Based on the segmented gradually expanding contour data after smoothing, a continuous geometric contour of the gradually expanding buffer segment is generated, and the continuous geometric contour, the position of each control section, and the area value of each control section are correlated to generate preliminary buffer structure data.

[0125] In a preferred embodiment of the present invention, based on the preliminary buffer structure data, the expansion angle and length of the gradually expanding buffer section are defined to satisfy a functional relationship corresponding to the maximum allowable flow velocity value, thereby generating target buffer structure data, including:

[0126] Based on the preliminary buffer structure data, extract the control section position and corresponding section area of ​​the gradually expanding buffer section, and generate section parameter data;

[0127] The target velocity reduction of the molten metal in the gradually expanding buffer section is determined based on the maximum allowable velocity value, and the target velocity reduction is allocated between adjacent control sections to generate velocity reduction sequence data.

[0128] Based on the velocity decrease sequence data, the axial length between adjacent control sections is segmented and set so that the axial length of each segment corresponds to the corresponding velocity decrease, thus generating axial length distribution data.

[0129] Based on the axial length distribution data, the expansion angle between adjacent control sections is calculated segment by segment, and the expansion angle is restricted so that the expansion angle decreases with the increase of axial length, thereby generating expansion angle distribution data.

[0130] Based on the axial length distribution data and the expansion angle distribution data, the gradually expanding buffer section is combined and constructed to generate initial structural parameter data;

[0131] Based on the initial structural parameter data, the flow velocity change is checked. When the flow velocity change between any adjacent control sections does not meet the preset continuous decrease condition, the axial length and expansion angle of the corresponding section are linked for correction processing to generate corrected structural parameter data. The preset continuous decrease condition is that the flow velocity decrease between adjacent structural sections along the direction of molten metal flow is gradually decreasing.

[0132] The target buffer structure data is generated based on the corrected structure parameter data.

[0133] In this embodiment of the invention, the target velocity reduction is determined based on the maximum permissible velocity value, and this reduction is distributed between adjacent control sections. This ensures that the velocity reduction within the gradually expanding buffer section no longer depends on the expansion of a single section, but is completed segment by segment along multiple control sections. The axial length between adjacent control sections is set according to the velocity reduction sequence, and the expansion angle is limited by the axial length, causing the expansion angle to decrease as the axial length increases. This results in a controlled velocity reduction process for the molten metal within the buffer section. By verifying the initial structural parameters for velocity changes and adjusting the axial length and expansion angle in conjunction with the velocity changes when they do not meet the continuous reduction condition, the flow direction disturbance caused by excessively rapid local velocity reduction in the buffer section can be reduced. This makes the flow state of the molten metal before entering the sensitive scouring zone closer to the impact state corresponding to the maximum permissible velocity value.

[0134] In a preferred embodiment of the present invention, based on the velocity decrease sequence data, the axial length between adjacent control sections is segmented and set so that the axial length of each segment corresponds to the corresponding velocity decrease, thereby generating axial length distribution data, including:

[0135] Based on the velocity decrease sequence data, the target velocity value corresponding to each control section is extracted, and the velocity decrease between adjacent control sections is determined to generate segmented velocity decrease data.

[0136] Based on the segmented flow velocity drop data, the length allocation order between adjacent control sections is determined, and the flow velocity drop between each adjacent control section is used as the basis for the allocation of the corresponding axial length.

[0137] Based on the velocity reduction of each section, the axial length between adjacent control sections is set in segments so that the axial length corresponding to the velocity reduction can provide the transition distance required for the molten metal to complete the velocity reduction of that section.

[0138] The axial lengths of adjacent sections along the direction of molten metal flow are continuously adjusted to ensure sequential connection between the axial lengths of each section.

[0139] Based on the axial length of each segment after continuous adjustment and its corresponding control section, axial length distribution data is generated.

[0140] In a preferred embodiment of the present invention, based on axial length distribution data, the expansion angle between adjacent control sections is calculated segment by segment, and the expansion angle is restricted so that the expansion angle decreases with the increase of axial length, thereby generating expansion angle distribution data, including:

[0141] Based on the axial length distribution data, the axial length between adjacent control sections is extracted, and combined with the cross-sectional area values ​​corresponding to the adjacent control sections, segmented geometric change data is generated.

[0142] Based on the segmented geometric change data, determine the cross-sectional boundary expansion amount between each adjacent control section, and determine the expansion angle of the segment based on the cross-sectional boundary expansion amount and the corresponding axial length.

[0143] Based on the distribution relationship of the axial length of each segment along the direction of molten metal flow, the expansion angles of each segment are sorted to generate an initial expansion angle sequence.

[0144] The initial expansion angle sequence is constrained to reduce the expansion angle corresponding to the structural segment with increased axial length, and to make the expansion angle between adjacent structural segments transition continuously.

[0145] Based on the expansion angles of each segment after the restriction processing and their corresponding axial lengths, expansion angle distribution data is generated.

[0146] The limitation range of the expansion angle is determined based on the change in cross-sectional area of ​​the gradually expanding buffer section, the axial length distribution data, the reduction in the target flow velocity before the molten metal enters the sensitive scouring zone, and the allowable space for sand molding.

[0147] In a preferred embodiment of the present invention, the gradually expanding buffer segment is constructed by combining axial length distribution data and expansion angle distribution data to generate initial structural parameter data, including:

[0148] Based on the axial length distribution data, determine the axial spacing between adjacent control sections and the spatial position of each control section in the gradually expanding buffer section, and generate control section spatial arrangement data.

[0149] Based on the expansion angle distribution data, the contour expansion direction and expansion degree between each adjacent control section are determined, and segmented expansion contour data are generated;

[0150] Based on the spatial layout data of the control sections and the segmented expansion profile data, the gradually expanding profiles between adjacent control sections are connected in sequence to form a segmented structure of the gradually expanding buffer section.

[0151] The cross-sectional boundaries, axial positions, and expansion directions between adjacent structural segments are made consistent to ensure continuity at the connection points.

[0152] Based on the segmented structure after consistency processing, initial structural parameter data is generated, including control section position, axial length, expansion angle, cross-sectional area, and contour connection relationship.

[0153] In a preferred embodiment of the present invention, based on initial flow channel data, the inner cavity flow channel is segmented along a preset flow path of the molten metal to form an inlet guiding zone, a stable conveying zone, and a sensitive scouring zone, and flow channel partition data is generated, including:

[0154] Based on the initial flow channel data, the center path of the internal flow channel, the cross-sectional area corresponding to each path point, the flow direction corresponding to each path point, and the initial flow parameters corresponding to each path point are extracted to generate path cross-sectional flow data. The initial flow parameters include the initial flow velocity value and the initial wall impact strength value corresponding to each path point. The initial flow velocity value and the initial wall impact strength value are obtained from the initial filling calculation results corresponding to the initial flow channel data.

[0155] Based on the flow data of the path section, the center path is used as the reference for the flow division. The internal flow channel is divided into continuous units along the preset flow path of the molten metal, and the path length between adjacent flow units is determined to generate flow unit sequence data.

[0156] Based on the flow unit sequence data, an initial flow characteristic analysis along the flow path is performed on each flow unit for partition identification. The cross-sectional area change rate, velocity gradient, and wall impact intensity change rate between adjacent flow units are obtained, and cross-sectional area change rate data, velocity gradient data, and impact intensity change rate data are generated respectively.

[0157] Based on the cross-sectional area change rate data, flow velocity gradient data, and impact intensity change rate data, risk labeling is performed on each flow unit.

[0158] When the velocity gradient data corresponding to the same flow unit exceeds the velocity gradient judgment threshold and the impact intensity change rate data exceeds the impact intensity change rate judgment threshold, the flow unit is marked as a scour risk unit.

[0159] A scouring risk unit is identified as a sensitive scouring unit when it meets any of the following conditions: the cross-sectional area change rate data exceeds the cross-sectional area change rate judgment threshold; or the flow direction change exceeds the flow direction change judgment threshold.

[0160] The adjacent and continuous sensitive scouring units along the preset flow path of the molten metal in the flow unit sequence data are grouped into sensitive scouring regions, and sensitive scouring region data is generated by the starting boundary of the first sensitive scouring unit and the ending boundary of the last sensitive scouring unit in the sensitive scouring region.

[0161] The flow unit directly connected to the molten metal inlet is used as the inlet starting unit, and it extends downstream along the preset flow path of the molten metal to the flow unit before the first sensitive scouring zone to generate inlet guide zone data.

[0162] The remaining flow units in the flow unit sequence data that are not classified as sensitive scour zones or inlet guide zones are divided into one or more stable transport sub-regions according to the continuous distribution relationship along the preset flow path of the molten metal, and stable transport zone data is generated.

[0163] Flow channel partitioning data is generated based on data from the sensitive scouring zone, stable transport zone, and inlet guide zone.

[0164] In this embodiment of the invention, the partitioning stage is not based solely on the geometric location of the flow channel, but rather on risk marking based on the rate of change of the cross-sectional area of ​​the flow unit, the velocity gradient, and the rate of change of the wall impact intensity. This ensures that the determination of the sensitive scour zone simultaneously reflects geometric abrupt changes and changes in flow impact. Flow units whose velocity gradient and rate of change of impact intensity both exceed the corresponding judgment threshold are marked as scour risk units. Sensitive scour units are then determined by combining the rate of change of cross-sectional area or the change of flow direction, thus associating the sensitive scour zone with the actual scour causes. Adjacent and continuous sensitive scour units are merged into sensitive scour zones, and the remaining flow units not included in the sensitive scour zone and the inlet guide zone are classified as stable transport zones. This ensures the integrity of the internal flow channel partitioning boundaries, providing clear targets for subsequent velocity constraints and buffer section settings.

[0165] In a preferred embodiment of the present invention, initial flow characteristic analysis along the flow path for partition identification is performed on each flow unit, including:

[0166] Based on the flow unit sequence data, the starting boundary, ending boundary, cross-sectional area, flow direction, and adjacency relationship of each flow unit are extracted to generate basic feature data of the flow unit.

[0167] Based on the basic characteristic data of the flow unit, the cross-sectional area of ​​adjacent flow units is compared along the flow path, and the cross-sectional area difference between adjacent flow units is processed as a percentage of the cross-sectional area of ​​the upstream flow unit to generate cross-sectional area change rate data.

[0168] Based on the basic characteristic data of the flow units, the velocity values ​​of adjacent flow units are compared along the flow path, and the velocity difference between adjacent flow units is correlated with the corresponding flow path length to generate velocity gradient data.

[0169] Based on the basic characteristic data of the flow unit, the wall impact intensity of adjacent flow units is compared along the flow path, and the wall impact intensity difference between adjacent flow units is processed as a proportion of the wall impact intensity of the upstream flow unit to generate impact intensity change rate data.

[0170] Based on the basic characteristic data of the flow unit, the angle between the flow directions of adjacent flow units is determined, and flow direction change data is generated.

[0171] Based on the cross-sectional area change rate data, velocity gradient data, impact intensity change rate data, and flow direction change data, each flow unit is associated and labeled to generate initial flow characteristic data along the flow path for zone identification.

[0172] In a preferred embodiment of the present invention, the criteria for setting the velocity gradient determination threshold, the impact intensity change rate determination threshold, the cross-sectional area change rate determination threshold, and the flow direction change determination threshold include:

[0173] Acquire data on the erosion resistance of the molding sand used in the target casting sand mold, the range of molten metal pouring speed, the wall thickness distribution of the target casting, the minimum cross-sectional dimensions of the internal cavity flow channel, and the flow path data of historical qualified castings to generate basic data for threshold setting.

[0174] Based on the threshold setting base data, extract the flow velocity gradient range corresponding to the flow unit in historical qualified castings that has not experienced sand inclusion, impurity and leakage defects, generate flow velocity gradient reference data, and determine the flow velocity gradient judgment threshold based on the flow velocity gradient reference data.

[0175] Based on the threshold setting data, extract the range of wall impact strength change rate corresponding to the flow unit where the sand wall of the historical qualified casting has not been eroded and damaged, generate impact strength change rate reference data, and determine the impact strength change rate judgment threshold based on the impact strength change rate reference data.

[0176] Based on the threshold setting of the basic data, the range of cross-sectional area change rate corresponding to the continuous transition position of the flow channel section in the historical qualified castings is extracted, cross-sectional area change rate reference data is generated, and the cross-sectional area change rate judgment threshold is determined based on the cross-sectional area change rate reference data.

[0177] Based on the threshold setting of the basic data, the flow direction change range in the flow channel turning position of historical qualified castings without scouring defects is extracted, flow direction change reference data is generated, and the flow direction change judgment threshold is determined based on the flow direction change reference data.

[0178] When there is insufficient flow data along the flow path for historical qualified castings, trial filling verification is carried out based on the erosion resistance data of the molding sand used in the target casting sand mold, the range of molten metal pouring speed, and the minimum cross-sectional size data of the internal flow path. Based on the flow characteristic range in which no molding sand erosion defects are generated during the trial filling verification, the threshold values ​​for velocity gradient, impact strength change rate, cross-sectional area change rate, and flow direction change are determined.

[0179] In a preferred embodiment of the present invention, the process of performing callback correction includes:

[0180] Based on the comparison between the area change rate between adjacent control sections and the preset ratio threshold, adjacent control sections with an area change rate greater than the preset ratio threshold are identified as the over-limit section group.

[0181] Based on the cross-sectional area of ​​the previous control section in the over-limit cross-section group and the preset proportional threshold, determine the target callback area of ​​the next control section, so that the area change rate between the previous control section and the next control section is not greater than the preset proportional threshold.

[0182] Adjust the cross-sectional area of ​​the next control section to the target callback area to generate local callback cross-sectional area data;

[0183] Based on the local callback cross-sectional area data, the areas of each control section downstream of the next control section are sequentially corrected along the direction of molten metal flow, so that the area of ​​each downstream control section is greater than the area of ​​its adjacent upstream control section, and the area of ​​each downstream control section is within the range of the corresponding cross-sectional area value.

[0184] During the sequential correction process, the area change rate between each group of adjacent control sections is limited to no more than a preset proportional threshold, generating linkage correction section area data.

[0185] Based on the local callback cross-sectional area data and the linkage correction cross-sectional area data, a constrained cross-sectional area sequence is generated.

[0186] In this embodiment of the invention, when the area change rate between adjacent control sections exceeds a preset proportional threshold, the corresponding adjacent control sections are identified as an over-limit section group. The target correction area of ​​the next control section is determined by the cross-sectional area of ​​the previous control section and the preset proportional threshold, thus limiting the local area change to a controllable range. After the correction of the next control section is completed, the area of ​​the downstream control section is sequentially corrected along the direction of molten metal flow, ensuring that each downstream control section maintains an increasing area relationship and remains within the corresponding cross-sectional area value range. Therefore, local correction does not disrupt the overall contour of the gradually expanding buffer section, reduces abrupt changes in the downstream section caused by single-point correction, and allows the molten metal to maintain a continuous deceleration state as it flows along the buffer section.

[0187] In a preferred embodiment of the present invention, the process of generating flow rate decreasing sequence data includes:

[0188] Based on the cross-sectional parameter data, the arrangement order of each control section in the gradually expanding buffer section along the direction of molten metal flow is determined, and the control section near the stable conveying zone is determined as the starting control section, and the control section near the sensitive scouring zone is determined as the ending control section.

[0189] The inlet velocity value corresponding to the initial control section is determined based on the zonal flow parameter data, and the target velocity reduction is determined based on the inlet velocity value and the maximum allowable velocity value.

[0190] Based on the arrangement order of each control section, the target velocity reduction is distributed among adjacent control sections, and the velocity reduction between adjacent control sections far from the sensitive scour zone is greater than the velocity reduction between adjacent control sections close to the sensitive scour zone.

[0191] Based on the velocity reduction of each segment after allocation, the target velocity value of each control section is determined sequentially along the direction of molten metal flow, so that the target velocity value of each control section decreases continuously along the direction of molten metal flow, and the velocity reduction between adjacent control sections decreases segment by segment along the direction of molten metal flow.

[0192] Generate a velocity decrease sequence data based on the target velocity values ​​of each control section.

[0193] In this embodiment of the invention, the control section near the stable conveying zone in the gradually expanding buffer section is used as the initial control section, and the control section near the sensitive scour zone is used as the final control section. The target velocity reduction is determined based on the inlet velocity and the maximum allowable velocity. The target velocity reduction is distributed between adjacent control sections, with the velocity reduction further away from the sensitive scour zone being greater than that closer to it. This ensures that the molten metal completes its main velocity reduction in the initial stage of the buffer section and continues to decrease velocity more gradually as it approaches the sensitive scour zone. Consequently, the velocity change of the molten metal before entering the sensitive scour zone remains continuous, reducing the concentration of wall impacts caused by abrupt velocity reductions near the inlet of the sensitive scour zone.

[0194] In a preferred embodiment of the present invention, the process of generating modified structural parameter data includes:

[0195] Based on the initial structural parameter data, extract the axial length, expansion angle and corresponding flow velocity decrease between adjacent control sections to generate structural segment data to be checked;

[0196] Based on the data of the structural segment to be checked, the velocity drop corresponding to each structural segment is extracted sequentially along the direction of molten metal flow. Starting from the second structural segment, the velocity drop of the current structural segment is compared with the velocity drop of its adjacent upstream structural segment. When the velocity drop of the current structural segment is greater than the velocity drop of its adjacent upstream structural segment, the current structural segment is determined as the structural segment to be corrected.

[0197] Within the design length range of the gradually expanding buffer section, based on the velocity reduction corresponding to the structural section to be corrected, the axial length of the structural section to be corrected is increased, and the expansion angle of the structural section to be corrected is simultaneously decreased to generate correction parameter data.

[0198] Based on the corrected parameter data, the velocity reduction relationship between the structural segment to be corrected and its adjacent upstream structural segment is re-determined. When the velocity reduction of the structural segment to be corrected is still greater than the velocity reduction of its adjacent upstream structural segment, the axial length increase processing and expansion angle reduction processing are continued until the velocity reduction between adjacent structural segments along the direction of molten metal flow gradually decreases.

[0199] Replace the corresponding axial length and expansion angle in the initial structural parameter data with the axial length and expansion angle that satisfy the step-by-step decreasing state to generate the corrected structural parameter data.

[0200] In this embodiment of the invention, the axial length, expansion angle, and velocity decrease of each structural segment are extracted based on the initial structural parameter data. Starting from the second structural segment, the velocity decrease of the current structural segment is compared with the velocity decrease of the adjacent upstream structural segment. If the velocity decrease of the current structural segment is greater than that of the adjacent upstream structural segment, the current structural segment is identified as the structural segment to be corrected, and the axial length is increased and the expansion angle is decreased within the design length range of the gradually expanding buffer section. By repeatedly verifying the velocity decrease relationship between the structural segment to be corrected and the adjacent upstream structural segment, the velocity decrease between adjacent structural segments is gradually reduced along the direction of molten metal flow, thereby reducing flow disturbances caused by excessively rapid local velocity reduction within the buffer section.

[0201] Embodiments of the present invention also provide an optimized design system for the internal flow channel of a casting sand mold, the system comprising:

[0202] The initial flow channel data generation module is used to obtain the three-dimensional structural model of the target casting sand mold and construct the corresponding initial internal flow channel structure accordingly, thereby generating initial flow channel data.

[0203] The flow channel partition data generation module is used to divide the inner cavity flow channel into segments along the preset flow path of the molten metal based on the initial flow channel data, forming an inlet guiding zone, a stable conveying zone, and a sensitive scouring zone, and generating flow channel partition data.

[0204] The partition flow parameter generation module is used to calculate the local flow velocity and wall impact intensity of the molten metal during the filling process for each partition based on the flow channel partition data, generate partition flow parameter data, and extract the maximum actual flow velocity value and maximum wall impact intensity value of the sensitive scouring zone from the partition flow parameter data.

[0205] The flow velocity control constraint data generation module is used to determine the maximum allowable flow velocity value based on the comparison between the maximum wall impact intensity value of the sensitive scour zone and the preset molding sand failure threshold. When the maximum wall impact intensity value is greater than the preset molding sand failure threshold, the maximum actual flow velocity value is reduced to a value where the corresponding wall impact intensity is not greater than the preset molding sand failure threshold, and the reduced flow velocity value is used as the maximum allowable flow velocity value. When the maximum wall impact intensity value is not greater than the preset molding sand failure threshold, the maximum actual flow velocity value is used as the maximum allowable flow velocity value. Flow velocity control constraint data is generated based on the maximum allowable flow velocity value.

[0206] The preliminary buffer structure data generation module is used to construct a gradually expanding buffer section upstream of the sensitive scour zone based on the flow velocity control constraint data, and control the cross-sectional area of ​​the gradually expanding buffer section to change monotonically along the flow direction, and the area change rate between adjacent sections is not greater than a preset proportional threshold, thereby generating preliminary buffer structure data.

[0207] The target buffer structure data generation module is used to determine the expansion angle and length of the gradually expanding buffer section based on the preliminary buffer structure data, so that it satisfies the functional relationship corresponding to the maximum allowable flow velocity value, and generate the target buffer structure data.

[0208] The continuous transition channel data generation module is used to continuously adjust the curvature of the connection position between the stable conveying zone and the gradually expanding buffer section based on the target buffer structure data, so that the rate of change of flow direction is less than the preset rate of change of flow direction threshold, and generate continuous transition channel data.

[0209] The final structural parameter generation module is used to perform verification calculations on the filling process based on the continuous transition channel data to obtain updated flow parameter data. When the impact intensity of the inner wall of the sensitive scour zone is lower than the preset molding sand failure threshold, the final optimized structural parameters of the inner cavity channel are generated.

[0210] It should be noted that this system is a system corresponding to the above method. All implementation methods in the above method embodiments are applicable to this embodiment and can achieve the same technical effect.

[0211] Embodiments of the present invention also provide a computing device, including: a processor and a memory storing a computer program, wherein the computer program, when executed by the processor, performs the method described above. All implementations in the above method embodiments are applicable to this embodiment and can achieve the same technical effects.

[0212] Embodiments of the present invention also provide a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the method described above. All implementations in the above method embodiments are applicable to this embodiment and can achieve the same technical effects.

[0213] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for optimizing the internal flow channel design of a casting sand mold, characterized in that, The method includes: Obtain the three-dimensional structural model of the target casting sand mold, and construct the corresponding initial structure of the internal cavity flow channel based on it, generating initial flow channel data; Based on the initial flow channel data, the internal flow channel is divided into segments along the preset flow path of the molten metal to form an inlet guiding zone, a stable conveying zone, and a sensitive scouring zone, and flow channel partition data is generated. Based on the flow channel partition data, the local flow velocity and wall impact intensity of the molten metal during the filling process are calculated for each flow channel partition, generating partition flow parameter data, and extracting the maximum actual flow velocity and maximum wall impact intensity value of the sensitive scouring zone from the partition flow parameter data. The maximum allowable flow velocity is determined by comparing the maximum wall impact strength in the sensitive scour zone with the preset molding sand failure threshold. When the maximum wall impact strength exceeds the preset molding sand failure threshold, the maximum actual flow velocity is reduced to a value where the wall impact strength is not greater than the preset molding sand failure threshold, and the reduced flow velocity is used as the maximum allowable flow velocity. When the maximum wall impact strength is not greater than the preset molding sand failure threshold, the maximum actual flow velocity is used as the maximum allowable flow velocity. Flow velocity control constraint data is generated based on the maximum allowable flow velocity. Based on the flow velocity control constraint data, a gradually expanding buffer section is constructed upstream of the sensitive scour zone, and the cross-sectional area of ​​the gradually expanding buffer section is controlled to change monotonically along the flow direction, and the area change rate between adjacent sections is not greater than a preset proportional threshold, thereby generating preliminary buffer structure data. Based on the preliminary buffer structure data, the expansion angle and length of the gradually expanding buffer section are limited to satisfy the functional relationship with the maximum allowable flow velocity value, thereby generating the target buffer structure data; Based on the target buffer structure data, the curvature of the connection position between the stable conveying zone and the gradually expanding buffer section is continuously adjusted so that the rate of change of flow direction is less than the preset flow direction change rate threshold, thereby generating continuous transition channel data. The filling process is verified and calculated based on the continuous transition channel data to obtain updated flow parameter data. When the impact intensity of the inner wall of the sensitive scour zone is lower than the preset molding sand failure threshold, the final optimized structural parameters of the inner cavity channel are generated.

2. The method for optimizing the internal flow channel design of a casting sand mold according to claim 1, characterized in that, Based on flow velocity control constraint data, a gradually expanding buffer section is constructed upstream of the sensitive scour zone. The cross-sectional area of ​​the gradually expanding buffer section is controlled to increase monotonically along the flow direction, and the rate of change of area between adjacent sections does not exceed a preset proportional threshold. Preliminary buffer structure data is generated, including: Based on the flow velocity control constraint data, the target flow velocity reduction range before the molten metal enters the sensitive scouring zone is determined, and the target flow velocity reduction range is discretized along the flow direction to generate target flow velocity interval data. Based on the target flow velocity range data, the range of cross-sectional area values ​​for each flow velocity range is determined, and cross-sectional area range data is generated. Based on the cross-sectional area range data, the gradually expanding buffer section is divided into sub-segments along the flow direction, and multiple control sections are set in each sub-segment to generate control section position data. Based on the control section location data and section area range data, each control section is assigned a corresponding section area value to generate an initial section area sequence; The initial cross-sectional area sequence is adjusted incrementally one by one to make the area of ​​the subsequent control cross-section larger than the area of ​​the previous control cross-section, thus generating an incremental cross-sectional area sequence. Based on the increasing cross-sectional area sequence, determine the area increment between any adjacent control sections, and then process the area increment with the cross-sectional area of ​​the previous control section to generate the area change rate between adjacent control sections. The area change rate between adjacent control sections is compared with a preset ratio threshold. When the area change rate is greater than the preset ratio threshold, a callback correction process is performed on the cross-sectional area of ​​the next control section to make the corrected cross-sectional area fall within the corresponding cross-sectional area value range, until the area change rate is no greater than the preset ratio threshold, and a constrained cross-sectional area sequence is generated. Based on the constrained cross-sectional area sequence, a continuous geometric profile of the gradually expanding buffer segment is constructed, generating preliminary buffer structure data.

3. The method for optimizing the internal flow channel design of a casting sand mold according to claim 1, characterized in that, Based on the preliminary buffer structure data, the expansion angle and length of the gradually expanding buffer section are defined to satisfy a functional relationship with the maximum allowable flow velocity, generating the target buffer structure data, including: Based on the preliminary buffer structure data, extract the control section position and corresponding section area of ​​the gradually expanding buffer section, and generate section parameter data; The target velocity reduction of the molten metal in the gradually expanding buffer section is determined based on the maximum allowable velocity value, and the target velocity reduction is allocated between adjacent control sections to generate velocity reduction sequence data. Based on the velocity decrease sequence data, the axial length between adjacent control sections is segmented and set so that the axial length of each segment corresponds to the corresponding velocity decrease, thus generating axial length distribution data. Based on the axial length distribution data, the expansion angle between adjacent control sections is calculated segment by segment, and the expansion angle is restricted so that the expansion angle decreases with the increase of axial length, thereby generating expansion angle distribution data. Based on the axial length distribution data and the expansion angle distribution data, the gradually expanding buffer section is combined and constructed to generate initial structural parameter data; Based on the initial structural parameter data, the flow velocity change is checked. When the flow velocity change between any adjacent control section does not meet the preset continuous decrease condition, the axial length and expansion angle of the corresponding section are linked for correction processing to generate corrected structural parameter data. The preset continuous decrease condition is that the flow velocity decrease between adjacent structural sections along the direction of molten metal flow is gradually decreasing. The target buffer structure data is generated based on the corrected structure parameter data.

4. The method for optimizing the internal flow channel design of a casting sand mold according to claim 1, characterized in that, Based on the initial flow channel data, the internal flow channel is segmented along the preset flow path of the molten metal to form an inlet guiding zone, a stable conveying zone, and a sensitive scouring zone, and flow channel partition data is generated, including: Based on the initial flow channel data, extract the center path of the internal flow channel, the cross-sectional area of ​​each path point, the flow direction of each path point, and the initial flow parameters of each path point to generate path cross-sectional flow data. Based on the flow data of the path section, the center path is used as the reference for the flow division. The internal flow channel is divided into continuous units along the preset flow path of the molten metal, and the path length between adjacent flow units is determined to generate flow unit sequence data. Based on the flow unit sequence data, an initial flow characteristic analysis along the flow path is performed on each flow unit for partition identification. The cross-sectional area change rate, velocity gradient, and wall impact intensity change rate between adjacent flow units are obtained, and cross-sectional area change rate data, velocity gradient data, and impact intensity change rate data are generated respectively. Based on the cross-sectional area change rate data, flow velocity gradient data, and impact intensity change rate data, risk labeling is performed on each flow unit. When the velocity gradient data corresponding to the same flow unit exceeds the velocity gradient judgment threshold and the impact intensity change rate data exceeds the impact intensity change rate judgment threshold, the flow unit is marked as a scour risk unit. A scouring risk unit is identified as a sensitive scouring unit when it meets any of the following conditions: the cross-sectional area change rate data exceeds the cross-sectional area change rate judgment threshold; or the flow direction change exceeds the flow direction change judgment threshold. The adjacent and continuous sensitive scouring units along the preset flow path of the molten metal in the flow unit sequence data are grouped into sensitive scouring regions, and sensitive scouring region data is generated by the starting boundary of the first sensitive scouring unit and the ending boundary of the last sensitive scouring unit in the sensitive scouring region. The flow unit directly connected to the molten metal inlet is used as the inlet starting unit, and it extends downstream along the preset flow path of the molten metal to the flow unit before the first sensitive scouring zone to generate inlet guide zone data. The remaining flow units in the flow unit sequence data that are not classified as sensitive scour zones or inlet guide zones are divided into one or more stable transport sub-regions according to the continuous distribution relationship along the preset flow path of the molten metal, and stable transport zone data is generated. Flow channel partitioning data is generated based on data from the sensitive scouring zone, stable transport zone, and inlet guide zone.

5. The method for optimizing the internal flow channel design of a casting sand mold according to claim 2, characterized in that, The process of executing callback correction includes: Based on the comparison between the area change rate between adjacent control sections and the preset ratio threshold, adjacent control sections with an area change rate greater than the preset ratio threshold are identified as the over-limit section group. Based on the cross-sectional area of ​​the previous control section in the over-limit cross-section group and the preset proportional threshold, determine the target callback area of ​​the next control section, so that the area change rate between the previous control section and the next control section is not greater than the preset proportional threshold. Adjust the cross-sectional area of ​​the next control section to the target callback area to generate local callback cross-sectional area data; Based on the local callback cross-sectional area data, the areas of each control section downstream of the next control section are sequentially corrected along the direction of molten metal flow, so that the area of ​​each downstream control section is greater than the area of ​​its adjacent upstream control section, and the area of ​​each downstream control section is within the range of the corresponding cross-sectional area value. During the sequential correction process, the area change rate between each group of adjacent control sections is limited to no more than a preset proportional threshold, generating linkage correction section area data. Based on the local callback cross-sectional area data and the linkage correction cross-sectional area data, a constrained cross-sectional area sequence is generated.

6. The method for optimizing the internal flow channel design of a casting sand mold according to claim 3, characterized in that, The process of generating flow rate decreasing sequence data includes: Based on the cross-sectional parameter data, the arrangement order of each control section in the gradually expanding buffer section along the direction of molten metal flow is determined, and the control section near the stable conveying zone is determined as the starting control section, and the control section near the sensitive scouring zone is determined as the ending control section. The inlet velocity value corresponding to the initial control section is determined based on the zonal flow parameter data, and the target velocity reduction is determined based on the inlet velocity value and the maximum allowable velocity value. Based on the arrangement order of each control section, the target velocity reduction is distributed among adjacent control sections, and the velocity reduction between adjacent control sections far from the sensitive scour zone is greater than the velocity reduction between adjacent control sections close to the sensitive scour zone. Based on the velocity reduction of each segment after allocation, the target velocity value of each control section is determined sequentially along the direction of molten metal flow, so that the target velocity value of each control section decreases continuously along the direction of molten metal flow, and the velocity reduction between adjacent control sections decreases segment by segment along the direction of molten metal flow. Generate a velocity decrease sequence data based on the target velocity values ​​of each control section.

7. The method for optimizing the internal flow channel design of a casting sand mold according to claim 3, characterized in that, The process of generating corrected structural parameter data includes: Based on the initial structural parameter data, extract the axial length, expansion angle and corresponding flow velocity decrease between adjacent control sections to generate structural segment data to be checked; Based on the data of the structural segment to be checked, the velocity drop corresponding to each structural segment is extracted sequentially along the direction of molten metal flow. Starting from the second structural segment, the velocity drop of the current structural segment is compared with the velocity drop of its adjacent upstream structural segment. When the velocity drop of the current structural segment is greater than the velocity drop of its adjacent upstream structural segment, the current structural segment is determined as the structural segment to be corrected. Within the design length range of the gradually expanding buffer section, based on the velocity reduction corresponding to the structural section to be corrected, the axial length of the structural section to be corrected is increased, and the expansion angle of the structural section to be corrected is simultaneously decreased to generate correction parameter data. Based on the corrected parameter data, the velocity reduction relationship between the structural segment to be corrected and its adjacent upstream structural segment is re-determined. When the velocity reduction of the structural segment to be corrected is still greater than the velocity reduction of its adjacent upstream structural segment, the axial length increase processing and expansion angle reduction processing are continued until the velocity reduction between adjacent structural segments along the direction of molten metal flow gradually decreases. Replace the corresponding axial length and expansion angle in the initial structural parameter data with the axial length and expansion angle that satisfy the step-by-step decreasing state to generate the corrected structural parameter data.

8. A system for optimizing the internal flow channel design of a casting sand mold, characterized in that, The system, used in any one of claims 1 to 7, comprises: The initial flow channel data generation module is used to obtain the three-dimensional structural model of the target casting sand mold and construct the corresponding initial internal flow channel structure accordingly, thereby generating initial flow channel data. The flow channel partition data generation module is used to divide the inner cavity flow channel into segments along the preset flow path of the molten metal based on the initial flow channel data, forming an inlet guiding zone, a stable conveying zone, and a sensitive scouring zone, and generating flow channel partition data. The partition flow parameter generation module is used to calculate the local flow velocity and wall impact intensity of the molten metal during the filling process for each partition based on the flow channel partition data, generate partition flow parameter data, and extract the maximum actual flow velocity value and maximum wall impact intensity value of the sensitive scouring zone from the partition flow parameter data. The flow velocity control constraint data generation module is used to determine the maximum allowable flow velocity value based on the comparison between the maximum wall impact intensity value of the sensitive scour zone and the preset molding sand failure threshold. When the maximum wall impact intensity value is greater than the preset molding sand failure threshold, the maximum actual flow velocity value is reduced to a value where the corresponding wall impact intensity is not greater than the preset molding sand failure threshold, and the reduced flow velocity value is used as the maximum allowable flow velocity value. When the maximum wall impact intensity value is not greater than the preset molding sand failure threshold, the maximum actual flow velocity value is used as the maximum allowable flow velocity value. Flow velocity control constraint data is generated based on the maximum allowable flow velocity value. The preliminary buffer structure data generation module is used to construct a gradually expanding buffer section upstream of the sensitive scour zone based on the flow velocity control constraint data, and control the cross-sectional area of ​​the gradually expanding buffer section to change monotonically along the flow direction, and the area change rate between adjacent sections is not greater than a preset proportional threshold, thereby generating preliminary buffer structure data. The target buffer structure data generation module is used to determine the expansion angle and length of the gradually expanding buffer section based on the preliminary buffer structure data, so that it satisfies the functional relationship corresponding to the maximum allowable flow velocity value, and generate the target buffer structure data. The continuous transition channel data generation module is used to continuously adjust the curvature of the connection position between the stable conveying zone and the gradually expanding buffer section based on the target buffer structure data, so that the rate of change of flow direction is less than the preset rate of change of flow direction threshold, and generate continuous transition channel data. The final structural parameter generation module is used to perform verification calculations on the filling process based on the continuous transition channel data to obtain updated flow parameter data. When the impact intensity of the inner wall of the sensitive scour zone is lower than the preset molding sand failure threshold, the final optimized structural parameters of the inner cavity channel are generated.

9. A computing device, characterized in that, include: One or more processors; A storage device for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a program that, when executed by a processor, implements the method as described in any one of claims 1 to 7.

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