A method for manufacturing a wooden mold for an injection molding machine

Abstract

The application relates to the technical field of wood mold manufacturing, in particular to a wood mold manufacturing method for an injection molding machine and a die casting machine, which comprises the following steps: obtaining and scanning a target casting to obtain a three-dimensional graph of the target casting; checking whether the three-dimensional graph contains a cavity; determining the cavity position of the three-dimensional graph containing the cavity; determining the non-detachable position of the original wood mold according to the cavity position; projecting the non-detachable position to the parting surface of the target casting to obtain a first graph; analyzing the projection area of the first graph to determine whether the detachable area of the movable block in the wood mold needs to be changed; for the case that the detachable area of the movable block needs to be changed, detecting the shape complexity of the first graph, and determining the segmentation number of the movable block according to the shape complexity. The shape complexity is determined by the ratio of the actual curvature of the graph and the projection area, the segmentation number of the movable block is accurately determined, and the influence of the movable block on the mold during demolding is effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wood mold manufacturing, and particularly relates to a wood mold manufacturing method for an injection molding machine die casting machine. BACKGROUND

[0002] The existing process method is a traditional wood mold manufacturing process. A sand core is placed to form a cavity structure of a casting. A core box is manufactured for a position requiring the sand core in the process. The sand core is manufactured by using the core box. The sand core is coated with refractory material and baked. The sand core is placed into an outer mold and fixed in a series of operations. For specific structures, please refer to Figure 5 . The manufacturing cycle is long, delivery is slow, and material and labor cost consumption is large. The mold stripping process of taking the sand core out of the core box is easy to damage the sand core, resulting in poor appearance of the sand core, and even direct scrap in severe cases. In addition, when the sand core is placed into the sand mold in the mold closing process, the sand core and the sand mold are easy to rub and have scattered sand falling off. The scattered sand finally enters the iron liquid to form a casting, causing the material to be weak and easy to crack. When the size of the sand core is large, a suitable threaded steel framework needs to be designed and embedded in the sand core to prevent the sand core from breaking, further increasing the material and labor cost consumption.

[0003] Chinese Patent Publication No. CN103231022A discloses a pump body casting coated sand core assembly structure, which comprises: the sand core is a split core assembly structure, which comprises a first sand core, a second sand core and a third sand core, and is connected and fixed through concave-convex positioning grooves; the first sand core constitutes two side casting holes, an intermediate cavity, a bottom part of a two-side rhombic protrusion and a lower part of a left and right core head of the casting; the second sand core constitutes a top part of a left-side rhombic protrusion, an upper part of a left core head and a sand hanging supplement part below the casting; and the third sand core constitutes a top part of a right-side rhombic protrusion and an upper part of a right core head. The present application has the advantages that: the core box is convenient to manufacture; the number of movable blocks used in the core manufacturing process is the least, the operation is simple, and the core manufacturing production efficiency is improved; the sand hanging supplement core replaces the sand mold sand hanging, avoids the sand mold concave-convex parting, and also avoids the sand hanging, so that the molding quality is stable, and the size precision and the casting surface quality of the casting are ensured.

[0004] It can be seen that the prior art has the following problems: due to the lack of determination of shape complexity by actual curvature and projection area ratio of a graph, the split number of movable blocks cannot be accurately determined. SUMMARY

[0005] Therefore, the present application provides a wood mold manufacturing method for an injection molding machine die casting machine, which overcomes the problem in the prior art that due to the lack of determination of shape complexity by actual curvature and projection area ratio of a graph, the split number of movable blocks cannot be accurately determined.

[0006] To achieve the above object, the application provides a wood mold manufacturing method for injection molding machine and die casting machine, comprising the following steps: obtaining and scanning a target casting to obtain a three-dimensional graph of the target casting; checking whether the three-dimensional graph contains a cavity; determining a cavity position of the three-dimensional graph containing the cavity; determining an undetachable position of a wood mold according to the cavity position;

[0007] projecting the undetachable position to a parting surface of the target casting to obtain a first graph; analyzing a projection area of the first graph to determine whether a detachable area of a movable block in the wood mold needs to be changed;

[0008] for the case that the detachable area of the movable block needs to be changed, detecting a shape complexity of the first graph, and determining a splitting number of the movable block according to the shape complexity.

[0009] Further, the process of obtaining and scanning the target casting to obtain the three-dimensional graph of the target casting comprises the following steps: placing the target casting on a scanning table; starting a scanning device and performing omnidirectional scanning around the target casting to obtain the three-dimensional graph of the target casting.

[0010] Further, the process of determining the undetachable position of the wood mold according to the cavity position comprises the following steps: marking the cavity position of the three-dimensional graph to obtain a first marking point; marking a wood mold position based on the first marking point to obtain a second marking point; and determining whether the second marking point is an undetachable marking point.

[0011] Further, the process of projecting the undetachable position to the parting surface of the target casting comprises the following steps: projecting the undetachable position to a plane where the parting surface is located based on the second marking point to obtain the first graph; calculating an area of the first graph; and determining whether the area of the movable block needs to be changed according to a projection area ratio.

[0012] The projection area ratio is a ratio of the area of the first graph to an area of the parting surface.

[0013] Further, the process of detecting the shape complexity of the first graph comprises the following steps: detecting an actual aspect ratio of the first graph to obtain a graph actual aspect ratio; comparing the graph actual aspect ratio with a graph standard aspect ratio interval to obtain a graph aspect ratio comparison result; and determining whether the movable block needs to be split according to the graph aspect ratio comparison result.

[0014] Further, the process of determining whether the movable block needs to be split according to the graph aspect ratio comparison result comprises the following steps: for the case that the actual aspect ratio is in the graph standard aspect ratio interval, maintaining the original number of movable blocks;

[0015] for the case that the actual aspect ratio is greater than a maximum value of the graph standard aspect ratio interval, determining that the movable block needs to be split;

[0016] For the case that the actual aspect ratio is less than the minimum value of the graphic standard aspect ratio interval, the active block is redesigned;

[0017] The actual parameter value is a value for determining whether to split the original active block.

[0018] Further, the process of determining the number of times of splitting the active block comprises determining an actual parameter value of the active block according to the difference between the maximum value of the graphic standard aspect ratio interval and the actual aspect ratio and the first parameter, comparing the actual parameter value with a standard parameter value, and determining the number of times of splitting the active block according to a comparison result.

[0019] The first parameter is an influence compensation parameter of the difference between the maximum value of the graphic standard aspect ratio interval and the actual aspect ratio on the actual parameter value.

[0020] Further, the process of determining the number of times of splitting the active block according to the comparison result comprises, for the case that the actual parameter value is less than or equal to the standard parameter value, determining that the number of times of splitting the active block is one.

[0021] For the case that the actual parameter value is greater than the standard parameter value, it is determined that the number of times of splitting the active block is not less than two.

[0022] Further, the process of detecting the shape complexity of the first graphic comprises detecting the curvature of the first graphic to obtain a graphic actual curvature, comparing the graphic actual curvature with a graphic standard curvature threshold value to obtain a graphic curvature comparison result, and determining whether to split the active block according to the graphic curvature comparison result.

[0023] The graphic standard curvature threshold value comprises a first standard curvature threshold value and a second standard curvature threshold value, and the first standard curvature threshold value is less than the second standard curvature threshold value.

[0024] When the graphic actual curvature is less than or equal to the first standard curvature threshold value, it is determined that the shape complexity is low complexity, and the number of original active blocks is maintained.

[0025] When the graphic actual curvature is greater than the first standard curvature threshold value and less than or equal to the second standard curvature threshold value, it is determined that the shape complexity is medium complexity, and the active block is split once.

[0026] When the graphic actual curvature is greater than the second standard curvature threshold value, it is determined that the shape complexity is high complexity, and the active block is split at least twice.

[0027] Further, the process of determining the number of times of splitting the active block according to the shape complexity comprises determining a shape complexity coefficient according to the graphic actual curvature and the projection area ratio, and the calculation formula of the shape complexity coefficient is: shape complexity coefficient = graphic actual curvature × projection area ratio × second parameter.

[0028] The second parameter is a comprehensive adjustment coefficient.

[0029] The shape complexity coefficient is used to determine the number of live block partitions, specifically:

[0030] When the shape complexity coefficient is less than or equal to a first threshold value, the number of live block partitions is 0.

[0031] When the shape complexity coefficient is greater than the first threshold value and less than or equal to a second threshold value, the number of live block partitions is 1.

[0032] When the shape complexity coefficient is greater than the second threshold value and less than or equal to a third threshold value, the number of live block partitions is 2.

[0033] When the shape complexity coefficient is greater than the third threshold value, the number of live block partitions is 3 or more.

[0034] Compared with the prior art, the present application has the beneficial effects that by adjusting the position of the casting and performing multi-angle scanning around it, the entire surface features of the multi-curved and complex structure casting can be completely captured, avoiding missing models due to scanning dead angles. For example, in the hidden areas such as grooves and corners of box-type castings, multi-angle scanning can ensure that the point cloud data is not missed, providing a complete data basis for subsequent cavity detection. Using a high-precision three-dimensional laser scanner can accurately obtain the details of the casting surface. Laser scanning does not require contact with the casting surface, avoiding damage to the iron casting material, and is particularly suitable for the detection of thin-walled parts or surface plated castings. The generated three-dimensional point cloud model corresponds one-to-one to the physical casting, which can be permanently saved and called at any time. In batch production, by comparing the three-dimensional models of different batches of castings, changes in cavity position caused by mold wear and casting process fluctuations can be quickly found, such as the appearance of cavities at the top of a batch of castings due to design problems with the sprue, which can be adjusted in time by comparing the models.

[0035] Further, by accurately marking the three-dimensional graphic cavity and determining the non-detachable position of the original wooden mold, damage to the casting caused by improper disassembly of the original wooden mold can be avoided. In the production of complex structure iron box castings, if the original wooden mold supporting the key stress part of the casting is mistakenly disassembled, the casting is prone to deformation or fracture under stress, which will increase the scrap rate. Accurate determination of the non-detachable position can effectively reduce the scrap rate, significantly improve the casting quality and pass rate, and reduce the waste of raw materials and production costs. The detailed determination process provides an accurate basis for casting process optimization. Based on the non-detachable marking points, technicians can clearly understand the relationship between the original wooden mold and the casting structure, and can optimize the mold design in advance for positions that are difficult to disassemble or critical to the shape of the casting. For example, for positions where the original wooden mold is difficult to separate from the casting groove, a demolding slope can be added during mold design to simplify the disassembly process, shorten the production cycle, and improve production efficiency.

[0036] Further, the influence of the non-detachable position on demolding is converted into a quantitative index through the projection area ratio. This scheme integrates three dimensions of data quantification, geometric optimization, and process verification, upgrading the traditional casting live block design mode relying on experience and trial and error to a model-based system engineering, especially suitable for the production of multi-variety small-batch, high-precision complex castings, providing a quantifiable and traceable technical path for process optimization in the context of intelligent manufacturing.

[0037] Further, the influence of the non-detachable position on demolding is converted into a quantitative index through the projection area ratio. This scheme integrates three dimensions of data quantification, geometric optimization, and process verification, upgrading the traditional casting live block design mode relying on experience and trial and error to a model-based system engineering, especially suitable for the production of multi-variety small-batch, high-precision complex castings, providing a quantifiable and traceable technical path for process optimization in the context of intelligent manufacturing.

[0038] Further, the live block segmentation decision is upgraded from experience judgment to numerical decision through quantitative indicators such as aspect ratio and actual parameter value, avoiding human error. Combined with the characteristics of ferrous materials, a standard interval is set, making the process scheme of similar products reusable and improving the design efficiency of new castings.

[0039] Further, the greater the curvature, such as 0.020 mm in case C1 -¹ , the more dramatic the surface fluctuation, and the more uneven the resistance distribution when the live block is demolded, which can easily cause the castings to be damaged or the mold to be broken. By setting a first standard curvature threshold of 0.005 mm and a second standard curvature threshold of 0.015 mm -¹ , the complexity of the curved surface is divided into low, medium, and high levels, providing geometric basis for segmentation decision. The larger the projection area ratio, such as 0.6 in case C1, the higher the proportion of complex curved surface on the parting surface, and the more significant the impact on the overall mold disassembly. When the actual curvature of the graph is greater than the second standard curvature threshold, segmentation at least twice can decompose the high-curvature live block into multiple low-curvature sub-live blocks, dispersing the demolding resistance and effectively protecting the mold. The second parameter serves as a comprehensive adjustment coefficient and can dynamically correct the segmentation strategy according to the modulus of elasticity of wood. For example, softwoods such as pine have low bending strength, so by increasing the second parameter to 0.8, segmentation can be triggered in advance to avoid mold failure due to wood deformation; hardwoods such as birch can reduce the second parameter to 0.6 to ensure strength while reducing unnecessary segmentation. After segmentation once in the medium-curvature region such as case B1, the live block projection area ratio decreases from 0.4 to 0.2, and the flow path of the plastic melt in the cavity becomes more regular. After segmentation, the surface complexity of each sub-live block in the high-curvature region is reduced, which can reduce the impact on the mold when the live block is disassembled. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1Flowchart of the method for making a wooden mold for an injection molding machine or a die-casting machine in the embodiment;

[0041] Figure 2 Flowchart of a process for determining a change in a movable block area in a method for manufacturing a wooden mold for an injection molding machine or a die-casting machine in an embodiment;

[0042] Figure 3 Flow chart of the splitting live piece determination process of the method for manufacturing a wooden mold for an injection molding machine or a die-casting machine in the embodiment;

[0043] Figure 4 Flowchart of the process of determining the active piece segmentation of the method for manufacturing a wooden mold for an injection molding machine or a die-casting machine in the embodiment;

[0044] Figure 5 A schematic diagram of a casting structure of a traditional wooden mold manufacturing process in the background art;

[0045] Figure 6 Schematic diagram of the casting structure of the method for making a wooden mold for an injection molding machine or a die-casting machine in the embodiment.

[0046] In the figure, 1-first sand core; 2-second sand core; 3-third sand core; 4-fourth sand core; 5-first movable block; 6-second movable block; 7-third movable block; 8-fourth movable block; 9-cavity. DETAILED DESCRIPTION

[0047] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0048] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0049] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0050] Moreover, it needs to be explained that in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0051] Please refer to Figures 1-4 as shown, Figure 1 is a flow chart of the wood mold manufacturing method for injection molding machine die casting machine in the embodiment; Figure 2 is a flow chart of the movable block area change determination process of the wood mold manufacturing method for injection molding machine die casting machine in the embodiment; Figure 3 is a flow chart of the split movable block determination process of the wood mold manufacturing method for injection molding machine die casting machine in the embodiment; Figure 4 is a flow chart of the movable block segmentation process of the wood mold manufacturing method for injection molding machine die casting machine in the embodiment; Figure 5 is a schematic diagram of the casting structure of the traditional wood mold manufacturing process in the background art; Figure 6 is a schematic diagram of the casting structure of the wood mold manufacturing method for injection molding machine die casting machine in the embodiment.

[0052] The embodiment provides a wood mold manufacturing method for injection molding machine die casting machine, comprising the following steps,

[0053] Step S1, obtaining and scanning a target casting to obtain a three-dimensional graph of the target casting, checking whether the three-dimensional graph contains a cavity, determining the cavity position of the three-dimensional graph containing the cavity, and determining the non-detachable position of the original wood mold according to the cavity position;

[0054] Step S2, projecting the non-detachable position to the parting surface of the target casting to obtain a first graph, analyzing the projection area of the first graph to determine whether the detachable area of the movable block in the wood mold needs to be changed;

[0055] Step S3, for the case that the detachable area of the movable block needs to be changed, detecting the shape complexity of the first graph, and determining the segmentation number of the movable block according to the shape complexity.

[0056] Please refer to Figure 6 as shown, and Figure 5 compared with Figure 6 the movable block in the embodiment is replaced Figure 5 the sand core position, which can simplify the steps of mold manufacturing and improve the preparation efficiency.

[0057] Specifically, the process of obtaining and scanning the target casting to obtain the three-dimensional graph of the target casting includes placing the target casting on the scanning table, turning on the scanning device and performing a full-range scan around the target casting to obtain the three-dimensional graph of the target casting.

[0058] In this embodiment, the specific scenario is that a batch of box body castings with multiple curved surfaces are produced in a certain precision injection molding factory.

[0059] The target casting is placed on the scanning workbench, the position of the casting is adjusted to ensure that it is within the effective scanning range of the scanner and each part can be completely scanned. The three-dimensional laser scanner is started, and the scanning resolution is set. The specific value is subject to the actual scene requirements to ensure that sufficient detailed casting surface data is obtained; and the casting surface is fully covered. The scanner is turned on to scan the target casting. The scanner emits a laser beam, measures the time for the laser to be emitted and reflected back to the scanner, calculates the distance from each point on the casting surface to the scanner according to the speed of light, and records the angle information of the laser at the same time, thereby obtaining the three-dimensional coordinate data of the casting surface to form point cloud data. Due to the complex structure of the casting, it needs to be scanned from multiple angles. After scanning is completed, the point cloud data at each angle is imported into professional three-dimensional modeling and analysis software. The automatic splicing function of the software is used to accurately splice the point cloud data at different angles together through feature matching and global registration algorithm to form a complete three-dimensional point cloud model of the target casting. The process of scanning the casting to form a three-dimensional graph is prior art, and will not be described here.

[0060] By adjusting the position of the casting and performing multi-angle scanning around it, all surface features of the multi-curved and complex structure casting can be completely captured, and model missing caused by scanning dead angles can be avoided. For example, in the hidden areas such as grooves and corners of box body castings, multi-angle scanning can ensure that the point cloud data is not missed, providing a complete data basis for subsequent cavity detection. High-precision three-dimensional laser scanners can accurately obtain the details of the casting surface. Laser scanning does not require contact with the casting surface, which avoids damage to the iron casting material, and is especially suitable for the detection of thin-walled parts or surface plated castings. The generated three-dimensional point cloud model corresponds one-to-one to the physical casting, which can be permanently saved and called at any time. In batch production, by comparing the three-dimensional models of different batches of castings, changes in cavity position caused by mold wear and casting process fluctuations can be quickly found, for example, a batch of castings has a cavity at the top due to a design problem with the sprue, and the pouring system can be adjusted in time through model comparison.

[0061] Specifically, the process of determining the non-detachable position of the log type according to the cavity position includes marking the cavity position of the three-dimensional graph to obtain a first marking point, marking the position of the log type based on the first marking point to obtain a second marking point, and determining whether the second marking point is a non-detachable marking point.

[0062] The mouse pointer is moved to the area where the cavity is displayed in the three-dimensional figure by using the marking tool of the software, and a mark point is added at the boundary vertex, key turning point, etc. of the cavity by clicking operation. For example, if the cavity is irregularly shaped, mark at the four corner points, top of the convex part, bottom of the concave part, and other key positions. For a larger cavity, mark points are added at intervals of, for example, 5 mm inside and on the boundary to ensure that the shape and position of the cavity can be completely depicted, and finally a series of first mark points representing the position of the cavity are obtained. At the same time, in order to distinguish, these first mark points are set to red display.

[0063] The three-dimensional figure of the casting and the corresponding three-dimensional model of the original wood mold are imported into the same software workspace, and the two are accurately aligned according to the assembly relationship of the casting and the original wood mold during design by using the alignment function of the software. With the first mark point as a reference, the corresponding position of the first mark point is found on the original wood mold model along the contact direction of the casting and the original wood mold. For example, if the first mark point is located in the cavity near the side wall inside the casting, a mark point is added at the corresponding position of the inside of the side wall on the original wood mold model. These mark points added on the original wood mold model are the second mark points. Similarly, in order to distinguish, the second mark points are set to blue display. According to the design drawing of the casting and the mechanical performance requirement, if the second mark point is located in the area where the original wood mold supports the key stress part of the casting, such as the position of the original wood mold column supporting the bottom reinforcing rib of the casting, removing the original wood mold at this position may cause the casting to deform or break under stress, affecting the mechanical performance of the casting, then it is determined that the second mark point is a non-removable mark point. Check the complexity and spatial position of the structure around the second mark point. If the second mark point is in an area where the original wood mold and the complex curved surface inside the casting are closely fitted and difficult to separate, such as the original wood mold embedded in the groove inside the casting and closely fitted with the groove side wall, forcibly removing it may damage the integrity of the casting surface or cause damage to the original wood mold. Then it is determined that the second mark point is a non-removable mark point. At the same time, considering the accessibility of the dismounting tool, if the conventional dismounting tool cannot be used for operation at this position, it is also determined as a non-removable mark point. If the original wood mold at the position of the second mark point plays an important supporting and shaping role during the cooling and solidification process of the casting, and early removal may cause the casting to deform due to internal stress release, such as the position of the original wood mold support block in the thin-walled area at the top of the casting, it is determined that the second mark point is a non-removable mark point. After the determination of all second mark points is completed, the positions of all second mark points determined as non-removable mark points are highlighted on the three-dimensional model of the original wood mold.

[0064] By accurately marking the three-dimensional graphic cavity and determining the non-detachable position of the log pattern, damage to the casting caused by improper disassembly of the log pattern can be avoided. In the production of iron box castings with complex structures, if the log pattern supporting the key stress part of the casting is mistakenly disassembled, the casting is prone to deformation or fracture when stressed, which will increase the scrap rate. Accurate determination of the non-detachable position can effectively reduce the scrap rate, significantly improve the casting quality and qualification rate, and reduce the waste of raw materials and production cost. The detailed determination process provides an accurate basis for casting process optimization. Based on the non-detachable marking points, the technical personnel can clearly understand the mutual relationship between the log pattern and the casting structure. For positions that are difficult to disassemble or are critical to the shaping of the casting, the mold design can be optimized in advance, and the structure and assembly method of the log pattern can be adjusted. For example, for positions where the log pattern is difficult to separate from the recess in the casting, a demolding slope can be added during mold design to simplify the disassembly process, shorten the production cycle, and improve production efficiency.

[0065] Specifically, the process of projecting the non-detachable position to the parting surface of the target casting includes projecting the non-detachable position to the plane where the parting surface is based on the second marking point to obtain a first graph, calculating the area of the first graph, and determining whether the movable block area needs to be changed according to the projection area ratio.

[0066] Wherein, the projection area ratio is the ratio of the first graph area to the parting surface area.

[0067] In this embodiment, the parting surface is the maximum contour plane of the casting mold. The three-dimensional contour of the non-detachable position is projected to the plane where the parting surface is in the demolding direction to generate a first graph. The first graph area and the projection area are calculated based on the computer. The projection area ratio is determined according to the ratio of the first graph area to the projection area, wherein the demolding direction is perpendicular to the parting surface

[0068] Compare the projection area ratio with the projection area ratio threshold value,

[0069] If the projection area ratio is less than or equal to the projection area ratio threshold value, maintain the original movable block area;

[0070] If the projection area ratio is greater than the projection area ratio threshold value, reduce the movable block area according to the difference between the projection area ratio threshold value and the projection area ratio;

[0071] When the projection area ratio is less than or equal to 0.15, maintain the original movable block area;

[0072] When the projection area ratio is 0.16 greater than 0.15, the movable block area needs to be adjusted. Set the original movable block area to 0.12m 2 Then the adjusted movable block area is the original movable block area plus the product of the original movable block area and 1 minus the projection area ratio threshold value / projection area ratio, that is, 0.12+0.12×(1-0.15 / 0.16)=0.1275m 2 .

[0073] The projection area ratio threshold is determined according to the specific casting material and structural characteristics, for example, the casting material is brittle and has low shear strength, and the structure is a boss root, and the projection area ratio threshold can be set to 0.25.

[0074] The influence of the non-detachable position on demolding is converted into a quantitative index by the projection area ratio. This scheme integrates three dimensions of data quantification, geometric optimization and process verification, upgrades the traditional casting live block design mode relying on experience and trial and error to a model-based system engineering, and is especially suitable for the production of multi-variety small batch, high precision and complex castings, and provides a quantifiable and traceable technical path for process optimization in the context of intelligent manufacturing.

[0075] Specifically, the process of detecting the shape complexity of the first graph includes detecting the aspect ratio of the first graph to obtain an actual aspect ratio of the graph, comparing the actual aspect ratio of the graph with a standard aspect ratio interval of the graph to obtain an aspect ratio comparison result of the graph, and determining whether to split the live block according to the aspect ratio comparison result of the graph.

[0076] Specifically, the process of determining whether to split the live block according to the aspect ratio comparison result of the graph includes, for the case that the actual aspect ratio is in the standard aspect ratio interval of the graph, maintaining the original number of live blocks.

[0077] For the case that the actual aspect ratio is greater than the maximum value of the standard aspect ratio interval of the graph, it is determined that the live block needs to be split.

[0078] For the case that the actual aspect ratio is less than the minimum value of the standard aspect ratio interval of the graph, the live block is re-designed.

[0079] The actual parameter value is a value for determining whether to split the original live block.

[0080] Specifically, the process of determining the split live block includes determining an actual parameter value of the split live block according to the difference between the maximum value of the standard aspect ratio interval of the graph and the actual aspect ratio and a first parameter, comparing the actual parameter value with a standard parameter value, and determining the number of times of splitting the live block according to the comparison result.

[0081] The first parameter is an influence compensation parameter of the difference between the maximum value of the standard aspect ratio interval of the graph and the actual aspect ratio on the actual parameter value.

[0082] Specifically, the process of determining the number of times of splitting the live block according to the comparison result includes, for the case that the actual parameter value is less than or equal to the standard parameter value, determining that the number of times of splitting the live block is one.

[0083] For the case that the actual parameter value is greater than the standard parameter value, it is determined that the number of times of splitting the live block is not less than two.

[0084] Through three-dimensional scanning and projection analysis, the actual aspect ratio of the first pattern is respectively:

[0085] Case A: the actual aspect ratio is 1.8, which falls within the pattern standard aspect ratio interval [1.2, 2.5];

[0086] Case B: the actual aspect ratio is 3.2, which is greater than the maximum value 2.5 of the pattern standard aspect ratio interval;

[0087] Case C: the actual aspect ratio is 0.9, which is less than the minimum value 1.2 of the pattern standard aspect ratio interval;

[0088] Case A: maintain the original number of active blocks;

[0089] Case B: the active block needs to be split, and the number of splits is calculated;

[0090] Case C: redesign the active block, such as adjusting the position or shape of the active block, without splitting.

[0091] In this embodiment, the first parameter is set to 0.8; the standard parameter value is 1; the pattern standard aspect ratio interval is [1.2, 2.5], which is the basic threshold for determining whether the active block needs to be split. The setting is based on the actual functional requirements and assembly feasibility of the active block: if the aspect ratio is too small, such as close to 1, close to a square, it may lead to redundant active block structure, occupying too much space or increasing processing cost; if the aspect ratio is too large, such as much larger than 2.5, it may lead to a decrease in the stability of the active block structure, such as easy deformation, difficulty in positioning during assembly, or not meeting the size requirements of subsequent processes. The interval [1.2, 2.5] is a reasonable range determined by considering the structural stability, processing convenience, and space utilization of the active block. Active blocks within this interval do not need to be adjusted to meet normal use requirements. The first parameter is an influence compensation parameter of the difference between the maximum value of the pattern standard aspect ratio interval and the actual aspect ratio on the actual parameter value. Its role is to adjust the influence strength of the difference on the number of splits. The difference between the actual aspect ratio and the standard maximum value, such as 3.2-2.5=0.7 in case B, directly reflects the degree of deviation of the active block from the standard. However, this deviation does not need to be directly transmitted to the number of splits, i.e. the difference is not directly used as the basis for judgment. If the first parameter is 1, the difference will directly determine the actual parameter value, which may lead to over-sensitivity to the number of splits, such as considering that multiple splits are needed if the difference is slightly large. By setting the first parameter to 0.8, the influence of the difference can be appropriately weakened to avoid over-splitting. The compensation coefficient of 0.8 is the result of actual case verification, which can ensure necessary splitting of active blocks that deviate too much from the standard, and make the number of splits meet the actual processing capacity, such as one split to meet the aspect ratio requirements of the sub-active block,

[0092] Actual parameter value = difference between maximum value of pattern standard aspect ratio interval and actual aspect ratio x first parameter;

[0093] Case B corresponds to the actual parameter value = (3.2-2.5) x 0.8 = 0.7 x 0.8 = 0.56; the actual parameter value corresponding to case B is less than the standard parameter value, and the number of times of dividing the original active block is one; the original active block is divided into two sub-active blocks along the long edge direction, and the length-width ratio of each sub-active block is ensured to fall within the standard interval [1.2, 2.5],

[0094] For example:

[0095] The size of the original active block is: length 320mm x width 100mm, and the length-width ratio is 3.2

[0096] The size of the sub-active block after division is: length 160mm x width 100mm, and the length-width ratio is 1.6, which meets the standard length-width ratio interval of the figure;

[0097] Suppose the actual length-width ratio is 4.0, and the actual parameter value is (4.0-2.5) x 0.8 = 1.5 x 0.8 = 1.2,

[0098] The actual parameter value is greater than the standard parameter value, and the number of times of division is not less than two,

[0099] The division scheme: the original active block is divided into three sub-active blocks along the long edge direction, and the length-width ratio of each sub-active block is about 1.33, which meets the standard length-width ratio interval of the figure.

[0100] The actual parameter value reflects the degree of deviation of the length-width ratio from the standard, and is corrected by the first parameter. Through historical data statistics, when the actual parameter value is less than or equal to the standard parameter value, single division can make the length-width ratio of the sub-active block fall within the standard interval. When the actual parameter value is greater than the standard parameter value, multiple divisions can effectively reduce the length-width ratio.

[0101] By calculating the length-width ratio, the actual parameter value and other quantitative indicators, the active block division decision is upgraded from experience judgment to numerical decision, avoiding human error. Combined with the characteristics of iron materials, the standard interval is set, so that the process scheme of similar products can be reused. The "length-width ratio-actual parameter value" database established by the factory can improve the design efficiency of new castings.

[0102] Specifically, the process of detecting the shape complexity of the first figure includes detecting the actual curvature of the figure to obtain a figure actual curvature, comparing the figure actual curvature with a figure standard curvature threshold to obtain a figure curvature comparison result, and determining whether to split the active block according to the figure curvature comparison result.

[0103] The figure standard curvature threshold includes a first standard curvature threshold and a second standard curvature threshold, and the first standard curvature threshold is less than the second standard curvature threshold.

[0104] When the actual curvature of the figure is less than or equal to the first standard curvature threshold, the shape complexity is determined to be low complexity, and the original number of active blocks is maintained;

[0105] When the actual curvature of the figure is greater than the first standard curvature threshold and less than or equal to the second standard curvature threshold, the shape complexity is determined to be medium complexity, and the active blocks are divided once;

[0106] When the actual curvature of the figure is greater than the second standard curvature threshold, the shape complexity is determined to be high complexity, and the active blocks are divided at least twice.

[0107] Specifically, the process of determining the number of divisions of the active blocks according to the shape complexity includes determining a shape complexity coefficient according to the actual curvature of the figure and the projection area ratio, and the calculation formula of the shape complexity coefficient is: shape complexity coefficient = actual curvature of figure × projection area ratio × second parameter;

[0108] Wherein, the second parameter is a comprehensive adjustment coefficient;

[0109] The number of active block divisions is determined based on the shape complexity coefficient, specifically:

[0110] When the shape complexity coefficient is less than or equal to the first threshold, the number of active block divisions is 0;

[0111] When the shape complexity coefficient is greater than the first threshold and less than or equal to the second threshold, the number of active block divisions is 1;

[0112] When the shape complexity coefficient is greater than the second threshold and less than or equal to the third threshold, the number of active block divisions is 2;

[0113] When the shape complexity coefficient is greater than the third threshold, the number of active block divisions is 3 or more.

[0114] Five key points of the first figure contour are extracted, the curvature radius of each point is calculated according to a figure software such as CAD, and the actual curvature of the figure is calculated according to the curvature radius of each point,

[0115] In this embodiment, the first standard curvature threshold is set to 0.005 mm -¹ , the second standard curvature threshold is set to 0.015 mm -¹ , and the second parameter is 0.7,

[0116] The Gaussian curvature of the first figure is extracted from the three-dimensional scanning data, and three cases are assumed,

[0117] The curvature of case A1 is 0.003 mm -¹ , which is low curvature and gentle surface;

[0118] The curvature of case B1 is 0.010 mm -¹, medium curvature, general curved surface;

[0119] The curvature of case C1 is 0.020 mm -¹ , high curvature, complex curved surface;

[0120] The total area of the parting surface in this embodiment is 5000 mm 2 , the first pattern area is respectively:

[0121] Case A1: 1200 mm², the corresponding projection area ratio is 1200 / 5000 = 0.24;

[0122] Case B1: 2000 mm², the corresponding projection area ratio is 2000 / 5000 = 0.4;

[0123] Case C1: 3000 mm², the corresponding projection area ratio is 3000 / 5000 = 0.6;

[0124] The shape complexity is the actual curvature of the pattern multiplied by the projection area ratio multiplied by the second parameter,

[0125] The shape complexity corresponding to case A1 is 0.003 x 0.24 x 0.7 = 0.000504;

[0126] The shape complexity corresponding to case B1 is 0.010 x 0.4 x 0.7 = 0.028;

[0127] The shape complexity corresponding to case C1 is 0.020 x 0.6 x 0.7 = 0.084;

[0128] The shape complexity corresponding to case A1 is less than the first threshold value, and the number of live block segmentation is 0;

[0129] The shape complexity corresponding to case B1 is greater than the first threshold value and less than or equal to the second threshold value, and the number of segmentation is 1;

[0130] The shape complexity corresponding to case C1 is greater than the second threshold value and less than or equal to the third threshold value, and the number of live block segmentation is 2.

[0131] The greater the curvature, such as 0.020 mm -¹ , the more dramatic the surface fluctuation, and the more uneven the resistance distribution when the live block is demolded, which is easy to cause the casting to be pulled or the mold to be broken. By setting the first standard curvature threshold value 0.005 mm and the second standard curvature threshold value 0.015 mm -¹The complexity of the curved surface is divided into three grades of low, medium and high, which provides geometric basis for the segmentation decision. The larger the projection area ratio is, such as 0.6 in case C1, the higher the proportion of the complex curved surface on the parting surface is, and the more significant the influence on the mold disassembly is. When the actual curvature of the graph is greater than the second standard curvature threshold, the high-curvature core is decomposed into multiple low-curvature sub-cores by segmentation at least twice, so as to disperse the demolding resistance and effectively protect the mold. The second parameter is used as a comprehensive adjustment coefficient, which can dynamically correct the segmentation strategy according to the elastic modulus of wood. For example, the bending strength of soft wood such as pine is low, and the segmentation can be triggered in advance by increasing the second parameter to avoid mold failure caused by wood deformation; the second parameter of hard wood such as birch can be reduced to ensure the strength while reducing unnecessary segmentation. After the segmentation of the medium-curvature area such as case B1, the core projection area ratio is reduced from 0.4 to 0.2, and the flow path of the plastic melt in the cavity is more regular. After the segmentation of the high-curvature area, the surface complexity of each sub-core is reduced, which can reduce the influence on the mold when the core is disassembled.

[0132] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to related technical features without departing from the principles of the present application, and the technical solutions after the changes or replacements will fall within the protection scope of the present application.

[0133] The above description is only the preferred embodiments of the present application and is not used to limit the present application; for those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for making a wooden mold for an injection molding machine or a die-casting machine, characterized in that: include, Acquire and scan the target casting to obtain a three-dimensional image of the target casting, check whether the three-dimensional image contains a cavity, determine the position of the cavity in the three-dimensional image containing the cavity, and determine the non-detachable position of the log mold based on the cavity position; Projecting the non-detachable position onto the parting surface of the target casting to obtain a first figure, and analyzing the projected area of ​​the first figure to determine whether the detachable area of ​​the movable block in the wooden mold needs to be changed; In the case where the detachable area of ​​the movable block needs to be changed, detecting the shape complexity of the first figure, and determining the number of divisions of the movable block according to the shape complexity; The process of determining the non-detachable position of the log type according to the cavity position includes: Marking the cavity position of the three-dimensional figure to obtain a first marking point, obtaining a second marking point based on the first marking point corresponding to the marked log position, and determining whether the second marking point is a non-detachable marking point; The process of projecting the non-detachable position onto the parting surface of the target casting includes: Based on the second marking point, the non-detachable position is projected onto the plane where the parting surface is located to obtain a first figure, the area of ​​the first figure is calculated, and whether the area of ​​the movable piece needs to be changed according to the projection area ratio; Wherein, the projected area ratio is the ratio of the area of ​​the first figure to the area of ​​the parting surface; The process of detecting the shape complexity of the first graphic includes: Detecting the aspect ratio of the first graphic to obtain an actual aspect ratio of the graphic, comparing the actual aspect ratio of the graphic with a standard aspect ratio range of the graphic to obtain a graphic aspect ratio comparison result, and determining whether to split the live block based on the graphic aspect ratio comparison result; or; the process of detecting the shape complexity of the first graphic includes: The curvature of the first figure is detected to obtain an actual curvature of the figure, the actual curvature of the figure is compared with a standard curvature threshold of the figure to obtain a figure curvature comparison result, and whether to split the live block is determined according to the figure curvature comparison result.

2. The method for manufacturing a wooden mold for an injection molding machine or a die-casting machine according to claim 1, wherein: The process of acquiring and scanning the target casting to obtain a three-dimensional image of the target casting includes: The target casting is placed on the scanning table, the scanning device is turned on and an all-around scan is performed around the target casting to obtain a three-dimensional image of the target casting.

3. The method for manufacturing a wooden mold for an injection molding machine or a die-casting machine according to claim 2, wherein: The process of determining whether to split the live block according to the aspect ratio comparison result of the graphic includes: If the actual aspect ratio is within the standard aspect ratio range of the graphic, the original number of active blocks is maintained; If the actual aspect ratio is greater than the maximum value of the standard aspect ratio range of the graphic, it is determined that the live block needs to be split; If the actual aspect ratio is smaller than the minimum value of the standard aspect ratio range of the graphic, the live block will be redesigned; The actual parameter value is used to determine whether to split the original live block.

4. The method for manufacturing a wooden mold for an injection molding machine or a die-casting machine according to claim 3, wherein: The process of determining the segmentation block includes: determining an actual parameter value for segmenting the live block based on a difference between a maximum value of the standard aspect ratio interval of the graphic and the actual aspect ratio and the first parameter, comparing the actual parameter value with the standard parameter value, and determining the number of segmentations based on the comparison result; The first parameter is a compensation parameter for the effect of the difference between the maximum value of the standard aspect ratio range of the graphic and the actual aspect ratio on the actual parameter value.

5. The method for manufacturing a wooden mold for an injection molding machine or a die-casting machine according to claim 4, wherein: The process of determining the number of times to split the live block based on the comparison results includes: When the actual parameter value is less than or equal to the standard parameter value, the number of times the active block is split is determined to be once; When the actual parameter value is greater than the standard parameter value, the number of times of splitting the live block is determined to be no less than twice.

6. The method for manufacturing a wooden mold for an injection molding machine or a die-casting machine according to claim 2, wherein: The standard curvature threshold of the graphic includes a first standard curvature threshold and a second standard curvature threshold, and the first standard curvature threshold is smaller than the second standard curvature threshold; When the actual curvature of the graphic is less than or equal to the first standard curvature threshold, the shape complexity is determined to be low complexity and the original number of active blocks is maintained; When the actual curvature of the graphic is greater than the first standard curvature threshold and less than or equal to the second standard curvature threshold, the shape complexity is determined to be medium complexity, and the live block is split once; When the actual curvature of the graphic is greater than the second standard curvature threshold, the shape complexity is determined to be high complexity, and the live block is divided at least twice.

7. The method for manufacturing a wooden mold for an injection molding machine or a die-casting machine according to claim 6, wherein: The process of determining the number of segmentations of the live block according to the shape complexity includes: Determine the shape complexity coefficient according to the actual curvature of the figure and the projected area ratio, wherein the shape complexity coefficient is calculated as follows: shape complexity coefficient = actual curvature of the figure × projected area ratio × second parameter; Wherein, the second parameter is a comprehensive adjustment coefficient; The number of live block divisions is determined based on the shape complexity coefficient, specifically: When the shape complexity coefficient is less than or equal to the first threshold, the number of active block divisions is 0; When the shape complexity coefficient is greater than the first threshold and less than or equal to the second threshold, the number of active block divisions is 1; When the shape complexity coefficient is greater than the second threshold and less than or equal to the third threshold, the number of active block divisions is 2; When the shape complexity coefficient is greater than the third threshold, the number of active block divisions is 3 or more.

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