Plastic mold design method and device

Abstract

The invention relates to the technical field of plastic molds, and discloses a plastic mold design method and device. The method comprises the steps that an initial three-dimensional model, a mold core and a coordinate origin of the plastic part and the position and size of a pouring gate of a mold are obtained; mold core shape data are determined; judging whether boundary lines of the mold core are intersected or not, performing corresponding operation according to whether the boundary lines are intersected or not, and updating the three-dimensional model; calculating the contact pressure value of the mold core; according to the contact pressure value and the shape data of the mold adjusting core, the buffer value and the mold clamping force of the mold are obtained through calculation; and generating operation is carried out based on the three-dimensional model, the mold core shape data, the position and size of a pouring gate of the mold, a mold buffer value and a mold clamping force, and a mold design scheme of the plastic part is obtained. According to the method, various parameters of the initial plastic part and the initial mold are calculated through an algorithm, the contact pressure distribution of the mold closing surface of the mold is effectively obtained, a buffer mechanism is designed according to the contact pressure distribution, and the performance and efficiency of the mold are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic molds, and in particular to a plastic mold design method and device. Background Art

[0002] Molds, as an indispensable core tool in the manufacturing industry, are specifically used to accurately and efficiently produce various parts and components. They are widely used in machinery, electronics, automobile manufacturing, aerospace and many other high-tech fields. Mold design is not only the cornerstone for these industries to achieve large-scale, high-quality product production, but its core goal is to ensure the ultimate molding accuracy and consistency of parts through precise design, thus occupying a key position in the rapidly changing manufacturing market.

[0003] Mold design is a complex task that involves many factors, including material selection, structural design, stress analysis, cooling system layout, etc. In the mold design process, the contact pressure distribution on the mold surface is very important because it is directly related to the performance and service life of the mold. The final contact pressure of the mold surface is determined by the structure and parameters of each part of the mold. Therefore, a reasonable design method is very important to ensure the quality and efficiency of the mold.

[0004] At present, when designing plastic molds, the common practice is to follow the user's experience, which requires multiple simulations and tests, lacking scientific calculations and optimization, which often leads to a decline in mold performance and a shortened service life. In particular, when considering the contact pressure distribution on the mold surface, there is no unified standard and algorithm, resulting in the inability to effectively guarantee the performance and efficiency of the mold. Summary of the invention

[0005] The present invention provides a plastic mold design method and device to effectively calculate the contact pressure distribution of the mold mating surface, and design a buffer mechanism based on the calculation to improve the performance and efficiency of the mold.

[0006] In a first aspect, in order to solve the above technical problems, the present invention provides a plastic mold design method, comprising: Obtain the initial 3D model, core, coordinate origin of the plastic part, and determine the gate position and size of the mold; Calculating the thickness of each boundary line of the core to determine the core shape data; Determine whether the boundary lines of the core intersect, if so, cut the intersecting boundary lines in order of size until all lines are cut to obtain a cut three-dimensional model; if not, find all adjacent planes whose angles are less than a preset first angle threshold and cut them to obtain a cut three-dimensional model; wherein the angle is the angle between all planes in the shape of the core; Calculating the contact pressure value of the core, and when the contact pressure value is greater than the preset yield strength of the core material, adjusting the thickness of the core, and recalculating according to the adjusted core thickness until the contact pressure value is less than the yield strength; Calculating a mold cushion value according to the contact pressure value and the core shape data; Calculating the mold clamping force according to the contact pressure value and the adjusted core thickness; A generation operation is performed based on the cut three-dimensional model, the core shape data, the gate position and size of the mold, the mold buffer value, and the mold clamping force to obtain a mold design solution for the plastic part.

[0007] In an optional implementation, determining the gate position and size of the mold includes: Calculating the weight of the plastic part; Subtracting the weight and volume of plastic equal to the weight of the plastic part from the core; The gate location and size of the mold are determined on the remaining portion of the core.

[0008] In an optional implementation, calculating the thickness of each boundary line of the core to determine the core shape data includes: Setting the initial thickness of each boundary line of the core; Starting from the end point of each boundary line of the core, linear calculation is performed to the coordinate origin of the core to obtain the thickness of each boundary line of the core; The core shape data is determined by the thickness of each boundary line of the core, the three-dimensional model of the core, and the gate height and angle of the core.

[0009] In an optional implementation, if the lines intersect, the intersecting boundary lines are cut in order of size until all the lines are cut, including: The intersecting boundary lines are sheared in order of angles to obtain new sheared edges; It is determined whether the angle of the boundary line of the new trimming is greater than a preset second angle threshold. If so, a pair of intersecting boundary lines are trimmed; if not, trimming is repeated and the determination is made again.

[0010] In an optional implementation, if the two planes do not intersect, finding all adjacent planes whose included angles are smaller than a preset first angle for shearing includes: Calculating the angles between all adjacent planes in the core; All planes containing angles smaller than a preset first angle threshold are sheared until there is no angle smaller than the first angle threshold.

[0011] In an optional implementation, the step of calculating the mold buffer value according to the contact pressure value and the core shape data includes: The die cushion value is calculated according to the following formula, in, is the final height of the core, is the rigid contact point between the core and the upper die of the mold, is the initial distance from the core to the buffer pressure surface, is the distance from the core to the buffer pressure surface, is the compressed thickness, is the initial slope of the core slope, is the slope of the core slope, is the contact pressure value between the molding surface and the mold, is the natural logarithm, is the mold buffer value.

[0012] In an optional implementation, the calculating the mold clamping force according to the contact pressure value and the adjusted core thickness includes: The mold clamping force is calculated according to the following formula: in, is the contact pressure value between the molding surface and the mold, is the cumulative coefficient of the cube of the core thickness, is the cumulative coefficient of the fifth power of the core thickness, is the cube of the core thickness, is the resultant force on contact surface 2, is the resultant force on contact surface 3, is the normal mold clamping force, Parameters for determining whether the area has the mold clamping force.

[0013] In an optional embodiment, the linear calculation to the coordinate origin of the core to obtain the thickness of each boundary line of the core includes: Predetermine the thickness values ​​of several points on the boundary line ; The thickness of the boundary line is calculated according to the following formula: in, is a point on the boundary line, is the thickness value of a certain point, is the shape parameter of the core, is the thickness of the boundary line required; By solving the simultaneous equations, we can obtain , and obtain the thickness of each boundary line of the core.

[0014] In an optional implementation, the step of shearing the intersecting boundary lines in order of angles to obtain new sheared edges includes: Determine the boundary line angle formed by the intersecting boundary lines, and record the two boundary lines as the first tangent line and the second tangent line respectively; Wherein, the first tangent line includes a boundary point , the second tangent line contains the boundary point , and pass the point Find the angle between the two tangent lines ; Line segment and Bisect the boundary line angle and the angle , and sum to get the new angle ; Line segment and Bisect the boundary line angle and the angle , and sum to get the new angle ; Line segment and Bisect the boundary line angle and the angle , and sum to get the new angle ; The new boundary point is calculated according to the following formula, in, is the ideal shear increment of the first tangent line, is the ideal shear increment of the second tangent line; the new boundary point The value range is , The value range is ; The new trimming edge is calculated based on the new boundary point.

[0015] In a second aspect, the present invention provides a plastic mold design device, comprising: The data acquisition module is used to obtain the initial three-dimensional model, core, coordinate origin of the plastic part, and determine the gate position and size of the mold; A shape determination module, used for calculating the thickness of each boundary line of the core and determining the shape data of the core; A cutting module is used to determine whether the boundary lines of the core intersect. If they intersect, the intersecting boundary lines are cut in order of size until all lines are cut to obtain a cut three-dimensional model; if they do not intersect, all adjacent planes with an angle less than a preset first angle threshold are found and cut to obtain a cut three-dimensional model; wherein the angle is the angle between all planes in the shape of the core; A thickness calculation module, used for calculating the contact pressure value of the core, and when the contact pressure value is greater than the yield strength of the preset core material, adjusting the thickness of the core, and recalculating according to the adjusted core thickness until the contact pressure value is less than the yield strength; A buffer value calculation module, used for calculating the mold buffer value according to the contact pressure value and the core shape data; A clamping force calculation module, used for calculating the mold clamping force according to the contact pressure value and the adjusted core thickness; A solution generation module is used to generate a mold design solution for the plastic part based on the cut three-dimensional model, the core shape data, the gate position and size of the mold, the mold buffer value and the mold clamping force.

[0016] In a third aspect, the present invention further provides an electronic device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements any one of the above-mentioned plastic mold design methods when executing the computer program.

[0017] In a fourth aspect, the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute any one of the plastic mold design methods described above.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a plastic mold design method, comprising obtaining an initial three-dimensional model, a core, and a coordinate origin of a plastic part, and determining a gate position and size of the mold; calculating the thickness of each boundary line of the core to determine the shape data of the core; judging whether the boundary lines of the core intersect, if so, cutting the intersecting boundary lines in order of size until all lines are cut to obtain a cut three-dimensional model; if not, finding all adjacent planes whose angles are less than a preset first angle threshold to cut, to obtain a cut three-dimensional model; wherein the angle is the angle between all planes in the shape of the core; calculating the thickness of each boundary line of the core and when the contact pressure value is greater than the yield strength of the preset core material, the thickness of the core is adjusted, and the contact pressure value is recalculated according to the adjusted core thickness until the contact pressure value is less than the yield strength; a mold buffer value is calculated according to the contact pressure value and the core shape data; a mold clamping force is calculated according to the contact pressure value and the adjusted core thickness; and a generation operation is performed based on the trimming three-dimensional model, the core shape data, the gate position and size of the mold, the mold buffer value, and the mold clamping force to obtain a mold design scheme for the plastic part.

[0019] The method designs an algorithm to calculate the various parameters of the initial plastic part and the initial mold multiple times, accurately and effectively obtains the contact pressure distribution of the mold mating surface, and designs a buffer mechanism based on this, adjusts the mold structure, optimizes the material distribution, and improves the performance and efficiency of the mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic flow chart of a plastic mold design method provided by a first embodiment of the present invention; Figure 2 Schematic diagram of the structure of a plastic mold design device provided by the second embodiment of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Reference Figure 1 The first embodiment of the present invention provides a plastic mold design method, comprising the following steps: S1, obtaining the initial 3D model, core, and coordinate origin of the plastic part, and determining the gate position and size of the mold; S2, calculating the thickness of each boundary line of the core to determine the core shape data; S3, determining whether the boundary lines of the core intersect, if so, cutting the intersecting boundary lines in order of size until all lines are cut to obtain a cut three-dimensional model; if not, finding all adjacent planes whose angles are less than a preset first angle threshold and cutting them to obtain a cut three-dimensional model; wherein the angle is the angle between all planes in the shape of the core; S4, calculating the contact pressure value of the core, and when the contact pressure value is greater than the preset yield strength of the core material, adjusting the thickness of the core, and recalculating according to the adjusted core thickness until the contact pressure value is less than the yield strength; S5, calculating a mold cushion value according to the contact pressure value and the core shape data; S6, calculating the mold clamping force according to the contact pressure value and the adjusted core thickness; S7, performing a generation operation based on the cut 3D model, the core shape data, the gate position and size of the mold, the mold buffer value, and the mold clamping force to obtain a mold design solution for the plastic part.

[0023] It should be noted that in traditional mold design solutions, it usually relies on the user's experience and skills, which requires long-term practice and training, and there is uncertainty in the production process, and multiple trials are required to obtain the final mold. At the same time, due to the lack of scientific calculation and optimization, the mold produced cannot have good performance and long life. In addition, the mold design process needs to consider multiple factors, such as structure, material, process, etc., and the traditional mold design solution lacks comprehensive consideration and optimization, which often leads to increased product development costs and development time, as well as a decline in mold quality.

[0024] In the present invention, by using the mold design system in the computer program, the defects existing in the mold design process can be optimized. Through the automated calculation of the mold design system, the user only needs to input sufficient initial mold parameters and set the corresponding redundancy, and the final mold design solution is completed by the system design. During the design process, the user does not need to perform additional correction operations, which greatly saves labor costs and time. In addition, the mold designed by the system can be more suitable for the actual production environment, improving the performance and use efficiency of the mold.

[0025] In step S1, the user needs to pre-set the initial 3D model, core and coordinate origin of the expected plastic part, and input these data into a computer file for storage. It should be noted that during the production process of plastic parts, there may be some adjustments, optimizations or other changes, resulting in changes in the values ​​of the 3D model, core and coordinate origin. The user needs to take these changes into account and set the corresponding redundancy to ensure the accuracy of the calculation results.

[0026] In one embodiment, determining the gate position and size of the mold includes: calculating the weight of the plastic part; subtracting the weight and volume of plastic equal to the weight of the plastic part from the core; and determining the gate position and size of the mold in the remaining portion of the core.

[0027] Specifically, the weight of the plastic part is calculated based on the data of the plastic part to be produced; then the weight and volume of plastic equal to the weight of the plastic part is subtracted from the core; finally, based on the conditions in actual production, such as material type, required temperature, and cost, the optimal gate position and size of the mold are determined in the remaining part of the core.

[0028] In step S2, the thickness of each boundary line of the core is calculated to determine the core shape data, including: S21, setting the initial thickness of each boundary line of the core; S22, starting from the end point of each boundary line of the core, linearly calculating to the coordinate origin of the core to obtain the thickness of each boundary line of the core; S23, determining the core shape data according to the thickness of each boundary line of the core, the three-dimensional model of the core, and the gate height and angle of the core.

[0029] First, in step S21, it is necessary to set the initial thickness of each boundary line of the core.

[0030] Specifically, according to the initial data of the mold and the plastic part, and the external conditions of the production environment, the initial thickness of each boundary line of the core is set. The thickness of the core is determined by the vertex thickness of the predefined core and the thickness of the boundary lines on both sides of the predefined core. By setting and calculating each boundary line of the core, the specific data of each boundary line and each face of the core can be obtained.

[0031] In step S22, the linear calculation to the coordinate origin of the core to obtain the thickness of each boundary line of the core includes: Pre-measure a given boundary line of each boundary line of the core to obtain the thickness values ​​of several points on the given boundary line. Then, an equation is established according to the following formula to calculate the thickness of the boundary line: in, is a point on the boundary line, is the thickness value of a certain point, is the shape parameter of the core, is the thickness of the two endpoints of the boundary line. For each point, an equation can be established, and through the simultaneous equations, the solution can be obtained. The specific value of .

[0032] Furthermore, for each boundary line of the core, the steps of establishing and solving the set of equations are repeated to obtain thickness data of each boundary line of the core, and the thickness of each boundary line of the core is recorded in sequence into a file.

[0033] It should be noted that the thickness of the boundary line is usually not a fixed value, but will fluctuate due to the design of the core. In order to describe the boundary line more accurately, the thickness of the boundary line can be calculated by assuming more unknowns to increase the accuracy of the design. Since solving each boundary line requires a set of equations, if the set of equations is to have a feasible solution, the number of equations should be greater than or equal to the number of unknowns, and it should be noted that the value points of the boundary line are representative to reflect the actual situation.

[0034] In step S23, the core shape data is determined based on the thickness of each boundary line of the core, the three-dimensional model of the core, and the gate height and angle, and the three-dimensional model is updated and recorded in the file.

[0035] Specifically, the core shape data includes the thickness of each boundary line of the core, the three-dimensional model of the core, the gate height and angle, and the cavity layout, parting surface position, and exhaust system of the core. According to the above data and the expected plastic parts to be produced, the specific core shape data is determined.

[0036] In step S3, it is determined whether the obtained core has intersecting boundary lines, and different operations are performed according to the determination result: In one implementation, if they intersect, the intersecting boundary lines are cut in order of size until all lines are cut to obtain a cut 3D model, including the following steps: S31, cutting the intersecting boundary lines in order of angles to obtain new cut edges.

[0037] Specifically, the boundary line angle formed by the two boundary lines is determined, and the two boundary lines are recorded as the first tangent line and the second tangent line. Four boundary points are selected on the first tangent line and recorded as ; Select three boundary points on the second tangent line, and record them as . Passing through the boundary point Find the angle between the first tangent line and the second tangent line, recorded as angle . Find the line segment With line segment Bisect the boundary line angle and the angle , and sum to get a new angle, recorded as the included angle ; Find the line segment With line segment Bisect the boundary line angle and the angle , and sum to get a new angle, recorded as the included angle ; Find the line segment With line segment Bisect the boundary line angle and the angle , and sum to get a new angle, recorded as the included angle .

[0038] The new boundary point is calculated according to the following formula, in, is the ideal shear increment of the first tangent line, The ideal shear increment for the second tangent line. New boundary point The value range is , The value range is According to the new boundary point , , substituting into the original boundary points, the new trimming edge can be obtained.

[0039] S32, judging whether the angle of the boundary line of the newly trimmed edge is greater than a preset second angle threshold, if so, cutting the next pair of intersecting boundary lines; if not, cutting again and judging.

[0040] First, a preset first angle threshold is set, which is used as a criterion for judging whether the angle between adjacent planes needs to be adjusted. Then, the obtained new trimming edge is compared with the preset second angle threshold. If the new trimming edge is greater than the second angle threshold, the next pair of intersecting boundary lines are trimmed; if the new trimming edge is not greater than the second angle threshold, the current new trimming edge is trimmed again and judged. When all boundary line angles have completed the trimming operation and meet the conditions, the trimmed three-dimensional model can be obtained, and the core shape data is updated and stored in the file.

[0041] In another embodiment, if they do not intersect, then all adjacent planes whose included angles are less than a preset first angle threshold are found for clipping to obtain a clipped three-dimensional model, including the following steps: S33, calculating the angles between all adjacent planes in the core, wherein the angles are the angles between all planes in the shape of the core.

[0042] Specifically, all adjacent planes in the core are found in the three-dimensional model according to the image recognition algorithm, and the angles between all adjacent planes are calculated. The value of the angle and the corresponding adjacent plane are stored in a file. If the curved surface part in the core does not meet the prerequisite of the plane, it will not participate in the calculation of the angle.

[0043] S34, shearing the planes containing all the angles smaller than a preset first angle threshold until there is no angle smaller than the first angle threshold.

[0044] Specifically, a preset first angle threshold is set, and this value is used as a standard for judging whether the angle between adjacent planes needs to be adjusted. Then, the preset first angle threshold is compared with the angles between all the adjacent planes, and all the angles smaller than the first angle threshold are sheared. The shearing rule is to maintain the flatness of the sheared plane and gradually increase the angle between adjacent planes until there is no angle smaller than the first angle threshold, and at the same time, the core shape data is updated and stored in the file. After shearing, it is necessary to re-judge whether the updated core has intersecting boundary lines.

[0045] It should be noted that if no shearing occurs during the entire comparison process, that is, all the angles are greater than the first angle threshold, the core design fails, and the user needs to redesign the initial parameters of the plastic part and the mold and complete the design steps again.

[0046] In step S4, the contact pressure value of the core is first calculated.

[0047] Specifically, the updated core shape data is obtained and substituted into numerical simulation software (such as CAE). The software calculates the contact pressure value of the core according to the core shape data and records it in a file.

[0048] It should be noted that the formula for calculating the core contact pressure value is not a fixed and universally applicable expression. It is affected by many factors, including the properties of the plastic (such as shrinkage, elastic modulus), the shape and size of the core, the injection molding process parameters (such as injection pressure, temperature, time) and mold design.

[0049] Next, it is determined whether the contact pressure value is greater than the preset yield strength of the core material.

[0050] Specifically, the contact pressure value is compared with the yield strength of the preset core material. When the contact pressure value is greater than the yield strength, the thickness of the core is adjusted and recalculated according to the adjusted core thickness until the contact pressure value is no greater than the yield strength. When adjusting the thickness, in order to improve efficiency and accuracy, the data change of similar molds that have been successfully produced before can be referred to.

[0051] In step S5, the following steps are included: S51, calculating the initial slope and current slope of the core slope.

[0052] The initial slope and current slope of the core slope are calculated by the following formula: in, is the initial slope of the core slope, is the slope of the core slope, is the initial distance from the core to the buffer pressure surface, is the distance from the core to the buffer pressure surface, is the natural logarithm.

[0053] S52, calculating the rigid contact point between the core and the upper die of the mold.

[0054] The rigid contact point between the core and the upper die of the mold is calculated by the following formula: in, is the rigid contact point between the core and the upper die of the mold, is the contact pressure value between the molding surface and the mold.

[0055] S53, calculating the mold buffer value.

[0056] The die cushion value is calculated by the following formula, in, is the mold buffer value. After obtaining the mold buffer value, it is recorded in a file. It should be noted that in order to make the calculation result of the mold buffer value more realistic, other small planes of the mold in the buffer part can be processed during the calculation process. Then, the feature design in the mold can be performed within the mold buffer value range.

[0057] Furthermore, in a preferred embodiment, in order to process other small planes of the mold in the buffer part, the usual step is to select a curved surface, and usually generate a mold closing surface with a curved surface as the low-pressure part (or high-pressure part), and remove the thickness of the mold buffer layer. Then, the mold closing surface after removing this part is subjected to pressure. Then, the mold closing surface after the buffer layer is set, and the buffer pressure is regained. Finally, the force on the low-pressure part and the force on the area without the buffer part remain unchanged, and the total mold closing force after the buffer is calculated by the following formula, in, is the total clamping force after buffering, To compress the pressure of the low pressure part, is the area of ​​the die surface outside the small plane, is the area of ​​the buffer, The calculated total clamping force after buffering is used as an additional condition for calculating the mold buffer value.

[0058] In step S6, the following steps are included: S61, calculate the mold clamping force in the normal direction by the following formula: in, is the normal mold clamping force, is the contact pressure value between the molding surface and the mold. It should be noted that in actual production, the mold clamping force is small in some cases or has little impact on production, so the mold clamping force can be regarded as non-existent to reduce the calculation complexity. Therefore, after obtaining the mold clamping force, the value of the mold clamping force is temporarily recorded and judged later.

[0059] S62, calculating and judging whether the area has the mold clamping force parameter by the following formula: in, is the cumulative coefficient of the cube of the core thickness, is the cumulative coefficient of the fifth power of the core thickness, is the cube of the core thickness, is the resultant force on contact surface 2, is the resultant force on contact surface 3, After calculating the parameters for determining whether the area has the mold clamping force, the judgment is made based on the parameters. , indicating that there is clamping force in this area, the temporarily recorded value of the clamping force is saved in the file; if , indicating that there is no clamping force in this area, the temporarily recorded value of the clamping force is deleted, and the mold clamping force is recorded as 0 in the file, or it is marked that the mold clamping force in this area is not considered.

[0060] For example, for some molds, they cannot be directly generated by one mold surface in the actual production process, but are formed by the combination of the upper mold surface and the lower mold surface. The mold surface formed by the combination of the upper mold surface and the lower mold surface needs to meet certain conditions, which requires reference to the density of the polymer of the mold being equal to the density of the polymer in the manufacturing process, and in the actual production process, the pressure curve of the injection molding machine after loading the mold clamping force is used to determine the clamping force between the upper and lower mold surfaces. The clamping force is stored in the file as an additional parameter for the production of this type of special mold.

[0061] Considering the actual production process, the mold locking force and the clamping force need to meet the technical requirements. When the available technical conditions are met, the mold locking force is set greater than the clamping force to ensure that the mold can meet the requirements; if the mold locking force is not enough to achieve the required clamping force, the mold locking force must be enhanced. Some feasible methods for enhancing the mold locking force include: meeting the filling characteristics according to the material properties of the plastic part; replacing the material or design structure with a greater mold locking force. The thickness of the existing core after clamping minus the mold buffer value is the core thickness in the reference model, so that the manufacturing dimensions of the upper mold and the lower mold of the model can be obtained.

[0062] In step S7, the computer obtains the trimming three-dimensional model, the core shape data, the gate position and size of the mold, the mold buffer value and the mold clamping force, and integrates and generates these data to obtain a specific mold design scheme for the plastic part. The mold design scheme is stored in a file for preservation, or directly input into the injection molding machine control system through an interface for production testing.

[0063] It should be noted that the setting of the injection molding machine is consistent with the mold, the pressure stroke is kept unchanged, and the same mold clamping force and the same pressure curve are used for injection molding.

[0064] To facilitate understanding of the present invention, the working process of the present invention is described below using a common scenario as an example: In this embodiment, the factory plans to use the plastic mold design system to design a new mold for producing a new type of plastic parts. The system is intended to design the mold with lower cost and fewer trials, and ensure that the designed mold has better performance and higher efficiency.

[0065] The general working process is as follows: Step 1: Based on the expected plastic parts to be produced, the factory pre-designs the initial 3D model, core, coordinate origin of the plastic parts, determines the gate location and size of the mold, and inputs this data information into the system.

[0066] Step 2: The system calculates the thickness of each boundary line of the core, determines the core shape data and updates the data stored in the file.

[0067] Step 3: The system identifies the boundary lines of the core and determines the boundary lines that intersect.

[0068] Step 4: The system cuts the intersecting boundary lines in order of size according to certain rules. After completing the cutting of all the boundary lines, the core shape data is updated.

[0069] Step 5: The system calculates the contact pressure value of the core and determines that the contact pressure value is greater than the preset yield strength of the core material.

[0070] Step 6: The system adjusts the thickness of the core and recalculates the contact pressure value according to the adjusted core thickness until the contact pressure value is less than the yield strength. After the thickness adjustment is completed, the core shape data is updated.

[0071] Step 7: The system calculates the mold buffer value based on the contact pressure value and the core shape data, and stores it in the file data.

[0072] Step 8: The system calculates the mold clamping force according to the contact pressure value and the adjusted core thickness, and stores it in the file data.

[0073] Step 9: The system records the 3D model, the core, the coordinate origin, the gate position and size of the mold, the mold buffer value and the mold clamping force, and integrates these data into a specific mold design plan. The mold design plan will be presented to the staff for inspection and testing by the system.

[0074] Through the above steps, the system can design high-performance and high-efficiency molds to meet the needs of the factory.

[0075] In summary, the present invention provides a plastic mold design method, including obtaining an initial three-dimensional model, a core, a coordinate origin of a plastic part, and determining the gate position and size of the mold; calculating the thickness of each boundary line of the core to determine the core shape data; judging whether the boundary lines of the core intersect, if they intersect, cutting the intersecting boundary lines in order of size until all lines are cut to obtain a cut three-dimensional model; if they do not intersect, finding all adjacent planes whose angles are less than a preset first angle threshold to cut, to obtain a cut three-dimensional model; wherein the angle is the angle between all planes in the shape of the core; calculating the The contact pressure value of the core is calculated, and when the contact pressure value is greater than the yield strength of the preset core material, the thickness of the core is adjusted, and the contact pressure value is recalculated according to the adjusted core thickness until the contact pressure value is less than the yield strength; the mold buffer value is calculated according to the contact pressure value and the core shape data; the mold clamping force is calculated according to the contact pressure value and the adjusted core thickness; the mold design scheme of the plastic part is obtained by performing a generation operation based on the three-dimensional cutting model, the core shape data, the gate position and size of the mold, the mold buffer value and the mold clamping force. The method designs a set of algorithms to calculate the various parameters of the initial plastic part and the initial mold multiple times, accurately and effectively obtains the contact pressure distribution of the mold mating surface, and designs a buffer mechanism accordingly, adjusts the mold structure, optimizes the material distribution, and improves the performance and efficiency of the mold.

[0076] Reference Figure 2 The second embodiment of the present invention provides a plastic mold design device, comprising: The data acquisition module is used to obtain the initial three-dimensional model, core, coordinate origin of the plastic part, and determine the gate position and size of the mold; A shape determination module, used for calculating the thickness of each boundary line of the core and determining the shape data of the core; A cutting module is used to determine whether the boundary lines of the core intersect. If they intersect, the intersecting boundary lines are cut in order of size until all lines are cut to obtain a cut three-dimensional model; if they do not intersect, all adjacent planes with an angle less than a preset first angle threshold are found and cut to obtain a cut three-dimensional model; wherein the angle is the angle between all planes in the shape of the core; A thickness calculation module, used for calculating the contact pressure value of the core, and when the contact pressure value is greater than the yield strength of the preset core material, adjusting the thickness of the core, and recalculating according to the adjusted core thickness until the contact pressure value is less than the yield strength; A buffer value calculation module, used for calculating the mold buffer value according to the contact pressure value and the core shape data; A clamping force calculation module, used for calculating the mold clamping force according to the contact pressure value and the adjusted core thickness; A solution generation module is used to generate a mold design solution for the plastic part based on the cut three-dimensional model, the core shape data, the gate position and size of the mold, the mold buffer value and the mold clamping force.

[0077] It should be noted that a plastic mold design device provided in an embodiment of the present invention is used to execute all process steps of a plastic mold design method in the above embodiment, and the working principles and beneficial effects of the two correspond one to one, so they will not be described in detail.

[0078] The embodiment of the present invention further provides an electronic device. The electronic device includes: a processor, a memory, and a computer program stored in the memory and executable on the processor, such as a plastic mold design program. When the processor executes the computer program, the steps in the above-mentioned plastic mold design method embodiments are implemented, such as Figure 1 Alternatively, when the processor executes the computer program, the functions of the modules / units in the above-mentioned device embodiments are realized, such as the cropping module.

[0079] Exemplarily, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program in the electronic device.

[0080] The electronic device may be a computing device such as a desktop computer, a notebook, a PDA, and a smart tablet. The electronic device may include, but is not limited to, a processor and a memory. Those skilled in the art will appreciate that the above components are merely examples of electronic devices and do not constitute a limitation on the electronic device. The electronic device may include more or fewer components than the above components, or may combine certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0081] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the electronic device, and uses various interfaces and lines to connect various parts of the entire electronic device.

[0082] The memory can be used to store the computer program and / or module, and the processor realizes various functions of the electronic device by running or executing the computer program and / or module stored in the memory, and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0083] Wherein, if the module / unit integrated in the electronic device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0084] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0085] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A plastic mold design method, characterized in that: include: Obtain the initial 3D model, core, coordinate origin of the plastic part, and determine the gate position and size of the mold; Calculating the thickness of each boundary line of the core to determine the core shape data; Determine whether the boundary lines of the core intersect, if so, cut the intersecting boundary lines in order of size until all lines are cut to obtain a cut three-dimensional model; if not, find all adjacent planes whose angles are less than a preset first angle threshold and cut them to obtain a cut three-dimensional model; wherein the angle is the angle between all planes in the shape of the core; Calculating the contact pressure value of the core, and when the contact pressure value is greater than the preset yield strength of the core material, adjusting the thickness of the core, and recalculating according to the adjusted core thickness until the contact pressure value is less than the yield strength; Calculating a mold cushion value according to the contact pressure value and the core shape data; Calculating the mold clamping force according to the contact pressure value and the adjusted core thickness; A generation operation is performed based on the cut three-dimensional model, the core shape data, the gate position and size of the mold, the mold buffer value, and the mold clamping force to obtain a mold design solution for the plastic part.

2. The plastic mold design method according to claim 1, characterized in that: Determining the gate position and size of the mold includes: Calculating the weight of the plastic part; Subtracting the weight and volume of plastic equal to the weight of the plastic part from the core; The gate location and size of the mold are determined on the remaining portion of the core.

3. The plastic mold design method according to claim 1, characterized in that: The step of calculating the thickness of each boundary line of the core and determining the core shape data comprises: Setting the initial thickness of each boundary line of the core; Starting from the end point of each boundary line of the core, linear calculation is performed to the coordinate origin of the core to obtain the thickness of each boundary line of the core; The core shape data is determined by the thickness of each boundary line of the core, the three-dimensional model of the core, and the gate height and angle of the core.

4. The plastic mold design method according to claim 1, characterized in that: If they intersect, the intersecting boundary lines are cut in order of size until all lines are cut, including: The intersecting boundary lines are sheared in order of angles to obtain new sheared edges; It is determined whether the angle of the boundary line of the new trimming is greater than a preset second angle threshold. If so, a pair of intersecting boundary lines are trimmed; if not, trimming is repeated and the determination is made again.

5. The plastic mold design method according to claim 1, characterized in that: If they do not intersect, finding all adjacent planes whose included angles are smaller than a preset first angle for shearing includes: Calculating the angles between all adjacent planes in the core; All planes containing angles smaller than a preset first angle threshold are sheared until no angle smaller than the first angle threshold exists.

6. The plastic mold design method according to claim 1, characterized in that: The step of calculating the mold cushion value according to the contact pressure value and the core shape data includes: The die cushion value is calculated according to the following formula, ； ； ； ； in, is the final height of the core, is the rigid contact point between the core and the upper die of the mold, is the initial distance from the core to the buffer pressure surface, is the distance from the core to the buffer pressure surface, is the compressed thickness, is the initial slope of the core slope, is the slope of the core slope, is the contact pressure value between the molding surface and the mold, is the natural logarithm, is the mold buffer value.

7. The plastic mold design method according to claim 6, characterized in that: The step of calculating the mold clamping force according to the contact pressure value and the adjusted core thickness includes: The mold clamping force is calculated according to the following formula: ； ； ； ； in, is the contact pressure value between the molding surface and the mold, is the cumulative coefficient of the cube of the core thickness, is the cumulative coefficient of the fifth power of the core thickness, is the cube of the core thickness, is the resultant force on contact surface 2, is the resultant force on contact surface 3, is the normal mold clamping force, Parameters for determining whether the area has the mold clamping force.

8. The plastic mold design method according to claim 3, characterized in that: The linear calculation to the coordinate origin of the core to obtain the thickness of each boundary line of the core includes: Predetermine the thickness values ​​of several points on the boundary line ; The thickness of the boundary line is calculated according to the following formula: ； in, is a point on the boundary line, is the thickness value of a certain point, is the shape parameter of the core, is the thickness of the boundary line required; By solving the simultaneous equations, we can obtain , and obtain the thickness of each boundary line of the core.

9. The plastic mold design method according to claim 4, characterized in that: The step of shearing the intersecting boundary lines in order of angles to obtain new sheared edges includes: Determine the boundary line angle formed by the intersecting boundary lines, and record the two boundary lines as the first tangent line and the second tangent line respectively; Wherein, the first tangent line includes a boundary point , the second tangent line contains the boundary point , and pass the point Find the angle between the two tangent lines ; Line segment and Bisect the boundary line angle and the angle , and sum to get the new angle ; Line segment and Bisect the boundary line angle and the angle , and sum to get the new angle ; Line segment and Bisect the boundary line angle and the angle , and sum to get the new angle ; The new boundary point is calculated according to the following formula, ； ； in, is the ideal shear increment of the first tangent line, is the ideal shear increment of the second tangent line; the new boundary point The value range is , The value range is ; The new trimming edge is calculated based on the new boundary point.

10. A plastic mold design device, characterized in that: include: The data acquisition module is used to obtain the initial three-dimensional model, core, coordinate origin of the plastic part, and determine the gate position and size of the mold; A shape determination module, used for calculating the thickness of each boundary line of the core and determining the shape data of the core; A cutting module is used to determine whether the boundary lines of the core intersect. If they intersect, the intersecting boundary lines are cut in order of size until all lines are cut to obtain a cut three-dimensional model; if they do not intersect, all adjacent planes with an angle less than a preset first angle threshold are found and cut to obtain a cut three-dimensional model; wherein the angle is the angle between all planes in the shape of the core; A thickness calculation module, used for calculating the contact pressure value of the core, and when the contact pressure value is greater than the yield strength of the preset core material, adjusting the thickness of the core, and recalculating according to the adjusted core thickness until the contact pressure value is less than the yield strength; A buffer value calculation module, used for calculating the mold buffer value according to the contact pressure value and the core shape data; A clamping force calculation module, used for calculating the mold clamping force according to the contact pressure value and the adjusted core thickness; A solution generation module is used to generate a mold design solution for the plastic part based on the cut three-dimensional model, the core shape data, the gate position and size of the mold, the mold buffer value and the mold clamping force.

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