A method for predicting ejection force and related device
Through the construction and solution of the finite element model, the ejection force during mold opening in the die-casting process is calculated, which solves the problem of low prediction accuracy of ejection force in the prior art and achieves higher prediction accuracy.
Patent Information
- Application Number
- CN202510045859.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-13
- Publication Date
- 2025-05-23
- Estimated Expiration
- 2045-01-13
AI Technical Summary
In the prior art, the calculation accuracy of the ejection force during the die-casting process is low, resulting in the inaccuracy of the ejection force prediction results.
By constructing a finite element model of the target metal casting, the contact area between the target pole and the metal casting is detected, and the fixed boundary condition of the finite element model is set as the force boundary condition. The finite element model is solved to obtain the stress tensor, and the ejection force is then calculated.
The accuracy of the prediction results of the ejection force is improved, and the ejection force of each ejection rod can be calculated more accurately, thereby optimizing the die-casting process.
Smart Images
Figure CN119475924B_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of die-casting simulation technology, and in particular to a method for predicting ejection force and a related device. Background Art
[0002] Die casting is a metal casting process. The die casting process is to use the mold cavity to apply high pressure to the molten metal, so that the molten metal is filled from the material barrel into the mold cavity. After the molten metal solidifies to form a metal casting, the mold is opened, and after the solidified metal casting is taken out, the metal casting is cooled by water cooling or air cooling. Since there is not only a metal casting in the mold cavity, but also a metal liquid flow channel and other parts connected to the metal casting, after cooling, the material outside the metal casting is cut off by punching or laser trimming to obtain a basically formed metal casting product.
[0003] In the die-casting process, when the mold is opened, due to the effects of thermal expansion and contraction, the cooled and solidified metal casting shrinks and clamps the mold, generating clamping pressure. The metal casting needs to be ejected by at least one target ejector rod of the ejection mechanism to overcome the friction generated by the clamping pressure.
[0004] In the prior art, empirical formulas are usually used to calculate the total ejector force based on parameters such as the overall size of the product, draft angle, and material properties. The calculation results of the ejector force are relatively inaccurate. Therefore, a method for predicting the ejector force during mold opening is urgently needed to improve the accuracy of the prediction results of the ejector force. Summary of the invention
[0005] In view of the above problems, the present application provides a method and a related device for predicting ejection force to achieve the purpose of improving the accuracy of the prediction result of ejection force. The specific scheme is as follows:
[0006] The first aspect of the present application provides a method for predicting ejection force, comprising:
[0007] Construct a finite element model of the target metal casting;
[0008] For each target ejector pin in the target ejector pin set, a contact area between the target ejector pin and the target metal casting is detected as an ejector pin contact area of the target ejector pin; the target ejector pin set includes at least one target ejector pin used to eject the target metal casting out of a target mold; the ejector pin contact area includes a grid on the target metal casting that contacts the target ejector pin;
[0009] The push rod contact area of the target push rod is set as the fixed boundary condition of the finite element model, the unit friction force of each grid in the push rod contact area of the target push rod is used as the force boundary condition of the finite element model, and the finite element model is solved to obtain the stress tensor of each grid in the push rod contact area of the target push rod;
[0010] Based on the stress tensor of each grid in the push rod contact area of the target push rod, the ejection resultant force of the target push rod is calculated;
[0011] Outputting an ejection force prediction result, wherein the ejection force prediction result includes the ejection resultant force of each of the target ejector rods in the target ejector rod set.
[0012] In a possible implementation, constructing a finite element model of a target metal casting includes:
[0013] Acquiring the geometric shape and material properties of the target metal casting;
[0014] Obtaining a mesh division result of the target metal casting, wherein the mesh division result of the target metal casting includes a finite number of meshes obtained by dividing the target metal casting and nodes connecting the meshes;
[0015] A finite element model of the target metal casting is constructed according to the geometric shape, material properties and mesh division results of the target metal casting.
[0016] In a possible implementation, before setting the ejector contact area of the target ejector as a fixed boundary condition of the finite element model and using the unit friction force of each grid in the ejector contact area of the target ejector as a force boundary condition of the finite element model, and solving the finite element model, the ejection force prediction method further includes:
[0017] receiving an ejection force prediction instruction before mold opening, and obtaining a temperature drop distribution of the target metal casting; the temperature drop distribution includes the temperature drop of each node of the target metal casting, and the ejection force prediction instruction instructs to use the target ejector rod set to eject the target metal casting out of the target mold;
[0018] Detecting a contact area between the target metal casting and the target mold as a mold contact area; the mold contact area includes a grid on the target metal casting that contacts the target mold;
[0019] Taking the temperature drop distribution as the temperature load of the finite element model and the mold contact area as the boundary condition of the finite element model, solving the finite element model to obtain the stress tensor of each grid in the mold contact area;
[0020] Based on the stress tensor of each mesh in the mold contact area, the unit friction force of the target metal casting on each mesh in the mold contact area subjected to the target mold is calculated.
[0021] In a possible implementation, calculating the unit friction force of each mesh of the target metal casting in the mold contact area subjected to the target mold based on the stress tensor of each mesh in the mold contact area includes:
[0022] Based on the stress tensor of each mesh in the mold contact area, the normal pressure of each mesh in the mold contact area is calculated as the unit clamping force using the Cauchy slope stress formula;
[0023] Based on the ejection direction and unit clamping force of each grid in the mold contact area, the unit friction force of the target metal casting on each grid in the mold contact area is calculated.
[0024] In a possible implementation, calculating the ejection resultant force of the target ejector based on the stress tensor of each grid in the ejector contact area of the target ejector includes:
[0025] Based on the stress tensor of each grid in the push rod contact area of the target push rod, the normal pressure of each grid in the push rod contact area of the target push rod is calculated using the Cauchy inclined plane stress formula as the unit push force;
[0026] The ejection force of each grid unit in the ejector rod contact area of the target ejector rod is summed to obtain the ejection resultant force of the target ejector rod.
[0027] A second aspect of the present application provides a device for predicting ejection force, comprising:
[0028] A model building unit, used for building a finite element model of a target metal casting;
[0029] a first contact area detection unit, configured to detect, for each target ejector pin in a target ejector pin set, a contact area between the target ejector pin and the target metal casting as an ejector pin contact area of the target ejector pin; the target ejector pin set includes at least one target ejector pin for ejecting the target metal casting out of a target mold; the ejector pin contact area includes a grid on the target metal casting that contacts the target ejector pin;
[0030] A first model solving unit is used to set a push rod contact area of the target push rod as a fixed boundary condition of the finite element model, use the unit friction force of each grid in the push rod contact area of the target push rod as the force boundary condition of the finite element model, solve the finite element model, and obtain the stress tensor of each grid in the push rod contact area of the target push rod;
[0031] A first force calculation unit, configured to calculate the ejection resultant force of the target ejector pin based on the stress tensor of each grid in the ejector pin contact area of the target ejector pin;
[0032] The prediction result output unit is used to output the ejection force prediction result, wherein the ejection force prediction result includes the ejection resultant force of each of the target ejector rods in the target ejector rod set.
[0033] In a possible implementation, when the model building unit is used to build a finite element model of a target metal casting, it is specifically used to:
[0034] Acquiring the geometric shape and material properties of the target metal casting;
[0035] Obtaining a mesh division result of the target metal casting, wherein the mesh division result of the target metal casting includes a finite number of meshes obtained by dividing the target metal casting and nodes connecting the meshes;
[0036] A finite element model of the target metal casting is constructed according to the geometric shape, material properties and mesh division results of the target metal casting.
[0037] A third aspect of the present application provides a computer program product, including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements the ejection force prediction method of the first aspect or any implementation of the first aspect.
[0038] A fourth aspect of the present application provides an electronic device, comprising at least one processor and a memory connected to the processor, wherein:
[0039] The memory is used to store computer programs;
[0040] The processor is used to execute the computer program so that the electronic device can implement the ejection force prediction method of the first aspect or any implementation of the first aspect.
[0041] A fifth aspect of the present application provides a computer storage medium, which carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can use the method for predicting the ejection force of the first aspect or any implementation of the first aspect.
[0042] By means of the above technical scheme, the present application provides a method for predicting ejection force and a related device, and constructs a finite element model of a target metal casting. For each target ejector in a target ejector set, the contact area between the target ejector and the target metal casting is detected as the ejector contact area of the target ejector. The target ejector set includes at least one target ejector for ejecting the target metal casting out of a target mold. The ejector contact area includes a grid on the target metal casting that contacts the target ejector. The ejector contact area of the target ejector is set as a fixed boundary condition of the finite element model, and the unit friction force of each grid in the ejector contact area of the target ejector is used as the force boundary condition of the finite element model. The finite element model is solved to obtain the stress tensor of each grid in the ejector contact area of the target ejector. Based on the stress tensor of each grid in the ejector contact area of the target ejector, the ejection resultant force of the target ejector is calculated. The ejection force prediction result is output, and the ejection force prediction result includes the ejection resultant force of each target ejector in the target ejector set. It can be seen that this method improves the accuracy of ejection force prediction by constructing a finite element model to calculate the ejection force of each target ejector pin of each ejection target mold. BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and the originals and elements are not necessarily drawn to scale.
[0044] Figure 1 A schematic diagram of a method for predicting ejection force provided in this application;
[0045] Figure 2 A schematic diagram of a specific implementation method of a method for predicting ejection force provided in the present application;
[0046] Figure 3 A schematic diagram of the structure of a device for predicting ejection force provided in this application;
[0047] Figure 4 A schematic diagram of the structure of an electronic device provided in this application. DETAILED DESCRIPTION
[0048] The following describes the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. The terms used in the implementation method section of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.
[0049] The embodiments of the present application are described below in conjunction with the accompanying drawings. Those skilled in the art will appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.
[0050] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and need not be used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, which is only to describe the distinction mode adopted by the objects of the same attributes when describing in the embodiments of the present application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.
[0051] A method for predicting ejection force provided in an embodiment of the present application is applied to the prediction of ejection force in a die-casting simulation scenario. Die-casting simulation is to carry out virtual numerical experiments of the die-casting process with the help of computer software to predict the flow, temperature, shrinkage, etc. of the molten metal. It should be noted that the purpose of using computer-aided engineering CAE (Computer Aided Engineering) to implement die-casting simulation is to assist engineers in predicting and evaluating the performance of product structures in advance through virtual simulation experiments during the industrial product design stage. Compared with the high cost and long cycle of real experiments, die-casting simulation can effectively reduce the cost of real experiments.
[0052] When the existing technology calculates the total ejector force based on an empirical formula, it can only calculate the total ejector force of all ejectors acting together, ignores the ejector force differences caused by different local structures, and cannot accurately calculate the ejector forces on different ejectors. Therefore, the ejector force prediction accuracy is low and the ejection effect is poor.
[0053] Therefore, in order to solve the above problem, the embodiment of the present application provides a method for predicting the ejection force, which uses the finite element analysis method to calculate the ejection force on each ejector pin according to the clamping state between the metal casting and the mold, and then applies the ejection force of each ejector pin to the corresponding ejector pin, so that all ejector pins are applied to the designated position of the metal casting. In this way, the accuracy of the ejection force prediction result is improved.
[0054] It should be noted that the finite element method is a numerical technique for solving mathematical and physical problems. It discretizes the continuous solution domain into a combination of a finite set of units that are connected to each other in a certain way. An approximate function is assumed inside each unit to represent the unknown field function to be solved in the entire solution domain in pieces. By solving the approximate solution in each unit, the approximate solution of the entire solution domain is derived. The finite element method not only has high calculation accuracy, but also can adapt to various complex shapes. Therefore, it has become an effective engineering analysis tool and is widely used in elastic-plastic mechanics, fracture mechanics, fluid mechanics, heat conduction and other fields).
[0055] The method for predicting ejection force provided in the embodiment of the present application can be applied to a simulation electronic device configured with a simulation processor. Figure 1 , Figure 1 A schematic diagram of a method for predicting ejection force provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the method may include S101 to S105, and these steps are described in detail below.
[0056] S101. Construct a finite element model of a target metal casting.
[0057] S102 . For each target ejector pin in the target ejector pin set, a contact area between the target ejector pin and the target metal casting is detected as the ejector pin contact area of the target ejector pin.
[0058] In this embodiment, the target ejector pin set includes at least one target ejector pin used to eject the target metal casting out of the target mold. The ejector pin contact area includes a grid on the target metal casting that contacts the target ejector pin.
[0059] In this embodiment, at least one group of ejector pins is determined from a plurality of ejector pins pre-set in the ejection mechanism to obtain a target ejector pin set, wherein a group of ejector pins includes at least one ejector pin, and the target ejector pin set includes at least one group of ejector pins. It should be noted that the at least one group of ejector pins used to eject the target metal casting from the target mold is determined based on the position and shape of the target mold and the positional relationship with the target metal casting.
[0060] S103, setting the push rod contact area of the target push rod as the fixed boundary condition of the finite element model, using the unit friction force of each grid in the push rod contact area of the target push rod as the force boundary condition of the finite element model, solving the finite element model, and obtaining the stress tensor of each grid in the push rod contact area of the target push rod.
[0061] S104, calculating the ejection resultant force of the target ejector pin based on the stress tensor of each grid in the ejector pin contact area of the target ejector pin.
[0062] In this embodiment, the stress tensor is composed of multiple stress components, each stress component represents a component of the stress of a grid point on a plane, and the plane is formed by a first direction and a second direction. The first direction and the second direction are two directions of the three coordinate axis directions constituting the three-dimensional coordinate system.
[0063] S105. Output the ejection force prediction result.
[0064] In this embodiment, the ejection force prediction result includes the ejection resultant force of each target ejector rod in the target ejector rod set.
[0065] It can be seen from the above technical scheme that an ejection force prediction method provided in an embodiment of the present application constructs a finite element model of a target metal casting. For each target ejector in a target ejector set, the contact area between the target ejector and the target metal casting is detected as the ejector contact area of the target ejector. The target ejector set includes at least one target ejector for ejecting the target metal casting out of a target mold. The ejector contact area includes a grid on the target metal casting that contacts the target ejector. The ejector contact area of the target ejector is set as a fixed boundary condition of the finite element model, and the unit friction force of each grid in the ejector contact area of the target ejector is used as the force boundary condition of the finite element model. The finite element model is solved to obtain the stress tensor of each grid in the ejector contact area of the target ejector. Based on the stress tensor of each grid in the ejector contact area of the target ejector, the ejection resultant force of the target ejector is calculated. Outputting the ejection force prediction result, it can be seen that this method improves the accuracy of ejection force prediction by constructing a finite element model and calculating the ejection force of each target ejector pin that ejects the target mold based on the clamping state of the target metal casting and the target mold. In addition, the accuracy and efficiency of simulation prediction are improved through finite element analysis, and the research and development cost of casting process simulation is reduced.
[0066] Furthermore, the embodiment of the present application provides a specific implementation process of a method for predicting ejection force. Figure 2 A schematic diagram of a specific implementation flow of a method for predicting ejection force provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, this method specifically includes:
[0067] S201. Obtain the geometric shape and material properties of the target metal casting.
[0068] In this embodiment, the target metal casting is a metal casting to be ejected from a target mold.
[0069] S202, obtaining the meshing result of the target metal casting.
[0070] In this embodiment, the mesh division result of the target metal casting includes a finite number of meshes obtained by dividing the target metal casting and nodes connecting the meshes.
[0071] S203: construct a finite element model of the target metal casting based on the geometric shape, material properties and meshing results of the target metal casting.
[0072] S204, receiving an ejection force prediction instruction before mold opening, and obtaining a temperature drop distribution of a target metal casting.
[0073] In this embodiment, the temperature drop distribution includes the temperature drop of each node of the target metal casting. The temperature drop of the target node (any node) refers to the temperature of the target node on the target metal casting after it changes from liquid to solid inside the target mold (that is, the instantaneous high temperature when the target metal casting is formed) minus the temperature when the mold is opened (that is, the temperature of the target metal casting after cooling).
[0074] It should be noted that the temperature drop of each node of the target metal casting is related to the cooling rate of each node inside the target mold. The node with a fast cooling rate has a large temperature drop.
[0075] S205 , detecting a contact area between the target metal casting and the target mold as a mold contact area.
[0076] In this embodiment, the mold contact area includes a mold contact grid set, which is composed of grids on the target metal casting that have a contact relationship with the target mold. The grids in the contact area between the target metal casting and the target mold are mold contact grids.
[0077] S206, using the temperature drop distribution as the temperature load of the finite element model, using the mold contact area as the boundary condition of the finite element model, solving the finite element model, and obtaining the stress tensor of each mold contact grid on the target metal casting.
[0078] In this embodiment, the method for detecting the contact mesh set is to determine whether each mesh is inside the mold, and if so, determine that the mesh is a contact mesh.
[0079] In this embodiment, the finite element model of the model is solved to calculate the stress tensor on each grid during the cooling process of the target metal casting. The stress tensor is composed of multiple stress components, each stress component represents the component of the stress of the grid point on a plane formed by the first direction and the second direction.
[0080] In this embodiment, the stress tensor of the mold contact grid is recorded as { }.in, represents the component of stress corresponding to the ij plane, and Respectively represent the first direction and the second direction in the constructed three-dimensional coordinate system, that is, the first direction is one of the X, Z or Y directions in the three-dimensional coordinate system, and the second direction is one of the X, Z or Y directions in the three-dimensional coordinate system. For example, and denote x and y, respectively, stress components Represents a component of stress on the plane represented by the X-axis and the Y-axis.
[0081] S207. For each mold contact grid on the target metal casting, based on the stress tensor of the mold contact grid, the normal pressure of the mold contact grid is calculated using the Cauchy slope stress formula as the unit clamping force corresponding to the mold contact grid.
[0082] In this embodiment, for any mold contact grid, that is, the target mold contact grid, the normal pressure p of the target mold contact grid is calculated by the Cauchy slope stress formula according to the stress tensor on the target mold contact grid. The formula for calculating the normal pressure is as follows:
[0083] ;
[0084] Among them, the variable The value range is ,variable The value range is , and The target mold contact grid points to the target metal casting Axis direction and The normal vector in the axis direction is a known parameter.
[0085] In this embodiment, the positive pressure of the target mold contact grid represents the clamping force exerted on the target metal casting by the target mold at the target mold contact grid.
[0086] S208, based on the target ejection direction and the unit clamping force, calculating the unit friction force of the target mold on the target metal casting at each target mold contact grid.
[0087] In this embodiment, the friction force of the target mold on the target metal casting is related to the mold opening movement direction of the target mold. Different molds have different mold opening movement directions, that is, the ejection directions of the ejector pins to eject the target metal casting are different. Therefore, it is necessary to determine the target ejection direction based on the identification of the target mold, and calculate the unit friction force of the target mold on the target metal casting at each target mold contact grid according to the target ejection direction and the unit clamping force.
[0088] The formula for calculating the element friction force at the target mold contact mesh is as follows:
[0089] ;
[0090] in, represents the element friction force at the target mold contact mesh, represents the friction coefficient, is the element holding force at the target mold contact mesh.
[0091] In this embodiment, the direction of the unit friction force is the tangential movement direction of the target mold relative to the target mold contact grid.
[0092] S209, determining a target ejector rod set, and detecting a contact area between each ejector rod in the target ejector rod set and the target metal casting as an ejector rod contact area.
[0093] In this embodiment, the target ejector set includes at least one target ejector for ejecting the target metal casting out of the target mold. The ejector contact area between the target ejector (any ejector in the target ejector set) and the target metal casting includes an ejector contact grid set, and the ejector contact grid set is composed of grids on the target metal casting that have a contact relationship with the target ejector, and the grids in the contact area between the target metal casting and the target ejector are ejector contact grids.
[0094] S210, setting the push rod contact area corresponding to the target push rod as the fixed boundary condition of the finite element model, using the unit friction force of each push rod contact grid as the force boundary condition of the finite element model, solving the finite element model, and obtaining the stress tensor of each push rod contact grid.
[0095] In this embodiment, the stress tensor of the push rod contact grid under the action of unit friction force is obtained by solving the finite element model. The stress tensor of the push rod contact grid is composed of multiple stress components, each stress component represents the component of the stress of the grid point on a plane formed by the first direction and the second direction.
[0096] In this embodiment, the stress tensor of the top rod contact grid is recorded as { }.in,{ } indicates that the stress corresponds to The weight of the plane, and Respectively represent the first direction and the second direction in the constructed three-dimensional coordinate system, that is, the first direction is one of the X, Z or Y directions in the three-dimensional coordinate system, and the second direction is the other of the X, Z or Y directions in the three-dimensional coordinate system. For example, and denote x and y, respectively, stress components Represents a component of stress on the plane represented by the X-axis and the Y-axis.
[0097] S211. For each push rod contact grid of the target push rod, based on the stress tensor of the push rod contact grid, the normal pressure of the push rod contact grid is calculated using the Cauchy slope stress formula as the unit ejection force.
[0098] In this embodiment, for any push rod contact grid, that is, the target push rod contact grid, the normal pressure q of the target mold contact grid is calculated by the Cauchy slope stress formula according to the stress tensor on the target push rod contact grid. The formula for calculating the normal pressure is as follows:
[0099] ;
[0100] Among them, the variable The value range is ,variable The value range is , and The target mold contact grid points to the target metal casting Axis direction and The normal vector in the axis direction is a known parameter.
[0101] S212, summing the ejection forces of the cells of the target ejector rod contacting the grid to obtain the ejection resultant force of the target ejector rod.
[0102] In this embodiment, by setting the ejector pin contact area corresponding to each target ejector pin as a fixed boundary condition, and taking the unit friction force of the ejector pin contact grid in the ejector pin contact area as the force boundary condition, a finite element model of the target metal casting is constructed and solved, and the deformation and stress state of each ejector pin contact grid of the target metal casting at the ejection moment is obtained. By summing the unit ejection forces of the ejector pin contact grid in the ejector pin contact area of the target ejector pin, the ejection resultant force of the target ejector pin can be obtained.
[0103] It should be noted that for each target ejector pin, the ejection resultant force can be calculated according to S210 to S212. It should be noted that the direction of the ejection resultant force is determined based on factors such as the contact area position between the target ejector pin and the target metal casting and the ejection direction.
[0104] S213, generating a prediction result of the ejection force for ejecting the target metal casting out of the target mold.
[0105] In this embodiment, the ejection force prediction result includes a target ejector rod and a corresponding ejection resultant force.
[0106] It can be seen from the above technical solution that an ejection force prediction method provided by an embodiment of the present application is as follows: first, after detecting the contact area between the target metal casting and the target mold, the temperature drop distribution is used as the temperature load of the finite element model, and the mold contact area is used as the boundary condition of the finite element model. The finite element model is solved to obtain the stress tensor of each mold contact grid on the target metal casting, and the unit clamping force corresponding to each mold contact grid in the contact area between the target metal casting and the target mold is calculated based on the stress tensor, that is, the clamping state between the target metal casting and the target mold is detected by the finite element analysis method.
[0107] Furthermore, after detecting the contact area between each push rod in the target push rod set and the target metal casting as the push rod contact area, the push rod contact area corresponding to the target push rod is set as the fixed boundary condition of the finite element model based on the clamping state corresponding to the push rod contact area, and the unit friction force of each push rod contact grid is used as the force boundary condition of the finite element model. The finite element model is solved to obtain the stress tensor of each push rod contact grid, and the normal pressure of the push rod contact grid in the contact area between the push rod and the target metal casting is calculated based on the stress tensor as the unit ejection force. That is, the finite element analysis method is used again to detect the force between the target metal casting and the target push rod based on the clamping state.
[0108] In summary, this method can calculate the ejection force when a single ejector pin ejects the target metal casting out of the target mold by constructing finite element models under different states. By realizing the prediction of the ejection force of a single ejector pin, the accuracy of the overall ejection force for ejecting the target metal casting out of the target mold is improved.
[0109] A method for predicting ejection force provided in an embodiment of the present application is introduced above, and a device for executing the method for predicting ejection force will be introduced below.
[0110] See also Figure 3 , Figure 3 This is a schematic diagram of the structure of a prediction device for ejection force provided in an embodiment of the present application. Figure 3 As shown, the ejection force prediction device 300 comprises:
[0111] A model building unit 301 is used to build a finite element model of a target metal casting;
[0112] A first contact area detection unit 302 is used to detect, for each target ejector pin in a target ejector pin set, a contact area between the target ejector pin and the target metal casting as an ejector pin contact area of the target ejector pin; the target ejector pin set includes at least one target ejector pin used to eject the target metal casting out of a target mold; the ejector pin contact area includes a grid on the target metal casting that contacts the target ejector pin;
[0113] A first model solving unit 303 is used to set the push rod contact area of the target push rod as the fixed boundary condition of the finite element model, use the unit friction force of each grid in the push rod contact area of the target push rod as the force boundary condition of the finite element model, solve the finite element model, and obtain the stress tensor of each grid in the push rod contact area of the target push rod;
[0114] A first force calculation unit 304 is used to calculate the ejection resultant force of the target ejector based on the stress tensor of each grid in the ejector contact area of the target ejector;
[0115] The prediction result output unit 305 is used to output the ejection force prediction result, wherein the ejection force prediction result includes the ejection resultant force of each of the target ejector rods in the target ejector rod set.
[0116] In a possible implementation, when the model building unit is used to build a finite element model of a target metal casting, it is specifically used to:
[0117] Acquiring the geometric shape and material properties of the target metal casting;
[0118] Obtaining a mesh division result of the target metal casting, wherein the mesh division result of the target metal casting includes a finite number of meshes obtained by dividing the target metal casting and nodes connecting the meshes;
[0119] A finite element model of the target metal casting is constructed according to the geometric shape, material properties and mesh division results of the target metal casting.
[0120] In a possible implementation, the ejection force prediction device further includes:
[0121] A second model solving unit is used for setting the ejector contact area of the target ejector as the fixed boundary condition of the finite element model, taking the unit friction force of each grid in the ejector contact area of the target ejector as the force boundary condition of the finite element model, receiving an ejection force prediction instruction before mold opening before solving the finite element model, and obtaining a temperature drop distribution of the target metal casting; the temperature drop distribution includes the temperature drop of each node of the target metal casting, and the ejection force prediction instruction indicates to use the target ejector set to eject the target metal casting out of the target mold; detecting the contact area between the target metal casting and the target mold as a mold contact area; the mold contact area includes the grids on the target metal casting that are in contact with the target mold; taking the temperature drop distribution as the temperature load of the finite element model, taking the mold contact area as the boundary condition of the finite element model, solving the finite element model, and obtaining the stress tensor of each grid in the mold contact area;
[0122] The second force calculation unit is used to calculate the unit friction force of the target metal casting on each mesh in the mold contact area based on the stress tensor of each mesh in the mold contact area.
[0123] In a possible implementation, the second force calculation unit is used to calculate the unit friction force of each grid of the target metal casting in the mold contact area subjected to the target mold based on the stress tensor of each grid in the mold contact area, and is specifically used to:
[0124] Based on the stress tensor of each mesh in the mold contact area, the normal pressure of each mesh in the mold contact area is calculated as the unit clamping force using the Cauchy slope stress formula;
[0125] Based on the ejection direction and unit clamping force of each grid in the mold contact area, the unit friction force of the target metal casting on each grid in the mold contact area is calculated.
[0126] In a possible implementation, the first force calculation unit is used to calculate the ejection resultant force of the target ejector based on the stress tensor of each grid in the ejector contact area of the target ejector, specifically to:
[0127] Based on the stress tensor of each grid in the push rod contact area of the target push rod, the normal pressure of each grid in the push rod contact area of the target push rod is calculated using the Cauchy inclined plane stress formula as the unit push force;
[0128] The ejection force of each grid unit in the ejector rod contact area of the target ejector rod is summed to obtain the ejection resultant force of the target ejector rod.
[0129] The present application also provides an electronic device in an embodiment. Figure 4 As shown, it shows a schematic diagram of the structure of an electronic device suitable for implementing the embodiment of the present application. The electronic device in the embodiment of the present application may include but is not limited to fixed terminals such as mobile phones, laptops, PDAs (personal digital assistants), PADs (tablet computers), desktop computers, etc. Figure 4 The electronic device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.
[0130] like Figure 4As shown, the electronic device may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 401, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 402 or a program loaded from a storage device 408 to a random access memory (RAM) 403. When the electronic device is powered on, various programs and data required for the operation of the electronic device are also stored in the RAM 403. The processing device 401, the ROM 402, and the RAM 403 are connected to each other via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.
[0131] Typically, the following devices may be connected to the I / O interface 405: an input device 406 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 407 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 408 including, for example, a memory card, a hard disk, etc.; and a communication device 409. The communication device 409 may allow the electronic device to communicate with other devices wirelessly or by wire to exchange data. Although Figure 4 An electronic device having various devices is shown, but it should be understood that it is not required to implement or possess all the devices shown. More or fewer devices may be implemented or possessed instead.
[0132] The present application also provides a computer program product including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements any of the ejection force prediction methods provided in the present application, as follows:
[0133] Construct a finite element model of the target metal casting;
[0134] For each target ejector pin in the target ejector pin set, a contact area between the target ejector pin and the target metal casting is detected as an ejector pin contact area of the target ejector pin; the target ejector pin set includes at least one target ejector pin used to eject the target metal casting out of a target mold; the ejector pin contact area includes a grid on the target metal casting that contacts the target ejector pin;
[0135] The push rod contact area of the target push rod is set as the fixed boundary condition of the finite element model, the unit friction force of each grid in the push rod contact area of the target push rod is used as the force boundary condition of the finite element model, and the finite element model is solved to obtain the stress tensor of each grid in the push rod contact area of the target push rod;
[0136] Based on the stress tensor of each grid in the push rod contact area of the target push rod, the ejection resultant force of the target push rod is calculated;
[0137] Outputting an ejection force prediction result, wherein the ejection force prediction result includes the ejection resultant force of each of the target ejector rods in the target ejector rod set.
[0138] The present application also provides a computer-readable storage medium, which carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement any of the ejection force prediction methods provided in the present application, as follows:
[0139] Construct a finite element model of the target metal casting;
[0140] For each target ejector pin in the target ejector pin set, a contact area between the target ejector pin and the target metal casting is detected as an ejector pin contact area of the target ejector pin; the target ejector pin set includes at least one target ejector pin used to eject the target metal casting out of a target mold; the ejector pin contact area includes a grid on the target metal casting that contacts the target ejector pin;
[0141] The push rod contact area of the target push rod is set as the fixed boundary condition of the finite element model, the unit friction force of each grid in the push rod contact area of the target push rod is used as the force boundary condition of the finite element model, and the finite element model is solved to obtain the stress tensor of each grid in the push rod contact area of the target push rod;
[0142] Based on the stress tensor of each grid in the push rod contact area of the target push rod, the ejection resultant force of the target push rod is calculated;
[0143] Outputting an ejection force prediction result, wherein the ejection force prediction result includes the ejection resultant force of each of the target ejector rods in the target ejector rod set.
[0144] It should also 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 over 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 drawings of the device embodiments provided by the present application, 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.
[0145] Through the description of the above implementation methods, the technicians in the relevant field can clearly understand that the present application can be implemented by means of software plus necessary general hardware, and of course, it can also be implemented by special hardware including special integrated circuits, special CPUs, special memories, special components, etc. In general, all functions completed by computer programs can be easily implemented by corresponding hardware, and the specific hardware structures used to implement the same function can also be various, such as analog circuits, digital circuits or special circuits. However, for the present application, software program implementation is a better implementation method in more cases. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer floppy disk, U disk, mobile hard disk, ROM, RAM, disk or optical disk, etc., including a number of instructions to enable a computer device (which can be a personal computer, training equipment, or network equipment, etc.) to execute the methods described in each embodiment of the present application.
[0146] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.
[0147] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, a computer, a training device, or a data center to another website, a computer, a training device, or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a training device, a data center, etc. that includes one or more available media integrations. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)), etc.
Claims
1. A method for predicting ejection force, characterized in that: include: Construct a finite element model of the target metal casting; For each target ejector pin in the target ejector pin set, a contact area between the target ejector pin and the target metal casting is detected as an ejector pin contact area of the target ejector pin; the target ejector pin set includes at least one target ejector pin used to eject the target metal casting out of a target mold; the ejector pin contact area includes a grid on the target metal casting that contacts the target ejector pin; receiving an ejection force prediction instruction before mold opening, and obtaining a temperature drop distribution of the target metal casting; the temperature drop distribution includes the temperature drop of each node of the target metal casting, and the ejection force prediction instruction instructs to use the target ejector rod set to eject the target metal casting out of the target mold; Detecting a contact area between the target metal casting and the target mold as a mold contact area; the mold contact area includes a grid on the target metal casting that contacts the target mold; Taking the temperature drop distribution as the temperature load of the finite element model and the mold contact area as the boundary condition of the finite element model, solving the finite element model to obtain the stress tensor of each grid in the mold contact area; Calculating the unit friction force of the target metal casting on each grid in the mold contact area based on the stress tensor of each grid in the mold contact area; The push rod contact area of the target push rod is set as the fixed boundary condition of the finite element model, the unit friction force of each grid in the push rod contact area of the target push rod is used as the force boundary condition of the finite element model, and the finite element model is solved to obtain the stress tensor of each grid in the push rod contact area of the target push rod; Based on the stress tensor of each grid in the push rod contact area of the target push rod, the ejection resultant force of the target push rod is calculated; Outputting an ejection force prediction result, wherein the ejection force prediction result includes the ejection resultant force of each of the target ejector rods in the target ejector rod set.
2. The method for predicting ejection force according to claim 1, characterized in that: The finite element model of the target metal casting is constructed, comprising: Acquiring the geometric shape and material properties of the target metal casting; Obtaining a mesh division result of the target metal casting, wherein the mesh division result of the target metal casting includes a finite number of meshes obtained by dividing the target metal casting and nodes connecting the meshes; A finite element model of the target metal casting is constructed according to the geometric shape, material properties and mesh division results of the target metal casting.
3. The method for predicting ejection force according to claim 1, characterized in that: The step of calculating the unit friction force of each mesh of the target metal casting in the mold contact area subjected to the target mold based on the stress tensor of each mesh in the mold contact area comprises: Based on the stress tensor of each mesh in the mold contact area, the normal pressure of each mesh in the mold contact area is calculated as the unit clamping force using the Cauchy slope stress formula; Based on the ejection direction and unit clamping force of each grid in the mold contact area, the unit friction force of the target metal casting on each grid in the mold contact area is calculated.
4. The method for predicting ejection force according to claim 1, characterized in that: The step of calculating the ejection resultant force of the target ejector rod based on the stress tensor of each grid in the ejector rod contact area of the target ejector rod comprises: Based on the stress tensor of each grid in the push rod contact area of the target push rod, the normal pressure of each grid in the push rod contact area of the target push rod is calculated using the Cauchy inclined plane stress formula as the unit push force; The ejection force of each grid unit in the ejector rod contact area of the target ejector rod is summed to obtain the ejection resultant force of the target ejector rod.
5. A device for predicting ejection force, characterized in that: include: A model building unit, used for building a finite element model of a target metal casting; a first contact area detection unit, configured to detect, for each target ejector pin in a target ejector pin set, a contact area between the target ejector pin and the target metal casting as an ejector pin contact area of the target ejector pin; the target ejector pin set includes at least one target ejector pin for ejecting the target metal casting out of a target mold; the ejector pin contact area includes a grid on the target metal casting that contacts the target ejector pin; a second model solving unit, configured to set the ejector contact area of the target ejector as a fixed boundary condition of the finite element model, use the unit friction force of each grid in the ejector contact area of the target ejector as a force boundary condition of the finite element model, and receive an ejection force prediction instruction before mold opening before solving the finite element model, and obtain a temperature drop distribution of the target metal casting; the temperature drop distribution includes the temperature drop of each node of the target metal casting, and the ejection force prediction instruction indicates to use the target ejector set to eject the target metal casting out of the target mold; Detecting a contact area between the target metal casting and the target mold as a mold contact area; the mold contact area includes a grid on the target metal casting that contacts the target mold; Taking the temperature drop distribution as the temperature load of the finite element model and the mold contact area as the boundary condition of the finite element model, solving the finite element model to obtain the stress tensor of each grid in the mold contact area; A second force calculation unit, configured to calculate a unit friction force of each mesh of the target metal casting in the mold contact area on the target mold based on a stress tensor of each mesh in the mold contact area; A first model solving unit is used to set a push rod contact area of the target push rod as a fixed boundary condition of the finite element model, use the unit friction force of each grid in the push rod contact area of the target push rod as the force boundary condition of the finite element model, solve the finite element model, and obtain the stress tensor of each grid in the push rod contact area of the target push rod; A first force calculation unit, configured to calculate the ejection resultant force of the target ejector pin based on the stress tensor of each grid in the ejector pin contact area of the target ejector pin; The prediction result output unit is used to output the ejection force prediction result, wherein the ejection force prediction result includes the ejection resultant force of each of the target ejector rods in the target ejector rod set.
6. The ejection force prediction device according to claim 5, characterized in that: The model building unit, when used to build a finite element model of a target metal casting, is specifically used to: Acquiring the geometric shape and material properties of the target metal casting; Obtaining a mesh division result of the target metal casting, wherein the mesh division result of the target metal casting includes a finite number of meshes obtained by dividing the target metal casting and nodes connecting the meshes; A finite element model of the target metal casting is constructed according to the geometric shape, material properties and mesh division results of the target metal casting.
7. A computer program product, characterized in that The method comprises computer-readable instructions, and when the computer-readable instructions are executed on an electronic device, the electronic device implements the method for predicting the ejection force as claimed in any one of claims 1 to 4.
8. An electronic device, characterized in that: The method comprises at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is used to execute the computer program so that the electronic device can implement the ejection force prediction method as described in any one of claims 1 to 4.
9. A computer storage medium, characterized in that The storage medium carries one or more computer programs, and when the one or more computer programs are executed by an electronic device, the electronic device can implement the ejection force prediction method as described in any one of claims 1 to 4.