Charging timing determination device, charging timing determination method, and charging timing determination program

Abstract

When performing forging, a challenge is to determine the appropriate and efficient timing for filling the material. [Solution] The filling timing determination device 10 generates multiple analysis meshes that constitute the mold model and the molded product model, performs numerical analysis, and calculates the distance between the mold model and the molded product model at the nodes of each analysis mesh. The filling timing determination device 10 calculates the difference between the calculated distance and the distance between the mold model and the molded product model in the previous analysis. If the difference is greater than or equal to a predetermined threshold, it calculates an approximation line from a predetermined number of distance history data, starting from the time when the distance between the mold model and the molded product model became 0 or less. If the difference is less than the predetermined threshold, it calculates an approximation line from the calculated distance history data, starting from the time immediately preceding the time when the difference was determined to be less than the predetermined threshold, calculates the time when the distance becomes 0 from the approximation line, and determines that the calculated time is the filling timing.

Description

Technical Field

[0001] The present invention relates to a filling timing determination device, a filling timing determination method, and a filling timing determination program that can appropriately and efficiently determine the filling timing when performing forging.

Background Art

[0002] Conventionally, forging is often performed by hitting a lump of metal in the form of an ingot or a cylinder with a hammer or a mold, applying a large force, and plastically deforming it to form a shape. An analysis technique for simulating the plastic deformation of the lump of metal generated during such forging is known (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the technology of Patent Document 1 enables quantitative evaluation of the amount and manner of burrs during the manufacture of forging at the design stage, and there is a problem that it cannot determine the timing when the mold is filled with the molded product in order to confirm the presence or absence of undercuts within the product shape in forging.

[0005] Therefore, when performing forging, how to appropriately and efficiently determine the filling timing between the mold and the molded product has become an important issue.

[0006] The present invention was made to solve the problems (issues) of the above-mentioned prior art, and aims to provide a filling timing determination device, a filling timing determination method, and a filling timing determination program that can determine the filling timing appropriately and efficiently when performing forging. [Means for solving the problem]

[0007] To solve the above-mentioned problems and achieve the objective, the present invention provides a filling timing determination device that calculates the distance between a mold model and a molded product model at each forming time of forging and determines the filling timing based on the distance, comprising: a distance calculation unit that calculates the distance between corresponding nodes between nodes of a plurality of analytical meshes constituting the mold model and nodes of a plurality of analytical meshes constituting the molded product model; an approximation line calculation unit that calculates an approximation line based on the distance history data calculated by the distance calculation unit; and a determination unit that determines the timing at which the molded product model has filled the mold model based on the approximation line.

[0008] Furthermore, the present invention further comprises a distance difference calculation unit that calculates the distance difference between a first distance calculated in a first molding time and a second distance calculated in a second molding time immediately preceding the first molding time, and a distance difference determination unit that determines whether the change in distance is normal based on the distance difference, wherein the approximation line calculation unit changes the distance history data used to calculate the approximation line based on the determination result of the distance difference determination unit.

[0009] Furthermore, the present invention is characterized in that, in the above invention, the approximation line calculation unit calculates the approximation line using a predetermined number of distance history data, starting from the time when the distance difference is equal to or greater than a predetermined threshold.

[0010] Furthermore, the present invention is characterized in that, when the distance difference is smaller than a predetermined threshold, the approximation line calculation unit calculates the approximation line using a predetermined number of distance history data, starting from a second time that is one time prior to the first time when the distance difference became smaller than the predetermined threshold.

[0011] Furthermore, the present invention is characterized in that, in the above invention, the determination unit determines that the mold model has filled the mold model when the distance obtained from the approximation line becomes 0.

[0012] Furthermore, the present invention relates to a method for determining the filling timing of a filling timing determination device that calculates the distance between a mold model and a molded product model at each forming time of forging and determines the filling timing based on the distance, and is characterized by including a distance calculation step of calculating the distance between the nodes of a plurality of analytical meshes constituting the mold model and the nodes of a plurality of analytical meshes constituting the molded product model; an approximation line calculation step of calculating an approximation line based on the distance history data calculated in the distance calculation step; and a determination step of determining the timing at which the molded product model has filled the mold model based on the approximation line.

[0013] Furthermore, the present invention relates to a filling timing determination program executed by a filling timing determination device that calculates the distance between a mold model and a molded product model at each forming time of forging and determines the filling timing based on the distance, characterized in that a computer executes a distance calculation procedure for calculating the distance between the nodes of a plurality of analytical meshes constituting the mold model and the nodes of a plurality of analytical meshes constituting the molded product model; an approximation line calculation procedure for calculating an approximation line based on the distance history data calculated in the distance calculation procedure; and a determination procedure for determining the timing at which the molded product model has filled the mold model based on the approximation line. [Effects of the Invention]

[0014] According to the present invention, when performing forging, the filling timing can be determined appropriately and efficiently.

Brief Description of the Drawings

[0015] [Figure 1] FIG. 1 is a diagram showing an overview of a filling timing determination device according to an embodiment. [Figure 2] FIG. 2 is a functional block diagram showing the configuration of the filling timing determination device shown in FIG. 1. [Figure 3] FIG. 3 is a diagram showing an example of generation of an analysis mesh. [Figure 4] FIG. 4 is an explanatory diagram for explaining the change in the distance between the nodes of the mold model and the nodes of the molded product model when remeshing is performed. [Figure 5] FIG. 5 is an explanatory diagram (Part 1) for explaining the determination of the filling timing. [Figure 6] FIG. 6 is an explanatory diagram (Part 2) for explaining the determination of the filling timing. [Figure 7] FIG. 7 is a flowchart showing the processing procedure of the filling timing determination device shown in FIG. 2. [Figure 8] FIG. 8 is a flowchart showing the processing procedure of the distance calculation process shown in FIG. 7. [Figure 9] FIG. 9 is a diagram showing an example of the hardware configuration.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of a filling timing determination device, a filling timing determination method, and a filling timing determination program according to the present invention will be described in detail based on the drawings.

[0017] The overview of the filling timing determination device according to this embodiment will be described. FIG. 1 is a diagram showing an overview of the filling timing determination device according to the embodiment.

[0018] <Overview of the Filling Timing Determination Device 10> As shown in Figure 1(a), conventionally, the manufacturing of products using forging technology involves multiple molding processes to form the product. Figure 1(a) shows the state of molding as time progresses in a particular molding process. Specifically, it shows the state in which the molded product is prepared at molding time 1, molding is repeated for each part at each molding time, molding is completed at molding time 100 after molding time 30. During forging, the time when the distance between the mold and the molded product becomes 0 or less is called the "filling timing," and generally, the filling timing is determined using analysis.

[0019] During the analysis, if the shape of the analysis area changes significantly, remeshing is performed to reconstruct the mesh to match the deformed shape in order to improve the accuracy of the analysis. However, this remeshing can cause discontinuities in the distance between the nodes of the analysis mesh of the mold model and the corresponding nodes of the analysis mesh of the molded product model, making it difficult to accurately determine the filling timing.

[0020] As shown in Figure 1(b), the present invention performs numerical analysis based on a molded product model in each forming step of forging, calculates the distance between the nodes of the mold model and the molded product model, and determines the filling timing based on this distance. The filling timing determination device 10 generates an analysis mesh consisting of multiple nodes that constitute the molded product model. The filling timing determination device 10 performs numerical analysis while remeshing as necessary. In the numerical analysis, the distance from the nodes of the analysis mesh constructed on the inner surface of the mold model to the corresponding nodes of the analysis mesh of the molded product model is calculated for each forming time.

[0021] Subsequently, the filling timing determination device 10 determines the filling timing based on distance. Specifically, it calculates the difference between the calculated distance from the mold model to the node of the molded product model and the distance from the mold model to the node of the molded product model calculated for the previous molding time. If the molding time includes a period in which the difference is greater than or equal to a predetermined threshold, the filling timing determination device 10 calculates an approximation line from a predetermined number of distance history data, starting from the time when the distance between the mold model and the node of the molded product model becomes 0 or less, calculates the time when the distance from the approximation line becomes 0, and determines that time as the filling timing.

[0022] On the other hand, if the filling timing determination device 10 includes a molding time in which the difference is smaller than a predetermined threshold, it calculates an approximation line from a predetermined number of distance history data calculated before the time in which the difference is determined to be smaller than the predetermined threshold, starting from the time immediately preceding this time, calculates the time when the distance from the approximation line becomes 0, and determines that the calculated time as the filling timing. The predetermined threshold is, for example, 0.4 mm.

[0023] In this way, the filling timing determination device 10 performs a process to reconsider the filling timing if, during the process of uniformly decreasing distance as the molding time progresses, a molding time occurs in which the distance or the change in distance shows an abnormal value. If the reduction width suddenly becomes small at a certain molding time, the filling timing determination device 10 can determine the filling timing from the distances of multiple molding times prior to that molding time, without including the molding time in which the reduction width showed an abnormal value, and from this approximation line. The filling timing determination device 10 sets a threshold for detecting abnormalities in the reduction width of the distance and detects the abnormality as described above to determine the filling timing.

[0024] <Configuration of the charging timing determination device 10> Next, the configuration of the charging timing determination device 10 shown in Figure 1 will be described. Figure 2 is a functional block diagram showing the configuration of the charging timing determination device 10 shown in Figure 1. The charging timing determination device 10 has a display unit 11, an input unit 12, a storage unit 14, and a control unit 15. The display unit 11 is a display device such as a liquid crystal display that displays various information. The input unit 12 is an input device such as a mouse or keyboard.

[0025] The storage unit 14 is a storage device such as a hard disk drive or non-volatile memory, and stores forging process data 14a, mesh data 14b, and distance history data 14c. The forging process data 14a is data of the molded product model in each molding process using forging technology. The mesh data 14b is data of an analysis mesh consisting of multiple nodes generated on the surface of the mold model and the molded product model for analysis.

[0026] Distance history data 14c is data that shows the distance between each node of the analysis mesh of the molded product model and the corresponding node of the analysis mesh of the mold model. Distance history data 14c stores the elapsed time from molding time 1 to each molding time (hereinafter referred to as "time") and the distance between each corresponding node of the molded product model and the mold model calculated at each molding time, in association with each other. If remeshing is performed, the node in the analysis mesh of the molded product model that is closest in distance from the node of the analysis mesh of the mold model after remeshing is considered to be the node corresponding to the node of the mold model.

[0027] The control unit 15 is a control unit that controls the entire filling timing determination device 10, and includes a mesh generation unit 15a, a numerical analysis unit 15b, a distance calculation unit 15c, a distance difference calculation unit 15d, a distance difference determination unit 15e, an approximation line calculation unit 15f, and a determination unit 15g. In practice, by loading these programs into the CPU and executing them, the mesh generation unit 15a, the numerical analysis unit 15b, the distance calculation unit 15c, the distance difference calculation unit 15d, the distance difference determination unit 15e, the approximation line calculation unit 15f, and the determination unit 15g will each execute the corresponding processes.

[0028] The mesh generation unit 15a is a processing unit that generates an analysis mesh 40 consisting of multiple nodes for analysis on the mold model and the molded product model 60. The size of the generated analysis mesh 40 is varied in density according to the shape of the mold model and the molded product model 60. For example, as shown in Figure 3, a finer analysis mesh 40 is generated in areas of the molded product model 60 that have changes in shape.

[0029] The numerical analysis unit 15b is a processing unit that performs numerical analysis based on the nodes of the generated analysis mesh. For example, the finite element method may be used for the numerical analysis.

[0030] The distance calculation unit 15c is a processing unit that calculates the distance between a node in the mold model and a corresponding node in the molded product model 60. Specifically, it calculates the distance between a node in the analysis mesh 40 of the mold model and a node in the analysis mesh 40 of the molded product model 60, starting from the node in the analysis mesh 40 of the mold model. The distance calculation unit 15c then stores the calculated distance as distance history data 14c in the storage unit 14. The mold model does not deform, and the analysis mesh 40 of the mold model is not remeshed even as molding time progresses. Therefore, by starting the calculation of the distance from the node in the analysis mesh 40 of the mold model, the accuracy of the calculated distance is maintained even if the analysis mesh 40 of the molded product model 60 is remeshed.

[0031] The distance difference calculation unit 15d is a processing unit that calculates the difference between a first distance calculated at a predetermined molding time and a second distance calculated at the molding time immediately preceding the predetermined molding time. Specifically, it reads the first distance and the second distance from the distance history data 14c of the storage unit 14, and calculates the difference by subtracting the first distance from the second distance.

[0032] The distance difference determination unit 15e is a processing unit that determines whether the distance difference calculated by the distance difference calculation unit 15d is greater than or equal to a predetermined threshold. Specifically, if the distance difference is greater than or equal to the predetermined threshold, it is determined to be "normal," and if the distance difference is less than the predetermined threshold, it is determined to be "abnormal."

[0033] The approximation line calculation unit 15f is a processing unit that calculates the coefficients of the approximation line using the least squares method or the like, using a predetermined number of distance history data points from a predetermined time in the distance history data 14c. For example, if the approximation line is y = ax + b, the approximation line calculation unit 15f calculates the coefficients a and b using a predetermined number of distance history data points. Based on the determination result of the distance difference determination unit 15e, if the determination result is "normal", the approximation line calculation unit 15f calculates the coefficients from a predetermined number of distance history data points starting from the time when the distance became 0. If the determination result is "abnormal", the approximation line calculation unit 15f calculates the coefficients from a predetermined number of distance history data points from a time prior to the time when it was determined to be "abnormal". The predetermined number is, for example, 10.

[0034] The determination unit 15g is a processing unit that calculates the time when the distance becomes 0 and determines that this time is the timing when the molded product has filled the mold. Specifically, the determination unit 15g calculates the time when the distance becomes 0 from the equation of the approximation line calculated by the approximation line calculation unit 15f. For example, if the approximation line is represented as y=ax+b, the determination unit 15g finds the x at which y=0 and determines that this x is the filling timing.

[0035] <Changes in the distance between the mold model and the molded product model when remeshing is performed> Next, we will explain the change in the distance between the nodes of the mold model and the nodes of the molded product model when remeshing is performed. Figure 4 is an explanatory diagram illustrating the change in the distance between the nodes of the mold model and the nodes of the molded product model when remeshing is performed. As shown in Figure 4(a), the forming time of forging progresses, and the distance distribution between the nodes of the mold model and the nodes of the molded product model at a certain forming time N is determined. Then, as shown in Figure 4(b), when remeshing is performed at forming time N+1, an analysis mesh 40 with new nodes is generated in region A. Figure 4(b) shows that the new nodes generated in region A have a larger value than the distance at forming time N.

[0036] <Determining the timing of filling> Next, we will explain how to determine the filling timing of the mold and the molded product. Figures 5 and 6 are explanatory diagrams for explaining how to determine the filling timing. As shown in Figure 5, if the distance between the nodes of the mold model and the corresponding nodes of the molded product model simply decreases, the time when the distance becomes 0 (here, t) n+5 Starting from a predetermined number of distance history data points, the coefficients a and b of the approximation line equation (y=ax+b) are calculated, and the x value at which y=0 is found from the approximation line equation, and this x value is determined to be the filling timing.

[0037] On the other hand, as shown in Figure 6, if there is a discontinuity in the decrease in the distance between the nodes of the mold model and the nodes of the molded product model, then the time t at which the discontinuity occurred will be considered. n+4 The time t before that n+3 Starting from a predetermined number of distance history data points, the coefficients a and b of the equation of the approximation line (y=ax+b) are calculated, and the x at which y=0 is found from the equation of the approximation line, and this x is determined to be the filling timing. Note that the time t at which a discontinuity occurs in the decrease in the distance between the mold model and the molded product model is determined. n+4 This is the time at which the distance difference determination unit 15e determined that the situation was "abnormal".

[0038] <Processing procedure of the charging timing determination device 10> Next, the processing procedure of the filling timing determination device 10 will be described. Figure 7 is a flowchart showing the processing procedure of the filling timing determination device 10 as shown in Figure 2. As shown in Figure 7, the filling timing determination device 10 generates analysis meshes for the mold model and the molded product model (step S101).

[0039] Then, the filling timing determination device 10 performs distance calculation processing (step S102). After that, the filling timing determination device 10 calculates the distance difference (step S103). Then, the filling timing determination device 10 determines whether the distance difference is greater than or equal to a predetermined threshold (step S104).

[0040] If the distance difference is less than a predetermined threshold (step S104: No), the charging timing determination device 10 calculates an approximation line using a predetermined number of distance histories from the time immediately preceding the time when the distance difference was less than the predetermined threshold (step S105), and proceeds to step S108. On the other hand, if the distance difference is greater than or equal to a predetermined threshold (step S104: Yes), the charging timing determination device 10 determines whether the distance has become 0 or not (step S106).

[0041] If the charging timing determination device 10 determines that the distance is not 0 (step S106: No), it proceeds to step S104. If the charging timing determination device 10 determines that the distance is 0 (step S106: Yes), it calculates an approximation line using a predetermined number of distance histories from the time when the distance becomes 0 (step S107).

[0042] Then, the filling timing determination device 10 calculates the time when the distance becomes 0 based on the approximation line (step S108). After that, the filling timing determination device 10 determines that the time when the distance becomes 0 is the filling timing (step S109).

[0043] <Processing steps for distance calculation> Next, the processing procedure for the distance calculation process shown in Figure 7 will be explained. Figure 8 is a flowchart showing the processing procedure for the distance calculation process shown in Figure 7. As shown in Figure 8, the distance calculation process performs numerical analysis using the finite element method, etc. (step S201).

[0044] The distance calculation process then calculates the distance between the nodes of the analysis mesh of the mold model and the corresponding points of contact of the analysis mesh of the molded product model (step S202). Subsequently, the distance calculation process determines whether the molding time for which the numerical analysis was performed is the final molding time (step S203). If the molding time for which the numerical analysis was performed is not the final molding time (step S203), the distance calculation process reads the data of the molded product model for the next molding time (step S204) and proceeds to step S201.

[0045] On the other hand, if the molding time for which numerical analysis was performed is the final molding time (step S203: Yes), the distance calculation process proceeds to step S103 shown in Figure 7.

[0046] As described above, in this embodiment, the filling timing determination device 10 generates an analysis mesh consisting of multiple nodes that constitute the molded product model. The filling timing determination device 10 then performs numerical analysis and calculates the distance between the mold model and the molded product model at the nodes of each analysis mesh based on each analysis mesh. Subsequently, the filling timing determination device 10 calculates the difference between the calculated distance between the mold model and the molded product and the distance between the mold model and the molded product at the previous molding time. If the difference is greater than or equal to a predetermined threshold, it calculates an approximation line from a predetermined number of distance history data starting from the time when the distance between the mold model and the molded product became 0 or less. If the difference is less than the predetermined threshold, it calculates an approximation line from the calculated distance history starting from the time immediately preceding the time when the difference was determined to be less than the predetermined threshold, calculates the time when the distance becomes 0 from the approximation line, and determines that calculated time as the filling timing.

[0047] In the above embodiment, we described a case where an approximation line is calculated even when the distance difference is greater than or equal to a predetermined threshold, and the filling timing is determined from the approximation line. However, when the distance difference is greater than or equal to a predetermined threshold, the time when the calculated distance becomes 0 may be determined as the filling timing.

[0048] Furthermore, although the above embodiment described an example in which an anomaly is detected by comparing the difference in distance during molding time with a threshold, the detection method is not particularly limited as long as it is possible to detect that the distance between the mold and the molded product, which gradually decreases as the molding time progresses, shows an abnormal value. For example, an anomaly may be detected by comparing the differences in distance, or an anomaly may be detected by calculating the derivative of the change in distance.

[0049] Furthermore, although the above embodiment described the case in which an approximation line is calculated when the distance becomes 0 during the analysis, the approximation line may also be calculated when the distance falls below a predetermined distance threshold. The predetermined distance threshold is, for example, 0.01 mm.

[0050] <Relationship with hardware> Next, the correspondence between the filling timing determination device 10 according to this embodiment and the main hardware configuration of the computer will be described. Figure 9 shows an example of the hardware configuration.

[0051] Generally, a computer consists of components such as a CPU 81, ROM 82, RAM 83, and non-volatile memory 84, connected by a bus 85. A hard disk drive may be provided instead of the non-volatile memory 84. For the sake of explanation, Figure 9 shows only the basic hardware configuration.

[0052] Here, the ROM 82 or non-volatile memory 84 stores programs necessary for starting the operating system (hereinafter simply referred to as "OS"), and the CPU 81 reads and executes the OS program from the ROM 82 or non-volatile memory 84 when the power is turned on.

[0053] On the other hand, various application programs executed on the OS are stored in non-volatile memory 84, and the CPU 81 executes the application programs using RAM 83 as main memory, thereby executing the processes corresponding to the applications.

[0054] Furthermore, the filling timing determination program for the filling timing determination device 10 according to this embodiment is stored in non-volatile memory 84 or the like, just like other application programs, and the CPU 81 loads and executes this filling timing determination program. In the case of the filling timing determination device 10 according to this embodiment, the filling timing determination program, which includes routines corresponding to the mesh generation unit 15a, numerical analysis unit 15b, distance calculation unit 15c, distance difference calculation unit 15d, distance difference determination unit 15e, approximation line calculation unit 15f, and determination unit 15g shown in Figure 2, is stored in non-volatile memory 84 or the like. When the filling timing determination program is loaded and executed by the CPU 81, a filling timing determination process corresponding to the mesh generation unit 15a, numerical analysis unit 15b, distance calculation unit 15c, distance difference calculation unit 15d, distance difference determination unit 15e, approximation line calculation unit 15f, and determination unit 15g is generated.

[0055] The configurations illustrated in the above embodiments are functional schematics and do not necessarily have to be physically represented as shown. In other words, the distributed and integrated forms of each device are not limited to those shown, and all or part of them can be functionally or physically distributed and integrated in any unit according to various loads and usage conditions. [Industrial applicability]

[0056] The filling timing determination device, filling timing determination method, and filling timing determination program according to the present invention are suitable for determining the filling timing appropriately and efficiently when performing forging. [Explanation of Symbols]

[0057] 10. Filling timing determination device 11 Display section 12 Input section 14 Storage section 14a Forging process data 14b Mesh data 14c Distance History Data 15 Control Unit 15a Mesh generation section 15b Numerical Analysis Section 15c Distance calculation section 15d Distance difference calculation section 15e Distance difference judgment section 15f Approximate line calculation section 15g Judgment part 40 Mesh for analysis 60 Molded Models 81 CPU 82 ROM 83 RAM 84 Non-volatile memory 85 Bus

Claims

1. A filling timing determination device that calculates the distance between the mold model and the molded product model at each forming time of forging and determines the filling timing based on the said distance, A distance calculation unit calculates the distance between corresponding nodes between a plurality of analysis mesh nodes constituting the mold model and a plurality of analysis mesh nodes constituting the molded product model. An approximation line calculation unit calculates an approximation line based on the distance history data calculated by the distance calculation unit, A determination unit that determines the timing at which the molded product model fills the mold model based on the aforementioned approximation line. A filling timing determination device characterized by being equipped with the following features.

2. A distance difference calculation unit calculates the distance difference between a first distance calculated during a first molding time and a second distance calculated during a second molding time immediately preceding the first molding time. The system further includes a distance difference determination unit that determines whether the change in distance is normal or not based on the distance difference, The approximation line calculation unit changes the distance history data used to calculate the approximation line based on the determination result of the distance difference determination unit. The filling timing determination device according to feature 1.

3. The aforementioned approximation line calculation unit, If the distance difference is greater than or equal to a predetermined threshold, the approximation line is calculated using a predetermined number of distance history data, starting from the time when the distance became zero. The filling timing determination device according to feature 2.

4. The aforementioned approximation line calculation unit, If the distance difference is smaller than a predetermined threshold, the approximation line is calculated using a predetermined number of distance history data, starting from a second time point that is one time point prior to the first time point in which the distance difference became smaller than the predetermined threshold. The filling timing determination device according to feature 2.

5. The determination unit, When the distance obtained from the approximation line becomes 0, it is determined that the mold model has filled the molded product model, and this is the filling timing. The filling timing determination device according to feature 2.

6. A method for determining the filling timing of a filling timing determination device, which calculates the distance between the mold model and the molded product model at each forming time of forging and determines the filling timing based on the said distance, A distance calculation step for calculating the distance between the nodes of the multiple analytical meshes constituting the mold model and the nodes of the multiple analytical meshes constituting the molded product model, A approximation line calculation step, which calculates an approximation line based on the distance history data calculated in the distance calculation step, A determination step of determining the timing at which the molded product model fills the mold model based on the aforementioned approximation line. A method for determining the timing of filling, characterized by including the following:

7. A filling timing determination program executed by a filling timing determination device that calculates the distance between the mold model and the molded product model at each forming time of forging and determines the filling timing based on the said distance, A distance calculation procedure for calculating the distance between the nodes of the multiple analytical meshes constituting the mold model and the nodes of the multiple analytical meshes constituting the molded product model, A procedure for calculating an approximation line based on the distance history data calculated in the distance calculation procedure, A determination procedure for determining the timing at which the molded product model fills the mold model based on the aforementioned approximation line. A charging timing determination program characterized by having a computer perform the operation.

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