Metal mold design system and metal mold design method

Abstract

To provide a metal mold design system which improves, while reducing the time and trouble of metal mold design, design efficiency of the metal mold without being influenced by worker's proficiency.SOLUTION: A metal mold design system comprises: a simulation part; a resistance estimation part; a map; and a shape selection part. The simulation part calculates: a first inflow which is an inflow of material when a bead shape of a metal mold is a first shape; and a second inflow which is an inflow of material when the bead shape thereof is a second shape. The resistance estimation part identifies a candidate resistance force that is a bead resistance force estimated within a prescribed target range of the inflow of material based on the first inflow and the second inflow. The map memorizes the relation between the bead resistance force and the bead shape. The shape selection part selects a bead shape corresponding to the candidate resistance force in the map as a candidate of the bead shape of the metal mold.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system for designing a mold. [Background technology]

[0002] Some molds have a molding section that molds a plate-shaped material into the shape of a product, and a drawbead molding section that sandwiches the material outside the edge of the molding section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-108880 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of the present invention have focused on the following problem in designing such a die. Hereinafter, the shape of the drawbead molding portion will be referred to as the "bead shape." When pressing is performed using such a die, the portion of the material that was located outside the edge of the molding portion flows into the molding portion. Furthermore, depending on the amount of material flowing in, the drawbead molding portion generates a "bead resistance force" as a tension that pulls the material toward the outside of the molding portion.

[0005] It is preferable that the amount of material flowing in be within a predetermined target range, because if the amount of flowing in is insufficient, the thickness of the material will be reduced too much during press forming, which may result in cracks, whereas if the amount of flowing in is too great, the thickness of the material will be too great, which may result in wrinkles.

[0006] Therefore, when designing such a die, the worker must set a candidate bead shape that they think will keep the material inflow amount within a target range, and then perform a molding simulation to perform press molding using that setting.The worker then adopts the candidate shape as the bead shape of the die, provided that the material inflow amount calculated by the molding simulation falls within a predetermined target range.

[0007] However, with this method, the operator must repeatedly perform molding simulations while changing candidate shapes through trial and error until the inflow volume falls within the target range. This not only makes mold design time-consuming, but also makes the design efficiency of the mold significantly dependent on the operator's skill level.

[0008] The present invention has been made in consideration of the above circumstances, and aims to reduce the effort required for designing a mold and to make mold design efficiency less susceptible to the influence of the worker's level of skill. [Means for solving the problem]

[0009] The inventors discovered that the above object can be achieved by utilizing the correlation between bead resistance and a bead shape suitable for it, and thus arrived at the present invention. The present invention is the following die design system (1) to (13) and die design method (14).

[0010] (1) A mold having a molding section that molds a plate-shaped material into the shape of a product and a drawbead molding section that sandwiches the material outside the edge of the molding section, and when press molding is performed, the part of the material that was located outside the edge of the molding section flows into the molding section, and a bead resistance force as a tension that pulls the material toward the outside of the molding section is generated by the drawbead molding section depending on the amount of material that flows in. A mold design system for designing, a simulation unit that, when a bead shape as a shape of the drawbead molding portion is set to a predetermined first shape, calculates a first inflow amount as the inflow amount for the first shape by performing a molding simulation of the press molding, and, when the bead shape is set to a second shape different from the first shape, calculates a second inflow amount as the inflow amount for the second shape by performing the molding simulation; a resistance estimation unit that identifies a candidate resistance force as the bead resistance force that is estimated to have an inflow amount within a predetermined target range from the first inflow amount and the second inflow amount; a map storing a relationship between the bead resistance force and the bead shape; a shape selection unit that selects the bead shape corresponding to the candidate resistance in the map as a candidate shape for the bead shape of the mold; A mold design system comprising:

[0011] According to this configuration, the simulation unit calculates the first inflow rate and the second inflow rate through a molding simulation. The resistance estimation unit identifies a candidate resistance from the first inflow rate and the second inflow rate. The shape selection unit selects a bead shape corresponding to the candidate resistance in the map as a candidate shape. This allows a candidate shape to be automatically selected from the candidate resistance based on the correlation between the bead resistance and the bead shape. This reduces the effort required for mold design compared to when an operator selects candidate shapes through trial and error, and makes mold design efficiency less susceptible to the influence of the operator's level of skill.

[0012] (2) The simulation unit further calculates a candidate inflow amount as the inflow amount in the case of the candidate shape by performing the molding simulation when the bead shape is set as the candidate shape; The mold design system further comprises: a suitability determination unit that adopts the candidate shape as the bead shape of the mold on the condition that the candidate inflow amount falls within the target range; The mold design system according to (1) above.

[0013] According to this configuration, it is possible to automatically determine whether or not a candidate shape is actually adopted, thereby further reducing the effort required for designing a mold.

[0014] (3) the resistance estimation unit re-identifies the candidate resistance from the first inflow, the second inflow, and the candidate inflow, on the condition that the candidate inflow does not fall within the target range; the shape selection unit reselects, as the candidate shape, the bead shape corresponding to the re-identified candidate resistance in the map. The mold design system according to (2) above.

[0015] According to this configuration, when a candidate shape should not be adopted, the next candidate shape can be quickly and automatically reselected, which further reduces the effort required for designing a mold.

[0016] (4) The simulation unit sets the second shape so that the smaller of the first inflow amount and the second inflow amount is smaller than a minimum value within the target range, and the larger of the first inflow amount and the second inflow amount is larger than a maximum value within the target range. The mold design system according to any one of (1) to (3) above.

[0017] According to this configuration, since the first inflow amount and the second inflow amount are located on both sides of the target range, it becomes easier to accurately fit the candidate inflow amount based on them within the target range.

[0018] (5) When the first inflow amount is smaller than a minimum value within the target range, the simulation unit sets the second shape based on an expected breaking bead resistance as the bead resistance that is expected to cause the plate-shaped material to break. The mold design system according to (4) above.

[0019] According to this configuration, the second shape can be set efficiently so that the second inflow amount is greater than the target range.

[0020] (6) The information about the bead shape stored in the map includes information about a radius of curvature of a predetermined portion in the drawbead molding portion, the shape selection unit selects at least the radius of curvature in the candidate shape; The mold design system according to any one of (1) to (5) above.

[0021] According to this configuration, the radius of curvature can be efficiently selected.

[0022] (7) The information about the bead shape stored in the map includes information about the position of a predetermined portion in the drawbead molding portion, the shape selection unit selects at least the position in the candidate shape; The mold design system according to any one of (1) to (6) above.

[0023] According to this configuration, the position can be efficiently selected.

[0024] (8) The information about the bead shape stored in the map includes information about the depth of a predetermined portion in a predetermined direction in the drawbead molding portion, the shape selection unit selects at least the depth in the candidate shape; The mold design system according to any one of (1) to (7) above.

[0025] According to this configuration, the depth can be efficiently selected.

[0026] (9) The information about the bead shape stored in the map includes information about a combination of shapes of a plurality of parts in the drawbead molding portion, the shape selection unit selects at least the combination from the candidate shapes; The mold design system according to any one of (1) to (8) above.

[0027] According to this configuration, the combination can be efficiently selected.

[0028] (10) A series of processes including the process by the simulation unit, the process by the resistance estimation unit, and the process by the shape selection unit is automatically performed. The mold design system according to any one of (1) to (9) above.

[0029] According to this configuration, the series of processes can be performed automatically, thereby further reducing the effort required for designing a mold.

[0030] (11) The simulation unit performs the molding simulation for each of a plurality of cross sections different from one another in the mold, the resistance estimation unit identifies the candidate resistance for each cross section; the shape selection unit selects the candidate shape for each of the cross sections; The mold design system according to any one of (1) to (10) above.

[0031] According to this configuration, bead shapes can be efficiently designed for multiple cross sections in the mold.

[0032] (12) The resistance estimation unit identifies the candidate resistance using an approximation formula that indicates a relationship between the inflow amount and the bead resistance, the die design system stores the approximation formula updated based on the result of the molding simulation using the shape adopted for the bead shape of the die. The mold design system according to any one of (1) to (11) above.

[0033] According to this configuration, by saving the approximation formula updated based on the results of the molding simulation for the final bead shape, it can be used as reference data for the next and subsequent design of the mold.

[0034] (13) When a predetermined shape is adopted as the bead shape of the mold, predetermined information is stored; the predetermined information includes at least one of a result of the molding simulation, information about a three-dimensional shape of the mold, and information about a two-dimensional cross-sectional shape of the mold related to the molding simulation. The mold design system according to any one of (1) to (12) above.

[0035] According to this configuration, by storing the predetermined information, it can be used as reference data for the next time and thereafter.

[0036] (14) A mold having a molding section that molds a plate-shaped material into the shape of a product and a drawbead molding section that sandwiches the material outside the edge of the molding section, and when the material is press-molded into the product, the portion of the material that was located outside the edge of the molding section flows into the molding section, and a bead resistance force as a tension that pulls the material toward the outside of the molding section is generated by the drawbead molding section depending on the amount of material that flows in. A mold design method for designing, a simulation step of calculating a first inflow amount as the inflow amount for a case where a bead shape as a shape of the drawbead molding portion is set to a predetermined first shape by performing a molding simulation of the press molding, and calculating a second inflow amount as the inflow amount for a case where the bead shape is set to a second shape different from the first shape by performing the molding simulation; a resistance estimation step of identifying a candidate resistance force as the bead resistance force estimated to have an inflow amount falling within a predetermined target range from the first inflow amount and the second inflow amount; a shape selection step of selecting the bead shape corresponding to the candidate resistance force in a map storing the relationship between the bead resistance force and the bead shape as a candidate shape for the bead shape of the die; A mold design method including:

[0037] In the method of this configuration, similar to the system (1) above, candidate shapes can be mechanically selected based on the correlation between bead resistance and bead shape. [Effects of the Invention]

[0038] As described above, the system of (1) and the method of (14) can reduce the effort required for designing a mold and make the mold design efficiency less susceptible to the influence of the skill level of the worker. Furthermore, the configurations of (2) to (13) that cite (1) above can provide additional effects. [Brief explanation of the drawings]

[0039] [Figure 1] FIG. 1 is a configuration diagram showing a mold design system according to a first embodiment. [Figure 2] FIG. 2 is a front cross-sectional view showing the mold when it is opened. [Figure 3] FIG. 2 is a front cross-sectional view showing the mold when it is closed. [Figure 4] 10 is a graph illustrating a technique for identifying candidate resistance using the relationship between material inflow and bead resistance force. [Figure 5] 10 is a graph showing a technique for re-identifying candidate resistances using the relationship between the amount of material inflow and the bead resistance force. [Figure 6] FIG. [Figure 7] 10 is a flowchart showing a processing flow by the die design system. [Figure 8] 10 is a flowchart showing a process flow in a modified example. [Figure 9] 10 is a graph illustrating a technique for identifying candidate resistance using the relationship between material inflow and bead resistance force. [Figure 10] 1 is a graph showing the relationship between plate thickness reduction rate and bead resistance force. DETAILED DESCRIPTION OF THE INVENTION

[0040] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments and can be appropriately modified and implemented within the scope of the present invention.

[0041] [First embodiment] The die design system 50 shown in FIG. 1 is a system for automatically designing a die 60 as shown in FIG. 2, for example.

[0042] As shown in Figure 2, the mold 60 includes a die 60a, a clamping member 60b, and a punch 60c. Hereinafter, two predetermined directions that are perpendicular to each other in a horizontal plane will be referred to as the "X direction" and the "Y direction." One of the X directions will be referred to as the "X- direction," and the opposite direction will be referred to as the "X+ direction." One of the Y directions will be referred to as the "Y- direction," and the opposite direction will be referred to as the "Y+ direction."

[0043] As shown in FIGS. 2 and 3, the clamping portion 60b is located outside an edge 61e of a molding portion 61 of the punch 60c, which will be described later. The clamping portion 60b is configured to be movable up and down and is biased upward by a biasing member such as a spring. Therefore, when the mold 60 is opened, the clamping portion 60b is located at the upper end of its movable range. The die 60a is closed from above against the punch 60c and the clamping portion 60b. At this time, the die 60a first contacts the clamping portion 60b with the material 70 sandwiched between them. From this state, the die 60a presses down the clamping portion 60b, causing the die 60a to contact the punch 60c with the material 70 sandwiched between them, as shown in FIG. 3. This allows the material 70 to be molded into the shape of the product.

[0044] As shown in FIG. 3, this mold 60, in terms of function, comprises a molding section 61 and a die face molding section 65. The molding section 61 is a section that molds a plate-shaped material 70 into the shape of a product. Therefore, the aforementioned "edge 61e of the molding section 61" is the edge of the "section that molds the plate-shaped material 70 into the shape of a product." In other words, it is a section that molds the boundary between the section that will become the product and the section that will be cut out and discarded. The die face molding section 65 is located outside the edge 61e of the molding section 61. Note that, for example, a die-draw molding section or an excess molding section is provided between the molding section 61 and the die face molding section 65.

[0045] 2, the molding section 61 is provided on the lower surface of the die 60a and the upper surface of the punch 60c at portions facing each other. The die face molding section 65 is provided on the lower surface of the die 60a and the upper surface of the clamping section 60b at portions facing each other.

[0046] 3, a drawbead molding portion 66 is formed in the die face molding portion 65. The drawbead molding portion 66 has a wave-like shape when viewed in the Y direction.

[0047] When material 70 is press-molded into the shape of the product using this mold 60, the portion of material 70 that was located outside the edge of molding portion 61 when viewed from above flows into molding portion 61. In accordance with the inflow amount Q of material 70, a "bead resistance force R" is generated by draw bead molding portion 66 as a tension that pulls material 70 toward the outside of molding portion 61.

[0048] Hereinafter, the inflow amount Q of the material 70 into the molding section 61 will be simply referred to as the "inflow amount Q." Also, hereinafter, the target range of the inflow amount Q will be simply referred to as the "target range A." This target range A is, for example, the range of the inflow amount Q within which the thickness reduction rate of a predetermined portion of the material 70 is estimated to fall within a predetermined range. Note that the thickness reduction rate here is a value obtained by subtracting from 100% the ratio of the thickness after press-forming to the thickness before press-forming.

[0049] The mold design system 50 shown in Fig. 1 includes an operation unit 50a, a calculation unit 50b, and a display unit 50c. The operation unit 50a includes, for example, a keyboard and a mouse, and is configured to be able to input commands and the like to the calculation unit 50b. The display unit 50c includes a display and the like, and displays a screen based on commands from the calculation unit 50b. The calculation unit 50b includes a CPU, a memory, and the like. Functionally, the calculation unit 50b includes a simulation unit 51, a resistance estimation unit 52, a map 53, a shape selection unit 54, and a suitability determination unit 55.

[0050] Hereinafter, a simulation of press-molding the material 70 into the shape of a product in a cross section including the drawbead molding portion 66 as shown in Figures 2, 3, etc. will be referred to as a "molding simulation." Also, the shape of the drawbead molding portion 66 will be referred to as a "bead shape F." Note that the shape of the portion other than the bead shape F in the two-dimensional cross-sectional shape of the die 60 related to the molding simulation is set by the simulation unit 51 based on information about the three-dimensional shape of the die 60 input by, for example, an operator.

[0051] In the following description, the two different predetermined bead shapes F are referred to as the "first shape F1" and the "second shape F2." The case where the bead shape F is set to the first shape F1 is simply referred to as the "case of the first shape F1." The case where the bead shape F is set to the second shape F2 is simply referred to as the "case of the second shape F2."

[0052] The simulation unit 51 shown in FIG. 1 performs a molding simulation for the first shape F1. As a result, it calculates a "first inflow amount Q1" as the inflow amount Q for the first shape F1 and a "first resistance force R1" as the bead resistance force R for the first shape F1. Furthermore, the simulation unit 51 performs a molding simulation for the second shape F2. As a result, it calculates a "second inflow amount Q2" as the inflow amount Q for the second shape F2 and a "second resistance force R2" as the bead resistance force R for the second shape F2.

[0053] Specifically, for the first shape F1, the worker arbitrarily sets a bead shape F such that the inflow amount Q is likely to fall within the target range A. On the other hand, for the second shape F2, a bead shape F is set such that the inflow amount Q is likely to approach the target range A based on the results of the molding simulation for the first shape F1. Specifically, when the first inflow amount Q1 is larger than the target range A, a bead shape F is set for the second shape F2 such that the inflow amount Q is likely to be smaller than that for the first shape F1. On the other hand, when the first inflow amount Q1 is smaller than the target range A, a bead shape F is set for the second shape F2 such that the inflow amount Q is likely to be larger than that for the first shape F1.

[0054] The resistance estimation unit 52 shown in Fig. 1 identifies a "candidate resistance force R3" as the bead resistance force R estimated when the inflow amount Q falls within the target range A, based on the results of the molding simulation for the first shape F1 and the results of the molding simulation for the second shape F2. Specifically, as shown in Fig. 4, for example, the results of the molding simulation for the first shape F1 and the results of the molding simulation for the second shape F2 are plotted on a two-dimensional coordinate plane QR, with the horizontal axis representing the inflow amount Q and the vertical axis representing the bead resistance force R. The bead resistance force R corresponding to the intersection p3 between a straight line Lf2 passing through these two plots and a predetermined target line Lq is identified as the candidate resistance force R3.

[0055] Here, the target line Lq is a straight line indicating a predetermined inflow amount Q within the target range A. More specifically, as shown in Fig. 4, when the inflow amounts Q1 and Q2 for the two shapes F1 and F2 are larger than the target range A, the target line Lq is a straight line indicating the lower limit of the target range A. On the other hand, contrary to Fig. 4, when the inflow amounts Q1 and Q2 for the two shapes F1 and F2 are smaller than the target range A, the target line Lq is a straight line indicating the upper limit of the target range A.

[0056] 6, the map 53 stores the relationship between the bead resistance force R and the bead shape F. Hereinafter, information about the bead shape F stored in the map 53 will be referred to as "bead shape information." Specifically, in this embodiment, the bead shape information includes information about a combination of shapes of multiple parts in the drawbead molding portion 66.

[0057] More specifically, the bead shape information includes information about the radius of curvature C1 of a predetermined first portion 661 in the drawbead molding portion 66, and information about the radius of curvature C2 of a predetermined second portion 662. Furthermore, the bead shape information includes information about the position of a predetermined first recess 665 in the drawbead molding portion 66, and information about the position of a predetermined second recess 666. Furthermore, the bead shape information includes information about the depth D1 of the first recess 665, i.e., the dimension of the first recess 665 in the up-down direction, and information about the depth D2 of the second recess 666, i.e., the dimension of the second recess 666 in the up-down direction.

[0058] The shape selection unit 54 shown in Fig. 1 selects the bead shape F corresponding to the candidate resistance force R3 as the candidate shape F3 in the map 53 shown in Fig. 6. Hereinafter, the case where the bead shape F is set as the candidate shape F3 will be simply referred to as "the case of the candidate shape F3."

[0059] 1 further performs a molding simulation for the candidate shape F3, thereby calculating a "candidate inflow volume Q3" as the inflow volume Q for the candidate shape F3.

[0060] The suitability determination unit 55 shown in Fig. 1 adopts the candidate shape F3 as the bead shape of the mold 60 if the candidate inflow volume Q3 falls within the target range A as shown in Fig. 4. On the other hand, if the candidate inflow volume Q3 does not fall within the target range A as shown in Fig. 5, the suitability determination unit 55 shown in Fig. 1 plots the results of the molding simulations for the three previous shapes F1, F2, and F3 on, for example, the two-dimensional coordinate plane QR mentioned above. The suitability determination unit 55 identifies a new candidate resistance force R4, which is the bead resistance force R corresponding to the intersection p4 between the approximation line Lf3 extending averagely along these three plots and the target line Lq mentioned above. In other words, the candidate resistance force is re-identified.

[0061] The shape selection unit 54 shown in Fig. 1 selects the bead shape F corresponding to the new candidate resistance force R4 as the new candidate shape F4 in the map 53 shown in Fig. 6. In other words, the candidate shape is selected again.

[0062] 1 performs a molding simulation again using the candidate shape F4, thereby calculating a new candidate inflow volume Q4. In other words, the candidate inflow volume is recalculated.

[0063] As shown in Fig. 5, the suitability determination unit 55 shown in Fig. 1 adopts the new candidate shape F4 as the bead shape of the mold 60, on the condition that the new candidate inflow volume Q4 falls within the target range A. On the other hand, contrary to Fig. 5, if the new candidate inflow volume Q4 does not fall within the target range A, the same procedure as above is repeated to reselect the candidate shape until the candidate inflow volume falls within the target range A. In other words, the suitability determination unit 55 shown in Fig. 1 adopts the last selected candidate shape as the bead shape F of the mold 60, on the condition that the last calculated candidate inflow volume falls within the target range A.

[0064] Next, the flow of the series of processes shown above will be explained with reference to the flowchart in Fig. 7. Note that in the following, "S" before the numbers stands for step.

[0065] First, in S11, the operator operates the operation unit 50a according to the guidance displayed on the display unit 50c to set the bead shape F to a first shape F1 that is likely to cause the inflow amount Q to fall within the target range A. Next, in S12, the simulation unit 51 performs a molding simulation for the first shape F1, thereby calculating the first resistance force R1 and the first inflow amount Q1.

[0066] Next, in S13, the suitability determination unit 55 determines whether the first inflow amount Q1 is within the target range A. If the determination is affirmative, in S14 the suitability determination unit 55 adopts the first shape F1 as the bead shape F of the mold. Then, the adopted bead shape F is displayed on the display unit 50c. On the other hand, if the determination is negative in S13, the processing proceeds to S21.

[0067] In S21, the simulation unit 51 identifies a second shape F2 based on the results of the molding simulation for the first shape F1, which is more likely to bring the inflow amount Q closer to the target range A than the first shape F1. Next, in S22, the simulation unit 51 performs a molding simulation for the second shape F2, thereby calculating the second resistance force R2 and the second inflow amount Q2.

[0068] Next, in S23, the suitability determination unit 55 determines whether the second inflow amount Q2 is within the target range A. If the determination is affirmative, in S24, the suitability determination unit 55 adopts the second shape F2 as the bead shape F of the mold 60. Then, the adopted bead shape F is displayed on the display unit 50c. On the other hand, if the determination is negative in S23, the processing proceeds to S30.

[0069] In S30, the resistance estimation unit 52 identifies a candidate resistance force R3 based on the results of the molding simulation for the first shape F1 and the second shape F2. Next, in S31, the shape selection unit 54 selects the bead shape F corresponding to the candidate resistance force R3 in the map 53 as a candidate shape F3. Next, in S32, the simulation unit 51 performs a molding simulation for the candidate shape F3. This calculates a candidate inflow volume Q3.

[0070] Next, in S33, the suitability determination unit 55 determines whether the candidate inflow volume Q3 falls within the target range A. If the determination is affirmative, in S34 the suitability determination unit 55 adopts the candidate shape F3 as the bead shape F of the mold 60. Then, the adopted bead shape F is displayed on the display unit 50c. On the other hand, if the determination is negative in S34, the processing returns to S30.

[0071] In step S30, the resistance estimation unit 52 identifies a new candidate resistance force R4 from the results of the molding simulations for the previous shapes F1, F2, and F3. Next, in step S31, the shape selection unit 54 selects the bead shape F corresponding to the new candidate resistance force R4 in the map 53 as a new candidate shape F4. Next, in step S32, the simulation unit 51 performs a molding simulation for the new candidate shape F4. This calculates a new candidate inflow volume Q4.

[0072] Next, in S33, the suitability determination unit 55 again determines whether the new candidate inflow volume Q4 falls within the target range A. If the determination is affirmative, in S34, the suitability determination unit 55 again adopts the new candidate shape F4 as the bead shape F of the mold 60. Then, the adopted bead shape F is displayed on the display unit 50c. On the other hand, if the determination is negative in S33, the processing returns to S30.

[0073] Thereafter, the above steps S30 to S33 are repeated to reselect a candidate shape until the candidate inflow volume falls within the target range A. At S33 for each repetition, the suitability determination unit 55 adopts the last selected candidate shape as the bead shape F of the mold 60, on the condition that the last calculated candidate inflow volume falls within the target range A. Then, the adopted bead shape F is displayed on the display unit 50c.

[0074] The above flow is performed automatically by robotic process automation using the mold design system 50 shown in Fig. 1. That is, the mold design system 50 automatically performs a series of processes including processing by the simulation unit 51, processing by the resistance estimation unit 52, processing by the shape selection unit 54, and processing by the suitability determination unit 55.

[0075] Furthermore, the mold design system 50 also performs the above-described processing on a plurality of cross sections of the mold 60 other than the cross sections shown in FIGS.

[0076] The configuration and effects of this embodiment are summarized below.

[0077] The simulation unit 51 shown in FIG. 1 calculates a first inflow rate Q1 and a second inflow rate Q2 through a molding simulation. As shown in FIG. 4, the resistance estimation unit 52 identifies a candidate resistance force R3 from the first inflow rate Q1 and the second inflow rate Q2. The shape selection unit 54 selects a bead shape F corresponding to the candidate resistance force R3 in the map 53 shown in FIG. 6 as a candidate shape F3. This allows the candidate shape F3 to be automatically selected from the candidate resistance force R3 based on the correlation between the bead resistance force R and the bead shape F. This reduces the effort required to design the mold 60 compared to when an operator selects the candidate shape F3 through trial and error, and makes the design efficiency of the mold 60 less susceptible to the influence of the operator's level of skill.

[0078] The suitability determination unit 55 adopts the candidate shape F3 as the bead shape F of the mold 60 on the condition that the candidate inflow amount Q3 falls within the target range A, as shown in FIG. 4. Therefore, it is possible to efficiently and automatically determine whether or not to actually adopt the candidate shape F3. This further reduces the effort required to design the mold 60.

[0079] The resistance estimation unit 52 identifies a new candidate resistance force R4 from the results of molding simulations for multiple shapes F1, F2, and F3, including the previous candidate shape F3, on the condition that the candidate inflow rate Q3 does not fall within the target range A, as shown in Figure 5. The shape selection unit 54 selects the bead shape F corresponding to the new candidate resistance force R4 in the map 53 shown in Figure 6 as the new candidate shape F4. This makes it possible to quickly and automatically select the next new candidate shape F4 when the selected candidate shape F3 should not be adopted. This further reduces the effort required to design the mold 60.

[0080] 6 includes information about the radii of curvature C1 and C2 of the predetermined portions 661 and 662 in the drawbead molding portion 66. This allows the radii of curvature C1 and C2 to be efficiently selected.

[0081] The bead shape information stored in the map 53 includes information about the positions of the predetermined portions 665, 666 in the drawbead molding portion 66. From this, the positions can be efficiently selected.

[0082] The bead shape information stored in the map 53 includes information about the depths D1 and D2 in predetermined directions of the predetermined portions 665 and 666 in the drawbead molding portion 66. This allows the depths D1 and D2 to be efficiently selected.

[0083] The bead shape information stored in the map 53 includes information about the combination of shapes of multiple parts in the drawbead molding portion 66. This allows the combination to be efficiently selected.

[0084] 1 automatically performs a series of processes including a process by a simulation unit 51, a process by a resistance estimation unit 52, a process by a shape selection unit 54, and a process by a suitability determination unit 55. This further reduces the effort required to design a mold 60.

[0085] The simulation unit 51 performs molding simulation for each of a plurality of different cross sections in a mold 60 as shown in Fig. 3. The resistance estimation unit 52 identifies a candidate resistance force R3 for each cross section. The shape selection unit selects a candidate shape F3 for each cross section. This allows for efficient design of bead shapes F for the plurality of cross sections in the mold 60.

[0086] In the mold design system 50 shown in FIG. 1, the processing by the simulation unit 51 corresponds to the implementation of a simulation step. Furthermore, the processing by the resistance estimation unit 52 corresponds to the implementation of a resistance estimation step. Furthermore, the processing by the shape selection unit 54 corresponds to the implementation of a shape selection step. Furthermore, the processing by the suitability determination unit 55 corresponds to the implementation of a suitability determination step. Therefore, according to this embodiment, a mold design method including these simulation step, resistance estimation step, shape selection step, and suitability determination step can be implemented.

[0087] [Second embodiment] Next, a second embodiment will be described with reference to Figures 9 and 10. This embodiment will be described based on the first embodiment, focusing on differences from the first embodiment, and descriptions of the same or similar aspects to the first embodiment will be omitted as appropriate.

[0088] As shown in Figure 9, the simulation unit 51 sets the second shape F2 so that the smaller of the first inflow Q1 and the second inflow Q2 is smaller than the minimum value within the target range A, and the larger of the first inflow Q1 and the second inflow Q2 is greater than the maximum value within the target range A.

[0089] Specifically, when the first inflow rate Q1 is smaller than the target range A, the simulation unit 51 acquires information showing the relationship between the bead resistance force R and the thickness reduction rate as shown in FIG. 10 by simulating a test piece made of the same material as the material 70. From this information, the simulation unit 51 calculates an "expected breaking bead resistance force Rx" as the bead resistance force R at which the material 70 is expected to break. The simulation unit 51 sets a second shape F2 shown in FIG. 9 based on the expected breaking bead resistance force. Specifically, the simulation unit 51 sets the second shape F2 so that the second resistance force R2 is the expected breaking bead resistance force Rx or a value close to it.

[0090] Furthermore, contrary to the case shown in FIG. 9, when the first inflow amount Q1 is larger than the target range A, the simulation unit 51 sets the second shape F2 so that the second resistance force R2 is sufficiently small.

[0091] 9, the resistance estimation unit 52 plots the results of the molding simulation for the first shape F1 and the results of the molding simulation for the second shape F2 on a two-dimensional coordinate plane QR. The resistance estimation unit 52 identifies the bead resistance force R corresponding to the intersection p3 between a straight line Lf2 passing through these two plots and a target line Lq located in the middle of the target range A as a candidate resistance force R3.

[0092] The subsequent steps are the same as in the first embodiment. That is, a candidate inflow volume Q3 is calculated as the inflow volume Q for the candidate shape F3 that is the bead shape F corresponding to the candidate resistance force R3. Then, the suitability determination unit 55 determines whether the candidate inflow volume Q3 falls within the target range A.

[0093] According to this embodiment, as shown in FIG. 9, the simulation unit 51 sets the second shape F2 so that the smaller of the first inflow amount Q1 and the second inflow amount Q2 is smaller than the minimum value within the target range A, and the larger of the first inflow amount Q1 and the second inflow amount Q2 is greater than the maximum value within the target range A. As a result, the first inflow amount Q1 and the second inflow amount Q2 are located on both sides of the target range A. This makes it easier to fit the candidate inflow amount Q3 within the target range A in one calculation. This reduces the need to calculate the candidate inflow amount Q4 again, thereby reducing the computational load.

[0094] 9, the simulation unit 51 sets the second shape F2 based on the predicted breaking bead resistance force Rx when the first inflow rate Q1 is smaller than the minimum value within the target range A. As a result, the second shape F2 can be efficiently set so that the second inflow rate Q2 is larger than the maximum value within the target range A.

[0095] [Other embodiments] The embodiment described above can be modified as follows, for example.

[0096] The suitability determination unit 55 shown in FIG. 1 may be eliminated, and the candidate shape F3 selected by the shape selection unit 54 may be unconditionally adopted as the bead shape F of the mold 60. In particular, in the second embodiment, this mode can be preferably adopted because it is easier to bring the candidate inflow volume Q3 within the target range A in one try. In this case, it is not necessary to determine whether the candidate inflow volume Q3 falls within the target range A (S33) as shown in FIG. 8, or to calculate the candidate inflow volume Q4 again if the determination is negative, thereby further reducing the computational load.

[0097] The function of the suitability determination unit 55 may be limited so that the second or subsequent candidate shape F3 is unconditionally adopted as the bead shape F of the mold 60. In these cases, compared to the first embodiment, there is a higher risk that the inflow amount Q will not fall within the target range A, but the number of molding simulations can be reduced, thereby reducing the calculation load.

[0098] The die design method of each embodiment may be performed based on manual operations by an operator without using the die design system 50.

[0099] As shown in S14, S24, and S34 of FIG. 8, when the suitability determination unit 55 adopts a predetermined shape for the bead shape F of the mold 60, the resistance estimation unit 52 may again update the approximation line Lf3 shown in FIG. 5 etc. to an approximation line that extends along the average of the previous plots (F1, F2, F3, and F4). Then, as shown in S15, S25, and S35 of FIG. 8, the mold design system 50 may store the final approximation line. Note that this "approximation line" corresponds to an approximate equation that shows the relationship between the inflow amount Q and the bead resistance force R. Furthermore, when the suitability determination unit 55 adopts a predetermined shape for the bead shape F of the mold 60 in this way, the mold design system 50 may store predetermined information such as previous settings and calculation results as shown in S15, S25, and S35 of the same. Specifically, for example, the results of each molding simulation, information about the three-dimensional shape of the mold 60, and information about the two-dimensional cross-sectional shape of the mold 60 related to the molding simulation may be saved.

[0100] This information serves as reference data for subsequent mold designs, and its use by workers and the mold design system 50 is expected to further improve mold design accuracy. Specifically, for example, the surface quality (product accuracy) of molded products can be improved by using approximate formula data and inflow control information. Furthermore, by processing (AI learning, statistical processing) the accumulated data in this way, the processed data can be used in other mold designs. For example, if there is a mold with similar conditions, it can be used as is, and the same data can also be used to consider molds with similar conditions. This eliminates the need for repeated consideration. Therefore, the above inflow control information can replace the traditional expert-based consideration based on empirical rules with a system. In other words, this mold molding system enables more accurate designs by accumulating simulation information and other information. [Explanation of symbols]

[0101] 50 Mold Design System 51 Simulation Department 52 Resistance estimation section 53 Maps 54 Shape selection section 55 Compliance Determination Section 60 molds 61 Molding section 66 Drawbead forming section 70 materials A. Target Range C1 Radius of curvature of the first part C2 Radius of curvature of the second part D1 Depth of the first recess D2 Depth of the second recess F Bead shape F1 1st shape F2 2nd shape F3 Candidate shape F4 Another candidate shape R Bead resistance R1 First Resistance R2 2nd resistance force R3 Candidate Resistance R4: Another candidate resistance Rx Expected breaking bead resistance Q inflow amount Q1 1st inflow Q2 2nd inflow amount Q3 Candidate inflow Q4 Re-candidate inflow

Claims

1. A mold has a molding section that molds a plate-shaped material into the shape of a product, and a drawbead molding section that sandwiches the material outside the edge of the molding section, and when press molding is performed, the part of the material that was located outside the edge of the molding section flows into the molding section, and a bead resistance force as a tension that pulls the material toward the outside of the molding section is generated by the drawbead molding section depending on the amount of material that flows in. A mold design system for designing, a simulation unit that, when a bead shape as a shape of the drawbead molding portion is set to a predetermined first shape, calculates a first inflow amount as the inflow amount for the first shape by performing a molding simulation of the press molding, and, when the bead shape is set to a second shape different from the first shape, calculates a second inflow amount as the inflow amount for the second shape by performing the molding simulation; a resistance estimating unit that identifies a candidate resistance as the bead resistance, based on the first inflow amount and the second inflow amount, when the inflow amount is estimated to fall within a predetermined target range; a map storing a relationship between the bead resistance force and the bead shape; a shape selection unit that selects the bead shape corresponding to the candidate resistance in the map as a candidate shape for the bead shape of the mold; A mold design system comprising:

2. the simulation unit further performs the molding simulation when the bead shape is set as the candidate shape, thereby calculating a candidate inflow amount as the inflow amount in the case of the candidate shape; The mold design system further comprises: a suitability determination unit that adopts the candidate shape as the bead shape of the mold on the condition that the candidate inflow amount falls within the target range; The mold design system according to claim 1 .

3. the resistance estimator re-identifies the candidate resistance from the first inflow rate, the second inflow rate, and the candidate inflow rate, on the condition that the candidate inflow rate does not fall within the target range; the shape selection unit reselects, as the candidate shape, the bead shape corresponding to the re-identified candidate resistance in the map. The mold design system according to claim 2 .

4. the simulation unit sets the second shape such that the smaller of the first inflow rate and the second inflow rate is smaller than a minimum value within the target range, and the larger of the first inflow rate and the second inflow rate is larger than a maximum value within the target range. The mold design system according to any one of claims 1 to 3.

5. the simulation unit sets the second shape based on an expected breaking bead resistance as the bead resistance that is expected to cause the plate-shaped material to break when the first inflow amount is smaller than a minimum value within the target range. The mold design system according to claim 4 .

6. the information about the bead shape stored in the map includes information about a radius of curvature of a predetermined portion in the drawbead molding portion, the shape selection unit selects at least the radius of curvature in the candidate shape; The mold design system according to any one of claims 1 to 3.

7. the information about the bead shape stored in the map includes information about a position of a predetermined portion in the drawbead molding portion, the shape selection unit selects at least the position in the candidate shape; The mold design system according to any one of claims 1 to 3.

8. the information about the bead shape stored in the map includes information about a depth in a predetermined direction of a predetermined portion in the drawbead molding portion, the shape selection unit selects at least the depth in the candidate shape; The mold design system according to any one of claims 1 to 3.

9. the information about the bead shape stored in the map includes information about a combination of shapes of a plurality of parts in the drawbead molding portion, the shape selection unit selects at least the combination from the candidate shapes; The mold design system according to any one of claims 1 to 3.

10. a series of processes including the process by the simulation unit, the process by the resistance estimation unit, and the process by the shape selection unit are automatically performed; The mold design system according to any one of claims 1 to 3.

11. the simulation unit performs the molding simulation for each of a plurality of cross sections different from one another in the mold, the resistance estimation unit identifies the candidate resistance for each cross section; the shape selection unit selects the candidate shape for each of the cross sections; The mold design system according to any one of claims 1 to 3.

12. the resistance estimation unit identifies the candidate resistance using an approximation formula that indicates a relationship between the inflow amount and the bead resistance; the die design system stores the approximation formula updated based on the results of the molding simulation using the shape adopted for the bead shape of the die. The mold design system according to any one of claims 1 to 3.

13. When a predetermined shape is adopted as the bead shape of the mold, predetermined information is stored; the predetermined information includes at least one of a result of the molding simulation, information about a three-dimensional shape of the mold, and information about a two-dimensional cross-sectional shape of the mold related to the molding simulation. The mold design system according to any one of claims 1 to 3.

14. A mold having a molding section that molds a plate-shaped material into the shape of a product and a draw bead molding section that sandwiches the material outside the edge of the molding section, and when the material is press-molded into the product, the portion of the material that was located outside the edge of the molding section flows into the molding section, and a bead resistance force as a tension that pulls the material toward the outside of the molding section is generated by the draw bead molding section depending on the amount of material that flows in. A mold design method for designing, a simulation step of calculating a first inflow amount as the inflow amount for a case where a bead shape as a shape of the drawbead molding portion is set to a predetermined first shape by performing a molding simulation of the press molding, and calculating a second inflow amount as the inflow amount for a case where the bead shape is set to a second shape different from the first shape by performing the molding simulation; a resistance estimation step of identifying a candidate resistance force as the bead resistance force estimated to have an inflow amount falling within a predetermined target range from the first inflow amount and the second inflow amount; a shape selection step of selecting the bead shape corresponding to the candidate resistance force in a map storing the relationship between the bead resistance force and the bead shape as a candidate shape for the bead shape of the die; A mold design method including:

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