Malfunction determination method, malfunction determination program, and malfunction determination device

Abstract

To provide a malfunction determination method, a malfunction determination program, and a malfunction determination device, capable of predicting presence or absence of a malfunction in a bending process of a hollow member.SOLUTION: In a malfunction determination method according to the present invention, a computer determines a malfunction of a hollow member after a bending process that applies bending processing using a mold. The malfunction determination method comprises: an analysis step of reading out a model of the hollow member and a fixture for applying the bending processing from a storage unit, and executing a CAE analysis on the basis of a processing condition of the bending processing using the model; and a determination step of determining the malfunction of the hollow member after the bending processing on the basis of the analysis result by the CAE analysis.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fault determination method, a fault determination program, and a fault determination device. [Background technology]

[0002] In recent years, hollow molded products have been used as structural members for automobiles and the like in order to reduce weight. These molded products are produced, for example, by bending a long hollow member. In this case, the molded product is produced by pressing a pressure die against the hollow member while rotating a bending die that holds the hollow member (see, for example, Patent Document 1). Regarding this manufacturing method, a method has been disclosed in which the bending shape is obtained using finite element analysis, the shape after processing is compared with a reference shape to calculate the amount of deviation (amount of springback), and the processing conditions are optimized based on the amount of deviation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-161332 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in Patent Document 1, optimized machining conditions are output based on the amount of deviation, but there has been a demand for confirmation as to whether or not the machining conditions are ones that may actually cause problems.

[0005] The present invention has been made in consideration of the above, and aims to provide a defect determination method, a defect determination program, and a defect determination device that can predict whether or not a defect will occur during bending processing of a hollow component. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the defect determination method of the present invention is a defect determination method in which a computer determines a defect in a hollow member after bending processing, which has been performed using a mold, and includes an analysis step of reading out a model of the hollow member and a jig that performs the bending processing from a memory unit, and using the model to perform a CAE analysis based on the processing conditions of the bending processing, and a determination step of determining a defect in the hollow member after the bending processing based on the analysis results of the CAE analysis.

[0007] In addition, in the defect determination method of the present invention, in the above invention, the analysis step includes a first analysis step of calculating a first parameter for determining whether or not buckling has occurred in the hollow member based on the analysis results of the CAE analysis, and the determination step includes a first determination step of determining whether or not buckling has occurred in the hollow member based on the first parameter.

[0008] In addition, in the defect determination method of the present invention, in the above invention, the first determination step determines that buckling has occurred when the maximum radial deformation amount of the hollow member after the bending process is 10% or more of the radial length of the hollow member before the bending process.

[0009] In addition, in the defect determination method of the present invention, in the above invention, the analysis step includes a second analysis step of calculating a second parameter for determining whether or not the springback amount of the hollow member is within an acceptable range based on the analysis results of the CAE analysis, and the determination step includes a second determination step of determining whether or not the springback amount of the hollow member is within an acceptable range based on the second parameter.

[0010] In the defect determination method according to the present invention, in the above invention, the second analysis step calculates the second parameter for the hollow member before a cooling treatment.

[0011] In the defect determination method according to the present invention, in the above invention, the second analysis step calculates the second parameter for the hollow member after a cooling treatment.

[0012] In the defect determination method according to the present invention, in the above-mentioned invention, the hollow member is formed using resin.

[0013] In the defect determination method according to the present invention, in the above invention, the analysis step performs an analysis including the contribution of temperature change during bending and / or viscoelastic properties of the resin in the CAE analysis.

[0014] In addition, in the defect determination method of the present invention, in the above invention, the analysis step uses an artificial hand model that resembles a rigid body as a human hand, and performs an analysis when the artificial hand model presses the model of the hollow member against the model of the mold and performs the bending process.

[0015] In addition, the defect determination method of the present invention, in the above invention, further includes a model creation step of creating a model of the hollow member and a jig that performs the bending process, and the analysis step performs an analysis process using the model created in the model creation step.

[0016] In addition, the defect determination program of the present invention is a defect determination program that causes a computer to determine a defect in a hollow member after bending processing, which has been performed using a mold, and causes the computer to execute an analysis step of performing a CAE analysis based on the processing conditions of the bending processing using a model of the hollow member and a jig that performs the bending processing, and a determination step of determining a defect in the hollow member after the bending processing based on the analysis results of the CAE analysis.

[0017] In addition, the defect determination device of the present invention is a defect determination device that determines a defect in a hollow member after bending processing, which has been performed using a mold, and includes an analysis unit that performs CAE analysis based on the processing conditions of the bending processing using a model of the hollow member and a jig that performs the bending processing, and a determination unit that determines a defect in the hollow member after the bending processing based on the analysis results of the CAE analysis. Effect of the Invention

[0018] According to the present invention, it is possible to predict whether or not a defect will occur during bending of a hollow member. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a block diagram showing a configuration of a fault determination device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a flowchart showing an outline of the determination process performed by the malfunction determination device according to the first embodiment of the present invention. [Diagram 3] FIG. 3 is a diagram (part 1) for explaining the analysis process. [Figure 4] FIG. 4 is a diagram (part 2) for explaining the analysis process. [Diagram 5] FIG. 5 is a diagram (part 3) for explaining the analysis process. [Figure 6] FIG. 6 is a diagram for explaining a method for determining buckling. [Figure 7] FIG. 7 is a diagram for explaining parameter calculation when performing the cooling process. [Figure 8] FIG. 8 is a diagram for explaining a method for measuring the amount of springback. [Figure 9] FIG. 9 is a diagram showing a schematic configuration of a fault determination device according to the second embodiment of the present invention. [Figure 10] FIG. 10 is a flowchart showing an outline of the determination process performed by the malfunction determination device according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, embodiments of a fault determination method, a fault determination program, and a fault determination device according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to these embodiments. Also, the individual embodiments of the present invention are not independent, and can be appropriately implemented in combination with each other.

[0021] (Embodiment 1) [System Configuration] 1 is a block diagram showing a configuration of a fault determination device according to a first embodiment of the present invention. The fault determination device 1 includes a model creation unit 11, an analysis unit 12, a determination unit 13, an input unit 14, an output unit 15, a storage unit 16, and a control unit 17.

[0022] The model creation unit 11 creates a model of a hollow member when bending the hollow member. The model creation unit 11 also creates a model of a jig such as a bending die used in bending as necessary. When bending is performed by a worker's hand, a model of the hand is also created. The model creation unit 11 creates design data using, for example, CAD (Computer Aided Design).

[0023] The analysis unit 12 uses the created model to calculate stress, deformation, strain, etc., during bending by CAE (Computer Aided Engineering) analysis. A known method can be adopted for the CAE analysis.

[0024] The judgment unit 13 uses the analysis results of the analysis unit 12 to judge whether or not there is a defect in the shape after bending.

[0025] The input unit 14 receives various types of information input from the outside and is composed of user interfaces such as a keyboard, a mouse, a microphone, and a touch panel, and an input port for a medium in which data is stored.

[0026] The output unit 15 outputs various information. The output unit 15 is configured using, for example, a display made of liquid crystal or organic EL (Electro Luminescence) or the like, an audio output device such as a speaker, or the like.

[0027] The input unit 14 and the output unit 15 may be connectable to a communication network that allows one-way or two-way communication with an external device. The communication network referred to here is configured using, for example, an existing public line network, a LAN (Local Area Network), a WAN (Wide Area Network), etc., and may be wired or wireless.

[0028] The storage unit 16 stores various programs for operating the defect determination device 1, and data including various parameters necessary for the operation of the defect determination device 1. The various programs include a defect determination program for determining defects during bending. The storage unit 16 is configured using a ROM (Read Only Memory) in which the various programs are pre-installed, a RAM (Random Access Memory), an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc. for storing calculation parameters and data for each process.

[0029] The various programs can be widely distributed by recording them on computer-readable recording media such as HDDs, flash memories, CD-ROMs, DVD-ROMs, Blu-ray (registered trademark), etc. The communication network referred to here is configured using, for example, an existing public line network, a LAN (Local Area Network), a WAN (Wide Area Network), etc., and may be wired or wireless.

[0030] The control unit 17 controls the overall operation of the malfunction determination device 1.

[0031] The fault determination device 1 having the above-described functional configuration is a computer configured using one or more hardware components such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), and an FPGA (Field Programmable Gate Array).

[0032] [Failure determination process] FIG. 2 is a flowchart showing an outline of the malfunction determination process performed by the malfunction determination device. When an instruction to judge a defect is input to the defect determination device 1, first, the model creation unit 11 creates a model of the hollow member to be bent (step S11). The model creation unit 11 is created using, for example, three-dimensional CAD (Computer Aided Design).

[0033] Thereafter, the analysis unit 12 performs an analysis using the model (step S12). FIGS. 3 to 5 are diagrams for explaining the analysis process. The analysis unit 12 performs an analysis during bending using, for example, the model M100 shown in FIG. 3. Here, an example is described in which a hollow member is bent by 90° along a bending die by an operator. The hollow member is formed, for example, using a resin or metal material. An example in which a hollow member made of resin is used is described below. In step S11 or S12, information necessary for bending, such as processing conditions, is input.

[0034] The model M100 is composed of a hollow member model M110 (hereinafter referred to as hollow member M110) and a jig model M120 (hereinafter referred to as jig M120). The jig M120 is composed of a bending die model M121 (hereinafter referred to as bending die M121), a left hand model M122 (hereinafter referred to as left hand M122), and a right hand model M123 (hereinafter referred to as right hand M123). The left hand M122 and the right hand M123 are pseudo-hand models in which a model of a curved rigid body such as a steel plate is modeled to resemble a hand (for example, a thumb and thenar eminence).

[0035] The analysis unit 12, while holding one end of the hollow member M110 with the right hand M123, presses the hollow member M110 against the bending die M121 with the left hand M122, and bends the hollow member M110 along the bending die M121 (see FIG. 4). At this time, the left hand M122 moves along the bending die M121 to generate a bent shape of the hollow member M110 according to the applied load.

[0036] The analysis unit 12 calculates parameters such as deformation amount, stress, and strain for the hollow member M110 that has been subjected to bending. For example, a stress distribution for the hollow member M110 is obtained by analysis, as shown in FIG. 5. In FIG. 5, it can be seen that the higher the stress, the lighter the color, and the higher the stress in the bent portion. The parameters are generated by calculating a representative value from this stress distribution. The representative value can be a maximum value, a minimum value, a mode value, an average value, or the like.

[0037] Returning to FIG. 2, the judgment unit 13 judges defects in the formed product after bending based on the analysis results (step S13). The judgment unit 13 judges defects in the formed product based on, for example, threshold values ​​that are set in advance for the parameters. The threshold values ​​are set based on various values ​​that may cause defects such as buckling or springback. For example, when the judgment unit 13 judges that the parameter is equal to or greater than the threshold value, it judges that a defect may occur. On the other hand, when the judgment unit 13 judges that the parameter is less than the threshold value, it judges that a defect may not occur.

[0038] Here, examples of analysis and determination of defects will be described. Fig. 6 to Fig. 8 are diagrams for explaining the determination examples. Note that, although an example in which the analysis unit 12 calculates parameters for determination will be described below, the determination unit 13 may perform the calculations.

[0039] [Buckling analysis] FIG. 6 is a diagram for explaining the calculation of parameters for detecting the occurrence of buckling. The parameter for buckling judgment is the change in the amount of deformation in the radial direction from the center of the hollow member M110 at a point on the outermost surface. For example, as shown in FIG. 6, the analysis unit 12 calculates the radial distance R110 from the center to the outermost surface of the annular end face (or cross section) of the hollow member M110 in a plan view seen from the penetration direction of the hollow member M110, and calculates the difference between this distance R110 and the radial distance of the corresponding position in the hollow member M110 before bending. Then, the analysis unit 12 obtains the maximum deformation amount of each deformation amount at the calculation target position as a parameter. The judgment unit 13 uses this maximum deformation amount as a judgment parameter and judges the occurrence of a defect based on a preset threshold value. For example, the judgment unit 13 judges that buckling has occurred when the maximum deformation amount is 10% or more of the radial length of the hollow member M110 before bending. The radial direction here refers to the direction extending from the center of the ring shape formed by connecting the outer surface, inner surface, or center of the thickness of the hollow member M110 toward the outer periphery when viewed in a plan view from the penetration direction of the hollow member M110, and corresponds to the thickness direction of the hollow member. Furthermore, in addition to the amount of change, a rate of change may be used to determine whether a defect exists.

[0040] [Cooling analysis] FIG. 7 is a diagram for explaining parameter calculation when a cooling process is performed. When bending is performed with heating, a cooling process may be performed. When this cooling process is performed, as shown in FIG. 7, after bending, the hollow member M110 is fixed to a jig M120 and cooled from 100° C. to 20° C. in, for example, 5 minutes. Thereafter, the analysis unit 12 calculates stress and the like for the hollow member M110 after cooling. The judgment unit 13 uses this stress as a judgment parameter and judges whether or not a defect occurs based on a preset threshold value.

[0041] [Springback analysis] FIG. 8 is a diagram for explaining parameter calculation for making a springback allowance judgment. The parameter for making a springback allowance judgment is the distance of the hollow member M110 from a reference point BP set with respect to a reference line BL of the hollow member M110. Here, the reference line BL is a straight line along one end of the hollow member M110. The reference point BP is a point MP1 on the hollow member M110 that is a distance from the reference line BL in a direction perpendicular to the reference line BL, for example, a set distance H100. The parameter is the distance of the hollow member M110 that is a distance H110 (>H100) from the reference line BL, which is the distance L110 from the reference point BP to point MP1 in the reference line BL direction, or the distance L120 from the reference point BP to point MP2 in the reference line BL direction, which is the distance H120 (>H110) from the reference line BL. The determination unit 13 uses the distances L110 and L120 as parameters for determination and determines whether or not a defect has occurred based on a preset threshold value. At this time, the distance used for the determination may be either the distance L110 or L120, or both of them. The distance H120 is set to be shorter than the distance to the end of the hollow member M110 after bending. The determination of whether springback is permissible may be performed on the hollow member after the cooling treatment, for example, if a cooling treatment is performed, or may be performed on the hollow member before the cooling treatment.

[0042] 2, the control unit 17 outputs the determination result by the determination unit 13 (step S14). The control unit 17 causes the display to display the determination result. At this time, for example, the display displays the determination result indicating whether or not a defect may occur in the hollow member for the processing conditions under which the analysis process was executed.

[0043] In the above-described first embodiment, it is determined whether or not a defect may occur in the formed material after the bending process based on parameters obtained from the analysis results of the CAE analysis and threshold values ​​set based on values ​​at which defects such as buckling, springback, etc. may occur. According to the first embodiment, it is possible to predict whether or not a defect will occur in the bending process of a hollow member because it is determined whether or not a defect may occur from the analysis results.

[0044] In the first embodiment, a CAE analysis may be performed that includes the contribution of temperature changes during bending work and the viscoelastic properties of the resin, in addition to the load from the hand. By performing an analysis that includes the contribution of temperature changes, the stress generated by bending can be analyzed with higher accuracy.

[0045] Furthermore, the present invention is not limited to analysis of bending performed by hand, but can also be applied to a configuration in which mechanical bending is performed using a jig.

[0046] (Embodiment 2) [System Configuration] Next, a second embodiment of the present invention will be described. Note that the same components as those in the first embodiment are given the same reference numerals and the description thereof will be omitted. Fig. 9 is a diagram showing a schematic configuration of a malfunction determination device according to the second embodiment of the present invention.

[0047] The fault determination device 1A of embodiment 2 includes a model creation unit 11, a first analysis unit 21, a first judgment unit 22, a second analysis unit 23, a second judgment unit 24, an input unit 14, an output unit 15, a memory unit 16, and a control unit 17.

[0048] The first analysis unit 21 calculates the amount of deformation at a point on the outermost surface of the hollow member after bending by CAE analysis, and obtains the maximum amount of deformation.

[0049] The first judgment section 22 uses the analysis results of the first analysis section 21 to judge the presence or absence of buckling in the shape after bending.

[0050] The second analysis unit 23 calculates the amount of deformation after bending by CAE analysis. Specifically, the second analysis unit 23 calculates the amount of deviation of the shape after bending from a reference.

[0051] The second judging section 24 uses the analysis results of the first analyzing section 21 to judge the presence or absence of springback in the shape after bending.

[0052] [Failure determination process] FIG. 10 is a flowchart showing an outline of the malfunction determination process performed by the malfunction determination device. When an instruction to judge a defect is input to the defect judgment device 1A, first, the model creation unit 11 creates a model of the hollow member to be bent in the same manner as in step S11 (step S21).

[0053] Thereafter, the first analysis unit 21 performs a first analysis using the model (step S22). In the first analysis, the rate of change of the above-mentioned points on the outermost surface is calculated for the hollow member after bending.

[0054] Based on the analysis results, the first judgment unit 22 judges whether or not buckling has occurred in the molded product after bending (step S23: first judgment process). The first judgment unit 22 judges whether or not buckling has occurred based on the above-mentioned maximum deformation amount and a preset threshold value (for example, 10% of the radial length before bending). For example, when the first judgment unit 22 judges that the maximum deformation amount is equal to or greater than the threshold value, it judges that a defect may occur. On the other hand, when the first judgment unit 22 judges that the maximum deformation amount is less than the threshold value, it judges that a defect may not occur.

[0055] If the first determination unit 22 determines that a malfunction may occur (step S24: Yes), the control unit 17 proceeds to step S27. On the other hand, if the first determination unit 22 determines that a malfunction may not occur (step S24: No), the control unit 17 proceeds to step S25.

[0056] In step S25, the second analysis unit 23 executes a second analysis to calculate parameters for determining whether springback is acceptable, as shown in Fig. 8. The second analysis unit 23 calculates distances L110 and L120 shown in Fig. 8 as parameters for determining whether springback is acceptable.

[0057] The second judgment unit 24 judges whether the springback of the formed product after bending is within the allowable range based on the analysis result (step S26: second judgment process). For example, when the second judgment unit 24 judges that the above-mentioned distance is equal to or greater than the threshold, it judges that the springback exceeds the allowable range, that is, a defect has occurred. On the other hand, when the second judgment unit 24 judges that the distance is less than the threshold, it judges that the springback is within the allowable range, that is, no defect has occurred.

[0058] Returning to Fig. 9, the control unit 17 outputs the determination result by the first determination unit 22 and / or the second determination unit 24 (step S27). The control unit 17 causes the display to display the determination result. At this time, the determination result related to this determination process is, for example, one of the following: 1. Buckling has occurred 2. Springback exceeds the allowable range (no buckling occurs) 3. No defects (no buckling, springback is within the allowable range)

[0059] In the above-described flowchart, if it is determined that buckling has occurred, the springback allowance determination is not performed, but the springback allowance determination may be performed regardless of the result of the buckling determination. In this case, the buckling determination and the springback allowance determination may be performed simultaneously. In the above-described flow chart, the springback tolerance determination may be performed first, and the buckling determination may be performed based on the result of the springback tolerance determination.

[0060] In the above-described second embodiment, it is determined whether or not a defect may occur in the formed material after the bending process based on an analytical value obtained from the results of the CAE analysis and a threshold value set based on a stress that may cause defects such as buckling, springback, etc. According to the second embodiment, it is possible to predict whether or not a defect will occur in the bending process of a hollow member because it is determined whether or not a defect may occur from the analysis results.

[0061] Moreover, according to the second embodiment, whether or not both buckling and springback are likely to occur is determined from the analysis results, so that defects in the bending of a hollow member can be predicted with high accuracy.

[0062] In the second embodiment, a step of calculating a parameter when the cooling process is performed and a step of judging whether or not a defect occurs based on the parameter and a threshold value may be further executed. In this case, for example, the third analysis unit and the third judgment unit execute the analysis process and the judgment process.

[0063] (Other embodiments) Although the embodiments for carrying out the present invention have been described above, the present invention should not be limited to the above-described embodiments. [Industrial Applicability]

[0064] The defect determination method, defect determination program, and defect determination device of the present invention can be applied to any bending process of hollow members, and can be particularly suitably applied to hollow members made of resin. [Explanation of symbols]

[0065] 1. 1A Malfunction determination device 11 Model Creation Department 12 Analysis Department 13 Judgment section 14 Input section 15 Output section 16 Memory section 17 Control Unit 21 1st Analysis Department 22 1st Judgment Section 23 2nd Analysis Department 24 Second Judgment Section

Claims

1. A defect determination method for determining a defect in a hollow member after bending processing performed by a computer using a die, comprising the steps of: an analysis step of reading out a model of the hollow member and a jig that performs the bending process from a storage unit, and performing a CAE analysis based on a processing condition of the bending process using the model; a determination step of determining a defect in the hollow member after the bending process based on an analysis result of the CAE analysis; A method for determining a defect, comprising:

2. The analyzing step includes: a first analysis step of calculating a first parameter for determining whether or not buckling has occurred in the hollow member based on an analysis result of the CAE analysis; Including, The determining step includes: a first determination step of determining whether or not buckling has occurred in the hollow member based on the first parameter; The method of determining a defect according to claim 1 , comprising:

3. The first determination step determines that buckling has occurred when a maximum radial deformation amount of the hollow member after the bending process is 10% or more of a radial length of the hollow member before the bending process. The defect determination method according to claim 2 .

4. The analyzing step includes: a second analysis step of calculating a second parameter for determining whether or not a springback amount of the hollow member is within an allowable range based on an analysis result of the CAE analysis; Including, The determining step includes: a second determination step of determining whether or not a springback amount of the hollow member is within an allowable range based on the second parameter; The method for determining a defect according to claim 1 or 2, comprising:

5. The second analysis step calculates the second parameters for the hollow member before a cooling treatment. The method for determining a defect according to claim 4.

6. The second analysis step calculates the second parameters for the hollow member after the cooling treatment. The method for determining a defect according to claim 4.

7. The hollow member is formed using a resin. The defect determination method according to claim 1 .

8. In the analysis step, an analysis is performed including a contribution of a temperature change during bending and / or a viscoelastic property of a resin in the CAE analysis. The method for determining a defect according to claim 7.

9. The analyzing step includes: an artificial hand model, which is a rigid body representing a human hand, performs an analysis when the model of the hollow member is pressed against the model of the mold and the bending process is performed; The defect determination method according to claim 1 .

10. a model creation step of creating a model of the hollow member and a jig for performing the bending process; Further comprising: The analysis step executes an analysis process using the model created in the model creation step. The defect determination method according to claim 1 .

11. A defect determination program for causing a computer to determine a defect in a hollow member after bending processing using a die, the program comprising: an analysis step of performing a CAE analysis based on processing conditions of the bending process using a model of the hollow member and a jig that performs the bending process; a determination step of determining a defect in the hollow member after the bending process based on an analysis result of the CAE analysis; A defect determination program that causes the computer to execute the above.

12. A defect determination device for determining a defect in a hollow member after bending processing using a die, comprising: an analysis unit that executes a CAE analysis based on processing conditions of the bending process using a model of the hollow member and a jig that performs the bending process; a determination unit that determines a defect of the hollow member after the bending process based on an analysis result of the CAE analysis; and A malfunction determination device comprising:

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