JP7626018B2 - Bending apparatus, bending method, and computer program - Google Patents

Description

The present invention relates to a bending forming device, a bending forming method, and a computer program.

Forming devices that bend steel plates to a specified angle are known (see, for example, Patent Documents 1 and 2). In the bending method described in Patent Document 1, when bending a long workpiece, an angle sensor measures the bending angle of the workpiece. The amount of springback is corrected according to the measurement result of the angle sensor, and the workpiece is bent. This allows the correction amount of the pressing amount to be calculated from the amount of springback.

The bending device described in Patent Document 2 performs correction forming on the bent part using the difference between the estimated value of the bent part after bending and the target value of the bending angle of the bent part. The bending described in Non-Patent Document 1 tilts the upper mold that performs bending, thereby forming the part at the target bending angle in one bending operation.

JP 2013-180339 A JP 2020-099935 A

Masaaki Otsu, "High-precision V-bending of tailored blanks", Amada Foundation, Research Grant Report, 2016, Vol. 29

Tailored blank materials, which are sheet materials in which steel plates of different strengths and thicknesses are butt-jointed, are known as objects to be bent. The processing methods of Patent Documents 1 and 2 cannot form tailored blank materials to the target bending angle. In addition, the processing method of Non-Patent Document 1 requires an upper die that is inclined according to the shape and material of the formed part. Therefore, the processing method of Non-Patent Document 1 requires a dedicated die for each tailored blank material, and therefore cannot process a variety of tailored blank materials.

The present invention was made to solve the above-mentioned problems, and aims to form a variety of tailored blank materials to the target bending angle with a small number of processing steps using a single processing device.

The present invention has been made to solve the above-mentioned problems, and can be realized in the following form: A bending device comprising: a bending forming section that bends a tailored blank material, in which plate materials having different bending strengths are joined, in a predetermined direction, a bend-back forming section that bends back the tailored blank material bent by the bend forming section in a direction opposite to the predetermined direction, and a condition calculation section that calculates a bend angle greater than a bend target value and a bend-back angle smaller than the bend target value according to a bend target value after forming of the tailored blank material, wherein when the tailored blank material is formed by joining a first member and a second member, the condition calculation section calculates the bend angle and the bend-back angle with respect to the first member. a bending apparatus which creates a prediction model to predict a forming angle, which is the angle of the tailored blank material after forming, using a first angle, which is the angle of the first member after forming, determined by an angle between the first member and the second member, and a second angle, which is the angle of the second member after forming, determined by the bending angle and the bend-back angle relative to the second member, and the bending forming unit bends the tailored blank material to obtain the bend angle calculated by the condition calculation unit, and the bend-back forming unit bends back the tailored blank material bent by the bending forming unit to obtain the bend-back angle calculated by the condition calculation unit.

(1) According to one aspect of the present invention, a bending device is provided. The bending device includes a bending section that bends a tailored blank material, which is made up of joined plate materials having different bending strengths, in a predetermined direction, and a bending-back section that bends the tailored blank material bent by the bending section back in a direction opposite to the predetermined direction.

According to this configuration, a tailored blank material in which plate materials with different bending strengths are joined is bent by the bending forming section, and then bent back by the bending back forming section. When bending a tailored blank material, it is necessary to bend the plate material with low bending strength more than the target bending angle in accordance with the plate material with high bending strength. In particular, in the case of a metal plate material, springback occurs, so that the plate material cannot be shaped to the target bending angle unless it is bent more than the target bending angle. According to this configuration, since there is a bending back forming section that bends back the tailored blank material after bending it by the bending forming section, it can be shaped to the target bending angle with a small number of processing operations. In addition, no special mold or the like according to the material of the tailored blank material is required. Therefore, a variety of tailored blank materials can be processed by using the same forming device, simply by changing the forming conditions of the bending angle by the bending forming section and the bending back angle by the bending back forming section.

(2) The bending forming apparatus of the above aspect may further include a condition calculation unit that calculates a bend angle greater than a target bend value and a bend-back angle smaller than the target bend value in accordance with a target bend value after forming of the tailored blank material. After the bend forming unit bends the tailored blank material to obtain the calculated bend angle, the bend-back forming unit may bend the tailored blank material back to obtain the calculated bend-back angle.
According to this configuration, the bending section forms the tailored blank material at a bending angle greater than the target bending value. When a tailored blank material made of metal is bent, springback occurs. In contrast, the bending device of this configuration bends a plate material with low bending strength that has been bent excessively beyond the target bending value back to the target bending value, so that the tailored blank material can be formed to the target bending value with fewer processing operations.

(3) In the bending forming apparatus of the above aspect, when the tailored blank material is formed by joining a first member and a second member, the condition calculation unit may create a prediction model to predict a forming angle, which is the angle of the tailored blank material after forming, using a first angle, which is the angle of the first member after forming, determined by the bending angle and the bend-back angle with respect to the first member, and a second angle, which is the angle of the second member after forming, determined by the bending angle and the bend-back angle with respect to the second member.
According to this configuration, a prediction model is created using a first angle and a second angle after forming, which are determined by the bending angle and the unbending angle, for each of the first member and the second member used as a tailored blank material. There are a plurality of combinations of bending angles and unbending angles for forming the bend to the target value. In contrast, by determining a common solution that satisfies the bending target value in which the first angle and the second angle are the same from combinations that form the first angle and the second angle, the tailored blank material can be formed to the bending target value with fewer processing operations.

(4) In the bending forming apparatus of the above aspect, a correction unit may be further provided that corrects the prediction model using a predicted value of the forming angle obtained using the prediction model and a measured value of the forming angle.
According to this configuration, the prediction model is corrected using the predicted values of the prediction model and the measured values of the actually formed tailored blank material, thereby improving the prediction accuracy of the prediction model. By using a prediction model with improved accuracy, the tailored blank material can be formed to the target bending value with fewer processing operations.

(5) In the bending forming apparatus of the above aspect, a bending angle acquisition unit may be further provided that acquires the first angle and the second angle, and the correction unit may correct the prediction model using the first angle and the second angle acquired by the bending angle acquisition unit.
According to this configuration, the prediction model is corrected using the first angle and the second angle acquired for the first member and the second member, respectively, so that the accuracy of the prediction model can be further improved.

(6) The bending forming apparatus of the above aspect may further include a conveying unit that conveys the tailored blank sheet in a feed direction, and the tailored blank sheet is joined along the feed direction in the order of the first member, the second member, and the third member, so that the tailored blank sheet is formed in the order of the first member, the second member, and the third member, and when an angle of the third member after forming, which is determined by the bend angle and the bend-back angle for the third member, is defined as a third angle, the bending forming unit and the bend-back forming unit may form the first member at the bend angle and the bend-back angle using the predictive model created using the first angle and the second angle, form the third member at the bend angle and the bend-back angle using the predictive model created using the second angle and the third angle, and gradually change the second member from the bend angle and the bend-back angle at the time of forming the first member to the bend angle and the bend-back angle at the time of forming the third member, using the second angle, as the feed amount by the conveying unit increases.
According to this configuration, the tailored blank material in which three members are joined along the conveying direction is processed by the bending section and the bending back section while being conveyed by the conveying section. The first member is formed by the bending angle and bending back angle of a common solution predicted from the first angle and the second angle. The third member is formed by the bending angle and bending back angle of a common solution predicted from the second angle and the third angle. The forming angle when the second member sandwiched between the first member and the third member is bent and bent back changes as the feed amount increases so as to connect from the common solution when forming the first member to the common solution when forming the third member. In addition, the second angle when processing the second member to the bending target value is used for this change. Therefore, according to this configuration, while forming the first member and the third member to the bending target value, the second member connecting the first member and the third member can also be formed to the bending target value. Furthermore, the shaping change from the first member to the second member and the shaping change from the second member to the third member can be smoothly connected.

The present invention can be realized in various forms, for example, in bending apparatus, processing apparatus, manufacturing apparatus, apparatus and systems including these, bending methods, processing methods, manufacturing methods, computer programs for executing these systems and methods, server devices for distributing these computer programs, non-transitory storage media storing computer programs, etc.

1 is a schematic block diagram of a bending apparatus according to a first embodiment of the present invention; FIG. 2 is an explanatory diagram of a plate material which is a tailored blank material. FIG. 2 is an explanatory diagram of a plate material which is a tailored blank material. FIG. 2 is an explanatory diagram of a plate material which is a tailored blank material. FIG. FIG. 1 is an explanatory diagram of bending back forming. FIG. 10 is an explanatory diagram of a load applied to a plate material. FIG. 11 is an explanatory diagram of a bending angle during bending and a bending-back angle during bending-back. FIG. 11 is an explanatory diagram of a bending angle during bending and a bending-back angle during bending-back. 10 is an explanatory diagram for determining the bending angle and the unbending angle of a plate material. FIG. FIG. 11 is an explanatory diagram of correction of a prediction model. FIG. 11 is an explanatory diagram of correction of a prediction model. 4 is a flowchart of the bending method of the present embodiment. FIG. 4 is an explanatory diagram of the relationship between a bending target value and a bending angle after processing. FIG. 4 is an explanatory diagram of the relationship between a bending target value and a bending angle after processing. FIG. 4 is an explanatory diagram of the relationship between a bending target value and a bending angle after processing. FIG. 4 is an explanatory diagram of the relationship between a bending target value and a bending angle after processing. FIG. 11 is an explanatory diagram of the bending angle of a plate material before and after correction of a prediction model. FIG. 11 is an explanatory diagram of the bending angle of a plate material before and after correction of a prediction model. FIG. 11 is an explanatory diagram of a bending apparatus according to a second embodiment. FIG. 11 is an explanatory diagram of a bending apparatus according to a second embodiment. FIG. 11 is an explanatory diagram of a bending apparatus according to a second embodiment. 11 is a schematic perspective view of a plate material processed by the bending apparatus of the second embodiment. FIG. FIG. 4 is an explanatory diagram of a state of a forming tool during bending. FIG. 4 is an explanatory diagram of a state of a forming tool during bending. FIG. 4 is an explanatory diagram of a state of a forming tool during bending. 10 is an explanatory diagram of the position of a bending tool and the position of an unbending tool relative to the feed amount of a plate material. FIG. 10 is an explanatory diagram of the position of a bending tool and the position of an unbending tool relative to the feed amount of a plate material. FIG. 10 is an explanatory diagram of the position of a bending tool and the position of an unbending tool relative to the feed amount of a plate material. FIG. 10 is an explanatory diagram of the position of a bending tool and the position of an unbending tool relative to the feed amount of a plate material. FIG. 10 is an explanatory diagram of the position of a bending tool and the position of an unbending tool relative to the feed amount of a plate material. FIG. 10 is an explanatory diagram of the position of a bending tool and the position of an unbending tool relative to the feed amount of a plate material. FIG. 10 is an explanatory diagram of a bending angle and an unbending angle when bending a second member and a third member. FIG. FIG. 11 is a schematic perspective view of a bending apparatus according to a third embodiment. 4 is a schematic cross-sectional view perpendicular to the feeding direction of the second feed roller. FIG. 2 is a schematic cross-sectional view perpendicular to the feed direction of the bending tool. FIG. FIG. 2 is a schematic cross-sectional view perpendicular to the feed direction of the bending back forming tool. FIG. 13 is a schematic front view of a bending apparatus according to a fourth embodiment. 13 is an explanatory diagram of a bending target value in the fourth embodiment. FIG. FIG. 2 is a schematic front view of the bending device during bending. FIG. 2 is a schematic front view of the bending device during unbending. 13 is a flowchart of a bending method according to a modified example.

First Embodiment
1. Overview of bending equipment:
Fig. 1 is a schematic block diagram of a bending apparatus 100 according to a first embodiment of the present invention. The bending apparatus 100 shown in Fig. 1 bends a plate material OB to be processed in a predetermined direction, and then bends the plate material OB back in the opposite direction to the predetermined direction, thereby forming the plate material OB to a target bending angle. By using the bending apparatus 100 according to this embodiment, when processing a tailored blank material in which steel plates with different strengths are joined, the tailored blank material can be processed to a target bending angle with a small number of processing operations.

The bending device 100 of this embodiment is a V-bending device that performs bending on a plate material OB, which is a tailored blank material in which steel plates of different strengths are joined. As shown in FIG. 1, the bending device 100 includes an upper die 10 and a lower die 20 that bend the plate material OB, a first camera (bending angle acquisition unit) 30 and a second camera (bending angle acquisition unit) 40 that photograph the plate material OB, and a control device 50 that controls the movement of the upper die 10 and the lower die 20.

As shown in FIG. 1, the upper mold 10 includes a central upper mold 12 located in the middle, and outer upper molds 11 and 13 arranged on either side of the central upper mold 12. Similarly, the lower mold 20 includes a central lower mold 22 located in the middle, and outer lower molds 21 and 23 arranged on either side of the central lower mold 22. Each of the upper molds 11 to 13 and each of the lower molds 21 to 23 move up and down separately along the vertical direction (Z-axis direction) DR21. Each of the upper molds 11 to 13 and each of the lower molds 21 to 23 are arranged at positions opposite to each other on the XY plane. The vertical movements of each of the upper molds 11 to 13 and each of the lower molds 21 to 23 are controlled by the control device 50, so that the plate material OB can be bent. The orthogonal coordinate system CS formed by the X-axis, Y-axis, and Z-axis shown in FIG. 1 corresponds to the orthogonal coordinate system CS shown in FIG. 5 and subsequent figures.

Each of Figures 2 to 4 is an explanatory diagram of plate material OB, which is a tailored blank material. Figure 2 shows a schematic perspective view of a body frame FR of an automobile that uses tailored blank material. Figure 3 shows an example of tailored blank material OB1 used as an upper frame UF of the body frame FR. As shown in Figure 3, tailored blank material OB1 has a hollow rectangular column shape. In tailored blank material OB1, two members, a first member MA and a second member MB, which have different strengths, are joined along a center line parallel to the longitudinal direction. Note that in Figures 3 and 4, the first member MA and the second member MB are distinguished by different hatching.

Figure 4 shows an example of a tailored blank material OB2 used as a rocker frame RF of the vehicle body frame FR. As shown in Figure 4, the tailored blank material OB2 is a member formed by bending a plate material at several points along the longitudinal direction. The tailored blank material OB2 is formed by joining a first member MA and a second member MB, which have different strengths, in a cross section perpendicular to the longitudinal direction. The bending device 100 of this embodiment bends the tailored blank materials OB1 and OB2.

The first camera 30 and the second camera 40 shown in FIG. 1 are arranged in positions where they can capture the bending angle of the bent plate material OB. Specifically, as shown in FIG. 1, the first camera 30 and the second camera 40 are arranged at one end side and the other end side opposite to the one end side in the longitudinal direction (Y-axis direction) of the upper mold 10 and the lower mold 20, respectively. Therefore, the first camera 30 can capture the bending angle of the first member MA in the plate material OB. Similarly, the second camera 40 can capture the bending angle of the second member MB in the plate material OB. The captured images by the first camera 30 and the second camera 40 are transmitted to the control device 50 and used to control the upper mold 10 and the lower mold 20.

The control device 50 is a personal computer that acquires images captured by the first camera 30 and the second camera 40 and controls the upper mold 10 and the lower mold 20. As shown in FIG. 1, the control device 50 includes a CPU 51, a memory unit 56, a communication unit 57 that transmits and receives information to and from other devices, an output unit 58, and an input unit 59.

The input unit 59 is composed of a keyboard and a mouse. The input unit 59 transmits the input received by the input unit 59 to the CPU 51 as input information. The output unit 58 has a monitor capable of displaying various images and a speaker for outputting sound. The output unit 58 performs various outputs in response to the output information transmitted from the CPU 51. The storage unit 56 stores a prediction model MD that calculates the load that each of the upper mold 10 and the lower mold 20 applies to the plate material OB from a bending target value θ _target , which is a target bending angle, when bending the plate material OB using the upper mold 10 and the lower mold 20. Details of the prediction model MD will be described later.

The CPU 51 executes a program stored in a ROM (Read Only Memory) (not shown) by expanding the program in a RAM (Random Access Memory). The CPU 51 functions as a setting unit 55 that sets a bending target value θ _target of the plate material OB, a calculation unit (condition calculation unit) 53 that calculates a load to be applied to the plate material OB, a drive control unit 52 that controls the upper mold 10 and the lower mold 20 based on the load calculated by the calculation unit 53, and a correction unit 54 that corrects the prediction model MD. The calculation unit 53 calculates the load that the upper mold 10 and the lower mold 20 apply to the plate material OB using the prediction model MD stored in the memory unit 56.

Figure 5 is an explanatory diagram of bending. As shown in Figure 5, when bending the plate material OB, the drive control unit 52 first performs bending in a predetermined direction using the upper die 10 and the lower die 20. In this embodiment, the drive control unit 52 bends the plate material OB in the downward direction in the vertical directions DR11 to DR13 and DR21 to DR23 as the predetermined direction. At this time, as shown in Figure 5, the drive control unit 52 uses the central upper die 12 to apply a load to the plate material OB in the downward vertical direction DR22. At the same time, the drive control unit 52 uses the outer lower dies 21 and 23 to apply a load to the plate material OB in the upward vertical directions DR11 and DR13. The drive control unit 52 does not apply a load to the outer upper dies 11 and 13 and the central lower die 22, so that the outer upper dies 11 and 13 and the central lower die 22 follow the movement of the plate material OB to be bent.

Figure 6 is an explanatory diagram of bending back. As shown in Figure 6, the drive control unit 52 uses the upper die 10 and the lower die 20 to perform bending back forming, which bends the plate material OB in the opposite direction to the specified direction after bending. The drive control unit 52 bends back the plate material OB in the upward direction in the vertical directions DR11-DR13 and DR21-DR23, which is the opposite direction to the specified direction. At this time, the drive control unit 52 uses the central lower die 22 to apply a load to the plate material OB in the upward direction DR22, as shown in Figure 6. At the same time, the drive control unit 52 uses the outer upper dies 11 and 13 to apply a load to the plate material OB in the downward direction in the vertical directions DR11 and DR13, as shown in Figure 6. The drive control unit 52 does not apply a load to the central upper die 12 and the outer lower dies 21, 23, so that the central upper die 12 and the outer lower dies 21, 23 follow the movement of the sheet material OB to be bent. The load to be applied to the sheet material OB during bending and unbending is calculated by the calculation unit 53 using the prediction model MD. In this embodiment, the central upper die 12 and the outer lower dies 21, 23 correspond to the bending forming section. The outer upper dies 11, 13 and the central lower die 22 correspond to the unbending forming section.

FIG. 7 is an explanatory diagram of the load applied to the plate material OB. FIG. 7 shows a schematic perspective view of the plate material OB bent to the bending target value θ _target . In the plate material OB, the bending strength of the first member MA is different from that of the second member MB. In addition, since the first member MA and the second member MB are metal steel plates, springback occurs during bending. Therefore, the drive control unit 52 of this embodiment uses the upper mold 10 and the lower mold 20 to bend the plate material OB more than the target value θ _target during bending, and then bends the plate material OB back by bending back.

8 and 9 are explanatory diagrams of the bending angle θ _{f_load} during bending and the bending back angle θ _{b_load} during bending back. In FIG. 8 and FIG. 9, the bending angle θ unload_A and the bending back angle θ _{unload_B} of each member after bending are shown when the first member MA and the second member MB are bent at the bending angle θ _{f_load} during bending and at the bending back angle θ _{b_load} during _bending back. The calculation unit 53 acquires the results of bending the first member MA and the second member MB at a plurality of bending angles θ _{f_load} and bending back angles θ _{b_load} . The calculation unit 53 uses the acquired results to create a prediction model MD, which is a curved surface representing the bending angles θ _{unload_A} and θ _{unload_B} after forming determined by the bending angle θ _{f_load} and the bending back angle θ _{b_load} . In this embodiment, the created prediction model MD is a regression model. The bending angle θ _{unload_A} after forming corresponds to the first angle, and the bending angle θ _{unload_B} corresponds to the second angle.

The calculation unit 53 calculates the curve CBa of the first member MA from the relationship shown in Fig. 8 and calculates the curve CBb of the second member MB from the relationship shown in Fig. 9 so that the bending target value θ _target becomes _{the bending} angles θ unload_A and θ unload_B after forming. Fig. 10 is an explanatory diagram for determining the bending angle θ _{f_load} and the bending back angle θ _{b_load} of the plate material OB. As shown in Fig. 10, the calculation unit 53 calculates an intersection CP1 between the curve CBa of the first member MA and the curve CBb of the second member MB. The calculation unit 53 adopts the bending angle θ _{f_load} and the bending back angle θ _{b_load} derived from the intersection CP1 as forming conditions when the drive control unit 52 processes the plate material OB.

The correction unit 54 shown in FIG. 1 corrects the prediction model MD using the captured images of the first camera 30 and the second camera 40. The first camera 30 and the second camera 40 acquire captured images of the bending angle θ _unload after forming of the plate material OB processed using the bending angle θ _{f_load} and the bending back angle θ _{b_load} calculated using the prediction model MD. The correction unit 54 calculates the error between the measured value of the bending angle θ _unload after processing for which the captured image is calculated and the predicted value using the prediction model MD. If the calculated error is within the range of the allowable error set in advance, the correction unit 54 ends the processing of the plate material OB. On the other hand, if the calculated error is outside the allowable range, the correction unit 54 corrects the prediction model MD so that the actual measurement value and the predicted value match.

11 and 12 are explanatory diagrams for the correction of the prediction model MD. In this embodiment, as shown in FIG. 11, the correction unit 54 corrects the bending angle θ _{unload_A} after forming of the first member MA by multiplying the bending angle θ _{unload_A} after forming of the first member MA before correction by the correction coefficient C _A. Similarly, as shown in FIG. 12, the correction unit 54 corrects the bending angle θ _{unload_B} after forming of the second member MB by multiplying the bending angle θ _{unload_B} after forming of the second member MB before correction by the correction coefficient C _B. The correction unit 54 corrects the prediction model MD before correction using the corrected bending angle θ _{unload_A} after forming of the first member MA and the bending angle θ _{unload_B} after forming of the second member MB. The drive control unit 52 reshapes the formed plate material OB using the corrected prediction model MD. The correction unit 54 corrects the prediction model MD until the actual measurement value of the reshaped plate material OB falls within the range of the allowable error of the predicted value.

2. Bending process:
Fig. 13 is a flowchart of the bending method of this embodiment. In the bending flow shown in Fig. 13, first, the setting unit 55 sets a bending target value θ _target of the plate material OB (step S1). The setting unit 55 sets the bending target value θ _target of the plate material OB based on input information acquired via the input unit 59 or the communication unit 57.

The calculation unit 53 calculates the bending angle and the unbending angle of the sheet material OB using the prediction model MD stored in the storage unit 56 (step S2). The calculation unit 53 calculates the bending angle θ _{f_load} and the unbending angle θ _{b_load} at which the bending target value θ _target becomes the bending angle θ _unload after forming of the prediction model MD.

As shown in Fig. 5, the drive control unit 52 executes a bending process in which the upper die 10 and the lower die 20 are controlled to bend the sheet material OB (step S3). The drive control unit 52 controls the central upper die 12 and the outer lower die 21, 23 so that the bending angle of the sheet material OB becomes the calculated bending angle θ _{f_load} . As shown in Fig. 6, the drive control unit 52 executes a bending-back process in which the upper die 10 and the lower die 20 are controlled to bend back the sheet material OB (step S4). The drive control unit 52 controls the outer upper die 11, 13 and the central lower die 22 so that the bending-back angle of the sheet material OB becomes the calculated bending-back angle θ _{b_load} .

The correction unit 54 calculates the measurement value of the bending angle of the plate material OB after forming using the images captured by the first camera 30 and the second camera 40 (step S4). The correction unit 54 determines whether the calculated measurement value is within a preset allowable error range for the bending target value θ _target (step S6). If the measurement value is within the error range (step S6: YES), the processing of the plate material OB is completed.

In step S6, if the measured value is outside the error range (step S6: NO), the correction unit 54 corrects the prediction model MD (step S7). As shown in Figs. 11 and 12, the correction unit 54 of this embodiment corrects the prediction model MD using correction coefficients C _A and C _B calculated based on the measured values for the bending angle θ _{unload_A} after forming of the first member MA and the bending angle θ _{unload_B} after forming of the second member MB before correction. The calculation unit 53 uses the corrected prediction model MD to calculate the bending angle θ _{f_load} and the unbending angle θ _{b_load} of the plate material OB to be reprocessed. Then, the processes from step S3 onwards are repeated.

3. Effects:
Each of the figures from FIG. 14 to FIG. 17 is an explanatory diagram of the relationship between the bending target value θ _target and the bending angle after processing. FIG. 14 shows an example of the relationship between the bending angle θ _{f_load} and the bending back angle θ _{b_load} calculated using the prediction model MD when the bending target value θ _target is 40, 45, and 50 degrees. FIG. 14 also shows the bending angle after processing of the first member MA calculated from the image captured by the first camera 30 and the bending angle after processing of the second member MB calculated from the image captured by the second camera 40. For example, when the bending target value θ _target of the plate material OB is 40 degrees, the bending angle θ _{f_load} calculated using the prediction model MD is 45.55 degrees, and the bending back angle θ _{b_load} is 37.84 degrees. The bending angle of the first member MA after forming is 40.09 degrees, and the bending angle of the second member MB is 40.14 degrees. In the examples shown in FIGS. 14 to 17, the allowable error range is set to ±0.5 degrees from the bending target value θ _target .

15 to 17 show the relationship between the X-coordinate position and the Z-coordinate position of the plate material OB after forming when the bending target value θ _target is 40 degrees, 45 degrees, and 50 degrees. In each figure, the relationship of the first member MA calculated from the image captured by the first camera 30 is shown by a solid line, and the relationship of the second member MB calculated from the image captured by the second camera 40 is shown by a dashed line. Since the bending strength of the first member MA and the bending strength of the second member MB are different, in the example shown in FIGS. 15 to 17, the position of the first member MA after processing and the position of the second member MB do not completely match. As shown in FIG. 14, the bending angle of the first member MA and the bending angle of the second member when the bending target value θ _target is 50 degrees are outside the range of allowable error, so the correction unit 54 corrects the prediction model MD.

18 and 19 are explanatory diagrams of the bending angle of the plate material OB before and after the correction of the prediction model MD. FIG. 18 shows the bending angle when a new plate material OB is processed by the corrected prediction model MD. When the prediction model MD corrected by the correction unit 54 is used, as shown in FIG. 18, the new plate material OB is bent at a bending angle θ _{f_load} of 58.01 degrees and bent back at a bend back angle θ _{b_load} of 46.04 degrees. As a result, the bending angle of the first member MA in the processed plate material OB is 50.48 degrees, and the bending angle of the second member MB is 49.96 degrees.

Fig. 19 shows the relationship between the X-coordinate position and the Z-coordinate position after a new plate material OB is machined using the corrected prediction model MD with a bending target value θ _target of 50 degrees. In Fig. 19, the relationship of the first member MA is shown by a solid line, and the relationship of the second member MB is shown by a dashed line, as in Fig. 17. As shown in Figs. 17 to 19, the accuracy of machining the plate material OB using the prediction model MD is improved by correcting the prediction model MD.

As described above, in the bending apparatus 100 of this embodiment, when bending the plate material OB, the drive control unit 52 uses the upper die 10 and the lower die 20 to perform bending in a predetermined direction. After bending, the drive control unit 52 uses the upper die 10 and the lower die 20 to perform bending back the plate material OB in the direction opposite to the predetermined direction. When bending the plate material OB, it is necessary to bend the plate material with low bending strength (e.g., the second member MB) more than the bending target value θ _target in order to match the plate material with high bending strength (e.g., the first member MA). In particular, when the plate material OB is made of metal,
In the case of B, springback occurs, so the plate material OB cannot be shaped to the bending target value θ _target unless it is bent more than the bending target value θ _target . According to the bending device 100 of this embodiment, the plate material OB is bent using the upper die 10 and the lower die 20, and then the plate material OB is bent back using the upper die 10 and the lower die 20, so that the plate material OB can be shaped to the bending target value θ _target with a small number of processing steps. In addition, in this embodiment, a special upper die or lower die according to the material constituting the plate material OB is not required. Therefore, by using the same bending device 100, various plate materials OB can be processed simply by changing the forming conditions, which are the bending angle θ _{f_load} and the bending back angle θ _{b_load} .

In addition, in the bending apparatus 100 of this embodiment, the drive control unit 52 uses the upper mold 10 and the lower mold 20 to bend the plate material OB more than the target value θ _target during bending, and then bends the plate material OB back by bending back. When a plate material OB made of metal is bent, springback occurs. In contrast, in the bending apparatus 100 of this embodiment, a plate material with low bending strength that is bent more than the bending target value θ _target is bent back to the bending target value θ _target , so that the plate material OB can be shaped to the bending target value θ _target with fewer processing times.

Further, the calculation unit 53 of this embodiment acquires the results of bending the first member MA and the second member MB with a plurality of bending angles θ _{f_load} and unbending angles θ _{b_load} . Using the acquired results, the calculation unit 53 creates a prediction model MD, which is a curved surface representing the bending angles θ _{unload_A} and θ _{unload_B} after forming determined by the bending angle θ _{f_load} and the unbending angle θ _{b_load} . There are a plurality of combinations of the bending angle θ _{f_load} and the unbending angle θ _{b_load} for forming to the bending target value θ _target . In contrast, in this embodiment, a common solution that satisfies the bending target value θ target where the bending angle θ _{unload_A} and the bending angle θ _{unload_B} are the same are determined from the combination that constitutes the bending angle θ _{unload_A} after forming of the first member MA and the bending angle θ _{unload_B} after forming of the second member MB. As a result, the bending forming device 100 of this embodiment can form the plate material OB _{to the bending target value θ target with} fewer processing times.

In addition, the correction unit 54 of this embodiment corrects the prediction model MD using the captured images of the first camera 30 and the second camera 40. The first camera 30 and the second camera 40 acquire captured images of the bending angle θ unload after forming of the plate material OB processed using the bending angle θ _{f_load} and the bending back angle θ _{b_load} calculated using the prediction model MD. The correction unit 54 calculates the error between the measured value of the bending angle θ _unload after processing for _which the captured image is calculated and the predicted value using the prediction model MD. Since the prediction model MD is corrected using the predicted value of the prediction model MD and the measured value of the plate material OB that has actually been formed, the prediction accuracy of the prediction model MD is improved. By using the prediction model MD with improved accuracy, the plate material OB can be formed to the bending target value θ _target with fewer processing times. In addition, the prediction model MD is corrected using the bending angles θ _{unload_A} and θ _{unload_B} after forming when the first member MA and the second member MB are bent and formed separately. As a result, the bending apparatus 100 of this embodiment can further improve the accuracy of the predictive model MD.

Second Embodiment
Each of the figures from FIG. 20 to FIG. 22 is an explanatory diagram of a bending apparatus of the second embodiment. In the second embodiment, a forming tool 10A, which replaces the upper mold 10 and the lower mold 20 of the first embodiment, forms the plate material OBa while feeding it. The plate material OBa formed in the second embodiment is a tailored blank material in which three different steel materials are joined in order. FIG. 20 shows a schematic front view of the forming tool 10A. FIG. 21 shows a schematic view of the a-a cross section in FIG. 20. FIG. 22 shows a schematic view of the bb cross section in FIG. 20. Note that the configuration of the control device that controls the forming tool 10A of the second embodiment is the same as the configuration of the control device 50 of the first embodiment, so it is omitted in FIG. 20.

As shown in Figures 20 to 22, the forming tool 10A includes three upper rollers (conveying sections) 10a1 to 10a3 arranged on the Z-axis positive side (upper side) of the plate material OBa to be processed, and three lower rollers (conveying sections) 10b1 to 10b3 arranged on the Z-axis negative side (lower side). The upper rollers 10a1 to 10a3 and the lower rollers 10b1 to 10b3 perform bending and unbending on the plate material OBa while conveying the plate material OBa in a feed direction parallel to the Y-axis. As shown in Figures 21 and 22, the upper roller 10a2 of the upper rollers 10a1 to 10a3 and the rollers 10b1 and 10b3 of the lower rollers 10b1 to 10b3 are arranged upstream of the other rollers 10a1, 10a2, and 10b2 in the feed direction (Y-axis negative direction).

The upper rollers 10a1-10a3 and the lower rollers 10b1-10b3 move up and down along the Z-axis direction. As a result, the upper roller 10a2, which is located upstream in the feed direction, and the lower rollers 10b1 and 10b3 perform bending on the plate material OBa. Meanwhile, the upper rollers 10a1 and 10a3 and the lower roller 10b2, which are located downstream in the feed direction (positive Y-axis direction), perform bending back on the plate material OBa. Hereinafter, the upper roller 10a2 and the lower rollers 10b1 and 10b3 that perform bending back are also referred to as bending tools 10a2, 10b1, and 10b3. The upper rollers 10a1 and 10a3 and the lower roller 10b2 that perform bending back are also referred to as bending back tools 10a1, 10a3, and 10b2.

Figure 23 is a schematic perspective view of a plate material OBa processed by the bending device of the second embodiment. The bending device of the second embodiment processes the plate material OBa in a direction perpendicular to the portion where different materials are joined, as the feed direction. Specifically, the bending device processes the first member MA, the second member MB, and the third member MC in the feed order.

Each of the figures from Fig. 24 to Fig. 26 is an explanatory diagram of the state of the forming tool 10A during bending and unbending. Fig. 24 shows a schematic front view of the forming tool 10A. Fig. 25 shows a schematic view of the a-a cross section in Fig. 24. Fig. 26 shows a schematic view of the b-b cross section in Fig. 24. As shown in Fig. 25, the bending forming tools 10a2, 10b1, and 10b3 feed the plate material OBa in the feed direction by rotating around the X-axis. The bending forming tools 10a2, 10b1, and 10b3 further move up and down in the Z-axis direction to form the plate material OBa at a bending angle θ _{f_load} .

As shown in Fig. 26, the bending-back forming tools 10a1, 10a3, and 10b2 rotate around the X-axis to feed the sheet material OBa in the feed direction. The bending-back forming tools 10a1, 10a3, and 10b2 further move up and down in the Z-axis direction to form the sheet material OBa at a bending-back angle θ _{b_load} . In Fig. 26, the sheet material OBa formed at the bending angle by the bending forming tools 10a2, 10b1, and 10b3 shown in Fig. 25 is shown by a dashed line for comparison with the bending-back angle.

Each of the figures from Fig. 27 to Fig. 32 is an explanatory diagram of the position PTf of the bending tools 10a2, 10b1, 10b3 and the position PTb of the unbending tools 10a1, 10a3, 10b2 with respect to the feed amount of the plate material OBa. Figures 27, 29, and 31 show the relationship between the position PTf of the bending tools 10a2, 10b1, 10b3 and the position PTb of the unbending tools 10a1, 10a3, 10b2 with respect to the plate material OBa. Figures 28, 30, and 32 show the transition of the bending angle θ _{f_load} of the bending tools 10a2, 10b1, 10b3 and the unbending angle θ _{b_load} of the bending tools 10a2, 10b1, 10b3 according to the feed amount of the plate material OBa.

Fig. 28 shows a state where bending of the first member MA of the plate material OB shown in Fig. 27 has started. The calculation unit 53 of the control device 50 of the second embodiment calculates the bending angle θ _{f_load and the unbending angle θ b_load in the section PA by using the bending angle θ unload_A of} the first member MA after forming and the bending angle θ _{unload_B} of the second member MB after forming. The drive control unit 52 sets the position PTf of the bending tools 10a2, 10b1, and _10b3 in the state shown in Fig. 28 so that the bending angle of the plate material OBa becomes the bending angle θ _{f_load} represented as the intersection point CP1 in Fig. 10 of the first embodiment within the range of the section PA. Similarly, the drive control unit 52 sets the position PTb of the bending-back forming tools 10a1, 10a3, and 10b2, which have not yet performed bending-back forming of the first member MA, in the section PA so that the bending-back angle of the plate material OBa becomes the bending-back angle θ _{b_load} represented as the intersection point CP1 in Figure 10.

Figure 30 shows a state in which the feed rate of the plate material OBa has increased from the state shown in Figure 28, and bending back the first member MA of the plate material OB shown in Figure 29 has begun. In this state, as shown in Figure 30, the positions PTf and PTb of the bending tools 10a2, 10b1, and 10b3 are the same as those shown in Figure 28.

Figure 32 shows a state in which the feed rate of the plate material OBa has increased from the state shown in Figure 30, and bending of the second member MB of the plate material OB shown in Figure 31 has begun. In this state, the drive control unit 52 changes the positions PTf of the bending tools 10a2, 10b1, and 10b3 in accordance with the feed rate, as shown in section PB in Figure 32.

Fig. 33 is an explanatory diagram of the bending angle θ _{f_load} and the bend-back angle θ _{b_load} during bending of the second member MB and the third member MC. Fig. 33 shows the relationship between the bending angle θ f_load and the bend-back angle θ _{b_load} determined by the first member MA, the second member MB, and the third member MC as in Fig. 10. The intersection point CP1 represents the bending angle θ _{f_load} and the bend-back angle θ _{b_load} calculated by the prediction model MD of the first member _MA and the second member MB.

In section PA in Fig. 32, the drive control section 52 controls the forming tool 10A so as to correspond to the bending angle θ _{f_load} and the unbending angle θ _{b_load} corresponding to the intersection point CP1. Similarly, in section PC in Fig. 32 where processing of the third member MC starts, the drive control section 52 controls the forming tool 10A so as to correspond to the bending angle θ _{f_load} and the unbending angle θ _{b_load} corresponding to the intersection point CP1. Specifically, the calculation section 53 calculates the bending angle θ f_load and the unbending angle θ _{b_load} in the section PC using the bending angle θ _{unload_B} after forming of the second member MB and the bending angle (third angle) after forming of _{the third member} .

On the other hand, in the section PB where the forming process of the second member MB starts, the drive control unit 52 controls the forming tool 10A so that the bending angle θ f_load (or the bending back angle θ b_load ) gradually changes along the curve C _PB from the intersection point CP1 to the intersection point CP2 along the curve CBb of the second member MB from the start of forming the second member to the completion of forming. Specifically, the calculation unit 53 gradually changes the bending angle θ _{f_load} (or the bending back angle θ _{b_load} ) of the first member MA from the bending angle θ _{f_load} (or the bending back angle θ _{b_load} ) of the third member MC as the feed amount of the plate material OBa increases. In the section PB, the drive control unit 52 changes the bending angle θ _{f_load} (or the bending back angle θ _{b_load} ) along the curve C _PB where the bending angle θ _{unload_B} after forming _of the second member _MB is the same. As a result, in section PB in FIG. 32, the positions PTf of the bending tools 10a2, 10b1, and 10b3 and the positions PTb of the unbending tools 10a1, 10a3, and 10b2 change according to the feed amount in response to the gradually changing bending angle θ _{f_load} and unbending angle θ _{b_load} .

As described above, the drive control unit 52 of the second embodiment performs bending and bending back using the bending angle θ f_load and the bending back angle θ _{b_load in the section PA calculated using the bending angle θ unload_A after forming of the first member MA and the bending angle θ unload_B after forming of the second member MB. The drive control unit 52 performs bending and bending back using the bending angle θ f_load and the bending back angle θ b_load in the section PC} calculated using the bending angle θ _{unload_B} after forming of the second member MB and the bending angle (third angle) after forming of the third member. As the feed amount of the plate material OBa increases, the drive control unit 52 gradually changes the bending angle θ _{f_load} (or the bending back angle θ _{b_load} ) from the bending angle θ _{f_load} (or the bending _back angle θ _{b_load} ) of the first member MA to the bending angle θ _{f_load} (or the bending back angle θ _{b_load} ) of the third member MC. In the section PB, the drive control unit 52 changes the bending angle θ _{f_load} (or the bending back angle θ _{b_load} ) along the curve C _PB where the bending angle θ _{unload_B} after forming of the second member MB is the same. Therefore, the bending angle and bending back angle when the second member MB sandwiched between the first member MA and the third member MC is formed change as the feed amount increases so as to connect from the common solution when forming the first member MA to the common solution when forming the third member MC. In addition, the curve CBb shown in FIG. 33 when processing the second member MB to the bending target value θ _target is used for this change. Therefore, the bending forming device of this embodiment can form the first member MA and the third member MC to the bending target value θ _target , while also forming the second member MB connecting the first member MA and the third member MC to the bending target value θ _target . Furthermore, the changes in the bending angle θ _{f_load} and the bending back angle θ _{b_load} from the first member MA to the second member MB can be smoothly connected to the changes in the bending angle θ _{f_load} and the bending back angle θ _{b_load} from the second member MB to the third member MC.

Third Embodiment
Fig. 34 is a schematic perspective view of a bending apparatus according to the third embodiment. In the third embodiment, a forming tool 10B, which is a substitute for the forming tool 10A in the second embodiment, forms a plate material OBb, which is a tailored blank material, while feeding it. Note that the control device that controls the forming tool 10B in the third embodiment is the same as the control device 50 in the first embodiment, and is therefore omitted from Fig. 34.

As shown in FIG. 34, the forming tool 10B of the third embodiment includes, in order from the upstream side in the feed direction parallel to the Y axis, first feed rollers 10c1 to 10c3, second feed rollers 10d1 to 10d3, bending forming tools 10e1 and 10e2, and unbending forming tools 10f1 and 10f2.

Figure 35 is a schematic cross-sectional view perpendicular to the feed direction of the second feed rollers 10d1 to 10d3. Figure 35 shows a schematic view of the cross section d in Figure 34. In the third embodiment, each of the second feed rollers 10d1 to 10d3 is a roller that rotates in a direction that feeds the plate material OBb in the feed direction. As shown in Figure 35, the second feed roller 10d3 is arranged so that it can move along the Z-axis direction. That is, as the second feed roller 10d3 moves along the Z-axis direction, the second feed rollers 10d1 to 10d3 feed the plate material OBb while bending the plate material OBb to a predetermined angle. Note that the first feed rollers 10c1 to 10c3 bend the plate material OBb to a smaller angle than the second feed rollers 10d1 to 10d3 before bending the plate material OBb by the second feed rollers 10d1 to 10d3.

Fig. 36 is a schematic cross-sectional view perpendicular to the feed direction of the bending tools 10e1 and 10e2. Fig. 36 shows a schematic view of the cross section e in Fig. 34. The bending tool 10e1 is a roller that rotates in a direction that feeds the plate material OBb in the feed direction. The bending tool 10e2 is a jig that bends the plate material OBb fed by the bending tool 10e1 to a bending angle θ _{f_load} . As shown in Fig. 36, the bending tool 10e2 is arranged so as to be rotatable around the Y axis on the cross section e. Therefore, the bending angle θ _{f_load} is set according to the rotation angle of the bending tool 10e2 around the Y axis.

Fig. 37 is a schematic cross-sectional view perpendicular to the feed direction of the bending back forming tools 10f1 and 10f2. Fig. 37 shows a schematic view of the cross section f in Fig. 34. The bending back forming tool 10f1 is a roller that rotates in a direction in which the plate material OBb is fed in the feed direction. The bending back forming tool 10f2 is a jig that bends back the plate material OBb fed by the bending back forming tool 10f1 at a bending back angle θ _{b_load} . As shown in Fig. 37, the bending back forming tool 10f2 is disposed so as to be rotatable around the Y axis on the cross section f. Therefore, the bending back angle θ _{b_load} is set according to the rotation angle of the bending back forming tool 10f2 around the Y axis.

As in the forming apparatus of the third embodiment, before the bending tools 10e1 and 10e2 are formed to the bending angle θ _{f_load} , the first feed rollers 10c1 to 10c3 and the second feed rollers 10d1 to 10d3 may bend the plate material OBb at an angle smaller than the bending angle θ _{f_load} . In addition, one of the bending tools 10e1 and 10e2 may have a function of conveying the plate material OBb in the feed direction, and the other may not have a conveying function. Similarly, one of the bending tools 10f1 and 10f2 may have a function of conveying the plate material OBb in the feed direction, and the other may not have a conveying function. In other embodiments, all of the bending tools 10e1 and 10e2 and the bending tools 10f1 and 10f2 may have a conveying function, or all of them may not have a conveying function, and the plate material OBb may be conveyed by the first feed rollers 10c1 to 10c3, etc.

Fourth Embodiment
38 is a schematic front view of the bending apparatus 100C of the fourth embodiment. The bending apparatus 100C of the fourth embodiment is a press molding machine including an upper mold 10C and a lower mold 20C. In the plate material OBc formed in the fourth embodiment, the first member MA and the second member MB are joined in the ZX plane perpendicular to the depth direction parallel to the Y axis direction. Note that the control device that controls the upper mold 10C and the lower mold 20C of the fourth embodiment is the same as the control device 50 of the first embodiment, and is therefore omitted in FIG. 38.

The upper mold 10C moves along the Z-axis direction by a device not shown. As shown in FIG. 38, the upper mold 10C includes a movable upper mold 10C1, driving devices 10C2 and 10C3, joints 10C4 and 10C5, and cranks 10C6 and 10C7. The movable upper mold 10C1 includes an upper portion 10C1a extending along the X-axis direction, a column portion 10C1b having one end connected to the upper portion 10C1a, a left end portion 10C1c connected to the X-axis negative side of the upper portion 10C1a, and a right end portion 10C1d connected to the X-axis positive side of the upper portion 10C1a. The other end of the column portion 10C1b that is not connected to the upper portion 10C1a extends from the center of the upper portion 10C1a in the X-axis direction to the Z-axis negative side. Of the left end 10C1c and the right end 10C1d, the other end that is not connected to the upper portion 10C1a extends in the negative direction of the Z axis. The extension length of the left end 10C1c and the right end 10C1d is shorter than the length of the pillar portion 10C1b. A driving device 10C2 is fixed to the lower end of the left end 10C1c. Similarly, a driving device 10C3 is fixed to the lower end of the right end 10C1d.

The drive unit 10C2 supports one end of the joint 10C4 on the negative side of the X-axis so that it can swing along the X-axis direction. Similarly, the drive unit 10C3 supports one end of the joint 10C5 on the positive side of the X-axis so that it can swing along the X-axis direction. The cranks 10C6 and 10C7 are rod-shaped members extending along the longitudinal direction. As shown in FIG. 38, grooves GR6 and GR7 are formed along the longitudinal direction at one end of the cranks 10C6 and 10C7. The other end of the cranks 10C6 and 10C7, where grooves GR6 and GR7 are not formed, is supported rotatably around the Y-axis at the lower end of the column portion 10C1b on the negative side of the Z-axis.

The other end of the joint 10C4, which is not supported by the driving device 10C2, is supported so as to be able to swing in a groove GR6 formed in the crank 10C6. Specifically, a pin PN4 formed at the other end of the joint 10C4 is engaged with the groove GR6. Similarly, the other end of the joint 10C5, which is not supported by the driving device 10C3, is supported so as to be able to swing in a groove GR7 formed in the crank 10C7. A pin PN5 formed at the other end of the joint 10C5 is engaged with the groove GR7. Since the upper mold 10C has the structure described above, the angle formed by the cranks 10C6, 10C7 and the YZ plane of the lower end of the column portion 10C1b that rotatably supports the cranks 10C6, 10C7 changes depending on the amount of swing of the joints 10C4, 10C5 controlled by the driving devices 10C2, 10C3.

As shown in FIG. 38, the lower mold 20C includes a fixed lower mold 20C1, driving devices 20C2-20C5, joints 20C6-20C9, and cranks 20C10 and 20C11. The fixed lower mold 20C1 includes a lower portion 20C1a extending along the X-axis direction, a column portion 20Cb2 having one end connected to the lower portion 20C1a, a left end portion 20C1c connected to the X-axis negative side of the lower portion 20C1a, and a right end portion 20C1d connected to the X-axis positive side of the lower portion 20C1a. The other end of the column portion 20C1b that is not connected to the lower portion 20C1a extends from the center of the lower portion 20C1a in the X-axis direction to the Z-axis positive side. The other ends of the left end portion 20C1c and the right end portion 20C1d that are not connected to the lower portion 20C1a extend to the Z-axis positive side. The extension length of the left end 20C1c and the right end 20C1d is greater than the length of the column portion 20Cb2. A driving device 20C2 is fixed to the upper end of the left end 20C1c. A driving device 20C3 is fixed between the upper and lower ends of the left end 20C1c. Similarly, a driving device 20C4 is fixed to the upper end of the right end 20C1d. A driving device 20C5 is fixed between the upper and lower ends of the right end 20C1d.

Driver 20C2 supports one end of joint 20C6 on the negative X-axis side so that it can swing along the X-axis direction. Driver 20C3 supports one end of joint 20C7 on the negative X-axis side so that it can swing along the X-axis direction. Similarly, driver 20C4 supports one end of joint 20C8 on the positive X-axis side so that it can swing along the X-axis direction. Driver 20C5 supports one end of joint 20C9 on the positive X-axis side so that it can swing along the X-axis direction.

The cranks 20C10 and 20C11 are rod-shaped members extending along the longitudinal direction. As shown in FIG. 38, the cranks 20C10 and 20C11 have grooves GR10 and GR11 formed along the longitudinal direction at one end thereof. The other end of the crank 20C10 where the groove GR10 is not formed is supported rotatably around the Y axis at the other end of the joint 20C6 that is not supported by the drive unit 20C2. Similarly, the other end of the crank 20C11 where the groove GR11 is not formed is supported rotatably around the Y axis at the other end of the joint 20C8 that is not supported by the drive unit 20C4.

The other end of the joint 20C7, which is not supported by the drive unit 20C3, is supported so as to be able to swing in a groove GR10 formed in the crank 20C10. Specifically, the pin PN7 formed at the other end of the joint 20C7 is engaged with the groove GR10. Similarly, the other end of the joint 20C9, which is not supported by the drive unit 20C5, is supported so as to be able to swing in a groove G11 formed in the crank 20C11. The pin PN9 formed at the other end of the joint 20C9 is engaged with the groove GR11. Since the lower mold 20C has the structure described above, the angle formed between the crank 20C10 and the XY plane of the upper end of the joint 20C6, which supports the other end of the crank 20C10 in rotation, changes depending on the amount of swing of the joints 20C6 and 20C7 controlled by the drive units 20C2 and 20C3. Similarly, the angle between crank 20C11 and the XY plane of the upper end of joint 20C8, which supports the rotation of the other end of crank 20C11, changes depending on the amount of swing of joints 20C8 and 20C9 controlled by drive devices 20C4 and 20C5.

FIG. 39 is an explanatory diagram of the bending target value θ _target in the fourth embodiment. FIG. 39 shows a schematic cross-sectional view showing four bending target values θ _target when bending the plate material OBc. In the fourth embodiment, the four bending target values θ _target are the same angle, but in other embodiments, they may be different angles. In the fourth embodiment, the drive control unit 52 controls the swing amount of the six drive devices 10C2, 10C3, 20C2 to 20C5 to make the bending angle θ _{f_load} larger than the bending target value θ _target . In addition, the drive control unit 52 makes the unbending angle θ _{b_load} smaller than the bending target value θ _target .

FIG. 40 is a schematic front view of the bending apparatus 100C during bending. The drive control unit 52 uses the prediction model MD to determine the bending angle θ _{f_load} during bending. The drive control unit 52 controls the drive units 10C2, 10C3, and 20C2 to 20C5 so that the plate material OBc can be bent at the bottom dead center of the forming to the determined bending angle θ _{f_load} . As shown in FIG. 40, the drive unit 10C2 swings the joint 10C4 to the positive direction of the X-axis. The drive unit 10C3 swings the joint 10C5 to the negative direction of the X-axis. As a result, the angle formed by the cranks 10C6, 10C7 and the column portion 10C1b changes to the bending angle θ _{f_load} . Similarly, the drive unit 20C2 swings the joint 20C6 to the positive direction of the X-axis. The drive unit 20C3 swings the joint 20C7 to the negative direction of the X-axis. The driving device 20C4 swings the joint 20C8 in the negative direction of the X-axis. The driving device 20C5 swings the joint 20C9 in the positive direction of the X-axis. As a result, the angle between the crank 20C10 and the upper end of the joint 20C6 changes to the bending angle θ _{f_load} . Similarly, the angle between the crank 20C11 and the upper end of the joint 20C8 changes to the bending angle θ _{f_load} .

FIG. 41 is a schematic front view of the bending apparatus 100C during bending back. The drive control unit 52 controls the drive units 10C2, 10C3, and 20C2 to 20C5 so that the plate material OBc can be bent back to the determined bending back angle θ _{b_load} . As shown in FIG. 41, the drive unit 10C2 swings the joint 10C4 in the negative direction of the X-axis from the state during bending. The drive unit 10C3 swings the joint 10C5 in the positive direction of the X-axis. As a result, the angle between the cranks 10C6 and 10C7 and the column portion 10C1b changes to the bending back angle θ _{b_load} . Similarly, the drive unit 20C2 swings the joint 20C6 in the positive and negative directions of the X-axis from the state during bending. The drive unit 20C3 swings the joint 20C7 in the positive direction of the X-axis. The driving device 20C4 swings the joint 20C8 in the positive direction of the X-axis. The driving device 20C5 swings the joint 20C9 in the negative direction of the X-axis. As a result, the angle between the crank 20C10 and the upper end of the joint 20C6 changes to the bending back angle θ _{b_load} . Similarly, the angle between the crank 20C11 and the upper end of the joint 20C8 changes to the bending back angle θ _{b_load} . When the upper mold 10C and the lower mold 20C are released from the state shown in FIG. 41, the plate material OBc is shaped to the bending target value θ _target .

The press molding machine, which is the bending apparatus 100C of the fourth embodiment, may perform bending and unbending at a plurality of positions on the plate material OBc to be bent. The clamps 10C6, 10C7, 20C10, and 20C11 for setting the bending angle θ _{f_load} and the unbending angle θ _{b_load} may be freely set.

<Modifications of the embodiment>
The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit of the present invention, for example, the following modifications are possible: In the above-described embodiment, a part of the configuration realized by hardware may be replaced by software, and conversely, a part of the configuration realized by software may be replaced by hardware.

In the above embodiment, the bending apparatus 100 performs bending and unbending after bending.
Although an example of the bending apparatus has been described, the configuration of the bending apparatus can be modified. As the bending apparatus, a known apparatus can be applied to the extent that it can perform bending and bending back on the tailored blank material. The bending apparatus 100 does not need to be equipped with the control device 50, the first camera 30, and the second camera 40. The bending apparatus of the modified example may be configured, for example, with an upper mold 10 and a lower mold 20 that are driven in response to a control signal from another apparatus. In addition, in bending and bending back, the tailored blank material may be formed by the bending angle and bending back angle set by the user without using the prediction model MD. In addition, even in the processing in which the prediction model MD is used, the prediction model MD may not be corrected. In addition, the correction of the prediction model MD may be performed by comparing the forming simulation value with the predicted value, rather than by comparing the actual value with the predicted value.

Figure 42 is a flowchart of a modified bending method. The processing of each step S11 to S14 of the bending flow shown in Figure 42 is the same as the processing corresponding to steps S1 to S4 of the bending flow of the above embodiment (Figure 13). As shown in Figure 42, the bending flow does not have to include a process of correcting the prediction model MD.

In the above embodiment, the bending apparatus 100 and the like are described using an orthogonal coordinate system CS defined by the X-axis, Y-axis, and Z-axis, but the definition of the coordinate system can be modified. In the above first and fourth embodiments, the plate materials OB, OBc are processed using the upper mold 10, 10C and the lower mold 20, 20C that operate along the Z-axis parallel to the vertical direction, but the plate materials OB, OBc may be formed by a forming mold that moves in a horizontal direction, such as the X-axis or Y-axis. In addition, a tailored blank material may be processed by a bending apparatus that includes a forming mold other than the upper mold 10, 10C and the lower mold 20, 20C.

Although this aspect has been described above based on the embodiment and modified examples, the embodiment of the above-mentioned aspect is intended to facilitate understanding of this aspect and does not limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents are included in this aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate.

10, 10C... Upper mold 10A, 10B... Molding tool 10C1... Movable upper mold 10C1a... Upper part of upper mold 10C1b... Upper mold column 10C1c... Left end of upper mold 10C1d... Right end of upper mold 10C2, 10C3... Upper mold drive device 10C4, 10C5... Upper mold joint 10C6, 10C7... Upper mold crank 10a1 to 10a3... Upper roller (conveyor section)
10b1 to 10b3: Lower rollers (transport section)
10c1 to 10c3: First feed rollers 10d1 to 10d3: Second feed rollers 10e1, 10e2: Bending tool 10f1, 10f2: Bending back tool 11, 13: Outer upper die 12: Central upper die 20, 20C: Lower die 20C1: Fixed lower die 20C10, 20C11: Crank of lower die 20C1a: Lower part of lower die 20C1b: Column part of lower die 20C1c: Left end part of lower die 20C1d: Right end part of lower die 20C2 to 20C5: Drive device of lower die 20C6 to 20C9: Joint of lower die 20Cb2: Column part of lower die 21: Outer lower die 22: Central lower die 30: First camera (bending angle acquisition unit)
40...Second camera (bending angle acquisition unit)
50: Control device 51: CPU
52: Drive control unit 53: Calculation unit (condition calculation unit)
54: correction unit 55: setting unit 56: memory unit 57: communication unit 58: output unit 59: input unit 100, 100C: forming device C _A : correction coefficient of first member C _B : correction coefficient of second member CBa: curve of first member CBb, C _PB : curve of second member CP1, CP2: intersection CS: Cartesian coordinate system DR11 to DR13, DR21 to DR23: up and down direction FR: body frame GR6, GR7, GR10, GR11: groove MA: first member MB: second member MC: third member MD: prediction model OB: plate material OB1, OB2: tailored blank material OB, OBa, OBb, OBc: plate material (tailored blank material)
PA...section PB...section PC...section PN4, PN5, PN7, PN9...pin PTf...position of bending tool PTb...position of unbending tool RF...rocker frame UF...upper frame θ _{f_load} ...bending angle θ _{b_load} ...unbending angle θ _target ...bending target value θ _{unload_A} ...bending angle after forming of the first member (first angle)
θ _{unload_B} … bending angle after forming of the second member (second angle)

Claims (6)

A bending forming apparatus,
a bending forming section that bends a tailored blank material in which plate materials having different bending strengths are joined in a predetermined direction;
a bending-back forming section that bends the tailored blank material bent by the bending forming section back in a direction opposite to the predetermined direction;
a condition calculation unit that calculates a bend angle larger than a target bend value and a bend-back angle smaller than a target bend value according to a target bend value after forming of the tailored blank material;
Equipped with
The condition calculation unit
When the tailored blank material is formed by joining a first member and a second member,
a first angle, which is an angle of the first member after forming, determined by the bending angle and the bending back angle of the first member;
a second angle, which is an angle of the second member after forming, determined by the bending angle and the bending back angle of the second member;
A prediction model is created to predict a forming angle, which is the angle of the tailored blank material after forming, using
the bending forming unit bends the tailored blank material to the bending angle calculated by the condition calculation unit,
The bending forming device, wherein the bend-back forming unit bends back the tailored blank material bent by the bend forming unit so as to achieve the bend-back angle calculated by the condition calculation unit . The bending apparatus according to claim 1 , further comprising:
A bending forming apparatus comprising: a correction unit that corrects the prediction model using a predicted value of the forming angle obtained using the prediction model and a measured value of the forming angle. The bending apparatus according to claim 2 , further comprising:
A bending angle acquisition unit that acquires the first angle and the second angle,
A bending forming apparatus, wherein the correction unit corrects the prediction model using the first angle and the second angle acquired by the bending angle acquisition unit. The bending apparatus according to any one of claims 1 to 3 , further comprising:
a conveying section that conveys the tailored blank material in a feed direction,
the tailored blank material is formed in the order of the first member, the second member, and the third member by being joined in the feed direction in that order,
When an angle of the third member after forming, which is determined by the bending angle and the bending-back angle of the third member, is defined as a third angle,
The bent forming portion and the bent back forming portion are
forming the first part at the bend angle and the unbend angle using the predictive model created using the first angle and the second angle;
forming the third part at the bending angle and the unbending angle using the predictive model created using the second angle and the third angle;
A bending forming device that gradually changes the second member from the bending angle and the bend-back angle when forming the first member to the bending angle and the bend-back angle when forming the third member by using the second angle as the feed rate by the conveying section increases. A bending method comprising:
a bending forming process in which a tailored blank material in which plate materials having different bending strengths are joined is bent in a predetermined direction;
a bending back process of bending back the tailored blank material bent in the bending process in a direction opposite to the predetermined direction;
a condition calculation step of calculating a bending angle larger than a bending target value after forming of the tailored blank material and a bending back angle smaller than the bending target value;
Equipped with
The condition calculation step includes:
When the tailored blank material is formed by joining a first member and a second member,
a first angle, which is an angle of the first member after forming, determined by the bending angle and the bending back angle of the first member;
a second angle, which is an angle of the second member after forming, determined by the bending angle and the bending back angle of the second member;
A prediction model is created to predict a forming angle, which is the angle of the tailored blank material after forming, using
The bending step includes bending the tailored blank material to the bending angle calculated in the condition calculation step,
A bending method, comprising: bending back the tailored blank material bent in the bending forming step so as to achieve the bend-back angle calculated in the condition calculation step. A computer program comprising:
A bending forming function that bends tailored blank materials, which are made by joining plate materials with different bending strengths, in a specified direction.
a bending-back forming function for bending back the tailored blank material bent by the bending forming function in a direction opposite to the predetermined direction;
a condition calculation function for calculating a bending angle larger than a bending target value after forming of the tailored blank material and a bending back angle smaller than the bending target value;
This is realized in bending equipment ,
The condition calculation function is
When the tailored blank material is formed by joining a first member and a second member,
a first angle, which is an angle of the first member after forming, determined by the bending angle and the bending back angle of the first member;
a second angle, which is an angle of the second member after forming, determined by the bending angle and the bending back angle of the second member;
A prediction model is created to predict a forming angle, which is the angle of the tailored blank material after forming, using
the bending function bends the tailored blank material to the bending angle calculated by the condition calculation function;
The bend-back forming function is a computer program for bending back the tailored blank material bent by the bending forming function so as to achieve the bend-back angle calculated by the condition calculation function .

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