Bending processing method and bending processing system

Abstract

A bending method is a method for bending a workpiece by means of a bending system, the bending system comprising: a bending machine having a metal mold, the metal mold having a punch and a die configured to be relatively movable; a robot that positions the workpiece relative to the metal mold; and a control device that controls the bending machine and the robot to perform the bending method, the bending method comprising a resetting process, in which, during the automatic operation of the bending process of the workpiece performed by the bending machine, the amount of penetration of the punch relative to the die or the origin position of the punch is reset for each predetermined trigger condition.

Description

Technical Field

[0001] The invention relates to a bending method and a bending system for bending a workpiece. Background Art

[0002] A bending machine is known which, when bending a workpiece by the bending machine, obtains an approximate formula for the bending load based on the initial bending load and the relative movement position of the punch with respect to the die in order to be able to perform bending with higher precision than before (for example, refer to the following patent document 1).

[0003] The bending machine uses an approximate formula to set the moving position when the bending load is zero as the so-called impact origin where the punch contacts the workpiece, so that a higher-precision bending process is achieved by setting the vicinity of the bending load increase as the impact origin. That is, the approximate formula is obtained each time the bending process is performed, or at each predetermined number of times of the bending process, or at each arbitrary number of times of the bending process, so that the change in the bending angle caused by the displacement of the frame over time (time-dependent change) of the bending machine is corrected.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2006-88183 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, when the conventional bending machine disclosed in the above-mentioned Patent Document 1 is used to perform bending processing by, for example, automatic operation, in order to correct the change in the bending angle caused by the change over time as described above, it is necessary to perform processing for obtaining an approximate formula for each predetermined number of bending processing, and to perform correction while temporarily stopping the movement of the punch of the bending machine. Therefore, the machine operation is stopped every time correction is performed, and there is a problem that the tact time and cycle time are prolonged, thereby reducing productivity.

[0009] The present invention is made in view of the above situation, and its purpose is to provide a bending method and a bending system that can correct the change of the bending angle caused by the change over time in an automatically operated bending system without stopping the operation, and can improve the productivity and quality.

[0010] Means for solving problems

[0011] The bending processing method of the present invention is a method for performing bending processing on a workpiece by means of a bending processing system, wherein the bending processing system comprises: a bending processing machine having a metal mold, wherein the metal mold has a punch and a die which are configured to be relatively movable; a robot which positions the workpiece relative to the metal mold; and a control device which controls these bending processing machines and the robot to perform bending processing. The bending processing method is characterized in that it includes a resetting process, wherein, during the automatic operation of the bending processing of the workpiece performed by the bending processing machine, the amount of penetration of the punch relative to the die or the origin position of the punch is reset for each predetermined trigger condition.

[0012] In one embodiment of the present invention, the trigger condition is at least one of room temperature, time, and number of processes.

[0013] In another embodiment of the present invention, after the trigger condition is satisfied, the resetting process is performed when a resetting condition is satisfied.

[0014] In another embodiment of the present invention, the resetting condition is that the robot is loading the workpiece or unloading the workpiece.

[0015] In another embodiment of the present invention, the bending method includes a validity / invalidity setting step of setting validity / invalidity of the resetting step performed by the control device.

[0016] In another embodiment of the present invention, in the resetting step, the pressing amount is reset based on a D-axis mold origin position when a predetermined load is applied to the mold.

[0017] Another embodiment of the present invention includes a calculation step of calculating the temporal change in the position of the metal mold origin as a correction value for the pressing amount, and using the calculated correction value to correct the pressing amount during the automatic operation to perform bending of the workpiece.

[0018] In another embodiment of the present invention, in the resetting step, the origin position of the punch is reset based on the D-axis position when the workpiece is clamped between the die.

[0019] The bending processing system of the present invention comprises: a bending processing machine with a metal mold, the metal mold having a punch and a die that are configured to be relatively movable; a robot that positions the workpiece relative to the metal mold; and a control device that controls these bending processing machines and the robot to perform bending processing. The bending processing system is characterized in that during the automatic operation of the bending processing of the workpiece performed by the bending processing machine, the control device resets the pressing amount of the punch relative to the die or the origin position of the punch for each predetermined trigger condition to perform bending processing.

[0020] In one embodiment of the present invention, the trigger condition is at least one of room temperature, time, and number of processes.

[0021] In another embodiment of the present invention, after the trigger condition is satisfied, the pressing amount or the origin position of the punch is reset when a reset condition is satisfied.

[0022] In another embodiment of the present invention, the resetting condition is that the robot is loading the workpiece or unloading the workpiece.

[0023] In another embodiment of the present invention, the control device sets validity / invalidity of resetting the pushing amount or the origin position of the punch.

[0024] In another embodiment of the present invention, the push-in amount is reset based on the mold origin position of the D-axis when a predetermined load is applied to the mold.

[0025] In another embodiment of the present invention, the control device calculates the temporal change in the origin position of the metal mold as a correction value for the pressing amount, and uses the calculated correction value to correct the pressing amount during the automatic operation to perform bending of the workpiece.

[0026] In another embodiment of the present invention, the origin position of the punch is reset based on the D-axis position when the die clamps the workpiece.

[0027] Effects of the Invention

[0028] According to the present invention, changes in the bending angle due to changes over time can be corrected without stopping the operation, and the productivity and quality can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic overall configuration of a bending system for executing a bending method according to a first embodiment of the present invention is shown.

[0030] Figure 2An outline of a general metal mold used in a plate bender of this bending system is shown.

[0031] Figure 3 1 is a block diagram showing a schematic internal structure of a control device of the bending system.

[0032] Figure 4 This is a flowchart showing an outline of a processing procedure of a bending method executed by the bending system.

[0033] Figure 5 An outline of a general metal mold used for a plate bender in a bending system according to a second embodiment of the present invention is shown. DETAILED DESCRIPTION

[0034] Hereinafter, the bending method and bending system according to the embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following embodiments do not limit the inventions involved in the claims, and not all combinations of features described in the embodiments are necessary for the solutions of the invention.

[0035] (First Embodiment)

[0036] Figure 1 A schematic overall configuration of a bending system for executing a bending method according to a first embodiment of the present invention is shown. Figure 2 The following is an overview of a general metal mold used in a plate bender of the bending processing system. Figure 1 As shown, the bending system 1 includes: a plate bender 10 as a bending machine; an automatic robot 20 which is a manipulator for positioning a workpiece relative to a die of the plate bender 10; and a control device 30 which controls the plate bender 10 and the automatic robot 20 to perform bending of the workpiece.

[0037] The basic structures of the plate bender 10 and the automatic robot 20 are already known, so only an outline is described here. In addition, in the following description, the "X-axis direction" refers to the left-right direction when facing the front of the plate bender 10, the "Y-axis direction" refers to the depth direction at this time, and the "Z-axis direction" refers to the up-down direction at this time.

[0038] The plate bender 10 of the bending processing system 1 has an upper table 11 and a lower table 12 arranged in the vertical direction (Z-axis direction) in the center of the front side, with one surface in the depth direction (Y-axis direction), for example, the outer plate surface facing the front side. In addition, the plate bender 10 has a support portion 13 that supports these tables 11 and 12 and is arranged on the left and right sides, respectively.

[0039] In the present embodiment, the plate bender 10 includes, for example, a drive mechanism 16 configured to reciprocate the upper table 11 in the vertical direction relative to the lower table 12. In addition, the plate bender 10 includes a position detection sensor 17 (see Figure 3 ), the position detection sensor 17 detects the moving position when the upper workbench 11 is moved by the driving mechanism 16.

[0040] The upper table 11 is composed of a plate-like member such as metal, and has a plurality of upper die holders 14 for holding upper dies such as punches P at its lower portion. The lower table 12 is composed of a plate-like member such as metal as the upper table 11, and has a lower die holder 15 for holding lower dies such as punches D at its upper portion. In the present embodiment, each support portion 13 is composed of, for example, a plate-like side frame formed in a substantially "コ (Japanese katakana)" shape when viewed from the side, but is not limited thereto, and may also be composed of a rod-like connecting rod or the like.

[0041] The driving mechanism 16 is, for example, a hydraulic cylinder that is a driving source of the upper table 11, and is mounted on the upper portion of each support portion 13. Each driving mechanism 16 is configured to reciprocate (move up and down) the upper table 11 relative to the lower table 12 in the vertical direction. Each driving mechanism 16 may also use other driving mechanisms such as servo motors instead of hydraulic cylinders.

[0042] The position detection sensor 17 detects the relative movement position of the punch P with respect to the die D when the upper table 11 is moved by the driving mechanism 16. The position detection sensor 17 is composed of, for example, an encoder or a linear scale, and is a well-known sensor, so detailed description thereof is omitted here.

[0043] The position detection sensor 17 can detect the amount of pressing (movement stroke) (mm), which represents the distance between the cutting edges of the metal mold composed of the punch P and the die D on the D axis. Figure 2 As shown, for example, when the position when the punch P and the die D are engaged in a state without a workpiece is set as the reference position (0 mm) of the metal mold, and the position of the front end (lower end) of the punch P at a predetermined position in the direction of the punch P away from the reference position is set as the stroke start (SS) position, the pressing amount represents the distance from the reference position to the SS position (the so-called cutting edge distance). In the first embodiment, the value of the D axis when a predetermined load F (for example, 1t) is applied to the reference position is read, and the time-dependent change amount of the metal mold is calculated based on the read value. Then, the calculated time-dependent change amount is used as a correction value for the pressing amount of the punch P, for example, by adding the correction value to the pressing amount to correct the pressing amount.

[0044] The plate bending machine 10 is further provided with a bending load detection sensor 18 (see Figure 3 ), the bending load detection sensor 18 is used to detect the bending load applied to the punch P when the upper table 11 is moved by the driving mechanism 16 so that the punch P and the die D are engaged to perform the bending process of the workpiece. The bending load detection sensor 18 can detect the fluid pressure when the driving mechanism 16 is composed of a hydraulic cylinder, for example, as described above, and can detect the torque and load current when it is composed of an electric motor. In addition, as the bending load detection sensor 18, various structures such as a piezoelectric element provided at the mounting portion of the punch P relative to the upper table 11 (or, provided at the mounting portion of the die D relative to the lower table 12) can be adopted.

[0045] The automatic robot 20 includes, for example, a slider 22 that freely moves in the left-right direction along a guide rail 21 that extends in the left-right direction (X-axis direction), and a base frame 23 placed on the slider 22. In addition, the automatic robot 20 includes a rotating base 24 that freely rotates in the horizontal direction and is provided on the base frame 23. The rotating base 24 includes a first arm 25 that freely swings (rotates) up and down around a horizontally extending rotation axis. In addition, a second arm 26 that is provided on the front end side of the first arm 25 in a manner that allows free rotation around a horizontally extending rotation axis.

[0046] In addition, a robot 27 is provided at the front end side of the second arm 26, and the robot 27 is freely rotatable around a rotation axis extending horizontally, and is freely rotatable around a rotation axis in a direction perpendicular to the length direction of the second arm 26. The automatic robot 20 carries the workpiece of the plate bending machine 10 into and supplies it between the punch P and the die D (i.e., carries the workpiece into and supplies it to the metal die), and discharges and carries out the workpiece after the bending process from the plate bending machine 10. In the bending system 1 of the present embodiment, these plate bending machines 10 and the automatic robot 20 are controlled by the control device 30 to cooperate with each other, thereby, for example, being able to perform a predetermined number of batches of bending processes through automatic operation.

[0047] Figure 3 1 is a block diagram showing a schematic internal structure of the control device 30 of the bending system 1 .

[0048] like Figure 3 As shown in FIG. 1 , the control device 30 includes: a computing unit 31 including a CPU, a storage unit 32 including a RAM, a ROM, etc., an action driver 33 for actuating the drive mechanism 16, an input interface (I / F) 34, a communication interface (I / F) 35, and a display unit 36 ​​for displaying various screens such as a setting screen on a display unit such as a display. The configuration of each part of the control device 30 is well known, so a detailed description thereof is omitted. The above-mentioned position detection sensor 17 and bending load detection sensor 18 are connected to the communication I / F 35, as well as a room temperature sensor 38 for measuring room temperature such as a thermocouple (see FIG. 1 ). Figure 3 ) In addition, the display unit 36 ​​may be formed of a touch panel having the function of the input unit 37.

[0049] In the control device 30, the operation unit 31 executes the bending program stored in the storage unit 32, and controls the operation of the drive mechanism 16 of the plate bending machine 10 through the motion driver 33 under the control of the program. In addition, the control device 30 can also control the operation of the automatic robot 20 through the motion driver 33.

[0050] The calculation unit 31 performs various calculation processes related to the bending process based on the processing conditions such as the plate thickness, material, bending angle, and metal mold conditions of the workpiece inputted via the input unit 37 such as a keyboard or a mouse and the input I / F 34. In addition, the calculation unit 31 also calculates the amount of the punch P pressed from the SS position to the reference position relative to the die D, the contact position where the punch P contacts the workpiece, and the amount of pressing relative to the contact position for bending the workpiece to a desired bending angle.

[0051] The control device 30 can determine whether the reset function of the press-in amount of the punch P relative to the die D is valid or invalid based on the input information input through the input unit 37. For example, when the number of batches of the bending process is large, the operator can arbitrarily set the reset function of the press-in amount to valid (ON), thereby automatically correcting the change of the bending angle due to the change over time. In addition, when the number of batches of the bending process is small, the operator can arbitrarily set the reset function of the press-in amount to invalid (OFF), thereby automatically operating without setting the trigger condition, etc.

[0052] In addition, the control device 30 can determine whether the acquisition condition for setting the initial reference position and the reset condition for resetting the pressing amount are satisfied. As a case where the acquisition condition and the reset condition are satisfied, for example, the control device 30 determines that the workpiece is being loaded or unloaded by the automatic robot 20. When the reset function is valid, the control device 30 waits until the acquisition condition and the reset condition are satisfied, and if the acquisition condition is satisfied, the value of the D axis is obtained as the reference position, and if the reset condition is satisfied, the time change amount is calculated as a correction value, for example, the correction value is added to the pressing amount to correct the pressing amount, and then the pressing amount of the punch P is reset.

[0053] The control device 30 of the bending system 1 of the present embodiment performs a resetting process of resetting the above-mentioned push-in amount for each predetermined trigger condition during the automatic operation of the workpiece bending process performed by the plate bending machine 10. More specifically, when the automatic operation of the bending process starts, the initial reference position is obtained to set the push-in amount, and thereafter, the time-dependent change amount of the reference position is calculated for each predetermined trigger condition to correct the push-in amount.

[0054] Thus, for example, by comparing the reference position obtained later with the reference position obtained initially, the temporal variation of the entire mechanical system including the metal mold and the drive mechanism 16, etc., caused by external factors such as room temperature is calculated, and the calculated temporal variation is used as a correction value of the pressing amount of the punch P related to the bending angle (i.e., a correction value of the processing conditions), and thus the automatic operation of the bending process can be continued until the operation is completed after the pressing amount is corrected by addition and subtraction operations based on the correction value. Therefore, the change in the bending angle caused by the temporal variation can be corrected without stopping the operation of the bending process, and the productivity and quality of the bent product can be improved.

[0055] Figure 4 This is a flowchart schematically showing a processing procedure of a bending method executed by the bending system 1 .

[0056] like Figure 4 As shown, the control device 30 starts the bending processing program read from the storage unit 32 by the operation unit 31, and first determines whether the resetting function of the pressing amount of the metal mold is valid (ON) (step S100) based on the user operation input via the input unit 37 and the input I / F34 or via the touch panel of the display unit 36, or the setting input from other external PCs, etc. (hereinafter referred to as "input information").

[0057] That is, in step S100, the validity / invalidity of the reset function is determined based on the input information. For example, as described above, when the number of batches of bending processing is small, the operator can arbitrarily disable the reset function of the pressing amount, and the setting process of the trigger condition described later can be skipped to perform automatic operation.

[0058] In step S100, when it is determined that the reset function of the pressing amount is valid (ON) ("Yes" in step S100), that is, when the reset process is executed, a trigger condition for resetting the pressing amount (for executing the reset process) is set based on the input information (step S101). As the trigger condition, at least one of the time, room temperature, and number of processes is set, for example.

[0059] Here, when the trigger condition to be set is time, for example, a time condition such as every one hour or every two hours from the start of the automatic operation is set.

[0060] In addition, when the trigger condition is set to room temperature, for example, the following situations can be set as room temperature conditions: the room temperature at the start of automatic operation is used as a reference value, and the temperature changes by ±10% each time relative to the reference value, or the value when the absolute temperature rises or falls by a few degrees relative to the room temperature set as the reference value is set as the next reference value, and such settings are repeated.

[0061] Furthermore, when the trigger condition to be set is the number of processing, for example, a condition of processing the number of batches such as every 50 batches or every 100 batches from the start of the automatic operation is set.

[0062] In addition, as a trigger condition, for example, when a metal mold needs to be replaced between processes, it can also be set to detect that the same metal mold is placed due to the replacement. In the following, the room temperature is used as a trigger condition to be set, and the increase or decrease of the room temperature such as a predetermined temperature change relative to the room temperature at the start of the automatic operation is used as a trigger to reset the pressing amount.

[0063] After the trigger conditions are set in this way, the plate bending machine 10 and the automatic robot 20 are operated to perform trial processing (inspection operation) of the workpiece (step S102), and the processing state is inspected by measuring the bending angle and various dimensions (step S103), and the correction values ​​(processing correction values) related to the bending angle and various dimensions relative to the set processing conditions, and the pressing amount of the punch P are calculated. Then, the processing correction value is input and set based on the input information (step S104), and the temperature is measured by the room temperature sensor 38 to start the operation of product processing (step S105).

[0064] After the machining operation is started, first, it is determined whether the acquisition condition for setting the reference value of the press-in amount for the first time is satisfied (step S106). In the present embodiment, the acquisition condition refers to the workpiece being loaded by the automatic robot 20. Therefore, the control device 30 waits until the acquisition condition is satisfied (for example, until the workpiece is being loaded for the first time) ("No" in step S106), and if the acquisition condition is satisfied (loading is being done) ("Yes" in step S106), the value of the first reference position (reference value UT0) is acquired to set the metal mold condition (step S107).

[0065] If the reference value UT0 thus obtained is stored in the storage unit 32, for example, when the same metal mold is used to process products on different dates, the reference value UT0 can be used to set the metal mold conditions, so there is no need to obtain the reference value UT0 again. Then, the bending process of the workpiece is performed in an automatic operation under the processing conditions including the set metal mold conditions (step S108).

[0066] During the automatic operation of the bending process, it is determined whether the trigger condition is satisfied (whether the trigger condition is reached) based on the room temperature measured by the room temperature sensor 38, that is, whether the room temperature increase or decrease such as a predetermined temperature change occurs relative to the room temperature at the start of the automatic operation (step S109). If it is determined that the room temperature increase or decrease such as a predetermined temperature change does not occur relative to the room temperature at the start of the automatic operation and the trigger condition is not satisfied ("No" in step S109), the bending process of step S108 is continued.

[0067] On the other hand, when it is determined that the room temperature has increased or decreased by a predetermined temperature change relative to the room temperature at the start of the automatic operation, thereby satisfying the trigger condition (Yes in step S109), it is determined whether the reset condition for resetting the next pressing amount is satisfied (step S110). That is, as described above, the control device 30 waits until the reset condition is satisfied (No in step S110), and if the reset condition is satisfied (Yes in step S110), the value of the next reference position (measured value UT1) is obtained (step S111).

[0068] If the measured value UT1 obtained in this way is compared with the reference value UT0 obtained for the first time, Figure 2 As shown, the difference ΔUT of the reference position (the difference between the measured value UT1 and the reference value UT0) can be calculated. When the reference position is set to 0, for example, when observing the moving stroke of the punch P on the D axis, the direction toward the die D can be set as positive, and the direction away from the die D can be set as negative. Then, based on the difference ΔUT, the correction value (time change amount) ΔUT1 of the first time change relative to the reference position is calculated, for example, by adding the correction value ΔUT1 to the initial pressing amount to correct the pressing amount and set the metal mold condition (step S112). The correction of the pressing amount is not limited to adding the correction value ΔUT1.

[0069] After the metal mold conditions are set, it is determined whether the end condition of the automatic operation is reached, for example, whether the number of batches of workpieces (200 batches, etc.) set in advance is reached (step S113). If it is determined that the end condition is not reached ("No" in step S113), the automatic operation of the bending process of the workpiece (step S108) is continued based on the processing conditions including the metal mold conditions set in step S112. On the other hand, if it is determined that the end condition is reached ("Yes" in step S113), the automatic operation is terminated, and the processing of the bending process method of this embodiment is terminated.

[0070] If the automatic operation of the bending process is continued in the above-mentioned step S108, it is determined whether the trigger condition is satisfied during the automatic operation, for example, whether the room temperature increase or decrease that results in a predetermined temperature change relative to the room temperature after the last increase or decrease is determined (step S109). When the room temperature increase or decrease does not result in the predetermined temperature change, the bending process is continued as if the trigger condition is not satisfied ("No" in step S109). However, when there is a predetermined temperature change, the trigger condition is satisfied ("Yes" in step S109), and it is determined whether the reset condition for resetting is satisfied (step S110).

[0071] Here, as described above, the control device 30 waits until the reset condition is satisfied ("No" in step S110), and if the reset condition is satisfied ("Yes" in step S110), the value of the next reference position (measured value UT2) is obtained (step S111). Then, the measured value UT2 is compared with the initial reference value UT0, the difference ΔUT of the reference position (the difference between the measured value UT2 and the reference value UT0) is calculated, and the correction value (time change amount) ΔUT2 of the second time change relative to the reference position is calculated. Based on the correction value ΔUT2, for example, the correction value ΔUT2 is added to the initial pressing amount to correct the pressing amount, thereby setting the metal mold condition (step S112), executing the next judgment process (step S113), and repeating the subsequent processes.

[0072] In this way, the bending system 1 of the present embodiment can repeatedly obtain the value of the reference position multiple times (for example, n times) before reaching the end condition of the automatic operation, for example, at the stage where the reset condition is satisfied each time the trigger condition is satisfied. As a result, the reference value UT0 of the reference position obtained for the first time can be compared with the measured values ​​UT1 to UTn of the reference position obtained for the first to nth times, respectively, and the difference ΔUT accompanying the time change of the metal mold and the mechanical system can be calculated, and the correction values ​​ΔUT1 to ΔUTn of the time change for the first to nth times can be calculated. Then, using the correction values ​​ΔUT1 to ΔUTn, for example, the pressing amount is corrected by adding each correction value ΔUT1 to ΔUTn to the pressing amount, and then the automatic operation of the bending process can be continued, so that the change in the bending angle caused by the time change can be corrected without stopping the automatic operation, and the productivity and quality can be improved.

[0073] In the above step S100, when it is determined that the reset function of the pressing amount is not valid (invalid (OFF)) ("No" in step S100), the plate bending machine 10 and the automatic robot 20 are used to perform trial processing (step S114) without going through the above-mentioned trigger condition setting process (step S101), and the processing state is checked (step S115) to calculate the processing correction value. Then, the processing correction value is input and set based on the input information (step S116), the operation of product processing is started (step S117), and the bending processing of the workpiece is performed by automatic operation or manual operation (step S118).

[0074] Afterwards, determine whether the operation end conditions have been met (step S119). If the end conditions have not been met ("No" in step S119), continue the bending processing (step S118). If the end conditions have been met ("Yes" in step S119), end the bending operation and end the processing of the bending processing method of this embodiment.

[0075] In the above example, the reference value UT0 is compared with each of the measured values ​​UT1 to UTn to calculate the difference ΔUT, and then the correction values ​​ΔUT1 to ΔUTn of the pressing amount are calculated. However, for example, each time the value of the reference position is obtained, the measured value obtained is compared with the measured value (or reference value) obtained previously to calculate the difference ΔUT, and then the correction value is calculated. Even if the pressing amount is corrected using the correction values ​​ΔUT1 to ΔUTn calculated in this way, the automatic operation of the bending process as described above can be continued.

[0076] In the above example, the acquisition condition or the reset condition for resetting is that the automatic robot 20 is loading the workpiece, but these conditions may also refer to that the automatic robot 20 is unloading the workpiece. If the reference position is acquired or the push-in amount is reset during the loading / unloading of the workpiece, the operation of the automatic operation of the bending process will not be affected, so corrections can be made more reliably without stopping the automatic operation.

[0077] Furthermore, in the above example, the amount of press-in of the punch P used in product processing relative to the die D (i.e., the metal mold) is measured, but the present invention is not limited thereto, and the amount of press-in of a metal mold other than the metal mold actually used (e.g., the amount of press-in of the punch P not used for bending processing relative to the die D mounted on the upper mold holder 14 and the lower mold holder 15) may also be measured. In this way, the same correction value of the change over time as described above can also be calculated. That is, as long as the structure is such that the reference value UT0 and the measured value UTn as described above can be obtained from the same metal mold, the effect of the present embodiment can be achieved regardless of whether it is used for bending processing or not.

[0078] (Second Embodiment)

[0079] Figure 5 The following is an overview of a general metal die used in a plate bender of a bending system according to a second embodiment of the present invention. In the following description, the same reference numerals are used for the same or corresponding components as those of the first embodiment and its modified examples, and duplicate descriptions are omitted.

[0080] The difference between the bending processing method of the second embodiment and the bending processing method of the first embodiment in which the pressing amount is reset based on the reference position for each trigger condition is that, for each trigger condition, the origin position of the punch P is reset based on the D-axis position when the workpiece is clamped between the punch P and the die D, that is, when the workpiece is clamped in the metal die, and the pressing amount does not change.

[0081] That is, in this case, Figure 5 As shown, for example, when a workpiece of plate thickness T is placed on the die D, the origin position of the punch P is set to the position (reference position (0 mm)) when the tip of the punch P contacts the surface of the workpiece. The pressing amount ST represents the distance from the reference position to the bottom (lower end) of the V-groove of the die D.

[0082] Furthermore, in the bending method of the second embodiment, for example, the initial origin position of the punch P is acquired and set at the start of the automatic operation of the bending process, and then the origin position of the punch P is acquired and reset for each predetermined trigger condition. In this way, after the origin position of the punch P is set for each trigger condition, the automatic operation of the bending process is continued until the operation is completed. In this case, the origin position of the punch P is set without changing the pressing amount ST (including the pressing amount). In the bending method of the second embodiment, the change in the bending angle caused by the change over time can be corrected without stopping the operation, and the productivity and quality of the bent product can be improved.

[0083] Several embodiments of the present invention have been described above, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments and their variations are included in the scope or spirit of the invention, and are included in the invention and its equivalents recorded in the scope of the protection scope.

[0084] For example, in the first embodiment described above, a metal mold including a punch P and a die D is used to obtain a correction value based on a reference position to correct the pressing amount, but this is not limited to this. In addition to this, for example, the deformation amount caused by the influence of the load can be calculated based on the extension (change) amount of the support part 13 itself when there is no load measured by a strain gauge of the support part 13 provided on the bending machine 10, or the extension of the support part 13 itself when there is a predetermined load, and then the correction value is obtained by calculation based on the result.

[0085] Description of Reference Numerals

[0086] 1Bending processing system

[0087] 10 Plate bending machine

[0088] 11 Upper workbench

[0089] 12 Lower workbench

[0090] 13 Supporting part

[0091] 14 Upper die holder

[0092] 15 Lower die holder

[0093] 16 Driving mechanism

[0094] 17 Position detection sensor

[0095] 18 Bending load detection sensor

[0096] 20 Automatic robots

[0097] 30 control devices.

Claims

1. A bending method for bending a workpiece by a bending system, the bending system comprising: a bending machine having a metal mold, the metal mold having a punch and a die arranged to be relatively movable; a robot for positioning the workpiece relative to the metal mold; and a control device for controlling the bending machine and the robot to perform bending. It is characterized in that The bending method includes a resetting step in which, during the automatic operation of the bending process of the workpiece by the bending machine, the amount of penetration of the punch relative to the die or the origin position of the punch is reset for each predetermined trigger condition. After the trigger condition is satisfied, the control device executes the resetting process when it is determined that the resetting condition is satisfied. The reset condition is that the robot is loading the workpiece or unloading the workpiece, The trigger condition is at least one of room temperature, time, and number of processes.

2. The bending method according to claim 1, characterized in that: The bending method includes a validation / invalidation setting step of setting validation / invalidation of the resetting step performed by the control device.

3. The bending method according to claim 1, characterized in that: In the resetting step, the push-in amount is reset based on the mold origin position of the D-axis when a predetermined load is applied to the mold.

4. The bending method according to claim 3, characterized in that: The bending method includes a calculation step of calculating a temporal change in the position of the origin of the metal mold as a correction value of the pressing amount. The workpiece is bent by correcting the pressing amount using the calculated correction value in the automatic operation.

5. The bending method according to claim 1, characterized in that: In the reset step, the origin position of the punch is reset based on the D-axis position when the workpiece is clamped in the die.

6. A bending processing system, comprising: Bending machine with a metal die, wherein The metal mold has a punch and a die that are arranged to be relatively movable; A robot that positions the workpiece relative to the metal mold; A control device controls these bending machines and robots to perform bending, It is characterized in that In the automatic operation of the bending process of the workpiece by the bending machine, the control device resets the amount of the punch pressed relative to the die or the origin position of the punch for each predetermined trigger condition to perform the bending process, After the trigger condition is satisfied, the control device resets the pressing amount or the origin position of the punch when it is determined that the reset condition is satisfied. The reset condition is that the robot is loading the workpiece or unloading the workpiece, The trigger condition is at least one of room temperature, time, and number of processes.

7. The bending processing system according to claim 6, characterized in that: After the trigger condition is satisfied, when a reset condition is satisfied, the pressing amount or the origin position of the punch is reset.

8. The bending processing system according to claim 7, characterized in that: The reset condition is that the robot is loading the workpiece or unloading the workpiece.

9. The bending processing system according to claim 6, characterized in that: The control device sets validity / invalidity of resetting the pushing amount or the origin position of the punch.

10. The bending processing system according to claim 6, characterized in that: The pressing amount is reset based on the mold origin position of the D-axis when a predetermined load is applied to the mold.

11. The bending processing system according to claim 10, characterized in that: The control device calculates a temporal change amount of the origin position of the metal mold as a correction value of the push-in amount, and uses the calculated correction value to correct the push-in amount in the automatic operation to perform bending of the workpiece.

12. The bending processing system according to claim 6, characterized in that: The origin position of the punch is reset based on the D-axis position when the workpiece is clamped in the die.

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