Press work simulator

Abstract

Press work simulator (1) simulating and testing the operation of a press work system comprising a robot transferring a workpiece and a press machine processing the workpiece while the workpiece is held between dies, wherein the press work simulator (1) comprises: a robot program memory section (18) that stores a robot program that instructs the robot on how to move; a press program storage section (14) which stores a press program which instructs the press machine how to move; a profile data setting section (16) that causes the press program storage section (14) to store the press program according to profile data that records the position of the die at each time when the press machine is actually being moved; a model placement section (12) that places three-dimensional models of the workpiece, the robot and the press machine in a virtual space; a press movement processing section (15) that causes the three-dimensional model of the press machine to move according to the press program; and a robot motion processing section (19) that causes the three-dimensional model of the robot to move according to the robot program.

Description

[0001] The present invention relates to a press work simulation.

[0002] A known press working system includes a press machine that presses a workpiece while holding the workpiece between a pair of dies (movable and fixed dies); and a robot that feeds the workpiece to the press machine and removes the pressed workpiece. To improve the productivity of such a press working system, it is desirable to cause the press machine and the robot to move in a coordinated manner so that the robot feeds and removes the workpiece before the movable die in the press reaches the top dead center and after a certain gap is formed between the movable and fixed dies.

[0003] Regarding the technique for causing a press machine and a robot to move in a coordinated manner, for example, Patent Document 1 discloses a method for controlling a transfer robot for reciprocating machines such that, when the transfer robot transfers a workpiece between adjacent ones of the reciprocating machines arranged in line, the transfer section of the transfer robot does not interfere with the moving sections of the reciprocating machines, the method including: sequentially detecting positions of the moving sections during work by the reciprocating machines; and controlling the movement of the transfer section of the transfer robot based on a data table that stores relationships between positions of the moving sections and positions of the transfer section where it does not interfere with the moving sections.

[0004] See also patent documents 2-7. Patent document 1: JP 2005 - 216 112 A Patent document 2: DE 10 2019 001 970 A1 Patent document 3: DE 10 2016 012 779 A1 Patent document 4: DE 10 2016 008 867 A1 Patent document 5: DE 10 2013 008 062 B4 Patent document 6: DE 10 2012 021 374 B4 Patent document 7: JP 2009 - 022 996 A

[0005] In the technique of Patent Document 1, the data table stores relationships previously calculated between phase angles of a main gear in the press machine and coordinate positions of a crossbeam in the transfer robot where the crossbeam is at the limit of interference with the movable die. However, in such a press working system, any component other than the crossbeam and the transfer robot, or the workpiece held by the transfer robot, may interfere with the press machine. Therefore, there is a need to provide a technique that enables detailed verification of whether a robot program is suitable for a press working system including a press machine and a robot that work cooperatively.

[0006] This object is achieved by a press work simulator that simulates and tests the operation of a press work system including a robot that transfers a workpiece and a press machine that machines the workpiece while the workpiece is held between dies, the press work simulator including: a robot program storage section that stores a robot program that instructs the robot how to move; a press program storage section that stores a press program that instructs the press machine how to move; a profile data setting section that causes the press program storage section to store the press program according to profile data that records what position the die is at at each time when the press machine is actually moved;a model placement section that places three-dimensional models of the workpiece, the robot, and the press machine in a virtual space; a press motion processing section that causes the three-dimensional model of the press machine to move according to the press program; and a robot motion processing section that causes the three-dimensional model of the robot to move according to the robot program.

[0007] The press work simulator according to the present disclosure makes it possible to check in detail whether or not a robot program is suitable for a press work system including a press machine and a robot that work cooperatively. Fig. 1 is a schematic diagram showing a configuration of a press work simulator according to an embodiment of the present disclosure; Fig. 2 is a schematic diagram showing three-dimensional models formed by a model placing section in the press work simulator of Fig. 1 are placed; Fig. 3 is a graph showing an example of profile data obtained by a profile data setting section in the press work simulator of Fig. 1 are stored; Fig. 4 is a graph showing modified examples of a pressing program created by a pressing program modification section in the press work simulator of Fig. 1 are generated; Fig. 5 is a graph showing a modified example of a different pressing program than that in Fig. 4 shows which is created by the press program modification section in the press work simulator of Fig. 1 is generated; Fig. 6 is a schematic diagram showing examples of target positions according to a program stored by a robot program storage section in the press work simulator of Fig. 1 shows a saved robot program; and Fig. 7 is a flowchart showing a procedure of simulations by the press work simulator of Fig. 1 shows.

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram showing a configuration of a press work simulator 1 according to an embodiment of the present disclosure. The press work simulator 1 can be implemented by causing a computer, including, for example, a CPU, a memory, and other components, to execute an appropriate program.

[0009] The press work simulator 1 includes a virtual space information storage section 11, a model placement section 12, an interference detection section 13, a press program storage section 14, a press motion processing section 15, a profile data setting section 16, a press program modification section 17, a robot program storage section 18, a robot motion processing section 19, a template program setting section 20, and a robot program modification section 21. These components are distinguishable in terms of function and do not need to be clearly distinguishable based on a program structure.

[0010] The press work simulator 1 is a system that reproduces the operation of a press work system in a virtual space to simulate and test the operation, in other words, a system that simulates the operation of a press work system. The press work simulator can reproduce the operation of a press work system including: one or more press machines that process a workpiece while holding it between dies (movable and fixed dies); and a robot that holds and transfers a workpiece, feeds the workpiece to the press machine, and removes the workpiece from the press machine. This press work system can be a device that includes multiple press machines and a robot, and is configured to form a single workpiece step by step with the press machines and cause the robot to transfer the workpiece from an upstream to a downstream of the press machines.The press work simulator 1 may be a robot programming system that generates a robot program based on a result of the simulation, which enables a robot to move correctly in a press work system.

[0011] The virtual space information storage section 11 stores information about three-dimensional models placed in a virtual space. Specifically, the virtual space information storage section 11 stores information about three-dimensional models of a workpiece, a press machine, and a robot placed by the model placement section 12 described below.

[0012] As in Fig. As illustrated in Figure 2, the model placement section 12 places a three-dimensional model of a workpiece W, three-dimensional models of press machines P, and a three-dimensional model of a robot R in a virtual space. In other words, it causes the virtual space information storage section 11 to store information about the three-dimensional models. Therefore, the model placement section 12 stores information necessary for making three-dimensional models, including the geometry and axial arrangements of the workpiece W, the press machines P, and the robot R.

[0013] These three-dimensional models can be made by modeling only components that potentially interfere with each other in the actual press working system and are necessary for calculating the system's operation. As in Fig. As shown in Figure 2, a specific example of the three-dimensional model of the press machine P may include only dies (the movable die M1 and a fixed die M2) and tables (a movable table T1 and a fixed table T2) that support the dies M1 and M2. The three-dimensional model of the robot R may include the base B, a plurality of arms A1, A2, and A3, and a workpiece W holding hand H that are connected to each other.

[0014] The interference detection section 13 detects interference between the three-dimensional models of the workpiece W, the press machines P, and the robot R, in other words, determines whether the robot R can move properly. Specifically, the interference detection section 13 may be configured to determine coordinates in an overlap zone between two or more three-dimensional models and to determine three-dimensional models containing such coordinates.

[0015] The pressing program storage section 14 stores a pressing program that instructs the pressing machines P how to move.

[0016] The pressing motion processing section 15 causes the pressing machines P to move, specifically, causes components of the pressing machines P, the movable dies M1 and the movable tables T1, to move in the virtual space based on the pressing program stored in the pressing program storage section 14.

[0017] The profile data setting section 16 causes the pressing program storage section 14 to store a pressing program according to profile data that records the positions of the movable dies at each time when the actual pressing machines are actually moved. Specifically, the profile data setting section 16 stores profile data about the actual pressing machines and initializes the pressing program to be stored in the pressing program storage section 14 so that the pressing program instructs movement to the actual pressing machines in accordance with the profile data.

[0018] Fig. Figure 3 shows an example of profile data stored by the profile data setting section 16. In the example shown, the position of the movable die is represented by the angle through which the drive shaft rotates to drive the movable die, with the origin defined as the bottom dead center at which the movable die comes into contact with the fixed die during pressing.

[0019] The press program modifying section 17 modifies the press program stored in the press program storing section 14 according to any difference between the press machine movement conditions to be checked and the press machine movement conditions under which the profile data is recorded while the real press machines are moved.

[0020] If the press work cycle for the press machines to be tested is different from that during the recording of the profile data, the press program modification section 17, as in Fig. 4, modify the pressing program in the pressing program storage section 14 into a pressing program according to a profile which is formed by expanding or compressing the profile data in the time axis direction. Fig. 4 shows an example (solid line) in which the pressing cycle is reduced to one half by expanding the profile data (indicated by the broken line) by twice in the time axis direction, and an example (alternating long and short dash lines) in which the pressing cycle is increased by two times by compressing the profile data to one half in the time axis direction.

[0021] Alternatively, the press program modifying section 17 may be configured to modify, for example, the length of time during which the movable die is at the top dead center and the moving speed of the movable die, as shown in Fig. 5 shown. Fig. 5 illustrates an example in which the slope of the graph is shifted parallel to the right to delay the time at which the movable die moves from the bottom dead center to the top dead center, so that the graph is deformed to have a more linear slope, resulting in a shorter time period during which the movable die is at the top dead center. To make such a modification, the pressing program modification section 17 may be configured to display a profile data graph on a screen and allow the user to modify the graph using a mouse or other device, thereby modifying the pressing program.

[0022] The robot program storage section 18 stores a robot program that instructs the robot how to move. The robot program is written using a protocol similar to that used to program real robots. Specifically, the robot program can specify target positions (teaching points) at which reference points, such as a hand, should be located, and times at which the reference points should be located at the target positions.

[0023] According to the robot program stored in the robot program storage section 18, the robot motion processing section 19 moves the robot R, specifically each component B, A1, A2, A3 and H of the robot R and the workpiece W held by the robot R, in the virtual space.

[0024] The template program setting section 20 causes the robot program storage section 18 to store, as an initial version of the robot program, a template program that instructs the robot R how to fundamentally move. For this purpose, the template program setting section 20 stores a preset template program.

[0025] Fig. 6 schematically shows an example of the template program stored by the template program setting section 20. This template program is a robot program that causes the robot R to move to remove the workpiece W from a fixed die M2 in an upstream press machine P and place the workpiece W on a fixed die M2 in a downstream press machine P, with eight target positions Q1 to Q8 being provided at which reference points for a hand H are to be located.

[0026] According to the template program of Fig. 6, the hand H of the robot R uses a first target position Q1 as a starting point and moves to a second target position Q2 above the fixed die M2 in the upstream press machine P. At a third target position Q3, the hand H comes into contact with the workpiece W and holds the workpiece W, and then moves to a fourth target position Q4 to remove the workpiece W from the fixed die M2. The hand H then moves to a fifth target position Q5 to place the workpiece W above the fixed die M2 in a downstream press machine P. The hand H then moves to a sixth target position Q6 to place the workpiece W on the fixed die M2. After the hand H releases the workpiece at the sixth target position Q6, the hand H moves to a target position Q7 to move far away from the fixed die M2 and the workpiece W.The hand H then moves to a target position Q8 so that the robot R moves away from an area where the movable die M1 and the movable table T1 have to move.

[0027] The robot program modification section 21 modifies the robot program to prevent interference between the robot R and the press machines P detected by the interference detection section 13 when the press motion processing section 15 causes the press machines P to move according to the press program and the robot motion processing section 19 causes the robot R to move according to the robot program. The detection of the interference by the interference detection section 13 and the modification of the robot program by the robot program modification section 21 can be performed per unit of movement, which corresponds to the movement of the robot R and the press machine P performed during one movement from a target position Qn (n is a target position number) to a next target position Qn+1 according to the robot program.

[0028] If it is detected that the robot R or the workpiece W interferes with the press machine P while moving from the target position Pn to the target position Qn+1, the robot program modification section 21 modifies the robot program to change the coordinates of the target position Qn+1. If the coordinates of the target position Qn+1 are changed, the press work simulator 1 can cause the press movement processing section 15 and the robot movement processing section 19 to again move from the target position Qn to the changed target position Qn+1 and cause the interference detection section 13 to check whether or not interference occurs between the robot R or the workpiece W and the press machine P. In other words, the press work simulator 1 can modify the robot program at each target position so as to prevent interference between the robot R or the workpiece W and the press machine P.

[0029] When the interference detection section 13 detects interference, the robot program modification section 21 preferably shifts the target position Qn+1 in a direction in which the movable die M1 moves, more specifically, in a direction in which the movable die M1 approaches the fixed die M2. If the target position Qn+1 is shifted in the direction in which the movable die M1 moves, the direction in which the workpiece W is placed on the fixed die M2 and the direction in which the workpiece W is removed from the fixed die M2 can remain unchanged.

[0030] Typically, the direction in which the movable die M1 moves is the same as the direction in which the workpiece W is placed on the fixed die M2 and the direction in which the workpiece W is removed from the fixed die M2. Therefore, the robot program modification section 21 can shift the target position Qn+1 to the previous target position Qn or the next target position Qn+2. The shift amount of the target position Qn+1 can be a constant distance or a constant proportion of the distance between the target position Qn+1 and the previous target position Qn or the next target position Qn+2.

[0031] The shift amount of the target position Qn+1 for preventing interference between the robot R or the workpiece W and the press machine P should be determined within a range where the workpiece W does not interfere with the fixed die M2. Therefore, the shift amount may have a lower limit set to the distance between the shifted target position Qn+1 and the previous target position Qn or the next target position Qn+2. If such a lower limit is not sufficient for the shift of the target position Qn+1 to prevent interference between the robot R or the workpiece W and the press machine P, the previous target position Qn or the next target position Qn+2, whose relationship with the target position Qn is not in the direction of movement of the die, may be shifted in a direction in which the movable die M1 departs from the fixed die M2.This makes it possible to prevent the hand H from overshooting the movable die M1 during passage through the target position Qn, while preventing the interference between the robot R or the workpiece W and the press machine P.

[0032] In a specific example, if interference occurs during the movement from the first target position Q1 to the second target position Q2 according to the template program of Fig. 6 is detected, the robot program modification section 21 can shift the second target position Q2 in a direction toward the fixed die M2, that is, the third target position Q3. This makes it possible to prevent interference during the movement from the first target position Q1 to the second target position Q2.

[0033] If an interference occurs during the movement from the third target position Q3 to the fourth target position Q4 according to the template program of Fig. 6 is detected, the robot program modifying section 21 may shift the fourth target position Q4 in a direction toward the fixed die M2, that is, to the third target position Q3. Similarly, if interference is detected during movement from the fourth target position Q4 to the fifth target position Q5, the robot program modifying section 21 may shift the fifth target position Q5 to the sixth target position Q6, and if interference is detected during movement from the sixth target position Q6 to the seventh target position Q7, the robot program modifying section 21 may shift the seventh target position Q7 to the sixth target position Q6.

[0034] The robot program modification section 21 can further adjust the movement speed or acceleration of the robot R in the robot program. When the movement speed or acceleration of the robot R is increased, the time required for the robot R to move can be shortened. This allows the robot R to transfer the workpiece during a time period when the distance between the movable die M1 and the fixed die M2 is relatively large in the press machine P, so that interference between the robot R or the workpiece W and the press machine P can be prevented under various conditions.

[0035] Next, Fig.7 shows a procedure in which the press work simulator 1 modifies a robot program. The modification of the robot program includes placing three-dimensional models (step S1); setting profile data (step S2); modifying a press program (step S3); writing a template program (step S4); moving three-dimensional models (step S5); checking whether interference occurs (step S6); modifying a robot program (step S7); and determining whether to terminate the program (step S8).

[0036] The step S1 of placing three-dimensional models may include causing the model placing section 12 to place three-dimensional models of the robot R, the pressing machines P, and the workpiece W in a virtual space virtually generated by the virtual space information storage section 11.

[0037] The step S2 of setting profile data may include causing the profile data setting section 16 to instruct the pressing program storage section 14 to store a pressing program based on profile data.

[0038] The step S3 of modifying the pressing program may include modifying the pressing program stored in the pressing program storage section 14 based on the requirements for the pressing work to be checked.

[0039] The step S4 of writing a template program may include causing the template program setting section 20 to write a template program and store it, as an initial version of a robot program, in the robot program storage section 18.

[0040] The three-dimensional model moving step S5 may include causing the pressing motion processing section 15 to move a three-dimensional model of the pressing machine P based on the pressing program stored in the pressing program storage section 14, and causing the robot motion processing section 19 to move three-dimensional models of the robot R and the workpiece W based on the robot program stored in the robot program storage section 18.

[0041] The step S6 of checking whether interference occurs may include causing the interference detection section 13 to check whether or not interference occurs between the three-dimensional model of the press machine P and the three-dimensional model of the robot R or the three-dimensional model of the workpiece W. If the interference detection section 13 detects interference, the process proceeds to step S7, and if the interference detection section 13 does not detect interference, the process proceeds to step S8.

[0042] The step S7 of modifying the robot program may include causing the robot program modification section 21 to modify the robot program stored in the robot program storage section 18 so as to prevent interference between the three-dimensional model of the press machine P and the three-dimensional model of the robot R or the three-dimensional model of the workpiece W. If the robot program is modified in step S7, the process returns to step S5, in which the three-dimensional models are moved according to the robot program.

[0043] Step S8 of checking whether the program should be terminated may include checking whether the pressing program and the robot program are executed to completion. If the pressing program and the robot program are executed to completion, the process is terminated. If at least one part of the pressing program and the robot program remains unexecuted, the process returns to step S15, where the three-dimensional models are moved according to the remaining part of the program.

[0044] The press work simulator 1 includes the profile data setting section 16, which causes the press program storage section 14 to store a press program according to the profile data recording the position of the die M1 or M2 at each time when the real press machine P is actually moved. Therefore, the three-dimensional model of the press machine P can be moved to approximate the movement of the real press machine P. Therefore, the press work simulator 1 can accurately check in detail whether the robot program is suitable or not.

[0045] In addition, the press work simulator 1 including the interference detection section 13 and the robot program modification section 21 can function as a robot programming system for automatically generating an appropriate robot program.

[0046] Furthermore, the press work simulator 1 includes the template program setting section 20, which causes the robot program storage section 18 to store, as an initial version of the robot program, a template program instructing the robot R how to fundamentally move, making it possible to easily and reliably generate an appropriate robot program.

[0047] While embodiments of the press work simulator according to the present disclosure have been described, it should be understood that the embodiments are not intended to limit the press work simulator according to the present disclosure. It should be understood that the advantageous effects shown in the above embodiments are merely examples of the most preferred effects produced by the press work simulator according to the present disclosure and are not intended to limit the advantageous effects of the press work simulator according to the present disclosure.

[0048] The press work simulator according to the present disclosure may have any configuration for the robot program and may have any configuration for detecting interference. The press work simulator according to the present disclosure may be configured to display the movement of three-dimensional models on a screen, allow the user to observe interference on the screen, and allow the user to determine how the robot program should be modified to prevent interference.

[0049] The press work simulator according to the present disclosure can place any number of three-dimensional models of press machines and robots in virtual space. For example, the press work simulator according to the present disclosure can be configured to move, in a virtual space, a three-dimensional model of a robot that feeds a workpiece to and removes the workpiece from a single press machine. In the press work simulator according to the present disclosure, all press machines and robots placed in the virtual space can move in a coordinated manner along a single time axis. EXPLANATION OF REFERENCE SYMBOLS 1 press work simulator 11 Virtual Space Information Storage Section 12 Model placement section 13 Interference detection section 14 Press program storage section 15 Press movement processing section 16 Profile data setting section 17 Press program modification section 18 Robot program memory section 19 Robot motion processing section 20 Template program setting section 21 Robot program modification section

Claims

[1] Press work simulator (1) which simulates and tests the operation of a press work system comprising a robot which transfers a workpiece and a press machine which machines the workpiece while the workpiece is held between dies, the press work simulator (1) comprising: a robot program storage section (18) that stores a robot program that instructs the robot how to move; a pressing program storage section (14) that stores a pressing program that instructs the pressing machine how to move; a profile data setting section (16) that causes the pressing program storage section (14) to store the pressing program according to profile data recording at which position the die is at each time when the pressing machine is actually moved; a model placing section (12) that places three-dimensional models of the workpiece, the robot and the press machine in a virtual space; a pressing movement processing section (15) which causes the three-dimensional model of the pressing machine to move according to the pressing program; and a robot motion processing section (19) that causes the three-dimensional model of the robot to move according to the robot program. [2] A press work simulator (1) according to claim 1, further comprising a press program modifying section (17) that modifies the press program according to a difference between press machine movement conditions to be checked and press machine movement conditions under which the profile data are recorded. [3] Press work simulator (1) according to claim 1 or 2, further comprising: an interference detection section (13) which detects interference between the three-dimensional models of the workpiece, the robot and the press machine; and a robot program modification section (21) which modifies the robot program to prevent interference, which is detected by the interference detection section (13).

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