Control system, control method, control program, and conveyance device

Abstract

Provided are a control system, a control method, a control program, and a conveyance device that can reduce the likelihood of machine tool and conveyance device failure while continuing a machining schedule for a plurality of machine tools within a possible range. This control system comprises a plurality of machine tools and a conveyance device that loads and unloads workpieces to and from the plurality of machine tools. The conveyance device performs loading and unloading of workpieces to and from the plurality of machine tools by the conveyance device in accordance with a machining schedule. The conveyance device detects an abnormality that has occurred in any one of the plurality of machine tools (S11). The conveyance device determines the open / closed state of a shutter of the one machine tool in which the abnormality has been detected (S17, S27). When the shutter is in the open state, the conveyance device stops the drive process for the plurality of machine tools (S35). When it is determined that the shutter is in the closed state, the conveyance device stops the drive process for the one machine tool and continues the drive process for another machine tool (S19, S29).

Description

Control System, Control Method, Control Program, and Transfer Device

[0001] The present invention relates to a control system, a control method, a control program, and a transfer device that control a plurality of machine tools and a transfer device that transfers workpieces in and out of the plurality of machine tools.

[0002] A transfer device that transfers workpieces in and out of a plurality of machine tools is known. In the machine tool line described in Patent Document 1, when a failure occurs in one of the plurality of machine tools, the process that the failed machine tool is in charge of is executed by another machine tool.

[0003] Japanese Patent No. 6377722

[0004] It is desirable that the processing schedules of a plurality of machine tools be continued as much as possible even when the processing in one machine tool is interrupted. For this reason, it is also desirable that the transfer device that transfers workpieces in and out of the plurality of machine tools be driven so that the processing is continued in other machine tools excluding the one machine tool in which the processing has been interrupted. On the other hand, depending on the type of abnormality that causes the interruption of processing, it may be desirable to stop the driving of the transfer device to stop all the processing of the plurality of machine tools.

[0005] For example, the transfer of workpieces by the transfer device may be performed by opening a shutter provided at the transfer in / out port of the machine tool. Here, an abnormality detected in the state where the shutter is open may be an abnormality caused by the transfer device during the transfer of the workpiece. When the processing of one machine tool is interrupted due to such an abnormality and the transfer device is driven so that the processing is continued in other machine tools, there is a problem that the machine tool and the transfer device may fail.

[0006] An object of the present invention is to provide a control system, a control method, a control program, and a transfer device that can reduce the possibility of failure of the machine tool and the transfer device while continuing the processing schedules of a plurality of machine tools as much as possible.

[0007] A control system according to a first aspect of the present invention is a control system that controls a plurality of machine tools that perform processing on workpieces brought in through an entrance / exit with a shutter for opening and closing an entrance / exit for loading and unloading workpieces, and a transport device for loading and unloading workpieces to and from the plurality of machine tools, and is characterized by executing a drive process for loading and unloading the workpieces to and from the plurality of machine tools by the transport device according to a predetermined processing schedule, a detection process for detecting an abnormality that has occurred in any of the plurality of machine tools, a first determination process for determining the open / closed state of the shutter in the machine tool in which the abnormality was detected by the detection process, a first control process for stopping the drive process to the plurality of machine tools if the first determination process determines that the shutter is in an open state, and a second control process for stopping the drive process to the one machine tool and continuing the drive process to the other machine tools if the first determination process determines that the shutter is in a closed state.

[0008] The control system stops the drive process for multiple machine tools if the shutter of one machine tool where an abnormality has been detected is open. This reduces the possibility of failure of multiple machine tools and conveying equipment. On the other hand, if the shutter of one machine tool where an abnormality has been detected is closed, the control system continues the drive process for the other machine tools. This allows the control system to continue the machining schedule as much as possible.

[0009] In the present invention, the detection process may detect a machining abnormality that occurred during the machining of the workpiece in any of the plurality of machine tools as the abnormality. In this case, if a machining abnormality occurs in any of the plurality of machine tools, the control system can control the plurality of machine tools according to the state of the shutter.

[0010] In the present invention, the detection process may detect a reset stop that stops the machining of the workpiece by one machine tool as the abnormality. In this case, if a reset stop occurs in multiple machine tools, the control system can drive the multiple machine tools according to the state of the shutters.

[0011] In the present invention, a second determination process may be performed to determine whether an operation to emergency stop the conveying device or one machine tool has been performed, and a third control process may be performed to stop the drive process for the multiple machine tools if the second determination process determines that the operation has been performed, regardless of the determination result of the first determination process. If an operation to emergency stop the conveying device or one machine tool is performed, it is highly likely that it will be difficult to continue the machining schedule with the multiple machine tools. Therefore, the control system stops the drive process for the multiple machine tools in such a case. This allows the control system to quickly stop the machining schedule.

[0012] A control method according to a second aspect of the present invention is a control method for controlling a plurality of machine tools that perform processing on workpieces brought in through an entrance / exit with a shutter for opening and closing an entrance / exit for loading and unloading workpieces, and a conveying device for loading and unloading workpieces to the plurality of machine tools, characterized in that it comprises: a drive step for loading and unloading the workpieces to the plurality of machine tools by the conveying device according to a predetermined processing schedule; a detection step for detecting an abnormality occurring in any of the plurality of machine tools; a first determination step for determining the open / closed state of the shutter in the machine tool in which the abnormality was detected by the detection step; a first control step for stopping the drive step for the plurality of machine tools if it is determined in the first determination step that the shutter is in an open state; and a second control step for stopping the drive step for the one machine tool and continuing the drive step for the other machine tools if it is determined in the first determination step that the shutter is in a closed state. According to the second aspect, the same effects as the first aspect can be achieved.

[0013] A control program according to a third aspect of the present invention causes a computer that controls a plurality of machine tools equipped with shutters for opening and closing an entrance / exit for loading and unloading workpieces, and which perform processing on the workpieces loaded through the entrance / exit, and a transport device for loading and unloading the workpieces to and from the plurality of machine tools, to execute a drive process for loading and unloading the workpieces to and from the plurality of machine tools by the transport device, according to a predetermined processing schedule, a detection process for detecting an abnormality occurring in any of the plurality of machine tools, a first determination process for determining the open / closed state of the shutter in the machine tool in which the abnormality was detected by the detection process, a first control process for stopping the drive process for the plurality of machine tools if the first determination process determines that the shutter is in an open state, and a second control process for stopping the drive process for the one machine tool and continuing the drive process for the other machine tools if the first determination process determines that the shutter is in a closed state. According to the third aspect, the same effects as the first aspect can be achieved.

[0014] A fourth aspect of the present invention is a conveying device that includes a shutter for opening and closing an entrance / exit for loading and unloading workpieces, and is a conveying device that loads and unloads workpieces to a plurality of machine tools that process the workpieces loaded through the entrance / exit, and is characterized by performing the following: a drive process for loading and unloading the workpieces to the plurality of machine tools according to a predetermined processing schedule; a detection process for detecting an abnormality occurring in any of the plurality of machine tools; a first determination process for determining the open / closed state of the shutter in the machine tool in which the abnormality was detected by the detection process; a first control process for stopping the drive process to the plurality of machine tools if the first determination process determines that the shutter is in an open state; and a second control process for stopping the drive process to the one machine tool and continuing the drive process to the other machine tools if the first determination process determines that the shutter is in a closed state. The fourth aspect can achieve the same effects as the first aspect.

[0015] This is a perspective view showing the control system 1. This is a perspective view showing the conveying device 1C. This is a block diagram showing the electrical configuration of the machine tools 1A, 1B and the conveying device 1C. This is a diagram showing the drive process. This is a flowchart of the monitoring process.

[0016] A control system 1 according to one embodiment of the present invention will be described. The referenced drawings are used to illustrate the technical features that the present invention may adopt. The configurations, controls, etc., shown in the drawings are not intended to be the sole limiting factors, but are merely illustrative examples. In the following description, the left / right, front / back, and up / down directions indicated by arrows in the drawings will be used. The left / right direction, up / down direction, and front / back direction are the X-axis direction, Z-axis direction, and Y-axis direction of the machine tools 1A and 1B, respectively.

[0017] <Overview of Control System 1> As shown in Figure 1, the control system 1 includes machine tools 1A and 1B, and a transport device 1C. Machine tools 1A and 1B perform various machining operations on the workpiece. These operations include drilling using drills and taps, and side machining using end mills and milling cutters. The operation in which machine tools 1A and 1B perform various machining operations on the workpiece is called a "machining operation". The transport device 1C loads and unloads workpieces to and from machine tools 1A and 1B.

[0018] Machine tool 1A is located to the left of conveying device 1C. Machine tool 1B is located to the right of conveying device 1C. Machine tools 1A, 1B, and conveying device 1C are arranged in a left-to-right direction.

[0019] The machine tool 1A has a main body 20 and a housing 30.

[0020] The main body 20 comprises a base 21, a column 22, a Z-axis movement mechanism, a spindle head 23, a spindle 24, a table device 25, a tool changer 26, and a control box 27. The base 21 is a roughly rectangular metal base. The column 22 is fixed to the upper rear of the base 21. The Z-axis movement mechanism is positioned in front of the column 22. The Z-axis movement mechanism moves the spindle head 23 in the Z-axis direction in response to the drive of the Z-axis motor.

[0021] The spindle 24 is located inside the spindle head 23. The spindle 24 has a mounting hole at its lower end. The spindle 24 rotates in response to the drive of the spindle motor, with a tool holder mounted in the mounting hole. The tool holder holds the tool 29.

[0022] The table device 25 includes a Y-axis movement mechanism, a Y-axis table 25A, a table 25B, an X-axis movement mechanism, and the like. The Y-axis movement mechanism is positioned on the upper surface of the base 21. The Y-axis movement mechanism moves the Y-axis table 25A in the Y-axis direction in response to the drive of the Y-axis motor.

[0023] The X-axis movement mechanism is positioned on the upper surface of the Y-axis table 25A. The X-axis movement mechanism moves the table 25B in the X-axis direction in response to the drive of the X-axis motor. Therefore, the table 25B can move in both the X-axis and Y-axis directions on the base 21 by the X-axis movement mechanism and the Y-axis movement mechanism.

[0024] Three pallet clamps 250 are fixed to the table 25B. The pallet clamps 250 secure the pallet P shown in Figure 2 onto the table 25B. With the pallet P fixed onto the table 25B, the three pallet clamps 250 are inserted into the three holes on the bottom surface of the pallet P.

[0025] The tool changer 26 is located in front of the spindle head 23 and includes a tool magazine 26A. The tool magazine 26A has a plurality of grip arms 260 arranged in a circle on its outer circumference. The grip arms 260 grip the tool holder. The tool changer 26 has a magazine motor at its top. The magazine motor rotates the tool magazine 26A.

[0026] The control box 27 is fixed to the rear side of the column 22 and houses the numerical control device 10 shown in Figure 3. The numerical control device 10 controls the Z-axis motor, spindle motor, X-axis motor, Y-axis motor, magazine motor, and the opening / closing motor described later. The numerical control device 10 performs various machining operations on the workpiece by moving the workpiece, which is attached to the pallet P held on the table 25B, relative to the tool 29 attached to the spindle 24.

[0027] The housing 30 prevents chips generated during machining by the machine tool 1A and the scattering of cleaning fluid from the machine tool 1A. The housing 30 has a cover 31 and a shutter 32.

[0028] The cover 31 has a box shape and surrounds the main body 20. An entrance / exit 310 is formed in the wall 31N of the cover 31 that is close to the conveying device 1C. Wall 31N is the right wall of the cover 31.

[0029] The shutter 32 is installed in the wall 31N. The shutter 32 moves vertically by an opening / closing motor. By moving vertically, the shutter 32 can open and close the loading / unloading entrance 310.

[0030] The state in which the shutter 32 opens the loading / unloading entrance 310 is called the "open state". The state in which the shutter 32 closes the loading / unloading entrance 310 is called the "closed state".

[0031] The configuration of machine tool 1B is the same as that of machine tool 1A. Of the housing 30 of machine tool 1B, the wall 31N adjacent to the conveying device 1C is the left wall of cover 31.

[0032] As shown in Figure 2, the transport device 1C has a robot arm 40 and a housing 50.

[0033] The robot arm 40 is a known articulated industrial robot. The robot arm 40 includes a base 41, a plurality of rotary joints 42, a plurality of links 43, a ball joint 44, and an end effector 45. The plurality of rotary joints 42 and the plurality of links 43 are referred to as the "arm section 4A".

[0034] The arm section 4A rotates around the base 41. Multiple links 43 extending from the base 41 are connected by multiple rotary joints 42. As each of the multiple rotary joints 42 rotates, the multiple links 43 can move freely. An end effector 45 is connected to the tip of the arm section 4A via a ball joint 44. The end effector 45 is capable of attaching and detaching a pallet P.

[0035] The housing 50 has a cover 51 and a support base 52.

[0036] The cover 51 has a box shape and surrounds the robot arm 40. An entrance 56L is formed in the left wall 51L of the cover 51. The entrance 56L is located to the right of the entrance 310 of the machine tool 1A. An entrance 56R is formed in the right wall 51R of the cover 51. The entrance 56R is located to the left of the entrance 310 of the machine tool 1B.

[0037] An operation panel 57 is positioned on the front of the front wall 51F of the cover 51. The operation panel 57 includes a display 57A and an operation unit 57B. Various screens are displayed on the display 57A. Various inputs, instructions, settings, etc., are input to the operation unit 57B.

[0038] The support base 52 includes a front support base 52F and a rear support base 52B. The front support base 52F is fixed to the rear surface of the front wall 51F of the cover 51. The rear support base 52B is fixed to the front surface of the rear wall 51B of the cover 51.

[0039] The front support base 52F and the rear support base 52B each consist of five plates arranged vertically. Multiple pallets P are placed on the top surface of the five plates of the front support base 52F and the rear support base 52B. The front support base 52F and the rear support base 52B function as shelves for the pallets P. The pallets P, while placed on the front support base 52F and the rear support base 52B, are housed inside the cover 51.

[0040] <Electrical Configuration> Referring to Figure 3, the electrical configurations of the machine tools 1A and 1B, and the conveying device 1C will be described.

[0041] The transport device 1C includes a control unit 60, a display 57A, an operating unit 57B, communication interfaces 63 and 64, and a motor assembly 40A. The motor assembly 40A includes various motors that drive the base 41, rotary joint 42, ball joint 44, and end effector 45 of the robot arm 40. Hereinafter, the interface will be referred to as "I / F".

[0042] The control unit 60, display 57A, operation unit 57B, communication I / F 63, 64, and motor assembly 40A are electrically connected.

[0043] The control unit 60 includes a CPU 61 and a memory 62. The CPU 61 globally controls the transfer device 1C. The memory 62 stores a drive program, a processing schedule, a monitoring program, set values, various parameters, etc. for the CPU 61 to execute processing. The drive program is a program for executing the drive process shown in FIG. 4. The monitoring program is a program for executing the monitoring process shown in FIG. 5.

[0044] The communication I / F 63 is a connection device for communicating with the machine tool 1A. The communication I / F 64 is a connection device for communicating with the machine tool 1B.

[0045] Each numerical control device 10 of the machine tools 1A and 1B includes a control unit 70, a display 73, an operation unit 74, a communication I / F 75, and a motor assembly 76. The motor assembly 76 includes an X-axis motor, a Y-axis motor, a Z-axis motor, a spindle motor, a magazine motor, an opening / closing motor, etc.

[0046] The control unit 70, the display 73, the operation unit 74, the communication I / F 75, and the motor assembly 76 are electrically connected.

[0047] The control unit 70 includes a CPU 71 and a memory 72. The CPU 71 globally controls the numerical control device 10. The memory 72 stores a processing program, an NC program, set values, various parameters, etc. for the CPU 71 to execute processing. The NC program describes the machining operations of the machine tools 1A and 1B by a plurality of control commands in a predetermined programming language.

[0048] The display 73 is a device for displaying various screens. Various inputs, instructions, settings, etc. are input to the operation unit 74. The communication I / F 75 is a connection device for communicating with the transfer device 1C.

[0049] <Drive Process> Referring to FIG. 4, the drive process will be described. The drive process is executed by the CPU 61 of the transfer device 1C. The machining process is started when the CPU 61 reads and executes the drive program.

[0050] In the drive process, the transport device 1C controls the machine tools 1A and 1B. Then, according to the machining schedule, the workpieces are loaded and unloaded, and the machining operations are performed. Let's take the example of a machining schedule in which the machining operations are performed in the order of machine tools 1A, 1B, 1A, ...

[0051] The CPU 61 outputs an instruction signal to the machine tool 1A to open the shutter 32. The CPU 71 of the machine tool 1A detects the instruction signal and opens the shutter 32.

[0052] The CPU 61 controls the robot arm 40. The robot arm 40 holds the pallet P with the workpiece attached in the end effector 45 and removes the pallet P from the support base 52. The robot arm 40 passes its arm portion 4A through the entrance / exit 56L of the transport device 1C and the entrance / exit 310 of the machine tool 1A. As a result, the pallet P is brought into the housing 30 of the machine tool 1A. The brought-in pallet P is fixed to the table 25B of the machine tool 1A.

[0053] After the pallet P is fixed to the table 25B, the robot arm 40 houses the arm section 4A, the ball joint 44, and the end effector 45 into the housing 50. With this, the loading of the workpiece into the machine tool 1A is completed (T11).

[0054] The CPU 61 outputs an instruction signal to the machine tool 1A to close the shutter 32. The CPU 71 of the machine tool 1A detects the instruction signal and closes the shutter 32.

[0055] The CPU 61 outputs an instruction signal to the machine tool 1A to select the NC program with identification code "001" (T13). The CPU 71 of the machine tool 1A detects the instruction signal. The CPU 71 of the machine tool 1A reads the NC program with identification code "001" from the memory 72.

[0056] The CPU 61 outputs an instruction signal to the machine tool 1A to mount the specified tool 29 onto the spindle 24 (T15). The CPU 71 of the machine tool 1A detects the instruction signal. The CPU 71 of the machine tool 1A drives the tool changer 26 to mount the specified tool 29 onto the spindle 24 (U11). After mounting the tool 29, the CPU 71 of the machine tool 1A outputs a notification signal to the transport device 1C to indicate that mounting is complete. The CPU 61 detects the notification signal (T17).

[0057] The CPU 61 outputs a start signal to the machine tool 1A to initiate the machining operation (T19). The CPU 71 of the machine tool 1A detects the start signal. The CPU 71 of the machine tool 1A executes the machining operation based on the NC program read from the memory 72 (U13). As a result, machining is performed on the workpiece attached to the pallet P.

[0058] The CPU 71 of the machine tool 1A outputs a notification signal to the transport device 1C to indicate the completion of the machining operation after the machining operation is finished. The CPU 61 detects the notification signal (T21).

[0059] The CPU 61 outputs an instruction signal to the machine tool 1A to open the shutter 32. The CPU 71 of the machine tool 1A detects the instruction signal and opens the shutter 32.

[0060] The CPU 61 controls the robot arm 40. The robot arm 40 passes its arm portion 4A through the loading / unloading entrance 56L of the transport device 1C and the loading / unloading entrance 310 of the machine tool 1A. The robot arm 40 holds the pallet P, which is fixed to the table 25B of the machine tool 1A, with the end effector 45 and detaches it from the table 25B. The robot arm 40 houses its arm portion 4A, ball joint 44, and end effector 45 in the housing 50. As a result, the pallet P is unloaded from inside the housing 30 of the machine tool 1A.

[0061] The robot arm 40 places the pallet P, on which the processed workpiece is attached, onto the support base 52. With this, the removal of the workpiece from the machine tool 1A is completed (T23).

[0062] The CPU 61 outputs an instruction signal to the machine tool 1A to close the shutter 32. The CPU 71 of the machine tool 1A detects the instruction signal and closes the shutter 32.

[0063] The processes T31 to T43 in which the CPU 61 causes the machine tool 1B to execute a machining operation correspond to the processes T11 to T23 in which the CPU 61 causes the machine tool 1A to execute a machining operation. The CPU 71 of the machine tool 1B mounts the specified tool 29 onto the spindle 24 (U31). The CPU 71 of the machine tool 1B executes a machining operation based on the NC program with identification code "002" (U33).

[0064] The processes T51 to T63 in which the CPU 61 causes the machine tool 1A to execute a machining operation correspond to the processes T11 to T23 in which the CPU 61 causes the machine tool 1A to execute a machining operation. The CPU 71 of the machine tool 1A mounts the specified tool 29 onto the spindle 24 (U51). The CPU 71 of the machine tool 1A executes a machining operation based on the NC program with identification code "003" (U53).

[0065] The operation of the control system 1 based on the machining schedule is not limited to the above. For example, the timing of the machining operations of machine tools 1A and 1B may overlap. In this case, for example, after the loading of the workpiece into machine tool 1A is completed at T11, and before the unloading of the workpiece is completed at T27, the loading of the workpiece into machine tool 1A may occur at T31.

[0066] <Monitoring Process> Referring to Figure 5, the monitoring process performed by the CPU 61 of the transport device 1C will be described. The monitoring process is performed in parallel with the drive process while the drive process is being executed. The monitoring process is started when the CPU 61 reads and executes the monitoring program.

[0067] The CPU 61 outputs a request signal to machine tools 1A and 1B, respectively, to request status. The CPU 71 in machine tools 1A and 1B detects the request signal. The CPU 71 in machine tools 1A and 1B then determines the following status: (1) Whether or not an abnormality has occurred (2) The open / closed state of the shutter 32

[0068] Furthermore, (1) whether or not an abnormality has occurred includes whether or not the following abnormalities have occurred: (a) an abnormality that occurs during machining operation and is caused by machining operation; (b) a reset stop abnormality in which an operation to stop the machining operation and reset is performed on the operation unit 74; (c) an emergency stop abnormality in which an operation to emergency stop the machine tools 1A and 1B is performed on the operation unit 74 of the machine tools 1A and 1B.

[0069] Machining abnormalities include motor abnormalities occurring in the motor assemblies 76 of machine tools 1A and 1B. Machining abnormalities also include clamp abnormalities occurring in the mechanism that secures the pallet P to the three pallet clamps 250 of table 25B.

[0070] The CPUs 71 of machine tools 1A and 1B each output a notification signal to the transport device 1C indicating the specified state.

[0071] The CPU 61 detects notification signals output from machine tools 1A and 1B. Based on the detected notification signals, the CPU 61 detects the respective states of machine tools 1A and 1B (S11).

[0072] Based on the state of the machine tool 1A detected in S11, the CPU 61 determines whether an abnormality has occurred in the machine tool 1A (S13). If the CPU 61 determines that no abnormality has occurred (S13: NO), it proceeds to S23.

[0073] If the CPU 61 determines that an abnormality has occurred in the machine tool 1A (S13: YES), it proceeds to S15. The CPU 61 determines that the type of abnormality is (a) an emergency stop abnormality (S15). If the CPU 61 determines that it is an emergency stop abnormality (S15: YES), it proceeds to S35. The CPU 61 stops the drive processing for machine tools 1A and 1B (S35). The CPU 61 terminates the monitoring process.

[0074] When the drive process for machine tools 1A and 1B is completed, the output of various signals from the transport device 1C to machine tools 1A and 1B is stopped. Also, the loading and unloading of workpieces between machine tools 1A and 1B and the transport device 1C is stopped. As a result, the drive of machine tools 1A and 1B is stopped. For example, if machining operations are currently being performed on machine tools 1A and 1B, the drive of machine tools 1A and 1B will be stopped after the completion of the machining operations.

[0075] If the CPU 61 determines that the type of abnormality is not an emergency stop abnormality (S15: NO), it proceeds to S17. In this case, (b) a machining abnormality or (c) a reset stop abnormality has occurred in the machine tool 1A.

[0076] Based on the state of the machine tool 1A detected in S11, the CPU 61 determines whether the shutter 32 of the machine tool 1A is closed (S17). If the CPU 61 determines that the shutter 32 of the machine tool 1A is open (S17: NO), the process proceeds to S35. The CPU 61 stops the drive processing for the machine tools 1A and 1B (S35). The CPU 61 terminates the monitoring process.

[0077] If the CPU 61 determines that the shutter 32 of the machine tool 1A is closed (S17: YES), it proceeds to S19. The CPU 61 stops the drive process for the machine tool 1A (S19). On the other hand, the CPU 61 continues the drive process for the machine tool 1B (S19). The CPU 61 proceeds to S23.

[0078] When the drive process for machine tool 1A is completed, the drive of machine tool 1A is stopped. On the other hand, the drive process for machine tool 1B is not terminated. Therefore, the output of various signals from the transport device 1C to machine tool 1B, and the loading and unloading of workpieces between machine tool 1B and the transport device 1C are not stopped. As a result, machining operations based on the machining schedule continue in machine tool 1B.

[0079] In steps S23 to S29, the same processing as in steps S11 to S17 is performed. In steps S21 to S27, machine tool 1A, which was the subject of the decision in steps S13 to S19, is changed to machine tool 1B.

[0080] If the CPU 61 determines that an emergency stop abnormality has occurred in the machine tool 1B (S25: YES), it proceeds to S35. If the CPU 61 determines that the shutter 32 of the machine tool 1B is open (S27: NO), it proceeds to S35. The CPU 61 stops the drive processing for the machine tools 1A and 1B (S35).

[0081] If the CPU 61 determines that the shutter 32 of the machine tool 1B is closed (S27: YES), it stops the drive processing for the machine tool 1B (S29). On the other hand, the CPU 61 continues the drive processing for the machine tool 1A (S29). The CPU 61 then proceeds to S31.

[0082] The CPU 61 determines whether an emergency stop operation for the transport device 1C has been performed on the operation unit 57B of the transport device 1C (S31). If the CPU 61 determines that an emergency stop operation has been performed (S31: YES), it proceeds to S35. The CPU 61 stops the drive processing for the machine tools 1A and 1B (S35). The CPU 61 terminates the monitoring process.

[0083] If the CPU 61 determines that no emergency stop operation has been performed (S31: NO), it proceeds to S33. The CPU 61 determines whether the drive processes for both machine tools 1A and 1B have stopped (S33). If the CPU 61 determines that the drive process for at least one of the machine tools 1A and 1B has not stopped (S33: NO), it returns to S11.

[0084] If the CPU 61 determines that the drive processes for both machine tools 1A and 1B have stopped (S33: YES), it terminates the monitoring process.

[0085] <Operation and Effects of This Embodiment> Any abnormalities that occur in machine tools 1A and 1B when the shutter 32 is open may be caused by the transport device 1C during workpiece loading and unloading. For example, if the transport device 1C fails to position the pallet P and cannot fix the pallet P to the pallet clamp 250 of the table 25B, a clamping abnormality may occur in machine tools 1A and 1B. Also, if the end effector 45 of the transport device 1C comes into contact with the table 25B, a motor abnormality may occur in machine tools 1A and 1B. Furthermore, if the arm portion 4A of the transport device 1C is inserted into the machine tools 1A and 1B even though machining is in progress, the user may operate the operation unit 74 to cause a reset stop abnormality.

[0086] If an abnormality is detected in the open machine tool 1A, and the transport device 1C is driven to allow the machining operation to continue in the machine tool 1B, there is a possibility that the machine tools 1A, 1B, and the transport device 1C may malfunction. This malfunction may occur, for example, when the arm portion 4A comes into contact with the main body 20 or housing 30 of the machine tools 1A and 1B due to a malfunction of the transport device 1C.

[0087] In response to this, if the shutter 32 of the machine tool 1A, in which an abnormality has been detected, is open (S17: NO), the control system 1 stops the drive processing for both machine tools 1A and 1B (S35). The same applies if an abnormality is detected in machine tool 1B (S27: NO → S35).

[0088] This allows the control system 1 to reduce the possibility of failure of the machine tools 1A and 1B and the conveying device 1C.

[0089] On the other hand, in the control system 1, if the shutter 32 of the machine tool 1A where an abnormality has been detected is in the closed state (S17: YES), the drive process of the machine tool 1B is continued (S19). This allows the control system 1 to continue the machining schedule as much as possible.

[0090] The abnormalities detected by machine tools 1A and 1B include machining abnormalities that occur during machining operations. When a machining abnormality occurs in machine tools 1A and 1B, the control system 1 can control machine tools 1A and 1B according to the state of the shutter 32.

[0091] The abnormalities detected in machine tools 1A and 1B include reset stop abnormalities that stop the machining operation and reset the machine. When a reset stop abnormality occurs in machine tools 1A and 1B, the control system 1 can control machine tools 1A and 1B according to the state of the shutter 32.

[0092] If an operation is performed to emergency stop a machine tool 1A, 1B, or a conveying device 1C, it is highly likely that it will be difficult to continue the machining schedule. In contrast, in the control system 1, if an operation is performed to emergency stop a conveying device 1C, or machine tools 1A, 1B, the drive processing for machine tools 1A, 1B is stopped regardless of the state of the shutter 32 (S35). As a result, the control system 1 can quickly stop the machining schedule when it is necessary to emergency stop a conveying device 1C, or machine tools 1A, 1B.

[0093] <Modifications> The present invention is not limited to the above embodiments, and various modifications are possible. In the control system 1, the number of machine tools is not limited to two, but may be three or more. In the case of three or more machine tools, the drive processing for all machine tools is stopped in S35 of the monitoring process.

[0094] The mechanism by which the transport device 1C loads and unloads workpieces into and out of machine tools 1A and 1B is not limited to the robot arm 40, but may be any other mechanism.

[0095] The drive and monitoring processes do not necessarily have to be performed by the CPU 61 of the transport device 1C. For example, the control system 1 may include a control device that controls the machine tools 1A and 1B to perform machining operations according to a machining schedule. The control device may be, for example, a PC.

[0096] The abnormalities identified by machine tools 1A and 1B are not limited to (a) machining abnormalities, (b) reset stop abnormalities, or (c) emergency stop abnormalities. For example, machine tools 1A and 1B may identify tool change abnormalities that occur when changing tools, opening / closing abnormalities that occur when opening and closing the shutter 32, or communication error abnormalities that result in failure of communication with the conveying device 1C.

[0097] If an emergency stop malfunction occurs in machine tools 1A or 1B, the transport device 1C may output an emergency stop signal to machine tools 1A or 1B. If machine tools 1A or 1B are in the middle of a machining operation when they detect the emergency stop signal, they may stop the machining operation.

[0098] In the monitoring process, the process in S31 does not need to be executed.

[0099] <Other> T11 to T63 are examples of the "driving process" and "driving steps" of the present invention. The process in S11 is an example of the "detection process" and "detection steps" of the present invention. The processes in S13 and S23 are examples of the "first judgment process" and "first judgment steps" of the present invention. The process in S35 is an example of the "first control process" and "first control steps" of the present invention. The processes in S19 and S29 are examples of the "second control process" and "second control steps" of the present invention. The processes in S15, S25, and S33 are examples of the "second judgment process" of the present invention.

[0100] 1: Control system 1A, 1B: Machine tool 1C: Conveying device 32: Shutter 61: CPU 74: Operating unit 310: Entrance / exit

Claims

1. A control system for controlling a plurality of machine tools that perform processing on workpieces brought in through an entrance / exit with a shutter for opening and closing an entrance / exit for loading and unloading workpieces, and a transport device for loading and unloading workpieces to and from the plurality of machine tools, characterized in that it performs: a drive process for loading and unloading the workpieces to and from the plurality of machine tools by the transport device according to a predetermined processing schedule; a detection process for detecting an abnormality that has occurred in any of the plurality of machine tools; a first determination process for determining the open / closed state of the shutter in the machine tool in which the abnormality was detected by the detection process; a first control process for stopping the drive process to the plurality of machine tools if the first determination process determines that the shutter is in an open state; and a second control process for stopping the drive process to the one machine tool and continuing the drive process to the other machine tools if the first determination process determines that the shutter is in a closed state.

2. The control system according to claim 1, characterized in that the detection process detects a machining abnormality that occurred during the machining of the workpiece in any of the plurality of machine tools as the abnormality.

3. The control system according to claim 1, characterized in that the detection process detects a reset stop that stops the machining of the workpiece by the machine tool as the abnormality.

4. The control system according to claim 1, further comprising: a second determination process for determining whether an operation to emergency stop the transport device or the one machine tool has been performed; and a third control process for stopping the drive process for the plurality of machine tools, regardless of the determination result of the first determination process, if the second determination process determines that the operation has been performed.

5. A control method for controlling a plurality of machine tools that perform processing on workpieces brought in through an entrance / exit with a shutter for opening and closing an entrance / exit for loading and unloading workpieces, and a conveying device for loading and unloading the workpieces to the plurality of machine tools, comprising: a drive step for loading and unloading the workpieces to the plurality of machine tools by the conveying device according to a predetermined processing schedule; a detection step for detecting an abnormality occurring in any of the plurality of machine tools; a first determination step for determining the open / closed state of the shutter in the machine tool in which the abnormality was detected by the detection step; a first control step for stopping the drive step for the plurality of machine tools if it is determined in the first determination step that the shutter is in an open state; and a second control step for stopping the drive step for the one machine tool and continuing the drive step for the other machine tools if it is determined in the first determination step that the shutter is in a closed state.

6. A control program for a computer that controls a plurality of machine tools, each equipped with a shutter for opening and closing an entrance / exit for loading and unloading workpieces, and which perform processing on the workpieces loaded through the entrance / exit, and a transport device for loading and unloading the workpieces to and from the plurality of machine tools, to execute: a drive process for loading and unloading the workpieces to and from the plurality of machine tools by the transport device according to a predetermined processing schedule; a detection process for detecting an abnormality occurring in any of the plurality of machine tools; a first determination process for determining the open / closed state of the shutter in the machine tool in which the abnormality was detected by the detection process; a first control process for stopping the drive process for the plurality of machine tools if the first determination process determines that the shutter is in an open state; and a second control process for stopping the drive process for the one machine tool and continuing the drive process for the other machine tools if the first determination process determines that the shutter is in a closed state.

7. A conveying device that loads and unloads workpieces to a plurality of machine tools that process the workpieces loaded through the loading and unloading entrance, the conveying device comprising: a drive process that loads and unloads the workpieces to the plurality of machine tools according to a predetermined processing schedule; a detection process that detects an abnormality occurring in any of the plurality of machine tools; a first determination process that determines the open / closed state of the shutter in the machine tool in which the abnormality was detected by the detection process; a first control process that stops the drive process to the plurality of machine tools if the first determination process determines that the shutter is in an open state; and a second control process that stops the drive process to the one machine tool and continues the drive process to the other machine tools if the first determination process determines that the shutter is in a closed state.

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