Cycle time display device and cycle time display system

Abstract

To provide a cycle time display device and a cycle time display system, in which a graph of cycle time is displayed in order to be able to more appropriately determine the state of a machine tool.SOLUTION: A cycle time display device comprises a user interface and a processing unit. The processing unit includes: an acquisition processing for acquiring cycle time information about the cycle time of a machine tool for processing a workpiece; and a display processing for displaying a graph, which is arranged with a cycle time axis showing the cycle time and a date-and-time axis showing a date and time, on the user interface. In the display processing, on the basis of the cycle time information acquired by the acquisition processing, the cycle time when the processing of each of multiple workpieces is performed by the machine tool is displayed on the graph in association with the date and time when the processing of each of the multiple workpieces is performed by the machine tool, and in addition, change factors, which are the factors of the change of the cycle time, are also displayed on the graph.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a technique for displaying the cycle time of a machine tool. [Background technology]

[0002] Patent Document 1 listed below describes an operation status display device that displays the cycle time of a machine tool. The operation status display device in Patent Document 1 displays the machining time per workpiece as the cycle time. The operation status display device classifies and displays the cycle time for each cycle time width, which is a predetermined time width. The operation status display device then displays, in the form of a bar graph, the ratio of the number of workpieces for each cycle time width to the total number of workpieces machined in a unit period. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-174443 A (Figure 3) Summary of the Invention [Problem to be solved by the invention]

[0004] Cycle time varies due to various factors. For this reason, if cycle time information collected from machine tools is displayed on a single graph, the graph will also include cycle times that have fluctuated due to various factors. As a result, there is a risk that users looking at the graph will not be able to properly determine the state of the machine tool based on the cycle time.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a cycle time display device and a cycle time display system that display a cycle time graph that allows for more appropriate assessment of the state of a machine tool. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, this specification discloses a cycle time display device that includes a user interface and a processing unit, wherein the processing unit executes an acquisition process to acquire cycle time information related to the cycle time of a machine tool that processes a workpiece, and a display process to display on the user interface a graph having a cycle time axis indicating the cycle time and a date and time axis indicating date and time, and in the display process, based on the cycle time information acquired by the acquisition process, the cycle time when machining each of a plurality of workpieces is performed by the machine tool is displayed on the graph in correspondence with the date and time when machining each of the plurality of workpieces is performed by the machine tool, and change factors that are factors that cause the cycle time to change are displayed on the graph. The contents of the present disclosure are not limited to implementation as a cycle time display device, but are also extremely useful when implemented as a cycle time display system including a machine tool and a display device. [Effects of the Invention]

[0007] According to the cycle time display device and cycle time display system disclosed herein, cycle time information of a machine tool is acquired, and the cycle time is displayed on a graph with a cycle time axis and a date and time axis set based on the acquired cycle time information. Then, in the graph display process, the change factors that change the cycle time are displayed on the graph. This makes it possible to confirm the cycle time value by comparing it with the change factors. The acquired cycle times may include cycle times measured during equipment adjustment or cycle times measured when a malfunction has occurred. Such cycle time data that is not valid as reference data can be excluded and confirmed. Furthermore, if the cycle time can be shortened due to a change factor, the change factor can be confirmed. The state of the cycle time can be more appropriately determined based on the cycle time and the change factors. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram of a machine tool system according to an embodiment of the present invention. [Figure 2] A diagram showing the cycle time display screen displayed on a PC. [Figure 3] FIG. 10 is a diagram showing each change factor and the conditions for recording the change factor. [Figure 4] FIG. 10 is a diagram showing a position where a comment section for a program change is displayed. [Figure 5] FIG. 10 shows the graph display section displaying the comment section when all of the change factors (2) to (4) are checked. [Figure 6] FIG. 10 is a diagram showing a cycle time display screen when a bar graph is selected. DETAILED DESCRIPTION OF THE INVENTION

[0009] A machine tool system, which is one embodiment of the cycle time display system of the present disclosure, will be described in detail below with reference to the drawings. Fig. 1 is a block diagram of a machine tool system 10 of this embodiment. As shown in Fig. 1, the machine tool system 10 of this embodiment includes a machine tool 11 and a personal computer (hereinafter referred to as PC) 12. The machine tool system 10 is a system that collects information related to production and operation from the machine tool 11 to the PC 12, and displays graphs and diagnostic results on the PC 12.

[0010] The machine tool 11 is, for example, a turret-type lathe and includes a workpiece spindle unit 21, a turret unit 22, a robot 23, an entrance unit 24, an exit unit 25, an inspection unit 26, an operation panel 27, a control unit 28, and the like. The configuration of the machine tool 11 shown in FIG. 1 is merely an example. For example, the machine tool 11 may be a comb-tooth lathe. The machine tool 11 may also be a lathe equipped with multiple sets of workpiece spindle units 21 and turret units 22, or may be a so-called multi-tasking machine equipped with a tool spindle unit in addition to the turret unit 22. The machine tool of the present disclosure is not limited to a lathe, and machine tools of various configurations, such as a machining center, milling machine, drilling machine, hobbing machine, and grinding machine, may be used. The machine tool 11 does not necessarily have to include a workpiece transport unit such as the robot 23. The machine tool of the present disclosure may also be a variety of machine tools capable of acquiring a cycle time.

[0011] The workpiece spindle device 21 is equipped with a gripping mechanism (chuck jaws or collet chuck) for gripping a workpiece and is a device for gripping the workpiece and rotating it around the workpiece spindle. The turret device 22 is equipped with, for example, a turret (not shown) to which multiple cutting tools (such as cutting tools or rotary tools) can be attached, and a servo motor (not shown) for rotating the turret, and performs machining of the workpiece gripped by the workpiece spindle device 21 using the cutting tools attached to the turret.

[0012] The robot 23 is, for example, a gantry-type loader, and is equipped with a head for gripping the workpiece and a slide device for sliding the head in each direction. The robot 23 transports the workpiece between the workpiece spindle device 21, the entrance device 24, the exit device 25, the inspection device 26, etc. The robot 23 may also be a workpiece transport device of another configuration, such as an articulated robot.

[0013] The entrance device 24 is, for example, a device that transfers the workpiece to the robot 23 before machining, and can employ a workpiece stocker or a device that transfers the workpiece to a device in a previous process. The exit device 25 can employ a workpiece stocker that receives the machined workpiece from the robot 23 and stores the machined workpiece, or a device that transfers the workpiece to a device in a subsequent process. The inspection device 26 is, for example, a device that has a contactor and inspects the machining accuracy of the machined workpiece.

[0014] The operation panel 27 includes, for example, a touch panel 29 and an operation unit 31, and displays information related to the machine tool 11 and receives operation instructions. Various operation devices such as a selector switch, a button, a slide switch, and a rotary switch can be used as the operation unit 31. The operation panel 27 is an example of a user interface of the present disclosure. The user interface of the present disclosure is not limited to the configuration of the operation panel 27 described above. For example, the user interface of the present disclosure may include a display device that only performs display, such as an LCD or an organic EL panel, and the operation unit 31. The user interface may also be a portable device such as a teaching pendant.

[0015] Machine tool 11 is equipped with a control device 28 and a plurality of drive circuits 33 that connect each of the above-mentioned devices (workpiece spindle device 21, turret device 22, robot 23, entrance device 24, exit device 25, inspection device 26, and operation panel 27). Control device 28 is electrically connected to each device via drive circuits 33 and is able to control each device. Drive circuits 33 are, for example, motor driver circuits that drive the drive sources of each device and amplifier circuits that amplify each signal.

[0016] The control device 28 is a device that controls the machine tool 11 in an integrated manner and includes a numerical control device 35 and a PLC 36. The numerical control device 35 includes a CPU 38 and a storage device 39. The PLC 36 includes a CPU 41 and a storage device 43. The storage device 39 includes, for example, RAM, ROM, flash memory, and HDD. The configuration of the storage device 39 is not limited to the above configuration and may include an SSD, an external storage device such as a USB memory, or a storage medium such as a DVD-RAM, or a combination of these. The storage device 39 stores multiple NC programs 45 that numerically control the operation of the workpiece spindle device 21 and other components. The numerical control device 35 executes the NC program 45 using the CPU 38 and controls the operation of each device via the drive circuit 33 in accordance with the numerical commands written in the NC program 45.

[0017] The PLC 36 is a programmable logic controller. The storage device 43 stores a ladder program 46 for constructing a ladder circuit that processes various signals. The PLC 36 executes the ladder program 46 on the CPU 41 and performs sequence processing based on the ladder program 46 to, for example, output signals to drive various elements such as lamps, relays, and solenoids provided in the machine tool 11, and input signals from elements such as limit switches and sensors. The PLC 36 is also connected to the numerical control device 35 via a communication bus 47, enabling communication with the numerical control device 35. The PLC 36 executes the ladder program 46 and relays (input / output) signals between the numerical control device 35 and external I / O (sensors, etc.) provided in the machine tool 11.

[0018] Control device 28 also stores log data 49 of machine tool 11 in storage device 39. Similarly, PLC 36 stores log data 51 of machine tool 11 in storage device 43. Control device 28 stores, for example, the cycle time, the change history of NC program 45, and information about NC program 45 used to machine the workpiece in log data 49. PLC 36 also stores, for example, information about actuator operation times, override information, retry operation information, and results of signal processing by ladder program 46, as log data 51, which will be described later. This information is registered in log DB 61, which will be described later, as cycle time information 62 used to display the cycle time, which will be described later.

[0019] Furthermore, machine tool 11 is equipped with an external IF (abbreviation of interface) 53. Furthermore, PC 12 is equipped with an external IF 54. External IFs 53, 54 are, for example, LAN interfaces, and are connected via a LAN cable 55. PC 12 can acquire log data 49, 51 via LAN cable 55. Note that communication connecting machine tool 11 and PC 12 is not limited to LAN, and other communication such as USB communication may also be used. Furthermore, communication connecting machine tool 11 and PC 12 is not limited to wired communication, and may be wireless communication.

[0020] Furthermore, the contents of the log data 49, 51 described above are merely examples. Furthermore, PC 12 may obtain the information contained in the log data 49, 51 described above, i.e., the information to be displayed on PC 12, by calculating information obtained from machine tool 11. Therefore, machine tool 11 does not necessarily have to store all of the information described above as log data 49, 51. Specifically, PC 12 may obtain the operation time of each device involved in machining the workpiece, and calculate the cycle time from the obtained information on the operation time, without obtaining the cycle time value from machine tool 11. In this case, control device 28 may not store the cycle time as log data 49.

[0021] In addition to the external IF 54, the PC 12 also includes a CPU 56, a storage device 57, and a user IF 58. As with the storage devices 39 and 43, the storage device 57 can be a RAM, a ROM, a flash memory, a HDD, or the like. The user IF 58 is, for example, an input device such as a keyboard or a mouse, and a display device such as a monitor. Note that the user IF 58 is not limited to the above-mentioned devices, and may be another device such as a touch panel.

[0022] The storage device 57 stores a display control program 59 in addition to an operating system (not shown). The storage device 57 also stores a log DB (short for database) 61. By executing the display control program 59 on the CPU 56, the PC 12 utilizes services provided by the operating system to acquire log data 49, 51, register the acquired log data 49, 51 in the log DB 61, and perform display based on the log DB 61. In the following description, the PC 12 that executes the display control program 59 may be referred to simply by its device name. For example, the statement "PC 12 acquires log data 49, 51" means "PC 12 acquires log data 49, 51 by executing the display control program 59 on the CPU 56."

[0023] PC 12 acquires log data 49, 51 from machine tool 11, for example, at predetermined intervals or when display control program 59 starts to execute, and registers the acquired log data 49, 51 in log DB 61. Note that PC 12 may acquire log data 49, 51 in response to a user instruction or an operating condition of machine tool 11 (such as completion of machining). Log DB 61 stores identification information, such as a workpiece number that identifies the type of workpiece, a program name that identifies NC program 45, a machine name that identifies machine tool 11, and a process name that identifies the machining process, in association with each piece of information in log data 49, 51. Specifically, change information for NC program 45, which will be described later, actuator operation time, override information, retry operation information, and the like are associated with the identification information and stored as cycle time information 62.

[0024] (Cycle time display processing) Next, the cycle time display process will be described. FIG. 2 shows a cycle time display screen 63 displayed on the PC 12. The PC 12 displays the cycle time display screen 63 on the monitor of the user IF 58 based on a predetermined operation input to the user IF 58. For example, when the PC 12 receives an instruction via the user IF 58 to start processing for displaying the cycle time of the display control program 59, the PC 12 displays a screen (not shown) for selecting the machine tool 11 and machining process for which the cycle time is to be displayed. The PC 12 may display, as this selection screen, a screen displaying a model selection section 65 and a process selection section 66, which will be described later. The PC 12 displays the cycle time of the machine tool 11, etc. selected on the selection screen on the cycle time display screen 63. Note that the PC 12 may not accept a selection (on the selection screen, etc.) before displaying the cycle time display screen 63, but may accept a selection of a machine name, etc., on the model selection section 65, etc. after displaying the cycle time display screen 63. Alternatively, the PC 12 may accept a selection on the selection screen but not after displaying the cycle time display screen 63.

[0025] 2, the PC 12 displays a model selection section 65, a process selection section 66, a graph display section 67, a display explanation section 68, a change factor selection section 69, a time axis change section 71, and a graph switching section 72 on a cycle time display screen 63. Note that the screen configuration shown in FIG. 2 is an example.

[0026] The model selection unit 65 is an operation unit that accepts the selection of identification information (such as machine name) of the machine tool 11 for which the cycle time is to be displayed. The process selection unit 66 is an operation unit that accepts the selection of identification information (such as process name) of the machining process for which the cycle time is to be displayed. The PC 12, for example, displays the machine names of all machine tools 11 stored in the log DB 61, that is, the machine names of all machine tools 11 that have been acquired and registered in the log DB 61, in the model selection unit 65 so that they can be selected using a pull-down menu. In the example shown in FIG. 2, the model selection unit 65 has selected the machine name "MT1."

[0027] Note that, as shown in FIG. 1 , if there is a one-to-one relationship between the machine tool 11 and the PC 12, it is not necessary to accept the selection of the machine tool 11 to be displayed. Furthermore, if multiple machine tools 11 are connected to the PC 12 via a LAN and log data 49, 51 is acquired from the multiple machine tools 11, the selection of the machine tool 11 may be accepted. Furthermore, when processing the log data 49, 51 of such multiple machine tools 11, a DB server for storing a log DB 61 may be installed separately from the PC 12, and the log data 49, 51 of the machine tools 11 connected to the LAN may be collected in the DB server. The PC 12 may then acquire necessary data from this DB server and display it. In this case, the PC 12 does not need to store the log DB 61 in its own device. Therefore, the acquisition process of the present disclosure may be a process executed on a device other than the machine tool 11. Furthermore, the log DB 61 (cycle time information 62) may be stored in the machine tool 11.

[0028] Furthermore, the PC 12 displays, for example, all process names associated with the machine name of the machine tool 11 selected in the model selection unit 65, from among all the machining processes stored in the log DB 61, in a selectable manner in a pull-down menu in the process selection unit 66. That is, the PC 12 displays, in a selectable manner, the machining processes executed by the machine tool 11 selected in the model selection unit 65 in the process selection unit 66. In the example shown in FIG. 2, the process name "OP1" is selected in the process selection unit 66.

[0029] When a machine tool 11 or a machining process is selected on a selection screen before displaying the cycle time display screen 63 or on the model selection section 65 and process selection section 66 displayed on the cycle time display screen 63, the PC 12 acquires cycle time information 62 for the selected model name and process name from the log DB 61 (an example of the acquisition process of the present disclosure), and displays the cycle time included in the acquired cycle time information 62 on the graph display section 67. The log DB 61 stores, for example, the cycle time for each machining process when the machine tool 11 machines a workpiece as cycle time information 62. The PC 12 displays the cycle times acquired from the log DB 61 on the graph display section 67 as a scatter plot.

[0030] As shown in FIG. 2, the PC 12 sets the cycle time axis as the vertical axis and the date and time axis as the horizontal axis, and plots points indicating cycle times according to cycle time values ​​and dates and times (an example of a display process according to the present disclosure). The cycle time axis indicates that the cycle time increases as one moves higher. The PC 12 displays cycle times in a scatter plot for the selected model name and process name, corresponding to the dates and times when the machine tool 11 performed machining on each of multiple workpieces. Therefore, in the example shown in FIG. 2, the PC 12 displays, in order along the date and time axis, the cycle times for each workpiece machined by the machine tool 11 with the selected model name and in the machining process with the selected process name. While the cycle time displayed in this embodiment is the cycle time for each machining process, it may also be the cycle time for each workpiece (all machining processes for one workpiece), each workpiece spindle unit 21, each machine tool 11, or another unit. In this case, the PC 12 may accept a selection of the workpiece type, workpiece spindle unit 21, etc. for which the cycle time is to be displayed.

[0031] The display explanation section 68 is a display section that shows an explanation of the content displayed on the graph display section 67. In the illustrated example, the display explanation section 68 shows that the cycle time is displayed as a circle and the target cycle time is displayed as a solid line. The target cycle time is the cycle time that is targeted for machining a workpiece. The target cycle time is set, for example, by operating the touch panel 29 of the machine tool 11, and the user sets a target value for each type of workpiece and each machining process. The PC 12 acquires and displays information about this target cycle time from the log data 49 of the control device 28. Alternatively, the PC 12 may receive the target cycle time itself by operating the user IF 58.

[0032] As shown by the solid line in Figure 2, the PC 12 displays the target cycle time along the vertical cycle time axis. The target cycle time is set to an appropriate value depending on the workpiece number (workpiece type) and the details of the machining process. Therefore, the target cycle time graph changes depending on the workpiece number and machining process to be machined, forming a rectangular waveform parallel to the horizontal date and time axis. Changes in this graph indicate changes to the workpiece number or machining process. For example, in the example shown in Figure 2, the machine name "MT1" and process name "OP1" are selected, and the machining process is fixed. Therefore, in the example shown in Figure 2, the target cycle time for each workpiece number for the machine name "MT1" and process name "OP1" is displayed, indicating that the target cycle time changes depending on the change in workpiece number. This makes it possible to understand the relationship between the displayed cycle time and the target cycle time. In a scatter plot, if each plotted point is below the target cycle time line, it can be indicated that the machining process meets the target cycle time. Conversely, if each plotted point is above (exceeds) the target cycle time line, it indicates that the machining process is not meeting the target cycle time and that some kind of delay factor is occurring in the machining process. Also, by checking the change point in the target cycle time, it is possible to know that the workpiece number has changed. Note that if the target cycle time is the same even though the workpiece number is different, the target cycle time graph will be parallel to the date and time axis. In this case, the color of the graph may be changed before and after the change to indicate when the workpiece number was changed.

[0033] As described above, the log DB 61 stores the cycle time for each machining process executed by the machine tool 11. The PC 12 accepts the selection of a machining process via the user IF 58 and acquires the cycle time of the selected machining process from the log DB 61. The PC 12 displays a graph based on the acquired cycle time. This allows, for example, when it is desired to improve the cycle time of a bottleneck machining process with the longest cycle time among all the machining processes for a workpiece, the cycle time can be confirmed by narrowing down the display to one machining process for one model. It is also possible to display cycle times by narrowing down to consecutive machining processes for the same workpiece spindle, for example.

[0034] The PC 12 also displays, in a graph, the factors that cause the cycle time to change. There are other factors that cause the cycle time to change besides the above-mentioned changes in workpiece number and changes in the machining process content. In this embodiment, the PC 12 executes a log display process for the factors of change: (1) program changes, (2) actuator operation time, (3) overrides, (4) retry operations, and (5) others.

[0035] (1) Program change is a change factor that changes the NC program 45 used for machining. When the workpiece number is changed, the NC program 45 to be used is also changed, and the machining details (feed, path, tool to be used, tool switching, etc.), loader operation, etc. change. Therefore, the cycle time changes when the NC program 45 is changed.

[0036] 3 shows an example of each change factor and the conditions for recording the change factor. For example, the PC 12 acquires and checks the log data 49 to determine whether the edit date and time of the NC program 45 has been changed. If the edit date and time has been changed, the PC 12 determines that a program change has occurred and stores this in the log DB 61 in association with the date and time of the change. Information related to each of these change factors is stored in the log DB 61 as cycle time information 62. Note that the determination of the occurrence of a program change or other change factor may be performed by another device, such as the machine tool 11.

[0037] The PC 12 displays check boxes in the change factor selection section 69 for switching between displaying and hiding the above five change factors. In FIG. 2, the program change check box is checked, setting it to display. Therefore, the PC 12 displays comment sections 73 and 74, which are speech bubbles displaying the words "program change," for example, in the graph display section 67. This allows the user to confirm the cycle time in relation to the change factors that change the cycle time. Note that the PC 12 may not always display the comment sections 73 and 74, but may display the comment sections 73 and 74 only when the mouse pointer approaches the display position.

[0038] (2) The actuator operating time is a variable that affects the operating time of the actuator used as the drive source for the gripping mechanism of the workpiece spindle device 21. This actuator is driven by a fluid pressure cylinder, such as an air cylinder or a hydraulic cylinder. If the pressure supplied to the fluid pressure cylinder or the pressure of the supply source decreases for some reason, the operating time increases. Here, the cause may be a fluctuation in the voltage of the power source connected to the supply source or aging deterioration of each device. As a result, the time required for the workpiece chucking or unchucking operation by the workpiece spindle device 21 increases, resulting in an increase in cycle time. For example, the PLC 36 monitors the pressure of such fluid pressure cylinders. As shown in FIG. 3, for example, if the pressure value of the fluid pressure cylinder falls below a predetermined threshold based on the log data 51 of the PLC 36, the PC 12 determines that a change in the actuator operating time has occurred and stores the date and time of the occurrence in the log DB 61. The PC 12 may determine the change based on a threshold value for the pressure inside the cylinder or the pressure of the fluid supply source. The PC 12 may also monitor the actuator operating time based on the log data 51. For example, the PC 12 may determine whether the operation time of the actuator is equal to or greater than a predetermined threshold time, and if it is equal to or greater than the threshold time, store the date and time of occurrence in the log DB 61.

[0039] (3) An override is a variable that changes the cutting feed rate, spindle rotation speed, and cutting tool movement speed when not cutting, specified by the numerical control device 35 or the NC program 45, by a percentage of the command value of 100%. Specifically, this includes a rapid traverse override and a feed override. For example, a user may set the override to 100% when performing normal machining, but may set the override to less than 100% for test cutting immediately after changing the NC program 45 to observe the movement of the cutting tool. Alternatively, when checking the NC program 45 in a state where the cutting tool does not contact the workpiece, such as air cutting, the user may set the override to greater than 100%. The user can change the override by rotating the rotary switch on the operation unit 31. Setting the override to less than 100% increases the time required for feed and other operations, thereby lengthening the cycle time. Conversely, setting the override to greater than 100% shortens the cycle time. For example, if a user starts machining without remembering that they have made the change, cutting will be performed at a high feed rate, thereby shortening the cycle time. As shown in FIG. 3, the PC 12 monitors the log data 51 in the same manner as the actuator operation time, and if it detects that the override is set to a value other than 100% during automatic operation, it determines that a change in the override has occurred and stores the date and time of the occurrence in the log DB 61.

[0040] (4) A retry operation is a change factor that causes a retry operation when the process of confirming whether a workpiece is properly seated on the workpiece spindle device 21 fails. Specifically, a retry operation is an operation that is performed again when the process of correcting the posture of a workpiece seated on the workpiece spindle device 21 using a pusher fails, or when the process of confirming the seating state of a workpiece seated on the workpiece spindle device 21 fails. Alternatively, a retry operation is a change factor that causes a retry operation when the process of inspecting a workpiece fails. Specifically, a retry operation is an operation that is performed again when the process of inspecting the machined shape, etc. of a workpiece held by the workpiece spindle device 21 or placed on the inspection device 26 using a contactor fails. The occurrence of a retry operation increases the cycle time compared to when the process is successful the first time. As shown in FIG. 3, the PC 12 monitors the log data 51, for example, in the same way as the actuator operation time. When a retry operation is detected, the PC 12 stores the date and time of the occurrence in the log DB 61.

[0041] (5) Others are change factors other than the above (1) to (4). Examples of other change factors include changes in parameters of the numerical control device 35. When parameters such as the maximum speed of each slide axis, acceleration / deceleration values, and time constants representing the time required to reach the target speed are changed, the cycle time changes as the speeds change. The PC 12 detects, for example, from the log data 49, the history of changes to the parameters of the numerical control device 35, and when a parameter affecting the cycle time is changed by a value equal to or greater than a predetermined threshold, it determines that a parameter change has occurred and stores the date and time of the change in the log DB 61.

[0042] For the change factors selected in the change factor selection unit 69, the PC 12 displays the change factors on a graph according to the timing at which the selected change factor affected the cycle time. Specifically, Fig. 4 shows (1) the relationship between the change date and time of a program change and the positions at which the comment sections 73, 74 are displayed. For a change factor such as the NC program 45, where the time at which the change occurred differs from the time at which the change affects the cycle time, the PC 12 does not display the comment sections 73, 74 at the position of the occurrence date and time, but displays the comment sections 73, 74 at the time at which the change affected the cycle time.

[0043] For example, as shown in FIG. 4, assume that an NC program 45 with program number 0002 (hereinafter referred to as the target program) was executed during a certain execution period, with the target cycle time shown in the center of the graph display section 67. In this case, if the target program is changed before April 14, when execution of the target program began, a comment section 73 corresponding to the change is displayed at the start position of the execution period (April 14), as shown in FIG. 2. That is, the comment section 73 is displayed at the timing when the target program is executed for the first time after the change and the change has affected the cycle time. The PC 12 determines the date and time of the change and the execution period of the NC program 45 from the log DB 61, and displays the comment section 73 so as to indicate, for example, the position on the graph of the target cycle time. Furthermore, if the target program is changed during the execution period, for example, on April 19, a comment section 74 corresponding to the change is displayed at the date and time when the change occurred (April 19), as shown in FIG. That is, if the target program is changed during execution, the effect of the change is immediately reflected, so the comment section 74 is displayed at the date and time position. Furthermore, if the target program is changed after the execution period, as shown in FIG. 4, a comment section (not shown) is displayed at the start position of the next execution period of the target program.

[0044] In this way, for change factors where the timing at which a change occurs differs from the timing at which the change affects the cycle time, by displaying the comment sections 73 and 74 at the timing at which the change affects the cycle time, more useful information can be provided to the user. The user can easily and accurately grasp the timing at which the change factor affected the cycle time. By checking the display positions of the comment sections 73 and 74, if there is a change in the cycle time before and after that, the user can grasp that the cycle time changed due to the occurrence of a change factor.

[0045] The PC 12 similarly displays other change factors (2) to (5) according to the timing at which they affect the cycle time. For (2) to (4), the cycle time is affected when the change factor occurs. For example, (2) actuator operation time affects the cycle time from the point at which a delay in operation time occurs. Therefore, for example, when "actuator operation time" is checked in the checkbox of the change factor selection section 69, the PC 12 displays the same information as in the comment section 73 on the date and time when the pressure value of the fluid pressure cylinder becomes equal to or lower than a predetermined threshold.

[0046] FIG. 5 shows the graph display section 67 displaying comment sections 75, 76, and 77 when all of the change factors (2) to (4) are checked. As shown in FIG. 5, the PC 12 displays a comment section 75 displaying, for example, the text "Air cylinder pressure has dropped below XX" at the position of the occurrence date and time. This allows the user to recognize that the cycle time is being lengthened due to a drop in air cylinder pressure. Appropriate measures can be taken, such as repairing the air cylinder or air supply source. Note that the PC 12 may also display a comment section at the position where the pressure value of the fluid pressure cylinder returns to normal after dropping below a predetermined threshold, for example.

[0047] Similarly, the PC 12 displays the (3) override comment section 76, for example, with the date and time when the override value was changed. As shown in the comment section 76 of FIG. 5, the PC 12 may display the words "Period during which the override was 80%" and parentheses indicating the period during which the override was set to 80%. This allows the user to recognize that the cycle time has changed due to the override change. It also allows the user to realize that they have forgotten to reset the override and are continuing machining.

[0048] Furthermore, the PC 12 (4) displays a comment section 77 for the retry operation, for example, at the date and time when the retry operation occurred. Retry operations may occur discretely. For this reason, the PC 12 displays the comment section 77, as shown in FIG. 5, indicating a dot at the cycle time when the retry operation occurred. This allows the user to recognize that the cycle time has been delayed due to the retry operation (failure of the seating operation), for example, when an extremely slow cycle time occurs. The user can check the state of the machine tool 11 when the retry operation occurred and find the cause.

[0049] Furthermore, for (5) other change factors, for example, changes in parameters of the numerical control device 35, similar to (1) program changes, a comment section can be displayed according to the timing at which the change affected the cycle time. For example, by displaying the comment section at the timing at which the NC program 45 with the changed parameters is executed after the parameters have been changed, the timing at which the parameter change affected the cycle time can be displayed more accurately.

[0050] The display modes of the comment sections 73 to 77 described above are merely examples. For example, the PC 12 may change the color of the corresponding dot in (4) displaying the retry operation to a color different from that of the other dots. Then, when the mouse pointer is placed on the dot whose color has been changed, the PC 12 may display the words "Retry operation occurred."

[0051] As described above, the cycle time information 62 of the log DB 61 stores information about the change factors (1) to (5). The PC 12 receives a selection of the type of change factor to be displayed in the graph display unit 67 from among the change factors via the change factor selection unit 69. The PC 12 displays the selected change factor in a graph according to the timing at which the change factor affected the cycle time. By selecting the change factor to be displayed, the relationship between each change factor and the cycle time can be confirmed separately or collectively. In this case, by displaying the selected change factor in a graph according to the timing at which the change factor affected the cycle time, the user can appropriately determine the influence of various change factors on the cycle time. The PC 12 may be configured to display at least one of the change factors (1) to (5) described above, or may be configured to display other change factors.

[0052] The time axis change unit 71 also has multiple buttons for changing the time span (scale) of the date and time axis of the graph display unit 67. In the example shown in FIG. 2, the time axis change unit 71 has three buttons: day, week, and month, with the week button selected. Therefore, the PC 12 sets a week time span on the time axis of the graph display unit 67 and displays the graph. Furthermore, when the PC 12 receives an operation to change the time span of the date and time axis via the time axis change unit 71, it changes the position where the above-mentioned change factors are displayed to match the changed date and time axis. Note that the time span shown in the time axis change unit 71 in FIG. 2 is an example, and buttons for time spans such as one hour may also be provided. Therefore, the date and time axis of the present application may only indicate time.

[0053] The graph switching section 72 is a button for changing the type of graph displayed in the graph display section 67. The PC 12 is capable of displaying, for example, a bar graph in addition to a scatter plot as the graph to be displayed. Note that the number of types of graph that can be displayed may be one, or graphs other than the above types, such as a bar graph or a line graph, may also be displayed.

[0054] Each time the graph switching unit 72 is operated, the PC 12 changes the type of graph displayed in the graph display unit 67 between a scatter plot and a bar graph. Fig. 6 shows the cycle time display screen 63 when a bar graph is selected by the graph switching unit 72. For example, when the weekly time span shown in Fig. 6 is selected by the time axis changing unit 71, the PC 12 displays the average value of the cycle time for each week as a bar graph. In addition, the PC 12 displays a comment section 73 regarding the factors of change, for example, at the bottom left of the bar graph that includes the target cycle time.

[0055] Specifically, for the (1) program change change factor, the comment section 73 is displayed so as to point to the bottom left of the bar graph that includes the start position of the execution period in which the effect of the change factor occurs or the cycle time during execution. Also, when multiple identical change factors are included in one bar graph, for example, when there are two (1) program change comment sections 73, 74 between April 12 and April 19 as shown in Figures 2 and 4, they may be displayed together or separately. Also, when multiple types of change factors are selected in the change factor selection section 69, each change factor may be displayed staggered.

[0056] Furthermore, with the scatter diagram shown in FIG. 2 displayed on the graph display unit 67, the PC 12 accepts, via the user IF 58, the selection of cycle times to be excluded from the multiple plotted cycle times. As described above, some cycle times have fluctuated due to variable factors, such as delays in actuator operation time and override changes. The user can confirm which dots of cycle times have fluctuated due to variable factors by operating the user IF 58 and the variable factor selection unit 69 and the time axis change unit 71. Therefore, the PC 12 accepts the user's selection of cycle times (dots) and excludes the selected cycle times when displaying the bar graph.

[0057] More specifically, the PC 12 accepts the selection of cycle times to be excluded from the dots in the scatter plot shown in Fig. 2 in response to mouse operations (click operations or operations to specify a range) of the user IF 58. The method of selecting cycle times to be excluded is not limited to mouse operations, and may also be operations of other user interfaces such as a keyboard. Furthermore, the PC 12 may change the color of the dots of the cycle times for which the setting to be excluded has been accepted, or may not display them.

[0058] When the PC 12 receives an operation to display a bar graph by operating the graph switching unit 72 after a cycle time to be excluded from the scatter plot has been selected, the PC 12 displays a bar graph of the remaining cycle times excluding the cycle times set to be excluded from the scatter plot. The PC 12 excludes the selected cycle times and displays, as a bar graph, the average cycle times included in each date and time scale indicated by the date and time axis (weekly in the case of Figure 6). This allows for the cycle times to be excluded from the bar graph if the cause of the irregular change, such as test cutting or parameter changes, is known and the average value of only the more effective (necessary) cycle times can be confirmed using the bar graph. Note that the PC 12 may be configured not to be able to perform the exclusion process described above.

[0059] Incidentally, the correspondence between the terms used in this embodiment and those described in the claims will be explained below. The machine tool system 10 of the above embodiment is an example of a cycle time display system. The PC 12 is an example of a cycle time display device or display device. The workpiece spindle device 21 is an example of a workpiece gripping device. The NC program 45 is an example of a control program. The information in the log data 49, log data 51, and log DB 61 is an example of cycle time information. The CPU 56 is an example of a processing unit.

[0060] As described above, the present embodiment has the following advantages. The PC 12, which is one aspect of the present disclosure, displays cycle times in a graph in association with the machining date and time of the machine tool 11 based on the cycle time information 62 in the log DB 61, and also displays the change factors (1) to (5) that cause changes in the cycle time on the graph. This allows the cycle time value to be compared with the change factors and allows the confirmation by excluding cycle time data that is not valid as reference data. Furthermore, if the cycle time can be shortened by a change factor (such as an improvement to the NC program 45), the change factor can be confirmed.

[0061] Furthermore, the contents of the present disclosure are not limited to the above-described embodiments, but can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. For example, in the above embodiment, the PC 12 is used as the cycle time display device of the present disclosure, but this is not limiting. A tablet terminal, a smartphone, or the like may also be used as the cycle time display device of the present disclosure. Furthermore, the PC 12 does not have to display the change factors according to the timing at which they affected the cycle time. For example, the PC 12 may display all change factors at the position of the occurrence date and time. Furthermore, the PC 12 may be configured to display only one type of change factor. Furthermore, when a machining center or the like is adopted as the machine tool of the present disclosure, the workpiece gripping device of the present disclosure may be a device that does not rotate the workpiece. Furthermore, the PC 12 may be configured not to display the target cycle time.

[0062] The contents of the present disclosure are not limited to the dependent relationships described in the claims. For example, this specification also discloses the technical idea of ​​changing "the cycle time display device according to claim 1 or claim 2" in claim 4 to "the cycle time display device according to any one of claims 1 to 3." For example, this specification also discloses the technical idea of ​​changing "the cycle time display device according to claim 1 or claim 2" in claim 5 to "the cycle time display device according to any one of claims 1 to 4." For example, this specification also discloses the technical idea of ​​changing "the cycle time display device according to claim 1 or claim 2" in claim 6 to "the cycle time display device according to any one of claims 1 to 5." For example, this specification also discloses the technical idea of ​​changing "the cycle time display device according to claim 1 or claim 2" in claim 7 to "the cycle time display device according to any one of claims 1 to 6." [Explanation of symbols]

[0063] 10 machine tool system (cycle time display system), 11 machine tool, 12 PC (cycle time display device, display device), 21 work spindle device (work gripping device), 35 numerical control device, 45 NC program (control program), 49 log data (cycle time information), 51 log data (cycle time information), 58 user IF, 56 CPU (processing unit), 61 log DB (cycle time information), 62 cycle time information.

Claims

1. A user interface; a processing unit; Equipped with The processing unit An acquisition process for acquiring cycle time information relating to the cycle time of a machine tool that processes a workpiece; a display process for displaying a graph on the user interface, the graph having a cycle time axis indicating the cycle time and a date and time axis indicating the date and time; Run In the display process, A cycle time display device that displays the cycle time when machining each of the plurality of workpieces by the machine tool on the graph based on the cycle time information acquired by the acquisition process, in correspondence with the date and time when machining each of the plurality of workpieces was performed by the machine tool, and also displays change factors that cause the cycle time to change on the graph.

2. The processing unit 2. The cycle time display device according to claim 1, wherein the change factors are displayed in association with the cycle time, and the change factors are displayed on the graph according to the timing at which the change factors have affected the cycle time.

3. The cycle time information includes: Information about a plurality of types of change factors is stored, The processing unit Accepting, via the user interface, a selection of the type of change factor to be displayed from among a plurality of types of change factors; 3. The cycle time display device according to claim 2, wherein the display process displays the selected change factor on the graph according to the timing at which the change factor affected the cycle time.

4. The change factor is:

3. A cycle time display device according to claim 1 or 2, wherein the cause of the change is at least one of the following: a change in a control program used to machine the workpiece; a change in the pressure of a fluid pressure cylinder equipped in the machine tool below a threshold; a change in an override; a failure to retry a process of checking whether the workpiece is properly seated in a workpiece gripping device equipped in the machine tool; a failure to retry a process of inspecting the workpiece gripped by the workpiece gripping device; and a change in parameters of a numerical control device equipped in the machine tool.

5. The processing unit 3. The cycle time display device according to claim 1, wherein in the display processing, a target cycle time, which is a target cycle time for machining the workpiece, is displayed on the graph, and the target cycle time is displayed on the graph for each type of the workpiece.

6. The cycle time information includes: the cycle time for each machining process executed by the machine tool is stored; The processing unit Accepting the selection of the processing step via the user interface; 3. The cycle time display device according to claim 1, wherein the cycle time of the selected machining process is acquired from the cycle time information, and the graph is displayed in the display process based on the cycle time acquired in the acquisition process.

7. The processing unit The graph can be a scatter plot or a bar graph, receiving, via the user interface, a selection of the cycle time to be excluded from the plurality of plotted cycle times while the scatter diagram is displayed; 3. The cycle time display device according to claim 1, wherein, when a bar graph is displayed, an average value of the cycle times included in each scale of date and time indicated by the date and time axis is displayed as a bar graph for the remaining cycle times excluding the cycle times set to be excluded.

8. A machine tool for processing the workpiece; a display device connected to the machine tool; Equipped with The display device includes: A user interface; a processing unit; Equipped with The processing unit an acquisition process of acquiring cycle time information relating to a cycle time of the machine tool from the machine tool; a display process for displaying a graph on the user interface, the graph having a cycle time axis indicating the cycle time and a date and time axis indicating the date and time; Run In the display process, A cycle time display system that displays the cycle time when machining each of the plurality of workpieces by the machine tool on the graph based on the cycle time information acquired by the acquisition process, in correspondence with the date and time when machining each of the plurality of workpieces was performed by the machine tool, and also displays change factors that cause the cycle time to change on the graph.

Images