Measurement waveform display device and program

Abstract

To provide a measurement waveform display device suitable for appropriately analyzing causes and so on of defective products.SOLUTION: A measurement waveform display device comprises: condition display means for displaying a condition selection screen (SR1) that includes an item selection column (922) which selectably represents a display object item of a plurality of items of measurement value data and a reference point selection column (928) which selectably represents a reference point of a time base from a plurality of reference point candidates including a start point and a bottom dead point of a press cycle; condition selection means for receiving selection of the display object item and the reference point from each of the item selection column and the reference point selection column of the condition selection screen; and graph display means for overlappingly displaying a plurality of cycles of measured waveforms with respect to the item selected in the item selection column with the reference point selected in the reference point selection column as a reference of the time base.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a measured waveform display device and a program, and more particularly to a measured waveform display device and a program that graphically display measured waveforms in units of press cycles in accordance with measurement data detected by sensors mounted on a press machine. [Background technology]

[0002] Forging presses, under the control of a PLC, continuously press workpieces to produce formed products by rotating the crankshaft of the press and raising and lowering the slide. As disclosed in Japanese Patent Laid-Open Publication No. 2019-13976 (Patent Document 1), such presses have traditionally acquired information (measurement data) from multiple sensors that detect the operating status of the press, and continuously displayed the measured waveforms as graphs on a monitoring PC. Patent Document 1 also proposes a technology in which the PLC compares a preset initial normal state with the measured operating status to predict press failures.

[0003] Furthermore, from the perspective of graphically displaying measurement data from a molding machine, there is a technology that allows the cause-and-effect relationships to be grasped by simultaneously displaying measurement waveforms for multiple processes in an injection molding machine in separate areas, as shown in, for example, Japanese Patent Laid-Open Publication No. 2003-200456 (Patent Document 2). Patent Document 2 discloses that the timing at which the waveforms displayed in each area start display can be standardized (selected). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-13976 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-200456 Summary of the Invention [Problem to be solved by the invention]

[0005] As in Patent Document 1, by constantly displaying measurement data for multiple items as a graph on a monitoring PC as waveforms along a time axis, an operator can immediately check whether there is a change in the operating condition (whether it is normal or not), but it is difficult to check even subtle changes in the operating condition by just looking at one cycle of measurement waveforms.

[0006] One way to check subtle changes in the operating conditions is to display a graph by overlapping the measured waveforms of common items, but simply overlapping multiple measured waveforms along a common time axis does not allow intuitive judgment of whether the measured waveform shape is abnormal. For this reason, it has traditionally been difficult to properly analyze the causes of defective products.

[0007] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a measurement waveform display device suitable for appropriately analyzing factors such as those causing defects. [Means for solving the problem]

[0008] A measured waveform display device according to one aspect of the present invention is a measured waveform display device that displays a graph of a measured waveform for each press cycle in accordance with measurement data detected by sensors mounted on a press machine, and includes an acquisition means, a condition display means, a condition selection means, and a graph display means. The acquisition means acquires measurement files for multiple cycles containing measurement data for multiple items detected by the sensors. The condition display means displays a condition selection screen including an item selection field that selects an item to be displayed from the multiple items and a reference point selection field that selects a reference point on a time axis from multiple reference point candidates including the start of the press cycle and bottom dead center. The condition selection means accepts selection of the item to be displayed and the reference point from the item selection field and the reference point selection field, respectively, on the condition selection screen. The graph display means displays a plurality of cycles of measured waveforms for the item selected in the item selection field, superimposed on each other, using the reference point selected in the reference point selection field as the reference for the time axis.

[0009] Preferably, the plurality of reference point candidates further includes a point in time at which an arbitrarily set threshold value is exceeded.

[0010] Preferably, the condition selection screen further includes at least one of a product number selection field that selectably displays the product numbers of the workpieces of the press machine, and a pattern selection field that selectably displays the arrangement pattern of the workpieces by the press machine.

[0011] It is desirable that the measurement waveform display device further include a list display means for displaying a list of file identification information of measurement files corresponding to a range of measurement waveforms specified by user operation when a portion of the measurement waveforms for multiple cycles displayed on the graph display means is specified.

[0012] It is also desirable that the measurement waveform display device further comprises an extraction means for extracting measurement files corresponding to a range of the measurement waveform specified by user operation when a portion of the measurement waveform for multiple cycles displayed on the graph display means is specified, and outputting the extracted measurement files all at once.

[0013] Preferably, the condition selection screen further includes a period input field for inputting the period to be displayed by the graph display means, and a number display field for displaying the number of measurement files included in the period input in the period input field.

[0014] A measurement waveform display program according to another aspect of the present invention causes a computer to execute the following steps: acquiring measurement files for multiple cycles, including measurement value data for multiple items detected by sensors mounted on a press machine; displaying a condition selection screen, including an item selection field that selectably displays an item to be displayed from the multiple items, and a reference point selection field that selectably displays a reference point on the time axis from multiple reference point candidates including the start of the press cycle and bottom dead center; accepting selections of the item to be displayed and the reference point from each of the item selection field and the reference point selection field on the condition selection screen; and displaying measurement waveforms for multiple cycles for the item selected in the item selection field, superimposed on each other, using the reference point selected in the reference point selection field as the reference for the time axis. [Effects of the Invention]

[0015] According to the present invention, the reference point on the time axis when displaying multiple cycles of measured waveforms in an overlapping manner can be selected from multiple reference point candidates, making it possible to visually determine whether the shapes of the multiple measured waveforms displayed in an overlapping manner match or mismatch. This allows intuitive determination of whether the shapes of the measured waveforms are abnormal, thereby enabling appropriate analysis of the causes of defective products, etc. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing a schematic configuration of a forging press device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram schematically illustrating specific examples of sensors mounted on a press machine according to an embodiment of the present invention. [Figure 3] FIG. 1 is a diagram schematically illustrating an example in which a press machine according to an embodiment of the present invention is a multi-stage press machine. [Figure 4]1 is a block diagram showing a configuration of a measured waveform display device according to an embodiment of the present invention; [Figure 5] 10A and 10B are diagrams showing specific examples of a condition selection screen and a graph display screen displayed on a display unit in an embodiment of the present invention. [Figure 6] 10A and 10B are diagrams showing differences in overlap of measurement waveforms when measurement data of slide positions are displayed in graphs based on a normal reference and a bottom dead center reference, respectively. [Figure 7] 4 is a flowchart showing the operation of the measured waveform display device according to the embodiment of the present invention. [Figure 8] FIG. 8 is a screen diagram showing an example of selection in step S6 of FIG. 7. [Figure 9] 10A and 10B are diagrams showing examples of display of measured waveforms of load values ​​when the time axis of the graph is set to a normal reference, a bottom dead center reference, and an arbitrary reference. [Figure 10] 10A and 10B are diagrams showing examples of display of the measured waveform of the clutch secondary side pressure when the time axis of the graph is set to a normal reference, a bottom dead center reference, and an arbitrary reference. [Figure 11] FIG. 10 is a diagram showing an example of a list display screen according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals and description thereof will not be repeated.

[0018] The measured waveform display device according to this embodiment displays a graph of the measured waveform for each press cycle in accordance with measurement data detected by sensors mounted on the press machine of the forging press.

[0019] <Outline of forging press equipment> First, the schematic configuration of a forging press 10 will be described with reference to Figures 1 and 2. As shown in Figure 1, the forging press 10 mainly comprises a press 11 that presses a material, which is a workpiece, and a PLC (Programmable Logic Controller) 40 that controls the operation of the press 11. The forging press 10 is a device that processes a workpiece by hot forging.

[0020] As shown in FIG. 2, the press 11 includes a slide 1 and a bolster 2 arranged vertically opposite each other within a frame 3. The press 11 is configured so that the slide 1, which is connected to a connecting rod 5, moves up and down when a crankshaft 4 is rotated. A flywheel 8, which is driven to rotate by a belt 7 driven by a main motor 6, is connected to one end of the crankshaft 4 via a clutch 9. A brake device 12 is attached to the other end of the crankshaft 4, stopping the rotation of the crankshaft 4 and thereby stopping the slide 1. The press 11 forges a workpiece placed on the bolster 2 by rotating the flywheel 8 at a constant speed using the main motor 6 and engaging the clutch 9 to transmit the rotation of the flywheel 8 to the crankshaft 4, thereby raising and lowering the slide 1.

[0021] The workpiece is processed into a size and shape according to the pattern of a die, which includes a lower die (not shown) installed on the bolster 2 and an upper die (not shown) installed at the lower end of the slide 1, to become the final product. "Die" refers to a die used for forging. Dies are typically made of special steel.

[0022] The press 11 may be a multi-stage press that processes a workpiece through multiple steps. That is, as shown in FIG. 3, the press 11 may be equipped with multiple (e.g., three) dies 51 to 53. The workpiece W is molded into a final product through a first step using die 51, a second step using die 52, and a third step using die 53. In the following description, when it is not necessary to distinguish between the dies 51 to 53, they will be referred to as "die 50."

[0023] The forging press 10 in this embodiment is equipped with a plurality of sensors as described below to detect the operating status of the (continuously operating) press 11. That is, the following sensors are mounted on the press 11. Load sensor 20: Detects the load applied to the workpiece. For example, it is configured with a strain gauge that detects the distortion of frame 3. Angle sensor 21: Detects the rotation angle (press angle) of the crankshaft 4 to detect the position of the slide 1, as well as the speed (stroke) and acceleration of the slide 1. Brake release pressure sensor 22: Detects the release pressure of the brake device 12. Clutch pressure sensor 23: Detects the pressure of the clutch 9. Clutch tank pressure sensor 24: Detects the pressure of the hydraulic oil that drives the clutch 9. Brake tank pressure sensor 25: Detects the pressure of the cooling water of the brake device 12. Coolant flow rate sensor 26: Detects the flow rate of the cooling water for the brake device 12. BKO position displacement sensor 27: Detects the position of the lower knockout device of the press machine 11 (BKO position). SKO position displacement sensor 28: Detects the position of the upper knockout device (SKO position). Resistance thermometer 29: Detects the temperature of each part of the press machine 11. Lubricant flow rate sensor 30: Detects the flow rate of the lubricant that lubricates the mold 50. Air blow pressure sensor 31: Detects the pressure of high-pressure air supplied to the press machine 11. Material temperature sensor 32: Detects the temperature of the material supplied to the press machine 11. Die height displacement sensor 33: Detects the die height of the press machine 11 (the distance between the bolster 2 and the bottom dead center position of the slide 1). Mold temperature sensor 34: Detects the temperature of the mold 50. Frame vibration meter 35: For example, this is constituted by an acceleration sensor, and detects vibrations of the frame 3. For example, it detects "upstream frame vibrations" based on a signal from the vibration meter 35 provided on the left support column 3c, and it detects "downstream frame vibrations" based on a signal from the vibration meter 35 provided on the right support column 3d. Motor speed sensor 36: Detects the speed (actual speed) of the main motor 6 by detecting the rotation angle of the rotary shaft of the main motor 6. Motor vibrometer 37: Consisting of, for example, an acceleration sensor, this detects vibrations of the main motor 6. For example, it detects "motor body side vibrations" based on signals from a vibrometer 37 provided on the main motor 6 body, and it detects "motor load side vibrations" based on signals from a vibrometer 37 attached to the main motor 6 that detects bearing vibrations.

[0024] In this embodiment, the load sensor 20 is attached to one of the support columns (for example, support column 3c) of the frame 3. A vibrometer 35 is attached to each of the left and right support columns 3c, 3d of the frame 3. One of the support columns 3c, 3d (support column 3c) is located upstream of the mold in the conveying direction, and the other of the support columns 3c, 3d (support column 3d) is located downstream of the mold in the conveying direction. Each vibrometer 35 detects vibrations in the approximately horizontal direction (front-back or left-right direction) of the support column 3c, 3d to which it is attached. Note that the vibrometer 35 may also be attached to the support columns 3a, 3b on the front side of the frame 3.

[0025] Based on signals from the sensors, the PLC 40 acquires measured values ​​(index values) of various items representing the operating status of the press machine 11 in chronological order and outputs measurement waveforms corresponding to the acquired measurement data to the monitoring PC 42. Specifically, for each press cycle, measurement waveforms of multiple items, including slide position, load, motor speed, brake release pressure, and clutch secondary side pressure, are displayed in graph form along a common time axis. The PLC 40 also accumulates the measurement data of the multiple items acquired for each press cycle in the press information storage unit 41. An example of the data structure of the press information storage unit 41 will be described later. The measured values ​​may be actual measured values ​​(primary data) obtained directly from the sensors, or values ​​(secondary data) obtained by converting the format of the actual measured values ​​(by calculating feature quantities).

[0026] In this embodiment, the PLC 40 and the measured waveform display device 100 are connected via a network, and the measured waveform display device 100 can acquire past measurement value data from the press information storage unit 41. The measured waveform display device 100 is an information processing device equipped with a user interface, and is realized by, for example, a tablet terminal, a smartphone, a PC, or the like. Note that, while FIG. 1 shows an example in which the press information storage unit 41 is a storage device attached to the PLC 40, the press information storage unit 41 is not limited to this example and may be realized by, for example, a cloud server, or the like.

[0027] <Configuration of measurement waveform display device> 4 is a block diagram showing the configuration of a measured waveform display device 100 according to this embodiment. Measured waveform display device 100 includes a CPU (Central Processing Unit) 101 that performs various arithmetic processing, memory 102 that stores various data and programs, an operation unit 103 that accepts instructions from a user, a display unit 104 that displays various information, a communication I / F (interface) 105 that transmits and receives data and programs to and from external devices, and a non-volatile storage device 106. Operation unit 103 and display unit 104 may be provided integrally to form a touch panel 107.

[0028] 4 further shows the functional configuration of CPU 101 as a processor. CPU 101 includes an acquisition unit 111, a display control unit 112, and an extraction unit 113 as its functions.

[0029] The acquisition unit 111 acquires past measurement value data accumulated in the press information storage unit 41. Specifically, it acquires multiple measurement files F including measurement value data for multiple items from the press information storage unit 41. Alternatively, it executes a process of reading all or part of multiple measurement files F that have been recorded in advance in the storage device 106 or the like. Thus, in this specification, "acquire" includes the meaning of reading.

[0030] The press information storage unit 41 stores a plurality of measurement files F generated for each press cycle, and the measurement date and time, the die pattern, and measurement data for a plurality of items are recorded in each measurement file F. Each measurement file F is a file (e.g., a CSV file) with file identification information (file ID) as a header.

[0031] The die pattern is data that includes both the part number and workpiece pattern of the target workpiece. The part number of the workpiece is input by a user (an operator or a manager) via an input unit (not shown) connected to the PLC 40, for example, before the forging press 10 starts operating the press. The workpiece pattern represents the arrangement pattern of the workpiece relative to the dies 51-53, and is detected, for example, by a workpiece pattern detection means (not shown) provided in the forging press 10. The workpiece pattern includes a plurality of arrangement patterns, such as a pattern in which workpieces are arranged in all of the dies 51-53, a pattern in which workpieces are arranged only in the die 51, and a pattern in which workpieces are arranged in both the die 51 and the die 53.

[0032] The measurement value items recorded in the measurement file F typically include items displayed on the monitor 42 connected to the PLC 40 of the forging press 10. Specifically, these include at least the slide position, load value, motor speed, brake release pressure, and clutch secondary side pressure, and preferably further include the flow rate of lubricating fluid for each of the upper and lower dies 51-53. Items related to these measurement values ​​may also include slide speed, slide acceleration, load peak value, die height value, and the above-mentioned frame upstream vibration, frame downstream vibration, motor main body side vibration, and motor load side vibration.

[0033] In this embodiment, the mold pattern data is included in the measurement file F along with the measurement date and time and measurement data, but this is not limited to this, and for example, the measurement file F containing the measurement date and time and measurement data may be stored separately in folders created for each mold pattern.

[0034] The acquisition unit 111 acquires, from the press information storage unit 41, the measurement file F within a period designated by the user via the operation unit 103.

[0035] The display control unit 112 controls the display of a condition selection screen and a graph display screen on the display unit 104. The condition selection screen is a screen that allows the user to select (specify) the conditions of the measured waveform to be displayed on the graph display screen. The display control unit 112 and the display unit 104 function as a condition display means and also as a graph display means. Specific examples of the condition selection screen and the graph display screen are shown in Figures 5(A) and (B).

[0036] Referring to FIG. 5(A), the condition selection screen SR1 includes at least an item selection field 922 and a reference point selection field 928. The item selection field 922 is an area for allowing the user to select (or input) an item to be displayed from among the above-mentioned multiple items. The reference point selection field 928 is an area for allowing the user to select (or input) a reference point on the time axis when a measured waveform is displayed graphically from multiple reference point candidates. The user can select an item to be displayed and a reference point from the item selection field 922 and the reference point selection field 928, respectively, via the operation unit 103. The operation unit 103 functions as a condition selection means. Details of the condition selection screen SR1 will be described later.

[0037] The multiple reference point candidates include at least the start of the press cycle (i.e., the start point of acquisition of each measurement data) and bottom dead center, and preferably also the point at which an arbitrarily set threshold is exceeded. When displaying a measurement waveform graphically, the start of the press cycle is generally used as the reference point of the time axis. In this embodiment, the reference point of the time axis can be set to bottom dead center or an arbitrary point. In the reference point selection field 928, one of three options can be selected: "Normal depiction" for displaying the graph at the start point; "Bottom dead center-aligned depiction" for displaying the graph based on bottom dead center; and "Arbitrary alignment depiction" for displaying the graph based on an arbitrary point. An input field is displayed near the arbitrary alignment depiction selection field for entering at least one of a threshold value serving as the reference value for the time axis (horizontal axis) and a threshold value serving as the reference value for the measurement value (vertical axis).

[0038] Referring to Fig. 5(B), the graph display screen SR2 includes a waveform display area 93. The display control unit 112 displays multiple cycles of measurement waveforms for the item selected in the item selection field 922 in an overlapping manner, with the reference point selected in the reference point selection field 928 as the reference for the time axis. Fig. 5(B) shows an example in which multiple measurement waveforms for a slide position are overlapped without any shift, with the start point as the reference. In this case, the bottom dead center timings of the multiple measurement waveforms are the same.

[0039] As mentioned above, when displaying a measurement waveform along the time axis, the start time is generally used as the reference point. However, there are cases where the logging timing (the timing when measurement data acquisition starts) in the PLC 40 is off. In this case, as shown in an exaggerated manner in Figure 6(A), the phase of the measurement waveform for the slide position is off, causing a shift in the bottom dead center timing. When multiple measurement waveforms are superimposed with the bottom dead center timing shifted in this way, it is difficult to visually check for abnormal measurement waveforms.

[0040] In this embodiment, the measured waveform can be displayed based on the bottom dead center, an important position on the press 11. This allows visual confirmation of abnormalities in the measured waveform without being affected by deviations in the logging timing, as shown in FIG. 6(B). In other words, the shapes of the measured waveforms before and after bottom dead center can be easily compared. If the shapes differ after passing bottom dead center, as shown in FIG. 6(B), it can be determined that a speed reduction due to a difference in load is occurring.

[0041] The display control unit 112 further has a function of displaying a list of file identification information of measurement files extracted by an extraction unit 113, which will be described later.

[0042] In response to a user operation specifying a range of a portion of the measurement waveform for multiple cycles displayed in the waveform display area 93, the extraction unit 113 searches for and extracts measurement files corresponding to the specified range of the measurement waveform from the multiple measurement files F acquired by the acquisition unit 111. Furthermore, when a user operation inputs an instruction for batch output, the extracted measurement files are output in a batch as, for example, a CSV file.

[0043] <Operation of the measurement waveform display device> 7 is a flowchart showing the operation of the measured waveform display device 100. Each process shown in FIG.

[0044] 7, first, acquisition unit 111 of CPU 101 reads press information from press information storage unit 41 (step S2). Specifically, a measurement file including measurement value data measured within a period designated by the user via operation unit 103 is read from press information storage unit 41 and temporarily stored in internal memory. This process is realized, for example, by requesting PLC 40 to transmit the measurement file via communication I / F 105.

[0045] Next, the display control unit 112 displays a condition selection screen SR1 as shown in Fig. 5(A) on the display unit 104 (step S4). The condition selection screen SR1 includes a period display area 91 and condition specification areas 92A and 92B. Note that the condition selection screen SR1 may also include a blank waveform display area 93.

[0046] When the condition selection screen SR1 is displayed, the CPU 101 sets the graph display target (step S6) based on input from the operation unit 103. The graph display target is specified by the display item, date (period), product number, and work pattern.

[0047] Here, the period display field 911 and the condition specification area 92A of the condition selection screen SR1 will be described in detail. The period display area 91 includes a period display field 911 that displays a period. It also includes a read button 912 for instructing the bulk reading of measurement files corresponding to the period shown in this field 911, and a change button 913 for instructing a change to measurement files that were previously bulk read. Note that the processing of step S2 above may be executed in response to the selection of the read button 912.

[0048] The condition specification area 92A includes a period input field 921 for inputting the period (dates) for which the graph is to be drawn, the above-mentioned item selection field 922, a product number selection field 923 for selecting the product number, a pattern selection field 924 for selecting the work pattern (work placement pattern), and a drawing button 925 for instructing the start of drawing the measured waveform.

[0049] 5(A), selectable items (display items) are listed in a pull-down format in an item selection field 922. Here, selectable items (i.e., items that form the vertical axis (display axis) of the graph) include, for example, slide position, load meter, motor speed, brake release pressure, clutch secondary side pressure, and the amount of lubricant (upstream side, downstream side) for each of the dies 51 to 53. Note that the items selectable in the item selection field 922 may be all or some of the items included in the measurement file F.

[0050] The condition specification area 92A also includes an obtain button 926 for obtaining the number of measurement files F corresponding to the period specified in the period input field 921, i.e., the number of measurement files (hereinafter referred to as "target files") that contain measurement value data measured within the specified period. Note that input into the period input field 921 is not essential, and if no input is made into the period input field 921, the entire period shown in the period display field 911 is considered to be the specified period. When the obtain button 926 is instructed, the number of target files is displayed in a number display field 927.

[0051] It is desirable that the part number selection field 923 displays the part numbers contained in the target file in a selectable manner. It is also desirable that the pattern selection field 924 displays the workpiece patterns contained in the target file in a selectable manner. Since the behavior of each part of the press 11 differs depending on the part number or workpiece pattern, by making the part number and workpiece pattern selectable, it is possible to eliminate the influence of differences in die patterns. In other words, it is possible to accurately grasp changes in the operating status of the press 11. Note that the part number and workpiece pattern may be input arbitrarily.

[0052] Following (or simultaneously with) the setting of the graph display target, the CPU 101 sets a reference point for graph display by specifying one of the multiple reference point candidates displayed in the reference point selection field 928 via the operation unit 103 (step S8). On the condition selection screen SR1, the condition specification area 92B includes the reference point selection field 928. As described above, the reference point selection field 928 includes three specification buttons corresponding to "normal drawing" for displaying the graph at the start point, "bottom dead center aligned drawing" for displaying the graph based on the bottom dead center, and "arbitrary aligned drawing" for displaying the graph based on an arbitrary point. Furthermore, when selecting "arbitrary point aligned drawing," a threshold value required (for example, at least one of a threshold value (time) for identifying a point on the horizontal axis and a threshold value for identifying a point on the vertical axis) can be input. It is desirable that the unit of the threshold value for the arbitrary reference vertical axis be displayed according to the display item selected in step S6.

[0053] In this embodiment, an example is shown in which the condition specification area is divided into two areas 92A and 92B sandwiching the waveform display area 93, but this is not limited to such an example, and for example, the above-mentioned selection fields and specification buttons may be displayed in a single area.

[0054] After the selection of various conditions is accepted on the condition selection screen SR1, when the drawing button 925 is selected, multiple measurement waveforms for multiple cycles are displayed overlapping in the waveform display area 93 of the graph display screen SR2 (step S10). That is, the measurement waveforms for multiple cycles for the item selected in the item selection field 922 are displayed overlapping in the waveform display area 93, with the reference point selected in the reference point selection field 928 as the reference of the time axis.

[0055] As shown in Fig. 8, it is assumed that "Load Value" is selected in the item selection field 922, and with the part number and workpiece pattern selected, the drawing button 925 is pressed. Fig. 9 shows examples of measured waveforms displayed under these display conditions when the time axis of the graph is set to the normal reference, bottom dead center reference, and optional reference.

[0056] Figures 9(A)-(C) are schematic diagrams showing examples of the measured "load value" waveform when the time axis of the graph is based on the normal standard, bottom dead center standard, and an arbitrary standard, respectively. If there is a discrepancy in the logging timing of the load value, the load peak times t1 and t2 may be offset as shown in Figure 9(A) when the normal standard is used. However, when the bottom dead center standard is used, the load peak times coincide as shown in Figure 9(B). Therefore, by using the bottom dead center standard, it is possible to accurately determine not only the discrepancy in the load peak values, but also whether the pre-forming waveform or the post-forming waveform is offset. The measured waveform shown by the dashed line is that of a defectively formed product. By using the bottom dead center standard, it can be seen that the measured waveform shown by the dashed line rises more slowly than the measured waveform shown by the solid line.

[0057] If you want to compare the load during molding using the rising point of the measured waveform in Figure 9(B) as the base point, you can set an arbitrary reference as shown in Figure 9(C) and overlay the waveforms. In the example in Figure 9(C), the starting point is Pa, the point when the workpiece (material) begins to contact the mold (for example, when the threshold value Va is set to 200 and the threshold value Va is reached). The waveform shown by the dashed line shows that the load rises differently from a normal waveform because the workpiece was molded while tilted.

[0058] Similarly, for items other than load values, detailed analysis can be performed by setting a certain point where a deviation occurs when the normal reference or bottom dead center reference is used as the threshold. For example, Figures 10(A) to 10(C) show schematic examples of the measured waveform of "clutch secondary side pressure" when the time axis of the graph is based on the normal reference, bottom dead center reference, and an arbitrary reference, respectively. In this example, the arbitrary reference is set to a point Pb where a deviation occurs when the bottom dead center reference is used (for example, the point where threshold Vb is reached when threshold Vb is set to 1000).

[0059] 7, with multiple measurement waveforms displayed superimposed on the graph display screen SR2, the user can specify a range R of a portion of the measurement waveform via the operation unit 103, as shown in FIG. 11(A). The range R is specified by dragging with a mouse or touch operation. With such a range specified, when the user indicates a list display instruction by pressing the "Range Specification List" button 94 (YES in step S12), the extraction unit 113 searches for and extracts the measurement files corresponding to the measurement waveforms in the specified range from the multiple measurement files acquired in step S2 (step S14). Then, the file identification information of the extracted measurement files is displayed as a list on a screen SR3 adjacent to the graph display screen SR2 or on a pop-up screen (step S16).

[0060] The SR3 screen in FIG. 11(A) displays one file name (file identification information). The file identification information includes information on the measurement date and time (production date and time), so it is easy to determine when the specified measurement waveform is the measurement waveform of the product produced. FIG. 11(A) displays a list of files when one measurement waveform is specified. FIG. 11(B) displays a list of files when multiple measurement waveforms are specified.

[0061] When the user inputs a file output instruction by pressing the "File Output" button 95 displayed on the list display screen SR3, the extraction unit 113 outputs the extracted measurement files in bulk, for example as a CSV file (step S18). Specifically, an application associated with the CSV extension displays information about the measurement files on the display unit 104. Alternatively, the extraction unit 113 may execute a process of storing all of the extracted measurement files in the storage device 106, or a process of transmitting the files to an external maintenance device or the like via the communication I / F 105.

[0062] In this way, by outputting a measurement file containing measurement data for all items, not just the measurement data for the items displayed on the graph display screen SR2, it is possible to comprehensively evaluate and analyze the causes of defective products, etc.

[0063] As described above, the measured waveform display device 100 according to this embodiment displays the condition selection screen SR1 before displaying the graph display screen SR2. The user can select a reference point on the time axis from multiple reference point candidates on the condition selection screen SR1, including the normal press cycle start point and bottom dead center. This allows the user to visually determine whether the shapes of multiple measured waveforms displayed overlaid on the graph display screen SR2 match or mismatch. This allows the user to intuitively determine whether the shapes of the measured waveforms are abnormal, thereby enabling appropriate analysis of factors such as defective products. Furthermore, the user can accurately capture changes in the operating status of the press 11, enabling detailed investigation of potential abnormalities in the press 11.

[0064] One technology uses machine learning to generate a learning model using a huge amount of measurement data as training data, and then automatically determines whether a product is good or bad using the generated learning model. In this case, it is effective to train the measurement data based on the bottom dead center. Therefore, if the output of the learning model indicates a defective product, the measured waveform display device 100 can display multiple cycles of measurement waveforms for each item over a period including the production date and time (measurement date and time) when the product became defective, superimposed with the bottom dead center as the reference. This has the advantage of enabling visual analysis of the factors (causes of anomalies) that led to the learning model's determination of the product as defective. Furthermore, the measurement waveforms of products generated before and after the defective product can be viewed, enabling detailed analysis.

[0065] Furthermore, in this embodiment, various conditions for plotting a measured waveform can be selected and input on a single condition selection screen SR1, thereby improving operability. Furthermore, since the condition selection screen SR1 and the graph display screen SR2 have a common screen configuration, it is easy to change the conditions for plotting a measured waveform. As a modified example not shown, for example, the item selection field 922 and the reference point selection field 928 may be displayed on separate screens.

[0066] <Modification> In this embodiment, an example has been described in which a corresponding measurement file is extracted by selecting (specifying a range) a portion of the measurement waveform displayed on the graph display screen SR2, but the user may also input a threshold value and extract measurement files that exceed the threshold value. In this case, for example, an input field (not shown) for inputting the threshold value may be provided near the "List of range specification" button displayed on the graph display screen SR2.

[0067] Furthermore, in this embodiment, one item can be selected in the item selection field 922 of the condition selection screen SR1, but two or more items may be selected. In this case, it is desirable to use a different color or line type for the measurement waveform for each item. This allows for more detailed analysis of the causes of defective products, etc.

[0068] Furthermore, although the present embodiment is directed to the press machine 11 of the forging press device 10, other types of press machines can also be used as long as they are press machines that use dies to form workpieces.

[0069] The measured waveform display method executed by the measured waveform display device 100 can also be provided as a program. Such a program can be provided by being recorded on an optical medium such as a CD-ROM (Compact Disc-ROM) or a computer-readable non-transitory recording medium such as a memory card. The program can also be provided by downloading it over a network.

[0070] The program according to the present invention may execute processing by calling necessary modules in a predetermined sequence at a predetermined timing among program modules provided as part of a computer's operating system (OS). In this case, the program itself does not include the modules, and executes processing in cooperation with the OS. Programs that do not include such modules may also be included in the program according to the present invention.

[0071] Furthermore, the program according to the present invention may be provided as a part of another program. In this case, the program itself does not include the modules included in the other program, and executes processing in cooperation with the other program. Such a program incorporated in another program may also be included in the program according to the present invention.

[0072] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0073] 100 measurement waveform display device, 101 CPU, 102 memory, 103 operation unit, 104 display unit, 105 communication I / F, 106 storage device, 107 touch panel, 111 acquisition unit, 112 display control unit, 113 extraction unit, 921 period input field, 922 item selection field, 923 product number selection field, 924 pattern selection field, 928 reference point selection field, SR1 condition selection screen, SR2 graph display screen, SR3 list display screen.

Claims

1. A measurement waveform display device that displays a graph of a measurement waveform in units of press cycles in accordance with measurement data detected by sensors mounted on a press machine that continuously forms workpieces by raising and lowering a slide using rotation of a flywheel, an acquisition means for acquiring measurement files for a plurality of past cycles, including measurement data of a plurality of items detected by the sensors and measurement dates and times; a condition display means for displaying a condition selection screen including a period input field for specifying a period to be displayed, an item selection field in which an item to be displayed among the plurality of items is displayed in a selectable manner, and a reference point selection field in which a reference point on a time axis is displayed in a selectable manner from a plurality of reference point candidates including the start time of the press cycle and the bottom dead center; a condition selection means for accepting selection of the item to be displayed and the reference point from the item selection field and the reference point selection field of the condition selection screen, respectively; and a graph display means for displaying, in superimposed form, measurement waveforms for multiple cycles corresponding to the measurement value data of the item selected in the item selection field among the measurement value data of multiple items measured within the period specified in the period input field, by matching the reference point selected in the reference point selection field on the time axis.

2. 2. The measurement waveform display device according to claim 1, wherein the plurality of reference point candidates further include a point in time at which an arbitrarily set threshold value is exceeded.

3. 2. The measured waveform display device according to claim 1, wherein the condition selection screen further includes at least one of a product number selection field that selectably displays product numbers of the workpieces of the press machine, and a pattern selection field that selectably displays a workpiece arrangement pattern by the press machine.

4. 2. The measurement waveform display device according to claim 1, further comprising a list display means for displaying a list of file identification information of measurement files corresponding to a range of the measurement waveforms specified by a user operation when a range of a portion of the measurement waveforms for the multiple cycles displayed on the graph display means is specified by a user operation.

5. 2. The measurement waveform display device according to claim 1, further comprising an extraction means for extracting measurement files corresponding to a range of the measurement waveforms specified by a user operation when a range of a portion of the measurement waveforms for the multiple cycles displayed on the graph display means is specified by a user operation, and outputting the extracted measurement files all at once.

6. The measurement waveform display device according to claim 1 , wherein the condition selection screen further includes a number display field that displays the number of the measurement files included in the period input in the period input field.

7. A step of acquiring measurement files for multiple past cycles, including measurement data and measurement dates and times of multiple items detected by sensors mounted on a press machine that continuously forms workpieces by raising and lowering a slide using rotation of a flywheel; displaying a condition selection screen including a period input field for specifying a period to be displayed, an item selection field displaying selectable items to be displayed among the plurality of items, and a reference point selection field displaying selectable reference points on a time axis from a plurality of reference point candidates including the start time of the press cycle and the bottom dead center; accepting selection of the item to be displayed and the reference point from the item selection field and the reference point selection field of the condition selection screen, respectively; and a step of overlapping and displaying measurement waveforms for multiple cycles corresponding to the measurement value data of the item selected in the item selection field among the measurement value data of multiple items measured within the period specified in the period input field by aligning the reference point selected in the reference point selection field on the time axis.

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