Preventive maintenance system for machine tools

Abstract

Provided is a preventive maintenance system for a machine tool, which can automatically and mechanically determine whether there is an abnormality, which originally depends on the operator's sense, so that abnormalities can be detected earlier and more accurately. The system comprises: a vibration detection unit, which is installed in the mechanism of the machine tool and is used to detect vibration; a sound detection unit, which detects sound waves generated when a workpiece is processed in the machine tool; a servo motor current value detection unit, which detects the current value of the servo motor; an abnormality determination unit, which compares the vibration, sound wave and current value of the servo motor with the pre-set vibration data, sound wave data and current value data during the operation of the machine tool to determine whether there is an abnormality in the mechanism of the machine tool; and a detection start and end instruction setting unit, which is used to add instructions for the detection start point and detection end point of at least one of the vibration, sound wave and current value of the servo motor in the processing program.

Description

Technical Field

[0001] The invention relates to a preventive maintenance system for a machine tool. Background Art

[0002] In the past, CNC (Computerized Numerical Control) technology was applied to machine tools such as NC lathes and machining centers, and the amount of tool movement and speed were numerically controlled by computers, thereby highly automating the repetition of the same machining process and the machining of complex shapes. In addition, the data produced by CAD and CAM are taken into CNC, and various data such as options, parameters, NC programs, macro programs, macro variables, workpiece origin offsets, tool offsets, tool shape data, and tool management data are input for control, thereby automating the machine tool from design to manufacturing.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-103284 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] On the other hand, when an abnormality occurs in the mechanism (main drive system) of a machine tool, abnormal vibrations and abnormal sounds are generated during the operation of the machine tool, and operators often know that an abnormality has occurred in the mechanism of the machine tool by feeling these abnormal vibrations and abnormal sounds.

[0008] However, when the judgment of whether a machine tool has an abnormality depends on the operator's feeling, the judgment of whether an abnormality exists is affected by the operator's proficiency and experience, resulting in differences in judgment and judgment timing for each person.

[0009] As a result, there are cases where abnormalities cannot be discovered early and accurately. Depending on the situation, processing operations may continue under abnormal conditions, resulting in defective products, a decrease in yield, and aggravation of machine tool failures.

[0010] In view of the above circumstances, an object of the present invention is to provide a preventive maintenance system for a machine tool that can automatically and mechanically determine the presence or absence of an abnormality, which has conventionally relied on the operator's senses, thereby enabling the abnormality to be detected earlier and more accurately.

[0011] Solutions for solving problems

[0012] The present inventors have found a method for automatically and mechanically determining the presence or absence of an abnormality, which originally relied on the operator's senses, and thereby detecting an abnormality earlier and more accurately, and have completed the present invention.

[0013] (1) The present invention is characterized in that it comprises at least one of a vibration detector (e.g., a vibration detector 13 described later), a sound detector (e.g., a sound detector 15 described later), and a servo motor current value detector (e.g., a servo motor current value detector 16 described later), wherein the vibration detector is mounted on a mechanism (e.g., a spindle 2 described later, a telescopic cover 10, an ATC door 12) of a machine tool (e.g., a machine tool 1 described later) and is used to detect vibration, the sound detector is disposed in the vicinity of the mechanism of the machine tool and is used to detect sound waves generated during operation of the machine tool, and the servo motor current value detector is used to detect a servo motor (e.g., a servo motor 6 described later) of a drive device (e.g., a drive device 6 described later) of the machine tool. The present invention also comprises: an abnormality determination unit (for example, the abnormality determination unit 14 described later), which compares the detection value of at least one of the vibration detected by the vibration detection unit, the sound wave detected by the sound detection unit, and the current value detected by the servo motor current value detection unit during the operation of the machine tool with at least one of the vibration data, sound wave data, and servo motor current value data acquired in advance during normal operation, to determine whether the mechanism has an abnormality; and a detection start and end instruction setting unit (for example, the detection start and end instruction setting unit 18 described later), which is used to add instructions for the detection start point and detection end point of at least one of the vibration, the sound wave, and the current value of the servo motor in the machining program.

[0014] Here, in the above (1), the "machine tool mechanism" is not limited to the "internal mechanism and driving mechanism of the main part of the machine tool" that processes the workpiece as the processing object in a strict sense, but also includes peripheral equipment mechanisms such as automatic tool changers (ATC) and additional equipment mechanisms such as telescopic covers.

[0015] (2) The present invention may also be that in the above (1), an M code is provided in the processing program, and the M code is used to instruct / set the detection start point and the detection end point of at least one of the vibration, the sound wave and the current value of the servo motor, and the detection start and end instruction setting unit sets the detection start point and the detection end point according to the instruction / setting of the M code for the auxiliary function used for processing.

[0016] (3) The present invention may also be that in the above (1) or (2), it further comprises: a judgment result display unit (for example, the judgment result display unit 19 described later), which makes the result obtained by comparing the vibration, the sound wave and at least one of the current values ​​of the servo motor detected during the operation of the machine tool with at least one of the preset normal vibration data, sound wave data and current value data of the servo motor reflected in the benchmark list for display; and a warning unit (for example, the warning unit 20 described later), which issues a warning when it is determined that an abnormality has occurred in the mechanism of the machine tool.

[0017] (4) The present invention may also be that in any of the above (1) to (3), the mechanism includes at least one of a spindle (e.g., spindle 2 described below) for supporting a tool (e.g., tool 3 described below), a telescopic cover (e.g., telescopic cover 10 described below) for preventing the adhesion of chips and / or cutting fluid generated by machining, and an ATC door (e.g., ATC door 12 described below) for protecting a tool magazine (e.g., tool magazine 11 described below).

[0018] (5) The present invention may also be that in any one of the above (1) to (4), a plurality of machine tools are installed in a factory, and the present invention further comprises a factory centralized management screen display unit (for example, the factory centralized management screen display unit 22 described later), which displays the machine tools determined to be abnormal by the abnormality determination unit on the factory centralized management screen.

[0019] Effects of the Invention

[0020] According to the present invention, it is possible to detect vibrations, sounds or current values ​​of servo motors generated by a machine tool's main shaft or feed axis for supporting tools, a telescopic cover or an ATC door (garage cover, door cover) for protecting a tool magazine, etc., to automatically detect abnormalities in the mechanism.

[0021] As a result, the determination of the presence or absence of abnormality, which has conventionally relied on the operator's senses, can be automatically performed mechanically, and abnormality can be detected earlier and more accurately.

[0022] As a result, the machining operation will not be continued in an abnormal state, and the occurrence of defective products can be effectively suppressed, thereby suppressing the reduction of the yield rate, the aggravation of machine tool failure, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a diagram showing a machine tool and a preventive maintenance system for the machine tool according to one embodiment of the present invention.

[0024] Figure 2This is a block diagram showing a preventive maintenance system for a machine tool according to one embodiment of the present invention.

[0025] Description of Reference Numerals

[0026] 1: machine tool; 2: spindle; 3: tool; 4: servo motor; 5: feed axis; 6: drive device; 9: automatic tool changer (ATC); 10: telescopic cover; 11: tool magazine; 12: ATC door; 13: vibration detection unit (detection unit); 14: abnormality judgment unit; 15: sound detection unit (detection unit); 16: servo motor current value detection unit (detection unit); 17: storage unit; 18: detection start and end instruction setting unit; 19: judgment result display unit; 20: warning unit; 21: centralized management unit; 22: factory centralized management screen display unit; 23: machine tool screen display unit; 25: first control unit; 26: second control unit; 27: third control unit; 28: detection information file forming unit; 29: file output unit; 30: control device (control system); A: preventive maintenance system for machine tools; W: workpiece. DETAILED DESCRIPTION

[0027] Below, refer to Figure 1 and Figure 2 A preventive maintenance system for a machine tool according to an embodiment of the present invention will be described.

[0028] Here, the present embodiment relates to a preventive maintenance system for a machine tool that can automatically determine the presence or absence of an abnormality in a mechanical manner, thereby being able to detect the abnormality earlier and more accurately.

[0029] Specifically, first, the machine tool 1 of this embodiment is a machine tool such as an NC lathe, a machining center, etc. Figure 1 As shown, for example, it is constructed to include: a spindle 2, which is arranged in a manner so that the axis O1 is oriented in the up-down direction; a rotation drive unit (spindle motor: not shown) for rotating the spindle 2 around the axis O1; a tool 3, which is mounted on the spindle 2; a drive device 6, which uses a servo motor 4 to rotate the feed axis 5 forward and reverse around the axis O2 extending in the up-down direction and to move the spindle 2 forward and backward in the up-down direction, so as to position the spindle 2 and then the tool 3; a mounting table 7, which is arranged below the spindle 2 and the tool 3 in a manner so that a workpiece W as a processing object can be fixed and supported on the upper surface and can be moved relative to the spindle 2 and the tool 3 in the up-down direction (Z) and the front-back direction (lateral direction: XY); and a preventive maintenance system A for the machine tool.

[0030] The tool 3 is coaxially arranged with the axis O1 of the spindle 2, and is connected to the spindle 2 via the holder 8 in a manner that allows for loading and unloading. In addition, in the present embodiment, the spindle 2 is configured to rotate around the axis O1, but the present invention is not limited thereto. For example, the tool 3 may be configured to include a substantially cylindrical spindle configured so that the axis O1 is oriented in the up-down direction, a rotating shaft supported via a bearing so as to be rotatable around the axis O1 inside the spindle, and a rotating drive unit for rotationally driving the rotating shaft, and the tool 3 is connected to the rotating shaft via the holder 8 in a manner that allows for loading and unloading, thereby mounting the tool 3 on the spindle.

[0031] In addition, the machine tool 1 of this embodiment is provided with an ATC (automatic tool changer) 9 for automatically replacing the tool 3, in addition to the machine tool body composed of the spindle 2, the rotation drive unit, the drive device 6, the mounting table 7, etc., and a telescopic cover 10 for protecting the drive device 6 of the machine tool body, etc., for preventing chips and cutting fluid from adhering to the drive device 6 (feed shaft 5, etc.) of the machine tool body.

[0032] The ATC 9 is constructed, for example, as follows: it has a library 11 for accommodating tools 3, an intermediate arm (not shown) for taking out the tools 3 from the library 11, an ATC arm (not shown) for replacing the tools 3, and an ATC door (liquidity cover, door cover) 12 for preventing chips and cutting fluid from adhering to these library 11 and arms to protect these library 11 and arms. The ATC 9 opens the ATC door 12 according to the instructions of the NC code when replacing the tool to accommodate the tool 3, rotate / position the library 11, and replace the tool 3 in the library 11 and the tool 3 of the spindle 2.

[0033] On the other hand, Figure 1 and Figure 2 As shown, the preventive maintenance system A of the machine tool of this embodiment comprises: a vibration detection unit (vibration sensor: detection unit) 13, which is respectively installed on the main shaft 2, telescopic cover 10, ATC door 12 and other mechanisms of the machine tool 1 for supporting the tool 3, and is used to detect vibration; and an abnormality judgment unit 14, which compares the vibration detected by the vibration detection unit 13 during the operation of the machine tool 1 with the normal vibration data acquired in advance, so as to judge whether there is any abnormality in the mechanism of the machine tool 1 (including the mechanism other than the main shaft 2, telescopic cover 10, ATC door 12).

[0034] In addition, there is also a sound detection unit (sound sensor: detection unit) 15, which is arranged near the main shaft 2, telescopic cover 10, and ATC door 12 of the machine tool 1, and is used to detect the sound waves (sound) generated during the operation of the machine tool 1. The abnormality judgment unit 14 compares the sound waves detected by the sound detection unit 15 during the operation of the machine tool 1 with the normal sound wave data acquired in advance to determine whether there is any abnormality in the mechanism of the machine tool 1.

[0035] In addition, there is also a servo motor current value detection unit (detection unit) 16 for detecting the current value of the servo motor 4. The abnormality judgment unit 14 compares the current value detected by the servo motor current value detection unit 16 during the operation of the machine tool 1 with the normal current value acquired in advance to determine whether there is any abnormality in the mechanism of the machine tool 1.

[0036] The preventive maintenance system A for a machine tool further includes a storage unit 17 for storing the detected vibration, sound wave, and current values, and for storing the vibration, sound wave, and current values ​​in a normal state.

[0037] That is, in the preventive maintenance system A of the machine tool of the present embodiment, the abnormality judgment unit 14 is configured to judge whether there is any abnormality in the mechanism of the machine tool 1 based on the vibration, sound wave, current value detected by the vibration detection unit 13, the sound detection unit 15 and the servo motor current value detection unit 16 during the operation of the machine tool 1 and the information data of the vibration, sound wave and current value under normal conditions stored in the storage unit 17.

[0038] In addition, in the present invention, it is sufficient that at least one of the vibration detection unit 13, the sound detection unit 15, and the servo motor current value detection unit 16 is provided, and the abnormality of the mechanism of the machine tool 1 is determined by the abnormality determination unit 14. In addition, the "near the mechanism of the machine tool 1" in the present invention means an area centered on the arbitrarily selected and determined mechanism of the machine tool 1 (in this embodiment, the spindle 2, the telescopic cover 10, and the ATC door 12 are selected) where sound waves can be detected by the sound detection unit 12 and the presence or absence of abnormality of the arbitrarily selected and determined mechanism of the machine tool 1 can be determined based on the detected sound waves.

[0039] The preventive maintenance system A for a machine tool of the present embodiment also comprises: a detection start and end instruction setting unit 18, which is used to add instructions for the detection start point and the detection end point of at least one of the vibration, sound wave and the current value of the servo motor in the machining program (for indication / setting); a judgment result display unit 19, which makes the result obtained by comparing at least one of the vibration, sound wave and the current value of the servo motor 4 detected during the operation of the machine tool 1 with at least one of the pre-set normal vibration data, sound wave data and the current value data of the servo motor 4 be reflected in the benchmark list for display; and a warning unit 20, which issues a warning when it is determined that an abnormality has occurred in the mechanism of the machine tool 1.

[0040] In the present embodiment, for example, an M code for performing auxiliary functions for machining includes an M code for indicating / setting a detection start point and a detection end point for at least one of vibration, sound waves, and a servomotor current value.

[0041] Moreover, the detection start and end instruction setting unit 18 is configured to add the detection start point and the detection end point to the machining program according to the indication / setting of the M code when an M code for indicating / setting the detection start point and the detection end point of at least one of vibration, sound wave and the current value of the servo motor is selected.

[0042] By using M codes as a unit for indicating / setting the detection start point and detection end point in this way, and by appropriately using macros (variables, operation instructions, conditional branches, etc.) in combination, the operator can freely start and end measurement in the machining program, and can automatically measure at least one of vibration, sound waves, and the current value of the servo motor whenever machining is performed using the machining program to be measured.

[0043] In other words, for example, in the field of numerical control of machine tools, by using the conventionally used M code as a means for instructing / setting the detection start point and the detection end point, application to a machining program can be easily performed.

[0044] Furthermore, the tool management system for a machine tool according to the present invention is not necessarily limited to using M codes as means for instructing / setting the detection start point and the detection end point.

[0045] For example, the detection start point and the detection end point may be instructed / set by using a macro function (macro variable, etc.), etc. In addition, an M code and a macro function may be used together.

[0046] That is, in addition to the M code, macro variables for measurement may be prepared, and the detection start may be set to 1 and the detection end may be set to 0. In addition, such a program may be subroutine-like and called.

[0047] However, when using a method other than M code, it is necessary to prepare logic separately, which may require a lot of effort when creating a program. In addition, readability may also be reduced.

[0048] In the present embodiment, a plurality of machine tools 1 are arranged in a factory, and these plurality of machine tools 1 are centrally managed by a centralized management unit 21 in a centralized management room. The present invention further comprises: a factory centralized management screen display unit 22, which displays the machine tool 1 determined to be abnormal on the factory centralized management screen when the abnormality determination unit 14 determines that the machine tool 1 is abnormal; and a machine tool screen display unit 23, which is arranged for the machine tool 1 determined to be abnormal and is used to indicate that an abnormality has occurred.

[0049] Here, in the machine tool 1 of the present embodiment, there is a control device (control system) 30, which has: a first control unit (for example, a numerical control device (CNC)) 25, which is used to control the machine tool body (machine tool 1); a second control unit (for example, a PMC) 26, which outputs a signal to an auxiliary device of the machine tool body (for example, an automatic tool changing device 9, etc.) via an I / O unit through a sequence program built into the numerical control device to control the auxiliary device of the machine tool body; and a third control unit (external controller) 27, which determines whether it is necessary to replace the tool 3, etc. based on the vibration, sound wave, and current value detected by the vibration detection unit 13, the sound detection unit 15, and the servo motor current value detection unit 16 during the operation of the machine tool 1.

[0050] In addition, the preventive maintenance system A for machine tools also includes: a detection information file forming unit 28, which creates a file that associates the detection results of at least one of vibration, sound waves, and the current value of the servo motor with the tool data and processing information stored in the storage unit 17; and a file output unit 29, which outputs the file created by the detection information file forming unit 28 to the outside.

[0051] In addition, the outside as the file output destination refers to, for example, a factory centralized management room, a machine tool side, etc.

[0052] In the preventive maintenance system A for a machine tool of the present embodiment, for example, a detection start and end command setting unit 18 is provided in the first control unit 25. A determination result display unit 19, a warning unit 20, a machine tool screen display unit 23, a detection information file forming unit 28, a file output unit 29, and a storage unit 17 for storing vibration, sound wave, and current values ​​and storing vibration, sound wave, and current values ​​in normal conditions are provided in the second control unit 26. An abnormality determination unit 14 is provided in the third control unit 27.

[0053] In addition, the control device 30 does not necessarily need to independently include the first control unit 25, the second control unit 26, and the third control unit 27. In addition, the means (units) provided in each of the control units 25, 26, and 27 do not need to be limited as described above.

[0054] In the preventive maintenance system A of the machine tool of this embodiment constituted by the above-mentioned structure, the operator etc. utilizes the detection start and end instruction setting unit 18 of the first control unit 25 to set the M code of the detection start point and the M code of the detection end point of the vibration, sound wave and the current value of the servo motor 4 in the machining program.

[0055] The instructions / settings of the M code of the detection start point and the M code of the detection end point are notified to the second control unit 26, and the second control unit 26 determines and extracts information such as the machine tool number, program number, sequence number, tool number, spindle, etc., information related to vibration, sound waves, and current values ​​under normal conditions, and information such as files created in the past that associate tool data, processing information, and arbitrarily selected mechanisms with vibration, sound waves, and current values ​​(benchmark lists, etc.) in the storage unit 17, and the abnormality judgment unit 14 of the third control unit 27 can obtain this information (download, etc.) and establish a measurement start flag, and the vibration detection unit 13, the sound detection unit 15, and the servo motor current value detection unit 16 begin to detect and measure vibration, sound, and current values.

[0056] At this time, if the abnormality determination unit 14 of the third control unit 27 can obtain this information and start measurement, the third control unit 27 notifies the second control unit 26 that the measurement can be started and sets an OK mark. In the case where the downloading, etc. are not completed smoothly and the measurement cannot be started, the third control unit 27 notifies the second control unit 26 that the measurement cannot be started and sets an NG mark. Thus, at the stage where the OK mark is confirmed by the second control unit 26, the first control unit 25 controls to start processing. In addition, when the NG mark is set in the second control unit 26, the warning unit 20 displays a PMC alarm, or issues a warning (alarm) such as lighting a warning light, so that the operator or the like can recognize that the NG mark has been set.

[0057] On the other hand, the abnormality judgment unit 14 of the third control unit 27 compares the measurement data (input data) of vibration, sound waves and servo motor current values ​​measured by the vibration detection unit 13, the sound detection unit 15 and the servo motor current value detection unit 16 during the operation of the machine tool 1 with the reference data (vibration, sound waves, current values ​​under normal conditions), etc. If the data exceeds a threshold value pre-set for the reference data, it is judged that an abnormality has occurred and this is notified to the second control unit 26 and the first control unit 25.

[0058] At this time, by comparing the vibration, sound wave, and current value of each mechanism at the time of abnormality stored in the storage unit 17 with the measurement data, it is possible to determine which mechanism has an abnormality (which mechanism has a high possibility of an abnormality).

[0059] At the same time, the operation of machine tool 1 is stopped, and warning unit 20 displays a PMC alarm or issues a warning such as lighting a warning lamp, so that an operator or the like can recognize that an abnormality has occurred in the mechanism of machine tool 1 .

[0060] If the detection end point is reached without exceeding the threshold, that is, if the detection end point is reached without confirming an abnormality, the first control unit 25 sends a notification of the end of measurement to the second control unit 26, and the OK flag and the NG flag are cleared.

[0061] In the event of an abnormality or when the detection end point is reached without exceeding the threshold, the detection results, judgment results, etc. of the vibration, sound waves, and servo motor current values ​​are overwritten on the benchmark list at the end of measurement and stored in the storage unit 17.

[0062] When the abnormality determination unit 14 determines that an abnormality has occurred, the factory centralized management screen display unit 22 displays the machine tool 1 in which the abnormality has occurred on the factory centralized management screen. The machine tool screen display unit 23 also displays that the abnormality has occurred in the machine tool 1 .

[0063] Therefore, in the preventive maintenance system A of the machine tool of the present embodiment, it is possible to detect vibrations, sounds or current values ​​of the servo motor 4 generated by the spindle 2 or feed shaft 5 of the machine tool 1 for supporting the tool 3, the telescopic cover 10 for preventing chips and cutting fluid from adhering to the tool magazine 11, the ATC door 12, etc., thereby automatically detecting abnormalities in the mechanism.

[0064] As a result, the determination of the presence or absence of abnormality, which has conventionally relied on the operator's senses, can be automatically performed mechanically, and abnormality can be detected earlier and more accurately.

[0065] Furthermore, by appropriately combining the three detection elements of vibration, sound waves, and the current value of the servo motor, it is possible to accurately detect abnormalities in the mechanism.

[0066] Here, not only when an abnormality occurs in the mechanism of the machine tool 1, for example, when an abnormality occurs in the workpiece W or when an abnormality occurs in the tool 3, the vibration, sound wave, and current value detected by the vibration detection unit 13, the sound detection unit 15, and the servo motor current value detection unit 16 during the operation of the machine tool 1 may be different from the normal vibration, sound wave, and current value (exceeding the threshold value).

[0067] In this regard, in the preventive maintenance system A of the machine tool of the present embodiment, the vibration, sound wave, and current value of the servo motor 4 are not simply detected and the abnormality of the mechanism is estimated and predicted based on their detected values. Instead, when a detected value different from the normal value (exceeding the threshold value) is detected, based on the information on the abnormality of the workpiece W and the information on the abnormality of the tool 3 stored in the storage unit 17, the measured data of the detected vibration, sound wave, and current value are compared with the data on the abnormality of the workpiece W and the tool 3, to determine whether the vibration waveform, sound waveform, and current value waveform are the ones when the mechanism of the machine tool 1 is abnormal, and the abnormality determination unit 14 determines whether the mechanism is abnormal based on this. In this way, it is possible to determine whether the mechanism is abnormal with high accuracy.

[0068] In the machine tool preventive maintenance system A of the present embodiment, the detection start and end command setting unit 18 can add detection start and end point commands to the machining program, so that abnormality of the mechanism can be determined at an appropriate timing during the operation of the machine tool 1 .

[0069] Specifically, for example, the detection start and end command setting unit 18 can add detection start and end point commands to the machining program, thereby enabling measurement to be started at the machining start position on any machining path that is susceptible to tool wear due to the rigidity of the workpiece W, the structure of the jig, etc., and to be ended at the machining end position. This can also reduce machining defects caused by tool wear. In addition, it is possible to obtain data only at necessary locations, so that accurate judgments can be made. That is, highly reliable judgments can be made.

[0070] In addition, in the preventive maintenance system A of the machine tool of the present embodiment, M codes (or macro variables, etc.) are used to indicate / set the detection start point and detection end point of vibration, sound wave, and current value. As a result, the operator can freely set the start and end of the measurement in the processing program. In addition, whenever the processing is performed using the processing program to be measured, the measurement can be automatically performed. Moreover, it can be simply applied to the program, there is no need to prepare logic separately, the creation of the program will not become difficult, and the readability can be properly maintained and ensured.

[0071] Furthermore, in the preventive maintenance system A for a machine tool of the present embodiment, the result obtained by comparing the vibration, sound wave, and current value of the servo motor 4 detected during the operation of the machine tool 1 with a preset threshold value (a result indicating the presence or absence of abnormality) can be reflected in the reference list for display by the judgment result display unit 19. The warning unit 20 can reliably allow an operator or the like to recognize that an abnormality has occurred in the mechanism.

[0072] In addition, by confirming the benchmark list, the operator can determine in advance the degree of deterioration of the mechanism, whether it is approaching its limit, and whether it is likely to exceed the threshold when used in the next processing. Based on this, it can also be determined whether maintenance is required and when to perform maintenance.

[0073] When the abnormality determination unit 14 determines that an abnormality has occurred in the mechanism, the factory centralized management screen display unit 22 can display the abnormal machine tool on the factory centralized management screen. The machine screen display unit 23 can display that an abnormality has occurred in the machine tool 1 .

[0074] Thus, management and maintenance of machine tool 1 can be performed efficiently and effectively.

[0075] Therefore, according to the preventive maintenance system A for a machine tool of the present embodiment, the occurrence of defective products can be effectively suppressed, thereby improving the manufacturing yield.

[0076] An embodiment of the preventive maintenance system for a machine tool according to the present invention has been described above, but the present invention is not limited to the above-described embodiment and can be modified as appropriate within the scope of the present invention.

Claims

1. A preventive maintenance system for a machine tool, comprising at least one of a vibration detector, a sound detector, and a servo motor current value detector, in, The vibration detection unit is installed on the mechanism of the machine tool and is used to detect vibration; The sound detection unit is arranged near the mechanism of the machine tool and is used to detect the sound waves generated during the operation of the machine tool; The servo motor current value detection unit is used to detect the current value of the servo motor of the driving device of the machine tool. In addition, the preventive maintenance system of the machine tool further comprises: an abnormality determination unit that compares at least one of the vibration detected by the vibration detection unit, the sound wave detected by the sound detection unit, and the current value detected by the servo motor current value detection unit during the operation of the machine tool with at least one of the vibration data, the sound wave data, and the current value data of the servo motor acquired in advance during normal operation, to determine whether the mechanism has an abnormality; and a detection start and end instruction setting unit for adding, in a machining program, instructions for detecting a start point and an end point of at least one of the vibration, the sound wave, and the current value of the servo motor, If at least one of the vibration data, the sound wave data, and the current value data of the servo motor in normal state is successfully acquired, the abnormality determination unit determines that it is possible to start measuring at least one of the vibration, the sound wave, and the current value of the servo motor, and sets an OK flag. If at least one of the vibration data, the sound wave data, and the current value data of the servo motor cannot be acquired during normal operation, the abnormality determination unit determines that it is impossible to start measuring at least one of the vibration, the sound wave, and the current value of the servo motor, and sets an NG flag; and The mechanism includes at least one of a spindle for supporting the tool, a telescopic cover for preventing the adhesion of chips and / or cutting fluid generated by machining, and an automatic tool changer door for protecting the tool magazine, and the at least one detection unit is installed on at least one of the spindle, the telescopic cover and the automatic tool changer door.

2. The preventive maintenance system for a machine tool according to claim 1, wherein: The machining program includes an M code for indicating or setting a detection start point and a detection end point of at least one of the vibration, the sound wave, and the current value of the servo motor. The detection start and end command setting unit sets the detection start point and the detection end point according to an instruction or setting of the M code for performing an auxiliary function of machining.

3. The preventive maintenance system for a machine tool according to claim 1 or 2, further comprising: a determination result display unit that displays a result of comparing at least one of the vibration, the sound wave, and the current value of the servo motor detected during the operation of the machine tool with at least one of the vibration data, the sound wave data, and the current value data of the servo motor in a preset normal state by reflecting it in a reference list; and The warning unit issues a warning when it is determined that an abnormality has occurred in the mechanism of the machine tool.

4. The preventive maintenance system for a machine tool according to claim 1 or 2, wherein: Setting up multiple machine tools in a factory, The preventive maintenance system further includes a factory centralized management screen display unit configured to display the machine tool determined to be abnormal by the abnormality determination unit on a factory centralized management screen.

5. The preventive maintenance system for a machine tool according to claim 3, wherein: Setting up multiple machine tools in a factory, The preventive maintenance system further includes a factory centralized management screen display unit configured to display the machine tool determined to be abnormal by the abnormality determination unit on a factory centralized management screen.

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