Tool checking device

Abstract

The present invention provides a tool inspection device that extracts teaching data and inspection data for a specific process even when a timing signal for the specific process is not supplied from a machine tool. The tool inspection device (1) includes: a data collection section (10) that imports waveform data for a batch amount of current supplied to a motor (50) that drives a tool of a machine tool (5); a teaching data generation section (11) that, at the time of generation of teaching data for comparison with inspection data for the tool, estimates a time range corresponding to a specific process of the machine tool (5) based on a feature of the waveform data, and extracts waveform data of the time range as the teaching data; and an inspection data generation section (13) that extracts, from the waveform data imported by the data collection section (10) at the time of inspection of the tool, waveform data of the same time position as the time range estimated by the teaching data generation section (11) as the inspection data.

Description

Technical Field

[0001] This invention relates to a tool inspection device for detecting abnormalities in machine tool cutting tools. Background Technology

[0002] Previously, the techniques disclosed in Patent Documents 1 and 2 have been used to detect abnormalities in machine tool cutting tools. In the techniques disclosed in Patent Documents 1 and 2, the presence or absence of an abnormality in the cutting tool is determined by comparing the electrical or current waveform of the motor driving the cutting tool with its normal waveform.

[0003] However, for machine tools, which have multiple cutting tools and use different tools depending on the cutting process, it is necessary to automatically determine the abnormality of different tools in each process and compare it with the waveform during normal operation.

[0004] However, in the absence of a timing signal for a finishing process supplied from the machine tool, it is necessary to infer the range of the finishing process from the diagnostic device side and extract the electrical or current waveform of the finishing process. However, this waveform extraction function has not been realized in previous technologies.

[0005] [Existing Technical Documents]

[0006] [Patent Literature]

[0007] Patent Document 1: Japanese Patent No. 4581622

[0008] Patent Document 2: Japanese Patent No. 6813517 Summary of the Invention

[0009] [The problem the invention aims to solve]

[0010] The present invention was made to solve the aforementioned problem, and aims to provide a tool inspection device and method that can extract teaching data and inspection data for a specific process even when no timing signal for a specific process is supplied from the machine tool.

[0011] [Technical means to solve the problem]

[0012] The tool inspection apparatus of the present invention includes: a data collection unit configured to import a batch of waveform data of the current supplied to the motor driving the tool of a machine tool; a teaching data generation unit configured to, when generating teaching data for comparison with the tool inspection data, infer a time range corresponding to a specific operation of the machine tool based on the characteristics of the waveform data, and extract waveform data within the time range as the teaching data; and an inspection data generation unit configured to, from the waveform data imported by the data collection unit during the tool inspection, extract waveform data at the same time position as the time range inferred by the teaching data generation unit as the inspection data.

[0013] Furthermore, the inspection data generation unit divides the teaching data into blocks along the time direction, aligning the time position of the teaching data with that of the inspection data in each block.

[0014] Furthermore, the teaching data generation unit includes: a first level determination unit configured to determine a first threshold level, the first threshold level being used to extract waveform data representing the range of the finishing process of the machine tool from a batch of waveform data imported by the data collection unit during the generation of the teaching data; a first extraction processing unit configured to extract a range of values ​​below the first threshold level before the batch ends from a batch of waveform data imported by the data collection unit during the generation of the teaching data, as the waveform data representing the range of the finishing process; a second level determination unit configured to determine a second threshold level, the second threshold level being used to detect the rise of the waveform within the range of the finishing process; and an extraction length determination unit configured to determine the length of the waveform within the range of the finishing process from the current... The length of the teaching data is determined by adding a predetermined time to the time from the point when the value first exceeds the second threshold level until the end of the batch; and the second interception processing unit is configured to intercept data from a batch of waveform data imported by the data collection unit during the generation of the teaching data, where the current value is below the first threshold level and the length is within the interception length range before the end of the batch, as the teaching data. The inspection data generation unit includes a third interception processing unit, which is configured to intercept data from a batch of waveform data imported by the data collection unit during the inspection of the tool, where the current value is below the first threshold level and the length is within the interception length range before the end of the batch, as the inspection data.

[0015] Furthermore, the first level determination unit, the first interception processing unit, the second level determination unit, and the interception length determination unit process waveform data imported multiple times by the data collection unit. The second interception processing unit uses the average value of the first threshold level and the average value of the interception length obtained through the multiple processing to intercept data from the batch of waveform data imported by the data collection unit when the teaching data is generated. The interception data is used as the teaching data because it is data that is about to end in the batch, has a current value below the average value of the first threshold level, and has a length within the range of the average interception length. The third interception processing unit intercepts data from the batch of waveform data imported by the data collection unit when the tool is inspected. The interception data is data that is about to end in the batch, has a current value below the average value of the first threshold level, and has a length within the range of the average interception length, and is used as the inspection data.

[0016] Furthermore, the teaching data generation unit includes: a first level determination unit configured to determine a first threshold level, the first threshold level being used to extract waveform data representing the range of the finishing process of the machine tool from a batch of waveform data imported by the data collection unit when the teaching data is generated; a first extraction processing unit configured to extract a range of values ​​below the first threshold level from the batch of waveform data imported by the data collection unit when the teaching data is generated, as the range of waveform data for the finishing process; a second level determination unit configured to determine a second threshold level, the second threshold level being used to detect the rise of the waveform within the range of the finishing process; an extraction length determination unit configured to determine the extraction length of the teaching data by adding a predetermined time to the length of time within the range of the finishing process from the point when the current value first exceeds the second threshold level until the end of the batch; and a second extraction processing unit configured to extract waveform data from the batch of waveform data imported by the data collection unit when the teaching data is generated, where the current value is below the first threshold level and the length is within the range of the first threshold level. The inspection data generation unit includes: a third interception processing unit configured to intercept data from a batch of waveform data imported by the data collection unit during the inspection of the tool, specifically data that is about to end in the batch, has a current value below a first threshold level, and has a length within the interception length range, as the inspection data; a third level determination unit configured to determine a third threshold level based on the instruction data, the third threshold level being used to detect the start time of position correction for the inspection data; a block extraction unit configured to set the time point in the instruction data where the current value exceeds the third threshold level as the start time of position correction, and to set the range between the start times of position correction for the instruction data as a position correction block; a correlation coefficient calculation unit configured to calculate, for each position correction block, the correlation coefficient between the position correction block of the instruction data and the inspection data in the same time interval as the position correction block; and a correction unit configured to perform the following processing for each position correction block: moving the time position of the inspection data in the block interval to maximize the correlation coefficient.

[0017] Furthermore, the first level determination unit, the first interception processing unit, the second level determination unit, and the interception length determination unit process waveform data imported multiple times by the data collection unit. The second interception processing unit uses the average value of the first threshold level and the average value of the interception length obtained through the multiple processing to intercept data from the batch of waveform data imported by the data collection unit when the teaching data is generated. The interception data is used as the teaching data because it is data that is about to end in the batch, has a current value below the average value of the first threshold level, and a length within the range of the average interception length. The third interception processing unit intercepts data from the batch of waveform data imported by the data collection unit when the tool is inspected. The interception data is data that is about to end in the batch, has a current value below the average value of the first threshold level, and a length within the range of the average interception length. The third level determination unit determines the third threshold level based on the average data of multiple teaching data. The block extraction unit extracts the position correction block from the average data of multiple teaching data.

[0018] Furthermore, the tool inspection method of the present invention includes: a first step of importing a batch of waveform data of the current supplied to the motor driving the tool of a machine tool; a second step of, when generating teaching data for comparison with the tool inspection data, inferring a time range corresponding to a specific operation of the machine tool based on the characteristics of the waveform data, and extracting waveform data within the time range as the teaching data; and a third step of, extracting waveform data at the same time position as the time range inferred by the second step from the waveform data imported during the tool inspection via the first step, and using it as the inspection data.

[0019] Furthermore, the third step includes the following steps: dividing the teaching data into blocks along the time direction, and aligning the time position of the teaching data with that of the inspection data in each block.

[0020] [The effects of the invention]

[0021] According to the present invention, by providing a teaching data generation unit and an inspection data generation unit, even when no timing signal for a specific process such as a finishing process is supplied from the machine tool, the range of a specific process can be estimated and the teaching data and inspection data for that specific process can be extracted from the tool inspection device side.

[0022] Furthermore, in this invention, the inspection data generation unit divides the teaching data into blocks along the time direction and aligns the time positions of the teaching data and the inspection data in each block. Thus, even if a time deviation occurs in the machining process of the machine tool in units of the control timing cycle inside the machine tool, the time deviation can be corrected. Attached Figure Description

[0023] Figure 1 This is a block diagram illustrating the structure of a tool inspection system according to an embodiment of the present invention.

[0024] Figure 2 This is a block diagram illustrating the structure of a tool inspection device according to an embodiment of the present invention.

[0025] Figure 3 This is a flowchart illustrating the teaching data generation and processing of an embodiment of the present invention.

[0026] Figure 4 This is a flowchart illustrating the teaching data generation and processing of an embodiment of the present invention.

[0027] Figure 5 (A) Figure 5 (B) in the figure is an example of a waveform representing a batch of current supplied to a motor.

[0028] Figure 6 This is a diagram illustrating an example of the current waveform representing the range of the finishing process.

[0029] Figure 7 This is a diagram illustrating an example of a current waveform representing a cut-off length within the range of a finishing process.

[0030] Figure 8 This is a flowchart illustrating the data generation process for inspection in an embodiment of the present invention.

[0031] Figure 9 This is an example of a graph showing the average waveform of teaching data representing the number of learning sessions.

[0032] Figure 10 (A) to Figure 10 (C) is a graph representing the position correction block of the teaching data, the waveform extracted from the position correction block, and the waveform extracted from the inspection data.

[0033] Figure 11 This is a block diagram illustrating an example of the structure of a computer implementing an embodiment of the tool inspection apparatus of the present invention.

[0034] [Explanation of Symbols]

[0035] 1: Tool Inspection Device

[0036] 2: CT scan

[0037] 3: Monitor

[0038] 4: External storage device

[0039] 5: Machine tools

[0040] 6: Terminal

[0041] 10: Data Collection Department

[0042] 11: Teaching Data Generation Department

[0043] 12: Teaching Data Accumulation Department

[0044] 13: Check the data generation department

[0045] 14: Check the data storage department

[0046] 15: Judgment Department

[0047] 16: Management Department

[0048] 50: Motor

[0049] 51: Control Department

[0050] 52: PLC

[0051] 110, 112, 132: Level Determination Unit

[0052] 111, 114, 131: Interception and Processing Department

[0053] 113: Determining the Length of the Cut-off Section

[0054] 115, 136: Storage Department

[0055] 133: Block Extraction Department

[0056] 134: Correlation Coefficient Calculation Department

[0057] 135: Revision Department

[0058] 200: CPU

[0059] 201: Storage device

[0060] 202: Interface device

[0061] CB: Position Correction Block

[0062] S100~S105, S200~S204, S300~S309: Steps

[0063] SH: Scope of finishing processes

[0064] T1: Duration

[0065] T2: Time

[0066] TC: Timing of Position Correction

[0067] TP: Trigger Point Detailed Implementation

[0068] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a block diagram illustrating the structure of a tool inspection system according to an embodiment of the present invention. The tool inspection system includes: a tool inspection device 1; a current transformer (CT) 2, which acts as a converter to convert the current supplied to the motor driving the tool of the machine tool 5 into a current of a magnitude that can be processed by the tool inspection device 1; a display 3 for displaying the inspection results of the tool by the tool inspection device 1; and an external storage device 4 for storing the data obtained by the tool inspection device 1.

[0069] Machine tool 5 includes: a cutting tool (not shown) for machining a workpiece; a motor 50 for driving the cutting tool; a control unit 51 for controlling the motor 50; and a programmable logic controller (PLC) 52 for controlling the entire machine tool.

[0070] Figure 2 This is a block diagram showing the structure of the tool inspection device 1. The tool inspection device 1 includes: a data collection unit 10, which imports a batch of waveform data of the current supplied to the motor 50 via the CT 2; a teaching data generation unit 11, which, when generating teaching data for comparison with tool inspection data, infers the time range corresponding to the finishing process of the machine tool 5 based on the characteristics of the waveform data, and extracts waveform data within the time range as teaching data; a teaching data accumulation unit 12, which accumulates teaching data; an inspection data generation unit 13, which extracts waveform data from the waveform data imported by the tool inspection data collection unit 10 at the same time position as the time range inferred by the teaching data generation unit 11 as inspection data; an inspection data accumulation unit 14, which accumulates inspection data; a judgment unit 15, which compares the teaching data and the inspection data to determine whether the tool has malfunctioned; and a management unit 16, which is used for accepting input from the operator, setting data collection conditions, etc.

[0071] The teaching data generation unit 11 includes: a level determination unit 110, which determines a first threshold level, the first threshold level being used to extract waveform data of the range of the finishing process of the machine tool 5 from a batch of waveform data imported by the data collection unit 10 during the generation of teaching data; an extraction processing unit 111, which extracts the range of values ​​below the first threshold level before the batch ends from the batch of waveform data imported by the data collection unit 10 during the generation of teaching data as waveform data of the range of the finishing process; a level determination unit 112, which determines a second threshold level, the second threshold level being used to detect the rise of the waveform within the range of the finishing process; an extraction length determination unit 113, which determines the extraction length of the teaching data by adding a predetermined time to the length of time within the range of the finishing process from the time point when the current value first exceeds the second threshold level until the end of the batch; an extraction processing unit 114, which extracts data from the batch of waveform data imported by the data collection unit 10 during the generation of teaching data that is below the first threshold level and whose length is within the range of the extraction length before the batch ends as teaching data; and a storage unit 115.

[0072] The inspection data generation unit 13 includes: a segmentation processing unit 131, which extracts data from a batch of waveform data imported by the tool inspection data collection unit 10, where the current value is below a first threshold level and the length is within the segmentation length range before the end of the batch, as inspection data; a level determination unit 132, which determines a third threshold level based on teaching data, the third threshold level being used to detect the start time of position correction for the inspection data; a block extraction unit 133, which sets the time point in the teaching data where the current value exceeds the third threshold level as the start time of position correction, and sets the range between the start times of position correction for the teaching data as a position correction block; a correlation coefficient calculation unit 134, which calculates the correlation coefficient of the position correction block of the teaching data and the inspection data of the block interval at the same time position as the position correction block for each position correction block; a correction unit 135, which performs the following processing for each position correction block, namely, moving the time position of the inspection data of the block interval to maximize the correlation coefficient; and a storage unit 136.

[0073] First, the method for generating teaching data for tool inspection will be explained. Figure 3 , Figure 4 This is a flowchart illustrating the generation and processing of teaching data.

[0074] When the cutting tools on the machine tool 5 are in a normal state, the operator of the cutting tool inspection device 1 operates the terminal 6 to instruct the generation of teaching data for the cutting tool inspection device 1.

[0075] When the tool inspection device 1 receives an instruction from the operator via the management unit 16, it performs a parameter determination process a predetermined number of times. This parameter determination process is used to extract the current waveform data of the workpiece in the finishing process from the current waveform data supplied to the motor 50 of the machine tool 5 as teaching data. Figure 3 Steps S100 and S101).

[0076] In the parameter determination process, the data collection unit 10 of the tool inspection device 1 imports a batch of current waveform data from the start time of the roughing operation of the workpiece to the end time of the finishing operation via the CT 2. Figure 4 Step S200). The data imported by the data collection unit 10 is stored in the storage unit 115 within the teaching data generation unit 11. A timing signal roughly representing a batch can be obtained from the PLC 52. An example of a batch current waveform is shown below. Figure 5 (A) in the middle. Figure 5 (B) in the text indicates Figure 5 The portion of the current waveform in (A) that is extracted for teaching or testing purposes.

[0077] Next, the teaching data generation unit 11 of the tool inspection device 1 determines the threshold level (hereinafter referred to as THLEVEL) of the current waveform data used to extract the range of the finishing process from a batch of current waveform data imported by the data collection unit 10. Figure 4 (Step S201). Specifically, the level determination unit 110 within the teaching data generation unit 11 sets the current value of half the current peak value in a batch of current waveform data as THLEVEL. Alternatively, a histogram of the current in a batch can be created, and the center value can be set as THLEVEL.

[0078] Furthermore, the interception and processing unit 111 within the teaching data generation unit 11 sets the last time point in a batch of current waveform data imported by the data collection unit 10 from a current value below THLEVEL (Low) to a current value above THLEVEL (High) as the trigger point TP (batch end time point), and intercepts the range of current values ​​below THLEVEL of the trigger point TP immediately preceding it as the current waveform data of the finishing process range SH. Figure 4 Step S202). The scope of the finishing process SH is shown in... Figure 6 .

[0079] like Figure 6As shown, the reason for selecting the range SH of the finishing process is that the data of a batch has the following characteristics: in the first half, during rough cutting and other operations, the current waveform has a large deviation, while in the second half of the finishing process, the waveform with small peaks is continuous. At the end of a batch, due to the back electromotive force of the motor stopping, the waveform will rise sharply once and then end.

[0080] Subsequently, the level determination unit 112 within the teaching data generation unit 11 determines the threshold level (hereinafter referred to as UPLEVEL) for detecting the rise of the current waveform within the range SH of the finishing process. Figure 4 Step S203). Specifically, the level determination unit 112 classifies the current waveform data of the finishing process range SH into two clusters using, for example, the K-means method. Furthermore, the level determination unit 112 sets the current value at the midpoint of the centroid of each of the two clusters as UPLEVEL.

[0081] Next, the truncation length determination unit 113 within the teaching data generation unit 11 determines the truncation length of the teaching data (hereinafter referred to as THLENGTH) as the length obtained by adding the time T1 of the specified header range to the time T2 within the range SH of the finishing process, from the point when the current value first exceeds UPLEVEL until the trigger point TP. Figure 4 Step S204). The above allows us to determine the two interception parameters, THLEVEL and THLENGTH, based on a batch of current waveform data. The interception parameters determine the end of the processing. An example of the current waveform for the THLENGTH quantity within the range SH of the finishing process is shown below. Figure 7 .

[0082] The data collection unit 10 and the teaching data generation unit 11 perform the interception parameter determination process in step S101 (S200~S204) whenever a batch of current waveform data is imported.

[0083] After the parameter determination process is performed a certain number of times, the interception processing unit 114 in the teaching data generation unit 11 sets the average value of multiple THLEVELs obtained from the current waveform data of the number of parameter determinations as THLEVELa, and sets the average value of multiple THLENGTHs obtained from the current waveform data of the number of parameter determinations as THLENGTHa. Figure 3 Step S102).

[0084] Subsequently, the interception processing unit 114 performs processing to extract teaching data from a batch of current waveform data stored in the storage unit 115 after a predetermined number of learning cycles. Figure 3Steps S103 and S104). Specifically, the interception processing unit 114 intercepts data from a batch of current waveform data stored in the storage unit 115, specifically the data of the trigger point TP immediately preceding the current value, with a current value of THLEVELa or less and a length within the range of THLENGTHa, as teaching data.

[0085] The interception and processing unit 114 saves the intercepted teaching data to the teaching data storage unit 12. Figure 3 Step S105). Similarly, the trigger point TP (batch end time point) is the last time point in a batch of current waveform data stored in the storage unit 115 when the current value below THLEVELa (Low) becomes a current value above THLEVELa (High).

[0086] At the point in time when teaching data was captured and saved according to a pre-defined number of learning sessions ( Figure 3 If step S103 is "No", the teaching data generation and processing is complete.

[0087] In addition, during the parameter determination processing stage, the data collection unit 10 imports a batch of current waveform data based on the number of parameter determinations, so the number of learning iterations only needs to be less than the number of parameter determinations.

[0088] Next, the operator operating terminal 6 of the tool inspection device 1 performs the inspection of the tools on the machine tool 5 as instructed by the tool inspection device 1.

[0089] When the tool inspection device 1 receives instructions from the operator via the management unit 16, it performs inspection data generation processing. Figure 8 This is a flowchart illustrating the data generation and processing for inspection.

[0090] The data collection unit 10 of the tool inspection device 1 imports a batch of current waveform data via the CT 2. Figure 8 (Step S300). The data imported by the data collection unit 10 is stored in the storage unit 136 within the inspection data generation unit 13.

[0091] The interception processing unit 131 in the inspection data generation unit 13 intercepts data from a batch of current waveform data stored in the storage unit 136, specifically the data of the immediately preceding trigger point TP, whose current value is below THLEVELa and whose length is within the range of THLENGTHa, as inspection data. Figure 8Step S301). The inspection data is stored in the storage unit 136 within the inspection data generation unit 13. Similarly, the trigger point TP (batch end time point) is the last time point in a batch of current waveform data stored in the storage unit 136 where the current value below THLEVELa (Low) becomes a current value above THLEVELa (High).

[0092] Subsequently, the level determination unit 132 within the inspection data generation unit 13 determines, based on the average data of the number of learning sessions stored in the instruction data accumulation unit 12, the threshold level (hereinafter referred to as UPLEVEL2) for detecting the start timing of position correction of the inspection data. Figure 8 Step S302). Specifically, the level determination unit 132 classifies the average data of the number of learning sessions into two clusters, for example, using the K-means method. Furthermore, the level determination unit 132 sets the current value at the midpoint of the centroid of each of the two clusters to UPLEVEL2.

[0093] Next, the block extraction unit 133 within the data generation unit 13 checks the current value in the average data of the number of learning sessions that exceeds UPLEVEL2 as the start time TC for position correction of the check data, and defines the range from the start time TC for position correction of the average data of the learning data to the next start time TC for position correction as the position correction block CB. Figure 8 Step S303). An example of the average waveform of the teaching data from the number of learning sessions is shown below. Figure 9 .

[0094] The correlation coefficient calculation unit 134 within the inspection data generation unit 13 extracts data of the width of the preceding and following window from the position correction block CB, which is the object of correlation coefficient calculation, centered on the position correction start time TC on the start side of the position correction block CB. It also extracts data of the width of the preceding and following window from the inspection data within the block interval at the same time position as the position correction block CB, centered on the position correction start time TC, and calculates the correlation coefficient between the data extracted from the position correction block CB and the data extracted from the inspection data. Figure 8 Step S305). The so-called block interval of the inspection data refers to the range in which the position correction block CB is located at the same time position when the beginning of the average data of the teaching data is set to time 0 and the beginning of the inspection data is set to time 0.

[0095] Figure 10 (A) represents the location correction block CB of the teaching data. Figure 10 (B) represents the waveform extracted from the position correction block CB. Figure 10(C) represents the waveform extracted from the inspection data of the block interval.

[0096] Next, the correlation coefficient calculation unit 134 will check the amount by which the time position of the data is shifted by a specified time t (t < window). Figure 8 (Step S306) From the position correction block CB, which is the object of correlation coefficient calculation, data of the width before and after the position correction start time TC on the start side of the position correction block CB is extracted. From the inspection data of the block interval that is at the same time position as the position correction block CB after the time position is moved, data of the width before and after the position correction start time TC is extracted. The correlation coefficient between the data extracted from the position correction block CB and the data extracted from the inspection data is calculated again (Step S305).

[0097] The correlation coefficient calculation unit 134 repeatedly calculates the correlation coefficient while moving the time position of the data to be checked within a specified time range (e.g., from TC-window to TC+window) centered on the position correction start time TC of the position correction block CB, which is the object of the correlation coefficient calculation.

[0098] After calculating all correlation coefficients within the specified time frame ( Figure 8 In step S307, the correction unit 135 within the inspection data generation unit 13 sets the position correction start time TC of the position correction block CB as the reference position, calculates the deviation of the time position where the correlation coefficient reaches its maximum relative to the reference position, and only for the inspection data in the inspection data stored in the storage unit 136 that is the block interval for which the correlation coefficient is calculated, shifts the time position by the deviation, thereby updating the inspection data stored in the storage unit 136. Figure 8 Step S308).

[0099] This ensures that the time positions of the location correction block CB and the inspection data of its corresponding block interval are aligned. Furthermore, in step S306, the time position of the entire inspection data is moved, but the inspection data stored in storage unit 136 is not updated. On the other hand, in step S308, only the time position of the inspection data for the block interval is changed, and the inspection data stored in storage unit 136 is updated.

[0100] Furthermore, the correction unit 135 only moves the data for the block interval being used for correlation coefficient calculation. Therefore, for example, if the data has been moved in the direction of time delay, the deviation amount is removed from the data at the end of this block interval. Furthermore, blank areas with no data may appear at the beginning of the block interval. Therefore, the correction unit 135 interpolates the data by appending the data with the deviation amount immediately following the end of the preceding block interval to the beginning of the current block interval.

[0101] Furthermore, when the correction unit 135 shifts the inspection data of the block interval, which is the object of the correlation coefficient calculation, in the direction of advancing the time, it removes the deviation amount from the data at the beginning of the block interval. Consequently, blank areas with no data appear at the end of the block interval; therefore, the correction unit 135 interpolates the data by appending the data of the deviation amount from the beginning of the subsequent block interval to the end of the block interval.

[0102] The inspection data generation unit 13 performs steps S305 to S308 on each position correction block CB of the average data of the teaching data. After processing is completed for all position correction blocks CB, the correction unit 135 saves the inspection data stored in the storage unit 136 to the inspection data accumulation unit 14. Figure 8 Step S309).

[0103] The determination unit 15 of the tool inspection device 1 compares the average data of the teaching data stored in the teaching data accumulation unit 12 with the inspection data stored in the inspection data accumulation unit 14 to determine whether the tool of the machine tool 5 has malfunctioned. The determination method in this case is a well-known technique, such as that disclosed in Patent Documents 1 and 2. Furthermore, the present invention is not limited to a specific determination method.

[0104] The judgment unit 15 displays, for example, the waveforms of the judgment result, the average data of the teaching data, and the waveforms of the inspection data on the display 3. Furthermore, the judgment unit 15 saves the judgment result, the average data of the teaching data, and the inspection data to the external storage device 4.

[0105] As described above, in this embodiment, even when no timing signal for the finishing process is supplied from the machine tool 5, the teaching data and inspection data for the finishing process can be extracted from the tool inspection device 1 by estimating the interval of the finishing process. Moreover, sometimes the machining time of the machine tool 5 may deviate in time in units of the machine tool's internal control timing cycle, but in this embodiment, the time positions of the teaching data and inspection data can be aligned in blocks, thereby correcting the time deviation.

[0106] The tool inspection device 1 described in this embodiment can be implemented using a computer including a central processing unit (CPU), storage devices, and interfaces, along with a program that controls these hardware resources. The structure of this computer is illustrated below. Figure 11 .

[0107] The computer includes a CPU 200, a storage device 201, and an interface device (interface (I / F)) 202. A display 3, an external storage device 4, a machine tool 5, and a terminal 6 are connected to the I / F 102. In this computer, a program for implementing the tool inspection method of the present invention is stored in the storage device 201. The CPU 200 executes the processing described in this embodiment based on the program stored in the storage device 201. Furthermore, at least a portion of the tool inspection device 1 can also be implemented in hardware.

[0108] [Industry availability]

[0109] This invention is applicable to the technology of detecting abnormalities in machine tool cutting tools.

Claims

1. A tool inspection device, characterized in that, include: The data collection unit is configured to import a batch of waveform data of the current supplied to the motor driving the cutting tool of the machine tool. The teaching data generation unit is configured to, when generating teaching data for comparison with inspection data of the cutting tool, infer a time range corresponding to a specific operation of the machine tool based on the characteristics of the waveform data, and extract waveform data of the time range as the teaching data. as well as The inspection data generation unit is configured to extract waveform data from the waveform data imported by the data collection unit during the inspection of the cutting tool, at a time position that corresponds to the time range predicted by the teaching data generation unit, and use this data as the inspection data. The teaching data generation unit includes: The first level determination unit is configured to determine a first threshold level, which is used to extract waveform data of the range of the finishing process of the machine tool from a batch of waveform data imported by the data collection unit when the teaching data is generated. The first interception processing unit is configured to intercept a range of values ​​below the first threshold level before the end of the batch of waveform data imported by the data collection unit when the teaching data is generated, and use this range of waveform data as the range of the finishing process. The second level determination unit is configured to determine a second threshold level, which is used to detect the rise of the waveform within the range of the finishing process; The truncation length determination unit is configured to determine the truncation length of the teaching data by adding a predetermined time to the time length obtained by adding the current value to the time from the point when it first exceeds the second threshold level within the range of the finishing process until the end of the batch; and The second interception processing unit is configured to intercept data from a batch of waveform data imported by the data collection unit during the generation of the teaching data. This data is selected just before the end of the batch, has a current value below the first threshold level, and a length within the interception length range, and is used as the teaching data. The inspection data generation unit includes a third interception processing unit, which is configured to intercept data from a batch of waveform data imported by the data collection unit during the inspection of the tool. The data intercepted is taken from the batch of waveform data that is about to end before the batch ends, and the current value is below the first threshold level and the length is within the interception length range, and is used as the inspection data.

2. The tool inspection device according to claim 1, characterized in that, The first level determination unit, the first truncation processing unit, the second level determination unit, and the truncation length determination unit each process a batch of waveform data imported multiple times by the data collection unit. The second interception processing unit uses the average value of the first threshold level obtained through the multiple processing steps and the average value of the interception length to intercept data from a batch of waveform data imported by the data collection unit when the teaching data is generated. The interception data is selected from the data just before the end of the batch, where the current value is below the average value of the first threshold level and the length is within the range of the average interception length, and is used as the teaching data. The third interception processing unit intercepts data from a batch of waveform data imported by the data collection unit during the inspection of the cutting tool. The intercepted data is taken from the data that is about to end the batch, has a current value below the average value of the first threshold level, and has a length within the range of the average interception length, and is used as the inspection data.

3. A tool inspection device, characterized in that, include: The data collection unit is configured to import a batch of waveform data of the current supplied to the motor driving the cutting tool of the machine tool. The teaching data generation unit is configured to, when generating teaching data for comparison with inspection data of the cutting tool, infer a time range corresponding to a specific operation of the machine tool based on the characteristics of the waveform data, and extract waveform data of the time range as the teaching data. as well as The inspection data generation unit is configured to extract waveform data from the waveform data imported by the data collection unit during the inspection of the cutting tool, at a time position that corresponds to the time range predicted by the teaching data generation unit, and use this data as the inspection data. The inspection data generation unit divides the teaching data into blocks along the time direction, aligning the time position of the teaching data with that of the inspection data within each block. The teaching data generation unit includes: The first level determination unit is configured to determine a first threshold level, which is used to extract waveform data of the range of the finishing process of the machine tool from a batch of waveform data imported by the data collection unit when the teaching data is generated. The first interception processing unit is configured to intercept a range of values ​​below the first threshold level before the end of the batch of waveform data imported by the data collection unit when the teaching data is generated, and use this range of waveform data as the range of the finishing process. The second level determination unit is configured to determine a second threshold level, which is used to detect the rise of the waveform within the range of the finishing process; The truncation length determination unit is configured to determine the truncation length of the teaching data by adding a predetermined time to the time length obtained by adding the current value to the time from the point when it first exceeds the second threshold level within the range of the finishing process until the end of the batch; and The second interception processing unit is configured to intercept data from a batch of waveform data imported by the data collection unit during the generation of the teaching data. This data is selected just before the end of the batch, has a current value below the first threshold level, and a length within the interception length range, and is used as the teaching data. The inspection data generation unit includes: The third interception processing unit is configured to intercept data from a batch of waveform data imported by the data collection unit during the inspection of the cutting tool. The data that is about to end in the batch and whose current value is below the first threshold level and whose length is within the range of the interception length is used as the inspection data. The third level determination unit is configured to determine a third threshold level based on the teaching data, and the third threshold level is used to detect the timing of starting the position correction of the inspection data. The block extraction unit is configured to set the time point when the current value in the teaching data exceeds the third threshold level as the position correction start time, and to set the range between the position correction start times of the teaching data as the position correction block. The correlation coefficient calculation unit is configured to calculate, for each of the position correction blocks, the correlation coefficient between the position correction block of the teaching data and the check data of the block interval that is at the same time position as the position correction block; and The correction unit is configured to perform the following processing for each location correction block: shifting the time position of the inspection data in the block interval to maximize the correlation coefficient.

4. The tool inspection device according to claim 3, characterized in that, The first level determination unit, the first truncation processing unit, the second level determination unit, and the truncation length determination unit each process a batch of waveform data imported multiple times by the data collection unit. The second interception processing unit uses the average value of the first threshold level obtained through the multiple processing steps and the average value of the interception length to intercept data from a batch of waveform data imported by the data collection unit when the teaching data is generated. The interception data is selected from the data just before the end of the batch, where the current value is below the average value of the first threshold level and the length is within the range of the average interception length, and is used as the teaching data. The third interception processing unit intercepts data from a batch of waveform data imported by the data collection unit during the inspection of the cutting tool. This interception data is taken just before the end of the batch, and the current value is below the average value of the first threshold level, with the length falling within the average range of the interception length. This interception data is then used as the inspection data. The third level determination unit determines the third threshold level based on the average data of multiple teaching data sets. The block extraction unit extracts the position correction block from the average data of multiple teaching data sets.

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