Machining condition management system, machining control device, machining system, and machining program

Abstract

A machining condition management system, a machining control device, a machining system, and a machining program are provided that are capable of appropriately correcting machining conditions based on a determination of the load on a cutting tool. [Solution] The machining condition management system includes a cutting tool having a cutting edge and a sensor, a memory unit that stores machining conditions of a machine tool that performs machining using the cutting tool and measurement values ​​measured by the sensor, and a calculation unit that corrects the machining conditions based on the machining conditions and measurement values ​​stored in the memory unit. The calculation unit determines the load on the cutting tool based on the measurement values ​​in a first cutting process under the machining conditions, calculates a correction value for correcting the machining conditions for at least one cutting section that satisfies a predetermined condition in the determination in the first cutting process, and updates and outputs the machining conditions for a second cutting process based on the calculated correction value.

Description

[Technical Field]

[0001] The present disclosure relates to a machining condition management system, a machining control device, a machining system, and a machining program. [Background technology]

[0002] Patent Document 1 (JP 2018-534680 A) discloses a method executed in a control system including a programmable logic controller configured to control the operation of a machine and a numerical controller configured to control relative motion between a tool of the machine and a workpiece. The method includes evaluating an input signal received by the programmable logic controller with respect to a first condition. The input signal includes information regarding a machining condition change process performed by a state of the tool or an interaction between the tool and the workpiece. The method includes providing information to the numerical controller in response to the input signal satisfying the first condition. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2018-534680 Summary of the Invention

[0004] The machining condition management system according to the present disclosure includes a cutting tool having a cutting edge and a sensor, a memory unit that stores machining conditions of a machine tool that uses the cutting tool to perform machining and measurement values ​​measured by the sensor, and a calculation unit that corrects the machining conditions based on the machining conditions and measurement values ​​stored in the memory unit. The calculation unit determines the load on the cutting tool based on the measurement values ​​in a first cutting process that machines a first workpiece under the machining conditions, calculates a correction value for correcting the machining conditions of at least one machining section that satisfies a predetermined condition in the determination in the first cutting process, updates the machining conditions in a second cutting process that machines a second workpiece in a different machining process based on the calculated correction value, and outputs the result. The distribution of the measured values ​​in the first cutting process is obtained, and the section in which the excessive load occurs is determined based on the statistics of the distribution. .

[0005] The machining control device according to the present disclosure includes a memory unit that stores machining conditions of a machine tool that uses a cutting tool having a cutting edge and a sensor and measurement values ​​measured by the sensor, a calculation unit that corrects the machining conditions based on the machining conditions and measurement values ​​stored in the memory unit, and a drive control unit that performs machining under the machining conditions. The calculation unit determines the load on the cutting tool based on the measurement values ​​in a first cutting process that machines a first workpiece under the machining conditions, calculates a correction value for correcting the machining conditions for at least one machining section that satisfies a predetermined condition in the determination in the first cutting process, updates the machining conditions in a second cutting process that machines a second workpiece in a different machining process based on the calculated correction value, and outputs the result to the drive control unit. The distribution of the measured values ​​in the first cutting process is obtained, and the section in which the excessive load occurs is determined based on the statistics of the distribution. .

[0006] A machining system according to the present disclosure includes a machine tool that performs machining using a cutting tool having a cutting edge and a sensor, and a machining control device that controls the machine tool based on machining conditions. The machining control device includes a memory unit that stores the machining conditions of the machine tool and measurement values ​​measured by the sensor, a calculation unit that corrects the machining conditions based on the machining conditions and measurement values ​​stored in the memory unit, and a drive control unit that performs machining under the machining conditions. The calculation unit determines the load on the cutting tool based on the measurement values ​​in a first cutting process that machines a first workpiece under the machining conditions, calculates a correction value for correcting the machining conditions for at least one machining section that satisfies a predetermined condition in the determination in the first cutting process, updates the machining conditions in a second cutting process that machines a second workpiece in a different machining process based on the calculated correction value, and outputs the result to the drive control unit. The distribution of the measured values ​​in the first cutting process is obtained, and the section in which the excessive load occurs is determined based on the statistics of the distribution. .

[0007] The machining program according to the present disclosure is executed by a calculation unit that corrects the machining conditions based on the machining conditions of a machine tool that uses a cutting tool having a cutting edge and a sensor and the measured values ​​measured by the sensor. The machining program includes the steps of: determining the load on the cutting tool based on the measured values ​​in a first cutting process that machines a first workpiece under the machining conditions; calculating a correction value for correcting the machining conditions in at least one machining section that satisfies a predetermined condition in the first cutting process; and updating and outputting the machining conditions in a second cutting process that machines a second workpiece in a different machining step based on the calculated correction value. A step of obtaining a distribution of measurement values ​​in the first cutting process and determining an interval in which an excessive load occurs based on statistics of the distribution; Includes: [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing the configuration of a processing system according to this embodiment. [Figure 2] FIG. 2 is a diagram showing the configuration of the sensor module according to this embodiment. [Figure 3] FIG. 3 is a diagram showing the configuration of the analysis device according to this embodiment. [Figure 4] FIG. 4 is a flowchart showing the processing executed by the processor of the analyzer according to this embodiment. [Figure 5] FIG. 5 is a diagram showing an example in which a processing section is identified from the measurement value of the sensor according to this embodiment. [Figure 6] FIG. 6 is a diagram showing an example of distribution evaluation of the measurement values ​​of the sensor according to this embodiment. [Figure 7] FIG. 7 is a diagram showing an example in which the results of distribution evaluation are applied to time-series data of measurement values ​​of a sensor according to this embodiment. [Figure 8] FIG. 8 is a diagram showing an example of correction values ​​for correcting machining conditions of the machine tool according to this embodiment. [Figure 9] FIG. 9 is a diagram showing an example of estimated sensor measurement values ​​after modifying the machining conditions of the machine tool according to this embodiment. [Figure 10]FIG. 10 is a diagram showing an example of distribution evaluation normalized to the measurement values ​​of the sensor according to this embodiment. [Figure 11] FIG. 11 is a diagram showing the configuration of a machining control device according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Problem to be solved by this disclosure] Patent Document 1 describes a technology for monitoring the condition of a cutting tool, but there is a need for a technology that goes beyond this technology and can more accurately determine the load on the cutting tool and modify the machining conditions based on that determination.

[0010] An object of the present disclosure is to provide a machining condition management system, a machining control device, a machining system, and a machining program that are capable of appropriately correcting machining conditions based on a determination of the load on a cutting tool.

[0011] [Effects of this disclosure] According to the present disclosure, it is possible to provide a machining condition management system, a machining control device, a machining system, and a machining program that are capable of appropriately correcting machining conditions based on a determination of the load on a cutting tool.

[0012] [Description of the embodiments of the present disclosure] First, the contents of the embodiments of the present disclosure will be listed and described.

[0013] (1) A machining condition management system according to the present disclosure includes a cutting tool having a cutting edge and a sensor, a memory unit that stores machining conditions of a machine tool that performs machining using the cutting tool and measurement values ​​measured by the sensor, and a calculation unit that corrects the machining conditions based on the machining conditions and measurement values ​​stored in the memory unit. The calculation unit determines a load on the cutting tool based on the measurement values ​​in a first cutting process under the machining conditions, calculates a correction value for correcting the machining conditions for at least one cutting section that satisfies a predetermined condition in the determination in the first cutting process, and updates and outputs the machining conditions for a second cutting process based on the calculated correction value.

[0014] In this way, the calculation unit determines the load on the cutting tool based on the measured value in the first cutting process under the machining conditions, and calculates a correction value to correct the machining conditions for at least one machining section that satisfies the specified conditions in the determination in the first cutting process, so that the machining conditions can be appropriately corrected based on the determination of the load on the cutting tool.

[0015] (2) Preferably, the calculation unit determines a section in which the measurement value in the first cutting process exceeds a predetermined threshold value as the cutting section.

[0016] With this configuration, for example, it is possible to distinguish and identify machining sections and non-machining sections in time-series data of measurement values ​​measured by a sensor, and to determine the load on the cutting tool for the machining sections.

[0017] (3) Preferably, the calculation unit obtains a distribution of the measurement values ​​in the first cutting process, and determines a section in which an excessive load occurs based on statistics of the distribution.

[0018] With this configuration, for example, it is possible to compare the loads on the cutting tool in adjacent machining paths and determine the section in which an excessive load has occurred.

[0019] (4) Preferably, the sensor includes at least one of a strain sensor, a pressure sensor, and a displacement sensor.

[0020] With this configuration, for example, the state of the cutting edge of a cutting tool can be determined more accurately.

[0021] (5) Preferably, the apparatus further includes a display unit capable of displaying time-series data of measurement values, and the calculation unit identifies a section for correcting the machining conditions for the time-series data of measurement values ​​and displays the section on the display unit.

[0022] With this configuration, for example, it is possible to easily grasp from the display section the section in which the machining conditions have been corrected based on the determined load on the cutting tool.

[0023] (6) A machining control device according to the present disclosure includes a memory unit that stores machining conditions of a machine tool that performs machining using a cutting tool having a cutting edge and a sensor and measurement values ​​measured by the sensor, a calculation unit that corrects the machining conditions based on the machining conditions and measurement values ​​stored in the memory unit, and a drive control unit that performs machining under the machining conditions. The calculation unit determines the load on the cutting tool based on the measurement values ​​in a first cutting process under the machining conditions, calculates a correction value for correcting the machining conditions for at least one machining section that satisfies a predetermined condition in the determination in the first cutting process, updates the machining conditions for a second cutting process based on the calculated correction value, and outputs the updated machining conditions to the drive control unit.

[0024] In this way, the calculation unit determines the load on the cutting tool based on the measured value in the first cutting process under the machining conditions, and calculates a correction value to correct the machining conditions for at least one machining section that satisfies the specified conditions in the determination in the first cutting process, so that the machining conditions can be appropriately corrected based on the determination of the load on the cutting tool.

[0025] (7) A machining system according to the present disclosure includes a machine tool that performs machining using a cutting tool having a cutting edge and a sensor, and a machining control device that controls the machine tool based on machining conditions. The machining control device includes a memory unit that stores the machining conditions of the machine tool and measurement values ​​measured by the sensor, a calculation unit that corrects the machining conditions based on the machining conditions and measurement values ​​stored in the memory unit, and a drive control unit that performs machining under the machining conditions. The calculation unit determines the load on the cutting tool based on the measurement values ​​in a first cutting process under the machining conditions, calculates a correction value for correcting the machining conditions for at least one cutting section that satisfies a predetermined condition in the determination in the first cutting process, updates the machining conditions for a second cutting process based on the calculated correction value, and outputs the updated machining conditions to the drive control unit.

[0026] In this way, the calculation unit determines the load on the cutting tool based on the measured value in the first cutting process under the machining conditions, and calculates a correction value to correct the machining conditions for at least one machining section that satisfies the specified conditions in the determination in the first cutting process, so that the machining conditions can be appropriately corrected based on the determination of the load on the cutting tool.

[0027] (8) A machining program according to the present disclosure is executed by a calculation unit that corrects the machining conditions based on machining conditions of a machine tool that performs machining using a cutting tool having a cutting edge and a sensor and measurement values ​​measured by the sensor. The machining program includes the steps of: determining the load on the cutting tool based on the measurement values ​​in a first cutting process under the machining conditions; calculating a correction value for correcting the machining conditions for at least one cutting section that satisfies a predetermined condition in the determination in the first cutting process; and updating and outputting the machining conditions in a second cutting process based on the calculated correction value.

[0028] In this way, the calculation unit determines the load on the cutting tool based on the measured value in the first cutting process under the machining conditions, and calculates a correction value to correct the machining conditions for at least one machining section that satisfies the specified conditions in the determination in the first cutting process, so that the machining conditions can be appropriately corrected based on the determination of the load on the cutting tool.

[0029] [Details of the embodiments of the present disclosure] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, the same or corresponding elements are designated by the same reference numerals, and detailed description thereof will not be repeated.

[0030] <Processing system configuration> The configuration of a processing system 1 according to this embodiment will be described with reference to FIGS.

[0031] 1 is a diagram showing the configuration of a machining system according to this embodiment. As shown in FIG. 1, the machining system 1 includes a cutting tool 100, an analyzing device 200, a wireless device 201, a machine tool 300, and a machining control device 301.

[0032] The cutting tool 100 is attached to a machine tool 300. A machining control device 301 controls the machine tool 300 in accordance with set machining path information and cutting conditions, and cuts a workpiece with the attached cutting tool 100. Here, the machining path information includes information such as the coordinate position of the cutting tool 100, the trajectory of the cutting tool 100, and the number of passes. The cutting conditions include information such as the depth of cut of the cutting tool 100, the feed (feed rate) of the cutting tool 100, and the cutting speed of the cutting tool 100. In this embodiment, the machining path information and the cutting conditions are collectively referred to as machining conditions, and hereinafter, the machining conditions include information on at least one of the machining path information and the cutting conditions.

[0033] In the machining system 1 according to this embodiment, the cutting tool 100 is provided with a sensor module 120, and the load on the cutting tool 100 can be measured by the sensor. Therefore, the machining system 1 utilizes information about the load on the cutting tool 100 measured by the sensor module 120 to perform control to correct the machining conditions so that the load on the cutting tool 100 does not become excessive during the machining process. By performing control to correct the machining conditions in this way, the machining system 1 reduces the occurrence of a temporary excessive load on the cutting tool 100, which could result in a decrease in machining accuracy or damage to the cutting tool 100.

[0034] Specifically, the machining system 1 transmits information about the load of the cutting tool 100 measured by the sensor module 120 to the wireless device 201 by wireless signal, and the information about the load of the cutting tool 100 received by the wireless device 201 is analyzed by the analysis device 200. The analysis device 200 calculates correction values ​​for the machining conditions, updates the machining conditions based on the calculated correction values, and outputs the updated values ​​to the machining control device 301.

[0035] The machining system 1 can be realized by combining an existing machine tool 300 with a cutting tool 100 having a built-in sensor module 120, an analysis device 200, and a wireless device 201. That is, the machining system 1 can be realized by preparing a machining condition management system 2 including the cutting tool 100, the analysis device 200, and the wireless device 201, and subsequently incorporating the machining condition management system 2 into the existing machine tool 300. However, the machining system 1 and the machining condition management system 2 shown in FIG. 1 are merely examples, and other configurations are also possible. Furthermore, the machining system 1 is not limited to a configuration including one cutting tool 100, but may be a configuration including multiple cutting tools 100. Furthermore, the machining system 1 is not limited to a configuration including one analysis device 200, but may be a configuration including multiple analysis devices 200.

[0036] Each of the components will be described in more detail below. <Cutting tools> 1, cutting tool 100 is fixed by being sandwiched from above and below by tool rest 50 of machine tool 300. Cutting tool 100 is, for example, a turning tool used to process a rotating workpiece, and is attached to machine tool 300 such as a lathe.

[0037] The part of the cutting tool 100 that cuts the workpiece is a cutting insert 110 having a cutting edge, and the cutting insert 110 is replaceable when worn or damaged. Specifically, the cutting tool 100 includes the cutting insert 110 and a shank 111 that holds the cutting insert 110. In other words, the cutting tool 100 is a so-called throw-away cutting tool. The cutting insert 110 is held to the shank 111 by fixing members 113A and 113B.

[0038] The cutting tool 100 may have a cutting edge itself, without including the fixing members 113A and 113B. That is, the cutting tool 100 may be a solid cutting tool or a brazed cutting tool.

[0039] Furthermore, cutting tool 100 may be attached to a machine tool such as a milling machine for, for example, a machining method in which the tool rotates on a fixed workpiece. More specifically, cutting tool 100 may be a milling cutter or drill to which cutting insert 110 can be attached, or may be an end mill or drill that does not use a cutting insert.

[0040] <Sensor module> 2 is a diagram showing the configuration of a sensor module according to this embodiment. The sensor module 120 includes an acceleration sensor 121, a strain sensor 122, a processing unit 123, a communication unit 124, a storage unit 125, and a battery 129. The sensor module 120 is activated, for example, by a user operation.

[0041] The processing unit 123 is realized by a processor such as a CPU (Central Processing Unit) and a DSP (Digital Signal Processor). The processor may be a hardware circuit such as an ASIC (Application Specific Integrated Circuit). The communication unit 124 is realized by a communication circuit such as a communication IC (Integrated Circuit). The storage unit 125 is, for example, a non-volatile memory.

[0042] The battery 129 is, for example, a power storage device including a primary battery, a secondary battery, a solar cell, or a capacitor, and may have a contactless power supply function. The battery 129 supplies power to the acceleration sensor 121, the strain sensor 122, and each circuit of the processing unit 123 and the communication unit 124.

[0043] The acceleration sensor 121 and the strain sensor 122 are provided, for example, near the cutting edge of the cutting tool 100. The sensor module 120 is not limited to a configuration including one acceleration sensor 121, but may be a configuration including multiple acceleration sensors 121. The sensor module 120 is not limited to a configuration including one strain sensor 122, but may be a configuration including multiple strain sensors 122. The sensor module 120 may be configured to include other sensors, such as a pressure sensor, a displacement sensor, etc., instead of at least one of the acceleration sensor 121 and the strain sensor 122, or in addition to the acceleration sensor 121 and the strain sensor 122.

[0044] Processing unit 123 generates measurement information indicating the measurement values ​​of acceleration sensor 121 and the measurement values ​​of strain sensor 122. Specifically, processing unit 123 performs AD (Analog-to-Digital) conversion on the analog signals received from acceleration sensor 121 and strain sensor 122 at sampling timings according to a predetermined cycle, and generates the sensor measurement values ​​as converted digital values.

[0045] Processing unit 123 outputs the measurement information including the measurement value of the sensor to communication unit 124. Communication unit 124 transmits the packet containing the measurement information received from processing unit 123 to analysis device 200 via wireless device 201.

[0046] <Analyzer> 3 is a diagram showing the configuration of an analysis device according to this embodiment. As shown in FIG. 3, the analysis device 200 includes a processor 211 (a computing unit), a communication device 212, a memory 213 (a storage unit), a display 214, an input interface 215, and a media reading device 216.

[0047] The processor 211 is a computing entity that executes various programs (for example, a processing program 231 described later) to perform various processes related to the analysis device 200. The processor 211 is configured with a processor such as a CPU and a DSP, for example. The processor 211 may also be configured with a processing circuitry.

[0048] The communication device 212 establishes communication with each of the processing control device 301 and the sensor module 120 via a communication means such as a network, and transmits and receives data (information) between each of the processing control device 301 and the sensor module 120.

[0049] The memory 213 is configured by volatile memory such as DRAM (Dynamic Random Access Memory) and SRAM (Static Random Access Memory), or non-volatile memory such as ROM (Read Only Memory), SSD (Solid State Drive), and HDD (Hard Disk Drive). The memory 213 stores a machining program 231, machining conditions 232 of the machine tool acquired from the machining control device 301, and measurement values ​​233 measured by a sensor. The machining conditions 232 of the machine tool and measurement values ​​233 measured by a sensor may be stored in a storage device (e.g., a server) connected to the analysis device 200 directly or via a network, instead of in the memory 213.

[0050] Machining program 231 is a program that is executed by processor 211 (arithmetic unit) and determines the load on cutting tool 100 based on measurements taken by a sensor, and modifies the machining conditions of machine tool 300. By executing machining program 231, processor 211 performs the processing of the flowchart in Fig. 4, which will be described later.

[0051] The media reading device 216 receives a recording medium 220 that records various programs and data, and reads the programs and data from the recording medium 220. Examples of the recording medium 220 include a CD (Compact Disk), an SD card (Secure Digital card), and a USB memory (Universal Serial Bus memory). In this embodiment, the media reading device 216 reads a processing program 231 stored in the recording medium 220 and stores the processing program 231 in the memory 213.

[0052] The display 214 is a display unit that displays images to notify the user of various information such as time-series data of measurement values.

[0053] The input interface 215 is an interface that accepts data input to the analysis device 200. For example, a user may input data to the input interface 21 5, an ID and password can be entered, or information specified by the user can be entered.

[0054] <Wireless device> Wireless device 201 is connected to analysis device 200, for example, by wire. Wireless device 201 is, for example, an access point. Wireless device 201 acquires a wireless signal received from cutting tool 100 and relays it to analysis device 200. Wireless device 201 communicates with cutting tool 100 wirelessly using a communication protocol such as ZigBee (registered trademark) compliant with IEEE 802.15.4, Bluetooth (registered trademark) compliant with IEEE 802.15.1, or UWB (Ultra-Wide Band) compliant with IEEE 802.15.3a. Note that a communication protocol other than those described above may also be used between cutting tool 100 and wireless device 201.

[0055] <Processing system processing> Next, a description will be given of the processing of the processing system 1. Fig. 4 is a flowchart showing the processing executed by the processor 211 of the analysis device according to this embodiment. The processing steps (hereinafter abbreviated as "S") shown in Fig. 4 are realized by the processor 211 of the analysis device 200 executing the processing program 231.

[0056] The analysis device 200 determines whether or not it has received machining information of the machine tool 300 and measurement preparation information of the sensor provided on the cutting tool 100 (S101). The machining information of the machine tool 300 includes information such as the machining process, machining path, tools used, and cutting conditions, and is received, for example, from the machining control device 301 or 301 The measurement preparation information can be acquired from information such as an NC program or CAM before being input to the analyzer 200. The measurement preparation information includes information such as the type of sensor used (strain sensor / acceleration sensor, etc.), the number of channels (CH) of each sensor, the used channel number, sampling rate, sensor gain, measurement range, battery voltage, and radio wave intensity, and can be acquired from, for example, the sensor module 120. Note that the measurement preparation information may also include parameters such as a threshold value used to determine the machining section, a section used to determine excessive load, and a measurement tolerance coefficient, in order to ensure stable processing by the machining system 1. The parameters may be values ​​preset by a user and input to the analyzer 200 via, for example, the input interface 215. The parameters may also be values ​​estimated by statistical processing, machine learning, or a database of previously measured values.

[0057] If it is determined that information has not been received (NO in S101), the analysis device 200 returns the process to S101 and maintains the information reception state. On the other hand, if it is determined that information has been received (YES in S101), the analysis device 200 determines whether or not a measurement value measured by the sensor of the cutting tool 100 has been received (S102). When the machining control device 301 controls the machine tool 300 in accordance with the machining conditions including the set machining path information and cutting conditions, and starts a machining process (first cutting process) in which the workpiece is cut with the attached cutting tool 100, the analysis device 200 acquires the sensor measurement value during the machining process from the sensor module 120.

[0058] If it is determined that no measurement values ​​have been received (NO in S102), the analysis device 200 returns to S102 and maintains the state of receiving measurement values. On the other hand, if it is determined that measurement values ​​have been received (YES in S102), the analysis device 200 calculates feature quantities from the sensor measurement values ​​obtained during the processing step (S103). Specifically, the analysis device 200 receives measurement values ​​from the acceleration sensor 121 and strain sensor 122 provided in the sensor module 120 and performs feature quantity calculations on the received measurement values, such as preprocessing, basic statistics, and correlation calculations. Preprocessing includes calculations such as missing value removal and interpolation, noise reduction, FFT (Fast Fourier Transform) processing, vector transformation (magnitude, direction), and dimensionality reduction. Furthermore, basic statistics include calculations such as the arithmetic mean, geometric mean, trimmed mean, variance, standard deviation, skewness, kurtosis, median, maximum value, and minimum value. As correlations, for example, covariance, correlation coefficient, partial correlation coefficient, factor loading, principal component score, etc. are calculated. Note that the feature calculations may include preprocessing calculations to ensure smooth subsequent processing, and calculations of basic statistics and correlations to be used in subsequent determination processing. Furthermore, based on the measurement preparation information received in S101, analysis device 200 may limit the feature values ​​to be calculated in order to reduce the load of feature calculations.

[0059] The analysis device 200 determines the machining zone and the non-machining zone from the acquired time-series data of the measurement values ​​(S104). In the machining process of the machine tool 300, load is not applied to the cutting tool 100 in all zones, but rather the cutting tool 100 performs intermittent machining, or there are short idle zones where the cutting tool 100 does not come into contact with the workpiece. Therefore, the analysis device 200 determines the machining zone and the non-machining zone in order to reduce the amount of information by narrowing the analysis target to only the measurement values ​​of the machining zone. Specifically, the analysis device 200 determines the machining zone and the non-machining zone from the time-series data of the measurement values ​​using the threshold value used to determine the machining zone set in S101.

[0060] FIG. 5 is a diagram showing an example of identifying a machining section from sensor measurement values ​​according to this embodiment. The time-series data of measurement values ​​shown in FIG. 5 is time-series data of measurement values ​​from the strain sensor 122. The strain sensor 122 has two sensors attached at different positions on the cutting tool 100. The channel number used for one sensor is CH0, and the channel number used for the other sensor is CH1. In the time-series data of measurement values ​​shown in FIG. 5, the measurement values ​​from the sensor CH0 are the positive time-series data, and the measurement values ​​from the sensor CH1 are the negative time-series data. If the threshold value set in S101 used to determine the machining section is an absolute value, the positive value of the threshold is set as the threshold Th0 for the measurement values ​​from the sensor CH0, and the negative value of the threshold is set as the threshold Th1 for the measurement values ​​from the sensor CH1. In this embodiment, multiple machining sections are identified when one product is machined. Multiple machining sections may also be identified when multiple products are machined consecutively.

[0061] The analysis device 200 identifies a section where the measurement value from the sensor of CH0 is greater than a threshold value Th0 as a processing section, and colors the measurement values ​​of the non-processing section in gray as shown in Fig. 5, and applies the corresponding non-processing section to CH1 as well, displaying it in gray. Note that the analysis device 200 may identify a section where the measurement value from the sensor of CH1 is less than a threshold value Th1 as a processing section, and color the measurement values ​​of the non-processing section as shown in Fig. 5 in gray. In Fig. 5, four processing sections are identified for each of the sensors of CH0 and CH1 from the section of one processing step.

[0062] Although the analysis device 200 determines the processed section and the non-processed section based on the threshold value set in S101, the threshold value does not have to be a preset value. The analysis device 200 may set the threshold value from the percentile of the measurement value near zero (unprocessed value) based on a distribution evaluation such as a histogram, for example. The analysis device 200 may also set the threshold value by utilizing the feature calculated in S103. Furthermore, the analysis device 200 may display the time-series data of the measurement values ​​for which the processed section shown in FIG. 5 has been identified on the display 214. Note that, for example, the 1st percentile value of each data (the value of the data corresponding to 1% when sorted from the largest absolute value of the maximum or minimum value) is calculated as an example.

[0063] Next, the analysis device 200 performs a distribution evaluation on the measurement values ​​of the machining section identified in S104 (S105). Specifically, the analysis device 200 creates a histogram from the time-series data of the measurement values ​​of the machining section and evaluates the magnitude of the load applied to the cutting tool 100 and the measurement frequency. FIG. 6 is a diagram showing an example of distribution evaluation performed on the measurement values ​​of the sensors according to this embodiment. FIG. 6 also shows the feature values ​​calculated in S103. Specifically, the histogram in FIG. 6 shows the average value AVE0, maximum value MAXV0, and percentile value PC0 of the measurement values ​​measured by the sensor for CH0, and the average value AVE1, minimum value MAXV1, and percentile value PC1 of the measurement values ​​measured by the sensor for CH1.

[0064] Here, the maximum value MAXV0 is used for the measurement values ​​measured by the CH0 sensor, and the minimum value MAXV1 is used for the measurement values ​​measured by the CH1 sensor. This is because the value with the larger absolute value is used between the maximum and minimum measurement values. In other words, since the measurement values ​​measured by the CH0 sensor are positive values, the maximum value with the larger absolute value is used, and since the measurement values ​​measured by the CH1 sensor are negative values, the minimum value with the larger absolute value is used.

[0065] The percentile value PC0 of the sensor for CH0 is a value in a predetermined order (or a predetermined interval) arranged from largest to smallest based on the maximum value MAXV0. The percentile value PC1 of the sensor for CH1 is a value in a predetermined order (or a predetermined interval) arranged from smallest to largest based on the minimum value MAXV1. The predetermined order (or predetermined interval) may be determined in advance by the user, or may be set as a rank estimated by statistical processing, a rank estimated by machine learning, or a rank estimated based on a database of previously measured values.

[0066] The analysis device 200 compares the maximum value MAXV0 or percentile value PC0 shown in FIG. 6 with the measurement tolerance ACV0 to determine whether an excessive load is being applied locally to the cutting tool 100. The analysis device 200 also compares the minimum value MAXV1 or percentile value PC1 shown in FIG. 6 with the measurement tolerance ACV1 to determine whether an excessive load is being applied locally to the cutting tool 100. The measurement tolerance ACV0 is calculated by multiplying a preset measurement tolerance coefficient K by the average value AVE0. Similarly, the measurement tolerance ACV1 is calculated by multiplying a preset measurement tolerance coefficient K by the average value AVE1. In other words, the analysis device 200 allows loads up to a multiple of the measurement tolerance coefficient K relative to the average load applied to the cutting tool 100, thereby correcting the machining conditions. For example, if the measurement tolerance coefficient K is 2.5, the measurement tolerances ACV0 and ACV1 are 2.5 times the average values ​​AVE0 and AVE1.

[0067] Note that the measurement tolerance coefficient K may be set in advance to a different value for each feature, each type of sensor, and each channel number (e.g., CH0, CH1) used by the sensor. Furthermore, while the distribution evaluation shown in FIG. 6 is performed using a histogram, time-series data (measurement waveform) of the sensor's measurement values ​​may also be used. FIG. 7 is a diagram showing an example in which the results of the distribution evaluation are applied to time-series data of the sensor's measurement values ​​according to this embodiment. Specifically, the average value AVE0, percentile value PC0, and measurement tolerance value ACV0 of the measurement values ​​measured by the sensor of CH0, and the average value AVE1, percentile value PC1, and measurement tolerance value ACV1 of the measurement values ​​measured by the sensor of CH1 are shown in the measurement waveforms of FIG.

[0068] Analysis device 200 may display the histogram shown in Fig. 6 or the measurement waveform shown in Fig. 7 on display 214. Note that when analysis device 200 has multiple sensors attached at different positions on cutting tool 100 (for example, CH0, CH1), it may limit the number of sensors for which distribution evaluation is performed in order to reduce the calculation load.

[0069] 4, the analysis device 200 determines whether an overload has occurred in the measurement values ​​measured by the sensors based on the distribution evaluation processed in S105 (S106). Specifically, the analysis device 200 determines whether an overload has occurred in the measurement values ​​measured by the sensor of CH0 by comparing the maximum value MAXV0 or percentile value PC0 with the measurement tolerance value ACV0, and determines that an overload has occurred in the cutting tool 100 if the maximum value MAXV0 or percentile value PC0 is greater than the measurement tolerance value ACV0. Similarly, the analysis device 200 determines whether an overload has occurred in the measurement values ​​measured by the sensor of CH1 by comparing the minimum value MAXV1 or percentile value PC1 with the measurement tolerance value ACV1, and determines that an overload has occurred in the cutting tool 100 if the minimum value MAXV1 or percentile value PC1 is smaller than the measurement tolerance value ACV1.

[0070] That is, the analysis device 200 determines that an overload has occurred in the cutting tool 100 depending on whether the overload occurrence condition |MAXV|>|ACV| or |PC|>|ACV| is satisfied. Here, |MAXV| represents the absolute value of the maximum or minimum value, |ACV| represents the absolute value of the measurement allowable value, and |PC| represents the absolute value of the percentile value.

[0071] Furthermore, the analysis device 200 determines the occurrence of an overload on the cutting tool 100 using the absolute value of the percentile value instead of the absolute value of the maximum or minimum value, thereby making it possible to eliminate sudden measurement values ​​and measurement values ​​of abnormal values ​​when making a determination. In other words, the analysis device 200 can determine a state in which an overload is continuously applied to the cutting tool 100 within a predetermined section, and can more accurately identify a section in which the machining conditions need to be corrected. Note that the predetermined section is set in advance in S101 as a section to be used for determining an overload.

[0072] The analysis device 200 may display the histogram shown in FIG. 6 or the measurement waveform shown in FIG. 7 on the display 214, allow the user to manually specify the section where an overload occurs from the histogram or measurement waveform, and receive that information from the input interface 215.

[0073] If it is determined that an excessive load has occurred (YES in S106), the analysis device 200 corrects the machining conditions for the section where the excessive load identified in S106 has occurred (S107). For example, the analysis device 200 corrects the machining conditions for the section where the excessive load has occurred based on a correction coefficient. FIG. 8 is a diagram showing an example of correction values ​​for correcting the machining conditions of the machine tool according to this embodiment. FIG. 8 shows the feed (feed rate) of the cutting tool 100, which is one of the machining conditions, and the feed rate is set for each time period. Note that the horizontal axis of FIG. 8 represents time, and the vertical axis represents the feed rate.

[0074] As shown in Fig. 8, the analyzer 200 identifies the section from approximately 13.29 seconds to approximately 13.42 seconds as the section where excessive load occurs, and performs a correction to slow down the feed rate by multiplying the feed rate in this section by a correction coefficient. The correction coefficient is, for example, the percentile value PC1 divided by the minimum value MAXV1, which is approximately 0.8 in the example shown in Fig. 6. Therefore, the original feed rate (approximately 0.7 mm / rev) in the section from approximately 13.29 seconds to approximately 13.42 seconds shown in Fig. 8 is multiplied by the correction coefficient (approximately 0.8) to correct it to a feed rate (approximately 0.56 mm / rev).

[0075] The analysis device 200 estimates the sensor measurement values ​​after the machining conditions have been corrected, and returns the process to S106 to again determine whether an overload has occurred. FIG. 9 is a diagram showing an example of estimated sensor measurement values ​​after the machining conditions of the machine tool according to this embodiment have been corrected. FIG. 9 shows percentile values ​​PC0, PC1 and measurement allowable values ​​ACV0, ACV1 calculated for the estimated sensor measurement values ​​with respect to the time series data (measurement waveforms) of the estimated sensor measurement values ​​CH0, CH1. As can be seen from FIG. 9, the percentile value PC1 calculated from the estimated sensor measurement values ​​is -14.1 (με), which is smaller than the absolute value of the measurement allowable value ACV1, and therefore satisfies the overload occurrence condition. do not have In Figure 9, the sensor measurements that were suppressed by the modified machining conditions are colored gray.

[0076] On the other hand, if the estimated sensor measurement value is still an excessive load, the analysis device 200 determines that the correction of the machining conditions is insufficient and corrects them again. Note that the analysis device 200 corrects the machining conditions in a direction that reduces the load applied to the cutting tool 100, so that the excessive load occurrence condition is not satisfied. do not As a result, the calculations converge within a range of realistic machining conditions.

[0077] The analysis device 200 modifies the machining conditions based on the calculation results and outputs the updated machining conditions to the machining control device 301 (S108). The analysis device 200 outputs the updated machining conditions to the machining control device 301 and ends the process. The machining control device 301 controls the machine tool 300 in accordance with the updated machining conditions and cuts the workpiece with the attached cutting tool 100. The analysis device 200 may use a sensor to measure the load applied to the cutting tool 100 when machining under the updated machining conditions and determine whether an excessive load exists again. Note that if it is determined that an excessive load has not occurred (NO in S106), the analysis device 200 ends the process without modifying the machining conditions.

[0078] In the above example, the analysis device 200 corrects only the feed (feed rate) of the cutting tool 100 among the machining conditions, but this is not limited to this, and any one or a combination of conditions related to the amount of workpiece material cut, such as the coordinate position of the cutting tool 100, the trajectory of the cutting tool 100, the number of passes, and the depth of cut of the cutting tool 100, may be corrected.

[0079] The flowchart shown in Fig. 4 shows an example in which the analysis device 200 corrects the machining conditions based on the sensor measurement values ​​measured in the first cutting process, and causes the machining control device 301 to perform the subsequent cutting process (second cutting process) under machining conditions that do not generate excessive loads. However, the present invention is not limited to this, and the analysis device 200 may perform feedback control in which the analysis device 200 executes the flowchart shown in Fig. 4 while the machining process is continuing, automatically correcting the machining conditions based on the sensor measurement values ​​measured previously, and causing the machining control device 301 to perform machining under machining conditions that do not generate excessive loads. This allows the machining system 1 or the machining condition management system 2 to automatically equalize the load applied to the cutting tool 100 in the machining process.

[0080] [Action and effect] According to the machining condition management system 2, the processor 211 determines the load of the cutting tool 100 based on the measurement value in the first cutting process under the machining conditions, calculates a correction value for correcting the machining conditions for at least one machining section that satisfied the predetermined condition in the determination in the first cutting process, and updates and outputs the machining conditions for the second cutting process based on the calculated correction value. As a result, the processor 211 determines the load of the cutting tool 100 based on the measurement value in the first cutting process under the machining conditions, and calculates a correction value for correcting the machining conditions for at least one machining section that satisfied the predetermined condition in the determination in the first cutting process, so that the machining conditions can be appropriately corrected based on the determination of the load on the cutting tool 100.

[0081] According to the machining condition management system 2, the processor 211 determines a section where the measurement value in the first cutting process exceeds a predetermined threshold as a machining section. This makes it possible to identify the section by dividing the time-series data of the measurement value measured by the sensor into a machining section and a non-machining section.

[0082] According to the machining condition management system 2, the processor 211 obtains the distribution of the measurement values ​​in the first cutting process and determines the section where an excessive load has occurred based on the statistics of the distribution. This makes it possible to compare the loads on the cutting tool in nearby machining paths and determine the section where an excessive load has occurred.

[0083] According to the machining condition management system 2, the sensor includes at least one of a strain sensor, a pressure sensor, and a displacement sensor, which makes it possible to more accurately determine the state of the cutting edge of the cutting tool.

[0084] According to the machining condition management system 2, the processor 211 identifies the section for which the machining conditions are to be corrected based on the time-series data of the measurement values ​​and displays it on the display 214. This makes it possible to easily grasp from the display section the section for which the machining conditions have been appropriately corrected based on the judgment of the load on the cutting tool.

[0085] [Variations] In the present embodiment, the histogram shown in FIG. 6 evaluates the distribution as the measurement frequency of the sensor-measured values ​​themselves. However, the distribution may also be evaluated by normalizing the sensor-measured values ​​by dividing them by the absolute value of the maximum or minimum value of the measured values. FIG. 10 illustrates an example of a distribution evaluation normalized to the sensor-measured values ​​according to this embodiment. In FIG. 10, the maximum value of the measured values ​​is "1" and the minimum value is "-1." Variables such as the average values ​​AVE0 and AVE1, the measurement tolerance values ​​ACV0 and ACV1, and the percentile values ​​PC0 and PC1 are also calculated by dividing them by the absolute value of the maximum or minimum value. Therefore, the analysis device 200 can directly use the calculated variables without calculating correction coefficients when calculating the correction values ​​for the machining conditions. Specifically, the analysis device 200 can calculate the correction values ​​for the machining conditions for the section where an excessive load occurs by simply multiplying the percentile value PC1 (approximately 0.8) by the feed rate of the cutting tool 100.

[0086] 4 is performed by the analysis device 200, these processes may be performed by the sensor module 120. This reduces the amount of data transmitted from the sensor module 120 to the analysis device 200, and also reduces the calculation load on the analysis device 200.

[0087] Furthermore, if the processing capacity of the processor of the processing unit 123 of the sensor module 120 is high, the processes from S104 onwards, such as distribution evaluation, excessive load determination, and machining condition correction, may be performed by the sensor module 120. In this case, the analysis device 200 is not necessary, and the machining conditions corrected by the sensor module 120 are output directly to the machining control device 301.

[0088] 1, the machine tool 300 and the machining control device 301 are shown as separate components, but the machine tool 300 and the machining control device 301 may be integrated into one component. Also, a machining system may be provided in which a plurality of machine tools 300 are connected to one machining control device 301.

[0089] 11 is a diagram showing the configuration of a machining control device according to this embodiment. As shown in FIG. 11, the machining control device 301 includes a calculation unit 310, a communication unit 320, a storage unit 330, a display unit 340, an input unit 350, and a drive control unit 360.

[0090] Arithmetic unit 310 is a processor that executes various programs (for example, a control program that controls machine tool 300), and is a computing entity that executes various processes related to machining control device 301. Arithmetic unit 310 is configured with processors such as a CPU and a DSP, for example.

[0091] The communication unit 320 establishes communication with each of the analytical device 200 and the machine tool 300 via a communication means such as a network, and transmits and receives data (information) between each of the analytical device 200 and the machine tool 300.

[0092] Storage unit 330 is configured with volatile memory such as DRAM and SRAM, or non-volatile memory such as ROM, SSD, and HDD. Storage unit 330 stores control programs, machining conditions for machine tool 300, and the like.

[0093] Display unit 340 is a display unit that notifies the user of various information such as machining conditions of machine tool 300 by displaying images.

[0094] The input unit 350 is an interface that accepts data input to the processing control device 301. For example, a user can input an ID and a password, or input information designated by the user, via the input unit 350.

[0095] Drive control unit 360 controls machine tool 300 based on a control program executed in accordance with preset machining conditions, and cuts the workpiece with attached cutting tool 100.

[0096] Since the machining control device 301 has a calculation unit 310, the calculation unit 310 may execute the machining program 231 of the analysis device 200 to correct the machining conditions based on the sensor measurement values. In this case, the analysis device 200 is not necessary, and the machining control device 301 receives the sensor measurement values ​​directly from the sensor module 120.

[0097] Furthermore, since the processing control device 301 has a memory unit 330, the processing conditions 232 of the machine tool stored in the memory 213 of the analysis device 200 and the measurement values ​​233 measured by the sensor may be stored in the memory unit 330.

[0098] The embodiments and examples disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present disclosure is defined by the claims, not the above-described embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0099] 1 Machining system, 2 Machining condition management system, 211 Processor, 50 Tool rest, 55, 215 Input interface, 100 Cutting tool, 110 Cutting insert, 113A, 113B Fixing member, 120 Sensor module, 121 Acceleration sensor, 122, CH0, CH1 sensor, 123 Processing unit, 124, 320 Communication unit, 125, 330 Memory unit, 129 Battery, 200 Analysis device, 201 Wireless device, 212 Communication device, 213 Memory, 214 Display, 216 Media reading device, 220 Recording medium, 231 Machining program, 232 Machining conditions, 233 Measurement value, 300 Machine tool, 301 Machining control device, 310 Calculation unit, 340 Display unit, 350 Input unit, 360 Drive control unit.

Claims

1. a cutting tool having a cutting edge and a sensor; a memory unit that stores machining conditions of a machine tool that uses the cutting tool for machining and measurement values ​​measured by the sensor; a calculation unit that corrects the machining conditions based on the machining conditions stored in the storage unit and the measurement values, The calculation unit determining a load on the cutting tool based on the measured value in a first cutting process for machining a first workpiece under the machining conditions; Calculating a correction value for correcting the machining conditions for at least one machining section that satisfies a predetermined condition in the determination in the first cutting process; Based on the calculated correction value, the machining conditions for a second cutting process for machining a second workpiece in a different machining step are updated and output. A machining condition management system that obtains a distribution of the measurement values ​​in the first cutting process and determines an interval in which an excessive load occurs based on statistics of the distribution.

2. The calculation unit The machining condition management system according to claim 1 , wherein a section in which the measurement value in the first cutting process exceeds a predetermined threshold value is determined to be the machining section.

3. 3. The machining condition management system according to claim 1, wherein the sensor includes at least one of a strain sensor, a pressure sensor, and a displacement sensor.

4. Further, a display unit capable of displaying time series data of the measurement values ​​is provided, The calculation unit 4. The machining condition management system according to claim 1, wherein a section in which the machining conditions are to be corrected is identified for the time series data of the measurement values ​​and displayed on the display unit.

5. a memory unit that stores machining conditions of a machine tool that uses a cutting tool having a cutting edge and a sensor, and measurement values ​​measured by the sensor; a calculation unit that corrects the machining conditions based on the machining conditions stored in the storage unit and the measurement values; a drive control unit that performs machining under the machining conditions, The calculation unit determining a load on the cutting tool based on the measured value in a first cutting process for machining a first workpiece under the machining conditions; Calculating a correction value for correcting the machining conditions for at least one machining section that satisfies a predetermined condition in the determination in the first cutting process; Based on the calculated correction value, the machining conditions for a second cutting process for machining a second workpiece in a different machining step are updated and output to the drive control unit; A machining control device that obtains a distribution of the measurement values ​​in the first cutting process and determines an interval in which an excessive load occurs based on statistics of the distribution.

6. A machining system comprising: a machine tool that performs machining using a cutting tool having a cutting edge and a sensor; and a machining control device that controls the machine tool based on machining conditions, The processing control device includes: a memory unit that stores the machining conditions of the machine tool and the measurement values ​​measured by the sensor; a calculation unit that corrects the machining conditions based on the machining conditions stored in the storage unit and the measurement values; a drive control unit that performs machining under the machining conditions, The calculation unit determining a load on the cutting tool based on the measured value in a first cutting process for machining a first workpiece under the machining conditions; Calculating a correction value for correcting the machining conditions for at least one machining section that satisfies a predetermined condition in the determination in the first cutting process; Based on the calculated correction value, the machining conditions for a second cutting process for machining a second workpiece in a different machining step are updated and output to the drive control unit; A machining system that determines a distribution of the measurement values ​​in the first cutting process and determines an area in which an excessive load has occurred based on statistics of the distribution.

7. A machining program executed by a calculation unit that corrects machining conditions of a machine tool that uses a cutting tool having a cutting edge and a sensor and measurements measured by the sensor, The processing program determining a load on the cutting tool based on the measured value in a first cutting process for machining a first workpiece under the machining conditions; Calculating a correction value for correcting the machining conditions of at least one machining section that satisfies a predetermined condition in the determination in the first cutting process; updating and outputting the machining conditions for a second cutting process for machining a second workpiece in a different machining step based on the calculated correction value; determining a distribution of the measurement values ​​in the first cutting process and determining an interval in which an excessive load has occurred based on statistics of the distribution.

Images