JP6722372B2 - Machine tool monitoring and predictive control system with tool recognition function - Google Patents

Description

The present invention relates to a machine tool system for monitoring, predicting, and controlling a machine tool by mounting the machine tool on the machine machine later.

A conventional machine tool does not have a function of remotely monitoring the operating status of the machine tool, a function of predicting the occurrence of a failure, and a function of remotely controlling when a failure occurs.

Therefore, in the prior art, in order to confirm whether the machine tool is operating normally, the current is measured, and a threshold value is set to monitor (for example, Patent Document 1, Patent Document 2, Patent Document 3, non-patent document). Document 1, non-patent document 2, non-patent document 3).

JP-A-62-34755 JP-A-5-253799 JP-A-5-116056

Taguchi, “Development of remote monitoring device using composite sensor”, 2012 Nagasaki Industrial Technology Center Research Report, pp. 3-7, August 30, 2013 Taguchi, “Development of intelligent remote monitoring device for mechanical devices”, 2013 Nagasaki Industrial Technology Center Research Report, pp. 6-7, August 29, 2014 Taguchi, “Development of Machinery Intelligent Remote Monitoring Device”, 2014 Nagasaki Industrial Technology Center Research Report, pp. 8-9, August 31, 2015

If it is a machine tool that uses only one tool, it can be monitored using conventional technology, but in the case of a machine tool that exchanges tools or a machine tool that has an automatic tool changer, it can be monitored by the tool used. It was necessary to change the threshold value.

It is possible to recognize the tool to be used from the control signal that controls the automatic tool changer and change the threshold automatically, but in the case of a conventional machine tool that does not have a monitoring function, in order to extract the control signal Was difficult to realize because it was necessary to modify the machine tool and read the control signal to the automatic tool changer.

When a monitoring device is later attached to a machine tool that does not have a monitoring function and a monitoring function is added, an attempt has been made to recognize the currently installed tool using an image sensor, but the machine tool is used. It was difficult to eliminate the influence of dust and lubricants generated in the environment where it was used, and the place of use was limited.

Further, in order to use the image sensor, it is necessary to use a high-performance computer device, which causes a problem that environmental resistance performance of the monitoring device is deteriorated and the device becomes expensive.

The present invention relates to a machine tool system monitoring device that is mounted on a machine tool to monitor the machine tool for tool replacement, identify the tool, and monitor the standard value for each tool.

In addition, a machine tool system predicting apparatus that predicts the occurrence of a failure is realized by recording the monitored contents together with time series in the recording unit and performing comparative analysis.

Furthermore, a control signal is generated based on the result of monitoring by the machine tool system monitoring device and the result predicted by the machine tool system predicting device, and the machine tool body is installed by attaching the mechanical part to the machine tool or the control panel of the machine tool. The present invention relates to a machine tool system control device that realizes a machine tool system control device without modifying the machine tool.

A block diagram showing components of the invention 1 is shown in FIG. A first aspect of the present invention is a machine tool system in which a tool or a work is driven by a spindle to perform machining. There is a measuring section for measuring a state of the spindle, and the measuring section measures a current of the spindle and a vibration of the spindle. Having a measuring means for measuring, and using a current data and vibration data measured by the measuring means has a determination unit for identifying a tool attached to the machine tool system, for each tool identified by the determination unit It has a recording unit for recording standard values, and has a monitoring unit for comparing and analyzing current data or vibration data measured by the measuring unit or current data and standard values called from the recording unit. A machine tool system monitoring device for monitoring the operation of a machine tool system by using the machine tool system.

Invention 1 uses a sensor for measuring at least one current and a sensor for measuring at least one vibration to obtain current data and vibration data when the spindle rotates with no load, and the spindle data when a load is applied by cutting. By measuring current data and vibration data and comparing and analyzing them, characteristic features of the tool can be analyzed, and by specifying the tool, it is possible to monitor the machine tool based on the standard value set for each tool. It will be possible.

A second aspect of the present invention is the machine tool system monitoring apparatus according to the first aspect, which has a recording unit that records the current data or vibration data or the current data and the vibration data measured in association with the specified tool together with the time series. The current data or vibration data or current data and vibration data associated with the tool stored together with the time series has a prediction unit for comparing and analyzing the current data or vibration data or the current data and vibration data measured by the measuring unit, It is a machine tool system predicting device for predicting an abnormality occurrence of a machine tool system by a predicting unit.

By recording the measured current data and vibration data together with the time series for each type of tool specified by the first aspect of the invention, it is possible to estimate the change in the cutting situation and perform comparative analysis to predict the occurrence of a machine tool failure. It will be possible.

A receiving unit for receiving the monitoring result from the machine tool system monitoring device according to claim 1 or the prediction result from the machine tool system predicting device according to claim 2, and based on the monitoring result or the prediction result received by the receiving unit. It has a control section for controlling, and has a mechanism section for operating a machine tool or an operation section of a control panel of the machine tool by a signal from the control section, and the mechanism section operates a machine tool or a control panel of the machine tool. A machine tool system control device for controlling a machine tool system by operating parts.

The machine tool system monitoring device according to the first aspect of the present invention or the machine tool system predicting device according to the second aspect of the present invention operates the machine tool or the operating portion of the machine tool control panel by a mechanism unit that is later attached to the machine tool or the control panel of the machine tool. However, it is possible to realize a machine tool system that controls a machine tool without modifying the machine tool body.

Note that it is possible to use a plurality of sensors for measuring current and sensors for measuring vibration, and further, a sensor such as a force sensor, a temperature sensor, or an acoustic sensor may be added.

Since the present invention is configured as described above, it has the effects described below.

Invention 1 measures current data and vibration data of a machine tool with a sensor that measures at least one current and a sensor that measures at least one vibration, and attaches to a machine tool using the measured current data and vibration data. It is possible to specify the tool that is used.

After the tool is specified, the load or force applied to the tool can be estimated from the measured current data or vibration data or the current data and vibration data, and the operating status of the machine tool can be measured and monitored.

In the case of a machine tool in which a tool is driven by a spindle, a characteristic amount unique to the tool can be measured from current data and vibration data measured when the tool is operating with no load.

A tool currently attached is specified based on the measured characteristic amount, and current data or vibration data to be monitored or standard values of the current data and vibration data are read from the recording unit and determined.

The standard value may be set individually in advance for each current and vibration, or may be set using both current and vibration.

Alternatively, it may be dynamically set from current data, vibration data, or current data and vibration data using a machine learning method or a quality engineering method.

In the case of a machine tool that drives the tool by the spindle, further details can be obtained by measuring the current data and vibration data during cutting after identifying the tool with the current data and vibration data when the tool is driven with no load. It is possible to specify a proper tool.

In the case of a machine tool that drives a workpiece with a spindle, the tool is specified by the current data and vibration data during cutting.

After the tool is specified, the acquired current data and vibration data are classified for each tool, and the characteristic of the normal state is recorded in the recording unit as the standard value, whereby the standard value can be corrected.

When the deviation from the standard value of the characteristic of the normal state recorded for each tool is compared and analyzed, and when the deviation exceeding the specified range is measured, an alarm signal is transmitted.

The alarm signal may be transmitted to a personal computer, a smartphone, a mobile phone or a mobile terminal via a communication line or an internet line.

According to the second aspect of the present invention, it is possible to predict the occurrence of the abnormality before the abnormality occurs by recording the current data or the vibration data or the current data and the vibration data together with the time series for each tool specified in the first aspect and performing the comparative analysis. It is a machine tool system prediction device.

Since an alarm can be issued before an abnormality occurs, it is effective in reducing the product defect rate and improving the productivity of machine tools.

A third aspect of the present invention is a machine tool system control in which a machine tool is controlled by an alarm signal to control a machine tool by a mechanical section that operates an operation section of a control panel of the machine tool. It is a device.

It becomes possible to perform an emergency stop and restart of the machine tool when a failure occurs, which has the effect of improving the operating rate of the machine tool.

INDUSTRIAL APPLICABILITY The present invention can be used not only in a milling machine in which a tool rotates, a drilling machine, and a grinder, but also in a lathe in which a work rotates, a die cutting machine in which a tool and a work reciprocate, a planing machine, and a vertical cutting machine.

A mode for carrying out the invention 1 is shown in FIG. FIG. 2 shows an apparatus for monitoring the operation status when the workpiece 2 is machined by the tool 3 in the machine tool equipment 1. The current data and the vibration data obtained by using the sensor 5 for measuring at least one current attached to the motor driving the spindle 4 and the sensor 6 for measuring at least one vibration attached to the bearing portion of the spindle. On the basis of this, a monitoring device 7 for identifying and monitoring the tool 3 attached to the machine tool is configured.

The monitoring device 7 converts the signals from the sensor 5 for measuring the current and the sensor 6 for measuring the vibration by the interface circuit 8 and reads them by the CPU 9 for the monitoring device, and the standard value for each tool stored in the recording unit 10 for the monitoring device. Monitoring is performed by performing a comparative analysis with, and when an abnormality is detected, an alarm is notified to the personal computer, smart phone, mobile phone, and mobile terminal 11.

The operation of the machine tool system monitoring device will be described with reference to the program flow diagram of the invention 1 shown in FIG.

FIG. 10 shows an example of the measuring unit. First, in the machine tool spindle shown in FIG. 10, the current flowing through the motor driving the spindle 4 is measured by the current sensor 5, and the vibration sensor 6 mounted near the spindle bearing measures the vibration accompanying the spindle rotation.

Using the measured current data and vibration data, only the vibration data when the spindle is driven by the current data as shown in FIG. 12 is measured.

The measured current data and vibration data are the maximum value, the minimum value, the average value, the variance and the FFT calculation result on the time axis, and the maximum value on the frequency axis calculated by the wavelet calculation result as shown in FIG. The minimum value and each frequency are calculated, and the feature amount is calculated.

Using the feature amount of the current data and the vibration data as shown in FIG. 14, and comparative analysis of the difference between the feature quantity of each tool that is registered in the recording unit 10, the difference is the smallest tool holding al is Specify.

Further, the standard value set for each tool is read from the recording unit 10, and if it deviates from the standard value, an alarm signal is notified.

An alarm signal may be used to notify an abnormality using a siren or a lamp, or an abnormality may be notified to a personal computer, smartphone, mobile phone, or mobile terminal 11 via a network.

Even a CNC machine tool equipped with an automatic tool changer (ATC, auto match tool changer) to estimate the attached tool from the current data and vibration data, does not modify the machine tool body It is possible to monitor the driving status of the.

A mode for carrying out the invention 2 is shown in FIG. A second aspect of the invention is to use the tool information identified by the machine tool system monitoring device 7 of the first aspect, current data or vibration data, or current data and vibration data by the CPU 13 to continuously collect the data along with the time series, and to use the prediction device. This is a machine tool system predicting apparatus that predicts an abnormality occurrence of a cutting tool or a machine tool by a predicting apparatus 12 having a function of storing and analyzing in a recording unit 14 and notifying the abnormality.

When the prediction device 12 predicts a failure that will occur in the future, it issues a warning signal. An alarm signal may be used to notify an abnormality using a siren or a lamp, or an abnormality may be notified to a personal computer, smartphone, mobile phone, or mobile terminal 11 via a network.

The operation of the machine tool system prediction device will be described with reference to the program flow diagram of the invention 2 shown in FIG.

The predicting device reads the tool estimated value estimated by the monitoring device, and then reads the current data and the vibration data.

Based on the read current data and vibration data, the vibration data when the machine tool is driven is measured as shown in FIG. 12, and the measured vibration data is the maximum value and the minimum value on the time axis as shown in FIG. , The average value, the variance and the FFT calculation result, and the maximum value, the minimum value, and each frequency on the frequency axis calculated by the wavelet calculation result are calculated, and the feature amount is calculated.

The calculated feature amount is stored in the recording unit 14 together with the time series, and the past feature amount and the time change of the feature amount are read.

If the acquired feature amount, the past feature amount, and the temporal change of the feature amount are within the specified range, the processing is continued.

If the acquired feature amount, the past feature amount, and the time change of the feature amount are out of the specified range, it is predicted that an abnormality will occur and an alarm is notified.

When normal machining is performed, characteristic quantities of current data and vibration data are acquired, and the range of deviation is set together with the time series to predict the occurrence of defects and issue an alarm. Is possible.

The setting of the stipulated range may be dynamically set using a method of quality engineering or machine learning.

As shown in FIG. 4, the functions of the monitoring device and the prediction device may be integrated into a monitoring/prediction device 12a constructed by one CPU 13a and one recording unit 14a.

An embodiment for carrying out the invention 1 or the invention 2 is shown in FIG. A control that has a receiving unit 15 that receives a monitoring result of the mechanical system monitoring device of the first aspect of the invention or a prediction result of the mechanical system predicting device of the second aspect of the invention, and controls based on the monitoring result or the prediction result received by the receiving unit. By attaching a mechanism section 17 having a section 16 and operating a machine tool or a control panel of the machine tool by a signal from the control section, by operating an operation section of the machine tool or the control panel 18 of the machine tool. , A machine tool system control device for controlling a machine tool.

By using a mechanism part that is attached to the machine tool or the control panel of the machine tool, you can control the machine tool such as temporary stop, emergency stop, reset, restart by operating the operation part without modifying the machine tool body. It can be performed.

As shown in FIG. 6, the monitoring device, the receiving unit, and the control unit may be integrated into a monitoring/control device 7a.

Further, as shown in FIG. 7, the prediction device, the reception unit, and the control unit may be integrated into a prediction/control device 12b.

Further, as shown in FIG. 8, the functions of the monitoring device, the prediction device, and the control device may be integrated into a monitoring/prediction/control device 12C constructed by one CPU and one recording unit.

With the present invention 1, since the operating status can be monitored even when different tools are used without modifying the machine tool, a CNC equipped with an automatic tool changer (ATC, automatic match tool changer) is used. It is possible to improve the operation rate of machine tools and take quick countermeasures against defects.

By using the present invention 2, since it is possible to predict the occurrence of a failure and notify it before a failure occurs, it is possible to contribute to improving the operating rate of machine tools and reducing defective products.

If Invention 1 or Invention 2 is used, processing such as temporary stop, emergency stop, reset, and restart can be performed when an abnormality occurs without modifying the machine tool, thus contributing to improved safety and improved machine tool operating rate. it can.

It is a block diagram showing the structure of the invention 1. It is a block diagram which shows the form of 1st Example which concerns on invention 1. It is a block diagram which shows the form of 1st Example which concerns on invention 2. It is a block diagram which shows the form of 2nd Example which concerns on invention 2. FIG. It is a block diagram which shows the form of 1st Example which concerns on invention 1 or invention 2 . It is a block diagram which shows the form of 2nd Example which concerns on invention 1 or invention 2 . It is a block diagram which shows the form of 3rd Example which concerns on invention 1 or invention 2 . It is a block diagram which shows the form of 4th Example which concerns on invention 1 or invention 2. FIG. It is a flowchart of the program which concerns on invention 1. It is explanatory drawing which shows an example of a measurement part. It is a flowchart of the program which concerns on invention 2. It is an example of a method of calculating vibration data during driving. It is an example of a method of calculating a feature amount. It is an example of a tool estimation recording unit.

1 machine tool 2 work (workpiece)
3 Tool 4 Spindle 5 Current Sensor 6 Vibration Sensor 7 Monitoring Device 7a Monitoring/Control Device 8 Interface Circuit 9 Monitoring Device CPU
10 monitoring device recording unit 11 mobile terminal, personal computer 12 prediction device 12a monitoring/prediction device 12b prediction/control device 12c monitoring/prediction/control device 13 prediction device CPU
13a CPU for monitoring/prediction device
14 Predictor recording unit 14a Monitoring/Predictor recording unit 15 Receiver 16 Control unit 17 Mechanism unit 18 Machine tool operating unit

Claims (2)

In a machine tool system capable of performing machining by driving the tool by the spindle, the tool is attached to a machine tool system using the vibration data of the current data and the main axis of the measured major axis when running with no load has a determination section for specifying a tool, said has a recording unit which records a standard value for each identified tool by the determination unit, the said current data or the vibration data or the current data measured by the measuring unit vibration the data has a monitoring unit for comparative analysis and standard values called from the recording unit, the operation unit or the operation unit of the control panel of the machine tool of the machine tool by the mechanism which is externally arranged in retrofitted with physical manipulation apparatus retrofit of a machine tool system for performing operations including stop. In attaching device after machine tool system of claim 1, comprising a recording unit which records with time series vibration data of the current data and the main axis of the vibration data or the main shaft of the current data or main axis of the main shaft as measured in association with the identified tool the recording unit the current data or the vibration data or the vibration data of the current data and the main axis of the vibration data or the main shaft of the current data or main axis of the spindle associated with the stored tool with chronological was measured by the measurement unit to a prediction unit for comparative analysis between the current data and the vibration data, the operation unit of the control panel of the operating unit or the machine tool of the machine tool by the mechanism which is externally arranged in retrofitted to physical manipulation, operations including a stop retrofit device of a machine tool system for performing.