JP2017140675A - Cutting tool monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tool monitoring device capable of detecting an illegal operation related to replacement of a tool.SOLUTION: The invention is configured to: determine whether or not an integration power change amount ΔS is larger than a threshold C (step S15), when a replacement signal memory (flag or the like) is on (step S13); consider that tool replacement has been executed actually, and a switch 63 has not been operated for an illegal purpose, then determine that an operation state is a normal operation state (step S16), when the integration power change amount ΔS is smaller than the threshold C (NO in step S15); and consider that tool replacement has not been executed and the switch 63 has been operated for an illegal purpose (step S18) when a processing power change amount ΔP is larger than the threshold C (YES in step S15), and output a warning (step S19).SELECTED DRAWING: Figure 2

Description

  The present invention relates to the field of cutting machining such as drills and taps.

  In the field of metal cutting such as drills and taps, the state of cutting edge tools such as drills greatly affects the machining quality. For example, Patent Documents 1 and 2 are known as techniques for monitoring the state of the cutting edge tool and issuing an alarm in the event of an abnormality.

  In the technique of Patent Document 1, an abnormality in the operating unit is detected based on the rate of change in the power supplied to the motor that drives the operating unit. The abnormality of the operating part is, for example, that an abnormality such as a defect has occurred in the cutting tool K. Further, Patent Document 1 discloses that when the blade K is broken, it is in a no-load state and the power supplied to the motor M is abnormally reduced.

  In the technique of Patent Document 2, when the current flowing through the motor, that is, the load current value is greater than or equal to the threshold value, the fact that an abnormality has occurred in the equipment is displayed on the display device, and whether or not the number of times of machining is greater than or equal to the set number. Determine. If the number of times the tool has been processed is equal to or greater than the set number, it is determined that the tool has reached the end of its life, and a display for instructing the operator to replace the tool is displayed.

  If the cutting edge tool is repeatedly cut, the cutting edge deteriorates and the machining quality cannot be maintained. For this reason, tool manufacturers usually set the recommended number of cuts for each cutting edge tool, and when the recommended number of cuttings is reached, the user replaces the tool with a new one, or re-grinds the cutting edge. use. Failure to replace or re-grind with a new tool will result in inferior processing quality and production of defective products. The “blade edge tool” may be referred to as “blade tool” or simply “tool”.

In order to prevent the production of such defective products, the following techniques are known.
(1) Means for registering / storing the number of cuttings recommended by the tool manufacturer (recommended number of cuttings) (2) Counting means for the number of cuttings for each tool (3) Compare the number of cuttings (count number) for each tool with the recommended number of cuttings Means (4) Means for outputting an alarm for prompting tool change when the number of times of cutting exceeds the recommended number of times of cutting (5) Means for notifying that the tool has been changed (blade exchange signal output) (6) Means for canceling the alarm Count the number of cuttings from the beginning of using the tool, and issue an alarm when the number of cuttings (count number) exceeds the value recommended by the tool manufacturer. Therefore, the number of times of cutting is kept below the number recommended by the manufacturer to protect the machining quality.

Moreover, the prior art of patent document 3 is known.
In the invention of Patent Document 3, the idle fluctuation amount in the previous cycle is added to the threshold value in the current cycle, and then the measured value of the electric energy of the motor during the machining operation in the current cycle is compared with the threshold value. As a result, the load abnormality can be accurately detected even when the amount of power of the motor used for detecting the load abnormality fluctuates during idle drilling or the like. The idle fluctuation is a fluctuation as shown in FIG. 2 of Patent Document 3, for example. If there is an idle fluctuation, the electric power of the motor is shifted so as to increase.

For example, the prior art described in Patent Document 4 is known.
The invention of Patent Document 4 provides a method capable of correctly automatically calculating an alarm set value even when a blade is replaced. Therefore, based on the feature of the active power waveform data for each cutting tool of the machine tool 11, an alarm set value calculation method is prepared for each cutting tool in advance. Then, the diagnostic device 12 connected to the machine tool collects the active power waveform data such as the power value from the machine tool, and adds the tool information indicating which tool is used at the time of the collection to the active power waveform data. In addition, by selecting an alarm set value calculation method based on the blade information, the alarm set value is correctly calculated even if the blade is replaced.

Japanese Patent Laid-Open No. 2000-152689 Japanese Patent Laid-Open No. 10-6170 JP 2009-78338 A JP 2006-82154 A

  As described above, in the conventional system, for example, as an example, when the number of cuttings (count number) reaches the recommended number of cuttings, an alarm for prompting tool replacement is output and a signal for notifying that tool replacement has been performed ( The alarm is released by the blade exchange signal.

  In the conventional system, when an operator or the like operates a predetermined switch, the above-mentioned blade tool replacement signal is output. That is, when an alarm is generated, a worker or the like normally releases the alarm by operating the predetermined switch after performing a tool change operation. The alarm may be canceled and the number of cuttings (count number) may be reset to zero by the cutting tool replacement signal.

  However, tool change work often takes time, and field workers who want to proceed with the work as planned perform the above switch operation without performing the tool change work, and send the blade tool change signal to cancel the alarm. In many cases, fraudulent work was made to continue processing.

  Alternatively, in a system provided with a monitoring device that monitors the machine that performs the cutting, the blade tool replacement signal is used to distinguish whether the blade tool is abnormal (blade breakage) or immediately after the blade tool is replaced. There was also. That is, for example, when the power value in the “cutting region” disclosed in Patent Document 4 is used, it is known that the power value becomes extremely small because the target is not cut, for example, when the blade breaks. Yes. In addition, the blade is deteriorated as it continues to be used, and accordingly, the power value in the “cutting region” gradually increases. That is, immediately after the blade is replaced, the power value in the “cutting region” is small, and thereafter, the power value gradually increases. This is because when the tool is new, the cutting edge is sharp and the power consumption required for the cutting process is low, and when cutting is repeated, the cutting edge is worn, and the power consumption necessary for the cutting process increases. When the predetermined number of times is reached and the tool is changed, the cutting edge is restored from a worn state to a sharp state, and the power value necessary for cutting returns to a small value again.

  As described above, the power value in the “cutting region” is small both when the blade is abnormal (blade breakage) and immediately after the blade is replaced. Furthermore, when both are compared, the power value of the broken blade becomes smaller. However, even if an attempt is made to distinguish between the two using some threshold value, for example, there may be a fluctuation in the power value such as an idle fluctuation, so that it cannot always be accurately distinguished.

  From the circumstances described above, it is considered to use the above-mentioned blade tool replacement signal in order to distinguish whether the blade tool is abnormal (blade breakage) or just after the blade tool is replaced. That is, when it is determined that “the power value is small” using a threshold or the like, if there is a blade replacement signal at that time, it is determined “immediately after blade replacement”, and if there is no blade replacement signal, “blade” It is determined that it is “broken”. Such a technology is called a prerequisite technology.

Here, FIG. 7 shows a system configuration example of the base technology.
In FIG. 7, first, a monitoring target and the like by the illustrated cutting machine monitoring apparatus 50 according to the above premise technique will be described. The monitoring target is a machine tool 61, which is a machine having a tool (cutting tool) for performing a cutting process, and here shows a case where the cutting tool is a drill. A motor 62 that drives the machine tool 61 (rotates the drill) is also provided. Further, a measuring device (not shown) for detecting the power consumption by the motor 62 is provided. The power consumption value measured by this measuring device is input to the cutting machine monitoring device 50.

  The machine tool 61 (and the motor 62) performs cutting (making a hole) on a workpiece not shown. A cutting frequency counting device 64 that counts the number of times of cutting (for example, the number of workpieces that have been cut) and a blade tool replacement alarm device 65 are further provided. The blade tool replacement alarm device 65 issues an alarm when the count number of the cutting frequency counting device 64 reaches the preset recommended cutting frequency. There are various methods for issuing an alarm, such as light and sound, and blinking of an alarm lamp, display of an alarm message, a buzzer, a siren, and the like are possible.

  A switch 63 is provided. When an operator or the like depresses the switch 63, the blade replacement signal is output (ON), thereby releasing the alarm by the blade replacement alarm device 65, and the count number of the cutting frequency counting device 64 is' 0. Reset to '. The cutting tool replacement signal is also input to the cutting machine monitoring device 50. This is an example, and the present invention is not limited to this example. For example, the cutting tool replacement signal may be input only to the cutting machine monitoring device 50 and may not be used for alarm release or count number resetting. Further, the blade tool replacement alarm device 65 may not be provided. In this case, for example, an operator refers to the count number of the cutting number counting device 64 to determine the blade tool replacement time by himself, and manually resets the count number when the blade tool is replaced.

  As described above, the cutting machine monitoring device 50 is input with the measured value of the power consumption of the motor 62 at any time and the cutting tool replacement signal when the switch 63 is pressed. The power consumption measurement value is accumulated and stored in the data storage unit 51, for example.

  The illustrated data processing unit 52 of the cutting machine monitoring device 50 determines the presence or absence of an abnormality (blade breakage) of the cutting tool based on these inputs. In that case, it can distinguish and judge from the case immediately after replacement | exchange of a blade tool. First, based on the measured power consumption value of the motor 62, it is determined whether or not it is in a normal state.

  And when it determines with it not being in a normal state, it is determined whether it is the case where it is the abnormality (blade breakage) of a blade tool, or immediately after replacement | exchange of a blade. As described above, this is determined to be immediately after replacement of the blade when the blade replacement signal is present. It should be noted that even if it is determined that the state is not normal once, if it is immediately after the replacement of the blade, it may be regarded as being in a normal state.

  In this way, the cutting machine monitoring device 50 of the above-mentioned base technology can determine whether or not there is an abnormality (blade breakage) in the blade tool while distinguishing from the case where it is not actually abnormal (when the blade tool is just replaced). it can.

However, in the base technology, a correct determination result may not be obtained if there is an unauthorized work.
Such a premise technique is an example, but in any case, the switch 63 is operated improperly (unauthorized operation related to tool change), that is, the operator does not actually replace the cutting tool. It is desirable to be able to determine that an unauthorized operation of pressing is performed and a cutting tool replacement signal is being output.

  The subject of this invention is providing the cutting machine monitoring apparatus etc. which can detect the unauthorized operation regarding a tool exchange.

The cutting machine monitoring apparatus of the present invention has the following means.
Power value input means for inputting a power consumption value of a driving device that drives a tool for cutting an arbitrary workpiece;
-State management means for setting a tool replacement state when a cutting tool replacement signal, which is a signal notifying that the tool has been changed, is generated when a predetermined switch operation is performed;
-In the tool change consideration state, a predetermined value related to the power consumption value is changed from the previous value to the current value by using the previous value and the current value that are values before and after the tool change consideration state. Tool change determining means for determining whether the tool has been changed or not changed based on a change;
A warning means for setting a warning state to issue a warning that the tool is not changed when it is determined that the tool is not changed;

  According to the cutting machine monitoring apparatus and the like of the present invention, it is possible to detect an unauthorized operation related to tool change.

It is a functional block diagram of the cutting machine monitoring apparatus of this example. It is a flowchart figure which shows a part of process of a cutting machine monitoring apparatus. (A)-(c) is a specific example of the electric power value data and integrated electric energy input into a cutting machine monitoring apparatus. (A) and (b) are specific examples of the integrated power amount S and its change amount ΔS and each threshold value. (A), (b) is a figure for demonstrating the case where a tool change is implemented. (A), (b) is a figure for demonstrating the case where tool replacement is not implemented. It is a functional block diagram of the cutting machine monitoring apparatus of a base technology.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a functional configuration diagram of the cutting machine monitoring apparatus 10 of the present example.
Further, FIG. 1 also shows a monitoring target and the like of the cutting machine monitoring apparatus 10 of this example. This monitoring target or the like may be the same as that of the base technology, and here, the configuration shown in FIG. That is, the machine tool 61, the motor 62, the switch 63, the cutting frequency counting device 64, and the cutting tool replacement alarm device 65 are shown. However, the cutting frequency counting device 64 and the blade tool replacement alarm device 65 are not necessarily required (they may not be provided).

  Since each of these components has already been described, the machine tool 61 is a cutting machine including a cutting tool such as the cutting edge tool (blade tool). Note that the cutting edge tool (cutting tool) may be simply referred to as “tool”. The cutting tool is, for example, a drill or the like, and the motor 62 rotationally drives the drill or the like to cut (perforate or the like) a workpiece (not shown).

  The number-of-cuts counting device 64 counts the number of times of the cutting, and the blade tool replacement alarm device 65 issues an alarm when the counted number reaches the recommended number of cuttings. The warning is canceled and the count value of the number of cuttings is reset to zero by the cutting tool replacement signal output when the operator or the like presses the switch 63. In addition, as above-mentioned, this is an example and is not restricted to this example. As described above, the blade replacement signal is a signal for notifying that the tool has been changed (a signal for notifying that the blade replacement has been completed).

  When an alarm is issued by the blade tool replacement alarm device 65, an operator or the like normally presses the switch 63 after replacing the blade tool (drill or the like) of the machine tool 61. However, as described above, the drill or the like is replaced. There is a case where an illegal act of pressing the switch 63 without doing so is performed. The cutting machine monitoring apparatus 10 of this example can cope with such an illegal act.

  First, the input to the cutting machine monitoring device 10 is the cutting tool replacement signal and the power measurement value of the motor 62 as in the cutting machine monitoring device 50 of the base technology. Although not particularly shown, a measurement device (not shown) that measures the power consumption of the motor 62 is provided, as in the above-described prerequisite technology.

  Similarly to the above-described base technology, the blade tool replacement alarm device 65 outputs an alarm for prompting tool replacement when the count value of the number of times of driving (the number of times of cutting) of the machine tool 61 reaches a preset recommended number of times of cutting. Thereafter, when there is an output (ON signal) of the cutting tool replacement signal, the alarm is canceled and the cutting frequency count value is reset to "0".

  When the operator depresses the predetermined switch 63, a blade replacement signal is output. As described above, the blade tool replacement signal is used to cancel the alarm, but is also input to the cutting machine monitoring device 10.

  When a cutting tool replacement signal is input, the cutting machine monitoring apparatus 10 turns on an unillustrated replacement signal memory (such as a flag). This flag ON means that the tool change is regarded as a state. The tool replacement consideration state is a state that means that a tool change should be performed if there is no unauthorized operation. Thus, in the specific example described later, the determination in step S15 described later is performed when the tool replacement is in a state of determination, and it is determined whether the tool replacement is actually performed or not (unauthorized operation). To do. Details will be described later.

  Further, the cutting machine monitoring apparatus 10 holds a previous value of a predetermined value (such as an integrated power amount S described later) obtained from the input power measurement value of the motor 62. Here, an explanation will be given taking an integrated power amount S described later as an example. Each time a cutting operation is performed on an arbitrary workpiece, the cutting machine monitoring apparatus 10 inputs a power measurement value of the motor 62 associated therewith, and obtains an integrated power amount S described later. Then, the accumulated power amount S (current value) obtained this time is held as a new previous value. Then, a new current value, which is the accumulated power amount S obtained with the cutting operation for the next workpiece, the previous value held above, a preset threshold value, and the exchange signal memory (flag) Etc.) and the like, the presence / absence of blade tool abnormality (blade breakage, etc.) and blade tool replacement is determined. As a result, it is possible to detect fraud related to tool change. In addition, this makes it possible to reliably determine whether the tool is abnormal (blade breakage, etc.) or tool replacement. An example of this processing is shown in FIG. FIG. 2 will be described later.

Here, various functions of the cutting machine monitoring apparatus 10 of FIG. 1 and various data to be generated / held will be described.
The cutting machine monitoring apparatus 10 includes a data processing unit 11 and a data storage unit 16. The data processing unit 11 includes various functional units such as a variation threshold registration processing unit 12, a measurement processing unit 13, a variation calculation processing unit 14, and a determination processing unit 15. This is merely an example, and the present invention is not limited to this example. For example, the cutting machine monitoring apparatus 10 may have various functional units (not shown) described later.

  The cutting machine monitoring device 10 is realized on a computer device having a calculation processor such as a CPU / MPU (not shown), a storage unit such as a memory (not shown), and the like. A predetermined application program is stored in the storage unit in advance. When the arithmetic processor executes this application program, the processing of the various functional units in FIG. 1 and the processing of the various functional units (not shown) are realized.

  Moreover, the cutting machine monitoring apparatus 10 may further include an alarm unit 17 and an operation panel 18 shown in the drawing. The alarm unit 17 may be anything such as a buzzer, a lamp, a siren, a display, or the like that can notify the user of an alarm (warning) in some form.

  The operation panel 18 is a keyboard or the like, for example. However, the operation panel 18 is not limited to this example, and may be anything as long as the user (human) can input desired data. Here, in particular, the user operates the operation panel 18 to set and input a desired change amount threshold value. The change amount threshold value registration processing unit 12 stores the set “change amount threshold value” in the data storage unit 16. Note that threshold A, threshold B, threshold C, and the like, which will be described later, are examples of the “change amount threshold”, but are not limited to this example.

  For example, the measurement processing unit 13 inputs a power consumption value at the time of cutting of a driving device that drives a tool for cutting an arbitrary workpiece. For example, a power measurement value of the motor 62 is input. Then, for example, an integrated power amount S described later is obtained from the input power measurement value of the motor 62.

  The cutting machine monitoring apparatus 10 further includes, for example, a state management unit (not shown) that sets a tool exchange consideration state when a cutting tool exchange signal generated when a predetermined switch operation is performed is input. There may be.

  The change amount calculation processing unit 14 obtains a value indicating a change from the previous value of the predetermined value related to the power consumption value to the current value. For example, this calculates an integrated power change amount ΔS described later from an integrated power amount S described later, but is not limited to this example. For example, the predetermined value related to the power consumption value is the integrated power amount S that is an integrated value of the power consumption value during a predetermined period (for example, a cutting period described later).

  The determination processing unit 15 actually performs tool replacement based on a change from a previous value to a current value of a predetermined value (integrated power amount S) related to the power consumption value when the tool replacement is in the above state. Determine whether it has been done or not implemented. In other words, for example, it is determined whether or not there is an unauthorized operation of the switch 63. For example, a threshold value for tool change determination corresponding to the difference between the previous value and the current value is set in advance, and the determination processing unit 15 actually performs tool replacement based on the difference and the threshold value. It is determined whether it has been done or not implemented.

  For example, the determination processing unit 15 performs predetermined determination including determination of an unauthorized operation of the switch 63 based on the integrated power change amount ΔS, the change amount threshold value, a flag, and the like. Furthermore, if it is determined that the switch 63 has been illegally operated, some warning (warning that tool replacement has not been performed) is issued via the alarm unit 17. This warning is subsequently continued until it is determined that the blade has been replaced. Details will be described later with reference to FIG.

  The cutting machine monitoring apparatus 10 may further include, for example, an abnormality determination unit (not shown) that determines whether the state is a normal state or an abnormal state. An abnormality determination unit (not shown) determines whether or not it is in a normal state based on a predetermined value (integrated power amount S) relating to the power consumption value, for example, when not in the tool replacement state.

FIG. 2 is a flowchart showing a part of the processing of the cutting machine monitoring apparatus 10.
For example, the cutting machine monitoring apparatus 10 performs the process of FIG. 2 every time a cutting operation of a workpiece (not shown) is performed. When the process of FIG. 2 is executed, it is assumed that the current integrated power amount S (current value) is obtained by the measurement processing unit 13.

  Here, the cutting machine monitoring apparatus 10 is based on the previous value and the current value of the integrated electric energy S immediately after the start of the process of FIG. 2 (or before making a determination in the process of step S11 or step S15). Thus, the integrated power change amount ΔS (= current value−previous value) is calculated.

Although not shown, for example, at the end of the process of FIG. 2, a process of holding the current value as a new previous value is also performed.
Here, the integrated electric energy S will be described with reference to FIG.

  FIGS. 3A to 3C are specific examples of power value data (power measurement value of the motor 62) input to the cutting machine monitoring apparatus 10. FIG. The illustrated power value data is time series data from the start to the end of cutting for an arbitrary workpiece, and the integrated power amount S is obtained from the time series data, for example. In addition, about such electric power value data (time series data), the said patent document 3 and the patent document 4 have substantially the same disclosure, for example.

First, the illustrated power value data itself will be described with reference to a typical example shown in FIG.
When cutting is started, the drill starts rotating from a stopped state. The power value required for such activation becomes very large as shown in the figure. After that, after the drill reaches a predetermined number of revolutions, it is in an idling state (idling state) until the drill starts cutting the workpiece. In the idling state, as shown in the figure, the power value is very small.

  When the cutting starts, the power value increases as shown in the figure, and when the cutting ends, the power value becomes the same value as in the idle state. Such a period from the start to the end of cutting is called a cutting period.

  The integrated power amount S is, for example, an integrated value of power values during the cutting period, that is, the area S of the region indicated by the hatched lines in the figure. Since the method for obtaining the area S is well known (eg, integration), it will not be described in particular.

  Here, for example, the maximum value or the average value of the power value in this cutting period is referred to as a machining power value P. In the figure, an example in which the machining power value P is the maximum value, that is, a case where the machining power value P is the maximum value in the power value (instantaneous value) group in the cutting period is shown, and this example will be used in the following description. To do.

Moreover, in FIG.3 (b), the various specific examples of integrated electric energy are shown.
First, it is assumed that the integrated power amount S shown in FIG. 3A is the previous integrated power amount S1 shown in FIG. This integrated electric power amount S1 is shown by an integrated value (area) of electric power values in a solid line cutting period in FIG. And as an example of this integrated electric energy, the example of three types of illustration is shown. The normal value is indicated by the integrated value (area) of the power value in the cutting period of the one-dot chain line, and the example in which the cutting tool is changed is indicated by the integrated value (area) of the power value in the cutting period of the dotted line. An example is shown by the integrated amount (area) of the power value in the cutting period of the two-dot chain line.

  The previous integrated power amount S indicated by the solid line data is S1, the current integrated power amount S that is not replaced by the blade tool indicated by the one-dot chain line data is S2, the current integrated power amount S immediately after the blade tool replacement indicated by the dotted line data is S3, 2 The integrated electric energy S after the cutting of the blade indicated by the dotted line data is S4. Therefore, the change amount ΔS (= current value−previous value) of the integrated power amount is ΔS2 = S2-S1 when the blade is not replaced, and ΔS3 = S3-S1 when the blade is replaced, and the blade breakage In this case, ΔS4 = S4−S1.

  When the blade power is not replaced, the current power value is a value that is not much different from the previous value (the power value tends to increase gradually every time). On the other hand, in the case of blade replacement or blade breakage, the current value is much smaller than the previous value. As a result, the integrated power change amount ΔS becomes a relatively small value (slight increase or decrease) when it is normal, but becomes a relatively large negative value when the blade is replaced or broken. Further, in the comparison between the blade replacement and the blade breakage, the accumulated power amount S is smaller in the case of blade breakage than in the case of blade replacement. Therefore, the integrated power change amount ΔS is a negative value larger when the blade is broken than when the blade is replaced. Therefore, it can be said that the relationship between the integrated power variation amounts ΔS is a relationship of ΔS2> ΔS3> ΔS4.

  Regarding the integrated power amount S and the integrated power change amount ΔS, the processing power value P and the change amount ΔP are substantially the same. In this embodiment, the process using the amount of change in the integrated power amount S (area S) is performed, and both threshold values (a plurality of threshold values) on the increase side and the decrease side are provided. This will be described below with reference to FIG.

  4A and 4B, the vertical axis represents the integrated power amount S, and the illustrated integrated power amounts S1, S2, and S3 are shown as specific examples. The accumulated power amount S1 is a previous value, and the accumulated power amounts S2 and S3 are current values.

  As shown in FIG. 4A, the current value S2 of the integrated power amount is a current value when the blade is not replaced, and is almost the same as the previous value S1 of the integrated power amount. Therefore, the integrated power change amount ΔS becomes a relatively small value (slight increase or decrease) as shown in the figure. As the tendency of the integrated power consumption every time, the tendency is to gradually increase (not shown).

  Further, as shown in FIG. 4B, the current value S3 of the integrated power amount is a current value when the blade is replaced, and is greatly reduced from the previous value integrated power amount S1. Therefore, the integrated power change amount ΔS is a relatively large negative value as shown in the figure.

Although not shown in the figure, when there is a break in the blade, the current value is a value smaller than the integrated power amount S3.
Here, in the present embodiment, the three types of threshold values shown (threshold value A, threshold value B, and threshold value C) are used. As illustrated, the threshold value A is a positive value, and the threshold values B and C are negative values.

The threshold value B is a threshold value corresponding to the case where the blade is broken, and the abnormality determination unit determines that the blade is broken when the integrated power change amount ΔS is less than the threshold value B (ΔS <B). To do.
The threshold C is a threshold corresponding to the case where the blade has been replaced. When the integrated power change amount ΔS is less than the threshold C (ΔS <C), the determination processing unit has the blade replaced. Is determined. As described above, since the integrated power amount S3 shown in FIG. 4B is a value when the blade is replaced, the integrated power change amount ΔS in this case is less than the threshold C as shown. In other words, the integrated power change amount ΔS in this case is a negative value larger than the threshold value C as shown in the figure.

  Here, as described above, when the blade breaks, the integrated power amount S becomes a very small value, and thus the threshold value B is provided accordingly. However, the abnormal state is not limited to the bending of the blade, and there is a processing failure such as “chip of chips”. When such a processing defect occurs, an increase in change value becomes abnormal. The threshold value A according to such processing defects as “chip biting” is the threshold value A. As shown in FIG. 4A, the threshold A is a positive value larger than the normal accumulated power change amount ΔS shown in the figure. When the integrated power change amount ΔS is larger than the threshold value A (ΔS> A), the abnormality determination unit determines that there is a processing defect such as “chip biting”.

In the present embodiment, for example, for example, the processing illustrated in FIG. 2 is performed using the above three types of threshold values (threshold value A, threshold value B, and threshold value C).
Returning to the description of FIG.

  FIG. 3C shows a specific example of the integrated power amount in a normal case. Here, two types are shown, which are indicated by a thin solid line and a thick solid line. The one indicated by the integrated value (area) of the power value in the thin solid line cutting period is, for example, the integrated electric energy in the morning, and the one indicated by the integrated value (area) of the electric power value in the thick solid line cutting period is, for example, in the evening Is the integrated power amount at.

  In the illustrated example, the integrated power amount is generally smaller in the morning than in the evening. However, the present invention is not limited to this example, and conversely, in the morning, there may be a phenomenon in which the integrated power amount is larger as a whole than in the evening. The reason why such a phenomenon (the overall fluctuation of the integrated electric energy) occurs is unknown, but is a phenomenon that actually occurs in the field.

  As described above, even in a normal state, there is a possibility that the integrated electric energy varies as a whole. Therefore, when the abnormality determination is performed using the threshold with respect to the integrated power amount S, there is a possibility of erroneous determination due to the influence of fluctuation. However, this variation is a variation related to a relatively long period such as morning and evening as described above, and does not vary in a short period like the previous time and this time. Therefore, the integrated power change amount ΔS is hardly affected by such fluctuations. Therefore, according to this method, it is possible to correctly determine whether there is an unauthorized operation or the like even if the power value data fluctuates.

In the above, FIG. 3 was demonstrated.
Returning to the description of FIG.
As described above, in this embodiment, the above three types of threshold values (threshold value A, threshold value B, and threshold value C) related to the integrated power change amount ΔS are arbitrarily set and stored in a memory or the like. The values of A, B, and C may be arbitrarily determined. In this example, A is a positive value, B and C are negative values, and the relationship of “B <C <A” is satisfied. Set as follows.

Hereinafter, the process of FIG. 2 will be described.
In the process of FIG. 2, it is first checked whether or not the exchange signal memory (flag or the like) is ON (step S13). In other words, it is determined whether or not it is in a tool change state.

  If the flag is OFF (step S13, NO), it is determined whether the integrated power change amount ΔS is within a normal range (step S11). That is, it is determined whether the integrated power change amount ΔS is within a range between the threshold value B and the threshold value A (normal range; B <ΔS <A). The threshold value C is a threshold value for determining whether or not the blade is replaced, and is not for determining normality / abnormality.

  When the integrated power change amount ΔS is within the normal range (B <ΔS <A) (step S11, YES), it is determined that the state is normal (step S12), and no particular processing is performed. .

  If the integrated power change amount ΔS is not within the normal range (B <ΔS <A) (step S11, NO), it is determined that the state is abnormal (step S14). The abnormal state is, for example, a processing failure such as the above-mentioned broken blade or the above-mentioned “chip of chips”. If ΔS ≦ B, the blade is broken, and if ΔS ≧ A, there is a processing defect such as “chip biting”.

  Here, as described above, when the blade is not in a normal state and the blade tool is not replaced, the current value of the integrated power value S is almost the same as the previous value, so the integrated power change amount ΔS (= current value−previous value). ) Is a very small value. On the other hand, when the blade is broken, the integrated power change amount ΔS has a relatively large negative value. Further, in the case of a processing failure such as “chip biting”, the integrated power change amount ΔS is a relatively large positive value. For the thresholds A and B, for example, arbitrary values considering such characteristics are determined and set in advance by a developer or the like.

On the other hand, when the replacement signal memory (flag or the like) is ON (step S13, YES), in other words, when the tool replacement is in a state of consideration, the present method takes into account the possibility that the above-described unauthorized operation has occurred. I do. That is, it is determined whether or not the integrated power change amount ΔS is larger than the threshold C (ΔS> C) (step S15). From the above, ΔS> C should be satisfied when the blade is in a normal state and the blade is not replaced.
In addition, when it is in the tool replacement state, it can be said that the current value and the previous value in the integrated power change amount ΔS (= current value−previous value) are values before and after the tool replacement state. In this case, the integrated power change amount ΔS is obtained from the previous value and the current value obtained by using the previous value and the current value that are values before and after the predetermined value related to the power consumption value is changed to the tool change state. It can also be said that it is an example of a value indicating the fluctuation of (a difference between the previous value and the current value).

  From this, when ΔS> C (step S15, YES), it is assumed that the switch 63 has been improperly operated because the tool change is not actually performed (step S18). Some warning is output (step S19). This outputs a warning from the alarm unit 17 as described above. In this way, in this method, it is possible to determine an unauthorized action by a worker or the like, issue a warning, and prompt the user to perform tool replacement.

  On the other hand, when the integrated power change amount ΔS is equal to or less than the threshold value C (ΔS ≦ C) (step S15, NO), the switch 63 is illegally operated because the tool is actually changed. Therefore, it is determined that the tool change state is normal (step S16). In this case, the exchange signal memory (flag or the like) is reset (turned off). That is, the tool replacement look state is canceled (step S17).

As described with reference to FIG. 4B, immediately after the tool change, the integrated power amount S becomes small, and thus the integrated power change amount ΔS becomes a somewhat large negative value, so that ΔS <C. It becomes.
In step S17, if a warning is generated in step S19, the warning state is further canceled. The process of FIG. 2 is repeatedly executed. In the previous process of FIG. 2, step S19 is executed and the warning state is entered, but in this process of FIG. 2, step S15 is NO. In step S17, the warning state is canceled. In this case, since the process of step S17 is performed, in the next process of FIG. 2, the determination of step S13 is NO and the determination of step S11 is performed. If there is a broken blade or the like, the determination in step S11 is NO.

  Here, FIGS. 5B and 6B respectively show specific examples of the integrated power amount S at the time of machining for each workpiece. The horizontal axis represents the number of processes, and may be considered to be the count value T1 of the cutting number counting device 64. Here, it is assumed that the recommended number of cuts is 100. Therefore, when the count value T1 reaches 1, 2, 3,... 99, 100 times, the count value T1 returns to 1 and starts counting from 1 again. The vertical axis represents the integrated power amount S, which is the integrated power amount S at the time of cutting each workpiece corresponding to each count value.

  FIG. 5 (b) shows the case where the blade is replaced when the count value T1 reaches 100 times, and FIG. 6 (b) shows the blade replacement when the count value T1 reaches 100 times. This shows the case where is not performed.

  As shown in FIGS. 5B and 6B, as the count value T1 increases as the cutting work continues, the tendency of the integrated electric energy S every time increases gradually. In addition, the accumulated power change amount ΔS during processing is a relatively small value (slight increase or decrease) during normal processing. For this reason, the 100th integrated power amount S1 is somewhat larger than the first integrated power amount S. For this reason, as shown in FIG. 5B, when cutting of the final product (100th unit) is completed and the cutting tool is replaced, the integrated power amount S3 of the first product (first unit) after the replacement becomes small. Therefore, the integrated power change amount ΔS is a large negative value.

  In normal machining, the cutting edge gradually wears, and the tendency of the accumulated power consumption every time tends to increase gradually. In the machining immediately after the tool is replaced, the integrated power amount S rapidly decreases, and the trend of the subsequent integrated power amount S gradually increases.

  On the other hand, when the cutting of the final product (100th unit) is completed and the next (101st) cutting operation is performed without replacing the cutting tool, as shown in FIG. The amount of change ΔS in the integrated power amount between the first and 101st units is a small value (slight increase or decrease) as usual.

  From the above, an appropriate threshold value is set in advance, and each time cutting is performed, a change amount ΔS from the integrated power amount at the previous machining to the integrated power amount at the current machining is calculated and compared with the threshold value. Thus, it can be determined whether or not the cutting tool has actually been replaced. When the blade is replaced, the accumulated power change amount ΔS becomes a relatively large negative value as shown in FIG. 5B. Therefore, a threshold value (negative value; here, the illustrated threshold value C) is used. When the integrated power change amount ΔS is less than the threshold value C, it can be considered that there is a blade replacement.

FIG. 5 (a) shows processing by the present technique when the blade is normally exchanged as shown in FIG. 5 (b).
The threshold C is a threshold corresponding to the case where “integrated power change amount ΔS = current value S3−previous value S1”. Thus, the threshold value C is basically a negative value. Therefore, as shown in FIG. 6B described later, when the integrated power change amount ΔS is a positive value (in the case of slight increase), the integrated power change amount ΔS is always greater than the threshold value C.

  As described above, since the recommended number of times is 100 here, when the count value T1 of the cutting number counting device 64 reaches 100 times, the operator normally replaces the cutting tool and switches the switch 63. Manipulate. As a result, the count number of the cutting frequency counting device 64 is reset to “0” and the cutting tool replacement signal is input to the cutting machine monitoring device 10. Accordingly, the cutting machine monitoring apparatus 10 turns on the exchange signal memory (flag or the like).

  After that, the worker restarts the cutting operation, and when the cutting process of the next cycle (current time) is performed, in the case of the blade after replacement, the resistance (cutting resistance) related to cutting becomes low. As shown in (b), the machining power value P becomes very low, and the integrated power change ΔS becomes a relatively large negative value. For this reason, when the cutting machine monitoring apparatus 10 makes a determination based on the integrated power change amount ΔS and the replacement signal memory (flag or the like), it determines that “tool change execution is normal” in step S16.

  FIG. 6 (a) shows processing by this method when the blade tool is not exchanged as shown in FIG. 6 (b). However, regarding the processing of “confirm that the value is larger than the threshold value C” shown in the figure, an example using the threshold value C is shown.

  In this case, although the count number of the cutting number counting device 64 has reached 100, the operator operates the switch 63 without exchanging the cutting tool. As a result, the count number of the cutting frequency counting device 64 is reset to “0” and the cutting tool replacement signal is input to the cutting machine monitoring device 10. Thus, the cutting machine monitoring device 10 turns on the exchange signal memory (flag or the like) as described above. This is the same as FIG.

  After that, the worker resumes the cutting work, and when the next cycle (current time) is cut, in this case, since the cutting tool is not replaced, the integrated power amount S during the processing remains high. In the illustrated example, the integrated power amount S is larger than the threshold value C. For this reason, when the cutting machine monitoring apparatus 10 makes a determination based on, for example, the integrated power change amount ΔS and the replacement signal memory (flag or the like), it is determined that “tool replacement is not performed” in step S18.

  From the above, the difference between the integrated power amount S at the time of machining at an arbitrary specified number of times of cutting (100th unit) and the integrated power amount S at the time of machining immediately after changing the tool thereafter (decrease in the integrated power amount) The amount is determined in advance for each tool, and a developer or the like determines a threshold value corresponding to the amount of power decrease (corresponding to the integrated power change amount ΔS during machining) for each tool. . An example of the threshold value is the threshold value C, but is not limited to this example.

  The “threshold value C” shown in FIGS. 5B and 6B is a threshold value for the change amount ΔS of the integrated power amount S during the machining. The accumulated power change amount ΔS between the final product and the first product is obtained in advance by empirical / actual measurement or the like, and a value slightly larger than the value of the accumulated power change amount ΔS is set as the tool change determination threshold value C. In the tool replacement assumed state, when a decrease in the integrated power amount S at the time of machining, which is the current value, is more than the threshold value C, it can be determined that the tool is changed, and the integrated power amount S at the time of processing is greater than the threshold value C. If no decrease is observed, it can be determined that the tool is not changed. When the tool is not actually changed, ΔS is a relatively small value (slight increase or decrease).

  When the number of cuttings progresses and the counter value T1 reaches a predetermined number of times, and then the exchange signal memory is turned ON, when the next machining is finished in this state, if the tool is actually exchanged, The electric power integration amount S of FIG. 4 indicates a decrease of the threshold value C or more from the previous value. When the machining is continued without changing the tool, the change amount ΔS of the integrated power amount S during machining becomes a relatively small value (slight increase or decrease).

  Normally, when the amount of change in decrease from the previous value is large, it is considered abnormal (blade breakage, etc.), but when a large amount of change in change appears in the tool replacement state (the change signal memory is ON) Can be considered to be a tool change rather than an abnormality. Only when the execution of the tool change can be detected, the held tool change consideration state is canceled.

In this way, since it is determined from the machining power data whether or not the tool is changed in the state where the tool change is considered, the fraud can be prevented by detecting the fraud.
In addition, although the various function parts which the cutting machine monitoring apparatus 10 has are shown in FIG. 1 as an example, it is not restricted to this example. The cutting machine monitoring apparatus 10 can be considered to have various functional units (not shown) described below, for example.

A power value input unit that inputs a power consumption value of a driving device (for example, the motor 62) that drives a tool for cutting an arbitrary workpiece;
A state management unit that sets the above-described tool replacement state when there is an input of a blade replacement signal generated when a predetermined switch operation is performed;
The predetermined switch operation is, for example, an operation of pressing the switch 63.

-Tool change determination that determines whether the tool has been changed or not based on the change from the previous value to the current value of the predetermined value related to the power consumption value when the tool change is considered Part;
A warning unit that sets a warning state to issue a warning that the tool has not been replaced when it is determined that the tool has not been replaced;
For example, when the tool replacement determination unit determines that the tool has been replaced in the warning state, the warning unit cancels the warning state.

Moreover, it can be considered that the cutting machine monitoring apparatus 10 further includes, for example, various functional units (not shown) described below.
An abnormality determination unit that determines whether the tool is in a normal state based on a predetermined value related to the power consumption value when the tool change is not in the above state;
For example, when it is determined that the tool has been replaced, the tool replacement determination unit cancels the tool replacement state.

The “predetermined value related to the power consumption value” is an integrated value of the power consumption value in a predetermined period, for example, the integrated power amount S. Thus, the “change from the previous value of the predetermined value related to the power consumption value to the current value” is, for example, the integrated power change amount ΔS, but of course is not limited to this example as described above.
The predetermined period is, for example, the above-described cutting period.

<Other examples>
In the above-described example, the integrated power amount S and the change amount ΔS thereof are used. However, the present invention is not limited to this example. For example, the machining power value P and the change amount ΔP described in FIG. Value) may be used. In this case, each threshold value for comparison with ΔP is newly set.

In the above example, the case where the cutting tool is a drill or the like has been described. However, the present invention is not limited to this example, and the cutting tool may be, for example, a polishing system (brush or the like).
Here, when the cutting tool is a polishing system (brush or the like), the characteristics are different from those of a drill or the like. That is, in a polishing system (brush or the like) tool, the power consumption tends to decrease as the tool deteriorates. This is because when a grindstone rotates like a grinder or belt grinding, multiple sharp edges are hit against the workpiece, and an electric power load is applied during grinding, but when the edges gradually become flat and become flat (worn out) It is considered that the power load decreases due to slippage on the workpiece. When the tool of the polishing system (brush or the like) is changed, the power consumption is greatly increased compared to the previous value because it returns to the original value.

  Thus, a polishing system (brush or the like) tool exhibits characteristics opposite to those of a drill or the like. That is, in the case of a polishing system (brush or the like) tool, the accumulated power change amount ΔS is a relatively small negative value when the tool is normal and the blade tool is not replaced, and is normal when the blade tool is replaced. A relatively large positive value. Thus, the threshold value D is arbitrarily set in advance.

  Even in the case of a tool of a polishing system (brush or the like), the processing of FIG. 2 is basically executed. However, in the processing of step S15, “ΔS <D ??” is used instead of the determination of “ΔS> C?”. Is determined. If “ΔS <D”, the process proceeds to step S18. If “ΔS ≧ D”, the process proceeds to step S16.

DESCRIPTION OF SYMBOLS 10 Cutting machine monitoring apparatus 11 Data processing part 12 Change amount threshold value registration process part 13 Measurement process part 14 Change amount calculation process part 15 Judgment process part 16 Data storage part 17 Alarm part 18 Operation panel 61 Machine tool 62 Motor 63 Switch 64 Cutting frequency Counting device 65 Cutting tool replacement alarm device

Claims (7)

A power value input means for inputting a power consumption value of a drive device for driving a tool for cutting an arbitrary workpiece;
A state management means that is generated when a predetermined switch operation is performed, and in which a tool replacement signal that is a signal notifying that a tool change has been performed is input, and in which a tool replacement state is set.
Using the previous value and the current value, which are values before and after the predetermined value related to the power consumption value, when the tool change is considered in the tool change state, the change from the previous value to the current value is performed. Based on the tool change determining means for determining whether the tool has been changed or not, and
When it is determined that the tool has not been replaced, warning means for issuing a warning indicating that the tool has not been replaced;
A cutting machine monitoring device comprising:   2. The cutting machine monitoring apparatus according to claim 1, wherein the warning unit cancels the warning state when the tool replacement determination unit determines that the tool has been changed in the warning state.   3. The apparatus according to claim 1, further comprising: an abnormality determination unit that determines whether the tool is in a normal state based on a predetermined value related to the power consumption value when the tool change is not in a state of being considered. Cutting machine monitoring device.   The cutting machine monitoring apparatus according to claim 1, wherein the predetermined value related to the power consumption value is an integrated power value that is an integrated value of the power consumption value during a predetermined period.   The cutting machine monitoring apparatus according to claim 4, wherein the predetermined period is a cutting period.   2. The cutting machine monitoring device according to claim 1, wherein the tool change determination unit cancels the tool change consideration state when it is determined that the tool has been changed. The fluctuation of the predetermined value related to the power consumption value from the previous value to the current value is a difference between the previous value and the current value,
A threshold for tool change determination according to the difference is preset,
The tool change determining means determines whether the tool change is performed or not based on the difference and the threshold value. Cutting machine monitoring device.