JPH11309648A - Abrasion detecting device for cutting tool, and recording medium capable of reading computer storing abrasion detecting program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the working accuracy while accurately detecting abrasion, and to prevent the generation of defective work after the working by providing an abrasion detecting means for detecting abrasion on the basis of the thrust force. SOLUTION: When the thrust force data DS detected by a thrust force detecting sensor 2 exceeds a second thrust force set value F2 , a second comparing unit 9 outputs the signal S2 to a timer 10. The timer 10 stops the count of time, and thereafter, the counted time is output as a timer data To to a third comparing part 12. As a result, a third comparing part 12 compares the measurement time obtained from the timer data To with the abrasion time judging threshold value Tm. In a case where the time T exceeds the abrasion judging time threshold value Tm, the third comparing part 12 outputs the signal S3 to a signal generating part 15. The signal generating part 15 outputs the abrasion detecting signal Sm corresponding to the signal S3 to a control part 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for detecting wear of a cutting tool used for detecting wear of a drill and the like, and a computer-readable recording medium on which a wear detection program is recorded.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 6-198547 discloses a method for predicting breakage of a rotary cutting tool, which predicts breakage of a cutting tool such as a drill by focusing on the cutting torque when cutting a workpiece. According to this method, the cutting torque and the cutting feed power when cutting the test work with a new cutting tool on a trial basis are used, and the cutting tool breakage dangerous torque and the cutting feed power threshold of a size before the cutting tool breaks. The value is set. The cutting torque and the cutting feed power are measured by a magnetostrictive torque sensor and a load cell, respectively. When the breakage is predicted, the cutting torque and the cutting feed power at each cutting when a large number of workpieces are actually cut by the cutting tool are respectively detected, and the cutting torque and the cutting feed power are detected as the cutting tool breakage dangerous torque. When the cutting power exceeds the threshold value, breakage of the cutting tool is predicted.

[0003]

However, in the conventional method for predicting breakage of a cutting tool, when cutting is performed using a certain kind of cutting tool or under certain cutting conditions, the cutting torque (or cutting force) of a new cutting tool is reduced. There may be little difference between the feed power) and the cutting torque of the worn tool. Therefore, in the conventional method for predicting breakage of a cutting tool,
Despite the tool being worn enough to need replacement,
There has been a problem that a false breakage prediction that replacement is unnecessary is made. Further, in the conventional method for predicting the breakage of a cutting tool, when a so-called chatter vibration in which the cutting torque increases momentarily occurs, the cutting tool is not broken, but is in a state before the cutting tool is broken. There is a problem that the wrong break prediction is made.

[0004] Here, the fact that the cutting torque of the new cutting tool and the cutting torque of the worn cutting tool hardly differ from the result of a test conducted by the inventor of the present invention (Fig. 9).
(See (a) and (b)). FIG. 9A is a diagram showing a time-torque characteristic when a test work is cut using a new cutting tool (drill), and FIG. 9B is a diagram after 800 holes are drilled in the test work. FIG. 4 is a diagram showing time-torque characteristics when a test work is cut using the cutting tool of FIG. FIG. 9 (a)
As is clear from (b) and (b), there is almost no difference between the two torque characteristics. FIG. 10 is a graph showing the relationship between the number of machined holes when drilling holes in the test work using the cutting tool and the average torque during cutting, which was measured each time 100 holes were drilled. As is clear from this figure, since the average torque of the cutting tool hardly changes regardless of the number of drilled holes, the conventional method for predicting breakage of the cutting tool uses:
It is presumed that it is actually difficult to predict the breakage of the cutting tool due to the torque change.

[0005] Further, in cutting using a cutting tool, high machining accuracy (accuracy such as the position of the machining hole and the roundness of the machining hole) may be required. In this case, the machining accuracy is greatly affected. It is necessary to detect abrasion of the chisel edge portion of the cutting tool which exerts the following, and to judge whether or not it is necessary to replace the cutting tool based on the detection result. However, the conventional method for predicting breakage of a cutting tool is a method for roughly predicting breakage, and cannot meet such a demand since the wear of the chisel edge cannot be detected. For this reason, in the related art, it is not possible to manage the life of the cutting tool to maintain high processing accuracy, and as a result, the time to replace the cutting tool is exceeded, and as a result, the processing accuracy is reduced. was there. The present invention has been made under such a background, and a device and method for detecting wear of a cutting tool and a wear detecting program capable of accurately detecting wear of the cutting tool and appropriately managing the life of the cutting tool. It is an object of the present invention to provide a computer-readable recording medium on which is recorded.

[0006]

According to a first aspect of the present invention, there is provided a cutting tool for processing a workpiece, a thrust force detecting means for detecting a thrust force of the cutting tool, and a detection result of the thrust force detecting means. Based on the above, it is determined whether the thrust force has risen, and a time counting means for counting a time from when the thrust force reaches a preset thrust force, the time counting result of the time counting means, and whether the blade is worn. And a wear detecting means for detecting that the cutting tool is worn when the time measurement result exceeds the wear determination time threshold. And According to a second aspect of the present invention, there is provided the wear detecting device for a cutting tool according to the first aspect, wherein the detection result of the thrust force detecting means and a defect for determining whether or not the defect is generated in the cutting tool. It is characterized by comprising a loss detecting means for comparing the threshold value with a determination thrust force threshold and detecting that the cutting tool is defective when the detection result exceeds the loss determination thrust force threshold. . According to a third aspect of the present invention, there is provided the blade tool wear detecting device according to the second aspect, further comprising a notifying unit that notifies each detection result of the wear detecting unit and the loss detecting unit. . According to a fourth aspect of the present invention, in the wear detecting device for a cutting tool according to the second or third aspect, when a defect of the cutting tool is detected based on a detection result of the defect detecting means, A drive control means for stopping the drive is provided. According to a fifth aspect of the present invention, there is provided a first step of detecting a thrust force of a cutting tool for processing a workpiece, and a time period from when the thrust force rises to when the thrust force reaches a preset thrust force. A second step of measuring the time, and comparing the result of the time measurement in the second step with a wear determination time threshold value for determining whether the blade tool is worn. A third step of detecting that the cutting tool is worn when the judgment time threshold value is exceeded. According to a sixth aspect of the present invention, there is provided a cutting tool for processing a workpiece, a thrust force detecting means for detecting a thrust force of the cutting tool, and the thrust force based on a detection result of the thrust force detecting means. From the rise to the predetermined thrust force, a timing result of the timing means, and a wear determination time threshold for determining whether the cutting tool is worn or not. When the timed result exceeds the wear determination time threshold, a computer reads a wear detection program for causing a computer to function as wear detection means for detecting that the blade is worn. It is a possible recording medium. Further, the invention according to claim 7 is a cutting tool for processing a workpiece, a thrust force detecting means for detecting a thrust force of the cutting tool, and a thrust force based on a detection result of the thrust force detecting means. Time measuring means for starting time measurement after standing up, and time determining means for determining whether or not the time measured by the time measuring means has exceeded a wear determination time threshold value for determining whether or not the cutting tool is worn. And, based on the determination result of the time determination means, when the timing result exceeds the wear determination time threshold,
The detection result of the thrust force detecting means is compared with a wear determination thrust force threshold value for determining whether the cutting tool is worn, and the detection result is smaller than the wear determination thrust force threshold value. And a wear detecting means for detecting that the cutting tool is worn. According to an eighth aspect of the present invention, there is provided the cutting tool wear detecting device according to the seventh aspect, wherein the detection result of the thrust force detecting means and a defect for judging whether the defect has occurred in the cutting tool. It is characterized by comprising a loss detecting means for comparing the threshold value with a determination thrust force threshold and detecting that the cutting tool is defective when the detection result exceeds the loss determination thrust force threshold. . Claim 9
The invention described in (1) is characterized in that, in the device for detecting wear of a cutting tool according to (8), a notifying means for notifying each detection result of the wear detecting means and the loss detecting means is provided. According to a tenth aspect of the present invention, in the wear detecting device for a cutting tool according to the eighth or ninth aspect, when a defect of the cutting tool is detected based on a detection result of the defect detecting means, A drive control means for stopping the drive is provided. According to the eleventh aspect of the present invention, the first step of detecting a thrust force of a cutting tool that performs machining on a work, and a time measurement after the thrust force rises based on the detection result of the thrust force. A second step of determining whether or not the result exceeds a wear determination time threshold for determining whether or not the cutting tool is worn; and determining the time based on the determination result in the second step. When the result exceeds the wear determination time threshold value, the detection result of the thrust force is compared with a wear determination thrust force threshold value for determining whether the cutting tool is worn or not. And a third step of detecting that the cutting tool is worn when the result is smaller than the wear determination thrust force threshold value. Also,
According to a twelfth aspect of the present invention, there is provided a cutting tool for processing a workpiece, thrust force detecting means for detecting a thrust force of the cutting tool, and the thrust force rising based on a detection result of the thrust force detecting means. Timer means for starting time counting afterwards, and time determination means for determining whether or not the time measurement result of the time measurement means has exceeded a wear determination time threshold value for determining whether or not the cutting tool is worn. When the time measurement result exceeds the wear determination time threshold based on the determination result of the time determination means, it is determined whether or not the detection result of the thrust force detection means and the cutting tool are worn. To the thrust force threshold value for wear determination for
A computer-readable recording recording a wear detection program for causing a computer to function as wear detection means for detecting that the cutting tool is worn when the detection result is smaller than the wear determination thrust force threshold value; Medium.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. First, the point of view of the inventor of the present invention will be described with reference to FIGS. FIG. 1 is a characteristic diagram showing a time change of a thrust force when a processing hole is drilled in a test work using a cutting tool (for example, a drill). FIG. 2 is an enlarged view of an ellipse R shown in FIG. It is a characteristic diagram. The inventor took data (1000 data) of each thrust force of the cutting tool when 1 to 1000 holes were sequentially formed in the test work using a new cutting tool. In FIG. 1, one hole, one hole,
00 holes, 200 holes, ..., 900 holes (characteristic line A), 10
Convenient 11 data of 00 holes (characteristic line B) at 100 hole intervals are plotted. As can be seen from this figure, only the characteristic line A (900 holes) and the characteristic line B (1000 holes) show different characteristics from the other characteristic lines. That is, while the characteristic lines A and B change in the vicinity of the thrust force of 10 × 100N, the characteristic lines other than the characteristic lines A and B (1, 100,..., 800 holes) Is 6 × 100
It varies between N and 8 × 100N.

Further, the inventor of the present invention has found that a cutting tool having 900 holes (characteristic line A) and 1000 holes (characteristic line B) has a defect, and a cutting tool having a diameter of 800 holes or less has a defect. It was confirmed by observation of the cutting tool that no cutting was performed. From this fact, the inventor paid attention to the fact that the thrust force suddenly increased when the number of machining holes exceeded a certain number (900 holes), and at this time, the cutting tool was damaged.

In addition, as can be seen from FIG. 2, immediately after the start of machining (0 to 0.2 sec), characteristic lines C, D, and E having one, 100, and 200 holes are formed.
Is different from other characteristic lines in which the number of processed holes is 300 or more. That is, while the characteristic lines C, D, and E show a rapid rising tendency, the other characteristic lines show a tendency to gradually increase and then rise.

Here, when the number of processed holes is from 1 to 200, the positions of the processed holes are processed with high processing accuracy without exceeding the tolerance of the fine grade.
After the hole, the position of the machined hole exceeded the allowable value of the fine grade and was machined with low accuracy. That is, the number of machining holes is one or more.
The tendency of the thrust force up to 200 holes indicates that the state of wear of the cutting tool is sufficient to obtain high machining accuracy,
The tendency of the thrust force when the number of machining holes is 300 or more indicates that the state of wear of the cutting tool is insufficient to obtain high machining accuracy. From this fact, the inventor paid attention to the fact that the wear of the cutting tool can be detected from the difference in the tendency of the thrust force shown in FIG. In the following description, a tool that has been worn such that the fineness of the position of the machining hole exceeds the allowable value is referred to as a "worn tool", while the wear is such that the fineness does not exceed the allowable value. The cutting tool that has only occurred is called "new cutting tool".

<First Embodiment> FIG. 3 is a block diagram showing the construction of a blade tool wear detecting device according to an embodiment of the present invention. In this figure, reference numeral 1 denotes a machine tool for performing drilling on a work using a cutting tool (for example, a drill), and includes a thrust force detection sensor 2 and a control unit 3. The thrust force detection sensor 2 detects a thrust force of a cutting tool (drill) not shown, and outputs a detection result as a thrust force detection signal Ss. The control unit 3 controls each unit of the machine tool 1 (drive control of a cutting tool, and the like).

Reference numeral 4 denotes a sensor amplifier for amplifying the thrust force detection signal Ss. 5 converts the thrust force detection signal Ss amplified by the sensor amplifier 4 into digital thrust force data Ds. Reference numeral 6 denotes a first storage unit that stores data of the first thrust force set value F1. Here, the first thrust force set value F1 will be described with reference to FIGS. FIG. 4 shows the time-
This is a simplified thrust force characteristic. In FIG. 4, a characteristic line F indicates the characteristic lines A and B shown in FIG. 1, and indicates a change in the thrust force when a defective cutting tool is used. Here, the missing tool has a machining hole number of 9
It refers to a cutting tool having 00 holes to 1000 holes and having defects. The characteristic line G indicates a characteristic line other than the characteristic lines A and B shown in FIG. 1 and indicates a change in the thrust force when using a cutting tool that is not missing. here,
The cutting tool that is not missing refers to a cutting tool having 800 holes or less. In addition, the tools that are not missing include both worn tools and new tools.

FIG. 5 is a simplified version of the time-thrust force characteristic shown in FIG. In FIG. 5, the characteristic line H is
FIG. 3 shows characteristic lines other than the characteristic lines C, D, and E shown in FIG. 2, and shows a change in thrust force when a worn blade tool is used. The characteristic line I shows the characteristic lines C, D and E shown in FIG. 2, and shows the change in the thrust force when a new cutting tool is used. Under such a premise, the first thrust force set value F1 is a set value for triggering the rising time of the thrust force shown in FIG. 5, and is set to a value slightly higher than zero.

Reference numeral 7 shown in FIG. 3 denotes a first comparing section for comparing the thrust force data Ds with a first thrust force set value F1 (see FIG. 5), and the thrust force data Ds is used as the first thrust force. The signal S1 exceeding the set value F1 is output. 8 is
It is a second storage unit for storing data of the second thrust force set value F2. As shown in FIG. 5, the second thrust force set value F2 is about one third of the steady value of the thrust force during machining.
, Which is a reference value for determining whether or not the cutting tool is worn. Reference numeral 9 denotes a second comparing section which compares the thrust force data Ds with the second thrust force set value F2, and outputs a signal S2 when the thrust force data Ds exceeds the second thrust force set value F2. I do.

Reference numeral 10 denotes a timer for measuring time, and a signal S
The timer starts when 1 is input, stops when the signal S2 is input, and outputs the timer result as timer data To when the clock is stopped. Reference numeral 11 denotes a third storage unit that stores data of the wear determination time threshold value Tm. The wear determination time threshold value Tm is used as a reference value for determining whether or not the cutting tool is worn as shown in FIG. 5, and is obtained from test data shown in FIG.

Reference numeral 12 denotes a third comparing unit for comparing the timer data To with the wear determination time threshold value Tm, and outputs a signal S3 when the timer data To exceeds the wear determination time threshold value Tm. On the other hand, when the timer data To is equal to or less than the wear determination time threshold Tm, the signal S3 is not output. Here, when the timer data To exceeds the wear determination time threshold Tm, it means that the cutting tool is worn as shown in FIG. 5, while the timer data To is less than the wear determination time threshold Tm. Sometimes it means that the cutting tool is new.

Reference numeral 13 shown in FIG. 3 is a fourth storage unit for storing data of the loss determination thrust force threshold value Fk. Here, the loss determination thrust force threshold value Fk is an intermediate thrust force between the thrust force of the flat portion of the characteristic line F shown in FIG. 4 and the thrust force of the flat portion of the characteristic line G shown in FIG. It is determined from the test data shown. The threshold value Fk for determining the loss of thrust is used as a criterion for determining whether the cutting tool is defective.

Reference numeral 14 denotes a fourth comparing section for comparing the thrust force data Ds with the loss determination thrust force threshold value Fk. When the thrust force data Ds exceeds the loss determination thrust force threshold value Fk, a signal is output. Outputs S4. Here, the fact that the thrust force data Ds exceeds the loss determination thrust force threshold value Fk means that the blade has a loss, while the thrust force data Ds is less than the loss determination thrust force threshold value Fk. The presence means that the cutting tool has no defect.

Reference numeral 15 denotes a signal generator which generates a wear detection signal Sm indicating that wear of the cutting tool has been detected and a loss detection signal Sk indicating that the cutting tool has been lost.
The signal generator 15 outputs the wear detection signal Sm to the controller 3 when the signal S3 is input, and outputs the loss detection signal Sk to the controller 3 when the signal S4 is input.

Next, the operation of the blade tool wear detecting device according to the first embodiment will be described. When the processing on the workpiece is started by the cutting tool at time t1 shown in FIG. 5, the thrust force of the cutting tool increases. This thrust force is detected by the thrust force detection sensor 2, and the thrust force detection sensor 2 outputs a thrust force detection signal Ss corresponding to the thrust force. Then, after the thrust force detection signal Ss is amplified by the sensor amplifier 4,
Further, the data is converted into thrust force data Ds by the A / D converter 5. The thrust force data Ds is input to the first comparing unit 7, the second comparing unit 9, and the fourth comparing unit 14, respectively.

Then, when the thrust force data Ds is input to the first comparing unit 7, the first comparing unit 7 compares the thrust force data Ds with the first thrust force set value F1.
Then, at time t2 shown in FIG. 5, the thrust force (thrust force data Ds) is changed to the first thrust force set value F1.
Is exceeded, the first comparing section 7 outputs a signal S1 to the timer 10. Thereby, the timer 10 starts measuring time.

In this case, assuming that a worn blade tool is used, the thrust force gradually changes from time t1 and rises rapidly as shown by a characteristic line H shown in FIG. Then, at time t4 shown in FIG. 5, when the thrust force data Ds exceeds the second thrust force set value F2, the second comparator 9 sends the signal S2 to the timer 1
Output to 0. Thus, after stopping the time measurement, the timer 10 outputs the time T02 from the time t2 to the time t4 to the third comparing unit 12 as the timer data To.

As a result, the third comparing section 12 compares the time T02 obtained from the timer data To with the wear determination time threshold Tm. In this case, since the time T02 exceeds the wear determination time threshold Tm, the third comparison unit 12
Outputs the signal S3 to the signal generator 15. As a result, the wear detection signal Sm corresponding to the signal S3 is output from the signal generation unit 15 to the control unit 3, and the control unit 3 notifies that the wear of the cutting tool has been detected via a buzzer, a display, and the like. .

The thrust force of the blade increases as shown in FIG. Assuming that the cutting tool currently used has a defect, the thrust force is represented by a characteristic line F shown in FIG.
It changes like Now, at time t5 shown in FIG. 4, since the thrust force (thrust force data Ds) exceeds the loss determination thrust force threshold value Fk, the fourth comparing unit 14 sends the signal S4 to the signal generating unit 15. Output. Accordingly, the signal generation unit 15 outputs a loss detection signal Sk indicating that the loss of the cutting tool has been detected to the control unit 3. And the control part 3 notifies that the defect of the cutting tool was detected via a buzzer, a display, etc., and stops driving of the cutting tool.

On the other hand, assuming that there is no defect in the cutting tool currently used, the thrust force changes as shown by a characteristic line G in FIG. In this case, since the thrust force does not exceed the loss determination thrust force threshold value Fk from time t1 to time t6, the signal S4 is not output from the fourth comparison unit 14 to the signal generation unit 15.

Assuming that a new cutting tool is used, the thrust force shows a sudden rise from time t1, as indicated by a characteristic line I shown in FIG. Then, at time t3 shown in FIG. 5, when the thrust force data Ds exceeds the second thrust force set value F2, the second comparator 9 outputs a signal S2 to the timer 10. Thus, after stopping the time measurement, the timer 10 outputs the time T01 from the time t2 to the time t3 to the third comparing unit 12 as the timer data To.

As a result, the third comparing section 12 compares the time T01 obtained from the timer data To with the wear determination time threshold Tm. In this case, since the time T01 is equal to or less than the wear determination time threshold Tm, the third comparison unit 12
The signal S3 is not output to the signal generator 15. That is, in this case, it is determined that a new cutting tool is used.

As described above, according to the device for detecting wear of a cutting tool according to the above-described first embodiment, wear and tear of the cutting tool are determined based on a change in thrust force instead of a conventional change in torque.
Since the defect is detected, the following effects can be obtained. (1) Even if the change in torque due to wear due to the type of cutting tool or cutting conditions is slight, or if chatter vibration occurs in which the torque increases momentarily, the wear of the cutting tool is accurately detected. be able to. (2) Since the wear of the cutting tool closely related to the processing accuracy can be accurately detected, the life of the cutting tool can be managed in consideration of the processing accuracy such as the position of the processing hole and the roundness.
Furthermore, because it is possible to detect the wear of the cutting tool,
It is possible to prevent loss or breakage due to the progress of wear of the cutting tool. (3) It is possible to shift the management of the replacement time of the cutting tool from the conventional management based on the use time and the number of processing holes to the quantitative management, so that the life of the cutting tool can be extended as a result, As a result, the cost of the cutting tool can be reduced. (4) Since the wear detection algorithm of the cutting tool by a simple predetermined combination is adopted, the arithmetic processing can be reduced, and as a result, the wear detection speed can be increased. Therefore, before the next processing step starts, the control unit 3
, The replacement of worn or missing blades can be encouraged, and the occurrence of defective products can be prevented. (5) Since the wear of the cutting tool can be detected in a short time immediately after the start of the processing, the detection of the wear or the breakage of the cutting tool that requires real-time performance may be affected. I will not give.

<Second Embodiment> FIG. 6 is a block diagram showing the configuration of a blade tool wear detecting device according to a second embodiment of the present invention. In this figure, parts corresponding to the respective parts in FIG. 3 are denoted by the same reference numerals, and description thereof is omitted. Reference numeral 20 shown in FIG. 6 is a first storage unit for storing data of the first thrust force set value F1 (see FIG. 7). The first thrust force set value F1 is the same as that shown in FIG. Same setting value. Reference numeral 21 denotes a first comparing unit for comparing the thrust force data Ds with the first thrust force set value F1 (see FIG. 7), and the thrust force data Ds is used as the first thrust force set value F1.
Signal S1 is output when the value exceeds.

Reference numeral 22 denotes a timer which starts counting from the time when the signal S1 is input.
Output as o. Reference numeral 23 denotes a second storage unit that stores data of the wear determination time threshold value Tm. The wear determination time threshold value Tm is a value serving as a reference time for determining whether or not the cutting tool is worn as shown in FIG. Reference numeral 24 denotes a second comparing section for comparing the timer data To with the wear determination time threshold Tm, and outputs a signal S2 when the timer data To exceeds the wear determination time threshold Tm.

25 is a thrust force threshold value Fm for determining wear.
3 is a third storage unit for storing the data of FIG. The wear determination thrust force threshold value Fm is, as shown in FIG. 7, approximately 1/3 of the steady value of the thrust force during machining, and is a criterion for determining whether the cutting tool is worn. Is the value
26 is the thrust force data Ds when the signal S2 is input.
A thrust force threshold value Fm, and a signal generation unit that generates a signal S3 when the thrust force obtained from the thrust force data Ds is smaller than the wear determination thrust force threshold value Fm. 15 is output. Also, the third
When the thrust force exceeds the wear determination thrust force threshold value Fm as a result of the comparison, the signal S4
To the first comparison unit 21.

Next, the operation of the blade tool wear detecting device according to the second embodiment will be described with reference to the flowchart shown in FIG. In step SA1 shown in FIG. 8, a setting unit (not shown) sets a first thrust force set value F1, a wear determination time threshold Tm, and a wear determination thrust force threshold Fm (see FIG. 7). These set values are determined based on the test data shown in FIG.

Then, at the time t1 shown in FIG. 7, when the processing of the workpiece by the cutting tool is started by the drive control of the control unit 3, the thrust force of the cutting tool increases. This thrust force is detected by the thrust force detection sensor 2, and the thrust force detection sensor 2 outputs a thrust force detection signal Ss corresponding to the thrust force. Then, after the thrust force detection signal Ss is amplified by the sensor amplifier 4, the thrust force data D is further amplified by the A / D converter 5.
Converted to s. The thrust force data Ds is input to the first comparing unit 21 and the third comparing unit 26, respectively.

When the thrust force data Ds is input to the first comparing section 21, the first comparing section 21 proceeds to step SA3, and after taking in the thrust force data Ds, proceeds to step SA4. In step SA4, the first
The comparison unit 21 compares the thrust force data Ds with the first thrust force set value F1, and determines that the thrust force data Ds is the first thrust force data Ds.
Is equal to or less than the set value F1, the determination is "NO" and the same determination is repeated. Then, at time t2 shown in FIG. 7, the thrust force (thrust force data D
If s) exceeds the first thrust force set value F1, the first comparing section 21 outputs a signal S1 to the timer 22.

As a result, the timer 22 sets the step SA
5 starts the time measurement, and outputs the time measurement result to the timer data To.
Are sequentially output to the second comparing section 24. This allows
The second comparing unit 24 proceeds to step SA6, compares the timer data To with the wear determination time threshold Tm, and if the timer data To is equal to or less than the wear determination time threshold Tm,
The same judgment is repeated with the judgment result being “NO”. here,
Assuming that a worn blade tool is used, the thrust force gradually changes from time t1 as shown by a characteristic line H in FIG.

At time t3 shown in FIG. 7, if the timer data To exceeds the wear determination time threshold Tm,
The second comparing unit 24 determines that the determination result of step SA6 is “Y
The signal S2 is output to the third comparing section 26 as "ES". As a result, the third comparison unit 26 determines in step SA7
Then, the program proceeds to step SA8 after fetching the thrust force data Ds. In step SA8, the third comparison unit 2
No. 6 compares the thrust force data Ds with the wear determination thrust force threshold value Fm. In this case, the thrust force data Ds
Since the thrust force obtained from the above is Fm2 (<Fm) shown in FIG. 7, the third comparing unit 26 sets the determination result of step SA8 to "YES", proceeds to step SA9, and outputs the signal S3 to the signal generating unit 15 Output to As a result, the wear detection signal Sm corresponding to the signal S3 is output from the signal generation unit 15 to the control unit 3, and the control unit 3 notifies that the wear of the cutting tool has been detected via a buzzer, a display, and the like. .

Assuming that a new cutting tool is used, the thrust force shows a sudden rise from time t1 as shown by a characteristic line I shown in FIG. When the timer data To exceeds the wear determination time threshold Tm at time t3 shown in FIG.
4 makes the determination result of step SA6 "YES",
The signal S2 is output to the third comparing section 26. This allows
The third comparing unit 26 proceeds to step SA7 in the same manner as the operation described above, and after fetching the thrust force data Ds, proceeds to step SA8.

In step SA8, the third comparing unit 26
Compares the thrust force data Ds with the wear determination thrust force threshold value Fm. In this case, since the thrust force obtained from the thrust force data Ds is Fm1 (> Fm) shown in FIG. 7, the third comparing unit 26 sets the determination result of step SA8 to “NO” and sets the signal S4 to the 1 to the comparison unit 21. Note that, in this case, the third comparing unit 26 outputs the signal S
3 is not output to the signal generator 15.

When the signal S4 is input to the first comparing section 21, the first comparing section 21 proceeds to step SA10, fetches the thrust force data Ds, and then proceeds to step SA11. In step SA11, the first comparing section 21 compares the thrust force data Ds with the first thrust force set value F1, and the thrust force obtained from the thrust force data Ds now becomes the first thrust force set value F1. Is exceeded, the result of the determination is "NO", the flow returns to step SA10, and the above-described operation is repeated. And now,
When the processing of the workpiece by the cutting tool is completed, the thrust force becomes equal to or less than the first thrust force set value F1. Thereby, the first comparing unit 21 sets the determination result of step SA11 to "YES", returns to step SA3, and repeats the above-described operation.

As described above, the apparatus for detecting wear of a cutting tool according to the above-described second embodiment has the same advantages as the apparatus for detecting wear of a cutting tool according to the first embodiment. In the blade tool wear detecting device according to the second embodiment described above, similarly to the blade tool wear detecting device according to the first embodiment, the loss determination thrust force threshold value Fk shown in FIG.
The defect of the cutting tool may be detected by comparing the thrust force with the thrust force. In this case, in the cutting tool wear detecting device shown in FIG. 6, the fourth storage unit 1 shown in FIG.
The third and fourth comparison units 14 may be added.

Although the embodiment of the present invention has been described in detail, the specific configuration is not limited to this embodiment, and even if there is a design change or the like within a range not departing from the gist of the present invention, the present invention is not limited thereto. included. For example, in the blade wear detecting devices according to the first and second embodiments described above, a program for realizing the above-described functions is stored in a flexible disk, a CD-ROM, a magneto-optical disk, an IC card, a DVD-ROM, or the like. The wear / loss of the cutting tool may be detected by recording the program on a computer-readable recording medium and reading and executing the program recorded on the recording medium by a computer system.
Also, the above program is stored on a floppy disk, CD-
The whole or a part thereof is recorded or stored in a portable medium such as a ROM or a storage device such as a hard disk. The program is read by a computer, and all or a part of the operation is executed. The recording medium referred to here is not limited to a medium in which a program is statically recorded, such as a magneto-optical disk, but may be a communication line for transmitting a program through a communication line such as a dedicated line of the Internet or a telephone line. In this case, a program that dynamically holds a program for a short time, and a program that holds a program for a certain period of time, such as a server or a memory in a computer in that case, are included.

[0042]

As described above, according to the present invention,
Since the wear detection is performed based on the thrust force, an effect is obtained that the wear detection can be performed more accurately than when the wear detection is performed based on the conventional torque. Therefore, according to the present invention, it is possible to appropriately manage the life of the cutting tool, to improve the processing accuracy, and to prevent the occurrence of defective workpieces after processing. . Also,
According to the invention described in claims 2 to 4 and claims 8 to 10,
Since it is configured to detect the loss of the cutting tool in addition to the wear detection, it is possible to more appropriately manage the life of the cutting tool,
As a result, the effect of reducing the incidence of defective products can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the operation principle of a blade tool wear detection device according to first and second embodiments of the present invention.

FIG. 2 is a diagram for explaining the operation principle of the blade tool wear detection device according to the first and second embodiments.

FIG. 3 is a block diagram showing a configuration of a blade tool wear detection device according to the first embodiment.

FIG. 4 is a view for explaining the operation of the blade tool wear detection device according to the first embodiment.

FIG. 5 is a view for explaining the operation of the blade tool wear detection device according to the first embodiment.

FIG. 6 is a block diagram showing a configuration of a blade tool wear detection device according to the second embodiment.

FIG. 7 is a view for explaining the operation of the blade tool wear detection device according to the second embodiment.

FIG. 8 is a flowchart illustrating the operation of the blade tool wear detection device according to the second embodiment.

FIG. 9 is a view for explaining a problem of a conventional method for predicting breakage of a cutting tool.

FIG. 10 is a diagram illustrating a problem of a conventional method for predicting breakage of a cutting tool.

[Explanation of symbols]

 Reference Signs List 1 machine tool 2 thrust force detection sensor 3 control unit 4 sensor amplifier 5 A / D conversion unit 6 first storage unit 7 first comparison unit 8 second storage unit 9 second comparison unit 10 timer 11 third Storage unit 12 Third comparison unit 13 Fourth storage unit 14 Fourth comparison unit 15 Signal generation unit 20 First storage unit 21 First comparison unit 22 Timer 23 Second storage unit 24 Second comparison unit 25 third storage unit 26 third comparison unit

Claims (12)

[Claims] 1. A cutting tool for processing a workpiece, a thrust force detecting means for detecting a thrust force of the cutting tool, and a thrust force rising based on a detection result of the thrust force detecting means. A time measuring means for measuring the time until the set thrust force is reached, and a timed result of the time measuring means, and a wear determination time threshold value for determining whether the blade is worn or not, A wear detecting means for detecting that the cutting tool is worn when the timing result exceeds the wear determination time threshold value. 2. A detection result of the thrust force detecting means,
Compare the loss determination thrust force threshold value to determine whether or not the blade has a loss, when the detection result exceeds the loss determination thrust force threshold, the blade is missing. The wear detecting device for a cutting tool according to claim 1, further comprising a defect detecting means for detecting the presence of the cutting tool. 3. An apparatus for detecting wear of a cutting tool according to claim 2, further comprising a notifying means for notifying each detection result of said wear detecting means and said loss detecting means. 4. The apparatus according to claim 2, further comprising a drive control unit for stopping driving of the blade when a defect of the blade is detected based on a detection result of the defect detection unit. An apparatus for detecting wear of a cutting tool as described in the above. 5. A first step of detecting a thrust force of a cutting tool for machining a workpiece, and a second step of measuring a time from when the thrust force rises to when the thrust force reaches a preset thrust force. And comparing the timing result in the second step with a wear determination time threshold value for determining whether or not the cutting tool is worn, wherein the timing result indicates the wear determination time threshold value. And a third step of detecting that the cutting tool is worn when it is exceeded. 6. A cutting tool for processing a workpiece, a thrust force detecting means for detecting a thrust force of the cutting tool, and a thrust force rising based on a detection result of the thrust force detecting means. A time measuring means for measuring the time until the set thrust force is reached, and a timed result of the time measuring means, and a wear determination time threshold value for determining whether the blade is worn or not, A computer-readable recording medium storing a wear detection program for causing a computer to function as wear detection means for detecting that the cutting tool is worn when the time measurement result exceeds the wear determination time threshold. 7. A cutting tool for machining a workpiece, a thrust force detecting means for detecting a thrust force of the cutting tool, and a time measurement after the thrust force rises based on a detection result of the thrust force detecting means. Timer means for starting, time determining means for determining whether or not the result of the time measurement by the timer means has exceeded a wear determination time threshold value for determining whether or not the cutting tool is worn, and the time determination. When the timed result exceeds the wear determination time threshold based on the determination result of the means, the detection result of the thrust force detection means and a wear determination for determining whether the cutting tool is worn. Abrasion detecting means for comparing a thrust force threshold value and detecting that the cutting tool is worn when the detection result is smaller than the wear determination thrust force threshold value. Wear detection device of the cutting tool according to claim. 8. A detection result of the thrust force detection means,
Compare the loss determination thrust force threshold value to determine whether or not the blade has a loss, when the detection result exceeds the loss determination thrust force threshold, the blade is missing. The wear detecting device for a cutting tool according to claim 7, further comprising a defect detecting means for detecting the presence of the cutting tool. 9. The wear detecting device for a cutting tool according to claim 8, further comprising a notifying unit for notifying the detection results of the wear detecting unit and the loss detecting unit. 10. The apparatus according to claim 8, further comprising a drive control unit that stops driving of the blade when a defect of the blade is detected based on a detection result of the defect detection unit. An apparatus for detecting wear of a cutting tool as described in the above. 11. A first step of detecting a thrust force of a cutting tool for machining a workpiece, and a time measurement result after the thrust force rises based on a detection result of the thrust force, wherein the cutting time of the cutting tool is A second step of determining whether or not a wear determination time threshold value for determining whether or not the wear is exceeded; and, based on a determination result in the second step, the time measurement result is the wear determination time. When the threshold value is exceeded, the detection result of the thrust force is compared with a wear determination thrust force threshold value for determining whether the cutting tool is worn, and the detection result indicates that the wear determination thrust. A third step of detecting that the cutting tool is worn when the force is smaller than the force threshold value. 12. A cutting tool for processing a workpiece, a thrust force detecting means for detecting a thrust force of the cutting tool, and measuring a time after the thrust force rises based on a detection result of the thrust force detecting means. Timer means for starting, time determining means for determining whether or not the result of the time measurement by the timer means has exceeded a wear determination time threshold value for determining whether or not the cutting tool is worn, and the time determination. When the timed result exceeds the wear determination time threshold based on the determination result of the means, the detection result of the thrust force detection means and a wear determination for determining whether the cutting tool is worn. A thrust force threshold value is compared, and when the detection result is smaller than the wear determination thrust force threshold value, a computer is used as wear detection means for detecting that the cutting tool is worn. A computer-readable recording medium wear detection program for causing a data.