JPH0825180A - Tool edge point detecting device - Google Patents

Abstract

PURPOSE:To provide a tool edge point detecting device whereby machining of high dimensional accuracy can be performed in a machine tool by calculating a tool correction value, considering a tool deformation amount, automatically set to the machine tool. CONSTITUTION:A tool edge point detecting device comprises an edge point position contact detecting part l outputting a contact detection signal by detecting contact with a tool edge point by a probe, measuring mode generating means 2 executing an edge point position measuring mode and a tool rigidity measuring mode and an edge point position detecting means 3 feeding a shaft moving distance in a probe pressing process when measured tool rigidity by outputting an edge point position data when received the contact detection signal. Further, the device comprises a probe displacement amount detecting part 4 outputting a displacement detection signal by detecting a displacement amount of the probe pressed by a tool in the probe pressing process and an edge point rigidity arithmetic part 5 calculating tool rigidity from the shaft moving distance in the probe pressing process and from the probe displacement amount detected in the probe displacement amount detecting part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool blade edge detecting device mounted on an NC machine tool for detecting a tool blade edge position and setting a tool correction value. The present invention relates to a tool cutting edge detection device having a function of automatically generating a tool correction amount for detecting and correcting a machining error caused by the deformation of a tool due to cutting resistance, and automatically setting the amount.

[0002]

2. Description of the Related Art In machining a workpiece with an NC machine tool, a tool blade edge detector mounted on the machine tool detects the blade edge position with respect to the machine origin of the tool used for machining and attaches a reference tool before machining. In this case, the tool correction value is calculated from the difference between the cutting edge position and the tool correction value, and the tool correction value is set and input to the NC machine tool to correct the machining program for machining. FIG. 11 is an explanatory diagram showing a conventional tool edge detection device mounted on an NC lathe for setting a tool correction value. In this tool edge detecting device, a sensor arm 17 which is rotatable around a pivot axis perpendicular to the spindle 36 is mounted on a headstock 37, and is attached to the tip of the sensor arm 17 when the sensor arm 17 is extended. The touch sensor 38 is located on the front surface of the chuck 39. Then, when the turret tool post 15 is moved, the tool edge Tp is touched by the touch sensor 38.
Contact detection is performed by the tool, and the relative coordinate value between the position data of the tool drive shaft at this time and the position data when the reference tool is brought into contact with the probe 38a is calculated as a tool correction value. , NC lathe device is set and input. If you want to perform machining work with high dimensional accuracy, enter the tool correction value, perform trial cutting, add the error amount obtained by measuring the work after cutting to the previous tool correction value, and add that value. Was input again as a new tool correction value and the machining operation was executed.

[0003]

The above-mentioned conventional tool edge position detecting device mounted on a machine tool accurately detects the tool edge position with respect to the machine origin, calculates a tool correction value, and sets it in the machine tool. be able to. However, even if this tool correction value is set and input, the cutting edge portion of the tool is deformed by the resistance during cutting, so that the machine tool cannot process the workpiece with high dimensional accuracy.

The present invention solves the above problems by accurately detecting the tool edge position, estimating the amount of deformation of the tool due to the resistance during cutting from the rigidity of the tool and the machining conditions, and using the tool. An object of the present invention is to provide a tool edge detection device that can make a machine tool perform machining with high dimensional accuracy by calculating a tool correction value in consideration of the amount of deformation and automatically setting it in the machine tool.

[0005]

The structure of the present invention is mounted on an NC lathe, detects a blade edge position of a tool attached to the NC lathe, calculates a tool correction value, and sets the blade edge of the NC lathe. A detection device, a blade tip position contact detection unit that detects contact with the tool blade tip by a contact point having a blade tip contact surface and outputs a contact detection signal, and a blade tip position measurement mode and tool rigidity that contact-detects the tool blade tip. Measuring position generating means for executing a cutting edge rigidity measuring mode for detecting the cutting edge position, and cutting edge position data for outputting the cutting edge position data at the time of receiving the contact detection signal and sending out the axial movement amount in the probe pressing process at the time of measuring the tool rigidity. Means, a probe displacement amount detection unit that detects a displacement amount of the probe pressed by a tool in the probe pressing process, and outputs a displacement detection signal; and an axial movement amount in the probe pressing process. From the gauge the amount of displacement detected by serial measurement element displacement detecting unit that is provided between the tool rigidity calculation unit for calculating a tool rigidity.

Further, the tool is mounted on an NC machine tool in which a tool is mounted on a spindle rotatably supported on the spindle head for machining, and the tool tip value of the tool mounted on the spindle of the machine tool is detected to detect a tool correction value. Is a tool edge detection device that calculates and sets in the machine tool, detects the contact between the tool edge and a probe having a blade contact surface, and outputs a contact detection signal Measuring mode generating means for executing a blade edge position measuring mode for detecting contact with the tool and a tool rigidity measuring mode for detecting tool rigidity, and outputting the blade edge position data at the time of receiving the contact detection signal to measure a probe pressing process during tool rigidity measurement. Blade position detecting means for sending the amount of axial movement of the probe and the displacement detection of the probe which detects the displacement of the probe pressed by the tool in the probe pressing process and outputs a displacement detection signal. If, in the provision and edge stiffness calculator for calculating a tool rigidity from the detected measuring element displacement axis movement amount from the measuring element displacement amount detection section at the gauge head pressing process.

[0007]

[Function] After the blade tip of the tool is brought into contact with the blade tip contact surface of the probe, the tool blade tip position with respect to the machine origin is detected, and in that state, the tool blade tip is further pressed against the blade tip contact surface for measurement. The child is displaced. Then, the amount of displacement of the tracing stylus and the amount of axial movement at this time are detected, and the rigidity of the tool is calculated from these values and the stiffness of the tracing stylus that has been obtained in advance. Further, the resistance during cutting is estimated from the tool rigidity and the machining conditions, and the amount of deformation of the tool caused by the resistance during cutting is calculated. Then, a tool correction value that compensates for the deformation amount is calculated, and the correction value is set and input to the machine tool. Therefore, the machine tool equipped with the tool edge detection device operates so as to correct the correction value in which the amount of deformation is taken into consideration. Therefore, it is necessary to perform machining with high dimensional accuracy with reduced machining error due to deformation of the tool. You can

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. [Embodiment 1] FIG. 1 is a block diagram showing a basic configuration of a tool edge position detecting device for an NC lathe according to the present invention.
The tool edge position detecting device includes a tool edge Tp of the tool T driven by the servomotor 14 and an edge contact surface 16 of the probe S.
When the and are in contact, the blade tip position contact detection unit 1 that outputs a contact detection signal and the displacement amount of the probe S pressed by the tool T after the contact detection are detected, and the probe displacement amount detection that simultaneously outputs the displacement detection signal is detected. Part 4 and a measurement mode generating means 2 for executing a cutting edge position measuring mode at the time of measuring the cutting edge position and a tool rigidity measuring mode at the time of measuring the tool rigidity in the measuring program.
And a blade edge position detecting means 3 for detecting axis position data at the time of receiving the signal when receiving the contact detection signal output from the blade edge position contact detection section 1 and the displacement detection signal output from the tracing stylus displacement amount detection section 4. A cutting edge rigidity calculation section 5 for calculating the tool rigidity from the measuring element displacement amount and the axial movement amount detected in the measuring element pressing process at the time of measuring the tool rigidity, and the previously verified rigidity of the measuring element; A function generator 6 for outputting a position command corresponding to the rigidity measurement mode,
Machining that stores the machining conditions input from the input interface 8 and the position control device 7 that controls the servomotor 14 so that the tool edge Tp is positioned as instructed while feeding back the current position data from the position detector 13. The condition memory unit 9, the cutting back force component calculating unit 10 for estimating the cutting back force component from the machining condition read out from the machining condition memory unit 9, the deformation amount of the tool caused by the cutting back force component at the time of cutting, and the tool rigidity. A tool deformation amount calculation unit 11 calculated from
A tool correction value generation unit 12 that generates a tool correction value from the tool tip position data at the time of contact between the tool blade tip Tp and the probe S and the tool deformation amount due to the cutting back force component is provided.

The blade edge position detecting means 3 detects the position data at the time of receiving the contact detection signal from the position detector 13 and temporarily stores the position data as the first position data, and then the position data at the time of receiving the displacement detection signal is detected. The second position data is detected, and the axial movement amount in the probe pressing process from the contact of the cutting edge to the end of pressing the probe is obtained from the difference between the first position data and the second position data and output. The cutting edge position data is obtained from the data and output. Tool correction value generator 12
Is the tool edge Tp detected by the edge position detecting means 3.
The relative coordinates of the blade tip position data when the contact point of the probe and the probe S and the blade tip position data of the reference tool are obtained, and the tool blade edge position with respect to the machine origin when both the probe of the measurement object and the reference tool contact the probe point is the same. As described above, a temporary tool correction value of the tool to be measured is determined, and the blade edge deformation amount due to the back force during cutting is added to the temporary tool correction value to generate a true tool correction value. Note that FIG. 2 shows a state in which the tool blade tip Tp is brought close to the probe S of the tool blade tip detection device mounted on the sensor arm 17.

Next, the procedure for calculating the tool edge deformation amount caused by the cutting back force will be described. FIG. 3 is an explanatory view showing a state in which the tool cutting edge Tp of the tool T is brought into contact with the probe S from the X-axis plus direction (the direction of the arrow in FIG. 3) and a state in which the probe S is pressed. X is the position data when the contact point
1. If the position data after pressing the tracing stylus is X2, the axial movement amount Xt during the pressing of the tracing stylus can be obtained by the following mathematical formula.

## EQU1 ## Xt = X2-X1 When the displacement amount of the tracing stylus S at this time is e and the rigidity of the tracing stylus previously tested is Ks, the tool edge rigidity Kt is obtained by the following mathematical formula.

[Equation 2] Kt = Ks · e / Xt And the tool edge deformation amount δ caused by the cutting back force
Is the tool edge rigidity Kt and the cutting back force Fp obtained by the equation 2.
It is calculated by the following formula using and.

[Equation 3] δ = Fp / Kt The cutting back force is estimated by inputting the data in Table 1 below from the input interface 8 and simplifying the three-dimensional cutting by regarding it as an accumulation of narrow two-dimensional cutting. can do.

[Table 1]

Further, the vertical cross section and the horizontal cross section of the cutting edge position contact detection unit 1 and the tracing stylus displacement amount detection unit 4 are shown in FIGS. 4 and 5, respectively.
Shown in FIG. 6 is an enlarged explanatory diagram of the tracing stylus displacement amount detection unit 4. The shaft 19 is rotatably attached to the housing 30 together with the probe S and the mover 21 via ball bearings 20a and 20b. The tracing stylus S has a rectangular parallelepiped shape, and is provided with a cutting edge abutting surface 16 at one end of each side surface at a predetermined distance from the center of the shaft 19 so as to be able to detect the cutting edges of various tools. There is. In addition, the coil spring 22 wound around the outer periphery of the lower end of the shaft 19 so that both ends are locked by the stopper 23 and the movable element 21 is moved by the coil spring 22.
Are urged to close the contacts between the first contact 24a and the second contact 24b.

Next, the operation of the blade tip position contact detector 1 and the contact point displacement amount detector 4 will be described. In the blade tip position measurement mode, when the blade tip Tp of the tool T attached to the turret tool post 15 contacts the probe S, the probe S rotates a minute amount against the biasing force of the torsion coil spring 22, and the probe The mover 21 which is integral with the S and the shaft 19 rotates. As the mover 21 rotates, the torsion coil spring 22 urges the first contact point abutting against the second contact point 24b.
Contact 24a is separated and the contact is opened. When the detection switch 25 detects that the contact has been opened, it sends a contact detection signal. Subsequently, the cutting edge rigidity measurement mode is executed, the mover 21 rotates, the contact of the cutting edge Tp of the tool is detected, and at the same time, by the piston 26 attached to the shaft 19 at a position symmetrical to the first contact point 24a. , Spindle 2
The oscillating body 28 integrated with the oscillating body 7 oscillates and rotates about the support shaft 27.

When the oscillating member 28 oscillates and rotates by the pressing force of the piston 26, a torsion moment is applied to the support shaft 27, and the support shaft 27 causes a torsion angle and shear strain on the surface at the same time. This shear strain
On the shaft surface at the lower end of the support shaft 27, 45 ° to the axial direction,
The twist angle of the support shaft 27 is obtained by detecting the strain gauges 29 attached to the 45 ° direction. Then, this twist angle is converted into the displacement amount of the probe S based on the relationship between the strain amount of the support shaft 27 and the displacement amount of the probe S which has been verified in advance. When the tracing stylus displacement amount detection unit 4 detects the amount in which the tracing stylus displacement amount exceeds the set value, a displacement detection signal is output to the measurement mode generating means 2 and the tool tip Tp presses the tracing stylus S. The stop command for the turret tool post 15 is executed. At this time, the final amount of displacement of the tracing stylus is detected.

Further, a stopper 23 is provided between the mover 21 and the oscillating element 28, and the measuring element contact surface 16 is provided.
Even when the tool receives an excessive pressing force by the tool edge Tp, the stopper 23 locks the mover 21 and the piston 2
Since the stroke of the No. 6 to the rocker 28 is suppressed to a certain amount or less, an excessive torsion moment is not applied to the support shaft 27, and the shear strain detector attached to the support shaft 27 is not damaged.

When the turret tool post 15 is retracted after the displacement of the tracing stylus is detected, the first contact point 24a and the second contact point 24b are brought into contact with each other by the biasing force of the torsion coil spring 22 to return to the initial state. Restored. The mover 21 is
Since it is biased by the torsion coil spring 22, the tool edge detection signal will not be erroneously output by an external force such as vibration other than the pressing of the tool edge Tp.

In the blade edge position contact detector 1 and the probe displacement amount detector 4, the shaft 1 is longer than the length from the center of the shaft 19 which is a fulcrum to the force point of the blade abutment surface 16 which receives pressure.
Since the length from the center of 9 to the first contact 24a on the mover 21 and from the center of the shaft 19 to the piston 26 is sufficiently long, even a slight displacement with respect to the force point is greatly amplified. Therefore, the responsivity and detection accuracy of the tool edge contact detection and the probe displacement amount detection are extremely high. Further, in the tracing stylus displacement amount detecting section 4, the rigidity of the supporting portion of the tracing stylus S including the ball bearings 20a, 20b and the support shaft 27 is configured to be sufficiently higher than the rigidity of the tool edge to be detected. Therefore, the tool edge rigidity is detected with high accuracy.

Next, the operation procedure of the above-mentioned tool edge detecting device will be described with reference to the flow chart shown in FIG. In step S1, the blade tip detection operation of the tool T is started, and the sensor arm 17 located at the retracted position in the headstock 33.
Is rotated to the detection position on the front surface of the chuck 35. Then, in step S2, the turret tool post 15 is moved at a very small speed, and the tool blade tip Tp is moved to the blade tip contact surface 16 of the probe S.
Contact. Then, when the measurement mode generation means 2 receives the contact detection signal from the blade tip position contact detection unit 1 in step S3, the operation of the turret tool post 15 is temporarily stopped, and the position data when the turret tool post 15 is stopped is determined in step S4. Is detected and stored as the first position data.

Then, in step S5, the turret tool post 15 is moved again at a minute speed, the blade tip contact surface 16 is pressed by the tool blade tip Tp, and the tracing stylus S is displaced by a minute amount. Displacement detector 4
The displacement amount of the tracing stylus S is detected in step S7, and the displacement amount of the tracing stylus is compared with a preset set value in step S7. At this time, if the probe displacement amount does not exceed the set value, the pressing of the tool T is continued. If the set value is exceeded, the tracing stylus displacement amount detection section 4 outputs a displacement detection signal to the measurement mode generation means 2 and the blade tip position detection means 3, and then step S8 and subsequent steps are continued. Then, in step S8, the measurement mode generating means 2 executes a stop command of the turret tool post 15, and in step S9, the final displacement amount of the tracing stylus S after the turret tool post 15 is stopped is detected.

In step S10, the turret tool post 15 is moved by the cutting edge position detecting means 3 which has received the displacement detection signal.
The second position data after the stop is detected, the axial movement amount in the probe pressing process is calculated from the difference between the first position data and the second position data, and in the subsequent step S11, the measurement in the probe pressing process is performed. The rigidity of the cutting edge of the tool T is calculated from the amount of displacement of the probe, the amount of axial movement, and the stiffness of the probe S that has been verified in advance. Then, in step S12, the processing conditions at the time of using the tool are input from the input interface 8, in step S13, the back force at the time of cutting is estimated from the processing conditions, and at step S14, the tool cutting edge rigidity and the cutting back force are cut. The tool edge deformation amount in the cutting direction is calculated from the component force. Then, in step S15, from the tool tip position data when the tool tip Tp output from the tool tip position detection means 3 and the contact point S are in contact, the provisional tool correction value is set so as to match the tool tip position with respect to the machine origin of the reference tool. Is generated, and a true tool correction amount that takes into account the tool edge deformation amount due to the cutting back force is also generated and set. Then, in step S16, the turret tool post 15 is retracted, and in step S17, the sensor arm 17 is moved to the retracted position in the headstock 33 to end the operation.

In the present embodiment, the tracing stylus displacement amount detecting section 4 is
In the blade edge rigidity measurement mode, the tool blade edge Tp and the probe S
It is configured to detect the displacement amount of the tracing stylus S when the tracing stylus S is pressed by further moving the tool edge Tp by a small amount after the contact with the tracing stylus displacement amount detecting unit 4 In order to eliminate a detection error in the amount of displacement of the tracing stylus due to the alignment error of the above, after the tool blade tip Tp is brought into contact with the tracing stylus S, the amount of displacement when the tracing stylus S is only slightly pressed and then further pressed. The difference from the displacement when
It can also be configured to detect as the amount of displacement of the tracing stylus. In addition, in the present embodiment, a case is shown in which a general tool having an acute cutting edge surface is attached, but the tool cutting edge detection device of the present invention can be applied to a machine tool such as a parting bite, or a front-rear lateral direction. Even when a tool having a cutting edge parallel to the drive shaft, such as a cutting tool that can be machined in any direction (for example, a cut grip manufactured by Kyocera Corporation) is attached, the same effect can be exhibited.

[Embodiment 2] FIG. 8 is a block diagram showing the basic construction of a tool blade edge detecting device mounted on a machining center. In FIG. 8, the same components as those of the tool edge detection device of the first embodiment are designated by the same reference numerals. It should be noted that description of the same components as those of the first embodiment will be omitted because there is no difference in operation.
A spindle 33 is rotatably supported on the spindle head 32,
A tool 34 is attached to the tip of the main shaft 33 via a holder (not shown).
Is held. The difference from the tool edge detection device of the first embodiment (FIG. 1) is that the cutting feed force component of the cutting resistance is estimated from the machining conditions read from the machining condition memory unit 9 instead of the cutting back force component calculation unit. The cutting feed force calculating unit 35 is provided. That is, the tool correction value generation unit 1
2 is configured to generate a tool correction value from the tool tip position data at the time of contact between the tool tip Tp and the probe S, and the tool deformation amount due to the cutting feed component force calculated by the cutting feed component force calculation unit 35. ing.

Next, the procedure for calculating the tool deformation amount caused by the resistance during cutting in the second embodiment will be described. FIG. 9 is an explanatory diagram showing a state in which the tool T is brought into contact with the tracing stylus S from the X-axis plus direction (the direction of the arrow in FIG. 3) and a state in which the tracing stylus S is pressed. As in the first embodiment, if the position data when the probe is in contact is X1 and the position data after pressing the probe is X2, the axial movement amount Xt in the process of pressing the probe is calculated by the following formula.

## EQU00004 ## Xt = X2-X1 When the displacement amount of the tracing stylus S at this time is e and the rigidity of the tracing stylus previously tested is Ks, the tool rigidity Kt is obtained by the following mathematical formula.

## EQU5 ## Kt = Ks.e / Xt Then, from the tool edge rigidity Kt and the feed force Fp of the cutting resistance obtained in the equation 5, the tool edge deformation amount .delta.

(6) δ = Fp / Kt

FIG. 10 shows a state in which the tool cutting edge is brought into contact with the tracing stylus from the Z axis plus direction, and the tool rigidity Kt at this time is obtained by the following equation.

[Equation 7] Kt = Ks · e / Zt

Although the tool edge detecting device mounted on the lathe and the machining center has been described above with reference to the first and second embodiments, the tool edge detecting device of the present invention is not limited to these machine tools, and the drilling machine is not limited thereto. Needless to say, it can be widely mounted on NC machine tools in general, such as boring machines. Further, in addition to the calculation of the tool correction value considering the tool deformation amount due to the back force component on the lathe and the feed component force at the machining center, the tool correction value considering the tool deformation amount due to the main force component etc. can be calculated in the same manner. it can.

[0025]

According to the tool edge detecting device of the present invention, since the tool correction value predicting the tool deformation amount during work can be automatically set and input, after the tool correction value is once set as in the conventional case. Not only does it take time and labor to perform trial cutting and reset the tool compensation value again, but it also allows the machine tool to perform machining with extremely high dimensional accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a tool edge detection device according to a first embodiment.

FIG. 2 is an explanatory diagram showing a state in which a tool blade tip is brought close to a probe of the tool blade tip detection device of the first embodiment.

3A and 3B are explanatory views showing a state in which the tool tip is brought into contact with the tracing stylus of the tool blade tip detection device of the first embodiment and a state in which the tracing stylus is pressed by the tool tip.

FIG. 4 is a partial vertical cross-sectional explanatory view showing a state in which a part of a blade tip position contact detection portion and a tracing stylus displacement amount detection portion of the tool blade edge detection device of the first embodiment is cut away.

5 is an explanatory cross-sectional view taken along the line AA of FIG.

FIG. 6 is an enlarged explanatory diagram of a tracing stylus displacement amount detection unit of the tool blade edge detection device of the first embodiment.

FIG. 7 is a flowchart showing an operation procedure of the tool edge detection device of the first embodiment.

FIG. 8 is a block diagram showing a basic configuration of a tool edge detection device according to a second embodiment.

FIG. 9 is an explanatory diagram showing a state in which the tool tip is brought into contact with the probe of the tool edge detection device of the second embodiment, and a state in which the probe is pressed by the tool tip.

FIG. 10 is an explanatory diagram showing a state in which the tool tip of the tool tip detection device of the second embodiment is brought into contact with the probe tip from the Z-axis plus direction.

FIG. 11 is an explanatory diagram showing a conventional tool edge detection device.

[Explanation of symbols]

1 ... Blade edge position contact detector 2, Measurement mode generator 3, Blade edge position detector 4, Measuring element displacement amount detector 5, Blade rigidity calculator 6, Function generator, 7.
・ Position control device, 8 ・ ・ Input interface, 9 ・ ・ Machining condition memory unit, 10 ・ ・ Cutting back force calculation unit, 11 ・ ・
Cutting edge deformation amount calculation unit, 12 ... Tool correction value generation unit, 13 ...
・ Position detector, 14 ・ ・ Servo motor, 15 ・ ・ Turret tool post, 16 ・ ・ Blade tip contact surface, 17 ・ ・ Sensor arm, 18 ・ ・ Turret tool drive shaft, 19 ・ ・ Axis, 20a, 20
b ... Ball bearing, 21 ... Mover, 22 ... Torsion coil spring, 23 ... Stopper, 24a ... First contact,
24b ... Second contact, 25 ... Detection switch, 26 ...
.Pistons, 27 ... Spindles, 28 ... Oscillators, 29 ...
Strain gauge, 30 ··· Housing, 31 · · Detection switch mounting part, 32 · · Spindle head, 33 · · Spindle, 34 ·
・ Tool, 35 ・ ・ Cutting feed component force calculator, e ・ ・ Measurement element displacement amount, Ks ・ ・ Measurement element rigidity, Kt ・ ・ Tool edge rigidity, S
..Stylus, T ... Tool, Tp ... Tool edge, X1 ...
Position data when touching the stylus, X2 ··· Position data after pressing the stylus, Xt · · Axial movement amount when the stylus is pressed, δ ·
-Amount of tool edge deformation.

Claims (2)

[Claims] 1. A tool cutting edge detection device which is mounted on an NC lathe, detects a cutting edge position of a tool mounted on a tool rest of the NC lathe, calculates a tool correction value, and sets the tool correction value on the NC lathe, comprising: A blade tip position contact detection unit that detects contact with the tool blade tip by a contact point having a contact surface and outputs a contact detection signal, a blade tip position measurement mode that detects the tool blade tip contact, and a tool rigidity measurement mode that detects tool rigidity Measuring mode generating means for executing, a cutting edge position detecting means for outputting the cutting edge position data at the time of receiving the contact detection signal, and sending out the axial movement amount in the measuring piece pressing process at the time of tool rigidity measurement, and the measuring piece pressing In the process, a displacement amount detection unit for detecting the displacement amount of the tracing stylus pressed by the tool and outputting a displacement detection signal, an axial movement amount in the tracing stylus pressing process, and the tracing stylus displacement amount detection Tool edge detecting apparatus characterized by comprising a cutting edge rigidity calculation unit for calculating a tool rigidity from the gauge the amount of displacement detected from. 2. A tool compensation is performed by being mounted on an NC machine tool for machining by mounting a tool on a spindle rotatably supported on a spindle head, and detecting a cutting edge position of the tool mounted on the spindle of the NC machine tool. A tool edge detecting device for calculating a value and setting it in an NC machine tool, which detects a contact between a tool edge and a probe having a blade contact surface, and outputs a contact detection signal, Measuring mode generating means for executing a blade edge position measuring mode for detecting the contact of the tool blade edge and a tool rigidity measuring mode for detecting the tool rigidity, and a blade for measuring the tool rigidity by outputting the blade edge position data when the contact detection signal is received. Blade tip position detecting means for sending the amount of axial movement in the pressing process, and probe displacement for detecting the displacement of the probe pressed by the tool in the probe pressing process and outputting a displacement detection signal. A tool comprising: a detection unit; and a blade edge rigidity calculation unit that calculates tool rigidity from the amount of axial movement during the pressing of the tracing stylus and the amount of displacement of the tracing stylus detected from the amount of displacement of the tracing stylus. Blade edge detection device.