JPH09108995A - Machine tool and machining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dissolve an error resulting from the displacement due to disturbance during machining of a knife edge position measuring means by providing a calibrating means in which a position measuring means is provided to measure the position of the cutter edge position measuring means for calibrating it. SOLUTION: A NC device 19 abuts a position measuring sensor 5 moved by a driving means against a position detecting sensor calibrating reference article 20 for measuring the positions in directions of Z and X axes of the above reference article 20, and the position of the position measuring sensor 5 itself is calibrated through the NC device 19. In addition, the calibrated position measuring sensor 5 is moved b a driving means to abut a cutter edge position measuring sensor 16 for measuring the positions in directions of Z and X axes of the above sensor 16, and the position of the cutter edge position measuring sensor 16 is thereby calibrated.

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 machining method for a machine tool, particularly an NC lathe.

[0002]

2. Description of the Related Art A conventional NC lathe employs a mechanism in which a sensor for measuring a blade edge position is attached to a rotatable sensor arm.

FIG. 12 is an overall configuration diagram showing a conventional NC lathe. When a cutting edge position measurement command is issued from the NC device 19, the X-axis ball screw 12 and the X-axis motor 13 are driven, and the tool mounted on the turret 7 is shown. 6 moves and comes into contact with the blade edge position measuring sensor 16 which is set in advance at the center position of the spindle. Then, the electric signal is turned on, the electric signal is transmitted to the NC device 19, and the movement is stopped. The position at this time is detected by the X-axis position detection encoder 14, and the NC device 19 calculates the tool offset amount from the spindle center position. This operation is performed before machining to maintain machining accuracy. Further, the cutting edge position measuring sensor 16 is attached to the sensor arm 17, can be rotated by the sensor arm motor 18, and is automatically fed into the machine only when performing measurement. Since a plurality of tools 6 are used according to the workpiece 1, the above-mentioned blade edge position measurement is also performed for a plurality of tools.

[0004]

However, in the above-mentioned conventional NC lathe, the sensor arm 17 is displaced due to disturbances such as cutting heat during machining and heat generation of the built-in motor 3, and therefore the cutting edge position measuring sensor. There was a possibility that 16 positions would be displaced from the preset spindle center position. This displacement causes an error in the measurement of the position of the cutting edge and causes a deterioration in processing accuracy. This effect is particularly large in the part where measurement after processing is difficult.

Further, since only the pre-machining measurement by the blade edge position measurement is performed, it is not possible to confirm whether or not the machined product has been machined within the allowable dimension, and there is a possibility that a large number of machined defective products may be produced.

Furthermore, since the amount of tool wear of the tool 6 cannot be clearly recognized, it is impossible to predict the tool replacement time.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to measure the position of the cutting edge without causing an error due to disturbance during processing, monitor the product after processing, and measure the amount of tool wear. It is to provide a machine tool capable of measurement and a processing method.

[0008]

In order to solve the above-mentioned problems, a machine tool of the present invention comprises a tool driving means capable of moving a tool with respect to a spindle of the machine tool and a position of a cutting edge of the abutting tool. Blade position measuring means for measuring the position, position measuring means for measuring the position of the blade position measuring means in contact with the detector, position measuring means moving means for moving the attached position measuring means, and driving means And position detecting means for detecting the position of the position measuring means moving means, a reference object having a known shape and fixed to the spindle, and a position of the spindle detected by abutting the detecting portion on the reference object. Calibration means for determining the position of the blade edge position measuring means based on the position of the detecting portion and the position of the detecting portion detected by bringing the detecting portion into contact with the blade edge position measuring means. And wherein the Rukoto.

Further, the reference object is a ring which is on the center line of the main shaft and is fixed to the main shaft.

Further, a tool driving means capable of moving the tool with respect to the spindle of the machine tool, a cutting edge position measuring means for measuring a position of a cutting edge of the abutting tool, and a position detecting means for detecting a position of the driving means. And a tool wear amount measuring means having a common reference surface that is a reference surface for measuring the amount of tool wear and can be measured by the cutting edge position measuring means, and the position of the cutting edge of the tool before machining and The position of the common reference surface is measured by the cutting edge position measuring means, and the position of the cutting edge of the tool and the position of the common reference surface are again measured by the cutting edge position measuring means after machining,
The feature is that the tool wear amount is obtained from these measured values.

Further, a tool driving means capable of moving the tool with respect to the spindle of the machine tool, a cutting edge position measuring means for measuring the position of the cutting edge of the abutting tool, and a position detecting means for detecting the position of the driving means. And a tool wear amount measuring means having a tool position reference surface located in the vicinity of the tool, and measuring the position of the cutting edge of the tool and the position of the tool position reference surface with the cutting edge position measuring means before machining. After machining, the position of the cutting edge of the tool and the position of the tool position reference plane are measured again by the cutting edge position measuring means, and the tool wear amount is obtained from these measured values.

Further, the machining method according to the present invention comprises a tool driving means capable of moving a tool with respect to a spindle of a machine tool, and a cutting edge position measuring means for measuring a position of a cutting edge of the abutting tool.
Position measuring means for measuring the position of the cutting edge position measuring means in contact with the detecting portion, position measuring means moving means for moving the attached position measuring means, positions of the driving means and the position measuring means moving means In a machine tool having a position detecting means for detecting a reference object and a reference object having a known shape and fixed to the spindle, the position measuring means itself measures the position of the reference object having the known shape by the position measuring means. A step of calibrating the position, a step of calibrating the position of the blade edge position measuring means by abutting the calibrated position measuring means to the blade edge position measuring means, and a blade edge of each tool with the calibrated blade edge position measuring means And measuring the position of the cutting edge of each tool.

Further, a tool driving means capable of moving the tool with respect to the spindle of the machine tool, a cutting edge position measuring means for measuring a position of a cutting edge of the abutting tool, and a position detecting means for detecting a position of the driving means. And a tool wear amount measuring means having a common reference surface which is a reference surface for measuring the amount of tool wear and can be measured by the cutting edge position measuring means, and the cutting edge position measuring means before machining. With the step of measuring the position of the cutting edge of the tool, the step of measuring the position of the reference surface with the cutting edge position measuring means before processing, the step of measuring the position of the cutting edge of the tool with the cutting edge position measuring means after processing, It is characterized by including a step of measuring the position of the reference surface by the cutting edge position measuring means after processing and a step of obtaining the tool wear amount from these measured values.

In the above machine tool and machining method,
Since the position measuring means is provided and the position of the blade edge position measuring means is measured and calibrated, it is possible to eliminate the error caused by the displacement of the blade edge position measuring means due to the disturbance during machining, which makes measurement difficult after machining. The precision of the part is also improved. Further, it is possible to measure the size of the processed product and monitor the processed product. Furthermore, since it also has a tool wear measurement function, it is possible to perform tool replacement that predicts tool loss.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of an embodiment of a machine tool according to the present invention. The tool 6 is mounted on the turret 7 by the Z-axis ball screw 9 and the Z-axis motor 10.
It is driven in the axial direction, and its position is detected by the Z-axis position detecting encoder 11. Further, the X-axis ball screw 12 and the X-axis motor 13 are driven in the X-axis direction, and the position is detected by the X-axis position detecting encoder 14, and linear position detection is also performed by the X-axis position detecting linear scale 15. Has been done. Note that this linear position detecting means is not limited to a linear scale, and an inductosyn can be considered, and can also be applied to the Z axis. Further, the position measuring sensor 5 as a position measuring means having a detecting portion at the tip and measuring the position of the blade edge position measuring sensor 16 in contact with the detecting portion is attached to the turret 7. , Is moved by the driving means of the tool 6.
That is, the driving means of the tool 6 constituted by the Z-axis ball screw 9, the Z-axis motor 10, the X-axis ball screw 12 and the X-axis motor 13 is also the moving means of the position measuring sensor 5,
The position detecting means of the tool 6 including the Z-axis position detecting encoder 11, the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15 is also the position detecting means of the position measuring sensor 5.

On the other hand, the cutting edge position measuring sensor 16 is mounted on the sensor arm 17 and automatically swung into the machine tool by the sensor arm motor 18 only at the time of measurement. The blade edge position measuring means configured by these measures the Z axis and X axis direction positions of the blade edge of the tool 6 that has moved and abutted. It is also possible to manually transfer the sensor arm 17 into the machine tool. Further, the workpiece 1 is held by the spindle chuck 2 and rotated by the built-in motor 3, and the rotation angle thereof is detected by the rotation angle detection encoder 4. The spindle chuck 2 is equipped with a reference object 20 for position measurement sensor calibration. The NC device 19 causes the position of the detection unit relative to the position of the spindle detected by contacting the detection unit with the position detection sensor calibration reference object 20 and the position of the detection unit with the blade edge position measurement sensor 16. Sensor 1 for measuring the position of the blade edge based on the detected position of the detector
It is a calibrating means for obtaining the position of 6. That is, the NC device 1
Reference numeral 9 measures the position of the position detection sensor calibration reference object 20 in the Z-axis and X-axis directions by bringing the position measurement sensor 5 moved by the driving means into contact with the position detection sensor calibration reference object 20. , NC device 19 calibrates the position of position measuring sensor 5 itself. Further, the calibrated position measuring sensor 5 is moved by the driving means, and the blade position measuring sensor 16 is brought into contact therewith to measure the position of the blade position measuring sensor 16 in the Z-axis and X-axis directions, and the blade position is measured. The position of the measuring sensor 16 is calibrated.

A tool as a tool wear amount measuring means having a reference surface for measuring the tool wear amount on the turret 7 and having a common reference surface 22 for measuring the tool wear amount which can be measured by the sensor 16 for measuring the cutting edge position. When the wear amount measuring unit is provided, the NC device 19 moves the common reference surface 22 for tool wear amount measurement and the cutting edge of the tool 6 by the driving means before machining and brings them into contact with the cutting edge position measuring sensor 16. The positions of the tool wear amount measurement common reference plane 22 in the Z-axis and X-axis directions and the positions of the cutting edge of the tool 6 in the Z-axis and X-axis directions are measured and stored. Then, after machining, the tool wear amount measurement common reference surface 22 and the cutting edge of the tool 6 are moved again by the driving means and brought into contact with the cutting edge position measurement sensor 16 to make the Z axis of the tool wear amount measurement common reference surface 22. Also, the position in the X-axis direction and the position of the cutting edge of the tool 6 in the Z-axis and X-axis directions are measured. The NC device 19 obtains the tool wear amount from these measured values. The blade edge position measuring sensor 16 and the position measuring sensor 5
The detection method is not limited to the contact type, and a non-contact type may be considered. Further, even if the contact type is used, not only the ON / OFF detection but also the moving distance after the contact of the sensor can be detected by the analog detection, the accuracy is further improved.

FIG. 2 is a diagram showing a positional relationship of essential parts of the machine tool according to the present embodiment. The distance X16 from the center position of the spindle of the blade position measuring sensor 16 is displaced by X16E due to the influence of external disturbance such as heat while machining. Further, the distance X7 between the center position of the turret 7 equipped with the position measuring sensor 5 and the tool 6 and the center position of the spindle is also displaced by X7E. Furthermore, as the machining progresses, tool wear causes tool 6
The distance X6 from the center position of the turret 7 is also displaced by X6E.

3 to 5 are diagrams used for explaining a method of calibrating the position of the position measuring sensor 5 mounted on the turret 7 in the present embodiment. FIG. 3 is a diagram used for explaining a method of calibrating the position of the position measuring sensor 5 using the spindle chuck grasping type reference object 20a of the present embodiment. As shown in the left diagram of FIG. 3, a spindle chuck gripping type reference object 20a having a known dimension is held by the spindle chuck 2,
The position measuring sensor 5 mounted on the turret 7 is moved and brought into contact with the spindle chuck grasping type reference object 20a by a driving means. When the ON signal at the time of this contact is transmitted to the NC device 19, the movement is stopped. The position at this time is the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 1.
It is detected at 5. Similarly, as shown in the central view of FIG. 3, the position of the other end is also measured and the size of the spindle chuck gripping type reference object 20a is determined by the NC device 19. Since the dimension of the spindle chuck gripping reference object 20a is known, the distance X7 from the spindle center position of the turret 7 on which the position measuring sensor 5 is mounted is calibrated from the measurement result of the position measuring sensor 5. Further, the chucking error when the spindle chuck grasping reference object 20a is held by the spindle chuck 2 is detected by rotating the built-in motor 3 by an arbitrary angle and detecting the angle by the rotation angle detecting encoder 4. This is solved by repeating the operation of measuring the dimensions of the spindle chuck grasping type reference object 20a and averaging the measured values. Further, although the X-axis direction is described in FIG. 3, the same applies to the Z-axis direction. The known dimension of the spindle chuck gripping type reference object 20a is not limited to the outer diameter and may be the inner diameter.

FIG. 4 is a diagram used for explaining a method of calibrating the position of the position measuring sensor 5 using the spindle chuck built-in reference object 20b of the present embodiment. As shown in the left diagram of FIG. 4, a reference object 20b with a built-in spindle chuck having known dimensions.
4 is built in the spindle chuck 2, and the position measuring sensor 5 mounted on the turret 7 is mounted on the spindle chuck built-in reference object 20b as shown in the central view of FIG. Move the main spindle chuck type reference object 20
b. The ON signal at the time of this contact is the NC device 19
When it is transmitted to, it stops moving. The position at this time is detected by the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15. Subsequently, as shown in the right diagram of FIG. 4, the driving means is moved in the X-direction to bring the spindle chuck built-in reference object 20b into contact again. The ON signal at this contact is N
When it is transmitted to the C device 19, the movement is stopped again. This 2
Encoder 14 for X-axis position detection
And the linear scale 15 for X-axis position detection,
The dimensions of the spindle chuck built-in reference object 20b are obtained by the NC device 19. Since the dimension of the reference object 20b with the built-in spindle chuck is known, the turret 7 on which the position measuring sensor 5 is mounted is measured based on the measurement result of the position measuring sensor 5.
The distance X7 from the center position of the spindle is calibrated. Further, although the X-axis direction is described in FIG. 4, the same applies to the Z-axis direction. The known dimension portion of the spindle chuck built-in reference object 20b is not limited to the inner diameter but may be the outer diameter.

FIG. 5 shows a machinable type reference article 2 of this embodiment.
It is a figure used in order to demonstrate the method of calibrating the position of the position measurement sensor 5 using 0c. As shown in the left diagram of FIG. 5, the machinable reference object 20c is mounted on the spindle chuck 2, the spindle chuck 2 is rotated by the built-in motor 3, and the tool 6 mounted on the turret 7 is moved by the driving means to perform cutting. The mold reference object 20c is processed into an arbitrary commanded dimension. continue,
Fig. 5 Machinable type reference object 20c machined as shown in the central view
Then, the position measuring sensor 5 mounted on the turret 7 is moved and brought into contact with the driving means as shown in the right side of FIG. When the ON signal at the time of this contact is transmitted to the NC device 19, the movement is stopped. The position at this time is detected by the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15.
Since the machinable reference object 20c is machined to an arbitrary command dimension, the distance X7 from the center position of the spindle of the turret 7 equipped with the position measuring sensor 5 is determined from the command dimension and the measurement result of the position measuring sensor 5. Be calibrated. Further, although the X-axis direction is described in FIG. 5, the same applies to the Z-axis direction. A method of measuring the workpiece 1 instead of the machinable type reference object 20c is also conceivable.

FIG. 6 is a diagram used for explaining the method of calibrating the position of the blade edge position measuring sensor 16 of this embodiment. The position measurement sensor 5 whose position is calibrated as shown in FIGS. 3 to 5 and mounted on the turret 7 is moved by the driving means from the state shown in the left diagram of FIG. 6 to the right diagram of FIG. The sensor 16 for contact is made to contact. The detection of this contact is
It is an OR logic circuit of the ON signal of the position measuring sensor 5 and the ON signal of the cutting edge position measuring sensor 16, and an electric signal of either the position measuring sensor 5 or the cutting edge position measuring sensor 16 is sent to the NC device 19. When it is transmitted, it stops moving.
The position at this time is detected by the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15. Then, the NC device 19 calibrates the distance X16 from the center position of the spindle of the blade position measuring sensor 16. Further, although the X-axis direction is described in FIG. 6, the same applies to the Z-axis direction. In addition to the above methods, the method of detecting the contact of the sensor may have a structure in which the signal of the sensor always comes out first when the sensor contacts either of them.

Then, the tool 6 mounted on the turret 7 is moved by the driving means before processing, and the blade position measuring sensor 16 is moved.
Contact. When the ON signal at the time of this contact is transmitted to the NC device 19, the movement is stopped. At this time, X is before position X6
It is detected by the axis position detecting encoder 14 and the X-axis position detecting linear scale 15, and is stored in the NC device 19. Subsequently, after machining, the distance X16 from the center position of the spindle of the blade position measuring sensor 16 is calibrated by the method shown in FIGS. 3 to 6, and the tool 6 mounted on the turret 7 is moved again by the driving means to measure the blade position. The sensor 16 for contact is made to contact. When the ON signal at the time of this contact is transmitted to the NC device 19, the movement is stopped. After the position X6 at this time, it is detected by the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15, and the position before the position X6 of the tool 6 before machining stored in the NC device 19 is detected. The tool wear amount of the tool 6 is obtained from the difference. In addition, although the X-axis direction has been described above, the same applies to the Z-axis direction.

7 and 8 show the turret 7 of this embodiment.
FIG. 6 is a diagram used for explaining a method of measuring the amount of tool wear of the tool 6 attached to the tool 6 without calibrating the distance X16 from the center position of the spindle of the blade position measuring sensor 16. FIG.
FIG. 6 is a diagram used for explaining a method of measuring the amount of tool wear using the tool vicinity tool position reference surface 21 of the present embodiment. As shown in the left diagram of FIG. 7, the tool vicinity tool position reference surface 21 mounted on the turret 7 before machining is moved by the driving means and brought into contact with the cutting edge position measuring sensor 16. ON at this contact
When the signal is transmitted to the NC device 19, the movement is stopped. The position before the position X21 at this time is detected by the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15.

Subsequently, as shown in the right diagram of FIG. 7, the tool 6 mounted on the turret 7 is similarly moved by the driving means and brought into contact with the blade edge position measuring sensor 16. When the ON signal at the time of this contact is transmitted to the NC device 19, the movement is stopped. The position before the position X6 at this time is detected by the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15. And
The difference between the position X21 of the tool position reference plane 21 near the tool and the position X6 of the tool 6 is stored in the NC device 19. Subsequently, after the machining, the tool vicinity tool position reference surface 21 mounted on the turret 7 is again moved by the driving means and brought into contact with the blade tip position measuring sensor 16. When the ON signal at the time of this contact is transmitted to the NC device 19, the movement is stopped. Position X at this time
After 21, it is detected by the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15.

Subsequently, the tool 6 mounted on the turret 7 is similarly moved by the driving means and brought into contact with the cutting edge position measuring sensor 16. When the ON signal at the time of this contact is transmitted to the NC device 19, the movement is stopped. After the position X6 at this time, it is detected by the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15. Then, the difference between after the position X21 of the tool vicinity tool position reference plane 21 and after the position X6 of the tool 6 and before the position X21 of the tool vicinity tool position reference plane 21 before machining stored in the NC device 19 and before the tool The tool wear amount of the tool 6 is obtained from the difference of the position 6 before the position X6. Regarding the method of calculating the tool wear amount, the difference between before the position X21 of the tool vicinity tool position reference plane 21 before machining and after the position X21 of the tool vicinity tool position reference plane 21 after machining, and the tool 6 before machining A method of calculating from the difference between before the position X6 and after the machining after the position X6 of the tool 6 is also conceivable. Further, although the X-axis direction is described in FIG. 6, the same applies to the Z-axis direction.

FIG. 8 is a diagram used for explaining the method of measuring the tool wear amount by the common reference surface 22 for measuring the tool wear amount of the present embodiment. Similar to the method of FIG. 7 described above, the tool wear amount common reference surface 22 mounted on the turret 7 is moved by the drive means and brought into contact with the blade edge position measurement sensor 16 as shown in the left diagram of FIG. The ON signal at the time of this contact is the NC device 1
When it is transmitted to 9, it stops moving. Position X22 at this time
The former is detected by the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15. Subsequently, as shown in the central view of FIG. 8, the tool 6 mounted on the turret 7 is similarly moved by the driving means and brought into contact with the blade edge position measuring sensor 16. When the ON signal at the time of this contact is transmitted to the NC device 19, the movement is stopped. Before the position X6 at this time, the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 1 are provided.
It is detected at 5. Then, the difference between the position X22 of the common reference plane 22 for tool wear amount measurement and the position X6 of the tool 6 is NC.
It is stored in the device 19.

Subsequently, after machining, the tool wear amount common reference surface 22 mounted on the turret 7 is moved again by the driving means and brought into contact with the cutting edge position measuring sensor 16. When the ON signal at the time of this contact is transmitted to the NC device 19, the movement is stopped. After the position X22 at this time, it is detected by the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15. Then, the tool 6 mounted on the turret 7 is similarly moved by the driving means to be brought into contact with the blade position measuring sensor 16. When the ON signal at the time of this contact is transmitted to the NC device 19, the movement is stopped. After the position X6 at this time, it is detected by the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15. Then, the difference between the position X22 of the tool wear amount measurement common reference plane 22 and the position after the tool X6 position X6 and the position of the tool wear amount measurement common reference face 22 before machining stored in the NC device 19 in advance. Before X22 and position X of tool 6
The tool wear amount of the tool 6 is obtained from the difference before 6. Regarding the method of calculating the tool wear amount, the difference between before the position X22 of the common reference surface 22 for tool wear amount measurement before machining and after the position X22 of the common reference surface 22 for tool wear amount measurement after machining and before machining A method of calculating the difference between the position before the position X6 of the tool 6 and the position after the position X6 of the tool 6 after machining can be considered.

Subsequently, the turret 7 is swung to index another tool 6a, and the tool 6a is also brought into contact with the cutting edge position measuring sensor 16 to detect the position thereof to obtain the tool wear amount. This method is sequentially performed and the tool wear amount is measured for all tools. The positioning error due to the turning of the turret 7 is smaller than the error X6E due to the tool wear amount, and the tool wear amount common reference plane 22 is common to all tools. Further, although the X-axis direction is described in FIG. 6, the same applies to the Z-axis direction. The mounting position of the common reference surface 22 for measuring the amount of tool wear is not limited to the turret 7 and may be any position that does not interfere with the processing and measurement of the position of the cutting edge of the tool 6 and can be measured by the cutting edge position measuring sensor 16. Good place.

FIG. 9 is a diagram used to explain the method of measurement after processing according to the present embodiment. As shown in the left diagram of FIG. 9, the turret 7 is attached to the processed workpiece 1 held by the spindle chuck 2.
The position measuring sensor 5 mounted on the is moved by the driving means and brought into contact therewith. The ON signal at the time of this contact is transmitted to the NC device 19 and stopped, and the position at this time is detected by the X-axis position detecting encoder 14 and the X-axis position detecting linear scale 15. Similarly, as shown in the right diagram of FIG. 9, the position of the other end is also measured and the size of the processed workpiece 1 is obtained by the NC device 19. Further, although the X-axis direction is described in FIG. 9, the same applies to the Z-axis direction. It should be noted that the dimension measurement portion of the processed workpiece 1 is not limited to the outer diameter and may be the inner diameter.

Next, referring to FIG. 10, N of the present embodiment will be described.
The operation status of the C lathe during machining will be described. FIG. 10 is a flow chart showing the operation status during machining on the NC lathe using this embodiment. When the workpiece 1 is the first product, pre-machining measurement described later is performed, and the tool offset amount is calculated and corrected by the NC device 19. Then, the machining is started, and when the number of measured insertions, which has been input to the NC device 19 in advance, is reached, the post-machining measurement command is issued from the NC device 19, and the workpiece 1 is processed as described above with reference to FIG. Take measurements. Then, when the measured dimension is out of the allowable dimension range which has been input to the NC device 19 in advance, the machining is immediately stopped, and an alarm is displayed on the NC device 19 so that many defective products are not machined. . If it is within the allowable dimension range, then the tool wear amount is measured by the method previously described with reference to FIGS. 7 and 8. Then, when the measured tool wear amount is less than the allowable tool wear amount that has been input to the NC device 19 in advance, machining is continued, and when the measured tool wear amount is greater than or equal to the allowable tool wear amount, the tool is replaced and the first product is machined. In the same manner as above, perform the pre-processing measurement and then restart the processing. It should be noted that the post-machining measurement and the tool wear amount measurement can be separately inserted after machining an arbitrary number of pieces, and a method in which the insertion is determined by the machining time instead of the number of pieces machined is also conceivable.

FIG. 11 is a block diagram showing the operating condition of pre-machining measurement according to this embodiment. When the pre-machining measurement command is issued from the NC device 19, the spindle measurement sensor calibration reference object 20 gripped by the spindle chuck 2 is measured as previously described with reference to FIGS. 3 to 5, and is attached to the turret 7. The position of the measured position measuring sensor 5 is calibrated. Subsequently, the position of the cutting edge position measuring sensor 16 is measured by the position measuring sensor 5 whose position is calibrated as described above with reference to FIG. 6, and the position is calibrated. Then, the tool 6 is brought into contact with the cutting edge position measuring sensor 16 to measure the position, the NC device 19 calculates the tool offset amount, and the pre-machining measurement ends.

The methods of pre-machining measurement, post-machining measurement and tool wear amount measurement can be selected according to the required accuracy of the workpiece 1 and the machining time limit, and the measurement insertion time can also be set individually. is there. Further, this embodiment can be applied not only to the NC lathe but also to other machine tools.

[0034]

As described above, according to the machine tool and the machining method of the present invention, the position of the blade edge position measuring means can be measured and calibrated, so that an error caused by a disturbance such as heat during machining can occur. Can be eliminated, and the accuracy of the portion that is difficult to measure after processing can be improved.

Further, it is possible to measure the size of the processed product and monitor the processed product.

Further, since the tool wear measuring function is also provided, it is possible to replace the tool by predicting tool loss. The above-described measurement can be arbitrarily inserted during processing, and the measurement time can be selected according to the required processing accuracy of the product, delivery date, cost, and the like.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an embodiment of a machine tool according to the present invention.

FIG. 2 is a diagram showing a positional relationship of main parts of the machine tool according to the present embodiment.

FIG. 3 is a diagram used for explaining a method of calibrating the position of the position measuring sensor using the spindle chuck grasping type reference object of the present embodiment.

FIG. 4 is a diagram used for explaining a method of calibrating the position of the position measuring sensor using the spindle chuck built-in reference object of the present embodiment.

FIG. 5 is a diagram used for explaining a method of calibrating the position of the position measuring sensor using the machinable reference object of the present embodiment.

FIG. 6 is a diagram used for explaining a method for calibrating the position of the blade edge position measuring sensor according to the present embodiment.

FIG. 7 is a diagram used for explaining a method for measuring a tool wear amount using a tool vicinity tool position reference surface of the present embodiment.

FIG. 8 is a diagram used for explaining a method of measuring a tool wear amount using a common reference surface for tool wear amount measurement according to the present embodiment.

FIG. 9 is a diagram used for explaining a method of post-machining measurement according to the present embodiment.

FIG. 10 is a flowchart showing an operation state during machining in the NC lathe according to the present embodiment.

FIG. 11 is a block diagram showing an operating condition of pre-machining measurement according to the present embodiment.

FIG. 12 is an overall configuration diagram showing a conventional NC lathe.

[Explanation of symbols]

1 workpiece, 2 spindle chuck, 3 built-in motor, 4 rotation angle encoder, 5 position measuring sensor, 6 tools, 7 turret, 8 turret, 9 Z axis ball screw, 10 Z axis motor, 11 Z axis position detection Encoder, 12 X-axis ball screw, 13 X-axis motor, 1
4 X-axis position detection encoder, 15 X-axis position detection linear scale, 16 Blade edge position measurement sensor, 17 Sensor arm, 18 Sensor arm rotation motor, 19
NC device, 20 Position measurement sensor calibration reference material, 20
a spindle chuck grasping type reference object, 20b spindle chuck built-in type reference object, 20c machinable type reference object, 21 tool near tool position reference surface, 22 common reference surface for tool wear amount measurement.

Claims (6)

[Claims] 1. A tool driving means capable of moving a tool with respect to a spindle of a machine tool, a cutting edge position measuring means for measuring a position of a cutting edge of the abutting tool, and a cutting edge position measuring means abutting on a detecting section. Position measuring means for measuring the position of, position measuring means moving means for moving the attached position measuring means, position detecting means for detecting the positions of the driving means and the position measuring means moving means, and a known shape Is a reference object fixed to the main shaft, the position of the detection unit with respect to the position of the main shaft detected by abutting the detection unit to the reference object, and the detection unit abuts on the cutting edge position measuring means A machine tool, comprising: a position of the detection unit detected by the above, and a calibration unit that determines the position of the blade edge position measuring unit based on the position. 2. The machine tool according to claim 1, wherein the reference object is a ring which is on the center line of the spindle and is fixed to the spindle. 3. A tool driving means capable of moving a tool with respect to a spindle of a machine tool, a blade edge position measuring means for measuring a position of a blade edge of the abutting tool, and a position detecting means for detecting a position of the driving means. And a tool wear amount measuring means having a reference surface for measuring the amount of tool wear and having a common reference surface that can be measured by the cutting edge position measuring means, and the position of the cutting edge of the tool before machining and The position of the common reference surface is measured by the cutting edge position measuring means, the position of the cutting edge of the tool after machining and the position of the common reference surface are measured again by the cutting edge position measuring means, and the tool wear amount is obtained from these measured values. A machine tool characterized by. 4. A tool driving means capable of moving a tool with respect to a spindle of a machine tool, a blade edge position measuring means for measuring a position of a blade edge of the abutting tool, and a position detecting means for detecting a position of the driving means. And a tool wear amount measuring means having a tool position reference surface located in the vicinity of the tool, and the tool tip position and the position of the tool position reference surface are measured by the tool tip position measuring means before machining. A machine tool characterized in that after machining, the position of the cutting edge of the tool and the position of the tool position reference plane are measured again by the cutting edge position measuring means, and the tool wear amount is obtained from these measured values. 5. A tool driving means capable of moving a tool with respect to a spindle of a machine tool, a cutting edge position measuring means for measuring a position of a cutting edge of the abutting tool, and a cutting edge position measuring means abutting on a detecting section. Position measuring means for measuring the position of, position measuring means moving means for moving the attached position measuring means, position detecting means for detecting the positions of the driving means and the position measuring means moving means, and a known shape In a machine tool having a reference object fixed to the spindle, a step of calibrating the position of the position measuring means itself by measuring the position of the reference object having a known shape by the position measuring means, Calibrating the position of the cutting edge position measuring means by abutting the position measuring means to the cutting edge position measuring means, and measuring the position of the cutting edge of each tool with the calibrated cutting edge position measuring means. And a step of measuring, wherein the position of the cutting edge of each tool is measured. 6. A tool driving means capable of moving a tool with respect to a spindle of a machine tool, a blade edge position measuring means for measuring a position of a blade edge of the abutting tool, and a position detecting means for detecting a position of the driving means. And a tool wear amount measuring means having a reference surface for measuring the amount of tool wear and having a common reference surface that can be measured by the cutting edge position measuring means, wherein the cutting edge position measuring means before machining A step of measuring the position of the cutting edge of the tool with, a step of measuring the position of the reference surface with the cutting edge position measuring means before processing, a step of measuring the position of the cutting edge of the tool with the cutting edge position measuring means after processing, A machining method comprising: a step of measuring a position of a reference plane by a cutting edge position measuring means after machining; and a step of obtaining a tool wear amount from these measured values.