JPH05200649A - Tool centering device - Google Patents

Abstract

PURPOSE:To provide a tool centering device for an aspheric surface finishing machine or the like, capable of according a tool center of a grinding wheel and so on with the turning center of a table highly accurately in an easy manner. CONSTITUTION:A detection sensor 13 is clamped to the side of a slide 1 traveling in the longitudinal direction, while a rotary table 8 is installed on a slide table 2 traveling in both directions, and a tool such as a grinding wheel 12 or the like is set up on this rotary table 8 via a triaxial regulating table 9, through which decentering length in the tool longitudinal direction at the time when the rotary table 8 is phase-divided into two spots apart as far as 180 degrees is detected by the detection sensor 13. In addition, a half of difference in length detected by a computing element 33 is operated, and a tool position is compensated as far as the operated length in the longitudinal direction by the regulating table 9, thus the tool cater is accorded with the turning center of the rotary table 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool centering device for a machine tool such as a CNC precision aspherical surface processing machine.

[0002]

2. Description of the Related Art The aspherical surface processing machine will be described with reference to FIGS. 1 and 2 showing an embodiment of the present invention. In FIGS. 1 and 2, 1 is a feed table, 2 is a slide table, which are engaged and supported on the beds 3a and 3b, the feed table 1 is in the front-back (Z) direction, and the slide table 2 is in the left-right (X) direction. ) Direction, and is configured to reciprocate linearly in each direction.

A spindle headstock 4 is fixed on the feed table 1, a spindle 5 driven by a spindle motor is supported on the spindle stock 4, and a workpiece 6 is attached to and detached from the tip of the spindle 5 by a chuck or the like. It is configured to hold as much as possible. On the slide table 2, a rotary table 8 which is rotated in the forward and reverse directions by a rotary table electric motor 7 about a vertical axis is mounted, and a triaxial adjustment table 9 is eccentrically provided on the rotary table 8. A grindstone base 10, which is a tool base, is fixed to the upper surface of the three-axis adjusting base 9 which is inclined downward, and the grindstone base 10 is supported by a grindstone shaft 11 driven by an electric motor for a grindstone. A cylindrical grindstone 12 which is a tool is detachably attached to the tool.

The precision aspherical surface processing machine configured as described above rotates with the spindle 5 by the reciprocating movement of the feed base 1 in the front-back (Z) direction and the reciprocating movement of the slide table 2 in the left-right (X) direction. The table 8 is horizontally moved in the front-rear direction and the left-right direction, and the rotary table 8 is reciprocally rotated about the axis. At the same time, the spindle 5 and the grindstone shaft 11 are rotated around the axes to rotate the workpiece 6 and the grindstone 12, while pressing them, the end surface of the workpiece 6 is processed by the grindstone 12 into a non-spherical concave surface. To do.

In the above-mentioned aspherical surface processing machine, since the processing is performed on the rotation center of the rotary table 8, the tool, that is, the grindstone 1 is used.
The centering of 2 must be performed in the left-right (X), up-down (Y), and front-back (Z) directions with respect to the center of rotation of the turntable 8. The positioning device using a microscope (not shown) incorporated in the processing machine is used to move the tip of the grindstone 12 in the vertical and longitudinal directions. Further, in the horizontal positioning, the center is roughly centered when setting the three-axis adjustment table 7, and the operator performs position correction based on the experience from the shape of the workpiece 6 by the shape measuring machine attached to the processing machine after trial machining. However, centering is performed in the left and right (X) directions.

[0006]

However, the centering of the above-mentioned conventional tool in the left-right direction is as follows.
Since the operator corrects the center position of the tool based on experience, it is not possible to perform centering with high accuracy in the left and right directions, and it takes a long time to perform centering work. There is a problem that it is difficult to perform precision machining.

The present invention solves the above-mentioned problems,
We provide a tool centering device for machine tools such as precision aspherical surface processing machines that can align the center of a tool such as a grindstone with the center of rotation of a rotary table with high accuracy and facilitate centering of the tool in the left-right direction. The purpose is to do.

[0008]

SUMMARY OF THE INVENTION The present invention is a tool centering device for a machine tool having a feed table provided with a headstock as described above and a slide table provided with a rotary table with an adjusting table. , The detection sensor fixed to the feed table side and the rotary table are phase-indexed at two positions 180 ° apart, and the detection sensor detects the misalignment length in the left-right direction of the tool at each of the two phase-indexed positions. However, a control device for correcting the position of the tool in the left-right direction by the adjusting table according to the misalignment lengths is provided.

[0009]

The tool centering device according to the present invention detects the position of the outer circumference on the right side of the grindstone on the rotary table which is phase-indexed to the predetermined position by the detection sensor, and then rotates the rotary table 180 ° to rotate the grindstone. The position of the outer circumference on the left side of is detected by the detection sensor, and the misalignment length of the tool such as the grindstone is calculated by the control device.

Then, the position of the tool mounted on the adjusting table via the tool table is moved by moving the adjusting table provided eccentrically on the rotary table in the lateral direction by an appropriate means according to the calculation result. The correction is performed so that the tool center coincides with the rotation center of the rotary table. Therefore, according to the present invention, centering of a tool such as a grindstone in the left-right direction can be performed more easily and more accurately than in the conventional case.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A tool centering device according to an embodiment of the present invention will be described below with reference to FIGS. 1 and 2 together with a CNC precision aspherical surface processing machine. As shown in FIGS. 1 and 2, a detection sensor 13 composed of a touch sensor is fixed to the right side of the spindle 5 on the tip surface of the headstock 4 fixed to the feed table 1, and the tip of this sensor 13 is slid from the feed table 1. It is projected to the table 2 side. In addition, the feed base 1 includes a front-back feed servo motor 14
Is driven to move in the front-back (Z) direction by the ball screw shaft 15.

The slide table 2 is constructed so as to be moved in the left-right (X) direction by a ball screw shaft 17 by driving a left-right feed servomotor 16. In addition, the triaxial adjustment base 9 provided on the rotary table 8 includes a pair of lower piezo actuators 19 between the bracket 18 a of the mounting base 18 fixed on the rotary table 8 and the pair of brackets 20 a of the front-back adjustment base 20. A front / rear adjustment base 20 provided and moved in the front / rear (Z) direction by the lower piezo actuator 19 is engaged with and supported by the mounting base 18. A pair of middle-stage piezo actuators 21 is provided between the bracket 20b of the front-rear adjustment base 20 and a pair of brackets 22b of the left-right adjustment base 22, and the left-right adjustment base 22 is moved by the middle-stage piezo actuator 21 in the left-right (X) direction. The front and rear adjustment table 20 is engaged and supported. Furthermore, the left and right adjustment table 22
Bracket 22c of the inclined upper portion 22a of the
A pair of upper piezo actuators 23 are provided between the pair of brackets 24a,
The vertical adjustment base 24, which is slanted in the vertical (Y) direction, is engaged with and supported by the horizontal adjustment base 22, and the grindstone base 10 is fixed to the upper surface of the vertical adjustment base 24.

Although not shown, the main spindle 5 is the headstock 4
In addition, the grindstone shafts 11 of the grindstones 12 are respectively supported by the grindstone bases 10 by gas bearings, and the table shafts provided at the center of the rotary table 8 are supported by the slide table 2 by static pressure bearings.

In FIG. 1, reference numeral 25 is a central processing unit (CP).
U), the central processing unit 25 includes pulse generator circuits 26, 2 for front-rear feed and left-right feed servomotors 14, 16.
7 and the drive circuits 28 and 29 to give a command to the middle-stage piezo actuator 21 via an actuator amplifier 30, and at the same time to the servo motors 14 and 1
Encoders 31 and 32 attached to 6 and detection sensor 1
The signal from 3 is input.

Reference numeral 33 denotes an arithmetic unit that constitutes a control unit together with the central processing unit 25 and the like, receives a signal from the detection sensor 13 and stores it, and moves the grindstone from the stored signal and the grindstone correction program. A length for position correction is calculated, and 34 is an input device. In order to avoid duplication of description, description of the same configuration, processing operation, and positioning operation of the grindstone in the front-rear direction and the vertical direction as described above in the related art will be omitted.

The position correction of the grindstone 12 in the left-right (X) direction according to this embodiment is performed at the original position where the feed table 1 is retracted as shown in FIGS. 1 and 6, and the rotary table 8 is rotated on the extension of the axis of the spindle 5. A case in which there is a center and the center of the grindstone 12 is shifted to the right and parallel to these centers will be described with reference to FIG.

In the above state, first, the slide table 2
To the right with the left-right feed servomotor 16 and the detection sensor 1
3 and the grindstone 12 are associated with each other, and the slide table 2 is stopped. Next, turn the rotary table 8 counterclockwise (+ direction).
Turn 90 ° to stop. Subsequently, the feed table 1 is moved forward by the forward-backward servomotor 14 to move the headstock 4 and the detection sensor 13 forward, and the tip of the sensor 13 is brought into contact with the right outer peripheral surface of the grindstone 12 (see FIG. 4).

When the tip of the detection sensor 13 comes into contact with the grindstone 12, the detection signal from the detection sensor 13 is sent to the central processing unit 2.
5 receives and stops the headstock 4 together with the feed table 1. Further, the length l ₁ from the original position to the stop position of the headstock 4, that is, the position of the headstock 4, is measured by the encoder 31 for the rotation of the servo motor 14 for forward and backward feed, and is stored in the calculator 33. Further, the headstock 4 together with the feed base 1 is retracted to the original position and stopped.

After that, the rotary table 8 is rotated clockwise (-direction) by 180 ° and stopped, and then the slide table 2 is moved rightward so that the detection sensor 13 and the grindstone 12 correspond to each other and the slide table 2 is moved. Stop. Then, the headstock 4 and the detection sensor 13 are advanced together with the feed base 1, and the tip of the sensor 13 is brought into contact with the left outer peripheral surface of the grindstone 12 (see FIG. 5).

When the tip of the detection sensor 13 comes into contact with the grindstone 12, the feedstock 1 and the headstock 4 are stopped, and the length l ₂ from the original position to the stop position of the headstock 4 is calculated by the calculator 33.
To memorize. Since the difference between the longitudinal movement lengths l ₁ and l ₂ of the headstock 4 obtained by the above-mentioned operation is _twice the axial length of the grindstone shaft 11, that is, the length N of the lateral displacement of the grindstone 12 center, the calculator 33 (L ₁ −l ₂ ) / 2 = N is calculated by the whetstone position correction program of ( ₁ ).

Then, the three-axis adjustment base 9 having the above-mentioned shift length N is used.
By moving the left and right adjustment base 22 of the
The centers of the grindstone shaft 11 and the grindstone 12 are set on the center of rotation of the rotary table 8. That is, the movement of the left-right adjustment table 22 is
This is performed by operating the middle stage piezo actuator 21 via the actuator amplifier 30 according to the shift length N of the calculation result from the arithmetic unit 33 to the central processing unit 25.

After performing the above-mentioned operation, the headstock 4 together with the feed base 1 is returned to the original position, the rotary table 8 is rotated 90 ° counterclockwise, and the slide table 2 is further moved leftward to return to the original position. Therefore, the grindstone 12 shown in FIG.
From the state in which the center of the tool shifts from the center line of the rotary table 8 in the left-right direction, the operation for correcting the position to match the position shown in FIG. To do.

Next, a tool centering device according to another embodiment of the present invention will be described with reference to FIGS. 8, 9 and 10. 8 and 10, the same reference numerals as those in FIGS. 1 and 2 indicate corresponding parts, and 35 is a detection sensor. This sensor 35 is fixed by a bracket 36 to the right side of the spindle 5 on the tip surface of the feed table 1. is there. The detection sensor 35 is shown in FIG.
As shown in FIG. 3, the laser light emitting section 38 and the CC are provided on the upper side and the lower side of the U-shaped sensor frame 37 that opens to the right.
The light receiving portions 39 composed of D sensors are opposed to each other and fixed, and the grindstone 12 is fitted with a gap between them. The structure of this embodiment other than that described above is substantially the same as that of the embodiment shown in FIGS.

Left and right of the grindstone 12 according to another embodiment (X axis)
The position correction in the direction is performed by moving the slide table 2 to the left in the state shown in FIG. 8, and as shown in FIG. 9, FIG. 10, and FIG.
The grindstone 12 is placed in the sensor frame 37, and a part of the laser beam 40 emitted from the light emitting unit 38 is blocked by the grindstone 12, so that the length l ₁ from the tip of the sensor frame 37 to the right side of the grindstone 12 is reduced. Measure and store in the calculator.

After that, the rotary table 8 is rotated by 180 ° to bring the grindstone 12 into the sensor frame 37 to the state shown in FIG. In this state, a part of the laser light 40 emitted from the light emitting section 38 is blocked by the grindstone 12 so that the length l ₂ from the tip of the sensor frame 37 to the left side of the grindstone 12 is measured. Store it in the calculator.

Then, by the arithmetic unit, (l ₁ + l ₂ ) /
2 = N is calculated, the triaxial adjustment base 9 is operated by the misalignment length N, and the grindstone 12 is moved in the left-right direction, so that the center of the grindstone 12 is corrected to a position that coincides with the rotation center of the rotary table 8. At the same time, the feed table 1, the rotary table 8 and the slide table 2 are returned to the reference positions, the horizontal centering of the grindstone 12 is completed, and the workpiece 6 is machined.

In the tool centering device of both the above-described embodiments, the grindstone 12 is provided by the detection sensors 13 and 35 provided on the feed base 1 side.
The length of misalignment in the left-right direction is detected by indexing the rotary table 8 into two positions 180 ° apart, and the calculator 33
By calculating 1/2 of the difference between the misalignment lengths detected at two locations by using the triaxial adjustment table 9 to move 1/2 of the difference between the misalignment lengths in either the left or right direction. The correction of the misalignment of the grindstone 12 in the left-right direction can be automatically and highly accurately performed.

Therefore, the center of the grindstone 12 and the center of rotation of the rotary table 8 can be easily positioned in the left-right direction, and the positioning accuracy is improved. It can be carried out. The detection sensors 13 and 35 can also measure the change in the diameter of the grindstone, that is, the amount of wear of the grindstone.

In the present invention, the detection sensor is not necessarily limited to that of the embodiment, and can be changed as appropriate, the mounting position and orientation of the detection sensor can be changed as appropriate, and the movement of the grindstone by the triaxial adjustment table can be changed by the servo motor. And ball screw shaft,
A tool that uses a ball nut or the like or one that is manually scanned can be changed as appropriate, and the tool is not limited to a grindstone and may be a bite.

The present invention can also be applied to a machine tool provided with a feed table that linearly reciprocates in the left-right direction and a slide table that linearly reciprocates in the front-rear direction.

[0031]

As described above, according to the present invention, the workpiece is attached to and detached from the headstock fixed to the feed table, which has the feed table and the slide table that linearly reciprocate in the front-rear direction and the left-right direction. A tool centering device for a machine tool, in which a main shaft for holding is provided, an eccentric adjustment table is provided on a rotary table provided on the slide table, and a tool is mounted on the adjustment table via a tool table, The detection sensor fixed to the feed base side and the rotary table were phase-indexed at two positions separated by 180 °, and the phase-indexed 2
A detection device is provided with a control device that detects the misalignment length of the tool in the left-right direction at each location by the detection sensor, and corrects the tool position in the left-right direction by the adjustment table according to the misalignment length. ..

In the present invention, the detection sensor detects the position of the outer circumference on the right side of the grindstone on the rotary table which is phase-indexed to a predetermined position, and then the rotary table is rotated 180 ° to detect the position of the outer circumference on the left side of the grindstone. Is detected by a detection sensor, and the controller calculates the misalignment length of a tool such as a grindstone.

Then, the position of the tool mounted on the adjusting table through the tool table is moved by moving the adjusting table provided eccentrically on the rotary table in the left-right direction by an appropriate means according to the calculation result. The correction is performed so that the tool center coincides with the rotation center of the rotary table.

Therefore, according to the present invention, centering of a tool such as a grindstone in the left-right direction can be performed more easily and with higher accuracy than in the conventional case. Therefore, the tool can be mounted on a spindle of a machine tool such as a precision aspherical surface processing machine. There is an effect that processing such as aspherical surface grinding can be performed with high accuracy on a machined work using a tool such as a grindstone.

[Brief description of drawings]

FIG. 1 shows a tool centering device C according to an embodiment of the present invention.
Schematic plan view with NC aspherical surface processing machine

2 is a partially enlarged front view of FIG.

FIG. 3 is an explanatory view showing an operation pattern of a tool centering device according to an embodiment of the present invention.

FIG. 4 is an enlarged plan view showing a detection state by the detection sensor of FIG.

FIG. 5 shows a rotary table 180 by the detection sensor of FIG.
Plan view showing the detection state after rotating by °

FIG. 6 is a plan view illustrating the positions of a grindstone and a rotary table in a misaligned state.

FIG. 7 is a plan view showing the positions of the grindstone and the rotary table after the misalignment is corrected.

FIG. 8 is a partial schematic plan view showing a tool centering device according to another embodiment of the present invention together with a CNC aspherical surface processing machine.

9 is an enlarged front view showing the detection sensor of FIG.

10 is a plan view of the detection state of FIG.

11 is an enlarged plan view showing a detection state by the detection sensor of FIG.

FIG. 12 shows a rotary table that uses the detection sensor of FIG.
Plan view showing the detection state when rotated by 0 °

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Feed table 2 Slide table 4 Spindle base 5 Spindle 6 Workpiece 7 Electric motor for rotary table 8 Rotary table 9 3-axis adjustment stand 10 Grindstone stand (tool stand) 12 Grindstone (tool) 13 Detection sensor 14 Front-rear feed servo motor 16 Left and right Servo motor for feeding 21 Middle-stage piezo actuator 22 Left and right adjusting stand 25 Central processing unit 33 Computing unit 35 Detection sensor 37 Sensor frame 38 Light emitting unit 39 Light receiving unit

Claims (1)

[Claims] 1. A spindle base having a feed table that linearly reciprocates in the front-rear direction and the left-right direction and a slide table, and a spindle that is detachably held on a spindle head fixed to the feed platform, A tool centering device for a machine tool in which an adjusting table is provided eccentrically on a rotary table provided on a slide table, and a tool is mounted on the adjusting table via a tool table, which is a detection sensor fixed to the feed table side. And, the rotary table is phase-indexed at two positions separated by 180 °, and the misalignment lengths in the left-right direction of the tool are respectively detected by the detection sensors at the two phase-indexed positions. A tool centering device, comprising: a control device that corrects the position of the tool in the left-right direction by the adjustment table.