JP4690276B2 - Calibration method for roundness measuring apparatus - Google Patents

Description

The present invention relates to a method for calibrating a roundness measuring apparatus you calibrate the roundness measuring apparatus for measuring the roundness of the object to be measured.

Conventionally, a roundness measuring device for measuring the roundness of an object to be measured is calibrated by, for example, a static or dynamic method of a probe. Here, as a static calibration method, a method of measuring displacement by replacing a set of block gauges below the probe is known. On the other hand, as a dynamic calibration method, there is a method of measuring a so-called flick standard that is a cylinder or cylinder that is precisely machined with a predetermined diameter and measured and priced with a high-precision measuring machine. Are known. In addition, a probe of a roundness measuring device is applied to the surface driven by the piezoelectric element to output a detection signal and measure the displacement. At the same time, the displacement of the surface is measured with a laser interferometer with high accuracy. A method for calibrating a roundness measuring device by comparing two measurement results is also known. In this calibration method, Jusko has proposed a method for calibrating using a jig having a concavo-convex shape combining sine waves with different periods (see, for example, Non-Patent Document 1 and Non-Patent Document 2). ).
The one described in Non-Patent Document 1 is called a cylindrical full-wavelength standard, and the inner peripheral surface has a cutoff frequency (5, 15, 50, 150, 500 peaks / rotation; UPR), Concavities and convexities having different amplitudes are provided. This full wavelength standard can be used to calibrate the sensitivity of the roundness measuring device.

O. Jusko, F. Ludicke, Novel multi-wave standards for the calibration of form measuring instruments, Proc. 1st EuSPEN, Bremen, Vol. 2, 1999, p. 299-302 Schneider, U., H ▲ u ▲ bner, G .: Dynamic Calibration and Testing of Roundness Measuring Devices by Means of a Waviness Standard, Proc. 4th Int. Symp.Dimensional Metrology in Production and Quality Control, Tampere, Finland, 1992, p.394-414

However, in the calibration that calibrates the roundness measuring device using the conventional full-wavelength standard described in Non-Patent Document 1 and Non-Patent Document 2 described above, the calibration process is difficult, and for example, harmonics having different measurement results. The calculation process becomes complicated due to the influence of the interaction. In particular, a roundness measuring instrument that measures high amplification, that is, a surface irregularity of an object to be measured at a high magnification, is not suitable for good calibration because the amplitude is too large for a high-frequency scale that is generally measured. For this reason, there is a problem that it is difficult to perform good calibration dynamically at both high and low frequencies.
Jig that can be

An object of the present invention, in view of the above problems, provides a method for calibrating a roundness measuring apparatus that good calibration is obtained a roundness measuring apparatus.

The roundness measuring apparatus calibration method according to the present invention includes an evaluation track having a sinusoidal undulation in a circumferential direction on an evaluation surface provided on at least one of an inner peripheral surface and an outer peripheral surface. There are provided a plurality of detectors that scan the circumferential surface of the object to be measured using a roundness measuring apparatus calibration jig whose amplitude spectrum of the evaluation track is disclosed as calibration data. A calibration method for calibrating a roundness measuring device for detecting an amplitude spectrum of a peripheral surface of an object , wherein the roundness measuring device calibration jig includes evaluation tracks provided in parallel with three types of undulations, and The cycle is 2 cycles, 50 cycles and 500 cycles, the amplitude of 2 cycles is 1.5 μm, the amplitude of 50 cycles is 0.2 μm, and the amplitude of 500 cycles is 0.1 μm. the end measurement apparatus roundness measuring device Evaluation track on the evaluation surface of Shoji device, the amplitude spectrum detected by scanning the detector in the circumferential direction, the differences by comparing the amplitude spectrum of the calibration data of the roundness measuring device calibration jig The roundness measurement is performed to correct the amplitude of the second harmonic in the amplitude spectrum obtained by Fourier transforming the signal from the detector obtained by the measurement of the roundness measuring device calibration jig. A division process is performed by the undulation amplitude in the amplitude spectrum of the apparatus calibration jig, and a value obtained by the division process is set as a probe magnification of the roundness measuring apparatus .
In this invention, the evaluation track is provided with three types of undulations in the circumferential direction, and the period is 2 periods, 50 periods and 500 periods in the entire circumference, the amplitude of 2 periods is 1.5 μm, and the amplitude is 50 periods. Is 0.2 μm and 500 cycles of amplitude is 0.1 μm roundness measuring device calibration jig , and the evaluation track on the evaluation surface of this roundness measuring device calibration jig is scanned in the circumferential direction to undulate High-accuracy calibration can be easily obtained simply by measuring, comparing the measurement result with the undulation of the roundness measuring device calibration jig, and correcting the difference.
That is, the dynamic calibration for the high frequency and the low frequency in the roundness measuring apparatus is a simple configuration provided with a plurality of evaluation tracks having sinusoidal undulations in which at least one of a plurality of periods and amplitudes is different. Using the roundness measuring device calibration jig having the configuration, it is possible to carry out with high accuracy by a simple method of measuring a plurality of evaluation tracks in the same manner as the roundness measurement. Furthermore, even with a high-magnification roundness measuring device capable of measuring the minute unevenness of the surface shape of the object to be measured, a roundness measuring device calibration jig having a relatively simple configuration provided with three types of evaluation tracks is used. Highly accurate calibration can be obtained.

In the present invention, the second harmonic amplitude of the signal from the detector obtained by measurement before Symbol roundness measuring device calibration jig in the amplitude spectrum obtained by Fourier transform, the roundness the amplitude of the undulating division processing of the measurement device calibration jig in the amplitude spectrum, to set the value obtained by this division processing as probes magnification of the roundness measuring apparatus.
As a result, an evaluation track which is a measurement surface provided with a predetermined undulation of the roundness measuring device calibration jig is measured, and an easy Fourier transform is performed based on the amplitude of the second harmonic of the obtained amplitude spectrum. High-accuracy calibration of the probe magnification can be easily performed only by performing arithmetic processing such as calculation and division.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In the first embodiment, the roundness measuring device calibrated using the roundness measuring device calibration jig of the present invention is exemplified. However, for example, calibration data for calibration is automatically stored and stored. May be calibrated automatically.
FIG. 1 is a block diagram showing a schematic configuration of a roundness measuring apparatus according to one embodiment.

[Configuration of roundness measuring instrument]
As shown in FIG. 1, the roundness measuring apparatus 1 scans the outer peripheral surface of the workpiece W and measures the roundness.
The roundness measuring apparatus 1 includes a base 2, a measured object rotating mechanism 3 that is disposed on one side of the upper surface of the base 2, and rotates the measured object W, and is disposed on the other side of the upper surface of the base 2. A position detection mechanism 7 for detecting the outer surface position of the object W, and the like.

The measured object rotating mechanism 3 includes a rotating table 4 and an XY table 5.
The turntable 4 is rotatably provided on the base 2 via a rotation drive mechanism (not shown). The XY table 5 is disposed on the upper surface of the rotary table 4 and places the object to be measured W thereon.
The rotary table 4 is provided with adjustment knobs 6A and 6B for moving the XY table 5 in directions (X and Y directions) orthogonal to the rotation center axis Z of the rotary table 4 and orthogonal to each other. Yes. Further, the rotary table 4 is provided with an inclination knob (not shown) for inclining the upper surface (measurement object placement surface) of the XY table 5.

The position detection mechanism 7 includes a column 8, a slider 9, a first horizontal arm 10, a rotating member 11, a second horizontal arm 12, a probe holder 13, a probe 14 as a detector, a motor 15, It has.
The support column 8 is erected vertically to the base 2 (parallel to the Z axis). The slider 9 is provided on the column 8 so as to be movable up and down. The first horizontal arm 10 is provided on the slider 9 so as to be slidable in a direction orthogonal to the support column 8 (X-axis direction that is a direction orthogonal to the Z-axis). The rotating member 11 is provided on the distal end side of the first horizontal arm 10 so as to be rotatable with respect to the axis A of the first horizontal arm 10. The second horizontal arm 12 is attached to the rotating member 11 and is provided in parallel with the first horizontal arm 10. The probe holder 13 is provided on the second horizontal arm 12 so as to be capable of reversing 180 degrees with respect to the rotation axis B. The probe 14 is provided in the probe holder 13 and has a stylus 14A as a stylus that is a sensor. That is, the probe 14 includes a detection sensor including an electronic micrometer (not shown) that outputs a signal in accordance with the unevenness of the surface of the workpiece W, with the stylus 14A biased by the spring on the surface of the workpiece W. . The motor 15 changes the direction by rotating the probe holder 13. That is, by driving the motor 15, the probe holder 13 is rotated to a predetermined angle (for example, two positions opposite to 180 degrees), and the posture of the probe holder 13 is measured with the stylus 14A. It is possible to reverse the posture at the time of measuring the outer diameter and the posture at the time of measuring the inner diameter to measure the inner diameter.

[Reference jig configuration]
Next, a calibration jig 20 that is a roundness measuring apparatus calibration jig in the present invention for calibrating the above-described roundness measuring apparatus 1 will be described with reference to the drawings.
FIG. 2 is a perspective view showing a schematic configuration of the calibration jig. FIG. 2 conceptually shows the undulation of the track for convenience of explanation.

As shown in FIG. 2, the calibration jig 20 is formed in a cylindrical shape having an outer diameter of 30 mm and a length dimension of 20 mm, for example.
On the outer peripheral surface of the calibration jig 20, for example, three tracks 21 are provided substantially in the axial direction in the circumferential direction, and these tracks 21 are provided with undulations (not shown) that are periodic in the circumferential direction in a sinusoidal shape. Yes. The undulations of each track 21 are the whole circumference of the calibration jig 20 in the circumferential direction, for example, three periods of 2 periods, 50 periods, and 500 periods, and the amplitude of 2 periods is 1.5 μm and the amplitude of 50 periods Is 0.2 μm, and the amplitude of 500 cycles is 0.1 μm. That is, the calibration jig 20 provided with these undulations is suitable for the high-resolution roundness measuring device 1.
In addition, it was formed in a state in which two periods, 15 periods and 150 periods were different, the amplitude of 2 periods was 1.5 μm, the amplitude of 15 periods was 0.2 μm, and the amplitude of 150 periods was 0.1 μm. A so-called standard type having a track 21 may be designed.
The calibration jig 20 is hardened and hardened at least in the track 21 by, for example, high frequency induction heating. Then, after the calibration jig 20 is manufactured, the undulation state of the outer peripheral surface of the track 21 is measured by the reference roundness measuring device 1 calibrated in advance, and the amplitude spectrum corresponding to the undulation is disclosed in advance by the measurement. The That is, the undulation amplitude spectrum in the calibration jig 20 is acquired in advance as calibration data for each calibration jig 20.

[Operation of roundness measuring device]
Next, as an operation of the roundness measuring apparatus 1, a calibration method for the roundness measuring apparatus 1 using the calibration jig 20 will be described.
This calibration is performed, for example, before shipment of the roundness measuring device 1 or during regular maintenance management of the roundness measuring device 1.

First, the calibration jig 20 is placed and fixed on the turntable 4 of the roundness measuring device 1. Further, the orientation of the probe 14 is set as an outer diameter measurement posture.
Then, similarly to the measurement operation of the roundness of the inner peripheral surface of the workpiece W, the probe 14 is scanned in a state where the probe 14 is relatively slid on the outer peripheral surface of the calibration jig 20 in the circumferential direction while rotating the rotary table 4. Then, an amplitude spectrum obtained by measuring the undulation of the track 21 of the calibration jig 20 is detected to obtain measurement data.
Thereafter, the amplitude spectrum of the obtained measurement data is compared with the calibration data of the calibration jig 20 disclosed in advance to evaluate the difference error.

Then, the roundness measuring device 1 is adjusted in order to correct the obtained difference error. That is, the probe magnification, the dynamic probe characteristic, the filtering characteristic, the rotation continuity, and the like of the roundness measuring device 1 are calibrated.
Specifically, the measured amplitude of the second harmonic in the amplitude spectrum obtained by Fourier-transforming the signal corresponding to the amplitude of the track 21 of each cycle is compared with the amplitude of the calibration data of the track 21 of each cycle. Thus, the probe magnification of the roundness measuring device 1 can be calibrated.

[Effects of Embodiment]
As described above, in the above-described embodiment, a plurality of tracks 21 having sinusoidal undulations having different periods and amplitudes are provided on the outer peripheral surface.
For this reason, for example, dynamic calibration for high frequency and low frequency in the roundness measuring apparatus 1 that measures the roundness by bringing the probe 14 into contact with the surface shape of the workpiece W is performed with a plurality of different periods and amplitudes, respectively. With a simple configuration provided with a plurality of tracks 21 having sinusoidal undulations, a simple method of measuring the plurality of tracks 21 similarly to the measurement of roundness can be carried out with high accuracy.

The plurality of tracks 21 are undulations of three different periods of 2 periods, 50 periods, and 500 periods, and the amplitude of 2 periods is 1.5 μm, the amplitude of 50 periods is 0.2 μm, and 500 periods. The amplitude is 0.1 μm.
For this reason, even with a high-magnification (high-resolution) roundness measuring apparatus 1 capable of measuring the minute unevenness of the surface shape of the workpiece W, highly accurate calibration can be performed with a relatively simple configuration in which three types of tracks 21 are provided. can get.

In addition, the diameter of the outer peripheral surface of the calibration jig 20 where the undulations of the track 21 are provided is 30 mm.
For this reason, it is possible to form the calibration jig 20 which can be formed with high accuracy even with undulations of 500 cycles at a high frequency, and can be formed relatively easily with a relatively small size.

In addition, since the undulations are provided on the outer peripheral surface, inconveniences such as damage to the undulations 22 due to external impacts are hardly caused, the handleability is improved, and good high-precision calibration can be easily obtained.

Then, as calibration using the calibration jig 20, the track 21 of the calibration jig 20 is measured by scanning the probe 14 in the circumferential direction, and the amplitude spectrum of the obtained measurement data and the calibration jig 20 disclosed in advance are measured. Is calibrated by adjusting the difference error obtained. That is, the amplitude spectrum of the measurement data is adjusted to a state where the spectrum distribution is the same as that of the calibration data.
That is, high-precision calibration can be performed by a simple operation and processing in which the unevenness of the track 21 of the calibration jig 20 is measured and compared so that the known undulations of the track 21 of the calibration jig 20 are reproduced. can get.

[Modification of Embodiment]
The aspect described above shows one aspect of the present invention, and the present invention is not limited to each of the above-described embodiments, and within the scope of achieving the objects and effects of the present invention. Needless to say, variations and improvements are included in the content of the present invention. In addition, the specific structure and shape in carrying out the present invention may be used as other structures and shapes within the scope of achieving the object and effect of the present invention.

That is, the roundness measuring apparatus calibration jig of the present invention is a cylindrical shape having a diameter of 30 mm as the outer diameter on which the undulation is provided, but the outer diameter is not limited to this, and the outer diameter can be appropriately designed. Similarly, the length dimension in the axial direction is not limited to 20 mm, and can be appropriately designed.
Further, the description has been given by providing three types of tracks 21 of 2, 50, and 500 cycles, but as described above, for example, three types of tracks 21 of 2 cycles, 15 cycles, and 150 cycles may be provided. Other combinations of periods may be used.
Moreover, although the track 21 was provided on the outer peripheral surface, the track 21 may be provided on the inner peripheral surface as shown in FIG. 3, for example. Specifically, the calibration jig 21 shown in FIG. 3 is formed in a cylindrical shape, and an evaluation unit 22 in which the inner peripheral surface becomes an evaluation surface in a rib shape in the circumferential direction is provided on the inner peripheral surface. Are provided with a plurality of tracks 21 having different periods and amplitudes. Note that FIG. 3 conceptually shows the undulation of one track 21 for convenience of explanation.
Furthermore, the calibration jig 20 may provide the tracks 21 on both the outer peripheral surface and the inner peripheral surface.
Further, although the undulations having different periods and amplitudes are used, a sine wave shape having only one of the periods and the amplitudes may be different.

  In addition, the specific structure and shape in the implementation of the present invention may be other structures as long as the object of the present invention can be achieved.

It is a side view which shows schematic structure of the roundness measuring apparatus based on this invention. It is a perspective view which shows the calibration jig | tool in the said embodiment. It is a perspective view which shows schematic structure of the other calibration jig | tool which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Roundness measuring device as a roundness measuring device 3 ... Measuring object rotation mechanism 14 ... Probe as a detector 14A ... Stylus as a stylus 20 ... As a roundness measuring device calibration jig Calibration jig 21 …… Track that is the evaluation track W …… Measurement object

Claims (1)

A plurality of evaluation tracks having sinusoidal undulations in the circumferential direction are provided on an evaluation surface provided on at least one of the inner peripheral surface and the outer peripheral surface, and the amplitude spectrum of these evaluation tracks is disclosed as calibration data. Further, a roundness measuring apparatus that includes a detector that scans the circumferential surface of the object to be measured using a calibration jig for the roundness measuring apparatus, and detects an amplitude spectrum of the circumferential surface of the object to be measured by scanning the detector. A calibration method for calibrating
In the roundness measuring apparatus calibration jig, the evaluation track is provided in parallel with three types of undulations, and the period is 2 periods, 50 periods, and 500 periods, and the amplitude of the 2 periods is 1. 5 μm, 50 period amplitude is 0.2 μm, 500 period amplitude is 0.1 μm,
The evaluation tracks on the evaluation surface of the roundness measuring device calibration jig roundness measuring apparatus, the amplitude spectrum detected by scanning the detector in the circumferential direction, the roundness measuring device calibration jig Compare the amplitude spectrum of the calibration data of the tool and correct the difference ,
The second harmonic amplitude in the amplitude spectrum obtained signal by Fourier transform from the detector obtained by the measurement of the roundness measuring device calibration fixture, the amplitude of the roundness measuring device calibration jig A method for calibrating a roundness measuring apparatus, characterized in that division processing is performed by the amplitude of undulations in a spectrum, and a value obtained by the division processing is set as a probe magnification of the roundness measuring apparatus.

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