JP3851045B2 - Method for correcting rotational accuracy of measuring instrument and measuring instrument - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotational accuracy correction method for a measuring machine and a measuring machine . For example, the present invention relates to a rotation accuracy correction method for a measuring machine and a measuring machine that correct the rotation accuracy of the rotating mechanism in a measuring machine having a rotating mechanism such as a roundness measuring machine .
[0002]
[Background]
For example, when a workpiece is measured in a measuring machine equipped with a rotating mechanism as a guide (reference), such as a roundness measuring machine, the measurement data includes the workpiece shape data and the mechanical accuracy (rotational accuracy) of the rotating mechanism. In order to extract the true workpiece shape, it is necessary to separate and remove the rotation accuracy of the rotation mechanism from the measurement data.
[0003]
Conventionally, as a method of separating and removing the rotation accuracy of the rotation mechanism from the measurement data,
(1) A method of measuring a spherical master work having a smooth surface, for example, a hemispherical master work (reference hemisphere), and separating and removing the measurement data from the work measurement data as rotational accuracy;
(2) a phase difference method in which the reference hemisphere is measured while shifting the phase by a fixed pitch with respect to the rotary table;
Etc. are known.
[0004]
[Problems to be solved by the invention]
However, the conventional methods (1) and (2) described above have the following problems.
The measurement method (1) has low reliability due to the presence of a shape error in the reference hemisphere.
In the phase difference method (2), it is necessary to perform measurement while shifting the reference hemisphere by a fixed pitch with respect to the rotary table. In order to accurately shift the phase, special jigs and skilled techniques are required. As the number of divisions increases, the measurement man-hours also increase.
[0005]
An object of the present invention is to solve the disadvantages of the above-described conventional measurement methods, particularly the phase difference method, and to correct the rotational accuracy of the measuring instrument that can obtain highly reliable measurement data without improving existing devices. And providing a measuring machine .
[0006]
[Means for Solving the Problems]
Therefore, the rotational accuracy correction method for a measuring machine according to the present invention employs the following configuration in order to achieve the above object.
A rotational accuracy correction method for a measuring machine related to the present invention is a rotational accuracy correcting method for a measuring device having a rotating mechanism, and the shape data at a data collection position is measured with high accuracy in advance using the rotating mechanism of the measuring device. While rotating the master workpiece priced by the device, the shape of the data collection position of the master workpiece is measured by a detector, and the rotation accuracy of the rotation mechanism is subtracted from the measured shape data from the master workpiece measurement data Rotation accuracy data calculation step for obtaining data, a workpiece measurement data calculation step for measuring the shape of the workpiece by a detector while rotating the workpiece using the rotation mechanism of the measuring machine, and obtaining the workpiece measurement data, A workpiece shape calculation step for subtracting the rotation accuracy data from the workpiece measurement data to obtain true workpiece data. The features.
[0007]
According to this configuration, in the rotation accuracy data calculation step, the shape of the data collection position of the master work is rotated while rotating the master work to which the shape data at the data collection position has been previously priced using the rotation mechanism of the measuring machine. Is measured by a detector, and the rotational accuracy data of the rotating mechanism is obtained by subtracting the priced shape data from the master work measurement data. In the workpiece measurement data calculation step, the workpiece measurement data is obtained by measuring the shape of the workpiece with a detector while rotating the workpiece using the rotating mechanism of the measuring machine. In the workpiece shape calculation step, the true value data of the workpiece is obtained by subtracting the rotation accuracy data from the workpiece measurement data.
Therefore, in the rotation accuracy data calculation process, unlike the phase difference method, it is not necessary to shift the master work with respect to the rotation mechanism by a fixed pitch, so the disadvantage of the phase difference method, that is, the disadvantage that skill and man-hours are required. Can be resolved. In addition, since it is a technique for processing workpiece measurement data, highly reliable measurement data can be obtained without any special work on the measuring machine. Further, the calculation of the rotation accuracy data and the correction processing of the rotation accuracy data with respect to the workpiece measurement data can be performed by an application independent of the measuring machine. Data processing such as processing to obtain the average value from multiple masterwork measurement data obtained by repeated measurement under the same measurement conditions) reduces variation in measurement data due to electrical noise and measurement environment, and more Highly accurate correction can be realized.
[0008]
A rotational accuracy correction method for a measuring machine related to the present invention is a rotational accuracy correcting method for a measuring device having a rotating mechanism, and the shape data at a data collection position is measured with high accuracy in advance using the rotating mechanism of the measuring device. While rotating the master workpiece priced by the device, the shape of the data collection position of the master workpiece is measured by a detector, and the rotation accuracy of the rotation mechanism is subtracted from the measured shape data from the master workpiece measurement data A rotation accuracy data calculation step for obtaining data, a rotation accuracy data storage step for storing the rotation accuracy data obtained in the rotation accuracy data calculation step, and the workpiece while rotating the workpiece using the rotation mechanism of the measuring machine. The workpiece measurement data calculation process to obtain the workpiece measurement data by measuring the shape of the workpiece with the detector, and the workpiece measurement data calculation The workpiece measurement data storage step for storing the workpiece measurement data obtained in the process, and the workpiece measurement data and the rotation accuracy data stored in each of the storage steps are read, and the workpiece accuracy data is subtracted from the workpiece measurement data. And a workpiece shape calculation step for obtaining value data.
[0009]
According to this configuration, since the rotation accuracy data storage step for storing the rotation accuracy data and the workpiece measurement data storage step for storing the workpiece measurement data are added to the above-described invention , these rotation accuracy data are added. It is also possible to obtain and store workpiece measurement data at different points in time, and to obtain true value data of the workpiece by subtracting the rotation accuracy data from the workpiece measurement data at any time (when necessary).
[0010]
The rotational accuracy correction method of the measuring machine related to the present invention is the above-described rotational accuracy correction method of the measuring device, in the rotational accuracy data calculation step, a cylindrical pedestal having a hemispherical master work on the upper surface, and the pedestal Alternatively, use a measurement jig with a reference sphere for setting the origin that is partly exposed in the master work, and set the measurement origin by positioning the detector of the measuring device at the apex of the reference sphere. After that, the detector is positioned at the data collection position of the master work, and the master work is measured while the master work is rotated by the rotation mechanism.
[0011]
According to this configuration, a measuring jig having a base having a hemispherical master work on the upper surface and a reference sphere for setting the origin is used. First, the detector of the measuring machine is positioned on the reference sphere for setting the origin. After setting the measurement origin, the detector was positioned at the master workpiece data collection position, and the master workpiece was measured while rotating the master workpiece by the rotation mechanism. Therefore, the masterwork can be measured with high accuracy.
The rotational accuracy correction method for a measuring machine according to claim 1 is a rotational accuracy correction method for a measuring device having a rotating mechanism, and the shape data at the data collection position is highly accurate in advance using the rotating mechanism of the measuring device. While rotating the master workpiece priced by the measuring device, measure the shape of the data collection position of the master workpiece with a detector, and subtract the priced shape data from the master workpiece measurement data to rotate the rotation mechanism The first rotation accuracy data calculation step for obtaining accuracy data, and the data of the semi-master work while rotating the semi-master work that does not require pricing of the shape data at the data collection position in advance using the rotation mechanism of the measuring machine. From the quasi-master work measurement step of measuring the shape of the sampling position with a detector and the measured value measured by this quasi-master work, the first time The true value data storage process that saves the true value data obtained by subtracting the accuracy measurement data, and the semi-master work is measured again after a certain period of time, and the new value is obtained by subtracting the true value data from this measurement data. A second rotation accuracy data calculation step for obtaining data, a second rotation accuracy data storage step for storing the second rotation accuracy data calculated in the second rotation accuracy data calculation step, and a rotation mechanism of the measuring instrument. While rotating the workpiece, measure the shape of the workpiece with the detector, calculate the workpiece measurement data to obtain the workpiece measurement data, and save the workpiece measurement data to save the workpiece measurement data obtained in this workpiece measurement data calculation step Reading the work measurement data and the second rotation accuracy data stored in each of the storage steps, and the workpiece measurement data Characterized in that it comprises a workpiece shape calculating step for obtaining the true value data of the workpiece from the data by subtracting the second rotational accuracy data.
According to a second aspect of the present invention, the measuring machine corrects the rotation mechanism by the rotational accuracy correction method of the measuring machine described in the first aspect.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment is an example applied to a rotational accuracy correction method of a roundness measuring machine.
FIG. 1 shows a roundness measuring machine 1 according to this embodiment. The roundness measuring machine 1 includes a base 2, a turntable 3 arranged to be rotatable around an axis (Z axis) perpendicular to the upper surface side (left side) of the base 2, and the base 2. A column 4 disposed parallel to the Z-axis toward the other side (right side) of the upper surface, a slider 5 provided so as to be movable up and down along the column 4 (Z-axis direction), and the column on the slider 5 An arm 6 provided so as to be able to advance and retreat in a direction perpendicular to X 4 (X-axis direction), and a detector 7 attached to the tip of this arm 6 so as to be position-adjustable in the Y-axis direction and having a probe 7A at the tip. It is composed of
[0013]
A workpiece (not shown) is placed on the rotary table 3 and a master workpiece MW is placed via a measuring jig 11.
The measurement jig 11 includes a short columnar pedestal 12 having a master work MW on the upper surface 13, and a reference sphere 15 embedded with a half exposed on the peripheral surface of the pedestal 12. The outer diameter of the base 12 and the master work MW are arranged concentrically. The master work MW is formed in a hemispherical shape, and shape data on a predetermined data collection position 14, in this case, the outer diameter of the vicinity of the maximum diameter is measured and priced by another high-precision measuring device. .
[0014]
The rotation angle data of the rotary table 3, the height position of the slider 5 (position data in the Z-axis direction), the advance / retreat amount of the arm 6 (position data in the X-axis direction), the adjustment amount of the detector 7 (in the Y-axis direction) Position data) can be detected by a detection means (not shown).
In addition, the rotary table 3 and a drive mechanism (not shown) that rotates the rotary table 3 constitute a rotary mechanism (guide) that rotates the workpiece or the master workpiece MW about the Z axis.
[0015]
FIG. 2 shows a data processing device 21 that takes in and processes measurement data from the roundness measuring machine 1. The data processing device 21 includes a control device 22, a storage device 23, and a display device 24.
The control device 22 has a function of executing each process (process) shown in FIGS. 3 to 5 in accordance with a processing program stored in advance. That is, when the roundness measuring device 1 measures the shape of the data collection position 14 of the master work MW to which the shape data at the data collection position 14 is preliminarily measured, the master work measurement data is taken in, and this master work measurement data is captured. A rotation accuracy data calculation step for obtaining rotation accuracy data of the rotation mechanism by subtracting the priced shape data from the workpiece measurement data, and a rotation accuracy data storage step for storing the rotation accuracy data obtained in this rotation accuracy data calculation step (See FIG. 3) When the workpiece is measured in the roundness measuring machine 1, the workpiece measurement data calculation step for obtaining the workpiece measurement data and the workpiece measurement data obtained in the workpiece measurement data calculation step are stored. Workpiece measurement data storage step (see FIG. 4), the stored workpiece measurement data and rotation accuracy Reads over data, a function of executing the workpiece shape calculation step (see FIG. 5) to determine the true value data of the workpiece by subtracting the rotational accuracy data from the work measurement data.
[0016]
Next, the measurement method of this embodiment will be described.
(Rotation accuracy data calculation process and rotation accuracy data storage process)
The roundness measuring device 1 is used to measure the shape of the data collection position 14 of the hemispherical master work MW to which the shape data at the predetermined data collection position 14 is priced. After calculating the rotational accuracy data of the rotating mechanism by subtracting the priced shape data, the rotational accuracy data is stored.
Specifically, as shown in FIG. 3, in step (ST) 1, first, the master work MW is measured. That is, as shown in FIG. 6A, the measuring jig 11 having the master work MW is placed on the turntable 3, and the reference sphere 15 and the turntable 3 are rotated while being aligned with 0 °. Adjustment is made so that the axis of the table 3 and the outer diameter of the base 12 are concentric. After that, the measuring element 7A of the detector 7 is brought into contact with the reference sphere 15, and the position of the detector 7 is adjusted so that the measuring element 7A catches the apex of the reference sphere 15 both vertically and front and rear, and then the height counter ( Z-axis direction position detector) is set to “0”.
Next, as shown in FIG. 6B, the probe 7A of the detector 7 is brought into contact with and positioned at the data collection position 14 of the master work MW, and in this state, the rotary table 3 is rotated to measure the roundness. Do. Then, since the measuring element 7A of the detector 7 is displaced according to the shape of the master work MW and the rotation accuracy of the rotary table 3, the displacement amount is sent to the control device 22 of the data processing device 21 together with the position data in each axial direction. The control device 22 calculates the height of the slider 5 (Z-axis direction position), the advance / retreat amount of the arm 6 (X-axis direction position), the adjustment amount of the detector 7 (Y-axis direction position), and the displacement amount of the measuring element 7A. The shape of the data collection position 14 of the master work MW is calculated, and the master work measurement data is written in the storage device 23.
[0017]
Next, in ST2, the rotational accuracy data is obtained by subtracting the preliminarily shaped shape data from the master work measurement data. At this time, the shape data of the data collection position 14 of the master work MW is measured by another high precision measuring device and stored in the storage device 23 in advance. Accordingly, the master work measurement data and the shape data priced for the master work MW are read from the storage device 23, and the rotation accuracy data is obtained by subtracting the shape data from the master work measurement data.
Next, in ST3, the obtained rotation accuracy data is stored in the storage device 23.
[0018]
(Work measurement data calculation process and work measurement data storage process)
After measuring the workpiece W using the roundness measuring device 1 and obtaining the workpiece measurement data, the workpiece measurement data is stored.
Specifically, as shown in FIG. 4, in ST11, the workpiece W is first measured. After the workpiece W is placed vertically on the rotary table 3, the measuring element 7A of the detector 7 is brought into contact with the measurement surface of the workpiece W to perform measurement (see FIG. 7). In this case, measurements such as roundness and cylindricity are performed.
Next, in ST12, workpiece measurement data is stored. That is, since the workpiece measurement data measured in ST11 is sent to the data processing device 21, the workpiece measurement data is stored in the storage device 23.
[0019]
(Work shape calculation process)
The workpiece measurement data and the rotation accuracy data stored in each storage process are read out, and the rotation accuracy accuracy data is subtracted from the workpiece measurement data to obtain the true value data of the workpiece.
Specifically, as shown in FIG. 5, workpiece measurement data is read from the storage device 23 in ST21.
Next, in ST22, rotation accuracy data is read from the storage device 23.
Next, in ST23, the rotation accuracy data is subtracted from the read workpiece measurement data to obtain workpiece true value data.
Next, in ST24, the obtained true value data of the work is stored in the storage device 23. That is, the storage device 23 stores the true value data of the workpiece in which the rotation accuracy of the rotation mechanism is corrected with respect to the workpiece measurement data, so that highly reliable measurement data can be obtained.
[0020]
According to the above-described embodiment, in the rotational accuracy data calculation step, the master work MW to which the shape data of the data collection position 14 is preliminarily measured is measured using the roundness measuring device 1, and the master work measurement is performed. By subtracting the priced shape data from the data, the rotation accuracy data of the rotation mechanism of the roundness measuring machine 1 is obtained, and separately from this, the roundness measuring machine 1 is used in the workpiece measurement data calculation process to W is measured, the workpiece measurement data is obtained, and after these steps, in the workpiece shape calculation step, the rotational accuracy data is subtracted from the workpiece measurement data to obtain the true value data of the workpiece.
[0021]
Accordingly, in the rotation accuracy data calculation step, it is not necessary to shift the master work MW with respect to the turntable 3 by a certain pitch, so that the disadvantage of the phase difference method, that is, the skill and man-hours can be solved. In addition, since it is a technique for processing workpiece measurement data, highly reliable measurement data can be obtained without any special work on the measuring machine. Further, the calculation of the rotation accuracy data and the correction processing of the rotation accuracy data with respect to the workpiece measurement data can be performed by an application independent of the measuring machine. Data processing such as processing to obtain the average value from multiple masterwork measurement data obtained by repeated measurement under the same measurement conditions) reduces variation in measurement data due to electrical noise and measurement environment, and more Highly accurate correction can be realized.
[0022]
Furthermore, since the rotation accuracy data and the workpiece measurement data are separately stored in the storage device 23, the rotation accuracy data and the workpiece measurement data are acquired and stored at different points in time, and the workpiece measurement is performed when necessary. The true value data of the workpiece can be obtained by subtracting the rotation accuracy data from the data.
[0023]
Further, since the master work MW is measured using the measurement jig 11 having the base 12 having the master work MW on the hemisphere and the reference sphere 15 for setting the origin, the master work is always determined in advance. The locus of the MW data collection position 14 can be measured. That is, the measuring element 7A of the detector 7 is brought into contact with the reference sphere 15 of the measuring jig 11, and the origin in the height direction can be set. Therefore, the detector 7 is accurately moved to the data collection position 14 based on the reference point. Thus, the measuring element 7A can be contacted and positioned at the data collection position 14 of the master work MW. Therefore, the trajectory of the data collection position 14 of the master work MW determined in advance can always be measured.
[0024]
In the above embodiment, the measurement jig 11 having the master work MW is placed on the turntable 3 and the master work MW is measured in this state. However, the measurement jig 11 is used. Instead, the master work MW may be placed directly on the rotary table 3 for measurement.
[0025]
In the above-described embodiment, either the rotation accuracy data calculation step or the workpiece measurement data calculation step may be performed first. For example, the workpiece W is measured first and workpiece measurement data is obtained and stored, then the master workpiece MW is measured to obtain rotation accuracy data, and the workpiece measurement data is corrected with the rotation accuracy data at any time. You may do it.
In addition, the correction result (workpiece true value data) obtained by correcting the rotation accuracy data with respect to the workpiece measurement data is not limited to being stored as a separate file from the workpiece measurement data. The correction result (workpiece true value data) obtained by correcting the above may be replaced and stored as work measurement data.
[0026]
In the measurement jig 11 described above, the reference sphere 15 for setting the origin is embedded in the pedestal 12. However, the present invention is not limited to this, and the same effect can be expected even if the reference sphere is embedded in the master work MW. .
Moreover, although embodiment mentioned above demonstrated the roundness measuring device, this invention is applicable not only to this but the measuring device which has a rotation mechanism generally.
[0027]
Furthermore, the present invention can be applied to the correction of the secular change of the rotation accuracy of the measuring machine as follows.
In general, a hemispherical standard (master work) that can be used as a master work is expensive, and it is difficult for general users to prepare for calibration of a measuring machine.
[0028]
Therefore, the rotation accuracy data (this is referred to as rotation accuracy data 1) is created by the master work shown in the present embodiment only for the first time, and immediately after that, generally available hemisphere reference (accuracy is arbitrarily determined and priced) Unnecessary: Semi-master work) is prepared and measured to obtain work measurement data (this is called work measurement data 1), and the rotational accuracy data 1 is subtracted from this to determine the true value of this hemisphere standard (quasi-master work). Value data is obtained and stored in the storage device 23. In other words,
(Work measurement data 1) − (Rotational accuracy data 1) = True value data is obtained and stored in the storage device 23.
Next, after elapse of a certain period (usually about one year), the hemispherical standard (quasi-master work) is measured again, and the true value data is subtracted from the work measurement data (this is called work measurement data 2), New rotation accuracy data (this is referred to as rotation accuracy data 2) is obtained. In other words,
(Work measurement data 2)-(true value data) = rotational accuracy data 2
Ask for.
The rotational accuracy data 2 thus obtained is stored in the storage device 23 and used as rotational accuracy data up to the next calibration time.
[0029]
According to such a method, master work measurement using a high-precision hemisphere reference is only required once, and then high-precision rotational accuracy data is obtained using an inexpensive hemisphere reference (quasi-master work). Since it can be obtained at any time, periodic rotation accuracy calibration of the measuring machine can be performed at low cost.
[0030]
【The invention's effect】
According to the rotational accuracy correction method of the measuring instrument of the present invention, the disadvantages of the conventional measuring method can be solved, and highly reliable measurement data can be obtained without improving existing devices.
[Brief description of the drawings]
FIG. 1 is a perspective view of a roundness measuring machine showing an embodiment of the present invention.
FIG. 2 is a block diagram showing a data processing apparatus according to the embodiment.
FIG. 3 is a flowchart showing a rotation accuracy data calculation step and a rotation accuracy data storage step in the embodiment.
FIG. 4 is a flowchart showing a workpiece measurement data calculation step and a workpiece measurement data storage step in the embodiment.
FIG. 5 is a flowchart showing a workpiece shape calculation step in the embodiment.
FIG. 6 is a diagram showing a relationship between a master work and a measuring element of a detector in a rotation accuracy data calculation step.
FIG. 7 is a diagram showing a relationship between a workpiece and a measuring element of a detector in a workpiece measurement data calculation step.
[Explanation of symbols]
1 Roundness measuring machine 3 Rotary table (rotating mechanism)
7 Detector 11 Measuring jig 12 Pedestal 13 Workpiece mounting surface 15 Reference ball MW Master work W Workpiece

Claims (2)

A rotation accuracy correction method for a measuring machine having a rotation mechanism,
Measure the shape of the data collection position of the master work with a detector while rotating the master work, the shape data at the data collection position being pre-valued with a high precision measurement device using the rotation mechanism of the measuring machine, A first rotation accuracy data calculation step of subtracting the priced shape data from the master workpiece measurement data to obtain rotation accuracy data of the rotation mechanism;
A semi-master work in which the shape of the data collection position of the semi-master work is measured by a detector while rotating the semi-master work that does not require pricing of the shape data at the data collection position in advance using the rotation mechanism of the measuring machine. Measuring process;
A true value data storing step for storing true value data obtained by subtracting the first rotational accuracy measurement data from the measured value measured by the quasi-master work;
A second rotation accuracy data calculation step of measuring the semi-master work again after a certain period of time and subtracting the true value data from the measurement data to obtain new rotation accuracy data;
A second rotation accuracy data storage step for storing the second rotation accuracy data calculated in the second rotation accuracy data calculation step;
While rotating the workpiece using the rotating mechanism of the measuring machine, measuring the shape of the workpiece with a detector, and calculating the workpiece measurement data to obtain the workpiece measurement data,
A workpiece measurement data storage step for storing workpiece measurement data obtained in the workpiece measurement data calculation step;
A workpiece shape calculation step of reading the workpiece measurement data and second rotation accuracy data stored in each of the storage steps, and subtracting the second rotation accuracy data from the workpiece measurement data to obtain true value data of the workpiece. A method for correcting the rotational accuracy of the measuring machine.   A measuring machine, wherein the rotating mechanism is corrected by the rotation accuracy correcting method of the measuring machine according to claim 1.

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