JP7092348B2 - Calibration gauge for comparative measuring machine and calibration method for comparative measuring machine - Google Patents

Description

The present invention relates to a calibration gauge for a comparative measuring machine and a calibration method for the comparative measuring machine.

Conventionally, as a method of measuring the dimensions of an object to be measured, there is a means called comparative measurement. The comparative measurement is a method in which a master (measurement standard) such as a gauge block or a ring gauge is used to determine the dimension of the object to be measured from the difference from the object to be measured by a measuring instrument such as a dial gauge. In the comparative measurement, the master placed at the reference position on the stage of the comparative measuring machine is measured, and then the object to be measured is placed on the stage to measure the object to be measured.

Japanese Unexamined Patent Publication No. 2014-052273

When arranging the object to be measured on the stage, if the object to be measured is displaced from the reference position of the stage, a measurement error will occur. Therefore, the measurement error due to the displacement of the object to be measured is determined by the comparative measuring machine. It is necessary to confirm that the accuracy is within the guaranteed range. However, a method for confirming that the measurement error due to the misalignment of the object to be measured is within the accuracy guarantee range of the comparative measuring machine has not yet been technically established.

It is an object of the present invention to provide a calibration gauge for a comparative measuring machine and a calibration method for the comparative measuring machine, which can confirm that the measurement error due to the misalignment of the object to be measured is within the accuracy guarantee range of the comparative measuring machine.

According to one aspect of the following disclosure, it is a calibration gauge for a comparative measuring machine attached to the holding portion of a table having a table main body and a holding portion movably provided on the table main body, and the gauge main body and the gauge main body. , A calibration gauge for a comparative measuring machine having a plurality of measurement marks provided on the gauge body and a calibration value of at least one of the sizes of the plurality of measurement marks and the distance between the measurement marks. Provided.

Further, according to another aspect of the disclosure, the gauge body, a plurality of measurement marks provided on the gauge body, a table for giving a predetermined displacement to the gauge body, and the plurality of measurement marks. A step of measuring the size of the plurality of measurement marks or the distance between the measurement marks using a calibration gauge having at least one calibration value of the size and the distance between the measurement marks. A step of giving a predetermined displacement to the gauge body, a step of measuring the size of the plurality of measurement marks or the distance between the measurement marks after the predetermined displacement is applied, and the above. Provided is a calibration method of a comparative measuring machine including a step of comparing the size of the plurality of measuring marks before and after giving a predetermined displacement or the difference in distance between the measuring marks with the calibration value.

According to the following disclosure, the calibration gauge for a comparative measuring machine is a gauge body, a plurality of measurement marks provided on the gauge body, the size of the plurality of measurement marks, and the distance between the measurement marks. It has at least one calibration value. Further, the calibration gauge for a comparative measuring machine is attached to a holding portion of a table having a table main body and a holding portion movably provided on the table main body.

In the calibration method using this calibration gauge for a comparative measuring machine, first, the size of a plurality of measurement marks or the distance between the measurement marks is measured. Next, a predetermined displacement is applied to the gauge body, and the size of the plurality of measurement marks or the distance between the measurement marks after the predetermined displacement is applied is measured. Further, the size of the plurality of measurement marks before and after giving a predetermined displacement or the difference in the distance between the measurement marks is compared with the calibration value.

This makes it possible to confirm that the measurement error due to the misalignment of the object to be measured is within the accuracy guarantee range of the comparative measuring machine.

It is a perspective view which shows the calibration gauge for the comparative measuring machine of 1st Embodiment. It is a top view which shows the calibration gauge for the comparative measuring machine of 1st Embodiment. FIG. 3 is a plan view showing a state in which the calibration gauge for the comparative measuring machine of FIG. 2 is rotated by 180 °. It is a graph which shows the data which measured the calibration gauge for a comparative measuring machine of FIG. 2 with a three-dimensional measuring machine. It is a top view which shows the measurement point of the 0 ° −180 ° line of the calibration gauge for a comparative measuring machine of FIG. FIG. 5 is a plan view showing a measurement point of the 0 ° −180 ° line after rotating the calibration gauge for the comparative measuring machine of FIG. 5 by 180 °. It is a graph which shows the data of the measurement error of the comparative measurement obtained by using the calibration gauge for the comparative measuring machine of FIG. FIG. 3 is a perspective view showing a state in which the calibration gauge for the comparative measuring machine of FIG. 2 is tilted and installed on a support base. It is a top view which shows the calibration gauge for the comparative measuring machine of the other aspect of 1st Embodiment. 9 is a plan view showing a state in which the calibration gauge for a comparative measuring machine of FIG. 9 is rotated by 180 °. It is a perspective view which shows the calibration gauge for the comparative measuring machine of 2nd Embodiment. 11 is a plan view of the calibration gauge for the comparative measuring machine of FIG. 11 as viewed from above. FIG. 12 is a plan view showing a state in which the calibration gauge for the comparative measuring machine of FIG. 12 is rotated by 180 °. FIG. 11 is a perspective view showing a state in which the calibration gauge for the comparative measuring machine of FIG. 11 is installed on a table. FIG. 14 is a perspective view showing a state in which a table on which a calibration gauge for a comparative measuring machine of FIG. 14 is installed is installed on an inclined table. 16A is a plan view showing the calibration gauge for the comparative measuring machine of FIG. 14 arranged on the 0 ° -180 ° line, and FIG. 16B is a plan showing the calibration gauge for the comparative measuring machine rotated by 180 ° in FIG. 16A. It is a figure. FIG. 17A is a plan view showing the calibration gauge for the comparative measuring machine of FIG. 14 arranged on the 45 ° -225 ° line, and FIG. 17B is a plan showing the calibration gauge for the comparative measuring machine of FIG. 17A rotated by 180 °. It is a figure. FIG. 18A is a plan view showing the calibration gauge for the comparative measuring machine of FIG. 14 arranged on the 90 ° -270 ° line, and FIG. 18B is a plan showing the calibration gauge for the comparative measuring machine of FIG. 18A rotated by 180 °. It is a figure. FIG. 19A is a plan view showing the calibration gauge for the comparative measuring machine of FIG. 14 arranged on the 135 ° -315 ° line, and FIG. 19B is a plan showing the calibration gauge for the comparative measuring machine of FIG. 19A rotated by 180 °. It is a figure. It is a graph which shows the data of the deviation amount of the comparative measurement obtained by using the calibration gauge for the comparative measuring machine of FIG. 12 (the 1). It is a graph which shows the data of the deviation amount of the comparative measurement obtained by using the calibration gauge for the comparative measuring machine of FIG. 12 (the 2).

Hereinafter, embodiments will be described with reference to the accompanying drawings.
1. 1. First Embodiment (overall configuration)
1 to 8 are diagrams for explaining a calibration gauge for a comparative measuring machine according to the first embodiment. As shown in the perspective view of FIG. 1, the calibration gauge for a comparative measuring machine according to the first embodiment includes a gauge body 10. The gauge body 10 is a flat plate-shaped substrate, and is preferably formed of a metal containing aluminum as a main component, ceramics, or the like. The thickness of the gauge body 10 is, for example, 10 mm to 20 mm.

A plurality of spheres with shafts 5 are erected side by side on the surface of the gauge body 10. As shown in the partially enlarged view of FIG. 1, the shafted sphere 5 is formed of a sphere 12 and a columnar shaft portion 14 connected to the lower end of the sphere 12. The shaft portion 14 is formed of a small diameter portion 14a connected to the lower end of the sphere 12 and a large diameter portion 14b connected to the lower end of the small diameter portion 14a.

The large diameter portion 14b of the shaft portion 14 of the sphere 5 with a shaft is screwed into a screw hole provided on the surface of the gauge body 10. The diameter of the sphere 12 is set to be larger than the diameter of the large diameter portion 14b of the shaft portion 14. In this way, the sphere 12 is supported by the vertically extending shaft portion 14 and is arranged at a position upward away from the surface of the gauge body 10.

In the first embodiment, the sphere 12 of the plurality of shafted spheres 5 is an example of a plurality of measurement marks. As described above, the plurality of measurement marks are spheres 12 arranged radially on the gauge body 10 so as to project from the surface of the gauge body 10.

FIG. 2 is a plan view of the calibration gauge 1 for the comparative measuring machine of FIG. 1 as viewed from above. The gauge body 10 has an octagonal shape in a plan view. As the shape of the gauge body 10 in a plan view, various shapes such as a round shape or a square shape can be adopted according to the stage (not shown) of the comparative measuring machine. For example, the size of the gauge body 10 is set to a size of 2/3 or more of the measurable range in the stage of the comparative measuring machine. The gauge body 10 is provided with a mounting hole 10a. The mounting hole 10a is formed so as to penetrate from the upper surface to the lower surface of the gauge body 10.

The sphere 12 of the shafted sphere 5 erected from the gauge body 10 includes a white sphere 12a shown in white and a black sphere 12b shown in black. The diameters of the white sphere 12a and the black sphere 12b are different. For example, the diameter of the white sphere 12a can be 6 mm and the diameter of the black sphere 12b can be 4 mm.

The gauge body 10 is partitioned by a 0 ° -180 ° line that passes horizontally through the center position. Further, the gauge body 10 is divided into a 45 ° -225 ° line inclined at 45 ° from the 0 ° -180 ° line. Further, the gauge body 10 is divided into a 90 ° -270 ° line inclined at 90 ° from the 0 ° -180 ° line. Further, the gauge body 10 is divided into a 135 ° -315 ° line inclined at 135 ° from the 0 ° -180 ° line.

The white sphere P (12a) is arranged at the center position of the gauge body 10 which is the intersection of the 0 ° -180 ° line and the 90 ° -270 ° line. Then, four white spheres 12a are arranged side by side at intervals from the center position of the 0 ° -180 ° line to the right. Further, three black spheres 12b are arranged side by side with an interval in the left direction away from the center position of the 0 ° -180 ° line.

Further, four white spheres 12a are arranged side by side at an interval in the diagonally upper right direction from the center position of the 45 ° -225 ° line. Further, three black spheres 12b are arranged side by side at an interval in the diagonally lower left direction away from the center position of the 45 ° -225 ° line.

Further, four white spheres 12a are arranged side by side with an interval in the upward direction from the center position of the 90 ° -270 ° line. Further, three black spheres 12b are arranged side by side at intervals in the downward direction away from the center position of the 90 ° -270 ° line.

Further, four white spheres 12a are arranged side by side at an interval in the diagonally upper left direction from the center position of the 135 ° -315 ° line. Further, three black spheres 12b are arranged side by side at an interval in the diagonally lower right direction away from the center position of the 135 ° -315 ° line.

In this way, each of the 0 ° -180 ° line, 45 ° -225 ° line, 90 ° -270 ° line, and 135 ° -315 ° line partitioned by the gauge body 10 is white in one direction from the center position. The spheres 12a are arranged side by side, and the black spheres 12b are arranged side by side in the other direction away from the center position. In the following description, the above-mentioned 0 ° -180 ° line, 45 ° -225 ° line, 90 ° -270 ° line and 135 ° -315 ° line are also referred to as measurement lines.

The calibration gauge 1 for the comparative measuring machine has a white sphere 12a having a diameter of 6 mm and a black sphere 12b having a diameter of 4 mm, and the black sphere 12b has a diameter 2 mm smaller than that of the white sphere 12a. The black sphere 12b as the second mark and the white sphere 12a as the third mark are arranged substantially symmetrically with respect to the white sphere P (12a) as the first mark arranged at the center position of the gauge body 10. Symmetry means line symmetry, and more specifically, it means line symmetry with a perpendicular line passing through the center of the first mark as the axis of symmetry with respect to a straight line passing through the second mark and the third mark.

The white sphere 12a and the black sphere 12b at symmetrical positions are set to have the same center-to-center distance from the white sphere P (12a). The term "same" as used herein is not limited to the case of an exact match, but also includes the case of a slight difference. For example, paying attention to the 0 ° -180 ° line, the distance DX between the center of the white sphere P (12a) arranged at the center position of the gauge body 10 and the center of the adjacent black sphere 12b is the center position of the gauge body 10. The distance between the center of the white sphere P (12a) arranged in and the center of the adjacent white sphere 12a is set to be the same as the distance DY.

Here, as shown in FIG. 3, when the calibration gauge 1 for the comparative measuring machine of FIG. 2 is rotated by 180 °, the left and right sides of the 0 ° -180 ° line are reversed. As a result, the black spheres 12b are arranged side by side on the right side of the 0 ° -180 ° line, and the white spheres 12a are arranged side by side on the left side of the 0 ° -180 ° line.

By rotating the calibration gauge 1 for the comparative measuring machine by 180 ° in this way, the arrangements of the white spheres 12a and the black spheres 12b having different diameters are exchanged with each other, and a pseudo misalignment occurs. That is, by rotating the calibration gauge 1 for the comparative measuring machine by 180 °, it is possible to simulate a state in which the object to be measured is displaced from the reference position of the stage of the comparative measuring machine.

In the present embodiment, by rotating the calibration gauge 1 for the comparative measuring machine by 180 °, the black sphere 12b having a diameter of 4 mm is arranged at the position of the white sphere 12a having a diameter of 6 mm, and the position of the black sphere 12b having a diameter of 4 mm. A white sphere 12a having a diameter of 6 mm is arranged therein. Therefore, it is possible to simulate a state in which the object to be measured is displaced by 1 mm from the reference position of the stage of the comparative measuring machine. In the first embodiment, the step of giving a predetermined displacement to the gauge body 10 is to rotate the gauge body 10 by 180 ° as shown in FIGS. 2 and 3.

The effectiveness of the calibration gauge 1 for the comparative measuring machine of this embodiment was confirmed by using a highly accurate three-dimensional measuring machine. Specifically, the distance between the center position (0) of the gauge body 10 and the center of the sphere at each measurement position was measured by a coordinate measuring machine, and the measured values before and after 180 ° rotation were compared. The results are shown in FIG. The vertical axis of FIG. 4 shows the difference before and after rotation, and the horizontal axis shows the measurement position.

The 0 position on the horizontal axis of FIG. 4 corresponds to the white sphere P (12a) (origin) arranged at the center position of the 0 ° -180 ° line of the calibration gauge 1 for the comparative measuring machine of FIG. Further, the positions of 30, 85 and 140 correspond to the positions of the three white spheres 12a on the right side from the origin of FIG. 2, and the positions of -30, -85 and -140 correspond to the positions of the three black spheres on the left side of the origin of FIG. Corresponds to the position of 12b.

The difference before and after rotation is the distance from the center position (0) in the X direction (0 ° -180 ° line) of the calibration gauge 1 for the comparative measuring machine in Fig. 2 before rotation to each measurement position, and after 180 ° rotation. It is a difference from the distance from the center position (0) of the 0 ° -180 ° line of FIG. 3 to each measurement position. The same measurement was performed for the Y direction (90 ° -270 ° line) of the calibration gauge 1 for the comparative measuring machine, and the difference before and after rotation was calculated.

As shown in FIG. 4, at each measurement position of the calibration gauge 1 for the comparative measuring machine, the difference between the measured values of the distance before and after rotating the gauge body 10 by 180 ° is within about 0.6 μm, and the accuracy is 2 μm ±. It was 0.25 μm, and it was confirmed that the calibration gauge 1 for the comparative measuring machine could be used. The accuracy is a value calculated by a calibrated coordinate measuring machine, and considering that the measurement accuracy of the comparative measuring machine is ± 2 μm, it is necessary that the calibration gauge 1 for the comparative measuring machine is manufactured with high accuracy. Do you get it.

(How to check the measurement error)
Next, a method of confirming that the measurement error due to the positional deviation of the object to be measured is within the accuracy guarantee range of the comparative measuring machine in the comparative measurement using the calibration gauge 1 for the comparative measuring machine of the present embodiment will be described. ..

The calibration gauge 1 for the comparative measuring machine of the present embodiment is preliminarily attached with a measured value of the diameter of the white sphere 12a as a calibration value at each position where the white sphere 12a is arranged. Further, at each position where the black sphere 12b is arranged, a measured value of the diameter of the black sphere 12b is attached in advance as a calibration value.

First, the calibration gauge 1 for the comparative measuring machine of FIG. 2 is placed at the reference position of the stage (not shown) of the comparative measuring machine, and the coordinates (X, Y, Z) of all the white spheres 12a and the black sphere 12b are arranged by the comparative measuring machine. ) Is detected, and the diameters of the white sphere 12a and the black sphere 12b and the distance between the centers of the white sphere 12a and the black sphere 12b at symmetrical positions are measured from the coordinates.

Next, the calibration gauge 1 for the comparative measuring machine of FIG. 2 is rotated by 180 ° on the stage of the comparative measuring machine to bring it into the state of the calibration gauge 1 for the comparative measuring machine of FIG. 3 described above. The comparative measuring machine detects the coordinates (X, Y, Z) of all the white spheres 12a and the black spheres 12b of the calibration gauge 1 for the comparative measuring machine after rotation, and is symmetrical with the diameters of the white spheres 12a and the black spheres 12b. The distance between the centers of the white sphere 12a and the black sphere 12b in the above is measured.

FIG. 5 shows only the white spheres 12a and the black spheres 12b arranged on the 0 ° -180 ° line in the calibration gauge 1 for the comparative measuring machine of FIG. 2 for the sake of simplicity. As shown in FIG. 5, the measurement at the positions A1 and B1 of the distance DA between two points on the 0 ° -180 ° line will be described as an example. First, the coordinates of the white sphere 12a at the position A1 and the black sphere 12b at the position B1 at the distance DA between the two points of the calibration gauge 1 for the comparative measuring machine before rotation are detected. The design value of the distance DA between two points is 60 mm.

Next, the calibration gauge 1 for the comparative measuring machine of FIG. 2 is rotated by 180 ° on the stage of the comparative measuring machine to bring it into the state of the calibration gauge 1 for the comparative measuring machine of FIG. 3 described above. As a result, the arrangements of the white spheres 12a and the black spheres 12b having different diameters are exchanged, and a pseudo misalignment occurs.

FIG. 6 shows a state in which the calibration gauge 1 for the comparative measuring machine of FIG. 5 is rotated by 180 °. Focusing on the positions A1 and B1 of the distance DA between the two points in FIG. 6, the black sphere 12b is arranged at the position A1 and the white sphere 12a is arranged at the position B1. That is, the white spheres 12a and the black spheres 12b are interchanged and arranged. The coordinates of the black sphere 12b at the position A1 and the white sphere 12a at the position B1 at the distance DA between two points of the calibration gauge 1 for the comparative measuring machine are detected.

Next, from each of the obtained coordinates, the diameters of the white sphere 12a and the black sphere 12b and the distance between the centers before and after the rotation are measured. By comparing the diameters of the white sphere 12a and the black sphere 12b before and after rotation with the calibration values, it can be confirmed that the measurement error due to the positional deviation of the object to be measured is within the accuracy guarantee range. Further, by calculating the difference in the distance between the centers before and after the rotation, it can be confirmed that the measurement error due to the positional deviation in the distance DA of the 0 ° -180 ° line is within the accuracy guarantee range.

Comparative measurement is performed by the same measurement procedure at the two positions A2 and B2 having the two-point distance DB on the 0 ° -180 ° line in FIG. 5 and the two positions A3 and B3 having the two-point distance DC. Therefore, it is possible to obtain the measurement error due to the positional deviation of the object to be measured at each position and the positional deviation in the distance DB and DC. The design value of the distance DB between two points is 170 mm. The design value of the distance DC between two points is 280 mm.

Further, for each of the 45 ° -225 ° line, 90 ° -270 ° line, and 135 ° -315 ° line of the calibration gauge 1 for the comparative measuring machine described with reference to FIG. 2, the same measurement procedure is used before and after rotation. Comparative measurement Calculate the difference between the difference value and the calibration value. As a result, it is possible to obtain a measurement error due to a positional deviation in all directions of the measurable range of the stage of the comparative measuring machine.

From the above, the displacement of one axis of the X-axis of the 0 ° -180 ° line and the Y-axis of the 90 ° -270 ° line, the 45 ° -225 ° line and the 35 ° -315 ° line with respect to the stage of the comparative measuring machine. It is possible to obtain the measurement error when the displacement of the two axes of XY axes is given.

When the calibration gauge 1 for the comparative measuring machine is rotated by 180 °, the calibration gauge 1 for the comparative measuring machine of FIG. 2 may be directly arranged and rotated on the stage of the comparative measuring machine. Alternatively, as described in the second embodiment described later, a table (not shown) having a table main body and a holding portion movably provided on the table main body may be arranged on the stage of the comparative measuring machine. .. The calibration gauge 1 for the comparative measuring machine may be arranged in the holding portion of the table, and the calibration gauge 1 for the comparative measuring machine may be rotated by the rotation of the holding portion.

In the example of the first embodiment, the comparative measuring machine guarantees the accuracy so that the measurement error becomes ± 0.002 mm (2 μm) or less when the object to be measured is displaced by 1 mm from the reference position of the stage. (The accuracy guarantee range in FIG. 7).

The calibration gauge for the comparative measuring machine shown in FIG. 1 was actually manufactured, and it was verified that the accuracy error of the comparative measuring machine could be confirmed. The coordinates of the white sphere and the black sphere of the calibration gauge for the comparative measuring machine were detected, and the distance between the centers before and after the rotation of 180 ° was compared. The results are shown in FIG. The vertical axis of FIG. 7 indicates the difference in distance between the centers before and after rotation (mm), and the horizontal axis indicates the measurement point. As shown in FIG. 7, at the three measurement points of the calibration gauge 1 for the comparative measuring machine of FIG. 2, the 0 ° -180 ° line, the 45 ° -225 ° line, and the 135 ° -315 ° line, before and after rotation. The difference is within the accuracy guarantee range (± 0.002 mm) of the comparative measuring machine, and it can be seen that the accuracy is within the accuracy guarantee at these three measurement points.

On the other hand, in the distance DC (design value: 280 mm) between two points on the 90 ° -270 ° line of the calibration gauge 1 for the comparative measuring machine in FIG. 2, the difference before and after rotation is about 0.0025 mm (2.5 μm). , It is out of the accuracy guarantee range (± 0.002 mm) of the comparative measuring machine. Therefore, since this measurement point is not guaranteed for accuracy, it is necessary to calibrate the comparative measuring machine.

FIG. 8 shows how the calibration gauge 1 for the comparative measuring machine of FIG. 1 is attached to the support base 16. The upper surface of the support base 16 is an inclined surface, and the flat plate-shaped calibration gauge 1 for a comparative measuring machine of FIG. 1 is arranged on this inclined surface. As a result, the calibration gauge 1 for the comparative measuring machine is tilted at the same tilt angle as the tilted surface of the support base 16.

By comparing and measuring the displacement gauge 1 for the comparative measuring machine by the measurement procedure of rotating 180 ° with the calibration gauge 1 for the comparative measuring machine tilted, the X-axis, the Y-axis, and the stage of the comparative measuring machine are measured. It is possible to confirm the measurement error when the displacement of the three axes including the Z axis is given. The support base 16 may be attached to the above-mentioned table (not shown). That is, the calibration gauge 1 for the comparative measuring machine is fixed to the table via the support base 16. As a result, the calibration gauge 1 for the comparative measuring machine can be rotated by the rotation of the holding portion of the table in a state where the calibration gauge 1 for the comparative measuring machine is tilted.

As described above, the calibration gauge 1 for the comparative measuring machine of the first embodiment has the white sphere P (12a) (an example of the first mark) arranged at the center position of the gauge body 10 and the white sphere P (12a). It has a black sphere 12b (an example of a second mark) arranged substantially symmetrically with respect to the black sphere 12b and a white sphere 12a (an example of a third mark) having a size different from that of the black sphere 12b.

By rotating the calibration gauge 1 for the comparative measuring machine by 180 °, the arrangement of the white sphere 12a and the black sphere 12b is exchanged, and a pseudo misalignment occurs. Therefore, by comparing the distance between the centers of the white sphere 12a and the black sphere 12b before and after rotation, it is possible to confirm the measurement error due to the positional deviation between the axes connecting the white sphere 12a and the black sphere 12b. Further, since the calibration gauge 1 for the comparative measuring machine is provided with the calibration values of the diameters of the white sphere 12a and the black sphere 12b, the measurement error due to the misalignment at the measurement point can be obtained by comparing the measured value with the calibration value. Can be confirmed.

The gauge body 10 used in the calibration gauge 1 for a comparative measuring machine according to the first embodiment is a flat plate-shaped substrate extending evenly in the X direction and the Y direction. Therefore, by installing the calibration gauge 1 for the comparative measuring machine so as to correspond to the measurable range of the stage of the comparative measuring machine and rotating it by 180 °, many measurement points can be measured. It can be done in a short time.

Further, since the gauge body 10 used in the calibration gauge 1 for the comparative measuring machine of the first embodiment can be formed from an inexpensive metal containing aluminum as a main component, it can be manufactured at low cost. The gauge body 10 may be formed of ultra-low thermal expansion ceramics. Alternatively, the gauge body 10 can be formed of a metal or resin such as iron used in the comparative measuring machine. By forming the comparative measuring machine and the gauge body 10 from the same material, the amount of deformation when the temperature changes becomes the same.

In addition, in FIG. 2 and FIG. Is occurring. In addition to this method, a table (not shown) provided with a holding portion that can move in the X and Y directions may be provided on the stage of the comparative measuring instrument.

In this case, the first comparative measurement is performed on the calibration gauge 1 for the comparative measuring machine of FIG. 2 arranged on the table on the stage of the comparative measuring machine. Next, without rotating the calibration gauge 1 for the comparative measuring machine, the calibration gauge 1 for the comparative measuring machine is moved in the X direction and the Y direction so as to have a predetermined misalignment amount by moving the holding portion of the table. Is generated, and then a second comparative measurement is performed. The same effect as that of the above-described embodiment can be obtained by obtaining the first measurement result and the second measurement result measured in a state where the position shift is caused with respect to the first measurement.

(Other aspects of the first embodiment)
9 and 10 are plan views showing a calibration gauge for a comparative measuring machine according to another aspect of the first embodiment. In FIGS. 1 to 3 described above, the white sphere 12a and the black sphere 12b of the shafted sphere 5 formed on the gauge body 10 are used as the measurement marks. As shown in FIG. 9, in the calibration gauge 1a for a comparative measuring machine according to another aspect of the first embodiment, a plurality of convex portions 17 are provided upright from the surface of the gauge body 10 instead of a sphere. .. As the convex portion 17, a cylindrical body, a rectangular parallelepiped, or the like is used.

Similar to FIG. 5 described above, FIG. 9 shows only a plurality of convex portions 17 on the 0 ° −180 ° line for the sake of simplicity. As shown in FIG. 9, in the calibration gauge 1a for a comparative measuring machine of another aspect, the diameters (magnitudes) of the plurality of convex portions 17 in a plan view are set to be the same. Further, the second convex portion 17b (an example of the second mark) and the third convex portion are substantially symmetrical with respect to the first convex portion 17a (an example of the first mark) arranged at the center position of the gauge body 10. A portion 17c (an example of a third mark) is arranged.

The distance DE between the center of the first convex portion 17a and the center of the second convex portion 17b and the distance DF between the center of the first convex portion 17a and the center of the third convex portion 17c are different. For example, the distance DE is set to be about 1 mm longer than the distance DF. Therefore, as shown in FIG. 10, when the calibration gauge 1a for the comparative measuring machine of FIG. 9 is rotated by 180 °, the second convex portion 17b shown in black and the third convex portion 17c shown in white are formed. The arrangements are exchanged, and a pseudo misalignment occurs. In the calibration gauge 1a for the comparative measuring machine, each distance from the center is preliminarily attached as a calibration value at each position where the first convex portion 17a and the second convex portion 17b are arranged.

In the case of using the calibration gauge 1a for the comparative measuring machine in another aspect, first, the measurement procedure is as follows: first, the center of the second convex portion 17b and the third convex portion 17c of the calibration gauge 1a for the comparative measuring machine before rotation in FIG. The first distance DG1 from the center of is calculated. Further, as shown in FIG. 10, after rotating the calibration gauge 1a for the comparative measuring machine by 180 °, the second distance DG2 between the center of the third convex portion 17c and the center of the second convex portion 17b is calculated. Further, the difference between the measured value of the first distance DG1 and the measured value of the second distance DG2 is calculated, and the comparative measurement difference value of the distance is acquired.

Then, by calculating the difference between the comparative measurement difference value and the calibration value, the measurement error of the comparative measuring machine can be obtained in the same manner. The calibration value attached to the calibration gauge for the comparative measuring machine in other aspects is the first distance DG1 before and after the rotation measured by the three-dimensional measuring machine at the above-mentioned measurement position on the 0 ° -180 ° line (FIG. 9). This is the difference between the second distance DG2 (FIG. 10) and the second distance DG2 (FIG. 10).

Similarly, the measurement is performed by the same measurement procedure at each position having the distance between the other two points (FIG. 5) on the 0 ° -180 ° line. Further, the measurement is performed on the other measurement lines by the same measurement procedure, and the measurement error at each position is obtained.

As described above, the calibration method of the comparative measuring machine in the other aspect includes a step of measuring the distance of a plurality of measurement marks, a step of giving a predetermined displacement to the gauge body 10, and a plurality of measurements after the displacement is given. It has a step of measuring the distance of the mark for measurement and a step of comparing the difference between the distances of the plurality of measurement marks before and after giving the displacement and the calibration value.

The calibration gauge 1 for a comparative measuring machine and the calibration method of the first embodiment can be applied to a contact type or non-contact type comparative measuring machine, a machine tool using the comparative measurement, and the like.

2. 2. Second embodiment (overall configuration)
11 to 19 are diagrams for explaining the calibration gauge for the comparative measuring machine of the second embodiment. As shown in the perspective view of FIG. 11, the calibration gauge 2 for the comparative measuring machine of the second embodiment includes a strip-shaped gauge body 20 extending in one direction. The gauge body 20 is a rectangular shape in a rectangular shape in a plan view, and the cross section in the width direction orthogonal to the longitudinal direction is a quadrangle.

The gauge body 20 used in the calibration gauge 2 for the comparative measuring machine of the second embodiment is formed of a material having a small coefficient of thermal expansion. As a suitable example, Nexera (ultra-low thermal expansion ceramics) having a thermal expansion coefficient of almost zero at around room temperature (about 20 ° C to 30 ° C) is used. Therefore, even if the temperature of the measurement atmosphere changes at about 2 ° C to 3 ° C near room temperature, the dimensional change of the gauge body 20 is small, so that the measurement error can be reduced. If the measurement error due to the temperature change in the measurement atmosphere is not a problem, the gauge body 20 may be formed of a metal such as aluminum or general ceramics such as alumina.

Further, seven first to seventh opening holes (H1 to H7) are arranged at intervals in the gauge body 20. The first to seventh opening holes (H1 to H7) are formed so as to penetrate from the upper surface to the lower surface of the gauge body 20. In the second embodiment, the seven first to seventh opening holes (H1 to H7) provided in the gauge body 20 are examples of measurement marks. As described above, the plurality of measurement marks are holes arranged in a row on the gauge body 20 and penetrating in the thickness direction of the gauge body 20.

The fourth opening hole H4 is arranged at the center position of the gauge body 20, and the third opening hole H3, the second opening hole H2, and the first opening hole H1 are arranged at intervals on the right side of the fourth opening hole H4. .. Further, the fifth opening hole H5, the sixth opening hole H6, and the seventh opening hole H7 are arranged at intervals on the left side of the fourth opening hole H4 arranged at the center position of the gauge body 20.

FIG. 12 is a plan view of the calibration gauge 2 for the comparative measuring machine of FIG. 11 as viewed from above. As shown in FIG. 12, in the calibration gauge 2 for the comparative measuring machine of the second embodiment, the diameters HD of the first to seventh opening holes (H1 to H7) are set to be the same. Further, the distance D1 between the center of the fourth opening hole H4 and the center of the third opening hole H3 and the distance D2 between the center of the fourth opening hole H4 and the center of the fifth opening hole H5 are arranged differently from each other. ing.

In the example of FIG. 12, the design value of the distance D1 between the fourth opening hole H4 and the third opening hole H3 is 35 ± 0.01 μm, and the design of the distance D2 between the fourth opening hole H4 and the fifth opening hole H5. The values are 36 ± 0.01 μm, and the distances differ by about 1 mm.

The distance D3 between the fourth opening hole H4 and the second opening hole H2 is 70 ± 0.01 μm, and the distance D4 between the fourth opening hole H4 and the sixth opening hole H6 is 71 ± 0.01 μm. Is different by about 1 mm.

The distance between the center of the first opening hole H1 and the center of the second opening hole H2, and the distance between the center of the sixth opening hole H6 and the center of the seventh opening hole H7 are the third opening hole H3 and the fourth opening hole. It is set to 40 mm, which is 5 mm longer than the distance D1 (35 ± 0.01 mm) from H4. Therefore, the distance D5 between the fourth opening hole H4 and the first opening hole H1 is 110 ± 0.01 μm, and the distance D6 between the fourth opening hole H4 and the seventh opening hole H7 is 111 ± 0.01 μm. The distance is different by about 1 mm.

The calibration gauge 2 for the comparative measuring machine of the second embodiment is sequentially measured at a position rotated by 45 ° within the measurable range of the comparative measuring machine as described later. Therefore, the length of the gauge body 20 is adjusted according to the size of the measurable range of the stage of the comparative measuring machine. For example, the length in the stage of the comparative measuring machine may be set to 2/3 or more of the measurable range, specifically, the length of the gauge body 20 may be set to about 270 mm and the width may be set to about 40 mm.

Further, in the first to seventh opening holes (H1 to H7), ring-shaped inclined surfaces are provided on the front surface and the back surface of the gauge body 20 so as to extend outward from the inner wall of the hole, and the internal diameter HD is 20. The diameters on the front and back surfaces are set to ± 0.01 mm and 28 ± 0.01 mm.

As described above, the first to third opening holes (H1 to H3) on the right side of the fourth opening hole H4 and the fifth to seventh opening holes (H5 to H7) on the left side of the fourth opening hole H4 are the first. 4 The distances from the center of the opening holes H4 are different by about 1 mm.

As described above, the calibration gauge 2 for the comparative measuring machine of the second embodiment includes the gauge body 20. The fourth opening hole H4 arranged at the center of the gauge body 20 is an example of the first mark.

This is an example of the second mark and the third mark in which the third opening hole H3 and the fifth opening hole H5 arranged substantially symmetrically with respect to the fourth opening hole H4 are arranged substantially symmetrically with respect to the first mark. Alternatively, the second mark and the third mark arranged substantially symmetrically with respect to the first mark may be the second opening hole H2 and the sixth opening hole H6, or the first opening hole H1 and the first. 7 It may be an opening hole H7.

Here, as shown in FIG. 13, when the calibration gauge 2 for the comparative measuring machine of FIG. 12 is rotated by 180 °, the first to third opening holes (H1 to H3) are arranged on the left side of the fourth opening hole H4. , The fifth to seventh opening holes (H5 to H7) are arranged on the right side of the fourth opening hole H4.

In this way, by rotating the calibration gauge 2 for the comparative measuring machine of FIG. 12 by 180 °, the distances from the fourth opening holes H4 are different from each other, the first to third opening holes (H1 to H3) and the fifth to fifth. The arrangement with the seventh opening hole (H5 to H7) is exchanged, and a pseudo misalignment occurs. That is, by rotating the calibration gauge 2 for the comparative measuring machine by 180 °, it is possible to simulate a state in which the object to be measured is displaced from the reference position of the stage of the comparative measuring machine.

FIG. 14 shows how the calibration gauge 2 for the comparative measuring machine of FIG. 12 is installed on the table 30. The table 30 has a table main body 32 and a holding portion 34 movably provided on the table main body 32. Further, a pair of opposing holding portions 36 are connected on the holding portion 34, and the calibration gauge 2 for a comparative measuring machine is pressed and fixed to one of the pair of holding portions 36.

The holding portion 34 is rotatable about the fourth opening hole H4 (an example of the first mark) of the calibration gauge 2 for a comparative measuring machine with respect to the table main body 32. By rotating the rotary knob 38 connected to the holding portion 34, the calibration gauge 2 for the comparative measuring machine can be rotated by the rotation of the holding portion 34.

FIG. 15 shows a state in which the table 30 to which the calibration gauge 2 for the comparative measuring machine of FIG. 14 is fixed is installed on the support base 40. The support base 40 includes a horizontal plate 42 arranged in the horizontal direction and an inclined plate 44 inclined at a predetermined inclination angle from the horizontal plate 42, and the inclined plate 44 is connected to the horizontal plate 42 by a support pillar 46. .. The support base 40 supports the table 30 so as to be inclined in the thickness direction of the gauge body 20.

By installing the table 30 to which the calibration gauge 2 for the comparative measuring machine is fixed on the inclined plate 44 of the support base 40, the calibration gauge 2 for the comparative measuring machine can be tilted at the same inclination angle as the inclined plate 44 of the support base 40. can. This makes it possible to confirm the measurement error when the displacement of the three axes including the X-axis, the Y-axis, and the Z-axis is applied to the stage of the comparative measuring machine.

(How to check the measurement error)
Next, a method of confirming that the measurement error due to the positional deviation of the object to be measured is within the accuracy guarantee range of the comparative measuring machine in the comparative measurement using the calibration gauge 2 for the comparative measuring machine of the second embodiment will be described. do. The calibration gauge 2 for the comparative measuring machine is a master of the diameter of the first to seventh opening holes (H1 to H7), the distance from the center position (D1 to D6), and the distance measured in advance by the high-precision coordinate measuring machine. The difference value is attached as a calibration value.

First, the table 30 to which the calibration gauge 2 for the comparative measuring machine of FIG. 16A is fixed is arranged so as to face the X direction (0 ° -180 ° line) on the stage (not shown) of the comparative measuring machine, and the comparative measuring machine is used. The coordinates of the first to seventh opening holes (H1 to H7) are detected, and the diameter and the six distances (D1 to D6) of the calibration gauge 2 for the comparative measuring instrument before rotation in FIG. 12 described above are calculated.

Further, as shown in FIG. 16B, the calibration gauge 2 for the comparative measuring machine is rotated by 180 ° by rotating the holding portion 34 of the table 30 on the stage of the comparative measuring machine. Also in the second embodiment, the step of giving a predetermined displacement to the gauge body 20 is to rotate the gauge body by 180 °. As a result, as described with reference to FIGS. 12 and 13 described above, the first to third opening holes (H1 to H3) and the fifth to seventh openings having different distances from the fourth opening hole H4 at the center position are provided. The arrangement with the holes (H5 to H7) is exchanged, and a pseudo misalignment occurs. The coordinates of the first to seventh opening holes (H1 to H7) after 180 ° rotation of FIG. 16B are detected, and the diameter and the six distances (D1) of the calibration gauge 2 for the comparative measuring machine after rotation of FIG. 13 described above are described. ~ D6) is calculated.

Further, the first comparative measurement difference value at each position (-111 mm, -71 mm, -36 mm, 35 mm, 70 mm, 110 mm) of the 0 ° -180 ° line of the calibration gauge 2 for the comparative measuring machine is acquired. That is, the difference between the distance D6 of the calibration gauge 2 for the comparative measuring machine before rotation in FIG. 12 and the distance D5 of the calibration gauge 2 for the comparative measuring machine after rotation in FIG. 13 is calculated. This difference value becomes the first comparative measurement difference value at the position of -111 mm in FIG.

The difference between the distance D4 of the calibration gauge 2 for the comparative measuring machine before the rotation of FIG. 12 and the distance D3 of the calibration gauge 2 for the comparative measuring machine after the rotation of FIG. 13 is calculated. This difference value becomes the first comparative measurement difference value at the position of −71 mm in FIG.

The difference between the distance D2 of the calibration gauge 2 for the comparative measuring machine before rotation in FIG. 12 and the distance D1 of the calibration gauge 2 for the comparative measuring machine after rotation in FIG. 13 is calculated. This difference value becomes the first comparative measurement difference value at the position of −36 mm in FIG.

The difference between the distance D1 of the calibration gauge 2 for the comparative measuring machine before rotation in FIG. 12 and the distance D2 of the calibration gauge 2 for the comparative measuring machine after rotation in FIG. 13 is calculated. This difference value becomes the first comparative measurement difference value at the position of 35 mm in FIG.

The difference between the distance D3 of the calibration gauge 2 for the comparative measuring machine before the rotation of FIG. 12 and the distance D4 of the calibration gauge 2 for the comparative measuring machine after the rotation of FIG. 13 is calculated. This difference value becomes the first comparative measurement difference value at the position of 70 mm in FIG.

The difference between the distance D5 of the calibration gauge 2 for the comparative measuring machine before rotation in FIG. 12 and the distance D6 of the calibration gauge 2 for the comparative measuring machine after rotation in FIG. 13 is calculated. This difference value becomes the first comparative measurement difference value at the position of 110 mm in FIG.

The difference between the calibration value (difference value) and the first comparative measurement difference value calculated by the comparative measuring machine is calculated. As a result, the measurement error of the comparative measuring machine at each position (-111 mm, -71 mm, -36 mm, 35 mm, 70 mm, 110 mm) of the 0 ° -180 ° line of the calibration gauge 2 for the comparative measuring machine can be obtained, and the X-axis can be obtained. You can check the measurement error of one axis. Further, by comparing the measured values of the diameters of the first to seventh opening holes (H1 to H7) measured in FIGS. 16A and 16B described above with the calibration values, the first to third lines of the 0 ° -180 ° line are compared. 7 Measurement errors at the positions of the opening holes (H1 to H7) can be confirmed.

Next, as shown in FIG. 17A, the calibration gauge 2 for the comparative measuring machine of FIG. 16B is arranged on the 45 ° -225 ° line so that the first opening hole H1 is arranged on the upper right side. Next, the calibration gauge 2 for the comparative measuring machine of FIG. 17A detects the coordinates of the first to seventh opening holes (H1 to H7) by the comparative measuring machine, and the diameter and the six distances (D1) before the rotation of FIG. 12 are detected. ~ D6) is calculated.

After that, as shown in FIG. 17B, the calibration gauge 2 for the comparative measuring machine of FIG. 17A is rotated by 180 ° on the stage of the comparative measuring machine, and the first to seventh opening holes (H1 to H7) after 180 ° rotation are performed. The coordinates of the above are detected, and the diameter and the six distances (D1 to D6) after the rotation of FIG. 13 described above are calculated.

Then, by the same method as the measurement procedure in FIGS. 16A and 16B described above, the second comparative measurement difference value at each position (-111 mm, -71 mm, -36 mm, 35 mm, 70 mm, 110 mm) of the 45 ° -225 ° line is used. To get each. Second comparative measurement By calculating the difference between the difference value and the above calibration value (difference value), at each position (-111 mm, -71 mm, -36 mm, 35 mm, 70 mm, 110 mm) of the 45 ° -225 ° line. The measurement error of the comparative measuring machine can be obtained.

Next, as shown in FIG. 18A, the calibration gauge 2 for the comparative measuring machine of FIG. 17B is arranged along the 90 ° -270 ° line so that the seventh opening hole H7 is arranged on the upper side. By measuring the calibration gauge 2 for the comparative measuring machine with the comparative measuring machine by the same method as the measuring procedure in FIG. 16A described above, the diameter and the six distances (D1 to D6) before the rotation of FIG. 12 are calculated. ..

After that, as shown in FIG. 18B, the calibration gauge 2 for the comparative measuring machine of FIG. 18A is rotated by 180 ° on the stage of the comparative measuring machine, and the comparative measuring machine is used in the same manner as the measurement procedure in FIG. 16B described above. The diameter and the six distances (D1 to D6) after the rotation of FIG. 13 described above are calculated.

Further, the third comparative measurement difference value at each position (-111 mm, -71 mm, -36 mm, 35 mm, 70 mm, 110 mm) of the 90 ° -270 ° line by the same method as the measurement procedure in FIGS. 16A and 16B described above. To get each. The difference between the third comparative measurement difference value and the above calibration value (difference value) is calculated. As a result, a measurement error of the comparative measuring machine can be obtained at each position (-111 mm, −71 mm, −36 mm, 35 mm, 70 mm, 110 mm) of the 90 ° −270 ° line.

Next, as shown in FIG. 19A, the calibration gauge 2 for the comparative measuring machine of FIG. 18B is arranged on the 135 ° -315 ° line. By measuring the calibration gauge 2 for the comparative measuring machine with the comparative measuring machine by the same method as the measurement procedure in FIG. 16A described above, the diameter and the six distances of the calibration gauge 4 for the comparative measuring machine before the rotation of FIG. (D1 to D6) are calculated. After that, as shown in FIG. 19B, the calibration gauge 2 for the comparative measuring machine of FIG. 19A is rotated by 180 ° on the stage of the comparative measuring machine, and the comparative measuring machine is used in the same manner as the measurement procedure in FIG. 16B described above. The diameter and the six distances (D1 to D6) after the rotation of FIG. 13 described above are calculated.

Further, the fourth comparative measurement difference value at each position (-111 mm, -71 mm, -36 mm, 35 mm, 70 mm, 110 mm) of the 135 ° -315 ° line by the same method as the measurement procedure in FIGS. 16A and 16B described above. To get each. Fourth comparative measurement The difference between the difference value and the above calibration value (difference value) is calculated. As a result, a measurement error of the comparative measuring machine can be obtained at each position (-111 mm, −71 mm, −36 mm, 35 mm, 70 mm, 110 mm) of the 135 ° −315 ° line.

FIG. 20 shows the measurement results of the calibration gauge 2 for the comparative measuring machine arranged on the 135 ° -315 ° line measured by the above procedure. FIG. 20 is a graph showing each position from the origin (center) on the horizontal axis and the measurement error (mm) of the comparative measuring machine on the vertical axis. Also in the example of the second embodiment, the comparative measuring machine guarantees the accuracy so that the measurement error becomes ± 0.002 mm (2 μm) or less when the object to be measured is displaced by 1 mm from the reference position of the stage. (The accuracy guarantee range in FIG. 20).

In FIG. 20, the origin (center) of the calibration gauge 2 for the comparative measuring machine is shifted by about 0.9 mm from the rotation center of the holding portion 34 of the table 30 with “with offset”, and “without offset” coincides with the rotation center. The data at the time of "is shown.

As shown in FIG. 20, in the data (□) with “no offset”, the measurement error is within the accuracy guarantee range (± 0.002 mm) of the comparative measuring machine at all the positions from the origin (center). Therefore, when the calibration gauge 2 for the comparative measuring machine is installed on the table 30 without offset, it can be seen that the comparative measuring machine is within the accuracy guarantee at all the measuring points on the 135 ° -315 ° line.

On the other hand, in the data (◯) with “with offset”, the accuracy of the comparative measuring machine is out of the guaranteed range (± 0.002 mm) at the positions of -111 mm, -71 mm, and 110 mm from the origin. It is probable that the position was out of the accuracy range because the misalignment became larger by the offset and the measurement conditions became stricter.

By installing the origin of the calibration gauge 2 for the comparative measuring machine so as to coincide with the center of rotation of the holding portion 34 of the table 30, it is possible to reproduce the condition where a predetermined position shift occurs, and the measurement error of the comparative measuring machine main body is accurate. Can be measured.

FIG. 21 shows the results of measuring the calibration gauge 2 for the comparative measuring machine arranged on the 45 ° -225 ° line by the above procedure and confirming the influence of the temperature change. The vertical axis and the horizontal axis of FIG. 21 are the same as those of FIG. 20. FIG. 21 shows data when there is a “temperature drift” in which the temperature changes by about 2 ° C. before and after 180 ° rotation during measurement, and when there is “no temperature drift” in which the temperature does not change during measurement.

As shown in FIG. 21, in the data (□) with “no temperature drift” on the 45 ° 225 ° line, the measurement error is the measurement error at all positions from the origin within the accuracy guarantee range (± 0.002 mm) of the comparative measuring machine. It is in. In addition, even in the data (○) with “with temperature drift” on the 45 ° -225 ° line, the measurement error is within the accuracy guarantee range (± 0.002 mm) of the comparative measuring machine at all positions from the origin. ..

Therefore, it can be seen that the accuracy of the comparative measuring machine is within the accuracy guarantee at all the measuring points on the 45 ° -225 ° line regardless of “with temperature drift” and “without temperature drift”. From the above results, since the gauge body 20 of the calibration gauge 2 for the comparative measuring machine of the second embodiment is formed of ultra-low thermal expansion ceramics, the measurement error is stable even if the temperature changes near room temperature during the measurement. It was confirmed that it could be measured.

As described above, in the calibration gauge 2 for the comparative measuring machine of the second embodiment, as described with reference to FIG. 12, seven opening holes (H1 to H7) are arranged in the gauge body 20. The third opening hole H3, the second opening hole H2 and the first opening hole H1 are arranged on the right side of the fourth opening hole H4 arranged at the center position, and the fifth opening hole H5 and the fifth opening hole H5 are arranged on the left side of the fourth opening hole H7. The 6 opening hole H6 and the 7th opening hole H7 are arranged. The distance D1 between the center of the fourth opening hole H4 and the center of the third opening hole H3 and the distance D2 between the center of the fourth opening hole H4 and the center of the fifth opening hole H5 are arranged differently by about 1 mm. ..

Therefore, as described with reference to FIG. 13, when the calibration gauge 2 for the comparative measuring machine of FIG. 12 is rotated by 180 °, the first to third opening holes (H1 to H1 to different distances from the fourth opening hole H4) are different from each other. The arrangement of the H3) and the fifth to seventh opening holes (H5 to H7) are exchanged, and a pseudo misalignment occurs.

In order to confirm the measurement error of the comparative measuring machine by using the calibration gauge 2 for the comparative measuring machine of the second embodiment, as described in FIGS. 16A and 16B described above, the position of “-111 mm” in FIG. 12 For example, first, the distance D6 in FIG. 12 is calculated by a comparative measuring machine. Further, after rotating the calibration gauge 2 for the comparative measuring machine of FIG. 12 by 180 °, the distance D5 of FIG. 13 is calculated by the comparative measuring machine. Further, the difference between the distance D6 in FIG. 12 and the distance D5 in FIG. 13 is calculated to obtain a comparative measurement difference value.

Then, by calculating the difference between the comparative measurement difference value and the calibration value (difference value), the deviation amount of the comparative measurement at the position of "-111 mm" can be obtained. By repeating this measurement procedure at each position of the above-mentioned four measurement lines, it is possible to obtain a measurement error due to misalignment at each position of the four measurement lines in the measurable range of the stage of the comparative measuring machine. ..

As described above, the calibration method of the comparative measuring machine of the second embodiment includes a step of measuring the distance of a plurality of measurement marks, a step of giving a predetermined displacement to the gauge body 20, and a plurality of steps after giving the displacement. It has a step of measuring the distance of the measurement mark of the above, and a step of comparing the difference between the distances of the plurality of measurement marks before and after giving the displacement and the calibration value.

Further, the calibration gauge 2 for the comparative measuring machine of the second embodiment uses ultra-low thermal expansion ceramics having a coefficient of thermal expansion of almost zero near room temperature as the gauge main body 20. Therefore, since the gauge body 20 does not expand due to heat even if the temperature changes during the measurement, the measurement error can be obtained with higher accuracy than when the gauge body 10 made of metal or the like is used.

Further, since the calibration gauge 2 for the comparative measuring machine of the second embodiment uses the strip-shaped gauge main body 20, it is compact and easy to handle.

In addition, in FIGS. 12 and 13 described above, the calibration gauge 2 for the comparative measuring machine is rotated by 180 ° to replace the arrangement of the opening holes having different distances from the origin, thereby causing a pseudo misalignment. ing. In addition to this method, as described with reference to FIG. 14 described above, a table 30 provided with a holding portion 34 movable in the X direction and the Y direction may be provided on the stage of the comparative measuring machine.

In this case, the first comparative measurement is performed on the calibration gauge 2 for the comparative measuring machine arranged on the table 30 on the stage of the comparative measuring machine in FIG. 16A described above. Next, without rotating the calibration gauge 2 for the comparative measuring machine, the calibration gauge 2 for the comparative measuring machine is moved in the X direction and the Y direction so as to have a predetermined displacement amount by moving the holding portion 34 of the table 30. After the misalignment is generated, the second comparative measurement is performed.

Further, in FIG. 12 described above, the first to seventh opening holes (H1 to H7) are formed in the gauge body 20 as measurement marks, but instead of the opening holes, a convex portion is used to form the gauge body 20. The convex portions and the concave portions may be arranged alternately on the surface. As the convex portion, a block such as a sphere or a rectangular parallelepiped is used. The measurement error of the comparative measuring machine can be similarly obtained based on the measurement of the distance between the convex portions arranged on the gauge body 20 by the measurement procedure as described above.

Alternatively, in FIG. 12 described above, the distance D1 between the center of the fourth opening hole H4 and the center of the third opening hole H3 arranged at the center position, the center of the fourth opening hole H4, and the center of the fifth opening hole H5. The distance D2 may be set to be the same as that of the opening hole H3 so that the diameter of the opening hole H3 is different from the diameter of the opening hole H5.

The same relationship is set in the second opening hole H2 and the sixth opening hole H6, and the first opening hole H1 and the seventh opening hole H7, which are arranged substantially symmetrically with respect to the fourth opening hole H4. In the calibration gauge for a comparative measuring machine of this aspect, when it is rotated by 180 °, the opening holes at each position are replaced with opening holes having different diameters, so that a pseudo misalignment occurs.

In the measurement procedure in this embodiment, taking the position of −36 mm in FIG. 12 as an example, the measured value of the diameter HD of the fifth opening hole H5 before rotation in FIG. 12 and the third opening hole after rotation in FIG. The difference from the measured value of the diameter HD of H3 is calculated and the comparative measurement difference value is acquired. Then, the measurement error can be obtained by calculating the difference between the comparative measurement difference value and the calibration value.

The calibration gauge 2 for a comparative measuring machine and the calibration method of the second embodiment can be applied to a contact type or non-contact type comparative measuring machine, a machine tool using the comparative measurement, and the like.

1,1a, 2 Calibration gauge for comparative measuring machine 5 Sphere with shaft 10,20 Gauge body 10a Mounting hole 12 Sphere 12a White sphere 12b Black sphere 14 Shaft 14a Small diameter 14b Large diameter 16,40 Support base 30 Table 32 Table body 34 Holding part 36 Holding part 38 Rotating knob 42 Water plate 44 Inclined plate 46 Support pillar D1 to D6 Distance H1 1st opening hole H2 2nd opening hole H3 3rd opening hole H4 4th opening hole H5 5th opening hole H6 6th opening hole H7 7th opening hole P White sphere at the center of the gauge body

Claims (9)

A calibration gauge for a comparative measuring machine attached to the holding portion of a table having a table main body and a holding portion movably provided on the table main body.
Gauge body and
A plurality of measurement marks provided on the gauge body and
A calibration gauge for a comparative measuring machine comprising the size of the plurality of measurement marks and the calibration value of at least one of the distances between the measurement marks. The plurality of measurement marks have a first mark and a second mark and a third mark provided substantially symmetrically about the first mark.
The calibration gauge for a comparative measuring instrument according to claim 1, wherein the distance between the first mark and the second mark and the distance between the first mark and the third mark are different. The plurality of measurement marks have a first mark and a second mark and a third mark provided substantially symmetrically about the first mark.
The calibration gauge for a comparative measuring machine according to claim 1, wherein the second mark and the third mark have different sizes. The calibration gauge for a comparative measuring machine according to claim 2 or 3, wherein the holding portion is rotatable about the first mark with respect to the table body. The calibration gauge for a comparative measuring instrument according to any one of claims 1 to 4, further comprising a support base for supporting the table by inclining it in the thickness direction of the gauge body. The calibration gauge for a comparative measuring machine according to any one of claims 1 to 5, wherein the plurality of measurement marks are holes arranged in a row in the gauge body and penetrating in the thickness direction of the gauge body. .. The calibration for a comparative measuring machine according to any one of claims 1 to 5, wherein the plurality of measurement marks are spheres radially arranged on the gauge body and provided so as to project from the surface of the gauge body. gauge. Gauge body and
A plurality of measurement marks provided on the gauge body and
A table that gives a predetermined displacement to the gauge body,
Using a calibration gauge for a comparative measuring machine, the calibration value of at least one of the size of the plurality of measurement marks and the distance between the measurement marks is used.
The step of measuring the size of the plurality of measurement marks or the distance between the measurement marks, and
A step of giving a predetermined displacement to the gauge body,
A step of measuring the size of the plurality of measurement marks or the distance between the measurement marks after the predetermined displacement is applied.
A calibration method of a comparative measuring machine including a step of comparing the size of the plurality of measurement marks before and after giving the predetermined displacement or the difference in distance between the measurement marks with the calibration value. The calibration method for a comparative measuring machine according to claim 8, wherein the step of giving the predetermined displacement is to rotate the gauge body.

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