JPH06201375A - Cylindricity measuring device and measuring method - Google Patents

Abstract

PURPOSE:To calculate cylindricity on the basis of a roundness determined from the distance from the rotating central point of a material to be measured to a first measuring point to make possible a highly precise measurement. CONSTITUTION:A material 122 to be measured is placed on a rotating table 112, and a light emitting part and a light receiving part 116, 118 are adjusted to a determined measuring height of the material 122 to be measured by a height adjusting handle 124. The space distance r0 between a first measuring point n0 on the surface of the material 122 to be measured on the line connecting the rotating center O of the material 122 to a displacement standard edge 130 and the edge 130, and the radius R of the material 122 are detected 116, 118. Further, the material 122 to be measured is rotated 180 deg., the space distance between a second measuring point n180 180 deg.-relative to the measuring point n0 and the edge 130 is measured, and the distance X from the central point O to the measuring point n0 is calculated from X:(R+r180r0) by a computer. The circumferential measurement and operation are performed while rotating the material 122 to be measured, and the surface form at the measuring height is detected to measure the roundness. The light emitting and light receiving parts 116, 118 are then vertically moved, and the cylindricity is determined from the roundness measurement data at the determined height.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindricity measuring device and a measuring method, and more particularly to improvement of arithmetic processing thereof.

[0002]

2. Description of the Related Art Cylindricality measuring machines are used to measure the roundness and cylindricity of an object to be measured. Especially, the object to be measured is a rubber product, a thin pipe, a mirror-finished part, etc. is deformed or damaged. A non-contact cylindricity measuring instrument using a laser beam or the like is generally used for the measurement of the thing which is apt to occur. FIG. 5 shows a conventional non-contact cylindricity measuring machine. The cylindricity measuring machine shown in the figure has a rotary table 12 rotatably provided on the measuring machine body 10 and a support 14 provided upright on the measuring machine body 10.
And a light emitting portion 16 and a light receiving portion 18 which are provided on the support column 14 so as to be movable up and down and are opposed to each other; And a section 20.

When measuring the roundness of the object 22 to be measured, the object 22 to be measured is placed on the rotary table 12, and the light emitting portion 16 and the light receiving portion 18 are adjusted by the height adjusting knob 2.
Adjustment is made so as to be positioned at the height of the object 22 to be measured for roundness by 4. In this state, the gap between the knife edge portion 20 and the surface measurement point of the DUT 22 at the height is measured. That is, since it is very difficult to detect the absolute position of the surface of the object 22 to be measured, it is possible to measure the change in the gap between the knife edge portion 20 and the surface of the object 22 to be measured while rotating the object 22 to be measured. The roundness of the measurement object 22 is obtained.

The gap between the knife edge portion 20 and the surface measurement point of the object 22 to be measured is measured by the light emitting portion 16 and the light receiving portion 1.
8. That is, the laser light from the light emitting portion 16 is passed from the knife edge portion 20 to the object 22 to be measured. Therefore, the laser light is shielded by the knife edge portion 20 and the object to be measured 22, and only the laser light passing between the knife edge portion 20 and the object to be measured 22 is received by the light receiving portion 18. Then, from the signal received by the light receiving unit 18, in the distance calculation unit 26, the respective edge positions of the knife edge portion 20 and the DUT 22 and the surface measurement points of the knife edge portion 20 and the DUT 22 are measured. The gap is calculated.

Therefore, the measurement is performed while rotating the object to be measured 22, and the gap between the knife edge portion 20 and the surface of the object to be measured 22 is obtained at a predetermined angle in the circumferential direction to measure the position of the object to be measured 22. It is possible to detect the surface shape data as shown in FIG. 6 (A) at the height of, and it is possible to measure the roundness. On the other hand, when measuring the cylindricity of the object to be measured 22, the roundness measurement is performed at a predetermined position while changing the height of the measuring position of the object to be measured 22, and the object to be measured obtained at each measuring position. The data of the surface shape of No. 22 is shown in FIG.
As shown in (B), the cylindricity is obtained by superimposing them.

[0006]

By the way, when measuring the cylindricity of the object 22 to be measured, the edge line of the knife edge portion 20 and the rotation center axis Z (vertical table normal) of the object 22 to be measured are parallel to each other. Must have become. That is, since the cylindricity is determined by superimposing the data of the circularity measured at the height of the predetermined position of the object to be measured 22 as described above, the rotation of the object to be measured 22 in each circularity measurement is determined. The distance from the center point to the surface measurement point becomes necessary.

In the roundness measurement, since the gap between the knife edge portion 20 and the surface of the object 22 to be measured is measured, the distance from the rotation center point of the object 22 to the surface measurement point is measured. In order to obtain the height accurately, the distance from the reference rotation center point to the knife edge portion 20 must always be constant at all heights. Therefore, the variation in the distance between the rotation center point of the object 22 to be measured and the knife edge portion 20 at the measurement position due to the inclination of the knife edge portion 20 and the like directly occurs as a cylindricity measurement error.

Therefore, in the conventional roundness measurement,
Before measurement, the edge line 20a of the knife edge portion 20 is adjusted by the knife edge inclination adjusting knob 26 as shown in FIG. 7 so that the edge line 20a is parallel to the rotation center axis Z of the object to be measured 22, and the knife edge right angle operation is performed. There was a problem that it was very inefficient. Further, there is a limit to the accuracy of the right-angled output, and even if the right-angled output is accurately performed, it is impossible to measure the cylindricity higher than the straightness of the knife edge. The present invention has been made in view of the above-mentioned problems of the conventional art, and an object thereof is to provide a cylindricity measuring device and a cylindricity measuring method capable of measuring cylindricity of an object to be measured with extremely high accuracy. .

[0009]

In order to achieve the above-mentioned object, a cylindricity measuring device according to the present invention comprises distance detecting means,
It is characterized in that it comprises distance calculating means, roundness calculating means, and cylindricity calculating means. The distance detecting means detects the distance from the measurement reference means to the measurement point on the surface of the object to be measured and the diameter of the object to be measured. The distance calculating means includes respective distances from the measurement reference means to a first measurement point and a second measurement point which are 180 degrees opposite to each other on the surface of the measured object on a plane orthogonal to the rotation center axis of the measured object, and Based on the measured value of the diameter of the measured object that connects the first measurement point and the second measurement point, the distance X from the rotation center point of the measured object to the first measurement point,

[0010]

Equation 3] _{X = (R + r 180 -r} 0) / 2 where, R: radius r of the first measuring point and the measurement object connecting the second measuring point _0: distance from the metric means to the first measurement point r ₁₈₀ : Calculated from the distance from the measurement reference means to the second measurement point. The roundness calculating means calculates the roundness of the measured object in the orthogonal plane based on the distance from the rotation center point of the measured object to the surface of the measured object obtained by the distance calculation means. The cylindricity calculation means calculates the cylindricity of the object to be measured based on the roundness at the height of the predetermined position of the object to be measured, which is obtained by the circularity calculation means.

The cylindricity measuring method according to the present invention is
A distance detecting step, a distance calculating step, a roundness calculating step,
And a cylindricity calculation step. In the distance detecting step, the distance from the measurement reference means to the measurement point on the surface of the object to be measured and the diameter of the object to be measured are detected. In the distance calculation step, the distances from the measurement reference means to the first measurement point and the second measurement point that are 180 degrees opposite to each other on the surface of the measured object on the plane orthogonal to the rotation center axis of the measured object, and Based on the measured value of the diameter of the measured object that connects the first measurement point and the second measurement point, the distance X from the rotation center point of the measured object to the first measurement point,

[0012]

Equation 4] _{X = (R + r 180 -r} 0) / 2 where, R: radius r of the first measuring point and the measurement object connecting the second measuring point _0: distance from the metric means to the first measurement point r ₁₈₀ : Calculated from the distance from the measurement reference means to the second measurement point. In the roundness calculating step, the roundness of the measured object in the orthogonal plane is calculated based on the distance from the rotation center point of the measured object to the surface of the measured object obtained in the distance calculating step. In the cylindricity calculation step, the cylindricity of the object to be measured is calculated based on the circularity at the height of a predetermined location of the object to be measured, which is obtained in the roundness calculation step.

[0013]

As described above, the cylindricity measuring device and the measuring method according to the present invention can measure the surface of the object to be measured from the measuring reference means.
The center of rotation of the object to be measured based on the respective distances to the first measuring point and the second measuring point facing each other by 80 degrees and the measured value of the diameter of the object to be measured connecting the first measuring point and the second measuring point. The distance X from the point to the first measurement point is

[0014]

Equation 5] _{X = (R + r 180 -r} 0) / 2 where, R: radius r of the first measuring point and the measurement object connecting the second measuring point _0: distance from the metric means to the first measurement point r ₁₈₀ : Calculated from the distance from the measurement reference means to the second measurement point. Therefore, even if the distance from the rotation center point of the object to be measured to the measurement reference means is not constant, the distance from the rotation center point to the surface measurement point of the object to be measured can be accurately obtained.

That is, in the present invention, since the distance from the center of rotation to the surface of the object to be measured is calculated by calculating the difference between r ₁₈₀ and r ₀ and the data of R, the height of the measuring position can be measured. Even if there is a variation in the distance from the rotation center point of the measured object to the measurement reference means, the variation is included in the same amount in r ₀ and r ₁₈₀ and is offset. Therefore, the measurement of R, r ₀ , and r ₁₈₀ , and the _equation 5
The circularity is measured by performing the calculation for each predetermined angle of the object to be measured, and if the cylindricity is obtained from the data obtained by measuring the circularity at the height of the predetermined location, the measured Accurate cylindricity measurement is possible even if the distance from the rotation center point of the object to the measurement reference means is deviated.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external perspective view of a cylindricity measuring device according to an embodiment of the present invention. It should be noted that the reference numeral 100 is added to the portion corresponding to the above-mentioned prior art to omit the description. The cylindricity measuring device shown in FIG.
10, a rotary table 112 rotatably provided on which an object to be measured 122 is placed, a column 114 erected on the measuring machine main body 110, and a column 114 movably provided on the column 114 for measurement. The light emitting unit 116 and the light receiving unit 118 as distance detecting means arranged facing each other on both sides of the object 122, and the light emitting unit 11 arranged between the light emitting unit 116 and the light receiving unit 118.
6 and the light receiving portion 118, and a displacement reference edge 130 as a measurement reference means that moves up and down.

The light emitting section 116 includes a beam generator (not shown), a conversion unit for converting the laser beam from the beam generator into a scanning beam, a collimator lens for converting the scanning beam into a parallel scanning beam, and the like. It Further, the light receiving unit 118 includes a measurement light receiving device that detects the brightness of the parallel scanning beam that has passed through the displacement reference edge 130 and the DUT 122. Then, the parallel scanning beam is applied to the displacement reference edge 130 and the DUT 12.
The distance between the displacement reference edge 130 and the object to be measured 122 and the measured value of the diameter of the object to be measured 122 are obtained from the length of the dark part or the bright part that is shielded by 2.

Further, the distance detecting means and the measuring machine main body 1
A computer unit 132 serving as a distance calculation unit, a roundness calculation unit, and a cylindricity calculation unit is connected to the unit 10.
Then, in the computer unit 132, various measurement conditions are input by the keyboard 134, data from the distance detection unit based on the measurement conditions is arithmetically processed, and roundness and cylindricity are obtained. The above is the schematic configuration of the cylindricity measuring apparatus according to the present embodiment. Next, the measuring method will be described. When measuring the circularity and cylindricity of the DUT 122, the DUT 122 is first placed on the rotary table 112. Next, the light emitting section 116 and the light receiving section 118 are adjusted by operating the height adjusting knob 124 so that the height of the DUT 122 is a predetermined measurement position.

At the measured height, as shown in FIG.
As shown in (A), the first measurement point n _{0 on} the surface of the object to be measured 122 and the displacement reference edge 13 on the line connecting the rotation center point O of the object to be measured 122 and the edge portion of the displacement reference edge 130.
The distance r 0 of the gap of ₀ and the diameter R ₀ of the DUT 122 are detected by the distance detecting means. Further, the object 122 to be measured is rotated 180 degrees, and as shown in FIG. 2B, the second measurement point n _{180 on} the surface of the object 122 to be measured and the displacement reference edge 130 opposed to the first measurement point n ₀ by 180 degrees. Distance r between
Measure ₁₈₀ .

In the present embodiment, the computer unit 132 performs arithmetic processing based on the measurement values r ₀ , R ₀ , and r ₁₈₀ , so that the rotation center point O of the DUT 122 to the first measurement point n. _Find the distance X to ₀ . That is, as shown in FIG. 3A, when the first measurement point n ₀ is at the measurement position, the distance x from the rotation center point O of the DUT 122 to the displacement reference edge 130 is

[0021]

## EQU6 ## It can be expressed by x = X + r ₀ . In addition, as shown in FIG. 3B, the second measurement point n
_In the state where ₁₈₀ is in the measurement position, the DUT 122
From the rotation center point O of the to the displacement reference edge 130 x
Is

[0022]

## EQU7 ## It can be expressed by x = R−X + r ₁₈₀ . That is,

[0023]

## EQU8 ## X + r ₀ = R−X + r ₁₈₀ , and therefore

[0024]

The distance X from the rotation center point O of the object to be measured 122 to the first measurement point n ₀ is obtained by the arithmetic expression X = (R + r ₁₈₀ −r ₀ ) / 2. Therefore, regardless of the distance x from the rotation center point O to the displacement reference edge 130, the rotation center point O to the first measurement point n _0.
It is possible to obtain the distance X up to. Then, by performing the above-described measurement and calculation in the circumferential direction while rotating the DUT 122, the DUT 12 at the measurement height is measured.
The two surface shapes are detected, and the roundness can be measured based on the surface shape.

That is, the distance r i and the diameter R i between the displacement reference edge 130 and each of the first measurement points ni obtained by rotating the DUT 122 by the predetermined angle θi from the first measurement point n ₀ are measured. The distance r between the second measurement point ni ′ and the displacement reference edge 130, which are 180 degrees each opposite to the one measurement point ni
Measure i '. Then, the distance between each of the first measurement points and the rotation center point O is calculated and calculated based on the arithmetic expression of the equation (9). Next, in order to measure the cylindricity of the DUT 122, the light emitting unit 116 and the light receiving unit 118 are moved up and down, and the measurement and calculation are performed at the height of a predetermined position of the DUT 122. Then, the surface shape of each object 122 to be measured at the height of the predetermined location is detected, and the computer unit 132 performs the arithmetic processing based on the detected data to obtain the cylindricity.

Here, as described above, in the present embodiment, the distance X from the rotation center point O of the object to be measured 122 to the surface measurement point is obtained by the arithmetic expression of the above equation 9, so the rotation center point O Even if the distance x from the to the displacement reference edge 130 changes, the calculation of the distance X is not affected. Therefore, as shown in FIG. 4, even if the displacement reference edge 130 is deviated from the reference line Z ′ parallel to the rotation center axis Z due to the height of the measurement position of the object 122 to be measured, it is accurate at each height. The surface shape can be measured, and it becomes possible to obtain an extremely accurate cylindricity.

As described above, in the cylindricity measuring device and the measuring method according to the present embodiment, the inclination and straightness of the displacement reference edge 130 in the vertical movement do not affect the cylindricity measurement. The knife edge itself is no longer necessary, as well as the work of right angle cutting of the knife edge that was necessary. Therefore, it is possible to obtain a cylindrical measuring device having a simple configuration, and easily perform highly accurate cylindricity measurement. In this embodiment, the non-contact cylindricity measuring device using the laser beam was used, but two contact type detectors should be used to measure the surface position and the diameter of the object to be measured 180 degrees opposite to each other. Is also possible.

[0028]

As described above, according to the cylindricity measuring device and the measuring method of the present invention, the distance from the rotation center point of the measured object to the surface measurement point is calculated from the rotation center point of the measured object. Since no distance to the measurement reference means is required,
Even if the distance from the center of rotation of the object to be measured to the measurement reference means is deviated due to the measurement height of the object to be measured, an accurate surface shape can be detected, and cylindricity can be measured easily and with high accuracy.

[Brief description of drawings]

FIG. 1 is an external perspective view of a cylindricity measuring device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a cylindricity measuring method according to the present embodiment.

FIG. 3 is an explanatory diagram of a measurement principle of cylindricity measurement according to the present embodiment.

FIG. 4 is an explanatory diagram of a moving state of a displacement reference edge according to the present embodiment.

FIG. 5 is an external perspective view of a conventional cylindricity measuring device.

FIG. 6 is an explanatory diagram of measurement data of roundness and cylindricity.

FIG. 7 is an explanatory diagram of a right angle drawing operation of a knife edge portion.

[Explanation of symbols]

 10, 110 ... Measuring machine main body 12, 112 ... Rotating table 14, 114 ... Struts 16, 116 ... Light emitting part 18, 118 ... Light receiving part 130 ... Displacement reference edge 132 ... Computer part

Claims (2)

[Claims] 1. A support column provided upright on a base, a rotary table rotatably provided on the base and on which an object to be measured is mounted, and a support table provided on the support column and mounted on the rotary table. And a measurement reference means serving as a measurement reference of the distance to the measurement point on the surface of the measured object, and a distance detection means for detecting the distance from the measurement reference means to the measurement point on the surface of the measured object and the diameter of the measured object. The respective distances from the measurement reference means to the first measurement point and the second measurement point which are 180 degrees opposite to each other on the surface of the object to be measured in the plane orthogonal to the rotation center axis of the object to be measured, and the first measuring point And the second measurement point, the distance X from the rotation center point of the measurement object to the first measurement point is calculated as follows: X = (R + r ₁₈₀ −r ₀ ) / 2 where R: diameter of the object to be measured connecting the first measurement point and the second measurement point r ₀ : measurement base Distance from the quasi-means to the first measurement point r ₁₈₀ : Distance calculation means for calculating by the distance from the measurement reference means to the second measurement point, and the measured point from the rotation center point of the measured object obtained by the distance calculation means Roundness calculating means for calculating the roundness in the orthogonal surface of the measured object based on the distance to the object surface, and a perfect circle at the height of a predetermined location of the measured object obtained by the roundness calculating means. A cylindricity measuring device comprising: a cylindricity calculating means for calculating the cylindricity of the object to be measured based on the degree. 2. A support column provided upright on a base, a rotary table rotatably provided on the base and on which an object to be measured is mounted, and a support table provided on the support column and mounted on the rotary table. In the roundness measuring device having a measurement reference unit serving as a measurement reference of the distance to the measurement point on the surface of the object to be measured, the distance from the measurement reference unit to the measurement point on the surface of the object to be measured, and the object to be measured. A distance detection step of detecting the diameter of the measurement object, and a first measurement point and a second measurement point that are 180 degrees opposite to each other on the surface of the measurement object from the measurement reference means on a plane orthogonal to the rotation center axis of the measurement object. And the distance X from the rotation center point of the measured object to the first measured point based on the measured value of the diameter of the measured object connecting the first measurement point and the second measurement point, _{X = (R + r 180 -r} 0) / 2 where, R: a first measurement point and the second measurement point Diameter r ₀ of the object I: distance r ₁₈₀ from metric means to the first measurement point: the distance calculation step of calculating the distance from the metric unit to the second measuring point, obtained by said distance calculation step The roundness calculating step of calculating the roundness of the DUT on the orthogonal plane based on the distance from the rotation center point of the DUT to the surface of the DUT, and the roundness calculating step obtained by the roundness calculating step. And a cylindricity calculating step for calculating the cylindricity of the object to be measured based on the circularity at the height of a predetermined location of the object to be measured.