JPH08122050A - Contour shape-measuring method and tool for measurement - Google Patents

Abstract

PURPOSE: To provide a method for measuring contour shape which can surely measure the contour shape of an incomplete circumferential part of each kind of object, namely diameter and roundness using a contour shape-measuring instrument and a tool for measurement which is suitable for the execution of this method. CONSTITUTION: A table 1 is provided at a base plate 3 and the position and inclination in plane direction of the table 1 for a measurement means 2 can be compensated. The measurement means 2 is provided with a detector 4, a retention means 5 for retaining the detector 4 in a state where it can be moved in the radius direction of a table 1, and an elevation means 6 for retaining the retention means 5 for raising and lower the retention means 5 in a direction which is vertical to the surface of the table 1, thus adjusting the position of the detector 4 according to the diameter of the measurement surface of an object to be measured and the height from the table 1. Further, the detector 4 is connected to an operation means and the measurement data from the detector 4 are sent to the operation means for specific processing, thus calculating the contour shape of the measurement surface of the object to be measured, namely diameter and roundness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contour shape measuring method and a measuring jig, and more specifically to not only the diameter and roundness of a substantially perfect circular article but also the contour shape of an incomplete circumferential portion. That is, the present invention relates to a contour shape measuring method capable of surely measuring a diameter and a roundness, and a measuring jig suitably used when carrying out this measuring method.

[0002]

2. Description of the Related Art Conventionally, as a device for measuring the roundness of various articles, the state of the circumference of the object to be measured placed on a rotating table is detected by a detector, and the detected value is detected. A roundness measuring machine for measuring the roundness of the circumferential portion based on this is widely known.

[0003]

However, the conventional measuring method in the roundness measuring machine detects the state of substantially the entire circumference of the circumference of the object to be measured, and determines the radius from the average value of each detected value. In addition to calculating, the roundness of the circumference is measured based on the magnitude relationship of each detected value. Therefore, the object to be measured for the roundness is cylindrical, tubular, ring-shaped, etc. Or it was limited to a substantially circular shape.

For this reason, in the conventional roundness measuring machine, the diameter or the perfect circle of the incomplete circumferential portion of a profiled material such as a fan-shaped article, a crescent-shaped article, or a rice ball-shaped article, which is not a perfect circle, is used. The degree could not be measured. Further, as a means for obtaining the radius of these incomplete circumferential portions, a three-dimensional coordinate measuring machine or a projector is also used, but in the case of a three-dimensional coordinate measuring machine, the measuring point and the measuring time are However, in the case of a projector, there was a problem in skill and workability.

On the other hand, when measuring the circularity of an arc-shaped portion of a fan-shaped article or the like, the circumference of the arc-shaped portion is measured to find the center point of the circumference, and this center point is used as a table machine. Since the arc-shaped portion can be a part of a circle having the center of rotation of the table as the center point, the circularity of the arc-shaped portion can be theoretically measured. However, if the center point of the arc-shaped portion and the center of rotation of the table are not perfectly aligned, the roundness cannot be obtained with the desired accuracy, and it is not possible to completely align both centers. However, it is almost impossible at present from the viewpoint of machining accuracy and the like, and there is a problem in practicality.

Therefore, the present invention provides a contour shape measuring method capable of surely measuring the contour shape, that is, the diameter and the roundness of an incomplete circumferential portion of various articles, by using a contour shape measuring device which is usually used. It is an object of the present invention to provide a measuring jig suitable for carrying out this method.

[0007]

In order to achieve the above object, the contour shape measuring method of the present invention has, as a first configuration, a table on which an object to be measured is placed and rotated, and a mechanical table. The contour shape of the incomplete circumferential portion of the measured object is measured by using a measuring machine which is arranged movably in the radial direction with respect to the center of rotation and has a measuring means for measuring the contour shape of the measured object. In the method, the standard circumferential surface of the standard cylindrical body placed on the table is measured, and the measurement value at each measurement point and the radius of the standard circumferential surface are used to measure the mechanical rotation center of the table. After calibrating, place the object to be measured on the table in place of the standard cylinder, measure the incomplete circumferential portion with the measuring means, and determine the position of each measurement point.
Considered as a part of a circle drawn on the orthogonal coordinate axis with the center of mechanical rotation as the origin, the coordinates and radius of the center of the circle were obtained by the least squares method based on the formula of the circle, and the obtained center coordinates and radius And the measured value at each measurement point, the contour shape of the incomplete circumferential portion of the measured object, that is, the diameter and the roundness are measured.

Further, according to the second construction of the method of the present invention, the table on which the object to be measured is placed and rotated, and the table to be measured are arranged so as to be movable in the radial direction with respect to the mechanical rotation center of the table. A method for measuring the contour shape of an incomplete circumferential portion formed on the inner peripheral side of the measured object using a measuring machine equipped with a measuring device for measuring the contour shape of the object, comprising the rotation of the table. A standard cylindrical body having a standard inner peripheral surface having a radius corresponding to the design radius of the measurement circumferential portion of the object to be measured is inserted into the reference engagement hole formed in the center, and the standard inner peripheral surface of the standard cylindrical body is inserted. After calibrating the measuring means with respect to the mechanical rotation center of the table from the measured value at each measurement point and the radius of the standard inner peripheral surface, the standard engagement hole, in the standard of the standard cylindrical body Has a reference outer peripheral surface corresponding to the peripheral surface, and protrudes from the table Insert a reference cylindrical body having a height lower than the height of the measurement circumference of the measured object, and then with the measurement circumference of the measured object in contact with the outer peripheral surface of the reference cylinder. Placed on a table, the measurement circumferential portion is measured by the measuring means, the position of each measurement point is regarded as a part of a circle drawn on the orthogonal coordinate axis with the mechanical rotation center as the origin, The coordinates and radius of the center of the circle are obtained by the method of least squares based on the formula, and from the obtained center coordinates and radius and the measurement values at each measurement point, the contour shape of the incomplete circumferential portion of the measured object is obtained. That is, it is characterized by measuring the diameter and roundness.

Further, the contour shape measuring jig of the present invention comprises a table on which an object to be measured is placed and rotating, and a jig which is arranged so as to be movable in a radial direction with respect to a mechanical rotation center of the table. A jig used when measuring a contour shape of a measured object, that is, a diameter or a roundness, using a measuring machine equipped with a measuring means for measuring the contour shape of the measured object, the contour shape of the measured object A standard cylindrical body having a standard circumferential surface having a radius corresponding to the design radius of the measuring portion, and a reference cylindrical body having a reference circumferential surface in the opposite direction corresponding to the standard circumferential surface of the standard cylindrical body, The standard cylindrical body and the reference cylindrical body each have an engaging portion that engages with a reference engaging portion provided on the table, and the reference cylindrical body measures the protrusion height from the table by the object to be measured. It is characterized in that it is formed lower than the height of.

[0010]

[Operation] According to the above method, the position of each measurement point on the incomplete circumference is regarded as a part of the circle drawn on the Cartesian coordinate axes, the center coordinates and radius are calculated, and based on this, the measured object is measured. Since the contour shape, that is, the diameter and the roundness of the incomplete circumferential portion of the object is measured, the contour shape can be measured even with a small number of measuring portions. Further, since the measuring means is calibrated prior to the measurement, the error at each measuring point of the measured object with respect to the mechanical rotation center of the table can be minimized and accurate data can be obtained.

Further, by using the standard cylindrical body and the standard cylindrical body, it becomes possible to place the center point portion of the incomplete circumferential portion of the object to be measured near the center of mechanical rotation of the table, which improves workability. It is possible to improve the reliability and reliability of data.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in more detail based on an embodiment shown in the drawings. First, FIGS. 1 and 2 show an example of a contour shape measuring machine used in the present invention.

This contour shape measuring machine comprises a table 1 on which an object to be measured is placed and rotating, and a measuring means 2 for measuring the contour shape of the object to be measured. The table 1 is a well-known air bearing. Alternatively, it is provided on the base plate 3 via a mechanical bearing, a position adjusting means in the XY directions, a tilt mechanism, etc., and is formed so as to correct the position and inclination of the table 1 in the plane direction with respect to the measuring means 2. ing. Further, the measuring means 2 is provided with a detector 4 which is placed on the table 1 and comes into contact with a measurement surface of an object to be measured which is rotating, and which collects data, and the detector 4 is movable in the radial direction of the table 1. A holding means 5 for holding and a lifting means 6 for holding the holding means 5 so as to be able to move up and down in a direction perpendicular to the surface of the table 1 are provided.
It is formed so that the position of the detector 4 can be adjusted according to the diameter of the measurement surface of the object to be measured and the height from the table 1. Further, the detector 4 is connected to a calculation means (not shown), and the measurement data from the detector 4 is sent to the calculation means and subjected to a predetermined process, whereby the contour shape of the measurement surface of the measured object, that is, the diameter. And roundness is calculated.

The detector 4a of the detector 4 is formed so as to be movable only in the radial direction with respect to the center of mechanical rotation of the table 1, and at each measurement point on the measurement surface that rotates as the table 1 rotates. It is formed to collect the displacement amount. An electric micrometer is usually used for the detector 4, and a linear scale for detecting the position of the detector 4 is used for the holding means 5.

The contour measuring machine having the above structure can be used in the same manner as in the conventional case when measuring the roundness of the outer circumference of a tubular article or the inner circumference and outer circumference of a tubular article. .

Next, a procedure for measuring the contour shape of the incomplete circumferential portion of the object to be measured using the contour shape measuring device having the above-mentioned configuration will be described. Here, the incomplete circumferential portion usually indicates that the measurable circumferential portion of the object to be measured does not form a complete circumference, for example, the inner and outer peripheral portions of the fan-shaped article, the teeth of the gear. It represents a circumferential portion such as a tip surface. In addition, the size of the incomplete circumference that can be measured depends on the center angle, radius, length of the circumference, etc. If the center angle is large, the radius is small and the circumference is short. Is difficult to measure, and even if the center angle is small, it may be measurable if the radius is large and the length of the circumference is sufficient.

First, before measuring the contour shape of the incomplete circumferential portion of the object to be measured, the measuring means is first calibrated. This calibration corrects the measurement data of the measuring means with respect to the mechanical rotation center (mechanical origin) of the table. If this calibration operation is not performed, the measurement circumferential surface of the measured object will be The position data at each measurement point cannot be obtained accurately, and the measurement results such as the diameter and roundness also become inaccurate.

This calibration operation is carried out by placing a standard cylinder (master) on a table and measuring the standard circumferential surface of this standard cylinder with a measuring means. The standard cylindrical body has a standard circumferential surface, which has a predetermined radius and a substantially perfect roundness, on the outer peripheral portion or the inner peripheral portion thereof. In the measurement of the standard cylindrical body, correction of the inclination of the table and alignment (centering) are appropriately performed as necessary, as in the conventional measurement of circularity.

FIG. 3 is a view for explaining the measurement procedure when the standard circumferential surface Cm of the standard cylindrical body M is measured and the measuring means is calibrated. In the figure, Bo is the mechanical origin, Mo is the origin. Is the center point of the standard cylinder, and Mr _i is the i-th measurement point.

By measuring the standard circumferential surface Cm of the standard cylindrical body M, the position of the center point Mo of the standard cylindrical body M can be obtained as in the conventional roundness measurement, and the machine origin B
On the XY Cartesian coordinates with the origin of the machine origin Bo, the distance r between o and the center point Mo, the radius r of the circular locus drawn by the center point Mo with the rotation of the table can be obtained. Therefore, the coordinates of the center point Mo with respect to the mechanical origin Bo at the rotation angle θ of the table can be expressed as Mo (r, θ) by the rotation angle θ of the table and the radius r.

On the other hand, since the radius of the standard circumferential surface Cm, that is, the length of the line segment MoMr _i is predetermined,
The distance between the mechanical origin Bo and the i-th measurement point Mr _i (the length of the line segment BoMr _i ) can be calculated by the coordinates of the center point Mo and the radius of the standard circumferential surface Cm. Then, the sum of the reading of the linear scale of the holding means 5 and the reading of the electric micrometer of the detector 4 in the measuring means 2 is compared with this calculated value to calibrate the measuring means, and the linear scale reading and the electric Calculate a correction value to match the sum with the micrometer reading to the calculated value. This makes it possible to replace the measurement data at each measurement point with the distance from the machine origin Bo.

After calibrating the measuring means in this way, the object to be measured is placed on the table in place of the standard cylindrical body, centering is carried out if necessary, and the measurement surface of the object to be measured is measured. I do.

Then, as shown in FIG. 4, the respective measuring points on the measuring surface are placed on the XY orthogonal coordinates with the mechanical origin Bo as the origin, and the respective coordinates are obtained. That is, the coordinates of the first to n-th measurement points are set to Wr ₁ (x ₁ ,
y ₁ ), ..., Wr _i (x _i , y _i ), ..., Wr
_{It is calculated as n} (x _n , y _n ).

Next, it is considered that each of the above measurement points is a point on the circumference of the reference circle Cw drawn on the XY orthogonal coordinates,
Circle formula: (x−a) ² + (y−b) ² = r
Based on ² , the a, b, and r in the equation are calculated by the method of least squares, and the coordinates and radius of the center of the reference circle Cw are obtained. The a and b thus calculated are the coordinates (a and b) of the center point Wo of the measurement surface of the object to be measured, and r is the average radius W of the measurement surface.
r.

After the coordinates (a, b) of the center point Wo of the measurement surface and the average radius Wr are obtained in this way, as shown in FIG. 5, the distance between the measurement point W _i and the center point Wo (line Minutes BoW _i
Length) and the radius Wr of the reference circle Cw. That is, in FIG. 5, the position of the center point Wo is the mechanical origin B.
Distance between o and center point Wo (length of line segment BoWo) r
₀ and the rotation angle θ of the table, Wo (r ₀ ,
θ), the distance between the machine origin Bo and the measurement point W _i is the measurement value of the measuring means, and the distance between the point WJ _i on the reference circle Cw and the center point Wo is the reference circle Cw. Since it is a radius, the distance of the measurement point W _i to the reference circle Cw (the line segment W _i
The length of J _i W _i ) can be easily obtained by a simple calculation.

The above calculation is performed for each measurement point W _i (i = 1 to n) to find the maximum and minimum values of the length of the line segment WJ _i W _i , and the obtained maximum value and minimum value are calculated. If you calculate the difference,
The roundness (maximum value-minimum value) of the measurement surface can be obtained. As a result, the average radius and the roundness on the measurement surface of the measured object are measured.

Further, as shown in FIG. 6, when the contour of the diaper-shaped article D is measured, two points on a straight line passing through the center point Wo and a distance between Wp and Wq are obtained in the same manner as above. The maximum diameter (maximum distance), the minimum diameter (minimum distance), and the diameter of the reference circle of the article D can be obtained.

7 to 9 show an embodiment of a jig used for measuring the diameter and roundness of an incomplete circumferential portion. This jig is composed of a standard cylindrical body 11 shown in FIG. 7 and a standard cylindrical body 12 shown in FIGS. 8 and 9, both of which are used by being inserted into an engagement hole 13 provided at the center of the table 1. It is a thing.

The standard cylindrical body 11 has an insertion engagement portion 14 corresponding to the engagement hole 13 in the lower half portion thereof, and has a radius corresponding to the design radius of the measurement surface of the object to be measured on the inner periphery of the upper half portion. The reference cylindrical body 12 has a standard circumferential surface 15, and the reference cylindrical body 12 has an insertion engaging portion 16 similar to the insertion engaging portion 14 of the standard cylindrical body 11 in the lower half portion, and also has a standard cylindrical shape in the outer periphery of the upper half portion. The reference circumferential surface 17 has a radius corresponding to the standard circumferential surface 15 of the body 11 and is formed so that the height of protrusion from the table 1 is lower than the height of the measurement portion of the object to be measured. That is, the standard cylindrical body 11 and the reference cylindrical body 1 are inserted into the engaging holes 13 of the table 1.
The two circumferential surfaces are set such that the standard circumferential surface 15 of the standard cylindrical body 11 and the reference circumferential surface 17 of the reference cylindrical body 12 are located at the same position when 2 is inserted.

Next, the method of using the above jig will be described in accordance with the procedure for measuring the diameter and roundness of the inner peripheral surface 19 of the fan-shaped article 18.

First, as shown in FIG. 7, a standard cylindrical body 11
Is inserted into the engagement hole 13 of the table 1, the detecting portion 4a of the detector 4 is brought into contact with the standard circumferential surface 15 while the table 1 is rotated, and the measuring means is calibrated by the procedure described in FIG.

Next, after replacing the standard cylindrical body 11 with the standard cylindrical body 12 into the engaging hole 13 of the table 1, the article 18 is inserted.
Is placed on the table 1, and the inner circumferential surface 19 of the article 18, which is the measurement surface, is brought into contact with the outer circumferential reference circumferential surface 17 of the reference cylindrical body 12.

As a result, the inner circumferential surface 19 of the article 18 is set at substantially the same position as the standard circumferential surface 15 formed on the inner circumference of the standard cylindrical body 11, and the center of the arc of the inner circumferential surface 19 is set. The point is in a state of being substantially coincident with the center point of the standard circumferential surface 15.

In this state, the detector 4 is brought into contact with the inner peripheral surface 19 of the portion projecting from the reference cylindrical body 12, and the table 1 is rotated, so that the diameter of the inner peripheral surface 19 and the perfect circle can be obtained by the procedure described above. You can ask for degrees.

Therefore, the centering of the inner peripheral surface 19 of the article 18, which is an incomplete circumference, can be easily performed by performing the centering surely by using the standard cylindrical body 11 whose radius and roundness are known. The measurement accuracy can be significantly improved, and the article 21, which is the object to be measured, can be set very easily. Also, table 1
By forming the engaging hole 13 in the center of the table 1, the centering can be omitted, and even when the centering is performed, the operation can be performed easily and accurately.

When measuring the outer peripheral surface of an article, as shown in FIGS. 10 and 11, at least two engaging holes 21 and 21 are provided in the outer peripheral portion of the table 1, and the engaging holes 21 and 21 are provided. A hat-shaped standard cylindrical body 22 having a central portion protruding is engaged with the holes 21 and 21, and the measuring means is calibrated by a standard circumferential surface 23 formed on the outer periphery of the protruding portion, and then a ring-shaped reference cylindrical body. 24 is engaged with the engagement holes 21 and 21,
The outer circumferential surface 27, which is the measuring portion of the object 26 to be measured, may be brought into contact with the reference circumferential surface 25 formed on the inner circumferential surface. In this case, instead of the engaging hole 21, a protrusion for engaging the standard cylindrical body 22 or the reference cylindrical body 24 may be provided on the outer peripheral portion of the table 1, and a circumferential or radial groove or a groove may be formed on the table surface. It is also possible to provide a ridge and provide a jig with a ridge or groove corresponding to the ridge so that the jig and the groove can be fitted together.

[0037]

As described above, according to the contour shape measuring method of the present invention, it is possible to reliably measure the contour shape, that is, the diameter or the roundness of a portion which is not a perfect circle, and the corner of the profiled material can be surely measured. The diameter of the portion, the roundness, or the diameter of the gear with odd teeth can be easily obtained. Further, the maximum diameter and the minimum diameter of the profiled material and the diameter of the reference circle can be easily obtained.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a contour shape measuring machine used in the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is an explanatory diagram when calibrating the measuring means.

FIG. 4 is an explanatory diagram for obtaining a reference circle from the coordinates of each measurement point.

FIG. 5 is an explanatory diagram for obtaining roundness based on a reference circle.

FIG. 6 is an explanatory diagram for obtaining the maximum diameter and the minimum diameter of the profiled material.

FIG. 7 is a cross-sectional view showing an example of a standard cylindrical body of a measuring jig.

FIG. 8 is a sectional view showing an embodiment of a reference cylinder as well.

FIG. 9 is a plan view showing an embodiment of the reference cylindrical body.

FIG. 10 is a cross-sectional view showing another embodiment of the standard cylindrical body of the measuring jig.

FIG. 11 is a sectional view showing another embodiment of the reference cylindrical body.

[Explanation of symbols]

1 ... table, 2 ... measuring means, 4 ... detector 11,22
... Standard cylindrical body, 12,24 ... Standard cylindrical body, 15,23 ...
Standard circumferential surface, 17, 25 ... the reference circumferential surface Bo ... mechanical origin, Cw ... reference circle, Wo ... center point of the measurement surface, W _i ... measurement point

Claims (3)

[Claims] 1. A table on which an object to be measured is placed and which rotates, and a measuring means which is arranged so as to be movable in a radial direction with respect to a mechanical rotation center of the table and which measures the contour shape of the object to be measured. A method of measuring the contour shape of the incomplete circumferential portion of the measured object using a measuring machine equipped with, measuring the standard circumferential surface of the standard cylindrical body placed on the table, each measuring point After calibrating the measuring means with respect to the mechanical rotation center of the table from the measured value at and the radius of the standard circumferential surface, place the measured object in place of the standard cylindrical body on the table, The circumference is measured by the measuring means, the position of each measurement point is regarded as a part of a circle drawn on the orthogonal coordinate axis with the mechanical rotation center as the origin, and the least squares method based on the formula of the circle. The coordinates and radius of the center of the circle are obtained, and the obtained center coordinates and A contour shape measuring method characterized by measuring a contour shape of an incomplete circumferential portion of the measured object from a radius and a measurement value at each measurement point. 2. A table on which an object to be measured is placed and rotating, and a measuring means which is arranged so as to be movable in a radial direction with respect to a mechanical rotation center of the table and measures the contour shape of the object to be measured. A method for measuring the contour shape of an incomplete circumferential portion formed on the inner peripheral side of an object to be measured using a measuring machine equipped with a reference engaging hole formed in the center of rotation of the table. Insert a standard cylindrical body having a standard inner peripheral surface having a radius corresponding to the design radius of the measurement circumference of the object to be measured, measure the standard inner peripheral surface of the standard cylindrical body, and measure at each measurement point. After calibrating the measuring means with respect to the center of mechanical rotation of the table from and the radius of the standard inner peripheral surface, the reference engaging hole has a reference outer peripheral surface corresponding to the standard inner peripheral surface of the standard cylindrical body. Along with the height of the circumference of the measurement circumference of the DUT, Insert a reference cylindrical body formed lower than the height, then placed on the table in a state in which the measurement circumferential portion of the measured object is in contact with the outer peripheral surface of the reference cylindrical body,
The measurement circumference is measured by the measuring means, and the position of each measurement point is regarded as a part of a circle drawn on the orthogonal coordinate axis with the center of mechanical rotation as the origin, and the minimum autonomy is calculated based on the formula of the circle. Obtain the coordinates and radius of the center of the circle by multiplication, from the obtained center coordinates and radius and the measured value at each measurement point,
A contour shape measuring method characterized by measuring a contour shape of an incomplete circumferential portion of the object to be measured. 3. A table on which an object to be measured is placed and which rotates, and a measuring means which is arranged so as to be movable in a radial direction with respect to a mechanical rotation center of the table and measures the contour shape of the object to be measured. A jig used when measuring the contour shape of an object to be measured using a measuring machine equipped with a standard having a standard circumferential surface with a radius corresponding to the design radius of the contour shape measuring part of the object to be measured. It comprises a cylindrical body and a reference cylindrical body having a reference circumferential surface in the opposite direction corresponding to the standard circumferential surface of the standard cylindrical body, wherein the standard cylindrical body and the reference cylindrical body are the reference members provided on the table. A jig for contour shape measurement, characterized in that each of the reference cylindrical bodies has an engaging portion that engages with a mating portion, and that the reference height of the reference cylindrical body is lower than the height of the object to be measured. .