JP3516289B2 - Method and apparatus for measuring dimensions of cylindrical object - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for measuring a plurality of structural dimensions of a cylindrical object at once with high accuracy and at high speed.

[0002]

2. Description of the Related Art One of the cylindrical objects required to be mass-produced with extremely high dimensional accuracy is a part called a ferrule which is an important constituent element of an optical fiber connector for communication. The outer diameter of the ferrule is 2.5mm and the inner diameter is 125μ.
m, length is about 10 mm. The permissible deviations of the three dimensions of the outer diameter, inner diameter, and eccentricity of the ferrule to be the product are extremely small, from 1 μm to 0.1 μm. Therefore, selection and pass / fail judgment are performed based on highly accurate dimension measurement during manufacturing, and it is an essential requirement for manufacturing to perform all dimension measurement at a speed commensurate with the manufacturing speed at low cost. There is.

For the dimension measurement of the ferrule, a method of performing a combination of a plurality of highly precise measurement means of minute dimensions such as measurement by image processing and laser application measurement has been widely used. For example, a pin gauge, an electric micrometer, and a laser length measuring device have been used for measuring the outer diameter, and image measurement using an area sensor camera and an image processing device have been frequently used for measuring the inner diameter and eccentricity.

[0004]

However, the conventional method for measuring a plurality of dimension items by using the above-mentioned plurality of measuring means alone or in combination has the following problems. . That is, since a plurality of measuring means are required, the mechanism / configuration becomes complicated, the measuring time is slow, and the apparatus is expensive. Furthermore, the adjustment / calibration for maintaining accuracy becomes complicated.

An object of the present invention is to solve these problems of the conventional method of measuring a plurality of dimension items of a cylindrical object, namely, three dimension items of an outer diameter, an inner diameter, It is an object of the present invention to provide a novel method and apparatus that can measure each eccentric dimension based on one image measurement at low cost and at high speed, and facilitate adjustment and calibration for maintaining accuracy.

[0006]

Gage system of the cylindrical body according to the present invention for achieving the above object, according to an aspect of from one end face direction of the cylindrical object and the center line of the outer circumference of the cylindrical object wherein An image in which the loci of these two points are taken as the locus of the inner circumference in synchronization with the two points where the inner circumference of the cylindrical object intersects
The means for imaging the entire inner circumference in the direction of rotation around the center of the outer circumference intersects the center line of the outer circumference of the standard cylindrical object and the inner circumference.
Of the standard cylindrical object, which is the locus of two points
Inner circumference in the image over the entire inner circumference in the direction of rotation about the center
The position of the locus of the is set as a preset reference position, and the track of the inner circumference of each of the cylindrical objects obtained from the imaged image is obtained.
Each of said groups from the difference between the position and the reference position of each of the traces
Means for measuring the amount of displacement from the quasi-position, and the measured 2
A means for calculating the values of the outer diameter, the inner diameter, and the eccentricity of the cylindrical object from a set of displacement amounts by a constant calculation formula.

The means for picking up the image of the inner peripheral edge over the entire inner circumference includes means for rotating a cylindrical object, a line sensor camera, and a light source.

Further, a means for rotating the cylindrical object is constituted by a V-groove structure and a mount provided at one end of the V-groove structure for positioning the cylindrical object, and the V-groove. A rotary drive mechanism that has a rotation axis at an angle different from the valley line of the structure and that rotates in contact with a cylindrical object positioned on the mount table.

Further, the above-mentioned dimension measuring apparatus is characterized in that it is newly provided with a conveying means for sequentially conveying and replacing the cylindrical objects.

Further, the transporting means simultaneously traverses the first and second trays for arranging and holding a plurality of the cylindrical objects side by side and the cylindrical objects held in the first tray at the same time. In a direction, means for moving the cylindrical object from one end of the first tray to the mount base, and means for moving the cylindrical object from the mount base to the second mount.
And a means for moving the cylindrical objects held in the second tray in a horizontal direction at the same time.

Alternatively, the conveying means horizontally moves a tray for arranging and holding a plurality of the cylindrical objects side by side, and moves the tray in the lateral direction by one arrangement interval of the cylindrical objects held in the tray. And means for positioning any of the cylindrical objects on an extension of the V-groove valley line of the mount, and the cylindrical objects from the tray to the mount or from the mount to the tray or another tray. Means for moving along the direction of the V groove valley line of the mount base.

Further, in the above dimension measuring apparatus, means for generating a pass / fail judgment signal or a rank classification signal based on the numerical values obtained by the means for calculating the values of the outer diameter, the inner diameter and the eccentricity of the cylindrical object, When the transport means moves the cylindrical object from the mount to the second tray or the tray or another tray, the cylindrical object whose dimension has been measured is sorted by the quality determination signal or the rank classification signal. Means and are newly provided.

Meanwhile, the dimension measurement method of the cylindrical body according to the present invention for achieving the above object, a center line of the outer circumference of the cylindrical object from one of the end face direction of the cylindrical object
Come in synchronism with two points and the inner circumference of the cylindrical object intersect
The image to the inner periphery of the track the trajectory of the two points of the outer periphery of the
Imaging the entire inner circumference in the direction of rotation about the center ,
Two, where the center line of the outer circumference and the inner circumference of a standard cylindrical object intersect
Rotate around the center of the outer circumference of the standard cylindrical object, which is the locus of points
Of the locus of the inner circumference in the image over the entire inner circumference in the direction
The position of the inner circumference of the locus of the cylindrical body of each obtained from the captured image as a reference position set the location in advance
From the difference the reference position of each of the said reference position of each
The step of measuring the amount of displacement of the cylindrical object, and the outer diameter and the inner diameter of the cylindrical object according to a constant calculation formula based on the two measured displacement amounts.
And a step of calculating the value of the eccentricity.

Further, it is characterized in that measured values of a cylindrical object whose outer diameter and inner diameter measured by the same device are known are used as the respective preset reference values.

Further, among the above-mentioned fixed calculation formulas, the calculation formula for calculating the outer diameter D is as follows: the reference value of the outer diameter is D ₀ , the constant depending on the vertical positioning method is c, and the number of measurement points is n. of
A _(x) the displacement of the x-th inner periphery of the trajectory in the measurement position, the displacement of the x-th inner periphery of the trajectory in the other measuring position B _(x), and the measurement of the cylindrical object 1 revolution An expression where the score is m

[0016]

[Equation 6]

Or

[0018]

[Equation 7]

And the calculation formula for calculating the inner diameter d is
An expression in which the reference value of the inner diameter is d ₀

[0020]

[Equation 8]

And the formula for calculating the eccentricity C is
An expression in which the maximum value of the variable F _(x) is max [F _(x) ] and the minimum value of the variable F _(x) is min [F _(x) ].

[0022]

[Equation 9]

It is characterized in that

Further, the constant calculation formula is one measurement position
The displacement of the x-th inner track of the position is A _(x) ,
The displacement of the x-th inner track at one measurement position
B _(x) , m is the number of measurement points for one rotation of the cylindrical object, and the coefficient
Is numerically determined so as to optimally approximate all of the measured displacement amounts by using an equation A _(x) + B _(x) = p + qsin ((2πx / m) + r) where p, q, and r are factor p, a formula that uses a q and r, equation for calculating the outer diameter D is the reference value of the outer diameter
D ₀ and a constant depending on the vertical positioning method are c
Where D = D ₀ + (c × p) and the calculation formula for calculating the inner diameter d is the reference value of the inner diameter.
Where d ₀ and the number of measurement points are n

[0025]

[Equation 10]

And the calculation formula for calculating the eccentricity C is C = q / 2 Is characterized in that.

Further, the V groove angle of the V groove structure is 90.
And a constant c depending on the vertical positioning method is 1 / √2.

According to the present invention, the displacement amounts from the reference position at two substantially opposite edges of the inner peripheral edge portion of the cylindrical object are image-measured over the entire inner periphery, and the outer diameter, the inner diameter, and the eccentricity are calculated by a constant calculation formula. It is characterized in that the three dimension items are calculated only from the displacement amount. Furthermore, a mechanism for continuously capturing the images of the two inner peripheral edge portions over the entire inner periphery while rotating the cylindrical object at a fixed position while contacting the fixed surface where the outer periphery of the cylindrical object is positioned, It is characterized by being composed of a line sensor camera.

As described above, in the present invention, a single image measuring method for measuring a plurality of dimension items in a cylindrical object is realized by only one image pickup means and one image measurement means.
By being executed by the device, the structure of the device is simplified and the cost is reduced, and the dimension measurement is speeded up. In addition, the single image pickup means facilitates various adjustments and calibrations for maintaining accuracy such as image pickup line positioning adjustment, illumination adjustment, image pickup focus adjustment, and image pickup magnification adjustment.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The contents of the embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram for explaining a basic embodiment of the present invention, showing an example using a line sensor camera. Reference numeral 1 denotes a cylindrical object (hereinafter referred to as a cylinder) which is an object to be measured, 2 denotes an inner circumference formed by a hole formed in an end surface of the cylinder,
Reference numeral 3 denotes an imaging line, which is fixedly set on the center line of the outer circumference on one end surface of the cylinder, constitutes a line segment that intersects with the inner circumference of the cylinder at two locations, and represents the imaging visual field position. Reference numeral 4 denotes a light source, which illuminates the inside of the cylindrical hole by illuminating the hole to make the image of the inner peripheral edge portion clear. 5 is a mount base for holding the cylinder in a fixed position, for example, V
It is composed of a groove and a structure (not shown) for positioning the end surface of the cylinder. Reference numeral 6 denotes a rotary drive mechanism for rotating the cylinder at a substantially constant speed, which is composed of a roller or a belt which moves at a constant speed while being in contact with the outer circumference of the cylinder. Reference numeral 7 denotes a line sensor camera, which includes an optical lens, a reflecting mirror, etc., which is an optical system for forming an image on the line sensor element. Reference numeral 8 is an image processing device for measuring the displacement amount of the inner peripheral edge portion from the captured image, and 9 is a data processing device for calculating the three dimension items of the cylinder from the measured displacement amount.

In this embodiment, the cylinder 1 is mounted on the mount base 5.
Then, the rotary drive mechanism 6 rotates the rotary drive mechanism 6 in the direction of the arrow in FIG. 1, for example. An image at the position of the image pickup line 3 is formed on the line sensor camera 7, where it is converted into an electric signal by a CCD line sensor element or the like, and the image processing device 8 is operated.
Is input to the data processing unit 9 and the three size items of the cylinder 1 are calculated. Note that the position of the light source 4 is on the side facing the line sensor camera 7 with the cylinder 1 in between in FIG. 1, and since it constitutes transmissive illumination, it is captured as an image in which the inside of the hole is bright and the periphery is dark. Not limited to line sensor camera 7
May be on the same side as. In this case, the light is reflected illumination, and the inside of the hole is dark and the periphery is captured as a bright image. The method of capturing an image with one line sensor camera 7 as in the present embodiment is in the width direction (direction of the pixel array forming one line of the line sensor element) in the captured image.
The dimensional error is extremely unlikely to occur and high measurement accuracy can be obtained. This is because the array of pixels on the line sensor element is a straight line and is fixed to a fixed size.

FIG. 2 is a diagram for explaining the details of a captured image according to the present invention. Two points where the imaging line 3 set on the outer circumference centerline of the cylinder 1 intersects with the inner circumference 2 are designated as A and B, respectively. Reference numeral 10 is a camera image obtained by capturing an image of the imaging line 3 with the line sensor camera 7 and obtaining an electric signal. An arrow y indicates a pixel address in the horizontal scanning direction of the line sensor camera 7, and an arrow x indicates a pixel address in the vertical scanning direction of the line sensor camera 7, that is, a line direction. x uniquely corresponds to the rotation angle of the cylinder 1. 11 is the imaging line 3
This is the inner locus observed at point A above. Reference numeral 12 is an inner circumference locus observed at a point B on the imaging line 3. 11,
Reference numeral 12 is a linear locus generated by the rotation of the inner circumference 1 and has a repeating characteristic in which one rotation of the cylinder 1 is a cycle.
In general, when the light source 4 is arranged as shown in FIG. 1, the camera image 10 has a bright level inside the hole and a dark level other than the hole. Therefore, the boundary between the light level and the dark level is defined as the locus of the inner circumference. As an example, the inner diameter, that is, the inner diameter is 125 μm, and the length of the imaging line 3 is 155 μm.
In this case, if the specification of the line sensor camera 7 is a resolution of 5120 pixels / line, an image is captured with a resolution of 0.03 μm per pixel.

FIG. 3 is a diagram showing a concept of one embodiment of the present invention in which only the inner peripheral loci 11 and 12 and peripheral portions thereof necessary for image measurement in the captured camera image 10 are extracted as input images. Is. The purpose of this is to reduce the amount of processed images in image measurement, to shorten the processing time and to reduce the cost. 20 in FIG. 3A is a resolution 512.
It is a camera image imaged by the line sensor camera 7 of 0 pixel / line. Reference numeral 21 in FIG. 3B is 1 from y = 4096 to y = 5119 in the camera image 20.
It is an input image obtained by extracting 024 pixels, and includes the inner track 11 observed at a point A. Reference numeral 22 in FIG. 3C indicates y = 0 to y = 1023 in the camera image 20.
Is an input image obtained by extracting 1024 pixels up to and including the inner track 12 observed at point B. The resolution of the line sensor camera and the y address of the image to be extracted are not limited to the values in this example and can be set arbitrarily. Obtaining the input images 21 and 22 from the camera image 20 based on this concept can be electrically realized by scanning conversion processing and signal extraction / insertion processing, which are general methods in image signal processing by electronic circuits.

The concept of input image extraction can also be realized by using a general optical means such as combining a plurality of reflecting mirrors so as to form two distant images so as to be arranged close to each other. . In this case, since the points A and B are imaged close to each other on the line sensor camera, the resolution required by the line sensor camera 7 can be set smaller than when the entire length of the imaging line 3 is included. For example, when this optical means is not used, the resolution of the line sensor camera is 51
When 20 pixels / line is required, a line sensor camera having a smaller number of pixels, for example, a resolution of 1024 pixels / line or 2048 pixels / line can be used by applying this means, and the imaging time can be shortened. Becomes Reference numeral 30 in FIG. 3 (d) indicates 20 using the present optical means.
It is a camera image imaged by a line sensor camera of 48 pixels / line. The camera image 30 has a line 31 in which two images, an image including the point A and an image including the point B, are optical boundaries.
It is observed as an image connected by.

FIG. 4 is a diagram for explaining the definitions of the three dimension items of the cylinder and for explaining the displacement amount measured based on the locus of the inner circumference which is imaged and observed by the present invention. D is the outer diameter of the cylinder 1 to be measured, d is the inner diameter of the cylinder 1, C is the eccentricity of the cylinder 1, and is the distance between the center 50 of the outer circumference of the cylinder and the center 51 of the inner circumference of the cylinder. x is the rotation angle of the cylinder 1 that rotates in the direction of the arrow with the center 50 of the outer circumference of the cylinder as the center of rotation. Point A on input image 21
An image of the inner peripheral locus 11 is included in the image comparison calculation with the inner peripheral locus 61 at the point A of the standard cylinder having a known dimension previously captured and registered as an input image as a reference position. Thus, the displacement amount of the trajectory 11 with respect to the trajectory 61 in the y direction is obtained, and this is referred to as A _(x) . Similarly, in the input image 22, the locus 62 is obtained by the image comparison calculation using the locus 62 of the inner circumference at the point B of the standard cylinder as the reference position.
The amount of displacement of the trajectory 12 in the y direction with respect to
_(x) Trajectory 6 of the inner circumference of the standard cylinder as the reference position
The method of creating Nos. 1 and 62 is not limited to the method using an input image obtained by picking up one standard cylinder having a known size or an input image obtained by processing the standard cylinder by image processing. It may be created by adding processing for image stabilization and accuracy improvement such as averaging the locus of the inner circumference using the input image. By capturing the image of the standard cylinder with the same imaging device as the cylinder to be measured, and using the locus of this inner circumference as the reference position, stable and highly accurate measurement that is less susceptible to variations in the characteristics of the imaging device and changes over time is possible. To do.
In addition, adjustment and calibration of the image pickup device become easy. Alternatively, the virtual inner circumference locus artificially generated by setting the numerical values may be used as the inner circumference loci 61 and 62 of the standard cylinder.

By using the line sensor camera as an image pickup means, the cylinder is rotated at a high speed to take an image, so that the image pickup time can be shortened, and the displacement amount for the partial image focusing only on the inner peripheral edge portion can be measured. Since the processing time can be shortened, high speed measurement is possible. Also, since the observation values of the inner track have continuity and periodicity, mathematical,
The data processing based on the statistical analysis can effectively remove the disturbance and enable highly accurate measurement.

Although the embodiment in which the line sensor camera is used as the image pickup means has been described above, the present invention is not limited to this, and the present invention can be configured using an area sensor camera. That is, the relative displacement amount with respect to the preset reference position is image-measured from the image of the inner circumference of the cylinder captured by the area sensor camera, with respect to the two inner circumference edge portions facing each other at a certain position. By repeating this measurement for each constant rotation angle of the cylinder rotating at a fixed position,
The displacements A _(x) and B _{(x) of the} inner track are obtained. The area sensor camera captures a continuous still image by stopping the cylinder at a constant rotation angle to obtain a continuous still image, and by rotating the cylinder at a constant speed and exposing the shutter at constant time intervals to obtain a continuous still image. There is a method of obtaining it, and either method may be used.
For the image for setting the reference position, a standard cylinder can be used as in the case of using the line sensor camera.

The three dimensional items of the cylinder are calculated using the measured displacements A _(x) and B _(x) of the locus of the inner circumference based on a fixed calculation formula.

As one embodiment of the calculation formula, the following formula 1,
There are Formula 2, Formula 3, and Formula 4.

Outer diameter:

[0042]

[Equation 11]

Or

[0044]

[Equation 12]

Here, D ₀ is the known outer diameter of the standard cylinder registered as a reference or the outer diameter of the virtual standard cylinder obtained by calculation. n is the number of measurement points of the displacement amounts A _(x) and B _(x) , and it is desirable to set it in the range of n> m when the number of measurement points of one rotation of the cylinder is m. c is a constant depending on the positioning method in the y direction, and c = 1 / √2 in the case of the method of positioning by the right angle V groove as shown in FIG. k is k = m /
It is a constant given by 2. The outer diameter obtained by the equations 1 and 2 is an average value after one rotation of the cylinder or more.

Inside diameter:

[0047]

[Equation 13]

Here, d ₀ is the known inner diameter of the standard cylinder registered as a reference or the inner diameter of the virtual standard cylinder obtained by calculation. The inner diameter obtained by the equation 3 is an average value after one rotation of the cylinder.

Eccentricity:

[0050]

[Equation 14]

Where max [F _(x) ], min
[F _(x) ] is the maximum value and the minimum value of the variable F _(x) , respectively.

As other examples of the calculation formulas, there are the following formula 5, formula 6, formula 3 and formula 7.

Since the cylinder normally has an eccentricity, the sum of the two displacements (A _(x) + B _(x) ) can be approximated as a sine function. The approximate expression is set to Expression 5.

A _(x) + B _(x) = p + qsin ((2πx / m) + r) (Equation 5) Coefficients p, q, and r of Equation 5 based on the observed values of (A _(x) + B _(x) ) The optimum approximate value of can be obtained easily and at high speed by using an ordinary method such as an analytical method, a numerical calculation method, and a Fourier transform method. The three dimension items D, d, and C can be calculated using the coefficients p and q by the following calculation formulas.

D = D ₀ + (c × p) (Equation 6)

[0056]

[Equation 15]

C = q / 2 (Equation 7) Furthermore, (A _(x) + B _(x) ) or (A _(x) − ₎ obtained by combining two continuously observed displacements.
By frequency-analyzing the two observed values of B _(x) , the factor of measurement error can be removed and the measurement accuracy can be improved.
That is, it is possible to improve the variation factors due to various disturbances such as dimensional unevenness, motion unevenness, and image pickup unevenness of the cylindrical object by using well-known methods such as averaging, smoothing, and band-pass filter. In particular, the dimensional irregularity of a cylindrical object represented by roundness is an observed value that changes in synchronization with the rotation period, so it can be clearly separated from the noise component due to disturbance. That is, the above two observation values are decomposed into a DC component, a component synchronized with the rotation cycle, and a component that changes randomly, and the respective values are used as observation data, whereby the measurement accuracy can be further improved. Further, since the above-mentioned two observation values are periodically repeated, it is possible to correct the repetitive error and improve the accuracy by well-known statistical processing. Further, according to the principle of the present invention, since the locus corresponding to a constant inner peripheral edge portion is registered as a reference and the displacement amount obtained by the relative position comparison with this is used as the basic amount, the standard cylinder is imaged by the same imaging means. Then, by registering as a reference, it is possible to automatically perform correction even with respect to secular variation such as positioning conditions, imaging conditions, and the like, and stable measurement is possible. Variations in the positioning conditions include lateral deviation of the imaging line from the cylinder center line, vertical deviation of the imaging line, rotational deviation of the imaging line, and the like. Further, as the variation of the imaging condition, there are variations in the brightness of the captured image due to variations in the light amount of the light source, the inclination of the imaging optical axis, etc. When the degree of these fluctuations is relatively small, the measurement error due to these fluctuations can be reduced to a practical level by using the line sensor camera according to the present invention or setting the reference position by the standard cylinder.

FIG. 5 is a top view for explaining the structure of the first concrete embodiment according to the present invention.
71, 72, 73, 74 and 75 are trays for arranging and holding a plurality of cylindrical objects side by side, and 76 is a tray 70, 7
1 and 72, 77 is a transport mechanism that transports and positions the trays 73, 74 and 75 in the directions of the arrows, respectively, and 80 is a temporary holding of the cylindrical object 1c discharged from the positioned tray 71, and then the mount table 5 Supply stand for supplying to
The reference numeral 81 designates a tray 74 which holds the cylindrical object 1e ejected from the mount table 5 after the inspection is completed and which is then positioned.
It is a discharge table for sending to. Tray 70 is the tray to be inspected next, tray 71 is the tray under inspection, tray 7
Reference numeral 2 denotes an empty tray that has been inspected, and the six cylindrical objects 1a to 1f on the tray 71 are sequentially conveyed to the right as the inspection progresses.

Cylindrical object 1d under inspection on the mount table 5
Is rotated by the rotary drive mechanism 6, and a force is applied in the direction in which one end of the cylindrical object is constantly pressed against the stopper 13 in order to maintain highly accurate positioning in the longitudinal direction during rotation. This force is, for example, as shown in FIG.
As shown in the partially enlarged view of (b), the rotation drive mechanism 6 is configured, and an angle θ formed by, for example, the rotation axis of the roller rotating in contact with the cylindrical surface of the cylindrical object 1d and the rotation axis of the cylindrical object 1d.
Is provided by the roller as indicated by the arrow in relation to the direction of rotation in which the cylindrical object rotates counterclockwise and clockwise. This force can also be supplied by, for example, installing a drive mechanism that presses the end surface of the cylindrical object 1d on the side opposite to the end surface in contact with the stopper 13 in the rotation axis direction. A semicircular stopper 13 in the mount base 5 is usually arranged at one end on the extension of the V groove and constitutes the mount base 5 together with the V groove.

The inspected cylindrical object is further conveyed rightward and stored in the tray 74. When the tray 74 is full, the transport mechanism 77 transports the tray 74 together with the empty tray 73 and the full tray 75 in the direction of the arrow to a fixed position. The cylindrical objects stored in the tray in this manner are automatically mounted on the mount base 5 and inspected, and then automatically stored in the empty tray in sequence. Since the handling is performed by such a configuration and operation, the cylindrical object is transported, inspected, and stored in a unidirectional flow work, and in the case of the present embodiment example, it has a feature that it is fast and stable. is there. Although not shown, it is also possible to connect the transport mechanisms 76 and 77 to transport the empty tray 72 after the empty tray 73 and position it.

In this embodiment, the V groove is used as the mount base, but the mount base is not limited to the V groove, and the cylinder can be rotated at a fixed position, for example, a gap narrower than the outer diameter of the cylinder. The same effect can be obtained even with a pair of fixed rollers or the like.

Further, in the present embodiment, the V-grooves are arranged only when the opening side faces upward, but the openings may be arranged downward or sideways. For example, in the case of the downward arrangement, the cylinder is mounted and measured from below the V groove by the upward movement of a rotating mechanism such as a roller or a belt arranged below the cylinder from the transport tray. After that, by moving the rotating mechanism or the like that presses the cylinder against the V groove downward, the cylinder can be easily dismounted by being dropped by gravity and returned to the transport tray. Further, in the case where the opening is arranged downward, there is an advantage that the V-groove can be kept in a correct position for a long period of time with less contamination due to the adhesion of foreign matter such as dust.

FIG. 6 is a side view showing partial details of the embodiment shown in FIG. 5. Reference numeral 83 is for conveying the cylindrical objects 1a and 1b in the tray 71 on the supply side to the right step by step. The feeding-side feed pawl blade, 84 is a storage-side feed pawl blade for conveying the cylindrical object 1f in the tray 74 on the storage side to the right one step at a time, and 85 is a supply base 80.
It is a mount feed blade for simultaneously conveying the upper cylindrical object 1c and the cylindrical object 1d on the mount base 5 to the right by one step. Reference numeral 86 is a roller (or disk) for imparting rotation and axial movement to the cylindrical object 1d on the mount table 5, and 87 is a drive roller for supplying a rotational force to the roller 86. The rotation drive mechanism 6 is configured. The rotation axis of the roller 86 is movable and moves to the position indicated by the alternate long and short dash line in the direction of the arrow, for example. This action avoids the roller 86 from becoming an obstacle when the cylindrical object gets over the uppermost part of the supply table 80 or the mount table 5 along with the transportation of the cylindrical object 1c or 1d. The feed side feed claw blade 83, the storage side feed claw blade 84, and the mount feed blade 85 each move in the directions of the arrows (up → right → down → left), and as a result, the cylindrical objects are simultaneously moved in one cycle of movement. 1 step to the right. The three blades operate with constant timing synchronization as needed.

FIG. 7 is a top view for explaining the configuration of the second specific embodiment of the present invention, in which 90 is a cylindrical object 1d transferred between the tray 71 and the mount 5. The transfer mechanism 91 for moving the tray 71 to the right 1
A transport mechanism that transports and positions each step. The operation of transferring the cylindrical object 1d is as follows, for example. The stick constituting the transfer mechanism 90 moves back and forth in the direction of the arrow to transfer the cylindrical object 1d to the mount table 5,
Further, for example, an end surface of the cylindrical object 1d on the mount table 5 is adsorbed by a suction mechanism provided at the tip of the stick and transferred to the tray 71. At this time, when the light source 4 is arranged so as to face the line sensor camera 7 so as to sandwich the cylindrical object 1d, the light source 4 is temporarily provided so as not to hinder the movement of the cylindrical object 1d. Move the position of.

FIG. 8 is a side view showing partial details of the example embodiment of FIG. When the cylindrical object 1d is transferred by the mount 5, the roller 86 moves upward so that the cylindrical object 1d can move in the axial direction. Also, the cylindrical object 1d
Is mounted on the mount base 5 and imparts a rotational movement, the roller 86 is moved downward, and if necessary, the cylindrical object 1d is pressed against the mount base 5 in the direction of the arrow F.
Is applied.

FIG. 9 is a top view for explaining the configuration of the third specific example of the embodiment including the sorting mechanism according to the present invention, in which 101 is a cylindrical shape whose inspection result is rank A. Tray for storing objects, 102 for storing cylindrical objects whose inspection result is rank B, 103 for storing cylindrical objects whose inspection result is rank C, 104 is cylindrical shape after inspection It is a sorting mechanism that transfers the object 1e to a tray position determined based on a quality determination signal or a rank sorting signal which is an inspection result. In FIG. 9, the sorting positions are arranged in the front-back direction and the number of stages is three, but the arrangement is not limited to this, and the sorting positions may be arranged in the upper and lower directions, or the number of stages may be two or more. The present embodiment example can also be applied to the embodiment example of FIG. 5 by replacing the discharge table 81 in the embodiment example of FIG. 5 with a sorting mechanism. Further, in the present embodiment example, in the embodiment example of FIG. 7, a sorting mechanism is provided between the mount table 5 and the tray transport mechanism, and the transfer mechanism is configured to transfer the cylindrical object 1d after the inspection to the sorting mechanism. By operating 90, it is also applicable to the embodiment example of FIG. 7.

[0067]

As described above, according to the present invention, since the measurement of a plurality of dimension items in a cylindrical object can be performed by the method / apparatus composed of only one image pickup means and one image measurement means, It has the following advantages over the above method. That is, since the single image measurement is performed, the configuration of the device is simplified, the measurement is performed at high speed, and the device cost is reduced. Positioning adjustment of the imaging line, because the imaging means is single,
Various adjustments such as illumination adjustment, imaging focus adjustment, imaging magnification adjustment, and calibration are easy.

Further, according to the present invention, since the outer diameter can be measured only by observing the inner diameter of the cylindrical object, the field of view of the sensor may be within the range including the inner diameter, and the pixel (resolution) of the sensor can be effectively used. be able to. Further, design conditions such as distortion of the optical lens for measurement and depth of focus are alleviated. Further, there is a feature that even if there is an error in the processing accuracy of the outer peripheral end surface, or if the outer peripheral end surface is chamfered, it does not affect the outer diameter measurement accuracy.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the configuration of a basic embodiment example according to the present invention.

FIG. 2 is an explanatory diagram of an image captured by one image capturing unit according to the above-described embodiment.

3 (a), (b), (c), and (d) are conceptual diagrams in which an image only in the vicinity of an inner peripheral edge portion is extracted from the entire image captured in the above embodiment.

FIG. 4 is a diagram for defining a dimension item of a cylindrical object and explaining a displacement amount of an inner peripheral edge locus.

5 (a) and 5 (b) are top views for explaining the configuration of the first specific example of the embodiment according to the present invention.

FIG. 6 is a side view showing partial details of the configuration of the first specific example of the embodiment.

FIG. 7 is a top view for explaining the configuration of the second specific exemplary embodiment according to the present invention.

FIG. 8 is a side view showing partial details of the configuration of the second specific example of the embodiment.

FIG. 9 is a top view for explaining the configuration of the third specific example of the form including the sorting mechanism according to the present invention.

[Explanation of symbols]

1, 1a to 1f ... Cylindrical object 2 ... Inner circumference 3 of cylinder ... Imaging line 4 ... Light source 5 ... Mount base 6 ... Rotation drive mechanism 7 ... Line sensor camera 8 ... Image processing device 9 ... Data processing device 10, 20, 30 ... Camera image 11 ... Inner circumference locus 12 observed at point A ... Inner circumference locus 13 observed at point B ... Stoppers 21, 22 ... Input image 31 ... Optical boundary line 50 ... Center 51 of outer circumference of cylinder ... Center 61 of inner circumference of cylinder 61 Inner circumference locus at point A of standard cylinder 62 ... Inner circumference locus at point B of standard cylinder 70, 71, 72, 73, 74, 75 ... Holds a plurality of cylindrical objects Tray 76, 77 ... Conveying mechanism 80 ... Supplying table 81 ... Discharging table 83 ... Supplying side feeding claw blade 84 ... Storage side feeding claw blade 85 ... Mount feeding blade 86 ... Roller or disk 87 ... Driving roller 90 ... Transfer mechanism 91 ... Transport Structure 101, 102, 103 ... tray 104 ... sorting mechanism A _(x) ... displacement D ... outside the y-direction diameter of the trajectory 12 with respect to the y-direction displacement amount B _(x) ... trajectory 62 of the locus 11 for trajectory 61 d ... Inner diameter C ... Eccentricity

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masataka Hirai 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Inside Nippon Telegraph and Telephone Corporation (72) Masakatsu Futani 8-14, Nishishinjuku, Shinjuku-ku, Tokyo No. 24 in NTT Fanet Systems Co., Ltd. (56) Reference JP-A-8-128815 (JP, A) JP-A-5-280957 (JP, A) JP-A-8-15547 (JP, A) JP-A-8-15162 (JP, A) JP-A-4-194789 (JP, A) Actually opened 60-113509 (JP, U) Actually opened 59-71108 (JP, U) Actual Kaihei 1-85612 (JP, U) JP-B-54-27738 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01B 11/08-11/30 G01M 11/00

Claims (12)

(57) [Claims] 1. A centerline of the outer circumference of the cylindrical object and the inside of the cylindrical object from the end face direction of either one of the cylindrical objects.
A direction in which an image having the locus of these two points as the locus of the inner circumference in synchronization with the two points where the circumference intersects is rotated about the center of the outer circumference.
The means for imaging over the entire inner circumference, and the two that intersect the center line of the outer circumference of the standard cylindrical object and the inner circumference
Rotate around the center of the outer circumference of the standard cylindrical object, which is the locus of points
Of the locus of the inner circumference in the image over the entire inner circumference in the direction
The position of the inner circumference of the locus of the cylindrical body of each obtained from the captured image as a reference position set the location in advance
From the difference the reference position of each of the said reference position of each
And a means for calculating the values of the outer diameter, the inner diameter, and the eccentricity of the cylindrical object from the measured two sets of displacements according to a constant calculation formula. Dimensional measuring device for cylindrical objects. 2. The means for capturing an image of the inner peripheral edge portion over the entire inner circumference includes a means for rotating a cylindrical object, a line sensor camera, and a light source. The dimension measuring device for the cylindrical object described. 3. A mount base configured to rotate the cylindrical object, comprising: a V-groove structure and a structure provided at one end of the V-groove structure for positioning the cylindrical object; and the V-groove. 3. The cylinder according to claim 2, further comprising: a rotary drive mechanism that has a rotation axis having an angle different from a valley line of the structure and rotates in contact with a cylindrical object positioned on the mount table. Dimensional measuring device for objects. 4. The dimension measuring device for a cylindrical object according to claim 1, further comprising a conveying unit that sequentially conveys and replaces the cylindrical object. 5. The first and second trays, wherein the transport means arranges and holds a plurality of the cylindrical objects side by side, and the cylindrical objects held in the first tray are moved horizontally at the same time. Means for moving the cylindrical object from one end of the first tray to the mount base, and means for moving the cylindrical object from the mount base to the second tray from one end. The device for measuring the size of a cylindrical object according to claim 4, further comprising means for moving the cylindrical object held in the second tray in a horizontal direction at the same time. 6. A tray for horizontally arranging and holding a plurality of the cylindrical objects by the conveying means, and moving the tray in the lateral direction by an arrangement interval of the cylindrical objects held in the tray. And means for positioning any of the cylindrical objects on an extension of the V-groove valley line of the mount table, and the cylindrical object from the tray to the mount table or from the mount table to the tray or another tray. A means for moving the mount base along the direction of the V-groove valley line, and a dimension measuring apparatus for a cylindrical object according to claim 4. 7. A means for generating a pass / fail judgment signal or a rank classification signal based on numerical values obtained by means for calculating the values of the outer diameter, the inner diameter, and the eccentricity of the cylindrical object, and the conveying means for the cylindrical object. And a means for sorting the cylindrical objects whose dimension measurement has been completed by the pass / fail judgment signal or the rank classification signal when moving from the mount table to the second tray or the tray or another tray. 7. The dimension measuring device for a cylindrical object according to claim 5 or claim 6. 8. The center line of the outer circumference of the cylindrical object and the inside of the cylindrical object from the end face direction of either one of the cylindrical objects.
A direction in which an image having the locus of these two points as the locus of the inner circumference in synchronization with the two points where the circumference intersects is rotated about the center of the outer circumference.
The process of imaging over the entire inner circumference, and the two steps where the center line of the outer circumference of the standard cylindrical object and the inner circumference intersect
Rotate around the center of the outer circumference of the standard cylindrical object, which is the locus of points
Of the locus of the inner circumference in the image over the entire inner circumference in the direction
The position of the inner circumference of the locus of the cylindrical body of each obtained from the captured image as a reference position set the location in advance
From the difference the reference position of each of the said reference position of each
And a step of calculating the values of the outer diameter, the inner diameter, and the eccentricity of the cylindrical object from the measured two sets of displacements according to a constant calculation formula. A method for measuring the dimension of a cylindrical object characterized by. 9. As each of the preset reference values,
9. The method for measuring the dimension of a cylindrical object according to claim 8, wherein the measured values of the cylindrical object whose outer diameter and inner diameter are known are measured by the same device. 10. Among the fixed calculation formulas, the calculation formula for calculating the outer diameter D is such that the reference value of the outer diameter is D ₀ , the constant depending on the vertical positioning method is c, and the number of measurement points is n. Total
The displacement of the x-th inner track at the measurement position is A _(x) ,
An equation where the displacement amount of the x-th inner track at the other measurement position is B _(x) and the number of measurement points for one rotation of the cylindrical object is m Or [Equation 2] , And the and formulas for calculating the internal diameter d of the formula ## EQU3 ## for the reference value of the inner diameter d ₀ , And the and formulas for calculating the eccentricity C is the minimum value of the variable F the maximum value of _(x) max [F _(x)], the variable F _(x) min
The expression [F _(x) ] [Formula 4] The method for measuring the size of a cylindrical object according to claim 8 or 9, wherein 11. The constant calculation formula is one measurement position.
The displacement of the x-th inner track at A _(x) ,
The displacement of the x-th inner track at one measurement position is B
_(x) , m is the number of measurement points for one rotation of the cylindrical object, and the coefficient is
Coefficients numerically determined so as to optimally approximate all of the measured displacements using the equation A _(x) + B _(x) = p + qsin ((2πx / m) + r) where p, q, and r An equation using p, q, and r for calculating the outer diameter D is a reference value of the outer diameter D ₀ , and
An expression D = D for the constant depending on the vertical positioning method and _{c 0 + (c × p)} , and calculation formulas for calculating the inner diameter d is the reference value of the inner diameter d _0,
And an equation where the number of measurement points is n And the calculation formula for calculating the eccentricity C is C = q / 2. 10. The dimension measuring method for a cylindrical object according to claim 8 or 9, wherein 12. The V-groove angle of the V-groove structure is 90 degrees, and a constant c depending on the vertical positioning method is 1 / √2. Item 12. A method for measuring a dimension of a cylindrical object according to item 11.