JP2868382B2 - Outer diameter measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the outside diameter of an object to be measured having a circular cross section, such as a steel pipe or a wire.

[0002]

2. Description of the Related Art In a steel pipe manufacturing line, it is extremely important for quality assurance that the outer diameter of a steel pipe as a product is set to a predetermined value. Conventionally, in order to measure the outer diameter of a steel pipe, an operator has directly applied a large caliper, a tape measure, or the like to the steel pipe.

An outer diameter measuring device described in Japanese Patent Application Laid-Open No. 58-108406 has been proposed. In this outer diameter measuring device, a steel pipe to be measured is arranged between a projector and a light detector, and the ball screw mechanism moves the light detector in accordance with the outer diameter of the steel pipe to be measured. Is measured.

[0004]

However, when the outside diameter of the steel pipe is directly measured by using a caliper or a tape measure, the measurement value varies depending on the measurement state and individual differences of workers, and the measurement accuracy is low. . Further, in the steel pipe manufacturing process, the steel pipe moves in the axial direction, but the movement of the steel pipe needs to be stopped in order for an operator to directly measure the outer diameter of the steel pipe. For this reason, the productivity of the steel pipe may be reduced.

In the outside diameter measuring device described in the above publication,
Since the photodetector is supported by the ball screw mechanism, if the ball screw mechanism rattles, the photodetector becomes unstable and the accuracy of detecting the outer diameter decreases.

The present invention has been made in view of the above-described circumstances, and has a high accuracy in measuring the outer diameter of the object to be measured without affecting the manufacturing process of a product to be continuously manufactured. It is an object of the present invention to provide an outer diameter measuring device capable of measuring the diameter.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided a light projector for projecting light toward a device having a circular cross section, and a light from the light projector which is provided at a position opposite to the light projector with respect to the device to be measured. And a distance meter that measures the distance between the object to be measured and the light receiver, and the light received by the light receiver that is projected from the light emitter and is in contact with the outer peripheral surface of the object to be measured. A calculator for calculating the outer diameter of the object to be measured from the position and the distance measured by the distance meter, and an outer diameter measuring device ,
The rotating mirror is irradiated with laser light, and the rotating mirror is rotated.
Reflect the laser light toward the object to be measured, and
Scan in the horizontal direction perpendicular to the center axis of the product
The light receiver measures a large number of light receiving elements at a constant pitch.
The light receiving surface arranged in the horizontal direction orthogonal to the center axis of the fixed product,
The reflection point of the laser beam by the rotating mirror and the object to be measured
It is arranged so as to be orthogonal to the straight line connecting the center axis,
A straight line connecting the reflection point of the rotating mirror and the central axis of
The intersection with the light receiving surface of the optical device is defined as the origin O (0, 0) of the XY coordinates.
, The position of the reflection point of the rotating mirror (0, 0,
Y ₀ ), the light receiving position (X ₀ , 0) by the photodetector ,
Distance measuring distance _{Y 1} obtained by _{meter, Y = Y 0 -Y 1 X} = (Y / Y 0) X 0 The outer diameter D of the object to be measured is calculated by the following formula.
It is a thing.

[0008]

The object to be measured is placed between the light emitter and the light receiver, and the outer diameter of the object to be measured is measured in a non-contact manner by the light emitted from the light emitter, so that the object to be measured moves during the manufacture of the object to be measured. Even in the middle, the outer diameter of the measured object can be measured. As described above, since it is not necessary to stop the movement of the object to be measured during the measurement of the outer diameter, the production process of the object to be continuously manufactured is not adversely affected.

In the outer diameter measuring device, the light receiving element of the light receiver is
The laser projected from the rotating mirror and in contact with the outer peripheral surface of the DUT
The position of the receiver light is detected, and the distance meter
Measure the distance between the
The arithmetic unit measures the outer diameter D of the object to be measured, which is complicated.
No mechanical mechanism exists. For this reason, the mechanical mechanism
Measurement accuracy does not decrease with rattling
Can be measured with high accuracy. Emitter emits laser light
The rotating mirror is irradiated with laser light from the
The laser beam is reflected toward the DUT by the rotation of the
And scan in the horizontal direction perpendicular to the center axis of the DUT
, A compact configuration of the projector allows
It can cope well with various objects to be measured having various diameters. Times
Position of the reflection point of the mirror (0, Y ₀ )
Light position _(X 0, 0), using the measured distance _{Y 1} by rangefinder
Then, the outer diameter D of the object to be measured is calculated by the above formula.
Thus, the outer diameter D of the measured object can be measured with high accuracy.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the outer diameter measuring apparatus according to the present invention, and FIG. 2 is a sectional view taken along the line II-II in FIG.

As shown in FIG. 1, in this embodiment, an object to be measured having a circular cross section is, for example, a spiral steel pipe 10. The spiral steel pipe 10 is manufactured by using a steel strip 11 wound in a coil shape as a raw material, forming the unwound steel strip 11 into a spiral shape by a forming roll (not shown), and welding a joint. In the manufacturing process of the spiral steel pipe 10, the spiral steel pipe 10 moves in the direction of the arrow S while rotating around the central axis F.

As shown in FIG. 2, the outer diameter measuring device 12 for measuring the outer diameter of the spiral steel pipe 10 has a projector 13, a light receiver 14, a distance meter (for example, a laser distance meter) 15, and a calculator 16. It is composed.

The projector 13 irradiates a laser beam 18 from a laser oscillator 17 to a rotating mirror 19, and rotates the rotating mirror 19 to emit the laser beam 18 to the spiral steel tube 10.
The scanning is performed in the horizontal direction orthogonal to the central axis F of the spiral steel 10. The laser light 18 is
An example is helium neon laser light. Rotating mirror 19
Is set so that the reflection point A at which the laser beam 18 is reflected by the rotating mirror 19 is located directly above the central axis F of the spiral steel pipe 10.

The light receiver 14 is installed at a position opposite to the rotating mirror 19 of the light projector 13 with respect to the spiral steel pipe 10,
The laser beam 18 emitted from the rotating mirror 19 is received. The light receiver 14 includes a large number of light receiving elements (CCD; char)
This is an array type optical detector in which a light receiving surface 21 is configured by arranging a couple of devices 20 at a pitch of about 0.1 to 0.125 mm.

In the light receiver 14, the arrangement direction of the light receiving elements 20 coincides with the horizontal direction orthogonal to the central axis F of the spiral steel pipe 10, that is, the scanning direction of the laser beam 18 reflected and projected by the rotating mirror 19. It is set up to do.
The length of the light receiver 14 is, for example, 2500 mm. Furthermore,
The light receiving unit 21 is configured such that the light receiving surface 21 is a reflection point A of the rotating mirror 19.
And it is arrange | positioned orthogonally with respect to the straight line 22 which connects the center axis F of the spiral steel pipe 10. FIG.

The light receiving surface 21 of the light receiver 14 and the light projector 1
3 is equal to the distance L between the outer diameter measuring device 1 and the reflecting mirror 19.
2 is set to be 1.5 times or more the outer diameter of the spiral steel pipe 10 having the largest outer diameter among several types of spiral steel pipes having different outer diameters to be measured. When the outer diameter of the spiral steel pipe 10 to be measured is 150 mm to 1500 mm, the distance L between the light receiving surface 21 of the light receiver 14 and the rotating mirror 19 of the light projector 13 is 1.5 times or more of this 1500 mm, and in this embodiment, It is set to 3500mm.

The laser distance meter 15 is a straight line 2 connecting the reflection point A of the rotating mirror 19 and the central axis F of the spiral steel pipe 10.
2 and a laser beam 23 on this straight line 22.
And the lowermost point E of the spiral steel pipe 10 and the light receiver 14
Of the light receiving surface 21 is measured.

The arithmetic unit 16 is electrically connected to the photodetector 14 and the laser range finder 15, and of the laser beam 18 reflected by the rotating mirror 19 and projected toward the spiral steel tube 10, (Contact point C), the light receiving position B of the laser beam 18A received by the light receiver 14, the lowest point E of the spiral steel pipe 10 measured by the laser distance meter 15, and the light reception of the light receiver 14. The outer diameter of the spiral steel pipe 10 is calculated from the distance M between the surfaces 21.

That is, as shown in FIG.
Assuming that the intersection of the straight line 22 connecting the reflection point A of No. 9 and the central axis F of the spiral steel pipe 10 with the light receiving surface 21 of the light receiver 14 is the origin O (0,0) of the XY coordinate, the reflection point of the rotating mirror 19 is A
Is (0, Y ₀ ), and the lowest point E of the spiral steel pipe 10 is (0, Y ₀ ).
_1), and further the light receiving position B of the laser beam 18A becomes (X _0, 0). Here, the distance between the reflection point A and the lowest point E of the spiral steel pipe 10 is

[0020]

(Equation 1) Becomes Further, a parallel line parallel to the X axis is drawn from the lowest point E of the spiral steel pipe 10, and the intersection with the laser beam 18A is defined as B '.
age,

[0021]

(Equation 2) Becomes Also, the distance between the contact point C between the laser beam 18A and the spiral steel pipe 10 and the reflection point A of the rotating mirror 19

[0022]

(Equation 3) Is, if the radius of the spiral steel pipe 10 is R,

[0023]

(Equation 4) Becomes

Now, the diameter (outer diameter) of the spiral steel pipe 10
Is D (D = 2R), since △ AEB ′ and △ ACF are similar triangles,

(Equation 5) Becomes

From the above formulas, formulas and formulas, X ₀ and Y
The outer diameter D of the spiral steel pipe 10 can be calculated by measuring ₁ with the light receiver 14 and the laser distance meter 15, respectively.

According to the above embodiment, the spiral steel pipe 10
Is arranged between the light projector 13 and the light receiver 14, and the outer diameter D of the spiral steel pipe 10 is measured in a non-contact manner by the laser light 18 projected from the rotating mirror 19 of the light projector 13.
The outer diameter D of the spiral steel pipe 10 can be measured even while the spiral steel pipe 10 is moving along the central axis F during the manufacture of the spiral steel pipe 10. As described above, since it is not necessary to stop the movement of the spiral steel pipe 10 during the measurement of the outer diameter,
There is no adverse effect on the manufacturing process of the spiral steel pipe 10 manufactured continuously.

In the outer diameter measuring device 12, the light receiving element 20 of the light receiver 14 detects the light receiving position B of the laser light 18A projected from the rotating mirror 19 and in contact with the outer peripheral surface of the spiral steel tube 10, and The distance meter 15 measures the distance M between the light receiving surface 21 of the light receiver 14 and the lowest point E of the spiral steel pipe 10, and the calculator 16 measures the outer diameter D of the spiral steel pipe 10 based on these measured values. There is no complicated mechanical mechanism. Therefore, the measurement accuracy does not decrease with the backlash of the mechanical mechanism, and the outer diameter D of the spiral steel pipe 10 can be measured with high accuracy. FIG. 4 shows actual measurement results using the outer diameter measuring device 12 of this embodiment.
When the spiral steel pipe 10 having the measured outer diameter of 1500 mm is measured a number of times, the error between these measured values and the measured value is within a range of ± 1 mm, and the outer diameter measuring device 12 can accurately measure the spiral steel pipe 10. It can be seen that the outer diameter was measured. In addition, the light projector 13 receives the laser beam from the laser oscillator 17.
Laser light 18 is applied to a rotating mirror 19,
Rotation of the laser beam 18 causes the laser beam 18 to flow through the spiral steel pipe 10.
To the central axis of the spiral steel pipe 10
Because it scans in the intersecting horizontal direction,
The projector 13 has a simple configuration, so that various
It can cope well with the spiral steel pipe 10. Also, a rotating mirror
Position (0, Y ₀ ) of the reflection point of −19 , due to the photodetector 14
Light receiving position (X ₀ , 0), distance Y ₁ measured by distance meter 15
And the outside of the spiral steel pipe 10 is calculated according to the above formula.
Since the diameter D is calculated, the outer diameter D of the spiral steel pipe 10 is increased.
Can be measured with high accuracy.

Further, the light receiving surface 21 of the light receiver 14 and the light emitter 1
Since the distance L to the rotating mirror 19 is set to be at least 1.5 times the outer diameter of the largest spiral steel pipe 10 among the various kinds of spiral steel pipes 10 to be measured, the spiral steel pipe 24 having a small diameter is required. Also, even if the spiral steel pipe 10 has a large diameter, the outer diameter of the spiral steel pipe 10 and 23 having different outer diameters can be suitably adjusted without changing a part of the light projector 13 and the light receiver 14. Can be measured.

[0029]

Further, in the above-described embodiment, the case where the object to be measured is the spiral steel pipes 10 and 24 has been described. However, another steel pipe such as a seamless steel pipe may be used, or a cylindrical wire rod may be used.

[0031]

As described above, according to the outer diameter measuring apparatus of the present invention, the outer diameter of the object to be measured can be measured without affecting the manufacturing process of the continuously manufactured object. It can measure with high accuracy.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an outer diameter measuring device according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is an explanatory diagram for calculating the outer diameter of a spiral steel pipe.

FIG. 4 is a bar graph showing measurement results using the outer diameter measuring device of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Spiral steel pipe 12 Outer diameter measuring device 13 Emitter 14 Light receiver 15 Laser distance meter 16 Computing device 18, 18A Laser light B Light receiving position D Outside diameter of spiral steel pipe M Distance between the lowest point of spiral steel pipe and light receiving surface of light receiver

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01B 11/00-11/30

Claims (1)

(57) [Claims] A light projector for projecting light toward an object having a circular cross section; a light receiver installed at a position opposite to the light projector with respect to the object to receive light from the light projector; A distance meter that measures the distance between the object to be measured and the light receiver, and a position of light emitted from the light emitter and received by the light receiver in contact with the outer peripheral surface of the object to be measured and measured by the distance meter And a calculator for calculating the outer diameter of the object to be measured from the measured distance , wherein the projector emits a laser beam from a laser oscillator to a rotary mirror.
Laser light by the rotation of this rotating mirror.
Reflects toward the DUT and is orthogonal to the central axis of the DUT
The light receiver is configured to scan a large number of light receiving elements at a constant pitch.
Light-receiving surface arranged in a horizontal direction perpendicular to the central axis of the
Reflection point of laser beam by rotating mirror and central axis of DUT
And a straight line connecting the reflection point of the rotating mirror and the central axis of the DUT.
The point of intersection with the light receiving surface of the optical device is defined as the origin O (0,0) of the XY sitting Kong.
, The position of the reflection point of the rotating mirror (0, 0,
Y ₀ ), the light receiving position (X ₀ , 0) by the photodetector ,
Distance to obtain a measured distance _{Y 1} by _{meter, Y = Y 0 -Y 1 X} = (Y / Y 0) X 0 Calculation of the outer diameter D of the object to be measured by the formula
Outer diameter measuring device.