JPH06194128A - Outer diameter measuring device - Google Patents

Abstract

PURPOSE:To measure the outer diameter of a measured object with high accuracy without having influence on the manufacturing process of products by computing the outer diameter of the measured object from the position of light received by a light receiver and the distance measured with a range finder. CONSTITUTION:In an outer diameter measuring device 12, the light receiving element 20 of a light receiver 14 detects the light receiving position B on the outer peripheral surface of a spiral steel pipe 10 irradiated with a laser beam 18A projected from a rotating mirror 19. A laser range finder 15 measures the distance M between the light receiving face 21 of the light receiver 14 and the lowest point E of the spiral steel pipe 10. On the basis of these measured values, a computing element 16 computes the outer diameter D of the spiral steel pipe 10. Since there is no complicated mechanical mechanism, the lowering of measuring accuracy associated with the backlash of the mechanical mechanism is prevented, so that the outer diameter D of the spiral steel pipe 10 can be measured with high accuracy. In addition, there is no need to stop the movement of the spiral steel pipe 10 during outer diameter measurement so as to have no advance effect on the manufacturing process of the continuously manufactured spiral steel pipes 10.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In a steel pipe production line, it is extremely important for quality assurance that the outer diameter of a steel pipe, which is a product, is set to a predetermined value. Hitherto, in order to measure the outer diameter of a steel pipe, an operator directly applies a large caliper or a tape measure to the steel pipe.

Further, an outer diameter measuring device disclosed in Japanese Patent Laid-Open No. 58-108406 has been proposed. This outer diameter measuring device arranges the steel pipe to be measured between the projector and the photodetector, and moves the photodetector according to the outer diameter of the steel pipe to be measured by the ball screw mechanism. Is measured.

[0004]

However, when the outer diameter of the steel pipe is directly measured by using a caliper or a tape measure, the measured value varies depending on the measurement condition and individual differences of operators, and the measurement accuracy is low. . Further, in the manufacturing process of the steel pipe, the steel pipe moves in the axial direction thereof, but in order for the operator to directly measure the outer diameter of the steel pipe, it is necessary to stop the movement of the steel pipe. Therefore, the productivity of the steel pipe may be reduced.

Further, in the outer 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 is reduced.

The present invention has been made in consideration of the above-mentioned circumstances, and the outer diameter of the object to be measured can be accurately adjusted without affecting the manufacturing process of the continuously manufactured object to be measured. It is an object of the present invention to provide an outer diameter measuring device that can measure the inside diameter.

[0007]

DISCLOSURE OF THE INVENTION The present invention is directed to a projector for projecting light toward an object to be measured having a circular cross section, and a light from the projector installed at a position opposite to the object to be measured with respect to the object to be measured. A light receiver for receiving the light, a distance meter for measuring the distance between the object to be measured and the light projector, and a position of light projected from the light projector and in contact with the outer peripheral surface of the object to be measured and received by the light receiver. And a calculator that calculates the outer diameter of the object to be measured from the distance measured by the distance meter.

[0008]

Therefore, according to the outer diameter measuring device of the present invention, the object to be measured is arranged between the light projector and the light receiver, and the outer diameter of the object to be measured is measured in a non-contact manner by the light projected from the light projector. Therefore, the outer diameter of the measured object can be measured even when the measured object is moving during the manufacture of the measured object. in this way,
Since it is not necessary to stop the movement of the object to be measured during the measurement of the outer diameter, the manufacturing process of the object to be continuously manufactured is not adversely affected.

Further, since the light transmitter and the light receiver are not supported by the mechanical mechanism, the measurement accuracy does not decrease due to the rattling of the mechanical mechanism, and the outer diameter of the object to be measured can be accurately adjusted. Can be measured.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 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 line II-II of FIG.

As shown in FIG. 1, in this embodiment, the object having a circular cross section is, for example, a spiral steel pipe 10. The spiral steel pipe 10 is manufactured by using a strip steel 11 wound in a coil shape as a raw material, shaping the rewound strip steel 11 into a spiral shape by a forming roll (not shown), and welding a seam. 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, an outer diameter measuring device 12 for measuring the outer diameter of the spiral steel pipe 10 has a light projector 13, a light receiver 14, a distance meter (for example, a laser distance meter) 15 and a calculator 16. Consists of

The projector 13 irradiates the rotating mirror 19 with the laser light 18 from the laser oscillator 17, and the rotation of the rotating mirror 19 causes the laser light 18 to emit the laser light 18.
And is scanned in the horizontal direction orthogonal to the central axis F of the spiral steel 10. The laser light 18 is
For example, helium neon laser light. Rotating mirror 19
Letting A be a reflection point at which the laser light 18 is reflected by the rotating mirror 19, the reflection point A is installed so as to be located right 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 tube 10,
The laser beam 18 projected from the rotating mirror 19 is received. The light receiver 14 includes a large number of light receiving elements (CCD; char).
It is an array type optical detector in which the light receiving surface 21 is formed by arranging the ge couple device) 20 at a pitch of about 0.1 to 0.125 mm.

In this light receiver 14, the arrangement direction of the light receiving elements 20 is in the horizontal direction orthogonal to the central axis F of the spiral steel tube 10, that is, the scanning direction of the laser light 18 reflected by the rotating mirror 19 and projected. It is installed to do.
The length of the light receiver 14 is 2500 mm, for example. Furthermore,
The light receiving surface 21 of the light receiver 14 is a reflection point A of the rotating mirror 19.
Also, the spiral steel pipe 10 is arranged so as to be orthogonal to the straight line 22 that connects the central axes F of the spiral steel pipes.

Further, the light receiving surface 21 of the light receiver 14 and the light projector 1
The distance L between the reflection mirror 19 and the reflection mirror 19 is 3
2 is set to be 1.5 times or more of 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 rotary 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 3500 mm.

The laser rangefinder 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.
The laser beam 23 is arranged on this straight line 22
Of the spiral steel pipe 10 and the light receiver 14
The distance M from the light receiving surface 21 is measured.

The calculator 16 is electrically connected to the light receiver 14 and the laser range finder 15, is reflected by the rotating mirror 19, and is included in the laser beam 18 projected toward the spiral steel pipe 10. Of the laser beam 18A received by the photodetector 14, the lowest point E of the spiral steel pipe 10 measured by the laser distance meter 15, and the photodetector 14 receiving light. 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. 3, the rotating mirror 1
Assuming that the intersection point of the straight line 22 connecting the reflection point A of 9 and the central axis F of the spiral steel tube 10 and the light receiving surface 21 of the light receiver 14 is the origin O (0,0) of the XY coordinates, the reflection point of the rotating mirror 19 A
Becomes (0, Y ₀ ), and the lowest point E of the spiral steel pipe 10 is (0, Y ₀ ).
₁ ), and 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 In addition, a parallel line parallel to the X axis is drawn from the lowest point E of the spiral steel pipe 10 and the intersection point with the laser beam 18A is B ′.
age,

[0021]

[Equation 2] Becomes Further, 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] Let R be the radius of the spiral steel pipe 10,

[0023]

[Equation 4] Becomes

Now, the diameter (outer diameter) of the spiral steel pipe 10
Is D (D = 2R), ΔAEB ′ and ΔACF are similar triangles.

[Equation 5] Becomes

From the above equations, equations and expressions, 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.
Even when the spiral steel pipe 10 is moving along the central axis F during manufacturing of the spiral steel pipe 10, the outer diameter D of the spiral steel pipe 10 can be measured. In this way, 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 continuously manufactured spiral steel pipe 10.

Further, 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 which is projected from the rotating mirror 19 and is in contact with the outer peripheral surface of the spiral steel tube 10, and the laser is detected. 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. Yes, there are no complex mechanical mechanisms. Therefore, the measurement accuracy does not decrease due to rattling of the mechanical mechanism, and the outer diameter D of the spiral steel pipe 10 can be measured with high accuracy. An actual measurement result using the outer diameter measuring device 12 of this example is shown in FIG.
When the spiral steel pipe 10 whose outer diameter is actually measured is 1500 mm is measured many times, the difference between these measured values and the above measured value is ±
It is in the range of 1 mm, and it can be seen that the outer diameter measuring device 12 measures the outer diameter of the spiral steel pipe 10 with high accuracy.

Furthermore, the light receiving surface 21 of the light receiver 14 and the light projector 1
Since the distance L from the rotating mirror 19 of 3 is set to be 1.5 times or more of the outer diameter of the spiral steel pipe 10 having the largest diameter among the various types of spiral steel pipes 10 to be measured, the spiral steel pipe 24 having a small diameter is Also, even if the spiral steel pipe 10 has a large diameter, the outer diameter of the spiral steel pipes 10 and 23 having different outer diameters can be suitably adjusted without changing a part of the projector 13 and the light receiver 14. Can be measured.

In the above embodiment, the projector 13 is described as having the laser transmitter 17 and the rotating mirror 19, but as shown in FIG. 5, the projector is a point light source 25.
May be In FIG. 5, portions similar to those of the above-described embodiment shown in FIG. 2 are denoted by the same reference numerals and description thereof is omitted.

Further, in the above embodiment, the case where the object to be measured is the spiral steel pipes 10 and 24 has been described, but other steel pipes such as seamless steel pipes or cylindrical wire rods 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 controlled without affecting the manufacturing process of the continuously manufactured object to be measured. Can measure with high accuracy.

[Brief description of 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 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.

FIG. 5 is a sectional view of an outer diameter measuring device according to another embodiment of the present invention.

[Explanation of symbols]

 10 spiral steel pipe 12 outer diameter measuring device 13 light emitter 14 light receiver 15 laser distance meter 16 calculator 18, 18A laser light B light receiving position D spiral pipe outer diameter M distance between the bottom point of the spiral steel pipe and the light receiving surface of the light receiver

Claims (1)

[Claims] 1. A light projector for projecting light toward an object to be measured having a circular cross section, a light receiver installed at a position opposite to the light projector for the object to be measured, and receiving light from the light projector. A distance meter that measures the distance between the object to be measured and the light receiver, and the position of the light projected from the light projector 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 An outer diameter measuring device having an arithmetic unit that calculates the outer diameter of the object to be measured from the measured distance.