JP2011209092A - Round rod inspection apparatus and method of inspecting round rod - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a round rod inspection apparatus and a method of inspecting a round rod for easily detecting surface defects, such as a flaw and a smear in an outer peripheral surface of a round rod including an extremely thin pipe shape by a simple device consisting of only a laser light source and a light receiving sensor.SOLUTION: The round rod inspection apparatus includes: the laser light source for applying laser beams, namely parallel light, to an outer peripheral surface nearly vertically to an axis of the round rod including a pipe shape; and a light-receiving sensor provided so that an angle to an incidence direction of laser beams in the axis of the round rod is more than 90 degrees and less than 180 degrees, in axial cross-sectional view of the round rod. Reflection light on the outer peripheral surface of laser beams is received by the light receiving sensor, and the outer peripheral surface is inspected from the level of the received light.

Description

  The present invention relates to a round bar inspection apparatus and a round bar inspection method for inspecting surface defects such as wrinkles and dirt on the outer peripheral surface of a round bar including a pipe shape.

  Conventionally, inspection of surface defects such as wrinkles and dirt on the outer peripheral surface of a round bar such as a long steel material manufactured by rolling or the like has been performed. An example of this round bar inspection apparatus is shown in Patent Document 1. In the round bar inspection apparatus of Patent Document 1, the round bar is magnetized, and when the round bar is magnetized, a magnetic pole is generated on the surface of the round bar. The degree of wrinkles is determined by the degree. Specifically, the powder exhibits a pattern reflecting the shape of the surface wrinkles, the pattern is measured with an image sensor such as a CCD element, the pattern is analyzed by a method according to image processing, and the degree of wrinkles is determined. Yes.

  In the conventional round bar inspection apparatus, there is a problem that the round bar cannot be magnetized or image processing is performed and the apparatus is complicated and expensive, and the round bar that cannot be magnetized cannot be inspected. As a result, a round bar inspection apparatus shown in Patent Document 2 was invented.

  The round bar inspection apparatus shown in Patent Document 2 includes a light source that irradiates light to an outer peripheral surface substantially perpendicular to the axis of the round bar, and an incident direction of the light source on the axis of the round bar in a cross-sectional view of the round bar. And a light receiving sensor provided so that the angle is more than 90 degrees and less than 180 degrees, the light reflected from the outer peripheral surface of the light from the light source is received by the light receiving sensor, and the outer peripheral surface is inspected from the level of the received light It is characterized by doing.

JP 09-71068 A JP 2008-185356 A

  However, the diameter of a round bar that can be inspected with light from a conventional light source is 1 mm to 3 mm, and it is difficult to inspect a round bar with a smaller diameter.

  The present invention has been made in view of such circumstances, and it is possible to easily detect surface defects such as wrinkles and dirt on the outer peripheral surface of a round bar including an extremely fine pipe shape with a simple device including only a laser light source and a light receiving sensor. An object of the present invention is to provide a round bar inspection apparatus and a round bar inspection method that can be performed.

  The round bar inspection apparatus according to claim 1 is a laser light source that irradiates a laser beam that is parallel light to an outer peripheral surface substantially perpendicular to an axis of a round bar including a pipe shape; And a light receiving sensor provided so that an angle formed with the incident direction of the laser light on the shaft is more than 90 degrees and less than 180 degrees, and the light reflected by the outer peripheral surface of the laser light is received by the light receiving sensor and received. The outer peripheral surface is inspected from the light level.

  The round bar inspection apparatus according to claim 2 is characterized in that the angle formed between the incident direction of the laser beam on the axis of the round bar and the light receiving sensor is about 130 degrees to about 170 degrees.

  The round bar inspection apparatus according to claim 3 is characterized in that the wavelength of the laser light emitted from the laser light source is 300 nm to 700 nm.

  The round bar inspection apparatus according to claim 4 is characterized in that the light receiving sensors are provided at two positions, a clockwise position and a counterclockwise position with respect to the incident direction of the laser beam about the axis of the round bar. And

  According to a fifth aspect of the present invention, there is provided a round bar inspection apparatus provided with a light shielding plate for shielding laser light other than light reflected by the round bar with laser light from a laser light source.

  The method for inspecting a round bar according to claim 6 irradiates a laser beam which is parallel light to an outer peripheral surface substantially perpendicularly to an axis of a round bar including a pipe shape, and the laser beam on the axis of the round bar in a cross-sectional view of the round bar. The light receiving sensor is provided so that the angle formed with the incident direction of the laser beam becomes an obtuse angle, and the reflected light from the outer peripheral surface of the laser beam is received, and the outer peripheral surface is inspected from the level of the received light.

  According to the first, third, and sixth aspects of the invention, the angle formed by the laser beam incident direction on the axis of the round bar is more than 90 degrees and 180 degrees in a cross-sectional view of the round bar including the pipe shape. A light receiving sensor provided so as to be less than, and the reflected light on the outer peripheral surface of the laser light is received by the light receiving sensor, and the outer peripheral surface is inspected from the level of the received light, so only the laser light source and the light receiving sensor With this simple device, it is possible to easily detect surface defects such as wrinkles and dirt on the outer peripheral surface of an ultrafine round bar.

  According to the invention of claim 2, since the angle formed between the incident direction of the laser beam on the axis of the round bar and the light receiving sensor is about 130 degrees to about 170 degrees, it is suitable for surface defects such as wrinkles and dirt. Sensitivity is improved, and it becomes possible to detect surface defects such as wrinkles and dirt on the outer peripheral surface of a finer round bar with higher accuracy.

  According to the invention of claim 4, since the light receiving sensors are provided at two positions, the clockwise position and the counterclockwise position from the incident direction of the laser beam around the axis of the round bar, it is efficient. In addition, it is possible to detect surface defects such as wrinkles and dirt on the outer peripheral surface of an extremely thin round bar.

  According to the fifth aspect of the invention, since the light shielding plate for shielding the laser light other than the light reflected by the round bar is provided by the laser light from the laser light source, unnecessary light incident on the light receiving sensor is shielded. Thus, it becomes possible to detect surface defects such as wrinkles and dirt on the outer peripheral surface of the finer round bar with higher accuracy.

It is explanatory drawing which shows an example of the structure of the round bar inspection apparatus which concerns on this invention. It is explanatory drawing which shows the structure of the same round bar inspection apparatus. It is a block diagram which shows the structure of the same round bar inspection apparatus. It is explanatory drawing which shows operation | movement of the same round bar inspection apparatus.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 is an explanatory view showing an example of the structure of a round bar inspection apparatus according to the present invention. FIG. 2 is an explanatory view showing the structure of the same round bar inspection apparatus. FIG. 3 is a block diagram showing the configuration of the same round bar inspection apparatus. FIG. 4 is an explanatory view showing the operation of the round bar inspection apparatus.

  A round bar inspection apparatus 1 in the figure is an apparatus for inspecting surface defects such as wrinkles and dirt on the outer peripheral surface of a round bar w including a pipe shape and determining the presence or absence of surface defects such as wrinkles and dirt. The round bar inspection apparatus 1 has cylindrical cylindrical guide cylinders 7 and 8 through which a round bar w passes, and bearing bases 5 and 6 that rotatably support the guide cylinders 7 and 8 respectively. It is equipped in parallel to become. An annular rotary base 10 is provided between the guide tube 7 and the guide tube 8, and there is a space between the guide tube 7 and the guide tube 8. Further, the inner peripheries 7a and 8a of the guide cylinders 7 and 8 have a diameter sufficient for the round bar w to pass through. In particular, the inner peripheries 7a and 8a on the side where the guide cylinders 7 and 8 face each other. However, it is partly built up and has narrow inner peripheries 7b and 8b through which the round bar w can pass without vibration. The round bar inspection device 1 is configured such that the round bar w can pass through the rotation center 10 and the rotation centers of the guide cylinders 7 and 8. Further, a motor 32 is provided on the side of the guide tube 7 opposite to the guide tube 8, and the motor 32 rotates the guide tube 7, and the rotation base 10 and the guide tube 8 rotate simultaneously.

  The rotating base 10 holds the laser light source 20 that is held by the element base 21 and emits laser light toward the outer peripheral surface of the round bar w, and the laser light of the laser light source 20 that is held by the sensor bases 27a and 27b. Photodiodes 25a and 25b that are light receiving sensors that receive the reflected light reflected by the outer peripheral surface of the round bar w, condensing lenses 26a and 26b that collect the reflected light toward the photodiodes 25a and 25b, and a laser of the laser light source 20. A light shielding plate 15 is provided to prevent light from directly entering the photodiodes 25a and 25b. The laser light source 20 is disposed at a position where light strikes the outer peripheral surface of the round bar w substantially perpendicular to the axis of the round bar w. The laser light source 20 has a wavelength of 300 nm to 700 nm, and more specifically, a red laser (center wavelength: red (650 nm)), a green laser (center wavelength: green (532 nm)), a violet laser (center wavelength: blue purple ( 405 nm)), blue laser (center wavelength: blue (375 nm)) and the like.

  Here, there are two photodiodes which are light receiving sensors, and one photodiode 25a is formed with the incident direction of the laser light from the laser light source 20 on the axis of the round bar w in the sectional view of the axis of the round bar w. The angle (θa in FIG. 3, the angle at the counterclockwise position from the laser light source 20 in FIG. 3) is more than 90 degrees and less than 180 degrees. The other photodiode 25b has an angle (θb in FIG. 3; the laser light source in FIG. 3) formed with the incident direction of the laser light from the laser light source 20 on the axis of the round bar w in the axial cross-sectional view of the round bar w. The angle of the clockwise position from 20) is more than 90 degrees and less than 180 degrees. The rotation base 10 including the guide cylinders 7 and 8 is rotated by the motor 32 so that the arrangement of the round bar w, the laser light source 20, and the photodiodes 25a and 25b is maintained. The laser light source 20, the photodiodes 25a and 25b, and the light shielding plate 15 are rotated outside.

  As shown in FIG. 3, a power source 22 is connected to the laser light source 20, and laser light is emitted from the laser light source 20. The photodiode 25a is connected to a data analysis unit 30 that processes the level of received light output from the photodiode 25a and determines the presence or absence of surface defects such as wrinkles and dirt.

  The operation of the round bar inspection apparatus 1 configured as described above will be described with reference to FIG. In FIG. 4, the cross section of the round bar w is shown to be relatively large compared to the condensing lens 26a and the photodiode 25a, but this is for the purpose of emphasizing the round bar w. That is, as shown in FIG. 4A, the laser light from the laser light source 20 is reflected by the outer peripheral surface of the round bar w, and the reflected light is collected by the condenser lens 26a and enters the photodiode 25a. Although FIG. 4 and the present description are described with reference to the photodiode 25a, the same applies to the photodiode 25b.

  As shown in FIG. 4B, the level of reflected light captured by the photodiode 25a is almost constant (baseline level) if there is no surface defect such as wrinkles or dirt, but there is a surface defect. As a result, the amount of reflected light is reduced, and the amount is reduced by a level corresponding to the surface defect. By detecting this decrease in the amount of reflected light by the data analysis unit 30, it becomes possible to inspect surface defects such as wrinkles and dirt on the round bar w. Although the baseline level of the reflected light is almost stable but slightly fluctuated, a moving average of the levels may be performed so that only a decrease in the amount of reflected light can be appropriately determined. The inspection itself can be performed if the angles θa and θb are more than 90 degrees and less than 180 degrees. However, if the angles θa and θb are small, the level is less lowered due to surface defects. Is preferably in the range of about 130 degrees to about 170 degrees. It is also possible to judge from the absolute value of the amount of reflected light reduction due to surface defects, but considering that the level of reflected light (baseline level) differs depending on the angles θa and θb, the level of reflected light amount reduction (base It is preferable to use displacements relative to the line level.

  As described above, according to the round bar inspection apparatus 1 of the present embodiment, the reflected light on the outer peripheral surface of the laser light from the laser light source 20 is received by the photodiodes 25a and 25b, and the outer peripheral surface is determined from the level of the received light. From the inspection, it is possible to easily detect surface defects such as wrinkles and dirt on the outer peripheral surface of the round bar w with a simple apparatus including only the laser light source 20 and the photodiodes 25a and 25b. In addition, since the round bar inspection apparatus 1 according to the present embodiment performs a non-contact test, the round bar inspection apparatus 1 is not easily affected by the shaking or vibration of the round bar w. However, since the round bar w becomes extremely thin, the round bar inspection apparatus 1 according to the present embodiment is easily affected by vibration and vibration. Therefore, in the round bar inspection device 1 of this embodiment, the inner circumferences 7a and 8a of the guide cylinders 7 and 8 are narrowly inner circumferences 7b. , 8b. As an example of the thickness of the round bar w, for example, a surface defect having a diameter of about 0.1 mm and about 0.01 mm can be detected. In this way, when a light emitting diode is used as a conventional light source, a round bar having a diameter of about 1 mm to about 3 mm and a wrinkle having a width of about 0.1 mm to about 0.5 mm can be detected. In comparison with this, it is possible to detect the surface defect of the fine round bar w.

  In this embodiment, the laser light source 20 and the photodiodes 25a and 25b are rotated around the round bar w so that the entire circumference of the round bar w can be inspected. However, the laser light source 20 and the photodiodes 25a and 25b Can be fixed and the round bar w can be rotated to inspect the entire circumference. However, in the case of a round bar that is long and difficult to rotate itself, such as a wire, it is preferable that the laser light source 20 and the photodiodes 25a and 25b rotate.

  Here, when inspecting the entire circumference of the above-described ultrafine round bar w, it is possible to perform more efficient inspection by providing two light receiving sensors as in the present embodiment. It may be one. In the case of the present embodiment, for example, the round bar passing speed at the time of the entire circumference inspection of the round bar w is 25 mm / s, and the rotational speed of the rotary base 10 is 120 rpm.

  Incidentally, as in this embodiment, the light shielding plate 15 for shielding the laser light other than the light reflected by the round bar w with the laser light from the laser light source 20 is provided, so that the light enters the photodiodes 25a and 25b. Therefore, it becomes possible to detect surface defects such as wrinkles and dirt on the outer peripheral surface of the fine round bar w with higher accuracy.

  In addition, when a cheaper laser light source is used, a red laser may be used. However, when detection with higher accuracy is desired, a color having a long wavelength may be selected. Furthermore, in the present embodiment, a photodiode is used as the light receiving sensor, but a photomultiplier tube (photomultiplier) can also be used in order to perform finer detection.

  As described above, according to the present invention, it is possible to easily detect surface defects such as wrinkles and dirt on the outer peripheral surface of a round bar including an extremely fine pipe shape with a simple device including only a laser light source and a light receiving sensor. A bar inspection apparatus and a round bar inspection method can be provided.

DESCRIPTION OF SYMBOLS 1 ... Round bar inspection apparatus 4 ... Base 5 ... Bearing base 6 ... Bearing base 7 ... Induction cylinder 7a ... Inside Perimeter 7b ··· Narrow inner circumference 8 ··· Guide cylinder 8a ··· Inner circumference 8b ··· Narrow inner circumference 10 ··· Rotary base 15 ··· Shading plate 20 ··· ··· Laser source 21 ··· Element base 22 ··· Power source 25a ··· Photodiode 25b ··· Photodiode 26a · · · Condensing lens 26b · · Table 27b ... Sensor base 30 ... Data analysis unit 32 ... Motor

Claims (6)

In a round bar inspection device that inspects surface defects such as wrinkles and dirt on the outer peripheral surface of a round bar including a pipe shape,
A laser light source that irradiates the outer peripheral surface with laser light that is parallel light substantially perpendicular to the axis of the round bar;
A light receiving sensor provided so that an angle formed by the laser beam incident direction on the axis of the round bar is greater than 90 degrees and less than 180 degrees in an axial cross-sectional view of the round bar;
An apparatus for inspecting a round bar, characterized in that the reflected light of the laser beam on the outer peripheral surface is received by the light receiving sensor, and the outer peripheral surface is inspected from the level of the received light.   The round bar inspection apparatus according to claim 1, wherein an angle formed between the incident direction of the laser beam and the light receiving sensor on the axis of the round bar is about 130 degrees to about 170 degrees.   The round bar inspection apparatus according to claim 1 or 2, wherein a wavelength of laser light emitted from the laser light source is 300 nm to 700 nm.   The light receiving sensor is provided at two positions, a clockwise position and a counterclockwise position from the incident direction of the laser beam with the axis of the round bar as a center. 4. The round bar inspection apparatus according to any one of 3 above.   The round bar according to any one of claims 1 to 4, further comprising a light shielding plate for shielding laser light other than the reflected light from the round bar with the laser light from the laser light source. Inspection device. In the round bar inspection method for inspecting wrinkles and dirt on the outer peripheral surface of the round bar including the pipe shape,
Irradiating the outer peripheral surface with laser light that is parallel light substantially perpendicular to the axis of the round bar,
A light receiving sensor provided so that an angle formed by the incident direction of the laser beam on the axis of the round bar is an obtuse angle in a cross-sectional view of the round bar, and the reflected light of the laser beam on the outer peripheral surface is received. And
A round bar inspection method, wherein the outer peripheral surface is inspected from the level of the received light.

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