JP6166867B2 - Surface defect inspection apparatus and surface defect inspection method - Google Patents

Description

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

  Conventionally, inspection of surface defects due to 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 surface defect inspection apparatus is shown in Patent Document 1. In the surface defect inspection apparatus of Patent Document 1, a round bar is magnetized, and the round bar is magnetized, so that 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 surface defect inspection apparatus, there is a problem that the apparatus is complicated and expensive when the round bar is magnetized or subjected to image processing, and the round bar that cannot be magnetized cannot be inspected. Invented the surface defect inspection apparatus shown in Patent Document 2.

  The surface defect inspection apparatus shown in Patent Document 2 includes a light source that irradiates light to the 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.

  Moreover, as a surface defect inspection apparatus using a laser beam, there exists a thing as shown to patent document 3. FIG. The surface defect inspection apparatus of Patent Document 3 includes a light source that outputs inspection light applied to the surface of the inspected filament, an optical processing unit that irradiates the inspection light output from the light source onto the surface of the inspected filament, The at least two light receiving elements that receive the reflected light of the inspection light from the inspected line are arranged around the inspected line and on a plane including the central axis of the inspected line and the central axis of the inspection light. A light receiving unit arranged at a substantially symmetrical position, and a defect detection unit for calculating an output signal of the light receiving element arranged symmetrically and detecting a surface defect of the inspected filament based on the calculated output signal I have.

JP 2005-134177 A JP 2008-185356 A JP 2010-25642 A

  However, in the conventional inspection apparatus, even if the presence or absence of surface defects due to finer wrinkles or dirt can be detected, it is difficult to specify the type of surface defects.

  The present invention has been made in view of such circumstances, and provides a surface defect inspection apparatus and a surface defect inspection method capable of discriminating and detecting types of wrinkles and dirt on the outer peripheral surface of a round bar. It is in.

The surface defect inspection apparatus according to claim 1, wherein the laser light source irradiates the inspection point on the outer peripheral surface of the round bar with an elevation angle of 5 degrees to 45 degrees from the axis from the direction of the axis of the round bar; A plurality of light receiving sensors for receiving the reflected laser light reflected by the outer peripheral surface of the round bar; and a plurality of light receiving sensors for detecting surface defects based on the amount of received light. Reflection of laser light reflected on the outer peripheral surface of the round bar from the amount of light received by each of the plurality of light receiving sensors arranged in a grid shape, arranged in a grid shape along the outer edge of the outer periphery of the bar detecting the position of the ring, and the amount of light received by the light receiving sensor in the position of the reflection ring when the difference between the amount of light received by the light receiving sensor adjacent to the light-receiving sensor at the position of the reflection ring is equal to or higher than a predetermined surface portion of the difference as diffuse reflection due to defects, to detect surface defects It is characterized in.

  In the surface defect inspection apparatus according to claim 2, when the surface defect detection means is located on a plurality of light receiving sensors adjacent to each other in the radial direction of the reflecting ring, the total amount of light received by the adjacent light receiving sensors is The position of the light receiving sensor is detected, and the total value of the light receiving amounts of adjacent light receiving sensors is regarded as the light receiving amount of one light receiving sensor at the position of the reflection ring.

  The surface defect inspection apparatus according to claim 3, wherein the surface defect detection means sequentially irradiates laser beams to different inspection points separated by a predetermined distance in the axial direction of the round bar, and a plurality of positions of the reflection ring at each inspection point. A surface defect is detected by comparing the amount of light received by the light receiving sensors.

  The surface defect inspection device according to claim 4, wherein the surface defect detection means compares the amount of light received at each inspection point of the same light receiving sensor among the plurality of light receiving sensors, and detects the surface defect. To do.

The surface defect inspection apparatus according to claim 5, wherein the laser light source irradiates the inspection point on the outer peripheral surface of the round bar with an elevation angle of 5 to 45 degrees from the axis from the direction of the axis of the round bar, A plurality of light receiving sensors for receiving the reflected laser light reflected by the outer peripheral surface of the round bar; and a plurality of light receiving sensors for detecting surface defects based on the amount of received light. Reflection of laser light reflected on the outer peripheral surface of the round bar from the amount of light received by each of the plurality of light receiving sensors arranged in a grid shape, arranged in a grid shape along the outer edge of the outer periphery of the bar When the position of the ring is detected and the difference between the amount of light received by the light receiving sensor at the position of the reflective ring and the amount of light received by the light receiving sensor that is not at the position of the reflective ring is less than a predetermined value , and characterized by detecting a surface defect That.

The surface defect inspection method according to claim 6 irradiates the inspection point on the outer peripheral surface of the round bar with a laser beam having an elevation angle of 5 to 45 degrees from the axis in the direction of the axis of the round bar. The reflected laser beam reflected at the inspection point is received by a plurality of light receiving sensors arranged in a grid shape along the outer edge of the outer periphery of the round bar, and from the amount of light received by each of the plurality of light receiving sensors arranged in a grid shape The position of the reflection ring of the reflected laser beam reflected by the outer peripheral surface of the round bar is detected, the amount of light received by the light receiving sensor at the position of the reflecting ring, and the amount of light received by the light receiving sensor adjacent to the light receiving sensor at the position of the reflective ring When the difference between the two is greater than or equal to a predetermined value , the surface defect is detected by using the difference as irregular reflection due to the surface defect .

  In the surface defect inspection method according to claim 7, when the reflecting ring is positioned on a plurality of light receiving sensors adjacent in the radial direction of the reflecting ring, the position of the light receiving sensor is determined from the total amount of light received by the adjacent light receiving sensors. In addition to detecting, the total amount of light received by adjacent light receiving sensors is regarded as the amount of light received by one light receiving sensor at the position of the reflection ring.

  The surface defect inspection method according to claim 8 irradiates laser beams sequentially to different inspection points separated by a predetermined distance in the axial direction of the round bar, and the received light amounts of the plurality of light receiving sensors at the positions of the reflection rings at the respective inspection points. By comparing the above, surface defects are detected.

  The surface defect inspection method according to claim 9 is characterized in that the surface defect is detected by comparing the received light amounts at the respective inspection points of the same light receiving sensor among the plurality of light receiving sensors.

The surface defect inspection method according to claim 10 irradiates the inspection point on the outer peripheral surface of the round bar with a laser beam having an elevation angle of 5 to 45 degrees from the axis from the direction of the axis of the round bar. The reflected laser beam reflected at the inspection point is received by a plurality of light receiving sensors arranged in a grid shape along the outer edge of the outer periphery of the round bar, and from the amount of light received by each of the plurality of light receiving sensors arranged in a grid shape The position of the reflection ring of the reflected laser beam reflected by the outer peripheral surface of the round bar is detected, and the difference between the amount of light received by the light receiving sensor at the position of the reflective ring and the amount of light received by the light receiving sensor not at the position of the reflective ring is predetermined. In the following cases, a surface defect is detected by using a portion having no difference as irregular reflection due to the surface defect .

  According to the invention of claim 1 and claim 6, from the direction of the axis of the round bar, the inspection point on the outer peripheral surface of the round bar is irradiated with laser light having an elevation angle of 5 to 45 degrees from the axis, The reflected laser beam reflected at the inspection point of the bar is received by a plurality of light receiving sensors arranged in a grid shape along the outer edge of the outer periphery of the round bar, and received by each of the plurality of light receiving sensors arranged in a grid pattern. The position of the reflection ring of the reflected laser light reflected by the outer peripheral surface of the round bar is detected from the amount of light, the amount of light received by the light receiving sensor at the position of the reflecting ring, and the light receiving sensor adjacent to the light receiving sensor at the position of the reflecting ring. When the difference from the amount of received light is greater than or equal to a predetermined value, it is detected as a surface defect, and therefore, it is possible to determine and detect the type of wrinkles and dirt on the outer peripheral surface of the round bar.

  According to invention of Claim 2 and Claim 7, when a reflection ring is located on the some light reception sensor adjacent to the radial direction of a reflection ring, from the total value of the light reception amount of an adjacent light reception sensor, it is from a light reception sensor. Since the position is detected and the total amount of light received by adjacent light receiving sensors is regarded as the amount of light received by one light receiving sensor at the position of the reflecting ring, the position of the reflecting ring can be specified more accurately and more accurately. It is possible to detect surface defects.

  According to invention of Claim 3 and Claim 8, a surface defect is detected by comparing the light reception amount of the some light reception sensor of the position of a reflective ring in the position of predetermined distance in the axial direction of the round bar. Therefore, it is possible to discriminate more types of surface defects.

  According to the invention of claim 4 and claim 9, since the amount of light received at a position separated by a predetermined distance in the axial direction of the round bar of the same light receiving sensor is compared and surface defects are detected, more types of It is possible to discriminate surface defects.

  According to the invention of claim 5 and claim 10, from the direction of the axis of the round bar, the inspection point on the outer peripheral surface of the round bar is irradiated with laser light having an elevation angle of 5 degrees to 45 degrees from the axis, The reflected laser beam reflected at the inspection point of the bar is received by a plurality of light receiving sensors arranged in a grid shape along the outer edge of the outer periphery of the round bar, and received by each of the plurality of light receiving sensors arranged in a grid pattern. The position of the reflection ring of the reflected laser beam reflected by the outer peripheral surface of the round bar is detected from the amount of light, and the difference between the amount of light received by the light receiving sensor at the position of the reflective ring and the amount of light received by the light receiving sensor not at the position of the reflective ring Is detected as a surface defect, it is possible to determine and detect the type of wrinkles and dirt on the outer peripheral surface of the round bar.

It is explanatory drawing which shows an example of the structure of the surface defect inspection apparatus which concerns on this invention. It is explanatory drawing explaining operation | movement of the surface defect inspection apparatus. It is explanatory drawing which shows the light reception state by the light reception sensor of the surface defect inspection apparatus. It is explanatory drawing which shows the light reception amount of the light reception sensor of the same surface defect inspection apparatus. It is explanatory drawing which shows the mode of the comparison of the light reception amount of the light reception sensor of the same surface defect inspection apparatus. It is explanatory drawing which shows the mode of the light reception amount for every sampling period of the light reception sensor of the same surface defect inspection apparatus. It is explanatory drawing which shows the mode of the surface defect of 1st Example of the same surface defect inspection apparatus. It is explanatory drawing which shows the light reception state by the light reception sensor of 1st Example of the surface defect inspection apparatus. It is explanatory drawing which shows the light reception amount of the light reception sensor of 1st Example of the same surface defect inspection apparatus. It is explanatory drawing which shows the mode of the surface defect of the 2nd Example of the same surface defect inspection apparatus. It is explanatory drawing which shows the light reception state by the light reception sensor of 2nd Example of the same surface defect inspection apparatus. It is explanatory drawing which shows the light reception state by the light reception sensor of 2nd Example of the same surface defect inspection apparatus. It is explanatory drawing which shows the light reception amount of the light reception sensor of 2nd Example of the same surface defect inspection apparatus. It is explanatory drawing which shows the mode of the light reception amount from which the sampling period of the light reception sensor of the 2nd Example of the same surface defect inspection apparatus differs. It is explanatory drawing which shows the mode of the surface defect of the 3rd Example of the same surface defect inspection apparatus. It is explanatory drawing which shows the light reception state by the light reception sensor of the 3rd Example of the same surface defect inspection apparatus. It is explanatory drawing which shows the light reception amount of the light receiving sensor of the 3rd Example of the same surface defect 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 surface defect inspection apparatus according to the present invention. FIG. 2 is an explanatory view for explaining the operation of the surface defect inspection apparatus. FIG. 3 is an explanatory view showing a light receiving state by a light receiving sensor of the surface defect inspection apparatus. FIG. 4 is an explanatory diagram showing the amount of light received by the light receiving sensor of the surface defect inspection apparatus. FIG. 5 is an explanatory diagram showing a comparison of the amount of light received by the light receiving sensor of the surface defect inspection apparatus. FIG. 6 is an explanatory diagram showing the amount of received light for each sampling period of the light receiving sensor of the surface defect inspection apparatus.

  A surface defect inspection apparatus 1 in the figure is an apparatus for inspecting surface defects due to 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 due to wrinkles and dirt. The surface defect inspection apparatus 1 includes a laser light source 10 that irradiates a laser beam L toward an outer peripheral surface of a round bar W, and a reflected laser beam that is reflected by an inspection point P on the outer peripheral surface of the round bar W. A light receiving sensor 20 for receiving C is provided.

  The laser light source 10 is supplied with power from the power source 12 and emits laser light L. The wavelength is 300 nm to 700 nm, more specifically, a red laser (center wavelength: red (650 nm)), a green laser. (Center wavelength: green (532 nm)), violet laser (center wavelength: blue purple (405 nm)), blue laser (center wavelength: blue (375 nm)), and the like. The laser light source 10 irradiates the inspection point P on the outer peripheral surface of the round bar W with the laser beam L from the axis of the round bar W at a predetermined elevation angle θa. The elevation angle θa formed with the axis of the round bar W of the laser beam L is 5 to 45 degrees. The elevation angle θa is appropriately determined according to the material and thickness of the round bar W, the condition of the outer peripheral surface, and the type and size of the wound to be detected. The inspectable round bar W is a material that can reflect the laser beam L, and the thickness can be inspected from an object having a diameter of several μm.

  The light receiving sensor 20 receives the reflected laser light C reflected at the inspection point P of the round bar W, and is, for example, a photodiode that outputs the received light quantity. The light receiving sensor 20 is the position where the reflected laser beam C can be received most accurately, that is, the circumferential position with respect to the same round bar W as the laser light source 10, and the elevation angle θa between the axis of the round bar W and the laser beam L It heads toward the inspection point P at the same elevation angle θa ′. In FIG. 1, one of the light receiving sensors 20 is shown, but actually, as shown in FIG. 3, the plurality of light receiving sensors (positions 1a to 6d) are on the angle of elevation angles θa ′ to θb (θc). Are arranged in a grid pattern. Note that one light receiving sensor may be a type of sensor having a plurality of light receiving elements. The light receiving sensor 20 is connected to the data analysis unit 22.

  The data analysis unit 22 determines from the value of the light receiving sensor 20 whether the inspection point P of the round bar W has a surface defect due to wrinkles or dirt. The data analysis unit 22 may be an electronic computer such as a personal computer, or may be a digital processing means constituted by a logic circuit, and is not limited by the form.

  Next, the operation of the surface defect inspection apparatus 1 will be described. First, the reflection ring B on which the normal inspection point P of the round bar W is irradiated with the laser beam L and the reflected laser beam C is projected onto the light receiving sensor 20 is the outer peripheral surface of the round bar W as shown in FIG. It has a strong light amount in a ring shape along the curve. In addition, since the outer peripheral surface of the round bar W is not a perfect smooth surface, a portion having a weak light amount in a spot shape where the reflected laser light C diverges slightly occurs.

  In this way, the inspection point P of the round bar W is irradiated with the laser beam L, the reflection ring B formed by the reflected laser beam C is received by the light receiving sensor 20 and analyzed by the data analysis unit 22, and the inspection point P Judge whether there are any surface defects due to dirt.

  First, at a normal inspection point P, a beautifully continuous reflection ring B shown in FIG. FIG. 3 is a diagram schematically showing a light receiving state at each position of the light receiving sensor 20, but in the case of FIG. 3, the reflection ring B is partially broken due to a surface defect. FIG. 3 and subsequent figures show a state in which the number of light receiving sensors 20 is 4 in the vertical direction and 6 in the horizontal direction, and the total number is 24 (the total number and the way of arrangement are only examples, and are not limited to this case). The array of the light receiving sensors is an array arranged in a grid shape along the outer edge of the outer periphery of the round bar W. The values shown in each of the squares in FIG. 4 are numerical values representing the amount of light received by the light receiving sensor 20, and the larger the number, the greater the amount of received light (the intensity of the laser beam). Is shown.

  The data analysis unit 22 of the surface defect inspection apparatus 1 first captures the amount of light received by the light receiving sensor 20 as the movement of the surface defect detection means, and first performs mapping in a grid shape as shown in FIG. , Using the row and column codes shown in FIG. 3 and subsequent figures, the positions are represented as positions 1a to 6d).

  Next, the data analysis unit 22 detects the position of the reflection ring B along the curve of the outer peripheral surface of the round bar W shown in FIG. 2 from the received light amount mapped in a grid shape. In the example of FIG. 4, there are large values at positions 1b, 1c, 2c, 3c, 4c, 5c, 6b, and 6c, and it is expected that there is a reflection ring in this portion. Note that the values of the positions 2c, 3c, 4c, and 5c are extremely large in the same row (ad), so that if the reflection ring B is present at that position, it can be easily detected. On the other hand, at positions 1b, 1c, 6b, and 6c, there are positions with large values in the same row. Therefore, the received light amounts at the upper, lower, left, and right positions are added to detect the position of the reflection ring B. Thus, when the reflection ring B is located at two positions, the total amount of light received at adjacent positions (for example, positions 1b and 1c, positions 6b and 6c) is 1 at the position of the reflection ring B. The amount of light received by two light receiving sensors may be considered.

  A more specific method for detecting the reflection ring B will be described. The data analysis unit 22 first calculates the average of the light receiving sensors 20 arranged vertically (positions 1a to 1d, positions 2a to 2d, positions 3a to 3d, positions 4a to 4d, positions 5a to 5d, and positions 6a to 6d). Calculate the amount of received light. Then, the difference between the average received light amount at the vertical position and the received light amount at each position belonging to the vertical position is obtained. It is determined that the reflection ring B is at a position where the difference from the average value is the largest and the light receiving amount is the largest in the vertical arrangement. However, when there is little difference in the amount of received light from the position above and below the position where it is determined that the reflection ring B is present, it is determined that the reflection ring B is hanging around the middle. This calculation is performed up to vertical columns (position 1 to position 6), and the position of the reflection ring B is determined. Since the difference in the amount of received light varies depending on the round bar to be inspected, it is determined in advance by parameter designation and stored in advance.

  Normally, although the reflection ring B appears regardless of the presence or absence of a surface defect, the reflection ring B may not be determined depending on the type and state of the surface defect. This is a case where the surface defect state is particularly bad. For example, there may be a case with a severe diamond or poor finish (rough finish). When such a reflection ring B cannot be detected, the phenomenon itself is determined as a surface defect.

  Next, when the position of the reflection ring B is clarified, the amount of light received next to the position of the reflection ring B (up, down, left and right) is compared with the amount of light received, and attenuated or increased. It is determined whether the amount of light received at the position is not significantly different from the adjacent one. If there is a surface defect, the amount of light received at that position is attenuated compared to the amount of light received at the adjacent position. As shown in FIG. 5, in the position 3c where the reflection ring B is located, the amount of light received at the position 3c is attenuated compared to the adjacent positions 2c and 4c, and a surface defect exists at this position 3c. Can be detected.

  In addition, the data analysis unit 22 of the surface defect inspection apparatus 1 serves as surface defect detection means for each sampling cycle at the same position of the light receiving sensor 20 (the reflection ring at a position separated by a predetermined distance in the axial direction of the round bar W). It is also possible to detect a surface defect by grasping a change in the amount of received light) by increasing or decreasing the amount of received light. For example, as shown in FIG. 6, the received light amounts of the previous round bar W in the axial direction are compared with the received light amounts one before, two before, and so on. In addition, the amount of the predetermined distance away in the axial direction of the round bar W may be grasped as a length quantity, or the inspection point P is shifted by moving the round bar W or moving the surface defect inspection apparatus 1. While moving, the amount of received light may be measured at predetermined intervals, and as a result, it may be grasped as data for each sample period.

  As described above, the surface defect inspection apparatus 1 in the present embodiment has an elevation angle of 5 degrees to 45 degrees from the axis in the direction of the axis of the round bar W, and the inspection point P on the outer peripheral surface of the round bar W. The reflected laser beam C irradiated with the laser beam L and reflected at the inspection point P of the round bar W is received by a plurality of light receiving sensors 20 arranged in a grid pattern along the outer edge of the outer circumference of the round bar W, The position of the reflection ring B of the reflected laser beam C reflected from the outer peripheral surface of the round bar W is detected from the amount of light received by each of the plurality of light reception sensors 20 arranged in a shape, and the light reception sensor 20 at the position of the reflection ring B is detected. When the difference between the received light amount of the light receiving sensor 20 adjacent to the light receiving sensor 20 located at the position of the reflection ring B is equal to or greater than a predetermined value, it is detected as a surface defect, so that wrinkles and dirt on the outer peripheral surface of the round bar W are detected. It is possible to discriminate and detect the type.

  In addition, when the reflection ring B is positioned on the plurality of light receiving sensors 20 adjacent to each other in the radial direction of the reflection ring B, the position of the light receiving sensor 20 is detected from the total amount of light received by the adjacent light receiving sensors 20, By considering the total amount of light received by adjacent light receiving sensors 20 as the amount of light received by one light receiving sensor 20 at the position of the reflecting ring B, the position of the reflecting ring B can be specified more accurately, and a more accurate surface Defect detection is possible.

  Further, since the surface defects are detected by comparing the light receiving amounts of the plurality of light receiving sensors 20 at the position of the reflection ring B at positions separated by a predetermined distance in the axial direction of the round bar W, more types of surfaces are obtained. Defects can be identified.

  Furthermore, by comparing the amount of light received at a position a predetermined distance apart in the axial direction of the round bar W of the same light receiving sensor 20, more types of surface defects can be identified.

  Further, from the direction of the axis of the round bar W, the laser beam L is irradiated to the inspection point P on the outer peripheral surface of the round bar W with an elevation angle of 5 degrees to 45 degrees from the axis. Reflected reflected laser light C is received by a plurality of light receiving sensors 20 arranged in a grid shape along the outer edge of the outer periphery of the round bar W, and the amount of light received by each of the plurality of light receiving sensors 20 arranged in a grid shape. From this, the position of the reflection ring B of the reflected laser beam C reflected by the outer peripheral surface of the round bar W is detected, the amount of light received by the light receiving sensor 20 at the position of the reflection ring B, and the light receiving sensor 20 that is not the position of the reflection ring B. If the difference from the received light amount is less than or equal to a predetermined value, it can also be detected as a surface defect. In this case as well, it is possible to detect by detecting the type of wrinkles and dirt on the outer peripheral surface of the round bar W.

  In the above description, the detection of the surface defect has been described. However, the surface defect inspection apparatus 1 in the present application can determine the type of the surface defect as well as the detection of the surface defect. Will be explained. FIG. 7 is an explanatory view showing the state of surface defects of the first embodiment of the surface defect inspection apparatus. FIG. 8 is an explanatory view showing a light receiving state by the light receiving sensor of the first embodiment of the surface defect inspection apparatus. FIG. 9 is an explanatory diagram showing the amount of light received by the light receiving sensor of the first embodiment of the surface defect inspection apparatus.

  In the first embodiment, detection of the surface defect D1 remaining on the base metal scratch of the round bar W1 as shown in FIG. 7 will be described. The base material scratch residue is a material in which a defect (unprocessed) of the material before processing (base material) remains as it is. When the surface defect D1 remaining on the base material scratch is used as the inspection point P and the laser beam L is irradiated, the reflected laser beam C is irregularly reflected and the reflection ring B is partially lost as shown in FIG. In the data analysis unit 22, the amount of light received by the light receiving sensor 20 is mapped as shown in FIG. 9, and first, the position of the reflection ring B is specified. In the case of the first embodiment, the data analysis unit 22 detects the position of the reflection ring B as positions 1b, 1c, 2c, 3c, 4c, 5c, 6b, and 6c.

  Next, the data analysis unit 22 compares the received light amounts at positions adjacent to the specified position of the reflection ring B. When the position 2c is compared with the position 3c, the amount of received light is greatly different, and the surface defect D1 is detected at the position 2c where the amount of received light is significantly reduced. In the case where the base material scratch remains, since the chip of the reflection ring B can be detected at substantially the same position at a position (in each sample period) separated from the round bar W1 in the axial direction, the data analysis unit 22 can detect this surface defect D1. As a type, it is possible to specify the remaining scratch on the base material.

  Next, in Example 2, examples of other surface defects will be described. FIG. 10 is an explanatory view showing the state of surface defects of the second embodiment of the surface defect inspection apparatus. FIG. 11 is an explanatory view showing a light receiving state by the light receiving sensor of the second embodiment of the surface defect inspection apparatus. FIG. 12 is an explanatory view showing a light receiving state by the light receiving sensor of the second embodiment of the surface defect inspection apparatus. FIG. 13 is an explanatory diagram showing the amount of light received by the light receiving sensor of the second embodiment of the surface defect inspection apparatus. FIG. 14 is an explanatory view showing the amount of received light with different sampling periods of the light receiving sensor of the second embodiment of the surface defect inspection apparatus.

  In the second embodiment, detection of a surface defect D2 of a spiral flaw of the round bar W2 as shown in FIG. 10 will be described. Spiral scratches are spiral defects that occur during processing and have a constant spacing. When the laser beam L is irradiated with the surface defect D2 of the spiral flaw as the inspection point P, the reflected laser beam C is diffusely reflected as shown in FIGS. 11 and 12, and the reflection ring B is partially missing at a constant period. FIG. 11 and FIG. 12 show light receiving states at different positions in the axial direction of the round bar W2. And as FIG. 11 and FIG. 12 compare, the position where the reflective ring B was missing is different. In FIG. 11, it is missing at position 2c, and in FIG. 12, it is missing at position 3c. In the data analysis unit 22, the amount of light received by the light receiving sensor 20 is mapped as shown in FIGS. 13 and 14 (FIGS. 11 and 13 are paired with FIGS. 12 and 14). Specify the position of. In the case of the present Example 2, the data analysis part 22 detects the position of the reflective ring B as position 1b, 1c, 2c, 3c, 4c, 5c, 6b, 6c.

  Next, the data analysis unit 22 compares the received light amounts at positions adjacent to the specified position of the reflection ring B. In FIG. 13, when the position 2c and the position 3c are compared, the received light amount is greatly different, and the surface defect D2 is detected at the position 2c where the received light amount is significantly reduced. Then, at the position (another sample position) that is separated in the axial direction of the round bar W2 in FIG. 14, when the position 2c and the position 3c are compared, the amount of received light is greatly different, and the position 3c where the amount of received light is significantly reduced. The surface defect D2 will be detected. As described above, the data analysis unit 22 can identify the spiral flaw as the type of surface defect by the time change of the same position of the light receiving sensor 20 (data change for each sampling period).

  Next, in Example 3, another example of surface defects will be described. FIG. 15 is an explanatory view showing the state of surface defects of the third embodiment of the surface defect inspection apparatus. FIG. 16 is an explanatory view showing a light receiving state by the light receiving sensor of the third embodiment of the surface defect inspection apparatus. FIG. 17 is an explanatory diagram showing the amount of light received by the light receiving sensor of the third embodiment of the surface defect inspection apparatus.

  In the third embodiment, detection of the surface defect D3 of the diamond of the round bar W3 as shown in FIG. 15 will be described. The diamond is a fine surface irregularity defect generated during processing. When the surface defect D3 of the diamond is used as the inspection point P and the laser beam L is irradiated, the reflected laser beam C is irregularly reflected and the reflecting ring B is projected thinly as shown in FIG. In the data analysis unit 22, the amount of light received by the light receiving sensor 20 is mapped as shown in FIG. 17, and the position of the reflection ring B is first identified. However, in the case of the third embodiment, the amount of received light is generally small, and the data analysis unit 22 may not be able to detect the position of the reflection ring B firmly. In this way, the data analysis unit 22 can identify the diamond as the type of surface defect in the case of reflection that is totally blurred.

  As described above, according to the present invention, it is possible to provide a surface defect inspection apparatus and a surface defect inspection method capable of discriminating and detecting types of wrinkles and dirt on the outer peripheral surface of a round bar.

1... Surface defect inspection device 10... Laser light source 12... Power source 20. ..... Round bars W1-W3 ... Round bars D1-D3 ... Surface defects

Claims (10)

In the surface defect inspection device that detects surface defects due to wrinkles and dirt on the outer peripheral surface of the round bar including the pipe shape,
A laser light source for irradiating the inspection point on the outer circumferential surface of the round bar with a laser beam having an elevation angle of 5 degrees to 45 degrees from the axis direction of the round bar;
A plurality of light receiving sensors for receiving reflected laser light reflected by the outer peripheral surface of the round bar;
The plurality of light receiving sensors includes surface defect detection means for detecting the surface defects based on the amount of received light,
The plurality of light receiving sensors are arranged in a grid shape along the outer edge of the outer periphery of the round bar,
The surface defect detection means detects the position of the reflection ring of the laser beam reflected on the outer peripheral surface of the round bar from the amount of light received by each of the plurality of light receiving sensors arranged in a grid shape,
And received light amount of the light receiving sensor at a position of the reflecting ring, when the difference between the received light amount of the light receiving sensor adjacent the light receiving sensor at a position of the reflecting ring is higher than the predetermined, the surface portion of the difference A surface defect inspection apparatus , wherein the surface defect is detected as irregular reflection due to a defect. The surface defect detection means is
When the reflecting ring is positioned on a plurality of light receiving sensors adjacent in the radial direction of the reflecting ring, the position of the light receiving sensor is detected from the total amount of light received by the adjacent light receiving sensors;
2. The surface defect inspection apparatus according to claim 1, wherein a total value of received light amounts of the adjacent light receiving sensors is regarded as a received light amount of one of the light receiving sensors located at the position of the reflection ring.   The surface defect detection means sequentially irradiates the different inspection points that are separated by a predetermined distance in the axial direction of the round bar, and receives the light from the plurality of light receiving sensors at the position of the reflection ring at each inspection point. 3. The surface defect inspection apparatus according to claim 1, wherein the surface defect is detected by comparing amounts.   The said surface defect detection means compares the light reception amount in each said test | inspection point of the same said light reception sensor among these light reception sensors, and detects the said surface defect. Surface defect inspection device. In the surface defect inspection device that detects surface defects due to wrinkles and dirt on the outer peripheral surface of the round bar including the pipe shape,
A laser light source for irradiating the inspection point on the outer circumferential surface of the round bar with a laser beam having an elevation angle of 5 degrees to 45 degrees from the axis direction of the round bar;
A plurality of light receiving sensors for receiving reflected laser light reflected by the outer peripheral surface of the round bar;
The plurality of light receiving sensors includes surface defect detection means for detecting the surface defects based on the amount of received light,
The plurality of light receiving sensors are arranged in a grid shape along the outer edge of the outer periphery of the round bar,
The surface defect detection means detects the position of the reflection ring of the laser beam reflected on the outer peripheral surface of the round bar from the amount of light received by each of the plurality of light receiving sensors arranged in a grid shape,
When the difference between the amount of light received by the light receiving sensor at the position of the reflecting ring and the amount of light received by the light receiving sensor that is not at the position of the reflecting ring is equal to or less than a predetermined value, the portion without the difference is regarded as irregular reflection due to the surface defect. A surface defect inspection apparatus for detecting the surface defect. In the surface defect inspection method to detect surface defects due to wrinkles and dirt on the outer peripheral surface of the round bar including the pipe shape,
From the direction of the axis of the round bar, irradiate the inspection point on the outer peripheral surface of the round bar with a laser beam having an elevation angle of 5 degrees to 45 degrees from the axis,
The reflected laser beam reflected at the inspection point of the round bar is received by a plurality of light receiving sensors arranged in a grid shape along the outer edge of the outer circumference of the round bar,
From the amount of light received by each of the plurality of light receiving sensors arranged in a grid, the position of the reflection ring of the reflected laser light reflected by the outer peripheral surface of the round bar is detected,
And the amount of light received by the light receiving sensor at a position of the reflecting ring, when the difference between the received light amount of the light receiving sensor that is adjacent to the light receiving sensor at a position of the reflecting ring is higher than the predetermined, the surface portion of the difference A surface defect inspection method , wherein the surface defect is detected as irregular reflection due to a defect. When the reflecting ring is positioned on a plurality of light receiving sensors adjacent to each other in the radial direction of the reflecting ring, the position of the light receiving sensor is detected from the total amount of light received by the adjacent light receiving sensors,
7. The surface defect inspection method according to claim 6, wherein a total value of received light amounts of the adjacent light receiving sensors is regarded as a received light amount of one of the light receiving sensors at the position of the reflection ring.   By sequentially irradiating laser beams to different inspection points separated by a predetermined distance in the axial direction of the round bar, and comparing the received light amounts of the plurality of light receiving sensors at the positions of the reflection ring at the respective inspection points, The surface defect inspection method according to claim 6, wherein the surface defect is detected.   The surface defect inspection method according to claim 8, wherein the surface defect is detected by comparing light reception amounts at the respective inspection points of the same light reception sensor among the plurality of light reception sensors. In the surface defect inspection method to detect surface defects due to wrinkles and dirt on the outer peripheral surface of the round bar including the pipe shape,
From the direction of the axis of the round bar, irradiate the inspection point on the outer peripheral surface of the round bar with a laser beam having an elevation angle of 5 degrees to 45 degrees from the axis,
The reflected laser beam reflected at the inspection point of the round bar is received by a plurality of light receiving sensors arranged in a grid shape along the outer edge of the outer circumference of the round bar,
From the amount of light received by each of the plurality of light receiving sensors arranged in a grid, the position of the reflection ring of the reflected laser light reflected by the outer peripheral surface of the round bar is detected,
When the difference between the amount of light received by the light receiving sensor at the position of the reflecting ring and the amount of light received by the light receiving sensor that is not at the position of the reflecting ring is equal to or less than a predetermined value, the portion without the difference is regarded as irregular reflection due to the surface defect. A surface defect inspection method comprising detecting the surface defect.

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