JP2017198583A - Visual inspection method of specific area in cylindrical inner peripheral surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent, in a visual inspection of a specific area in a cylindrical inner peripheral surface of a cylindrical member or the like, an erroneous defect determination from occurring, by easily and efficiently removing an erroneous determination factor, before processing a photographed image by a computer and determining an exterior quality of a surface of the specific area according to a criteria set for a defect present on the surface of the specific area.SOLUTION: A visual inspection method includes, as a pretreatment, a laser processing step of irradiating a surface of a specific area 14 in a cylindrical inner peripheral surface with a laser beam La before performing a visual inspection, so as to remove unevenness of a plated layer or a deposit on the surface, which might cause an erroneous defect determination.SELECTED DRAWING: Figure 1

Description

  The present invention relates to the appearance (surface of a specific area) of a cylindrical inner peripheral surface such as an inner surface of a cylindrical member such as a cylindrical member that is an inspection object or an inner surface of the hole of an inspection object having a circular hole or the like. ).

  As a method for inspecting the appearance of a specific area on the inner surface (hereinafter also referred to as a cylindrical inner peripheral surface or inner peripheral surface) of a cylindrical member or the like, the cylindrical inner peripheral surface is imaged with a camera (CCD), and imaging is performed. A method is known in which a processed image is processed by a computer, and the quality of the appearance of the surface is determined based on a quality determination criterion set for defects present on the surface of the specific area (inspection area). As an example, light is applied to the cylindrical inner peripheral surface via an optical system such as a beam splitter, a reflecting mirror, or an objective convex lens, and the inner peripheral surface is imaged by a camera based on the reflected light on the irradiated surface. Based on the threshold value designated by the computer, image processing (for example, binarization processing), and based on such image information, the appearance (inner peripheral surface) in contrast to a predetermined pass / fail judgment criterion This is a method in which the quality is determined (see Patent Document 1).

  In the inspection method described above, for example, if there is a defect such as a recess on the inner circumferential surface of the cylinder, the amount of light incident on the reflecting mirror is reduced due to irregular reflection or scattering of reflected light at the damaged part. Such a light quantity reduction part is imaged as a dark part by the imaging device. The computer cuts out a defect candidate based on brightness and darkness from the image, performs image processing, and determines it as a defect when it should be determined as defective based on a set determination criterion.

JP 2013-142596 A

  By the way, in the case where, for example, a cylindrical member, which is an inspection object, is manufactured by cold forging or machining by cutting or the like including the inner peripheral surface of the cylinder, the oil content used in those processing steps. (Cutting oil is also a lubricant) and generated foreign matter such as scraps and oxides (hereinafter collectively referred to as “adhesives”) adhere to the area to be inspected on the machined surface. May have. In such a case, when the inspection as described above is performed, the processed surface itself, which is the inner circumferential surface of the cylinder, has a scratch of depth or size that should be determined (determined) as a defect (defect). However, due to these deposits, the image may be recognized as a defect in image processing or pass / fail judgment, and may be erroneously determined as defective (appearance defect). In addition, even when a coating such as a plating layer or a coating film (metal coating or non-metal coating; hereinafter also referred to as coating) is formed on the surface of a member after machining such as cutting, Although some processed surfaces do not have scratches of the depth or size that should be judged as defective, a part of the surface based on processing defects (plating defects, coating defects, etc.) of those coatings Due to the presence of discoloration or lightness unevenness (hereinafter referred to as “unevenness”), the surface portion may be recognized as a defect in image processing or pass / fail judgment, and may be erroneously determined as defective (appearance defect). is there.

  The image thus captured is subjected to image processing (for example, binarization processing) by a computer, and the quality of the appearance of the surface is judged based on the quality judgment criteria set for the defects present on the surface of the specific region. In the case of visual inspection, although it depends on the threshold value in the binarization process, it is not a defect (for example, a scratch) that should originally be determined as a defective appearance, but there are deposits and “unevenness” in the film. Due to such erroneous determination factors, there are cases where the appearance defect is erroneously determined (hereinafter, defective determination). Such defect misjudgment tends to occur as the finished surface roughness on the inner peripheral surface of the cylinder is set to a high level (the surface roughness is small), the judgment standard (inspection level) is increased, and the severity becomes severer. . For example, this is the case. The inner circumferential surface of the cylindrical member has concentric and different diameters in the upper and lower sides, and an annular shelf surface of a different diameter boundary in a different diameter shaft member inserted separately by inserting a metal washer in the annular shelf surface of the boundary of the different diameter. In an assembly structure in which a high degree of airtightness is desired to be maintained by metal contact between the two members, for example, in the case where a film (plating layer) is formed, the annular shelf surface It is necessary to tighten the level of appearance inspection, and in such a case, erroneous determination tends to occur. Also, in the inspection of the inner peripheral surface of such a cylindrical member, even in the processed stage such as cutting before film formation, due to the presence of the deposits as described above, it is similarly defective. An erroneous determination may be invited. As a result, the inspection method using the image processing as described above cannot be applied to such an inspection object as it is.

  On the other hand, the following measures are conceivable as measures for preventing such erroneous erroneous determination. For example, when a plating layer (film) is formed on the inner peripheral surface, an appropriate acidic solution (acid solution for plating removal) is poured into the cylindrical member before the inspection process, and in such plating In order to eliminate the “unevenness”, the surface of the film in a specific region is made uniform, or the plating layer in that portion is removed to remove an erroneous determination factor. Moreover, when the coating film is formed, it is possible to perform the same process by application | coating of the appropriate solvent according to it.

  However, in the removal of the misjudgment factor by such a method, the inspection level of the surface roughness is a specific region (a circular shelf in the above example) that is a part of the inner peripheral surface of the cylindrical member that is the inspection target part. If only a specific thickness is required for other parts, a masking process is applied to parts other than the specific area (parts other than the part to be inspected). This requires a lot of work, including the process and the removal of the mask after the process. Not only that, the cylindrical member to be inspected has an inner diameter as small as about 10 mm, for example, or the specific area of the inspection target on the inner peripheral surface of the cylindrical member is farther from the opening end of the cylindrical member, Masking itself is difficult when the position to be masked extends deeply. Therefore, in such a case, the processing method as described above cannot be applied. As a result, in the case where a high degree of surface accuracy (roughness) is required only in a specific region of the cylindrical inner peripheral surface as in the case of a cylindrical member having such a small inner diameter, such specification is required. There has been a problem that it is not easy to inspect the appearance by tightening the inspection level of only the area. It is also inefficient to clean the entire inner peripheral surface by pouring a solvent or the like and remove the deposits only for cleaning such a specific area.

  The present invention has been made in view of the above problems, and an appearance inspection of a specific area on a cylindrical inner peripheral surface of a cylindrical member or the like is performed on a surface of the specific area by processing the captured image with a computer. In the appearance inspection method for judging the quality of the appearance of the surface based on the quality judgment criteria set for the defect to be performed, the aforementioned erroneous judgment factors existing in the specific area are simply and efficiently removed prior to the inspection. It is an object of the present invention to make it possible to perform an accurate “defect determination” in order to prevent an erroneous “defect determination” so that an accurate determination can be made, and a highly reliable inspection can be realized easily and efficiently.

According to the first aspect of the present invention, the method for inspecting the appearance of the specific area on the cylindrical inner peripheral surface captures the specific area on the cylindrical inner peripheral surface with a camera, performs image processing on the captured image with a computer, and An appearance inspection method for determining the quality of the appearance of the surface based on the quality determination criteria set for defects existing on the surface of the region,
Before performing the appearance inspection, the surface of the specific region on the cylindrical inner peripheral surface is irradiated with laser light, and the film unevenness formed on the surface or the laser processing step for removing the film is a pretreatment step. It is characterized by including.

The method for inspecting the appearance of the specific area on the cylindrical inner peripheral surface according to the second aspect of the present invention is to capture the specific area on the cylindrical inner peripheral surface with a camera, subject the captured image to image processing by a computer, and An appearance inspection method for determining the quality of the appearance of the surface based on the quality determination criteria set for defects existing on the surface of the region,
Before performing the appearance inspection, a laser processing step of irradiating the surface of the specific region on the cylindrical inner peripheral surface with a laser beam and removing deposits adhering to the surface was included as a pretreatment step. It is characterized by.

The present invention described in claim 3 is a method for inspecting a specific region on a cylindrical inner peripheral surface according to any one of claims 1 and 2, wherein the laser beam is a non-thermal laser. is there.
The present invention according to claim 4 is characterized in that a beam splitter, a prism, or a reflecting mirror is used to irradiate the surface of the specific region with laser light, and is irradiated as reflected light. It is an external appearance inspection method of the specific area | region in the cylindrical internal peripheral surface of any one of these.

  According to the first aspect of the present invention, before the appearance inspection, as a pretreatment step, the surface of the specific region on the cylindrical inner peripheral surface is irradiated with laser light, and the film formed on the surface The laser processing step for removing the “unevenness” or the film is included as a pretreatment step. Here, the film is a plating film, a metal film such as a coating film, or a non-metal film. Then, the “unevenness” of the film in the specific region or the removal of the film is performed by laser processing, and can be easily and efficiently performed. That is, when the film is a plating layer, when removing a specific specific area on the inner peripheral surface by pouring an acidic solution, it takes time and labor to mask the unnecessary portion of the removal. However, laser processing does not have such a problem, and it can be easily and efficiently removed. The same applies to the case of solvent application and pouring when the film is a film. As described above, according to the present invention, in the appearance inspection for only the specific region, the “unevenness” of the film existing on the surface and causing the erroneous determination, and the erroneous determination factor due to the presence of the film can be simplified. Since it can be efficiently removed, an accurate pass / fail judgment can be obtained in the subsequent inspection. Note that “removal of“ unevenness ”means that unevenness is eliminated, the surface of the portion is made uniform, and an erroneous determination factor is removed.

  Thus, in the present invention, since the appearance inspection is performed after the laser processing step, it is possible to effectively prevent the occurrence of erroneous “defect determination” due to such a film. Thereby, it is possible to accurately determine whether the specific area is good or not without causing an increase in cost. It should be noted that in the unevenness of the film by such laser processing or the removal of the film, the surface of the object to be inspected itself (surface) and the scratches to be detected are not affected as long as they are present on the base. Depending on the film material, etc., the irradiation conditions of the laser beam to be irradiated should be set according to the film material so that the film surface can be removed by evaporation, etc., or the surface of the film can be made uniform by removing “unevenness”. That's fine.

  According to this invention of Claim 2, before performing an external appearance inspection, as a pre-processing process, the surface of the said specific area | region in the said cylindrical internal peripheral surface is irradiated with a laser beam, and it adheres to the surface Includes a laser processing step to remove deposits. In the present invention, since the removal of such deposits is also performed by laser processing, only the surface of the specific region is targeted, and the deposits existing there are easily realized compared to removal by a method such as pouring of a cleaning agent. it can. Since the appearance inspection is performed after the removal, it is possible to effectively prevent the occurrence of an erroneous “defect determination” due to such deposits, and therefore it is possible to accurately determine whether the specific area is good or bad. . In addition, even in the removal of deposits by such laser processing, the type of deposit (oil, oxide) as long as it does not affect the substrate (surface) to be inspected and the scratches to be detected. Depending on the metal powder, etc., the irradiation conditions of the laser beam to be irradiated, such as the output and the scanning speed, may be set so that they can be melted and evaporated.

  As is apparent from the above description, according to the present invention described in claims 1 and 2, for a specific region, a high (severe) inspection level for which a minute defect (unevenness or surface flaw) is desired to be determined as bad. Even in this case, it is possible to realize a low-cost and highly reliable appearance inspection. In addition, although various well-known things can be used for the laser beam to irradiate, it is preferable to use a non-thermal laser as described in Claim 3. This is because it is effective in avoiding thermal influence on the cylindrical inner peripheral surface to be inspected. Further, the cylindrical inner peripheral surface to be inspected is, for example, a concentric and different diameter cylindrical surface, and the surface of the specific region is an annular shelf surface (annular steeply tapered surface) at the different diameter boundary. In that case, the annular shelf surface, which is the surface of the specific region, is directly irradiated by irradiating laser light from the opening end side of the large-diameter cylindrical inner peripheral surface located in the direction in which the shelf surface faces. Laser processing is possible, but the specific area on the cylindrical inner peripheral surface is directed directly toward the axis (center) side of the cylindrical inner peripheral surface and parallel to the axis (hereinafter referred to as a parallel inner peripheral surface). When it is difficult or impossible to irradiate, it is preferable to use a beam splitter, a prism or a reflecting mirror as described in claim 4 to irradiate as reflected light.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of the embodiment which actualized this invention, Comprising: The left figure (A) is a laser of the specific area | region (upward-facing annular shelf surface) in the cylindrical internal peripheral surface of the cylindrical member shown with the half cross section. A conceptual diagram for explaining a state to be processed, and a right diagram (B) is a conceptual diagram for explaining a state in which a specific area is imaged by a camera after laser processing. In the laser processing of FIG. 1, the conceptual diagram (sectional drawing) for description of the state which laser-processes a specific area | region as a some branching laser beam using DOE. The conceptual diagram (sectional drawing) for description of the state which laser-processes the specific area | region (parallel cylindrical surface) in the cylindrical internal peripheral surface of the cylindrical member of FIG.

  An embodiment of the present invention will be described in detail with reference to FIG. However, in this example, the inspection object of the appearance inspection is a penetrating cylindrical member 10 (different diameter cylindrical member made of steel) as shown in FIG. 1, the outer diameter is constant, and its cylindrical inner periphery The surface (cylindrical inner peripheral surface) 11 has a small inner diameter portion (small inner peripheral surface) 13 having a relatively small diameter at the upper and lower ends, and the small inner diameter portion 13 and a large inner diameter portion (large A cylindrical member having a different diameter is provided with an upward circular shelf surface (step portion) 14 having a sharp taper taper at the boundary with the inner peripheral surface 15 as shown in the figure (S1-S1 in FIG. 1). See section). Such a cylindrical member 10 is formed through cold forging, cutting, and the like. In this example, after the processing, the entire inner and outer surfaces (all surfaces) are electroplated as a film, although not shown. A plating layer (for example, a nickel plating layer) is formed. Of the inner peripheral surface on which the plating layer is formed, an upwardly facing annular shelf surface (hereinafter also referred to as an annular shelf surface) 14 is set as a specific region to be subjected to appearance inspection, and the surface of the specific region is Since there is “unevenness” in a certain plating layer (surface), and the “unevenness” is likely to cause a misjudgment of defect in image processing, the “unevenness” is removed by laser light irradiation, The surface of the plating layer is made uniform, and then an appearance inspection is performed to determine whether or not there are any scratches (small cracks, dents, wrinkles, etc.) to be judged as defective on the annular shelf surface (surface) 14. And However, the laser used in this example is a non-thermal laser.

  In this example, prior to this appearance inspection, “unevenness” of the plating layer (surface) of the annular shelf surface 14 is removed as follows. The cylindrical member 10 is vertically positioned on the inspection table 20 to be positioned and fixed. On the other hand, as shown in the left figure (A) of FIG. 1, a laser oscillator (head) 100 that oscillates a laser beam La is arranged above the cylindrical member 10 and is shown by a thick broken line in the figure. The laser beam La is set so that it can be irradiated from above the cylindrical member 10 toward the upward circular shelf surface 14 inside the cylindrical member 10 with a predetermined irradiation spot (condensing point) diameter. This irradiation spot diameter is appropriately set so as to be suitable for removing “unevenness” of the plating layer (surface) in consideration of laser output, thermal influence on the annular shelf surface 14 and the like. On the other hand, the cylindrical member 10 can be rotated at an appropriate speed around the axis G of the cylindrical member 10 by the rotation of the inspection table 20 so that the laser beam La scans (moves) the annular shelf surface 14 in a circular manner. Is set to The optical axis in laser light irradiation may be parallel or substantially parallel to the axis (center axis) G of the cylindrical member 10, but in this example, the annular shelf surface 14 is as described above. Since it is tapered (about 30 degrees with respect to a plane perpendicular to the axis G), it is set to be inclined with respect to the axis G so that it is perpendicular to or close to the generatrix of the taper. ing.

  In this example, after the above setting and setting, the laser oscillator 100 is driven to irradiate the annular shelf surface 14 with the laser beam La with a predetermined irradiation spot diameter. From the start of the irradiation, the cylindrical member 10 is rotated around its axis G by the rotation of the inspection table 20, and the laser light La is rotated around the annular shelf surface 14 in the circumferential direction and scanned. However, in this irradiation process, for example, near the outer peripheral edge of the annular shelf surface 14 in relation to the spot diameter so that the entire surface (entire) of the annular shelf surface 14 is uniformly scanned with the laser beam La. The irradiation position of the laser beam La or the position of the laser oscillator 100 is changed so that the irradiation position is changed in the radial direction so as to go from the part sequentially toward the inner peripheral part, and the condensing point moves on a different circumference. To do. Thus, by performing laser processing by predetermined irradiation, the “unevenness” of the plating layer on the upwardly facing annular shelf surface 14 is removed by laser processing, and the surface is made uniform.

  It should be noted that the laser beam La used for such laser processing does not affect or change the original scratch to be detected, and can remove the “unevenness” of the plating layer (in this example, Depending on the type (material, melting point), thickness, etc. of the Ni plating, the condition may be set to an output that can melt or evaporate the surface layer in a very small thickness range. This can be set by determining a condition range in which desired uniformity (removal of “unevenness”) can be obtained based on repeated test irradiation (test laser processing) or the like. Incidentally, in this example, the thickness (design value) of the Ni plating layer is 1 to 10 μm, and the conditions of the laser oscillator (YAG laser (basic wavelength: 1064 nm) in this example) are: wavelength: 355 nm, output: 1. This is a pulse laser of 4 w (100% output about 4 w), frequency: 100 kHz, scanning speed: 400 mm / s, 4 μm pitch.

  In this example, in the upward annular shelf surface 14 that is a specific region on the inner peripheral surface, the “unevenness” of the plating layer, which has been a cause of erroneous determination of defects, can be easily and efficiently performed by the laser processing described above. Can be removed. That is, the surface of the plating layer is melted or burned and evaporated by laser processing to remove the unevenness of the surface and to make the surface uniform. As a result, the “unevenness” can be easily and efficiently removed, that is, the surface can be made uniform, in comparison with the technique for removing the “unevenness” from a part of the inner peripheral surface (the upward-facing annular shelf surface 14). Thereby, after this laser processing step, the upward-circular annular shelf surface 14 which is a specific region on the cylindrical inner peripheral surface 11 may be visually inspected.

  That is, as shown in the right figure (B) of FIG. 1, the camera 200 disposed above the cylindrical member 10 images the upward circular shelf surface 14 along the axis G, and the captured image is a computer. Then, the image processing is performed, and the appearance inspection for determining the quality of the appearance of the surface is performed based on the quality determination criteria set in advance for the defects existing on the upward circular shelf surface 14. In this inspection, the “unevenness” of the plating layer has been removed by the laser processing described above, which is the pre-processing step. Therefore, an erroneous “defect” that has occurred in the past due to the unevenness. The occurrence of “determination” is prevented. That is, since the “unevenness” that is an erroneous “defect determination” factor has disappeared, if the original flaw exists in the specific region (the upward-circular annular shelf surface 14), the flaw becomes obvious. Therefore, since it is only necessary to set a “defect determination” criterion in image processing (for example, a threshold value in binarization processing) using only such a scratch as a reference, it is possible to prevent erroneous “defect determination” from occurring. It is possible to make a pass / fail judgment.

  In the laser processing of the above example, as shown in FIG. 2, by using a DOE (diffraction optical element) 120, one laser beam La can be branched into a plurality of parts. That is, for example, the laser beam La is irradiated along the axis (center axis) G of the cylindrical member 10 to enter the DOE (diffraction optical element) 120, and the laser light (incident light) La is, for example, center axis A plurality of branched laser beams Lab branched into a plurality at equal angular intervals on a circumference coaxial with G, and this is irradiated at once to a plurality of circumferential locations on the upward circular shelf surface 14 via the condenser lens 140. You may make it do. In this way, even when combined with the rotation around the axis G relative to the cylindrical member 10 or the like, the entire laser processing of the annular shelf surface 14 can be performed in a short time.

  In the above example, the case where the “unevenness” of the plating layer, which is a film, is removed and the surface is made uniform has been described, but even when the film is a coating film and there is “unevenness”, By performing laser processing in the same manner as described above, the “unevenness” can be removed (the surface can be made uniform). Even in such a case, the laser irradiation conditions may be set so that the removal can be efficiently performed according to the material, thickness, and the like of the film (coating film). In the above example, the case where the “unevenness” on the surface of the film is removed has been described. However, the plating layer or the coating film (film) itself formed in a specific region of the inspection object may be removed from the substrate. In such a case, the entire coating (entire layer thickness) may be removed by laser processing. In such a case, laser processing conditions may be set so that only the coating is removed without affecting or changing the substrate itself under the coating. If it is desired to remove “unevenness” or a coating only on a part of the circumferential direction, the laser light may be irradiated with only that part as a specific region.

  In the above example, the cylindrical member 10 that has been processed by cutting or the like has been described as being formed with a film such as plating (film treatment). However, even with the cylindrical member 10 described above, such a film is formed. In the stage where the process is not performed, the upward circular shelf surface (base) 14 may be inspected for damage. Also in this inspection, if an object (foreign matter) is attached to the surface and it is desired to prevent it from being erroneously determined to be defective, the upward-circular annular shelf surface 14 is similar to that described above. Then, laser processing may be performed to remove the deposits by irradiating the laser beam.

  The removal of the deposits by such laser processing is simpler than the conventional method of cleaning and removing the deposits by melting or burning them with a laser and evaporating them. It can be removed efficiently. Even in the removal of such deposits, only the target deposits are removed without affecting or changing the substrate to be subjected to visual inspection and scratches such as microcracks and dents existing on the substrate. In this way, the processing conditions may be set, for example, by irradiating a laser beam with a necessary output suitable for the attached matter at an appropriate scanning speed. Then, after removing the deposits by such laser processing, the deposits are taken by performing an appearance inspection by taking an image of the upward circular shelf surface with a camera and performing image processing in the same manner as described above. Since the occurrence of erroneous “defect determination” due to the presence (attachment) is prevented, an accurate inspection can be performed.

  Next, although the inspection object is the same as the cylindrical member 10 in the above example, FIG. 3 shows the laser processing when the specific region to be inspected is not the upward annular shelf surface 14 in the above example. The description will be given with reference. In FIG. 3, the specific region to be inspected is a part of the cylindrical inner peripheral surface 11 that is parallel to the axis G facing the axis G (inner cylindrical wall surface) (one point in FIG. 3). This is the case of the region 17 between the chain lines. Even in this case, it is not impossible to directly irradiate the laser beam La, but is direct irradiation unfavorable because the cylindrical inner peripheral surface 11 is elongated and the specific region 17 is far from the opening at the upper end? If difficult, as shown in FIG. 3, the reflecting mirror 160 is inserted and arranged in the cylindrical member 10, and the optical axis in the irradiation with the laser light La from the laser oscillator 100 is, for example, the cylindrical member 10. If the laser beam La is rotated by 90 degrees, for example, to irradiate the inner wall surface of the specific region 17 at a right angle. Good.

  In other words, when it is difficult or impossible to directly irradiate the specific region 17 like such a portion, the reflecting mirror 160 may be used for irradiation. Even in such a case, the laser beam La can be scanned in the circumferential direction on the cylindrical inner peripheral surface 11 by rotating the cylindrical member 10 around the axis G at an appropriate rotational speed. In such a case, depending on the size (range) of the specific region 17 in the direction of the axis G, the cylindrical member 10 is moved in the direction of the axis G (up and down arrows in the figure) at the end of one scanning. By moving (shifting) an appropriate amount in the indicated direction in accordance with the irradiation spot diameter, irradiation in a necessary range (specific region 17) can be performed. This movement may be performed by moving the inspection table 20 up and down.

  The reflecting mirror used in the laser processing described above may be a prism or a beam splitter. Also, when using a reflecting mirror as in the laser processing described above, one laser beam La oscillated from the laser oscillator 100 is branched into a plurality of laser beams using a DOE, and is condensed and reflected. The light may be reflected by (a plurality of reflecting mirrors or an upward conical reflecting mirror) and irradiated at a plurality of locations at an angular interval in the circumferential direction on the inner circumferential surface of the cylinder. When a beam splitter is used, for example, the light is irradiated and transmitted through one beam splitter (half mirror) toward the parallel inner peripheral surface (inner cylinder wall surface) as a half light amount. Alternatively, the light amount may be irradiated with a reflecting mirror in the radial direction of the cylindrical inner peripheral surface 11, for example, in the opposite direction. By doing so, although a vertical shift occurs, the opposing inner wall surfaces of the pipe can be irradiated at the same time, which is suitable when the specific region is a wide range in the vertical direction. In addition, after such laser processing, appearance inspection can be performed in the same manner as described above by imaging the specific region 17 to be inspected with a camera from above the cylindrical member 10. In this case, a reflecting mirror may be disposed in the cylindrical member 10 to image the parallel inner peripheral surface (the specific region 17 on the cylinder inner wall surface), and the appearance inspection may be performed based on the image data.

  In each of the above examples, the inspection object is a cylindrical member, and the case where the appearance inspection of the specific area on the cylindrical inner peripheral surface is performed has been described. However, the present invention is not limited to the cylindrical inner peripheral surface (or the inner periphery of the hole of the member). Regardless of whether the surface has different diameters, the same diameter, the presence or absence of taper, etc., and not limited to the shape of the cross section, the length (the length of the cylindrical inner peripheral surface), etc. Regardless, the present invention can be widely applied to the appearance inspection of a specific region on the cylindrical inner peripheral surface having various cross sections. In other words, in the present invention, in the appearance inspection using image processing by a computer, an erroneous determination factor that causes an erroneous defect determination such as plating unevenness existing in a specific region to be inspected prior to the appearance inspection. The method can be widely applied to the appearance inspection of a specific region on the cylindrical inner peripheral surface, which can include a step of removing by laser processing with various lasers (YAG laser, semiconductor laser, CO2 laser, etc.) in advance. Note that such a laser oscillation mode may be selected from continuous oscillation or pulse oscillation (pulse width) according to the removal target.

10 Cylindrical member (inspection object)
11 Cylindrical inner peripheral surface (inner surface)
14 upward circular shelf surface (specific region on the cylindrical inner peripheral surface)
17 Specific area 100 in cylindrical inner peripheral surface Camera 160 Reflector La, Lab Laser light

Claims (4)

The specific area on the cylindrical inner peripheral surface is imaged by a camera, the captured image is processed by a computer, and the quality of the appearance of the surface is determined based on the quality criteria set for defects present on the surface of the specific area An appearance inspection method for determining
Before performing the appearance inspection, the surface of the specific region on the cylindrical inner peripheral surface is irradiated with laser light, and the film unevenness formed on the surface or the laser processing step for removing the film is a pretreatment step. An appearance inspection method for a specific region on a cylindrical inner peripheral surface, characterized in that The specific area on the cylindrical inner peripheral surface is imaged by a camera, the captured image is processed by a computer, and the quality of the appearance of the surface is determined based on the quality criteria set for defects present on the surface of the specific area An appearance inspection method for determining
Before performing the appearance inspection, a laser processing step of irradiating the surface of the specific region on the cylindrical inner peripheral surface with a laser beam and removing deposits adhering to the surface was included as a pretreatment step. A method for inspecting the appearance of a specific area on a cylindrical inner peripheral surface.   3. The appearance inspection method for a specific region on a cylindrical inner peripheral surface according to claim 1, wherein the laser beam is a non-thermal laser.   The cylindrical shape according to any one of claims 1 to 3, wherein a beam splitter, a prism, or a reflecting mirror is used to irradiate the surface of the specific region with a laser beam, and is reflected as reflected light. An appearance inspection method for a specific area on the inner peripheral surface.

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