JP5373714B2 - Surface defect inspection apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a surface defect inspection device to automatically, easily and surely inspect a surface defect regardless of an annular object of a large diameter to be inspected. <P>SOLUTION: An O ring 100 having an outer peripheral surface with a circular-arc cross section is rotated while being pulled with predetermined tension, a plurality of LEDs 15 for emitting irradiation light to the circumference of an inspection object part A that is extended linearly in the O ring 100 are arranged circularly, the inspection object part A is illuminated by the irradiation light from an oblique direction with respect to a normal line Y of the inspection object part A, specular reflected light from the inspection object part A is imaged by a plurality of line sensor cameras 20, each image data obtained by the plurality of line sensor cameras 20 is worked and processed, and a defect of the inspection object part A is inspected. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to an apparatus and a method for inspecting a surface defect by applying light to an object to be inspected and imaging the reflected light.

  Conventionally, for example, a surface inspection apparatus for inspecting defects on the surface of an O-ring as shown in Patent Document 1 is known. The surface inspection apparatus includes an illuminating unit that irradiates illumination light onto the surface of the object to be inspected, an image capturing unit that images the surface of the object to be inspected, and image data obtained by the image capturing unit to process and inspect Image processing means for outputting information relating to the surface of the body. And the defect is detected based on the illuminance difference obtained from the difference between the average illuminance distribution obtained by smoothing the illuminance distribution on the surface of the object to be inspected and the actual illuminance distribution.

  Moreover, as a surface defect inspection apparatus for a rod-like object, as in Patent Documents 2 and 3, LEDs (Light Emitting Diodes) are arranged in a semicircular shape or an annular shape around an inspection object, and rotate or move. There is known a technique in which light is applied to an inspection object and the surface of the inspection object is imaged by a single imaging device from the vertical direction of the inspection object.

  Further, as in Patent Document 4, the vertical distances from the cylindrical axis of the plurality of illumination means are equal, and the incident angles of the chief rays of light when irradiating the cylindrical surface of the cylindrical object are equal to each other. What is arranged in such a way is known.

JP 2001-66128 A JP 2007-93338 A JP-A-2005-37203 JP 2008-89408 A

  However, although the surface inspection apparatus of Patent Document 1 can inspect defects on the surface on the imaging means side in the small-diameter O-ring, the O-ring is placed on the mounting table and inspected. In addition, the size of the O-ring that can be inspected is limited, and it is impossible to inspect defects on the entire surface (cross-sectional circumference) of the large-diameter O-ring.

  Therefore, as in Patent Documents 2 and 3, the inspection must be performed while rotating or moving the inspection object. In these inspection apparatuses, scattered light is picked up and it is determined that there is a defect in a portion where the scattered light is present. However, the scattered light is not necessarily reflected to the side of one imaging apparatus, and may be overlooked. Further, since only one imaging means is used, the entire outer periphery of the inspection object cannot be imaged at once, and the inspection object needs to be rotated around its axial direction in order to inspect the entire surface.

  In Patent Document 4, although there is disclosure of imaging scattered light or specularly reflected light by changing the arrangement of the cameras, only one camera is used, so that the inspection object is similarly centered in the axial direction. It is necessary to take an image while rotating it.

  For this reason, conventionally, a large-diameter annular object to be inspected is visually inspected for defects, and the inspector varies in quality or takes a long time for inspection.

  The present invention has been made in view of such a point, and an object of the present invention is to automatically and reliably inspect surface defects even for a large-diameter annular inspection object. .

  In order to achieve the above object, in the present invention, the annular object to be inspected is rotated while being stretched, and the specularly reflected light is imaged by irradiating the irradiated light onto the surface of the linearly extended portion. did.

Specifically, in the first invention, a plurality of pulleys on which an annular inspection object made of an O-ring having an outer peripheral surface with an arc-shaped cross section is hung on the outer periphery, and the annular inspection object is rotated while being pulled with a predetermined tension. An inspection object feeder having a rotation mechanism; and
Comprising an annular body, the annular plurality of irradiation portions in the circumferential inner of the annular body for irradiating illumination light around an axis extending the central axis of the inspected portion extending in a straight line of the annular object to be inspected are evenly spaced, the illumination device for illuminating the inspected portion below 70 ° tilt angle 45 ° or more from an oblique direction with respect to the normal line of the inspected portion by該照Shako,
A plurality of imaging devices that are arranged at positions facing the irradiation device and that image the specularly reflected light from the site to be inspected, and that consist of line sensor cameras in which imaging elements are arranged in a straight line ;
Defect detecting means for processing and processing each image data obtained by the plurality of imaging devices, and inspecting the defect of the inspection target part,
Equipped with a,
The plurality of irradiating portions are composed of a plurality of LEDs whose directivity characteristics are set to -40 ° or more and 40 ° or less, and an arrangement interval in the annular body is set so that the inspection target portion is illuminated without a gap. Has been .

Similarly, in the eighth aspect of the invention, an annular inspection object made of an O-ring having an outer peripheral surface with an arcuate cross section is rotated while being pulled with a predetermined tension.
A plurality of irradiation parts made of LEDs in which directivity characteristics for irradiating irradiation light around the region to be inspected linearly in the annular inspection object are set to be −40 ° or more and 40 ° or less are arranged in an annular shape,
Illuminating the inspection target part with an inclination angle of 45 ° or more and 70 ° or less from the oblique direction with respect to the normal line of the inspection target part by the irradiation light,
The regular reflection light from the inspection target part is imaged by a plurality of imaging devices including line sensor cameras in which imaging elements are arranged in a straight line,
Each image data obtained by the plurality of imaging devices is processed and processed to inspect for defects in the inspection target part.

According to these configurations, in the inspection object feeding device, the annular inspection object having an outer peripheral surface having an arc-shaped cross section is hung on the outer periphery of the plurality of pulleys and pulled with a predetermined tension to keep the inspection object portion in a straight line. Can be made. By arranging a plurality of irradiation parts in an annular shape centering on the extension line of the central axis in this linearly extended inspection target region, irradiation light can be obliquely applied to the entire surface of the inspection target region. When the inspection target part has a defect by capturing images with a plurality of imaging devices arranged at opposite positions of the regular reflected light of the light, the irradiating light hitting that part is reflected without being regularly reflected Therefore, the defective part is extracted black. For this reason, the inspection object feeding device is used to inspect the defects visually by picking up an image with the image pickup device while feeding the annular inspection object, and automatically detecting the black portion extracted from the picked-up image with the defect detection means. Compared to the above, the entire surface of the annular inspection object can be surely inspected. In addition, as an annular test object having an outer peripheral surface having an arc-shaped cross section, it is only necessary to have an arc in at least a part of the cross section, such as an O-ring, a D-ring (Koumaru packing), and Kosan packing. is there. In addition, the “irradiation light” as used in the present invention does not mean light that travels straight without spreading at all, but light emitted from a light source such as an LED that has higher straightness than ordinary incandescent lamps and fluorescent lamps. Specifically, it has a directivity characteristic having an appropriate width so that light can be incident on the inspection target portion of the annular inspection object .

In addition , uniform light can be applied to the surface of the annular inspection object with a simple configuration, and accurate defect detection is possible. In addition, by selecting the directivity characteristics of the irradiation unit according to the interval at which the irradiation unit can be installed, uniform regular reflection light can be obtained by irradiating the irradiation light evenly to the site to be inspected without gaps, and defects can be easily found. Also, if the inclination angle is less than 45 °, even if there is a defect in the inspection target part, it is difficult to make a difference in the direction of reflection, so the difference in brightness of the specularly reflected light between the defective place and the non-defective place Becomes difficult to find and it becomes difficult to find defects. On the other hand, when the inclination angle is larger than 70 °, the depth of imaging with the imaging apparatus becomes wide, and it becomes difficult to focus on the entire imaging range, and it becomes difficult to find defects. However, by setting the tilt angle to 45 ° or more and 70 ° or less, the brightness of specularly reflected light is easily different between a place with a defect and a place without a defect, and the difference in brightness is reliably detected by the imaging device. it can. In addition, since an area that must be illuminated by each irradiation unit can be made narrower than an area sensor camera in which a large number of image sensors are arranged, it is possible to acquire a bright and clear image. In addition, since the defect of the large-diameter O-ring used in the sealed portion of a machine that requires a high degree of airtightness such as an aircraft can be detected easily and reliably, the quality of the O-ring is remarkably improved.

In the second invention, in the first invention,
The annular main body is configured to be separable and configured to be openable and closable so as to sandwich the annular inspection object.

  That is, in order to inspect the entire circumference surface of the inspection target part of the annular inspection object, the irradiation unit must be arranged so as to surround the inspection target part. According to the above configuration, the annular body is opened. After passing through the annular inspection object, the annular main body only needs to be closed, so that the irradiation parts can be arranged easily and reliably evenly without cutting the annular inspection object.

In the third invention, in the second invention,
An opening / closing mechanism is provided that supports each of the divided portions so as to be opened and closed, and opens and closes each divided portion by an actuator.

According to said structure, since each division | segmentation part can be opened and closed by an actuator, after attaching an annular to-be-inspected object to a to-be-inspected object feeding apparatus, an irradiation part can be arrange | positioned easily equally .

In a fourth invention, in any one of the first to third inventions,
Each of the plurality of imaging devices is configured to be displaceable so that the focal lengths to the examination target part are equal.

According to the above configuration, even when the cross-sectional shape or outer shape of the annular inspection object changes, it is possible to focus without using the autofocus function of each imaging device. The resolution can be adjusted. For this reason, it becomes easy to process the image data obtained by each imaging device .

In a fifth invention, in any one of the first to fourth inventions,
The inspected object feeder includes a pulley moving mechanism for adjusting the distance between the plurality of pulleys.

  According to the above configuration, since the distance between the pulleys can be easily changed by the pulley moving mechanism, even the annular inspected objects of different sizes can be advanced at a predetermined speed by the inspected object feeding device. It can be inspected with a surface defect inspection apparatus.

In a sixth invention, in any one of the first to fifth inventions,
The plurality of pulleys are V pulleys having grooves having a substantially V-shaped outer peripheral cross section.

  According to the above configuration, since the surface height of the annular inspection object can be easily calculated accurately from the substantially V-shaped groove shape and the cross-sectional shape of the annular inspection object, the image after focusing and imaging of the imaging device Processing becomes easy.

In a seventh invention, in any one of the first to sixth inventions,
There is provided a display device that displays each image picked up by each image pickup device and processed by the defect detection means at a time.

According to said structure, the defect of the test | inspection site | part reflected in black can be easily confirmed with the naked eye by looking at the several image imaged simultaneously .

  As described above, according to the present invention, the irradiation light is emitted from the plurality of irradiation units arranged in an annular shape around the inspection target portion that is linearly extended while the annular inspection object is rotated while being pulled with a predetermined tension. Is processed from the oblique direction, and the image data obtained by imaging the regular reflected light with a plurality of imaging devices are processed and processed to inspect defects in the inspection target part. Even in the case of an annular inspection object, surface defects can be inspected easily and reliably, and improvement in inspection quality and labor saving can be achieved.

It is a front view which shows the surface defect inspection apparatus concerning this embodiment. It is a top view which shows a surface defect inspection apparatus. It is a left view which shows a surface defect inspection apparatus. FIG. 2 is a partially enlarged view of FIG. 1. FIG. 3 is a partially enlarged view of FIG. 2. It is the side view which looked at four line sensor cameras from the left side. It is the VII-VII sectional view taken on the line of FIG. It is a perspective view which shows one side of the half of an irradiation apparatus. It is a front view which shows an irradiation apparatus. It is a figure which shows the sample of the captured image imaged simultaneously with four cameras.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 7 show a surface defect inspection apparatus 1 according to an embodiment of the present invention, and this surface defect inspection apparatus 1 includes an inspection apparatus main body 3 framed in a rectangular parallelepiped shape having a moving roller 2 at a lower end. Yes. In the lower part of the inspection apparatus main body 3, a control panel 50 for performing operation control of the entire surface defect inspection apparatus 1 and a UPS (Uninterruptible Power Supply) 51 which is an uninterruptible power supply apparatus are provided. With the UPS 51, even if an abnormality such as a power failure occurs in the input power supply, power can be continuously supplied for a certain period of time without a power failure. Further, a personal computer 52 for controlling the surface defect inspection apparatus 1 is provided at the lower stage of the inspection apparatus body 3.

  An inspection object feeder 5 is attached to the flat top surface 3 a of the inspection apparatus body 3. As shown in an enlarged view in FIG. 7, the inspection object feeder 5 includes a base portion 6 composed of a pair of I-shaped steel 6a and a top plate 6b fixed to the top surface 3a, and the top plate 6b. As shown in FIG. 2, a pair of lower rail members 6c extending in the longitudinal direction of the top plate 6b is provided. In the pair of lower rail members 6c, a rotating mechanism 7 that rotates an O-ring 100 having a circular cross section as an annular test object while pulling with a predetermined tension is slidable along the pair of lower rail members 6c. It is placed. A first electric cylinder 6d is provided on the top plate 6b in parallel with the pair of lower rail members 6c. The size of the O-ring 100 is a relatively large one, and for example, the inner diameter is 200 mm to 700 mm, and the cross-sectional diameter is about 2.5 mm to 10 mm. The rotation mechanism 7 has a rectangular plate-shaped flat inspection table 7a, and a tip 6e of the first electric cylinder 6d is connected to the inspection table 7a. By operating the first electric cylinder 6d to extend and contract, the entire rotation mechanism 7 can slide on the pair of lower rail members 6c with high accuracy. The annular inspected object does not necessarily have a circular cross section, and may be a continuous annular inspecting object that includes a circular arc in a part of the cross section and has a continuous arc-shaped outer peripheral surface. For example, the cross section may be a D-ring (former packing) having a rectangular inner periphery and a substantially semicircular outer periphery, or a mountain packing having a rectangular inner periphery and a chevron on the outer periphery. The material of the annular test object is not particularly limited, but an elastic elastomer that can rotate while applying a predetermined tension, for example, natural rubber that is vulcanized rubber, synthetic rubber, or urethane rubber that is a thermosetting resin-based elastomer. Some include silicon rubber, fluororubber and thermoplastic elastomer. In this embodiment, although it is the black O-ring 100, it is not limited to black.

  The inspection table 7a is provided with a pair of upper rail members 7b extending in the longitudinal direction. A second electric cylinder 7c is provided on the inspection table 7a in parallel with the pair of upper rail members 7b. A pulley moving mechanism 11 that rotatably supports the pair of driven pulleys 10 at a predetermined interval (for example, 400 mm) is provided on the pair of upper rail members 7b so as to be slidable along the pair of upper rail members 7b. It is placed. The pulley moving mechanism 11 is connected to the tip 7d of the second electric cylinder 7c. By operating the second electric cylinder 7c to expand and contract, the entire pulley moving mechanism 11 moves on the pair of upper rail members 7b with high accuracy. Slide movement is possible. Note that only one driven pulley 10 or three or more driven pulleys 10 may be provided. On the other end side of the inspection table 7a, there are provided a driving pulley 8 that rotates while the O-ring 100 is hung, and a driving motor 9 that is a stepping motor that rotatably supports the driving pulley 8. . As shown in FIG. 7, the center shaft 8 b of the drive pulley 8 is supported by a bearing (not shown), and the tip of the center shaft 8 b is connected to the drive shaft 9 a of the drive motor 9. As shown in FIG. 2, the driving pulley 8 and the pair of driven pulleys 10 are arranged on the same straight line in parallel with the upper rail member 7b in a plan view. Each of the driving pulley 8 and the driven pulley 10 has pulley grooves 8a and 10a having a V-shaped cross section on the outer periphery, and an O-ring 100 is hung on the pulley grooves 8a and 10a. With this configuration, the distance between the driving pulley 8 and one of the driven pulleys 10 (the farther driven pulley 10 when the two driven pulleys 10 are engaged) is adjusted by extending and contracting the second electric cylinder 7c. The O-ring 100 is hung on the drive pulley 8 and the driven pulley 10 and can be rotated at an arbitrary speed while being pulled by a predetermined tension.

  An LED light 13 as an irradiating device is disposed in the inspection target part A extending in a straight line of the O-ring 100. As shown in FIGS. 8 and 9, the LED light 13 includes, for example, an annular main body 14, and LEDs 15 as a plurality of irradiation units that irradiate irradiation light are evenly arranged on the inner periphery of the annular main body 14. Has been. As shown in FIG. 9, the annular main body 14 is integrated into an annular shape by abutting and abutting a pair of divided portions 14 a at a mating surface 14 b, and as shown in FIGS. 4, 5, and 8, An inclined surface 14c of 60 °, for example, is provided on the inner peripheral side. Eighteen LEDs 15 are built in the inclined surface 14c of each divided portion 14a with an interval of, for example, 10 °. That is, 36 LEDs 15 are arranged in a line on the circumference of the LED light 13 at equal intervals, but the arrangement number and interval are not limited to this. A harness 14d for supplying electric power to each LED 15 is connected to the dividing portion 14a. The LED 15 emits light that is more straight ahead than an incandescent lamp or a fluorescent lamp. For example, the directivity is about −40 ° to + 40 °, and the normal LED has a directivity of about −20 ° to + 20 °. Compared to that, it is wide. Although LED15 is red in this embodiment, it is not specifically limited, such as orange, yellow, yellowish green, and green. In short, the directivity characteristics of the LED 15 may be selected so that the entire inspection target site A is illuminated without any gaps in relation to the arrangement interval of the annular body 14.

  The annular main body 14 is configured to be openable and closable so that the pair of divided portions 14 a sandwich the O-ring 100. FIG. 7 shows a state in which one of the pair of divided portions 14a is closed and the other is opened. Each division part 14a is rotatably supported by the opening / closing mechanism 16, respectively. The opening / closing mechanism 16 includes an air actuator 18 that receives the high-pressure air from the high-pressure air supply unit 17 shown in FIG. By operating an operation button (not shown) of the control panel 50 to send a signal to the air actuator 18, each divided portion 14 a rotatably supported by the air actuator 18 can be automatically opened and closed. As a result, after the O-ring 100 is attached to the inspection object feeder 5, a plurality of LEDs 15 that irradiate irradiation light around the axis that extends the central axis X of the inspection target site A are arranged in an annular shape. The inspection target part A can be illuminated from the oblique direction with respect to the normal line Y of the inspection target part A by light. The inclination angle α with respect to the normal line Y of each LED light 13 is set to 45 ° or more and 70 ° or less (60 ° in the present embodiment).

  A plurality of (four in the present embodiment) imaging devices at positions facing the LED light 13, that is, at the inclination angle α with respect to the normal Y on the opposite side of the central axis X of the inspection target site A. The line sensor camera 20 is arranged. For example, as shown in FIG. 6, each line sensor camera 20 has the first line sensor camera 20 placed in a horizontal position and the second to fourth line sensor cameras 20 placed 100 degrees apart. Moreover, it is comprised so that a displacement is possible respectively so that the focal distance to the test object site | part A may become equal. Specifically, each line sensor camera 20 is supported by a stepping motor 21 so as to be slidable in one direction, and a camera support plate 22 to which four line sensor cameras 20 are fixed is a third electric cylinder 24. It is supported so that it can slide up and down. As a result, focusing on the inspection target part A can be performed without using autofocus, and specular reflection light from the inspection target part A can be imaged. In each line sensor camera 20, the image sensors are arranged in one or two lines in a straight line, so each line sensor camera 20 has an LED 15 compared to an area sensor camera in which a number of image sensors are arranged. The area that must be illuminated can be reduced. For this reason, it is possible to easily acquire a bright and clear image by accurately capturing regular reflection light.

  The captured image data is transmitted to the personal computer 52 that functions as a defect detection means via a signal line (not shown). As will be described later, the personal computer 52 can process and process each image data obtained by the plurality of line sensor cameras 20 to inspect defects in the inspection target part A.

  Also, a liquid crystal monitor 53 as a display device is provided on the top surface 3a, and each image captured by each line sensor camera 20 and processed by software in the personal computer 52 is displayed on one screen by the liquid crystal monitor 53. It can be projected on.

  Furthermore, a warning lamp 54 is provided near the line sensor camera 20 on the top surface 3a to alert the personnel when a defect is detected by the surface defect inspection apparatus 1. Not only the warning lamp 54 but also a buzzer for generating an alarm sound may be provided.

-Surface defect inspection method-
Next, the surface defect inspection method according to the present embodiment will be described.

  First, the O-ring 100 is first attached to the inspection object feeder 5. The control panel 50 is operated to expand and contract the first electric cylinder 6d, and the inspected object feeding device 5 is moved to the opposite side of the line sensor camera 20 as indicated by a virtual line in FIG.

  Next, the O-ring 100 is hooked on the driving pulley 8 and the driven pulley 10.

  Next, the second electric cylinder 7c is expanded and contracted to adjust the distance between the drive pulley 8 and the driven pulley 10, the O-ring 100 is pulled with a predetermined tension, and the inspection target part A is extended linearly. Thus, since the distance between the drive pulley 8 and the driven pulley 10 can be easily changed by the pulley moving mechanism 11, even the O-rings 100 of different sizes can be inspected by the same surface defect inspection apparatus 1. it can.

  Next, the first electric cylinder 6d is expanded and contracted to bring the inspected object feeder 5 close to the line sensor camera 20 side.

  Next, the pair of divided portions 14 a that are halved are closed by operating the air actuator 18, and a plurality of LEDs 15 that irradiate irradiation light around the region A to be inspected linearly in the O-ring 100 are annularly formed. Deploy. At this time, in order to inspect the entire surface of the inspection target part A of the O-ring 100, the LEDs 15 must be arranged so as to surround the inspection target part A. The O-ring 100 does not need to be cut because the portion 14a can be rotated and brought into contact to form an annular shape. Also. Since the LEDs 15 are evenly arranged on the inclined surface 14c, the LEDs 15 can be easily and reliably evenly arranged at a predetermined inclination angle α with a simple configuration. For this reason, uniform light can be applied to the entire surface of the O-ring 100, and accurate defect detection becomes possible. In the present embodiment, the inclination angle α with respect to the normal Y of the central axis X of the inspection target site A of all the LED lights 13 is set to 60 °. In other words, if the inclination angle α is smaller than 45 °, even if there is a defect in the inspection target region A, it is difficult to make a difference in the direction of reflection, so the brightness of the specularly reflected light between the place where there is a defect and the place where there is no defect. This makes it difficult to find the difference and makes it difficult to find defects. On the other hand, when the inclination angle α is larger than 70 °, the range captured by the line sensor camera 20 is widened, and it becomes difficult to focus on the entire imaging range, making it difficult to find defects. For this reason, the inclination angle α is preferably set to 45 ° or more and 70 ° or less.

  Next, the drive motor 9 is rotated to rotate the drive pulley 8, and the O-ring 100 is rotated at a predetermined speed to pass through the LED light 13.

  Next, the line sensor camera 20 is focused. The height of the central axis X of the site A to be inspected calculated from the cross-sectional shape of the drive pulley 8 and the cross-sectional shape of the O-ring 100 and the height of the focal center of each of the four line sensor cameras 20 are the third electric cylinder. Match with 24. At this time, when the O-ring 100 hangs down due to the influence of gravity or the like, the height of the central axis X is slightly lower than the center height of the cross section of the O-ring 100 at the drive pulley 8. Further, each line sensor camera 20 is moved by the stepping motor 21 so that each line sensor camera 20 is focused on the surface of the O-ring 100. As described above, the drive pulley 8 and the driven pulley 10 are V pulleys having a substantially V-shaped groove on the outer peripheral cross section. Therefore, the O-ring 100 can be easily obtained from the substantially V-shaped groove shape and the cross-sectional shape of the O-ring 100. The surface height of can be calculated accurately. For this reason, focusing of the line sensor camera 20 and image processing after imaging can be easily performed. Further, by adjusting the focus in this way, the focus can be achieved without using the autofocus function of each line sensor camera 20 even when the cross-sectional shape or outer shape of the O-ring 100 changes. For this reason, the magnification can be made equal among the line sensor cameras 20 to match the resolution, and post-processing of images obtained by the respective line sensor cameras 20 can be easily performed.

  In this state, the inspection target part A is illuminated obliquely with respect to the normal line Y of the inspection target part A by the irradiation light emitted from each LED 15, and the specularly reflected light from the inspection target part A is supplied to the four line sensor cameras 20. Take an image with. While the O-ring 100 rotates and makes a round, the entire surface of the O-ring 100 is imaged. At this time, since the directivity characteristic of the LED 15 is selected according to the interval at which the LED 15 can be installed, uniform regular reflection light can be obtained by shining light uniformly on the inspection target site A without any gap, and defects can be easily found. ing.

  When the O-ring 100 goes around the imaging area of the line sensor camera 20, the inspection is finished. Each image data obtained by the four line sensor cameras 20 is sent to the personal computer 52 as needed, and is processed and processed by a method set in advance by software in the personal computer 52. The inspection result is displayed on the liquid crystal monitor 53 using a software function.

  Specifically, as shown in FIG. 10, in each image data, the irradiation light of the LED 15 is regularly reflected on the surface of the O-ring 100, so that it is displayed in white. In FIG. 10 (c), black appearing is the adhesion of foreign matter, the dent after the foreign matter is attached, the dent due to rubber attached to the mold, the protrusions and other defects B in which the burrs cannot be sufficiently removed. Since the portion B is not regularly reflected, it becomes darker than the portion without the surrounding defect B and appears clearly on the liquid crystal monitor 53. Thus, by imaging the parallel regular reflection of the LED 15 with the four line sensor cameras 20, it is possible to capture an inspectable image while minimizing the influence of disturbance light. In addition, the inspection result is hardly affected by the difference in the surface state due to the material difference of the O-ring 100. Further, by viewing four images at a time on the liquid crystal monitor 53, it is possible to easily confirm the defect B of the inspection target portion A displayed in black with the naked eye. In addition, the inspection in the software in the personal computer 52 is inspected by a preset determination logic, and the position of the defect B is accurately displayed or stored, so that the defect B can be corrected in a later process. Can be destroyed. In addition, in FIG. 10, the grinder grinding | polishing surface C which is the trace which grind | polished the burr | flash which generate | occur | produced at the time of shaping | molding in the surface of the O-ring 100 appears linearly.

  When a defect B appears on the surface of the O-ring 100, an abnormality may be detected by image processing on the personal computer 52 and the warning lamp 54 may be automatically turned on, or the image data cannot be captured well. The warning lamp 54 may be illuminated.

  By this inspection method, for example, a defect B of a large-diameter O-ring 100 used in a sealed portion of a machine that requires a high degree of airtightness such as an aircraft can be easily and reliably detected. Can be improved.

  Therefore, according to the surface defect inspection apparatus 1 according to the present embodiment, it is not necessary for the inspector to visually inspect even the large-diameter O-ring 100, and the surface defect is automatically and reliably inspected. Can do. As a result, it is possible to improve inspection quality, shorten inspection time, and eliminate inspection unevenness by standardizing and stabilizing the inspection level. By performing this automatic inspection, the quality of the product is remarkably improved and labor saving can be realized.

(Other embodiments)
The present invention may be configured as follows with respect to the above embodiment.

  That is, in the said embodiment, although the LED light 13 as an illuminating device is divided into 2 so that the mating surface 14b may become vertical when closed, it is not limited to this dividing method, and is divided into 2 on a horizontal plane, You may divide into three or more divisions. Moreover, although the dividing part 14a is automatically opened and closed by the opening and closing mechanism 16, it may be opened and closed manually.

  In the above-described embodiment, the object to be inspected is an annular object to be inspected. However, the irradiation apparatus, the imaging apparatus, and the defect detection means of the present invention are configured in a rod-like (columnar, cylindrical, etc.) object to be inspected, for example, electric It can also be applied to cables. In that case, what is necessary is just to comprise the structure of a to-be-inspected object feeding apparatus so that a rod-shaped to-be-inspected object can be moved continuously.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use.

DESCRIPTION OF SYMBOLS 1 Surface defect inspection apparatus 5 Inspected object feeding apparatus 7 Rotating mechanism 8 Drive pulley 8a, 10a Pulley groove 10 Driven pulley 11 Pulley moving mechanism 13 LED light (irradiation apparatus)
14 Annular body 14a Dividing part 15 LED (irradiation part)
16 Opening / closing mechanism 18 Air actuator 20 Line sensor camera (imaging device)
52 PC (defect detection means)
53 LCD monitor (display device)
100 O-ring (annular specimen)
A Inspection site B Defect X Central axis Y Normal α Inclination angle

Claims (8)

A plurality of pulleys on which an annular object to be inspected comprising an O-ring having an outer peripheral surface having an arc-shaped cross section is hung on the outer periphery, and a device to be inspected having a rotation mechanism that rotates the annular object to be inspected with a predetermined tension;
Comprising an annular body, annular plurality of irradiation portions in the circumferential inner of the annular body for irradiating illumination light around an axis extending the central axis of the inspected portion extending in a straight line of the annular object to be inspected are evenly spaced, the illumination device for illuminating the inspected portion below 70 ° tilt angle 45 ° or more from an oblique direction with respect to the normal line of the inspected portion by該照Shako,
A plurality of imaging devices that are arranged at positions facing the irradiation device and that image the specularly reflected light from the site to be inspected, and that consist of line sensor cameras in which imaging elements are arranged in a straight line ;
Defect detecting means for processing and processing each image data obtained by the plurality of imaging devices, and inspecting the defect of the inspection target part,
Equipped with a,
The plurality of irradiating portions are composed of a plurality of LEDs whose directivity characteristics are set to -40 ° or more and 40 ° or less, and an arrangement interval in the annular body is set so that the inspection target portion is illuminated without a gap. A surface defect inspection apparatus characterized by being provided . In the surface defect inspection apparatus according to claim 1 ,
The annular defect body is configured to be separable, and is configured to be openable and closable so as to sandwich the annular object to be inspected. In the surface defect inspection apparatus according to claim 2 ,
A surface defect inspection apparatus comprising an opening / closing mechanism that supports the divided portions of the divided annular body so as to be opened and closed, and opens and closes each divided portion by an actuator. In the surface defect inspection apparatus according to any one of claims 1 to 3 ,
The surface defect inspection device, wherein the plurality of imaging devices are configured to be displaceable so that focal lengths to the inspection target part are equal. In the surface defect inspection apparatus according to any one of claims 1 to 4 ,
2. The surface defect inspection apparatus according to claim 1, wherein the inspection object feeder includes a pulley moving mechanism for adjusting a distance between the plurality of pulleys. In the surface defect inspection apparatus according to any one of claims 1 to 5 ,
2. The surface defect inspection apparatus according to claim 1, wherein each of the plurality of pulleys is a V pulley having a groove having a substantially V-shaped outer peripheral section. In the surface defect inspection apparatus according to any one of claims 1 to 6 ,
A surface defect inspection apparatus, comprising: a display device that displays each image picked up by each image pickup device and processed by the defect detection means at a time. Rotate an annular inspection object made of an O-ring having an outer peripheral surface with an arc-shaped cross section while pulling it with a predetermined tension,
A plurality of irradiation parts made of LEDs in which directivity characteristics for irradiating irradiation light around the region to be inspected linearly in the annular inspection object are set to be −40 ° or more and 40 ° or less are arranged in an annular shape,
Illuminating the inspection target part with an inclination angle of 45 ° or more and 70 ° or less from the oblique direction with respect to the normal line of the inspection target part by the irradiation light,
The regular reflection light from the inspection target part is imaged by a plurality of imaging devices including line sensor cameras in which imaging elements are arranged in a straight line ,
A surface defect inspection method, wherein each image data obtained by the plurality of imaging devices is processed and processed to inspect a defect in the inspection target part.