JP2009257979A - Method and device for inspecting inside of hole - Google Patents

Abstract

An entire surface of a hole with a diameter of several millimeters in a joint part of a structure can be inspected automatically or manually from an equal distance directly from the side without being broken.
A probe 11 is inserted into a hole 5 to be inspected, light is irradiated from above, the side surface of the hole is illuminated through a prism 26 at the tip of the probe, and light reflected from the side surface of the hole is collected by an objective lens 13 and a CCD camera. 15, the probe is rotated to record an image of the entire inside of the hole, and the image inside the hole to be inspected is recorded on a continuous image by the image processing device 16. Examine the presence / absence, size, depth, etc., and its exact position.
[Selection] Figure 1

Description

  The present invention efficiently and accurately inspects the inside of a hole without destroying the inside of the hole, such as a hole for passing a bolt, fastener and rivet of a mechanical joint part used in a structure. The present invention relates to a method and an apparatus for inspecting a hole.

  For example, when inspecting the inside of a bolt, fastener, and rivet connection hole in a joint part of a structure such as an aircraft at the maintenance stage, conventionally, after removing the bolt, fastener, and rivet so that the inside of the hole can be directly inspected from the side. A part of the hole to be inspected is deleted and damaged by cutting the plate material including the hole, and the inside of the hole cannot be inspected over the entire circumference (for example, see Non-Patent Document 1 or 2). ). Furthermore, when inspecting bolts, fasteners, and rivet connection holes inside the joints on the mechanism during manufacturing, the above destructive inspection cannot be applied, so the diagonal direction from the position above or below the holes. Therefore, it is impossible to inspect the entire inner surface of the hole accurately from the same distance, and visual inspection and inspection by image are difficult.

  Conventionally, as a surface inspection device for inspecting the inner surface of a non-inspection object (for example, a cylinder liner or cylinder bore of an internal combustion engine) in which a relatively large hole is formed, a rod-shaped inspection rod is inserted into the hole and rotated around the axis, or light There has been proposed a technique in which only a reflecting surface is rotated so that a defect or a foreign object can be detected by using the intensity of light that has been reflected on the inner surface of a hole (for example, see Patent Documents 1 and 2).

  In these inspection apparatuses, the structure of the inspection rod is complicated because the optical fiber for projection and the optical fiber for light reception are passed inside the hollow inspection rod and the light reflecting surface is rotated at the tip of the inspection rod. Because it becomes thick, it cannot be applied to holes for structural joints with a diameter of several millimeters. Further, since only the intensity of light reflected from the inner peripheral surface is used, image information necessary for three-dimensional measurement such as damage on the inspection surface, the color of corrosion, and the depth of damage cannot be obtained. Furthermore, although the light reflecting surface is rotated around the axis, the absolute value of the angle is not controlled, and the exact position cannot be recorded even if the presence or absence of a defect or foreign matter is known. Further, since the inspection rod does not have a function of moving and controlling the hole in the vertical direction with respect to the hole axis, there is a drawback in that automatic inner surface inspection of a large number of holes cannot be performed.

Piascik, R. S., and Willard, S. A., “The Characterization of Fatigue Damage in the Fuselage Riveted Lap Splice Joint”, NASA / TP-97-206257, November 1997, p47, Fig.5.1 James L. Rudd, “Applications of the Equivalent Initial Quality Method”, Technical Memorandum AFFDL-TM-77-58-FBE, July 1977, p7, Fig.3 JP-A-11-281582 JP 2007-315805 A

  Therefore, the present invention provides a non-destructive method for inspecting the entire inside of a hole directly in a non-destructive manner when inspecting the inside of a hole with a diameter of several millimeters, such as bolts, fasteners and rivet holes in a joint part of a structure, at the manufacturing stage and maintenance stage. It is an object of the present invention to provide a method and an apparatus for inspecting an inside of a hole, which can be inspected automatically or manually from an equal distance.

The method for inspecting the inner surface of a hole according to the first aspect of the present invention that solves the above-described problem is a method for inspecting an inner surface of a hole that enables non-destructive inspection of the inner peripheral surface of the hole formed in the member from an equal distance A probe having a mirror or prism that can be inserted into the inspection target hole at an angle is inserted on the central axis of the inspection target hole, and arranged on the opposite side across the probe and the inspection target hole. Light is applied to the mirror or prism from the objective lens side, and this light is reflected by the mirror or prism at the tip of the probe to illuminate at right angles to the inner peripheral surface of the hole to be inspected, and the light reflected from the inner peripheral surface of the hole is reflected in the mirror Alternatively, it is reflected on the objective lens by a prism and recorded by an image pickup means.
According to the present invention, since the probe has only a mirror or a prism at the tip, the structure is simple and can be formed in a small size, so that even a small hole can be inserted to accurately inspect the inner peripheral surface. it can.

According to a second aspect of the invention, in the hole internal inspection method according to the first aspect, the whole surface of the inner peripheral surface of the hole is recorded as a plurality of images from the same distance by rotating the probe. . Thereby, the inner peripheral surface of the hole can be accurately inspected with uniform accuracy.
According to a third aspect of the present invention, in the internal inspection method for holes according to the first or second aspect, the image recorded by the imaging means is checked for presence or absence of surface conditions such as damage, cracks, corrosion, etc. by an image processing device. It is characterized by discriminating the degree of sheath and depth and its accurate position. Thereby, it can contribute to the analysis improvement of cause analysis, such as damage.
Furthermore, the invention according to claim 4 is the internal inspection method for a hole for a structural joint according to any one of claims 1 to 3, wherein an image recorded on the entire inner peripheral surface of the hole by the imaging means is obtained by an image processing device. The image inside the hole to be inspected is recorded in one continuous image. Thereby, the whole inner peripheral surface of the hole can be easily observed with uniform accuracy and instantaneously.

  According to another aspect of the present invention, there is provided a hole internal inspection device according to claim 5 for carrying out the hole internal inspection method, wherein a mirror or prism that can be inserted into a hole to be inspected formed in a member is provided at an angled tip. An objective lens and an imaging means capable of recording the situation inside the hole by an image, an image processing device for image processing of the captured image, and displacement of the probe in three axial directions with respect to the inspection target hole A probe driving mechanism having a mechanism and a rotation mechanism around the probe axis, and an objective lens driving mechanism having a displacement mechanism in a triaxial direction with respect to the inspection object hole are provided. The probe drive mechanism and the objective lens drive mechanism may employ either manual or automatic drive control mechanisms.

According to a sixth aspect of the present invention, in the internal inspection device for a hole according to the fifth aspect of the present invention, the device includes a left-right positioning light source and a front-rear positioning light source for positioning the probe or the objective lens in three axial directions. It is a feature. Thereby, the probe and the objective lens can be automatically positioned at the center position of the inspection target hole.
According to a seventh aspect of the present invention, in the hole internal inspection device according to the fifth or sixth aspect, the objective lens is rotated on the inspection target hole in synchronization with the probe or asynchronously. It has an objective lens rotating means that can be used. Thereby, the incident condition of the reflected light with respect to the objective lens can be kept constant, and a clearer image can be obtained.
Furthermore, the invention according to claim 8 is the probe having the prism corresponding to the hole type in the hole internal inspection device according to any one of claims 5 to 7, which automatically recognizes the difference in the type of hole to be inspected. It has a probe selection mechanism which selects automatically.

  According to the present invention, when inspecting the inside of a hole with a diameter of several millimeters, such as for bolts, fasteners and rivets connected to a joint part of a structure, at the maintenance stage, a part of the inside of the hole to be inspected by cutting is not deleted and damaged. In addition, the inside of the hole can be inspected continuously and precisely, so that the quality of the inspection can be improved. By automating these devices, inspection of a large number of holes can be performed and the inspection time can be shortened. Furthermore, when inspecting the inside of bolts, fasteners and rivet coupling holes in the joint part of the structure at the time of manufacturing, it becomes possible to inspect the entire inside of the hole accurately from the same distance, contributing to the improvement of the joint quality at the time of manufacturing. The inspection time can be shortened by automating these devices. When inspecting the inside of a hole at the time of maintenance, it is possible to inspect and record the presence or absence of surface conditions such as damage, cracks, corrosion, etc., the size and depth, and their exact positions by image processing, improving maintenance accuracy And the inspection time can be shortened.

  The hole internal inspection method and apparatus according to the present embodiment is placed in a hole of several millimeters of the direct line to be inspected in order to enable non-destructive inspection of the entire inside surface of the hole directly from the side at exactly the same distance. A probe having an angleable mirror or prism at the tip, a device that adjusts the relative position of the probe and the hole to be inspected, an objective lens that can record the situation inside the hole with an image, and imaging Means, a device for adjusting the relative position of the hole to be inspected and the objective lens, and a device for image processing of the captured image. The probe is inserted into the hole to be inspected, and light is applied from above. The light is reflected by the mirror or prism at the tip of the probe to illuminate the side of the hole, and the light reflected from the side of the hole is reflected by the mirror or prism to the upper lens and is then reflected by the CCD camera. The image is recorded on the entire surface of the hole by rotating the probe, and the image inside the hole to be inspected is recorded on a continuous image by the image processing apparatus, and the image processing is performed on the recorded image. Thus, the presence or absence of surface conditions such as damage, cracks and corrosion, the degree of size and depth, and the exact position thereof are inspected.

  FIG. 1 is a schematic view of an internal inspection device for a structural joint hole according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a main part thereof. The internal inspection device for structural joint holes according to the present embodiment is a device for inspecting the internal surface of the hole for passing bolts, fasteners and rivets at the joint portion between the members in structural assembly or the like without destroying them. In this device, the entire inner peripheral surface inside the hole is optically inspected from an equal distance. As shown in FIG. 3, generally the shape of the hole in the joint portion is a flat hole 2 in which the inner surface of the hole is simply a cylindrical surface, and the inner peripheral surface of the hole is tapered with the outer peripheral portion of the hole inclined inward as a whole. There are three types, a dishing hole 3 which is inclined and widened, and a dishing hole 4 whose upper part is inclined like a dish, and these are inspection target holes 5 in the present embodiment. That is, the hole internal inspection device of this embodiment can be easily applied to inspection of holes of any shape.

  As shown schematically in FIG. 1, the internal inspection device 1 for a hole according to the present embodiment includes the probe 11, a probe driving device 12 that adjusts the position of the probe with respect to a hole to be inspected, An objective lens 13 capable of recording the situation by an image, a CCD (charge coupled device) camera 15 as an imaging means, an objective lens driving device 14 for adjusting the position of the objective lens with respect to a hole to be inspected, and an incorporated image The image processing device 16 performs image processing on the table, and they are arranged above and below the table 20 of the examination table 10. In this embodiment, the image processing device 16 is configured by a computer that also serves as a control unit for the probe driving device 12 and the objective lens driving device 14 described later.

  In the inspection table 10, a transmission hole 21 having an inner diameter sufficiently larger than the inner diameter of the inspection object hole 5 is formed at the center of the table 20, and the inspection object 6 is aligned with the hole position of the transmission hole 21. Place. The probe 11 has a reflecting mirror or prism 26 inclined at a predetermined angle at the tip of the probe shaft 25, and the illumination light is irradiated from the upper surface through the objective lens 13 at a right angle to the inner peripheral surface of the hole. In addition to bending the optical path, the image of the inner periphery of the hole is reflected perpendicularly to the objective lens and collected by the objective lens, and the inner peripheral surface of the hole can be photographed at an equal distance from the center by a CCD camera as an imaging means. It is to make. The reflecting mirror or prism 26 is attached to the tip of the probe shaft so that the reflecting surface thereof has an angle with respect to the rotation axis of the probe, and the angle depends on the type of the inspection object hole 5 (flat hole 2 shown in FIG. The dishing hole 3 and the dishing hole 4 are typical types.)

  The probe drive device 12 includes a drive mechanism that translates the probe 11 in the three axial directions of up and down (Z axis), front and rear (Y axis), and left and right (X axis) and rotates around the probe axis (Z axis). . As the drive mechanism, a well-known manual or automatic positioning mechanism composed of a combination of a three-axis drive mechanism having an XY axis stage and a Z-axis stage and a rotation drive mechanism around the Z axis can be adopted as appropriate. Is not particularly limited. When employing an automatic positioning drive mechanism, it is desirable to employ a servo motor as an actuator for controlling the drive in the respective axial directions as a drive source. As shown in FIG. 1, the table 20 is provided with the right and left positioning light sources 17 and the front and rear positioning light sources 18 so that the light beams are orthogonal to each other, and the probe 11 can be automatically positioned at the center of the hole as will be described later. .

  Similarly, on the objective lens side, similarly to the probe driving device 12, an objective lens driving device 14 comprising a combination of a three-axis driving mechanism having an XY axis stage and a Z-axis stage and a rotational driving mechanism around the Z axis is adopted. Thus, the objective lens 13 can be adjusted in the Z-axis direction according to the type of the hole, positioned to the center position of the hole, and the objective lens can be rotated in synchronization with the rotation of the probe at the time of photographing, thereby obtaining a clearer image. It becomes possible. The light source is installed on the objective lens side and moves integrally with the objective lens 13.

4 and 5 show an example of an automatic positioning method of the objective lens in the left-right direction (X-axis direction). The figure shows the case where the hole of the inspection object 6 is a flat hole, but the same can be done for other types of holes.
For example, as shown in FIG. 4, the objective lens 13 is aligned with the inspection target hole 5 at a rough position before the inspection, and only the objective lens 13 is automatically moved from the left to the right (or right) while applying light from the objective lens side. As shown in the graph of FIG. 5 (b), the intensity of the light received by the objective lens 13 by moving from the left to the left) is strong due to the large amount of reflected light at the position where there is no hole, and is gradually reflected by being applied to the hole. Light is reduced and weakened. Here, since it can be determined that the position of the objective lens when the light intensity is below a certain threshold is above the holed portion, the intermediate point Xcenter between the positions Xa and Xb shown in FIG. Judged as the hole position in the direction. The X coordinate point of the position is stored in the computer 16. Similarly, by automatically moving only the objective lens 13 from front to back (or from back to front), an intermediate point Ycenter in the Y-axis direction is obtained, and the Y coordinate point is similarly stored in the computer. The center coordinate point is obtained, and the X-axis drive actuator and the Y-axis drive actuator are driven to position the objective lens at the center position of the hole. The Z-axis direction is set in advance according to the type of the inspection object.

The probe positioning method is shown in FIGS.
Prior to the inspection, the objective lens 13 and the hole center position of the inspection object are aligned in advance as described above, and the probe 11 and the objective lens 13 are roughly approximated simultaneously in a state where the probe 11 is below the table 20 on which the inspection object 6 is placed. Move to the correct position. Thereafter, as shown in FIG. 7 (a), the light from the right-and-left positioning light source 17 is used to automatically move the probe 11 and the objective lens 13 simultaneously from the left to the right (or right) including the hole portion to the hole portion. 7), the intensity of the light received by the objective lens is as shown in FIG. 7B from the positional relationship between the light beam and the hole. Here, since it can be determined that the probe position when the light intensity is equal to or greater than a certain threshold is below the holed portion, an intermediate point Xcenter between positions Xa and Xb in FIG. Judged as the hole position. In this case, the positions Xa and Xb do not need to indicate the edge of the hole, and Xcenter indicates the hole center position in the left-right direction even if the probe moving direction does not pass through the hole center. Similarly, by automatically moving the probe 11 and the objective lens 13 from front to back (or back to front) including the hole portion from the portion without the hole automatically using the light of the longitudinal positioning light source 18. Get the center Ycenter in the front-rear direction. By doing so, the probe 11 can be automatically positioned and adjusted to the hole center position by driving and controlling the probe driving device based on the coordinate position information of the hole center positions Xcenter and Ycenter.

  The hole internal inspection device of the present invention is configured as described above, and in order to inspect the inside of the hole of the member, the angle of the mirror or prism 26 installed in the probe shaft 25 in advance is set according to the type of hole to be inspected, The inspection object 6 is automatically supplied onto the table 20 manually or by a manipulator or the like so that the inspection object hole 5 is positioned above the transmission hole 21 of the table 20, and then the objective lens driving device 14 and the probe driving device 12 are supplied. When driven, the objective lens 13 is positioned and then the probe 11 is positioned by the above-described method. In this state, the X-axis drive actuator of the probe driving device is actuated to drive the probe up to a position where the reflecting mirror or prism can accurately irradiate light at right angles to the inner peripheral surface of the hole to be inspected.

  At that time, as shown in FIG. 3, for example, a probe 11 having a prism corresponding to the type of hole of the inspection object is prepared, and the type of the hole for structural joint to be inspected is automatically recognized, and the recognized type It is also possible to provide a function for automatically selecting and preparing a probe corresponding to. As a method of automatically recognizing the type of the hole for the structural joint, for example, as shown in FIG. 8, the objective lens 13 having a specific inclination angle (45 ° in FIG. 8) and the axis of the probe 11 are centered on the inspection target hole. When the intensity of light received by the objective lens 13 is measured when the probe 11 is moved from the bottom to the top (or from the top to the bottom) of the inspection target hole in the state adjusted to, as shown in FIG. Since the curve on the graph indicating the light intensity varies depending on the type of each hole, the curve on the graph indicating the light intensity for each hole type is obtained in advance and measured immediately before measuring the hole to be inspected. The hole type can be automatically recognized by comparing with the shape of the curve on the graph indicating the intensity of the light. In addition, a function of automatically selecting a probe having a prism corresponding to the hole type can be added. A device that can automatically select and install a specific probe, for example, a probe changer that is equipped with a plurality of different probes in advance, such as the head change of an NC machine, and if the type of hole to be inspected is found, A probe having a prism or mirror having an appropriate inclination angle as shown in FIG. 3 according to the type is automatically mounted. In some cases, a function of automatically reversing the positional relationship between the objective lens and the probe may be provided.

  When the preparation for the inspection is completed in this way, the probe drive device 12 inserts the probe 11 into the hole to be inspected, shines light from above, and the light is reflected on the mirror or prism 26 at the probe tip to cause the hole. 360 light by illuminating the side surface, reflecting the light reflected from the side surface of the hole to the objective lens 13 located above by the mirror or prism 26 and recording it by the CCD camera 15, and further rotating the probe 11 by a predetermined angle and photographing. ° Record an image on the entire inside of the hole. Then, by using the obtained image data for each of the plurality of images and connecting them in order by image processing, the surface state inside the inspection target hole is recorded as a single image like a panoramic photograph. Then, the recorded surface conditions such as damage, cracks and corrosion inside the hole are classified from the color, brightness and focal length data of the image, the surface condition is classified, and the size area and depth of damage, cracks and corrosion are measured. , Distinguish the degree of the situation, and record its exact position.

  Furthermore, in the above inspection, a more accurate image can be obtained by rotating the objective lens 13 on the inspection object hole in synchronism with the probe or asynchronously. For example, the objective lens 13 is rotated exactly the same as the rotation angle of the probe 11 or is rotated regardless of the rotation angle of the probe (that is, asynchronously). At this time, when the image is recorded by rotating the objective lens asynchronously with the rotation of the probe, the angle of the surface image of the hole to be inspected in each image becomes arbitrary with respect to the frame of the image. When the image is recorded by rotating the objective lens 13 in synchronization with the rotation angle, all images can be recorded at the same position and angle with respect to the image frame, and a clearer image can be obtained. FIG. 10 is a photograph of the inner surface of the hole for a structural joint using the apparatus of the above embodiment, and the state of the inner peripheral surface of the hole is clearly shown.

  The internal inspection of the hole and the apparatus according to the present invention can be applied to the state of the entire peripheral surface of the hole to be inspected without destroying the inside of the hole such as a hole for passing the bolt, fastener and rivet of the joint part even with a small diameter hole. Images can be taken at an equal distance from the inside, and the inner surface of the hole can be inspected efficiently and precisely, and can be suitably used particularly for inspection of joint holes of various structures.

It is the schematic of the internal inspection apparatus of the hole which concerns on embodiment of this invention. It is the principal part enlarged view. It is explanatory drawing which shows the type of inspection object hole, (a) is a top view, (b) is explanatory drawing which shows the positional relationship with the probe in the AA cross section. It is explanatory drawing which positions an objective lens. (A) is an explanatory diagram of the positioning method in the X-axis direction, and (b) is a diagram showing the relationship between the movement of the objective lens and the intensity of light received by the objective lens. It is explanatory drawing which positions a probe. (A) is an explanatory diagram of the positioning method in the X-axis direction, and (b) is a diagram showing the relationship between the movement of the probe and the intensity of light received by the objective lens. It is explanatory drawing of the automatic recognition method of the type of the hole of a test subject. (A) is explanatory drawing of the recognition method in the case of a countersink hole, (b) is a diagram which shows the relationship between the vertical position of the center of a probe, and the intensity | strength of light received with an objective lens. It is an internal peripheral surface photograph of the inspection object hole inspected with the device of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal inspection apparatus of a hole 2 Flat hole 3 Countersink hole 4 Countersink hole 6 Inspection object 10 Inspection stand 11 Probe 12 Probe drive device 13 Objective lens 14 Objective lens drive device 15 CCD camera (imaging means) 16 Image processing device 17 Light source for left / right positioning 18 Light source for front / rear positioning 20 Table 21 Transmission hole 25 Probe shaft 26 Prism

Claims (8)

  An internal inspection method for holes that allows non-destructive inspection of the inner peripheral surface of a hole formed in a member from an equal distance. A mirror or prism that can be inserted into a hole to be inspected is attached to the tip at an angle. Insert the probe on the center axis of the hole to be inspected, and light is applied to the mirror or prism from the side of the objective lens arranged on the opposite side across the probe and the hole to be inspected. The light reflected from the mirror or prism and illuminated at right angles to the inner peripheral surface of the hole to be inspected, and the light reflected from the inner peripheral surface of the hole is reflected by the mirror or prism to the objective lens and recorded by the imaging means. Internal inspection method for holes.   The hole internal inspection method according to claim 1, wherein the entire inner peripheral surface of the hole is recorded as a plurality of images from the same distance by rotating the probe.   3. The image recorded by the imaging means is discriminated by an image processing device for the presence or absence of surface conditions such as damage, cracks, corrosion, etc., the size and depth, and the exact position thereof. Internal inspection method of the described hole.   The image recorded on the entire inner peripheral surface of the hole by the imaging unit is recorded by an image processing device on a continuous image of the image inside the hole to be inspected. The internal inspection method of the hole for structural joints described in 1.   A probe having an angled mirror or prism that can be inserted into a hole to be inspected formed in the member, an objective lens and an imaging means that can record the situation inside the hole by an image, and the captured image An image processing apparatus that performs image processing, a probe driving mechanism having a displacement mechanism in the three-axis direction with respect to the inspection target hole and a rotation mechanism around the probe axis, and a three-axis direction in which the objective lens is in the three-axis direction with respect to the inspection target hole An internal inspection device for a hole, comprising an objective lens drive mechanism having a displacement mechanism.   6. The hole internal inspection device according to claim 5, further comprising a left-right positioning light source and a front-rear positioning light source for positioning the probe or the objective lens in three axial directions.   7. The objective lens driving mechanism according to claim 5, further comprising an objective lens rotating unit capable of rotating the objective lens on the inspection target hole in synchronization with or asynchronously with the probe. Inside inspection device of the described hole.   8. A probe selection mechanism for automatically recognizing a difference in type of hole to be inspected and automatically selecting a probe having a mirror or a prism corresponding to the type of hole. Hole internal inspection device.