JPH08261947A - Inner face photographing device for tubular body - Google Patents

Abstract

PURPOSE: To inspect the whole inner periphery of a steel pipe without rotating the relative position between the steel pipe and an inspection device in the peripheral direction. CONSTITUTION: A lighting mechanism 1 having a parabolic mirror and the reflecting faces of truncated cone slant faces is arranged on the center axis of a steel pipe, and the circular region on the whole inner periphery of the steel pipe is concurrently illuminated. A light guide mechanism 2 having reflecting faces 21-24 similar to the slant faces of a pyramid is arranged at the position facing the illuminated region. The light reflected on the reflecting faces of the light guide mechanism 2 is received by optical systems having independent one-dimensional image sensors 31-34. The effective visual field of each optical system is set to 90 deg., and the whole peripheral direction is concurrently photographed by four optical systems.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for photographing an inner surface of a tubular body, which can be used, for example, to inspect irregularities on the inner wall surface of the tubular body.

[0002]

2. Description of the Related Art For example, in order to guarantee the quality of a tubular body such as a steel pipe, a surface flaw is inspected. However, since the entire inner surface of the steel pipe cannot be directly visually inspected, a special device must be used for the inspection.

As a conventional technique relating to an apparatus used for inspecting the inner surface of a steel pipe of this type, for example, Japanese Patent Laid-Open No. 59-10 is available.
9848 and JP-A-61-202109 are known.

In Japanese Unexamined Patent Publication No. 59-109848, a spot-like laser beam is radiated into the tube along its central axis through an optical system arranged outside the steel tube, and a cylindrical lens is arranged inside the tube. The laser light is expanded into a fan shape to irradiate the inner wall of the steel pipe to illuminate the area. Then, the illuminated area of the inner wall of the steel pipe is photographed using a linear image sensor camera arranged in the vicinity of the cylindrical lens. Further, in order to take an image over the entire circumference of the inner surface of the steel pipe, the steel pipe as the inspection object is configured to rotate about its axis. It is possible to identify the presence or absence of irregularities or flaws in the tube from the captured image.

Further, in Japanese Patent Laid-Open No. 61-202109, light from a light source is guided into the tube through an optical fiber, a part of the inner surface of the tube is illuminated through a mirror, and the illuminated part of the inner surface of the tube is illuminated. Light is guided to a light receiving optical fiber through a mirror and a lens, and an image is taken inside the tube by an image receiving portion arranged outside the tube. Further, in order to take an image over the entire circumference of the inner surface of the steel pipe, the tip portion of the image pickup section inserted into the pipe is configured to rotate using a motor.

[0006]

Problems to be Solved by the Invention JP-A-59-1098
In both Japanese Patent Laid-Open No. 48 and Japanese Patent Laid-Open No. 61-202109, in order to take a picture over the entire circumference of the tube,
The mechanical rotation scanning of the inspection object or the inspection device is performed. Due to the time required for this rotary scan, it is inevitable that the time required to inspect the entire tube will be quite long. In addition, in order to image the entire tube, it is necessary to perform axial scanning while performing rotational scanning. However, if both scannings are performed, spiral scanning is performed. May become discontinuous, and there may be a region that is not imaged. In order to prevent this, the scanning speed must be reduced.

Further, in Japanese Unexamined Patent Publication No. 61-202109, since the rotation range of the inspection device is limited by the twisting of the optical fiber, the scanning direction in the circumferential direction must be reversed for each rotation, and various rotations are required. Defect occurs.

Further, when the length of the steel pipe to be inspected is long, in order to stably support the portion of the inspection device to be inserted into the steel pipe, the supporting device is brought into contact with the inner wall of the steel pipe through, for example, wheels. In addition, the steel tube and the supporting device must be movable relative to each other for scanning. However, for example, a steel pipe called U0 pipe has a seam extending in the axial direction. Therefore, if there is a weld bead at this seam, the inspection device is used when the supporting device passes through the weld bead. It vibrates and you cannot shoot normally. When inspecting a steel pipe while rotating it, it is inevitable that the supporting device will pass through the weld bead.

An object of the present invention is to solve the above-mentioned problems of the inspection device.

[0010]

In order to solve the above problems, according to the present invention, there is provided an inner surface photographing apparatus for a tubular body, which is arranged in the inner space of the tubular body and optically photographs the inner peripheral surface thereof.
An illumination mechanism (1) for simultaneously illuminating an annular region of the inner peripheral surface of the tubular body; N or more N light reflection surfaces (21, 22, 2)
3, 24), each of the light reflecting surfaces of which is arranged at a position facing an annular region of the tubular inner peripheral surface of the tubular body illuminated by the illumination mechanism. A light guide mechanism (2) formed so as to surround the central axis of the tubular body; arranged at a position facing each of the N light reflection surfaces of the light guide mechanism, and illuminated by the illumination mechanism. N one-dimensional image pickup means (31, 32, 33) each receiving light from the peripheral surface of the tubular body and including a large number of light receiving elements arranged in a direction along the circumferential direction of the tubular body. , 34); and N lenses (41, 41) arranged respectively between the light reflecting surface and the one-dimensional imaging means facing each other, and guiding the light from the light reflecting surface to the light receiving surface of the one-dimensional imaging means. 42, 43, 4
4);

According to a second aspect of the present invention, the illumination mechanism has an illumination reflection member (11) having a light reflection surface formed in the shape of a cone or an inclined surface of a truncated cone, and at a position facing the illumination reflection member. It is provided with a parabolic mirror (12) arranged and a light source (13) arranged at the focal position of the parabolic mirror.

Further, according to a third aspect of the invention, there is further provided a first moving mechanism (5) for relatively moving the illumination mechanism and the light guiding mechanism with respect to the direction of the central axis of the tubular body.

According to a fourth aspect of the present invention, a second moving mechanism for moving the light reflecting surface of each of the light guiding mechanisms and each of the one-dimensional image pickup means relative to the direction of the central axis of the tubular body ( 6) is further provided.

Further, in claim 5, the illumination mechanism,
It further comprises a light guide mechanism, a base member for supporting N one-dimensional image pickup means and N lenses, and a lifting mechanism (7) for adjusting the position of the base member in the radial direction of the tubular body. .

Further, in claim 6, the illumination mechanism,
A light guiding mechanism, a base member supporting N one-dimensional image pickup means and N lenses, and a third moving mechanism (8) for moving the position of the base member in the axial direction of the tubular body. Is further provided.

The symbols shown in parentheses are for reference only to the reference numerals of the corresponding elements in the examples described later, and each component of the present invention is only a specific element in the examples. It is not limited to.

[0017]

In the present invention, the illumination mechanism (1) is arranged in the inner space of the tubular body to be inspected and simultaneously illuminates the annular area on the inner peripheral surface of the tubular body. The light guide mechanism (2) is 3
A reflecting mirror member having the above N light reflecting surfaces (21, 22, 23, 24) is included, and each of the light reflecting surfaces faces the annular region of the tubular inner peripheral surface illuminated by the illumination mechanism. The N light-reflecting surfaces are formed so as to surround the central axis of the tubular body. Further, N number of one-dimensional image pickup means (31, 32, 33, 34) are arranged at positions facing each of the N number of light reflecting surfaces of the light guide mechanism, and the tubular inner circumference of the body illuminated by the illumination mechanism. Each of the light receiving elements receives light from the surface and includes a large number of light receiving elements arranged in a direction along the circumferential direction of the tubular body. Further, a lens (41, 4) is provided between the light-reflecting surface and the one-dimensional imaging means, which face each other.
2, 43, 44) are arranged, and the light from the light reflecting surface is guided to the light receiving surface of the one-dimensional image pickup means.

Therefore, the reflected light from the entire area of the inner surface of the tubular body to be inspected in the circumferential direction is divided into N areas, and the reflected light in each area exists at the position opposite to that. The light is reflected by (21, 22, 23, 24), condensed by the lenses (41, 42, 43, 44) and simultaneously incident on the one-dimensional imaging means (31, 32, 33, 34). That is, it is possible to simultaneously capture images of the entire area of the inner surface of the tubular body in the circumferential direction without performing mechanical scanning in the circumferential direction. Since mechanical scanning in the circumferential direction is not required, the time required to image the entire tubular body is shortened and the control is simplified. Furthermore, since the mechanical scanning is only in the axial direction of the tubular body, the area actually imaged by this device is a continuous two-dimensional area, and even if the scanning speed is relatively fast, the area of the inspection omission is Is less likely to occur.

According to a second aspect of the present invention, the light emitted from the light source (13) is aligned by the parabolic mirror (12) in a direction substantially parallel to the central axis of the tubular body, and the illumination exists at a position facing the central axis. The light reflection surface of the reflective member (11) is irradiated. Since this light reflecting surface is formed in the shape of a cone or a truncated cone, light incident in a direction parallel to the axial direction is reflected in an oblique direction, and with respect to the inner wall of the tubular body,
An annular surface area having a certain width is simultaneously illuminated with uniform illuminance. By photographing the portion included in this annular surface area, it becomes possible to inspect the entire area in the circumferential direction at the same time.

According to the third aspect of the present invention, the function of the first moving mechanism (5) allows the illumination mechanism and the light guide mechanism to be relatively moved with respect to the direction of the central axis of the tubular body. Therefore, even if the diameter of the tubular object to be imaged changes, if the relative movement is performed according to the change, the light guide mechanism can always face the illumination position of the illumination mechanism.

Further, according to a fourth aspect of the present invention, by the action of the second moving mechanism (6), the light reflecting surface of each of the light guiding mechanisms and each of the one-dimensional image pickup means are directed in the direction of the central axis of the tubular body. Can be moved relative to. Therefore,
Even if the diameter of the tubular object to be imaged changes and the optical path length from the imaging position on the inner surface of the tubular body to the one-dimensional imaging means changes, if the relative movement is performed according to the change, the optical path length becomes constant. Can be maintained at.

Further, in claim 5, the elevating mechanism (7).
The position of the base member supporting the illumination mechanism, the light guiding mechanism, the N one-dimensional image pickup means and the N lenses can be adjusted in the radial direction of the tubular body by the function of. Therefore, even when the diameter of the tubular object to be imaged changes, the central position of the device composed of the illumination mechanism, the light guiding mechanism, the N one-dimensional imaging means, and the N lenses can be set to the central axis of the tubular object. Can be placed in position.

According to a sixth aspect of the present invention, the function of the third moving mechanism (8) causes the illumination mechanism, the light guiding mechanism, and the N mechanism.
Since the one-dimensional image pickup means and the N lenses can be moved in the axial direction of the tubular body, the photographing position can be scanned in the axial direction of the tubular object.

[0024]

EXAMPLE FIG. 3 shows the appearance of the inspection apparatus of the example. As shown in FIG. 3, this inspection device optically scans the inner peripheral surface of the steel pipe 100 while self-propelled in the axial direction of the pipe (left-right direction in FIG. 3) while being arranged inside the steel pipe 100. Then, the photographed image is processed to inspect for surface flaws. The steel pipe to be inspected has a diameter of 400 to 1500 m, for example.
m, and the length is about 12 m.

Referring to FIG. 3, this inspection apparatus is mounted on a carriage 103 which is movable inside a steel pipe by wheels 104. The dolly 103 is driven in the axial direction of the steel pipe 100 by an electric motor included in the dolly driving mechanism 8. The base member 102 that supports the main body of the inspection apparatus is horizontally supported on the carriage 103 via the elevating mechanism 7. By driving the electric motor included in the lifting mechanism 7, the base member 102 can be lifted and lowered while being kept horizontal.

Shaft 1 having illumination mechanism 1 fixed at one end
5 is horizontally supported on the base member 102 and is movable in the axial direction. A rack portion 15 a is formed at the other end of the shaft 15, and the rack portion 15 a is engaged with the illumination moving mechanism 5. Therefore, the illumination moving mechanism 5
The position of the illumination mechanism 1 can be moved in the axial direction by driving the electric motor included in.

The structure of the illumination mechanism 1 is shown in FIG. This will be described with reference to FIG. The illumination mechanism 1 is equipped with a lamp 13, a parabolic mirror 12, a diffusion mirror 11, and a casing 14. The central portion of the parabolic mirror 12 is fixed to one end of the shaft 15. The lamp 13 is fixed to the parabolic mirror 12 with its light emitting portion located at the focal point of the parabolic mirror 12. The shaft 15 is hollow, that is, formed in a pipe shape, and an electric wire for supplying electric power to the lamp 13 is wired through the inside of the shaft 15. Since the lamp 13 is arranged at the focal point of the parabolic mirror 12, the lamp 13
The light emitted from the parabolic mirror 12 is reflected by the surface of the parabolic mirror 12, is converted into parallel rays parallel to the axial direction, and enters the diffusion mirror 11.

As shown in FIG. 2, the diffusing mirror 11 is formed in the shape of a truncated cone. Therefore, the parallel rays incident on the diffusing mirror 11 are inclined on the outer peripheral surface 11 a of the diffusing mirror 11.
Is reflected by and diffused in the circumferential direction. Since the casing 14 is made of a transparent member in a portion necessary for lighting,
The light emitted from the diffusion mirror 11 passes through the casing 14 and enters the inner peripheral surface of the steel pipe 100 to illuminate the surface. The invalid light is blocked by the casing 14. By positioning so that the center of the illumination mechanism 1 coincides with the center of the axis of the steel pipe 100, the simultaneously illuminated area of the steel pipe 100 has an annular shape with a predetermined width W, as shown in FIGS. It becomes the area 101. By moving the dolly 103,
The illuminated area 101 on the steel pipe 100 can be moved axially.

The light guide mechanism 2 fixed on the base member 102 is arranged at a position facing the illuminated area 101 on the steel pipe 100. As shown in FIGS. 4 and 5 (showing a cross section taken along line VV in FIG. 3), the light guiding mechanism 2 includes four flat reflecting surfaces 21, 22, 23, and 24 in the peripheral portion, respectively. ing. These four reflective surfaces 21, 22,
23 and 24 are arranged so as to form a part of the inclined surface of the quadrangular pyramid, and the direction of each surface is inclined by 45 degrees with respect to the axial direction of the steel pipe 100. Further, a hole 20a through which the shaft 15 passes is formed in the center of the light guide mechanism 2, and an opening 20b for fitting with the base member 102 is formed below the hole 20a.

As shown in FIG. 3, an image pickup mechanism 3 is arranged on the base member 102 at a position facing the light guide mechanism 2. This image pickup mechanism 3 is shown in FIG. 6 (VI-VI in FIG. 3).
As shown in FIG. 4), a support member 30 supported by the base member 102 and slidable in the axial direction of the steel pipe 100 with respect to the base member 102, and a support member 30 fixed to the outside of the support member 30.
It has one one-dimensional image sensor 31, 32, 33 and 34. In addition, the one-dimensional image sensors 31, 32,
Wide-angle lenses 41, 42, 43, and 44 having a focusing mechanism FC are installed in the light receiving portions of 33 and 34, respectively. Then, the one-dimensional image sensors 31, 32,
Reference numerals 33 and 34 denote the reflecting surfaces 21 of the light guiding mechanism 2,
It is arranged at a position displaced from the central portion of 22, 23 and 24 along an axis parallel to the axis of the steel pipe 100, and is oriented so that the light receiving axis faces the reflecting surfaces 21, 22, 23 and 24.

Therefore, the light reflected by the inner peripheral surface of the steel pipe 100 and directed toward the center thereof, that is, in the direction perpendicular to the axis of the steel pipe 100, is reflected by any of the reflecting surfaces 21, 22, 23 and 24 of the light guide mechanism 2. Is reflected. Then, the light reflected by the reflecting surface 21 is condensed by the wide-angle lens 41 and is incident on the one-dimensional image sensor 31, and the light reflected by the reflecting surface 22 is condensed by the wide-angle lens 42 and is one-dimensional. The light that has entered the image sensor 32 and is reflected by the reflecting surface 23 is condensed by the wide-angle lens 43, and the one-dimensional image sensor 3
The light that has entered 3 and reflected by the reflecting surface 24 is condensed by the wide-angle lens 44 and enters the one-dimensional image sensor 34.

The one-dimensional image sensors 31, 32,
Since the image pickup devices 33 and 34 are arranged so that the arrangement directions of the respective image pickup devices coincide with the longitudinal directions of the reflecting surfaces 21, 22, 23 and 24, respectively, the one-dimensional image sensor 3 is shown.
1, 32, 33 and 34 respectively capture a one-dimensional image in the circumferential direction of the inner surface of the steel pipe 100. More specifically, in this embodiment, the effective visual field of each of the one-dimensional image sensors 31, 32, 33 and 34 including the wide-angle lens is set to 90 degrees. That is, the entire area of the inner surface of the steel pipe 100 in the circumferential direction is divided into four in the circumferential direction, and each 90 degree divided area is divided into one-dimensional image sensors 31, 32, 32 ,.
The optical system is configured so that images can be picked up by 33 and 34. Therefore, the areas RA, RB, R in the circumferential direction shown in FIG.
The ranges of C and RD are imaged by the one-dimensional image sensors 31, 32, 33 and 34, respectively.

In this embodiment, the entire circumferential region of the inspection target is divided into four parts, and the inner surface of the steel pipe is imaged by an independent optical system for each divided region. The number of divided regions is three. However, it does not matter even if it is 5 or more. For example, when the number of divisions is 3, the reflecting surface of the light guide mechanism 2 is arranged in the shape of a triangular pyramid so that the effective field of view of each image sensor is 120.
If the number of divisions is 5, the reflecting surface of the light guide mechanism 2 is arranged in the shape of a pentagonal pyramid and the effective field of view of each image sensor is set to 72 degrees. Good.

A screw is formed in the hole 30a formed in the supporting member 30 for supporting the one-dimensional image sensors 31, 32, 33 and 34. A screw rod 61 that penetrates the hole 30a is screwed into the hole 30a. Screw rod 61
Is connected to the light receiving unit moving mechanism 6. That is, when the electric motor included in the light receiving unit moving mechanism 6 is driven, the screw rod 61 rotates, and the support member 30 and the one-dimensional image sensors 31, 32, 33 and 34 screwed with the screw rod 61 are placed in the base. It moves on the member 102 in the axial direction of the steel pipe 100. Therefore,
Image sensors 31, 32, 33 and 3 from the inner peripheral surface of the steel pipe
The optical path length up to 4 can be adjusted by the light receiving unit moving mechanism 6 so that the optical path length up to 4 matches the distance from the peripheral surface of the steel pipe to its center. If such adjustment is made in advance, then only the focusing of the focusing mechanism FC can cope with the change in the diameter of the steel pipe. The light receiving unit moving mechanism 6 is omitted and the support member 30 is
It may be fixed on the support member 102.

The number of image pickup elements (number of pixels) forming each of the one-dimensional image sensors 31, 32, 33 and 34 is the maximum diameter of the steel pipe 100 to be inspected and the minimum flaw size to be inspected. It is determined in advance according to the size.

With respect to changes in the diameter of the steel pipe, the light receiving portion moving mechanism 6 is moved so that the optical path length from the inner peripheral surface of the steel pipe to the image sensors 31, 32, 33 and 34 becomes constant. May be. In that case, the visual field of each of the image sensors 31, 32, 33, and 34 may be adjusted so as to coincide with the ¼ region in the circumferential direction of the steel pipe with respect to the steel pipe having the maximum diameter. Further, in that case, when imaging a steel pipe having a small diameter, the image sensors 31, 32, 33 and 34 are imaged.
It is desirable to remove the overlapping portion by electrically processing the image signal, since portions overlapping each other are generated in the image picked up by.

FIG. 8 shows the configuration of the electric circuit of the inspection apparatus shown in FIG. Referring to FIG. 8, the inspection device includes an image control device 201, an image processing device 202, a CRT display device 203, a flaw detection processing device 204, and a brightness detection device 20.
5, an alarm display 206, a drive controller 207, and motor drivers DV1 to DV4 are included. Electric motors M1 to M4 are connected to the motor drivers DV1 to DV4. Electric motors M1, M2, M3 and M4
Are drive sources of the cart drive mechanism 8, the lifting mechanism 7, the illumination drive mechanism 5, and the light receiving unit moving mechanism 6, respectively. Further, the movement detector 81 connected to the electric motor M1 of the carriage drive mechanism 8 outputs a pulse signal S0 every minute rotation of the electric motor M1, that is, every minute movement of the carriage 103. Note that among these components, the CRT display device 203,
The flaw detection processing device 204 and the alarm display 206 are
It is installed outside the steel pipe 100 and is connected to a device on the carriage 103 via an electric cable (not shown).

The drive control device 207 is connected to a process computer (not shown) for managing production information,
Input the information of the steel pipe diameter that it outputs. Then, the drive control device 207 first performs the initial alignment of the inspection device. That is, based on the input information of the steel pipe diameter, the electric motor M2 is driven so that the axial center position of the shaft 15 (the central axis of the inspection device) coincides with the central axis of the steel pipe 100. The height of the member 102 is adjusted. Further, based on the information on the diameter of the steel pipe, the electric motor M3 is driven to move the shaft 15 and the illumination mechanism 1 in the axial direction, and the position of the region 101 illuminated by the illumination mechanism 1 on the inner surface of the steel pipe is determined. The light guide mechanism 2 is positioned so as to match the position of the light guide mechanism 2. Further after this, the one-dimensional image sensors 31, 32,
The position of the inspection device is finely adjusted based on the image signal obtained by imaging the inner surface of the steel pipe with 33 and 34. That is,
Based on the information indicating the brightness distribution of the image output from the brightness detection device 205, the axial center position of the shaft 15 is the steel pipe 1.
If it can be identified that the deviation is from the center of 00, the height of the base member 102 is corrected by driving the electric motor M2 so as to reduce the deviation. Further, the brightness detection device 20
If the illumination area 101 on the steel pipe and the position of the light guide mechanism 2 can be discriminated from each other on the basis of the information on the brightness of the image outputted from No. 5, the electric model is adjusted so as to reduce the deviation. -Drive M3 to correct the axial position of the illumination mechanism 1.

By operating the switch of the operator,
When the start instruction is given, the drive controller 207
The carriage 103 is moved in the axial direction of the steel pipe 100 by driving the electric motor M1 at a constant speed. In this state, the pulse signal S0 appears from the movement detector 81 in a substantially constant cycle. The pulse signal S0 is input to the image control device 201 and the drive control device 207. Image control device 201
Outputs a control signal generated based on the pulse signal S0 to the one-dimensional image sensors 31, 32, 33, 34 and the image processing device 202.

Actually, as shown in FIG. 10, every time one pulse signal S0 appears, the control signals S1, S2, S3 are generated.
And S4, one pulse each appears in sequence. 1
The three-dimensional image sensors 31, 32, 33 and 34 pick up an image of one line each time a pulse appears in the control signals S1, S2, S3 and S4 and output the image information. The image information S5, S6, S7 and S8 output by the four one-dimensional image sensors are applied to the image processing device 202.

The image processing apparatus 202 inputs the image information S5, S6, S7 and S8 in synchronization with the control signal S9,
The predetermined image processing is performed and the image signal S10 is output. The image processing device 202 is provided with an image memory of 2 frames inside thereof, and receives the input image information S5.
S6, S7 and S8 are sequentially written at addresses corresponding to the scanning position on the image memory of one frame. Further, the information in the image memory of the other frame is sequentially read and output as the image signal S10 together with the scanning synchronization signal. When information is stored at all addresses in the image memory of one frame, the writing frame and the reading / writing frame are switched. CR to which the image signal S10 is input
On the screen of the T display device 203, for example, as shown in FIG. 9, an image obtained by imaging the entire area of the steel pipe 100 in the circumferential direction is displayed as two-dimensional image information.

The image processing executed on the image processing apparatus 202 includes, for example, shading correction processing. This processing corrects the unevenness of the density distribution caused by the non-linearity of the light receiving optical system and the unevenness of the detection sensitivity distribution of each image sensor.

The flaw detection processing device 204 uses the image signal S10.
Enter to identify the presence or absence of defects. For example, when a rapid density change of a predetermined level or more is detected between adjacent pixels of an image, it is recognized as a defect. When a defect is detected, the alarm display 206 is activated.

The movement of the carriage 103, that is, the scanning of the inspection apparatus in the axial direction of the steel pipe is continued until the inspection position reaches the end of the steel pipe 100. That is, the drive control device 207 determines that the signal S
The actual scanning distance is constantly grasped by counting the number of pulses of 0, and the target scanning distance is calculated by adding the correction of the scanning start position of the inspection device from the previously input steel pipe length, and the actual scanning distance is the target scanning distance. When the distance is exceeded, scanning is stopped. Further, when it is recognized by the signal S11 output from the brightness detection device 205 that the inspection position has reached the end of the steel pipe 100, the scanning is stopped even before the actual scanning distance exceeds the target scanning distance.

In the above embodiment, the case in which the entire area in the circumferential direction of the inner surface of the steel pipe is inspected while scanning the carriage 103 of the inspection device in one direction of the axial direction of the steel pipe has been described.
The cart 103 of the inspection device may be driven so as to reciprocate along the axial direction of the steel pipe. In that case, if the position of the inspection device is shifted in the direction of rotation of the steel pipe each time scanning in one direction, it is not necessary to inspect the entire area in the circumferential direction by scanning in one direction.
The effective field of view of each image sensor can be narrower than 90 degrees.

According to the embodiment described above, the reflected light from the entire area of the inner surface of the tubular body to be inspected in the circumferential direction is divided into N areas, and the reflected light of each area faces it. Light reflecting surfaces 21, 22, 23, 24 existing at positions
And is condensed by the wide-angle lenses 41, 42, 43, 44, and at the same time the one-dimensional image pickup means (31, 32, 33,
34). That is, it is possible to simultaneously capture images of the entire area of the inner surface of the tubular body in the circumferential direction without performing mechanical scanning in the circumferential direction. Since mechanical scanning in the circumferential direction is not required, the time required to image the entire tubular body is shortened and the control is simplified. Furthermore,
Since the mechanical scanning is only in the axial direction of the tubular body, the area actually imaged by this device is a continuous two-dimensional area, which results in areas of inspection failure even when the scanning speed is relatively fast. Hateful.

The light emitted from the lamp 13, which is the light source, is aligned by the parabolic mirror 12 in a direction substantially parallel to the central axis of the tubular body, and is reflected by the light reflecting surface of the diffuser mirror 11 existing at a position opposite to it. Is irradiated. Since the light reflecting surface is formed in the shape of a truncated cone, light incident in a direction parallel to the axial direction is reflected in an oblique direction and has an annular width W with respect to the inner wall of the tubular body. It is possible to simultaneously illuminate the surface area of the with uniform illuminance. By photographing the portion included in this annular surface area, the entire area in the circumferential direction can be inspected at the same time.

Further, since the first moving mechanism (5) works, the illumination mechanism and the light guide mechanism can be moved relative to the direction of the central axis of the tubular body.
Even if the diameter of the tubular object to be imaged changes, the light guide mechanism can always face the illumination position of the illumination mechanism by performing the relative movement according to the change.

Further, by the action of the second moving mechanism (6), each light reflecting surface of the light guiding mechanism and each of the one-dimensional image pickup means are moved relative to the direction of the central axis of the tubular body. be able to. Therefore, even if the diameter of the tubular object to be imaged changes and the optical path length from the position of the illumination mechanism, which is the light source, to the one-dimensional imaging means changes, if the relative movement is performed according to the change, the optical path is changed. The length can be kept constant.

The position of the base member supporting the illumination mechanism, the light guide mechanism, the N one-dimensional image pickup means, and the N wide-angle lenses is controlled by the function of the elevating mechanism (7) to determine the diameter of the tubular body. It can be adjusted with respect to direction. Therefore,
Even if the diameter of the tubular object to be imaged changes, the central position of the device including the illumination mechanism, the light guide mechanism, the N one-dimensional image pickup means, and the N wide-angle lenses is set to the position of the central axis of the tubular object. Can be placed at.

By the action of the third moving mechanism (8), the illumination mechanism, the light guiding mechanism, the N one-dimensional image pickup means and the N wide-angle lenses can be moved in the axial direction of the tubular body. As a result, the imaging position can be scanned in the axial direction of the tubular object.

[Brief description of drawings]

FIG. 1 is an enlarged vertical sectional view showing a part of the inspection device of FIG.

FIG. 2 is a perspective view showing a part of the illumination mechanism of FIG.

FIG. 3 is a vertical cross-sectional view showing the entire mechanical portion of the inspection device arranged in the steel pipe.

4 is an enlarged perspective view showing a part of the inspection device of FIG.

5 is a cross-sectional view taken along the line VV of FIG.

6 is a cross-sectional view taken along line VI-VI in FIG.

FIG. 7 is a sectional view taken along line VI-VI in FIG.

FIG. 8 is a block diagram showing a configuration of an electrical component section of the inspection device of FIG.

9 is a schematic diagram showing an arrangement of display elements in a screen displayed on the display device 203. FIG.

10 is a time chart showing signals in the circuit shown in FIG.

[Explanation of symbols]

1: Illumination mechanism 2: Light guide mechanism 3: Imaging mechanism 5: Illumination moving mechanism 6: Light receiving part moving mechanism 7: Lifting mechanism 8: Truck driving mechanism 11: Diffusing mirror 12: Parabolic mirror 13: Lamp 14: Case Thing 15: Shaft 15a: Rack 20a: Hole 20b: Opening 21, 22, 23, 2
4: Reflective surface 30: Support member 31, 32, 33, 34: One-dimensional image sensor 41, 42, 43, 44: Wide-angle lens 81: Movement detector 100: Steel pipe 101: Illumination area 102: Base member 103 : Bogie 104: Wheel 201: Image control device 202: Image processing device 203: CRT display device 204: Defect detection processing device 205: Brightness detection device 206: Alarm display device 207: Drive control device FC: Focusing mechanism DV1 to DV1 DV4: Motor driver M1, M2, M3, M4: Electric motor

Claims (6)

[Claims] 1. An inner surface photographing apparatus for a tubular body, which is arranged in the inner space of the tubular body and optically photographs the inner peripheral surface thereof, wherein an illumination mechanism for simultaneously illuminating an annular region of the inner peripheral surface of the tubular body; A reflecting mirror member having three or more N light reflecting surfaces, each of the light reflecting surfaces being arranged at a position facing an annular region of the tubular inner peripheral surface illuminated by the illumination mechanism; A light guiding mechanism, in which a plurality of light reflecting surfaces are formed so as to surround the central axis of the tubular body; N of the light guiding mechanism.
The light-reflecting surface is arranged at a position facing each of the light-reflecting surfaces, receives light from the inner peripheral surface of the tubular body illuminated by the illumination mechanism, and is arranged in a direction along the circumferential direction of the tubular body. Including a large number of light receiving elements,
N number of one-dimensional imaging means; and arranged between the light reflecting surface and the one-dimensional imaging means facing each other,
N for guiding the light from the light reflecting surface to the light receiving surface of the one-dimensional image pickup means
An inner surface photographing apparatus for a tubular body, comprising: 2. The illumination mechanism has an illumination reflection member having a light reflection surface formed in the shape of a cone or an inclined surface of a truncated cone, a parabolic mirror arranged at a position facing the illumination reflection member, And a light source arranged at the focal position of the parabolic mirror,
The inner surface photographing device for a tubular body according to claim 1, further comprising: 3. The inner surface photographing apparatus for the tubular body according to claim 1, further comprising a first moving mechanism that relatively moves the illumination mechanism and the light guide mechanism with respect to a direction of a central axis of the tubular body. . 4. A second moving mechanism for moving the light reflecting surface of each of the light guide mechanisms and each of the one-dimensional imaging means relative to the direction of the central axis of the tubular body. Item 1. The inner surface photographing device for a tubular body according to Item 1. 5. A base member for supporting said illumination mechanism, light guide mechanism, N one-dimensional image pickup means and N lenses,
The apparatus for photographing an inner surface of a tubular body according to claim 1, further comprising an elevating mechanism for adjusting the position of the base member in the radial direction of the tubular body. 6. A base member for supporting said illumination mechanism, light guide mechanism, N number of one-dimensional image pickup means and N number of lenses,
2. The tubular body inner surface photographing apparatus according to claim 1, further comprising a third moving mechanism for moving the position of the base member in the axial direction of the tubular body.