JPH09297111A - Radiographic testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiograpnic testing device that can obtain an electronic image of high resolution and pick up the image of a defect such as a micro crack more clearly. SOLUTION: A radiographic testing device is provided with a target T of an X-ray generating device to be a radiation source, and an image pickup device positioned on the opposite side to the radiation source T with a steel pipe S placed in between. The image pickup device has a camera body provided with a scintillator 21, a CCD element for picking up images by the scintillator 21, and a cooling device such as a Peitier element for cooling the CCD element. A relative moving means moves the camera body and the radiation source T reiatively by micro distance at a time in the longitudinal direction L of the steel pipe S, almost along the surface of the steel pipe S. A plurality of images picked up by the CCD element are stored by an image storage means in each moving position of the camera body and radiation source T moved by the relative moving means, and these images are synthesized by an image processing means in each moving position to obtain an image of high resolution. The directions of a crack D or the like and a transmitted X-ray X2 are easily made coincide with each other by moving the radiation source T in the longitudinal direction L of the steel pipe L A clearer image of the crack D or the like can thereby be obtained.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a radiation source,
The present invention relates to a radiation transmission test apparatus including an imaging device located on the opposite side of the radiation source with a test body such as a steel pipe having a welded portion interposed therebetween.

[0002]

2. Description of the Related Art Conventionally, in the radiation transmission test apparatus as described above, an X-ray generator is used as a radiation source, and an II (image intensifier) apparatus or a radiation film is used as an image pickup apparatus. Then, while the radiation source and the image pickup device are fixed to the steel pipe or the like, the image of the welded portion or the like is taken.

By the way, when the II apparatus is used as the image pickup apparatus, since the image pickup can be made electronic, the transmission image of the test body can be visualized in real time and image processing can be easily performed as compared with the case where the radiation film is used. . But,
In the configuration using the II apparatus, the quality of the image is inferior to that of the radiation film, and there is a problem that it is difficult to find extremely fine cracks. Further, when the radiation source and the imaging device are fixed to the steel pipe or the like like the above-mentioned radiation transmission test device, the more the direction of the radiation from the radiation source to the imaging device and the direction of the cracks do not match, the more the imaging is performed. There was a problem that it was easy to become unclear.

[0004]

SUMMARY OF THE INVENTION In view of the conventional situation as described above, a first object of the present invention is to provide a radiation transmission test apparatus capable of obtaining an electronic image having a high resolution. .

A second object of the present invention is to provide a radiation transmission test apparatus capable of more clearly imaging defects such as fine cracks.

[0006]

In order to achieve the above-mentioned first object, the feature of the present invention is to provide a radiation source and an image pickup device located on the opposite side of the radiation source with the test body interposed therebetween. And a camera main body equipped with a scintillator, a CCD element for picking up an image by the scintillator, and a cooling device for cooling the CCD element, and a camera for testing the camera main body and the radiation source. Relative moving means for relatively moving a minute distance along the surface of the body, and the CC for each moving position by the relative moving means.
This is because an image storage means for storing an image captured by the D element and an image processing means for combining the images stored by the image storage means are provided.

According to this feature, by cooling the CCD element by the cooling device, the quantum noise in the CCD element can be reduced. As a result, even if a plurality of images are superposed, the blurring of the image caused by the integration of the quantum noise is caused. Is significantly reduced and the image quality is improved. On the other hand, by relatively moving the camera body and the radiation source along the surface of the test body by small distances, it is possible to capture a transmission image of the test body at slightly different positions for each moving position. Then, a large number of images are picked up for several minutes at each moving position, and these are superposed by the image processing means to generate a composite image. As a result, a high-resolution image can be obtained. "Relative movement means for relatively moving the camera body and the radiation source along the surface of the test body in small increments relative to each other" means means for moving only one of the camera body and the radiation source with respect to the test body. It is meant to include both means for moving both the camera body and the radiation source with respect to the test body.

In particular, by configuring the relative moving means so as to move the radiation source along the surface of the test body, it is possible to achieve the first and second objects of the present invention. . That is, according to such a configuration, the direction of the crack or the like and the direction of the radiation such as the X-ray that passes through the crack or the like from the radiation source and reaches the scintillator are easily matched, and a clearer image of the crack or the like can be obtained. It becomes possible to obtain.

In addition, the relative moving means may move both the camera body and the radiation source in directions opposite to each other along the surface of the test body. With this configuration, the angle between the radiation passing through the crack or the like and the crack or the like can be changed considerably, and it becomes easier to obtain a clearer image of the crack or the like.

The test body is, for example, a pipe having a welded portion, and in this case, the relative moving means may be configured to move the camera body or the radiation source along the longitudinal direction of the pipe. . If a Peltier element is used for the cooling device, the configuration will be simpler than when liquid nitrogen or the like is used.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a radiation transmission test apparatus 1 according to the present invention generally includes a radiation generation apparatus 2 that is a radiation source of radiation that generates X-rays, an imaging apparatus 3 that includes a camera body 20, and these radiation generation apparatuses. Device 2
And a relative moving means 4 for moving the camera body 20 in the longitudinal direction L of the steel pipe S. The relative moving means 4 is attached so that the target T and the scintillator 21 of the camera body 20 are located near the welded portion Sw of the steel pipe S. The fixed clamp 11 and the pair of rotary clamps 12, 12 in the relative moving means 4 can be opened and closed in the diameter direction of the steel pipe S via the hinges 11a, 12a, and the other ends of the hinges 11a, 12a are closed after being attached to the steel pipe S. . The fixed clamp 11 is non-rotatably fixed to the steel pipe S, while the pair of rotary clamps 12,
12 is rotatable around the central axis of the steel pipe S, and by fixing the relative position of the rotary clamp 12 with respect to the fixed clamp 11 by a fixing means (not shown), the inspection position in the circumferential direction near the welded part Sw is changed appropriately. It is possible. In addition, the rotary clamps 12 and 12 are connected to each other by four bridges 12.
The pair of left and right rotary clamps 12 and 12 can be integrally rotated around the central axis of the steel pipe S by connecting them at b.

The camera body 20 has first slide shafts 14a and 14b protruding from the left and right sides thereof, and a first guide member 15 provided on the left and right rotary clamps 12 and 12, respectively.
It is supported so as to be movable left and right by sliding with a and 15b. The left and right first slide shafts 14a, 14b are
The camera body 2 is placed so that it overlaps in the direction perpendicular to the plane of FIG.
One pair is provided on each of the left and right sides of 0. The first guide member 15a on the left side is provided with a first motor 41 configured as a stepping motor having a pinion gear, and the upper surface of the slide shaft 14a is provided with a rack meshing with the pinion gear. Then, by rotating the stepping motor 41, the camera body 20 can be moved to the left and right by a small distance. The radiation generator 2 also includes the reference numerals 14a, 14b, 15a, 15b, 41.
With the second guide shafts 16a and 16b, the second guide members 17a and 17b, and the second motor 42 corresponding to, it is possible to control the movement to the left and right by a small distance.

FIG. 2 is a logical block diagram showing an outline of the radiation transmission test apparatus 1. The radiation transmission test apparatus 1 comprises a radiation generation apparatus 2 and an image pickup apparatus 3, and the image pickup apparatus 3 generally includes a relative moving means 4, a camera body 20 and a personal computer 60.

The radiation generator 2 generates thermoelectrons by the high voltage transformer 2a and the filament 2b. Then, the thermoelectrons are accelerated by a high voltage and collide with the target T to generate X-rays.

The X-ray transmitted through the welded portion Sw of the steel pipe S reaches the scintillator 21 in the camera body 20 and is converted into an optical signal, which is reflected by the mirror 22 and passes through the lens 23 to the CCD element 24. Image on. C
The CD element 24 is always cooled by the Peltier element 25, and the heat transmitted to the cooling fins 26 connected to the Peltier element 25 is forcibly cooled by the blower 27. further,
Cooling air is sucked into the camera body 20 by the cooler 32a, and forced exhaust from the camera body 20 is performed by the suction device 32b. It is desirable to maintain the CCD element 24 so that it is cooled to about -30 ° C.

The signal imaged by the CCD element 24 is
It is sent to the personal computer 60 via the interface 28 and the controller 29. The optical signal reaching the CCD element 24 from the lens 23 is imaged at intervals of about 1/30 second by the shutter motor 30 and the shutter 31 controlled by the interface 28. The camera body 2 in the relative moving means 4
The first and second motors 41 and 42 that move 0 and the radiation generator 2 are controlled by the personal computer 60 via the motor driver 43.

The personal computer 60 stores the image picked up by the camera body 20 through the controller 29 and the first A / D converter 61a in the image storing means 6
2 is stored in each imaging position. The stored images are processed by the image processing means 63 so as to generate a composite image. The images are combined in the image processing means 63 by combining a large number of images for each moving position based on the information of each imaging position accumulated in the coordinate control unit 64. The position control of the camera body 20 and the radiation generator 2 by the relative moving means 4 is performed via the second A / D converter 61b and the motor driver 43 based on the operation of the operating means 65. Further, the operating means 65 controls the generation of X-rays in the previous radiation generating apparatus 2 via the third A / D converter 61c and the switching circuit 2c. The image combined by the image processing unit 63 is displayed as a video on the CRT monitor 67 by the video circuit 66 and is also output as print information to the printer 68.

As shown in FIG. 3, the inner surface of the case body 33 which constitutes the camera body 20 is shielded from X-rays by the lead shield plate 33a. In particular, the lead shield plate 33a facing the front surface side of the steel pipe S is particularly thick in order to improve the X-ray shielding effect. Camera body 2
The inside of 0 is divided into left and right by a partition plate 35, the scintillator 21 and the mirror 22 are arranged on the left side thereof, and the camera module 34 is arranged on the right side thereof. The scintillator 21 is a bundle of optical fibers cut out in a direction perpendicular to the fibers, and is attached to an opening provided on the lower surface of the case body 33.
The X-ray reaching the surface of the scintillator 21 is converted into a light image by the scintillator 21. The light image converted by the scintillator 21 is reflected by the mirror 22 on the support 22a, and the opening 3 of the partition plate 35 is reflected.
The lens 23 is reached via 5a. The partition plate 35 includes
The lead glass 35b for blocking the radiation and allowing only the light image to reach the lens 23 is fitted and closed.

The outer surface of the casing of the camera module 34 constitutes the cooling fin 26. Also,
The inside of the casing is divided into left and right by a CCD partition 34a, and a cooling blower for sucking air from a vent hole (not shown) and discharging the air from a vent hole 27a is provided in a cavity on the right side of the casing. 27 is provided. The circuit board 34b attached to the CCD partition 34a via a spacer constitutes the interface 28 and the like. The cavity on the right side of the CCD partition 34a is sealed except for a portion for taking in light from the lens 23 side, and the CCD element 24 and the Peltier element 2 are provided inside thereof.
5, a shutter motor 30 and a shutter 31. Peltier element 2 for cooling CCD element 24
For No. 5, it is desirable to use a stack of a plurality of plate-like elements in order to improve the cooling effect. Further, the case body 33 is provided with a cooling air suction hole 33b and a discharge port 33c connected to the suction device 32b, and the heat generated by the cooling fins 26 and the blower 27 is discharged to the outside of the case body 33.

A pair of slide portions 37a and 37b on a slider 37 are supported by a pair of upper and lower guides 36a and 36b provided inside the case body 33 so as to be slidable in the lateral direction. In addition, the camera module 34 is
It is attached to this slider 37, and its inclination is regulated by a lower roller 39. The upper guide 36b is provided with an adjusting shaft 38 in a direction perpendicular to the plane of FIG.
The adjustment knob 38b that pivotally supports a passes through the adjustment knob 38b.
The pinion gear 38c integrally provided on the 8b and the rack provided on the upper surface of the upper slider 37b mesh with each other.
Then, the adjustment knob 38b is rotated to integrally move the camera module 34 and the lens 23 far away from the mirror 22, so that fine adjustment can be performed so that an image is formed on the CCD element 24.

Next, with reference to FIG. 4, a procedure for capturing a transmission image of the welded portion Sw in the steel pipe S will be described. Reference numerals T1 and T2 denote targets T or radiation sources, respectively, and reference numerals W1 and W2 denote targets T1 and T2, respectively.
The irradiation range of X-rays in FIG. The symbol A indicates the moving range of the scintillator 21.

The scintillator 21 is moved ahead of the relative moving means 4
Further, the first motor 41 performs shooting while sequentially moving stepwise from one side to the other within the range indicated by A. The shutter motor 30 and the shutter 31
The image capturing interval for the CCD 24 is 1
It is about / 30 seconds, and 2-3 minutes are photographed for each moving position of the scintillator 21, so 360 to 540 unit images are photographed for each moving position. A large number of these unit images are sequentially combined for each moving position of the scintillator 21 to obtain a combined image. As a result, in the composite image of the transparent image, noise is reduced, so that there is no blurring of the image due to superposition, and a sharp and sensitive composite image can be obtained. The composite image for each moving position is displayed on the CRT by operating the operation means 65 of FIG.
It is possible to switch and display with 67 or the like.

Further, as can be seen from the figure, when the X-ray X1 passing through the crack D intersects slightly with the direction of the crack D, the image of the crack D tends to become unclear. In such a case, by moving the target T from the position T1 to the position T2, the directions of the X-ray X2 passing through the crack D and the crack D are made to substantially coincide with each other, and a very clear image of the crack D is captured. Can be obtained. That is, the code T
When an unclear image of the crack D is obtained during imaging with the target T positioned at 1, the target T
Is moved along the longitudinal direction L of the pipe to the position of the symbol T2, it is possible to obtain a clear image of the crack D. On the other hand, it is also effective to fix the scintillator 21 and move only the target T or the source side to obtain a composite image for each moving position of the target T.

Further, as shown in FIG. 5, it is also effective to move both the scintillator 21 and the target T with respect to the steel pipe S along the longitudinal direction L of the pipe in mutually opposite directions. For example, the scintillator 21 is moved to the right from the position of FIG. 5 within the range of the reference symbol A3, while the target T is moved to the left from the position of the reference symbol T1 to the position of the reference symbol T2. While the target T moves from the code T1 to the code T2, the direction of the X-ray passing through the crack D is
There will be a large swing from to X2. As a result, the probability of including the case where the crack D and the X-ray X are in the same direction in the imaging range is high, and there is an advantage that a very sharp image of the crack D can be easily obtained.

Next, the possibility of another embodiment of the present invention will be described. In the above embodiment, the CCD element 2
Although a Peltier element was used as the cooling device of No. 4, it is also possible to use a cooling device using liquid nitrogen or the like. However, it is desirable to use a Peltier device because of its ease of handling and stability of characteristics.

Although X-rays are used as the radiation generator 2 in the above embodiment, it is possible to use a radiation source and radiation means other than these depending on the nature of the test body. Further, an image intensifier tube may be interposed between the scintillator 21 and the CCD element 24.

In the above embodiment, the steel pipe was used as the test body, but it is of course possible to carry out the present invention on a test body other than steel, a flat plate or the like. Further, the relative movement direction between the radiation generator 2 and the camera body 20 is not limited to the longitudinal direction L direction of the tube, but may be the circumferential direction along the central axis of the tube.

[0028]

As described above, according to the features of the radiation transmission test apparatus according to the present invention, by combining a large number of images of a test body with transmitted radiation in a state where quantum noise is reduced, It has become possible to obtain electronic composite images with extremely high resolution. As a result, a more precise radiation transmission test has become possible.

Further, by moving the radiation source along the surface of the test body, and particularly by moving both the camera body and the radiation source in the opposite directions, the direction of the crack or the like and It became easier to match the direction of radiation such as X-rays that penetrate the cracks and reach the scintillator. Then, it becomes possible to obtain a clearer image of a crack or the like, and it is possible to further improve the accuracy of the radiation transmission test.

The reference numerals in the claims are merely for convenience of comparison with the drawings, and the present invention is not limited to the configurations of the accompanying drawings by the reference. .

[Brief description of drawings]

FIG. 1 is a side view showing a state in which a radiation transmission test apparatus according to the present invention is attached to a steel pipe as a test body.

FIG. 2 is a logical block diagram of a radiation transmission test apparatus.

FIG. 3 is a vertical sectional view of a camera body.

FIG. 4 is an explanatory diagram showing a relationship between a scintillator, a welded portion of a steel pipe, and a radiation source.

FIG. 5 is a view corresponding to FIG. 4 according to the second embodiment.

[Explanation of symbols]

 1 Radiation Transmission Test Device 2 Radiation Generation Device (Radiation Source) 2a High Voltage Transformer 2b Filament 2c Switching Circuit 3 Imaging Device 4 Relative Moving Means 11 Fixed Clamp 12 Rotating Clamps 11a, 12a Hinge 12b Bridges 14a, 14b First Slide Shaft 15a , 15b First guide member 16a, 16b Second slide shaft 17a, 17b Second guide member 20 Camera body 21 Scintillator 22 Mirror 22a Support stand 23 Lens 24 CCD element 25 Peltier element (cooling device) 26 Cooling fin 27 Blower 28 Interface 29 Controller 30 Shutter motor 31 Shutter 32a Cooler 32b Suction machine 33 Case body 33a Lead shield plate 33b Suction port 33c Discharge port 34 Camera module 34a C D partition 34b Circuit board 35 Partition plate 35a Opening 35b Lead glass 36a, b Guide 37 Slider 38a Adjustment shaft 38b Adjustment knob 38c Pinion gear 39 Roller 41, 42 First and second motor 43 Motor driver 60 Personal computer 61a-c First ~ Third A / D converter 62 Image storage means 63 Image processing means 64 Coordinate control section 65 Operating means 66 Video circuit 67 CRT monitor 68 Printer L Longitudinal direction of tube S Specimen Sw Weld zone D Crack T Target A Scintillator movement range

Front page continuation (72) Inventor Takuichi Imanaka 1-18-14 Kitahorie, Nishi-ku, Osaka City Nondestructive Inspection Co., Ltd.

Claims (6)

[Claims] 1. A radiation transmission test comprising a radiation source (2, T) and an imaging device (3) located on the opposite side of the radiation source (2, T) with a specimen (S) interposed therebetween. A scintillator (21) on the imaging device (3),
CCD for picking up an image by this scintillator (21)
A camera body (20) having an element (24) and a cooling device (25) for cooling the CCD element (24), a test body (S) including the camera body (20) and the radiation source (2, T). Relative moving means (4) for relatively moving a minute distance along the surface of the device, and image storage for storing the image taken by the CCD element (24) at each moving position by the relative moving means (4). A radiation transmission test apparatus provided with means (62) and image processing means (63) for synthesizing the images stored by the image storage means (62). 2. The radiation transmission test apparatus according to claim 1, wherein the relative moving means (4) moves the camera body (20) along the surface of the test body (S). 3. The radiation according to claim 1, wherein the relative moving means (4) moves the radiation source (2, T) along the surface of the test body (S). Transmission test equipment. 4. The relative moving means (4) moves both the camera body (20) and the radiation source (2, T) in opposite directions along the surface of the test body (S). The radiation transmission test apparatus according to claim 1. 5. The test body is a pipe (S) having a welded portion (Sw), and the relative moving means (4) connects the camera body (20) or the radiation source (2, T) to the pipe. The radiation transmission test apparatus according to any one of claims 1 to 4, which is moved along the longitudinal direction. 6. The radiation transmission test apparatus according to claim 1, wherein the cooling device (25) is a Peltier element.