KR100442325B1 - A centering device for radiography - Google Patents

Abstract

The present invention is to produce a stand used for the panoramic exposure in the radiographic inspection of the pipe welds with a spring and a lever, such that the installation and entry in the pipe is easy, as well as the radiation source is always in the center of the circumferential weld By placing it perpendicular to the pipe axis and making it parallel to the pipe axis, the distance between the film and the radiation source attached to the outside of the pipe is made constant so that the density of the radiograph obtained in the simultaneous shooting is the same. The present invention relates to a radiographic centering device capable of improving image quality of a radiograph by preventing distortion of an image.

The present invention provides support means for providing a movement path of the radiation source is located in the center of the internal defect identification object; A fixing ring fitted to and fixed to an outer circumferential surface of the distal end portion of the support means; A position adjusting means inserted into and fixed to a rear end side outer circumferential surface of the support means and sliding forward and rearward along its outer circumferential surface; Sliding means provided on an outer circumferential surface of the supporting means between the fixing ring and the position adjusting means and positioned at a predetermined interval; One side is rotatably fixed to the position adjusting means, the other side is rotatably fixed to one of the sliding means, the first lever having a rolling wheel in contact with the inner circumferential surface of the object to be identified at its intersection; One side is rotatably fixed to the other of the sliding means, the other side is rotatably fixed to the fixing ring, the second lever provided with a cloud wheel in contact with the inner circumferential surface of the object to be identified at its intersection; And one side is fixed to one of the sliding means, the other side is supported by the other of the sliding means provides a centering device for radiographic inspection comprising a movement limiting means for limiting the movement of the sliding means.

Description

Centering device for radiography {A centering device for radiography}

The present invention relates to a radiographic inspection apparatus for identifying an internal defect of a pipe welded portion, wherein the radiation source can be positioned at the inner center of the piped welded portion so as to simultaneously photograph the entire circumferential welded portion with a single exposure. In particular, it is possible to improve the quality of radiographic images by maintaining a constant distance between the radiation source and the film without a separate measuring tool by replacing the stand that rests the radiation source for a predetermined time at a designated position with a spring and a lever. The present invention relates to a centering device for radiographic examination.

In general, the radiographic examination apparatus, as shown in Figure 1, and the test body (2); A radiation source (1) for generating radiation at a predetermined distance from the test body (2); It consists of the film 3 which adheres to the lower part of the said test body 2, and is exposed by radiation.

In the conventional radiographic inspection apparatus as described above, the radiation emitted from the radiation source 1 is transmitted through the test body 2 for a predetermined time, and the film 3 is prevented by the radiation passing through the test body 2. The photosensitive and photosensitive film is deodorized from the test body (2) to obtain a radiographic image through development in the dark room, through which the defects present in the test body (2) are identified.

On the other hand, the apparatus for identifying the defect of the pipe welding portion, as shown in Figure 3, the source container 6 for storing the radiation source (1); A remote controller (4) mounted to the rear of the source container (6) and having a handle (5); A source guide tube 8 mounted in front of the source container 6 and drawn into the pipe 7; A source stopper 12 coupled to the distal end of the source guide tube 8; It consists of a stand 9 which temporarily fixes the source guide tube 8 in the state where the said source stop 12 was located in the center of the piping 7. As shown in FIG.

In the above-described configuration, the radiation source 1 stored in the source vessel 6 is moved to the source stop 12 along the source guide tube 8 by turning the handle 5 of the remote controller 4. The radiation source 1 is irradiated with radiation from the center of the pipe 7, and after the predetermined shooting time has elapsed, turn the handle 5 in the opposite direction to safely return the radiation source 1 to the source vessel 6. will be.

In the process of obtaining radiographic images as described above, the radiographic concentration, which is an important factor that determines the quality of radiographic images, is determined by the radiation intensity ( I ) and developing conditions reaching the film. when the radiation intensity (I) is and the more when the distance (D) away inversely proportional to the square of the distance (D), this relationship is represented by the formula in Figure 2 and following.

here : Street Radiation Intensity at

: Street Radiation Intensity at

In the conventional radiographic examination associated with such a formula, as shown in FIG. 3 and the above formula, the distance between the radiation source 1 and the film 10 is a factor that can be changed depending on the stationary method of the radiation source 1. In this case, the radiographic concentration varies depending on the site by the change of this factor ( D ). If the radiographic concentration exceeds the limit of the standard, the photograph itself is treated as a defect before the defect identification.

In the conventional radiographic inspection apparatus, since the height of the stand 9 is adjusted by using a tape measure capable of measuring a distance or by eye contact, the source stop region 12 is positioned at the center of the pipe welding portion 11, Before measuring the radiographic concentration, it is difficult to know whether each film 10 taken at the same time maintains exactly the same distance D from the radiation source 1, and the difficulty and economic loss of work that requires re-photography if the positioning fails. There is a problem of wearing.

In addition, in the process of leaving the source stop 12 coupled to the stand 9 at the center of the welding part 11, when the welding part 11 is far from the opening of the pipe 7, the center of the welding part is separated. In the case of the pipe 7 having a diameter that is difficult to position the source stop zone in the human being and carrying these devices, panorama shooting is not possible. In order to overcome this disadvantage, the radiation source 1 is located on one side of the outside of the pipe 7 and the film 10 is adhered to the other side of the outside of the pipe 7, but the film is photographed several times. As the time is increased by several orders of magnitude, there is a problem of increasing the radiation exposure of workers as well as the economic burden.

Accordingly, the present invention has been made to solve the above problems, and always maintains the same distance between the radiation source and the film without a separate measuring tool, so that the central axis of the source source and the pipe can be parallel. Its purpose is to provide a centering device for radiography.

In addition, another object of the present invention is to provide a centering device for radiographic inspection that facilitates stationary work of the source stop district regardless of the size of the pipe, and can significantly reduce the working time.

1 is a schematic diagram showing a photographic arrangement of a general radiographic examination.

2 is a basic conceptual diagram of the radiation intensity according to the distance change.

Figure 3 is a state diagram for the panorama photographing of the conventional pipe welding portion.

4 is a partial cross-sectional configuration of the present invention.

5 is a layout view of panorama photography using the present invention.

Explanation of symbols on the main parts of the drawings

1 ... radiation source 2 ... test specimen

3,10 ... film 4 ... remote control

5 ... handle 6 ... sailor vessel

7. Piping 8 ... Sailor Guide Tube

9 ... stand 11 ... weld

12 ... Seawon District 13 ... Centering Device

14 ... Coupling 15 ... Support Tube

16 ... adjusting ring 17, 17 '... first and second sliding ring

18 ... spring 19 ... connecting plate

20 ... retaining ring 21, 21 '... 1st and 2nd lever

22 ... wheels 23 ... pin

24 ... fixing groove

In order to achieve the above object, the present invention, the support means for providing a movement path of the radiation source is located in the center of the internal defect identification object; A fixing ring fitted to and fixed to an outer circumferential surface of the distal end portion of the support means; A position adjusting means inserted into and fixed to a rear end side outer circumferential surface of the support means and sliding forward and rearward along its outer circumferential surface; Sliding means provided on an outer circumferential surface of the supporting means between the fixing ring and the position adjusting means and positioned at a predetermined interval; One side is rotatably fixed to the position adjusting means, the other side is rotatably fixed to one of the sliding means, the first lever having a cloud wheel in contact with the inner circumferential surface of the object to be identified at its intersection; One side is rotatably fixed to the other of the sliding means, the other side is rotatably fixed to the fixing ring, the second lever provided with a cloud wheel in contact with the inner circumferential surface of the object to be identified at its intersection; And one side is fixed to one of the sliding means, the other side is supported by the other of the sliding means provides a centering device for radiographic inspection comprising a movement limiting means for limiting the movement of the sliding means.

In addition, the present invention further includes a spring force providing means that is inserted into the support means between the sliding means to provide a spring force to provide the same force to the contact of the rolling wheel.

By the above configuration, the radiation source and the pipe central axis are kept parallel, and the radiation source is left at the center of the circumferential weld of the pipe. The radiation irradiated from the radiation source reached to reliably penetrates the weld to record the two-dimensional image in the thickness direction on the film.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 4 and 5.

The centering device for radiographic examination according to the present invention enables the radiation source to be accurately positioned at the center position of the internal defect identification object without a separate measuring tool, and at the same time, reliably maintains the distance from the film. Regardless of the aperture, the radiation source 1 can be easily fixed and extracted, and FIG. 4 is a partial cross-sectional view showing an embodiment of a centering device according to the present invention, and FIG. 5 shows the centering device of the present invention. A panoramic photographing layout of a radiographic inspection apparatus for identifying internal defects in pipe welds. In this embodiment, the same reference numerals are given to the same components mentioned in the prior art.

The centering device 13 according to the present invention is located at the center point of the pipe 7 to provide a movement path of the radiation source 1, and a fixed groove 24 is formed at predetermined intervals in the axial direction on a predetermined section of the outer peripheral surface thereof. A support tube 15; A coupling 14 fitted to an outer circumferential surface of one side end of the support tube 15 to couple it to the source guide tube 8; A fixing ring 20 inserted into and fixed to an outer circumferential surface of the other end of the support tube 15; An adjustment ring 16 fitted to an outer circumferential surface of the support tube 15 on one side of the coupling 14 to move forward and backward along the outer circumferential surface of the support tube 15; A fixing pin (23) penetrating the adjustment ring (16) and inserted into the fixing groove (23) of the support tube (15) to fix the position of the adjustment ring (16); First and second sliding rings (17, 17 ') disposed on an outer circumferential surface of the support tube (15) between the adjustment ring (16) and the fixing ring (20) and positioned at predetermined intervals; One side is rotatably fixed to the adjustment ring 16, the other side is rotatably fixed to the first sliding ring 17, to facilitate the position adjustment by rolling contact with the inner peripheral surface of the pipe at the intersection portion A first lever 21 provided with a rolling wheel 22; One side is rotatably fixed to the second sliding ring 17 ', the other side is rotatably fixed to the fixing ring 20, and the rolling wheel 22' contacting the inner circumferential surface of the pipe at the intersection thereof A second lever 21 'provided; One side is fixed to the first sliding ring 17, and the other side is formed so that the long hole penetrates in the axial direction, and is supported through a fixing pin fixed to the second sliding ring 17 'through the long hole. Connecting plate 19; It is composed of a spring 18 that is fitted to the support tube 15 between the first and second sliding rings 17 and 17 'to provide a spring force to provide the same force to the contact point of the rolling wheel.

Here, the source stop 12 is separated from the source guide tube (8) is fitted to the front end of the support tube (15).

In this embodiment, the first and second levers 21 and 21 'are spaced 120 degrees apart from the outer circumferential surfaces of the adjustment ring 16, the first and second sliding rings 17 and 17' and the fixed ring 20. The rolling wheels are also positioned at intervals of 120 °, and thus the inner circumferential surface of the pipe has six structures, each of which has three contacts. In addition, the connecting plate 19 is for setting the moving section so that the first sliding ring 17 is moved only within the long tool section when sliding.

Referring to the working state of the present invention configured as described above are as follows.

First, the adjustment ring 16 fitted to the outer circumferential surface of the support tube 15, the fixing ring 20, the first and second sliding rings 17, 17 'and their outer peripheral surface are arranged and connected at 120 ° intervals, respectively The centering device 13, which is composed of a combination of first and second levers 21, 21 ′, is positioned on the central axis of the pipe 7. Then, the source stops 12 attached to the source guide tube (8) is separated and coupled to the front end of the support tube (15) of the centering device 13, and is provided on the rear end of the support tube (15) Coupling the source guide tube (8) using a coupling (14).

Next, the source guide tube 8 is pushed into the pipe 7, the coupling 14 is held by one hand, and the adjustment ring 16 is pushed by the other hand while the appropriate guide is made through the spring 18. When the spring force is detected, the fixing pin 23 is inserted into the fixing groove 24 of the support tube 15 to fix the adjustment ring 16 and the source fixing tool 12 is welded to the pipe 7. Move until you reach (11).

At this time, when the diameter of the pipe 7 is small and a person cannot access the inside of the pipe 7, the soft tape measure is tied to the source fixing tool 12, and the centering device 13 is pushed by a rod from the outside to the designated position. Move it. Then, the handle 5 of the remote manipulator 4 is turned to safely advance the radiation source 1 stored in the source container 6 to the source fixture 12.

At this time, when the geometry of the centering device 13, that is, the adjustment ring 16 is pushed in the axial direction of the support tube 15, the linkage-type first lever 21 is retracted and provided at the intersection thereof. The rolling wheels come into contact with the inner circumferential surface of the pipe, and at the same time, the cylindrical radiation source 1 is parallel to the central axis of the pipe 7 by the action of the spring 18 so as to be located at the center of the circumferential weld 11. do.

In a state where the radiation source 1 is located at the center of the pipe 7 with the welding part 11 interposed therebetween, the radiation emitted from the radiation source 1 penetrates the welding part 11 and is attached to the outside of the pipe 7. The film 10 is exposed, and the defect present in the welded part 11 is identified through the photograph obtained by developing the film 10.

By the above structure, when the radiation generated from the radiation source 1 is irradiated to the welding portion 11, the distance between the radiation source 1 and the film 10 becomes constant, so that radiographic photographs having a constant concentration can be obtained. Since the center axes of the radiation source 1 and the pipe 7 are parallel to each other, image distortion can be reduced, and image quality of the radiograph can be improved.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be apparent to those who have knowledge.

As described above, according to the present invention, since the same force acts on the total contact points of each of the front and rear three by the integrated spring and the lever, the distance between the radiation source and the film is always maintained without a separate measuring tool, At the same time, it has the effect of obtaining a radiographic image of a constant concentration on the welded part.

In addition, the present invention is easy to fix the stationary station irrespective of the size of the pipe, the inspection time is reduced by reducing the shooting time, the radiation exposure of the worker is reduced, the source axis is parallel to the pipe axis, image distortion Prevent other effects of improving the quality of radiographs.

Claims (7)

Support means positioned in the center of the internal defect identification object and providing a movement path of the radiation source 1; A fixing ring fitted to and fixed to an outer circumferential surface of the distal end portion of the support means; A position adjusting means inserted into and fixed to a rear end side outer circumferential surface of the support means and sliding forward and rearward along its outer circumferential surface; Sliding means provided on an outer circumferential surface of the supporting means between the fixing ring and the position adjusting means and positioned at a predetermined interval; One side is rotatably fixed to the position adjusting means, the other side is rotatably fixed to one of the sliding means, the first wheel having a rolling wheel 22 in contact with the inner circumferential surface of the object to be identified at its intersection lever; One side is rotatably fixed to the other of the sliding means, the other side is rotatably fixed to the fixing ring, the second lever provided with a cloud wheel in contact with the inner circumferential surface of the object to be identified at its intersection; And One side is fixed to one of the sliding means, the other side is supported by the other of the sliding means movement limiting means for limiting the movement of the sliding means Centering device for radiographic examination comprising a. The method of claim 1, The centering device for radiographic inspection, wherein the internal defect identification object is a cylindrical pipe in which a weld is formed. The method according to claim 1 or 2, And a coupling for coupling a source guide tube inserted into an outer circumferential surface of one end of the support means to guide a source of radiation. The method according to claim 1 or 2, The support means has a fixed groove is formed at predetermined intervals in the axial direction in a predetermined section of the outer peripheral surface thereof, And a fixing pin inserted into the fixing groove through the adjusting means to fix the position of the adjusting ring. The method according to claim 1 or 2, The movement limiting means has one side fixed to one sliding means, the long hole is formed in the axial direction through the other side, it is supported through a fixing pin fixed to the other sliding means through the long hole Centering device for radiography consisting of connecting plates. The method according to claim 1 or 2, And a spring force providing means inserted into the support means between the sliding means to provide a spring force to provide the same force to the contact point of the rolling wheel. The method according to claim 1 or 2, And a centering device for radiography, wherein the first and second levers are arranged at equal intervals of 120 °.