Radiation source fixing device for weld inspection

Abstract

The utility model relates to the field of weld ray detection, disclose a kind of weld detection is with the fixed device of radioactive source, the fixed device includes base and the support rod for installing the source guide tube of gamma-ray source connected on base, the base includes a adjustable level base plane, the support rod includes upper support rod and lower support rod, lower support rod is slidable connection relative to base, upper support rod is slidable fixed connection relative to lower support rod, the sliding direction of lower support rod, upper support rod is always perpendicular to the base plane, upper support rod is used as source guide tube support for fixing source guide tube parallel to the base plane. When using, first level base plane can be adjusted outside container and according to the radial pre-positioning of container inner diameter to fixed device, axial positioning is completed inside container, the fixation of source guide tube is reliable, positioning accuracy is high, and it is convenient to operate, more safe, easily guarantee detection quality.

Description

Technical Field

[0001] This utility model relates to the field of weld radiographic inspection, and in particular to a gamma-ray source detection device for inspecting circumferential welds of containers. Background Technology

[0002] Because of its advantages such as small size, strong penetrating power, high detection efficiency, and the ability to perform central illumination of circumferential welds in containers, allowing for the inspection of the entire weld in a single illumination, gamma-ray detection is widely used in the radiographic inspection of circumferential welds in containers. When performing a single-stage radiographic inspection of a container's circumferential weld, to ensure uniform exposure across the entire weld, the distance from the focal point of the gamma-ray source to every point on the weld should be equal. Therefore, the gamma-ray source needs to be fixed at the exact center of the circumferential weld, placing it at the center of the weld circle.

[0003] Currently, gamma-ray sources are typically fixed using straight-rod brackets, such as the structure shown in CN109975333A. The conduit used to fix the gamma-ray source is attached to the bracket. The conduit's position is determined by measuring inside the container with a tape measure, and then secured to the bracket with ropes based on the measurement results. The installation and fixation of both the bracket and the conduit are not stable enough. The impact force generated during the delivery of the gamma-ray source can cause the bracket to collapse, twisting the conduit, and in severe cases, even causing the source to become stuck. With existing straight-rod brackets, after entering the container, the straight rod fixing the source conduit always passes through the center of the circumferential weld, causing the source conduit tied to the rod to either deviate to the left or right, never reaching the center. To fix the gamma-ray source in the center of the circumferential weld, it is necessary to measure the distance from the source head to the weld with a tape measure while adjusting the position of the source head repeatedly. Even after wrapping the source head with tape, the center point of the circumferential weld can only be approximated. This requires repeated adjustments, is inefficient, and the obtained position is inaccurate. Furthermore, all of the above steps require operators to enter the container before they can be repeated. Some containers have small inner diameters and even smaller inlets and outlets, which not only makes operation inconvenient but also poses significant safety hazards.

[0004] Chinese utility model patents with announcement numbers CN209841735U and CN210800447U also disclose a radiation source positioning device for centrally irradiating the circumferential weld of a pipe, which also requires measurement and adjustment inside the container.

[0005] If the X-ray source is not precisely placed on the center line of the circumferential weld, it can easily lead to uneven X-ray transmission along the entire weld, resulting in significant differences in the film density. If the density difference exceeds the standard range and fails to meet the evaluation requirements, the X-ray source position needs to be readjusted and the X-ray inspection repeated. This not only consumes a lot of manpower and resources but also affects the production schedule in the workshop. Therefore, it is necessary to design a conveniently adjustable and reliably fixed X-ray source fixing device for weld inspection. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a gamma-ray source fixing device for weld inspection, which can conveniently and reliably fix the gamma-ray source to the required position relative to the circumferential weld of the container.

[0007] The technical solution adopted by this utility model to solve its technical problem is: a gamma-ray source fixing device for weld inspection, including a base and a support rod connected to the base for installing a source guide tube of a gamma-ray source. The base includes an adjustable horizontal base plane, and the support rod includes an upper support rod and a lower support rod. The lower support rod is slidably connected to the base, and the upper support rod is slidably fixedly connected to the lower support rod. The sliding direction of both the lower and upper support rods is always perpendicular to the base plane. The upper support rod serves as a source guide tube support to fix the source guide tube parallel to the base plane. In application, the position of the upper support rod relative to the base can be adjusted outside the container according to the container's inner diameter to determine the height of the source guide tube's centerline relative to the plane of the support base, thus pre-adjusting the source guide tube's position. After the device is moved into the container, the source position is then determined to coincide as closely as possible with the center position of the container's circumferential weld, making operation more convenient and easier. This will be described in detail later.

[0008] An angle adjustment disc is mounted on the upper support rod parallel to the base plane. The angle adjustment disc has an arc groove. A horizontally adjustable support rod is fixed to the top of the upper support rod by two positioning screws located within and at the center of the arc groove. This horizontally adjustable support rod serves as a source conduit support. The fixed position of the horizontally adjustable support rod on the angle adjustment disc can be changed as needed; that is, the horizontally adjustable support rod can be swung and fixed on the support surface of the angle adjustment disc to position the source at the center line of the circumferential weld on the container.

[0009] An adjustment rod mounting bracket is fixedly installed on the top of the upper support rod. The angle adjustment disc and the horizontally adjustable support rod are both connected to the adjustment rod mounting bracket, making it easy to fix the angle adjustment disc and the horizontally adjustable support rod.

[0010] The base is equipped with a retractable level relative to the base. The retraction direction of the level is perpendicular to the lower support rod and is used for internal visual observation and adjustment of the relative position of the weld and the source.

[0011] The upper and lower support rods are made of rectangular cross-section profiles of the same specifications. One side of the upper and lower support rods is flush with each other. The two sides adjacent to this side are provided with fixing plates and corresponding adjusting nuts. The fixing plates and adjusting nuts serve as connecting parts for the upper and lower support rods. The use of profiles facilitates manufacturing and reduces costs.

[0012] Each of the upper and lower support rods is provided with a handle, which is located on the side opposite to the side, so as to facilitate the adjustment of the height position of the top of the upper support rod, thereby pre-adjusting the position of the source conduit.

[0013] The base is provided with four adjustable feet that are retractable relative to the base plane. The four adjustable feet are distributed at the four corners of a rectangle. This distribution of adjustable feet can stably support the device on the cylindrical surface of the inner wall of the container. Furthermore, based on the stability of the support, it can be determined whether the upper support rod perpendicular to the base plane is approximately located in the radial direction of the container's cross-section.

[0014] A support base is fixedly installed on the base. The support base is provided with a support groove that matches the contour of the lower support rod. The axis of the support groove is coaxial with the axis of the lower support rod. The support groove has a sliding guide surface for the lower support rod, thereby making the positioning of the upper support rod and the source conduit more accurate.

[0015] The beneficial effects of this utility model are: by adjusting the upper and lower support rods, the device can be adapted to X-ray inspection of cylinders with different diameters, the source guide tube is reliably fixed, the positioning accuracy is greatly improved, and the operation is convenient, greatly reducing the time that personnel spend operating inside the container, which can improve the efficiency of X-ray inspection of circumferential seams, and is safer, thereby improving the success rate of X-ray inspection on the first take, with good stability and result reproducibility, and a high defect detection rate. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the X-ray source fixing device for weld inspection according to this utility model.

[0017] Figure 2 This is a schematic diagram showing how the upper support rod slides to different positions for fixing.

[0018] Figure 3 This is a schematic diagram of the gamma-ray source fixing device of this utility model, which is made of profiles.

[0019] Figure 4 This is a schematic diagram illustrating the principle that the fixing device of this utility model can be pre-adjusted outside the container.

[0020] The markings in the diagram are as follows: 1-base, 2-lower support rod, 3-upper support rod, 4-source conduit, 5-level, 6-handle, 7-fixing plate, 8-adjusting nut, 9-container, 10-base plane, 11-base adjusting foot, 12-support seat, 13-positioning screw, 14-conduit clamp, 30-adjusting rod mounting bracket, 31-angle adjusting disc, 32-horizontally adjustable support rod, 100-ground, 120-support groove, 310-arc groove, r-container inner diameter, d-container wall thickness, δ-height difference between the lower end of the base and the lower end of the lower support rod. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] like Figure 1 and Figure 2 As shown, the X-ray source fixing device for weld inspection of this utility model includes a base 1 and a support rod connected to the base 1 for mounting a source conduit 4 of a gamma-ray source. The base 1 includes an adjustable horizontal base plane 10, and the base 1 is supported by four adjustable base legs 11 that are retractable relative to the base plane 10. The four adjustable base legs 11 are distributed at the four corners of a rectangle. Since the inner wall of the container has a cylindrical structure, the four-point support can achieve a stable state. The support rod includes an upper support rod 3 and a lower support rod 2. The lower support rod 2 is slidably connected to the base 1, and the upper support rod 3 is slidably fixedly connected to the lower support rod 2. The sliding direction of the lower support rod 2 and the upper support rod 3 is always perpendicular to the base plane 10. The upper support rod 3 serves as a source conduit support to fix the source conduit 4 parallel to the base plane 10.

[0023] refer to Figure 4 In use, the fixing device is first placed on the ground 100 outside the container 9. The four base adjustment feet 11 on the base are adjusted to level it. The base 1 and the lower support rod 2 are both fixed by the ground 100. After calculating the required support height according to the inner diameter of the container, the position of the upper support rod 3 is pre-adjusted on the ground and fixed so that the height of the axis of the source conduit 4 from the ground is equal to the inner diameter r of the container. Because the lower support rod 2 is slidable relative to the base 1, when the entire fixing device is placed inside the container 9, since the inner wall of the container is concave, when the base 1 is supported by the inner wall of the container, the center of the base 1 is suspended. Under its own weight, the bottom of the lower support rod 2 will automatically slide down to contact the inner wall of the container, automatically compensating for the height difference δ between the fixed position of the source conduit 4 and the container axis caused by the base support point being higher than the lower support rod support point. After entering the container, there is no need to adjust the height position of the source conduit 4, and it does not affect the weld inspection effect. Therefore, this device can be pre-adjusted outside the container, and only one person needs to enter the container for verification, which is convenient for use. Scale lines can also be drawn on the lower and upper support rods, and pre-adjusted according to the inner diameter of the container and the scale lines, so that the fixed position of the source conduit 4 is approximately equal to the height of the container's inner diameter from the ground.

[0024] Specifically, the four adjustable feet 11 are height-adjustable screw supports, similar in structure to the adjustable feet of a household washing machine. Since the ground or the inner wall of the container is not perfectly flat, the entire device may tilt during source alignment, altering the established center position. The device can be leveled by adjusting the four adjustable feet 11, ensuring the source conduit is parallel to the axis of the workpiece's circumferential weld.

[0025] like Figure 1 As shown, an angle adjustment disc 31 is provided on the upper support rod 3 parallel to the base plane 10. The angle adjustment disc 31 is provided with an arc groove 310. A horizontally adjustable support rod 32 is connected by two positioning screws 13. Figure 1 , Figure 2 A positioning screw (not shown) is fixed at the top of the upper support rod 3. One positioning screw 13 is located inside the arc groove 310, and another positioning screw is located at the center of the arc groove 310. The horizontally adjustable support rod 32 serves as a source conduit support. The position of the horizontally adjustable support rod 32 can be adjusted by adjusting the positioning screw on the angle adjustment disc 31, thereby causing the source position to swing left and right, achieving fine-tuning of the source position to correct errors and make the source conduit as coaxial as possible with the container.

[0026] An adjusting rod mounting bracket 30 is fixedly installed on the top of the upper support rod 3. The angle adjusting disc 31 and the horizontally adjustable support rod 32 are both connected to the adjusting rod mounting bracket 30. The adjusting rod mounting bracket 30 is used to make up for the inconvenience of fixing the small end face of the upper support rod 3.

[0027] The front end of the source tube 4 must extend beyond the front end face of the base to avoid affecting the detection due to the base 1. The base 1 is equipped with a retractable horizontal ruler 5. The retraction direction of the horizontal ruler 5 is perpendicular to the lower support rod 2. The horizontal ruler 5 can measure horizontal distances. Outside the container, the distance between a reference point on the base and the front end of the source tube can be easily measured in the retraction direction of the horizontal ruler. Then, inside the container, the distance between the reference point of the base and the circumferential weld is measured using the horizontal ruler 5. In the axial direction, the γ-ray source is positioned as close as possible to the center of the circumferential weld, avoiding the inconvenience of only being able to visually observe the relative position of the front end of the source tube and the circumferential weld at the center of the container, which may require repeated adjustments to achieve alignment.

[0028] A support base 12 is fixedly installed on the base 1. The support base 12 is provided with a support groove 120 that matches the contour of the lower support rod 2. The axis of the support groove 120 is coaxial with the axis of the lower support rod 2. The support groove 120 can keep the axial position of the lower support rod 2 basically unchanged in the up-and-down sliding state, thereby greatly reducing the position error of the lower end of the lower support rod 2 caused by sliding and ensuring the positioning accuracy of the γ-ray source.

[0029] The fixing device of this invention can accurately place the X-ray source at the exact center of the circumferential seam. Adjustment via upper and lower support rods allows the device to be used for X-ray inspection of cylinders of different diameters, as well as for longitudinal seams of cylinders and weld seams on large workpieces. This device is convenient for X-ray inspection, especially suitable for situations where the internal space of a container is narrow and two people cannot operate simultaneously. It significantly reduces the rate of radiographic failures caused by inaccurate focus adjustment. This device offers high inspection efficiency, good stability, and excellent image quality.

[0030] Example:

[0031] refer to Figure 1 and Figure 2 ,like Figure 3 As shown, the X-ray source fixing device for weld inspection with the above-described structure has an upper support rod 3 and a lower support rod 2 made of rectangular cross-section profiles of the same specifications. One side of the upper support rod 3 and the lower support rod 2 are flush with each other. A fixing plate 7 and a corresponding adjusting nut 8 are provided on the two sides adjacent to this side. The fixing plate 7 and the adjusting nut 8 serve as connecting parts for the upper support rod 3 and the lower support rod 2. Loosening the adjusting nut 8 allows adjustment of the position of the upper support rod 3. Scale lines are also provided on the easily observable sides of the upper support rod 3 and the lower support rod 2.

[0032] Each of the upper support rod 3 and the lower support rod 2 is provided with a handle 6, which is located on the side opposite to the side to facilitate adjustment and fixation of the position of the upper support rod 3 relative to the lower support rod 2.

[0033] In addition, refer to Figure 3 Furthermore, a conduit clamp that is easy to open and close can be installed on the horizontally adjustable support rod 32 of the upper support rod 3 to facilitate the fixation of the source conduit 4.

[0034] The steps for using the device in this embodiment before inspecting circumferential welds are as follows:

[0035] 1) Place the device on a flat ground 100 and adjust the four base adjustment feet 11 on the base 1 to level it;

[0036] 2) Based on the inner wall radius r of container 9, adjust the upper support rod 3 relative to the lower support rod 2 to an appropriate height according to the scale line, and fix it; the appropriate height is that the distance between the lower end of the lower support rod 2 and the theoretical fixed position of the source conduit 4 on the upper support rod 3 is equal to the inner wall radius r of container 9.

[0037] 3) Place the device into the cylinder of container 9 with the front facing forward, that is, make the position of the source to be fixed tend to approach the position of the circumferential weld. Confirm the flatness again and ensure that the bottom surfaces of the four base adjustment feet 11 of the base 1 and the bottom support rod 2 are in full contact with the inner wall of the container.

[0038] 4) Use the conduit clamp to fix the source conduit 4 to the horizontally adjustable support rod 32, and use a tape measure to finally confirm that the source is located at the center of the circumferential weld on the container 9;

[0039] 5) Use level 5 to confirm the horizontal distance between the base reference point and the circumferential weld position. After measurement, retract level 5 and prepare for weld inspection.

[0040] Obviously, the order of steps 4) and 5) above can be reversed. In most cases, after the above five steps, the front end of the source conduit can be fixed in the accurate position without much further adjustment. If the source still needs fine-tuning at this time, the position of the horizontally adjustable support rod 32 can be adjusted by the angle adjustment disc 31 on the upper support rod 3. If necessary, the lifting height of the upper support rod 3 can be adjusted.

[0041] Those skilled in the art should understand that the aforementioned base reference point is only used to facilitate adjustment and observation when the source and the center of the circumferential weld are aligned as much as possible. It can be determined during use, as long as no other selection is made during the same use. Any of the above adjustment and positioning steps will inevitably have appropriate deviations, as long as they do not affect the subsequent weld inspection results.

Claims

1. A gamma-ray source fixing device for weld inspection, comprising a base (1) and a support rod connected to the base (1) for mounting a gamma-ray source conduit (4), characterized in that: The base (1) includes an adjustable horizontal base plane (10), and the support rod includes an upper support rod (3) and a lower support rod (2). The lower support rod (2) is slidably connected to the base (1), and the upper support rod (3) is slidably fixedly connected to the lower support rod (2). The sliding directions of the lower support rod (2) and the upper support rod (3) are always perpendicular to the base plane (10). The upper support rod (3) serves as a source conduit support to fix the source conduit (4) parallel to the base plane (10).

2. The X-ray source fixing device for weld inspection as described in claim 1, characterized in that: An angle adjustment disc (31) is provided on the upper support rod (3) parallel to the base plane (10). An arc groove (310) is provided on the angle adjustment disc (31). A horizontally adjustable support rod (32) is fixed to the top of the upper support rod (3) by two positioning screws respectively located in the arc groove (310) and at the center of the arc groove (310). The horizontally adjustable support rod (32) is used as a source conduit support.

3. The X-ray source fixing device for weld inspection as described in claim 2, characterized in that: An adjustment rod mounting bracket (30) is fixedly installed on the top of the upper support rod (3), and the angle adjustment disc (31) and the horizontally adjustable support rod (32) are both connected to the adjustment rod mounting bracket (30).

4. The X-ray source fixing device for weld inspection as described in claim 2, characterized in that: The base (1) is provided with a retractable horizontal ruler (5) relative to the base (1), and the retraction direction of the horizontal ruler (5) is perpendicular to the lower support rod (2).

5. The X-ray source fixing device for weld inspection as described in claim 2, characterized in that: The upper support rod (3) and the lower support rod (2) are made of rectangular cross-section profiles of the same specifications. One side of the upper support rod (3) and the lower support rod (2) are flush with each other. The two sides adjacent to this side are provided with fixing plates (7) and corresponding adjusting nuts (8). The fixing plates (7) and adjusting nuts (8) serve as connecting parts for the upper support rod (3) and the lower support rod (2).

6. The X-ray source fixing device for weld inspection as described in claim 5, characterized in that: Each of the upper support rod (3) and the lower support rod (2) is provided with a handle (6), and the handle (6) is located on the side opposite to the side.

7. The X-ray source fixing device for weld inspection as described in claim 1, characterized in that: The base (1) is provided with four retractable base adjustment feet (11) relative to the base plane (10), and the four base adjustment feet (11) are distributed at the four corners of a rectangle.

8. The X-ray source fixing device for weld inspection as described in any one of claims 1 to 7, characterized in that: A support seat (12) is fixedly installed on the base (1). The support seat (12) is provided with a support groove (120) that matches the contour of the lower support rod (2). The axis of the support groove (120) is coaxial with the axis of the lower support rod (2).

Images