阅读说明：本技术 一种小径管对接焊缝的检测装置及检测方法 (Detection device and detection method for butt weld of small-diameter pipe ) 是由 杨立晨 汤一炯 周玉山 周海波 于 2021-07-15 设计创作，主要内容包括：本发明公开了一种小径管对接焊缝的检测装置及检测方法,所述装置包括两个夹持杆和源固定部；每一夹持杆的第一端与源固定部活动连接,每一夹持杆的第二端与待检测的小径管连接；每一待检测的小径管设有待检区,待检区中远离源固定部的一侧设有曝光区,曝光区设有胶片；调整每一夹持杆的长度,以使源固定部的中心到待检测的小径管的中心之间的距离达到预设的检测焦距；源固定部用于向两个小径管的待检区发射检测射线；获取曝光后的胶片的图像并进行对比处理,得到检测结果。本检测装置及检测方法可以适用于不同规律分部的小径管对接焊缝与检测要求,且同时对两个小径管对接焊缝实施检测任务,大大提高了检测效率,并且可以保证每次检测的稳定性。(The invention discloses a detection device and a detection method for a butt weld of a small-diameter pipe, wherein the device comprises two clamping rods and a source fixing part; the first end of each clamping rod is movably connected with the source fixing part, and the second end of each clamping rod is connected with the small-diameter pipe to be detected; each small-diameter tube to be detected is provided with a to-be-detected area, one side, far away from the source fixing part, of the to-be-detected area is provided with an exposure area, and the exposure area is provided with a film; adjusting the length of each clamping rod to enable the distance between the center of the source fixing part and the center of the small-diameter pipe to be detected to reach a preset detection focal length; the source fixing part is used for emitting detection rays to the to-be-detected areas of the two small-diameter tubes; and acquiring an image of the exposed film and performing comparison processing to obtain a detection result. The detection device and the detection method can be suitable for the butt weld of the small-diameter pipes in different rule subsections and detection requirements, and simultaneously carry out detection tasks on the butt weld of the two small-diameter pipes, so that the detection efficiency is greatly improved, and the stability of detection at each time can be ensured.)

1. The utility model provides a detection apparatus for path pipe butt weld, is applicable to and detects the butt weld of two arbitrary path pipes in the pressure vessel, its characterized in that contains: two clamping rods (100) and a source fixing part (200); the first end of each clamping rod (100) is movably connected with the source fixing part (200), and the second end of each clamping rod (100) is connected with a small-diameter pipe to be detected;

each small-diameter tube to be detected is provided with a to-be-detected area, one side, far away from the source fixing part, of the to-be-detected area is provided with an exposure area, and the exposure area is provided with a film;

adjusting the length of each clamping rod (100) to enable the distance between the center of the source fixing part (200) and the center of the small-diameter pipe to be detected to reach a preset detection focal length;

the source fixing part (200) is used for emitting detection rays to the to-be-detected areas of the two small-diameter tubes;

and acquiring the exposed image of the film and carrying out comparison processing to obtain a detection result.

2. The apparatus for inspecting a butt weld of a small-diameter pipe according to claim 1, wherein each of the clamping rods (100) comprises: the clamping piece (104) is used for clamping the small-diameter pipe to be detected; and an adjusting rod (102) having one end connected to the clamping member (104) and the other end movably connected to the source fixing portion (200).

3. The device for detecting the butt weld of the small-diameter pipe as recited in claim 2, wherein the adjusting rod (102) is hollow and provided with internal threads;

each of the clamping bars (100) further comprises: a first screw (101) and a second screw (103);

one end of the first screw rod (101) is in threaded connection with the inner part of the second end of the adjusting rod (102), and the other end of the first screw rod is movably connected with the source fixing part (200);

one end of the second screw rod (103) is in threaded connection with the inner part of the first end of the adjusting rod (102), and the other end of the second screw rod is connected with the clamping piece (104);

and rotating the adjusting rod (102) to extend or shorten the first screw rod (101) or the second screw rod (103) so as to adjust the distance from the center of the source fixing part (200) to the center of the small-diameter pipe to be detected.

4. The apparatus for inspecting a butt weld of a small-diameter pipe according to claim 3, wherein the source fixing portion (200) includes: the source guide pipe (201), the source sleeve (202) and the hoop sleeve (203) are coaxially arranged;

the source sleeve (202) is sleeved on the outer part of the source guide pipe (201);

the collar sleeve (203) is sleeved on the outer part of the source sleeve (202);

the source sleeve (202) is used for fixing a radioactive source;

the interior of the source guide pipe (201) is hollow, and a radioactive source guide pipe penetrates through the source guide pipe (201) and is connected with the radioactive source;

the hoop sleeve (203) is used for being connected with the laser range finder through a connecting piece;

the detection rays emitted by the radioactive source are gamma rays, and the source sleeve (202) is adjusted to enable the gamma rays emitted by the radioactive source to be vertical to a connecting line between the areas to be detected of the two small-diameter tubes or deviate from the connecting line; the gamma rays expose the two films on the two small-diameter tubes to be detected at the same time to obtain two images;

the laser range finder is used for detecting the distance from the radioactive source to the to-be-detected areas of the two small-diameter tubes respectively to obtain two distance data, and the two distance data are calculated to obtain two geometric degrees of uncertainty;

and analyzing the image of each small-diameter pipe according to the geometric unsharpness of each small-diameter pipe to obtain the detection result of the butt weld of each small-diameter pipe.

5. The device for detecting the butt weld of the small-diameter pipe according to claim 4, wherein the connecting member is a distance meter clamp (204) which is arranged on the clamp sleeve (203), and the clamp sleeve (203) rotates around the center of the source guide pipe (201) to drive the laser distance meter to rotate.

6. The apparatus for detecting the butt weld of the small-diameter tube according to claim 5, wherein two first threaded rods (101) of the two clamping rods (100) are rotatably connected to the source casing (202) through a double semi-ring structure.

7. The device for detecting the butt weld of the small-diameter pipes as claimed in claim 2, wherein each clamping piece (104) is matched with the small-diameter pipes to be detected one by one; each clamping piece (104) is detachably arranged on the adjusting rod (102).

8. The method for inspecting a device for inspecting a butt weld of a small-diameter pipe according to any one of claims 1 to 7, comprising:

s1, fixing the laser range finder on a range finder hoop (204);

step S2, clamping two small-diameter tubes to be detected in the pressure container by using a clamping piece (104), marking the two small-diameter tubes as a first small-diameter tube and a second small-diameter tube, and arranging a film on an exposure area of each small-diameter tube;

step S3, adjusting the length of each clamping rod (100) to enable the distance between the center of the source fixing part (200) and the center of the small-diameter pipe to reach a preset detection focal length;

step S4, rotating a hoop sleeve (203), so that laser emitted by the laser range finder is over against the to-be-detected area of the small-diameter pipe, and obtaining the distance between the laser range finder and each to-be-detected area of the small-diameter pipe, and recording the distance as first distance data and second distance data;

s5, penetrating a radioactive source guide pipe through a source guide pipe (201), fixing a radioactive source on a source sleeve (202), and adjusting and fixing the source sleeve (202) to enable gamma rays emitted by the radioactive source to be perpendicular to a connecting line between the areas to be detected of the two small-diameter pipes or deviate from the connecting line;

step S6, starting the radioactive source, emitting the gamma rays towards the to-be-detected areas of the two small-diameter tubes, and exposing the two films on the two small-diameter tubes by the gamma rays to obtain two images which are recorded as a first image and a second image;

step S7, closing the radioactive source, and calculating a first geometric uncertainty and a second geometric uncertainty according to the first distance data and the second distance data; analyzing the first image according to the first geometric uncertainty to obtain a detection result of the butt weld of the first small-diameter pipe; analyzing the second image according to the second geometric unsharpness to obtain a detection result of the butt weld of the second small-diameter pipe;

and S8, replacing the two clamped small-diameter pipes, and repeating the steps S2-S7 until all the small-diameter pipes in the pressure container are detected.

9. The detection method of claim 8, further comprising: step S9, providing two detection devices of the butt-joint weld of the small-diameter pipes, and recording the detection devices as a first detection device and a second detection device, wherein the first detection device and the second detection device simultaneously detect three small-diameter pipes in the pressure container, and the three small-diameter pipes are recorded as a first small-diameter pipe, a second small-diameter pipe and a third small-diameter pipe; a first clamping rod in the first detection device clamps the first small-diameter pipe, a second clamping rod of the first detection device clamps the second small-diameter pipe, and a first clamping rod in the second detection device clamps the second small-diameter pipe; a second clamping rod clamps the third small-diameter pipe, and an included angle between two adjacent clamping rods in the first detection device and the second detection device is a detection angle;

and analyzing the detection angle to obtain the angle difference between two exposures of the second small-diameter pipe, and obtaining the detection results of the second small-diameter pipe at different angles.

10. The detection method of claim 9, further comprising: and adjusting an included angle between the two clamping rods of the first detection device and/or an included angle between the two clamping rods of the second detection device so as to adjust the detection angle.

Technical Field

The invention relates to the field of nondestructive testing, in particular to a device and a method for testing a butt weld of a small-diameter pipe.

Background

Standard NB/T47013.2-2015 bearing device nondestructive testing, section 2: the small-diameter tube is defined in the ray detection as a tube with the outer diameter D0 less than or equal to 100 mm. At present, the quality of the butt weld of the small-diameter pipe is widely inspected by adopting a ray detection technology in the field of nondestructive inspection. The annular welding joint is arranged by double-wall double-shadow transillumination, and the following two conditions are satisfied simultaneously: when T (wall thickness) is less than or equal to 8mm and g (welding seam width) is less than or equal to D0/4, elliptical imaging is carried out by adopting an inclined transillumination mode, when T/D0 is less than or equal to 0.12, transillumination is carried out for 2 times at intervals of 90 degrees, and when T/D0 is more than 0.12, transillumination is carried out for 3 times at intervals of 120 degrees or 60 degrees; if the conditions are not met or elliptical imaging is difficult, or if the root is mainly inspected to have incomplete penetration, overlapping imaging in a vertical transillumination mode can be adopted. When vertically transilluminating the overlapped image, the transillumination should be conducted 3 times at 120 ° or 60 ° intervals.

At present, the ray detection of the butt-jointed seam of the small-diameter pipe generally adopts an outside-source and double-wall transillumination mode to implement a detection task, and particularly in the detection of the small-diameter pipe of a large-sized pressure container, because a detection station is generally harsh, in the prior art, a special tool needs to be manufactured to fix a head of a radioactive source so as to ensure the distance and the angle between the radioactive source and a detected object, namely the detection focal distance and the detection angle.

Disclosure of Invention

The present invention is directed to solving the above problems. Therefore, the device and the method for detecting the small-diameter pipe butt weld can be suitable for the small-diameter pipe butt weld of different rule divisions and detection requirements, can complete detection tasks of two detection objects at one time by utilizing the characteristics of a design structure, greatly improves the detection efficiency and ensures the detection stability.

In order to solve the above problems, the present invention is realized by the following technical scheme:

the utility model provides a detection apparatus for path pipe butt weld, is applicable to and detects two arbitrary path pipe butt welds in the pressure vessel, its characterized in that contains: two clamping rods 100 and a source fixing part 200; the first end of each clamping rod 100 is movably connected with the source fixing part 200, and the second end of each clamping rod 100 is connected with a small-diameter pipe to be detected.

Optionally, each small diameter tube that awaits measuring is equipped with waits to examine the district, wait to examine in the district and keep away from one side of source fixed part is equipped with the exposure area, the exposure area is equipped with the film.

The length of each clamping rod 100 is adjusted so that the distance from the center of the source fixing part 200 to the center of the small-diameter tube to be detected reaches a preset detection focal length.

The source fixing part 200 is used for emitting detection rays to the to-be-detected regions of the two small-diameter tubes.

And acquiring the exposed image of the film and carrying out comparison processing to obtain a detection result.

Optionally, each of the clamping bars 100 includes: the clamping piece 104 is used for clamping the small-diameter pipe to be detected; and an adjusting lever 102 having one end connected to the clamping member 104 and the other end movably connected to the source fixing part 200.

Optionally, the adjusting rod 102 is hollow and provided with an internal thread.

Optionally, each of the clamping bars 100 further includes: a first screw 101 and a second screw 103.

Optionally, one end of the first screw 101 is connected with the inner thread of the second end of the adjusting rod 102, and the other end is movably connected with the source fixing part 200; one end of the second screw 103 is connected with the inner thread of the first end of the adjusting rod 102, and the other end is connected with the clamping piece 104.

The adjusting rod 102 is rotated to extend or shorten the first screw 101 or the second screw 103, so as to adjust the distance from the center of the source fixing part 200 to the center of the small-diameter pipe to be detected.

Optionally, the source fixing part 200 includes: a source catheter 201, a source cannula 202 and a collar cannula 203 arranged coaxially.

Optionally, the source casing 202 is sleeved on the outside of the source guide pipe 201; the collar sleeve 203 is placed over the exterior of the source sleeve 202; the source sleeve 202 is used for fixing a radioactive source; the source guide pipe 201 is hollow, and a radioactive source guide pipe penetrates through the source guide pipe 201 and is connected with the radioactive source; the clamp sleeve 203 is used to connect with a laser range finder through a connector.

Optionally, the detection ray emitted by the radiation source is a gamma ray, and the source sleeve 202 is adjusted to make the gamma ray emitted by the radiation source perpendicular to or deviated from a connecting line between the regions to be detected of the two small-diameter tubes; and simultaneously exposing the two films on the two small-diameter tubes to be detected by the gamma rays to obtain two images.

The laser range finder is used for detecting the distance between the radioactive source and the to-be-detected area of the two small-diameter tubes respectively to obtain two distance data, and the two distance data are calculated to obtain two geometric degrees of uncertainty.

And analyzing the image of each small-diameter pipe according to the geometric unsharpness of each small-diameter pipe to obtain the detection result of the butt weld of each small-diameter pipe.

Optionally, the connecting piece is distancer clamp 204, and it sets up on the clamp sleeve pipe 203, clamp sleeve pipe 203 encircles the guide source pipe 201 center is rotatory, drives laser range finder is rotatory.

Alternatively, two of the first screws 101 of the two clamping rods 100 are rotatably connected with the source casing 202 through a double half-ring structure.

Optionally, each clamping piece 104 is matched with the small-diameter pipe to be detected one by one; each of the clamps 104 is detachably mounted on the adjustment lever 102.

Optionally, the detection method of the detection device for the small-diameter pipe butt weld includes the following steps:

step S1, fixing the laser range finder on the range finder hoop 204;

step S2, clamping two small-diameter tubes to be detected in the pressure container by using a clamping piece 104, recording the two small-diameter tubes as a first small-diameter tube and a second small-diameter tube, and arranging a film on an exposure area of each small-diameter tube;

step S3, adjusting the length of each clamping rod 100 to make the distance between the center of the source fixing part 200 and the center of the small-diameter tube reach a preset detection focal length;

step S4, rotating the hoop sleeve 203 to enable the laser emitted by the laser range finder to face the to-be-detected area of the small-diameter pipe, and obtaining the distance between the laser range finder and each to-be-detected area of the small-diameter pipe and recording the distance as first distance data and second distance data;

step S5, a radioactive source guide tube penetrates through the source guide tube 201, a radioactive source is fixed on the source sleeve 202, and the source sleeve 202 is adjusted and fixed to enable gamma rays emitted by the radioactive source to be perpendicular to a connecting line between the areas to be detected of the two small-diameter tubes or deviate from the connecting line;

step S6, starting the radioactive source, emitting the gamma rays towards the to-be-detected areas of the two small-diameter tubes, and exposing the two films on the two small-diameter tubes by the gamma rays to obtain two images which are recorded as a first image and a second image;

step S7, a radioactive source is closed, a first geometric ambiguity and a second geometric ambiguity are calculated according to the first distance data and the second distance data, the first image is analyzed according to the first geometric ambiguity to obtain a detection result of the first small-diameter pipe butt-joint welding seam, and the second image is analyzed according to the second geometric ambiguity to obtain a detection result of the second small-diameter pipe butt-joint welding seam;

and S8, replacing the two clamped small-diameter pipes, and repeating the steps S2-S7 until all the small-diameter pipes in the pressure container are detected.

Optionally, the detection method of the detection device for the small-diameter pipe butt weld further includes: step S9, providing two detection devices of the butt-welded seam of the small-diameter pipes, which are recorded as a first detection device and a second detection device, wherein the first detection device and the second detection device simultaneously detect three small-diameter pipes in the pressure container, the three small-diameter pipes are recorded as a first small-diameter pipe, a second small-diameter pipe and a third small-diameter pipe, a first clamping rod in the first detection device clamps the first small-diameter pipe, a second clamping rod in the first detection device clamps the second small-diameter pipe, a first clamping rod in the second detection device clamps the second small-diameter pipe, a second clamping rod in the second detection device clamps the third small-diameter pipe, and an included angle between two adjacent clamping rods in the first detection device and the second detection device is a detection angle.

And analyzing the detection angle to obtain the angle difference between two exposures of the second small-diameter pipe, and obtaining the detection results of the second small-diameter pipe at different angles.

Optionally, the included angle between the two clamping rods of the first detection device and/or the included angle between the two clamping rods of the second detection device are adjusted to adjust the detection angle.

The invention has at least one of the following advantages:

1) detection can be performed on two objects at the same time in one exposure.

2) The gamma ray detection of different pipe diameters can be completed by using one set of device.

3) The focus data can be accurately measured, and stable and reliable detection conditions are provided.

4) The angle of the supporting rod can be adjusted, and different ray detection angles are provided.

Drawings

Fig. 1 is a schematic top view of a gamma-ray detection apparatus for a butt weld of a small-diameter tube according to an embodiment of the present invention;

fig. 2 is a schematic front structural view of a small-diameter tube butt weld γ -ray detection apparatus according to an embodiment of the present invention;

fig. 3 is a schematic front structural view of an adjusting rod of the small-diameter tube butt weld γ -ray detection apparatus according to an embodiment of the present invention;

FIG. 4 is a sectional view B-B of an adjusting rod of the gamma-ray detection device for the butt weld of the small-diameter tube according to an embodiment of the invention;

the reference numbers in the figures illustrate: 100. a clamping rod; 101. a first screw; 102. adjusting a rod; 103. a second screw; 104. a clamping member; 1041. clamping a female head; 1042. a gasket; 1043. a male clamp head; 1044. a fixed end pin; 200. a source fixing part; 201. a source guide pipe; 202. a source cannula; 203. a hoop sleeve; 204. a distance meter hoop; 205. a flange plate; 206. a first half ring; 207. a second half ring.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example (b):

as shown in fig. 2: the detection device of small-diameter tube butt weld of this embodiment includes: two clamping rods 100 and a source fixing part 200, wherein a first end of each clamping rod 100 is movably connected with the source fixing part 200; the second end of each clamping rod 100 is connected with a small-diameter pipe to be detected; each small-diameter tube that awaits measuring is equipped with waits to examine the district, wait to examine in the district and keep away from one side of source fixed part is equipped with the exposure area, the exposure area is equipped with the film.

In this embodiment, each of the clamping rods in the detecting device comprises: the clamping piece 104 is used for clamping the small-diameter pipe to be detected; and an adjusting lever 102 having one end connected to the clamping member 104 and the other end movably connected to the source fixing part 200.

Each of the clamping bars 100 in this embodiment further includes: a first screw 101 and a second screw 103; one end of the first screw 101 is in threaded connection with the inside of the second end of the adjusting rod 102, and the other end is movably connected with the source fixing part 200; one end of the second screw 103 is connected with the inner thread of the first end of the adjusting rod 102, and the other end is connected with the clamping piece 104.

As shown in fig. 3 and 4, the adjusting rod 102 is hollow and provided with an internal thread.

Referring to fig. 2, the source fixing part 200 in the present embodiment includes: a source guide pipe 201, a source sleeve 202 and a hoop sleeve 203 which are coaxially arranged; the source sleeve 202 is sleeved on the outer part of the source guide pipe 201; the collar sleeve 203 is placed over the exterior of the source sleeve 202; the source sleeve 202 is used for fixing a radioactive source; the source guide pipe 201 is hollow, and a radioactive source guide pipe penetrates through the source guide pipe 201 and is connected with the radioactive source; the clamp sleeve 203 is used to connect with a laser range finder through a connector.

In this embodiment the connecting piece is distancer clamp 204, and it sets up on the clamp sleeve pipe 203, clamp sleeve pipe 203 encircles the source pipe 201 center is rotatory, drives laser range finder is rotatory.

In this embodiment, two of the first screws 101 in the two clamping rods 100 are rotatably connected to the source casing 202 through a double half-ring structure, the double half-ring structure includes a first half ring 206 and a second half ring 207, the second half ring 207 is disposed outside the source casing 202, and the first half ring 206 is disposed outside the second half ring 207, so that the two first screws 101 rotate to drive the two clamping rods 100 to rotate.

In this embodiment, a portion of the second half ring 207 higher than the first half ring is provided with a thread, a flange 205 is installed on the thread, and the flange 205 is used for fixing the double-half ring structure.

In this embodiment, each of the clamping members 104 is matched with the small diameter pipe to be detected one by one; each of the clamps 104 is detachably mounted on the adjustment lever 102.

With reference to fig. 1 and fig. 2, the clamping member 104 of this embodiment is a clamp, the clamp includes a clamp female head 1041 and a clamp male head 1043, the clamp male head 1043 and the clamp female head 1041 are fixed by a gasket 1042 and a fixed end pin 1044, and this embodiment configures different clamps for small-diameter pipes of different sizes.

The detection object of the embodiment is N small-diameter tubes (N1, N2 and N3 … Nn) regularly distributed in a large pressure container, and overlapping imaging is required to be performed by adopting a vertical transillumination mode.

Firstly, dividing N small-diameter tubes into N groups, a first group of N1 and N2, a second group of N2 and N3, and an nth group of N3 and N4 and a third group of … Nn and N1.

The following describes the detection method of the present embodiment by taking the first group and the second group as examples:

the first embodiment is as follows: the detection device for the small-diameter pipe butt weld in the embodiment is used for detecting the first group of small-diameter pipes, and the detection method in the embodiment comprises the following steps:

step S1, the laser rangefinder is fixed to the rangefinder collar 204.

Step S2, clamping the first set of small diameter tubes (the first small diameter tube N1 and the second small diameter tube N2) by using the clamp 104, wherein a film is disposed on the exposure area of each of the first small diameter tube N1 and the second small diameter tube N2.

And step S3, roughly adjusting the length of the clamping rod 100 connected with each small-diameter tube according to the detection focal length required by the detection of each small-diameter tube.

Step S4, rotating the hoop sleeve 203 to enable the laser emitted by the laser range finder to face the to-be-detected area of the small-diameter pipe, and obtaining the distance between the laser range finder and each to-be-detected area of the small-diameter pipe and recording the distance as first distance data and second distance data; comparing the distance data (i.e., the first distance data and the second distance data) with the difference between the detection focal lengths required for the detection, adjusting the length of each clamping rod 100 again until the distance data reaches the detection focal length required for the detection, and finally recording the measured distance data as third distance data and fourth distance data.

And step S5, penetrating a radioactive source guide tube through the source guide tube 201, fixing a radioactive source on the source sleeve 202, and adjusting and fixing the source sleeve 202 to enable gamma rays emitted by the radioactive source to be vertical to the middle point of a connecting line between the areas to be detected of the two small-diameter tubes.

And step S6, starting the radioactive source, emitting the gamma rays to the to-be-detected areas of the two small-diameter tubes, and exposing the two films on the two small-diameter tubes by the gamma rays to obtain two images which are recorded as a first image and a second image.

And S7, closing the radioactive source, calculating a first geometric unsharpness and a second geometric unsharpness according to a formula according to a third distance data and a fourth distance data, analyzing the first image according to the first geometric unsharpness to obtain a detection result of the first small-diameter pipe N1 butt weld, and analyzing the second image according to the second geometric unsharpness to obtain a detection result of the second small-diameter pipe N2 butt weld.

The geometric unsharpness is calculated by the following formula;

Ug＝db/f (1)

calculating the f by the following formula:

f＝F-b (2)

and determining the blurring degree of the image according to the geometric unsharpness, wherein Ug is the geometric unsharpness, d is the focus size of a radioactive source, b is the distance from the to-be-detected area of the small-diameter tube to the film, F is the distance data, and F is the detection focal length.

Example two: the detection device for the butt weld of the small-diameter pipes in the two embodiments is used to detect the first group and the second group of small-diameter pipes, the two detection devices are marked as a first detection device and a second detection device, in this embodiment, the second small-diameter pipe N2 needs to be exposed 1 time every 90 °, that is, the detection angle of the second small-diameter pipe N2 is 90 °.

The detection method of the embodiment comprises the following steps:

step S1, fixing a laser range finder on each range finder hoop 204;

step S2, clamping the first group of small-diameter tubes (the first small-diameter tube N1 and the second small-diameter tube N2) by using the clamping member 104 of the first detecting device, and arranging a film on the exposure areas of the first small-diameter tube N1 and the second small-diameter tube N2; the second group of small diameter tubes (the second small diameter tube N2 and the third small diameter tube N3) is held by the holding member 104 of the second inspection apparatus, and a film is set on the exposure areas of the second small diameter tube N2 and the third small diameter tube N3.

Step S3, roughly adjusting the length of the clamping rod 100 connected with each small-diameter tube according to the detection focal length required by the detection of each small-diameter tube;

step S4, rotating the hoop sleeve 203 to enable the laser emitted by the laser range finder to respectively face the to-be-detected area of each small-diameter pipe, and obtaining distance data between the laser range finder and the to-be-detected area of each small-diameter pipe, and recording the distance data as fifth distance data, sixth distance data, seventh distance data and eighth distance data; comparing the difference between the distance data (fifth distance data, sixth distance data, seventh distance data and eighth distance data) and the preset detection focal length, adjusting the length of each clamping rod 100 again until the distance data reaches the detection focal length, and recording the finally measured distance data as ninth distance data, tenth distance data, eleventh distance data and twelfth distance data.

Step S5, adjusting an included angle between two clamping rods of the first detection device and/or an included angle between two clamping rods of the second detection device to enable the detection angle to reach 90 degrees;

step S6, a first radioactive source catheter penetrates through a source guide tube 201 of the first detection device, a first radioactive source is fixed on a first source sleeve 202 of the first detection device, and the first source sleeve is adjusted and fixed to enable first gamma rays emitted by the radioactive source to be perpendicular to the midpoint of a connecting line between the to-be-detected areas of a first small-diameter tube N1 and a second small-diameter tube N2;

step S7, opening the first radiation source, emitting the first γ -ray toward the to-be-detected areas of the first small-diameter tube N1 and the second small-diameter tube N2, exposing the two films on the first small-diameter tube N1 and the second small-diameter tube N2 to obtain two images, which are recorded as a third image and a fourth image, and closing the first radiation source;

step S8, a second radioactive source catheter penetrates through the source guiding tube 201 of the first detecting device, the second radioactive source is fixed on the second source sleeve 202 of the second detecting device, and the second source sleeve 202 is adjusted and fixed to enable the second gamma ray emitted by the second radioactive source to be perpendicular to the middle point of a connecting line between the to-be-detected areas of the second small-diameter tube N2 and the third small-diameter tube N3;

step S9, opening the second radiation source, emitting the second γ -ray toward the to-be-detected areas of the second small-diameter tube N2 and the third small-diameter tube N3, exposing the two films on the second small-diameter tube N2 and the third small-diameter tube N3 to obtain two images, which are recorded as a fifth image and a sixth image, and closing the second radiation source;

step S10, calculating a third geometric ambiguity, a fourth geometric ambiguity, a fifth geometric ambiguity, and a sixth geometric ambiguity according to the above formula (1) and formula (2) according to the ninth distance data, the tenth distance data, the eleventh distance data, and the twelfth distance data;

and analyzing the third image according to the third geometric uncertainty to obtain a detection result of the N1 butt weld of the first small-diameter pipe.

Analyzing the fourth image according to the fourth geometric dissimilarity to obtain a first detection result of the butt weld of the second small-diameter pipe N2, analyzing the fifth image according to the fifth geometric dissimilarity to obtain a second detection result of the butt weld of the second small-diameter pipe N2, and comparing the first detection result with the second detection result to obtain a final detection result of the second small-diameter pipe N2.

And analyzing the sixth image according to sixth geometric unsharpness to obtain a detection result of the butt weld of the third small-diameter pipe N3.

It should be noted that: in the second embodiment, one detection device can be used to detect the two groups of small-diameter pipes according to the clamping method of the first detection device and the second detection device.

In conclusion, the two clamping rods can simultaneously carry out detection tasks on the butt-jointed seams of the two small-diameter pipes, the detection focal length and the detection angle can be adjusted according to detection requirements, stable and reliable detection conditions are provided, the detection efficiency is greatly improved, and meanwhile, the stability of the detection process can be ensured, and the accuracy of the detection result is also ensured.

It should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.